CN113861295A

CN113861295A - anti-PD-1 antibodies and uses thereof

Info

Publication number: CN113861295A
Application number: CN202111394016.1A
Authority: CN
Inventors: 黄承浩; 熊丹; 林超龙; 游敏; 罗文新; 张军; 夏宁邵
Original assignee: Yang Sheng Tang Co Ltd; Xiamen University
Current assignee: Yang Sheng Tang Co Ltd; Xiamen University
Priority date: 2018-07-20
Filing date: 2019-07-19
Publication date: 2021-12-31
Anticipated expiration: 2039-07-19
Also published as: CN110734493B; CN110734493A; CN113861295B

Abstract

The present invention relates to the field of disease therapy and immunology, in particular, the present invention relates to antibodies or antigen-binding fragments thereof against PD-1, nucleic acid molecules encoding them, methods for preparing them, and pharmaceutical compositions comprising them. The invention further relates to the use of said antibody, in particular a humanized antibody, or an antigen binding fragment thereof, for the preparation of a medicament for increasing the activity of an immune cell, for enhancing an immune response, or for the prevention and/or treatment of a tumor or an infection.

Description

anti-PD-1 antibodies and uses thereof

The application is a divisional application of an invention application with the application number of 201910654839.X, the application date of 2019, 07 and 19, and the invention name of the invention application is 'anti-PD-1 antibody and application thereof'.

Technical Field

Background

The activation process of T cells requires two signals: firstly, the antigen peptide combined with MHC presented by APCs of antigen presenting cells is crosslinked with a cell receptor on the surface of T cells to generate a first stimulation signal, and the signal has antigen specificity; the second stimulation signal provided by the binding of the APCs surface molecule (such as B7 family) and the corresponding T cell surface molecule (such as CD28) mainly comprises two co-stimulatory factors for activating T cells and co-inhibitory factors for regulating T cells not to be over-stimulated, and is non-antigen-specific, but is necessary for the antigen-specific activation of T cells, and determines whether the antigen-stimulated T cells enter a proliferation and differentiation process called effector T cells or enter an inhibition state or apoptosis.

Programmed death molecule (PD-1; also known as CD279), which is an immunosuppressive molecule in a CD28 family member, plays an important role in maintaining immune tolerance of the body and has the function of protecting the body from being attacked by the autoimmune system. The PD-1 gene was cloned from the mouse apoptotic stage T-cell hybridoma 2B4.11 by a subtractive hybridization technique in 1992 by Ishida et al (Ishida Y, Agrata Y, et al, induced expression of PD-1, a novel member of the immunoglobulin gene family, upon programmed cell death [ J ]. EMBO J,1992,11(11): 3887-3895). PD-1 is composed of 288 amino acids, has a molecular weight of 50-55kDa, belongs to type I transmembrane protein, is one of CD28 family members, and has a gene Pcdd 1 positioned on mouse chromosome 1and human chromosome 2. PD-1 exists on the surface of the cell membrane in a monomeric form due to the lack of cysteine residues at the membrane proximal end. PD-1 contains an IgV-like region in the extracellular domain, the cytoplasmic domain contains 2 tyrosine residues, and the IgV-like region and the cytoplasmic domain are respectively connected with an Immunoreceptor Tyrosine Inhibition Motif (ITIM) and an immunoreceptor tyrosine transformation motif (ITSM), and the point mutation result shows that the ITSM motif plays an important role in PD-1signaling (Keir M E, button M J, et al. PD-1and its ligands in signaling and immunity [ J ]. Annu Rev 704 Immunol,2008,26: 677-.

PD-1 is expressed primarily on the surface of activated T cells, B cells, natural killer T cells, monocytes and dendritic cells. The resting T cells do not express PD-1 on their surface, but are activated to induce expression. After T cells are activated, PD-1 expression on the cell surface can be detected within 24h, and after binding to its ligand, a functional effect can be exerted within a few hours (Riley J L. PD-1signaling in primary T cells [ J ]. Immunol Rev,2009,229(1): 114-. PD-1 has two ligands, PD-L1 (also known as B7-H1, CD274) and PD-L2 (also known as B7-DC, CD273), which are found in 1999 and 2001 respectively, belong to B7 family I transmembrane proteins, and the extracellular domain has IgV and IgC domains. PD-L1 is expressed encoded by the gene CD274, 290 amino acids in total, which maps to mouse chromosome 19 and human chromosome 9. PD-L2 is encoded and expressed by gene Pdcd1lg2, which has 247 amino acids, and the gene is located on the same chromosome as the gene encoding PD-L1.

PD-L1 is expressed in both hematopoietic and non-hematopoietic cells. PD-L1 is constitutively expressed at high levels in T cells, B cells, dendritic cells, macrophages, mesenchymal stem cells and myeloid mast cells, and continues to upregulate expression upon cell activation. In some nonhematopoietic cells, mainly solid tumors such as kidney, ovarian cancer and non-small cell lung cancer, etc., PD-L1 also exhibits high expression level due to the abnormality of tumor signaling pathway or the induction of tumor cells by external signals. It has also been found that type I and type II interferons also cause immune cells to upregulate the expression of PD-L1 (Francisco L M, Sage P.T., et al. the PD-1pathway in toll and autoimmunity [ J ]. Immunol Rev,2010,236: 219-242). Compared with PD-L1, the expression profile of PD-L2 is relatively narrow, and usually is not expressed on the surface of resting cells, mainly expressed in myeloid DC cells, macrophage myeloid-derived mast cells and part of B cell lines, and is limited in expression in peripheral tissues and other cell types. Studies have also found that the effect of PD-L2 in inhibiting T cell activity is lower than that of PD-L1(Latchman Y, et al. PD-L2 is a second ligand for PD-1and inhibitors T cell activation [ J ]. Nat Immunol,2001,2(3): 261-268).

The molecular mechanism of PD-1 to inhibit T cell activity is primarily through the PI3K/Akt signaling pathway. After binding of PD-1and PD-L1/PD-L2 on the surface of T cell, tyrosine of ITIM and ITSM in PD-1 membrane domain is phosphorylated, dephosphorylating enzyme SHP-2, dephosphorylating TCR complex containing SH2 homologous domain is recruited, phosphorylation of CD3 zeta, ZAP70, PKC theta is inhibited, and further phosphorylation of PI3K is inhibited, so that phosphorylation of Akt is inhibited, leading to down-regulation expression of cytokines IL-2, IFN-gamma, and inhibition of activity, proliferation and cytokine expression of T cell (Chemnitz J M, Parry R V, et al, SHP-1and SHP-2 association with expression promoter type switched expression of expressed receptor 1 uplink immune man T cell stimulation, butyl receptor expression J2J) 954, et al.

In addition to the regulation and maintenance of autoimmune tolerance, PD-1/PD-L1 signals induce high expression of PD-L1 on the cell surface following viral invasion in patients with chronic infectious diseases, such as Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), and the like, leading to T cell apoptosis or failure. In tumor patients, high expression of PD-L1 can enhance tumor growth and metastatic ability, and thus can be used as an indicator of tumor patient prognosis (Ceraz S, Nowak E C, et al. B7 family checkpoint regulators in tumor regulation and disease [ J ]]Trends Immunol,2013,34(11): 556-563). It was found that various tumor cells highly express PD-L1, such as melanoma, non-small cell lung cancer, ovarian cancer, renal cell carcinoma, lymphoma, gastric cancer, liver cancer, breast cancer, pancreatic cancer, esophageal cancer, bladder cancer, liver cancer and the like (Chen L, Han, X.anti-PD-1/PD-L1 therapy of human cancer: past, present, and future [ J]J Clin Invest,2015,125(9): 3384-. In addition, tumor site invasive CD8⁺PD-1 is also highly expressed on the surface of the T cell, and the PD-1 interacts with PD-L1 on the surface of the tumor cell, so that the activation and the proliferation of the T cell are inhibited, the killing effect of the T cell on the tumor cell is lost, and the immune escape is caused. Therefore, the signal path of PD-1/PD-L1 is blocked in a targeted manner, and the killing of T cells to infectious disease pathogens and tumor cells can be enhanced. Currently, several anti-PD-1 and PD-L1 monoclonal antibody drugs have been approved by the FDA for cancer therapy with good clinical therapeutic efficacy (Sunshine J, Taube J M. PD-1/PD-L1 inhibitors [ J)]Curr Opin Pharmacol,2015,23: 32-38). By 2 months 2018, Pembrolizumab and Nivolumab have been approved by the U.S. FDA for useThe clinical treatment of nearly ten malignant tumors including non-small cell lung cancer, head and neck cancer, melanoma, bladder cancer, kidney cancer, Hodgson lymphoma, urothelial cancer and gastric cancer.

Although PD-1 antibody tumor immunotherapy has achieved a certain degree in recent years, analysis of PD-1 antibodies which have entered domestic clinical research on tumor therapy shows that the characteristics and functions of different PD-1 antibodies and the effect of tumor therapy are different due to heterogeneity of amino acid sequences, especially CDR sequences, of the antibodies. In general, existing PD-1 antibodies have the defects of certain toxic and side effects and obviously limited therapeutic dose in partial population, which greatly weakens the clinical therapeutic effect and universality of the PD-1 antibodies and causes certain safety hazards (Michot J M, Bigenwald C, et al.

Therefore, the development of anti-PD-1 antibodies with higher specificity, lower toxic and side effects and better clinical efficacy is urgent and necessary, which provides more medication options for patients with cancer, infection and other diseases.

Disclosure of Invention

In the present application, the inventors first developed a murine antibody with superior properties, which is capable of specifically recognizing/binding to human PD-1, blocking the binding of PD-1 to its ligand PD-L1, and is capable of enhancing immune cell activity in vitro/in vivo, stimulating immune response. Therefore, the murine antibody has potential for use in the prevention and/or treatment of tumors or infections.

On the basis, the inventor carries out a great deal of creative work, and carries out intensive research and modification on the murine antibody, thereby developing a humanized antibody of the murine antibody: the humanized antibody of the present invention has not only a very high degree of humanization but also substantially the same biological function as the murine antibody.

Thus, the antibodies (particularly humanized antibodies) of the invention are highly advantageous, not only retaining the functions and properties of the parent murine antibody, thereby having potential for the prevention and treatment of tumors or infections; but also has a high degree of humanisation so that it can be safely administered to human subjects without eliciting an immunogenic response. The antibody of the invention has great clinical value.

Antibodies of the invention

Accordingly, in one aspect, the invention provides an antibody or antigen-binding fragment thereof capable of specifically binding to PD-1, said antibody or antigen-binding fragment thereof comprising:

(a) the following 3 heavy chain variable region (VH) Complementarity Determining Regions (CDRs):

(i) a VH CDR1 having the sequence of CDR1 contained in VH as shown in any one of SEQ ID NOs:1, 9, 17, 25, or a sequence having substitution, deletion or addition of one or several amino acids (e.g. substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR1 contained in said VH;

(ii) a VH CDR2 having the sequence of CDR2 contained in VH as shown in any one of SEQ ID NOs:1, 9, 17, 25, or a sequence having substitution, deletion or addition of one or several amino acids (e.g. substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR2 contained in said VH; and

(iii) a VH CDR3 having the sequence of CDR3 contained in VH as shown in any one of SEQ ID NOs:1, 9, 17, 25, or a sequence having substitution, deletion or addition of one or several amino acids (e.g. substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR3 contained in said VH;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1 having the sequence of CDR1 contained in a VL as shown in any one of

SEQ ID NOs

2, 10, 18, 26, or a sequence having substitution, deletion or addition of one or several amino acids (e.g. substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR1 contained in said VL;

(v) a VL CDR2 having the sequence of CDR2 contained in a VL as shown in any one of

SEQ ID NOs

2, 10, 18, 26, or a sequence having substitution, deletion or addition of one or several amino acids (e.g. substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR2 contained in said VL; and

(vi) a VL CDR3 having the sequence of CDR3 as contained in a VL as shown in any one of SEQ ID NOs:2, 10, 18, 26 or a sequence having substitution, deletion or addition of one or several amino acids (e.g. substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR3 contained in said VL.

In certain preferred embodiments, the substitution recited in any one of (i) - (vi) is a conservative substitution.

In certain preferred embodiments, the CDR1, CDR2 and CDR3 contained in the heavy chain variable region (VH), and/or the CDR1, CDR2 and CDR3 contained in the light chain variable region (VL) are defined by the Kabat, Chothia or IMGT numbering system.

In certain exemplary embodiments, the CDR1, CDR2 and CDR3 contained in the heavy chain variable region (VH), and/or the CDR1, CDR2 and CDR3 contained in the light chain variable region (VL) are defined by the Kabat numbering system.

In some embodiments, an antibody or antigen-binding fragment thereof of the invention comprises:

(i) a VH CDR1 having the sequence of CDR1 contained in the VH set forth in SEQ ID NO:1, or a sequence having a substitution, deletion or addition of one or several amino acids (e.g., a substitution of 1,2, 3 or 4 amino acids) as compared to the sequence of CDR1 contained in said VH;

(ii) a VH CDR2 having the sequence of CDR2 contained in the VH set forth in SEQ ID NO:1, or a sequence having a substitution, deletion or addition of one or several amino acids (e.g., a substitution of 1,2, 3, 4,5 or 6 amino acids) compared to the sequence of CDR2 contained in said VH; and

(iii) a VH CDR3 having the sequence of CDR3 contained in the VH set forth in SEQ ID NO:1, or a sequence having a substitution, deletion or addition of one or several amino acids (e.g., a substitution of 1,2, 3, 4,5, 6 or 7 amino acids) as compared to the sequence of CDR3 contained in said VH;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1 having the sequence of CDR1 contained in VL as shown in SEQ ID No. 2, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution of 1,2, 3, 4,5, 6 or 7 amino acids) compared to the sequence of CDR1 contained in said VL;

(v) a VL CDR2 having the sequence of CDR2 contained in VL as set forth in SEQ ID NO:2, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution of 1 or 2 amino acids) as compared to the sequence of CDR2 contained in said VL; and

(vi) VL CDR3 having the sequence of CDR3 contained in VL as shown in SEQ ID NO:2 or a sequence with substitution, deletion or addition of one or several amino acids (e.g. 1,2, 3, 4,5 or 6 amino acid substitutions) compared to the sequence of CDR3 contained in said VL.

In certain preferred embodiments, the CDR1, CDR2 and CDR3 contained in the heavy chain variable region (VH), and/or the CDR1, CDR2 and CDR3 contained in the light chain variable region (VL) are defined by the Kabat, Chothia or IMGT numbering system. In certain exemplary embodiments, the CDR1, CDR2 and CDR3 contained in the heavy chain variable region (VH), and/or the CDR1, CDR2 and CDR3 contained in the light chain variable region (VL) are defined by the Kabat numbering system.

In certain preferred embodiments, the antibody or antigen-binding fragment thereof of the invention comprises:

(a) 3 CDRs contained in the heavy chain variable region (VH) shown in SEQ ID NO: 1;

and/or the presence of a gas in the gas,

(b) the variable region of the light chain (VL) as shown in SEQ ID NO 2 contains 3 CDRs.

In certain preferred embodiments, the 3 CDRs contained in the heavy chain variable region (VH) and/or the 3 CDRs contained in the light chain variable region (VL) are defined by the Kabat, Chothia or IMGT numbering system. In certain exemplary embodiments, the 3 CDRs contained in the heavy chain variable region (VH) and/or the 3 CDRs contained in the light chain variable region (VL) are defined by the Kabat numbering system.

In certain preferred embodiments, the antibody or antigen-binding fragment thereof of the invention comprises: 3 CDRs contained in the heavy chain variable region (VH) shown in SEQ ID NO: 1; and/or, 3 CDRs contained in the light chain variable region (VL) as set forth in SEQ ID NO: 2;

wherein the 3 CDRs contained in the heavy chain variable region (VH) and the 3 CDRs contained in the light chain variable region (VL) are determined by the Kabat numbering system.

In certain preferred embodiments, the antibody or antigen-binding fragment thereof comprises:

(a) the following 3 heavy chain variable region (VH) CDRs:

(i) a VH CDR1, consisting of the sequence: SEQ ID NO:3, or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1,2, 3 or 4 amino acid substitutions) as compared to SEQ ID NO:3,

(ii) a VH CDR2, consisting of the sequence: SEQ ID NO:4, or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4,5 or 6 amino acid substitutions) as compared to SEQ ID NO:4, and

(iii) a VH CDR3, consisting of the sequence: 5, or a sequence having one or several amino acid substitutions, deletions or additions (e.g. 1,2, 3, 4,5, 6 or 7 amino acid substitutions) compared to SEQ ID No. 5;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1, consisting of the sequence: SEQ ID NO:6, or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4,5, 6 or 7 amino acid substitutions) as compared to SEQ ID NO:6,

(v) a VL CDR2, consisting of the sequence: SEQ ID NO:7, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution of 1 or 2 amino acids) as compared with SEQ ID NO:7, and

(vi) a VL CDR3, consisting of the sequence: SEQ ID NO 8, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4,5 or 6 amino acid substitutions) as compared to SEQ ID NO 8;

wherein the heavy chain variable region (VH) CDRs and the light chain variable region (VL) CDRs are defined by the Kabat numbering system.

In certain preferred embodiments, the antibody or antigen-binding fragment thereof has one or more of the following characteristics:

(i) VH CDR1 has a structure as X₁X₂AFX₃RFX₄(SEQ ID NO: 49);

(ii) VH CDR2 has a structure as X₅X₆GGX₇X₈X₉X₁₀(SEQ ID NO: 50);

(iii) VH CDR3 has, for example, ARHX₁₁X₁₂X₁₃TX₁₄AX₁₅X₁₆X₁₇(SEQ ID NO: 51);

(iv) VL CDR1 has a sequence as X₁₈X₁₉X₂₀X₂₁X₂₂YX₂₃YX₂₄F (SEQ ID NO: 52);

(v) VL CDR2 has a common reference position as RX₂₅A (SEQ ID NO: 53); and

(vi) VL CDR3 has a shape like QX₂₆X₂₇X₂₈X₂₉X₃₀PX₃₁(SEQ ID NO: 54);

wherein, X₁To X₃₁Independently of one another, are any amino acids.

In certain preferred embodiments, X₁To X₃₁Independently of one another, from alanine (A), arginine (R), aspartic acid (D), cysteine (C), glutamine (Q), glutamic acid (E), histidine (H), isoleucine (I), glycine (G), aspartic acid (N), leucine (L), lysine (K), methionine (M), phenylalanine (F), proline (P), serine (S), threonine (T), tryptophan (W), tyrosine (Y) and valine (V).

In certain preferred embodiments, X₁Selected from G or A, X₂Selected from F or A, X₃Selected from S or A, X₄Selected from D or A, X₅Selected from I or A, X₆To X₈Independently of one another, from G or A, X₉Selected from R or A, X₁₀Selected from T or A, X₁₁Selected from G or A, X₁₂Selected from T or A, X₁₃To X₁₄Independently of one another, from G or A, X₁₅Selected from M or A, X₁₆Selected from D or A, X₁₇Selected from Y or A, X₁₈Selected from K or A, X₁₉Selected from S or A, X₂₀Selected from V or A, X₂₁Selected from D or A, X₂₂Selected from N or A, X₂₃Selected from G or A, X₂₄Selected from S or A, X₂₅Selected from S or A, X₂₆Selected from Q or A, X₂₇Selected from S or A, X₂₈Selected from N or A, X₂₉Selected from E or A, X₃₀Selected from D or A, X₃₁Is selected from T or A.

In certain preferred embodiments, X₆Is G, X₇Is G, X₁₀Is T, X₁₁Is G, X₁₃Is G, X₁₄Is G, X₁₅Is M, X₂₃Is G, X₂₄Is S, X₂₆Is Q, X₃₁Is T.

(1)X₁to X₄At most one of A;

(2)X₅to X₁₀At most one of A;

(3)X₁₁to X₁₇At most one ofIs A;

(4)X₁₈to X₂₄At most one of A;

(5)X₂₆to X₃₁At most one of which is a.

In certain preferred embodiments, X₁To X₁₇At most one of which is a.

In certain preferred embodiments, X₁₈To X₃₁At most one of which is a.

In certain preferred embodiments, X₁To X₃₁At most one of which is a.

(1) a VH CDR1 as set forth in any one of SEQ ID NOs:3, 55-58; VH CDR2 shown in SEQ ID NO. 4; and, VH CDR3 shown in SEQ ID NO. 5; VL CDR1 as shown in SEQ ID NO. 6; VL CDR 2as shown in SEQ ID NO. 7; and, VL CDR3 as set forth in SEQ ID NO. 8;

(2) VH CDR1 shown in SEQ ID NO 3; VH CDR 2as set forth in any one of SEQ ID NOs:4, 59-61; and, VH CDR3 shown in SEQ ID NO. 5; VL CDR1 as shown in SEQ ID NO. 6; VL CDR 2as shown in SEQ ID NO. 7; and, VL CDR3 as set forth in SEQ ID NO. 8;

(3) VH CDR1 shown in SEQ ID NO 3; VH CDR2 shown in SEQ ID NO. 4; and, a VH CDR3 as set forth in any one of SEQ ID NOs:5, 62-64; VL CDR1 as shown in SEQ ID NO. 6; VL CDR 2as shown in SEQ ID NO. 7; and, VL CDR3 as set forth in SEQ ID NO. 8;

(4) VH CDR1 shown in SEQ ID NO 3; VH CDR2 shown in SEQ ID NO. 4; and, VH CDR3 shown in SEQ ID NO. 5; a VL CDR1 as set forth in any one of SEQ ID NOs:6, 65-69; VL CDR 2as shown in SEQ ID NO. 7; and, VL CDR3 as set forth in SEQ ID NO. 8;

(5) VH CDR1 shown in SEQ ID NO 3; VH CDR2 shown in SEQ ID NO. 4; and, VH CDR3 shown in SEQ ID NO. 5; VL CDR1 as shown in SEQ ID NO. 6; VL CDR 2as set forth in SEQ ID NO. 7 or 70; and, VL CDR3 as set forth in SEQ ID NO. 8; or

(6) VH CDR1 shown in SEQ ID NO 3; VH CDR2 shown in SEQ ID NO. 4; and, VH CDR3 shown in SEQ ID NO. 5; VL CDR1 as shown in SEQ ID NO. 6; VL CDR 2as shown in SEQ ID NO. 7; and a VL CDR3 as set forth in any one of SEQ ID NOs: 71-74.

In certain preferred embodiments, the VH of an antibody or antigen-binding fragment thereof of the invention comprises: VH CDR1 shown in SEQ ID NO 3; VH CDR2 shown in SEQ ID NO. 4; and, VH CDR3 shown in SEQ ID NO. 5; and, the VL of the antibody or antigen-binding fragment thereof comprises: VL CDR1 as shown in SEQ ID NO. 6; VL CDR 2as shown in SEQ ID NO. 7; and, VL CDR3 as shown in SEQ ID NO. 8.

In other embodiments, an antibody or antigen-binding fragment thereof of the invention comprises:

(i) a VH CDR1 having the sequence of CDR1 contained in the VH set forth in SEQ ID NO:9, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR1 contained in said VH;

(ii) a VH CDR2 having the sequence of CDR2 contained in the VH set forth in SEQ ID NO:9, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR2 contained in said VH; and

(iii) a VH CDR3 having the sequence of CDR3 contained in the VH set forth in SEQ ID NO:9, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR3 contained in said VH;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1 having the sequence of CDR1 contained in VL as set forth in SEQ ID NO 10, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to the sequence of CDR1 contained in said VL;

(v) a VL CDR2 having the sequence of CDR2 contained in VL as set forth in SEQ ID NO 10, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to the sequence of CDR2 contained in said VL; and

(vi) VL CDR3 having the sequence of CDR3 as comprised in VL shown in SEQ ID NO 10 or a sequence with substitution, deletion or addition of one or several amino acids (e.g. 1,2 or 3 amino acid substitution, deletion or addition) compared to the sequence of CDR3 comprised in said VL.

(a) 3 CDRs contained in the heavy chain variable region (VH) shown in SEQ ID NO: 9;

and/or the presence of a gas in the gas,

(b) the variable region of the light chain (VL) as shown in SEQ ID NO 10 contains 3 CDRs.

In certain preferred embodiments, the antibody or antigen-binding fragment thereof of the invention comprises: 3 CDRs contained in the heavy chain variable region (VH) shown in SEQ ID NO: 9; and/or, 3 CDRs contained in the light chain variable region (VL) as set forth in SEQ ID NO: 10;

(a) the following 3 heavy chain variable region (VH) CDRs:

(i) a VH CDR1, consisting of the sequence: SEQ ID NO:11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO:11,

(ii) a VH CDR2, consisting of the sequence: 12 or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared with SEQ ID NO:12, and

(iii) a VH CDR3, consisting of the sequence: 13, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID No. 13;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1, consisting of the sequence: SEQ ID NO:14, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO:14,

(v) a VL CDR2, consisting of the sequence: SEQ ID NO:15, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO:15, and

(vi) a VL CDR3, consisting of the sequence: 16, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO: 16;

In certain preferred embodiments, the VH of an antibody or antigen-binding fragment thereof of the invention comprises: VH CDR1 shown in SEQ ID NO. 11; VH CDR2 shown in SEQ ID NO 12; and, VH CDR3 shown in SEQ ID NO 13; and, the VL of the antibody or antigen-binding fragment thereof comprises: VL CDR1 as shown in SEQ ID NO. 14; VL CDR 2as shown in SEQ ID NO. 15; and, VL CDR3 as shown in SEQ ID NO 16.

(i) a VH CDR1 having the sequence of CDR1 contained in the VH set forth in SEQ ID NO:17, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR1 contained in said VH;

(ii) a VH CDR2 having the sequence of CDR2 contained in the VH set forth in SEQ ID NO:17, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR2 contained in said VH; and

(iii) a VH CDR3 having the sequence of CDR3 contained in the VH set forth in SEQ ID NO:17, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR3 contained in said VH;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1 having the sequence of CDR1 contained in VL as set forth in SEQ ID NO:18, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to the sequence of CDR1 contained in said VL;

(v) a VL CDR2 having the sequence of CDR2 contained in VL as set forth in SEQ ID NO:18, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to the sequence of CDR2 contained in said VL; and

(vi) VL CDR3 having the sequence of CDR3 contained in VL as shown in SEQ ID NO:18 or a sequence with substitution, deletion or addition of one or several amino acids (e.g. 1,2 or 3 amino acid substitution, deletion or addition) compared to the sequence of CDR3 contained in said VL.

(a) the 3 CDRs contained in the variable region of the heavy chain (VH) shown in SEQ ID NO: 17;

and/or the presence of a gas in the gas,

(b) the variable region of the light chain (VL) as shown in SEQ ID NO 18 contains 3 CDRs.

In certain preferred embodiments, the antibody or antigen-binding fragment thereof of the invention comprises: the 3 CDRs contained in the variable region of the heavy chain (VH) shown in SEQ ID NO: 17; and/or, 3 CDRs contained in the light chain variable region (VL) as set forth in SEQ ID NO: 18;

(a) the following 3 heavy chain variable region (VH) CDRs:

(i) a VH CDR1, consisting of the sequence: SEQ ID NO:19, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO:19,

(ii) a VH CDR2, consisting of the sequence: SEQ ID NO:20, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to SEQ ID NO:20, and

(iii) a VH CDR3, consisting of the sequence: 21, or a sequence having one or several amino acid substitutions, deletions or additions (e.g. 1,2 or 3 amino acid substitutions, deletions or additions) compared to SEQ ID No. 21;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1, consisting of the sequence: SEQ ID NO:22, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO:22,

(v) a VL CDR2, consisting of the sequence: SEQ ID NO:23, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to SEQ ID NO:23, and

(vi) a VL CDR3, consisting of the sequence: 24, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID No. 24;

In certain preferred embodiments, the VH of an antibody or antigen-binding fragment thereof of the invention comprises: VH CDR1 shown in SEQ ID NO. 19; VH CDR2 shown as SEQ ID NO: 20; and, VH CDR3 shown in SEQ ID NO: 21; and, the VL of the antibody or antigen-binding fragment thereof comprises: VL CDR1 as shown in SEQ ID NO. 22; VL CDR 2as shown in SEQ ID NO. 23; and, VL CDR3 as shown in SEQ ID NO. 24.

(i) a VH CDR1 having the sequence of CDR1 contained in the VH set forth in SEQ ID NO:25, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR1 contained in said VH;

(ii) a VH CDR2 having the sequence of CDR2 contained in the VH set forth in SEQ ID NO:25, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR2 contained in said VH; and

(iii) a VH CDR3 having the sequence of CDR3 contained in the VH set forth in SEQ ID NO:25, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) compared to the sequence of CDR3 contained in said VH;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1 having the sequence of CDR1 contained in VL as shown in SEQ ID No. 26, or a sequence having substitution, deletion or addition of one or several amino acids (e.g. 1,2 or 3 amino acid substitution, deletion or addition) compared to the sequence of CDR1 contained in said VL;

(v) a VL CDR2 having the sequence of CDR2 contained in VL as shown in SEQ ID No. 26, or a sequence having substitution, deletion or addition of one or several amino acids (e.g. 1,2 or 3 amino acid substitution, deletion or addition) compared to the sequence of CDR2 contained in said VL; and

(vi) VL CDR3 having the sequence of CDR3 as comprised in VL shown in SEQ ID NO:26 or a sequence with substitution, deletion or addition of one or several amino acids (e.g. 1,2 or 3 amino acid substitution, deletion or addition) compared to the sequence of CDR3 comprised in said VL.

(a) the 3 CDRs contained in the heavy chain variable region (VH) shown in SEQ ID NO: 25;

and/or the presence of a gas in the gas,

(b) the variable region of the light chain (VL) as shown in SEQ ID NO 26 contains 3 CDRs.

In certain preferred embodiments, the antibody or antigen-binding fragment thereof of the invention comprises: the 3 CDRs contained in the heavy chain variable region (VH) shown in SEQ ID NO: 25; and/or, 3 CDRs contained in the light chain variable region (VL) as set forth in SEQ ID NO: 26;

(a) the following 3 heavy chain variable region (VH) CDRs:

(i) a VH CDR1, consisting of the sequence: SEQ ID NO:27, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO:27,

(ii) a VH CDR2, consisting of the sequence: SEQ ID NO:28, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to SEQ ID NO:28, and

(iii) a VH CDR3, consisting of the sequence: 29, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID No. 29;

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(iv) a VL CDR1, consisting of the sequence: SEQ ID NO:30, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO:30,

(v) a VL CDR2, consisting of the sequence: SEQ ID NO:31, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to SEQ ID NO:31, and

(vi) a VL CDR3, consisting of the sequence: 32, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2 or 3 amino acid substitutions, deletions or additions) as compared to SEQ ID NO: 32;

In certain preferred embodiments, the VH of an antibody or antigen-binding fragment thereof of the invention comprises: VH CDR1 shown as SEQ ID NO: 27; VH CDR2 shown as SEQ ID NO 28; and, VH CDR3 shown in SEQ ID NO. 29; and, the VL of the antibody or antigen-binding fragment thereof comprises: VL CDR1 as shown in SEQ ID NO. 30; VL CDR 2as shown in SEQ ID NO. 31; and, VL CDR3 as shown in SEQ ID NO: 32.

In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention further comprise a Framework Region (FR) derived from a mammalian (e.g., murine or human) immunoglobulin.

In certain preferred embodiments, the VH of an antibody or antigen-binding fragment thereof of the invention comprises a heavy chain variable region (VH) Framework Region (FR) derived from a murine immunoglobulin, and/or the VL of said antibody or antigen-binding fragment thereof comprises a light chain variable region (VL) Framework Region (FR) derived from a murine immunoglobulin.

In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention are humanized. In certain preferred embodiments, the antibodies or antigen binding fragments thereof of the invention are humanized to a degree of at least 75%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, 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%, at least 99%, or 100%.

In certain preferred embodiments, the VH of an antibody or antigen-binding fragment thereof of the invention comprises a heavy chain variable region (VH) Framework Region (FR) derived from a human immunoglobulin, and/or the VL of said antibody or antigen-binding fragment thereof comprises a light chain variable region (VL) Framework Region (FR) derived from a human immunoglobulin. In such embodiments, the heavy chain variable region FR and/or the light chain variable region FR of the antibody or antigen binding fragment thereof of the invention may comprise one or more non-human (e.g., murine) amino acid residues, e.g., the heavy chain framework region FR and/or the light chain framework region FR may comprise one or more amino acid back mutations in which there is a corresponding murine amino acid residue.

(a) a heavy chain framework region of a human immunoglobulin or a variant thereof having conservative substitutions of up to 20 amino acids (e.g., conservative substitutions of up to 15, up to 10, or up to 5 amino acids; e.g., conservative substitutions of 1,2, 3, 4, or 5 amino acids) in comparison to the sequence from which it is derived; and/or

(b) A light chain framework region of a human immunoglobulin or a variant thereof, which variant has conservative substitutions of up to 20 amino acids (e.g., conservative substitutions of up to 15, up to 10, or up to 5 amino acids; e.g., conservative substitutions of 1,2, 3, 4, or 5 amino acids) compared to the sequence from which it is derived.

In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the invention comprise framework regions of a human immunoglobulin, e.g., framework regions comprised in an amino acid sequence encoded by a human germline antibody gene. In certain preferred embodiments, the antibody or antigen-binding fragment thereof comprises: a heavy chain framework region comprised in the amino acid sequence encoded by the human heavy chain germline gene and/or a light chain framework region comprised in the amino acid sequence encoded by the human light chain germline gene.

In such embodiments, the framework regions (heavy chain framework regions and/or light chain framework regions) of the antibodies of the invention, or antigen-binding fragments thereof, may comprise one or more amino acid residues that are non-human (e.g., murine). In certain preferred embodiments, the framework regions (heavy chain framework regions and/or light chain framework regions) comprise one or more amino acid residues that are back-mutated to a corresponding murine residue or conservative amino acid substitutions of a corresponding murine residue (such mutations are referred to as back mutations).

Thus, in certain preferred embodiments, an antibody or antigen-binding fragment thereof of the invention comprises a framework region of a human immunoglobulin (e.g., a framework region comprised in an amino acid sequence encoded by a human germline antibody gene), which optionally comprises one or more back mutations from human residues to murine residues.

In certain exemplary embodiments, the antibody or antigen-binding fragment thereof comprises: heavy chain framework regions comprised in the amino acid sequence encoded by IGVH3-23 x 04, and light chain framework regions comprised in the amino acid sequence encoded by IGKV3-11 x 01, said heavy chain framework regions and/or light chain framework regions optionally comprising one or more back mutations from human residues to murine residues. In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention are humanized to a degree of at least 95%.

In certain exemplary embodiments, the antibody or antigen-binding fragment thereof comprises: heavy chain framework regions comprised in the amino acid sequence encoded by IGVH1-2 x 02 and light chain framework regions comprised in the amino acid sequence encoded by IGKV1-16 x 01, said heavy chain framework regions and/or light chain framework regions optionally comprising one or more back mutations from human residues to murine residues. In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention are humanized to a degree of at least 84%.

(a) a heavy chain variable region (VH) comprising an amino acid sequence selected from:

(i) SEQ ID NOs: 1. 9, 17, 25, 33, 35, 37, 39;

(ii) and SEQ ID NOs: 1. 9, 17, 25, 33, 35, 37, 39, which has one or more amino acid substitutions, deletions, or additions (e.g., 1,2, 3, 4, or 5 amino acid substitutions, deletions, or additions) as compared to the sequence set forth in any one of claims; or

(iii) And SEQ ID NOs: 1. 9, 17, 25, 33, 35, 37, 39, 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%, at least 99%, or 100% sequence identity;

and/or

(b) A light chain variable region (VL) comprising an amino acid sequence selected from the group consisting of:

(iv) SEQ ID NOs: 2. 10, 18, 26, 34, 36, 38, 40;

(v) and SEQ ID NOs: 2. 10, 18, 26, 34, 36, 38, 40 with one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence shown in any one of fig. 10, 18, 26, 34, 36, 38, 40; or

(vi) And SEQ ID NOs: 2. 10, 18, 26, 34, 36, 38, 40, at least 80%, 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%, at least 99%, or 100% sequence identity.

In certain preferred embodiments, the substitutions recited in (ii) or (v) are conservative substitutions.

(i) SEQ ID NO: 1;

(ii) and SEQ ID NO:1 compared to a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(iii) And SEQ ID NO:1, has at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NO: 2;

(v) and SEQ ID NO:2 compared to a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(vi) And SEQ ID NO:2, at least 80%, 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%, at least 99%, or 100% sequence identity.

(i) SEQ ID NO: 9;

(ii) and SEQ ID NO:9 (e.g., 1,2, 3, 4, or 5 amino acid substitutions, deletions, or additions) compared to the sequence of seq id no; or

(iii) And SEQ ID NO:9, at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NO: 10;

(v) and SEQ ID NO:10 with one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence set forth in seq id no; or

(vi) And SEQ ID NO:10, at least 80%, 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%, at least 99%, or 100% sequence identity.

(i) SEQ ID NO: 17;

(ii) and SEQ ID NO:17 with one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence shown in (b); or

(iii) And SEQ ID NO:17, has at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NO:18, or a sequence shown in seq id no;

(v) and SEQ ID NO:18 with one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence shown in (a); or

(vi) And SEQ ID NO:18, at least 80%, 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%, at least 99%, or 100% sequence identity.

(i) SEQ ID NO: 25;

(ii) and SEQ ID NO:25 compared to a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(iii) And SEQ ID NO:25, at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NO: 26;

(v) and SEQ ID NO:26 compared to a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(vi) And SEQ ID NO:26, has a sequence identity of at least 80%, 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%, at least 99%, or 100%.

(i) SEQ ID NO: 33;

(ii) and SEQ ID NO:33 compared to a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(iii) And SEQ ID NO:33, at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NO: 34;

(v) and SEQ ID NO:34 compared to a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(vi) And SEQ ID NO:34, has at least 80%, 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%, at least 99%, or 100% sequence identity.

(i) SEQ ID NO: 35;

(ii) and SEQ ID NO:35 compared to a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(iii) And SEQ ID NO:35, at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NO: 36;

(v) and SEQ ID NO:36 with one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence shown in (a); or

(vi) And SEQ ID NO:36, has a sequence identity of at least 80%, 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%, at least 99%, or 100%.

(i) SEQ ID NO: 37;

(ii) and SEQ ID NO:37 compared to a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(iii) And SEQ ID NO:37, at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NO: 38;

(v) and SEQ ID NO:38 compared to a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions); or

(vi) And SEQ ID NO:38, or a variant thereof, 38, a sequence having at least 80%, 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%, at least 99%, or 100% sequence identity.

(i) SEQ ID NO: 39;

(ii) and SEQ ID NO:39 with one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence set forth in seq id no; or

(iii) And SEQ ID NO:39, has at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NO: 40;

(v) and SEQ ID NO:40 with one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence set forth in seq id no; or

(vi) And SEQ ID NO:40, has at least 80%, 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%, at least 99%, or 100% sequence identity.

(1) VH having a sequence shown as SEQ ID NO. 1and VL having a sequence shown as SEQ ID NO. 2;

(2) VH having a sequence shown as SEQ ID NO.9 and VL having a sequence shown as SEQ ID NO. 10;

(3) VH having a sequence shown as SEQ ID NO. 17 and VL having a sequence shown as SEQ ID NO. 18;

(4) VH having a sequence shown as SEQ ID NO. 25 and VL having a sequence shown as SEQ ID NO. 26;

(5) VH having a sequence shown as SEQ ID NO. 33 and VL having a sequence shown as SEQ ID NO. 34;

(6) VH having a sequence shown as SEQ ID NO. 35 and VL having a sequence shown as SEQ ID NO. 36;

(7) VH having a sequence shown as SEQ ID NO. 37 and VL having a sequence shown as SEQ ID NO. 38; or

(8) VH having the sequence shown as SEQ ID NO. 39 and VL having the sequence shown as SEQ ID NO. 40.

In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention further comprise a constant region sequence derived from a mammalian (e.g., murine or human) immunoglobulin or a variant thereof having one or more amino acid substitutions, deletions or additions compared to the sequence from which it is derived. In certain preferred embodiments, the variant has conservative substitutions of one or more amino acids compared to the sequence from which it is derived.

In certain preferred embodiments, the heavy chain of an antibody or antigen-binding fragment thereof of the invention comprises a heavy chain constant region (CH) of a human immunoglobulin or a variant thereof having one or more amino acid substitutions, deletions or additions (e.g., substitutions, deletions or additions of up to 20, up to 15, up to 10, or up to 5 amino acids; e.g., substitutions, deletions or additions of 1,2, 3, 4, or 5 amino acids) compared to the sequence from which it is derived; and/or the presence of a gas in the gas,

the light chain of the antibody or antigen-binding fragment thereof of the invention comprises a light chain constant region (CL) of a human immunoglobulin or a variant thereof having conservative substitutions of up to 20 amino acids (e.g., conservative substitutions of up to 15, up to 10, or up to 5 amino acids; e.g., conservative substitutions of 1,2, 3, 4, or 5 amino acids) compared to the sequence from which it is derived.

In certain preferred embodiments, the heavy chain constant region is an IgG heavy chain constant region, e.g., an IgG1, IgG2, IgG3, or IgG4 heavy chain constant region. In certain preferred embodiments, the heavy chain constant region is a murine IgG1, IgG2, IgG3, or IgG4 heavy chain constant region. In certain preferred embodiments, the heavy chain constant region is a human IgG1, IgG2, IgG3, or IgG4 heavy chain constant region. In certain embodiments, preferably the heavy chain constant region is a human IgG1 or IgG4 heavy chain constant region.

In certain preferred embodiments, the light chain constant region is a kappa light chain constant region. In certain preferred embodiments, the light chain constant region is a murine kappa light chain constant region. In certain preferred embodiments, the light chain constant region is a human kappa light chain constant region.

In certain preferred embodiments, the antibodies of the invention are chimeric or humanized antibodies. In certain preferred embodiments, the antigen binding fragment of the invention is selected from the group consisting of scFv, Fab ', (Fab')₂Fv fragments, diabodies (diabodies).

The antibody or antigen-binding fragment thereof of the present invention has high specificity and high affinity for PD-1 (particularly human PD-1). In certain preferred embodiments, the antibodies of the invention orThe antigen binding fragment thereof can be about 1X 10^-10K of M or less_DBinding to PD-1 (particularly human PD-1); preferably at about 5 × 10^-11K of M or less_DBinds to PD-1 (especially human PD-1), or, alternatively, at about 1X 10^-11K of M or less_DBinds to PD-1 (particularly human PD-1).

In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention have at least one of the following biological functions:

(1) specifically recognizes/binds to PD-1 (particularly human PD-1);

(2) blocking the binding of PD-1 to PD-L1, or inhibiting and/or blocking intracellular signaling mediated by PD-1 binding to PD-L1;

(3) increasing immune cell (particularly T cell, e.g., antigen-specific T cell) activity in vitro and in vivo in a subject;

(4) increasing the level of secretion, proliferative activity, expression of an activation marker (e.g., CD25, CD69, etc.), and/or cell killing activity of an effector cytokine (e.g., IL-2, IFN- γ, etc.) by an immune cell (particularly a T cell, e.g., an antigen-specific T cell) in vitro and in vivo in a subject;

(5) enhancing immune responses (particularly T cell-mediated immune responses) in vitro and in a subject;

(6) preventing and/or treating a tumor (e.g., a tumor with microsatellite height instability (MSI-H) or mismatch repair deficiency (dMMR)) or an infection in a subject.

In the present invention, an antibody or antigen-binding fragment thereof of the present invention may include variants that differ from the antibody or antigen-binding fragment thereof from which it is derived only by conservative substitutions of one or more (e.g., conservative substitutions of up to 20, up to 15, up to 10, or up to 5 amino acids) amino acid residues, or that have at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to the antibody or antigen-binding fragment thereof from which it is derived, and that substantially retain the above-described biological functions of the antibody or antigen-binding fragment thereof from which it is derived.

Derivatized antibodies

The antibodies or antigen-binding fragments thereof of the invention can be derivatized, e.g., linked to another molecule (e.g., another polypeptide or protein). In general, derivatization (e.g., labeling) of an antibody or antigen-binding fragment thereof does not adversely affect its binding to PD-1, particularly human PD-1. Thus, the antibodies or antigen-binding fragments thereof of the present invention are also intended to include such derivatized forms. For example, an antibody or antigen-binding fragment thereof of the invention can be functionally linked (by chemical coupling, genetic fusion, non-covalent linkage, or other means) to one or more other molecular moieties, such as another antibody (e.g., to form a bispecific antibody), a detection reagent, a pharmaceutical agent, and/or a protein or polypeptide (e.g., avidin or polyhistidine tag) capable of mediating binding of the antibody or antigen-binding fragment to another molecule. In addition, the antibodies or antigen-binding fragments thereof of the present invention may also be derivatized with chemical groups, such as polyethylene glycol (PEG), methyl or ethyl, or glycosyl groups. These groups can be used to improve the biological properties of the antibody, for example to increase serum half-life.

Thus, in certain preferred embodiments, the antibodies of the invention or antigen-binding fragments thereof are labeled. In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the invention carry a detectable label, such as an enzyme, a radionuclide, a fluorescent dye, a luminescent substance (e.g., a chemiluminescent substance), or biotin. The detectable label of the present invention may be any substance detectable by fluorescence, spectroscopic, photochemical, biochemical, immunological, electrical, optical or chemical means. Such labels are well known in the art, examples of which include, but are not limited to, enzymes (e.g., horseradish peroxidase, alkaline phosphatase, beta-galactosidase, urease, glucose oxidase, etc.), radionuclides (e.g.,³H、¹²⁵I、³⁵S、¹⁴c or³²P), fluorescent dyes (e.g., Fluorescein Isothiocyanate (FITC), fluorescein, tetramethylrhodamine isothiocyanate (TRITC), Phycoerythrin (PE), Texas Red, Fluorescein Isothiocyanate (FITC), fluorescein isothiocyanate (TRITC), Fluorescein Isothiocyanate (FIT), fluorescein isothiocyanate (TRITC), fluorescein isothiocyanate (TEP), fluorescein isothiocyanate (TEX), Fluorescein Isothiocyanate (FIT), fluorescein isothiocyanate (TRITC), fluorescein isothiocyanate (TEX), fluorescein (PE), fluorescein (T), fluorescein (TCH), fluorescein isothiocyanate (TCH), fluorescein (P), fluorescein (TCH), and (TCH), P), fluorescent dyes (TCH), fluorescent dyes (I), and fluorescent dyes (I), fluorescent dyes (P), fluorescent dyes, fluorescent,Rhodamine, quantum dots, or cyanine dye derivatives (e.g., Cy7, Alexa 750)), luminescent substances (e.g., chemiluminescent substances such as acridine ester compounds), magnetic beads (e.g.,

) A calorimetric label such as colloidal gold or colored glass or plastic (e.g., polystyrene, polypropylene, latex, etc.) beads, and biotin for binding to the label-modified avidin (e.g., streptavidin) described above. Patents that teach the use of such markers include, but are not limited to, U.S. Pat. nos. 3,817,837; 3,850,752, respectively; 3,939,350, respectively; 3,996,345; 4,277,437; 4,275,149; and 4,366,241 (all incorporated herein by reference). Detectable labels as described above can be detected by methods known in the art. For example, radioactive labels can be detected using photographic film or scintillation calculators, and fluorescent labels can be detected using photodetectors to detect the emitted light. Enzyme labels are generally detected by providing a substrate for the enzyme and detecting the reaction product produced by the action of the enzyme on the substrate, and calorimetric labels are detected by simply visualizing the colored label. In certain embodiments, such labels can be suitable for use in immunological assays (e.g., enzyme-linked immunoassays, radioimmunoassays, fluorescent immunoassays, chemiluminescent immunoassays, and the like). In certain embodiments, a detectable label as described above can be attached to an antibody or antigen-binding fragment thereof of the invention via a linker of varying length to reduce potential steric hindrance.

In another aspect, the invention also provides a conjugate comprising an antibody or antigen-binding fragment thereof of the invention and a therapeutic agent linked to the antibody or antigen-binding fragment thereof.

In certain preferred embodiments, the conjugate is an antibody-drug conjugate (ADC). In certain preferred embodiments, the therapeutic agent is selected from a cytotoxin or a radioisotope. Non-limiting examples of suitable therapeutic agents in the present invention include antimetabolites, alkylating agents, DNA minor groove binders, DNA intercalators, DNA cross-linkers, histone deacetylase inhibitors, nuclear export inhibitors, proteasome inhibitors, topoisomerase I or II inhibitors, heat shock protein inhibitors, tyrosine kinase inhibitors, antibiotics, and antimitotic agents.

In certain preferred embodiments, the antibody or antigen-binding fragment thereof of the invention is conjugated to the therapeutic agent, optionally through a linker. In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention are conjugated to the therapeutic agent via a cleavable linker (e.g., a peptide linker, disulfide, or hydrazone linker).

Preparation of antibodies

The antibody of the present invention can be prepared by various methods known in the art, for example, by genetic engineering recombinant techniques. For example, DNA molecules encoding the heavy and light chain genes of the antibodies of the invention are obtained by chemical synthesis or PCR amplification. The resulting DNA molecule is inserted into an expression vector and then transfected into a host cell. The transfected host cells are then cultured under specific conditions and the antibodies of the invention are expressed.

Antigen-binding fragments of the invention may be obtained by hydrolysis of the whole antibody molecule (see Morimoto et al, J.Biochem.Biophys.methods 24:107-117(1992) and Brennan et al, Science 229:81 (1985)). Alternatively, these antigen-binding fragments can be produced directly from recombinant host cells (reviewed in Hudson, Curr. Opin. Immunol.11:548-557 (1999); Little et al, Immunol.today,21:364-370 (2000)). For example, Fab' fragments can be obtained directly from the host cell; fab 'fragments can be chemically coupled to form F (ab')₂Fragments (Carter et al, Bio/Technology,10: 163-. In addition, Fv, Fab or F (ab')₂The fragments may also be isolated directly from the culture medium of the recombinant host cell. Other techniques for preparing these antigen-binding fragments are well known to those of ordinary skill in the art.

Thus, in another aspect, the invention provides an isolated nucleic acid molecule comprising a nucleotide sequence encoding an antibody or antigen-binding fragment thereof of the invention, or a heavy chain variable region and/or a light chain variable region thereof. In certain preferred embodiments, the isolated nucleic acid molecule encodes an antibody or antigen-binding fragment thereof of the present invention, or a heavy chain variable region and/or a light chain variable region thereof.

In another aspect, the invention provides a vector (e.g., a cloning vector or an expression vector) comprising an isolated nucleic acid molecule of the invention. In certain preferred embodiments, the vectors of the invention are, for example, plasmids, cosmids, phages and the like. In certain preferred embodiments, the vector is capable of expressing an antibody or antigen-binding fragment thereof of the invention in a subject (e.g., a mammal, e.g., a human).

In another aspect, the invention provides a host cell comprising the isolated nucleic acid molecule of the invention or the vector of the invention. Such host cells include, but are not limited to, prokaryotic cells such as E.coli cells, and eukaryotic cells such as yeast cells, insect cells, plant cells, and animal cells (e.g., mammalian cells, e.g., mouse cells, human cells, etc.). In certain preferred embodiments, the host cell of the invention is a mammalian cell, such as CHO (e.g., CHO-K1, CHO-S, CHO DG 44).

In another aspect, there is provided a method of making an antibody or antigen-binding fragment thereof of the invention, comprising culturing a host cell of the invention under conditions that allow expression of the antibody or antigen-binding fragment thereof, and recovering the antibody or antigen-binding fragment thereof from the cultured host cell culture.

Methods of treatment and pharmaceutical compositions

The antibodies or antigen-binding fragments thereof of the present invention are useful for inhibiting and/or blocking intracellular signaling mediated by PD-1 binding to PD-L1, increasing immune cell activity, enhancing immune response, and for preventing and/or treating tumors or infections, in vitro or in a subject, or as an immunological adjuvant.

Thus, in another aspect, the invention provides a pharmaceutical composition comprising an antibody or antigen-binding fragment thereof of the invention or a conjugate of the invention, and a pharmaceutically acceptable carrier and/or excipient.

In certain preferred embodiments, the pharmaceutical composition may further comprise an additional pharmaceutically active agent.

In certain preferred embodiments, the additional pharmaceutically active agent is a drug having anti-tumor activity, such as an additional immune checkpoint inhibitor, an oncolytic virus, a chemotherapeutic agent, an anti-angiogenic drug, an anti-metabolite drug, a tumor-targeting drug, an immunostimulant, and the like.

In certain preferred embodiments, the additional pharmaceutically active agent is a drug for treating an infection, such as an antiviral agent, an antifungal agent, an antibacterial agent, an immunostimulant, and the like.

In certain preferred embodiments, in the pharmaceutical composition, the antibody or antigen-binding fragment thereof or conjugate of the invention and the additional pharmaceutically active agent are provided as separate components or as components of the same composition. Thus, the antibody or antigen-binding fragment thereof or conjugate of the invention and the additional pharmaceutically active agent may be administered simultaneously, separately or sequentially.

In certain exemplary embodiments, the medicament comprises a sterile injectable liquid (e.g., an aqueous or non-aqueous suspension or solution). In certain exemplary embodiments, such sterile injectable liquids are selected from water for injection (WFI), bacteriostatic water for injection (BWFI), sodium chloride solutions (e.g., 0.9% (w/v) NaCl), glucose solutions (e.g., 5% glucose), surfactant-containing solutions (e.g., 0.01% polysorbate 20), pH buffered solutions (e.g., phosphate buffered solutions), Ringer's solution, and any combination thereof.

In another aspect, the invention relates to the use of an antibody or antigen-binding fragment thereof or conjugate of the invention in the preparation of a medicament for:

(1) increasing immune cell (e.g., T cell) activity in vitro or in a subject (e.g., a human);

(2) enhancing an immune response (e.g., a T cell-mediated immune response) in a subject (e.g., a human);

(3) treating a tumor in a subject (e.g., a human); or

(4) Treating an infection in a subject (e.g., a human).

In certain preferred embodiments, the tumor is a tumor having microsatellite height instability (MSI-H) and/or mismatch repair deficiency (dMMR).

In another aspect, the invention provides an immunogenic composition comprising an antibody or antigen-binding fragment thereof of the invention, and an immunogen.

In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention act as adjuvants.

In certain preferred embodiments, the immunogen is selected from the group consisting of a tumor-associated antigen (e.g., a protein, polypeptide, or carbohydrate molecule), a tumor cell, a dendritic cell primed with the antigen, and any combination thereof.

In certain preferred embodiments, the immunogen is selected from the group consisting of an antigen (e.g., a protein, polypeptide, or carbohydrate molecule) associated with a pathogen (e.g., a virus), an inactivated or attenuated pathogen, a dendritic cell primed by the antigen, and any combination thereof.

In certain preferred embodiments, the immunogenic composition further comprises a pharmaceutically acceptable carrier and/or excipient. In certain preferred embodiments, the immunogenic composition comprises a stabilizer.

In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention are provided with the immunogen in the immunogenic composition as a separate component or as a component of the same composition. Thus, the antibody or antigen-binding fragment thereof of the invention and the immunogen may be administered simultaneously, separately or sequentially.

In another aspect, the invention relates to the use of an antibody or antigen-binding fragment thereof of the invention as an adjuvant, or in the preparation of an immunogenic composition for enhancing an immune response (e.g., a T cell-mediated immune response) in a subject; wherein the immunogenic composition comprises an antibody or antigen-binding fragment thereof of the invention and an immunogen.

In certain preferred embodiments, the immunogen is selected from the group consisting of a tumor-associated antigen (e.g., a protein, polypeptide, or carbohydrate molecule), a tumor cell, a dendritic cell primed with the antigen, and any combination thereof. In such embodiments, the immunogenic composition is for preventing and/or treating a tumor in a subject.

In certain preferred embodiments, the immunogen is selected from the group consisting of an antigen (e.g., a protein, polypeptide, or carbohydrate molecule) associated with a pathogen (e.g., a virus), an inactivated or attenuated pathogen, a dendritic cell primed by the antigen, and any combination thereof. In such embodiments, the immunogenic composition is for preventing and/or treating an infection in a subject.

In another aspect, the invention provides a method of increasing the activity of an immune cell (e.g., a T cell) in vitro, the method comprising the step of contacting the immune cell with an antibody or antigen-binding fragment thereof of the invention. Such methods may be used for therapeutic purposes, or for non-therapeutic purposes.

In certain preferred embodiments, any suitable indicator can be used to measure the activity of the immune cells. Non-limiting examples of such suitable indicators include: in the presence of an antibody or antigen-binding fragment thereof of the invention, an immune cell (e.g., a T cell) has an increased level of cytokine (e.g., IL-2, IFN- γ, etc.) secretion, proliferative activity, and/or expression of an activation marker (e.g., CD25, CD69, etc.).

In certain preferred embodiments, the methods are used to treat tumors. In such embodiments, the immune cells obtained by the above methods can be adoptively transferred into a subject to treat a tumor. Activation in vitro in the presence of an antibody or antigen-binding fragment thereof of the invention is expected to increase the activity of adoptively transferred immune cells, thereby facilitating tumor killing of these adoptively transferred immune cells in a subject. In certain preferred embodiments, the immune cell is a tumor-infiltrating lymphocyte (e.g., a tumor-infiltrating T cell).

In certain preferred embodiments, the method further comprises the step of contacting the immune cell with an additional pharmaceutically active agent, which may be selected from immunostimulatory cytokines. In certain exemplary embodiments, the additional pharmaceutically active agent is selected from, for example, IL-2, IL-3, IL-12, IL-15, IL-18, IFN- γ, IL-10, TGF- β, GM-CSF, and any combination thereof.

In certain preferred embodiments, the immune cell is a T cell, such as a cytotoxic T Cell (CTL), an antigen-specific T cell, or a tumor-infiltrating T cell (TIL-T). In certain exemplary embodiments, the immune cell is a tumor-infiltrating lymphocyte (e.g., a tumor-infiltrating T cell).

In another aspect, the invention provides a method of increasing immune cell activity and/or enhancing an immune response in a subject, the method comprising administering to a subject in need thereof an effective amount of an antibody (or antigen-binding fragment thereof) of the invention, a conjugate of the invention, a pharmaceutical composition of the invention, or an immunogenic composition of the invention.

In certain preferred embodiments, the immune response is a T cell-mediated immune response.

In certain preferred embodiments, the methods are used for the prevention and/or treatment of tumors. In such embodiments, the subject has a tumor. In certain preferred embodiments, the tumor is a tumor having microsatellite height instability (MSI-H) and/or mismatch repair deficiency (dMMR).

In certain preferred embodiments, the methods are used to prevent and/or treat infection. In such embodiments, the subject has an infection. In certain preferred embodiments, the infection is a viral infection, such as a chronic viral infection.

In certain preferred embodiments, the immune cell is a T cell, such as a cytotoxic T Cell (CTL), an antigen-specific T cell, or a tumor-infiltrating T cell (TIL-T). In certain exemplary embodiments, the immune cell is a tumor-infiltrating lymphocyte, such as a tumor-infiltrating T cell.

In another aspect, the invention provides a method for preventing and/or treating a tumor in a subject (e.g., a human), the method comprising administering to a subject in need thereof an effective amount of an antibody (or antigen-binding fragment thereof) of the invention, a conjugate of the invention, a pharmaceutical composition of the invention, or an immunogenic composition of the invention.

In certain preferred embodiments, the antibodies (or antigen-binding fragments thereof) or conjugates of the invention are used in combination with another drug having anti-tumor activity. Such additional agents having anti-tumor activity may be administered prior to, concurrently with, or subsequent to the administration of the antibody (or antigen-binding fragment thereof) or conjugate.

In certain preferred embodiments, the antibodies (or antigen-binding fragments thereof), conjugates, pharmaceutical compositions, or immunogenic compositions of the invention are administered in combination with additional therapies. Such additional therapy may be any therapy known for tumors, such as surgery, chemotherapy, radiation therapy, targeted therapy, immunotherapy, hormonal therapy, gene therapy, or palliative therapy. Such additional therapies may be administered prior to, concurrently with, or subsequent to the administration of the antibody (or antigen-binding fragment thereof), conjugate, pharmaceutical composition, or immunogenic composition of the invention.

In another aspect, the invention provides a method for preventing and/or treating an infection in a subject (e.g., a human), the method comprising administering to a subject in need thereof an effective amount of an antibody (or antigen-binding fragment thereof) of the invention, a conjugate of the invention, a pharmaceutical composition of the invention, or an immunogenic composition of the invention.

In certain preferred embodiments, the antibodies (or antigen-binding fragments thereof) or conjugates of the invention are used in combination with another agent for treating infection. Such additional drugs for treating infection may be administered prior to, concurrently with, or subsequent to administration of the antibody (or antigen-binding fragment thereof) or conjugate.

In certain preferred embodiments, the antibodies (or antigen-binding fragments thereof) of the present invention are used in combination with a vaccine. In certain preferred embodiments, the vaccine can be an antigen (e.g., a protein, polypeptide, or carbohydrate molecule) associated with a pathogen, an inactivated or attenuated pathogen, a dendritic cell primed by the antigen, or any combination thereof. In certain preferred embodiments, the pathogen may be a virus (e.g., hepatitis a, b, c virus, human immunodeficiency virus, human papilloma virus, or herpes virus), a fungus, a bacterium, or a parasite.

In the present invention, non-limiting examples of the tumor include melanoma (e.g., metastatic malignant melanoma), breast cancer, kidney cancer (e.g., clear cell cancer), prostate cancer, bladder cancer, pancreatic cancer, lung cancer (e.g., non-small cell lung cancer), colon cancer, esophageal cancer, head and neck squamous cell cancer, liver cancer, ovarian cancer, cervical cancer, thyroid cancer, glioblastoma, glioma, and hematological malignancies (e.g., lymphoma, leukemia), and the like.

Microsatellite Instability (MSI) has previously been reported to be a tumor phenotype associated with inactivating changes in the DNA Mismatch Repair (MMR) gene, which is present in up to 24 types of tumors. MSI is generally expressed as any change in the length of a microsatellite in tumour tissue, due to the insertion or deletion of repeat units, compared to normal tissue. There is increasing evidence that immune checkpoint inhibition is beneficial to microsatellite instability or mismatch repair deficient patient populations. Currently, PD-1 antibodies (drug name: pembrolizumab, trade name: Keytruda) have been approved by the FDA for use in identifying patients with unresectable or metastatic solid tumors with microsatellite high instability (MSI-H) or mismatch repair deficiency (dMMR), regardless of the body site and tissue type of origin of the tumor.

According to the classification criteria for MSI detection established by the National Cancer Institute (NCI) (Boland CR, et al cancer Res.1998Nov 15; 58(22):5248-57.), BAT26, BAT25, D2S123, D5S346, D17S250 for 5 microsatellite standard sites, as compared to normal tissue, are judged to be microsatellite highly unstable (MSI-H), i.e., mismatch repair function defective (dMMR), if the tumor tissue contains 2 or more sites of instability; if less than 2 or no bit instabilities, then microsatellite low instability (MSI-L) or microsatellite stability (MSS), i.e., complete mismatch repair function (pMMR), is determined.

Methods for detecting microsatellite height instability (MSI-H) or mismatch repair deficiency (dMMR) are known to those skilled in the art, e.g.by PCR or secondary sequencing to detect length changes in the above 5 standard microsatellite loci in tumour tissue, and if 2 or more loci are unstable, MSI-H is judged. Alternatively, tumor tissues may be tested for expression of MLH1, MSH2, MSH6, and PSM2 by Immunohistochemistry (ICH), and if all four proteins are positively expressed, pMMR is determined, and if any one protein is negatively expressed, dMMR is determined.

Thus, in certain preferred embodiments, the tumor according to the invention is a tumor with microsatellite height instability (MSI-H) and/or mismatch repair deficiency (dMMR). In certain preferred embodiments, the tumor is selected from the group consisting of colon adenocarcinoma, esophageal carcinoma, rectal adenocarcinoma, gastric adenocarcinoma, uterine body and endometrial carcinoma, and the like.

In the present invention, the infection refers to any infection caused by any pathogenic microorganism such as virus, bacteria, fungi, parasite, etc. Non-limiting examples of such viruses include hepatitis A, B, C, human immunodeficiency virus, human papilloma virus or herpes virus, and the like; non-limiting examples of such bacteria include chlamydia, mycobacteria, staphylococci, streptococci, pneumococci, meningococci, and the like; non-limiting examples of such fungi include Trichophyton, Epidermophyton, Microsporum, Candida albicans, Cryptococcus neoformans, and the like; non-limiting examples of such parasites include plasmodium, schistosoma, leishmania donovani, filarial worms, hookworms, and the like.

The antibody or antigen-binding fragment thereof of the present invention, the conjugate of the present invention, the pharmaceutical composition of the present invention, or the immunogenic composition of the present invention may be formulated into any dosage form known in the medical field, for example, tablets, pills, suspensions, emulsions, solutions, gels, capsules, powders, granules, elixirs, lozenges, suppositories, injections (including injections, sterile powders for injection and concentrated solutions for injection), inhalants, sprays, and the like. The preferred dosage form depends on the intended mode of administration and therapeutic use. The pharmaceutical compositions of the present invention should be sterile and stable under the conditions of manufacture and storage. One preferred dosage form is an injection. Such injections may be sterile injectable solutions. For example, sterile injectable solutions can be prepared by the following methods: the recombinant proteins of the present invention are incorporated in the necessary dosage in an appropriate solvent, and optionally, together with other desired ingredients (including, but not limited to, pH adjusting agents, surfactants, adjuvants, ionic strength enhancers, isotonic agents, preservatives, diluents, or any combination thereof), followed by filter sterilization. In addition, sterile injectable solutions can be prepared as sterile lyophilized powders (e.g., by vacuum drying or freeze-drying) for storage and use. Such sterile lyophilized powders may be dispersed in a suitable carrier, e.g., water for injection (WFI), bacteriostatic water for injection (BWFI), sodium chloride solution (e.g., 0.9% (w/v) NaCl), glucose solution (e.g., 5% glucose), surfactant-containing solution (e.g., 0.01% polysorbate 20), pH buffered solution (e.g., phosphate buffered solution), Ringer's solution, and any combination thereof, prior to use.

Furthermore, the antibody or antigen-binding fragment thereof of the invention or the conjugate of the invention may be present in a pharmaceutical or immunogenic composition in unit dosage form for ease of administration.

The antibody or antigen-binding fragment thereof, conjugate, pharmaceutical composition, or immunogenic composition of the invention can be administered by any suitable method known in the art, including, but not limited to, oral, buccal, sublingual, ocular, topical, parenteral, rectal, intrathecal, intracytoplasmic reticulum, inguinal, intravesical, topical (e.g., powder, ointment, or drops), or nasal route. However, for many therapeutic uses, the preferred route/mode of administration is parenteral (e.g., intravenous or bolus injection, subcutaneous injection, intraperitoneal injection, intramuscular injection). The skilled artisan will appreciate that the route and/or mode of administration will vary depending on the intended purpose. In a preferred embodiment, the antibody or antigen-binding fragment thereof, conjugate, pharmaceutical composition or immunogenic composition of the invention is administered by intravenous injection or bolus injection.

The pharmaceutical or immunogenic compositions of the invention may comprise a "therapeutically effective amount" or a "prophylactically effective amount" of an antibody or antigen-binding fragment or conjugate thereof of the invention. A "prophylactically effective amount" is an amount sufficient to prevent, or delay the onset of disease. By "therapeutically effective amount" is meant an amount sufficient to cure or at least partially arrest the disease and its complications in a patient already suffering from the disease. A therapeutically effective amount of an antibody or antigen-binding fragment thereof of the invention may vary according to the following factors: the severity of the disease to be treated, the general state of the patient's own immune system, the general condition of the patient, e.g. age, weight and sex, the mode of administration of the drug, and other treatments administered concurrently, etc.

In the present invention, the dosage regimen may be adjusted to obtain the optimal desired response (e.g., a therapeutic or prophylactic response). For example, the dosage may be given in a single dose, may be given multiple times over a period of time, or may be reduced or increased proportionally with the exigencies of the therapeutic situation.

A typical, non-limiting range of therapeutically or prophylactically effective amounts of an antibody or antigen-binding fragment thereof of the invention is 0.01-100 mg/kg, e.g., 0.1-100 mg/kg, 0.1-50 mg/kg, or 1-50 mg/kg. It should be noted that the dosage may vary with the type and severity of the condition to be treated. Furthermore, those skilled in the art will appreciate that for any particular patient, the particular dosage regimen will be adjusted over time according to the patient's needs and the professional judgment of the physician; the dosage ranges given herein are for illustrative purposes only and do not limit the use or scope of the pharmaceutical or immunogenic compositions of the invention.

In the present invention, the subject may be a mammal, such as a human.

Detection method and assayMedicine box

The antibodies or antigen-binding fragments thereof of the present invention are capable of specifically binding to PD-1and thus can be used to detect the presence or level of PD-1 in a sample.

Accordingly, in another aspect, the invention provides a kit comprising an antibody or antigen-binding fragment thereof of the invention. In certain preferred embodiments, the antibodies or antigen-binding fragments thereof of the present invention are detectably labeled. In a preferred embodiment, the kit further comprises a second antibody that specifically recognizes the antibody of the invention or an antigen-binding fragment thereof. Preferably, the second antibody further comprises a detectable label.

In the present invention, the detectable label may be any substance detectable by fluorescence, spectroscopic, photochemical, biochemical, immunological, electrical, optical or chemical means. It is particularly preferred that such labels be capable of being adapted for immunological detection (e.g., enzyme-linked immunoassays, radioimmunoassays, fluorescent immunoassays, chemiluminescent immunoassays, etc.). Such labels are well known in the art and include, but are not limited to, enzymes (e.g., horseradish peroxidase, alkaline phosphatase, beta-galactosidase, urease, glucose oxidase, etc.), radionuclides (e.g.,³H、¹²⁵I、³⁵S、¹⁴c or³²P), fluorescent dyes (e.g., Fluorescein Isothiocyanate (FITC), fluorescein, tetramethylrhodamine isothiocyanate (TRITC), Phycoerythrin (PE), texas red, rhodamine, quantum dots, or cyanine dye derivatives (e.g., Cy7, Alexa 750)), luminescent substances (e.g., chemiluminescent substances such as acridine ester compounds), magnetic beads (e.g.,

) A calorimetric label such as colloidal gold or colored glass or plastic (e.g., polystyrene, polypropylene, latex, etc.) beads, and biotin for binding to the label-modified avidin (e.g., streptavidin) described above. Patents that teach the use of such markers include, but are not limited to, U.S. Pat. nos. 3,817,837; 3,850,752, respectively;3,939,350, respectively; 3,996,345; 4,277,437; 4,275,149; and 4,366,241 (all incorporated herein by reference). The markers encompassed by the present invention can be detected by methods known in the art. For example, radioactive labels can be detected using photographic film or scintillation calculators, and fluorescent labels can be detected using photodetectors to detect the emitted light. Enzyme labels are generally detected by providing a substrate for the enzyme and detecting the reaction product produced by the action of the enzyme on the substrate, and calorimetric labels are detected by simply visualizing the colored label. In certain embodiments, a detectable label as described above can be attached to an antibody or antigen-binding fragment thereof of the invention via linkers of varying lengths to reduce potential steric hindrance.

In another aspect, the invention provides a method of detecting the presence or level of PD-1 in a sample, comprising the step of using an antibody or antigen-binding fragment thereof of the invention. In a preferred embodiment, the antibody or antigen-binding fragment thereof of the invention is further provided with a detectable label. In another preferred embodiment, the method further comprises detecting the antibody or antigen-binding fragment thereof of the invention using a reagent bearing a detectable label. The method may be used for diagnostic purposes, or for non-diagnostic purposes (e.g., the sample is a cell sample, not a sample from a patient). In certain preferred embodiments, the PD-1 is human PD-1.

In another aspect, there is provided the use of an antibody or antigen-binding fragment thereof of the invention in the preparation of a kit for detecting the presence or level of PD-1 in a sample. In certain preferred embodiments, the PD-1 is human PD-1.

Definition of terms

In the present invention, unless otherwise specified, scientific and technical terms used herein have the meanings that are commonly understood by those skilled in the art. Also, the procedures of cell culture, biochemistry, nucleic acid chemistry, immunological laboratories and the like used herein are all conventional procedures widely used in the corresponding fields. Meanwhile, in order to better understand the present invention, the definitions and explanations of related terms are provided below.

As used herein, the term "antibody" refers to an immunoglobulin molecule typically composed of two pairs of polypeptide chains, each pair having one Light Chain (LC) and one Heavy Chain (HC). Antibody light chains can be classified as kappa (kappa) and lambda (lambda) light chains. Heavy chains can be classified as μ, δ, γ, α or ε, and the antibody isotypes are defined as IgM, IgD, IgG, IgA, and IgE, respectively. Within the light and heavy chains, the variable and constant regions are connected by a "J" region of about 12 or more amino acids, and the heavy chain also contains a "D" region of about 3 or more amino acids. Each heavy chain consists of a heavy chain variable region (VH) and a heavy chain constant region (CH). The heavy chain constant region consists of 3 domains (CH1, CH2, and CH 3). Each light chain consists of a light chain variable region (VL) and a light chain constant region (CL). The light chain constant region consists of one domain CL. The constant domains are not directly involved in binding of the antibody to the antigen, but exhibit a variety of effector functions, such as may mediate binding of the immunoglobulin to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component of the classical complement system (C1 q). The VH and VL regions can also be subdivided into regions of high denaturation, called Complementarity Determining Regions (CDRs), interspersed with regions that are more conserved, called Framework Regions (FRs). Each V_HAnd V_LBy the following sequence: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4 are composed of 3 CDRs and 4 FRs arranged from amino terminus to carboxy terminus. The variable regions (VH and VL) of each heavy/light chain pair form the antigen-binding sites, respectively. The distribution of amino acids in each region or domain may follow Kabat, Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md. (1987and 1991)), or Chothia&Lesk (1987) J.mol.biol.196: 901-917; chothia et al (1989) Nature 342: 878-883.

As used herein, the term "complementarity determining region" or "CDR" refers to the amino acid residues in the variable region of an antibody that are responsible for antigen binding. The precise boundaries of these amino acid residues may be defined according to various numbering systems known in the art, for example as defined in the Kabat numbering system (Kabat et al, Sequences of Proteins of Immunological Interest,5th Ed. public Health Service, National Institutes of Health, Bethesda, Md.,1991), the Chothia numbering system (Chothia & Lesk (1987) J.Mol.biol.196: 901-917; Chothia et al (1989) Nature 342:878-883) or the IMGT numbering system (Lefranc et al, Dev.Comprant. Immunol.27:55-77,2003). For a given antibody, one skilled in the art will readily identify the CDRs defined by each numbering system. Also, the correspondence between the different numbering systems is well known to those skilled in the art (see, e.g., Lefranc et al, Dev. company. Immunol.27:55-77,2003).

In the present invention, the CDRs contained in the antibodies of the present invention or antigen binding fragments thereof can be determined according to various numbering systems known in the art. In certain embodiments, the CDRs contained by the antibodies or antigen binding fragments thereof of the present invention are preferably determined by the Kabat, Chothia, or IMGT numbering system. In certain embodiments, the CDRs contained by the antibodies or antigen binding fragments thereof of the present invention are preferably determined by the Kabat numbering system.

As used herein, the term "framework region" or "FR" residues refers to those amino acid residues in the variable region of an antibody other than the CDR residues as defined above.

The term "antibody" is not limited by any particular method of producing an antibody. For example, it includes recombinant antibodies, monoclonal antibodies and polyclonal antibodies. The antibody may be of a different isotype, for example, an IgG (e.g., IgG1, IgG2, IgG3, or IgG4 subtype), IgA1, IgA2, IgD, IgE, or IgM antibody.

As used herein, the term "antigen-binding fragment" of an antibody refers to a polypeptide comprising a fragment of a full-length antibody that retains the ability to specifically bind to the same antigen to which the full-length antibody binds, and/or competes with the full-length antibody for specific binding to the antigen, which is also referred to as an "antigen-binding portion". See generally, Fundamental Immunology, Ch.7(Paul, W., ed., 2nd edition, Raven Press, N.Y. (1989), which is incorporated herein by reference in its entirety for all purposesIncluding Fab, Fab ', F (ab')₂Fd, Fv, dAb, and Complementarity Determining Region (CDR) fragments, single chain antibodies (e.g., scFv), chimeric antibodies, diabodies (diabodies), linear antibodies (linear antibodies), nanobodies (technology from Domanitis), domain antibodies (technology from Ablynx), probody, and polypeptides comprising at least a portion of an antibody sufficient to confer specific antigen-binding capability to the polypeptide. Engineered antibody variants are reviewed in Holliger et al, 2005; nat Biotechnol,23: 1126-.

As used herein, the term "full-length antibody" means an antibody consisting of two "full-length heavy chains" and two "full-length light chains". Wherein "full-length heavy chain" refers to a polypeptide chain consisting of, in the N-terminal to C-terminal direction, a heavy chain variable region (VH), a heavy chain constant region CH1 domain, a Hinge Region (HR), a heavy chain constant region CH2 domain, a heavy chain constant region CH3 domain; and, when the full-length antibody is of IgE isotype, optionally further comprising a heavy chain constant region CH4 domain. Preferably, a "full-length heavy chain" is a polypeptide chain consisting of VH, CH1, HR, CH2, and CH3 in the N-terminal to C-terminal direction. A "full-length light chain" is a polypeptide chain consisting of a light chain variable region (VL) and a light chain constant region (CL) in the N-terminal to C-terminal direction. Two pairs of full length antibody chains are linked together by a disulfide bond between CL and CH 1and a disulfide bond between HR of the two full length heavy chains. The full length antibodies of the invention may be from a single species, e.g., human; chimeric antibodies or humanized antibodies are also possible. The full-length antibody of the present invention comprises two antigen-binding sites formed by VH and VL pairs, respectively, that specifically recognize/bind to the same antigen.

As used herein, the term "Fd fragment" means an antibody fragment consisting of VH and CH1 domains; the term "dAb fragment" means an antibody fragment consisting of a VH domain (Ward et al, Nature 341: 544546 (1989)); the term "Fab fragment" means an antibody fragment consisting of the VL, VH, CL and CH1 domains; the term "F (ab')₂Fragment "means an antibody fragment comprising two Fab fragments connected by a disulfide bridge at the hinge region; the term "Fab 'fragment" means a reductively linked F (ab')₂Two in a fragmentThe fragment obtained after disulfide bonding of the heavy chain fragments consists of an intact Fd fragment of the light and heavy chains, consisting of the VH and CH1 domains.

As used herein, the term "Fv fragment" means an antibody fragment consisting of the VL and VH domains of a single arm of an antibody. Fv fragments are generally considered to be the smallest antibody fragments that form an entire antigen binding site. It is generally believed that the six CDRs confer antigen binding specificity on the antibody. However, even one variable region (e.g., an Fd fragment, which contains only three CDRs specific for an antigen) is able to recognize and bind antigen, although its affinity may be lower than the entire binding site.

As used herein, the term "Fc fragment" means an antibody fragment formed by disulfide bonding of the second and third constant regions of a first heavy chain and the second and third constant regions of a second heavy chain of an antibody. The Fc fragment of an antibody has a number of different functions, but is not involved in antigen binding.

As used herein, The term "scFv" refers to a single polypeptide chain comprising VL and VH domains, wherein The VL and VH are linked by a linker (linker) (see, e.g., Bird et al, Science 242: 423-. Such scFv molecules can have the general structure: NH (NH)₂-VL-linker-VH-COOH or NH₂-VH-linker-VL-COOH. Suitable prior art linkers consist of repeated GGGGS amino acid sequences or variants thereof. For example, a polypeptide having an amino acid sequence (GGGGS)₄But variants thereof can also be used (Holliger et al (1993), Proc. Natl. Acad. Sci. USA 90: 6444-. Other linkers useful in the present invention are described by Alfthan et al (1995), Protein Eng.8: 725-. In some cases, a disulfide bond may also be present between the VH and VL of the scFv. As used hereinThe term "di-scFv" refers to an antibody fragment formed by the joining of two scFvs.

As used herein, the term "diabody" means that its VH and VL domains are expressed on a single polypeptide chain, but that a linker is used that is too short to allow pairing between the two domains of the same chain, thereby forcing the domains to pair with the complementary domains of the other chain and generating two antigen binding sites (see, e.g., Holliger P. et al, Proc. Natl. Acad. Sci. USA 90: 6444-.

As used herein, the term "probody" has the meaning commonly understood by those skilled in the art, and refers to a masked antibody that remains inert in healthy tissue, but is specifically activated in the disease environment (e.g., via protease cleavage by proteases that are either abundant or characteristic in the disease environment). For a detailed teaching thereof see, e.g., Desnoyers et al, sci. trans. med.,5:207ra144,2013. Similar masking techniques can be used for any of the antibodies or antigen-binding portions thereof described herein.

Each of the above antibody fragments retains the ability to specifically bind to the same antigen to which the full length antibody binds, and/or competes with the full length antibody for specific binding to the antigen.

Antigen-binding fragments of antibodies (e.g., antibody fragments described above) can be obtained from a given antibody (e.g., an antibody provided herein) using conventional techniques known to those skilled in the art (e.g., recombinant DNA techniques or enzymatic or chemical fragmentation methods), and the antigen-binding fragments of antibodies are specifically screened for specificity in the same manner as for intact antibodies.

Herein, when the term "antibody" is referred to, it includes not only intact antibodies, but also antigen-binding fragments of antibodies, unless the context clearly indicates otherwise.

As used herein, the terms "monoclonal antibody", "mAb" have the same meaning and are used interchangeably to refer to an antibody or a fragment of an antibody from a population of highly homologous antibody molecules, i.e., a population of identical antibody molecules except for natural mutations that may occur spontaneously. Monoclonal antibodies have high specificity for a single epitope on the antigen. Polyclonal antibodies are relative to monoclonal antibodies, which typically comprise at least 2 or more different antibodies that typically recognize different epitopes on an antigen. Furthermore, the modifier "monoclonal" is used merely to indicate that the antibody is characterized as being obtained from a population of highly homologous antibodies, and is not to be construed as requiring production of the antibody by any particular method.

Monoclonal antibodies of the invention can be prepared by a variety of techniques, such as hybridoma techniques (see, e.g., Kohler et al, Nature,256:495,1975), recombinant DNA techniques (see, e.g., U.S. Pat. No.4,816,567), or phage antibody library techniques (see, e.g., Clackson et al, Nature 352: 624-.

Antibodies can be purified by well-known techniques, such as affinity chromatography using protein a or protein G. Subsequently or alternatively, the specific antigen (the target molecule recognized by the antibody) or an epitope thereof may be immobilized on a column and the immunospecific antibody purified by immunoaffinity chromatography. Purification of immunoglobulins can be found, for example, in D.Wilkinson (The Scientist, published by The Scientist, Inc., Philadelphia Pa., Vol.14, No.8(Apr.17,2000), pp.25-28).

As used herein, the term "Chimeric antibody" (scieric antibody) "refers to an antibody in which a portion of the light chain or/and heavy chain is derived from one antibody (which may be derived from a particular species or belonging to a particular antibody class or subclass) and another portion of the light chain or/and heavy chain is derived from another antibody (which may be derived from the same or different species or belonging to the same or different antibody class or subclass), but which nevertheless retains binding activity to an antigen of interest (u.s.p. 4,816,567to harvesting cam et al.; Morrison et al., proc.natl.acad.sci.usa,81: 68516855 (1984)). For example, the term "chimeric antibody" can include an antibody (e.g., a human murine chimeric antibody) in which the heavy and light chain variable regions of the antibody are from a first antibody (e.g., a murine antibody) and the heavy and light chain variable regions of the antibody are from a second antibody (e.g., a human antibody).

As used herein, the term "humanized antibody" refers to a non-human antibody that has been genetically engineered to have an amino acid sequence modified to increase homology to the sequence of a human antibody. Generally, all or a portion of the CDR regions of a humanized antibody are derived from a non-human antibody (donor antibody), and all or a portion of the non-CDR regions (e.g., variable region FR and/or constant regions) are derived from a human immunoglobulin (acceptor antibody). Humanized antibodies typically retain the desired properties of the donor antibody, including, but not limited to, antigen specificity, affinity, reactivity, the ability to increase immune cell activity, the ability to enhance an immune response, and the like. The donor antibody can be a mouse, rat, rabbit, or non-human primate (e.g., cynomolgus monkey) antibody having a desired property (e.g., antigen specificity, affinity, reactivity, ability to increase immune cell activity, and/or ability to enhance an immune response).

Humanized antibodies are particularly advantageous because they retain both the desirable properties of non-human donor antibodies (e.g., murine antibodies) and are effective in reducing the immunogenicity of non-human donor antibodies (e.g., murine antibodies) in human subjects. However, due to matching issues between the CDRs of the donor antibody and the FRs of the acceptor antibody, the expected properties of humanized antibodies (e.g., antigen specificity, affinity, reactivity, ability to increase immune cell activity, and/or ability to enhance an immune response) are generally lower than non-human donor antibodies (e.g., murine antibodies).

In the present invention, in order for the humanized antibody to retain as much as possible the properties of the donor antibody (including, for example, antigen specificity, affinity, reactivity, ability to enhance the activity of immune cells and/or ability to enhance the immune response), the Framework Regions (FRs) in the humanized antibody of the present invention may comprise both the amino acid residues of the recipient antibody of human origin and the amino acid residues of the corresponding donor antibody of non-human origin.

In the present application, the desired properties of the antibodies of the invention include: (1) specifically recognizes/binds to PD-1 (particularly human PD-1); (2) the ability to block the binding of PD-1 to PD-L1; (3) the ability to inhibit and/or block intracellular signaling mediated by PD-1 binding to PD-L1; (4) the ability to increase the activity of immune cells (particularly T cells, e.g., antigen-specific T cells); (5) the ability to enhance an immune response (particularly a T cell-mediated immune response); (6) ability to prevent and/or treat tumors; (7) ability to prevent and/or treat infection. The humanized antibodies of the invention retain one or more of the above-mentioned desirable properties of the parent antibody (murine or murine-human chimeric).

The chimeric antibody or humanized antibody of the present invention can be prepared based on the sequence of the murine monoclonal antibody prepared as described above. DNA encoding the heavy and light chains can be obtained from a murine hybridoma of interest and engineered to contain non-murine (e.g., human) immunoglobulin sequences using standard molecular biology techniques.

To prepare chimeric antibodies, murine immunoglobulin variable regions can be joined to human immunoglobulin constant regions using methods known in the art (see, e.g., U.S. Pat. No.4,816,567 to Cabilly et al). For example, DNA encoding a VH is operably linked to another DNA molecule encoding a heavy chain constant region to obtain a full-length heavy chain gene. The sequence of the Human heavy chain constant region gene is known in the art (see, e.g., Kabat, E.A. et al (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. department of Health and Human Services, NIH Publication No.91-3242), and DNA fragments comprising these regions can be obtained by standard PCR amplification. The heavy chain constant region may be an IgG1, IgG2, IgG3, IgG4, IgA, IgE, IgM, or IgD constant region, but is typically preferably an IgG1 or IgG4 constant region. For example, the DNA encoding VL is operably linked to another DNA molecule encoding a light chain constant region CL to obtain a full-length light chain gene (as well as the Fab light chain gene). The sequence of the Human light chain constant region gene is known in the art (see, e.g., Kabat, E.A. et al (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. department of Health and Human Services, NIH Publication No.91-3242), and DNA fragments comprising these regions can be obtained by standard PCR amplification. The light chain constant region may be a kappa or lambda constant region, but is typically preferably a kappa constant region.

For the preparation of humanized antibodiesMurine CDR regions are inserted into human framework sequences using Methods known in the art (see, U.S. Pat. No.5,225,539 to Winter; U.S. Pat. Nos.5,530,101; 5,585,089; 5,693,762 and 6,180,370 to Queen et al; and Lo, Benny, K.C., editor, in Antibody Engineering: Methods and Protocols, volume 248, Humana Press, New Jersey, 2004). Alternatively, transgenic animals can also be used which are capable of not producing endogenous immunoglobulins after immunization and which are capable of producing a complete human antibody repertoire. For example, it has been reported that homozygous deletion of the antibody heavy chain joining region (JH) gene in chimeric and germline mutant mice completely inhibits endogenous antibody production, and then transfer of a human germline immunoglobulin gene array into the germline mutant mice results in the mice producing human antibodies upon encountering antigen stimulation (see, e.g., Jakobovits et al, 1993, Proc. Natl. Acad. Sci. USA 90: 2551; Jakobovits et al, 1993, Nature 362: 255-. Non-limiting examples of such transgenic animals include, HuMAb mice (Metarex, Inc.) that contain a human immunoglobulin gene minilocus (minioci) encoding unrearranged human heavy (μ and γ) and kappa light chain immunoglobulin sequences, plus targeted mutations that inactivate endogenous μ and kappa chain loci (see, e.g., Lonberg et al (1994) Nature 368(6474): 856-859); or "KM mice carrying human heavy chain transgenes and human light chain transchromosomes^TM"(see patent application WO 02/43478). Other methods of humanizing antibodies include phage display techniques (Hoogenboom et al, 1991, J.mol.biol.227: 381; Marks et al, J.mol.biol.1991, 222: 581 597; Vaughan et al, 1996, Nature Biotech 14: 309).

As used herein, the term "degree of humanization" is an index used to evaluate the number of non-human amino acid residues in a humanized antibody. The degree of humanization of a humanized antibody can be calculated, for example, by: the degree of humanization is (number of amino acids in the FR region-number of non-human amino acids remaining in the FR region)/number of amino acids in the FR region × 100%.

As used herein, the term "germline antibody gene (germline antibody gene)" or "germline antibody gene segment (germline antibody gene segment)" refers to immunoglobulin-encoding sequences present in the genome of an organism that have not undergone a maturation process that can lead to genetic rearrangements and mutations that express specific immunoglobulins. In the present invention, the expression "heavy chain germline gene" means the germline antibody gene or gene segment encoding the immunoglobulin heavy chain, which includes the V gene (variable), the D gene (diversity), the J gene (conjugation), and the C gene (constant); similarly, the expression "light chain germline gene" refers to germline antibody genes or gene segments encoding immunoglobulin light chains, which include the V gene (variable), the J gene (junction), and the C gene (constant). In the present invention, the amino acid sequence encoded by the germline antibody gene or germline antibody gene segment is also referred to as "germline sequence". Germline antibody genes or germline antibody gene fragments and their corresponding germline sequences are well known to those skilled in the art and can be obtained or queried from specialized databases (e.g., IMGT, unsmig, NCBI, or VBASE 2).

As used herein, the term "specific binding" refers to a non-random binding reaction between two molecules, such as a reaction between an antibody and an antigen against which it is directed. The strength or affinity of a specific binding interaction may be the equilibrium dissociation constant (K) of the interaction_D) And (4) showing. In the present invention, the term "K_D"refers to the dissociation equilibrium constant for a particular antibody-antigen interaction, which is used to describe the binding affinity between an antibody and an antigen. The smaller the equilibrium dissociation constant, the more tight the antibody-antigen binding and the higher the affinity between the antibody and the antigen. In certain embodiments, an antibody that specifically binds to (or is specific for) an antigen means that the antibody has less than about 10^-9M, e.g. less than about 10^-9M、10^-10M、10^-11M or 10^-12M or less affinity (K)_D) Binding the antigen. Specific binding properties between two molecules can be determined using methods well known in the art, for example in a BIACORE instrument using Surface Plasmon Resonance (SPR).

As used herein, the term "vector" refers to a nucleic acid delivery vehicle into which a polynucleotide can be inserted. When a vector is capable of expressing a protein encoded by an inserted polynucleotide, the vector is referred to as an expression vector. The vector may be introduced into a host cell by transformation, transduction, or transfection, and the genetic material elements carried thereby are expressed in the host cell. Vectors are well known to those skilled in the art and include, but are not limited to: a plasmid; phagemid; a cosmid; artificial chromosomes such as Yeast Artificial Chromosomes (YACs), Bacterial Artificial Chromosomes (BACs), or artificial chromosomes (PACs) derived from P1; bacteriophage such as lambda phage or M13 phage, animal virus, etc. Animal viruses that may be used as vectors include, but are not limited to, retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (e.g., herpes simplex virus), poxviruses, baculoviruses, papilloma viruses, papilloma polyoma vacuolatum viruses (e.g., SV 40). A vector may contain a variety of elements that control expression, including, but not limited to, promoter sequences, transcription initiation sequences, enhancer sequences, selection elements, and reporter genes. In addition, the vector may contain a replication initiation site.

As used herein, the term "host cell" refers to a cell that can be used for introducing a vector, and includes, but is not limited to, prokaryotic cells such as Escherichia coli or Bacillus subtilis, fungal cells such as yeast cells or Aspergillus, insect cells such as S2 Drosophila cells or Sf9, or animal cells such as fibroblast, CHO cells, COS cells, NSO cells, HeLa cells, BHK cells, HEK 293 cells, or human cells.

As used herein, the term "identity" is used to refer to the match of sequences between two polypeptides or between two nucleic acids. When a position in both of the sequences being compared is occupied by the same base or amino acid monomer subunit (e.g., a position in each of two DNA molecules is occupied by adenine, or a position in each of two polypeptides is occupied by lysine), then the molecules are identical at that position. The "percent identity" between two sequences is a function of the number of matching positions shared by the two sequences divided by the number of positions compared x 100. For example, if 6 of 10 positions of two sequences match, then the two sequences have 60% identity. For example, the DNA sequences CTGACT and CAGGTT share 50% identity (3 of the total 6 positions match). Typically, the comparison is made when the two sequences are aligned to yield maximum identity. Such alignments can be performed by using, for example, Needleman et al (1970) j.mol.biol.48: 443-453. The algorithm of E.Meyers and W.Miller (Compout.appl biosci., 4:11-17(1988)) which has been incorporated into the ALIGN program (version 2.0) can also be used to determine percent identity between two amino acid sequences using a PAM120 weight residue table (weight residue table), a gap length penalty of 12, and a gap penalty of 4. Furthermore, percent identity between two amino acid sequences can be determined using the Needleman and Wunsch (J MoI biol.48: 444-.

As used herein, the term "conservative substitution" means an amino acid substitution that does not adversely affect or alter the intended properties of the protein/polypeptide comprising the amino acid sequence. For example, conservative substitutions may be introduced by standard techniques known in the art, such as site-directed mutagenesis and PCR-mediated mutagenesis. Conservative amino acid substitutions include those in which an amino acid residue is replaced with an amino acid residue having a similar side chain, e.g., a substitution with a residue that is physically or functionally similar to the corresponding amino acid residue (e.g., of similar size, shape, charge, chemical properties, including the ability to form covalent or hydrogen bonds, etc.). Families of amino acid residues with similar side chains have been defined in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, and histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, tryptophan), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), beta-branched side chains (e.g., threonine, valine, isoleucine), and aromatic side chains (e.g., tyrosine, phenylalanine tryptophan, histidine). Thus, it is preferred to replace the corresponding amino acid residue with another amino acid residue from the same side chain family. Methods for identifying conservative substitutions of amino acids are well known in the art (see, e.g., Brummell et al, biochem.32:1180-1187 (1993); Kobayashi et al Protein Eng.12(10):879-884 (1999); and Burks et al, Proc. Natl Acad. set USA 94:412-417(1997), which are incorporated herein by reference).

The twenty conventional amino acids referred to herein are written following conventional usage. See, for example, Immunology-A Synthesis (2nd Edition, E.S. Golub and D.R.Gren, eds., Sinauer Associates, Sunderland, Mass. (1991)) which is incorporated herein by reference. In the present invention, the terms "polypeptide" and "protein" have the same meaning and are used interchangeably. Also, in the present invention, amino acids are generally represented by single-letter and three-letter abbreviations as is well known in the art. For example, alanine can be represented by A or Ala.

As used herein, the term "pharmaceutically acceptable carrier and/or excipient" refers to carriers and/or excipients that are pharmacologically and/or physiologically compatible with the subject and active ingredient, which are well known in the art (see, e.g., Remington's Pharmaceutical sciences. edited by geno AR,19th ed. pennsylvania: mach Publishing Company,1995), and include, but are not limited to: pH adjusting agents, surfactants, adjuvants, ionic strength enhancers, diluents, agents to maintain osmotic pressure, agents to delay absorption, preservatives. For example, pH adjusting agents include, but are not limited to, phosphate buffers. Surfactants include, but are not limited to, cationic, anionic or nonionic surfactants, such as Tween-80. Ionic strength enhancers include, but are not limited to, sodium chloride. Preservatives include, but are not limited to, various antibacterial and antifungal agents, such as parabens, chlorobutanol, phenol, sorbic acid, and the like. Agents that maintain osmotic pressure include, but are not limited to, sugars, NaCl, and the like. Agents that delay absorption include, but are not limited to, monostearate salts and gelatin. Diluents include, but are not limited to, water, aqueous buffers (e.g., buffered saline), alcohols and polyols (e.g., glycerol), and the like. Preservatives include, but are not limited to, various antibacterial and antifungal agents, for example, thimerosal, 2-phenoxyethanol, parabens, chlorobutanol, phenol, sorbic acid, and the like. Stabilizers have the meaning generally understood by those skilled in the art to be capable of stabilizing the desired activity of the active ingredient in a medicament, including, but not limited to, sodium glutamate, gelatin, SPGA, sugars (such as sorbitol, mannitol, starch, sucrose, lactose, dextran, or glucose), amino acids (such as glutamic acid, glycine), proteins (such as dried whey, albumin, or casein) or degradation products thereof (such as lactalbumin hydrolysate), and the like. In certain exemplary embodiments, the pharmaceutically acceptable carrier or excipient comprises a sterile injectable liquid (such as an aqueous or non-aqueous suspension or solution). In certain exemplary embodiments, such sterile injectable liquids are selected from water for injection (WFI), bacteriostatic water for injection (BWFI), sodium chloride solutions (e.g., 0.9% (w/v) NaCl), glucose solutions (e.g., 5% glucose), surfactant-containing solutions (e.g., 0.01% polysorbate 20), pH buffered solutions (e.g., phosphate buffered solutions), Ringer's solution, and any combination thereof.

As used herein, the term "prevention" refers to a method performed in order to prevent or delay the onset of a disease or disorder or symptom (e.g., tumor or infection) in a subject. As used herein, the term "treatment" refers to a method performed in order to obtain a beneficial or desired clinical result. For purposes of the present invention, beneficial or desired clinical results include, but are not limited to, alleviation of symptoms, diminishment of extent of disease, stabilization (i.e., no longer worsening) of the state of the disease, delay or slowing of disease progression, amelioration or palliation of the state of the disease, and remission (whether partial or total), whether detectable or undetectable. Furthermore, "treatment" may also refer to prolonging survival as compared to expected survival (if not treated).

As used herein, the term "subject" refers to a mammal, e.g., a primate mammal, e.g., a human. In certain embodiments, the subject (e.g., human) has a tumor or an infection, or is at risk for having a disease as described above.

As used herein, the term "effective amount" refers to an amount sufficient to obtain, or at least partially obtain, a desired effect. For example, a prophylactically effective amount (e.g., tumor or infection) refers to an amount sufficient to prevent, or delay the onset of a disease (e.g., tumor or infection); a therapeutically effective amount for a disease is an amount sufficient to cure or at least partially arrest the disease and its complications in a patient already suffering from the disease. It is well within the ability of those skilled in the art to determine such effective amounts. For example, an amount effective for therapeutic use will depend on the severity of the disease to be treated, the general state of the patient's own immune system, the general condition of the patient, e.g., age, weight and sex, the mode of administration of the drug, and other treatments administered concurrently, and the like.

As used herein, the term "immune cell" includes cells having hematopoietic origin and functioning in an immune response, such as lymphocytes, e.g., B cells and T cells; a natural killer cell; myeloid cells, such as monocytes, macrophages, eosinophils, mast cells, basophils and granulocytes. In certain preferred embodiments, the immune cell is a T cell, such as a cytotoxic T Cell (CTL), an antigen-specific T cell, or a tumor-infiltrating T cell (TIL-T).

As used herein, the term "immune response" refers to the action of immune cells (e.g., lymphocytes, antigen presenting cells, phagocytes, or granulocytes) and soluble macromolecules produced by the immune cells or liver (including antibodies, cytokines, and complement) that results in the selective damage, destruction, or elimination of invading pathogens, cells or tissues infected by pathogens, cancer cells, or normal human cells or tissues in the context of autoimmunity or pathological inflammation from the human body. In certain preferred embodiments, the immune response is a T cell-mediated immune response that results when the T cell-specific antigen stimulates the T cell. Non-limiting examples of responses produced by T cells upon antigen-specific stimulation include T cell proliferation and cytokine (e.g., IL-2) production.

Advantageous effects of the invention

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

(1) the antibody of the invention can not only specifically recognize/bind PD-1and block the binding of PD-1and PD-L1, but also enhance the activity of immunocytes in vitro/in vivo and stimulate immune response. Thus, the antibodies of the invention have potential for use in the prevention and/or treatment of tumors or infections.

(2) The antibodies (particularly humanized antibodies) of the invention not only retain the functions and properties of the parent murine antibody, thereby having potential for the prevention and treatment of tumors or infections; but also has a high degree of humanisation so that it can be safely administered to human subjects without eliciting an immunogenic response. It is particularly surprising that the antibodies of the invention have significantly improved blocking activity and the ability to induce T cell activation compared to commercial anti-PD-1 antibodies. Thus, the antibodies of the invention (particularly humanized antibodies) are of significant clinical value.

Embodiments of the present invention will be described in detail below with reference to the drawings and examples, but those skilled in the art will understand that the following drawings and examples are only for illustrating the present invention and do not limit the scope of the present invention. Various objects and advantageous aspects of the present invention will become apparent to those skilled in the art from the accompanying drawings and the following detailed description of the preferred embodiments.

Drawings

FIG. 1A schematically shows the principle of ELISA for detecting the binding activity between an antibody and PD-1/His.

FIG. 1B schematically shows the principle of FACS method for detecting the binding activity between an antibody and human PD-1 expressed on the cell surface.

FIG. 1C schematically shows the principle of ELISA to detect the ability of antibodies to block the binding of human PD-1/His to PD-L1/Fc.

FIG. 2 shows the results of detection of the binding activity of the murine antibodies (16F2, 10D6, 48G 7and 17D5) to human PD-1and murine PD-1 by ELISA in example 1.

FIG. 3 shows the results of the detection of the binding activity of murine antibodies (16F2, 10D6, 48G 7and 17D5) to cell surface-expressed human PD-1 by FACS method in example 2.

FIG. 4 shows the results of the detection of the ability of murine antibodies (16F2, 10D6, 48G 7and 17D5) to block the binding between human PD-1/His and PD-L1/Biotin by the CLEIA method in example 2. Control refers to a positive Control group in which PBS was used instead of anti-PD-1 monoclonal antibody.

FIG. 5 shows the inhibition rate curves of murine antibodies (16F2, 10D6, 48G 7and 17D5) on binding between human PD-1/His and PD-L1/Biotin in example 2. Control refers to a positive Control group in which PBS was used instead of anti-PD-1 monoclonal antibody.

FIG. 6 shows the results of measuring the level of IL-2 secretion induced by murine antibodies (16F2, 10D6, 48G 7and 17D5) in example 4, wherein control refers to a negative control group to which an anti-PD-1 antibody was not added.

FIG. 7 shows the results of detection of the antigen-binding activity of the chimeric antibodies 17D5-cAb and 48G7-cAb by ELISA in example 5.

FIG. 8 shows the results of the detection of the binding activity of humanized antibodies 17D5H1, 17D5H2, 48G7H1, 48G7H2 by the CLEIA method in example 6. Wherein PEM is Pembrolizumab, NIV is Nivolumab.

FIG. 9 shows the results of the detection of the blocking activity of humanized antibodies 17D5H1, 17D5H2, 48G7H1, 48G7H2 by the CLEIA method in example 6. Wherein PEM is Pembrolizumab, NIV is Nivolumab.

FIG. 10 shows the results of measurement of IL-2 secretion levels induced by humanized antibodies 17D5H1, 17D5H2, 48G7H1, 48G7H2 in example 6. Wherein PEM is Pembrolizumab, NIV is Nivolumab, and control is negative control group without anti-PD-1 antibody.

Sequence information

Information on the partial sequences to which the present invention relates is provided in table 1 below.

Table 1: description of the sequences

Detailed Description

The invention will now be described with reference to the following examples, which are intended to illustrate the invention, but not to limit it.

Unless otherwise indicated, the molecular biological experimental methods and immunoassay methods used in the present invention are essentially described by reference to j.sambrook et al, molecular cloning: a laboratory manual, 2nd edition, cold spring harbor laboratory Press, 1989, and F.M. Ausubel et al, eds. molecular biology laboratory Manual, 3 rd edition, John Wiley & Sons, Inc., 1995; the use of restriction enzymes follows the conditions recommended by the product manufacturer. The examples are given by way of illustration and are not intended to limit the scope of the invention as claimed.

Example 1: production of murine anti-PD-1 monoclonal antibodies

In this example, anti-human PD-1 monoclonal antibodies were obtained by conventional hybridoma fusion techniques; screening monoclonal antibodies with high binding activity by enzyme-linked immunosorbent assay (ELISA) and flow sorting (FACS); monoclonal antibodies that highly blocked the interaction between PD-1and PD-L1 were screened using chemiluminescence enzyme-linked immunoassay (CLEIA).

1.1 construction of PD-1 expression plasmid

A plasmid for PD-1 expression, named plv-PD-1, was constructed by amplifying the full-length human PD-1 sequence (genbank: NM-005018.2) by PCR using the primers shown in Table 2 and ligating it into plv vector (Addgene).

In addition, a plasmid (named plv-PD-L1) expressing full-length human PD-L1, the sequence of which is shown in genbank: NM _ 014143.3.

Table 2: primer sequences

1.2 construction of cell lines stably expressing PD-1

The plv-PD-1 plasmid and the packaging plasmid psPAX2(Addgene, cat. No. 12260) and pMD2.G (Addgene, cat. No. 12259) were co-transfected into 293T cells (purchased from ATCC, Inc., USA, cat. No. CRL-3216) using lipofectamine 2000 transfection reagent^TM). After 48 hours, the virus supernatant was collected by filtration, infected with U-2OS (purchased from ATCC, Inc., USA, Cat. No. HTB-96), and subjected to pressure-screening using a medium containing 1. mu.g/mL puromycin (Invitrogen, Cat. No. A11138-03) to select a cell line stably expressing human PD-1. Individual clones were obtained by limiting dilution. Finally, U-2OS cell clone (hereinafter referred to as U-2OS/PD-1) highly expressing PD-1 was screened with an anti-PD-1 antibody (eBioscience, Inc., cat. No. 16-9989-82) for subsequent experiments.

In addition, an plv-PD-L1 plasmid and a packaging plasmid were co-transfected into 293T cells by the same method, then the virus supernatant was infected with the 293T cells, individual clones were obtained by the same method, and finally a 293T cell clone highly expressing PD-L1 (hereinafter, abbreviated as 293T/PD-L1) was screened using an anti-PD-L1 antibody (BD Co., cat No. 558017) for subsequent experiments.

1.3 antigen immunization and cell fusion

6 weeks old BALB/c mice (obtained from Beijing Wittingle laboratory animal technology Co., Ltd.) were immunized with 100. mu.g of spleen and injected with 1.1The plv-PD-1 plasmid of (1), and primary immunization is carried out. Week 2 will be 1X 10⁶U-2OS/PD-1 cells were injected intraperitoneally into BALB/c mice after primary immunization. The same dose was used for the immunopotentiation at week 3, week 4, week 5 and week 6, and at week 6, serum was collected and tested for multiple antiserum titer on U-2OS/PD-1 cells by ELISPOT method, and then mice with high titer were selected for spleen immunization and injected with 1X 10⁶U-2OS/PD-1 cells. Three days later, standard techniques (Gefter M L, Margulies D H, et al. A simple method for polyethylene glycol-protein hybridization of mouse myobacteria cells [ J]Somatic Cell Gene, 1977,3: 231-.

1.4 detection of Positive clones

Human PD-1/His protein (Nano Biological Inc., cat # 10377-H08H) was diluted with CB buffer, coated in irradiated polystyrene 96-well plates at 100 ng/well, and after blocking with blocking solution, was drained and stored at 4 ℃ for further use. Adding diluted culture supernatant of fused myeloma cells into coated plate, reacting at 37 deg.C for 1h, washing the plate for 5 times, drying, adding HRP-labeled GAM secondary antibody (NOVUS, cat No. NBP1-73693), reacting at 37 deg.C for 0.5h, washing the plate for 5 times, and drying. The chemiluminescent chromogenic substrate was added and immediately placed in a microplate reader (Anchart laboratory instruments, PHOMO) for data reading. And (4) taking the cell culture medium as a negative control, and primarily judging as positive clone when the OD value is more than 2 times that of the negative control.

1.5 Mono-cloning and antibody expression purification

Positive cell lines can be subcloned by standard limiting dilution methods as described by Goding, Monoclonal Antibodies: Principles and Practice, pp.59-103, Academic Press, 1996. Taking out antibody positive hole cells, respectively seeding cell suspension into a micro culture disc by using a pipette, wherein the cell content is respectively 10/hole, 2/hole and 1/hole, selecting a hole with only one colony growing after culturing for 7-14 days, and detecting the binding activity of the culture solution antibody and the U-2OS/PD-1 cells. And (4) carrying out expanded culture on the antibody positive hole cells to establish a clone strain.

In addition, hybridoma cells can also be grown in animals as ascites tumors. By using traditionsThe immunoglobulin purification method of (1), such as protein A agarose gel, hydroxyapatite chromatography, gel electrophoresis, dialysis or affinity chromatography, can be used to separate the monoclonal antibody secreted by the subcloned cells from the cell culture fluid, ascites fluid or serum. Ascites is collected from mice producing ascites tumor, cell debris is removed by centrifugation at 3000rpm for 20min, the supernatant is purified by affinity chromatography after particulate matter is removed by a 0.22 μm disposable filter, and IgG antibody is purified by Protein A chromatography medium (GE Healthcare, cat # 17-1279-03), all in strict accordance with the instructions of the product

The purification is completed on an explor liquid chromatography purification system. The purity of the purified antibody was 95% or more, and the antibody concentration was measured by the Bradford method.

1.6 sequence analysis of murine anti-PD-1 monoclonal antibody

4 murine antibodies specifically binding to PD-1 were co-prepared according to the above method and named 16F2, 10D6, 48G 7and 17D5, respectively. The VH and VL sequences of the four antibodies are shown in table 3 below. Further, the CDR Sequences of four murine mAbs were determined using the method described by Kabat et al (Kabat et al, Sequences of Proteins of Immunological Interest, fifth edition, Public Health Service, national institutes of Health, Besseda, Md. (1991), p.647-669) (Table 4).

TABLE 3 murine antibody light and heavy chain variable region amino acid sequences

TABLE 4 CDR sequences of murine antibodies

1.7 ELISA method for detecting reactivity of PD-1 antibody and PD-1/His protein

The principle of ELISA for detecting the binding activity of PD-1 antibody is shown in FIG. 1A.

Human PD-1/His protein (Sino Biological Inc., cat # 10377-H08H) or murine PD-1/His protein (Sino Biological Inc., cat # 50124-M03H) was diluted with CB buffer, coated in irradiated polystyrene 96-well plates at 100 ng/well, and after blocking with blocking solution, was drained and stored at 4 ℃ for future use. Murine antibodies (16F2, 10D6, 48G 7and 17D5) diluted to 0.1. mu.g/mL with PBS were added to the coated plates, reacted at 37 ℃ for 1h, washed 5 times, spun-dried, added with secondary HRP-labeled antibody, reacted at 37 ℃ for 0.5h, washed 5 times, and spun-dried, respectively. The chemiluminescent chromogenic substrate was added and immediately placed in a microplate reader (Anchart laboratory instruments, PHOMO) for data reading. PBS was used as a negative control.

As a result, as shown in FIG. 2, four anti-human PD-1 murine antibodies (16F2, 10D6, 48G 7and 17D5) all bound to human PD-1 protein, but not to murine PD-1 protein.

Example 2: property identification of murine anti-PD-1 monoclonal antibody

2.1 Detection of PD-1 antibody binding Activity by FACS method

The principle of FACS method for detecting the binding activity of PD-1 antibody is shown in FIG. 1B.

The U-2OS/PD-1 cells to be detected were digested and blown up to prepare a single cell suspension, centrifuged and resuspended in PBS containing 3% fetal bovine serum. The cell suspension was filtered through a 200 mesh screen for detection, and approximately 1X 10 cells were collected per cell sample⁵And (4) cells. The antibody to be tested was diluted to 1. mu.g/mL and incubated with the above cells, and the binding activity of the PD-1 antibody was detected by using a FITC-labeled goat anti-mouse IgG antibody (Sigma, cat. No. F9006) and a flow cytometer (BD, FACS Asia II) using flow cytometry. The abscissa represents the fluorescence value of the test cells.

As a result, as shown in FIG. 3, all of the four murine anti-human PD-1 antibodies bound 100% to U-2OS cells expressing PD-1 protein. The positive control was a commercial anti-human PD-1 antibody (eBioscience, Inc., cat 16-9989-82), the FITC-labeled goat anti-mouse IgG antibody was a secondary antibody, and the negative control was PBS.

2.2 Detection of blocking activity of PD-1 antibody by CLEIA method

The functional schematic diagram of detecting the binding ability between human PD-1/His and PD-L1/Biotin by the CLEIA method is shown in FIG. 1C.

PD-1/Fc protein (BPS bioscience, cat. 71106) was diluted with CB buffer, coated at 100 ng/well in an irradiated, opaque polystyrene 96-well plate, blocked with a blocking solution, dried by suction, and stored at 4 ℃ for use. The anti-PD-1 monoclonal antibody was diluted in a gradient with an initial concentration of 60. mu.g/mL, and seven gradients of 20. mu.g/mL, 6.67. mu.g/mL, 2.22. mu.g/mL, 0.74. mu.g/mL, 0.25. mu.g/mL, 0.082. mu.g/mL, 0.027. mu.g/mL were serially diluted 3-fold. anti-PD-1 monoclonal antibodies or PBS diluted to different gradients and 100 ng/hole biotinylated PD-L1 protein PD-L1/Biotin (BPS bioscience, cat 71105) are added into the coated plate, unbound free protein or antibody is washed away after sufficient reaction, horseradish peroxidase-labeled avidin-HRP (GE, cat RPN4401) is added as a secondary antibody for reaction, unbound enzyme-labeled avidin is washed away, and a chemiluminescent chromogenic substrate is finally added, and the luminescent Value (RLU, Relative chemiluminescent Value) is read by a chemiluminescent instrument (Berthod, Orioni). The positive control is a detection group which is not added with the anti-PD-1 monoclonal antibody and is replaced by PBS. The values read by the chemiluminescence apparatus indicate the strength of the interaction of PD-1 with PD-L1 blocked by the PD-1 antibody. Wherein the RLU value is plotted as the ordinate against the log of the antibody concentration₁₀The reaction curve is plotted on the abscissa. Meanwhile, the corresponding antibody blocking rate can be calculated by a formula, wherein the blocking rate is (log)₁₀Positive control-log₁₀Reaction value)/(log₁₀Positive control-log₁₀Blank control). Calculation of the half inhibitory concentration (or half inhibitory Rate), IC, Using PRISM 6 software (GraphPad, Inc.)₅₀。

The results are shown in FIGS. 4 and 5, respectively. FIG. 4 shows the dose-dependent response curve of the murine mAb blocking the binding ability between human PD-1/His and PD-L1/Biotin, and the results show that murine antibodies 10D6, 48G7, 16F2 and 17D5 can effectively block the mutual combination between PD-1and PD-L1 proteins in vitro. FIG. 5 shows the half-inhibitory rate (IC) of antibodies blocking the interaction between PD-1and PD-L1 proteins₅₀) IC of 17D5, 48G7, 16F2, 10D6₅₀5.019 mu g/mL, 7.99 mu g/mL, 11.23 mu g/mL and 7.412 mu g/mL respectively show that the peptide has good inhibitory activity on the mutual binding between PD-1and PD-L1 proteins.

Example 3: detection of antigen affinity activity of antibody by Surface Plasmon Resonance (SPR)

Antigen affinity determination of the antibody was performed using BIACORE (tm) instrument (GE Healthcare, model BIACORE 3000). Anti-mouse Fc CM5 biosensor chips (GE Healthcare) were generated using standard primary amine coupling protocols. Murine antibody was captured on the anti-mouse Fc surface at a flow rate of 10. mu.l per minute for 1 minute. PD-1/Fc serially diluted from 3.3nM to 120nM was injected at the antibody-binding surface at a flow rate of 30. mu.l per minute for 3 minutes, followed by a 10 minute dissociation phase. Binding rate (K) was calculated using EIA evaluation software (GE Healthcare) on a one-to-one Langmuir (Langmuir) binding model_aOr K_on) And dissociation rate (K)_dOr K_off). At a ratio of K_off/K_onTo calculate the equilibrium constant (K)_D). The results are shown in the following table. The results show that 17D5, 48G7, 16F2, 10D6 all bind to human PD-1 protein with high affinity.

Table 5: results of SPR measurement

Antibodies	K_D
		10D6	6.01×10^-11
48G7	4.00×10^-11
		16F2	8.00×10^-11
17D5	5.91×10^-12

Example 4: evaluation of mouse anti-PD-1 monoclonal antibody induced T cell activation ability

100ng of anti-CD3 antibody per well (Biolegend, cat # 317302) and 100ng of CD28 antibody per well (Biolegend, cat # 302902) were coated in 96-well plates, peripheral blood mononuclear PBMC cells were separated from healthy human whole blood using Ficoll-Paque PLUS (GE Healthcare, cat # 17-1440-02) density gradient centrifugation, and 10 cells were separated⁴Adding the cells into the micro-wells, stimulating for 2 days, and adding 5 × 10⁴293T/PD-L1 cells obtained in example 1and various concentrations of PD-1 antibody (i.e., 10. mu.g/mL, 1. mu.g/mL, 0.1. mu.g/mL, 0.01. mu.g/mL, 0.001. mu.g/mL) were stimulated for 2-4 days while microwells to which no PD-1 antibody was added were used as control. Collecting supernatant and using human IL-2ELISA detection kit (R)&D Systems, Cat. No. D2050) was assayed for the level of secretion of IL-2.

As a result, as shown in table 6 and fig. 6, the IL-2 secretion levels were significantly increased after the treatment with 10D6, 48G7, 16F2, and 17D5, compared to the control group. This result indicates that 10D6, 48G7, 16F2 and 17D5 all were able to significantly induce T cell activation, enhance T cell immune response and thus kill tumor cells, wherein the activity of 17D5 inducing T cell activation was the highest (the baseline average value of IL-2 secretion was 26.2ng/mL, and the peak value was 1504.9 ng/mL). It follows that the antibodies of the invention are capable of enhancing immune cell activity and stimulating an immune response, and are therefore particularly useful in the treatment of tumors or infections.

Table 6: measurement of IL-2 secretion level

Example 5: humanization of murine anti-PD-1 monoclonal antibodies

The gene sequences encoding the heavy and light chain variable regions of the mouse monoclonal antibodies 17D5 and 48G7 were ligated to the gene sequences encoding the heavy and light chain constant regions of the human antibody, respectively, and recombinant-expressed in CHO cells to obtain chimeric antibodies 17D5-cAb and 48G 7-cAb. And binding activity of the chimeric antibody to human PD-1 was measured at various concentrations by ELISA as described in 1.7, and the results are shown in FIG. 7. The results showed that the chimeric antibodies 17D5-cAb and 48G7-cAb maintained good binding activity against human PD-1.

Further, in order to reduce immunogenicity caused when the alloantibody is administered to a human subject, it is necessary to humanize the mouse monoclonal antibodies 17D5 and 48G7 by a CDR grafting method. Based on extensive analysis and experiments, the present inventors used human germline gene sequences IGVH3-23 × 04(SEQ ID NO: 45) and IGKV3-11 × 01(SEQ ID NO: 46) as human antibody templates for receiving CDRs of mouse monoclonal antibody 17D5, which could be well matched with the heavy and light chain CDRs of 17D5, and could maximally retain 17D5 binding affinity for antigen; human germline gene sequences IGVH1-2 x 02(SEQ ID NO: 47) and IGKV1-16 x 01(SEQ ID NO: 48) were used as human antibody templates for receiving the CDRs of mouse monoclonal antibody 48G7, which were well matched to the heavy and light chain CDRs of 48G7, and which were able to retain 48G7 binding affinity to the greatest extent. The human embryonic gene sequence is SEQ ID NOs: specific sequences from 45 to 48 can also be found in public databases such as NCBI, Kabat and GenBank.

The heavy and light chain CDR regions of mouse monoclonal antibodies 17D5 and 48G7 were grafted onto the FR frameworks of humanized templates (i.e., human germline gene sequences IGVH3-23 × 04(SEQ ID NO: 45) and IGKV3-11 × 01(SEQ ID NO: 46) and IGVH1-2 × 02(SEQ ID NO: 47) and IGKV1-16 × 01(SEQ ID NO: 48), respectively). Furthermore, in combination with the analysis of the sequence and the conventional humanization experience, a series of back mutations were made to the amino acid residues in the FR region of the humanized template so that the humanized antibody retains the antigen-binding ability of the murine antibody as much as possible. 2 humanized 17D5 antibodies (designated 17D5H 1and 17D5H2) and 2 humanized 48G7 antibodies (designated 48G7H 1and 48G7H2) were prepared.

The amino acid sequences of the humanized antibodies 17D5H1, 17D5H2, 48G7H1, 48G7H2 are shown in the table below. In addition, also by the formula: the degrees of humanization of 17D5H1, 17D5H2, 48G7H1, and 48G7H2 were calculated as (number of amino acids in FR region-number of murine amino acids retained in FR region)/number of amino acids in FR region × 100%, and the results showed that the degrees of humanization of the above 4 humanized antibodies were 96.2%, 95.6%, 85.0%, and 84.3%, respectively.

Table 7: light and heavy chain variable region amino acid sequence of humanized antibody

Example 6: activity evaluation of humanized PD-1 monoclonal antibody

In this example, humanized antibodies 17D5H1, 17D5H2, 48G7H 1and 48G7H2 were evaluated for antigen affinity activity, blocking activity and T cell activation-inducing ability using a commercial antibody as a reference antibody.

Commercial antibodies used Pembrolizumab and Nivolumab. Pembrolizumab (trade name KEYTRUDA, Merck) disclosed in, for example, Hamid, O et al (2013) New England Journal of Medicine 369 (2): 134-44, WO2009/114335 and US 8,354,509. Pembrolizumab has an amino acid sequence such as SEQ ID NO: 41 and the heavy chain sequence shown in SEQ ID NO: 42, or a light chain sequence thereof. Nivolumab (trade name Opdivo, Shi Baishi Guibao Co.) is disclosed, for example, in U.S. Pat. No.8,008,449 and WO 2006/121168. Nivolumab has, for example, SEQ ID NO: 43 and the heavy chain sequence of SEQ ID NO: 44, or a light chain sequence thereof.

6.1 CLEIA METHOD FOR COMPARISON OF BINDING ACTIVITY OF HUMANIZED ANTIBODIES TO COMMERCIAL ANTIBODIES

PD-1/His protein (Nano Biological Inc., cat # 10377-H08H) was diluted with CB buffer to 100 ng/well is coated in an irradiated and lightproof polystyrene 96-well plate, and after sealing by the sealing liquid, the plate is dried and stored at 4 ℃ for later use. The humanized antibody and the reference antibody were diluted in a gradient starting at a concentration of 1. mu.g/mL, and seven gradients, 0.2. mu.g/mL, 0.04. mu.g/mL, 0.008. mu.g/mL, 0.0016. mu.g/mL, 0.00032. mu.g/mL, 0.000064. mu.g/mL, 0.0000128. mu.g/mL, were serially diluted 5-fold. anti-PD-1 monoclonal antibodies diluted to different gradients were added to the coated plate, after sufficient reaction, unbound free protein or antibody was washed away, HRP-labeled GAH secondary antibody was added, unbound enzyme-labeled antibody was washed away, and finally, a chemiluminescent chromogenic substrate (purchased from Berthod, orionto) was added, and the luminescence Value (RLU, Relative chemiluminiscence Value) was read by a Chemiluminescence apparatus (Berthod, orionto ii). Calculation of half maximal effect concentration, EC, using PRISM 6 software (GraphPad, Inc.)₅₀。

As shown in FIG. 8, the humanized antibodies 17D5H1, 17D5H2, 48G7H 1and 48G7H2 all bound well to PD-1 protein, and the corresponding ED₅₀The values are shown in the following table. The results showed that humanized antibodies 17D5H1, 17D5H2 had stronger PD-1 binding activity than Pembrolizumab, and the PD-1 binding activity of humanized antibodies 48G7H1, 48G7H2 was comparable to Pembrolizumab; compared with Nivolumab, the humanized antibodies 17D5H1, 17D5H2, 48G7H 1and 48G7H2 all have stronger PD-1 binding activity. This indicates that the humanized antibody of the present invention can be used for antitumor therapy at a lower dose with higher safety.

Table 8: results of measurement of binding Activity of humanized antibody

6.2 CLEIA METHOD FOR COMPARISON OF BLOCKING ACTIVITY OF HUMANIZED ANTIBODIES WITH COMMERCIAL ANTIBODIES

Blocking activity of four humanized antibodies as well as commercial antibodies was examined by CLEIA method described in example 2. The response curves are shown in FIG. 9, corresponding to IC₅₀The values are shown in the following table. The results showed that the humanized antibodies 17D5H1, 17D5H2. 48G7H 1and 48G7H2 can obviously block the mutual combination between PD-1and PD-L1 proteins, and are obviously superior to the commercial antibodies Pembrolizumab and Nivolumab. This indicates that the humanized antibody of the present invention has higher activity for anti-tumor therapy.

Table 9: results of blocking Activity assay

Antibodies	IC₅₀(μg/mL)
		Pembrolizumab	0.8302
Nivolumab	1.095
		17D5H1	0.6148
17D5H2	0.7597
		48G7H1	0.3745
48G7H2	0.4651

6.3 SPR method for comparing the antigen affinity Activity of humanized antibodies with that of commercial antibodies

The antigen affinity activity of the four humanized antibodies as well as the commercial antibody was examined by the SPR method described in example 3. As shown in the following Table, the humanized antibodies 17D5H 1and 17D5H2 had stronger affinity for PD-1 protein than Pembrolizumab belonging to Merck, and the humanized antibodies 48G7H 1and 48G7H2 were equivalent to Pembrolizumab; compared with Nivolumab of Baishi Shi Guibao, the humanized antibodies 17D5H1, 17D5H2, 48G7H 1and 48G7H2 have stronger affinity with PD-1 protein. This indicates that the humanized antibody of the present invention can be used for antitumor therapy at a lower dose with higher safety.

Table 10: results of SPR measurement

Antibodies	K_D
		Pembrolizumab	2.89×10^-11
Nivolumab	3.55×10^-9
		17D5H1	5.71×10^-12
17D5H2	1.34×10^-12
		48G7H1	3.25×10^-11
48G7H2	2.91×10^-11

6.4 IL-2 Release assay comparing the T cell activation inducing Capacity of humanized and commercial antibodies

The four humanized antibodies as well as the commercial antibody were tested for their ability to induce T cell activation by the method described in example 4. The results are shown in FIG. 10, where the mean value of IL-2 secretion baseline was 22.2ng/mL, the peak value of 17D5H1 was 1515.1ng/mL, the peak value of 17D5H2 was 1495.5ng/mL, the peak value of 48G7H1 was 1250.1ng/mL, the peak value of 48G7H2 was 1296.2ng/mL, the peak value of Pembrolizumab was 1255.8ng/mL, and the peak value of Nivolumab was 1163.5 ng/mL. It can be seen that the humanized antibodies 17D5H 1and 17D5H2 have stronger T cell activating and T cell proliferation promoting abilities than Pembrolizumab belonging to Merck, and the humanized antibodies 48G7H 1and 48G7H2 are equivalent to Pembrolizumab; compared with Nivolumab of Baishi Shi Guibao, the humanized antibodies 17D5H1, 17D5H2, 48G7H 1and 48G7H2 have stronger T cell activating and T cell proliferation promoting capabilities. The humanized antibody has the capacity of activating T cells obviously superior to that of Pembrolizumab and Nivolumab, and has higher anti-tumor treatment effect under the same dosage. In addition, as can be seen by comparison with the respective parent murine antibodies 17D5, 48G7, the humanized antibodies of the invention substantially retain the T cell activating ability of the parent antibody.

The above results indicate that the humanized antibody of the present invention not only has a high degree of humanization, can reduce the possibility of immune rejection, but also exhibits anti-tumor activity comparable to that of murine antibodies and superior to that of commercial antibodies. Such technical effect is remarkable and surprising.

Example 7: determination of key amino acids for binding of 17D5 antibody to antigen

To determine the key amino acid positions for antibody-antigen interactions, alanine scans of the 6 CDR regions HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 of 17D5 were performed to point mutate each amino acid to alanine (a). Key amino acids often have some conservation, such as amino acid residues that maintain the conformation of the antibody and embedded amino acid residues, which, when mutated to alanine, can result in loss of activity of the antibody. The binding activity of the mutated antibody to PD-1 was examined by the method described in example 1.7 and rEC50 (original antibody measurement value/mutated antibody measurement value, original antibody EC50 relative value is 1, complete loss of binding activity is indicated by 0) of the mutated antibody was calculated and classified according to rEC50 < 0.2 (5-fold decrease in activity), rEC50 < 0.5 (2-5-fold decrease in activity), rEC50 < 0.8 (1.25-2-fold decrease in activity) of 0.5. ltoreq. rEC50 ≥ 0.8 (no change in activity), and the results are shown in tables 11-12.

Table 11: rEC50 of 17D5 heavy chain variable region alanine point mutation antibody

Table 12: rEC50 of 17D5 light chain variable region alanine point mutation antibody

rEC50≥0.8	Mutation site	0.5≤rEC50＜0.8	Mutation site
				1.189637	K27A	0.585714	G33A
0.954678	S28A	0.782283	S35A
				1.003497	V29A	0.767251	Q94A
0.860731	D30A	0.792407	T100A
				0.828133	N31A
1.114022	S55A
				0.960669	S95A
1.137056	N96A
				1.037271	E97A
0.804203	D98A
				0.2≤rEC50＜0.5	Mutation site	rEC50＜0.2	Mutation site
0.200831	Y32A	0.114457	F36A
				0.213731	Y34A	0.188816	Q93A
0.20158	R54A	0.164913	P99A

The results show that the binding activity of the heavy chain variable region amino acids G26, F27, S30, D33, I51, G56, R57, T101, D107 and Y108 is basically unchanged after mutation to alanine; the binding activity is slightly reduced after the point mutation of G52, G55, T58, G100, G102, G104 and M106 into alanine; after the point mutation of F29, R31 and R32 to alanine, the binding activity is reduced by 2-5 times; the degree of decrease in the binding activity was large, 5 times or more, after mutation of the G53, G54, R98, H99, and T103 points to alanine, and it was considered to be an invariable site. The variable region amino acids K27, S28, V29, D30, N31, S55, S95, N96, E97 and D98 of the light chain have basically unchanged binding activity after point mutation to alanine; the binding activity is slightly reduced after the G33, S35, Q94 and T100 points are mutated into alanine; the binding activity is reduced by 2-5 times after the point mutation of Y32, Y34 and R54 to alanine; the degree of reduction of the binding activity is large, more than 5 times, after the point mutation of F36, Q93 and P99 into alanine, and the site is considered to be an invariable site.

While specific embodiments of the invention have been described in detail, those skilled in the art will understand that: various modifications and changes in detail can be made in light of the overall teachings of the disclosure, and such changes are intended to be within the scope of the present invention. A full appreciation of the invention is gained by taking the entire specification as a whole in the light of the appended claims and any equivalents thereof.

Sequence listing

<110> university of mansion

Yangshengtang Co., Ltd.

<120> anti-PD-1 antibody and use thereof

<130> IDC210029

<150> CN201810801294.6

<151> 2018-07-20

<160> 78

<170> PatentIn version 3.5

<210> 1

<211> 119

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 heavy chain variable region

<400> 1

Glu Val Gln Leu Val Glu Ser Gly Gly Gly Leu Val Lys Pro Gly Gly

1 5 10 15

Ser Leu Lys Leu Ser Cys Ala Ala Ser Gly Phe Ala Phe Ser Arg Phe

20 25 30

Asp Met Ser Trp Val Arg Gln Thr Pro Glu Lys Arg Leu Glu Trp Val

35 40 45

Ala Phe Ile Gly Gly Gly Gly Gly Arg Thr His Tyr Pro Asp Ala Val

50 55 60

Lys Gly Arg Phe Thr Val Ser Arg Asp Asn Ala Glu Glu Ile Leu Tyr

65 70 75 80

Leu Gln Met Thr Ser Leu Lys Ser Asp Asp Thr Ala Met Tyr Tyr Cys

85 90 95

Ala Arg His Gly Thr Gly Thr Gly Ala Met Asp Tyr Trp Gly Gln Gly

100 105 110

Thr Ser Val Thr Val Ser Ser

115

<210> 2

<211> 110

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 light chain variable region

<400> 2

Asp Ile Val Leu Thr Gln Ser Pro Ala Ser Leu Thr Val Ser Leu Gly

1 5 10 15

Gln Arg Ala Thr Ile Ser Cys Arg Ala Ser Lys Ser Val Asp Asn Tyr

20 25 30

Gly Tyr Ser Phe Met His Trp Tyr Gln Gln Arg Pro Gly Gln Pro Pro

35 40 45

Lys Leu Leu Ile Tyr Arg Ser Ala Asn Leu Ala Ser Gly Ile Pro Thr

50 55 60

Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Asn

65 70 75 80

Pro Val Glu Ala Asp Asp Phe Ala Thr Tyr Tyr Cys Gln Gln Ser Asn

85 90 95

Glu Asp Pro Thr Phe Gly Gly Gly Thr Lys Leu Glu Ile Lys

100 105 110

<210> 3

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR1

<400> 3

Gly Phe Ala Phe Ser Arg Phe Asp

1 5

<210> 4

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR2

<400> 4

Ile Gly Gly Gly Gly Gly Arg Thr

1 5

<210> 5

<211> 12

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR3

<400> 5

Ala Arg His Gly Thr Gly Thr Gly Ala Met Asp Tyr

1 5 10

<210> 6

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR1

<400> 6

Lys Ser Val Asp Asn Tyr Gly Tyr Ser Phe

1 5 10

<210> 7

<211> 3

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR2

<400> 7

Arg Ser Ala

1

<210> 8

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR3

<400> 8

Gln Gln Ser Asn Glu Asp Pro Thr

1 5

<210> 9

<211> 117

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7 heavy chain variable region

<400> 9

Glu Val Gln Leu Gln Gln Ser Gly Ala Glu Leu Val Arg Ser Gly Ala

1 5 10 15

Ser Val Lys Leu Ser Cys Thr Ala Ser Gly Phe Asn Phe Lys Asp Tyr

20 25 30

Tyr Val His Trp Met Lys Gln Arg Pro Glu Gln Gly Leu Glu Trp Ile

35 40 45

Gly Trp Ile Ala Pro Asp Asn Gly Ala Thr Glu Tyr Ala Pro Lys Phe

50 55 60

Gln Asp Lys Ala Thr Met Thr Ala Asp Thr Ser Ser Asn Thr Ala Tyr

65 70 75 80

Leu Gln Leu Ser Ser Leu Thr Ser Glu Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Asn Ala Val Tyr Tyr Asp Arg Phe Asp Tyr Trp Gly Gln Gly Thr Thr

100 105 110

Leu Thr Val Ser Ser

115

<210> 10

<211> 108

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7 light chain variable region

<400> 10

Asp Ile Val Met Thr Gln Ser Gln Lys Phe Met Ser Thr Ser Val Gly

1 5 10 15

Asp Arg Val Ser Val Thr Cys Lys Ala Ser Gln Asn Val Gly Ser Asn

20 25 30

Val Ala Trp Tyr Gln Gln Lys Pro Gly Gln Ser Pro Lys Ala Leu Ile

35 40 45

Phe Ser Ala Ser Tyr Arg Tyr Ser Gly Val Pro Asp Arg Phe Thr Gly

50 55 60

Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Val Thr Asn Val Gln Ser

65 70 75 80

Glu Asp Leu Ala Glu Tyr Phe Cys Gln Gln Tyr Asn Thr Tyr Pro Tyr

85 90 95

Thr Phe Gly Gly Gly Thr Lys Leu Glu Ile Lys Arg

100 105

<210> 11

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7 HCDR1

<400> 11

Gly Phe Asn Phe Lys Asp Tyr Tyr

1 5

<210> 12

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7 HCDR2

<400> 12

Ile Ala Pro Asp Asn Gly Ala Thr

1 5

<210> 13

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7 HCDR3

<400> 13

Asn Ala Val Tyr Tyr Asp Arg Phe Asp Tyr

1 5 10

<210> 14

<211> 6

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7 LCDR1

<400> 14

Gln Asn Val Gly Ser Asn

1 5

<210> 15

<211> 3

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7 LCDR2

<400> 15

Ser Ala Ser

1

<210> 16

<211> 9

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7 LCDR3

<400> 16

Gln Gln Tyr Asn Thr Tyr Pro Tyr Thr

1 5

<210> 17

<211> 121

<212> PRT

<213> Artificial sequence

<220>

<223> 16F2 heavy chain variable region

<400> 17

Gln Val Thr Leu Lys Glu Ser Gly Pro Gly Ile Leu Gln Ser Ser Gln

1 5 10 15

Thr Leu Ser Leu Thr Cys Ser Phe Ser Gly Phe Ser Leu Ser Ile Tyr

20 25 30

Gly Ile Gly Val Gly Trp Ile Arg Gln Pro Ser Gly Lys Gly Leu Glu

35 40 45

Trp Leu Ala His Ile Trp Trp Asn Asp Asn Lys Asp Tyr Asn Ser Val

50 55 60

Leu Lys Ser Arg Leu Thr Ile Ser Lys Asp Thr Ser Asn Asn Gln Val

65 70 75 80

Phe Leu Lys Ile Ala Ser Val Asp Thr Ala Asp Thr Ala Thr Tyr Tyr

85 90 95

Cys Ala Arg Ile Glu Gly Tyr Gly Tyr Asp Gly Met Asp Tyr Trp Gly

100 105 110

Gln Gly Thr Ser Val Thr Val Ser Ser

115 120

<210> 18

<211> 106

<212> PRT

<213> Artificial sequence

<220>

<223> 16F2 light chain variable region

<400> 18

Gln Ile Val Leu Thr Gln Ser Pro Ala Ile Met Ser Ala Ser Pro Gly

1 5 10 15

Glu Lys Val Thr Leu Thr Cys Ser Ala Asn Ser Arg Val Ser Tyr Met

20 25 30

His Trp Tyr Gln Gln Lys Ser Gly Thr Ala Pro Lys Arg Trp Ile Ser

35 40 45

Asp Thr Ser Thr Leu Ala Ser Gly Val Pro Ser Arg Phe Ser Gly Ser

50 55 60

Gly Ser Gly Thr Ser Tyr Ser Leu Thr Ile Asn Asn Met Glu Ala Glu

65 70 75 80

Asp Ala Ala Thr Tyr Tyr Cys Gln Gln Trp Ser Ser Tyr Pro Tyr Thr

85 90 95

Phe Gly Gly Gly Thr Lys Leu Glu Ile Lys

100 105

<210> 19

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 16F2 HCDR1

<400> 19

Gly Phe Ser Leu Ser Ile Tyr Gly Ile Gly

1 5 10

<210> 20

<211> 7

<212> PRT

<213> Artificial sequence

<220>

<223> 16F2 HCDR2

<400> 20

Ile Trp Trp Asn Asp Asn Lys

1 5

<210> 21

<211> 13

<212> PRT

<213> Artificial sequence

<220>

<223> 16F2 HCDR3

<400> 21

Ala Arg Ile Glu Gly Tyr Gly Tyr Asp Gly Met Asp Tyr

1 5 10

<210> 22

<211> 5

<212> PRT

<213> Artificial sequence

<220>

<223> 16F2 LCDR1

<400> 22

Ser Arg Val Ser Tyr

1 5

<210> 23

<211> 3

<212> PRT

<213> Artificial sequence

<220>

<223> 16F2 LCDR2

<400> 23

Asp Thr Ser

1

<210> 24

<211> 9

<212> PRT

<213> Artificial sequence

<220>

<223> 16F2 LCDR3

<400> 24

Gln Gln Trp Ser Ser Tyr Pro Tyr Thr

1 5

<210> 25

<211> 120

<212> PRT

<213> Artificial sequence

<220>

<223> 10D6 heavy chain variable region

<400> 25

Asp Val Gln Leu Gln Glu Ser Gly Pro Gly Leu Val Lys Pro Ser Gln

1 5 10 15

Ser Leu Ser Leu Thr Cys Thr Val Thr Gly Ser Ser Ile Thr Ser Asp

20 25 30

Phe Ala Trp Glu Trp Ile Arg Gln Phe Pro Gly Asn Lys Leu Glu Cys

35 40 45

Met Gly Tyr Ile Gly Tyr Ser Gly Gly Thr Ile Tyr Asn Pro Ser Leu

50 55 60

Lys Ser Arg Ile Ser Ile Thr Arg Asp Thr Ser Lys Asn Gln Phe Phe

65 70 75 80

Leu Gln Leu Asn Ser Val Thr Thr Glu Asp Thr Ala Thr Tyr Tyr Cys

85 90 95

Ala Arg Trp His Gly Ser Ser His Trp Tyr Phe Asp Val Trp Gly Gln

100 105 110

Gly Thr Thr Leu Thr Val Ser Ser

115 120

<210> 26

<211> 112

<212> PRT

<213> Artificial sequence

<220>

<223> 10D6 light chain variable region

<400> 26

Asp Val Leu Met Thr Gln Thr Pro Leu Phe Leu Pro Val Ser Leu Gly

1 5 10 15

Asp Gln Ala Ser Ile Phe Cys Arg Ser Ser Gln Asn Ile Val His Ile

20 25 30

Asn Gly Asn Thr Tyr Leu Glu Trp Tyr Leu Gln Lys Pro Gly Gln Phe

35 40 45

Pro Lys Leu Leu Met Tyr Lys Val Ser Asn Arg Phe Phe Gly Val Pro

50 55 60

Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Lys Ile

65 70 75 80

Ser Arg Val Glu Ala Glu Asp Leu Gly Val Tyr Tyr Cys Phe Gln Gly

85 90 95

Ser His Val Pro Trp Thr Phe Gly Gly Gly Thr Lys Leu Glu Ile Lys

100 105 110

<210> 27

<211> 9

<212> PRT

<213> Artificial sequence

<220>

<223> 10D6 HCDR1

<400> 27

Gly Ser Ser Ile Thr Ser Asp Phe Ala

1 5

<210> 28

<211> 7

<212> PRT

<213> Artificial sequence

<220>

<223> 10D6 HCDR2

<400> 28

Ile Gly Tyr Ser Gly Gly Thr

1 5

<210> 29

<211> 13

<212> PRT

<213> Artificial sequence

<220>

<223> 10D6 HCDR3

<400> 29

Ala Arg Trp His Gly Ser Ser His Trp Tyr Phe Asp Val

1 5 10

<210> 30

<211> 11

<212> PRT

<213> Artificial sequence

<220>

<223> 10D6 LCDR1

<400> 30

Gln Asn Ile Val His Ile Asn Gly Asn Thr Tyr

1 5 10

<210> 31

<211> 3

<212> PRT

<213> Artificial sequence

<220>

<223> 10D6 LCDR2

<400> 31

Lys Val Ser

1

<210> 32

<211> 9

<212> PRT

<213> Artificial sequence

<220>

<223> 10D6 LCDR3

<400> 32

Phe Gln Gly Ser His Val Pro Trp Thr

1 5

<210> 33

<211> 119

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5H1 heavy chain variable region

<400> 33

Glu Val Gln Leu Val Glu Ser Gly Gly Gly Leu Val Gln Pro Gly Gly

1 5 10 15

Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Ala Phe Ser Arg Phe

20 25 30

Asp Met Ser Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp Val

35 40 45

Ala Phe Ile Gly Gly Gly Gly Gly Arg Thr His Tyr Pro Asp Ser Val

50 55 60

Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr

65 70 75 80

Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Arg His Gly Thr Gly Thr Gly Ala Met Asp Tyr Trp Gly Gln Gly

100 105 110

Thr Leu Val Thr Val Ser Ser

115

<210> 34

<211> 110

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5H1 light chain variable region

<400> 34

Asp Ile Val Leu Thr Gln Ser Pro Ala Ser Leu Ala Val Ser Pro Gly

1 5 10 15

Gln Arg Ala Thr Ile Thr Cys Arg Ala Ser Lys Ser Val Asp Asn Tyr

20 25 30

Gly Tyr Ser Phe Met His Trp Tyr Gln Gln Lys Pro Gly Gln Pro Pro

35 40 45

Lys Leu Leu Ile Tyr Arg Ser Ala Asn Leu Asp Thr Gly Val Pro Ala

50 55 60

Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Asn

65 70 75 80

Pro Val Glu Ala Asn Asp Thr Ala Asn Tyr Tyr Cys Gln Gln Ser Asn

85 90 95

Glu Asp Pro Thr Phe Gly Ala Gly Thr Lys Leu Glu Ile Lys

100 105 110

<210> 35

<211> 119

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5H2 heavy chain variable region

<400> 35

Glu Val Gln Leu Val Glu Ser Gly Gly Gly Leu Val Gln Pro Gly Gly

1 5 10 15

Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Ala Phe Ser Arg Phe

20 25 30

Asp Met Ser Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp Val

35 40 45

Ala Phe Ile Gly Gly Gly Gly Gly Arg Thr His Tyr Pro Asp Ser Val

50 55 60

Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr

65 70 75 80

Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Arg His Gly Thr Gly Thr Gly Ala Met Asp Tyr Trp Gly Gln Gly

100 105 110

Thr Leu Val Thr Val Ser Ser

115

<210> 36

<211> 110

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5H2 light chain variable region

<400> 36

Glu Ile Val Leu Thr Gln Ser Pro Ala Thr Leu Ser Leu Ser Pro Gly

1 5 10 15

Glu Arg Ala Thr Leu Ser Cys Arg Ala Ser Lys Ser Val Asp Asn Tyr

20 25 30

Gly Tyr Ser Phe Met His Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro

35 40 45

Arg Leu Leu Ile Tyr Arg Ser Ala Asn Leu Ala Thr Gly Ile Pro Ala

50 55 60

Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser

65 70 75 80

Ser Leu Glu Pro Glu Asp Phe Ala Val Tyr Tyr Cys Gln Gln Ser Asn

85 90 95

Glu Asp Pro Thr Phe Gly Gln Gly Thr Lys Val Glu Ile Lys

100 105 110

<210> 37

<211> 117

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7H1 heavy chain variable region

<400> 37

Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Lys Lys Pro Gly Ala

1 5 10 15

Ser Val Lys Val Ser Cys Lys Ala Ser Gly Phe Asn Phe Lys Asp Tyr

20 25 30

Tyr Val His Trp Met Arg Gln Arg Pro Gly Gln Gly Leu Glu Trp Met

35 40 45

Gly Trp Ile Ala Pro Asp Asn Gly Ala Thr Glu Tyr Ala Pro Arg Phe

50 55 60

Gln Asp Lys Ala Thr Met Thr Pro Asp Thr Ser Thr Ser Thr Ala Tyr

65 70 75 80

Leu Glu Leu Arg Ser Leu Arg Ser Asp Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Asn Ala Val Tyr Tyr Asp Arg Phe Asp Tyr Trp Gly Gln Gly Thr Leu

100 105 110

Val Thr Val Ser Ser

115

<210> 38

<211> 107

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7H1 light chain variable region

<400> 38

Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly

1 5 10 15

Asp Arg Val Thr Ile Thr Cys Lys Thr Ser Gln Asn Val Gly Ser Asn

20 25 30

Val Ala Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys Ala Leu Ile

35 40 45

Phe Ser Ala Ser Tyr Arg Tyr Ser Gly Val Pro Ser Arg Phe Ser Gly

50 55 60

Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Ser

65 70 75 80

Glu Asp Phe Ala Ala Tyr Tyr Cys Gln Gln Tyr Asn Thr Tyr Pro Tyr

85 90 95

Thr Phe Gly Arg Gly Thr Lys Val Glu Ile Lys

100 105

<210> 39

<211> 117

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7H2 heavy chain variable region

<400> 39

Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Lys Lys Pro Gly Ala

1 5 10 15

Ser Val Lys Val Ser Cys Lys Ala Ser Gly Phe Asn Phe Lys Asp Tyr

20 25 30

Tyr Val His Trp Met Lys Gln Pro Pro Glu Gln Gly Leu Glu Trp Met

35 40 45

Gly Trp Ile Ala Pro Asp Asn Gly Ala Thr Glu Tyr Ala Pro Arg Phe

50 55 60

Gln Asp Lys Ala Thr Met Thr Ala Asp Thr Ser Thr Ser Thr Ala Tyr

65 70 75 80

Met Glu Leu Arg Ser Leu Arg Ser Asp Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Asn Ala Val Tyr Tyr Asp Arg Phe Asp Tyr Trp Gly Gln Gly Thr Leu

100 105 110

Val Thr Val Ser Ser

115

<210> 40

<211> 107

<212> PRT

<213> Artificial sequence

<220>

<223> 48G7H2 light chain variable region

<400> 40

Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly

1 5 10 15

Asp Arg Val Thr Ile Thr Cys Lys Ala Ser Gln Asn Val Gly Ser Asn

20 25 30

Val Ala Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys Ala Leu Ile

35 40 45

Phe Ser Ala Ser Tyr Arg Tyr Ser Gly Val Pro Tyr Arg Phe Ser Gly

50 55 60

Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Ser

65 70 75 80

Glu Asp Phe Ala Ala Tyr Tyr Cys Gln Gln Tyr Asn Thr Tyr Pro Tyr

85 90 95

Thr Phe Gly Arg Gly Thr Lys Val Glu Ile Lys

100 105

<210> 41

<211> 447

<212> PRT

<213> Artificial sequence

<220>

<223> Pembrolizumab heavy chain

<400> 41

Gln Val Gln Leu Val Gln Ser Gly Val Glu Val Lys Lys Pro Gly Ala

1 5 10 15

Ser Val Lys Val Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Asn Tyr

20 25 30

Tyr Met Tyr Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu Trp Met

35 40 45

Gly Gly Ile Asn Pro Ser Asn Gly Gly Thr Asn Phe Asn Glu Lys Phe

50 55 60

Lys Asn Arg Val Thr Leu Thr Thr Asp Ser Ser Thr Thr Thr Ala Tyr

65 70 75 80

Met Glu Leu Lys Ser Leu Gln Phe Asp Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Arg Arg Asp Tyr Arg Phe Asp Met Gly Phe Asp Tyr Trp Gly Gln

100 105 110

Gly Thr Thr Val Thr Val Ser Ser Ala Ser Thr Lys Gly Pro Ser Val

115 120 125

Phe Pro Leu Ala Pro Cys Ser Arg Ser Thr Ser Glu Ser Thr Ala Ala

130 135 140

Leu Gly Cys Leu Val Lys Asp Tyr Phe Pro Glu Pro Val Thr Val Ser

145 150 155 160

Trp Asn Ser Gly Ala Leu Thr Ser Gly Val His Thr Phe Pro Ala Val

165 170 175

Leu Gln Ser Ser Gly Leu Tyr Ser Leu Ser Ser Val Val Thr Val Pro

180 185 190

Ser Ser Ser Leu Gly Thr Lys Thr Tyr Thr Cys Asn Val Asp His Lys

195 200 205

Pro Ser Asn Thr Lys Val Asp Lys Arg Val Glu Ser Lys Tyr Gly Pro

210 215 220

Pro Cys Pro Pro Cys Pro Ala Pro Glu Phe Leu Gly Gly Pro Ser Val

225 230 235 240

Phe Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu Met Ile Ser Arg Thr

245 250 255

Pro Glu Val Thr Cys Val Val Val Asp Val Ser Gln Glu Asp Pro Glu

260 265 270

Val Gln Phe Asn Trp Tyr Val Asp Gly Val Glu Val His Asn Ala Lys

275 280 285

Thr Lys Pro Arg Glu Glu Gln Phe Asn Ser Thr Tyr Arg Val Val Ser

290 295 300

Val Leu Thr Val Leu His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys

305 310 315 320

Cys Lys Val Ser Asn Lys Gly Leu Pro Ser Ser Ile Glu Lys Thr Ile

325 330 335

Ser Lys Ala Lys Gly Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro

340 345 350

Pro Ser Gln Glu Glu Met Thr Lys Asn Gln Val Ser Leu Thr Cys Leu

355 360 365

Val Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn

370 375 380

Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser

385 390 395 400

Asp Gly Ser Phe Phe Leu Tyr Ser Arg Leu Thr Val Asp Lys Ser Arg

405 410 415

Trp Gln Glu Gly Asn Val Phe Ser Cys Ser Val Met His Glu Ala Leu

420 425 430

His Asn His Tyr Thr Gln Lys Ser Leu Ser Leu Ser Leu Gly Lys

435 440 445

<210> 42

<211> 218

<212> PRT

<213> Artificial sequence

<220>

<223> Pembrolizumab light chain

<400> 42

Glu Ile Val Leu Thr Gln Ser Pro Ala Thr Leu Ser Leu Ser Pro Gly

1 5 10 15

Glu Arg Ala Thr Leu Ser Cys Arg Ala Ser Lys Gly Val Ser Thr Ser

20 25 30

Gly Tyr Ser Tyr Leu His Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro

35 40 45

Arg Leu Leu Ile Tyr Leu Ala Ser Tyr Leu Glu Ser Gly Val Pro Ala

50 55 60

Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser

65 70 75 80

Ser Leu Glu Pro Glu Asp Phe Ala Val Tyr Tyr Cys Gln His Ser Arg

85 90 95

Asp Leu Pro Leu Thr Phe Gly Gly Gly Thr Lys Val Glu Ile Lys Arg

100 105 110

Thr Val Ala Ala Pro Ser Val Phe Ile Phe Pro Pro Ser Asp Glu Gln

115 120 125

Leu Lys Ser Gly Thr Ala Ser Val Val Cys Leu Leu Asn Asn Phe Tyr

130 135 140

Pro Arg Glu Ala Lys Val Gln Trp Lys Val Asp Asn Ala Leu Gln Ser

145 150 155 160

Gly Asn Ser Gln Glu Ser Val Thr Glu Gln Asp Ser Lys Asp Ser Thr

165 170 175

Tyr Ser Leu Ser Ser Thr Leu Thr Leu Ser Lys Ala Asp Tyr Glu Lys

180 185 190

His Lys Val Tyr Ala Cys Glu Val Thr His Gln Gly Leu Ser Ser Pro

195 200 205

Val Thr Lys Ser Phe Asn Arg Gly Glu Cys

210 215

<210> 43

<211> 440

<212> PRT

<213> Artificial sequence

<220>

<223> Nivolumab heavy chain

<400> 43

Gln Val Gln Leu Val Glu Ser Gly Gly Gly Val Val Gln Pro Gly Arg

1 5 10 15

Ser Leu Arg Leu Asp Cys Lys Ala Ser Gly Ile Thr Phe Ser Asn Ser

20 25 30

Gly Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp Val

35 40 45

Ala Val Ile Trp Tyr Asp Gly Ser Lys Arg Tyr Tyr Ala Asp Ser Val

50 55 60

Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Phe

65 70 75 80

Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Thr Asn Asp Asp Tyr Trp Gly Gln Gly Thr Leu Val Thr Val Ser

100 105 110

Ser Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Cys Ser

115 120 125

Arg Ser Thr Ser Glu Ser Thr Ala Ala Leu Gly Cys Leu Val Lys Asp

130 135 140

Tyr Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu Thr

145 150 155 160

Ser Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu Tyr

165 170 175

Ser Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser Leu Gly Thr Lys

180 185 190

Thr Tyr Thr Cys Asn Val Asp His Lys Pro Ser Asn Thr Lys Val Asp

195 200 205

Lys Arg Val Glu Ser Lys Tyr Gly Pro Pro Cys Pro Pro Cys Pro Ala

210 215 220

Pro Glu Phe Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro

225 230 235 240

Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val

245 250 255

Val Asp Val Ser Gln Glu Asp Pro Glu Val Gln Phe Asn Trp Tyr Val

260 265 270

Asp Gly Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln

275 280 285

Phe Asn Ser Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu His Gln

290 295 300

Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Gly

305 310 315 320

Leu Pro Ser Ser Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly Gln Pro

325 330 335

Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Gln Glu Glu Met Thr

340 345 350

Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser

355 360 365

Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr

370 375 380

Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr

385 390 395 400

Ser Arg Leu Thr Val Asp Lys Ser Arg Trp Gln Glu Gly Asn Val Phe

405 410 415

Ser Cys Ser Val Met His Glu Ala Leu His Asn His Tyr Thr Gln Lys

420 425 430

Ser Leu Ser Leu Ser Leu Gly Lys

435 440

<210> 44

<211> 214

<212> PRT

<213> Artificial sequence

<220>

<223> Nivolumab light chain

<400> 44

Glu Ile Val Leu Thr Gln Ser Pro Ala Thr Leu Ser Leu Ser Pro Gly

1 5 10 15

Glu Arg Ala Thr Leu Ser Cys Arg Ala Ser Gln Ser Val Ser Ser Tyr

20 25 30

Leu Ala Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro Arg Leu Leu Ile

35 40 45

Tyr Asp Ala Ser Asn Arg Ala Thr Gly Ile Pro Ala Arg Phe Ser Gly

50 55 60

Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Glu Pro

65 70 75 80

Glu Asp Phe Ala Val Tyr Tyr Cys Gln Gln Ser Ser Asn Trp Pro Arg

85 90 95

Thr Phe Gly Gln Gly Thr Lys Val Glu Ile Lys Arg Thr Val Ala Ala

100 105 110

Pro Ser Val Phe Ile Phe Pro Pro Ser Asp Glu Gln Leu Lys Ser Gly

115 120 125

Thr Ala Ser Val Val Cys Leu Leu Asn Asn Phe Tyr Pro Arg Glu Ala

130 135 140

Lys Val Gln Trp Lys Val Asp Asn Ala Leu Gln Ser Gly Asn Ser Gln

145 150 155 160

Glu Ser Val Thr Glu Gln Asp Ser Lys Asp Ser Thr Tyr Ser Leu Ser

165 170 175

Ser Thr Leu Thr Leu Ser Lys Ala Asp Tyr Glu Lys His Lys Val Tyr

180 185 190

Ala Cys Glu Val Thr His Gln Gly Leu Ser Ser Pro Val Thr Lys Ser

195 200 205

Phe Asn Arg Gly Glu Cys

210

<210> 45

<211> 98

<212> PRT

<213> Artificial sequence

<220>

<223> human germline gene sequence IGVH3-23 x 04

<400> 45

Glu Val Gln Leu Val Glu Ser Gly Gly Gly Leu Val Gln Pro Gly Gly

1 5 10 15

Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser Ser Tyr

20 25 30

Ala Met Ser Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp Val

35 40 45

Ser Ala Ile Ser Gly Ser Gly Gly Ser Thr Tyr Tyr Ala Asp Ser Val

50 55 60

Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr

65 70 75 80

Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Lys

<210> 46

<211> 88

<212> PRT

<213> Artificial sequence

<220>

<223> human germline gene sequence IGKV3-11 x 01

<400> 46

Glu Ile Val Leu Thr Gln Ser Pro Ala Thr Leu Ser Leu Ser Pro Gly

1 5 10 15

Glu Arg Ala Thr Leu Ser Cys Arg Ala Ser Gln Ser Val Ser Ser Tyr

20 25 30

Leu Ala Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro Arg Leu Leu Ile

35 40 45

Tyr Asp Ala Ser Asn Arg Ala Thr Gly Ile Pro Ala Arg Phe Ser Gly

50 55 60

Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Glu Pro

65 70 75 80

Glu Asp Phe Ala Val Tyr Tyr Cys

85

<210> 47

<211> 98

<212> PRT

<213> Artificial sequence

<220>

<223> human germline gene sequence IGVH1-2 x 02

<400> 47

Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Lys Lys Pro Gly Ala

1 5 10 15

Ser Val Lys Val Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Gly Tyr

20 25 30

Tyr Met His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu Trp Met

35 40 45

Gly Trp Ile Asn Pro Asn Ser Gly Gly Thr Asn Tyr Ala Gln Lys Phe

50 55 60

Gln Gly Arg Val Thr Met Thr Arg Asp Thr Ser Ile Ser Thr Ala Tyr

65 70 75 80

Met Glu Leu Ser Arg Leu Arg Ser Asp Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Arg

<210> 48

<211> 88

<212> PRT

<213> Artificial sequence

<220>

<223> human germline gene sequence IGKV1-16 x 01

<400> 48

Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly

1 5 10 15

Asp Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Gly Ile Ser Asn Tyr

20 25 30

Leu Ala Trp Phe Gln Gln Lys Pro Gly Lys Ala Pro Lys Ser Leu Ile

35 40 45

Tyr Ala Ala Ser Ser Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly

50 55 60

Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro

65 70 75 80

Glu Asp Phe Ala Thr Tyr Tyr Cys

85

<210> 49

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR1 formula

<220>

<221> MISC_FEATURE

<222> (1)..(2)

<223> X is an arbitrary amino acid

<220>

<221> MISC_FEATURE

<222> (5)..(5)

<223> X is an arbitrary amino acid

<220>

<221> MISC_FEATURE

<222> (8)..(8)

<223> X is an arbitrary amino acid

<400> 49

Xaa Xaa Ala Phe Xaa Arg Phe Xaa

1 5

<210> 50

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR2 formula

<220>

<221> MISC_FEATURE

<222> (1)..(2)

<223> X is an arbitrary amino acid

<220>

<221> MISC_FEATURE

<222> (5)..(8)

<223> X is an arbitrary amino acid

<400> 50

Xaa Xaa Gly Gly Xaa Xaa Xaa Xaa

1 5

<210> 51

<211> 12

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR3 formula

<220>

<221> MISC_FEATURE

<222> (4)..(6)

<223> X is an arbitrary amino acid

<220>

<221> MISC_FEATURE

<222> (8)..(8)

<223> X is an arbitrary amino acid

<220>

<221> MISC_FEATURE

<222> (10)..(12)

<223> X is an arbitrary amino acid

<400> 51

Ala Arg His Xaa Xaa Xaa Thr Xaa Ala Xaa Xaa Xaa

1 5 10

<210> 52

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR1 general formula

<220>

<221> MISC_FEATURE

<222> (1)..(5)

<223> X is an arbitrary amino acid

<220>

<221> MISC_FEATURE

<222> (7)..(7)

<223> X is an arbitrary amino acid

<220>

<221> MISC_FEATURE

<222> (9)..(9)

<223> X is an arbitrary amino acid

<400> 52

Xaa Xaa Xaa Xaa Xaa Tyr Xaa Tyr Xaa Phe

1 5 10

<210> 53

<211> 3

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR2 general formula

<220>

<221> MISC_FEATURE

<222> (2)..(2)

<223> X is an arbitrary amino acid

<400> 53

Arg Xaa Ala

1

<210> 54

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR3 general formula

<220>

<221> MISC_FEATURE

<222> (2)..(6)

<223> X is an arbitrary amino acid

<220>

<221> MISC_FEATURE

<222> (8)..(8)

<223> X is an arbitrary amino acid

<400> 54

Gln Xaa Xaa Xaa Xaa Xaa Pro Xaa

1 5

<210> 55

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR1-G26A

<400> 55

Ala Phe Ala Phe Ser Arg Phe Asp

1 5

<210> 56

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR1-F27A

<400> 56

Gly Ala Ala Phe Ser Arg Phe Asp

1 5

<210> 57

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR1-S30A

<400> 57

Gly Phe Ala Phe Ala Arg Phe Asp

1 5

<210> 58

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR1-D33A

<400> 58

Gly Phe Ala Phe Ser Arg Phe Ala

1 5

<210> 59

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR2-I51A

<400> 59

Ala Gly Gly Gly Gly Gly Arg Thr

1 5

<210> 60

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR2-G56A

<400> 60

Ile Gly Gly Gly Gly Ala Arg Thr

1 5

<210> 61

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR2-R57A

<400> 61

Ile Gly Gly Gly Gly Gly Ala Thr

1 5

<210> 62

<211> 12

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR3-T101A

<400> 62

Ala Arg His Gly Ala Gly Thr Gly Ala Met Asp Tyr

1 5 10

<210> 63

<211> 12

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR3-D107A

<400> 63

Ala Arg His Gly Thr Gly Thr Gly Ala Met Ala Tyr

1 5 10

<210> 64

<211> 12

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 HCDR3-Y108A

<400> 64

Ala Arg His Gly Thr Gly Thr Gly Ala Met Asp Ala

1 5 10

<210> 65

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR1-K27A

<400> 65

Ala Ser Val Asp Asn Tyr Gly Tyr Ser Phe

1 5 10

<210> 66

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR1-S28A

<400> 66

Lys Ala Val Asp Asn Tyr Gly Tyr Ser Phe

1 5 10

<210> 67

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR1-V29A

<400> 67

Lys Ser Ala Asp Asn Tyr Gly Tyr Ser Phe

1 5 10

<210> 68

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR1-D30A

<400> 68

Lys Ser Val Ala Asn Tyr Gly Tyr Ser Phe

1 5 10

<210> 69

<211> 10

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR1-N31A

<400> 69

Lys Ser Val Asp Ala Tyr Gly Tyr Ser Phe

1 5 10

<210> 70

<211> 3

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR2-S55A

<400> 70

Arg Ala Ala

1

<210> 71

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR3-S95A

<400> 71

Gln Gln Ala Asn Glu Asp Pro Thr

1 5

<210> 72

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR3-N96A

<400> 72

Gln Gln Ser Ala Glu Asp Pro Thr

1 5

<210> 73

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR3-E97A

<400> 73

Gln Gln Ser Asn Ala Asp Pro Thr

1 5

<210> 74

<211> 8

<212> PRT

<213> Artificial sequence

<220>

<223> 17D5 LCDR3-D98A

<400> 74

Gln Gln Ser Asn Glu Ala Pro Thr

1 5

<210> 75

<211> 35

<212> DNA

<213> Artificial sequence

<220>

<223> primer

<400> 75

accggtatgc agatcccaca ggcgccctgg ccagt 35

<210> 76

<211> 43

<212> DNA

<213> Artificial sequence

<220>

<223> primer

<400> 76

tctagatcag aggggccaag agcagtgtcc atcctcaggc ctc 43

<210> 77

<211> 56

<212> DNA

<213> Artificial sequence

<220>

<223> primer

<400> 77

tagagaattc ggatccatga ggatatttgc tgtctttata ttcatgacct actggc 56

<210> 78

<211> 56

<212> DNA

<213> Artificial sequence

<220>

<223> primer

<400> 78

ccatggctcg agcccgggtt acgtctcctc caaatgtgta tcactttgct tctttg 56

Claims

1. An antibody or antigen-binding fragment thereof capable of specifically binding to PD-1, said antibody or antigen-binding fragment thereof comprising:

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(vi) a VL CDR3 having the sequence of CDR3 contained in VL as set forth in SEQ ID NO 10, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to the sequence of CDR3 contained in said VL;

preferably, the substitution recited in any one of (i) - (vi) is a conservative substitution;

preferably, the CDR1, CDR2 and CDR3 comprised in the heavy chain variable region (VH) and/or the CDR1, CDR2 and CDR3 comprised in the light chain variable region (VL) are defined by the Kabat, Chothia or IMGT numbering system;

preferably, the antibody or antigen-binding fragment thereof comprises:

and/or the presence of a gas in the gas,

(b) 10 in the light chain variable region (VL) containing 3 CDR;

preferably, the 3 CDRs contained in the heavy chain variable region (VH) and/or the 3 CDRs contained in the light chain variable region (VL) are defined by the Kabat, Chothia or IMGT numbering system.

2. An antibody or antigen-binding fragment thereof capable of specifically binding to PD-1, said antibody or antigen-binding fragment thereof comprising:

(a) the following 3 heavy chain variable region (VH) CDRs:

and/or

(b) The following 3 light chain variable region (VL) CDRs:

preferably, the VH of the antibody or antigen-binding fragment thereof comprises: VH CDR1 shown in SEQ ID NO. 11; VH CDR2 shown in SEQ ID NO 12; and, VH CDR3 shown in SEQ ID NO 13; and, the VL of the antibody or antigen-binding fragment thereof comprises: VL CDR1 as shown in SEQ ID NO. 14; VL CDR 2as shown in SEQ ID NO. 15; and, VL CDR3 as shown in SEQ ID NO 16.

3. An antibody or antigen-binding fragment thereof capable of specifically binding to PD-1, said antibody or antigen-binding fragment thereof comprising:

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(vi) a VL CDR3 having the sequence of CDR3 contained in VL as set forth in SEQ ID NO:18, or a sequence having substitution, deletion or addition of one or several amino acids (e.g., substitution, deletion or addition of 1,2 or 3 amino acids) as compared to the sequence of CDR3 contained in said VL;

preferably, the antibody or antigen-binding fragment thereof comprises:

and/or the presence of a gas in the gas,

(b) 18 in the light chain variable region (VL) as shown in SEQ ID NO 3 CDR;

4. An antibody or antigen-binding fragment thereof capable of specifically binding to PD-1, said antibody or antigen-binding fragment thereof comprising:

(a) the following 3 heavy chain variable region (VH) CDRs:

and/or

(b) The following 3 light chain variable region (VL) CDRs:

preferably, the VH of the antibody or antigen-binding fragment thereof comprises: VH CDR1 shown in SEQ ID NO. 19; VH CDR2 shown as SEQ ID NO: 20; and, VH CDR3 shown in SEQ ID NO: 21; and, the VL of the antibody or antigen-binding fragment thereof comprises: VL CDR1 as shown in SEQ ID NO. 22; VL CDR 2as shown in SEQ ID NO. 23; and, VL CDR3 as shown in SEQ ID NO. 24.

5. An antibody or antigen-binding fragment thereof capable of specifically binding to PD-1, said antibody or antigen-binding fragment thereof comprising:

and/or

(b) The following 3 light chain variable region (VL) CDRs:

(vi) a VL CDR3 having the sequence of CDR3 contained in VL as shown in SEQ ID No. 26, or a sequence having substitution, deletion or addition of one or several amino acids (e.g. 1,2 or 3 amino acid substitution, deletion or addition) compared to the sequence of CDR3 contained in said VL;

preferably, the antibody or antigen-binding fragment thereof comprises:

and/or the presence of a gas in the gas,

(b) 26 in the light chain variable region (VL) containing 3 CDRs;

6. An antibody or antigen-binding fragment thereof capable of specifically binding to PD-1, said antibody or antigen-binding fragment thereof comprising:

(a) the following 3 heavy chain variable region (VH) CDRs:

and/or

(b) The following 3 light chain variable region (VL) CDRs:

preferably, the VH of the antibody or antigen-binding fragment thereof comprises: VH CDR1 shown as SEQ ID NO: 27; VH CDR2 shown as SEQ ID NO 28; and, VH CDR3 shown in SEQ ID NO. 29; and, the VL of the antibody or antigen-binding fragment thereof comprises: VL CDR1 as shown in SEQ ID NO. 30; VL CDR 2as shown in SEQ ID NO. 31; and, VL CDR3 as shown in SEQ ID NO: 32.

7. The antibody or antigen-binding fragment thereof of any one of claims 1-6, wherein the antibody or antigen-binding fragment thereof is humanized;

preferably, the antibody or antigen binding fragment thereof is humanized to a degree of at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, or at least 98%;

preferably, the antibody or antigen-binding fragment thereof further comprises a framework region of a human immunoglobulin (e.g., a framework region comprised in an amino acid sequence encoded by a human germline antibody gene), the framework region optionally comprising one or more (e.g., 1,2, 3, 4,5, 6, 7,8, 9, or 10) back mutations from human residues to murine residues;

preferably, the antibody or antigen-binding fragment thereof comprises: a heavy chain framework region comprised in the amino acid sequence encoded by the human heavy chain germline gene and/or a light chain framework region comprised in the amino acid sequence encoded by the human light chain germline gene.

8. The antibody or antigen-binding fragment thereof of claim 1 or 2, wherein the antibody or antigen-binding fragment thereof further comprises: heavy chain framework regions comprised in the amino acid sequence encoded by IGVH1-2 x 02 and light chain framework regions comprised in the amino acid sequence encoded by IGKV1-16 x 01, said heavy chain framework regions and/or light chain framework regions optionally comprising one or more (e.g., 1,2, 3, 4,5, 6, 7,8, 9, or 10) back mutations from human residues to murine residues;

preferably, the antibody or antigen-binding fragment thereof is humanized to a degree of at least 84%.

9. The antibody or antigen-binding fragment thereof of any one of claims 1-2, 7-8, wherein the antibody or antigen-binding fragment thereof comprises:

(i) SEQ ID NOs: 9. 37, 39 or a sequence represented by any one of seq id nos;

(ii) and SEQ ID NOs: 9. 37, 39 with one or more amino acid substitutions, deletions or additions (e.g., 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence set forth in any one of claims; or

(iii) And SEQ ID NOs: 9. 37, 39, at least 80%, 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%, at least 99%, or 100% sequence identity;

and

(iv) SEQ ID NOs: 10. 38, 40, or a variant thereof;

(v) and SEQ ID NOs: 10. 38, 40 with one or more amino acid substitutions, deletions or additions (e.g. 1,2, 3, 4 or 5 amino acid substitutions, deletions or additions) compared to the sequence shown in any one of the above; or

(vi) And SEQ ID NOs: 10. 38, 40, or a sequence having at least 80%, 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%, at least 99%, or 100% sequence identity;

preferably the substitutions described in (ii) or (v) are conservative substitutions;

preferably, the antibody or antigen-binding fragment thereof comprises:

(1) VH having a sequence shown as SEQ ID NO.9 and VL having a sequence shown as SEQ ID NO. 10;

(2) VH having a sequence shown as SEQ ID NO. 37 and VL having a sequence shown as SEQ ID NO. 38; or

(3) VH having the sequence shown as SEQ ID NO. 39 and VL having the sequence shown as SEQ ID NO. 40.

10. The antibody or antigen-binding fragment thereof of any one of claims 3-4, 7, wherein the antibody or antigen-binding fragment thereof comprises:

(i) SEQ ID NO: 17;

and

(iv) SEQ ID NO:18, or a sequence shown in seq id no;

(vi) And SEQ ID NO:18, at least 80%, 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%, at least 99%, or 100% sequence identity;

preferably, the antibody or antigen-binding fragment thereof comprises: VH having a sequence shown as SEQ ID NO. 17 and VL having a sequence shown as SEQ ID NO. 18.

11. The antibody or antigen-binding fragment thereof of any one of claims 5-7, wherein the antibody or antigen-binding fragment thereof comprises:

(i) SEQ ID NO: 25;

and

(iv) SEQ ID NO: 26;

(vi) And SEQ ID NO:26, has at least 80%, 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%, at least 99%, or 100% sequence identity;

preferably, the antibody or antigen-binding fragment thereof comprises: VH having the sequence shown as SEQ ID NO. 25 and VL having the sequence shown as SEQ ID NO. 26.

12. The antibody or antigen-binding fragment thereof of any one of claims 1-11, wherein the antigen-binding fragment is selected from the group consisting of scFv, Fab ', (Fab')₂Fv fragments and diabodies (diabodies); and/or, the antibody is a chimeric antibody or a humanized antibody.

13. The antibody or antigen-binding fragment thereof of any one of claims 1-12, wherein the antibody is an IgG antibody (e.g., an IgG1, IgG2, IgG3, or IgG4 antibody).

14. The antibody or antigen-binding fragment thereof of any one of claims 1-13, wherein the antibody or antigen-binding fragment thereof is labeled; preferably, the antibody or antigen-binding fragment thereof carries a detectable label, such as an enzyme (e.g., horseradish peroxidase), a radionuclide, a fluorescent dye, a luminescent substance (e.g., a chemiluminescent substance), or biotin.

15. An isolated nucleic acid molecule encoding the antibody or antigen-binding fragment thereof of any one of claims 1-14, or a heavy chain variable region and/or a light chain variable region thereof.

16. A vector comprising the nucleic acid molecule of claim 15; preferably, the vector is a cloning vector or an expression vector.

17. A host cell comprising the nucleic acid molecule of claim 15 or the vector of claim 16.

18. A method of making the antibody or antigen-binding fragment thereof of any one of claims 1-14, comprising culturing the host cell of claim 17 under conditions that allow expression of the antibody or antigen-binding fragment thereof, and recovering the antibody or antigen-binding fragment thereof from the cultured host cell culture.

19. A conjugate comprising the antibody or antigen-binding fragment thereof of any one of claims 1-14 and a therapeutic agent linked to the antibody or antigen-binding fragment thereof;

preferably, the therapeutic agent is selected from a cytotoxin or a radioisotope.

20. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof of any one of claims 1-14 or the conjugate of claim 19, and a pharmaceutically acceptable carrier and/or excipient;

preferably, the pharmaceutical composition further comprises an additional pharmaceutically active agent;

preferably, the additional pharmaceutically active agent is a drug with anti-tumor activity, such as an additional immune checkpoint inhibitor, an oncolytic virus, a chemotherapeutic agent, an anti-angiogenic drug, an anti-metabolite drug, a tumor-targeting drug or an immune stimulant;

preferably, the additional pharmaceutically active agent is a drug for the treatment of infections, such as an antiviral, antifungal, antibacterial or immunostimulating agent;

preferably, the antibody or antigen-binding fragment thereof or the conjugate and the additional pharmaceutically active agent are provided as separate components or as components of the same composition.

21. An immunogenic composition comprising the antibody or antigen-binding fragment thereof of any one of claims 1-14, and an immunogen;

preferably, the antibody or antigen-binding fragment thereof is used as an adjuvant;

preferably, the immunogen is selected from the group consisting of a tumor-associated antigen (e.g., a protein, polypeptide, or carbohydrate molecule), a tumor cell, a dendritic cell primed with the antigen, and any combination thereof;

preferably, the immunogen is selected from the group consisting of an antigen (e.g., a protein, polypeptide, or carbohydrate molecule) associated with a pathogen, an inactivated or attenuated pathogen, a dendritic cell primed by the antigen, and any combination thereof;

preferably, the antibody or antigen-binding fragment thereof is provided as a separate component from the immunogen or as a component of the same composition.

22. Use of the antibody or antigen-binding fragment thereof of any one of claims 1-14, or the conjugate of claim 19, or the pharmaceutical composition of claim 20, in the preparation of a medicament for:

(1) increasing immune cell activity in vitro or in a subject (e.g., a human);

(2) enhancing an immune response in a subject (e.g., a human);

(3) preventing and/or treating a tumor in a subject (e.g., a human); or

(4) Preventing and/or treating infection in a subject (e.g., a human);

preferably, the immune cell is a T cell;

preferably, the immune response is a T cell mediated immune response;

preferably, the tumor is a tumor with microsatellite high instability (MSI-H) and/or mismatch repair deficiency (dMMR);

preferably, the tumor is selected from melanoma (e.g., metastatic malignant melanoma), breast cancer, kidney cancer (e.g., clear cell carcinoma), prostate cancer, bladder cancer, pancreatic cancer, lung cancer (e.g., non-small cell lung cancer), colon cancer, esophageal cancer, head and neck squamous cell carcinoma, liver cancer, ovarian cancer, cervical cancer, thyroid cancer, glioblastoma, glioma, and hematological malignancies (e.g., lymphoma, leukemia);

preferably, the infection is selected from the group consisting of viral infection, bacterial infection, fungal infection and parasitic infection;

preferably, the subject is a mammal, such as a human.

23. Use of the antibody or antigen-binding fragment thereof of any one of claims 1-14 in the preparation of an immunogenic composition for enhancing an immune response in a subject; wherein the immunogenic composition comprises the antibody or antigen-binding fragment thereof and an immunogen;

preferably, the immunogen is selected from the group consisting of a tumor-associated antigen (e.g., a protein, polypeptide, or carbohydrate molecule), a tumor cell, a dendritic cell primed with the antigen, and any combination thereof; the immunogenic composition is for use in the prevention and/or treatment of a tumor in a subject;

preferably, the immunogen is selected from the group consisting of an antigen (e.g., a protein, polypeptide, or carbohydrate molecule) associated with a pathogen, an inactivated or attenuated pathogen, a dendritic cell primed by the antigen, and any combination thereof; the immunogenic composition is for use in the prevention and/or treatment of infection in a subject;

preferably, the subject is a mammal, such as a human.