TW202413417A - Novel anti-cd3 antibodies and uses thereof - Google Patents

Abstract

The present disclosure provides anti-CD3 antibodies or antigen-binding fragments thereof, isolated polynucleotides encoding the same, pharmaceutical composition comprising the same and the uses thereof.

Description

Novel anti-CD3 antibodies and their uses

The present invention generally relates to novel anti-CD3 antibodies, antigen-binding fragments thereof, and uses thereof.

The CD3 (cluster of differentiation 3) T cell co-receptor is a protein complex and consists of four different chains, namely the CD3γ chain, the CD3δ chain and two CD3ε chains. These chains bind to molecules called T cell receptors (TCRs) and the zeta chain to produce activating signals in T lymphocytes. The TCR, the zeta chain and the CD3 molecule together form the TCR-CD3 complex, where the TCR as a subunit recognizes and binds to antigens, and CD3 as a subunit transfers and transmits antigen stimulation to signaling pathways and ultimately regulates T cell activity. The CD3 protein is present in virtually all T cells.

Mouse monoclonal antibodies specific for human CD3, such as OKT3 (Kung et al., (1979) Science , 206: 347-9), are the first generation of CD3 antibodies used in therapy. Although OKT3 has strong immunosuppressive effects, its clinical application is hampered by serious side effects related to its immunogenicity and mitogenic potential (Chatenoud (2003) Nature Reviews Immunology 3: 123-132). The antiglobulin response induced by OKT3 promotes its own rapid clearance and neutralization (Chatenoud et al., (1982) Eur. J. Immunol. , 137: 830-8). In addition, OKT3 induces T cell proliferation and interleukin production in vitro and leads to massive release of interleukins in vivo (Hirsch et al., (1989) J. Immunol , 142: 737-43). Interleukin release (also known as "interleukin storm") leads to a "flu-like" syndrome characterized by fever, chills, headache, nausea, vomiting, diarrhea, respiratory distress, purulent meningitis and hypotension (Chatenoud (2003) Nature Reviews Immunology , 3: 123-132). Such severe side effects limit the wider application of OKT3 in transplantation and the expansion of its application to other clinical fields such as autoimmunity.

A more recent application of CD3 antibodies is in the form of bispecific antibodies that bind CD3 on the one hand and a tumor cell antigen on the other hand. The simultaneous binding of such an antibody to its two targets will force a transient interaction between the target cell and the T cell, leading to the activation of any cytotoxic T cells and subsequent lysis of the target cell.

There remains a need for new anti-CD3 antibodies.

Throughout the present invention, the articles "a", "an" and "the" as used herein refer to one or more than one (ie, at least one) of the grammatical object of the article. For example, "an antibody" means one antibody or more than one antibody.

In one embodiment, the present invention provides an antibody or an antigen-binding fragment thereof that specifically binds to CD3, the antibody or the antigen-binding fragment thereof comprising: One or two or three heavy chain complementary determining regions (HCDR1, HCDR2 and/or HCDR3), wherein the one or more heavy chain complementary determining regions are contained in any one of the heavy chain variable (VH) region sequences selected from the group consisting of: SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 and 245; and/or One or two or three light chain complementation determining regions (LCDR1, LCDR2 and/or LCDR3), wherein the one or more light chain complementation determining regions are contained in any one of the light chain variable (VL) region sequences selected from the group consisting of: SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 and 232.

In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention comprise at least one heavy chain or light chain complementarity determining region (CDR) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 17, 18, 19, 20, 21, 22, 25, 26, 27, 28, 29, 30, 33, 34, 35, 36, 37, 38, 41, 42, 43, 44, 45, 46, 49, 50, 51, 52, 53, 54, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 73, 74, 75, 76, 77, 78, 81, 82, 83, 84, 85, 86, 89, 90, 91, 92, 93, 94, 102, 103, 104, 105, 106, 107, 110, 111, 112, 113, 114, 115, 118, 1 19, 120, 121, 122, 123, 126, 127, 128, 129, 130, 131, 134, 135, 136, 137, 138, 139, 142, 143, 144, 145, 146, 147, 150, 151, 152, 153, 154, 155, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 201, 162, 167, 210, 211, 212, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228 and 229.

In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention comprise a VH region comprising one, two or three of HCDR1, HCDR2 and HCDR3, wherein the HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from the group consisting of SEQ ID NO: 1, 2, 3, 9, 10, 11, 17, 18, 19, 25, 26, 27, 33, 34, 35, 41, 42, 43, 49, 50, 51, 57, 58, 59, 65, 66, 67, 73, 74, 75, 81, 82, 83, 89, 90, 91, 102, 103, 104, 110, 111, 112, 118, 119, 120, 126, 127, 128, 134, 135, 136, 142, 143, 144, 150, 151, 152, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 201, 162, 210, 211, 212, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228 and 229.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention comprises a VL region, wherein the VL region comprises one, two or three of LCDR1, LCDR2 and LCDR3, wherein the LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from the group consisting of: SEQ ID NO: 4, 5, 6, 12, 13, 14, 20, 21, 22, 28, 29, 30, 36, 37, 38, 44, 45, 46, 52, 53, 54, 60, 61, 62, 68, 69, 70, 76, 77, 78, 84, 85, 86, 92, 93, 94, 105, 106, 107, 113, 114, 115, 121, 122, 123, 129, 130, 131, 137, 138, 139, 145, 146, 147, 153, 154, 155, 182, 183, 184, 185, 167, 214, 215 and 216.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention comprises: (a) HCDR1, wherein the HCDR1 comprises an amino acid sequence selected from the group consisting of: selected from SEQ ID NO: 1, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 102, 110, 118, 126, 134, 142, 150, 217, 218 and 219; (b) HCDR2, wherein the HCDR2 comprises an amino acid sequence selected from the group consisting of: selected from SEQ ID NO: 2, 10, 18, 26, 34, 42, 50, 58, 66, 74, 82, 90, 103, 111, 119, 127, 135, 143, 151, 171, 172, 173, 201, 210, 211, 212, 220 and 222; and (c) HCDR3 comprising an amino acid sequence selected from the group consisting of: selected from SEQ ID NO: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 104, 112, 120, 128, 136, 144, 152, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228, 229 and 162.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention comprises: (a) LCDR1, wherein LCDR1 comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 84, 92, 105, 113, 121, 129, 137, 145 and 153; (b) LCDR2, wherein LCDR2 comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 5, 13, 21, 29, 37, 45, 53, 61, 69, 77, 85, 93, 106, 114, 122, 130, 138, 146 and 154; and (c) LCDR3, wherein LCDR3 comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 6, 14, 22, 30, 38, 46, 54, 62, 70, 78, 86, 94, 107, 115, 123, 131, 139, 147, 155, 182, 183, 184, 185, 214, 215, 216 and 167.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention comprises: (a) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 1, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 2, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 3; (b) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11; (c) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 17, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 18, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 19; (d) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 25, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 26, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 27; (e) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 33, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 34, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 35; (f) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 41, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 42, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 43; (g) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: (h) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 57, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 58, and the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 59; (i) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 65, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 66, and the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 67; (j) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 73, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 74; (k) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 81, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 82, and the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 83; (l) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 89, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 90, and the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 91; (m) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 102, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 103, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 104; (n) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 110, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 111, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 112; (o) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 118, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 119, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 120; (p) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 126, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 127, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 128; (q) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 134, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 135, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 136; (r) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 142, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 143, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 144; (s) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 151, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152; (t) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 219, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 201, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 162; (u) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, 217 or 218, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, 171, 172, 173, 220 or 222, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228 or 229; (v) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 212, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 152; (w) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 210, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 152; or (x) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 211, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention comprises: (a) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 4, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 5, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 6; (b) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (c) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 20, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 21, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 22; (d) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 28, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 29, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 30; (e) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 36, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 37, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 38; (f) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 44, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 45, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 46; (g) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 52, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 53, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 54; (h) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 60, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 61, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 62; (i) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 68, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 69, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 70; (j) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 76, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 77, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 78; (k) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 84, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 85, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 86; (l) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 92, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 93, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 94; (m) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 105, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 106, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 107; (n) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 113, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 114, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 115; (o) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 121, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 122, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 123; (p) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 129, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 130, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 131; (q) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 137, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 138, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 139; (r) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 145, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 146, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 147; (s) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155; (t) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 167; or (u) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14, 182, 183, 184, 185, 214, 215 or 216.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention comprises: (a) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 1, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 2, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 3, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 4, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 5, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 6; (b) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (c) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 17, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 18, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 19, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 20, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 21, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 22; (d) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 25, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 26, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 27, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 28, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 29, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 30; (e) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 33, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 34, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 35, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 36, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 37, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 38; (f) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 41, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 42, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 43, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 44, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 45, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 46; (g) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 49, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 50, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 51, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 52, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 53, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 54; (h) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 57, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 58, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 59, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 60, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 61, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 62; (i) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 65, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 66, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 67, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 68, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 69, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 70; (j) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 73, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 74, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 75, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 76, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 77, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 78; (k) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 81, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 82, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 83, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 84, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 85, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 86; (l) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 89, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 90, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 91, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 92, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 93, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 94; (m) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 102, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 103, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 104, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 105, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 106, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 107; (n) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 110, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 111, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 112, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 113, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 114, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 115; (o) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 118, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 119, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 120, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 121, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 122, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 123; (p) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 126, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 127, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 128, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 129, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 130, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 131; (q) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 134, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 135, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 136, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 137, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 138, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 139; (r) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 142, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 143, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 144, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 145, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 146, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 147; (s) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 151, the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 153, the LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 154, and the LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 155; (t) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 171, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (u) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, and the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (v) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 173, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (w) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 174, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (x) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 175, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (y) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 176, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 14; (z) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 177, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (aa) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 178, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (bb) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 179, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (cc) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (dd) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 181, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (ee) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 182; (ff) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 183; (gg) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 184; or (hh) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 185; (ii) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 220, the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 14; (jj) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 221, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (kk) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 222, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (ll) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 223, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (mm) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 171, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 224, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (nn) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 214; (oo) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 215; (pp) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 216; (qq) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 222, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 214; (rr) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 222, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 215; (ss) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 223, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 214; (tt) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 223, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 215; (uu) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 225, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (vv) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 226, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (ww) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 227, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 14; (xx) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 228, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (yy) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 174, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (zz) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 229, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (aaa) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 217, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, and the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (bbb) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 218, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (ccc) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 219, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 201, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 162, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 167; (ddd) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 212, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, and the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155; (eee) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 210, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155; or (fff) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 211, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155.

In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention include a VH region having an amino acid sequence as shown in SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 or 245, or a VH region having an amino acid sequence as shown in SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 or 245 has a homologous sequence with at least 80% sequence identity.

In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention include a VL region having an amino acid sequence as shown in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 or 232, or a VL region having an amino acid sequence as shown in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 or 232 has a homologous sequence with at least 80% sequence identity.

In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention comprise a VH/VL amino acid sequence pair selected from the group consisting of: SEQ ID NO: 7/8, 15/16, 23/24, 31/32, 39/40, 47/48, 55/56, 63/64, 71/72, 79/80, 87/88, 95/96, 108/109, 116/117, 124/125, 132/133, 140/141, 148/149, 156/157, 163/168, 163/169, 163/1 70, 164/168, 164/169, 164/170, 165/168, 165/169, 165/170, 166/168, 166/169, 166/170, 186/169, 187/169, 188/169, 189/169, 190/169, 191/169, 192/169, 193/169, 194/169, 1 95/169、196/169、165/197、165/198、165/199、165/200、202/207、202/208、202/209、203/207、203/208、203/209、204/207、205/207、206/207、206/208、206/209、233/169、234/ 169, 235/169, 236/169, 237/169, 238/169, 239/169, 240/169, 241/169, 242/169, 243/169, 244/169, 245/169, 165/230, 165/231, 165/232, 235/230, 235/231, 236/230 and 236/231.

In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention further comprise one or more amino acid residue substitutions or modifications, but still retain specific binding affinity for CD3. In some embodiments, at least one of the substitutions or modifications is located in one or more CDR sequences of the VH region or the VL region. In some embodiments, at least one of the substitutions or modifications is located in one or more non-CDR sequences of the VH region or the VL region. In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention further comprise one or more non-natural amino acid (NNAA) substitutions. In some embodiments, NNAA can be bound.

In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention have one or more binding properties to CD3, and the one or more binding properties are selected from the group consisting of: (a) the ability to specifically bind to human CD3, as measured by FACS assay; (b) the ability to activate T cells, as measured by Jurkat NFAT-luciferase activation assay; and (c) the ability to activate PBMC, as measured by ELISA assay.

In another aspect, the present invention provides an antibody or an antigen-binding fragment thereof that competes with the antibody or antigen-binding fragment thereof described above for binding to CD3.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention is a chimeric antibody, a humanized antibody or a human antibody or an antigen-binding fragment thereof.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention is a labeled antibody, a bivalent antibody, an anti-idiotypic antibody or a fusion protein.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention is a bifunctional antibody (diabody), Fab, Fab', F(ab') ₂ , Fd, Fv fragment, disulfide-stabilized Fv fragment (dsFv), (dsFv) ₂ , bispecific dsFv (dsFv-dsFv'), disulfide-stabilized bifunctional antibody (ds diabody), single-chain antibody molecule (scFv), scFv dimer (bivalent bifunctional antibody), camellized single domain antibody, nanobody, domain antibody or bivalent domain antibody.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention further comprises an Fc region. In some embodiments, the Fc region is an Fc region of a human immunoglobulin (Ig). In some embodiments, the Fc region is an Fc region of a human IgG. In some embodiments, the Fc region is derived from human IgG1, IgG2, IgG3 or IgG4. In some embodiments, the Fc region is derived from human IgG1. In some embodiments, the Fc region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 97-99.

In some embodiments, the light chain of the antibody or antigen-binding fragment thereof of the present invention is a λ light chain or a κ light chain.

In some embodiments, the antibody or antigen-binding fragment thereof of the present invention is a bispecific antibody or a multispecific antibody or an antigen-binding fragment thereof. In some embodiments, the antibody or antigen-binding fragment thereof of the present invention can specifically bind to one or more additional antigens other than CD3, or a second epitope on CD3. In some embodiments, the one or more additional antigens other than CD3 are selected from the group consisting of CD16a, CD33, CD38, CD45, CD123, CD146, CD228, CLL-1, FLT3, FLT3L, TAF1, TgPRF, HVCN1, IL-6R, IL-11R, IL17A, IL-23R, IL-33, ILDR2, LAP, TSLP, TREM-1, ANGPT2, APOE, IFNAR, CypA, DOG-1, NKp30, CSF-1R, CCR2, LRRC15, mesothelin, Dickkopf2, DLL3, HER-2, C10orf54, TrkA, MEKK1, KRAS, ERK, XPO1, mTORC1/2, PAK4, NAMPT, ATR, EGFR, FGFR, VEGF, LILRB (e.g., LILRB1, LILRB2, LILRB3, LILRB4, LILRB5), c-MET, Her2, Her3, CTLA4, GITA, CD112R, CD2, CD7, CD16, CD19, CD20, CD24, CD27, CD30, CD34, CD37, CD39, CD70, CD73, CD83, CD28, CD80 (B7-1), CD86 (B7-2), CD40, CD40L (CD154), CD47, SIRPα, CD122, CD137, CD137L, OX40 (CD134), OX40L (CD252), BCMA (e.g., BCMA02), PSMA, CLDN18 (e.g., CLDN18.2), NKG2C, 4-1BB, LIGHT, PVRIG, SLAMF7, HVEM, BAFFR, ICAM-1, 2B4, LFA-1, GITR, ICOS (CD278), ICOSLG (CD275), LAG3 (CD223), A2AR, B7-H3 (CD276), B7-H4 (VTCN1), B7-H5, BTLA (CD272), CD160, CTLA-4 (CD152), GPRC5D, IDO (e.g., IDO1, IDO2), TDO, KIR, LAIR-1, NOX2, PD-1, PD-L1, PD-L2, TIM-3, VISTA, SIGLEC-7 (CD328), SIGLEC-9 (CD329), SIGLEC-15, TIGIT, PVR (CD155), TLR3, CLEC9A, DEC-205, STING and TGFβ.

In some embodiments, the antibodies or antigen-binding fragments thereof of the present invention are linked to one or more binding moieties. In some embodiments, the binding moieties include clearance modulators, chemotherapeutic agents, toxins, radioisotopes, indium elements, detectable labels (e.g., luminescent labels, fluorescent labels), enzyme-substrate labels, DNA alkylating agents, topoisomerase inhibitors, tubulin binding agents, purified moieties, or other anti-cancer drugs. In some embodiments, the binding moieties are covalently linked directly or via a linker.

In another aspect, the present invention provides a pharmaceutical composition comprising the antibody or antigen-binding fragment thereof of the present invention and one or more pharmaceutically acceptable carriers.

In another aspect, the present invention provides a chimeric antigen receptor, which includes an antibody or an antigen binding fragment thereof of the present invention, a transmembrane region and an intracellular signaling region. In some embodiments, the transmembrane region includes the transmembrane region of CD3, CD4, CD8 or CD28. In some embodiments, the intracellular signaling region is selected from the group consisting of: CD3, FcγRI, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, TLR or a combination thereof. In some embodiments, the antigen binding fragment of the chimeric antigen receptor is scFv.

In another aspect, the present invention provides an isolated polynucleotide encoding the antibody or antigen-binding fragment thereof of the present invention, and/or the chimeric antigen receptor of the present invention.

In another aspect, the present invention provides a vector comprising the isolated polynucleotide of the present invention.

In another aspect, the present invention provides a host expression system, which includes a vector of the present invention, or a polynucleotide of the present invention integrated into its genome. In some embodiments, the host expression system of the present invention is a microorganism, yeast or mammalian cell. In some embodiments, the microorganism is selected from the group consisting of Escherichia coli and Bacillus subtilis. In some embodiments, the yeast is Saccharomyces . In some embodiments, the mammalian cell is selected from the following group: COS, CHO-S, CHO-K1, HEK-293 and 3T3 cells.

In another aspect, the present invention provides a virus comprising the vector of the present invention.

In another aspect, the present invention provides a kit comprising the antibody or antigen-binding fragment thereof of the present invention and/or the pharmaceutical composition of the present invention and/or the chimeric antigen receptor of the present invention, and a second therapeutic agent.

In another aspect, the present invention provides a method for expressing the antibody or antigen-binding fragment thereof or chimeric antigen receptor of the present invention, comprising culturing the host expression system of the present invention under conditions for expressing the antibody or antigen-binding fragment thereof or chimeric antigen receptor of the present invention.

In another aspect, the present invention provides a method for treating, preventing or alleviating a disease, disorder or condition in an individual, comprising administering to the individual a therapeutically effective amount of the antibody or antigen-binding fragment thereof and/or pharmaceutical composition and/or chimeric antigen receptor of the present invention.

In another aspect, the present invention provides use of the antibody or antigen-binding fragment thereof and/or pharmaceutical composition and/or chimeric antigen receptor of the present invention in the preparation of a medicament for treating a CD3-related disease, disorder or condition in an individual.

In another aspect, the present invention provides use of the antibody or antigen-binding fragment thereof and/or chimeric antigen receptor and/or pharmaceutical composition of the present invention in the preparation of a diagnostic reagent for diagnosing a CD3-related disease, disorder or condition.

In some embodiments, the disease, disorder or condition is an immune disease, an inflammatory disease, a cancer or a nervous system disease. In some embodiments, the cancer is a solid tumor or a blood tumor. In some embodiments, the disease, disorder or condition is selected from the group consisting of lung cancer (e.g., non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), lung adenocarcinoma or lung squamous cell carcinoma), peritoneal cancer, carcinoid, bone cancer, pancreatic cancer, primitive neuroectodermal tumor, skin cancer, gallbladder cancer, head and neck cancer, squamous cell carcinoma, uterine cancer, ovarian cancer, rectal cancer, prostate cancer, bladder cancer (e.g., urothelial carcinoma), anal region cancer (e.g., anal squamous cell carcinoma), stomach cancer or gastric cancer (e.g., gastrointestinal cancer), esophageal cancer, colorectal cancer, breast cancer, uterine cancer, liver cancer (e.g., hepatoblastoma, hepatocellular carcinoma/hepatoma or hepatic cancer (hepatic carcinoma), bile duct cancer, sarcoma, colorectal cancer, fallopian tube cancer, salivary gland cancer, cervical cancer, endometrial cancer or uterine cancer, osteosarcoma, vaginal cancer, vulvar cancer, esophageal cancer, small intestine cancer, endocrine system cancer, thyroid cancer, parathyroid cancer, adrenal cancer, nasopharyngeal cancer, soft tissue sarcoma, polycythemia vera, urethral cancer, penile cancer, kidney or ureteral cancer (e.g., rhabdomyosarcoma of the kidney), cutaneous T-cell lymphoma, medulloblastoma, nephroblastoma, myelodysplastic syndrome, chronic and non-chronic myeloproliferative disorders, choroid plexus papilloma papilloma), renal cell carcinoma, renal pelvic carcinoma, central nervous system (CNS) tumors, soft tissue sarcomas (e.g., rhabdomyosarcoma, fibrosarcoma, Kaposi's sarcoma), spinal axis tumors ( tumor), neuroglioma (e.g., ependymoma, astrocytoma, anaplastic astrocytoma, oligodendroglioma, eye cancer (e.g., retinoblastoma), brain stem neuroglioma, or mixed neuroglioma such as oligoastrocytoma), brain tumor (e.g., glioblastoma/glioblastoma multiforme (GBM), non-glioblastic brain tumor, or meningioma), melanoma (e.g., cutaneous or intraocular melanoma), thrombocythaemia, mesothelioma, mycosis fungoides, Sezary syndrome, idiopathic myelofibrosis, solitary plasmacytoma, vestibular schwannoma schwannoma), Ewing's sarcoma, chondrosarcoma, MYH-related polyposis, pituitary adenoma, pediatric cancers such as pediatric sarcomas (e.g., neuroblastoma, rhabdomyosarcoma, and osteosarcoma), blood cancers, Hodgkin's lymphoma, non-Hodgkin's lymphoma, leukemias (e.g., lymphocytic/lymphoblastic leukemia), chronic or acute leukemias, mast cell leukemia, lymphocytic lymphoma, primary CNS lymphoma, chronic lymphocytic leukemia (CL L), acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), acute myeloid leukemia (AML), chronic myelomonocytic leukemia (CMML), chronic lymphoblastic leukemia, acute lymphoblastic leukemia, hairy cell leukemia (HCL), Burkitt's lymphoma (BL), multiple myeloma (e.g., relapsed or refractory multiple myeloma), T-cell lymphoma or B-cell lymphoma, mantle cell lymphoma (MCL) (e.g., relapsed or refractory mantle cell lymphoma), malignant melanoma, diffuse large B-cell lymphoma (DLBCL), DLBCL arising from follicular lymphoma, high-grade B-cell lymphoma, primary vertebral large B-cell lymphoma, follicular lymphoma (FL), and primary vertebral B-cell lymphoma.

In some embodiments, the individual is a human.

In some embodiments, administration is by a parenteral route, including subcutaneous, intraperitoneal, intravenous, intramuscular or intradermal injection; or a non-parenteral route, including transdermal, oral, intranasal, intraocular, sublingual, rectal or topical.

In some embodiments, the method of treating, preventing or alleviating a disease, disorder or condition in an individual further comprises administering an additional therapeutic agent to an individual in need thereof. In some embodiments, the additional therapeutic agent is selected from the group consisting of: active agents, imaging agents, cytotoxic agents, angiogenesis inhibitors, kinase inhibitors, co-stimulatory molecule agonists, co-inhibitory molecule inhibitors, adhesion molecule inhibitors, anti-cytokine antibodies or functional fragments thereof, detectable markers or reporters, antimicrobial agents, gene editors, beta agonists, viral RNA inhibitors, polymerase inhibitors, interferons and microRNAs. In some embodiments, an additional therapeutic agent is administered to a subject in need thereof before, after, or simultaneously with the antibody or antigen-binding fragment thereof and/or pharmaceutical composition and/or chimeric antigen receptor of the present invention.

In another aspect, the present invention provides a method for activating T cells expressing CD3 in vivo or in vitro, comprising contacting the T cells expressing CD3 with the antibody or antigen-binding fragment thereof and/or pharmaceutical composition and/or chimeric antigen receptor of the present invention.

In another aspect, the present invention provides a method for modulating CD3 activity in a cell expressing CD3, comprising exposing the cell expressing CD3 to the antibody or antigen-binding fragment thereof and/or pharmaceutical composition and/or chimeric antigen receptor of the present invention.

In another aspect, the present invention provides a method for promoting T cells expressing CD3 to process a second antigen in vivo or in vitro, comprising contacting the T cells expressing CD3 with the bispecific antibody or antigen-binding fragment thereof of the present invention, wherein the bispecific antibody or antigen-binding fragment thereof is capable of specifically binding to both the T cells expressing CD3 and the second antigen, thereby bringing the two into proximity.

In another aspect, the present invention provides a method for detecting the presence or amount of CD3 in a sample, comprising contacting the sample with the antibody or antigen-binding fragment thereof and/or pharmaceutical composition and/or chimeric antigen receptor of the present invention, and determining the presence or amount of CD3 in the sample.

In another aspect, the present invention provides a method for diagnosing a CD3-related disease or condition in an individual, comprising: a) contacting a sample obtained from the individual with an antibody or antigen-binding fragment thereof and/or chimeric antigen receptor and/or pharmaceutical composition of the present invention; b) determining the presence or amount of CD3 in the sample; and c) correlating the presence or amount of CD3 in the individual with the presence or status of a CD3-related disease or condition.

In another aspect, the present invention provides a kit comprising the antibody or antigen-binding fragment thereof and/or chimeric antigen receptor and/or pharmaceutical composition of the present invention for detecting CD3, optionally recombinant CD3, CD3 expressed on the surface of a cell, or a cell expressing CD3.

The following description of the present invention is intended only to illustrate various embodiments of the present invention. As such, the specific modifications discussed should not be construed as limitations on the scope of the present invention. It will be apparent to those skilled in the art that various equivalents, changes and modifications may be made without departing from the scope of the present invention, and it should be understood that such equivalent embodiments are to be included herein. All references cited herein, including publications, patents, and patent applications, are incorporated herein by reference in their entirety. Definitions

The term "antibody" used herein includes any immunoglobulin, monoclonal antibody, polyclonal antibody, multivalent antibody, bivalent antibody, monovalent antibody, multispecific antibody or bispecific antibody that binds to a specific antigen. A natural complete antibody includes two heavy (H) chains and two light (L) chains. Mammalian heavy chains are divided into α, δ, ε, γ and μ, each of which includes a variable region (VH) and a first constant region, a second constant region, a third constant region and, if appropriate, a fourth constant region (CH1, CH2, CH3, CH4, respectively); mammalian light chains are divided into λ or κ, and each light chain includes a variable region (VL) and a constant region. The antibody is "Y" shaped, where the stem of the Y structure includes the second constant region and the third constant region of two heavy chains bound together by disulfide bonds. Each arm of the Y includes a single heavy chain variable region and the first constant region combined with a single light chain variable region and constant region. The variable regions of the light and heavy chains are responsible for antigen binding. The variable region of each chain usually contains three hypervariable regions, called complementary determining regions (CDRs) (light chain CDRs include LCDR1, LCDR2, LCDR3, and heavy chain CDRs include HCDR1, HCDR2, HCDR3). The three CDRs are separated by flanking segments called framework regions (FRs) (LFR1, LFR2, LFR3, and LFR4 for light chains and HFR1, HFR2, HFR3, and HFR4 for heavy chains), which are more highly conserved than the CDRs and form a scaffold to support the highly variable loops. The constant regions of the heavy and light chains are not involved in antigen binding but exhibit a variety of effector functions. Antibodies can be divided into several classes based on the amino acid sequence of their heavy chain constant regions. The five major classes or isotypes of antibodies are IgA, IgD, IgE, IgG, and IgM, which are characterized by the presence of α, δ, ε, γ, and μ heavy chains, respectively. Several major antibody classes are divided into subclasses, such as IgG1 (γ1 heavy chain), IgG2 (γ2 heavy chain), IgG3 (γ3 heavy chain), IgG4 (γ4 heavy chain), IgA1 (α1 heavy chain), or IgA2 (α2 heavy chain).

In certain embodiments, the antibodies provided herein encompass any antigen-binding fragments thereof. As used herein, the term "antigen-binding fragment" refers to an antibody fragment formed by a portion of an antibody including one or more (e.g., 1, 2, 3, 4, 5 or 6) CDRs, or any other antibody fragment that binds to an antigen but does not include a complete native antibody structure. Examples of antigen-binding fragments include, but are not limited to, bifunctional antibodies (diabodies), Fab, Fab', F(ab') ₂ , Fd, Fv fragments, disulfide-stabilized Fv fragments (dsFv), (dsFv) ₂ , bispecific dsFv (dsFv-dsFv'), disulfide-stabilized bifunctional antibodies (ds diabodies), single-chain antibody molecules (scFv), scFv dimers (bivalent bifunctional antibodies), bispecific antibodies, multispecific antibodies, camel single domain antibodies, nanobodies, domain antibodies, or bivalent domain antibodies. The antigen-binding fragment can bind to the same antigen or epitope as the parent antibody.

The "Fab" of an antibody refers to a portion of an antibody composed of a single light chain (including a variable region and a constant region) and a single heavy chain variable region and the first constant region linked by a disulfide bond.

"Fab'" refers to the Fab fragment including a portion of the hinge region.

"F(ab') ₂ " refers to a dimer of Fab'.

The "Fc" of an antibody (e.g., IgG, IgA, or IgD isotype) refers to the portion of the antibody consisting of the second and third co-domains of the first heavy chain bound to the second and third co-domains of the second heavy chain via disulfide bonds. The Fc of antibodies of the IgM and IgE isotypes further includes a fourth co-domain. The Fc portion of an antibody is responsible for a variety of different effector functions, such as antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), but does not play a role in antigen binding.

The "Fv" of an antibody refers to the smallest antibody fragment that contains a complete antigen-binding site. The Fv fragment is composed of the variable region of a single light chain combined with the variable region of a single heavy chain.

"Single chain Fv antibody" or "scFv" refers to an engineered antibody composed of a light chain variable region and a heavy chain variable region, which are directly linked to each other or linked to each other by a linker (e.g., a peptide sequence) (Huston JS et al. Proc Natl Acad Sci USA , 85:5879 (1988)).

"Single-chain Fv-Fc antibody" or "scFv-Fc" refers to an engineered antibody composed of a scFv linked to the Fc region of the antibody.

"Camelized single domain antibody", "heavy chain antibody" or "HCAb" refers to an antibody containing two VH domains without light chains (Riechmann L. and Muyldermans S., J Immunol Methods Dec 10; 231(1-2):25-38 (1999); Muyldermans S., J Biotechnol . Jun; 74(4):277-302 (2001); WO94/04678; WO94/25591; U.S. Patent No. 6,005,079). Heavy chain antibodies were originally derived from the Camelidae family (camels, dromedaries and camels). Despite the absence of the light chain, the camelized antibody has a well-established antigen binding repertoire (Hamers-Casterman C. et al., Nature Jun 3; 363(6428):446-8 (1993); Nguyen VK. et al., Immunogenetics Apr; 54(1):39-47 (2002); Nguyen VK. et al., Immunology May; 109(1):93-101 (2003)). The variable region (VHH domain) of the heavy chain antibody represents the smallest known antigen binding unit produced by an adaptive immune response (Koch-Nolte F. et al., FASEB J. Nov; 21(13):3490-8 Epub 2007 Jun 15 (2007)).

"Nanoantibodies" refer to antibody fragments composed of the VHH domain from a heavy chain antibody and two constant domains, CH2 and CH3.

"Diabodies", "diabodies" or "dAbs" include small antibody fragments with two antigen binding sites, wherein the fragments include a VH domain and a VL domain linked on the same polypeptide chain (VH-VL or VL-VH) (see, e.g., Holliger P. et al., Proc Natl Acad Sci USA . Jul 15;90(14):6444-8 (1993); EP404097; WO93/11161). By using a linker that is too short to allow pairing between the two domains on the same chain, the domains are forced to pair with complementary domains of another chain, thereby generating two antigen binding sites. The antigen binding sites can target the same or different antigens (or epitopes). In certain embodiments, a "bispecific ds-bifunctional antibody" is a bifunctional antibody that targets two different antigens (or epitopes).

"Domain antibodies" refer to antibody fragments that contain only the heavy chain variable region or the light chain variable region. In some cases, two or more VH domains are covalently joined by a peptide linker to produce a bivalent or multivalent domain antibody. The two VH domains of a bivalent domain antibody can target the same or different antigens (or epitopes).

As used herein, the term "valent" refers to the presence of a specified number of antigen binding sites in a given molecule. The term "monovalent" refers to an antibody or antigen binding fragment that has only one antigen binding site; and the term "multivalent" refers to an antibody or antigen binding fragment that has multiple antigen binding sites. Thus, the terms "bivalent," "tetravalent," and "hexavalent" refer to the presence of two, four, and six antigen binding sites in an antigen binding molecule, respectively. In some embodiments, the antibody or antigen binding fragment thereof is bivalent.

As used herein, a "bispecific" antibody refers to an artificial antibody that has fragments derived from two different monoclonal antibodies and is capable of binding to two different epitopes. The two epitopes may be present on the same antigen, or they may be present on two different antigens.

As used herein, a "multispecific" antibody refers to an antibody that specifically binds to at least two different antigens or at least two different epitopes of the same antigen. A multispecific antibody can bind to, for example, two, three, four, five or more different antigens, or can bind to two, three, four, five or more different epitopes of the same antigen.

In certain embodiments, the "scFv dimer" is a bivalent bifunctional antibody (diabody) or a bispecific scFv (BsFv), which includes two dimerized VH-VL (linked by a peptide linker) parts, so that the VH of one part cooperates with the VL of the other part to form two binding sites, and the two binding sites can target the same antigen (or epitope) or different antigens (or epitopes). In other embodiments, the "scFv dimer" is a bispecific bifunctional antibody, which includes mutually associated VH1-VL2 (linked by a peptide linker) and VL1-VH2 (also linked by a peptide linker), so that VH1 and VL1 cooperate, VH2 and VL2 cooperate, and each cooperative pair has a different antigen specificity.

"dsFv" refers to a disulfide-stabilized Fv fragment in which a single light chain variable region and a single heavy chain variable region are connected by a disulfide bond. In some embodiments, "(dsFv) ₂ " or "(dsFv-dsFv')" includes three peptide chains: two VH parts are connected by a peptide linker (e.g., a long flexible linker) and are respectively bound to two VL parts by disulfide bonds. In some embodiments, dsFv-dsFv' has bispecificity, in which each pair of heavy and light chains paired by disulfide bonds has different antigenic specificity.

As used herein, the term "chimeric" refers to an antibody or antigen-binding fragment having a portion of the heavy chain and/or light chain derived from one species and the remainder of the heavy chain and/or light chain derived from another different species. In an illustrative example, a chimeric antibody may include a constant region derived from a human and a variable region derived from a non-human animal, such as a mouse. In some embodiments, the non-human animal is a mammal, such as a mouse, rat, rabbit, goat, sheep, guinea pig, or hamster.

As used herein, the term "humanized" refers to an antibody or antigen-binding fragment comprising CDRs derived from non-human animals, FR regions derived from humans, and, when applicable, constant regions derived from humans. The CDRs of the humanized antibodies provided by the present invention may contain mutations compared to the CDRs of their parental antibodies.

As used herein, the term "affinity" refers to the strength of the non-covalent interaction between an immunoglobulin molecule (ie, antibody) or antigen-binding fragment thereof and an antigen.

Antibodies or antigen-binding fragments thereof that "specifically bind" (specific binding) to a target (e.g., epitope) are terms well known in the art, and methods for determining such specific binding are also well known in the art. A molecule is said to exhibit "specific binding" if it reacts or associates with a particular cell or substance more frequently, more rapidly, longer, and/or with greater affinity than it does with alternative cells or substances. An antibody "specifically binds" to a target if it binds with greater affinity, higher avidity, more readily, and/or longer than it binds to other substances. For example, an antibody that specifically binds to a CD3 epitope is one that binds to that CD3 epitope with greater affinity, with higher affinity, more readily, and/or for a longer duration than it binds to other CD3 epitopes or non-CD3 epitopes. It should also be understood by reading this definition that, for example, an antibody (or portion or epitope) that specifically binds to a first target may or may not specifically bind to a second target. Thus, "specific binding" (specifically bind) does not necessarily require (although it may include) exclusive binding. Typically, but not necessarily, reference to binding refers to specific binding.

As used herein, the ability to "compete for binding to CD3" refers to the ability of a first antibody or antigen-binding fragment to inhibit the binding interaction between CD3 and a second anti-CD3 antibody to any detectable extent. In certain embodiments, the antibody or antigen-binding fragment that competes for binding to CD3 inhibits the binding interaction between CD3 and a second anti-CD3 antibody by at least 85%, or at least 90%. In certain embodiments, the inhibition may be greater than 95% or greater than 99%.

As used herein, the term "epitope" refers to a specific group of atoms or amino acids on an antigen to which an antibody binds. If two antibodies exhibit competitive binding to an antigen, they may bind to the same or a closely related epitope within the antigen. Epitopes may be linear or conformational (i.e., include spaced amino acid residues). For example, an antibody or antigen-binding fragment may be considered to bind to the same or a closely related epitope as a reference antibody if it blocks the binding of a reference antibody to the antigen by at least 85%, or at least 90%, or at least 95%.

As used herein, the term "amino acid" refers to an organic compound containing amine (-NH ₂ ) and carboxyl (-COOH) functional groups and side chains unique to each amino acid. Amino acid names are also represented in the present invention by standard single-letter or three-letter codes, which are summarized as follows: Name Three letter code Single letter code Alanine Ala A Arginine Arg R Asparagine Asn N Aspartic acid Asp D Cysteine Cys C Glutamine Glu E Glutamine Gln Q Glycine Gly G Histidine His H Isoleucine Ile I Leucine Leu L Lysine Lys K Methionine Met M Phenylalanine Phe F Proline Pro P Serine Ser S Threonine Thr T Tryptophan Trp W Tyrosine Tyr Y Valine Val V

"Conservative substitution" with respect to amino acid sequences refers to replacing an amino acid residue with an amino acid residue of a different side chain having similar physicochemical properties. For example, conservative substitutions can be made between amino acid residues having hydrophobic side chains (e.g., Met, Ala, Val, Leu, and Ile), between amino acid residues having neutral hydrophilic side chains (e.g., Cys, Ser, Thr, Asn, and Gln), between amino acid residues having acidic side chains (e.g., Asp, Glu), between amino acid residues having basic side chains (e.g., His, Lys, and Arg), or between amino acid residues having aromatic side chains (e.g., Trp, Tyr, and Phe). As is known in the art, conservative substitutions generally do not cause significant changes in the conformational structure of the protein and thus may retain the biological activity of the protein.

As used herein, the term "homologous" refers to a nucleic acid sequence (or a complement thereof) or an amino acid sequence that has at least 60% (e.g., at least 65%, 70%, 75%, 80%, 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%) sequence identity to another sequence when optimally aligned.

"Percentage (%) of sequence identity" with respect to an amino acid sequence (or nucleic acid sequence) is defined as the percentage of amino acid (or nucleic acid) residues in a candidate sequence that are identical to the amino acid (or nucleic acid) residues in a reference sequence, after the sequences have been aligned and gaps introduced, if necessary, to achieve the maximum number of identical amino acids (or nucleic acids). In other words, the percentage (%) of sequence identity of an amino acid sequence (or nucleic acid sequence) can be calculated by dividing the number of identical amino acid residues (or bases) relative to the reference sequence to which it is compared by the total number of amino acid residues (or bases) in the candidate sequence or the reference sequence (whichever is shorter). Conservative substitutions of amino acid residues may or may not be considered identical residues. For example, publicly available tools such as BLASTN, BLASTp (available on the website of the US National Center for Biotechnology Information (NCBI), see also Altschul SF et al., J. Mol. Biol. , 215:403-410 (1990); Stephen F et al., Nucleic Acids Res. , 25:3389-3402 (1997)), ClustalW2 (available on the website of the European Bioinformatics Institute, see also Higgins DG et al., Methods In Enzymology , 266:383-402 (1996); Larkin MA et al., Bioinformatics (Oxford, England), 23(21):2947-8 (2007) and ALIGN or Megalign can be used. (DNASTAR) software is used to perform the alignment to determine the percentage of amino acid (or nucleic acid) sequence identity. Those skilled in the art can use the default parameters provided by the tool or can customize the parameters appropriately according to the needs of the alignment, for example, by selecting an appropriate algorithm.

As used herein, "effector function" refers to the biological activity caused by the binding of the Fc region of an antibody to its effectors (e.g., C1 complex and Fc receptor). Exemplary effector functions include complement-dependent cytotoxicity (CDC) mediated by the interaction of the antibody and C1q on the C1 complex; antibody-dependent cell-mediated cytotoxicity (ADCC) mediated by the binding of the Fc region of an antibody to Fc receptors on effector cells; and phagocytosis. Effector function can be assessed using various assays, such as Fc receptor binding assays, C1q binding assays, and cell lysis assays.

As used herein, "antibody-dependent cell-mediated cytotoxicity" or "ADCC" refers to a cell-mediated reaction in which effector cells expressing Fc receptors (FcRs) recognize bound antibodies or antigen-binding fragments on target cells and subsequently cause lysis of the target cells. "ADCC activity" or "ADCC effector" refers to the ability of an antibody or antigen-binding fragment bound to a target cell to elicit an ADCC reaction as described above.

As used herein, "complement-dependent cytotoxicity" or "CDC" refers to a mechanism by which an antibody can mediate specific target cell lysis by activating the complement system of an organism. In CDC, C1q binds to the antibody and this binding triggers the complement cascade, which leads to the formation of a membrane attack complex (MAC) (C5b to C9) at the surface of the target cell as a result of classical pathway complement activation. "CDC activity" or "CDC effect" refers to the ability of an antibody or antigen-binding fragment bound to a target cell to elicit a CDC reaction as described above.

As used herein, "target cells" refer to cells to which an antibody specifically binds that includes an Fc region. "Effector cells" are leukocytes that express one or more Fc receptors and perform effector functions. Examples of human leukocytes that mediate ADCC include peripheral blood mononuclear cells (PBMCs), natural killer (NK) cells, monocytes, cytotoxic T cells, and neutrophils; PBMCs and NK cells are preferred. Effector cells can be isolated from their natural sources, such as from blood or PBMCs as known in the art.

An "isolated" substance has been artificially altered from its natural state. If an "isolated" composition or substance occurs in nature, it has been altered or removed from its original environment, or both. For example, a polynucleotide or polypeptide naturally present in a living animal is not "isolated," but it is considered "isolated" if it is sufficiently separated from the substances with which it coexists in nature and exists in a substantially pure state. An "isolated nucleic acid sequence" refers to the sequence of an isolated nucleic acid molecule. In certain embodiments, an “isolated antibody or antigen-binding fragment thereof” refers to an antibody or antigen-binding fragment thereof that is at least 60%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% pure as determined by an electrophoretic method (e.g., SDS-PAGE, isoelectric focusing, capillary electrophoresis) or a chromatographic method (e.g., ion exchange chromatography or reversed phase HPLC).

As used herein, the term "vector" refers to a medium into which a polynucleotide encoding a protein can be operably inserted so as to cause the expression of the protein. A vector can be used to transform, transduce or transfect a host cell so that the genetic elements it carries are expressed in the host cell. Examples of vectors include plasmids, phagemids, cosmids, artificial chromosomes such as yeast artificial chromosomes (YACs), bacterial artificial chromosomes (BACs) or P1-derived artificial chromosomes (PACs), bacteriophages such as lambda phage or M13 phage, and animal viruses. Classes of animal viruses used as vectors include retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (e.g., herpes simplex virus), poxviruses, bacilliviruses, papillomaviruses, and papovaviruses (e.g., SV40). The vector may contain a variety of elements for controlling expression, including promoter sequences, transcription initiation sequences, enhancer sequences, selectable elements and reporter genes. In addition, the vector may also contain a replication origin. The vector may also include materials that assist it in entering cells, including but not limited to viral particles, liposomes or protein coatings. The vector may be an expression vector or a selection vector. The present invention provides a vector (e.g., an expression vector) containing a nucleic acid sequence encoding an antibody or an antigen-binding fragment thereof provided herein, at least one promoter (e.g., SV40, CMV, EF-1α) operably linked to the nucleic acid sequence, and at least one selection marker. Examples of vectors include, but are not limited to, retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (e.g., herpes simplex virus), poxviruses, bacilli, papillomaviruses, papovaviruses (e.g., SV40), lambda phage and M13 phage, plasmids pcDNA3.3, pMD18-T, pOptivec, pCMV, pEGFP, pIRES, pQD-Hyg-Gseu, pALTER, pBAD, pcDNA, pCal, pL, pET, pGEMEX , pGEX, pCI, pEGFT, pSV2, pFUSE, pVITRO, pVIVO, pMAL, pMONO, pSELECT, pUNO, pDUO, Psg5L, pBABE, pWPXL, pBI, p15TV-L, pPro18, pTD, pRS10, pLexA, pACT2.2, pCMV-SCRIPT.RTM., pCDM8, pCDNA1.1/amp, pcDNA3.1, pRc/RSV, PCR 2.1, pEF-1, pFB, pSG5, pXT1, pCDEF3, pSVSPORT, pEF-Bos, etc.

As used herein, the phrase "host cell" refers to a cell into which an exogenous polynucleotide and/or vector may be introduced or has been introduced.

The term "subject" includes humans and non-human animals. Non-human animals include all vertebrates, such as mammals and non-mammals, such as non-human primates, mice, rats, cats, rabbits, sheep, dogs, cows, chickens, amphibians and reptiles. Except where otherwise indicated, the terms "patient", "subject" or "individual" are used interchangeably herein.

The term "anti-tumor activity" means a decrease in tumor cell proliferation, viability, or metastatic activity. For example, anti-tumor activity can be indicated by a decrease in the growth rate of abnormal cells that appear during treatment, or a stable or reduced tumor size, or a longer survival rate due to treatment, compared to a control that does not use the treatment. Such activity can be evaluated using recognized in vitro or in vivo tumor models, including but not limited to xenograft models, allograft models, mouse mammary tumor virus (MMTV) models, and other known models known in the art to study anti-tumor activity.

As used herein, "treating" or "treatment" of a disease, disorder or condition includes preventing or alleviating the disease, disorder or condition, slowing the rate of onset or development of a disease, disorder or condition, reducing the risk of developing a disease, disorder or condition, preventing or delaying the development of symptoms associated with the disease, disorder or condition, reducing or ending symptoms associated with the disease, disorder or condition, causing complete or partial regression of the disease, disorder or condition, curing the disease, disorder or condition, or some combination thereof.

The term "diagnosis" refers to the identification of a pathological state, disease or condition, such as the identification of a CD3-related disease, or the identification of an individual with a CD3-related disease who may benefit from a specific treatment regimen. In some embodiments, the diagnosis includes the identification of an abnormal amount or activity of CD3. In some embodiments, the diagnosis refers to the identification of cancer in an individual.

As used herein, the term "biological sample" or "sample" refers to a biological composition obtained from or derived from an individual of interest, which contains cells and/or other molecular entities to be characterized and/or identified, for example, based on physical, biochemical, chemical and/or physiological properties. Biological samples include, but are not limited to, cells, tissues, organs and/or biological fluids of an individual obtained by any method known to those skilled in the art. In some embodiments, the biological sample is a body fluid sample. In some embodiments, the body fluid sample is whole blood, plasma, serum, mucus (including nasal drainage and sputum), peritoneal fluid, pleural fluid, pleural fluid, saliva, urine, synovial fluid, cerebrospinal fluid (CSF), thoracentesis fluid, peritoneal effusion, ascites, or pericardial fluid. In some embodiments, the biological sample is a tissue or cell obtained from the stomach, heart, liver, spleen, lung, kidney, skin, or blood vessel of the individual.

As used herein, "CD3" refers to cluster of differentiation 3 protein, and includes any variants, conformations, isotypes and species homologs of CD3 expressed naturally by cells or by cells transfected with the CD3 gene. For example, the CD3 described herein may refer to a cluster of differentiation 3 protein derived from any vertebrate source, including mammals such as primates (e.g., humans, monkeys) and rodents (e.g., mice and rats). In mammals, the CD3 molecule is a six-chain multiprotein complex, including: a homodimer of a CD3γ chain, a CD3δ chain, two CD3ε chains and a CD3ζ chain, wherein the CD3ζ chain is the intracellular tail of the CD3 molecule, and the CD3γ, CD3δ and CD3ε chains all contain an extracellular domain (ECD) expressed on the surface of T cells. Exemplary sequences of human CD3 include human CD3ε protein (NCBI Ref Seq No. NP_000724), human CD3δ protein (NCBI Ref Seq No. NP_000723), and human CD3γ protein (NCBI Ref Seq No. NP_000064). Exemplary sequences of non-human CD3 include cynomolgus macaque (monkey) CD3ε protein (NCBI Ref Seq No. NP_001270544), cynomolgus macaque ( Macaca fascicularis ) (monkey) CD3δ protein (NCBI Ref Seq No. NP_001274617), cynomolgus macaque (monkey) CD3γ protein (NCBI Ref Seq No. NP_001270839); Mus musculus (mouse) CD3ε protein (NCBI Ref Seq No. NP_031674), Mus musculus (mouse) CD3δ protein (NCBI Ref Seq No. NP_038515), Mus musculus (mouse) CD3γ protein (NCBI Ref Seq No. AAA37400); Rattus norvegicus (rat) CD3ε protein (NCBI Ref Seq No. NP_001270544), Macaca fascicularis (monkey) CD3δ protein (NCBI Ref Seq No. NP_001274617), and cynomolgus (monkey) CD3γ protein (NCBI Ref Seq No. NP_001270839); Mus musculus (mouse) CD3ε protein (NCBI Ref Seq No. NP_031674), Mus musculus (mouse) CD3δ protein (NCBI Ref Seq No. NP_038515), and Mus musculus (mouse) CD3γ protein (NCBI Ref Seq No. AAA37400); Rattus norvegicus (rat) CD3ε protein (NCBI Ref Seq No. No. NP_001101610), Rattus norvegicus (rat) CD3δ protein (NCBI Ref Seq No. NP_037301), Rattus norvegicus (rat) CD3γ protein (NCBI Ref Seq No. NP_001071114). In certain embodiments, the CD3 used herein may also be recombinant CD3, for example, including recombinant CD3ε protein, recombinant CD3δ protein and recombinant CD3γ protein, and the recombinant CD3 may be expressed in the form of a recombinant CD3 complex as appropriate. The recombinant CD3 complex may be expressed on the cell surface, or may be expressed in a soluble form that is not bound to the cell surface. In certain embodiments, CD3 is human CD3. The terms "CD3", "CD-3", "CD 3", and "differentiation cluster 3" may be used interchangeably in the present invention.

The term "anti-CD3 antibody" refers to an antibody that specifically binds to CD3 (e.g., human CD3). The term "anti-human CD3 antibody" refers to an antibody that specifically binds to human CD3. In some embodiments, the anti-CD3 antibodies provided herein specifically bind to CD3γ protein. In some embodiments, the anti-CD3 antibodies provided herein specifically bind to CD3δ protein. In some embodiments, the anti-CD3 antibodies provided herein specifically bind to CD3ε protein.

As used herein, the term "CD3γ" is intended to encompass any form of CD3γ, for example, 1) the naturally occurring unprocessed CD3γ molecule, the "full-length" CD3γ chain or a naturally occurring CD3γ variant, including, for example, a splice variant or an allelic variant; 2) any form of CD3γ produced by processing in a cell; or 3) full-length, fragments (e.g., truncated forms, extracellular/transmembrane domains) or modified forms (e.g., mutant forms, glycosylated/pegylated, His-tagged/immunofluorescent fusion forms) of a CD3γ subunit produced by recombinant methods.

As used herein, the term "CD3δ" is intended to encompass any form of CD3δ, for example, 1) the naturally occurring unprocessed CD3δ molecule, the "full-length" CD3δ chain or a naturally occurring CD3δ variant, including, for example, a splice variant or an allelic variant; 2) any form of CD3δ produced by processing in a cell; or 3) full-length, fragments (e.g., truncated forms, extracellular/transmembrane domains) or modified forms (e.g., mutant forms, glycosylated/pegylated, His-tagged/immunofluorescent fusion forms) of a CD3δ subunit produced by recombinant methods.

As used herein, the term "CD3ε" is intended to encompass any form of CD3ε, for example, 1) the naturally occurring unprocessed CD3ε molecule, the "full-length" CD3ε chain or a naturally occurring CD3ε variant, including, for example, a splice variant or an allelic variant; 2) any form of CD3ε produced by processing in a cell; or 3) full-length, fragments (e.g., truncated forms, extracellular/transmembrane domains) or modified forms (e.g., mutant forms, glycosylated/pegylated, His-tagged/immunofluorescent fusion forms) of a CD3ε subunit produced by recombinant methods.

In some embodiments, the anti-CD3 antibodies provided herein specifically bind to CD3ε, but do not bind to CD3γ (or CD3δ) or bind to CD3γ (or CD3δ) poorly, for example, the binding affinity for CD3ε is at least 10 times lower than the binding affinity for CD3γ (or CD3δ), or at least 50 times lower than the binding affinity for CD3γ (or CD3δ), or at least 100 times lower, or at least 200 times lower. In some embodiments, the anti-CD3 antibodies provided herein do not have detectable binding affinity for CD3γ (or CD3δ). In some embodiments, the binding affinity is determined by FACS assay. In some embodiments, the binding affinity is determined by the mean fluorescence intensity (MFI) detected by FACS assay.

As used herein, a "CD3 related" disease, disorder, or condition refers to any disease, disorder, or condition that is caused, exacerbated, or otherwise linked to an increase or decrease in the expression or activity of CD3. In some embodiments, a CD3 related disease, disorder, or condition is a disorder associated with excessive cell proliferation, such as cancer. In certain embodiments, the disease, disorder, or condition is characterized by the expression or overexpression of CD3 or a gene associated with CD3.

The term "pharmaceutically acceptable" means that the specified carrier, vehicle, diluent, excipient and/or salt is generally chemically and/or physically compatible with the other ingredients of the formulation and physiologically compatible with the recipient.

As used herein, the term "cell expressing CD3" refers to a cell that expresses CD3 on the surface of the cell. Anti- CD3 Antibody

The present invention provides anti-CD3 antibodies and antigen-binding fragments thereof. The anti-CD3 antibodies and antigen-binding fragments provided herein are capable of binding (eg, specifically binding) to CD3 (eg, human CD3).

The binding affinity of the antibodies or antigen-binding fragments thereof provided herein can be expressed by a _KD value, which represents the ratio of the dissociation rate to the association rate when the binding between the antigen and the antigen-binding molecule reaches equilibrium ( _koff / _kon ). Antigen binding affinity (e.g., _KD ) can be appropriately determined using appropriate methods known in the art (including, for example, flow cytometry assay). In some embodiments, the binding of an antibody or an antigen-binding fragment thereof to different concentrations of an antigen can be measured by flow cytometry, and the determined mean fluorescence intensity (MFI) can first be plotted against the antibody concentration. Then, using Prism version 5 (GraphPad Software, San Diego, CA), the _KD value can be calculated by fitting the dependence of the specific binding fluorescence intensity (Y) and the antibody concentration (X) to a site saturation equation: Y = _Bmax *X/( _KD + X), where _Bmax refers to the maximum specific binding of the tested antibody to the antigen.

The binding of the antibodies or antigen-binding fragments thereof provided herein to CD3 can also be expressed as a "half maximal effective concentration" ( _EC50 ) value, which refers to the concentration of the antibody at which 50% of its maximal binding is observed. _EC50 values can be measured by binding assays known in the art, such as direct or indirect binding assays, such as enzyme-linked immunosorbent assays (ELISA), FACS assays, and other binding assays. In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of specifically binding to human CD3 (e.g., as measured by a FACS assay). In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of specifically binding to both human and cynomolgus macaque CD3 (e.g., as measured by a FACS assay).

In certain embodiments, the antibodies or antigen binding fragments thereof provided herein have T cell activation ability. In certain embodiments, the antibodies or antigen binding fragments thereof provided herein have T cell activation ability higher than OKT3. OKT3 is the first monoclonal antibody drug with specificity for human CD3 antigen approved by the U.S. FDA in 1986. OKT3 is described in the prior art as an effective T cell mitogen (Van Wauve, J. Immunol. , 124 (1980), 2708-18) and an effective T cell killer (Wong et al., Transplantation 50 (1990), 683-9). In certain embodiments, compared with BMK-B219 or BMK-TCB, the antibodies or antigen binding fragments thereof provided herein have higher or at least equivalent T cell activation ability. BMK-B219 is an anti-CD3 antibody developed by Johnson & Johnson, and information thereof can be found, for example, in WO2019224717A2. BMK-TCB is an anti-CD3 antibody developed by Roche, and information thereof can be found, for example, in WO2019154890A1.

The T cell activation ability of anti-CD3 antibodies can be measured by methods well known in the art, for example, by Jurkat NFAT-luciferase activation assay. In certain embodiments, the T cell activation ability is measured by the methods described in Examples 2.3 and 3.2 of the present invention.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein have PBMC activation ability. In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein have higher PBMC activation ability than OKT3, BMK-B219 and/or BMK-TCB. The PBMC activation ability of anti-CD3 antibodies can be determined by methods well known in the art, for example, by ELISA assays, for example, measuring IL-2 and/or IFNγ release levels, measuring CD25 expression on CD3 ⁺ T cells. In certain embodiments, PBMC activation ability is measured by the method described in Example 3.6 of the present invention. Exemplary anti- CD3 antibodies

In certain embodiments, the present invention provides an antibody or an antigen-binding fragment thereof that specifically binds to CD3, comprising: One or two or three heavy chain complementary determining regions (HCDR1, HCDR2 and/or HCDR3), wherein the heavy chain complementary determining region is contained in any one of the heavy chain variable (VH) region sequences selected from the group consisting of: : SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 and 245; and/or One or two or three light chain complementation determining regions (LCDR1, LCDR2 and/or LCDR3), the light chain complementation determining region being contained in any one of the light chain variable (VL) region sequences selected from the group consisting of: SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 and 232.

Those skilled in the art can define or determine the CDR boundaries of a VH or VL region by methods known in the art, as long as the amino acid sequence of the VH or VL region is known. For example, the CDR boundaries of an antibody or antigen-binding fragment thereof can be defined or determined by the Kabat, IMGT, Chothia or Al-Lazikani rules (Al-Lazikani, B., Chothia, C., Lesk, AM, J. Mol. Biol. , 273(4), 927 (1997); Chothia, C. et al., J. Mol. Biol. Dec 5;186(3):651-63 (1985); Chothia, C. and Lesk, AM, J. Mol. Biol. , 196,901 (1987); Chothia, C. et al., Nature . Dec 21-28;342(6252):877-83 (1989); Kabat EA et al., Sequences of Proteins of Immunological Interest, 5th ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991); Marie-Paule Lefranc et al., Developmental and Comparative Immunology , 27: 55-77 (2003); Marie-Paule Lefranc et al., Immunome Research , 1(3), (2005); Marie-Paule Lefranc, Molecular Biology of B cells (2nd ed.), Chapter 26, 481-514, (2015)). In some embodiments, the CDR boundaries of the antibodies or antigen-binding fragments thereof provided herein are determined according to the Kabat rule. In some embodiments, the CDR boundaries of the antibodies or antigen-binding fragments thereof provided herein are determined according to the IMGT rule. In some embodiments, the CDR boundaries of the antibodies or antigen-binding fragments thereof provided herein are determined according to the Chothia rule. In some embodiments, the CDR boundaries of the antibodies or antigen-binding fragments thereof provided herein are determined according to the Al-Lazikani rule.

In certain embodiments, the present invention provides antibodies or antigen-binding fragments thereof that specifically bind to CD3, wherein the antibodies or antigen-binding fragments thereof include anti-CD3 antibodies 25-G12-G6-C12, 40-C12-C10-E9, 8-B12-F9-B11, 31-F8-F5-C5, 16-F2-C11-D9, 20-E11-E11-C2, 7-D9-G10-H2, 7 -D8-G12-E4, 2-F12-A6-G2, 3-C6-C11-F12, 4-F12-F1-A4, 3-F3-G12-E2, 124E3D6, 126A11A4, 127E2D3, 133B4C7, 140D2B10, 147C6F3, or 147E11E2, or more (e.g., 1, 2, 3, 4, 5, or 6) CDR sequences.

As used herein, the antibody "25-G12-G6-C12" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 7 and a light chain variable region having the sequence of SEQ ID NO: 8.

As used herein, the antibody "40-C12-C10-E9" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 15 and a light chain variable region having the sequence of SEQ ID NO: 16.

As used herein, the antibody "8-B12-F9-B11" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 23 and a light chain variable region having the sequence of SEQ ID NO: 24.

As used herein, the antibody "31-F8-F5-C5" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 31 and a light chain variable region having the sequence of SEQ ID NO: 32.

As used herein, the antibody "16-F2-C11-D9" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 39 and a light chain variable region having the sequence of SEQ ID NO: 40.

As used herein, the antibody "20-E11-E11-C2" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 47 and a light chain variable region having the sequence of SEQ ID NO: 48.

As used herein, the antibody "7-D9-G10-H2" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 55 and a light chain variable region having the sequence of SEQ ID NO: 56.

As used herein, the antibody "7-D8-G12-E4" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 63 and a light chain variable region having the sequence of SEQ ID NO: 64.

As used herein, the antibody "2-F12-A6-G2" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 71 and a light chain variable region having the sequence of SEQ ID NO: 72.

As used herein, the antibody "3-C6-C11-F12" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 79 and a light chain variable region having the sequence of SEQ ID NO: 80.

As used herein, the antibody "4-F12-F1-A4" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 87 and a light chain variable region having the sequence of SEQ ID NO: 88.

As used herein, the antibody "3-F3-G12-E2" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 95 and a light chain variable region having the sequence of SEQ ID NO: 96.

As used herein, the antibody "124E3D6" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 108 and a light chain variable region having the sequence of SEQ ID NO: 109.

As used herein, antibody "126A11A4" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 116 and a light chain variable region having the sequence of SEQ ID NO: 117.

As used herein, antibody "127E2D3" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 124 and a light chain variable region having the sequence of SEQ ID NO: 125.

As used herein, antibody "133B4C7" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 132 and a light chain variable region having the sequence of SEQ ID NO: 133.

As used herein, antibody "140D2B10" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 140 and a light chain variable region having the sequence of SEQ ID NO: 141.

As used herein, the antibody "147C6F3" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 148 and a light chain variable region having the sequence of SEQ ID NO: 149.

As used herein, antibody "147E11E2" refers to a mouse monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 156 and a light chain variable region having the sequence of SEQ ID NO: 157.

The specific amino acid sequences of the heavy chain variable region and the light chain variable region of each exemplary antibody described above are shown in Table 3 below.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 7 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 8.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 15 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 16.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 23 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 24.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 31 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 32.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 39 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 40.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 47 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 48.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 55 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 56.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 63 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 64.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 71 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 72.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 79 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 80.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 87 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 88.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 95 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 96.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 108 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 109.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 116 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 117.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 124 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 125.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 132 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 133.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 140 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 141.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 148 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 149.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 156 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 157.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 163 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 168.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 163 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 163 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 170.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 164 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 168.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 164 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 164 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 170.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 168.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 170.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 166 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 168.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 166 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 166 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 170.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 186 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 187 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 188 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 189 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 190 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 191 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 192 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 193 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 194 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 195 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 196 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 197.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 198.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 199.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 200.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 202 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 207.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 202 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 208.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 202 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 209.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 203 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 207.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 203 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 208.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 203 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 209.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 204 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 207.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 205 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 207.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 206 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 207.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 206 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 208.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 206 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 209.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 233 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 234 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 235 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 236 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 237 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 238 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 239 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 240 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 241 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 242 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 243 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 244 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 245 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 169.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 230.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence shown in SEQ ID NO: 231.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 165 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 232.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 235 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 230.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 235 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 231.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained in the VH region sequence as shown in SEQ ID NO: 236 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained in the VL region sequence as shown in SEQ ID NO: 230.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence shown in SEQ ID NO: 236 and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence shown in SEQ ID NO: 231.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include at least one (e.g., 1, 2, or 3) heavy chain CDR or light chain CDR comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 17, 18, 19, 20, 21, 22, 25, 26, 27, 28, 29, 30, 33, 34, 35, 36, 37, 38, 41, 42, 43, 44, 45, 46, 49, 50, 51, 52, 53, 54, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 73, 74, 75, 76, 77, 78, 81, 82, 83, 84, 85, 86, 89, 90, 91, 92, 93, 94, 102, 103, 104, 105, 106, 107, 110, 111, 112, 113, 114, 115, 118, 1 19, 120, 121, 122, 123, 126, 127, 128, 129, 130, 131, 134, 135, 136, 137, 138, 139, 142, 143, 144, 145, 146, 147, 150, 151, 152, 153, 154, 155, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 201, 162, 167, 210, 211, 212, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228 and 229.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include a VH region, the VH region including one, two or three of HCDR1, HCDR2 and HCDR3, the HCDR1, HCDR2 and HCDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 1, 2, 3, 9, 10, 11, 17, 18, 19, 25, 26, 27, 33, 34, 35, 41, 42, 43, 49, 50, 51, 57, 58, 59, 65, 66, 67, 73, 74, 75, 81, 82, 83, 89, 90, 91, 102, 103, 104, 110, 111, 112, 118, 119, 120, 126, 127, 128, 134, 135, 136, 142, 143, 144, 150, 151, 152, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 201, 162, 210, 211, 212, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228 and 229.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include a VL region, the VL region including one, two or three of LCDR1, LCDR2 and LCDR3, the LCDR1, LCDR2 and LCDR3 comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 4, 5, 6, 12, 13, 14, 20, 21, 22, 28, 29, 30, 36, 37, 38, 44, 45, 46, 52, 53, 54, 60, 61, 62, 68, 69, 70, 76, 77, 78, 84, 85, 86, 92, 93, 94, 105, 106, 107, 113, 114, 115, 121, 122, 123, 129, 130, 131, 137, 138, 139, 145, 146, 147, 153, 154, 155, 182, 183, 184, 185, 167, 214, 215, and 216.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include HCDR1, HCDR2 and HCDR3, wherein the HCDR1 includes an amino acid sequence selected from the group consisting of: SEQ ID NO: 1, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 102, 110, 118, 126, 134, 142, 150, 217, 218 and 219; and the HCDR2 includes an amino acid sequence selected from the group consisting of: SEQ ID NO: 2, 10, 18, 26, 34, 42, 50, 58, 66, 74, 82, 90, 103, 111, 119, 127, 135, 143, 151, 171, 172, 173, 201, 210, 211, 212, 220 and 222; the HCDR3 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 104, 112, 120, 128, 136, 144, 152, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228, 229 and 162.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include LCDR1, LCDR2 and LCDR3, wherein the LCDR1 includes an amino acid sequence selected from the group consisting of SEQ ID NO: 4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 84, 92, 105, 113, 121, 129, 137, 145 and 153; the LCDR2 includes an amino acid sequence selected from the group consisting of SEQ ID NO: 5, 13, 21, 29, 37, 45, 53, 61, 69, 77, 85, 93, 106, 114, 122, 130, 138, 146 and 154; the LCDR3 includes an amino acid sequence selected from the group consisting of SEQ ID NO: 6, 14, 22, 30, 38, 46, 54, 62, 70, 78, 86, 94, 107, 115, 123, 131, 139, 147, 155, 182, 183, 184, 185, 214, 215, 216 and 167.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include: (a) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 includes the amino acid sequence shown in SEQ ID NO: 1, the HCDR2 includes the amino acid sequence shown in SEQ ID NO: 2, and the HCDR3 includes the amino acid sequence shown in SEQ ID NO: 3; (b) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 includes the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 includes the amino acid sequence shown in SEQ ID NO: 10, and the HCDR3 includes the amino acid sequence shown in SEQ ID NO: 11; (c) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 includes the amino acid sequence shown in SEQ ID NO: 17, the HCDR2 includes the amino acid sequence shown in SEQ ID NO: 18, and the HCDR3 includes the amino acid sequence shown in SEQ ID NO: 19; (d) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 25, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 26, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 27; (e) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 33, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 34, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 35; (f) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 41, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 42, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 43; (g) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: (h) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 57, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 58, and the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 59; (i) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 65, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 66, and the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 67; (j) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 73, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 74; (k) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 81, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 82, and the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 83; (l) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 89, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 90, and the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 91; (m) HCDR1, HCDR2 and HCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 102, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 103, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 104; (n) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 110, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 111, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 112; (o) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 118, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 119, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 120; (p) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 126, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 127, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 128; (q) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 134, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 135, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 136; (r) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 142, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 143, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 144; (s) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 151, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152; (t) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 219, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 201, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 162; (u) HCDR1, HCDR2 and HCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, 217 or 218, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, 171, 172, 173, 220 or 222, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228 or 229; (v) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 212, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 152; (w) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 210, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 152; or (x) HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 211, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include: (a) LCDR1, LCDR2 and LCDR3, wherein LCDR1 includes the amino acid sequence shown in SEQ ID NO: 4, the LCDR2 includes the amino acid sequence shown in SEQ ID NO: 5, and the LCDR3 includes the amino acid sequence shown in SEQ ID NO: 6; (b) LCDR1, LCDR2 and LCDR3, wherein LCDR1 includes the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 includes the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 includes the amino acid sequence shown in SEQ ID NO: 14; (c) LCDR1, LCDR2 and LCDR3, wherein LCDR1 includes the amino acid sequence shown in SEQ ID NO: 20, the LCDR2 includes the amino acid sequence shown in SEQ ID NO: 21, and the LCDR3 includes the amino acid sequence shown in SEQ ID NO: 22; (d) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 28, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 29, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 30; (e) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 36, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 37, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 38; (f) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 44, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 45, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 46; (g) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 52, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 53, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 54; (h) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 60, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 61, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 62; (i) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 68, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 69, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 70; (j) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 76, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 77, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 78; (k) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 84, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 85, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 86; (l) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 92, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 93, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 94; (m) LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 105, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 106, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 107; (n) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 113, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 114, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 115; (o) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 121, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 122, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 123; (p) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 129, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 130, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 131; (q) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 137, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 138, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 139; (r) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 145, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 146, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 147; (s) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155; (t) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 167; or (u) LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14, 182, 183, 184, 185, 214, 215 or 216.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include: (a) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 includes the amino acid sequence shown in SEQ ID NO: 1, the HCDR2 includes the amino acid sequence shown in SEQ ID NO: 2, the HCDR3 includes the amino acid sequence shown in SEQ ID NO: 3, the LCDR1 includes the amino acid sequence shown in SEQ ID NO: 4, the LCDR2 includes the amino acid sequence shown in SEQ ID NO: 5, and the LCDR3 includes the amino acid sequence shown in SEQ ID NO: 6; (b) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 includes the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 includes the amino acid sequence shown in SEQ ID NO: 10, and the HCDR3 includes the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (c) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 17, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 18, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 19, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 20, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 21, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 22; (d) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 25, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 26, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 27, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 28, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 29, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 30; (e) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 33, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 34, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 35, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 36, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 37, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 38; (f) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 41, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 42, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 43, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 44, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 45, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 46; (g) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 49, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 50, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 51, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 52, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 53, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 54; (h) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 57, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 58, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 59, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 60, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 61, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 62; (i) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 65, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 66, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 67, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 68, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 69, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 70; (j) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 73, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 74, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 75, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 76, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 77, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 78; (k) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 81, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 82, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 83, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 84, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 85, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 86; (l) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 89, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 90, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 91, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 92, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 93, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 94; (m) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 102, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 103, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 104, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 105, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 106, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 107; (n) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 110, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 111, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 112, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 113, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 114, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 115; (o) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 118, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 119, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 120, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 121, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 122, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 123; (p) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 126, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 127, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 128, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 129, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 130, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 131; (q) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 134, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 135, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 136, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 137, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 138, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 139; (r) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 142, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 143, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 144, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 145, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 146, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 147; (s) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 151, the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 153, the LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 154, and the LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 155; (t) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 171, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (u) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, and the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (v) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 173, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (w) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 174, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (x) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 175, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (y) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 176, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 14; (z) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 177, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (aa) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 178, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (bb) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 179, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (cc) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (dd) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 181, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (ee) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 182; (ff) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 183; (gg) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 184; (hh) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 185; (ii) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 220, the HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 14; (jj) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 221, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (kk) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 222, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (ll) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 223, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (mm) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 171, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 224, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (nn) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 214; (oo) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 215; (pp) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 216; (qq) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 222, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 214; (rr) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 222, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 215; (ss) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 223, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 214; (tt) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 223, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 215; (uu) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 225, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (vv) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 226, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (ww) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 227, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 14; (xx) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 228, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (yy) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 174, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (zz) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 229, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (aaa) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 217, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, and the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (bbb) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 218, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; (ccc) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 219, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 201, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 162, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 167; (ddd) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 212, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, and the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155; (eee) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 210, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155; or (fff) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 211, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155.

The SEQ ID NOs of the heavy chain (denoted as "H") variable region, light chain (denoted as "L") variable region, HCDR and LCDR of each of the 19 monoclonal antibodies are shown in Table 1 below. Unless otherwise specified, the CDR boundaries as described herein are defined or determined by the Kabat rule. The amino acid sequences of each CDR of 19 exemplary monoclonal antibodies are shown in Table 2 below. The amino acid sequences of each VH and VL of 19 exemplary monoclonal antibodies are shown in Table 3 below. Table 1. SEQ ID NOs of VH , VL , HCDR and LCDR of 19 exemplary monoclonal antibodies antibody Chain Variable region (SEQ ID NO) CDR1 (SEQ ID NO) CDR2 (SEQ ID NO) CDR3 (SEQ ID NO) 25-G12-G6-C12 H 7 1 2 3 L 8 4 5 6 40-C12-C10-E9 H 15 9 10 11 L 16 12 13 14 8-B12-F9-B11 H twenty three 17 18 19 L twenty four 20 twenty one twenty two 31-F8-F5-C5 H 31 25 26 27 L 32 28 29 30 16-F2-C11-D9 H 39 33 34 35 L 40 36 37 38 20-E11-E11-C2 H 47 41 42 43 L 48 44 45 46 7-D9-G10-H2 H 55 49 50 51 L 56 52 53 54 7-D8-G12-E4 H 63 57 58 59 L 64 60 61 62 2-F12-A6-G2 H 71 65 66 67 L 72 68 69 70 3-C6-C11-F12 H 79 73 74 75 L 80 76 77 78 4-F12-F1-A4 H 87 81 82 83 L 88 84 85 86 3-F3-G12-E2 H 95 89 90 91 L 96 92 93 94 124E3D6 H 108 102 103 104 L 109 105 106 107 126A11A4 H 116 110 111 112 L 117 113 114 115 127E2D3 H 124 118 119 120 L 125 121 122 123 133B4C7 H 132 126 127 128 L 133 129 130 131 140D2B10 H 140 134 135 136 L 141 137 138 139 147C6F3 H 148 142 143 144 L 149 145 146 147 147E11E2 H 156 150 151 152 L 157 153 154 155 Table 2. Amino acid sequences of each CDR of 19 exemplary monoclonal antibodies describe SEQ ID NO Amino acid sequence HCDR1 1 SYVIY 9 SYVIH 17 DYNAMIC 25 RYPIH 33 DFNIH 41 DYYMN 49 GYFMN 57 SYPMS 65 SYGVS 73 TYGMH 81 SYTMS 89 DYYMN 102 SYW 110 SYW 118 SYW 126 SYW 134 SYW 142 SYW 150 SYW HCDR2 2 YINPYKDVTKYSEKFND 10 YINPYNDVIKYNEKFKG 18 YISSASGKIYYADTVKG 26 YINPRNDYTKYTQRFKD 34 YINPNDGGSTYNQKFKG 42 DINPIHGGISSNQKFSD 50 RFNPYNGDTFYNQNFKG 58 TISSGGGNTYYPDSVKG 66 VIWGDGNTNYNSDLKT 74 YISNGGSTIYYADSVKG 82 TISSGGGNTFYADSVKG 90 EINPNNGGTTYRQTFKG 103 NINPSNGDTNYNEKFKS 111 NINPSNGDTNYNEKFKS 119 NIYPGSSSINYNEKFKS 127 NINPSNGDTNFNEKFKS 135 NINPSNGESNYNEKFKS 143 NLNPSNGEINYNEKFKH 151 NINPSNGATNYNEKFKS HCDR3 3 AIYHDYDGFGY 11 DSYYSYDGFAY 19 VLRWSVNYVMDY 27 SINDYDGFAY 35 PFLDS 43 RIYYGYDWYFDV 51 GDY 59 GLYWYD 67 VYWY 75 PTWGGFAY 83 SLYYYDGTYVRKDYYAMDY 91 SGY 104 DRSSQYYFDY 112 DRSSQYYFDY 120 DRSSQYYFDY 128 DRSSQYYFDY 136 DRSSQYYFDY 144 DRSSQYYFDY 152 DRSSQYYFDY LCDR1 4 SASSSVTYIN 12 SASSSVSYMH 20 ESSQSVLYSSNQKNYLA 28 SASSSVSYMN 36 KASQDINSYLR 44 SASSSVTSRYFF 52 KSSQSLLDSDGKTYLN 60 RSSQSIAHSNGDTYLE 68 RASENIYSYLA 76 RSSQSIAHSNGDTYLE 84 RASENIFSNLA 92 RSSQSIVHSNGNTYLE 105 KSSQSLLNSRTRKNYLA 113 KSSQSLLNSRTRKNYLA 121 KSSQSLLNSRTRKNYLA 129 KSSQSLLNSRTRKNYLA 137 KSSQSLLNSRTRKNYLA 145 KSSQSLLNSRTRKNYLA 153 KSSQSLLNSRSRKNYLA LCDR2 5 DTSKLAS 13 DTSKLAS twenty one WASTRES 29 DTSKLAS 37 GASSLVD 45 STSNLAS 53 LVSKLDS 61 KVSNRIS 69 NAKTLPE 77 KVSNRIS 85 AATNLAE 93 KVSNRFS 106 WASTRES 114 WASTRES 122 WASTRES 130 WASTRES 138 WASTRES 146 WASTRES 154 WASTRES LCDR3 6 QQWSRNPLT 14 QQWSSNPPT twenty two HQYLSSWT 30 QQWSSNPLT 38 LQYDEVPLT 46 QQYSTSPST 54 WQGTHFPFT 62 FQSHPY 70 QHHYGTPPT 78 FQSHPY 86 QQFWGTPWT 94 FQSHPRT 107 QQSYN 115 QQSFILRT 123 QS 131 QQSYTL 139 QQSYTL 147 QQSYILRT 155 QSqRT Table 3. Amino acid sequences of each VH and VL of 19 exemplary monoclonal antibodies antibody VH (SEQ ID NO) VL (SEQ ID NO) 25-G12-G6-C12 EVQLQQSGPELVKPGASVKMSCKASGYKFTSYVIYWVKQKPGQGLEWIGYINPYKDVTKYSEKFNDKATLTSDKSSSTAYMEISSLTSEDSAVYYCARAIYHDYDGFGYWGQGTLVIVSA (SEQ ID NO: 7) QIVLTQSPAIMSASPGEKVTMTCSASSSVTYINWYQQMSGTSPKRWIYDTSKLASGVPARFSGSGSGTSYSLTISSLEAEDAATYYCQQWSRNPLTFGAGTKLELK (SEQ ID NO: 8) 40-C12-C10-E9 EVQLQLSGPELVKPGASVKMSCKASGYTFSSYVIHWVKQKPGQGLEWIGYINPYNDVIKYNEKFKGKATLTSDKSSSTAYMELSSLTSEDSAVYYCARDSYYSYDGFAYWGQGTLVTVSA (SEQ ID NO: 15) QIVLTQSPAIMSASPGEKVTMTCSASSSVSYMHWYQQKSGTSPKRWIYDTSKLASGVPARFSGSGSGTSYSLTISSMEAEDAATYYCQQWSSNPPTFGGGTKVEIK (SEQ ID NO: 16) 8-B12-F9-B11 EVQLVESGGGIVKPGGSRKLSCAASGFTFSDYGMHWVRQAPEKGLEWIAYISSASGKIYYADTVKGRFTISRDNAKNILFLQMTSLRSEDTAMYYCARVLRWSVNYVMDYWGQGTSVTVSS (SEQ ID NO: 23) DIVMTQSPSSLAVSAGEKVTMNCESSQSVLYSSNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFTGTGSGTDFTLTISSVQAEDLAVYYCHQYLSSWTFGGGTKLEIK (SEQ ID NO: 24) 31-F8-F5-C5 EVQLQQSGAELARPGASVRMSCKASGYTFTRYPIHWVKQRPGQGLEWIGYINPRNDYTKYTQRFKDKATLTADKSSSTAYMQLSSLTSEDSAVYYCAKSINDYDGFAYWGQGTLVTVSA (SEQ ID NO: 31) DIVLSQSPTILSASPGEKVTMTCSASSSVSYMNWYQQRSGTSPKRWIYDTSKLASGVPARFSGSGSGTSYSLTISSMEAEDAATYYCQQWSSNPLTFGAGTKLELK (SEQ ID NO: 32) 16-F2-C11-D9 EVQLQQSGPELVKPGASVKMSCKASGYTFTDFNIHWVKQSLGKSLEWIGYINPNDGGSTYNQKFKGKATLTINKSSSSAYMELRSLTSEDSAVYYCAIPFLDSWGQGTSVTVSS (SEQ ID NO: 39) TLMMTQSPSSMYASLGERVTITCKASQDINSYLRWYQQKPGKSPKTLIYGASSLVDGVPSRFSGRGSGQDYSLTISSLEYEDMGIYYCLQYDEVPLTFGAGTKLELK (SEQ ID NO: 40) 20-E11-E11-C2 EVQLQQSGPEVVKPGASVKISCKASGYTFTDYYMNWVKQSHGKNLEWIGDINPIHGGISSNQKFSDKATLTVDKSSNTAYLELRSLTSEDSAIYYCARRIYYGYDWYFDVWGTGTTVTVSS (SEQ ID NO: 47) DIVLSQSPAIMSASPGERVTMTCSASSSVTSRYFFWYQQKPGSSPKLWIYSTSNLASGVPVRFSGSGSGTSYSLTINNMAAEDAATYYCQQYSTSPSTFGAGTKLELK (SEQ ID NO: 48) 7-D9-G10-H2 EVQLQQSGPELVKPGASVKISCKASGYSFTGYFMNWVKQSHGKSLEWIGRFNPYNGDTFYNQNFKGKATLTVDKSSSTAHMELRSLTSEDSAVYYCARGDYWGQGTTLTVSS (SEQ ID NO: 55) DIQMTQSPLTLSVTIGQPASISCKSSQSLLDSDGKTYLNWLLQRPGQSPKRLIYLVSKLDSGVPDRFTGSGSGTDFTLKISRVEAEDLGVYYCWQGTHFPFTFGSGTKLEIK (SEQ ID NO: 56) 7-D8-G12-E4 EVKLVESGGGLVKPGGSLKLSCAASGFTFSSYPMSWVRQTPAKRLEWVATISSGGGNTYYPDSVKGRFTISRDNARNTLYLQMSSLRSEDTAMYYCARGLYWYFDVWGAGTTVTVSS (SEQ ID NO: 63) DIVLTQSPLSLPVSLGDQASISCRSSQSIAHSNGDTYLEWYLQNPGQSPKLLIYKVSNRISGVPDRFSGSGSGTDFTLKISRVEAEDLGVYYCFQGSHVPYTFGGGTKLEIK (SEQ ID NO: 64) 2-F12-A6-G2 EVQLVESRPGLVAPSQSLSITCTVSGFSLTSYGVSWVRQPPGKGLEWLGVIWGDGNTNYNSDLKTSLSISKDNSKSQVFLKLDSLQTDDTATYYCAKVSYWYFDVWGTGTTVTVSS (SEQ ID NO: 71) DIQLTQPPASLSASVGETVTITCRASENIYSYLAWYQQKQGKSPQLLVYNAKTLPEGVPSRFSGSGSGTQFSLKINSLQPEDFGTYYCQHHYGTPPTFGTGTKLELK (SEQ ID NO: 72) 3-C6-C11-F12 EVHLVESGGGLVQPGGSRKLSCAGSGFTFSTYGMHWVRQAPEKGLEWVAYISNGGSTIYYADSVKGRFTISRDNPNDTLFLHMTSLGSEDTAMYYCARPTWGGFAYWGQGTLVTVSA (SEQ ID NO: 79) DIVLTQSPLSLPVSLGDQASISCRSSQSIAHSNGDTYLEWYLQNPGQSPKLLIYKVSNRISGVPDRFSGSGSGTDFTLKISRVEAEDLGVYYCFQGSHVPYTFGGGTKLEIK (SEQ ID NO: 80) 4-F12-F1-A4 EVKLVESGGGLVKPGGSLKLSCAASGFTFSSYTMSWIRQTPAKRLEWVATISSGGGNTFYADSVKGRFTISRDNARNTLNLQMSSLRSEDTAMYYCARSLYYYDGTYVRKDYYAMDYWGQGSSVTVSS (SEQ ID NO: 87) DIQMTQSPASLSVSVGETVTISCRASENIFSNLAWYQQKQGKSPQLLVYAATNLAEGVPSRFSGSRSGTQFSLKINSLQSEDFGSYYCQQFWGTPWTFGGGTKLEVK (SEQ ID NO: 88) 3-F3-G12-E2 EVQLQQSGPELVKPGASVKISCKASGNTFTDYYMNWVKQSHGKSLEWIGEINPNNGGTTYRQTFKGKATLTVDKSSTTAYMELRSLTSEDSAVYYCVLSGYWGQGTGLTVSS (SEQ ID NO: 95) DIVMTQSPLSLPVSLGDQVAISCRSSQSIVHSNGNTYLEWYLQKPGQSPKLLIYKVSNRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYYCFQGSHVPRTFGGGTKLELK (SEQ ID NO: 96) 124E3D6 QVQLQQPGTELVKPGASVKLSCKASGYTFTSYWMHWVKQRPGQGLEWIGNINPSNGDTNYNEKFKSKATLTVDKSSSTAYMQLSSLTSEDSAVYYCARDRSSQYYFDYWGQGTTLTVSS (SEQ ID NO: 108) DIVMSQSPSSLAVSAGEKVTMSCKSSQSLLNSRTRKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFTGSGSGTDFTLTISSVQAEDLAVYYCKQSYNLRTFGGGTKLEIK (SEQ ID NO: 109) 126A11A4 QVQLQQPGTELVKPGASVKLSCKASGYTFTSYWMHWVKQRPEQGLEWIGNINPSNGDTNYNEKFKSKATLTVDKASNTAYMQLSSLTSEDSAVYYCGRDRSSQYYFDYWGQGTTLTVSS (SEQ ID NO: 116) DIVMSQSPSSLAVSAGEKVTMSCKSSQSLLNSRTRKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFTGSGSGTDFTLTISSVQAEDLAVYFCKQSFILRTFGGGTKLEIK (SEQ ID NO: 117) 127E2D3 QVQLQQPGTELVKPGASVKLSCKASGYTFTSYWMHWVKQRPGEGLEWIGNIYPGSSSINYNEKFKSKATLTVDKSSSTAYMQLSSLTSEDSAVYYCARDRSSQYYFDYWGQGTTLTVSS (SEQ ID NO: 124) DIVMSQSPSSLAVSAGEKVTMSCKSSQSLLNSRTRKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFTGSGSGTDFTLTISSVQAEDLAVYYCTQSYNLRTFGGGTKLEIK (SEQ ID NO: 125) 133B4C7 QVQLQQPGTELVKPGASVKLSCKASGYTFTSYWMHWVKQRPGQGLEWIGNINPSNGDTNFNEKFKSKATLTVDKSSSTAYMQLSSLTSEDSAVYYCARDRSSQYYFDYWGQGTTLTVSS (SEQ ID NO: 132) DIVMSQSPSSLAVSAGEKVTMSCNSSQSLLNSRTRKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFTGSGSGTDFTLTISSVQAEDLAVYYCKQSYTLRTFGGGTKLEIK (SEQ ID NO: 133) 140D2B10 QVQLQQPGTELVKPGASVKLSCKASGYTFTSYWMHWVKQRPGQGLEWIGNINPSNGESNYNEKFKSKATLTVDKSSSTAYMQLSSLTSEDYAVYYCARDRSSQYYFDYWGQGTTLTVSS (SEQ ID NO: 140) DIVMSQSPSSLAVSAGEKVTMSCKSSQSLLNSRTRKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFTGSGSGTDFTLTISSVQAEDLAVYYCKQSYTLRTFGGGTKLEIK (SEQ ID NO: 141) 147C6F3 QVQLQQPGTELVKPGASVKLSCKASGYTFDSYWMHWVKQRPGQGLEWIGNLNPSNGEINYNEKFKHKATLTVDKSSSTAYMQLSSLTSEDSAVYYCSRDRSSQYYFDYWGQGTTLTVSS (SEQ ID NO: 148) DIVMSQSPSSLAVSAGEKVTLSCKSSQSLLNSRTRKNYLAWYQQKSGQSPKLLMYWASTRESGVPDRFTGSGSGTDFTLTITNVQAEDLAVYYCKQSYILRTFGGGTKLEIK (SEQ ID NO: 149) 147E11E2 QVQLQQPGTELVKPGTSVKLSCKASGYTFTSYWMHWVKQRPGQGLEWIGNINPSNGATNYNEKFKSKATLTVDKSSSTAYMQLSSLTSEDSAVYYCARDRSSQYYFDYWGQGTTLTVSS (SEQ ID NO: 156) DIVMSQSPSSLAVSAGEKVTMSCKSSQSLLNSRSRKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFTGSGSGTDFTLTISSVQAEDLAVYYCTQSYTLRTFGGGTKLEIK (SEQ ID NO: 157)

Considering that each of the 19 exemplary monoclonal antibodies can bind to CD3, and the antigen-binding specificity is mainly provided by the CDR1 region, CDR2 region, and CDR3 region, the HCDR1 sequence, HCDR2 sequence, and HCDR3 sequence, and the LCDR1 sequence, LCDR2 sequence, and LCDR3 sequence of each of the 19 exemplary monoclonal antibodies can be "mixed and matched" (i.e., CDRs from different antibodies can be mixed and matched, but each antibody must include HCDR1, HCDR2, and HCDR3, and LCDR1, LCDR2, and LCDR3) to generate the anti-CD3 antibodies or antigen-binding fragments thereof of the present invention. The binding assays described above and in the examples can be used to test the binding of such "mixed and matched" antibodies to CD3. Preferably, when VH CDR sequences are mixed and matched, the HCDR1 sequence, HCDR2 sequence and/or HCDR3 sequence from a particular VH sequence is replaced by a structurally similar CDR sequence. Similarly, when VL CDR sequences are mixed and matched, the LCDR1 sequence, LCDR2 sequence and/or LCDR3 sequence from a particular VL sequence is preferably replaced by a structurally similar CDR sequence. For example, the HCDR1 of antibodies 25-G12-G6-C12 and 40-C12-C10-E9 share some structural similarities and are therefore easily mixed and matched. It is apparent to those skilled in the art that novel VH and VL sequences can be generated by replacing one or more VH and/or VL CDR sequences with structurally similar sequences from the CDR sequences disclosed herein of the 19 exemplary monoclonal antibodies.

It is known that CDR is responsible for antigen binding. However, it has been found that not all 6 CDRs are indispensable or unchangeable. In other words, one or more CDRs of each of the 19 exemplary monoclonal antibodies can be replaced or changed or modified, but the specific binding affinity for CD3 is basically retained.

In certain embodiments, the anti-CD3 antibodies and antigen-binding fragments provided herein include the heavy chain CDR3 sequence of one of the anti-CD3 antibodies 25-G12-G6-C12, 40-C12-C10-E9, 8-B12-F9-B11, 31-F8-F5-C5, 16-F2-C11-D9, 20-E11-E11-C2, 7-D9-G10-H2, 7-D8-G12-E4, 2-F12-A6-G2, 3-C6-C11-F12, 4-F12-F1-A4, 3-F3-G12-E2, 124E3D6, 126A11A4, 127E2D3, 133B4C7, 140D2B10, 147C6F3 and 147E11E2. In certain embodiments, the anti-CD3 antibodies and antigen-binding fragments provided herein include a heavy chain CDR3 sequence selected from the group consisting of SEQ ID NO: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 104, 112, 120, 128, 136, 144 and 152. The heavy chain CDR3 region is located in the center of the antigen binding site and is therefore believed to be in the closest contact with the antigen and to provide the antibody with the most free amount of affinity for the antigen. It is also believed that, through a variety of diversification mechanisms, the heavy chain CDR3 is by far the most diverse CDR of the antigen binding site in terms of length, amino acid composition and conformation (Tonegawa S. Nature 302: 575-81). The diversity of the heavy chain CDR3 is sufficient to produce most antibody specificities (Xu JL, Davis MM. Immunity. 13:37-45) and ideal antigen binding affinity (Schier R et al., J Mol Biol. 263:551-67).

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include a VH region having an amino acid sequence as set forth in SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, or 245, or a sequence similar to SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 or 245 has a homologous sequence with at least 80% (e.g., at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include a VL region having an amino acid sequence as set forth in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 or 232 or a sequence similar to SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 or 232 have at least 80% (e.g., at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein include a VH/VL amino acid sequence pair selected from the group consisting of SEQ ID NO: 7/8, 15/16, 23/24, 31/32, 39/40, 47/48, 55/56, 63/64, 71/72, 79/80, 87/88, 95/96, 108/109, 116/117, 124/125, 132/133, 140/141, 148/149, 156/157, 163/168, 163/169, 163/1 70, 164/168, 164/169, 164/170, 165/168, 165/169, 165/170, 166/168, 166/169, 166/170, 186/169, 187/169, 188/169, 189/169, 190/169, 191/169, 192/169, 193/169, 194/169, 1 95/169、196/169、165/197、165/198、165/199、165/200、202/207、202/208、202/209、203/207、203/208、203/209、204/207、205/207、206/207、206/208、206/209、233/169、234/ 169, 235/169, 236/169, 237/169, 238/169, 239/169, 240/169, 241/169, 242/169, 243/169, 244/169, 245/169, 165/230, 165/231, 165/232, 235/230, 235/231, 236/230 and 236/231.

In certain embodiments, the antibodies and antigen-binding fragments thereof provided herein include suitable framework region (FR) sequences, as long as the antibodies and antigen-binding fragments thereof can specifically bind to CD3. The CDR sequences provided in Table 2 above are obtained from mouse antibodies, but the CDR sequences can be transplanted into any suitable FR sequence of any suitable species such as mouse, human, rat, rabbit, etc. using suitable methods known in the art such as recombinant technology.

In certain embodiments, the antibodies and antigen-binding fragments thereof provided herein are humanized. The desired humanized antibodies or antigen-binding fragments thereof have reduced immunogenicity in humans. Humanized antibodies are chimeric in their variable regions because non-human CDR sequences are transplanted to human or substantially human FR sequences. Humanization of antibodies or antigen-binding fragments can be performed essentially by replacing the corresponding human CDR genes in human immunoglobulin genes with non-human (e.g., mouse) CDR genes (see, e.g., Jones et al. (1986) Nature 321:522-525; Riechmann et al. (1988) Nature 332:323-327; Verhoeyen et al. (1988) Science 239:1534-1536).

Appropriate human heavy and light chain variable domains can be selected for this purpose using methods known in the art. In an illustrative example, a "best fit" approach can be used, in which a non-human (e.g., rodent) antibody variable domain sequence is screened or BLASTed against a database of known human variable domain sequences, and the human sequence closest to the non-human query sequence is identified and used as a human framework for grafting non-human CDR sequences (see, e.g., Sims et al., (1993) J. Immunol. 151:2296; Chothia et al. (1987) J. Mot. Biol. 196:901). Alternatively, a framework derived from the consensus sequence of all human antibodies can be used to graft non-human CDRs (see, e.g., Carter et al. (1992) Proc. Natl. Acad. Sci. USA , 89:4285; Presta et al. (1993) J. Immunol. , 151:2623).

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein are humanized. In certain embodiments, in addition to non-human CDR sequences, the humanized antibodies or antigen-binding fragments thereof provided herein are composed of substantially all human sequences. In some embodiments, the variable region FR and the constant region (if present) are completely or substantially derived from human immunoglobulin sequences. Human FR sequences and human constant region sequences can be derived from different human immunoglobulin genes, for example, FR sequences are derived from one human antibody and the constant region is derived from another human antibody. In some embodiments, the humanized antibody or antigen-binding fragment thereof includes human heavy chain HFR1, HFR2, HFR3 and HFR4 and/or light chain LFR1, LFR2, LFR3 and LFR4.

In some embodiments, the FR region derived from humans may include an amino acid sequence identical to the human immunoglobulin from which it is derived. In some embodiments, one or more amino acid residues of human FR are replaced by corresponding residues from a parent non-human antibody. In some embodiments that may be desired, the humanized antibody or its fragment is very close to the structure of the non-human parent antibody, thereby optimizing its binding properties (e.g., increasing binding affinity). In some embodiments, the humanized antibody or its antigen-binding fragment provided herein includes no more than 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid residue substitutions in each human FR sequence in a plurality of somatic FR sequences, or includes no more than 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid residue substitutions in all FR sequences of the heavy chain variable domain or the light chain variable domain. In some embodiments, such changes in amino acid residues may be present only in the heavy chain FR region, only in the light chain FR region, or in both chains. In certain embodiments, one or more amino acids in the human FR sequence are randomly mutated to increase binding affinity. In certain embodiments, one or more amino acids in the human FR sequence are back-mutated to the corresponding amino acids of the parent non-human antibody to increase binding affinity.

In some embodiments, one, two, three or four amino acids at positions selected from the group consisting of positions 45, 46, 48 and 70 (corresponding to positions 46, 47, 49 and 71 according to Kabat numbering, or positions 52, 53, 55 and 87 according to IMGT numbering, respectively) of the human light chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 are back-mutated to the corresponding amino acids of the parental mouse antibody.

For example, an amino acid at position 45 (corresponding to position 46 according to Kabat numbering, or corresponding to position 52 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a leucine at position 45 (corresponding to position 46 according to Kabat numbering, or corresponding to position 52 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the leucine at position 45 (corresponding to position 46 according to Kabat numbering, or corresponding to position 52 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is mutated to arginine (i.e., L45R).

For another example, an amino acid at position 46 (corresponding to position 47 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a leucine at position 46 (corresponding to position 47 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the leucine at position 46 (corresponding to position 47 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is mutated to tryptophan (i.e., L46W).

For another example, an amino acid at position 48 (corresponding to position 49 according to Kabat numbering, or position 55 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a lysine at position 48 (corresponding to position 49 according to Kabat numbering, or position 55 according to IMGT numbering) of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the lysine at position 48 (corresponding to position 49 according to Kabat numbering, or position 55 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is mutated to tyrosine (i.e., K48Y).

For another example, an amino acid at position 70 (corresponding to position 71 according to Kabat numbering, or position 87 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a phenylalanine at position 70 (corresponding to position 71 according to Kabat numbering, or position 87 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the phenylalanine at position 70 (corresponding to position 71 according to Kabat numbering, or position 87 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is mutated to tyrosine (i.e., F70Y).

For yet another example, an amino acid at position 45 relative to SEQ ID NO: 168 (corresponding to position 46 according to Kabat numbering, or position 52 according to IMGT numbering) and an amino acid at position 48 relative to SEQ ID NO: 168 (corresponding to position 49 according to Kabat numbering, or position 55 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are back-mutated to the corresponding amino acids of the parental mouse antibody. In one embodiment, the leucine at position 45 relative to SEQ ID NO: 168 (corresponding to position 46 according to Kabat numbering, or position 52 according to IMGT numbering) and the lysine at position 48 relative to SEQ ID NO: 168 (corresponding to position 49 according to Kabat numbering, or position 55 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are back-mutated to the corresponding amino acids of the parental mouse antibody. In another embodiment, the leucine at position 45 relative to SEQ ID NO: 168 (corresponding to position 46 according to Kabat numbering, or position 52 according to IMGT numbering) and the lysine at position 48 relative to SEQ ID NO: 168 (corresponding to position 49 according to Kabat numbering, or position 55 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are back-mutated to arginine and tyrosine, respectively (i.e., L45R+K48Y).

For yet another example, each of the amino acids at positions 45, 46, 48 and 70 (corresponding to positions 46, 47, 49 and 71 according to Kabat numbering, or positions 52, 53, 55 and 87 according to IMGT numbering, respectively) of the human light chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 168 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, leucine, leucine, lysine and phenylalanine at positions 45, 46, 48 and 70, respectively, relative to SEQ ID NO: 168 (corresponding to positions 46, 47, 49 and 71, respectively, according to Kabat numbering, or corresponding to positions 52, 53, 55 and 87, respectively, according to IMGT numbering) of the human light chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are back-mutated to the corresponding amino acids of the parental mouse antibody. In another embodiment, leucine, leucine, lysine and phenylalanine at positions 45, 46, 48 and 70, respectively, relative to SEQ ID NO: 168 (corresponding to positions 46, 47, 49 and 71, respectively, according to Kabat numbering, or positions 52, 53, 55 and 87, respectively, according to IMGT numbering) of the human light chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are mutated to arginine, tryptophan, tyrosine and tyrosine, respectively (i.e., L45R+L46W+K48Y+F70Y).

In some embodiments, one, two, three, four or five amino acids at positions selected from the group consisting of positions 27, 48, 68, 70 and 72 (corresponding to positions 27, 48, 67, 69 and 71 according to Kabat numbering, or positions 28, 53, 76, 78 and 80 according to IMGT numbering, respectively) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 are back-mutated to the corresponding amino acids of the parental mouse antibody.

For example, an amino acid at position 27 (corresponding to position 27 according to Kabat numbering, or corresponding to position 28 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a glycine at position 27 (corresponding to position 27 according to Kabat numbering, or corresponding to position 28 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the glycine at position 27 (corresponding to position 27 according to Kabat numbering, or corresponding to position 28 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is backmutated to tyrosine (i.e., G27Y).

For another example, an amino acid at position 48 (corresponding to position 48 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a methionine at position 48 (corresponding to position 48 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the methionine at position 48 (corresponding to position 48 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is backmutated to isoleucine (i.e., M48I).

For another example, an amino acid at position 68 (corresponding to position 67 according to Kabat numbering, or corresponding to position 76 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a valine at position 68 (corresponding to position 67 according to Kabat numbering, or corresponding to position 76 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the valine at position 68 (corresponding to position 67 according to Kabat numbering, or corresponding to position 76 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is backmutated to alanine (i.e., V68A).

For another example, an amino acid at position 70 (corresponding to position 69 according to Kabat numbering, or corresponding to position 78 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, an isoleucine at position 70 (corresponding to position 69 according to Kabat numbering, or corresponding to position 78 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the isoleucine at position 70 (corresponding to position 69 according to Kabat numbering, or corresponding to position 78 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is backmutated to leucine (i.e., I70L).

For another example, an amino acid at position 72 (corresponding to position 71 according to Kabat numbering, or corresponding to position 80 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, an alanine at position 72 (corresponding to position 71 according to Kabat numbering, or corresponding to position 80 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the alanine at position 72 (corresponding to position 71 according to Kabat numbering, or corresponding to position 80 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is backmutated to serine (i.e., A72S).

For yet another example, each of the amino acids at positions 27, 70 and 72 (corresponding to positions 27, 69 and 71 according to Kabat numbering, or positions 28, 78 and 80 according to IMGT numbering, respectively) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, glycine, isoleucine and alanine at positions 27, 70 and 72, respectively, relative to SEQ ID NO: 163 (corresponding to positions 27, 69 and 71, respectively, according to Kabat numbering, or positions 28, 78 and 80, respectively, according to IMGT numbering) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are mutated to tyrosine, leucine and serine, respectively (i.e., G27Y+I70L+A72S).

For yet another example, each of the amino acids at positions 27, 48, 68, 70 and 72 (corresponding to positions 27, 48, 67, 69 and 71 according to Kabat numbering, or positions 28, 53, 76, 78 and 80 according to IMGT numbering, respectively) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 163 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, glycine, methionine, valine, isoleucine and alanine at positions 27, 48, 68, 70 and 72, respectively, relative to SEQ ID NO: 163 (corresponding to positions 27, 48, 67, 69 and 71, respectively, according to Kabat numbering, or positions 28, 53, 76, 78 and 80, respectively, according to IMGT numbering) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are mutated to tyrosine, isoleucine, alanine, leucine and serine, respectively (i.e., G27Y+M48I+V68A+I70L+A72S).

In some embodiments, one, two, three, four, five or six amino acids at positions selected from the group consisting of positions 27, 30, 48, 68, 70 and 72 (corresponding to positions 27, 30, 48, 67, 69 and 71 according to Kabat numbering, or positions 28, 35, 53, 76, 78 and 80 according to IMGT numbering, respectively) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 are back-mutated to the corresponding amino acids of the parental mouse antibody.

For example, an amino acid at position 27 (corresponding to position 27 according to Kabat numbering, or corresponding to position 28 according to IMGT numbering) of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a glycine at position 27 (corresponding to position 27 according to Kabat numbering, or corresponding to position 28 according to IMGT numbering) of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the glycine at position 27 (corresponding to position 27 according to Kabat numbering, or corresponding to position 28 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to tyrosine (i.e., G27Y).

For another example, an amino acid at position 30 (corresponding to position 30 according to Kabat numbering, or corresponding to position 35 according to IMGT numbering) of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a serine at position 30 (corresponding to position 30 according to Kabat numbering, or corresponding to position 35 according to IMGT numbering) of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the serine at position 30 (corresponding to position 30 according to Kabat numbering, or corresponding to position 35 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is backmutated to threonine (i.e., S30T).

For another example, an amino acid at position 48 (corresponding to position 48 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a methionine at position 48 (corresponding to position 48 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the methionine at position 48 (corresponding to position 48 according to Kabat numbering, or corresponding to position 53 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to isoleucine (i.e., M48I).

For another example, an amino acid at position 68 (corresponding to position 67 according to Kabat numbering, or corresponding to position 76 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a valine at position 68 (corresponding to position 67 according to Kabat numbering, or corresponding to position 76 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the valine at position 68 (corresponding to position 67 according to Kabat numbering, or corresponding to position 76 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is backmutated to alanine (i.e., V68A).

For another example, an amino acid at position 70 (corresponding to position 69 according to Kabat numbering, or corresponding to position 78 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, an isoleucine at position 70 (corresponding to position 69 according to Kabat numbering, or corresponding to position 78 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the isoleucine at position 70 (corresponding to position 69 according to Kabat numbering, or corresponding to position 78 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is backmutated to leucine (i.e., I70L).

For another example, an amino acid at position 72 (corresponding to position 71 according to Kabat numbering, or corresponding to position 80 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, an alanine at position 72 (corresponding to position 71 according to Kabat numbering, or corresponding to position 80 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the alanine at position 72 (corresponding to position 71 according to Kabat numbering, or corresponding to position 80 according to IMGT numbering) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is backmutated to valine (i.e., A72V).

For another example, each amino acid at positions 27 and 30 (corresponding to positions 27 and 30 according to Kabat numbering, or corresponding to positions 28 and 35 according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, glycine and serine at positions 27 and 30 (corresponding to positions 27 and 30 according to Kabat numbering, or corresponding to positions 28 and 35 according to IMGT numbering, respectively) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 are back-mutated to the corresponding amino acids of the parental mouse antibody. In another embodiment, the glycine and serine at positions 27 and 30, respectively, relative to SEQ ID NO: 213 (corresponding to positions 27 and 30, respectively, according to Kabat numbering, or positions 28 and 35, respectively, according to IMGT numbering) of the human heavy chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are mutated to tyrosine and threonine, respectively (i.e., G27Y+S30T).

For yet another example, each of the amino acids at positions 27, 30, 70 and 72 (corresponding to positions 27, 30, 69 and 71 according to Kabat numbering, or positions 28, 35, 78 and 80 according to IMGT numbering, respectively) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, glycine, serine, isoleucine and alanine at positions 27, 30, 70 and 72, respectively, relative to SEQ ID NO: 213 (corresponding to positions 27, 30, 69 and 71, respectively, according to Kabat numbering, or positions 28, 35, 78 and 80, respectively, according to IMGT numbering) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are back-mutated to the corresponding amino acids of the parental mouse antibody. In another embodiment, glycine, serine, isoleucine and alanine at positions 27, 30, 70 and 72, respectively, relative to SEQ ID NO: 213 (corresponding to positions 27, 30, 69 and 71, respectively, according to Kabat numbering, or positions 28, 35, 78 and 80, respectively, according to IMGT numbering) of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein are mutated to tyrosine, threonine, leucine and valine, respectively (i.e., G27Y+S30T+I70L+A72V).

For yet another example, each of the amino acids at positions 27, 30, 48, 68, 70 and 72 of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 (corresponding to positions 27, 30, 48, 67, 69 and 71 according to Kabat numbering, or corresponding to positions 28, 35, 53, 76, 78 and 80 according to IMGT numbering, respectively) is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, glycine, serine, methionine, valine, isoleucine and alanine at positions 27, 30, 48, 68, 70 and 72 of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 (corresponding to positions 27, 30, 48, 67, 69 and 71 according to Kabat numbering, or corresponding to positions 28, 35, 53, 76, 78 and 80 according to IMGT numbering, respectively) are back-mutated to the corresponding amino acids of the parental mouse antibody. In another embodiment, glycine, serine, methionine, valine, isoleucine and alanine at positions 27, 30, 48, 68, 70 and 72 of the human heavy chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 213 (corresponding to positions 27, 30, 48, 67, 69 and 71 according to Kabat numbering, or corresponding to positions 28, 35, 53, 76, 78 and 80 according to IMGT numbering, respectively) are mutated to tyrosine, threonine, isoleucine, alanine, leucine and valine, respectively (i.e., G27Y+S30T+M48I+V68A+I70L+A72V).

In some embodiments, an amino acid at position 49 (corresponding to position 43 according to Kabat numbering, or corresponding to position 49 according to IMGT numbering) of the human light chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 207 is back-mutated to the corresponding amino acid of the parental mouse antibody. In one embodiment, a proline at position 49 (corresponding to position 43 according to Kabat numbering, or corresponding to position 49 according to IMGT numbering) of the human light chain FR sequence of a humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 207 is back-mutated to the corresponding amino acid of the parental mouse antibody. In another embodiment, the proline at position 49 (corresponding to position 43 according to Kabat numbering, or corresponding to position 49 according to IMGT numbering) of the human light chain FR sequence of the humanized anti-CD3 antibody or antigen-binding fragment thereof provided herein relative to SEQ ID NO: 207 is back-mutated to serine (i.e., P49S).

In some embodiments, the present invention provides a humanized antibody or antigen-binding fragment thereof that is pure 40-C12-C10-E9 (also referred to herein as "humanized 40-C12-C10-E9"). In some embodiments, the present invention provides 12 humanized 40-C12-C10-E9, which are respectively named hu40E9-L1H1, hu40E9-L1H2, hu40E9-L1H3, hu40E9-L1H4, hu40E9-L2H1, hu40E9-L2H2, hu40E9-L2H3, hu40E9-L2H4, hu40E9-L3H1, hu40E9-L3H2, hu40E9-L3H3 and hu40E9-L3H4. The SEQ ID NOs of the heavy chain and light chain variable regions of each humanized 40-C12-C10-E9 are shown in Table 20 below (the CDR sequences identified by the convention of Kabat are underlined). Each of the 12 humanized 40-C12-C10-E9 clones includes HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, which include the amino acid sequences shown in SEQ ID NOs: 9, 10, 11, 12, 13 and 14, respectively.

In some embodiments, the present invention provides a humanized antibody or antigen-binding fragment thereof that is pure 147E11E2 (also referred to as "humanized 147E11E2" in the present invention). In some embodiments, the present invention provides 11 humanized 147E11E2, which are respectively named hu147E2-L1H2, hu147E2-L1H3, hu147E2-L1H3a, hu147E2-L1H3b, hu147E2-L1H4, hu147E2-L2H2, hu147E2-L2H3, hu147E2-L2H4, hu147E2-L3H2, hu147E2-L3H3 and hu147E2-L3H4. The SEQ ID NOs of the heavy chain and light chain variable regions of each humanized 147E11E2 are shown in Table 20 below (the CDR sequences identified by the convention of Kabat are underlined). Each of the 11 humanized 147E11E2 clones includes HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, which include the amino acid sequences shown in SEQ ID NOs: 150, 212, 152, 153, 154 and 155, respectively.

In some embodiments, some motifs that are prone to deamidation (e.g., N55G56 motif) can be identified in one or more CDRs (e.g., HCDR2) of a humanized antibody or an antigen-binding fragment thereof. In order to remove such deamidation sites, different mutations can be introduced into the motif while retaining specific binding to CD3. In some embodiments, the deamidation site is identified in the amino acid sequence of hu147E2-H3 (i.e., SEQ ID NO: 203), which has the same CDRs as the heavy chain of the homologous 147E11E2. In some embodiments, one or more amino acids in one or more CDRs of the candidate antibody are mutated to remove the deamidation site. In some embodiments, the mutation occurs in HCDR2 of the candidate antibody (e.g., position 55 relative to SEQ ID NO: 213). Thus, the present invention provides an anti-CD3 antibody or antigen-binding fragment thereof having the same CDRs as the clone 147E11E2, except that the amino acid sequence of HCDR2 is different. For example, the anti-CD3 antibody or antigen-binding fragment thereof provided herein comprises a HCDR2 comprising an amino acid sequence as set forth in SEQ ID NO: 212. In some embodiments, the present invention provides a humanized antibody hu147E2-L1H3a comprising a HCDR2 comprising an amino acid sequence as set forth in SEQ ID NO: 210, wherein the HCDR2 carries a single mutation (i.e., N55Q) compared to the parental HCDR2 (i.e., SEQ ID NO: 151) to remove the deamidation site NG motif. In some embodiments, the present invention provides a humanized antibody hu147E2-L1H3b, which includes a HCDR2 comprising an amino acid sequence as shown in SEQ ID NO: 211, and compared with the parent HCDR2 (i.e., SEQ ID NO: 151), the HCDR2 carries a single mutation (i.e., N55S) to remove the deamidation site NG motif.

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 212, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, which comprise the amino acid sequences shown in SEQ ID NOs: 150, 212, 152, 153, 154 and 155, respectively. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, which respectively comprise the amino acid sequences shown in SEQ ID NOs: 150, 210, 152, 153, 154 and 155. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, which respectively comprise the amino acid sequences shown in SEQ ID NOs: 150, 211, 152, 153, 154 and 155. The amino acid sequences of SEQ ID NOs: 210, 211 and 212 are shown in Table 22 below.

In some embodiments, the humanized antibodies or antigen-binding fragments thereof provided herein include a VH region having an amino acid sequence as shown in SEQ ID NO: 163, 164, 165, 166, 213, 202, 203, 204, 205, 206, or a homologous sequence having at least 80% (e.g., at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 163, 164, 165, 166, 213, 202, 203, 204, 205 or 206. In some embodiments, the humanized antibodies or antigen-binding fragments thereof provided herein include a VL region having an amino acid sequence as shown in SEQ ID NO: 168, 169, 170, 207, 208, 209, or a homologous sequence having at least 80% (e.g., at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 168, 169, 170, 207, 208 or 209.

The present invention also provides exemplary humanized antibodies of pure 40-C12-C10-E9, including: 1) "hu40E9-L1H1", which includes the heavy chain variable region of hu40E9-H1 (SEQ ID NO: 163) and the light chain variable region of hu40E9-L1 (SEQ ID NO: 168); 2) "hu40E9-L1H2", which includes the heavy chain variable region of hu40E9-H2 (SEQ ID NO: 164) and the light chain variable region of hu40E9-L1 (SEQ ID NO: 168); 3) "hu40E9-L1H3", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L1 (SEQ ID NO: 168); 4) "hu40E9-L1H4", which includes the heavy chain variable region of hu40E9-H4 (SEQ ID NO: 166) and the light chain variable region of hu40E9-L1 (SEQ ID NO: 168); 5) "hu40E9-L2H1", which includes the heavy chain variable region of hu40E9-H1 (SEQ ID NO: 163) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 6) "hu40E9-L2H2", which includes the heavy chain variable region of hu40E9-H2 (SEQ ID NO: 164) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 7) "hu40E9-L2H3", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 8) "hu40E9-L2H4", which includes the heavy chain variable region of hu40E9-H4 (SEQ ID NO: 166) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 9) "hu40E9-L3H1", which includes the heavy chain variable region of hu40E9-H1 (SEQ ID NO: 163) and the light chain variable region of hu40E9-L3 (SEQ ID NO: 170); 10) "hu40E9-L3H2", which includes the heavy chain variable region of hu40E9-H2 (SEQ ID NO: 164) and the light chain variable region of hu40E9-L3 (SEQ ID NO: 170); 11) "hu40E9-L3H3", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L3 (SEQ ID NO: 170); or 12) "hu40E9-L3H4", which includes the heavy chain variable region of hu40E9-H4 (SEQ ID NO: 166) and the light chain variable region of hu40E9-L3 (SEQ ID NO: 170).

The present invention also provides exemplary humanized antibodies of cloned 147E211E2, including: 1) "hu14E2-L1H2", which includes the heavy chain variable region of hu14E2-H2 (SEQ ID NO: 202) and the light chain variable region of hu14E2-L1 (SEQ ID NO: 207); 2) "hu14E2-L1H3", which includes the heavy chain variable region of hu14E2-H3 (SEQ ID NO: 203) and the light chain variable region of hu14E2-L1 (SEQ ID NO: 207); 3) "hu14E2-L1H3a", which includes the heavy chain variable region of hu14E2-H3a (SEQ ID NO: 204) and the light chain variable region of hu14E2-L1 (SEQ ID NO: 207); 4) "hu14E2-L1H3b", which includes the heavy chain variable region of hu14E2-H3b (SEQ ID NO: 205) and the light chain variable region of hu14E2-L1 (SEQ ID NO: 207); 5) "hu14E2-L1H4", which includes the heavy chain variable region of hu14E2-H4 (SEQ ID NO: 206) and the light chain variable region of hu14E2-L1 (SEQ ID NO: 207); 6) "hu14E2-L2H2", which includes the heavy chain variable region of hu14E2-H2 (SEQ ID NO: 202) and the light chain variable region of hu14E2-L2 (SEQ ID NO: 208); 7) "hu14E2-L2H3", which includes the heavy chain variable region of hu14E2-H3 (SEQ ID NO: 203) and the light chain variable region of hu14E2-L2 (SEQ ID NO: 208); 8) "hu14E2-L2H4", which includes the heavy chain variable region of hu14E2-H4 (SEQ ID NO: 206) and the light chain variable region of hu14E2-L2 (SEQ ID NO: 208); 9) "hu14E2-L3H2", which includes the heavy chain variable region of hu14E2-H2 (SEQ ID NO: 202) and the light chain variable region of hu14E2-L3 (SEQ ID NO: 209); 10) "hu14E2-L3H3", which includes the heavy chain variable region of hu14E2-H3 (SEQ ID NO: 203) and the light chain variable region of hu14E2-L3 (SEQ ID NO: 209); or 11) "hu14E2-L3H4", which includes the heavy chain variable region of hu14E2-H4 (SEQ ID NO: 206) and the light chain variable region of hu14E2-L3 (SEQ ID NO: 209). Table 20. Amino acid sequences of each VH and VL of humanized 40-C12-C10-E9 and 147E11E2 describe SEQ ID NO Amino acid sequence hu40E9-H1 163 EVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYVIHWVRQAPGQGLEWMG YINPYNDVIKYNEKFKG RVTITADKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-H2 164 EVQLVQSGAEVKKPGSSVKVSCKASGYTFS SYVIH WVRQAPGQGLEWMG YINPYNDVIKYNEKFKG RVTITADKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-H3 165 EVQLVQSGAEVKKPGSSVKVSCKASGYTFS SYVIH WVRQAPGQGLEWMG YINPYNDVIKYNEKFKG RVTLTSDKSTSTAYMELSSLRSEDTAVYYCAR DSYYSYDGFAY WGQGTLVTVSS hu40E9-H4 166 EVQLVQSGAEVKKPGSSVKVSCKASGYTFS SYVIH WVRQAPGQGLEWIG YINPYNDVIKYNEKFKG RATLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-L1 168 EIVLTQSPDFQSVTPKEKVTITC SASSSVSYMH WYQQKPDQSPKLLIK DTSKLAS GVPSRFSGSGSGTDFTLTINSLEAEDAATYYC QQWSSNPPT FGGGTKVEIK hu40E9-L2 169 EIVLTQSPDFQSVTPKEKVTITC SASSSVSYMH WYQQKPDQSPKRLIY DTSKLAS GVPSRFSGSGSGTDFTLTINSLEAEDAATYYC QQWSSNPP TFGGGTKVEIK hu40E9-L3 170 EIVLTQSPDFQSVTPKEKVTIT CSASSSVSYMH WYQQKPDQSPKRWIY DTSKLAS GVPSRFSGSGSGTDYTLTINSLEAEDAATYYC QQWSSNPP TFGGGTKVEIK hu147E2-H1 213 EVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYWMH WVRQAPGQGLEWMGNINPSNGATNYNEKFKSRVTITADDKSTSTAYMELSSLRSEDTAVYYCARDRSSQYYFDY WGQGTTVTVSS hu147E2-H2 202 EVQLVQSGAEVKKPGSSVKVSCKASGYTFT SYWMH WVRQAPGQGLEWM GNINPSNGATNYNEKFK SRVTITADKSTSTAYMELSSLRSEDTAVYYCARDRSSQYYFDYWGQGTTVTVSS hu147E2-H3 203 EVQLVQSGAEVKKPGSSVKVSCKASGYTFTSYWMHWVRQAPGQGLEWMGNINPSNGATNYNEKFKSRVTLTVDKSTSTAYMELSSLRSEDTAVYYCARDRSSQYYFDY WGQGTTVTVSS hu147E2-H3a 204 EVQLVQSGAEVKKPGSSVKVSCKASGYTFT SYWMH WVRQAPGQGLEWM GNINPSQGATNYNEKFK SRVTLTVDKSTSTAYMELSSLRSEDTAVYYCAR DRSSQYYFDY WGQGTTVTVSS hu147E2-H3b 205 EVQLVQSGAEVKKPGSSVKVSCKASGYTFT SYWMH WVRQAPGQGLEWMG NINPSSGATNYNEKFKS RVTLTVDKSTSTAYMELSSLRSEDTAVYYCAR DRSSQYYFDY WGQGTTVTVSS hu147E2-H4 206 EVQLVQSGAEVKKPGSSVKVSCKASGYTFT SYWMH WVRQAPGQGLEWI GNINPSNGATNYNEKFKS RATLTVDKSTSTAYMELSSLRSEDTAVYYCAR DRSSQYYFDY WGQGTTVTVSS hu147E2-L1 207 DIVMTQSPDSLAVSLGERATINC KSSQSLLNSRSRKNYLA WYQQKPGQPPKLLIY WASTRES GVPDRFSGSGSGTDFTLTISSLQAEDVAVYYC TQSYTLRT FGGGTKVEIK hu147E2-L2 208 DIVMTQSPDSLAVSLGERATINC KSSQSLLNSRSRKNYLA WYQQKPGQSPKLLIY WASTRES GVPDRFSGSGSGTDFTLTISSLQAEDVAVYYC TQSYTLRT FGGGTKVEIK hu147E2-L3 209 DIQMTQSPSSLSASVGDRVTITC KSSQSLLNSRSRKNYLA WYQQKPGKAPKLLIY WASTRES GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC TQSYTLRT FGGGTKVEIK

The present invention also provides humanized and affinity-improved antibodies or antigen-binding fragments thereof that specifically bind to CD3. In some embodiments, affinity maturation is performed based on the sequences of hu40E9-H3 and hu40E9-L2, which have the same CDRs as the clone 40-C12-C10-E9. In some embodiments, one or more amino acids within one or more CDRs of the candidate antibody are mutated to improve affinity, for example, the mutation occurs in HCDR1 (e.g., positions 31-33 relative to SEQ ID NO: 165), HCDR2 (e.g., positions 54-56 relative to SEQ ID NO: 165), HCDR3 (e.g., positions 99-106 relative to SEQ ID NO: 165), or LCDR3 (e.g., positions 91-93 relative to SEQ ID NO: 169) of the candidate antibody. Therefore, the present invention provides an anti-CD3 antibody or an antigen-binding fragment thereof, which has the same CDRs as clone 40-C12-C10-E9 except that the amino acid sequences of HCDR1, HCDR2, HCDR3 and/or LCDR3 are different.

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise a HCDR1 comprising the amino acid sequence shown as SEQ ID NO: 219. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise a HCDR1 comprising the amino acid sequence shown as SEQ ID NO: 9, 217 or 218.

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise a HCDR2 comprising the amino acid sequence shown as SEQ ID NO: 201. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise a HCDR2 comprising the amino acid sequence shown as SEQ ID NO: 10, 171, 172, 173, 220 or 222.

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise a HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 162. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise a HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 11, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228, or 229.

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise a LCDR3 comprising the amino acid sequence shown as SEQ ID NO: 167. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein comprise a LCDR3 comprising the amino acid sequence shown as SEQ ID NO: 14, 182, 183, 184, 185, 214, 215 or 216.

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include HCDR1, HCDR2 and HCDR3, wherein the HCDR1 includes the amino acid sequence shown in SEQ ID NO: 219, the HCDR2 includes the amino acid sequence shown in SEQ ID NO: 201, and the HCDR3 includes the amino acid sequence shown in SEQ ID NO: 162. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include LCDR1, LCDR2 and LCDR3, wherein the LCDR1 includes the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 includes the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 includes the amino acid sequence shown in SEQ ID NO: 167. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, which include the amino acid sequences shown in SEQ ID NOs: 219, 201, 162, 12, 13 and 167, respectively.

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include HCDR1, HCDR2 and HCDR3, wherein the HCDR1 includes the amino acid sequence shown as SEQ ID NO: 9, 217 or 218, the HCDR2 includes the amino acid sequence shown as SEQ ID NO: 10, 171, 172, 173, 220 or 222, and the HCDR3 includes the amino acid sequence shown as SEQ ID NO: 11, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228 or 229. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include LCDR1, LCDR2 and LCDR3, wherein the LCDR1 includes the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 includes the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 includes the amino acid sequence shown in SEQ ID NO: 14, 182, 183, 184, 185, 214, 215 or 216. In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 includes the amino acid sequence of SEQ ID NO: 9, 217 or 218, the HCDR2 includes the amino acid sequence of SEQ ID NO: 10, 171, 172, 173, 220 or 222, the HCDR3 includes the amino acid sequence of SEQ ID NO: 11, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228 or 229, the LCDR1 includes the amino acid sequence of SEQ ID NO: 12, the LCDR2 includes the amino acid sequence of SEQ ID NO: 13, the LCDR3 includes the amino acid sequence of SEQ ID NO: The amino acid sequence shown in 14, 182, 183, 184, 185, 214, 215 or 216.

The amino acid sequences of SEQ ID NOs: 171-185, 201, 162, 167 and 214-229 are shown in Table 22 below. As shown in Table 22 below, each hu40E9 HCDR comprises one or more mutations compared to its corresponding HCDR contained in hu40E9-H3 (i.e., SEQ ID NO: 165), and the mutated amino acids are underlined; similarly, each hu40E9 LCDR3 comprises one or more mutations compared to the LCDR3 contained in hu40E9-L2 (i.e., SEQ ID NO: 169), and the mutated amino acids are also underlined; similarly, each hu147E2 HCDR2 comprises one mutation compared to the HCDR2 contained in hu40E9-H3 (i.e., SEQ ID NO: 165), and the mutated amino acids are also underlined.

In some embodiments, the present invention provides an antibody or antigen-binding fragment thereof that specifically binds to CD3, comprising one or two or three HCDRs contained in any one of the VH region sequences selected from the group consisting of SEQ ID NO: 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 and 245; and/or one or two or three LCDRs contained in any one of the VL region sequences selected from the group consisting of SEQ ID NO: 197, 198, 199, 200, 230, 231 and 232. In some embodiments, the present invention also provides an anti-CD3 antibody or an antigen-binding fragment thereof, which includes HCDR1, HCDR2 and HCDR3, which are contained in any one of the VH region sequences selected from the group consisting of SEQ ID NO: 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 and 245; and LCDR1, LCDR2 and LCDR3, which are contained in any one of the VL region sequences selected from the group consisting of SEQ ID NO: 197, 198, 199, 200, 230, 231 and 232.

In some embodiments, the present invention provides an antibody or an antigen-binding fragment thereof that specifically binds to CD3, comprising one, two or three HCDRs contained in any one of the VH region sequences selected from the group consisting of SEQ ID NOs: 213, 202, 203, 204, 205 and 206; and/or one, two or three LCDRs contained in any one of the VL region sequences selected from the group consisting of SEQ ID NOs: 207, 208 and 209. In some embodiments, the present invention also provides an anti-CD3 antibody or an antigen-binding fragment thereof, which comprises HCDR1, HCDR2 and HCDR3 contained in any one of the VH region sequences selected from the group consisting of SEQ ID NOs: 213, 202, 203, 204, 205 and 206; and LCDR1, LCDR2 and LCDR3 contained in any one of the VL region sequences selected from the group consisting of SEQ ID NOs: 207, 208 and 209.

The amino acid sequences of SEQ ID NOs: 186-200 and 230-245 are shown in Table 21 below. As shown in Table 21 below, each VH region comprises one, two or three mutations compared to the amino acid sequence of hu40E9-H3 (i.e., SEQ ID NO: 165), and the mutated amino acids are underlined; similarly, each VL region comprises one or two mutations compared to the amino acid sequence of hu40E9-L2 (i.e., SEQ ID NO: 169), and the mutated amino acids are also underlined. Table 21. Amino acid sequences of exemplary VH and VL regions describe SEQ ID NO Amino acid sequence hu40E9-H3-N55S.H 186 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPY S DVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-H3-D99E.H 187 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCAR ESYYSYDGFAYWGQGTLVTVSS hu40E9-H3-Y101F.H 188 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDS F YSYDGFAYWGQGTLVTVSS hu40E9-H3-D105E.H 189 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSY EGFAYWGQGTLVTVSS hu40E9-H3-G106A.H 190 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSYD A FAYWGQGTLVTVSS hu40E9-H3-Y54G.H 191 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPGNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-H3-D56G.H 192 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYN G VIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-H3-D99R.H 193 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCAR R SYYSYDGFAYWGQGTLVTVSS hu40E9-H3-S100R.H 194 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARD R YYSYDGFAYWGQGTLVTVSS hu40E9-H3-Y102S.H 195 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSY SSYDGFAYWGQGTLVTVSS hu40E9-H3-D105R.H 196 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSY R GFAYWGQGTLVTVSS hu40E9-H5 233 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPGSGVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-H6 234 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCAR E S FS SYDGFAYWGQGTLVTVSS hu40E9-H7 235 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINP G N G VIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYSSYDGFAYWGQGTLVTVSS hu40E9-H8 236 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPGNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARESYSSYDGFAYWGQGTLVTVSS hu40E9-H9 237 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPY S DVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARES F YSYDGFAYWGQGTLVTVSS hu40E9-H10 238 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSY EA FAYWGQGTLVTVSS hu40E9-H11 239 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSY RA FAYWGQGTLVTVSS hu40E9-H12 240 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARD D YYSYDGFAYWGQGTLVTVSS hu40E9-H13 241 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARD G YYSYDGFAYWGQGTLVTVSS hu40E9-H14 242 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCAR ESYYSYDGFAYWGQGTLVTVSS hu40E9-H15 243 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCAR G SYYSYDGFAYWGQGTLVTVSS hu40E9-H16 244 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSDYVIHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-H17 245 EVQLVQSGAEVKKPGSSVKVSCKASGYTFSSY Y IHWVRQAPGQGLEWMGYINPYNDVIKYNEKFKGRVTLTSDKSTSTAYMELSSLRSEDTAVYYCARDSYYSYDGFAYWGQGTLVTVSS hu40E9-L2-N93S.L 197 EIVLTQSPDFQSVTPKEKVTITCSASSSVSYMHWYQQKPDQSPKRLIYDTSKLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCQQWSSSPPTFGGGTKVEIK hu40E9-L2-S91R.L 198 EIVLTQSPDFQSVTPKEKVTITCSASSSVSYMHWYQQKPDQSPKRLIYDTSKLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCQQWRSNPPTFGGGTKVEIK hu40E9-L2-N93R.L 199 EIVLTQSPDFQSVTPKEKVTITCSASSSVSYMHWYQQKPDQSPKRLIYDTSKLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCQQWSSRPPTFGGGTKVEIK hu40E9-L2-N93W.L 200 EIVLTQSPDFQSVTPKEKVTITCSASSSVSYMHWYQQKPDQSPKRLIYDTSKLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCQQWSSWPPTFGGGTKVEIK hu40E9-L4 230 EIVLTQSPDFQSVTPKEKVTITCSASSSVSYMHWYQQKPDQSPKRLIYDTSKLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCQQW R S R PPTFGGGTKVEIK hu40E9-L5 231 EIVLTQSPDFQSVTPKEKVTITCSASSSVSYMHWYQQKPDQSPKRLIYDTSKLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCQQW R S S PPTFGGGTKVEIK hu40E9-L6 232 EIVLTQSPDFQSVTPKEKVTITCSASSSVSYMHWYQQKPDQSPKRLIYDTSKLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCQQW R S W PPTFGGGTKVEIK Table 22. Amino acid sequences of exemplary CDRs describe SEQ ID NO Amino acid sequence hu40E9-H16(HCDR1) 217 YVH hu40E9-H17(HCDR1) 218 Y General formula of hu40E9 HCDR1 219 X13YX14IH (where X13=S or D; X14=V or Y) hu40E9-H3-N55S.H(HCDR2) 171 YINPY S DVIKYNEKFKG hu40E9-H3-Y54G.H(HCDR2) 172 YIN P GNDVIKYNEKFKG hu40E9-H3-D56G.H(HCDR2) 173 YINPYN G VIKYNEKFKG hu40E9-H5(HCDR2) 220 YINP GSG VIKYNEKFKG hu40E9-H7(HCDR2) 222 YINP G N GV IKYNEKFKG General formula of hu40E9 HCDR2 201 YINPX1X2X3VIKYNEKFKG (where X1 = Y or G; X2 = N or S; and X3 = D or G) hu40E9-H3-D99E.H(HCDR3) 174 E SYYSYDGFAY hu40E9-H3-Y101F.H(HCDR3) 175 DS F YSYDGFAY hu40E9-H3-D105E.H(HCDR3) 176 DSYYSY E GFAY hu40E9-H3-G106A.H(HCDR3) 177 DSYYSYD A FAY hu40E9-H3-D99R.H(HCDR3) 178 R SYYSYDGFAY hu40E9-H3-S100R.H(HCDR3) 179 D R YYSYDGFAY hu40E9-H3-Y102S.H(HCDR3) 180 DSY S SYDGFAY hu40E9-H3-D105R.H(HCDR3) 181 DSYYSY R GFAY hu40E9-H6(HCDR3) 221 E S FS SYDGFAY hu40E9-H8(HCDR3) 223 E SY S SYDGFAY hu40E9-H9(HCDR3) 224 E S F YSYDGFAY hu40E9-H10(HCDR3) 225 DSYYSY EA FAY hu40E9-H11(HCDR3) 226 DSYYSY RA FAY hu40E9-H12(HCDR3) 227 D D YYSYDGFAY hu40E9-H13(HCDR3) 228 D GY YSYDGFAY hu40E9-H15(HCDR3) 229 G SYYSYDGFAY General formula of hu40E9 HCDR3 162 X4X5X6X7SYX8X9FAY (where X4 = D or E or R or G; X5 = S or R or D or G; X6 = Y or F; X7 = Y or S; X8 = D or E or R; X9 = G or A) hu40E9-L2-N93S.L(LCDR3) 182 QQWSS S PPT hu40E9-L2-S91R.L(LCDR3) 183 QQW R SNPPT hu40E9-L2-N93R.L(LCDR3) 184 QQWSS R PPT hu40E9-L2-N93W.L(LCDR3) 185 QQWSS W PPT hu40E9-L4(LCDR3) 214 QQW R SRPPT hu40E9-L5(LCDR3) 215 QQW R S S PPT hu40E9-L6(LCDR3) 216 QQW R S W PPT General formula of hu40E9 LCDR3 167 QQWX10SX11PPT (where X10 = S or R; X11 = N or S or R or W) hu147E2-H3a-N55Q(HCDR2) 210 NINPS Q GATNYNEKFKS hu147E2-H3a-N55S(HCDR2) 211 NINPS S GATNYNEKFKS Formula of hu147E2 HCDR2 212 NINPSX12GATNYNEKFKS (X12=Q, S or N)

The present invention further provides exemplary humanized and affinity-improved antibodies of pure 40-C12-C10-E9, including: 1) "hu40E9-L2H3-N55S.H", which includes the heavy chain variable region of hu40E9-H3-N55S.H (SEQ ID NO: 186) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 2) "hu40E9-L2H3-D99E.H", which includes the heavy chain variable region of hu40E9-H3-D99E.H (SEQ ID NO: 187) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 3) "hu40E9-L2H3-Y101F.H", which includes the heavy chain variable region of hu40E9-H3-Y101F.H (SEQ ID NO: 188) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 4) "hu40E9-L2H3-D105E.H", which includes the heavy chain variable region of hu40E9-H3-D105E.H (SEQ ID NO: 189) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 5) "hu40E9-L2H3-G106A.H", which includes the heavy chain variable region of hu40E9-H3-G106A.H (SEQ ID NO: 190) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 6) "hu40E9-L2H3-Y54G.H", which includes the heavy chain variable region of hu40E9-H3-Y54G.H (SEQ ID NO: 191) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 7) "hu40E9-L2H3-D56G.H", which includes the heavy chain variable region of hu40E9-H3-D56G.H (SEQ ID NO: 192) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 8) "hu40E9-L2H3-D99R.H", which includes the heavy chain variable region of hu40E9-H3-D99R.H (SEQ ID NO: 193) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 9) "hu40E9-L2H3-S100R.H", which includes the heavy chain variable region of hu40E9-H3-S100R.H (SEQ ID NO: 194) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 10) "hu40E9-L2H3-Y102S.H", which includes the heavy chain variable region of hu40E9-H3-Y102S.H (SEQ ID NO: 195) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 11) "hu40E9-L2H3-D105R.H", which includes the heavy chain variable region of hu40E9-H3-D105R.H (SEQ ID NO: 196) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 12) "hu40E9-L2H3-N93S.L", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L2-N93S.L (SEQ ID NO: 197); 13) "hu40E9-L2H3-S91R.L", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L2-S91R.L (SEQ ID NO: 198); 14) "hu40E9-L2H3-N93R.L", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L2-N93R.L (SEQ ID NO: 199); 15) "hu40E9-L2H3-N93W.L", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L2-N93W.L (SEQ ID NO: 200); 16) "hu40E9-L2H5", which includes the heavy chain variable region of hu40E9-H5 (SEQ ID NO: 233) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 17) "hu40E9-L2H6", which includes the heavy chain variable region of hu40E9-H6 (SEQ ID NO: 234) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 18) "hu40E9-L2H7", which includes the heavy chain variable region of hu40E9-H7 (SEQ ID NO: 235) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 19) "hu40E9-L2H8", which includes the heavy chain variable region of hu40E9-H8 (SEQ ID NO: 236) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 20) "hu40E9-L2H9", which includes the heavy chain variable region of hu40E9-H9 (SEQ ID NO: 237) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 21) "hu40E9-L2H10", which includes the heavy chain variable region of hu40E9-H10 (SEQ ID NO: 238) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 22) "hu40E9-L2H11", which includes the heavy chain variable region of hu40E9-H11 (SEQ ID NO: 239) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 23) "hu40E9-L2H12", which includes the heavy chain variable region of hu40E9-H12 (SEQ ID NO: 240) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 24) "hu40E9-L2H13", which includes the heavy chain variable region of hu40E9-H13 (SEQ ID NO: 241) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 25) "hu40E9-L2H14", which includes the heavy chain variable region of hu40E9-H14 (SEQ ID NO: 242) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 26) "hu40E9-L2H15", which includes the heavy chain variable region of hu40E9-H15 (SEQ ID NO: 243) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 27) "hu40E9-L2H16", which includes the heavy chain variable region of hu40E9-H16 (SEQ ID NO: 244) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 28) "hu40E9-L2H17", which includes the heavy chain variable region of hu40E9-H17 (SEQ ID NO: 245) and the light chain variable region of hu40E9-L2 (SEQ ID NO: 169); 29) "hu40E9-L4H3", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L4 (SEQ ID NO: 230); 30) "hu40E9-L5H3", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L5 (SEQ ID NO: 231); 31) "hu40E9-L6H3", which includes the heavy chain variable region of hu40E9-H3 (SEQ ID NO: 165) and the light chain variable region of hu40E9-L6 (SEQ ID NO: 232); 32) "hu40E9-L4H7", which includes the heavy chain variable region of hu40E9-H7 (SEQ ID NO: 235) and the light chain variable region of hu40E9-L4 (SEQ ID NO: 230); 33) "hu40E9-L4H8", which includes the heavy chain variable region of hu40E9-H8 (SEQ ID NO: 236) and the light chain variable region of hu40E9-L4 (SEQ ID NO: 230); 34) "hu40E9-L5H7", which includes the heavy chain variable region of hu40E9-H7 (SEQ ID NO: 235) and the light chain variable region of hu40E9-L5 (SEQ ID NO: 231); or 35) "hu40E9-L5H8", which includes the heavy chain variable region of hu40E9-H8 (SEQ ID NO: 236) and the light chain variable region of hu40E9-L5 (SEQ ID NO: 231).

In some embodiments, the anti-CD3 antibodies and antigen-binding fragments provided herein include all or a portion of a heavy chain variable domain and/or all or a portion of a light chain variable domain. In one embodiment, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein are single domain antibodies composed of all or a portion of a heavy chain variable domain provided herein. More information about such single domain antibodies can be obtained in the art (see, e.g., U.S. Patent No. 6,248,516).

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein further include an Fc region. In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein further include an Fc region of a human immunoglobulin (Ig). In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein further include a constant region, which further includes a heavy chain and/or light chain constant region as appropriate. In certain embodiments, the heavy chain constant region includes CH1, hinge and/or CH2-CH3 region (or CH2-CH3-CH4 region selected as appropriate). In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include a heavy chain constant region of human IgG1, IgG2, IgG3, IgG4, IgA1, IgA2 or IgM. In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include a lambda light chain or a kappa light chain. The constant region of the anti-CD3 antibodies or antigen-binding fragments thereof provided herein may be identical to the wild-type constant region sequence or may differ in one or more mutations.

In certain embodiments, the heavy chain constant region includes an Fc region. It is known that the Fc region mediates effector functions, such as antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) of antibodies. Fc regions of different Ig isotypes have different abilities to induce effector functions. For example, the Fc regions of IgG1 and IgG3 have been recognized to be more effective at inducing both ADCC and CDC than the Fc regions of IgG2 and IgG4. In certain embodiments, the anti-CD3 antibodies and antigen-binding fragments thereof provided herein include an Fc region of the IgG1 or IgG3 isotype, which can induce ADCC or CDC; or alternatively, a constant region of the IgG4 or IgG2 isotype, which has reduced or missing effector functions. In some embodiments, the Fc region is derived from human IgG1. In some embodiments, the Fc region is derived from human IgG1 with enhanced effector function. In some embodiments, the Fc region comprises an amino acid sequence as shown in SEQ ID NO: 97. ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK(SEQ ID NO: 97)

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein have specific binding affinity for human CD3, which is sufficient to provide diagnostic and/or therapeutic uses.

The antibodies or antigen-binding fragments thereof provided herein can be monoclonal antibodies, polyclonal antibodies, humanized antibodies, human antibodies, chimeric antibodies, recombinant antibodies, bispecific antibodies, multispecific antibodies, labeled antibodies, bivalent antibodies, anti-idiotype antibodies or fusion proteins. Recombinant antibodies are antibodies prepared in vitro rather than in animals using recombinant methods.

In certain embodiments, the present invention provides an anti-CD3 antibody or antigen-binding fragment thereof, which competes with an antibody or antigen-binding fragment thereof provided herein for binding to CD3. In certain embodiments, the present invention provides an anti-CD3 antibody or antigen-binding fragment thereof, which competes with antibodies 25-G12-G6-C12, 40-C12-C10-E9, 8-B12-F9-B11, 31-F8-F5-C5, 16-F2-C11-D9, 20-E11-E11-C2, 7-D9-G10-H2 、7-D8-G12-E4、2-F12-A6-G2、3-C6-C11-F12、4-F12-F1-A4、3-F3-G12-E2、124E3D6、126A11A4、127E2D3、133B4C7、140D2B10、147C6F3、147E11E2、hu40E9-L1H1、hu40E 9-L1H2、hu40E9-L1H3、hu40E9-L1H4、hu40E9-L2H1、hu40E9-L2H2、hu40E9-L2H3、hu40E9-L2H4、hu40E9-L3H1、hu40E9-L3H2、hu40E9-L3H3、hu40E9-L3H4、hu40E9-L2H 3-N55S.H、hu40E9-L2H3-D99E.H、hu40E9-L2H3-Y101F.H、hu40E9-L2H3-D105E.H、hu40E9-L2H3-G106A.H、hu40E9-L2H3-Y54G.H、hu40E9-L2H3-D56G.H、hu40E9-L2H3- D99R.H、hu40E9-L2H3-S100R.H、hu40E9-L2H3-Y102S.H、hu40E9-L2H3-D105R.H、hu40E9-L2H3-N93S.L、hu40E9-L2H3-S91R.L、hu40E9-L2H3-N93R.L、hu40E9-L2H3-N 93W.L、hu40E9-L2H5、hu40E9-L2H6、hu40E9-L2H7、hu40E9-L2H8、hu40E9-L2H9、hu40E9-L2H10、hu40E9-L2H11、hu40E9-L2H12、hu40E9-L2H13、hu40E9-L2H14、hu40E9- L2H15, hu40E9-L2H16, hu40E9-L2H17, hu40E9-L4H3, hu40E9-L5H3, hu40E9-L6H3, hu40E9-L4H7, hu40E9-L4H8, hu40E9-L5H7, hu40E9-L5H8, hu147E2-L1H2, hu147E2- Any of hu147E2-L1H3, hu147E2-L1H3a, hu147E2-L1H3b, hu147E2-L1H4, hu147E2-L2H2, hu147E2-L2H3, hu147E2-L2H4, hu147E2-L3H2, hu147E2-L3H3, and hu147E2-L3H4 competes for binding to human CD3. In some embodiments, the present invention provides anti-CD3 antibodies or antigen-binding fragments thereof that compete for the same epitope as the antibodies or antigen-binding fragments provided herein.

As used herein, the ability to "block binding" or "compete for binding" refers to the ability of an antibody or antigen-binding fragment to inhibit the binding interaction between two molecules (e.g., human CD3 and anti-CD3 antibody) to any detectable extent. In certain embodiments, the antibody or antigen-binding fragment thereof that blocks binding between two molecules inhibits the binding interaction between the two molecules by at least 85% or at least 90%. In certain embodiments, the inhibition may be greater than 85% or greater than 90%.

Those skilled in the art will recognize that by determining whether the human monoclonal antibodies prevent the antibodies of the present invention from binding to CD3, it is possible to determine whether the human monoclonal antibodies bind to the antibodies of the present invention (e.g., mouse monoclonal antibodies 25-G12-G6-C12, 40-C12-C10-E9, 8-B12-F9-B11, 31-F8-F5-C5, 16-F2-C1 1-D9, 20-E11-E11-C2, 7-D9-G10-H2, 7-D8-G12-E4, 2-F12-A6-G2, 3-C6-C11-F12, 4-F12-F1-A4, 3-F3-G12-E2, 124E3D6, 126A11A4, 127E2D3, 133B4C7, 140D2B10, 147C6F3 、147E11E2、hu40E9-L1H1、hu40E9-L1H2、hu40E9-L1H3、hu40E9-L1H4、hu40E9-L2H1、hu40E9-L2H2、hu40E9-L2H3、hu40E9-L2H4、hu40E9-L3H1、hu40E9-L3H2、hu40E9-L3H 3. hu40E9-L3H4, hu40E9-L2H3-N55S.H, hu40E9-L2H3-D99E.H, hu40E9-L2H3-Y101F.H, hu40E9-L2H3-D105E.H, hu40E9-L2H3-G106A.H, hu40E9-L2H3-Y54G.H, hu40E9-L2H3 3-D56G.H、hu40E9-L2H3-D99R.H、hu40E9-L2H3-S100R.H、hu40E9-L2H3-Y102S.H、hu40E9-L2H3-D105R.H、hu40E9-L2H3-N93S.L、hu40E9-L2H3-S91R.L、hu40E9-L2H3-N9 3R.L, hu40E9-L2H3-N93W.L, hu40E9-L2H5, hu40E9-L2H6, hu40E9-L2H7, hu40E9-L2H8, hu40E9-L2H9, hu40E9-L2H10, hu40E9-L2H11, hu40E9-L2H12, hu40E9-L2H13, hu40E9 9-L2H14, hu40E9-L2H15, hu40E9-L2H16, hu40E9-L2H17, hu40E9-L4H3, hu40E9-L5H3, hu40E9-L6H3, hu40E9-L4H7, hu40E9-L4H8, hu40E9-L5H7, hu40E9-L5H8, hu147E2-L1 If the test antibody competes with the antibody of the invention, as indicated by reduced binding of the antibody of the invention to the CD3 antigen polypeptide, then the two antibodies bind to the same or closely related epitope. Alternatively, if binding of the test antibody to the CD3 antigen polypeptide is inhibited by the antibody of the invention, then the two antibodies bind to the same or closely related epitope.

In certain embodiments, the present invention provides anti-CD3 antibodies or antigen-binding fragments thereof that have higher or comparable binding affinity to CD3 (e.g., human CD3 or cynomolgus macaque CD3) than OKT3, BMK-B219 and/or BMK-TCB.

In certain embodiments, the anti-CD3 antibody or antigen-binding fragment that competes for binding to CD3 with an antibody or antigen-binding fragment thereof provided herein is not OKT3, BMK-B219 or BMK-TCB.

As used herein, "OKT3" refers to an antibody or antigen-binding fragment thereof comprising a heavy chain variable region having an amino acid sequence of SEQ ID NO: 100 and a light chain variable region having an amino acid sequence of SEQ ID NO: 101. The CDR sequences are underlined in SEQ ID NO: 100 and SEQ ID NO: 101, respectively. QVQLQQSGAELARPGASVKMSCKASGYTFT RYTMH WVKQRPGQGLEWIG YINPSRGYTNYNQKFKD KATLTTDKSSSTAYMQLSSLTSEDSAVYYCAR YYDDHYCLDY WGQGTTLTVSS (SEQ ID NO: 100) QIVLTQSPAIMSASPGEKVTMTC SASSSVSYMN WYQQKSGTSPKRWIY DTSKLAS GVPAHFRGSGSGTSYSLTISGMEAEDAATYYC QQWSSNPFT FGSGTKLEINRAD (SEQ ID NO: 101)

As used herein, "BMK-B219" refers to an antibody or antigen-binding fragment thereof comprising a heavy chain variable region having an amino acid sequence of SEQ ID NO: 158 and a light chain variable region having an amino acid sequence of SEQ ID NO: 159. The CDR sequences are underlined in SEQ ID NO: 158 and SEQ ID NO: 159, respectively. EVQLVESGGGLVQPGGSLRLSCAASGFTFN TYAMN WVRQAPGKGLEWVA RIRSKYNNYATYYAASVKG RFTISRDDSKNSLYLQMNSLKTEDTAVYYCAR HGNFGNSYVSWFAY WGQGTLVTVSS (SEQ ID NO: 158) QTVVTQEPSLTVSPGGTVTLTC RSSTGAVTTSNYAN WVQQKPGQAPRGLIG GTNKRAP GTPARFSGSLLGGKAALTLSGVQPEDEAEYYC ALWYSNLWV FGGGTKLTVL (SEQ ID NO: 159)

As used herein, "BMK-TCB" refers to an antibody or antigen-binding fragment thereof comprising a heavy chain variable region having an amino acid sequence of SEQ ID NO: 160 and a light chain variable region having an amino acid sequence of SEQ ID NO: 161. The CDR sequences are underlined in SEQ ID NO: 160 and SEQ ID NO: 161, respectively. EVQLLESGGGLVQPGGSLRLSCAASGFTFS TYAMN WVRQAPGKGLEWVS RIRSKYNNYATYYADSVKG RFTISRDDSKNTLYLQMNSLRAEDTAVYYCVR HGNFGNSYVSWFAY WGQGTLVTVSS (SEQ ID NO: 160) QAVVTQEPSLTVSPGGTVTLTC GSSTGAVTTSNYAN WVQEKPGQAFRGLIG GTNKRAP GTPARFSGSLLGGKAALTLSGAQPEDEAEYYC ALWYSNLWV FGGGTKLTVL (SEQ ID NO: 161) Antibody variants

The antibodies and antigen-binding fragments thereof provided herein also encompass various variants of the antibody sequences provided herein.

In certain embodiments, the antibody variant comprises one or more amino acid residue substitutions or modifications, but still retains specific binding affinity for CD3. In certain embodiments, at least one of the substitutions or modifications is located in one or more CDR sequences of the VH region or the VL region. In certain embodiments, at least one of the substitutions or modifications is located in one or more non-CDR sequences of the VH region or the VL region. In certain embodiments, the antibody or antigen-binding fragment thereof of the present invention further comprises one or more non-natural amino acid (NNAA) substitutions. In certain embodiments, the NNAA can be bound.

For example, the antibody variant includes one or more of the CDR sequences provided in Table 2 above, one or more of the non-CDR sequences of the heavy chain variable region or light chain variable region provided in Table 3 above, and/or one or more amino acid residue substitutions or modifications in the constant region (e.g., Fc region). Such variants retain the binding specificity of their parent antibody to CD3, but have one or more desirable properties conferred by the modification or substitution. For example, the antibody variant may have improved antigen binding affinity, improved glycosylation pattern, reduced risk of glycosylation, reduced deamination, enhanced effector function, improved FcRn receptor binding, increased pharmacokinetic half-life, pH sensitivity and/or compatibility with binding (e.g., one or more introduced cysteine residues), etc.

Parent antibody sequences can be screened to identify suitable or preferred residues to be modified or substituted using methods known in the art, such as "alanine scanning mutagenesis" (see, e.g., Cunningham and Wells (1989) Science , 244: 1081-1085). Briefly, target residues (e.g., charged residues such as Arg, Asp, His, Lys, and Glu) can be identified and replaced with neutral or negatively charged amino acids (e.g., alanine or polyalanine), and modified antibodies generated and screened for properties of interest. If substitution at a particular amino acid position exhibits a functional change of interest, that position can be identified as a potential residue for modification or substitution. These potential residues can be further evaluated by substitution with another residue (e.g., a cysteine residue, a positively charged residue, etc.). Affinity Variants

The affinity variant of the antibody may contain modifications or substitutions in one or more CDR sequences provided in Table 2 above, one or more FR sequences, or the heavy chain variable region or light chain variable region sequences provided in Table 3 above. Those skilled in the art can easily identify the FR sequences based on the CDR sequences in Table 2 above and the variable region sequences in Table 3 above, because it is well known in the art that in the variable region, the CDR region is flanked by two FR regions. The affinity variant retains the specific binding affinity of the parent antibody for CD3, or even has a higher CD3 specific binding affinity than the parent antibody. In certain embodiments, at least one (or all) substitutions in the CDR sequence, FR sequence, or variable region sequence include conservative substitutions.

Those skilled in the art will appreciate that one or more amino acid residues may be substituted in the CDR sequences provided in Table 2 above and the variable region sequences provided in Table 3 above, but the resulting antibody or antigen-binding fragment still retains binding affinity or binding ability to CD3, or even has improved binding affinity or binding ability. Various methods known in the art may be used to achieve this goal. For example, a library of antibody variants (such as Fab or scFv variants) may be generated and displayed using phage display technology, and then screened for affinity binding to human CD3. For another example, computer software may be used to virtually simulate the binding of antibodies to human CD3 and identify the amino acid residues on the antibody that form the binding interface. Such residues may be avoided in substitutions to prevent decreased binding affinity, or may be targeted for substitution to obtain stronger binding.

In certain embodiments, the humanized antibodies or antigen-binding fragments thereof provided herein include one or more amino acid residue substitutions in one or more CDR sequences and/or one or more FR sequences. In certain embodiments, the affinity variants include no more than 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 substitutions in total in the CDR sequences and/or FR sequences.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include 1, 2 or 3 CDR sequences that have at least 80% (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%) sequence identity to the sequences listed in Table 2 above, but still retain specific binding affinity for CD3 at a similar or even higher level relative to its parent antibody.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include one or more variable region sequences that have at least 80% (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%) sequence identity with the sequences listed in Table 3 above, but still retain specific binding affinity for CD3 at a level similar to or even higher than that of its parent antibody. In some embodiments, a total of 1 to 10 amino acids are substituted, inserted or deleted in the variable region sequences listed in Table 3 above. In some embodiments, the substitutions, insertions or deletions occur in regions outside of CDRs (e.g., in FRs). Glycosylation variants

The anti-CD3 antibodies or antigen-binding fragments thereof provided herein also encompass glycosylation variants, which can be obtained to increase or decrease the degree of glycosylation of the antibodies or antigen-binding fragments thereof.

The antibodies or antigen-binding fragments thereof provided herein may include one or more modifications that introduce or remove glycosylation sites. A glycosylation site is an amino acid residue having a side chain to which a carbohydrate moiety (e.g., an oligosaccharide structure) can be attached. Glycosylation of an antibody is typically N-linked or O-linked. N-linked refers to the attachment of the carbohydrate moiety to the side chain of an asparagine residue (e.g., the asparagine residue in a tripeptide sequence such as asparagine-X-serine and asparagine-X-threonine), where X is any amino acid except proline. O-linked glycosylation refers to the attachment of one of N-acetylgalactosamine, galactose, or xylose to a hydroxyl amino acid, most commonly to serine or threonine. A native glycosylation site can be conveniently removed, for example by altering the amino acid sequence so that one of the above tripeptide sequences (for N-linked glycosylation sites) or a serine or threonine residue (for O-linked glycosylation sites) present in the sequence is substituted. New glycosylation sites can be generated in a similar manner by introducing such a tripeptide sequence or a serine or threonine residue. Cysteine engineered variants

The anti-CD3 antibodies or antigen-binding fragments thereof provided herein also encompass cysteine engineered variants comprising one or more introduced free cysteine amino acid residues.

A free cysteine residue is a cysteine residue that is not part of a disulfide bond. Cysteine engineered variants can be used to conjugate, for example, a cytotoxic compound and/or an imaging compound, a label or a radioisotope at the site of the engineered cysteine via, for example, a cis-butylenediamide or a halogenated acetyl group. Methods for engineering antibodies or antigen-binding fragments thereof to introduce free cysteine residues are known in the art, see, for example, WO2006/034488. Fc variants

The anti-CD3 antibodies and antigen-binding fragments provided herein also encompass Fc variants comprising one or more amino acid residue modifications or substitutions in the Fc region and/or hinge region thereof.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include one or more amino acid substitutions that improve pH-dependent binding to neonatal Fc receptors (FcRn). Such variants may have a prolonged pharmacokinetic half-life because they bind to FcRn at acidic pH, thereby protecting them from degradation in lysosomes and subsequently being translocated and released outside the cell. Methods for engineering antibodies or antigen-binding fragments thereof to improve binding affinity to FcRn are well known in the art, see, e.g., Vaughn, D. et al., Structure , 6(1): 63-73, 1998; Kontermann, R. et al., Antibody Engineering , Vol. 1, Chapter 27: Engineering of the Fc region for improved PK, published by Springer, 2010; Yeung, Y. et al., Cancer Research , 70: 3269-3277 (2010); and Hinton, P. et al., J. Immunology , 176: 346-356 (2006).

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include one or more amino acid substitutions that alter ADCC. Certain amino acid residues at the CH2 domain of the Fc region can be substituted to provide enhanced ADCC activity. Alternatively or additionally, the carbohydrate structure on the antibody can be altered to enhance ADCC activity. Methods for altering ADCC activity by antibody engineering are described in the art, see, e.g., Shields RL. et al., J Biol Chem. 2001 276(9): 6591-604; Idusogie EE. et al., J Immunol. 2000.164(8):4178-84; Steurer W. et al., J Immunol. 1995, 155(3): 1165-74; Idusogie EE. et al., J Immunol. 2001, 166(4):2571-5; Lazar GA. et al., PNAS , 2006, 103(11): 4005-4010; Ryan MC. et al., Mol. Cancer Ther. , 2007, 6: 3009-3018; Richards JO et al., Mol Cancer Ther. 2008, 7(8): 2517-27; Shields RL et al., J. Biol. Chem , 2002, 277: 26733-26740; Shinkawa T. et al., J. Biol. Chem , 2003, 278: 3466-3473.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include one or more amino acid substitutions that alter CDC, for example by improving or reducing C1q binding and/or CDC (see, e.g., WO99/51642; Duncan and Winter Science 322:738-40 (1988); U.S. Pat. No. 5,648,260; U.S. Pat. No. 5,624,821); and WO94/29351 for other examples of Fc region variants. One or more amino acid residues selected from amino acid residues at positions 329, 331, and 322 of the Fc region may be replaced with different amino acid residues to alter C1q binding and/or enhance CDC (see U.S. Pat. No. 6,194,551 to Idusogie et al.). One or more amino acid substitutions may also be introduced to alter the ability of the antibody to fix complement (see PCT Publication WO 94/29351 to Bodmer et al.).

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include one or more amino acid substitutions at positions 234 and/or 235 (according to EP numbering) in human immunoglobulins (e.g., IgG1). In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include two amino acid substitutions at positions 234 and 235 (according to EP numbering) in human immunoglobulins (e.g., IgG1). In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include L234A and L235A (according to EU numbering) amino acid substitutions.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include one or more amino acid substitutions at position 228 (according to EU numbering) in a human immunoglobulin (e.g., IgG4). In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include an S228P (according to EU numbering) amino acid substitution.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include one or more amino acid substitutions in the interface of the Fc region to facilitate and/or promote heterodimerization. Such modifications include the introduction of protrusions into a first Fc polypeptide and a cavity into a second Fc polypeptide, wherein the protrusions may be positioned in the cavity to promote the interaction of the first Fc polypeptide with the second Fc polypeptide to form a heterodimer or complex. Methods for producing antibodies with such modifications are known in the art, for example, as described in U.S. Patent No. 5,731,168.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include an amino acid substitution at position 366 (according to EP numbering) of the first Fc polypeptide, and include one, two or three amino acid substitutions at one, two or three positions of positions 366, 368 and 407 (according to EP numbering) of the second Fc polypeptide. In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include a T366W (according to EP numbering) substitution of the first Fc polypeptide, and include a T366S+L368A+Y407V (according to EP numbering) substitution of the second Fc polypeptide.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein also include one or more amino acid substitutions of the first Fc polypeptide and one or more amino acid substitutions of the second Fc polypeptide, thereby introducing a non-natural disulfide bond between the two Fc polypeptides. For example, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include an amino acid substitution at position 354 (according to EU numbering) of the first Fc polypeptide and include an amino acid substitution at position 349 (according to EU numbering) of the second Fc polypeptide. In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include an S354C (according to EU numbering) substitution of the first Fc polypeptide and include a Y349C (according to EU numbering) substitution of the second Fc polypeptide.

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein include a first Fc polypeptide including the amino acid sequence set forth in SEQ ID NO: 98 and a second Fc polypeptide including the amino acid sequence set forth in SEQ ID NO: 99. KTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCREEMTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 98) KTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSREEMTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 99) antigen binding fragment

Anti-CD3 antigen-binding fragments are also provided herein. Various types of antigen-binding fragments are known in the art and can be developed based on the anti-CD3 antibodies provided herein, including, for example, exemplary antibodies whose CDRs are shown in Table 2 above and whose variable sequences are shown in Table 3, and their different variants (e.g., affinity variants, glycosylation variants, Fc variants, cysteine engineered variants, etc.).

In certain embodiments, the anti-CD3 antigen-binding fragments provided herein are bifunctional antibodies (diabodies), Fab, Fab', F(ab') ₂ , Fd, Fv fragments, disulfide-stabilized Fv fragments (dsFv), (dsFv) ₂ , bispecific dsFv (dsFv-dsFv'), disulfide-stabilized bifunctional antibodies (ds diabody), single-chain antibody molecules (scFv), scFv dimers (bivalent bifunctional antibodies), multispecific antibodies, camellized single domain antibodies, nanobodies, domain antibodies, or bivalent domain antibodies.

Such antigen-binding fragments can be produced using a variety of techniques. Exemplary methods include enzymatic digestion of intact antibodies (see, e.g., Morimoto et al., Journal of Biochemical and Biophysical Methods 24: 107-117 (1992); and Brennan et al., Science , 229: 81 (1985)), recombinant expression by host cells such as E. coli (e.g., for Fab, Fv and ScFv antibody fragments), autophagosome display library screening as discussed above (e.g., for ScFv), and chemical coupling of two Fab'-SH fragments to form a F(ab') ₂ fragment (Carter et al., Bio/Technology 10: 163-167 (1992)). Other techniques for producing antibody fragments will be apparent to those skilled in the art.

In certain embodiments, the antigen binding fragment is a scFv. The generation of scFv is described in, for example, WO 93/16185; U.S. Patent No. 5,571,894; and No. 5,587,458. ScFv can be fused to an effector protein at the amino terminus or carboxyl terminus to provide a fusion protein (see, for example, Antibody Engineering, Borrebaeck, ed.).

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein are bivalent, tetravalent, hexavalent or multivalent. Any molecule with more than two valencies is considered multivalent, including, for example, trivalent, tetravalent, hexavalent, etc.

If both binding sites specifically bind to the same antigen or the same epitope, then the bivalent molecule may be monospecific. In some embodiments, this provides stronger binding to the antigen or epitope than the monovalent counterpart. Similarly, multivalent molecules may also be monospecific. In some embodiments, in a bivalent or multivalent antigen binding portion, the first valency of the binding site and the second valency of the binding site are structurally identical (i.e., have the same sequence) or structurally different (i.e., have different sequences but have the same specificity).

A bivalent may also be bispecific if the two binding sites are specific for different antigens or epitopes. This also applies to multivalent molecules. For example, a trivalent molecule may be bispecific when two binding sites are monospecific for a first antigen (or epitope) and the third binding site is specific for a second antigen (or epitope). Bispecific or multispecific antibodies

In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein are bispecific or multispecific. In certain embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein are further linked to a second functional portion or antigen-binding fragment thereof having a different binding specificity than the anti-CD3 antibody. In certain embodiments, the bispecific antibodies or multispecific antibodies and antigen-binding fragments thereof provided herein have a first specificity for CD3 and a second specificity. In certain embodiments, the second specificity is directed to CD3 but to a different epitope. In certain embodiments, the second specificity is directed to a second antigen different from CD3, and its presence in the vicinity of T cells expressing CD3 is desirable for the second antigen to be recognized by the immune system. For example, T cells expressing CD3 are brought into close proximity with tumor antigens or pathogen antigens, thereby promoting the recognition or elimination of such antigens by the immune system.

In some embodiments, the second specificity is directed to a tumor-associated antigen or an epitope thereof. The term "tumor-associated antigen" refers to an antigen that appears or can be presented on the surface of a tumor cell, or can be located on or within a tumor cell. In some embodiments, a tumor-associated antigen can only be presented by tumor cells, but not by normal cells (i.e., non-tumor cells). In some other embodiments, a tumor-associated antigen can be expressed exclusively on tumor cells or can represent a tumor-specific mutation relative to non-tumor cells. In some other embodiments, the tumor-associated antigen can be found in both tumor cells and non-tumor cells, but is overexpressed on tumor cells when compared to non-tumor cells, or is available for antibody binding in tumor cells due to the less compact structure of tumor tissue compared to non-tumor tissue. In some embodiments, the tumor-associated antigen is located on the vasculature of the tumor.

In certain embodiments, the bispecific antibodies or multispecific antibodies or antigen-binding fragments thereof provided herein are capable of specifically binding to one or more (e.g., 1, 2, 3, 4, 5 or more) additional antigens in addition to CD3, or specifically binding to a second epitope on CD3. In certain embodiments, the one or more additional antigens other than CD3 are selected from the group consisting of CD16a, CD33, CD38, CD45, CD123, CD146, CD228, CLL-1, FLT3, FLT3L, TAF1, TgPRF, HVCN1, IL-6R, IL-11R, IL17A, IL-23R, IL-33, ILDR2, LAP, TSLP, TREM-1, ANGPT2, APOE, IFNAR, CypA, DOG-1, NKp30, CSF-1R, CCR2, LRRC15, mesothelin, Dickkopf2, DLL3, HER-2, C10orf54, TrkA, MEKK1, KRAS, ERK, XPO1, mTORC1/2, PAK4, NAMPT, ATR, EGFR, FGFR, VEGF, LILRB (e.g., LILRB1, LILRB2, LILRB3, LILRB4, LILRB5), c-MET, Her2, Her3, CTLA4, GITA, CD112R, CD2, CD7, CD16, CD19, CD20, CD24, CD27, CD30, CD34, CD37, CD39, CD70, CD73, CD83, CD28, CD80 (B7-1), CD86 (B7-2), CD40, CD40L (CD154), CD47, SIRPα, CD122, CD137, CD137L, OX40 (CD134), OX40L (CD252), BCMA (e.g., BCMA02), PSMA, CLDN18 (e.g., CLDN18.2), NKG2C, 4-1BB, LIGHT, PVRIG, SLAMF7, HVEM, BAFFR, ICAM-1, 2B4, LFA-1, GITR, ICOS (CD278), ICOSLG (CD275), LAG3 (CD223), A2AR, B7-H3 (CD276), B7-H4 (VTCN1), B7-H5, BTLA (CD272), CD160, CTLA-4 (CD152), GPRC5D, IDO (e.g., IDO1, IDO2), TDO, KIR, LAIR-1, NOX2, PD-1, PD-L1, PD-L2, TIM-3, VISTA, SIGLEC-7 (CD328), SIGLEC-9 (CD329), SIGLEC-15, TIGIT, PVR (CD155), TLR3, CLEC9A, DEC-205, STING and TGFβ.

In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein can specifically bind to CD3 and CD19. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein can specifically bind to CD3 and CLDN18 (e.g., CLDN18.2). In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein can specifically bind to CD3 and PD-L1. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein can specifically bind to CD3 and BCMA. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein can specifically bind to CD3 and GPRC5D. Conjugates

In some embodiments, the anti-CD3 antibodies or antigen-binding fragments thereof provided herein further include one or more binding moieties. Binding moieties can be linked to antibodies or antigen-binding fragments thereof. Binding moieties are moieties that can be linked to antibodies or antigen-binding fragments thereof. It is conceivable that a variety of binding moieties can be linked to antibodies or antigen-binding fragments thereof provided herein (see, e.g., "Conjugate Vaccines", Contributions to Microbiology and Immunology, JM Cruse and RE Lewis, Jr. (eds.), Carger Press, New York, (1989)). Such binding moieties can be linked to antibodies or antigen-binding fragments thereof by covalent binding (e.g., disulfide bonds), affinity binding, embedding, coordination binding, complexation, association, blending or addition. In some embodiments, antibodies or antigen-binding fragments thereof can be linked to one or more binding agents by linkers or crosslinking agents. The linker or cross-linker includes a reactive chemical group that can react with the anti-CD3 antibody or antigen-binding fragment thereof provided herein. The reactive chemical group can be N-succinimidyl ester and N-sulfosuccinimidyl ester. In addition, the linker includes a reactive chemical group that can be a dithiopyridyl group that can react with the drug to form a disulfide bond. Linker molecules include, for example, N-succinimidyl 4-(cis-butenediimidomethyl)cyclohexanecarboxylate (SMCC), N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) (see, for example, Carlsson et al., Biochem. J. , 173: 723-737 (1978)), N-succinimidyl 4-(2-pyridyldithio) butyrate (SPDB) (see, for example, U.S. Patent No. 4,563,304), N-succinimidyl 4-(2-pyridyldithio) 2-sulfobutyrate (sulfo-SPDB) (see U.S. Publication No. 20090274713), N-succinimidyl 4-(2-pyridyldithio) pentanoate (SPP) (See, e.g., CAS Reg. No. 341498-08-6), 2-imidosulfane, or acetyl succinic anhydride. For example, an antibody or cell binding agent can be modified with a crosslinking agent, and the resulting antibody or cell binding agent containing free or protected thiol groups is then reacted with a disulfide or thiol-containing maytansinoid to produce a conjugate. The conjugate can be purified by chromatography, including but not limited to HPLC, size exclusion, adsorption, ion exchange and affinity capture, dialysis, or tangential flow filtration.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein can be engineered to contain specific sites other than the epitope binding moiety that can be used to bind to one or more binding moieties. For example, such sites can include one or more reactive amino acid residues, such as cysteine or histidine residues, to facilitate covalent attachment to the binding moiety.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein may be linked to a binding moiety indirectly or through another binding moiety. For example, the antibodies or antigen-binding fragments thereof provided herein may be bound to biotin and then indirectly bound to a second binding moiety bound to avidin. In some embodiments, the binding moiety includes a scavenging modifier (e.g., a polymer that extends half-life, such as PEG), a chemotherapeutic agent, a toxin, a radioisotope, a ytterbium element, a detectable label (e.g., a luminescent label, a fluorescent label, an enzyme substrate label), a DNA alkylating agent, a topoisomerase inhibitor, a tubulin binding agent, a purified moiety or other anticancer drug (e.g., an agonist of toll-like receptor 7 (TLR-7), TLR-8 and/or TLR-9, siRNA, an antibody or antigen-binding fragment thereof, a peptide (e.g., a short peptide), etc.).

A "toxin" can be any agent that is harmful to cells or that can damage or kill cells. Examples of toxins include, but are not limited to, paclitaxel, taxanes, CC-1065 and CC-1065 analogs, duocarmycin and duocarmycin analogs, enediynes such as calicheamicin, dolastatin and dolastatin analogs (including auristatin), tomaymycin derivatives, leptomycin derivatives, and oxadifenamicin. derivative), cisplatin, carboplatin, daunorubicin, cranberries, vincristine, vinblastine, melphalan, mitomycin C, chlorambucil and morpholino cranberries, cytochalasin B, cleavage peptide D, ethidium bromide, ipecacine, mitomycin, etoposide, tenoposide, MMAE, MMAF, DM1, DM4, vinblastine, colchicine, cranberries, daunorubicin, dihydroxy anthracin dione, mitoxantrone, mithramycin, actinomycin D D), 1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol, puromycin and its analogs, anti-metabolites (e.g., methotrexate, 6-hydroxypurine, 6-thioguanine, cytarabine, 5-fluorouracil, dacarbazine), alkylating agents (e.g., nitrogen mustard, thioepa chlorambucil, melphalan, carmustine (BSNU), and lomustine) (CCNU), cyclophosphamide, busulfan, dibromomannitol, streptozotocin, mitomycin C and dichlorodiamine platinum (II) (DDP cis platinum), anthracyclines (e.g., daunorubicin (formerly daunomycin and cranberry), antibiotics (e.g., dactinomycin (formerly actinomycin), bleomycin, mithramycin and anthramycin (AMC)), antimitotics (e.g., vincristine and vinblastine), topoisomerase inhibitors and tubulin binding agents.

Examples of detectable labels can include fluorescent labels (e.g., fluorescein, rhodamine, tansyl, phycoerythrin, or Texas Red), enzyme substrate labels (e.g., horseradish peroxidase, alkaline phosphatase, luciferase, glucoamylase, lysozyme, carbohydrate oxidase, or β-D-galactosidase), radioactive isotopes (e.g., ¹²³ I, ¹²⁴ I, ¹²⁵ I, ¹³¹ I, ³⁵ S, ³ H, ¹¹¹ In, ¹¹² In, ¹⁴ C, ⁶⁴ Cu, ⁶⁷ Cu, ⁸⁶ Y, ⁸⁸ Y, ⁹⁰ Y, ¹⁷⁷ Lu, ²¹¹ At, ¹⁸⁶ Re, ¹⁸⁸ Re, ¹⁵³ Sm, ²¹² Bi, and ³² P, other onium elements), luminescent labels, chromophore moieties, digoxigenin, biotin/avidin, DNA molecules or gold for detection.

In certain embodiments, the conjugate moiety may be a clearance modifier that helps increase the half-life of the antibody. Illustrative examples include water-soluble polymers such as PEG, carboxymethyl cellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone, copolymers of ethylene glycol/propylene glycol, and the like. The polymer may be of any molecular weight and may be branched or unbranched. The number of polymers attached to the antibody may vary, and if more than one polymer is attached, they may be the same or different molecules.

In certain embodiments, the binding moiety may be a purified moiety, such as a magnetic bead.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are used as substrates for conjugates.

In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are bound to a single peptide. Signal peptides (sometimes referred to as signal sequences, leader sequences or leader peptides) can be used to promote the secretion and separation of antibodies or antigen-binding fragments thereof provided herein. Signal peptides are typically characterized by a core of hydrophobic amino acids that are typically cleaved from mature proteins during secretion in one or more cleavage events. Such signal peptides contain processing sites that allow the signal sequence to be cleaved from the mature protein as the mature protein passes through the secretory pathway. Therefore, the present invention relates to the described polypeptides having a signal sequence and polypeptides in which the signal sequence has been proteolytically cleaved (i.e., cleavage products). In one embodiment, a nucleic acid sequence encoding a signal sequence can be operably linked in an expression vector to a protein of interest, such as a protein that is not normally secreted or otherwise difficult to separate. The signal sequence directs secretion of the protein, such as from a eukaryotic host into which the expression vector is transformed, and the signal sequence is subsequently or simultaneously cleaved. The protein can then be easily purified from the extracellular medium by methods well-known in the art. Alternatively, the signal sequence can be linked to the protein of interest using a sequence that facilitates purification, such as using a GST domain. Chimeric Antigen Receptors

In certain embodiments, the present invention provides a chimeric antigen receptor, which comprises an antibody or an antigen-binding fragment thereof provided herein, a transmembrane region, and an intracellular signaling region.

As used herein, the term "chimeric antigen receptor" or "CAR" refers to an engineered receptor that transfers antigen specificity to a cell (e.g., a T cell, such as a naive T cell, a central memory T cell, an effector memory T cell, a regulatory T cell, a natural killer cell, or any combination thereof). CAR is also referred to as an artificial cell receptor, a chimeric cell receptor, or a chimeric immune receptor. In some embodiments, CAR includes an antigen-specific targeting region (e.g., an antigen-binding fragment of an anti-CD3 antibody as provided herein), an extracellular region, a transmembrane region, one or more costimulatory regions, and an intracellular signaling region.

In some embodiments, the antigen-specific targeting region is scFv. In some embodiments, the transmembrane region includes the transmembrane region of CD3, CD4, CD8 or CD28. In some embodiments, the costimulatory region includes the costimulatory domain of CD28, ICOS, CD27, 4-1BB, OX40 and CD40L. In some embodiments, the intracellular signaling region is selected from the group consisting of: CD3, FcγRI, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, TLR or a combination thereof.

CARs can be transplanted into a variety of cells, for example, allogeneic cells, autologous cells, or xenogeneic cells.

As used herein, the term "allogeneic cell" refers to any cell derived from a different individual of the same species.

As used herein, the term "autologous cells" refers to any cells derived from the same individual that are subsequently reintroduced into that individual.

The term "xenogeneic cell" as used herein refers to any cell originating from a different individual of a different species.

In certain embodiments, the CAR is transplanted into immune effector cells, such as T cells, natural killer cells, macrophages, tumor infiltrating lymphocytes, etc. Polynucleotides and recombinant methods

The present invention provides isolated polynucleotides encoding anti-CD3 antibodies or antigen-binding fragments thereof provided herein and/or encoding chimeric antigen receptors provided herein. As used herein, the term "nucleic acid" or "polynucleotide" refers to deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) and polymers thereof in single-stranded or double-stranded form. Unless otherwise indicated, a particular polynucleotide sequence also implicitly encompasses conservatively modified variants thereof (e.g., degenerate codon substitutions), alleles, orthologs, SNPs and complementary sequences as well as the explicitly indicated sequences. Specifically, degenerate codon substitutions can be achieved by generating sequences in which the third position of one or more selected (or all) codons is substituted with mixed base and/or deoxyinosine residues (see Batzer et al., Nucleic Acid Res . 19:5081 (1991); Ohtsuka et al., J. Biol. Chem. , 260:2605-2608 (1985); and Rossolini et al., Mol. Cell. Probes , 8:91-98 (1994)) .

DNA encoding an antibody or antigen-binding fragment thereof or a chimeric antigen receptor provided herein is readily isolated and sequenced using known procedures (e.g., by using oligonucleotide probes that specifically bind to the genes encoding the heavy and light chains of the antibody). Coding DNA can also be obtained by synthetic methods.

The isolated polynucleotides encoding the anti-CD3 antibodies or antigen-binding fragments thereof provided herein and/or the chimeric antigen receptors provided herein can be inserted into vectors for further cloning (amplification of DNA) or expression using recombinant techniques known in the art. Many vectors are available. The vector composition generally includes, but is not limited to, one or more of the following: a signal sequence, an origin of replication, one or more marker genes, an enhancer element, a promoter (e.g., SV40, CMV, EF-1α), and a transcription termination sequence.

The present invention provides vectors comprising isolated polynucleotides provided herein. In certain embodiments, the polynucleotides provided herein encode antibodies or antigen-binding fragments thereof and/or chimeric antigen receptors, at least one promoter (e.g., SV40, CMV, EF-1α) operably linked to the nucleic acid sequence, and at least one selectable marker. Examples of vectors include, but are not limited to, retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (e.g., herpes simplex virus), poxviruses, bacilli, papillomaviruses, papovaviruses (e.g., SV40), phage lambda and phage M13, plasmids pcDNA3.3, pMD18-T, pOptivec, pCMV, pEGFP, pIRES, pQD-Hyg-GSeu, pALTER, pBAD, pcDNA, pCal, pL, pET, pGEMEX , pGEX, pCI, pEGFT, pSV2, pFUSE, pVITRO, pVIVO, pMAL, pMONO, pSELECT, pUNO, pDUO, Psg5L, pBABE, pWPXL, pBI, p15TV-L, pPro18, pTD, pRS10, pLexA, pACT2.2, pCMV-SCRIPT.RTM., pCDM8, pCDNA1.1/amp, pcDNA3.1, pRc/RSV, PCR 2.1, pEF-1, pFB, pSG5, pXT1, pCDEF3, pSVSPORT, pEF-Bos, etc.

A vector comprising a polynucleotide sequence encoding an antibody or antigen-binding fragment thereof and/or a chimeric antigen receptor provided herein can be introduced into a host expression system (e.g., a host cell) for cloning or gene expression. In certain embodiments, the host expression system provided herein is a microorganism, a yeast, or a mammalian cell. In certain embodiments, the microorganism is selected from the group consisting of Escherichia coli and Bacillus subtilis. In certain embodiments, the yeast is a genus Saccharomyces. In certain embodiments, the mammalian cell is selected from the group consisting of COS, CHO-S, CHO-K1, HEK-293, and 3T3 cells.

Suitable host cells for cloning or expressing the DNA in the vectors herein are the prokaryotic cells, yeast cells or higher eukaryotic cells described above. Suitable prokaryotes for this purpose include eubacteria, such as Gram-negative or Gram-positive organisms, for example, Enterobacteriaceae , such as Escherichia (e.g., E. coli), Enterobacter , Erwinia , Klebsiella , Proteus , Salmonella (e.g., Salmonella typhimurium ), Serratia (e.g., Serratia marcescans ), and Shigella , as well as Bacilli . ), such as Bacillus subtilis and B. licheniformis , Pseudomonas , such as P. aeruginosa , and Streptomyces .

In addition to prokaryotes, eukaryotic microorganisms (such as filamentous fungi or yeast) are also suitable hosts for the propagation or expression of vectors encoding anti-CD3 antibodies. Saccharomyces cerevisiae or common bread yeast is the most commonly used lower eukaryotic host microorganism. However, many other genera, species, and strains are commonly used and are suitable for use herein, such as Schizosaccharomyces pombe ; Kluyveromyces hosts, such as K. lactis , K. fragilis (ATCC 12,424), K. bulgaricus (ATCC 16,045), K. wickeramii (ATCC 24,178), K. waltii (ATCC 56,500), K. drosophilarum (ATCC 36,906), K. thermotolerans , and K. marxianus (ATCC 16,045); and K. truncatum (ATCC 24,178). K. marxianus ); Yarrowia (EP 402,226); Pichia pastoris (EP 183,070); Candida ; Trichoderma reesia (EP 244,234); Neurospora crassa ; Schwanniomyces , such as Schwanniomyces occidentalis ; and filamentous fungi, such as Neurospora , Penicillium , Tolypocladium and Aspergillus hosts (such as A. nidulans ) and black yeast ( A. niger )).

Suitable host cells for expressing the glycosylated antibodies or antigen-binding fragments thereof provided herein are derived from multicellular organisms. Examples of invertebrate cells include plant and insect cells. A variety of bacilliform virus strains and variants have been identified and corresponding permissive insect host cells from hosts such as Spodoptera frugiperda (caterpillar), Aedes aegypti (mosquito), Aedes albopictus (mosquito), Drosophila melanogaster (fruit fly), and Bombyx mori . A variety of virus strains for transfection are publicly available, such as the L-1 variant of Autographa californica NPV and the Bm-5 variant of Bombyx mori NPV, and these viruses can be used as viruses herein according to the present invention, particularly for transfecting Spodoptera frugiperda cells. Plant cell cultures of cotton, corn, potato, soybean, dwarf cattle, tomato and tobacco can also be used as hosts.

However, of greatest interest are vertebrate cells, and propagation of vertebrate cells in culture (tissue culture) has become a learned procedure. Examples of useful mammalian host cell strains are monkey kidney CV1 line transformed with SV40 (COS-7, ATCC CRL 1651); human embryonic kidney line (293 or 293 cells subselected for growth in suspension culture, Graham et al., J. Gen. Virol. 36/59 (1977)); baby hamster kidney cells (BHK, ATCC CCL 10); Chinese hamster ovary cells/-DHFR (CHO, Urlaub et al., Proc. Natl. Acad. Sci. USA 77:4216 (1980)); mouse Sertoli cells (TM4, Mather, Biol. Reprod. 23:243-251 (1980)); monkey kidney cells (CV1 ATCC CCL 70); African green monkey kidney cells (VERO-76, ATCC CRL-1587); human cervical carcinoma cells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34); buffalo rat liver cells (BRL 3A, ATCC CRL 1442); human lung cells (W138, ATCC CCL 75); human liver cells (Hep G2, HB 8065); mouse mammary tumor (MMT 060562, ATCC CCL51); TRI cells (Mather et al., Annals NY Acad. Sci. 383:44-68 (1982)); MRC 5 cells; FS4 cells; mouse forestomach carcinoma cells (MFC), SNU620 cells and human hepatoma cell line (Hep G2). In some embodiments, the host cell is a mammalian cultured cell line, such as CHO, BHK, NS0, 293, MFC, SNU620 and their derivatives.

Host cells are transformed with the above-described expression or selection vectors for anti-CD3 antibody production, and the host cells are cultured in a known nutrient medium modified to be suitable for inducing promoters, selecting transformants, or amplifying genes encoding the desired sequence. In another embodiment, the antibody can be produced by homologous recombination known in the art. In certain embodiments, the host cell is capable of producing the antibodies or antigen-binding fragments thereof provided herein.

The present invention also provides a method for expressing an antibody or antigen-binding fragment thereof and/or a chimeric antigen receptor provided herein, the method comprising culturing a host expression system provided herein under conditions for expressing the antibody or antigen-binding fragment thereof and/or a chimeric antigen receptor. The host expression system used to produce the antibody or antigen-binding fragment thereof and/or a chimeric antigen receptor provided herein can be cultured in a variety of culture media. Commercially available culture media such as Ham's F10 (Sigma), Minimal Essential Medium (MEM) (Sigma), RPMI-1640 (Sigma) and Dulbecco's Modified Eagle's Medium (DMEM) (Sigma) are suitable for culturing host cells. In addition, any medium described in the following can be used as a culture medium for host cells: Ham et al., Meth. Enz. 58:44 (1979); Barnes et al., Anal. Biochem. 102:255 (1980); U.S. Patent Nos. 4,767,704; 4,657,866; 4,927,762; 4,560,655; or 5,122,469; WO 90/03430; WO 87/00195; or U.S. Rep. 30,985. Any of these media may be supplemented as necessary with hormones and/or other growth factors (such as insulin, transferrin, or epidermal growth factor), salts (such as sodium chloride, calcium, magnesium, and phosphates), buffers (such as HEPES), nucleotides (such as adenosine and thymidine), antibiotics (such as GENTAMYCIN ^™ drugs), trace elements (defined as inorganic compounds whose final concentrations are usually in the micromolar range), and glucose or an equivalent energy source. Any other necessary supplements may also be included at appropriate concentrations known to those skilled in the art. Culture conditions such as temperature, pH, etc. are those previously used with the host cell selected for expression, and will be apparent to those skilled in the art.

When recombinant techniques are used, antibodies can be produced intracellularly, in the periplasmic space, or secreted directly into the culture medium. If the antibody is produced intracellularly, as a first step, particulate debris of host cells or lysed fragments can be removed, for example, by centrifugation or ultrafiltration. Carter et al., Bio/Technology 10:163-167 (1992) describe a procedure for isolating antibodies secreted into the periplasmic space of E. coli. Briefly, a cell paste is thawed in the presence of sodium acetate (pH 3.5), EDTA, and phenylmethylsulfonyl fluoride (PMSF) for about 30 minutes. Cell debris can be removed by centrifugation. When the antibody is secreted into the culture medium, the supernatant from such expression systems is usually first concentrated using a commercially available protein concentrator filter (e.g., Amicon or Millipore Pellicon ultrafiltration units). Protease inhibitors such as PMSF may be included in any of the above steps to inhibit proteolysis, and antibiotics may be included to prevent the growth of adventitious contaminants.

Anti-CD3 antibodies or antigen-binding fragments thereof and/or chimeric antigen receptors produced by the host expression system can be purified using, for example, hydroxyapatite chromatography, gel electrophoresis, dialysis, DEAE-cellulose ion exchange chromatography, ammonium sulfate precipitation, salt precipitation, and affinity chromatography, with affinity chromatography being a preferred purification technique.

In certain embodiments, protein A immobilized on a solid phase is used for immunoaffinity purification of the antibodies and antigen-binding fragments thereof and/or chimeric antigen receptors provided herein. Whether protein A is suitable as an affinity ligand depends on the type and isotype of any immunoglobulin Fc domain present in the antibody. Protein A can be used to purify antibodies based on human γ1, γ2 or γ4 heavy chains (Lindmark et al., J. Immunol. Meth. 62:1-13 (1983)). Protein G is recommended for all mouse isotypes and human γ3 (Guss et al., EMBO J. 5:1567 1575 (1986)). The matrix to which the affinity ligand is attached is most often agarose, but other matrices are also available. Mechanically stable matrices such as controlled pore glass or poly(styrenedivinyl)benzene allow faster flow rates and shorter processing times than can be achieved with agarose. In the case of antibodies comprising a CH3 domain, Bakerbond ABX™ resin (JT Baker, Phillipsburg, NJ) can be used for purification. Other techniques for protein purification are also available, depending on the antibody to be recovered, such as fractionation on an ion exchange column, ethanol precipitation, reverse phase HPLC, chromatography on silica, chromatography on heparin SEPHAROSETM, chromatography on anion or cation exchange resins (such as polyaspartic acid columns), chromatography focusing, SDS-PAGE, and ammonium sulfate precipitation.

Following any preliminary purification steps, the mixture comprising the antibody of interest and contaminants can be subjected to low pH hydrophobic interaction chromatography using an elution buffer having a pH between about 2.5-4.5, preferably at low salt concentrations (e.g., about 0-0.25 M salt). Pharmaceutical Compositions

The present invention further provides a pharmaceutical composition comprising an anti-CD3 antibody or an antigen-binding fragment thereof and/or a chimeric antigen receptor provided herein, and one or more pharmaceutically acceptable carriers.

Pharmaceutically acceptable carriers used in the pharmaceutical compositions disclosed herein may include, for example, pharmaceutically acceptable liquid, gel or solid carriers, aqueous vehicles, non-aqueous vehicles, antimicrobial agents, isotonic agents, buffers, antioxidants, anesthetics, suspending/partitioning agents, sequestrants or chelating agents, diluents, adjuvants, excipients or non-toxic auxiliary substances, other components known in the art, or various combinations thereof.

Suitable ingredients may include, for example, antioxidants, fillers, binders, disintegrants, buffers, preservatives, lubricants, flavorings, thickeners, coloring agents, emulsifiers or stabilizers, such as sugars and cyclodextrins. Suitable antioxidants may include, for example, methionine, ascorbic acid, EDTA, sodium thiosulfate, platinum, catalase, citric acid, cysteine, thioglycerol, hydroxyacetic acid, thiosorbitol, butylated hydroxanisol, butylated hydroxytoluene and/or propyl gallate. As disclosed herein, one or more antioxidants such as methionine are included in compositions comprising antibodies or AFs thereof and conjugates provided herein to reduce oxidation of the antibodies or AFs thereof. This reduction in oxidation can prevent or reduce the loss of binding affinity, thereby improving antibody stability and maximizing shelf life. Therefore, in certain embodiments, pharmaceutical compositions are provided that include one or more antibodies or AFs thereof as disclosed herein and one or more antioxidants such as methionine. Further provided are methods for preventing oxidation of antibodies or AFs provided herein, extending shelf life, and/or improving efficacy by mixing the antibodies or AFs with one or more antioxidants such as methionine.

For further explanation, pharmaceutically acceptable carriers may include, for example, aqueous vehicles such as sodium chloride injection, Ringer's injection, injection), isotonic dextrose injection, sterile water injection, or dextrose and lactated Ringer's injection; nonaqueous vehicles, such as fixed oils of vegetable origin, cottonseed oil, corn oil, sesame oil, or peanut oil; antimicrobial agents at bacteriostatic or fungistatic concentrations; isotonic agents, such as sodium chloride or dextrose; buffers, such as phosphate or citrate buffers; antioxidants, such as sodium bisulfate; local anesthetics, such as procaine hydrochloride; suspending and dispersing agents, such as sodium carboxymethylcellulose, hydroxypropylmethylcellulose, or polyvinylpyrrolidone; emulsifiers, such as polysorbate 80 (TWEEN-80); sequestrants or chelating agents, such as EDTA (ethylenediaminetetraacetic acid) or EGTA (ethylene glycol tetraacetic acid); ethanol; polyethylene glycol; propylene glycol; sodium hydroxide; hydrochloric acid; citric acid or lactic acid. Antimicrobial agents used as carriers may be added to the pharmaceutical composition in a multi-dose container and include phenol or cresol, mercury, benzyl alcohol, chlorobutanol, methyl and propyl parabens, thimerosal, benzoyl chloride and benzethonium chloride. Suitable excipients may include, for example, water, saline, dextrose, glycerol or ethanol. Suitable non-toxic auxiliary substances may include, for example, wetting or emulsifying agents, pH buffers, stabilizers, solubility enhancers or pharmaceutical agents such as sodium acetate, sorbitan monolaurate, triethanolamine oleate or cyclodextrins.

The pharmaceutical composition can be a liquid solution, suspension, emulsion, pill, capsule, tablet, sustained release formulation or powder. Oral formulations can include standard carriers such as pharmaceutical grade mannitol, lactose, starch, magnesium stearate, polyvinylpyrrolidone, sodium saccharin, cellulose, magnesium carbonate, etc.

In certain embodiments, the pharmaceutical composition is formulated as an injectable pharmaceutical composition. Injectable compositions can be prepared in any known form, such as a liquid solution, suspension, emulsion, or a solid form suitable for producing a liquid solution, suspension, or emulsion. Injectable preparations may include sterile and/or pyrogen-free solutions ready for injection, sterile dry soluble products (such as lyophilized powders, including subcutaneous tablets) ready for combination with a solvent before use, sterile suspensions ready for injection, sterile dry insoluble products ready for combination with a vehicle before use, and sterile and/or pyrogen-free emulsions. Solutions may be aqueous or non-aqueous.

In certain embodiments, the unit dose parenteral preparation is packaged in an ampoule, a vial or a syringe with a needle. As is known and practiced in the art, all preparations for parenteral administration should be sterile and pyrogen-free.

In certain embodiments, a sterile lyophilized powder is prepared by dissolving an antibody or antigen-binding fragment thereof as disclosed herein in a suitable solvent. The solvent may contain excipients that improve the stability of the powder or a reconstituted solution prepared from the powder or other pharmacological components. Excipients that may be used include, but are not limited to, water, dextrose, sorbitol, fructose, corn syrup, xylitol, glycerol, glucose, sucrose, or other suitable agents. The solvent may contain a buffer, such as citrate, sodium phosphate or potassium phosphate, or other such buffers known to those skilled in the art, and in one embodiment, the buffer is at about neutral pH. The solution is then sterile filtered and then lyophilized under standard conditions known to those skilled in the art to provide the desired formulation. In one embodiment, the resulting solution is dispensed into vials for lyophilization. Each vial may contain a single dose or multiple doses of an anti-CD3 antibody or antigen-binding fragment thereof, or a combination thereof. It is acceptable to overfill the vial with a slightly higher amount (e.g., about 10%) than required for each dose or multiple doses in order to facilitate accurate sampling and accurate dosing. The lyophilized powder may be stored under appropriate conditions, such as at about 4°C to room temperature.

The lyophilized powder is reconstituted with water for injection to provide a formulation for parenteral administration. In one embodiment, sterile and/or pyrogen-free water or other suitable liquid carrier is added to the lyophilized powder for reconstitution. The exact amount depends on the selected therapy to be administered and can be determined empirically. Kits

In certain embodiments, the present invention provides a kit comprising an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein. In certain embodiments, the present invention provides a kit comprising an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein and a second therapeutic agent. In certain embodiments, the second therapeutic agent is selected from the group consisting of: a detection agent, a chemotherapeutic agent, an anticancer drug, radiation therapy, an immunotherapy agent, an anti-angiogenic agent, a targeted therapy, a cell therapy, a gene therapy, a hormone therapy, an antiviral agent, an antibiotic, an analgesic, an antioxidant, a metal chelator, and an interleukin.

As will be apparent to one skilled in the art, such pharmaceutical kits may further include one or more of the various known kit components, such as a container with one or more pharmaceutically acceptable carriers, additional containers, etc., if desired. The kit may also include instructions (as an insert or as a label) indicating the amounts of the components to be administered, instructions for administration, and/or instructions for mixing the components.

The present invention also provides a method for treating, preventing or alleviating a disease, disorder or condition in an individual, comprising administering to the individual a therapeutically effective amount of an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein. In certain embodiments, the disease, disorder or condition is a CD3-related disease, disorder or condition. In certain embodiments, the individual is a human.

In some embodiments, the CD3-related disease, disorder or condition is characterized by the expression or overexpression of CD3.

In some embodiments, the disease, disorder or condition is an immune disease, an inflammatory disease, a cancer or a nervous system disease. In some embodiments, the cancer is a CD3-expressing cancer. As used herein, "CD3-expressing cancer" refers to a cancer characterized by the expression of CD3 protein in cancer cells (i.e., tumor-infiltrating immune cells) or the expression of CD3 in cancer cells (i.e., tumor-infiltrating immune cells), and its expression level is significantly higher than the expected level of normal cells. Various methods can be used to determine the presence and/or amount of CD3 in an individual's test biological sample. For example, the test biological sample can be exposed to an anti-CD3 antibody or an antigen-binding fragment thereof, which binds to and detects the expressed CD3 protein. Alternatively, CD3 can also be detected at the nucleic acid expression level using methods such as qPCR, reverse transcriptase PCR, microarrays, SAGE, FISH, etc. In some embodiments, the test sample is derived from cancer cells or tissues, or tumor infiltrating immune cells. The reference sample can be a control sample obtained from a healthy or non-diseased individual, or a healthy or non-diseased sample obtained from the same individual from which the test sample was obtained. For example, the reference sample can be a non-diseased sample adjacent to or in the vicinity of the test sample (e.g., tumor). In certain embodiments, the cancer is a solid tumor or a blood tumor.

In certain embodiments, the disease, disorder or condition is selected from the group consisting of lung cancer (e.g., non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC) (lung adenocarcinoma or lung squamous cell carcinoma), peritoneal cancer, carcinoid, bone cancer, pancreatic cancer, primitive neuroectodermal tumor, skin cancer, gallbladder cancer, head and neck cancer, squamous cell carcinoma, uterine cancer, ovarian cancer, rectal cancer, prostate cancer, bladder cancer (e.g., urothelial carcinoma), anal cancer (e.g., anal squamous cell carcinoma), gastric cancer (gastric or stomach cancer) (e.g., gastrointestinal cancer), esophageal cancer, colorectal cancer, breast cancer, uterine cancer, liver cancer (e.g., hepatoblastic carcinoma, hepatocellular carcinoma/hepatocellular carcinoma, or liver cancer), bile duct cancer, sarcoma, colorectal cancer, fallopian tube cancer, salivary gland cancer, cervical cancer, endometrial cancer, or uterine cancer, osteosarcoma, vaginal cancer, vulvar cancer, esophageal cancer, small intestine cancer, endocrine system cancer, thyroid cancer, parathyroid cancer, adrenal cancer, nasopharyngeal cancer, soft tissue sarcoma, polycythemia vera, urethral cancer, penile cancer, kidney or urethral cancer (e.g., renal rhabdomyosarcoma), cutaneous T-cell lymphoma, neurotubular cancer cytoma, nephroblastoma, myeloproliferative syndrome, chronic and non-chronic myeloproliferative disorders, choroidal papilloma, renal cell carcinoma, renal pelvic carcinoma, central nervous system (CNS) metastasis, soft tissue sarcoma (e.g., rhabdomyosarcoma, fibrosarcoma, Kaposi's sarcoma), spinal cord axonal tumor, glioma (e.g., ependymoma, astrocytoma, anaplastic astrocytoma, oligodendroglioma), eye cancer (e.g., retinoblastoma), brain stem glioma or mixed glioma such as oligoastrocytoma, brain tumor (e.g., glioblastoma/polymorphic glioblastoma), (GBM), non-gliomatous brain tumor or meningioma), melanoma (e.g., cutaneous or intraocular melanoma), thrombocytosis, mesothelioma, mycosis fungoides, Sezary syndrome, primary myelofibrosis, solitary plasmacytoma, vestibular schwannoma, Ewing's sarcoma, chondrosarcoma, MYH-related polyposis, pituitary adenoma, pediatric cancers such as pediatric sarcomas (e.g., neuroblastoma, rhabdomyosarcoma, and osteosarcoma), hematologic cancers, Hodgkin's lymphoma, non-Hodgkin's lymphoma, leukemia (e.g., lymphocytic/lymphoblastic leukemia), chronic or acute Leukemia, mast cell leukemia, lymphocytic lymphoma, primary CNS lymphoma, chronic lymphocytic leukemia (CLL), acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), acute myeloid leukemia (AML), chronic myelomonocytic leukemia (CMML), chronic lymphocytic leukemia, acute lymphocytic leukemia, hairy cell leukemia (HCL), Burkitt's lymphoma (BL), multiple myeloma (e.g., relapsed or refractory multiple myeloma), T-cell or B-cell lymphoma, mantle cell lymphoma (MCL) (e.g., relapsed or refractory mantle cell lymphoma), malignant melanoma, diffuse large B-cell lymphoma (DLBCL), DLBCL arising from follicular lymphoma, high-grade B-cell lymphoma, primary vertebral large B-cell lymphoma, follicular lymphoma (FL), and primary vertebral B-cell lymphoma.

In some embodiments, the individual has been identified as having cancer cells or tumor-infiltrating immune cells that express CD3, as the case may be, at levels significantly higher than those normally found on non-cancerous cells.

In another aspect, a method of treating, preventing or alleviating a disease, disorder or condition in an individual that would benefit from modulation of CD3 activity is provided, comprising administering to the individual a therapeutically effective amount of an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein. In certain embodiments, the disease, disorder or condition is a CD3-related disease, disorder or condition as defined above.

The therapeutically effective amount of the antibodies or antigen-binding fragments provided herein will depend on various factors known in the art, such as weight, age, past medical history, current drug therapy, individual health conditions and potential for cross-reactions, allergies, sensitivities and adverse side effects, as well as the route of administration and the extent of disease progression. A person skilled in the art (e.g., a physician or veterinarian) may proportionally reduce or increase the dosage based on these and other circumstances or requirements.

In certain embodiments, the antibodies or antigen-binding fragments and/or chimeric receptors provided herein can be administered in a therapeutically effective dose of about 0.01 mg/kg to about 100 mg/kg. In certain embodiments, the dosage can be changed during the course of treatment. For example, in certain embodiments, the initial dosage can be higher than the subsequent dosage. In certain embodiments, the dosage can be changed during the course of treatment according to the individual's response.

Dosage regimens may be adjusted to provide the optimal desired response (e.g., a therapeutic response). For example, a single dose may be administered, or multiple, divided doses may be administered over time.

The antibodies or antigen-binding fragments thereof and/or chimeric antigen receptors provided herein can be administered by any route known in the art, for example, by parenteral routes including subcutaneous injection, intraperitoneal injection, intravenous injection, intramuscular injection or intradermal injection; or by non-parenteral routes, including transdermal, oral, intranasal, intraocular, sublingual, rectal or topical.

In some embodiments, the antibodies or antigen-binding fragments thereof and/or chimeric antigen receptors provided herein can be administered alone or in combination with a therapeutically effective amount of a second therapeutic agent. For example, the antibodies or antigen-binding fragments thereof and/or chimeric antigen receptors disclosed herein can be administered in combination with a second therapeutic agent, such as a detection agent, a chemotherapeutic agent, an anticancer drug, a radiotherapeutic agent, an immunotherapy agent, a targeted therapy agent, a cell therapy agent, a gene therapy agent, a hormone therapy agent, an antiviral agent, an antibiotic, an analgesic, an antioxidant, a metal chelator, Interleukin, active agent, imaging agent, cytotoxic agent, angiogenesis inhibitor, kinase inhibitor, co-stimulatory molecule agonist, co-inhibitory molecule inhibitor, adhesion molecule inhibitor, anti-interleukin antibody or functional fragment thereof, detectable marker or reporter gene, antibacterial agent, gene editing agent, β agonist, viral RNA inhibitor, polymerase inhibitor, interferon or micro RNA.

As used herein, the term "immunotherapy" refers to a type of therapy that stimulates the immune system to fight a disease such as cancer or generally strengthens the immune system. Examples of immunotherapy include, but are not limited to, checkpoint modulators, secondary cell transfer, interleukins, oncolytic viruses, and therapeutic vaccines.

"Targeted therapy" is a type of therapy that acts on specific molecules associated with cancer, such as specific proteins that are present in cancer cells but not in normal cells or are more abundant in cancer cells, or target molecules in the cancer microenvironment that contribute to cancer growth and survival. Targeted therapy directs the therapeutic agent to the tumor, thereby sparing normal tissue from the effects of the therapeutic agent.

In some of these embodiments, the antibodies or antigen-binding fragments thereof provided herein and/or the pharmaceutical compositions provided herein and/or the chimeric antigen receptors provided herein are administered in combination with one or more additional agents, and may be administered simultaneously with one or more additional therapeutic agents, and in some of these embodiments, the antibodies or antigen-binding fragments thereof and/or the pharmaceutical compositions provided herein and/or the chimeric antigen receptors provided herein and the additional agents may be administered as part of the same pharmaceutical composition. However, the administration of antibodies or antigen-binding fragments thereof and/or the pharmaceutical compositions provided herein and/or the chimeric antigen receptors provided herein in combination with another agent does not necessarily require administration simultaneously with the agent or in the same composition as the agent. An antibody or antigen-binding fragment thereof, pharmaceutical composition or chimeric antigen receptor administered before or after another agent is considered to be administered "in combination" with that agent, as the phrase is used herein, even if the antibody or antigen-binding fragment thereof, pharmaceutical composition or chimeric antigen receptor and the second therapeutic agent are administered by different routes. Where possible, the additional agent administered in combination with an antibody or antigen-binding fragment thereof, pharmaceutical composition or chimeric antigen receptor disclosed herein is administered according to the schedule listed in the product information sheet of the additional therapeutic agent or according to the Physicians' Desk Reference 2003 (Physicians' Desk Reference, 57th Edition; Medical Economics Company; ISBN: 1563634457 57th Edition (November 2002)) or a regimen well known in the art.

The present invention further provides a method for activating T cells expressing CD3 in vivo or in vitro, comprising contacting T cells expressing CD3 with the antibody or antigen-binding fragment thereof provided herein and/or the pharmaceutical composition provided herein and/or the chimeric antigen receptor provided herein.

The present invention further provides a method for modulating CD3 activity in a cell expressing CD3, comprising exposing the cell expressing CD3 to an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein.

The present invention further provides a method for promoting CD3-expressing T cells to process a second antigen in vivo or in vitro, comprising contacting the CD3-expressing T cells with the bispecific antibody or antigen-binding fragment thereof provided herein, wherein the bispecific antibody or antigen-binding fragment thereof can specifically bind to the CD3-expressing T cells and the second antigen, thereby bringing the two into close proximity.

In another aspect, the present invention provides a method for detecting the presence or amount of CD3 in a sample, comprising contacting the sample with an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein, and determining the presence or amount of CD3 in the sample.

In another aspect, the present invention provides a method for diagnosing a CD3-related disease, disorder or condition in an individual, comprising: a) obtaining a sample from the individual, b) contacting the sample obtained from the individual with an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein; c) determining the presence or amount of CD3 in the sample; and d) correlating the presence or amount of CD3 in the individual with the presence or status of a CD3-related disease, disorder or condition.

In another aspect, the present invention provides kits provided herein, comprising an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein, optionally in combination with a detectable moiety, which kits can be used to detect CD3, optionally recombinant CD3, CD3 expressed on the surface of a cell, or a cell expressing CD3. The kits may further include instructions for use.

In another aspect, the present invention also provides a use of an antibody or antigen-binding fragment thereof provided herein and/or a pharmaceutical composition provided herein and/or a chimeric antigen receptor provided herein in the preparation of a medicament for treating, preventing or alleviating a CD3-related disease, disorder or condition in an individual, or in the preparation of a diagnostic reagent for diagnosing a CD3-related disease, disorder or condition.

The following examples are provided to better illustrate the claimed invention and should not be construed as limiting the scope of the invention. All specific compositions, materials and methods described below fall in whole or in part within the scope of the invention. These specific compositions, materials and methods are not intended to limit the invention, but are merely used to illustrate specific embodiments that fall within the scope of the invention. Those skilled in the art may develop equivalent compositions, materials and methods without exercising inventive power and without departing from the scope of the invention. It will be understood that many variations may be made in the procedures described herein while still remaining within the scope of the invention. It is the intention of the inventors of the present invention that such variations are included within the scope of the invention. Examples Example 1. Antibody Production 1.1. Immunization

To generate anti-CD3 antibodies, SJL, Balb/c and CD1 mice were immunized with cells (i.e., human CD3 overexpressing cells (Jurkat-hCD3mix or 293T-hCD3mix), human CD3 ⁺ T cells, activated human CD3 ⁺ T cells, cynomolgus macaque CD3 ⁺ T cells), CD3 proteins (i.e., human CD3δε complex and human CD3γε complex, cynomolgus macaque CD3δε complex and cynomolgus macaque CD3γε complex protein) or genes (PTT5-human CD3δε plasmid, PTT5-cynomolgus macaque CD3δε plasmid) in each group. The immunized Balb/c and CD1 mice are shown in Table 4. The immunized SJL mice are shown in Table 5. The primary immunization was followed by several booster immunizations until the animals produced satisfactory antiserum titers suitable for fusion tumor development. CPG was used as an adjuvant. The immunization schedule for each group of animals is shown in Tables 6, 7, 8, 9, 10 and 11 below. Table 4. Grouping of Balb/c and CD1 mice Group Immunogen Way Animal/ species Group size Dosage 1 Jurkat-hCD3mix Intraperitoneal injection Balb/c &CD1 5/5 5×10 ⁶ /mouse 2 Human CD3 ⁺ T cells Intraperitoneal injection Balb/c &CD1 5/5 5×10 ⁶ /mouse 3 Activated human CD3 ⁺ T cells Intraperitoneal injection Balb/c &CD1 5/5 5×10 ⁶ /mouse 4 Human CD3 δε complex Human CD3 γε complex Subcutaneous injection Balb/c &CD1 5/5 25 μg 25 μg Table 5. Grouping of SJL mice Group Immunogen Way Animal/ species Group size Dosage 5 pTT5-Cynomolgus macaque CD3 δε plasmid Gene Gun SLJ 3/3 4 μg pTT5-human CD3 δε plasmid Gene Gun 4 μg pTT5-human CD3 δε plasmid + pTT5-cynomolgus macaque CD3 δε plasmid & human CD3 δε complex + human CD3 γε complex + cynomolgus macaque CD3 δε complex + cynomolgus macaque CD3 γε complex Gene gun subcutaneous injection 2 μg+2 μg 12.5 μg+12.5 μg+12.5 μg+12.5 μg pTT5-human CD3 δε plasmid + pTT5-cynomolgus macaque CD3 δε plasmid Gene Gun 2 μg+2 μg pTT5-human CD3 δε plasmid + pTT5-cynomolgus macaque CD3 δε plasmid & human CD3 δε complex + human CD3 γε complex + cynomolgus macaque CD3 δε complex + cynomolgus macaque CD3 γε complex & Jurkat cells + cynomolgus macaque CD3 ⁺ T cells Gene gun Subcutaneous injection Intraperitoneal injection 2 μg+2 μg 12.5 μg+12.5 μg+12.5 μg+12.5 μg 5 × 10 ⁶ mice+5 × 10 ⁶ mice 6 pTT5-Cynomolgus macaque CD3 δε plasmid Gene Gun SLJ 2/2 4 μg pTT5-human CD3 δε plasmid Gene Gun 4 μg pTT5-human CD3 δε plasmid + pTT5-cynomolgus macaque CD3 δε plasmid & human CD3 δε complex + human CD3 γε complex + cynomolgus macaque CD3 δε complex + cynomolgus macaque CD3 γε complex Gene gun subcutaneous injection 2 μg+2 μg 12.5 μg+12.5 μg+12.5 μg+12.5 μg pTT5-human CD3 δε plasmid + pTT5-cynomolgus macaque CD3 δε plasmid Gene Gun 2 μg+2 μg pTT5-human CD3 δε plasmid + pTT5-cynomolgus macaque CD3 δε plasmid & 293T-hCD3mix cells + cynomolgus macaque CD3 ⁺ T cells Gene gun intraperitoneal injection 2 μg+2 μg 5×10 ⁶ mice+5×10 ⁶ mice Table 6. Immunization schedule for group 1 Day 0 Pre-blood collection (15-30 μL serum/mouse) Primary: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 21 Enhancement 1: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 35 Test blood collection (15-30 μL serum/mouse) (TB1) Day 42 Enhancement 2: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 56 Test blood collection (15-30 μL serum/mouse) (TB2) Day 77 Enhancement 3: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 91 Test blood collection (15-30 μL serum/mouse) (TB3) Data Analysis and Interim Conclusions Day 118 Pre-fusion (final) boost, for each mouse: 25 μg CD3 δε complex, sc, 25 μg CD3 γε complex, sc, 5 × 10 ⁶ Jurkat-hCD3mix, ip, 5 × 10 ⁶ activated CD3 ⁺ T cells, ip Animals not selected for cell fusion are maintained in cages and may be given additional boosters. Table 7. Immunization schedule for group 2 Day 0 Pre-blood collection (15-30 μL serum/mouse) Primary: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 21 Enhancement 1: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 35 Test blood collection (15-30 μL serum/mouse) (TB1) Day 42 Enhancement 2: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 56 Test blood collection (15-30 μL serum/mouse) (TB2) Day 77 Enhancement 3: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 91 Test blood collection (15-30 μL serum/mouse) (TB3) Data Analysis and Interim Conclusions Day 118 Pre-fusion (final) boost, for each mouse: 25 μg CD3 δε complex, sc, 25 μg CD3 γε complex, sc, 5 × 10 ⁶ Jurkat-hCD3mix, ip, 5 × 10 ⁶ activated CD3 ⁺ T cells, ip Animals not selected for cell fusion are maintained in cages and may be given additional boosters. Table 8. Immunization schedule for group 3 Day 0 Pre-blood collection (15-30 μL serum/mouse) Primary: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 21 Enhancement 1: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 35 Test blood collection (15-30 μL serum/mouse) (TB1) Day 42 Enhancement 2: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 56 Test blood collection (15-30 μL serum/mouse) (TB2) Day 77 Enhancement 3: 5 × 10 ⁶ cells/mouse, intraperitoneal injection Day 91 Test blood collection (15-30 μL serum/mouse) (TB3) Data Analysis and Interim Conclusions Day 118 Pre-fusion (final) boost, for each mouse: 25 μg CD3 δε complex, sc, 25 μg CD3 γε complex, sc, 5 × 10 ⁶ Jurkat-hCD3mix, ip, 5 × 10 ⁶ activated CD3 ⁺ T cells, ip Animals not selected for cell fusion are maintained in cages and may be given additional boosters. Table 9. Immunization schedule for group 4 Day 0 Pre-blood collection (15-30 μL serum/mouse) Primary: 25 μg CD3 δε complex, subcutaneous injection, 25 μg CD3 γε complex, subcutaneous injection Day 21 Enhancement 1: 25 μg CD3 δε complex, subcutaneous injection, 25 μg CD3 γε complex, subcutaneous injection in each mouse Day 35 Test blood collection (15-30 μL serum/mouse) (TB1) Day 42 Enhancement 2: 25 μg CD3 δε complex, subcutaneous injection, 25 μg CD3 γε complex, subcutaneous injection in each mouse Day 56 Test blood collection (15-30 μL serum/mouse) (TB2) Day 77 Enhancement 3: 25 μg CD3 δε complex, subcutaneous injection, 25 μg CD3 γε complex, subcutaneous injection in each mouse Day 91 Test blood collection (15-30 μL serum/mouse) (TB3) Data Analysis and Interim Conclusions Day 118 Pre-fusion (final) boost, for each mouse: 25 μg CD3 δε complex, sc, 25 μg CD3 γε complex, sc, 5 × 10 ⁶ Jurkat-hCD3mix, ip, 5 × 10 ⁶ activated CD3 ⁺ T cells, ip Animals not selected for cell fusion are maintained in cages and may be given additional boosters. Table 10. Immunization schedule for group 5 Day 0 Pre-blood collection (15-30 μL serum/mouse) Primary: pTT5-Cynomolgus macaque CD3 δε plasmid 4 μg, gene gun. Day 14 Enhancement 1: pTT5-human CD3 δε plasmid, 4 μg, gene gun. Day 21 Test blood collection (15-30 μL serum/mouse) (TB1) Day 28 Enhancement 2: pTT5-cynomolgus macaque CD3 δε plasmid 4 μg, gene gun. Day 35 Test blood collection (15-30 μL serum/mouse) (TB2) Day 42 Enhancement 3: pTT5-human CD3 δε plasmid 2 μg + pTT5-cynomolgus macaque CD3 δε plasmid 2 μg, gene gun; human CD3 δε complex 12.5 μg + human CD3 γε complex 12.5 μg + cynomolgus macaque CD3 δε complex 12.5 μg + cynomolgus macaque CD3 γε complex 12.5 μg, subcutaneous injection. Day 49 Test blood collection (15-30 μL serum/mouse) (TB3) Day 56 Enhancement 4: pTT5-human CD3 δε plasmid 2 μg + pTT5-cynomolgus macaque CD3 δε plasmid 2 μg, gene gun. Day 78 Enhancement 5: pTT5-human CD3 δε plasmid 2 μg + pTT5-cynomolgus macaque CD3 δε plasmid 2 μg, gene gun; human CD3 δε complex 12.5 μg + human CD3 γε complex 12.5 μg + cynomolgus macaque CD3 δε complex 12.5 μg + cynomolgus macaque CD3 γε complex 12.5 μg, subcutaneous injection. Day 85 Test blood collection (15-30 μL serum/mouse) (TB5) Data Analysis and Interim Conclusions Day 92 Pre-fusion (final) boost: pTT5-human CD3 δε plasmid 2 μg + pTT5-cynomolgus macaque CD3 δε plasmid 2 μg, gene gun; human CD3 δε complex 12.5 μg + human CD3 γε complex 12.5 μg + cynomolgus macaque CD3 δε complex 12.5 μg + cynomolgus macaque CD3 γε complex 12.5 μg, subcutaneous injection; 5 × 10 ⁶ Jurkat cells + 5 × 10 ⁶ cynomolgus macaque CD3 ⁺ T cells, intraperitoneal injection. ● Animals not selected for cell fusion are kept in cages and may be given additional boosters. Table 11. Immunization schedule for group 6 Day 0 Pre-blood collection (15-30 μL serum/mouse) Primary: pTT5-Cynomolgus macaque CD3 δε plasmid 4 μg, gene gun. Day 14 Enhancement 1: pTT5-human CD3 δε plasmid, 4 μg, gene gun. Day 21 Test blood collection (15-30 μL serum/mouse) (TB1) Day 28 Enhancement 2: pTT5-cynomolgus macaque CD3 δε plasmid 4 μg, gene gun. Day 35 Test blood collection (15-30 μL serum/mouse) (TB2) Day 42 Enhancement 3: pTT5-human CD3 δε plasmid 2 μg + pTT5-cynomolgus macaque CD3 δε plasmid 2 μg, gene gun; human CD3 δε complex 12.5 μg + human CD3 γε complex 12.5 μg + cynomolgus macaque CD3 δε complex 12.5 μg + cynomolgus macaque CD3 γε complex 12.5 μg, subcutaneous injection. Day 49 Test blood collection (15-30 μL serum/mouse) (TB3) Day 56 Enhancement 4: pTT5-human CD3 δε plasmid 2 μg + pTT5-cynomolgus macaque CD3 δε plasmid 2 μg, gene gun. Day 78 Enhancement 5: pTT5-human CD3 δε plasmid 2 μg + pTT5-cynomolgus macaque CD3 δε plasmid 2 μg, gene gun; 5 × 10 ⁶ 293T-hCD3mix cells + 5 × 10 ⁶ cynomolgus macaque CD3 ⁺ T cells, intraperitoneal injection. Day 85 Test blood collection (15-30 μL serum/mouse) (TB5) Data Analysis and Interim Conclusions Day 92 Pre-fusion (final) boost: pTT5-human CD3 δε plasmid 2 μg + pTT5-cynomolgus macaque CD3 δε plasmid 2 μg, gene gun; human CD3 δε complex 12.5 μg + human CD3 γε complex 12.5 μg + cynomolgus macaque CD3 δε complex 12.5 μg + cynomolgus macaque CD3 γε complex 12.5 μg, subcutaneous injection; 5 × 10 ⁶ Jurkat cells + 5 × 10 ⁶ cynomolgus macaque CD3 ⁺ T cells, intraperitoneal injection. ● Animals not selected for cell fusion are kept in cages and may be given additional boosters. 1.2 Fusion tumor generation and screening 1.2.1. Cell fusion and screening

Perform spleen cell fusions on mice with the best immune response by testing blood samples by FACS and/or ELISA. FACS assays are performed on 293F, HEK 293T, or Jurkat cell lines that stably overexpress human CD3. Using an optimized electrofusion protocol, lymphocytes from spleen and lymph nodes are fused with a mouse myeloma cell line (SP2/0). Perform multiple fusions to ensure project success.

The fused cells are plated (2 x 10 ⁴ to 10 ⁵ cells per well) into a stack of 96-well plates. The plates are monitored for cell growth and fed weekly. Wells with cell growth are screened within 10-14 days using primary screening assays such as FACS and/or other feasible assays such as ELISA (with biotin-labeled human CD3 δε complex). Multiple fusions are performed for each target antigen and screened. Positive parental clones showing positive binding to HEK293T-hCD3mix, Jurkat-hCD3mix, or CHO-K1 cells stably overexpressing human CD3 (CHO-K1-hCD3mix) and positive ELISA signals from the primary screen (e.g., ELISA signals to human CD3 δε complex and human CD3 γε complex) are expanded to 24-well plates for secondary screening. Fusions of interest (e.g., fusions showing positive cell-based binding to Jurkat and 293F-cynoCD3mix cells) are selected for secondary cloning. 1.2.2. Fusion cloning, screening, and cryopreservation

The parental fusion tumors with the desired reactivity and the same type as those obtained from the screening conditions are then sub-cloned by multiple rounds of limiting dilution or single cell sorting until individual clones are obtained.

Subselection plates are screened by protein, cell-based ELISA, or cell-based binding assays (e.g., cell-based binding assay for CHO-K1-hCD3mix cells, ELISA assays for human CD3 δε complex and human CD3 γε complex proteins), and subclones with good binding capacity are expanded to 24-wells for confirmation testing by cell-based binding assays for HEK293T and HEK293T-hCD3mix cells or Jurkat and 293F-cynoCD3mix cells.

Sequence the desired sub-selected cell lines and further expand them into culture flasks for cryopreservation. Initially cryopreserve 4-6 vials of each cell line at 0.5-13.0 × 10 ⁶ cells/vial. If necessary, establish a master cell bank and working cell bank for the most valuable cell lines selected.

As a result, 19 antibodies with unique sequences were found. Among the 19 antibodies, 12 antibodies showed positive binding to HEK293T cells (293T-hCD3mix) that stably overexpressed human CD3 protein, but not to parental HEK293T cells (as shown in Table 12 below), indicating that these antibodies are human CD3 recognition antibodies; the other 7 antibodies showed positive binding to Jurkat and 293F-cynoCD3mix cells, but not to Jurkat-KO or parental 293F cells (as shown in Table 13 below), indicating that these antibodies are human and cynomolgus macaque CD3 recognition antibodies. Table 12. FACS MFI of antibodies binding to HEK293T and 293T-hCD3mix antibody FACS MFI (HEK293T) FACS MFI (HEK293T-hCD3mix) 25-G12-G6-C12 200 38920 16-F2-C11-D9 2070 80290 20-E11-E11-C2 2140 55240 7-D9-G10-H2 4330 50980 31-F8-F5-C5 500 77328 7-D8-G12-E4 1616 65240 40-C12-C10-E9 290 13120 2-F12-A6-G2 880 53840 3-C6-C11-F12 1760 21750 8-B12-F9-B11 160 67080 4-F12-F1-A4 500 16760 3-F3-G12-E2 14080 92740 Table 13. MFI of antibodies binding to Jurkat , Jurkat-KO , 293F-cynoCD3mix and 293F cells antibody FACS_MFI (Jurkat) FACS_MFI (Jurkat-KO) FACS_MFI (293F-cynoCD3mix) FACS_MFI (293F) 124E3D6 126 97 400 98 126A11A4 1621 101 2215 101 127E2D3 930 109 1925 102 133B4C7 681 105 1785 100 140D2B10 872 100 2038 98 147C6F3 1857 101 2231 98 147E11E2 2453 104 2526 102 Example 2. Antibody Characterization 2.1 Antibodies

The fusion tumor antibody pure lines 25-G12-G6-C12, 40-C12-C10-E9, 8-B12-F9-B11, 31-F8-F5-C5, 16-F2-C11-D9, 20-E11-E11-C2, 7-D9-G10-H2, 7-D8-G12-E4, 2-F12-A6-G2, 3-C6-C11-F12, 4-F12-F1-A4, 3-F3-G12-E2, 124E3D6, 126A11A4, 127E2D3, 133B4C7, 140D2B10, 147C6F3 and 147E11E2 were characterized. 2.2 Fusion tumor sequencing

Total RNA was isolated from the fusion tumor cells according to the technical manual of RNAiso Plus (TAKARA catalog number 9109). Total RNA was then reverse transcribed into cDNA using isotype-specific antisense primers or universal primers according to the technical manual of PrimeScript II 1st strand cDNA synthesis kit (TAKARA catalog number 6210A). Antibody fragments of VH and VL were amplified according to TaKaRa Taq ^TM (catalog number R001A). The amplified antibody fragments were individually cloned into standard cloning vectors. Colony PCR was performed to screen for clones with inserts of the correct size. No less than five colonies with inserts of the correct size for each fragment were sequenced. Sequences of different clones were compared, and the consensus sequences of these clones were provided.

The variable region sequences of the fusion tumor antibodies are provided in Table 3 above. 2.3 Characterization of Antibodies 25-G12-G6-C12 , 40-C12-C10-E9 , 8-B12-F9-B11 , 31-F8-F5-C5 , 16-F2-C11-D9 , 20-E11-E11-C2 , 7-D9-G10-H2 , 7 -D8-G12-E4 , 2-F12-A6-G2 , 3-C6-C11-F12 , 4-F12-F1-A4 and 3-F3-G12-E2

The T cell activation capacity of these antibodies was determined by Jurkat NFAT-luciferase activation assay. OKT3 was used as a positive control. The protocol used for the activation assay is described as follows: ● Mouse antibodies were coated in 96-well plates at 37°C for 1 hour at 50 μg/mL and 100 μl/well; ● Jurkat-NFAT-luciferase cells were inoculated in each well for 24 hours at 2×10 ⁴ cells/well; ● 20 μL Bright-Glo was added to each well and the luciferase value was read using a microplate reader.

The results are shown in Table 14 below. As shown in Table 14, the activation ability of these mouse antibodies is higher than that of the positive control OKT3. Table 14. Activation of Jurkat-NFAT- luciferase by mouse antibodies Plate 1 No. Name RLU 1 OKT3 5626 5711 2 Isotype comparison 564 582 3 16-F2-C11-D9 941 789 4 20-E11-E11-C2 748 710 5 7-D9-G10-H2 772 712 6 40-C12-C10-E9 1101 1057 7 2-F12-A6-G2 786 688 8 4-F12-F1-A4 1504 1557 Plate 2 No. Name RLU 1 OKT3 2594 2520 2 Isotype comparison 386 380 3 25-G12-G6-C12 1503 1211 4 31-F8-F5-C5 606 722 5 7-D8-G12-E4 395 378 6 3-C6-C11-F12 509 513 Plate 3 No. Name RLU 1 OKT3 1131 1045 2 Isotype comparison 237 231 3 8-B12-F9-B11 1039 1144 Example 3. Production and Characterization of Chimeric Antibodies 3.1. Production of Chimeric Antibodies

16 fusion tumor antibodies were selected (25-G12-G6-C12, 4-F12-F1-A4, 7-D8-G12-E4, 20-E11-E11-C2, 7-D9-G10-H2, 40-C12-C10-E9, 31-F8-F5-C5, 8-B12-F9-B11, 3-F3-G12-E2, 133B4C7, 124E3D6, 147E 11E2, 126A11A4, 147C6F3, 127E2D3 and 140D2B10) sequences were used to generate and produce human IgG1 chimeric antibodies. DNA encoding the variable regions of 16 fusion tumor antibodies was synthesized and cloned into expression vectors that pre-contained human IgG constant genes. The vectors were transfected into mammalian cells for recombinant protein expression, and the expressed antibodies were purified using a protein A affinity column. The chimeric antibodies are referred to herein as ch25-G12-G6-C12, ch4-F12-F1-A4, ch7-D8-G12-E4, ch20-E11-E11-C2, ch7-D9-G10-H2, ch40-C12-C10-E9, ch31-F8-F5-C5, ch8-B12-F9-B11, ch3-F3-G12-E2, ch 133B4C7, ch124E3D6, ch147E11E2, ch126A11A4, ch147C6F3, ch127E2D3, ch140D2B10, wherein the prefix "ch" means "chimeric" and the suffix means a pure line of a fusion tumor antibody. For example, ch25-G12-G6-C12 indicates that it is a chimeric antibody derived from the fusion tumor antibody 25-G12-G6-C12. 3.2. T cell activation ability assay of ch124E3D6 , ch126A11A4 , ch127E2D3 , ch133B4C7 , ch140D2B10 , ch147C6F3 and ch147E11E2

The T cell activation ability of chimeric antibodies ch124E3D6, ch126A11A4, ch127E2D3, ch133B4C7, ch140D2B10, ch147C6F3 and ch147E11E2 was determined by Jurkat NFAT-luciferase activation assay. BMK-B219 (anti-CD3 antibody developed by JNJ) and BMK-TCB (anti-CD3 antibody developed by Roche) were used as positive controls, and hIgG1 isotype was used as negative control. The experimental steps used for the activation assay are described as follows: ● Serially diluted test antibodies were coated on a 96-well plate at 37°C for 2 hours, 100 μl/well; ● Jurkat-NFAT-luciferase cells were inoculated in each well and incubated for 24 hours, 2×10 ⁴ cells/well; ● The supernatant was removed and the cells were lysed with 25 μL/well of lysis reagent (Promega, RLB-E3971); ● The samples were frozen at -80°C for 30 minutes and then warmed in a biochemical incubator at 37°C for 15 minutes; ● The 96-well plate was then centrifuged at 500 xg for 10 minutes, and 20 μL of supernatant from each well was transferred to a new white opaque 96-well plate; ● 100 μL/well of luciferase assay substrate (Promega, E4530) was added to a 96-well plate; ● A microplate reader was used to determine the relative luminescence units (RLU) reflecting the level of luciferase activity.

The results are shown in Figure 1 and Table 15 below. As shown in Figure 1 and Table 15, the activation ability of the selected antibodies was higher than or similar to that of the two benchmark antibodies. Table 15. Activation of Jurkat-NFAT- luciferase by chimeric antibodies Sorting antibody _EC50 (nM) Maximum signal 1 ch133B4C7 27.97 290 2 ch124E3D6 32.38 482.3 3 ch147E11E2 32.99 420.8 4 ch126A11A4 33.56 681.7 5 ch147C6F3 57.36 427.8 6 BMK-TCB 59.35 752.6 7 ch127E2D3 61.68 336.6 8 BMK-B219 68.37 811.3 3.3. Cell-based binding affinity for Jurkat cells

The binding affinity of the generated chimeric antibodies and benchmark antibodies (OKT3, BMK-B219 or BMK-TCB) to the human patient-derived lymphocytic carcinoma cell line Jurkat was determined by FACS analysis, and the hIgG1 isotype was used as a negative control. The protocol for FACS analysis is described as follows: (a) Jurkat cells were harvested and resuspended in FACS buffer; (b) Cells were counted and the concentration was adjusted to 4×10^6 cells/ml. 50 μl/well of the cell suspension was added to a 96-well plate; (c) 50 μl/well of 2x serially diluted test antibodies were added to the plate. The plate was incubated at 4°C for 1 hour; (d) The plate was centrifuged at 300 g for 3 minutes and the supernatant was discarded; (e) The cells were washed twice in 200 μl FASC buffer and step (d) was repeated; (f) 100 μl/well of anti-human IgG-PE goat pAb or anti-mouse IgG-PE goat pAb secondary antibody was added to the plate. Incubate the plate at 4°C for 30 min; (g) Centrifuge the plate at 300 g for 3 min and discard the supernatant; (h) Wash the cells twice in 200 μl FASC buffer and repeat step (g); (i) Resuspend the cells in 150 μl FASC buffer and test on FACS.

As shown in Figure 2 and Table 16 below, chimeric antibodies ch31-F8-F5-C5, ch25-G12-G6-C12, ch40-C12-C10-E9 and ch8-B12-F9-B11 and the benchmark antibody OKT3 have positive binding affinity to Jurkat cells. As shown in Figure 3 and Table 17 below, the binding affinity of chimeric antibodies ch147E11E2, ch126A11A4 and ch147C6F3 to Jurkat cells is higher than or similar to the two benchmark antibodies BMK-B219 and BMK-TCB. Table 16. Binding affinity of selected chimeric antibodies to Jurkat cells Sorting antibody _EC50 (nM) Maximum FACS signal 1 OKT3 0.22 3124 2 ch31-F8-F5-C5 0.74 2540 3 ch25-G12-G6-C12 0.84 2790 4 ch40-C12-C10-E9 1.01 2545 5 ch8-B12-F9-B11 17.99 2721 Table 17. Binding affinity of selected chimeric antibodies to Jurkat cells Sorting antibody _EC50 (nM) Maximum signal 1 ch147E11E2 0.4192 2777 2 ch126A11A4 0.5668 1764 3 BMK-B219 1.47 3001 4 ch147C6F3 1.774 2282 5 BMK-TCB 1.912 3145 3.4. Cell-based binding affinity for 293T-cynoCD3mix cells

The binding affinity of selected chimeric antibodies and reference antibodies to HEK 293T cells stably overexpressing cynomolgus macaque CD3 (293T-cynoCD3mix) was determined by FACS analysis. BMK-B219 and BMK-TCB were used as positive controls, and the hIgG1 isotype was used as a negative control. The protocol used for FACS analysis is described as follows: (a) 293T-cynoCD3mix cells were harvested and resuspended in FACS buffer; (b) Cells were counted and the concentration was adjusted to 4×10^6 cells/ml. 50 μl/well of cell suspension was added to a 96-well plate; (c) 50 μl/well of 2x serially diluted test antibody was added to the plate and incubated at 4°C for 1 hour; (d) The plate was centrifuged at 300 g for 3 minutes and the supernatant was discarded; (e) The cells were washed twice in 200 μl FASC buffer and step (d) was repeated; (f) 100 μl/well of anti-human IgG-PE secondary antibody goat pAb (Abcam, ab98596) was added to the plate and incubated at 4°C for 30 minutes; (g) The plate was centrifuged at 300 g for 3 minutes and the supernatant was discarded; (h) The plate was centrifuged at 200 μl Wash cells twice in FASC buffer and repeat step (g); (i) Resuspend cells in 150 μl FASC buffer and test on FACS.

As shown in Figure 4 and Table 18 below, the binding affinity of the selected chimeric antibody to 293T-cynoCD3mix cells is higher than the binding affinity of the two benchmark antibodies to 293T-cynoCD3mix cells. Table 18. Binding affinity to 293T-cynoCD3mix cells Sorting antibody _EC50 (nM) Maximum signal 1 ch147E11E2 2.19 53876 2 ch127E2D3 2.33 46947 3 ch124E3D6 2.64 45795 4 ch140D2B10 2.81 52929 5 ch133B4C7 2.81 45246 6 ch126A11A4 2.91 57049 7 ch147C6F3 4.15 55201 8 BMK-B219 4.34 60013 9 BMK-TCB 4.72 60397 3.5. Jurkat-NFAT- luciferase activation assay

Jurkat-NFAT-Luciferase activation assay was performed for several selected chimeric antibodies and a benchmark antibody (OKT3) using the human patient-derived lymphocytic carcinoma cell line Jurkat as follows. (a) Plates were coated with 50 μl/well of serially diluted test antibodies for 2 hours at 37°C; (b) Jurkat-NFAT-Luc cells were harvested and resuspended in 1640 medium (10% FBS, 1% P/S); (c) Cells were counted and the concentration was adjusted to 2×10^5 cells/ml. 100 μl/well of the cell suspension was inoculated into a 96-well cell culture plate. Add 100 μl of culture medium as a negative control; (d) Return the cell plate to a 37°C, 5% _CO2 incubator for 24 hours; (e) Centrifuge at 500 g for 10 min and discard the supernatant; (f) Wash the cells once in PBS and repeat step (e); (g) Add 30 μl/well of 1x lysis buffer, place the plate in a -80°C refrigerator for 30 min, and then move to a 37°C incubator for 15 min; (h) Centrifuge at 500 g for 10 min and transfer 20 μl of supernatant to another 96-well plate (Coning 3903). Add 100 μl/well luciferase assay substrate and mix gently; (i) Read the plate on a microplate reader for luminescence signal (RLU).

As shown in Figure 5 and Table 19 below, the activation ability of the selected chimeric antibodies is higher than or similar to the benchmark antibody OKT3. Table 19. Activation ability of chimeric antibodies on Jurkat-NFAT-Luc cells Sorting antibody _EC50 (nM) Maximum FACS signal 1 ch25-G12-G6-C12 1.674 249.8 2 ch31-F8-F5-C5 3.83 253.2 3 OKT3 10.12 363.7 4 ch8-B12-F9-B11 11.27 457.2 5 ch40-C12-C10-E9 24.17 810.2 3.6. PBMC activation assay 3.6.1 Experiment 1

Primary human peripheral blood mononuclear cell (PBMC) based assay was used to determine the activation capacity of several selected chimeric antibodies on T cells. PBMC activation assay with selected chimeric antibodies and reference antibody (OKT3) and PBMC was performed as follows. (a) Plates were coated with 50 μl/well of serially diluted test antibody at 37°C for 2 hours; (b) Antibody solution was discarded and the wells of the plate were washed once with 200 μl of PBS; (c) PBMC were separated and resuspended with 1640 medium (10% FBS, 1% P/S); (d) Cells were counted and the concentration was adjusted to 1×10^6 cells/ml. 200 μl/well of the cell suspension was inoculated into a 96-well cell culture plate. 200 μl of culture medium was added as a negative control; (e) The cell plate was returned to a 37°C, 5% CO ₂ incubator for 120 hours; (f) The cells were centrifuged at 400 g for 5 minutes and the supernatant was collected to detect IL-2 and IFNγ cytokine release by ELISA.

ELISA assays were performed as follows. (a) Add 100 μl of diluted capture antibody to each well. Incubate overnight at 4°C; (b) Aspirate and wash 3 times; (c) Seal the plate: Add 200 μl of assay diluent to each well. Incubate for 1 hour at room temperature; (d) Aspirate and wash 3 times; (e) Add 100 μl of standard or sample to each well. Incubate for 2 hours at room temperature; (f) Aspirate and wash 5 times; (g) Add 100 μl of working detector (detector antibody + SAv-HRP) to each well. Incubate for 1 hour at room temperature; (h) Aspirate and wash 7 times (soak for 30 seconds to 1 minute); (i) Add 100 μl of substrate solution to each well. Incubate at room temperature in the dark for 30 minutes; (j) Add 50 μl of stop solution to each well; (k) Read absorbance at 450 nm within 30 minutes.

The results of IL-2 and IFNγ release are shown in Figures 6 and 7, respectively. As shown in Figure 6, the selected chimeric antibodies ch25-G12-G6-C12, ch40-C12-C10-E9, ch31-F8-F5-C5 and ch8-B12-F9-B11 and the benchmark antibody OKT3 significantly induced the release of IL-2. As shown in Figure 7, the selected chimeric antibodies ch25-G12-G6-C12, ch40-C12-C10-E9, ch31-F8-F5-C5, ch8-B12-F9-B11 and the benchmark antibody OKT3 significantly increased the release of IFNγ, and the PBMC activation ability of the selected chimeric antibodies was higher than that of the benchmark antibody OKT3 or at least similar to that of the benchmark antibody OKT3. 3.6.2. Experiment 2

Primary human peripheral blood mononuclear cell (PBMC) based assays were used to determine the activation capacity of several other selected chimeric antibodies on T cells. It is well known that when T cells are activated, the expression of the surface protein CD25 is upregulated. BMK-B219 and BMK-TCB were used as positive controls, and the hIgG1 isotype was used as a negative control. The protocol used for the activation assay is described as follows: (a) 100 μl/well of 10 μg/ml test antibody was coated in a 96-well plate at 37°C for 2 hours; (b) 2×10 ⁵ cells/well of fresh human PBMC were inoculated in each well and incubated for 3 days; (a) The cells were collected and transferred to a new 96-well plate. The plate was centrifuged at 400 g for 3 min and the supernatant was discarded; (c) the cells were resuspended in 100 μl FASC buffer containing anti-human CD25 Alexa Fluor 488-conjugated antibody (R&D, FAB9926G) and anti-human CD3 Brilliant Violet 421-conjugated antibody (Biolegend, 317344); (d) the plate was incubated at 4°C for 30 min; (e) the plate was centrifuged at 400 g for 3 min and the supernatant was discarded; (f) the cells were washed twice in 200 μl FASC buffer and step (d) was repeated; (g) 150 μl Resuspend cells in FASC buffer and test on FACS.

As shown in Figure 8, the positive controls BMK-B219 and BMK-TCB induced upregulation of CD25 on human T cells, as indicated by the subpopulation ratio of CD25 ⁺ cells in CD3 ⁺ T cells. Among the chimeric antibodies, several (i.e., ch124E3D6, ch126A11A4, ch140D2B10, ch147C6F3, and ch147E11E2) induced CD25 expression to a lesser extent than the positive controls. The chimeric antibodies ch127E2D3 and ch133B4C7 did not significantly induce CD25 upregulation. Example 4. Humanized Antibody of 40-C12-C10-E9 : Generation, Affinity Maturation, and Antibody Characterization 4.1 Generation of Humanized Antibodies

The chimeric antibody ch40-C12-C10-E9 was selected as a pure strain for humanization. The antibody sequence was aligned with the human germline sequence to identify the most suitable model. Based on the homology with the original mouse antibody sequence, the best matching human germline sequence was selected as the template for humanization. Generally, humanization of antibodies is performed by comparing the IMGT (https://www.imgt.org) human antibody heavy chain and light chain variable strain gene database, selecting heavy chain and light chain variable strain genes with high homology to mouse antibodies as templates, and transplanting the CDR of the mouse antibody into the corresponding human template. The variable region sequence with the order of FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 is formed. If necessary, key amino acids in the framework sequence were reduced and mutated to correspond to the amino acids of the mouse antibody to ensure original affinity.

By mixing and matching 3 variants of the humanized light chain variable region (i.e., hu40E9-L1, hu40E9-L2, and hu40E9-L3) and 4 variants of the humanized heavy chain variable region (i.e., hu40E9-H1, hu40E9-H2, hu40E9-H3, and hu40E9-H4), a total of 12 humanized antibodies against ch40-C12-C10-E9 were obtained. Likewise, the 12 humanized antibodies were named hu40E9-L1H1, hu40E9-L2H1, etc., as shown in Table 25 below. Immunogenicity risks and hotspots were evaluated for these generated humanized antibodies, and no immunogenicity risks or hotspots were identified. Table 25. Heavy and light chain variable regions of exemplary humanized antibodies against ch40-C12-C10-E9 VL Area VH Area hu40E9-L1 (SEQ ID NO: 168) hu40E9-L2 (SEQ ID NO: 169) hu40E9-L3 (SEQ ID NO: 170) hu40E9-H1 (SEQ ID NO: 163) hu40E9-L1H1 (SEQ ID NO: 168/163) hu40E9-L2H1 (SEQ ID NO: 169/163) hu40E9-L3H1 (SEQ ID NO: 170/163) hu40E9-H2 (SEQ ID NO: 164) hu40E9-L1H2 (SEQ ID NO: 168/164) hu40E9-L2H2 (SEQ ID NO: 169/164) hu40E9-L3H2 (SEQ ID NO: 170/164) hu40E9-H3 (SEQ ID NO: 165) hu40E9-L1H3 (SEQ ID NO: 168/165) hu40E9-L2H3 (SEQ ID NO: 169/165) hu40E9-L3H3 (SEQ ID NO: 170/165) hu40E9-H4 (SEQ ID NO: 166) hu40E9-L1H4 (SEQ ID NO: 168/166) hu40E9-L2H4 (SEQ ID NO: 169/166) hu40E9-L3H4 (SEQ ID NO: 170/166) 4.2 Affinity Maturation

Then the hu40E9-L2 variant (i.e., SEQ ID NO: 169) and the hu40E9-H3 variant (i.e., SEQ ID NO: 165) obtained in Example 4.1 were selected for affinity maturation. Specifically, positions 31-33 in CDR1 of SEQ ID NO: 165 (relative to SEQ ID NO: 165), positions 54, 55 and 56 in CDR2 of SEQ ID NO: 165 (relative to SEQ ID NO: 165), positions 99-106 in CDR3 of SEQ ID NO: 165 (relative to SEQ ID NO: 165), and positions 91, 92 and 93 in CDR3 of SEQ ID NO: 169 (relative to SEQ ID NO: 169) were selected for affinity engineering. After considering several factors, a total of 20 mutations were obtained, namely S31D, V33Y, N55S, D99E, Y101F, D105E, G106A, Y54G, D56G, D99R, D99G, S100R, S100D, S100G, Y102S or D105R in the heavy chain variable region as described in SEQ ID NO: 165; or N93S, S91R, N93R or N93W in the light chain variable region as shown in SEQ ID NO: 169.

Thus, for ch40-C12-C10-E9, 24 variants of the humanized ch40-C12-C10-E9 heavy chain variable region (i.e., hu40E9-H3-N55S.H, hu40E9-H3-D99E.H, hu40E9-H3-Y101F.H, hu40E9-H3-D105E.H, hu40 E9-H3-G106A.H、hu40E9-H3-Y54G.H、hu40E9-H3-D56G.H、hu40E9-H3-D99R.H、hu40E9-H3-S100R.H、hu40E9-H3-Y102S.H、hu40E9-H3-D105R.H、hu40E9-H5、hu40E9-H 6. hu40E9-H7, hu40E9-H8, hu40E9-H9, hu40E9-H10, hu40E9-H11, hu40E9-H12, hu40E9-H13, hu40E9-H14, hu40E9-H15, hu40E9-H16 and hu40E9-H17) and humanized ch40-C12-C10 -7 variants of the variable region of the E9 light chain (i.e., hu40E9-L2-N93S.L, hu40E9-L2-S91R.L, hu40E9-L2-N93R.L and hu40E9-L2-N93W.L, hu40E9-L4, hu40E9-L5 and hu40E9-L6) obtained a total of 34 somatically and affinity-matured antibody pure lines. The 34 humanized antibody clones were named hu40E9-L2H3-N55S.H, hu40E9-L2H3-N93S.L, hu40E9-L2H5, etc., as shown in Tables 26, 27, and 32-34 below, wherein the prefix "hu" means "humanized," and, for example, the suffix "L2H3-N55S.H" indicates the sequence number of the humanized antibody clone ch40-C12-C10-E9 having the hu40E9-L2 variant variable region and the hu40E9-H3-N55S.H variant variable region. For another example, humanized antibody hu40E9-L2H3-N93S.L represents the sequence number of a humanized antibody clone of ch40-C12-C10-E9 having a hu40E9-L2-N93S.L variant variable region and a hu40E9-H3 variant variable region. For yet another example, humanized antibody hu40E9-L2H5 represents the sequence number of a humanized antibody clone of ch40-C12-C10-E9 having a hu40E9-L2 variant variable region and a hu40E9-H5 variant variable region. Table 26. Heavy and light chain variable regions of exemplary humanized antibodies for ch40-C12-C10-E9 VL Area VH Area hu40E9-L2 (SEQ ID NO: 169) hu40E9-H3-N55S.H (SEQ ID NO: 186) hu40E9-L2H3-N55S.H (SEQ ID NO: 169/186) hu40E9-H3-D99E.H (SEQ ID NO: 187) hu40E9-L2H3-D99E.H (SEQ ID NO: 169/187) hu40E9-H3-Y101F.H (SEQ ID NO: 188) hu40E9-L2H3-Y101F.H (SEQ ID NO: 169/188) hu40E9-H3-D105E.H (SEQ ID NO: 189) hu40E9-L2H3-D105E.H (SEQ ID NO: 169/189) hu40E9-H3-G106A.H (SEQ ID NO: 190) hu40E9-L2H3-G106A.H (SEQ ID NO: 169/190) hu40E9-H3-Y54G.H (SEQ ID NO: 191) hu40E9-L2H3-Y54G.H (SEQ ID NO: 169/191) hu40E9-H3-D56G.H (SEQ ID NO: 192) hu40E9-L2H3-D56G.H (SEQ ID NO: 169/192) hu40E9-H3-D99R.H (SEQ ID NO: 193) hu40E9-L2H3-D99R.H (SEQ ID NO: 169/193) hu40E9-H3-S100R.H (SEQ ID NO: 194) hu40E9-L2H3-S100R.H (SEQ ID NO: 169/194) hu40E9-H3-Y102S.H (SEQ ID NO: 195) hu40E9-L2H3-Y102S.H (SEQ ID NO: 169/195) hu40E9-H3-D105R.H (SEQ ID NO: 196) hu40E9-L2H3-D105R.H (SEQ ID NO: 169/196) Table 27. Heavy and light chain variable regions of exemplary humanized antibodies against ch40-C12-C10-E9 VH Area VL Area hu40E9-H3 (SEQ ID NO: 165) hu40E9-L2-N93S.L (SEQ ID NO: 197) hu40E9-L2H3-N93S.L (SEQ ID NO: 197/165) hu40E9-L2-S91R.L (SEQ ID NO: 198) hu40E9-L2H3-S91R.L (SEQ ID NO: 198/165) hu40E9-L2-N93R.L (SEQ ID NO: 199) hu40E9-L2H3-N93R.L (SEQ ID NO: 199/165) hu40E9-L2-N93W.L (SEQ ID NO: 200) hu40E9-L2H3-N93W.L (SEQ ID NO: 200/165) Table 32. Heavy and light chain variable regions of exemplary humanized antibodies against ch40-C12-C10-E9 VL Area VH Area hu40E9-L2 (SEQ ID NO: 169) hu40E9-H5 (SEQ ID NO: 233) hu40E9-L2H5 (SEQ ID NO: 169/233) hu40E9-H6 (SEQ ID NO: 234) hu40E9-L2H6 (SEQ ID NO: 169/234) hu40E9-H7 (SEQ ID NO: 235) hu40E9-L2H7 (SEQ ID NO: 169/235) hu40E9-H8 (SEQ ID NO: 236) hu40E9-L2H8 (SEQ ID NO: 169/236) hu40E9-H9 (SEQ ID NO: 237) hu40E9-L2H9 (SEQ ID NO: 169/237) hu40E9-H10 (SEQ ID NO: 238) hu40E9-L2H10 (SEQ ID NO: 169/238) hu40E9-H11 (SEQ ID NO: 239) hu40E9-L2H11 (SEQ ID NO: 169/239) hu40E9-H12 (SEQ ID NO: 240) hu40E9-L2H12 (SEQ ID NO: 169/240) hu40E9-H13 (SEQ ID NO: 241) hu40E9-L2H13 (SEQ ID NO: 169/241) hu40E9-H14 (SEQ ID NO: 242) hu40E9-L2H14 (SEQ ID NO: 169/242) hu40E9-H15 (SEQ ID NO: 243) hu40E9-L2H15 (SEQ ID NO: 169/243) hu40E9-H16 (SEQ ID NO: 244) hu40E9-L2H16 (SEQ ID NO: 169/244) Table 33. Heavy and light chain variable regions of exemplary humanized antibodies against ch40-C12-C10-E9 VH Area VL Area hu40E9-H3 (SEQ ID NO: 165) hu40E9-L4 (SEQ ID NO: 230) hu40E9-L4H3 (SEQ ID NO: 230/165) hu40E9-L5 (SEQ ID NO: 231) hu40E9-L5H3 (SEQ ID NO: 231/165) hu40E9-L6 (SEQ ID NO: 232) hu40E9-L6H3 (SEQ ID NO: 232/165) Table 34. Heavy and light chain variable regions of exemplary humanized antibodies against ch40-C12-C10-E9 VH Area VL Area hu40E9-H7 (SEQ ID NO: 235) hu40E9-H8 (SEQ ID NO: 236) hu40E9-L4 (SEQ ID NO: 230) hu40E9-L4H7 (SEQ ID NO: 230/235) hu40E9-L4H8 (SEQ ID NO: 230/236) hu40E9-L5 (SEQ ID NO: 231) hu40E9-L5H7 (SEQ ID NO: 231/235) hu40E9-L5H8 (SEQ ID NO: 231/236) 4.3 Cell-based binding affinity for Jurkat cells

The binding affinity of the generated humanized 40-C12-C10-E9 antibody and the affinity matured antibody based on 40E9-L2H3 to the human patient-derived lymphocytic carcinoma cell line Jurkat was determined by FACS analysis. The benchmark antibody BMK-TCB was used as a positive control, and the hIgG1 isotype was used as a negative control. The protocol used for FACS analysis was described in Example 3.3, except that the test antibody used in step (c) was different.

As shown in Figures 9A and 9B and Table 23 below, the binding affinity of the generated humanized and/or affinity matured 40-C12-C10-E9 antibodies to Jurkat cells is higher than or similar to the benchmark antibody BMK-TCB. As shown in Figures 16A and 16B and Table 35 below, the selected humanized and/or affinity matured 40-C12-C10-E9 antibodies are able to bind to Jurkat cells. Table 23. Binding affinity of selected humanized antibodies to Jurkat cells Sorting antibody _EC50 (nM) Maximum FACS signal 1 hu40E9-L2H3-D99E.H 0.31 957 2 hu40E9-L2H3-S91R.L 0.32 1358 3 hu40E9-L2H3-D56G.H 0.32 1452 4 ch40-C12-C10-E9 0.45 1621 5 hu40E9-L2H3-Y102S.H 0.47 1165 6 hu40E9-L3H4 0.49 1365 7 hu40E9-L2H3-N93W.L 0.51 1210 8 hu40E9-L2H3-Y54G.H 0.51 1186 9 hu40E9-L2H3-N55S.H 0.51 1165 10 hu40E9-L3H2 0.52 1412 11 hu40E9-L2H3-D105R.H 0.56 1479 12 hu40E9-L2H3-N93S.L 0.60 1355 13 hu40E9-L2H3-N93R.L 0.63 1417 14 hu40E9-L2H3-Y101F.H 0.64 1187 15 hu40E9-L2H3 0.65 1578 16 hu40E9-L2H1 0.73 892 17 hu40E9-L3H1 0.75 1250 18 hu40E9-L2H2 0.81 1573 19 hu40E9-L2H4 0.86 1571 20 hu40E9-L2H3-D105E.H 1.16 1409 twenty one BMK-TCB 1.60 1739 twenty two hu40E9-L2H3-G106A.H 2.39 771 Table 35. Binding affinity of selected humanized antibodies to Jurkat cells. Sorting antibody _EC50 (nM) Maximum FACS signal 1 hu40E9-L2H5 0.36 1915 2 ch40-C12-C10-E9 0.41 2937 3 hu40E9-L2H14 0.43 2019 4 hu40E9-L5H7 0.48 1851 5 hu40E9-L2H9 0.56 1764 6 hu40E9-L2H7 0.66 2377 7 hu40E9-L5H3 0.66 2489 8 hu40E9-L6H3 0.80 1993 9 hu40E9-L2H16 1.27 2006 10 BMK-TCB 1.30 2574 11 hu40E9-L4H7 1.52 1903 12 hu40E9-L4H3 1.59 2491 13 hu40E9-L2H10 2.55 1682 14 hu40E9-L2H6 4.17 1255 15 hu40E9-L2H11 5.00 2001 16 hu40E9-L5H8 25.44 531 17 hu40E9-L4H8 26.92 255 18 hu40E9-L2H8 27.99 1237 19 hu40E9-L2H15 51.69 796 20 hu40E9-L2H12 72.92 850 twenty one hu40E9-L2H13 83.69 2051 4.4 Jurkat-NFAT- luciferase activation assay

The T cell activation ability of these antibodies was determined by Jurkat NFAT-luciferase activation assay. The benchmark antibody BMK-TCB was used as a positive control and the hIgG1 isotype was used as a negative control. The protocol for the activation assay is described below. a) Serially diluted test antibodies were coated on a 96-well plate for 2 hours at 37°C, 100 μl/well. b) Jurkat-NFAT-luciferase cells were inoculated in each well and incubated for 24 hours, 2×10 ⁴ cells/well. c) The supernatant was removed and the cells were lysed with 25 μL/well of lysis reagent (Promega, RLB-E3971). d) The samples were frozen at -80°C for 30 minutes and then warmed in a biochemical incubator at 37°C for 15 minutes. e) The 96-well plate was then centrifuged at 500 xg for 10 minutes and 20 μL of supernatant from each well was transferred to a new white opaque 96-well plate. f) 100 μL/well of luciferase assay substrate (Promega, E4530) was added to the 96-well plate. g) A microplate reader was used to determine the relative luminescence units (RLU) reflecting the level of luciferase activity.

The values of EC ₅₀ and maximum signal of activation on the same plate were normalized to ch40-C12-C10-E9, and the values of the benchmark antibody BMK-TCB were shown as average values. As shown in Figures 10A-F and Table 24 below, the activation ability of the selected humanized and/or affinity matured antibodies is higher than or similar to the benchmark antibody BMK-TCB. As shown in Figures 17A-E and Table 36 below, the selected humanized and/or affinity matured antibodies have the ability to activate Jurkat-NFAT-luciferase cells, which means that they have T cell activation ability. Table 24. Activation ability of humanized antibodies on Jurkat-NFAT- luciferase cells Sorting antibody EC ₅₀ _fold change Max FACS signal_fold change 1 hu40E9-L3H2 0.57 0.73 2 hu40E9-L3H4 0.61 0.64 3 hu40E9-L2H3-D56G.H 0.65 0.82 4 hu40E9-L2H3-N93W.L 0.72 0.88 5 hu40E9-L2H3-N93S.L 0.74 0.87 6 hu40E9-L2H3-S91R.L 0.79 0.95 7 hu40E9-L2H4 0.80 0.89 8 hu40E9-L2H3-N93R.L 0.81 1.07 9 hu40E9-L2H3-Y102S.H 0.87 0.96 10 ch40-C12-C10-E9 1.00 1.00 11 hu40E9-L2H3-Y54G.H 1.06 0.94 12 hu40E9-L2H3-D99E.H 1.19 0.91 13 hu40E9-L2H3-Y101F.H 1.23 0.94 14 hu40E9-L3H1 1.33 0.97 15 hu40E9-L2H3-N55S.H 1.35 1.03 16 hu40E9-L2H3-D105R.H 1.95 0.81 17 hu40E9-L2H2 2.14 1.28 18 hu40E9-L2H3 2.43 1.18 19 hu40E9-L2H3-D105E.H 3.77 0.74 20 hu40E9-L2H3-G106A.H 4.95 0.99 twenty one hu40E9-L2H1 5.73 1.37 twenty two BMK-TCB 8.17 0.48 Table 36. Activation ability of humanized antibodies on Jurkat-NFAT- luciferase cells antibody EC ₅₀ _fold change Maximum signal_fold change ch40-C12-C10-E9 1.00 1.00 hu40E9-L2H7 1.18 0.77 hu40E9-L2H5 1.29 0.79 hu40E9-L4H3 1.82 1.08 hu40E9-L4H7 1.95 1.12 hu40E9-L2H9 2.49 0.87 hu40E9-L2H11 2.97 0.85 hu40E9-L2H13 3.08 0.51 hu40E9-L5H7 3.41 1.15 hu40E9-L2H14 3.86 0.96 hu40E9-L6H3 4.34 0.95 hu40E9-L2H6 4.57 0.74 hu40E9-L2H16 6.18 1.35 hu40E9-L2H10 12.57 1.01 hu40E9-L2H8 18.35 0.69 hu40E9-L2H12 21.28 0.73 hu40E9-L5H3 23.19 1.47 hu40E9-L2H15 98.56 0.75 hu40E9-L4H8 - 0.32 hu40E9-L5H8 - 0.30 4.5 Human PBMC activation assay

Primary human peripheral blood mononuclear cell (PBMC) based assays were used to determine the activation capacity of humanized antibodies on T cells. It is well known that when T cells are activated, the expression of the surface protein CD25 is upregulated. The benchmark antibody BMK-TCB was used as a positive control, and the hIgG1 isotype was used as a negative control. The experimental procedures used for the activation assay were described in Example 3.6.2, except that the concentration and test antibody used in step (a) were different.

As shown in Figures 11 and 18 below, the positive control BMK-TCB induces upregulation of CD25 on human T cells, as indicated by the subpopulation ratio of CD25 ⁺ cells in CD3 ⁺ T cells. The activation effect of the humanized and/or affinity-matured antibodies is higher than or similar to the benchmark antibody BMK-TCB. Example 5. Humanized Antibody of 147E11E2 : Generation, Affinity Maturation and Antibody Characterization 5.1 Generation of Humanized Antibodies

The chimeric antibody ch147E11E2 was selected as a pure line for humanization. The antibody sequence was aligned with the human germline sequence to identify the most suitable model. Based on the homology with the original mouse antibody sequence, the best matching human germline sequence was selected as the template for humanization. Generally, humanization of antibodies is performed by comparing the IMGT (https://www.imgt.org) human antibody heavy chain and light chain variable strain gene database, selecting heavy chain and light chain variable strain genes with high homology to mouse antibodies as templates, and transplanting the CDR of the mouse antibody into the corresponding human template. The variable region sequence with the order of FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 is formed. If necessary, key amino acids in the framework sequence were reduced and mutated to correspond to the amino acids of the mouse antibody to ensure original affinity.

The immunogenicity risk and hotspots of these generated humanized antibodies were evaluated, and no immunogenicity risk was identified. A hotspot (N55G56 motif) susceptible to deamidation was identified in HCDR2 of 147E11E2 pure humanized antibodies (e.g., hu147E2-L1H3). In order to remove the deamidation site, different mutations were introduced into N55, and it was found that N55 could be mutated to a variety of residues, but still retain specific binding to CD3. For example, it was found that when N55 (relative to the position of SEQ ID NO: 213) was replaced by Q or S, the antibody binding affinity was retained and there was no negative effect on its binding to CD3. Other mutations, such as the G56 mutation, are also considered effective as long as the deamidation site is removed while retaining specific binding to CD3.

By mixing and matching 3 variants of humanized light chain variable regions (i.e., hu147E2-L1, hu147E2-L2, and hu147E2-L3) and 5 variants of humanized heavy chain variable regions (i.e., hu147E2-H2, hu147E2-H3, hu147E2-H3a, hu147E2-H3b, and hu147E2-H4), a total of 11 humanized antibodies were obtained from ch147E11E2. Similarly, the 11 humanized antibodies were named hu147E2-L1H2, hu147E2-L2H2, etc., as shown in Table 28 below. Table 28. Heavy and light chain variable regions of exemplary humanized antibodies for ch147E11E2 VL Area VH Area hu147E2-L1 (SEQ ID NO: 207) hu147E2-L2 (SEQ ID NO: 208) hu147E2-L3 (SEQ ID NO: 209) hu147E2-H2 (SEQ ID NO: 202) hu147E2-L1H2 (SEQ ID NO: 207/202) hu147E2-L2H2 (SEQ ID NO: 208/202) hu147E2-L3H2 (SEQ ID NO: 209/202) hu147E2-H3 (SEQ ID NO: 203) hu147E2-L1H3 (SEQ ID NO: 207/203) hu147E2-L2H3 (SEQ ID NO: 208/203) hu147E2-L3H3 (SEQ ID NO: 209/203) hu147E2-H3a (SEQ ID NO: 204) hu147E2-L1H3a (SEQ ID NO: 207/204) N/A N/A hu147E2-H3b (SEQ ID NO: 205) hu147E2-L1H3b (SEQ ID NO: 207/205) N/A N/A hu147E2-H4 (SEQ ID NO: 206) hu147E2-L1H4 (SEQ ID NO: 207/206) hu147E2-L2H4 (SEQ ID NO: 208/206) hu147E2-L3H4 (SEQ ID NO: 209/206) 5.2 Cell-based binding affinity for Jurkat cells

The binding affinity of the selected humanized 147E11E2 antibodies to the human patient-derived lymphocytic carcinoma cell line Jurkat was determined by FACS analysis. The benchmark antibody BMK-TCB was used as a positive control, and the hIgG1 isotype was used as a negative control. The protocol for FACS analysis was described in Example 3.3, except that the test antibody used in step (c) was different.

As shown in Figure 12 and Table 29 below, the selected humanized 147E11E2 antibody has a higher binding affinity to Jurkat cells than the benchmark antibody BMK-TCB. Table 29. Binding affinity of selected humanized antibodies to Jurkat cells Sorting antibody _EC50 (nM) Maximum FACS signal 1 ch147E11E2 0.6494 2775 2 hu147E2-L3H3 0.6589 2675 3 hu147E2-L3H4 0.6715 2675 4 hu147E2-L3H2 0.8911 2726 5 BMK-TCB 1.347 2366 5.3 Cell-based binding affinity for 293T-cynoCD3mix cells

The binding affinity of the selected humanized antibodies and the reference antibodies to HEK 293T cells stably overexpressing cynomolgus CD3 (293T-cynoCD3mix) was determined by FACS analysis. BMK-TCB was used as a positive control and the hIgG1 isotype was used as a negative control. The protocol for FACS analysis was described in Example 3.4, except that the test antibody used in step (c) was different.

As shown in Figure 13 and Table 30 below, the generated humanized 147E11E2 antibody has a higher binding affinity to 293T-cynoCD3mix cells than the benchmark antibody BMK-TCB. Table 30. Binding affinity of selected humanized antibodies to 293T-cynoCD3mix Sorting antibody EC50(nM) Maximum signal 1 ch147E11E2 1.23 17837 2 hu147E2-L3H4 1.29 16062 3 hu147E2-L1H4 1.31 18693 4 hu147E2-L1H3 1.51 19199 5 hu147E2-L3H3 1.63 18962 6 hu147E2-L2H2 1.64 20532 7 hu147E2-L1H3a 1.66 20682 8 hu147E2-L1H3b 1.68 21141 9 hu147E2-L3H2 1.77 19191 10 hu147E2-L2H3 1.86 21012 11 hu147E2-L1H2 2.01 19743 12 hu147E2-L2H4 2.02 21234 13 BMK-TCB 2.16 12509 5.4 Jurkat-NFAT- luciferase activation assay

The T cell activation capacity of these antibodies was determined by Jurkat NFAT-luciferase activation assay. The benchmark antibody BMK-TCB was used as a positive control, and the hIgG1 isotype was used as a negative control. The protocol used for the activation assay was described in Example 4.4, except that the test antibody used in step (a) was different.

The EC ₅₀ and maximum signal values of activation on the same plate were normalized to ch147E11E2, and the values of the benchmark antibody BMK-TCB were displayed as the average. As shown in Figures 14A-C and Table 31 below, the activation ability of the selected humanized antibodies was higher than that of the benchmark antibody BMK-TCB. Table 31. Activation ability of humanized antibodies on Jurkat-NFAT- luciferase cells Sorting antibody EC ₅₀ _fold change Max FACS signal_fold change 1 ch147E11E2 1.00 1.00 2 hu147E2-L1H4 1.21 0.92 3 hu147E2-L2H4 1.24 0.99 4 hu147E2-L3H3 1.36 0.68 5 hu147E2-L2H2 1.40 0.90 6 hu147E2-L2H3 1.65 0.78 7 hu147E2-L3H2 1.66 0.76 8 hu147E2-L1H3b 1.73 0.87 9 hu147E2-L1H3 1.98 1.00 10 hu147E2-L3H4 2.12 0.60 11 BMK-TCB 2.24 0.50 5.5 Human PBMC activation assay

Primary human peripheral blood mononuclear cell (PBMC) based assays were used to determine the activation capacity of humanized antibodies on T cells. It is well known that when T cells are activated, the expression of the surface protein CD25 is upregulated. The hIgG1 isotype was used as a negative control. The protocol used for the activation assay was described in Example 3.6.2, except that the concentration and test antibody used in step (a) were different.

As shown in FIG. 15 below, the humanized antibody induced upregulation of CD25 on human T cells, as indicated by the subpopulation ratio of CD25 ⁺ cells in CD3 ⁺ T cells.

FIG1 shows the activation ability of several selected antibodies on Jurkat-NFAT-Luc cells.

FIG. 2 shows the results of FACS analysis of the binding affinity of several selected chimeric antibodies and the reference antibody OKT3 to Jurkat cells.

FIG3 shows the results of FACS analysis of the binding affinities of several selected chimeric antibodies and the reference antibodies BMK-B219 and BMK-TCB to Jurkat cells.

FIG. 4 shows the binding affinity of several selected chimeric antibodies to 293T-cynoCD3mix cells.

FIG. 5 shows the activation ability of several selected chimeric antibodies and the reference antibody OKT3 on Jurkat-NFAT-Luc cells.

Figure 6 shows IL-2 release induced by several selected chimeric antibodies and the benchmark antibody OKT3 in a PBMC activation assay.

Figure 7 shows IFNγ release induced by several selected chimeric antibodies and the benchmark antibody OKT3 in a PBMC activation assay.

FIG. 8 shows CD25 expression of CD3+ human T cells induced by several selected chimeric antibodies and benchmark antibodies BMK-B219 and BMK-TCB in a PBMC activation assay.

Figures 9A and 9B show the binding affinity of several generated humanized or affinity matured 40-C12-C10-E9 antibodies to Jurkat cells.

Figures 10A-F show the activation abilities of several humanized or affinity matured 40-C12-C10-E9 antibodies and the benchmark antibody BMK-TCB on Jurkat-NFAT-Luc cells.

FIG. 11 shows the activation effects of several humanized or affinity matured 40-C12-C10-E9 antibodies and the benchmark antibody BMK-TCB in a PBMC activation assay.

FIG. 12 shows the binding affinity of several generated humanized 147E11E2 antibodies to Jurkat cells.

FIG. 13 shows the binding affinity of several generated humanized 147E11E2 antibodies to 293T-cynoCD3mix cells.

Figure 14A-C shows the activation ability of several humanized 147E11E2 antibodies and the benchmark antibody BMK-TCB on Jurkat-NFAT-Luc cells.

FIG. 15 shows the activation effects of several humanized 147E11E2 antibodies and the benchmark antibody BMK-TCB in a PBMC activation assay.

Figures 16A and 16B show the binding affinity of several generated humanized or affinity matured 40-C12-C10-E9 antibodies to Jurkat cells.

Figures 17A-E show the ability of several humanized or affinity matured 40-C12-C10-E9 antibodies to activate Jurkat-NFAT-Luc cells.

FIG. 18 shows the activation effects of several humanized or affinity matured 40-C12-C10-E9 antibodies and the benchmark antibody BMK-TCB in a PBMC activation assay.

TW202413417A_112114072_SEQL.xml

Claims (64)

An antibody or antigen-binding fragment thereof that specifically binds to CD3, comprising: One or two or three heavy chain complementary determining regions (HCDR1, HCDR2 and/or HCDR3), wherein the one or more heavy chain complementary determining regions are contained in any one of the heavy chain variable (VH) region sequences selected from the group consisting of: SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 and 245; and/or One or two or three light chain complementation determining regions (LCDR1, LCDR2 and/or LCDR3), wherein the one or more light chain complementation determining regions are contained in any one of the light chain variable (VL) region sequences selected from the group consisting of: SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 and 232. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment comprises at least one heavy chain or light chain complementation determining region (CDR) comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 17, 18, 19, 20, 21, 22, 25, 26, 27, 28, 29, 30, 33, 34, 35, 36, 37, 38, 41, 42, 43, 44, 45, 46, 49, 50, 51, 52, 53, 54, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 73, 74, 75, 76, 77, 78, 81, 82, 83, 84, 85, 86, 89, 90, 91, 92, 93, 94, 102, 103, 104, 105, 106, 107, 110, 111, 112, 113, 114, 115, 118, 1 19, 120, 121, 122, 123, 126, 127, 128, 129, 130, 131, 134, 135, 136, 137, 138, 139, 142, 143, 144, 145, 146, 147, 150, 151, 152, 153, 154, 155, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 201, 162, 167, 210, 211, 212, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228 and 229. The antibody or antigen-binding fragment thereof of claim 1 or 2, comprising a VH region, the VH region comprising one, two or three of HCDR1, HCDR2 and HCDR3, the HCDR1, HCDR2 and HCDR3 comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 1, 2, 3, 9, 10, 11, 17, 18, 19, 25, 26, 27, 33, 34, 35, 41, 42, 43, 49, 50, 51, 57, 58, 59, 65, 66, 67, 73, 74, 75, 81, 82, 83, 89, 90, 91, 102, 103, 104, 110, 111, 112, 118, 119, 120, 126, 127, 128, 134, 135, 136, 142, 143, 144, 150, 151, 152, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 201, 162, 210, 211, 212, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228 and 229. The antibody or antigen-binding fragment thereof of any of the preceding claims, comprising a VL region, wherein the VL region comprises one, two or three of LCDR1, LCDR2 and LCDR3, wherein the LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from the group consisting of: SEQ ID NO: 4, 5, 6, 12, 13, 14, 20, 21, 22, 28, 29, 30, 36, 37, 38, 44, 45, 46, 52, 53, 54, 60, 61, 62, 68, 69, 70, 76, 77, 78, 84, 85, 86, 92, 93, 94, 105, 106, 107, 113, 114, 115, 121, 122, 123, 129, 130, 131, 137, 138, 139, 145, 146, 147, 153, 154, 155, 182, 183, 184, 185, 167, 214, 215 and 216. An antibody or antigen-binding fragment thereof as claimed in any of the preceding claims, comprising: i. HCDR1, wherein the HCDR1 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 1, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 102, 110, 118, 126, 134, 142, 150, 217, 218 and 219; ii. HCDR2, wherein the HCDR2 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 2, 10, 18, 26, 34, 42, 50, 58, 66, 74, 82, 90, 103, 111, 119, 127, 135, 143, 151, 171, 172, 173, 201, 210, 211, 212, 220 and 222; and iii. HCDR3, the HCDR3 comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 104, 112, 120, 128, 136, 144, 152, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228, 229 and 162. An antibody or antigen-binding fragment thereof as claimed in any of the preceding claims, comprising: i. LCDR1, wherein LCDR1 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 84, 92, 105, 113, 121, 129, 137, 145 and 153; ii. LCDR2, wherein LCDR2 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 5, 13, 21, 29, 37, 45, 53, 61, 69, 77, 85, 93, 106, 114, 122, 130, 138, 146 and 154; and iii. LCDR3, wherein LCDR3 comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 6, 14, 22, 30, 38, 46, 54, 62, 70, 78, 86, 94, 107, 115, 123, 131, 139, 147, 155, 182, 183, 184, 185, 214, 215, 216 and 167. An antibody or antigen-binding fragment thereof as claimed in any of the preceding claims, comprising: i.    HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 1, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 2, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 3; ii.   HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11; iii.  HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 17, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 18, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 19; iv. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 25, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 26, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 27; v. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 33, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 34, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 35; vi. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 41, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 42, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 43; vii. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 49, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 50, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 51; viii. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 57, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 58, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 59; ix. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 65, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 66, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 67; x. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 73, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 74, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 75; xi.  HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 81, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 82, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 83; xii. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 89, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 90, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 91; xiii. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 102, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 103, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 104; xiv. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 110, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 111, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 112; xv. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 118, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 119, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 120; xvi. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 126, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 127, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 128; xvii. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 134, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 135, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 136; xviii.  HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 142, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 143, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 144; xix.   HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 151, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152; xx.     HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 219, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 201, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 162; xxi.    HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, 217 or 218, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, 171, 172, 173, 220 or 222, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: NO: 11, 174, 175, 176, 177, 178, 179, 180, 181, 221, 223, 224, 225, 226, 227, 228 or 229; xxii.   HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 212, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 152; xxiii.  HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 210, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 152; or xxiv. HCDR1, HCDR2 and HCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 211, and the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152. An antibody or antigen-binding fragment thereof as claimed in any of the preceding claims, comprising: i. LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 4, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 5, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 6; ii. LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; iii. LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 20, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 21, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 22; iv.   LCDR1, LCDR2 and LCDR3, the LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 28, the LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 29, and the LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 30; v.     LCDR1, LCDR2 and LCDR3, the LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 36, the LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 37, and the LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 38; vi.   LCDR1, LCDR2 and LCDR3, the LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 44, the LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 45, and the LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 46; vii. LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 52, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 53, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 54; viii. LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 60, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 61, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 62; ix.    LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 68, LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 69, and LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 70; x.     LCDR1, LCDR2 and LCDR3, wherein LCDR1 comprises the amino acid sequence shown in SEQ ID NO: NO: 76, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 77, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 78; xi.    LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 84, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 85, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 86; xii.   LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 92, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 93, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 94; xiii.  LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 105, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 106, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 107; xiv. LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 113, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 114, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 115; xv.   LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 121, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 122, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 123; xvi.  LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 129, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 130, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 131; xvii. LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 137, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 138, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 139; xviii.  LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 145, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 146, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 147; xix.  LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155; xx.   LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 167; or xxi.  LCDR1, LCDR2 and LCDR3, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14, 182, 183, 184, 185, 214, 215 or 216. The antibody or antigen-binding fragment thereof of any of the preceding claims, comprising: i. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 1, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 2, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 3, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 4, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 5, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 6; ii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 10, and the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; iii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 17, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 18, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 19, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 20, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 21, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 22; iv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 2 v. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 33, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 34, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 35, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 36, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 37, the LCDR3 comprising the amino acid sequence of SEQ ID NO: 38; v. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 34, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 35, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 36, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 37, the LCDR3 comprising the amino acid sequence of SEQ ID NO: vi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 41, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 42, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 43, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 44, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 45, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 46; vii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 49, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 50, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 51, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: NO: 52, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 53, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 54; viii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 57, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 58, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 59, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 60, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 61, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 62; ix. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 65, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 66, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 67, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 68, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 69, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 70; x. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 73, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 74, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 75, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 76, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 77, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: xi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 81, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 82, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 83, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 84, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 85, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 86; xii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 89, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 90, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 91, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 92, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 93, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 94; xiii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 102, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 103, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 104, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 105, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 106, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 107; xiv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 110, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 111, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 112, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 113, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 114, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 115; xv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 118, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 119, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 120, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 121, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 122, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 123; xvi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 126, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 127, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 128, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 129, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 130, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 131; xvii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 134, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: xviii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 142, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 143, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 144, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 145, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 146, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 147; xviii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 142, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 143, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 144, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 145, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 146, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 147; xix. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 150, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 151, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 152, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 153, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 154, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 155; xx. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 171, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; xxi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; xxii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; xxiii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 174, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xxiii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 174, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xxiv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 175, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 14; xxv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 176, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: xxvi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 177, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xxvii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 177, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xxvii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: xxviii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 179, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xxviii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 179, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: xxix.HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 180, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 14; xxx.HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: xxxi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 182; xxxii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 183; xxxiii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: xxxiv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, the LCDR3 comprising the amino acid sequence of SEQ ID NO: 185; xxxv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: xxxvi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 221, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xxxvi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 222, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, the LCDR3 comprising the amino acid sequence of SEQ ID NO: xxxvii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 222, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 180, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 14; xxxviii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 172, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: xxxix. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 171, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 224, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xxxix. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 171, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 224, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xl. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 11, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 214; xli. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 215; xlii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 216; xliii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 222, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 214; xliv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 222, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 180, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 215; xlv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 172, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 223, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 214; xlvi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 172, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 223, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 215; xlvii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: xlviii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 226, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xlviii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 226, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; xlix.HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 227, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 14; l.HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 9, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 228, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; li. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 174, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14; lii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 9, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 10, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 174, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 14. liii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence of SEQ ID NO: 217, the HCDR2 comprising the amino acid sequence of SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence of SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence of SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence of SEQ ID NO: 14; liv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 218, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 10, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 11, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 13, and the LCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 14; lv. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 219, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 201, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 162, the LCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 12, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 13, the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 167; lvi. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence shown in SEQ ID NO: 212, the HCDR3 comprises the amino acid sequence shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence shown in SEQ ID NO: 153, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO: 154, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155; lvii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 150, the HCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 210, the HCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 153, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: 154, and the LCDR3 comprises the amino acid sequence as shown in SEQ ID NO: 155; or lviii. HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, the HCDR1 comprising the amino acid sequence as shown in SEQ ID NO: 150, the HCDR2 comprising the amino acid sequence as shown in SEQ ID NO: 211, the HCDR3 comprising the amino acid sequence as shown in SEQ ID NO: 152, the LCDR1 comprises the amino acid sequence as shown in SEQ ID NO: 153, the LCDR2 comprises the amino acid sequence as shown in SEQ ID NO: The LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 154, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO: 155. The antibody or antigen-binding fragment thereof of any of the preceding claims, comprising a VH region having an amino acid sequence as shown in SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 or 245, or a VH region having an amino acid sequence as shown in SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 108, 116, 124, 132, 140, 148, 156, 163, 164, 165, 166, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 213, 202, 203, 204, 205, 206, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244 or 245 has a homologous sequence with at least 80% sequence identity. The antibody or antigen-binding fragment thereof of any of the preceding claims, comprising a VL region having an amino acid sequence as shown in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 or 232, or a VL region having an amino acid sequence as shown in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 109, 117, 125, 133, 141, 149, 157, 168, 169, 170, 197, 198, 199, 200, 207, 208, 209, 230, 231 or 232 has a homologous sequence with at least 80% sequence identity. The antibody or antigen-binding fragment thereof of any of the preceding claims, comprising a VH/VL amino acid sequence pair selected from the group consisting of SEQ ID NO: 7/8, 15/16, 23/24, 31/32, 39/40, 47/48, 55/56, 63/64, 71/72, 79/80, 87/88, 95/96, 108/109, 116/117, 124/125, 132/133, 140/141, 148/149, 156/157, 163/168, 163/169, 163/1 70, 164/168, 164/169, 164/170, 165/168, 165/169, 165/170, 166/168, 166/169, 166/170, 186/169, 187/169, 188/169, 189/169, 190/169, 191/169, 192/169, 193/169, 194/169, 1 95/169、196/169、165/197、165/198、165/199、165/200、202/207、202/208、202/209、203/207、203/208、203/209、204/207、205/207、206/207、206/208、206/209、233/169、234/ 169, 235/169, 236/169, 237/169, 238/169, 239/169, 240/169, 241/169, 242/169, 243/169, 244/169, 245/169, 165/230, 165/231, 165/232, 235/230, 235/231, 236/230 and 236/231. The antibody or antigen-binding fragment thereof according to any of the preceding claims, further comprising one or more amino acid residue substitutions or modifications, but still retaining specific binding affinity for CD3. An antibody or antigen-binding fragment thereof as claimed in claim 13, wherein at least one of the substitutions or modifications is located in one or more CDR sequences of the VH region or VL region. An antibody or antigen-binding fragment thereof as claimed in claim 13, wherein at least one of the substitutions or modifications is located in one or more non-CDR sequences of the VH region or VL region. The antibody or antigen-binding fragment of any of the preceding claims, further comprising one or more non-natural amino acid (NNAA) substitutions. The antibody or antigen-binding fragment of claim 16, wherein the NNAA is capable of being bound. An antibody or antigen-binding fragment thereof as claimed in any of the preceding claims, which has one or more properties for CD3, the one or more properties being selected from the group consisting of: i. capable of specifically binding to human CD3 (e.g., as measured by FACS assay); ii. capable of binding to both human CD3 and cynomolgus macaque CD3 (e.g., as measured by FACS assay); iii. capable of T cell activation (e.g., as measured by Jurkat NFAT-luciferase activation assay); and iv. capable of PBMC activation (e.g., as measured by ELISA assay). An antibody or an antigen-binding fragment thereof, which competes with the antibody or antigen-binding fragment thereof of any of the preceding claims for binding to CD3. The antibody or antigen-binding fragment thereof of any of the preceding claims, which is a chimeric antibody, a humanized antibody or a human antibody or an antigen-binding fragment thereof. The antibody or antigen-binding fragment thereof of any of the preceding claims, which is a labeled antibody, a bivalent antibody, an anti-idiotypic antibody or a fusion protein. The antibody or antigen-binding fragment thereof of any of the preceding claims, which is a diabody, Fab, Fab', F(ab') ₂ , Fd, Fv fragment, disulfide-stabilized Fv fragment (dsFv), (dsFv) ₂ , bispecific dsFv (dsFv-dsFv'), disulfide-stabilized bifunctional antibody (ds diabody), single chain antibody molecule (scFv), scFv dimer (bivalent bifunctional antibody), camellized single domain antibody, nanobody, domain antibody or bivalent domain antibody. The antibody or antigen-binding fragment thereof of any of the preceding claims, further comprising an Fc region, optionally an Fc region of a human immunoglobulin (Ig), or optionally an Fc region of a human IgG. The antibody or antigen-binding fragment thereof of claim 23, wherein the Fc region is derived from human IgG1, IgG2, IgG3 or IgG4. The antibody or antigen-binding fragment thereof of claim 24, wherein the Fc region comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 97-99. The antibody or antigen-binding fragment thereof of any of the preceding claims, wherein the light chain is a lambda light chain or a kappa light chain. The antibody or antigen-binding fragment thereof of any of the preceding claims, which is a bispecific antibody or a multispecific antibody or an antigen-binding fragment thereof. The antibody or antigen-binding fragment thereof of claim 27, which is capable of specifically binding to one or more additional antigens other than CD3, or a second epitope on CD3. The antibody or antigen-binding fragment thereof of claim 28, wherein the one or more additional antigens other than CD3 are selected from the group consisting of: CD16a, CD33, CD38, CD45, CD123, CD146, CD228, CLL-1, FLT3, FLT3L, TAF1, TgPRF, HVCN1, IL-6R, IL-11R, IL17A, IL-23R, IL-33, ILDR2, LAP, TSLP , TREM-1, ANGPT2, APOE, IFNAR, CypA, DOG-1, NKp30, CSF-1R, CCR2, LRRC15, mesothelin, Dickkopf2, DLL3, HER-2, C10orf54, TrkA, MEKK1, KRAS, ERK, XPO1, mTORC1/2, PAK4, NAMPT, ATR, EGFR, FGFR, VEGF, LILRB (e.g., LILRB1, LILRB2, LILRB3, LILRB4, LILRB5), c-MET, Her2, Her3, CTLA4, GITA, CD112R, CD2, CD7, CD16, CD19, CD20, CD24, CD27, CD30, CD34, CD37, CD39, CD70, CD73, CD83, CD28, CD80 (B7-1), CD86 (B7-2), CD40, CD40L (CD154), CD47, SIRPα, CD122, CD137, CD137L, OX40 (CD134), OX40L (CD252), BCMA (e.g., BCMA02), PSMA, CLDN18 (e.g., CLDN18.2), NKG2C, 4-1BB, LIGHT, PVRIG, SLAMF7, HVEM, BAFFR, ICAM-1, 2B4, LFA-1, GITR, ICOS (CD278), ICOSLG (CD275), LAG3 (CD223), A2AR, B7-H3 (CD276), B7-H4 (VTCN1), B7-H5, BTLA (CD272), CD160, CTLA-4 (CD152), GPRC5D, IDO (e.g., IDO1, IDO2), ILT3, TDO, KIR, LAIR-1, NOX2, PD-1, PD-L1, PD-L2, TIM-3, VISTA, SIGLEC-7 (CD328), SIGLEC-9 (CD329), SIGLEC-15, TIGIT, PVR (CD155), TLR3, CLEC9A, DEC-205, STING and TGFβ. An antibody or antigen-binding fragment thereof as claimed in any preceding claim, linked to one or more binding moieties. The antibody or antigen-binding fragment thereof of claim 30, wherein the binding moiety comprises a scavenging modifier, a chemotherapeutic agent, a toxin, a radioisotope, a lanthanide, a detectable marker, a DNA alkylating agent, a topoisomerase inhibitor, a microtubule binding agent, a purified moiety or other anticancer drug. The antibody or antigen-binding fragment thereof of claim 30 or 31, wherein the binding moiety is covalently linked directly or via a linker. A chimeric antigen receptor, comprising the antibody or antigen-binding fragment of any one of claims 1 to 29, a transmembrane region and an intracellular signaling region. The chimeric antigen receptor of claim 33, wherein the transmembrane region comprises the transmembrane region of CD3, CD4, CD8 or CD28. The chimeric antigen receptor of claim 33, wherein the intracellular signaling region is selected from the group consisting of: intracellular signaling region sequences of CD3, FcγRI, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, TLR, or a combination thereof. The chimeric antigen receptor of any one of claims 33 to 35, wherein the antigen binding fragment is scFv. The chimeric antigen receptor of any one of claims 33 to 36, wherein the chimeric antigen receptor is transplanted into allogeneic cells, autologous cells or xenogeneic cells. A chimeric antigen receptor as claimed in any one of claims 33 to 37, wherein the chimeric antigen receptor is transplanted into immune effector cells. The chimeric antigen receptor of any one of claims 33 to 38, wherein the chimeric antigen receptor is transplanted into T cells, natural killer cells, macrophages or tumor infiltrating lymphocytes. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof according to any one of claims 1 to 32, or the chimeric antigen receptor according to any one of claims 33 to 39, and one or more pharmaceutically acceptable carriers. An isolated polynucleotide encoding the antibody or antigen-binding fragment thereof of any one of claims 1 to 29, and/or the chimeric antigen receptor of any one of claims 33 to 39. A vector comprising the isolated polynucleotide of claim 41. A host-expression system comprising the vector of claim 42, or having the polynucleotide of claim 41 integrated into its genome. The host expression system of claim 43, which is a microorganism, a yeast or a mammalian cell, wherein the microorganism is selected from the group consisting of Escherichia coli and Bacillus subtilis, wherein the yeast is of the genus Saccharomyces , and wherein the mammalian cell is selected from the group consisting of COS, CHO-S, CHO-K1, HEK-293 and 3T3 cells. A virus comprising the vector of claim 42. A kit comprising the antibody or antigen-binding fragment thereof of any one of claims 1 to 29 and/or the chimeric antigen receptor of any one of claims 33 to 39 and/or the pharmaceutical composition of claim 40, and a second therapeutic agent. A method for expressing an antibody or antigen-binding fragment thereof as described in any one of claims 1 to 29 or a chimeric antigen receptor as described in any one of claims 33 to 39, comprising culturing a host expression system as described in claim 43 under conditions for expressing the antibody or antigen-binding fragment thereof as described in any one of claims 1 to 29 or a chimeric antigen receptor as described in any one of claims 33 to 39. A method for treating, preventing or alleviating a disease, disorder or condition in an individual, comprising administering to the individual a therapeutically effective amount of an antibody or antigen-binding fragment thereof as described in any one of claims 1 to 32 and/or a chimeric antigen receptor as described in any one of claims 33 to 39 and/or a pharmaceutical composition as described in claim 40. The method of claim 48, wherein the disease, disorder or condition is an immune disease, an inflammatory disease, cancer or a nervous system disease. The method of claim 49, wherein the cancer is a solid tumor or a hematological tumor. The method of any one of claims 48 to 50, wherein the disease, disorder or condition is selected from the group consisting of lung cancer (e.g., non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), lung adenocarcinoma or lung squamous cell carcinoma), peritoneal cancer, carcinoid, bone cancer, pancreatic cancer, primitive neuroectodermal tumor, skin cancer, gallbladder cancer, head and neck cancer, squamous cell carcinoma, uterine cancer, ovarian cancer, rectal cancer, prostate cancer, bladder cancer (e.g., urothelial carcinoma), anal region cancer (e.g., anal squamous cell carcinoma), stomach cancer or gastric cancer (e.g., gastrointestinal cancer), esophageal cancer, colorectal cancer, breast cancer, uterine cancer, liver cancer (e.g., hepatoblastoma, hepatocellular carcinoma/hepatocellular carcinoma or hepatocellular carcinoma), bile duct cancer , sarcoma, colorectal cancer, fallopian tube cancer, salivary gland cancer, cervical cancer, endometrial cancer or uterine cancer, osteosarcoma, vaginal cancer, vulvar cancer, esophageal cancer, small intestine cancer, endocrine system cancer, thyroid cancer, parathyroid cancer, adrenal cancer, nasopharyngeal cancer, soft tissue sarcoma, polycythemia vera, urethral cancer, penile cancer, kidney or ureteral cancer (e.g., renal transverse myeloid tumor), cutaneous T-cell lymphoma, medulloblastoma, nephroblastoma, myeloproliferative syndrome, chronic and nonchronic myeloproliferative disorders, choroidal papilloma, renal cell carcinoma, renal pelvic carcinoma, central nervous system (CNS) tumors, soft tissue sarcomas (e.g., rhabdomyosarcoma, fibrosarcoma, Kaposi's sarcoma, sarcoma), spinal axonal tumors, neurogliomas (e.g., ependymomas, astrocytomas, anaplastic astrocytomas, oligodendrogliomas, eye cancers (e.g., retinoblastomas), brain stem neurogliomas, or mixed neurogliomas such as oligoastrocytomas), brain tumors (e.g., glioblastoma/glioblastoma multiforme (GBM), non-glioblastic brain tumors, or meningiomas), melanomas (e.g., cutaneous or intraocular melanomas), thrombocythaemia, mesothelioma, mycosis fungoides, Sezary syndrome syndrome), idiopathic myelofibrosis, solitary plasmacytoma, vestibular schwannoma, Ewing's sarcoma, chondrosarcoma, MYH-related polyposis, pituitary adenoma, pediatric cancers such as pediatric sarcomas (e.g., neuroblastoma, rhabdomyosarcoma, and osteosarcoma), blood cancers, Hodgkin's lymphoma, lymphoma), non-Hodgkin's lymphoma, leukemia (e.g., lymphocytic/lymphoblastic leukemia), chronic or acute leukemia, mast cell leukemia, lymphocytic lymphoma, primary CNS lymphoma, chronic lymphocytic leukemia (CLL), acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), acute myeloid leukemia (AML), chronic myelomonocytic leukemia (CMML), chronic lymphoblastic leukemia, acute lymphoblastic leukemia, hairy cell leukemia (HCL), Burkitt's lymphoma (BL), multiple myeloma (e.g., relapsed or refractory multiple myeloma), T-cell lymphoma or B-cell lymphoma, mantle cell lymphoma (MCL) (e.g., relapsed or refractory mantle cell lymphoma), malignant melanoma, diffuse large B-cell lymphoma (DLBCL), DLBCL arising from follicular lymphoma, high-grade B-cell lymphoma, primary vertebral large B-cell lymphoma, follicular lymphoma (FL), and primary vertebral B-cell lymphoma. The method of any one of claims 48 to 51, wherein the individual is a human. The method of any one of claims 48 to 52, wherein the administration is by a parenteral route, including subcutaneous, intraperitoneal, intravenous, intramuscular or intradermal injection; or a non-parenteral route, including transdermal, oral, intranasal, intraocular, sublingual, rectal or topical. The method of any one of claims 48 to 53, further comprising administering an additional therapeutic agent to the individual in need thereof. The method of claim 54, wherein the additional therapeutic agent is selected from the group consisting of: an active agent, an imaging agent, a cytotoxic agent, an angiogenesis inhibitor, a kinase inhibitor, a co-stimulatory molecule agonist, a co-inhibitory molecule inhibitor, an adhesion molecule inhibitor, an anti-cytokine antibody or a functional fragment thereof, a detectable marker or reporter, an antimicrobial agent, a gene editing agent, a β agonist, a viral RNA inhibitor, a polymerase inhibitor, an interferon, and a microRNA. The method of claim 54, wherein the additional therapeutic agent is administered to the individual in need before, after or simultaneously with the antibody or antigen-binding fragment thereof of any one of claims 1 to 32 and/or the chimeric antigen receptor of any one of claims 33 to 39 and/or the pharmaceutical composition of claim 40. A method for activating T cells expressing CD3 in vivo or in vitro, comprising contacting the T cells expressing CD3 with the antibody or antigen-binding fragment thereof of any one of claims 1 to 32 and/or the chimeric antigen receptor of any one of claims 33 to 39 and/or the pharmaceutical composition of claim 40. A method for modulating CD3 activity in a cell expressing CD3, comprising exposing the cell expressing CD3 to the antibody or antigen-binding fragment thereof of any one of claims 1 to 32 and/or the chimeric antigen receptor of any one of claims 33 to 39 and/or the pharmaceutical composition of claim 40. A method for promoting a CD3-expressing T cell to process a second antigen in vivo or in vitro, comprising contacting the CD3-expressing T cell with a bispecific antibody or a multispecific antibody or an antigen-binding fragment thereof as described in any one of claims 27 to 32, wherein the bispecific antibody or the multispecific antibody or the antigen-binding fragment thereof is capable of binding to both the CD3-expressing T cell and the second antigen, thereby bringing the two into proximity. A method for detecting the presence or amount of CD3 in a sample, comprising contacting the sample with an antibody or antigen-binding fragment thereof as described in any one of claims 1 to 32 and/or a chimeric antigen receptor as described in any one of claims 33 to 39 and/or a pharmaceutical composition as described in claim 40, and determining the presence or amount of CD3 in the sample. A method for diagnosing a CD3-related disease or condition in an individual, comprising: a) contacting a sample obtained from the individual with an antibody or antigen-binding fragment thereof as described in any one of claims 1 to 32 and/or a chimeric antigen receptor as described in any one of claims 33 to 39 and/or a pharmaceutical composition as described in claim 40; b) determining the presence or amount of CD3 in the sample; and c) correlating the presence or amount of CD3 in the individual with the presence or status of the CD3-related disease or condition. Use of an antibody or antigen-binding fragment thereof as claimed in any one of claims 1 to 32 and/or a chimeric antigen receptor as claimed in any one of claims 33 to 39 and/or a pharmaceutical composition as claimed in claim 40 in the preparation of a medicament for treating a CD3-related disease, disorder or condition in an individual. Use of an antibody or an antigen-binding fragment thereof as claimed in any one of claims 1 to 32 and/or a chimeric antigen receptor as claimed in any one of claims 33 to 39 and/or a pharmaceutical composition as claimed in claim 40 in the preparation of a diagnostic reagent for diagnosing a CD3-related disease, disorder or condition. A kit comprising an antibody or an antigen-binding fragment thereof as described in any one of claims 1 to 32 and/or a chimeric antigen receptor as described in any one of claims 33 to 39 and/or a pharmaceutical composition as described in claim 40, for detecting CD3, optionally recombinant CD3, CD3 expressed on the surface of a cell, or a cell expressing CD3.