WO2023208182A1

WO2023208182A1 - Anti-ccr8 antibody and use thereof

Info

Publication number: WO2023208182A1
Application number: PCT/CN2023/091525
Authority: WO
Inventors: 张玲; 张明喜; 金薪盛; 李勋; 应华; 陶维康
Original assignee: 江苏恒瑞医药股份有限公司; 上海恒瑞医药有限公司
Priority date: 2022-04-29
Filing date: 2023-04-28
Publication date: 2023-11-02
Also published as: TW202400648A

Abstract

Disclosed in the present invention are an anti-CCR8 antibody and use thereof.

Description

Anti-CCR8 antibodies and their uses

Technical field

The present disclosure belongs to the field of biotechnology, and more specifically, the present disclosure relates to anti-CCR8 antibodies and applications thereof.

Background technique

The statements herein merely provide background information related to the present disclosure and do not necessarily constitute prior art.

CCR8 (chemokine C-C motif receptor 8) is a seven-transmembrane GPCR protein. The extracellular part exposed has an N-terminus and three loops. Its main ligand is CCL1. Among them, the N terminus and loop 2 play an important role in the binding of CCL1.

The CCL1-CCR8 axis plays an important role in the occurrence and development of tumors. Cancer stem cells, tumor-associated fibroblasts (CAF, cancer-associated fibroblasts) and tumor-associated macrophages (TAM, tumor-associated macrophages) in the tumor microenvironment secrete CCL1, driving CCR8-positive Tregs in peripheral blood to infiltrate into the tumor microenvironment. Inside the tumor tissue, the activity of Teff cells is inhibited, and at the same time, CCL1 and TGFβ secreted by tumor cells work together to convert CD4-positive Tconv into Tregs. CCR8 is also expressed on the surface of some tumor cells. Under the action of CCL1, it promotes tumor cell resistance to apoptosis (such as T-cell lymphoma), promotes tumor cell proliferation (such as bladder cancer), and promotes tumor cell metastasis (promotes melanoma to metastasize into lymph nodes). At the same time, vascular endothelial cells within tumor tissues also express CCR8, which promotes the formation of new blood vessels under the induction of CCL1. In addition, it has been found in various clinical tumors that the lower the expression of CCR8, the better the patient's survival. This is because patients with low CCR8 expression mean less Treg infiltration in the tumor microenvironment, and Teff The proportion and activity are relatively higher.

New research has found that CCR8 antibodies can specifically kill tumor-infiltrating Treg cells with high CCR8 expression through ADCC, eliminate Treg cells with immunosuppressive activity, and inhibit tumor growth. In addition, the combination of CCL1 and CCR8, in addition to inducing the enrichment of Tregs into the tumor microenvironment, will also enhance the tumor immunosuppressive ability by upregulating the expression of CCR8, FOXP3, IL-10 and other immunosuppressive factors in Tregs.

There are related patents for CCR8 antibodies that have been published, such as WO2018181425, WO2015048801 and CN110835371. Currently, many companies have developed antibodies against CCR8 and entered clinical trials. However, these CCR8 antibodies mainly bind to the N-terminus of CCR8 and have no cross-binding activity with monkey CCR8 or very weak cross-binding activity with monkey CCR8.

Contents of the invention

The present disclosure provides an anti-CCR8 antibody comprising:

HCDR1, HCDR2 and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO:10, and LCDR1, LCDR2 and LCDR3 contained in the light chain variable region shown in SEQ ID NO:11.

In some embodiments, the HCDR1-3 and LCDR1-3 are according to Kabat, IMTG, Chothia, Contact or AbM numbering rules are obtained.

In another aspect, the present disclosure provides an anti-CCR8 antibody comprising a heavy chain variable region and a light chain variable region, wherein:

(a) The heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 as set forth in SEQ ID NOs: 14, 15 and 16 respectively, and the light chain variable region comprises SEQ ID NOs: 17, 18 and 16 respectively. LCDR1, LCDR2 and LCDR3 shown in 19; or

(b) The heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 as set forth in SEQ ID NOs: 20, 21 and 22 respectively, and the light chain variable region comprises SEQ ID NOs: 23, 24 and 22 respectively. LCDR1, LCDR2 and LCDR3 shown in 25; or

(c) The heavy chain variable region includes HCDR1, HCDR2 and HCDR3 as shown in SEQ ID NO: 20, 21 and 22 respectively, and the light chain variable region includes SEQ ID NO: 34, 35 and 22 respectively. LCDR1, LCDR2 and LCDR3 shown in 36; or

(d) The heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 as set forth in SEQ ID NOs: 33, 21 and 22 respectively, and the light chain variable region comprises SEQ ID NOs: 34, 35 and 22 respectively. LCDR1, LCDR2 and LCDR3 shown in 36.

In some embodiments, the anti-CCR8 antibody as described above is a murine antibody, a chimeric antibody, or a humanized antibody.

In some embodiments, anti-CCR8 antibodies exert anti-tumor effects via ADCC as described above.

Specifically, the anti-CCR8 antibody further comprises a heavy chain constant region derived from human IgGl, IgG2, IgG3 and IgG4 or an isotype thereof, optionally the anti-CCR8 antibody is an afucosylated antibody.

In some embodiments, the anti-CCR8 antibody of any of the above is a humanized antibody.

In some embodiments, an anti-CCR8 antibody as described in any one above comprises the framework region (FR) of a human antibody.

In some embodiments, the anti-CCR8 antibody as described in any one of the above comprises FR1, FR2, FR3 of human IGHV2-26*01 or IGHV4-30-4*01, and FR4 of IGHJ6*01 as a heavy chain framework region template ; and FR1, FR2, FR3 of human IGKV6-21*01, IGKV1-39*01 or IGKV3-20*02, and FR4 of IGKJ4*01 as the light chain framework region template; or

The framework region includes FR1, FR2, FR3 of human IGHV3-72*01, IGHV3-66*01, IGHV3-23*01 or IGHV7-4-1*01, and the FR4 region of IGHJ6*01 as the heavy chain framework region Template; and FR1, FR2, FR3 of human IGKV2-28*01, IGKV3-11*01 or IGKV1-39*01, and FR4 of IGKJ4*01 as the light chain framework region template.

In some embodiments, the anti-CCR8 antibody as described in any one of the above, wherein the framework region of the antibody comprises an amino acid substitution, and in some embodiments, the amino acid substitution is a back mutation.

In some embodiments, the anti-CCR8 antibody of any one of the above, wherein:

(a) the heavy chain variable region includes HCDR1, HCDR2 and HCDR3 as shown in SEQ ID NO: 14, 15 and 16 respectively, and the FR of the heavy chain variable region includes selected from 1E, 27F, 28S, 30T, 71K, One or more amino acid substitutions in 73K, 78V, 44G and 49G; and

The light chain variable region includes LCDR1, LCDR2 and LCDR3 as shown in SEQ ID NO: 17, 18 and 19 respectively, and the FR of the light chain variable region includes selected from 43S, 45K, 46P, 47W, 58V , one or more amino acid substitutions in 60A, 71Y and 49Y; or

(b) The heavy chain variable region includes HCDR1, HCDR2 and HCDR3 as shown in SEQ ID NO: 20, 21 and 22 respectively, and the FR of the heavy chain variable region includes 27F, 48V, 69I, One or more amino acid substitutions in 71R, 75E, 29F and 93V; and

The light chain variable region includes LCDR1, LCDR2 and LCDR3 as shown in SEQ ID NO: 23, 24 and 25 respectively, and the FR of the light chain variable region includes optionally selected from 4V, 36L, 43S, 45Q, One or more amino acid substitutions in 60S and 100A; or

(c) The heavy chain variable region includes HCDR1, HCDR2 and HCDR3 as shown in SEQ ID NO: 20, 21 and 22 respectively, and the FR of the heavy chain variable region includes optionally selected from 27F, 48V, 69I , one or more amino acid substitutions in 71R, 75E, 29F and 93V; and

The light chain variable region includes LCDR1, LCDR2 and LCDR3 as shown in SEQ ID NO: 34, 35 and 36 respectively, and the FR of the light chain variable region includes optionally selected from 4V, 36L, 43S, 45Q, One or more amino acid substitutions in 60S and 100A; or

(d) The heavy chain variable region includes HCDR1, HCDR2 and HCDR3 as shown in SEQ ID NO: 33, 21 and 22 respectively, and the FR of the heavy chain variable region includes optionally selected from 27F, 48V, 69I , one or more amino acid substitutions in 71R, 75E, 29F and 93V; and

The light chain variable region includes LCDR1, LCDR2 and LCDR3 as shown in SEQ ID NO: 34, 35 and 36 respectively, and the FR of the light chain variable region includes optionally selected from 4V, 36L, 43S, 45Q, One or more amino acid substitutions in 60S and 100A;

The above amino acid substitution sites are based on Kabat numbering rules.

In some embodiments, the anti-CCR8 antibody as described in any one of the above, which comprises the framework region (FR) of a human antibody;

The anti-CCR8 antibody comprises SEQ ID NO: 27, 26 or 28, or has at least 80% (such as at least 80%, 85%, 86%, 87%, 88%, A heavy chain variable region sequence with 89%, 90%, 95%, 96%, 97%, 98% or 99%) sequence identity to SEQ ID NO: 31, 29, 30 or 32, or to SEQ ID NO: 31, 29, 30 or 32, or to SEQ ID NO: : 31, 29, 30 or 32, with at least 80% (such as at least 80%, 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%, 97%, 98% or 99 %) sequence identity of the light chain variable region sequence; or

The antibody comprises SEQ ID NO: 37, 38, 39 or 40, or has at least 80% (such as at least 80%, 85%, 86%, 87%, 88) of SEQ ID NO: 37, 38, 39 or 40. %, 89%, 90%, 95%, 96%, 97%, 98% or 99%) sequence identity to a heavy chain variable region sequence, and SEQ ID NO: 43, 41 or 42, or to SEQ ID NO: 43, 41 or 42, or to SEQ ID NO: : 43, 41 or 42 has at least 80% (e.g. at least 80%, 83%, 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%, 97%, 98% or 99 %)sequence identical Sexual light chain variable region sequence.

The anti-CCR8 antibody comprises a heavy chain variable having at least 90% (e.g., at least 90%, 95%, 96%, 97%, 98% or 99%) sequence identity to SEQ ID NO: 26, 27 or 28 region sequence, and a light chain variable region having at least 90% (e.g., at least 90%, 95%, 96%, 97%, 98% or 99%) sequence identity to SEQ ID NO: 29, 30, 31 or 32 sequence; or

The antibody comprises a heavy chain variable having at least 90% (e.g., at least 90%, 95%, 96%, 97%, 98% or 99%) sequence identity to SEQ ID NO: 37, 38, 39 or 40 region sequence, and a light chain variable region sequence having at least 90% (e.g., at least 90%, 95%, 96%, 97%, 98%, or 99%) sequence identity with SEQ ID NO: 41, 42, or 43.

In some embodiments, an anti-CCR8 antibody as described in any one of the above, comprising a heavy chain variable region sequence as set forth in SEQ ID NO: 26, 27 or 28, and a heavy chain variable region sequence as set forth in SEQ ID NO: 29, 30, 31 Or the light chain variable region sequence shown in 32.

In some embodiments, an anti-CCR8 antibody as described in any one of the above, comprising a heavy chain variable region sequence as set forth in SEQ ID NO: 37, 38, 39 or 40, and as set forth in SEQ ID NO: 43, 41 Or the light chain variable region sequence shown in 42.

In some embodiments, an anti-CCR8 antibody as described in any one of the above comprises:

i) The heavy chain variable region as set forth in SEQ ID NO: 27, and the light chain variable region as set forth in SEQ ID NO: 31; or

ii) a heavy chain variable region as set forth in SEQ ID NO: 37, and a light chain variable region as set forth in SEQ ID NO: 43.

In some embodiments, the anti-CCR8 antibody as described in any one of the above is a full-length antibody or an antibody fragment thereof; preferably, the antibody fragment is Fab, Fab', F(ab') ₂ , Fd, Fv , scFv, dsFv or dAb.

In some embodiments, the anti-CCR8 antibody of any one above is a Fab. In some embodiments, the Fab includes: the amino acid sequence shown in SEQ ID NO: 50 and the amino acid sequence shown in SEQ ID NO: 51; or the amino acid sequence shown in SEQ ID NO: 52 and SEQ ID NO: The amino acid sequence shown in 53.

In some embodiments, an anti-CCR8 antibody as described in any one of the above comprises a heavy chain constant region and a light chain constant region; specifically, the heavy chain constant region is derived from human IgGl, IgG2, IgG3 and IgG4 constant regions, so The light chain constant regions are derived from human kappa and lambda chain constant regions.

In some embodiments, the anti-CCR8 antibody as described in any one of the above comprises a heavy chain constant region and a light chain constant region, the heavy chain constant region is a constant region derived from human IgG1, which includes a human IgG1-derived constant region selected from the group consisting of those that can enhance ADCC. One or more amino acid substitutions in mutations S298A/E333A/K334A and S239D/I332E, wherein the amino acid substitution sites are numbered according to EU.

In some embodiments, an anti-CCR8 antibody as described in any one of the above comprises a heavy chain constant region and a light chain constant region, the heavy chain constant region comprising the amino acid sequence of SEQ ID NO: 44, and/or the light chain The constant region contains the amino acid sequence of SEQ ID NO: 45.

In some embodiments, an anti-CCR8 antibody as described in any one of the above comprises a heavy chain and a light chain, wherein:

The heavy chain comprises at least 85% (such as at least 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%, 97%, 98% or 99%) of SEQ ID NO:46. ), and the light chain comprises an amino acid sequence having at least 85% (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%) sequence identity to SEQ ID NO: 47 , 97%, 98% or 99%) sequence identity to an amino acid sequence; or

The heavy chain comprises at least 85% (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%, 97%, 98% or 99%) of SEQ ID NO:48. ), and the light chain comprises an amino acid sequence having at least 85% (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%) sequence identity to SEQ ID NO: 49 , 97%, 98% or 99%) sequence identity of the amino acid sequence.

The heavy chain comprises the amino acid sequence of SEQ ID NO: 46, and the light chain comprises the amino acid sequence of SEQ ID NO: 47; or

The heavy chain includes the amino acid sequence of SEQ ID NO: 48, and the light chain includes the amino acid sequence of SEQ ID NO: 49.

In another aspect, the present disclosure also provides an anti-CCR8 antibody as described above, which has one or more of the following properties:

A. The anti-CCR8 antibody has cross-binding activity with monkey CCR8; preferably, the EC ₅₀ value of binding to the monkey CCR8 protein on the cell surface is less than 1 nM; more preferably, the EC ₅₀ value of binding to the monkey CCR8 protein on the cell surface is less than 0.5nM;

B. The anti-CCR8 antibody binds to loop 2 of human CCR8 as set forth in SEQ ID NO: 65; and

C. The anti-CCR8 antibody binds to loop 3 of human CCR8 as shown in SEQ ID NO: 66.

In another aspect, the present disclosure also provides a pharmaceutical composition comprising the anti-CCR8 antibody as described in any one of the preceding items and one or more pharmaceutically acceptable carriers, diluents or excipients.

In another aspect, the present disclosure also provides an immunoconjugate comprising: the anti-CCR8 antibody and an effector molecule as described in any one of the preceding items, wherein the effector molecule is coupled to the anti-CCR8 antibody; preferably , the effector molecule is selected from antitumor agents, immunomodulators, biological response modifiers, lectins, cytotoxic drugs, chromophores, fluorophores, chemiluminescent compounds, enzymes, metal ions, and any combination thereof.

In another aspect, the present disclosure also provides a nucleic acid molecule encoding an anti-CCR8 antibody as described in the preceding item.

In another aspect, the present disclosure also provides a host cell containing the nucleic acid molecule as described above; preferably, the host cell is a microorganism, a plant or a non-human animal cell host cell; more preferably, the host The cells are host cells in which Glul and Fut8 genes have been knocked out.

In some embodiments, the present disclosure also provides a host cell, which may be selected from prokaryotic Cells and eukaryotic cells, preferably eukaryotic cells, more preferably mammalian cells, preferably mammalian cells excluding humans; wherein said mammalian cells include but are not limited to CHO, 293, NSO and are performed in mammalian cells Gene editing can change the glycosylation modification of the antibody or its antigen-binding fragment, thereby changing the cells of the ADCC function of the antibody or its antigen-binding fragment. For example, knocking out genes such as Fut8 or GnT-III for glycosylation modification.

In some embodiments, the present disclosure also provides a method for preparing the aforementioned anti-CCR8 antibody, which method includes the steps of culturing the aforementioned host cells, and then purifying and recovering the antibody.

In another aspect, the present disclosure also provides an anti-CCR8 antibody as described in any one of the preceding items, or a pharmaceutical composition as described above, or an immunoconjugate as described above, for use in the treatment of CCR8-related diseases. or use in medicines for diseases. Specifically, the CCR8-related disease or disorder is a disease or disorder with high expression of CCR8. More specifically, the CCR8-related disease or disorder is selected from cancers or tumors with elevated CCR8 expression. , inflammatory diseases and viral infections.

In another aspect, the present disclosure also provides the anti-CCR8 antibody as described in any one of the preceding items, or the pharmaceutical composition as described above, or the immunoconjugate as described above, when prepared for the treatment of cancer or tumors, Use in medicines for inflammatory diseases and viral infections; preferably, the cancer or tumor is selected from prostate cancer, bladder cancer, ovarian cancer, lung cancer (including non-small cell lung cancer and small cell lung cancer), liver cancer, gastric cancer, colon carcinoma, kidney cancer, dermatofibrosarcoma, osteosarcoma, cervical cancer, esophageal cancer, rectal cancer, head and neck squamous cell carcinoma, breast cancer, multiple myeloma, lymphoma and melanoma.

In another aspect, the present disclosure also provides a method of treating cancer or tumors, inflammatory diseases and viral infections, the method comprising administering to a patient in need thereof an anti-CCR8 antibody as described in any one of the preceding paragraphs or as described above The pharmaceutical composition, or the immunoconjugate as described above; preferably, the cancer or tumor is selected from prostate cancer, bladder cancer, ovarian cancer, lung cancer (including non-small cell lung cancer and small cell lung cancer), liver cancer , gastric cancer, colon cancer, kidney cancer, dermatofibrosarcoma, osteosarcoma, cervical cancer, esophageal cancer, rectal cancer, head and neck squamous cell carcinoma, breast cancer, multiple myeloma, lymphoma and melanoma.

In another aspect, the present disclosure also provides the anti-CCR8 antibody as described in any one of the preceding items, or the pharmaceutical composition as described above, or the immunoconjugate as described above, for use as a medicine. In some embodiments, used as a drug to treat cancer or tumors, inflammatory diseases, and viral infections. Preferably, the cancer or tumor is selected from prostate cancer, bladder cancer, ovarian cancer, lung cancer (including non-small cell lung cancer and small cell lung cancer), liver cancer, gastric cancer, colon cancer, kidney cancer, dermatofibrosarcoma, osteosarcoma, Cervical cancer, esophageal cancer, rectal cancer, head and neck squamous cell carcinoma, breast cancer, multiple myeloma, lymphoma and melanoma.

Detailed ways

the term

To make this disclosure easier to understand, certain technical and scientific terms are described below. Unless otherwise expressly defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

As used in the specification and claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

Unless the context clearly requires otherwise, in the patent specification and claims, the words "include", "have", "including", etc. should be understood to mean "including but not limited to" and not in the exclusive or exhaustive sense. .

The term "and/or" is meant to include both "and" and "or". For example the phrase "A, B and/or C" is intended to cover each of: A, B and C; A, B or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

The three-letter and single-letter codes for amino acids used in this disclosure are as described in J. biol. chem, 243, p3558 (1968).

The term "CCR8" refers to the full-length CCR8 protein, and human CCR8 has the amino acid sequence of SEQ ID NO: 1. Amino acid sequences of CCR8 molecules from non-human species (eg, mouse, monkey, rabbit, dog, pig, etc.) are available from public resources.

The term "amino acid" refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those that are later modified, such as hydroxyproline, gamma-carboxyglutamic acid, and O-phosphoserine. Amino acid analogs refer to compounds that have the same basic chemical structure (i.e., alpha carbon bonded to hydrogen, carboxyl, amino, and R groups) as naturally occurring amino acids, such as homoserine, norleucine, methionine sulfoxide , methionine methyl sulfonium. Such analogs have modified R groups (eg, norleucine) or modified peptide backbones but retain the same basic chemical structure as the naturally occurring amino acid. Amino acid mimetics refer to chemical compounds that have a structure that differs from the general chemical structure of amino acids, but act in a manner similar to naturally occurring amino acids.

The term "amino acid mutation" includes amino acid substitutions (also called amino acid substitutions), deletions, insertions and modifications. Any combination of substitutions, deletions, insertions and modifications can be made to achieve the final construct, as long as the final construct possesses the desired properties, such as reduction or binding to Fc receptors. Amino acid sequence deletions and insertions include deletions and insertions at the amino terminus and/or carboxyl terminus of the polypeptide chain. Specific amino acid mutations may be amino acid substitutions. In one embodiment, the amino acid mutation is a non-conservative amino acid substitution, ie, one amino acid is replaced by another amino acid with different structural and/or chemical properties. Amino acid substitutions include substitutions by non-naturally occurring amino acids or by derivatives of the 20 natural amino acids (e.g., 4-hydroxyproline, 3-methylhistidine, ornithine, homoserine, 5-hydroxylysine) . Amino acid mutations can be generated using genetic or chemical methods well known in the art. Genetic methods can include site-directed mutagenesis, PCR, gene synthesis, etc. It is anticipated that methods other than genetic engineering to alter amino acid side chain groups, such as chemical modification, may also be available. Various names may be used herein to refer to the same amino acid mutation. Herein, the amino acid residue at a specific position can be represented by position + amino acid residue, for example, 366W, indicating that the amino acid residue at position 366 is W. T366W means that the amino acid residue at position 366 has been mutated from the original T to W.

The term "antibody" is used in the broadest sense and encompasses a variety of antibody structures, including but not limited to monoclonal Antibodies, polyclonal antibodies; monospecific antibodies, multispecific antibodies (e.g., bispecific antibodies); full-length antibodies and antibody fragments (or antigen-binding fragments, or antigen-binding portions), so long as they exhibit the desired antigen-binding activity . "Native antibodies" refer to naturally occurring immunoglobulin molecules. For example, natural IgG antibodies are heterotetrameric proteins of approximately 150,000 Daltons, composed of two identical light chains and two identical heavy chains bonded by disulfide bonds. From N to C-terminus, each heavy chain has a variable region (VH), also known as variable heavy domain, heavy chain variable region, followed by a heavy chain constant region. Natural IgG heavy chain constant regions usually contain three Constant domains (CH1, CH2 and CH3). Similarly, from N to C terminus, each light chain has a variable region (VL), also called a variable light domain, or light chain variable domain, followed by a constant light domain (light chain constant region, CL ). The terms "full-length antibody", "intact antibody" and "whole antibody" are used interchangeably herein to refer to an antibody having a structure substantially similar to that of a native antibody or having a heavy chain with an Fc region as defined herein. The natural intact antibody light chain includes the light chain variable region VL and the constant region CL. VL is at the amino terminus of the light chain. The light chain constant region includes the kappa chain and lambda chain; the heavy chain includes the variable region VH and the constant region (CH1, CH2 and CH3), VH is at the amino terminus of the heavy chain, and the constant region is at the carboxyl terminus, with CH3 closest to the carboxyl terminus of the polypeptide. The heavy chain can belong to any isotype, including IgG (including IgG1, IgG2, IgG3 and IgG4 subtypes) , IgA (including IgA1 and IgA2 subtypes), IgM and IgE.

The term antibody "variable region" or "variable domain" refers to the domain of the antibody heavy or light chain that is involved in the binding of the antibody to antigen. Herein, the antibody heavy chain variable region (VH) and light chain variable region (VL) each contain four conserved framework regions (FR) and three complementarity determining regions (CDR). Among them, the term "complementarity determining region" or "CDR" refers to the region within the variable domain that mainly contributes to binding to the antigen; "framework" or "FR" refers to the variable domain residues other than CDR residues. VH contains 3 CDR areas: HCDR1, HCDR2 and HCDR3; VL contains 3 CDR areas: LCDR1, LCDR2 and LCDR3. Each VH and VL consists of three CDRs and four FRs arranged in the following order from the amino terminus (also called N terminus) to the carboxyl terminus (also called C terminus): FR1, CDR1, FR2, CDR2, FR3, CDR3 , FR4.

The amino acid sequence boundaries of CDRs can be determined by various well-known schemes, such as: "Kabat" numbering rule (see Kabat et al. (1991), "Sequences of Proteins of Immunological Interest", 5th edition, Public Health Service, National Institutes of Health , Bethesda, MD), "Chothia" numbering rule, "ABM" numbering rule, "contact" numbering rule (see Martin, ACR.Protein Sequence and Structure Analysis of Antibody Variable Domains[J].2001) and ImMunoGenTics (IMGT) numbering Rules (Lefranc, M.P. et al., Dev. Comp. Immunol., 27, 55-77 (2003); Front Immunol. 2018 Oct 16; 9:2278), etc.; the correspondence between various numbering systems is a matter for those skilled in the art Well-known and exemplary ones are shown in Table 1 below.

Table 1. Relationship between CDR numbering systems

Unless otherwise stated, the variable regions and CDRs in the embodiments of the present disclosure are all subject to the "Kabat" numbering rule.

The term "antibody fragment" refers to a molecule other than an intact antibody that contains portions of an intact antibody that bind to the antigen to which the intact antibody binds. Examples of antibody fragments include, but are not limited to, Fv, Fab, Fab', Fab'-SH, F(ab') ₂ , single domain antibody, single chain Fab (scFab), diabody, linear antibody, single chain antibody (e.g., scFv ); and multispecific antibodies formed from antibody fragments.

The term "Fc region" or "fragment crystallizable region" is used to define the C-terminal region of an antibody heavy chain, including native Fc regions and engineered Fc regions. In some embodiments, the Fc region contains two subunits that are the same or different. In some embodiments, the Fc region of a human IgG heavy chain is defined as extending from the amino acid residue at position Cys226 or from Pro230 to its carboxy terminus. Suitable Fc regions for use in the antibodies described herein include those of human IgGl, IgG2 (IgG2A, IgG2B), IgG3 and IgG4. In some embodiments, the boundaries of the Fc region may also vary, such as deletion of the C-terminal lysine of the Fc region (residue 447 according to the EU numbering system) or deletion of the C-terminal glycine and lysine of the Fc region (according to the EU numbering system Systemic residues 446 and 447). Unless otherwise stated, the numbering rule for the Fc region is the EU numbering system, also known as the EU index.

The term "chimeric" antibody refers to an antibody in which a portion of the heavy and/or light chain is derived from a specific source or species and the remaining portion of the heavy and/or light chain is derived from a different source or species.

The term "humanized" antibody is an antibody that retains the reactivity of a non-human antibody while having lower immunogenicity in humans. This can be accomplished, for example, by retaining the non-human CDR regions and replacing the remainder of the antibody with their human counterparts (ie, the constant regions as well as the framework portions of the variable regions).

The terms "human antibody", "humanized antibody", "fully human antibody" and "fully human antibody" are used interchangeably and mean an antibody in which the variable and constant regions are human sequences. The term covers antibodies derived from human genes but with sequence changes that, for example, reduce possible immunogenicity, increase affinity, eliminate cysteines or glycosylation sites that may cause undesired folding. This term encompasses antibodies produced recombinantly in non-human cells that may confer glycosylation not characteristic of human cells. The term also encompasses antibodies that have been raised in transgenic mice containing some or all immunoglobulin heavy and light chain loci. The meaning of human antibody specifically excludes humanized antibodies containing non-human antigen-binding residues.

The term "affinity" refers to the overall strength of non-covalent interactions between a single binding site of a molecule (eg, an antibody) and its binding partner (eg, an antigen). Unless otherwise specified, as used herein, binding "affinity" refers to internal binding affinity, which reflects a 1:1 interaction between members of a binding pair (eg, antibody and antigen). The affinity of a molecule X for its ligand Y can often be expressed by the dissociation constant (KD). Affinity can be measured by conventional methods known in the art, including those described herein.

As used herein, the term "kassoc" or "ka" refers to the association rate of a particular antibody-antigen interaction, and the term "kdis" or "kd" refers to the dissociation rate of a particular antibody-antigen interaction. The term "KD" refers to the dissociation constant, which is obtained from the ratio of kd to ka (i.e., kd/ka) and is expressed as molar concentration (M). The KD value of an antibody can be determined using methods well known in the art. For example, surface plasmon resonance is measured using biosensing systems such as systems such as Biacore, or affinity in solution is measured by solution equilibrium titration (SET).

The term "surface plasmon resonance" refers to the optical phenomenon of analyzing real-time interactions by detecting changes in protein concentration within a biosensor matrix, for example, using the BIAcoreTM system (Biacore LifeSciences division of GE Healthcare, Piscataway, NJ).

The term "effector function" refers to those biological activities that are attributable to the Fc region of an antibody (either a native sequence Fc region or a mutated amino acid sequence Fc region) and that vary with the antibody isotype. Examples of antibody effector functions include, but are not limited to: C1q binding and complement-dependent cytotoxicity, Fc receptor binding, antibody-dependent cell-mediated cytotoxicity (ADCC), phagocytosis, cell surface receptors (e.g., B cell receptors body) downregulation; and B cell activation.

The term "monoclonal antibody" refers to a population of antibodies that are substantially homogeneous, ie, the antibody molecules contained in the population are identical in amino acid sequence, except for natural mutations that may be present in minor amounts. In contrast, polyclonal antibody preparations typically contain multiple different antibodies with different amino acid sequences in their variable domains, often specific for different epitopes. "Monoclonal" refers to the characteristics of an antibody obtained from a substantially homogeneous population of antibodies and should not be construed as requiring that the antibody be produced by any particular method. In some embodiments, the antibodies provided by the present disclosure are monoclonal antibodies.

The term "antigen" refers to a molecule or portion of a molecule capable of being bound by a selective binding agent such as an antigen-binding protein (including, for example, an antibody), and which is otherwise capable of being used in an animal to generate antibodies capable of binding the antigen. An antigen may have one or more epitopes capable of interacting with different antigen-binding proteins (eg, antibodies).

The term "epitope" refers to an area or region on an antigen that is capable of specifically binding to an antibody or antigen-binding fragment thereof. An epitope may be formed from a contiguous string of amino acids (linear epitope) or comprise non-contiguous amino acids (conformational epitope) brought into spatial proximity, for example by folding of the antigen (ie by tertiary folding of the antigen in its proteinaceous nature). The difference between conformational epitopes and linear epitopes is that in the presence of denaturing solvents, the antibody's binding to the conformational epitope is lost. An epitope contains at least 3, at least 4, at least 5, at least 6, at least 7, or 8-10 amino acids in a unique spatial conformation. Screening for antibodies that bind a specific epitope (i.e., those that bind the same epitope) can be performed using methods routine in the art, such as, but not limited to, alanine scanning, peptide blotting, peptide cleavage analysis, epitope excision, epitope extraction, Chemical modification of antigen (see Prot. Sci. 9 (2000) 487-496), and cross-blocking.

The terms "capable of specifically binding,""specificallybinding," or "binding" refer to the ability of an antibody to bind to an antigen or an epitope on that antigen with higher affinity than to other antigens or epitopes. Typically, the antibody is present in a concentration of about 1×10 ⁻⁷ M or less (eg, about 1×10 ⁻⁸ M, 1×10 ⁻⁹ M, 1×10 ⁻¹⁰ M, 1×10 ⁻¹¹ M or less). The equilibrium dissociation constant (KD) binds the antigen or an epitope within the antigen. In some embodiments, the KD of the antibody binding to the antigen is 10% or less (eg, 1%) of the KD of the antibody binding to a non-specific antigen (eg, BSA, casein). KD can be measured using known methods, for example by Measured by surface plasmon resonance assay. However, antibodies that specifically bind to an antigen or an epitope within the antigen may Can be cross-reactive to other related antigens, for example, to antigens from other species (homologous) such as humans or monkeys, e.g. Macaca fascicularis (cynomolgus, cyno), Chimpanzees (Pan troglodytes) (chimpanzee, chimp )) or marmoset (Callithrix jacchus) (commonmarmoset, marmoset) corresponding antigens are cross-reactive.

The terms "anti-CCR8 antibody" and "antibody that binds CCR8" refer to antibodies that are capable of binding CCR8 with sufficient affinity.

The term "antigen-binding molecule" is used in the broadest sense and covers various molecules that specifically bind to antigens, including but not limited to antibodies, other polypeptides with antigen-binding activity, and antibody fusion proteins formed by the fusion of the two. Exemplarily, the antigen-binding molecule herein is a bispecific antigen-binding molecule (for example, a bispecific antibody), which may include two identical first chains and two identical second chains; or they may be different from each other. First strand, second strand, third strand and fourth strand. Illustratively, the chain is a polypeptide chain. Exemplarily, the first polypeptide chain or the third polypeptide chain can be the heavy chain of an antibody or a polypeptide containing the Fc region, and the second polypeptide chain or the fourth polypeptide chain can be the light chain of an antibody or Engineered antibody light chains. The term "bispecific antigen-binding molecule" refers to an antigen-binding molecule capable of specifically binding to two different antigens or at least two different antigenic epitopes of the same antigen.

The terms "linker", "Linker" or "linker" refer to the connecting unit that connects two polypeptide fragments, which usually has a certain degree of flexibility. The use of the linker will not cause the original function of the protein domain to be lost. In this context, linkers appearing in the same structure may be the same or different. The linker can be a peptide linker, which contains one or more amino acids, typically about 1-30, 2-24 or 3-15 amino acids. The linkers used herein may be the same or different.

The terms "antibody-dependent cellular cytotoxicity", "antibody-dependent cell-mediated cytotoxicity" or "ADCC" are mechanisms of induction of cell death that rely on antibody coating of target cells in conjunction with effector cells with lytic activity ( Such as natural killer cells (NK), monocytes, macrophages, and neutrophils) interact via Fcγ receptors (FcγR) expressed on effector cells. For example, NK cells express FcγRIIIa, while monocytes express FcγRI, FcγRII, and FcγRIIIa. The ADCC activity of the antibodies provided herein can be assessed using an in vitro assay using cells expressing the antigen as target cells and NK cells as effector cells. Cell lysis is detected based on markers released from lysed cells, such as radioactive substrates, fluorescent dyes, or native intracellular proteins.

The term "antibody-dependent cellular phagocytosis (ADCP)" refers to the mechanism by which antibody-coated target cells are eliminated by internalization by phagocytes, such as macrophages or dendritic cells.

The term "complement-dependent cytotoxicity" or "CDC" refers to a mechanism that induces cell death in which the Fc effector domain of a target-binding antibody binds and activates the complement component C1q, which in turn activates the complement cascade, resulting in target cell death. Activation of complement can also lead to the deposition of complement components on the surface of target cells, and these complement components promote CDC by binding to complement receptors (eg, CR3) on leukocytes.

The term "nucleic acid" is used interchangeably herein with the term "polynucleotide" and refers to deoxyribonucleotides or ribonucleotides and polymers thereof in single- or double-stranded form. The term covers the Glycoside analogs or modified backbone residues or linked nucleic acids, which are synthetic, naturally occurring and non-naturally occurring, have similar binding properties to the reference nucleic acid and in a manner similar to the reference nucleotide metabolism. Examples of such analogs include, but are not limited to, phosphorothioates, phosphoramidates, methylphosphonates, chiral-methylphosphonates, 2-O-methylribonucleotides, peptide-nucleic acids (PNA ). An "isolated" nucleic acid refers to a nucleic acid molecule that has been separated from components of its natural environment. Isolated nucleic acids include nucleic acid molecules contained in cells that normally contain the nucleic acid molecule but which are present extrachromosomally or at a chromosomal location that is different from its native chromosomal location. Isolated nucleic acid encoding a polypeptide or fusion protein refers to one or more nucleic acid molecules encoding a polypeptide or fusion protein, including such one or more nucleic acid molecules in a single vector or separate vectors, and present in a host cell One or more such nucleic acid molecules at one or more positions. Unless otherwise stated, a particular nucleic acid sequence also implicitly encompasses conservatively modified variants (eg, degenerate codon substitutions) and complementary sequences thereof as well as sequences explicitly indicated. Specifically, as detailed below, degenerate codon substitutions can be obtained by generating sequences in which the third position of one or more selected (or all) codons is mixed bases and/or deoxygenated. Inosine residue substitution.

The terms "polypeptide" and "protein" are used interchangeably herein to refer to a polymer of amino acid residues. The term applies to amino acid polymers in which one or more amino acid residues are artificial chemical mimetics of the corresponding naturally occurring amino acids, as well as to naturally occurring amino acid polymers and non-naturally occurring amino acid polymers. Unless stated otherwise, a particular polypeptide sequence also implicitly encompasses conservatively modified variants thereof.

The term sequence "identity" means that when two sequences are optimally aligned, gaps are introduced when necessary to achieve maximum percent sequence identity, and any conservative substitutions are not considered part of the sequence identity of the two sequences. The extent (percentage) that amino acids/nucleic acids of a sequence are identical at equivalent positions. To determine percent sequence identity, alignment can be accomplished by techniques known to those skilled in the art, for example using publicly available computer software such as BLAST, BLAST-2, ALIGN, ALIGN-2 or Megalign (DNASTAR) software. One skilled in the art can determine parameters suitable for measuring alignment, including any algorithms required to achieve maximal alignment over the full length of the sequences being compared.

The term "vector" means a polynucleotide molecule capable of transporting another polynucleotide to which it is linked. One type of vector is a "plasmid," which refers to a circular double-stranded DNA circle into which additional DNA segments can be ligated. Another type of vector is a viral vector, such as an adeno-associated viral vector (AAV or AAV2), in which additional DNA segments can be ligated into the viral genome. Certain vectors are capable of autonomous replication in the host cells into which they are introduced (eg, bacterial vectors with bacterial origins of replication and episomal mammalian vectors). Other vectors (eg, non-episomal mammalian vectors) can be introduced into the host cell and integrated into the host cell's genome, thereby replicating with the host genome. The term "expression vector" or "expression construct" refers to a vector capable of transforming a host cell and containing a vector that directs and/or controls (together with the host cell) the expression of one or more heterologous coding regions operably linked thereto. Nucleic acid sequence vectors. Expression constructs may include, but are not limited to, sequences that affect or control transcription, translation, and, in the presence of introns, RNA splicing of the coding region operably linked thereto.

The terms "host cell", "host cell line" and "host cell culture" are used interchangeably and And refers to cells into which exogenous nucleic acid has been introduced, including the progeny of such cells. Host cells include "transformants" and "transformed cells," which include the primary transformed cell and progeny derived therefrom, regardless of the number of passages. The progeny may not be identical in nucleic acid content to the parent cells, but may contain mutations. Mutant progeny having the same function or biological activity as screened or selected in the original transformed cell are included herein. Host cells include prokaryotic and eukaryotic host cells, where eukaryotic host cells include, but are not limited to, mammalian cells, insect cell line plant cells, and fungal cells. Mammalian host cells include human, mouse, rat, canine, monkey, porcine, goat, bovine, equine, and hamster cells, including but not limited to Chinese hamster ovary (CHO) cells, NSO, SP2 cells, HeLa cells, baby hamster kidney (BHK) cells, monkey kidney cells (COS), human hepatocellular carcinoma cells (eg, Hep G2), A549 cells, 3T3 cells, and HEK-293 cells. Fungal cells include yeast and filamentous fungal cells, including, for example, Pichia pastoris, Pichia finlandica, Pichia trehalophila, Pichia koclamae, Pichia membranaefaciens, Pichia minuta (Ogataea minuta, Pichia lindneri), Pichia opuntiae, Pichia thermotolerans, Pichia salictaria), Pichia guercuum, Pichia pijperi, Pichia stiptis, Pichia methanolica, Pichia genus, Saccharomycescerevisiae, Saccharomyces cerevisiae , Hansenula polymorpha, Kluyveromyces lactis, Kluyveromyces lactis, Candida albicans, Aspergillus nidulans, Aspergillus niger, Aspergillus oryzae, Trichoderma reesei, Chrysosporium lucknowense, Fusarium sp., Fusarium gramineum, Fusarium venenatum , Physcomitrella patens and Neurospora crassa. Pichia pastoris, any Saccharomyces spp., Hansenula polymorpha, any Kluyveromyces spp., Candida albicans, any Aspergillus spp., Trichoderma reesei, Luck Chrysosporium lucknowense, any species of Fusarium, Yarrowia lipolytica and Neurospora crassa.

As used in this application, the expressions "cell," "cell line," and "cell culture" are used interchangeably, and all such designations include progeny. Thus, the terms "transformant" and "transformed cells" include primary subject cells and cultures derived therefrom regardless of the number of passages. It should also be understood that not all progeny will have exactly the same DNA content due to intentional or unintentional mutations. Includes mutant progeny that have the same function or biological activity as the original transformed cells.

"Optional" or "optionally" means that the subsequently described event or circumstance can but need not occur, and that the description includes instances where the event or circumstance does or does not occur.

The term "pharmaceutical composition" refers to a mixture containing one or more anti-CCR8 antibody fusion proteins described herein and other chemical components, such as physiologically/pharmaceutically acceptable carriers and excipients.

The term "pharmaceutically acceptable carrier" refers to a pharmaceutical formulation that is distinct from the active ingredient and is effective in the subject non-toxic ingredients. Pharmaceutically acceptable carriers include, but are not limited to, buffers, excipients, stabilizers or preservatives.

The term "subject" or "individual" includes humans and non-human animals. Non-human animals include all vertebrates (eg, mammals and non-mammals) such as non-human primates (eg, cynomolgus monkeys), sheep, dogs, cattle, chickens, amphibians, and reptiles. Unless otherwise indicated, the terms "patient" or "subject" are used interchangeably herein. As used herein, the term "cyno" or "cynomolgus" refers to the crab-eating monkey (Macaca fascicularis). In certain embodiments, the individual or subject is a human.

"Administration" or "administration", when applied to an animal, human, experimental subject, cell, tissue, organ or biological fluid, means the administration of an exogenous drug, therapeutic, diagnostic or composition to an animal, human , contact with subjects, cells, tissues, organs or biological fluids.

The term "sample" refers to a collection of similar fluids, cells, or tissues isolated from a subject, as well as fluids, cells, or tissues present in a subject. Exemplary samples are biological fluids such as blood, serum and serosal fluids, plasma, lymph fluid, urine, saliva, cyst fluid, tears, excreta, sputum, mucosal secretions of secretory tissues and organs, vaginal secretions, ascites , fluids from the pleura, pericardium, peritoneum, abdominal cavity and other body cavities, fluid collected from bronchial lavage, synovial fluid, fluid solutions in contact with subjects or biological sources, such as cell and organ culture media (including cell or organ conditions culture medium), lavage fluid, etc., tissue biopsy samples, fine needle aspiration, surgically resected tissue, organ culture or cell culture.

"Treatment" and "treatment" (and their grammatical variations) refer to clinical intervention that attempts to alter the natural course of the individual being treated, and may be performed for prevention or during the course of clinical pathology. Desired effects of treatment include, but are not limited to, preventing the occurrence or recurrence of disease, alleviating symptoms, alleviating/reducing any direct or indirect pathological consequences of the disease, preventing metastasis, reducing the rate of disease progression, improving or alleviating the disease state, and regressing or ameliorating the disease. Prognosis. In some embodiments, the antibodies of the present disclosure are used to delay the development of disease or slow the progression of disease.

An "effective amount" is generally sufficient to reduce the severity and/or frequency of symptoms, eliminate these symptoms and/or underlying causes, prevent the occurrence of symptoms and/or their underlying causes, and/or ameliorate or ameliorate impairments caused by or associated with a disease state. (e.g. lung disease). In some embodiments, the effective amount is a therapeutically effective amount or a prophylactically effective amount. A "therapeutically effective amount" is one sufficient to treat a disease state or symptom, particularly a condition or symptom associated with that disease state, or to otherwise prevent, hinder, delay or reverse the disease state or any other adverse effect in any way related to the disease. The ideal amount of symptomatic progression. A "prophylactically effective amount" is an amount that, when administered to a subject, will have a predetermined prophylactic effect, such as preventing or delaying the onset (or recurrence) of the disease state, or reducing the likelihood of the onset (or recurrence) of the disease state or associated symptoms. . Complete therapeutic or prophylactic effect does not necessarily occur after administration of one dose but may occur after administration of a series of doses. Thus, a therapeutically or prophylactically effective amount may be administered in one or more administrations. "Therapeutically effective amount" and "prophylactically effective amount" may vary depending on a variety of factors such as the disease state, age, sex, and weight of the individual, as well as the ability of the therapeutic agent or combination of therapeutic agents to elicit the desired response in the individual. Exemplary indicators of an effective therapeutic agent or combination of therapeutic agents include, for example, improved health status of the patient.

Exemplary anti-CCR8 antibodies

In one aspect, the present disclosure provides an anti-CCR8 antibody comprising:

In another aspect, the present disclosure provides an anti-CCR8 antibody comprising a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region comprises SEQ ID NOs: 14, 15 and 16, respectively. HCDR1, HCDR2 and HCDR3, and the light chain variable region comprises LCDR1, LCDR2 and LCDR3 as shown in SEQ ID NO: 17, 18 and 19 respectively.

In some embodiments, the anti-CCR8 antibody as described above is a murine antibody, a chimeric antibody or a humanized antibody, preferably a humanized antibody.

In some embodiments, the anti-CCR8 antibody as described in any one of the above is a humanized antibody.

In some embodiments, the anti-CCR8 antibody as described in any one of the above, comprising the framework region (FR) of a human antibody.

In some embodiments, the anti-CCR8 antibody of any one of the above, wherein:

The heavy chain variable region includes HCDR1, HCDR2 and HCDR3 as shown in SEQ ID NO: 14, 15 and 16 respectively, and the FR of the heavy chain variable region includes optionally selected from 1E, 27F, 28S, 30T, One or more amino acid mutations in 71K, 73K, 78V, 44G and 49G; and

The light chain variable region includes LCDR1, LCDR2 and LCDR3 as shown in SEQ ID NO: 17, 18 and 19 respectively, and the FR of the light chain variable region includes optionally selected from 43S, 45K, 46P, 47W, One or more back mutations in 58V, 60A, 71Y and 49Y;

The above-mentioned back mutation sites or amino acid mutation sites are based on Kabat numbering rules.

Preferably, the antibody comprises at least 80% (e.g., at least 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99%) sequence with SEQ ID NO: 26, 27 or 28 A heavy chain variable region sequence having at least 80% identity (e.g., at least 80%, 85%, 90%, 95%, 96%, 97%, 98) with SEQ ID NO: 29, 30, 31 or 32 % or 99%) sequence identity of the light chain variable region sequence.

The heavy chain variable region includes the amino acid sequence shown in SEQ ID NO: 27, and the light chain variable region includes the amino acid sequence shown in SEQ ID NO: 31.

In some embodiments, the anti-CCR8 antibody as described in any one of the above, wherein the anti-CCR8 antibody is an antibody fragment; preferably, the antibody fragment is Fab, Fab', F(ab') ₂ , Fd, Fv, scFv, dsFv or dAb.

In some embodiments, the anti-CCR8 antibody as described in any one of the above, comprising a heavy chain constant region and a light chain constant region.

In some embodiments, an anti-CCR8 antibody as described in any one of the above, comprising a heavy chain constant region and Light chain constant region, the heavy chain constant region is a human IgG1 constant region, which contains one or more amino acid substitutions selected from mutations S298A/E333A/K334A and S239D/I332E that can enhance ADCC, wherein the amino acid substitutions Click on EU number.

In some embodiments, an anti-CCR8 antibody as described in any one of the above, comprising a heavy chain constant region and a light chain constant region, the heavy chain constant region comprising the amino acid sequence of SEQ ID NO: 44, and/or the The light chain constant region contains the amino acid sequence of SEQ ID NO: 45.

In some embodiments, an anti-CCR8 antibody as described in any one of the above, comprising a heavy chain and a light chain, wherein:

The heavy chain comprises at least 85% (such as at least 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%, 97%, 98% or 99%) of SEQ ID NO:46. ), and the light chain comprises an amino acid sequence having at least 85% (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%) sequence identity to SEQ ID NO: 47 , 97%, 98% or 99%) sequence identity of the amino acid sequence.

In some embodiments, an anti-CCR8 antibody as described in any one of the above, comprising a heavy chain as shown in SEQ ID NO: 46, and a light chain amino acid sequence as shown in SEQ ID NO: 47.

Antibody structure

In certain embodiments, the antibodies provided herein are full-length antibodies.

In certain embodiments, the antibodies provided herein are antibody fragments.

In one embodiment, the antibody fragment is a Fab, Fab', Fab'-SH or F(ab') ₂ fragment, in particular a Fab fragment. "Fab" is a monovalent fragment consisting of VL, VH, CL and CH1 domains. "Fab fragments" can be produced by papain cleavage of antibodies. "Fab'" contains VL, CL as well as VH and CH1, and also contains the region between the CH1 and CH2 domains such that interchain disulfide bonds can be formed between the two heavy chains of the two Fab' fragments to form F(ab')2 molecules. "Fab'-SH" is a Fab' fragment in which the cysteine residues of the constant region have free sulfhydryl groups. "F(ab') ₂ " is a bivalent fragment consisting of two Fab fragments linked by a disulfide bond in the hinge region.

In another embodiment, the antibody fragment is a diabody, a tribody, or a tetrabody. Diabodies are antibody fragments with two antigen-binding sites that contain linked VH and VL in the same polypeptide chain (VH-VL). By using a linker that is too short to allow pairing between two domains on the same chain, forcing these domains to pair with complementary domains on the other chain, thereby creating two antigen binding sites, the two antigens can be identical or different

In another embodiment, the antibody fragment is a single chain Fab fragment. A "single chain Fab fragment" or "scFab" is a polypeptide consisting of VH, CH1, VL, CL and a linker, wherein the antibody domain and the linker have one of the following sequences in the N-terminal to C-terminal direction: a) VH -CH1-joint-VL-CL, b)VL-CL-joint-VH-CH1, c)VH-CL-joint-VL-CH1 or d)VL-CH1-joint-VH-CL. In one embodiment, the linker is a polypeptide of at least 30 amino acids. In another embodiment, the linker is a polypeptide having between 32 and 50 amino acids. The single-chain Fab fragment is stabilized via the native disulfide bond between CL and CH1. Additionally, these single-chain Fab molecules can further stabilized.

In another embodiment, the antibody fragment is an Fv fragment consisting of the VH and VL domains of a single arm of the antibody.

In another embodiment, the antibody fragment is a single chain variable fragment (scFv). A "scFv" is a fusion protein comprising at least one antibody fragment containing a light chain variable region and at least one antibody fragment containing a heavy chain variable region, wherein the light chain variable region and the heavy chain variable region are connected through a short flexible peptide linker Continuously linked, the scFv can be expressed as a single-chain polypeptide in which the scFv retains the specificity of the intact antibody from which it was derived. Unless otherwise specified, the scFv herein may have VL and VH variable regions in either order, for example, with respect to the N-terminus and C-terminus of the polypeptide, the scFv may comprise VL-linker-VH or may comprise VH-linker-VL .

In another embodiment, the antibody fragment is a dsFv, dsFv is obtained by substituting a polypeptide in which one amino acid residue in each VH and VL is replaced with a cysteine residue via a disulfide between the cysteine residues. Obtained by connecting keys. Amino acid residues substituted by cysteine residues can be selected based on prediction of the three-dimensional structure of the antibody according to known methods (Protein Engineering. 7:697 (1994)).

In another embodiment, the antibody fragment is a single domain antibody (dAb). Single domain antibodies are antibody fragments that contain all or part of the heavy chain variable domain or all or part of the light chain variable domain of an antibody.

In certain embodiments, the antibodies provided herein are chimeric antibodies. In one example, a chimeric antibody comprises a non-human variable region (eg, a variable region derived from a mouse, rat, hamster, rabbit, or a non-human primate, such as a monkey) and a human constant region. In yet another example, a chimeric antibody is a "class-switched" antibody in which the class or subclass has been changed from that of the parent antibody.

In certain embodiments, the antibody is a humanized antibody. Typically, non-human antibodies are humanized to reduce immunogenicity in humans while retaining the specificity and affinity of the parent non-human antibody. Generally, a humanized antibody contains one or more variable regions, wherein the CDRs or portions thereof are derived from a non-human antibody and the FRs or portions thereof are derived from a human antibody. Optionally, the humanized antibody will also comprise a portion of a human constant region. In some embodiments, some FR residues in a humanized antibody can be replaced with corresponding residues from a non-human antibody (eg, an antibody that provides CDR sequences).

Humanized antibodies and methods for producing them are reviewed, for example, in Almagro and Fransson, Front. Biosci. 13:1619-1633 (2008), and further described in, for example, Riechmann et al., Nature 332:323-329 (1988); Queen et al., Proc. .Nat'l Acad.Sci.USA 86:10029-10033(1989); U.S. Patent Nos. 5,821,337, 7,527,791, 6,982,321 and 7,087,409; Kashmiri et al., Methods 36:25-34 (2005) (describing specificity determining region (SDR) grafting); Padlan, Mol. Immunol. 28:489-498 (1991) ( "resurfuacing" is described); Dall'Acqua et al., Methods 36:43-60 (2005) ("FR shuffling" is described); and Osbourn et al., Methods 36:61-68 (2005) and Klimka et al. , Br.J.Cancer 83:252-260 (2000) (describing the "guided selection" method of FR shuffling).

Human framework regions that can be used for humanization include, but are not limited to: framework regions selected using "best-fit" methods (see, eg, Sims et al., J. Immunol. 151:2296 (1993)); Framework regions derived from consensus sequences of human antibodies of a specific subgroup of light chain variable regions or heavy chain variable regions (see, e.g., Carter et al., Proc. Natl. Acad. Sci. USA, 89:4285 (1992); and Presta et al., J. Immunol., 151:2623 (1993)); human mature (somatically mutated) framework regions or human germline framework regions (see, e.g., Almagro and Fransson, Front. Biosci. 13:1619-1633 (2008 )); and framework regions obtained by screening FR libraries (see, for example, Baca et al., J. Biol. Chem. 272:10678-10684 (1997) and Rosok et al., J. Biol. Chem. 271:22611-22618 (1996) ).

In certain embodiments, the antibodies provided herein are multispecific antibodies, such as bispecific antibodies. Multispecific antibodies are monoclonal antibodies with binding specificities for at least two different sites (i.e., different epitopes on different antigens or different epitopes on the same antigen). In certain embodiments, multispecific antibodies have three or more binding specificities. In certain embodiments, one of the binding specificities is for CCR8 and the other specificity is for any other antigen. In certain embodiments, bispecific antibodies can bind two (or more) different epitopes of CCR8. Multispecific (eg, bispecific) antibodies can also be used to localize cytotoxic agents or cells to CCR8-expressing cells. Multispecific antibodies can be prepared as full-length antibodies or antibody fragments.

Techniques used to generate multispecific antibodies include, but are not limited to, recombinant coexpression of two immunoglobulin heavy chain-light chain pairs with different specificities (see Milstein and Cuello, Nature 305:537 (1983)), and "Pestrel" "Engineering (see, eg, U.S. Patent No. 5,731,168 and Atwell et al., J. Mol. Biol. 270:26 (1997)). Cross-linking of two or more antibodies or fragments can also be achieved by engineering electrostatic manipulation for generating antibody Fc-heterodimer molecules (see, e.g., WO 2009/089004); cross-linking two or more antibodies or fragments (see, e.g., U.S. Patent No. 4,676,980 and Brennan et al., Science, 229:81 (1985)); using leucine zippers to generate bispecific antibodies (see, e.g., Kostelny et al., J. Immunol., 148(5):1547-1553 (1992) and WO 2011/ 034605); using common light chain technology to circumvent the light chain mismatch problem (see e.g. WO 98/50431); using "double antibody" technology for generating bispecific antibody fragments (see e.g. Hollinger et al., Proc. Natl. Acad Sci. USA, 90:6444-6448 (1993)); and using single-chain Fv (sFv) dimers (see, e.g., Gruber et al., J. Immunol., 152:5368 (1994)); and e.g., Tutt et al. Trispecific antibodies were prepared to generate multispecific antibodies as described in J. Immunol. 147:60 (1991).

Variants of anti-CCR8 antibodies

In certain embodiments, encompassed are the amino acids of the anti-CCR8 antibodies or fusion proteins thereof provided herein Sequence variants. For example, it may be desirable to improve the binding affinity and/or other biological properties of the antibody. Amino acid sequence variants of antibodies can be prepared by introducing appropriate modifications into the nucleotide sequence encoding the antibody, or by peptide synthesis. Such modifications include, for example, deletions, and/or insertions, and/or substitutions of residues within the amino acid sequence of the anti-CCR8 antibody or fusion protein thereof. Any combination of deletions, insertions, and substitutions can be made to obtain the final construct, so long as the final construct possesses the desired characteristics, such as antigen-binding properties.

Substitute, insert, and delete variants

In certain embodiments, antibody variants with one or more amino acid substitutions are provided. Sites of interest for substitution mutagenesis include CDRs and FRs. Conservative substitutions are shown in Table 3 under the heading "Preferred substitutions". More substantial changes are provided in Table 2 under the heading "Exemplary Substitutions" and are described further below with reference to the amino acid side chain categories. Amino acid substitutions can be introduced into the antibody of interest and the product screened for desired activity, such as retained/improved antigen binding, reduced immunogenicity, or improved ADCC or CDC.

Table 2. Amino acid substitutions

According to common side chain properties, amino acids can be grouped as follows:

(1) Hydrophobic: Norleucine, Met, Ala, Val, Leu, Ile;

(2) Neutral, hydrophilic: Cys, Ser, Thr, Asn, Gln;

(3) Acidic: Asp, Glu;

(4) Basic: His, Lys, Arg;

(5) Residues that affect chain orientation: Gly, Pro;

(6) Aromatic: Trp, Tyr, Phe.

Non-conservative substitutions would require the substitution of a member of one of these classes for a member of another class.

One type of substitution variant involves the substitution of one or more CDR residues of a parent antibody (eg, a humanized or human antibody). Generally, the resulting variants selected for further study will have alterations (e.g., improvements) in certain biological properties (e.g., increased affinity, reduced immunogenicity) relative to the parent antibody, and/or will be substantially Retains certain biological properties of the parent antibody. One exemplary substitution variant is an affinity matured antibody, which may be conveniently produced, for example, using phage display-based affinity maturation techniques, such as those described herein. Briefly, one or more CDR residues are mutated, and the variant antibodies are displayed on phage and screened for specific biological activity (e.g., binding affinity). Changes (eg substitutions) can be made to the CDRs, for example to improve antibody affinity. Such changes can be made to CDR "hotspots," residues encoded by codons that undergo mutations at high frequency during the somatic maturation process, and/or residues that contact the antigen, while simultaneously modifying the resulting variant VH or VL tests binding affinity. In some embodiments of affinity maturation, diversity is introduced into the variable genes selected for maturation by any of a variety of methods, such as error-prone PCR, strand shuffling, or oligonucleotide-directed mutagenesis. middle. Then, create secondary libraries. The library is then screened to identify any antibody variants with the desired affinity. Another way to introduce diversity involves methods of CDR orientation, in which several CDR residues (eg 4-6 residues at a time) are randomized. CDR residues involved in antigen binding can be specifically identified, for example, using alanine scanning mutagenesis or modeling. In particular, HCDR3 and LCDR3 are often targeted.

In certain embodiments, substitutions, insertions, or deletions may occur within one or more CDRs as long as such changes do not substantially reduce the ability of the antibody to bind the antigen. For example, conservative changes (eg, conservative substitutions, as provided herein) can be made to the CDRs that do not substantially reduce binding affinity. Such changes may, for example, be external to the antigen-contacting residues in the CDRs. In certain embodiments of the variant VH and VL sequences provided above, each CDR is unchanged or contains no more than 1, 2, or 3 amino acid substitutions.

One method that can be used to identify residues or regions in an antibody that can be targeted for mutagenesis is called "alanine scanning mutagenesis." In this approach, a residue or target group of residues (e.g., charged residues such as Arg, Asp, His, Lys, and Glu) is identified and replaced with a neutral or negatively charged amino acid (e.g., Ala or polyalanine) to determine whether the interaction of the antibody with the antigen is affected. Further substitutions can be introduced at amino acid positions that show functional sensitivity to the initial substitution. In addition, the contact points between the antibody and the antigen can be identified by studying the crystal structure of the antigen-antibody complex. These contact residues and adjacent residues can be targeted or eliminated as substitution candidates. Variants can be screened to determine whether they contain the desired properties.

Amino acid sequence insertions include those ranging in length from 1 residue to polypeptides containing 100 or more residues. Amino and/or carboxyl terminal fusions, and intrasequence insertion of single or multiple amino acid residues. Examples of terminal insertions include antibodies with an N-terminal methionyl residue. Other insertional variants of antibody molecules include fusions of the N- or C-terminus of the antibody with enzymes or polypeptides that extend the serum half-life of the antibody.

Modification of Fc region

In one aspect, the Fc region of an anti-CCR8 antibody or anti-CCR8 antibody fusion protein of the present disclosure contains one or more amino acid substitutions that increase its binding to an Fc receptor, such as its binding to an Fcγ receptor. combination. The native IgG Fc region, specifically the _IgG1 Fc region or the _IgG4 Fc region, may cause the fusion proteins of the present disclosure to target cells expressing Fc receptors rather than cells expressing the antigen. In some embodiments, engineered Fc regions of the present disclosure exhibit increased binding affinity for Fc receptors and/or increased effector function.

Recombination method

Anti-CCR8 antibodies or anti-CCR8 antibody fusion proteins can be produced using recombinant methods. For these methods, one or more isolated nucleic acids encoding a polypeptide or fusion protein are provided.

In one embodiment, the present disclosure provides an isolated nucleic acid encoding an anti-CCR8 antibody or anti-CCR8 antibody fusion protein as described above. Such nucleic acids may independently encode any of the aforementioned polypeptide chains. In another aspect, the present disclosure provides one or more vectors (eg, expression vectors) comprising such nucleic acids. In another aspect, the present disclosure provides host cells comprising such nucleic acids. In one embodiment, a method of making a polypeptide or fusion protein is provided, wherein the method comprises culturing a host cell comprising a nucleic acid encoding the polypeptide or fusion protein under conditions suitable for expression, as provided above, and The anti-CCR8 antibody or anti-CCR8 antibody fusion protein is optionally recovered from the host cell (or host cell culture medium).

To recombinantly produce an anti-CCR8 antibody or anti-CCR8 antibody fusion protein, the nucleic acid encoding the protein is isolated and inserted into one or more vectors for further cloning and/or expression in host cells. Such nucleic acids can be readily isolated and sequenced using conventional procedures, or produced by recombinant methods or obtained by chemical synthesis.

Suitable host cells for cloning or expressing vectors encoding anti-CCR8 antibodies or anti-CCR8 antibody fusion proteins include prokaryotic or eukaryotic cells described herein. For example, it can be produced in bacteria, especially when glycosylation and Fc effector functions are not required. After expression, the bacterial cell paste can be isolated in a soluble fraction and further purified.

In addition to prokaryotes, eukaryotic microorganisms such as filamentous fungi or yeast are also suitable cloning or expression hosts for vectors encoding fusion proteins, including fungal and yeast strains. Suitable host cells for expression of fusion proteins may also be derived from multicellular organisms (invertebrates and vertebrates); examples of invertebrate cells include plant and insect cells. Many baculovirus strains have been identified that can be used in combination with insect cells, especially for transfection of Spodoptera frugiperda cells; plant cell cultures can also be used as hosts, such as US5959177, US6040498, US6420548, US7125978 and US6417429; Vertebrate animal cells can also be used as hosts, for example mammalian cell lines adapted for growth in suspension. Other examples of suitable mammalian host cell lines are SV40-transformed monkey kidney CV1 line (COS-7); human embryonic kidney line (293 or 293T cells); baby hamster kidney cells (BHK); mouse sertoli cells (TM4 cells); monkey kidney cells (CV1); African green monkey Kidney cells (VERO-76); human cervical cancer cells (HELA); canine kidney cells (MDCK); buffalo rat liver cells (BRL3A); human lung cells (W138); human liver cells (Hep G2); Mouse mammary tumor (MMT 060562); TRI cells; MRC 5 cells; and FS4 cells. Other suitable mammalian host cell lines include Chinese hamster ovary (CHO) cells, including DHFR-CHO cells; and myeloma cell lines, such as Y0, NSO, and Sp2/0. For a review of certain mammalian host cell lines suitable for antibody production see, for example, Yazaki, P. and Wu, AM, Methods in Molecular Biology, Vol. 248, Lo, BKC (Eds.), Humana Press, Totowa, NJ (2004) , pp. 255-268.

Determination

The anti-CCR8 antibodies or anti-CCR8 antibody fusion proteins provided herein can be identified, screened or characterized for their physical/chemical characteristics and/or biological activity by a variety of assays known in the art. In one aspect, the anti-CCR8 antibodies or anti-CCR8 antibody fusion proteins of the present disclosure are tested for activity, for example, by known methods such as ELISA, Western blotting, etc.

Treatment methods and routes of administration

The anti-CCR8 antibodies of the present disclosure (and any additional therapeutic agents) may be administered by any suitable means, including parenterally, intrapulmonary, and intranasal, and if local treatment is desired, intralesional administration. Parenteral infusion includes intramuscular, intravenous, intraarterial, intraperitoneal, or subcutaneous administration. Administration may be by any appropriate route, for example, by injection, such as intravenous or subcutaneous injection, depending in part on whether the administration is short-term or long-term. Various dosing schedules are contemplated herein, including, but not limited to, single or multiple administrations at multiple time points, bolus administration, and pulse infusion.

The anti-CCR8 antibodies of the present disclosure will be formulated, administered, and administered in a manner consistent with good medical practice. Factors considered in this context include the specific condition being treated, the specific mammal being treated, the clinical condition of the individual patient, the cause of the condition, the site of delivery of the agent, the method of administration, the timing of administration, and others known to the medical practitioner factor. The polypeptide or fusion protein may be formulated with or without one or more agents currently used to prevent or treat the disorder. The effective amount of such other agents depends on the amount present in the pharmaceutical composition, the type of condition or treatment, and other factors. These are generally used at the same dosages and routes of administration as described herein, or at about 1% to 99% of the dosages described herein, or at other dosages and by any route empirically/clinically determined to be appropriate.

To prevent or treat disease, appropriate dosages of the anti-CCR8 antibodies of the present disclosure (when used alone or in combination with one or more other additional therapeutic agents) will depend on the type of disease to be treated, the nature of the therapeutic molecule Type, severity and duration of disease, whether administration is for prophylactic or therapeutic purposes, previous treatments, patient's clinical history and response to therapeutic molecules, and the judgment of the attending physician. The therapeutic molecules are appropriately administered to the patient in one session or over a series of treatments.

Products

In another aspect of the present disclosure, an article of manufacture is provided, said article of manufacture comprising a or materials for diagnosing the above conditions. The article includes a container and a label or package insert on or associated with the container. Suitable containers include, for example, bottles, vials, syringes, IV solution bags, and the like. Containers can be formed from a variety of materials such as glass or plastic. A container containing a composition effective to treat, prevent and/or diagnose a condition, alone or in combination with another composition, and may have a sterile access port (e.g., the container may be a container with a stopper pierceable by a hypodermic needle bag or vial of intravenous solution). At least one active agent in the composition is an anti-CCR8 antibody or anti-CCR8 antibody fusion protein of the present disclosure. The label or package insert indicates use of the composition to treat the selected condition. Additionally, the article of manufacture can comprise: (a) a first container having a composition therein, wherein the composition comprises an anti-CCR8 antibody or an anti-CCR8 antibody fusion protein of the present disclosure; and (b) a second container having the composition therein. A container wherein the composition contains an additional cytotoxic agent or otherwise therapeutic agent. The article of manufacture in this embodiment of the present disclosure may further comprise a package insert indicating that the composition may be used to treat a particular condition. Alternatively, or additionally, the article of manufacture may further comprise a second (or third) container containing a pharmaceutically acceptable buffer. It may further include other materials required from a commercial and user standpoint, including other buffers, diluents, filters, needles and syringes.

Examples and test cases

The disclosure is further described below in conjunction with examples and test examples, but these examples and test examples do not limit the scope of the disclosure. Experimental methods without specifying specific conditions in the examples and test examples of this disclosure usually follow conventional conditions, such as Cold Spring Harbor's Antibody Technology Experiment Manual, Molecular Cloning Manual; or conditions recommended by raw material or product manufacturers. Reagents whose specific sources are not indicated are conventional reagents purchased in the market.

Example 1. Preparation of CCR8 fusion protein and stably transfected cells

1.1 Related protein sequences

The untagged human CCR8 gene, human CCR4 gene, and monkey CCR8 gene are transfected into CHOK1 and/or HEK293 cells to form CHOK1 or HEK293 cell lines expressing different species of CCR8 or human CCR4 proteins on the cell surface for subsequent antibody use. screening and identification. The Gqi5 gene and human CCR8 gene were transfected into CHOK1 cells, and the CHOK1-hCCR8-Gq cells formed were used for calcium flow inhibition experiments. Human CCR8 gene and Luc-GFP gene were transfected into HEK293 cells, and the formed HEK293-hCCR8/Luc-GFP cells were used for PBMC ADCC killing experiment detection. At the same time, the N-terminal sequence and Fc tag of the human or monkey CCR8 protein were cloned into mammalian cell expression vectors respectively. After expression and purification in 293E cells, the Fc fusion protein was obtained for use in the experiments of subsequent examples. The amino acid sequence of the related protein is as follows:

The sequence of human CCR8 protein expressed on the surface of CHOK1/HEK293 cells is as follows:

The sequence of monkey CCR8 protein expressed on the surface of CHOK1 cells is as follows:

The sequence of human CCR4 protein expressed on the surface of CHOK1 cells is as follows:

The sequence of Gqi5 protein expressed on the surface of CHOK1-hCCR8 cells is as follows:

The gene sequence of Luc-GFP expressed on the surface of HEK293-hCCR8 cells is as follows:

The human CCR8 N-terminal-human Fc (hereinafter referred to as hCCR8-hFc) protein sequence is as follows:

The human CCR8 N-terminal-mouse Fc (hereinafter referred to as hCCR8-mFc) protein sequence is as follows:

Note:

The monkey CCR8 N-terminal-human Fc (hereinafter referred to as cynoCCR8-hFc) protein sequence is as follows:

Note:

The monkey CCR8 N-terminal-mouse Fc (hereinafter referred to as cynoCCR8-mFc) protein sequence is as follows:

Note:

The single underline above is the signal peptide, the double underline is the N-terminus of the extracellular region, the wavy line is the connecting peptide, and the dotted line is the corresponding Fc fragment.

1.2 Purification of related proteins

Purification of Fc-containing proteins, chimeric antibodies and hybridoma antibodies.

The cell expression supernatant samples were centrifuged at high speed to remove impurities. The Fc-containing recombinant protein and chimeric antibody expression supernatants were purified using Protein A columns, and the hybridoma expression supernatants were purified using Protein G columns. The supernatant is loaded onto the column at a certain flow rate. Rinse the column with PBS until the A280 reading drops to baseline. Elute the target protein with 100mM acetic acid at pH 3.0 and neutralize with 1M Tris-HCl at pH 8.0. The eluted samples were concentrated and replaced with PBS and then aliquoted for use.

Example 2. Preparation of mouse anti-human CCR8 monoclonal antibody

SJL mice were immunized using human CCR8 overexpressing HEK293 and CHOK1 cell lines and human or monkey CCR8 N-terminal and human Fc fusion proteins. After 5 immunizations, blood was taken to determine the titer of the antibodies in the serum. Mice with high antibody titers in the serum and titers tending to a plateau were selected for spleen cell fusion. The fused hybridoma cells were spread in a 96-well cell culture plate. , placed in a 37°C, 5% CO ₂ incubator for culture. Take the cell culture supernatant and detect it through Mirrorball. The selected positive clones were amplified, cryopreserved and subcloned two to three times until single cell clones were obtained. Selected hybridoma clones were further used to prepare and purify antibodies using serum-free cell culture methods. The obtained hybridoma antibody was used to detect the binding of the antibody to the human and monkey CCR8 overexpressing cell lines using FACS (for the method, see Test Example 1 and Test Example 2 of this disclosure), and hybridoma cell lines with good binding activity and blocking activity were selected.

Sequences of cloned monoclonal antibodies were selected from the monoclonal hybridoma cell lines mAbCP11 and mAb28. The process is as follows: Collect hybridoma cells in logarithmic growth phase, extract RNA with Trizol (Invitrogen, Cat#15596-018), and reverse-transcribe into cDNA. Use cDNA as a template for PCR amplification and send it to a sequencing company for sequencing. The amino acid sequence of the variable region of the antibody corresponding to the obtained DNA sequence is as follows:

Amino acid sequence of mAbCP11 heavy chain variable region:

Amino acid sequence of mAb CP11 light chain variable region:

Amino acid sequence of mAb28 heavy chain variable region:

Amino acid sequence of mAb28 light chain variable region:

Table 3. Antibody CDR sequences

Note: The CDRs in Table 3 are confirmed based on the Kabat numbering system.

The above mAbCP11 and mAb28 candidate molecule variable region sequences were amplified by PCR to amplify the VH/VK sequences, and then homologous recombination was performed with the expression vector pTT5 (with signal peptide and hIgG1/hkappa constant region gene (CH1-Fc/CL) fragment) . Exemplarily, the human heavy chain IgG1 constant region sequence is shown in SEQ ID NO: 44, the human light chain kappa constant region sequence is shown in SEQ ID NO: 45, and the recombinant chimeric antibody full-length expression plasmid VH-CH1-Fc is constructed. -pTT5/VL-CL-pTT5, and then obtain its chimeric antibodies ChCP11 and Ch28.

Example 3. Humanized design of anti-human CCR8 monoclonal antibody

Humanization of murine monoclonal antibodies is carried out according to methods published in many documents in this field. Briefly, based on the obtained typical structure of mouse antibody VH/VL CDR, the homologous sequences of the light chain variable region (VL) and heavy chain variable region (VH) were searched from the human germline database. , transplant the CDR region of the mouse antibody onto the human template, substitute part of the amino acids of VL and VH, and replace the constant region of the mouse antibody with the human constant region to obtain the final humanized molecule.

1. Humanization of antibody mAbCP11

For the humanized antibody of mouse antibody mAbCP11, select FR1, FR2, FR3 of IGHV2-26*01 or IGHV4-30-4*01, and FR4 of IGHJ6*01 as the heavy chain framework region template; select IGKV6-21*01 or FR1, FR2, FR3 of IGKV1-39*01 or IGKV3-20*02 and FR4 of IGKJ4*01 were used as light chain framework region templates. Optionally, the amino acid residues at positions 1, 27, 28, 30, 44, 49, 71, 73 and/or 78 (numbered according to the Kabat numbering system) on the FR region of the heavy chain variable region of the humanized antibody are and/or substitute the amino acid residues at positions 43, 45, 46, 47, 49, 58, 60 and/or 71 on the FR region of the light chain variable region of the humanized antibody.

Table 4. Mutations of humanized antibody hCP11

Note: The sites in the above table are numbered according to the Kabat numbering system; Graft represents the mouse antibody CDR implanted into the human germline FR region sequence, and F71Y represents the mutation of F at position 71 back to Y according to the Kabat numbering system.

Use the reverse mutation design in Table 4 to obtain different humanized heavy chain variable regions and light chain variable regions, and combine the variable regions according to Table 5 to obtain different antibody molecules:

Table 5. hCP11 humanized antibody heavy and light chain variable region combination table

The specific sequences of the humanized and mutated variable regions are as follows:

2. Humanization of antibody mAb28

The heavy chain template of the mouse antibody mAb28 humanized antibody selects FR1, FR2, FR3, and IGHJ6*01 of human IGHV3-72*01 or IGHV3-66*01 or IGHV3-23*01 or IGHV7-4-1*01. FR4 region; the light chain template selects the FR1, FR2, FR3 of human IGKV2-28*01 or IGKV3-11*01 or IGKV1-39*01, and the FR4 region of IGKJ4*01. Optionally, the amino acid residues at positions 27, 29, 31, 48, 69, 71, 75 and/or 93 (numbered according to the Kabat numbering system) of the heavy chain variable region of the humanized antibody are substituted; and /or substitute the amino acid residues at positions 4, 27c, 29, 36, 43, 45, 51, 60, 93 and/or 100 of the light chain variable region of the humanized antibody.

Table 6. Mutations of humanized antibody h28

Note: The sites in the table are numbered according to the Kabat numbering system; Grafted represents the mouse antibody CDR implanted into the human germline FR region sequence, and V75E represents the mutation of the V at position 75 back to E according to the Kabat numbering system.

Among them, the above mutations include mutations selected from L27c A, G29R, M51K and E93Q on the CDR of the h28 antibody light chain variable region. P31I mutation was performed on HCDR1 in the h28 heavy chain variable region to obtain the following CDR combination:

Table 7. Humanized antibody h28 mutation sequence

Use the mutation design in Table 6 to obtain different humanized heavy chain variable regions and light chain variable regions, and combine the variable regions according to Table 8 to obtain different antibody molecules.

Table 8.H28 humanized antibody heavy and light chain variable region combination table

The specific sequences after humanization and mutation are as follows:

Example 4. Preparation of humanized antibodies

4.1 Sequence of humanized antibodies

Expression vectors for the antibody light chain and heavy chain were constructed respectively, and the humanized antibody light and heavy chains were cross-matched and combined respectively. After transfection into 293E cells, the culture supernatant was collected and purified to obtain the humanized full-length antibody. The humanized antibody heavy chain constant region can be selected from the group consisting of IgG1, IgG2, IgG3, and IgG4 constant regions. For example, the human heavy chain IgG1 constant region can be used, and the humanized antibody light chain constant region can be selected from the group consisting of human kappa and Lambda chain constant region, the constant region sequence of an exemplary antibody is as follows:

Amino acid sequence of human IgG1 heavy chain constant region

Amino acid sequence of human light chain kappa constant region:

Exemplarily, the humanized antibody heavy chain variable region of the aforementioned mAbCP11 or mAb28 is fused with the human heavy chain IgG1 constant region (sequence shown in SEQ ID NO: 44) to form an antibody full-length heavy chain, and the humanized antibody is The light chain variable region and the human light chain kappa constant region (sequence shown in SEQ ID NO: 45) were fused to form the full-length light chain of the antibody, and mAbCP11 and mAb28 humanized antibodies were obtained for subsequent experimental testing and final selection. The complete sequence of the most active humanized antibody is as follows:

Antibody hCP11-7:

hCP11-7 heavy chain sequence:

hCP11-7 light chain sequence:

Antibody h28-3:

h28-3 heavy chain sequence:

h28-3 light chain sequence:

Illustratively, the humanized antibody in the present disclosure is digested in vitro and degraded to obtain Fab fragments. The sequence of the humanized antibody Fab fragment is as follows:

hCP11-7Fab sequence

hCP11-7-Fab heavy chain:

hCP11-7-Fab light chain:

h28-3-Fab sequence

h28-3-Fab heavy chain:

h28-3-Fab light chain:

Exemplarily, in the present disclosure, the murine mIgG2a constant region is fused with the humanized variable region to obtain an antibody in the form of mIgG2a, which is used to evaluate the anti-tumor activity in mice. The antibody sequence for the mIgG2a form is as follows:

hCP11-7-mIgG2a heavy chain sequence:

hCP11-7-mIgG2a light chain sequence:

h28-3-mIgG2a heavy chain sequence:

h28-3-mIgG2a light chain sequence:

4.2. Sequence and preparation of control antibodies

The humanized antibody 4A19 of patent WO2021194942A1 is used as a control molecule in this disclosure, and its light and heavy chain amino acid sequences are as follows:

4A19 heavy chain sequence:

4A19 light chain sequence:

Antibody 10A11 in patent WO2020138489 is used as a control molecule in this disclosure, and its light and heavy chain amino acid sequences are as follows:

10A11 heavy chain sequence:

10A11 light chain sequence:

Example 5. Preparation of CCR8 monoclonal antibody in vitro defucosylated antibody

CCR8 antibodies work through cellular ADCC, so the defucose form of the antibody is more lethal than the normal IgG1 form of the antibody.

ADCC-enhanced antibodies are prepared by removing fucose in vitro from IgG1-form antibodies. The specific preparation process is as follows:

Deglycosylation: Adjust the concentration of IgG1 form antibody to approximately 10 mg/mL, adjust its pH to 7.0-7.4, and add endoglycosidase Endo S with a final concentration of 50 μg/mL and 1.5 mg/mL to the antibody solution. Alfc enzyme solution, incubate in 37°C water bath for 24 hours. Use SDS-PAGE to judge the deglycosylation effect of the antibody, then use Protein A magnetic beads to purify the antibody, and change the liquid into PBS through an ultrafiltration tube (cutoff: 50kDa).

Glycosylation transfer: Add the oxazoline substrate CT-oxa with a final concentration equal to 50 times the antibody concentration to the deglycosylated antibody solution (final antibody concentration 5 mg/mL, oxazoline final concentration 1.67mM), add EndoS2D184M at a final concentration of 0.1 mg/mL was incubated in a water bath at 30°C for 1 hour. Whether the prepared antibody is a fucose-free form is identified through mass spectrometry analysis, and the obtained antibody is a fucose-free form antibody.

In the following test examples, defucosylated humanized antibodies are represented by the suffix "(Defuc)". For example: the defucosylated form antibody of hCP11-7 is hCP11-7-Defuc; the defucosylated antibody of h28-3 is hCP11-7-Defuc. The fucose form of the antibody is h28-3-Defuc.

test case

Biological evaluation of in vitro activity

Test Example 1. Detection of the binding ability of antibodies to CCR8 expressed on the cell surface

In order to detect the binding of the antibody to the CCR8 protein on the cell surface, cells expressing CCR8 on the cell surface were used to detect the binding activity of the antibody by FACS.

Clone the full-length genes encoding human CCR8, human CCR4 or monkey CCR8 into mammalian cell expression vectors, using pCDH-human CCR8 or pCDH-human CCR4 or pCDH-cyno CCR8, and pVSV-G and pCMV-dR8.91 respectively. The seed plasmids were co-transfected into HEK293T cells ( CRL-11268) packaging virus. 48 hours after transfection, the virus was collected to infect CHO-K1 (ATCC, CCL-61) cells. After two weeks of selection by pressure, cell subcloning was performed. After FACS testing, the cell lines human CCR8-CHO-K1, human CCR4-CHO-K1, and cynoCCR8-CHO-K1, which highly express human CCR8, human CCR4, and monkey CCR8, were obtained respectively.

Collect cells, centrifuge at 400g for 5 minutes at 4°C; add pre-cooled PBS containing a final concentration of 10% FBS, centrifuge at 400g for 5 minutes at 4°C, repeat twice; distribute the cells to a 96-well plate, 10 ⁵ cells/well ; Add 100 μL of gradient diluted antibody solution to each well, incubate at 4°C for 60 minutes, centrifuge at 300g to remove the supernatant; add 200 μL of pre-cooled PBS containing a final concentration of 10% FBS to each well to resuspend the cells, centrifuge at 300g for 5 minutes at 4°C. Remove the supernatant and repeat twice; add 100 μL of secondary antibody Alexa FluorA488 goat anti-human IgG (H+L) (Lifetechologies, Cat#A11013) diluted at 1:1000, incubate at 4°C in the dark for 45 minutes, and centrifuge to remove the supernatant. ; Add 200 μL of pre-cooled PBS containing a final concentration of 10% FBS to each well and resuspend, centrifuge at 400 g for 5 minutes at 4°C, repeat twice; add 100 μL of pre-cooled PBS to each well and resuspend the cells; detect with flow cytometer ( BD, FACS CantoII); obtain the fluorescence signal value. The higher the signal, the stronger the binding activity of the antibody to the protein on the cell surface. The detection results were used to create a binding curve using PRISM analysis software, and the EC ₅₀ value of the binding activity of the antibody to the cell surface protein was obtained by fitting. The binding activity of humanized antibodies is shown in Table 9 below:

Table 9. Binding activity of humanized antibodies to cell surface CCR8 proteins of different species

Conclusion: The humanized antibodies of the present disclosure maintain similar binding activity to murine antibodies. Humanized antibody h28-3 has the strongest binding activity to human CCR8 and has no binding activity to monkey CCR8. hCP11-7 has good binding activity to human and monkey CCR8. Both positive antibodies had only weak monkey CCR8 binding activity.

Test Example 2, Biacore determines the affinity of the antibody to the CCR8 N-terminal fusion protein

Use Biacore (GE, T200) instrument to determine the affinity of the humanized antibody to be tested for the human CCR8 N-terminal fusion protein. The hCCR8-mFc fusion protein (Example 1) was affinity captured using the CM5 biosensor chip (Cat.#BR-1005-30, Cytiva), and then a certain concentration of human CCR8 antibody molecules was flowed on the chip surface, and the sample was continuously injected for 180 seconds, followed by 300 seconds of dissociation. Biacore T200 instrument was used to detect the reaction signal in real time to obtain binding and dissociation curves. After the dissociation of each test cycle is completed, the biosensor chip is washed and regenerated with Glycine1.5 (Cat. #BR-1003-54, Cytiva). The data obtained from the experiment are fitted using 1:1 or Steady State Model to obtain the affinity value. The results of the affinity test between humanized antibodies and CCR8N-mouse Fc fusion protein are shown in Table 10.

Table 10. Affinity of humanized antibodies and CCR8 N-terminal fusion protein

Conclusion: The disclosed humanized antibody h28-3 has strong affinity with the N-terminus of human CCR8 protein. However, hCP11-7 does not bind to the human CCR8 N-terminal fusion protein.

Test Example 3. Determination of the inhibitory effect of antibodies on calcium flux stimulated by ligand CCL1

The human CCR8-CHO-K1 cell line obtained in Test Example 1 was further transfected with the Gqi5 gene. The full-length gene encoding Gqi5 was cloned into a mammalian cell expression vector, and HEK293T cells were co-transfected with three plasmids: pVSV-G, pCMV-dR8.91 and pCDH-Gqi5 ( CRL-11268) to package the virus. 48 hours after transfection, the virus was collected to infect human CCR8-CHO-K1 cells. After two weeks of pressure screening, the cells were subcloned. After FACS detection, cells expressing both human CCR8 and Gqi5 proteins were obtained. Cell line human CCR8-Gq-CHO-K1.

After CCR8 on the surface of human CCR8-Gq-CHO-K1 cells is activated by the ligand CCL1, it will cause an increase in intracellular calcium ion levels. Further overexpression of Gqi5 protein on the CCR8-overexpressing CHOK1 cell line can improve the sensitivity of calcium flux detection. . Therefore, we used the CHOK1 cell line overexpressing CCR8 and Gqi5 to detect the inhibitory effect of the antibody on calcium flux stimulated by the ligand CCL1. The detection reagent was Fluo-4 DirectTM Calcium Assay kits (Invitrogen, Cat#F10473), which was configured and used according to the kit instructions. . The day before the experiment, cells were seeded into a 96-well plate at a density of 20,000 cells/well and cultured overnight in a 37°C incubator. The next day, after removing the supernatant from the culture plate, freshly prepare 100 μL/well of 1×Fluo-4 DirectTM calcium reagent loading solution (Invitrogen, Cat#F10473), and incubate at 37°C for 30 minutes. After the incubation, move the 96-well plate to room temperature and allow it to equilibrate for 10 to 30 minutes. Add the prepared gradient dilution antibody to the 96-well plate at 25 μL/well and incubate at room temperature for 30 minutes. Fluo-4 Direct ^TM calcium assay buffer (Invitrogen, Cat#F10473) was added to the negative control well. After the incubation, use a flexstation 3 microplate reader for detection. The machine automatically adds 25 μL/well of 40 nM CCL1 (Biolegend, Cat#582708), and reads the value immediately at EX494/EM516nm. The inhibitory effect of each antibody on intracellular calcium flow caused by CCL1 stimulation was calculated. used, as shown in Table 11 below.

Table 11. Inhibition of hCCL1-stimulated calcium flux by antibodies

Conclusion: The disclosed antibody has a strong inhibitory effect on intracellular calcium flux caused by CCL1 stimulation.

Test Example 4. Determination of the effect of antibodies on chemotaxis blocking caused by ligand CCL1

The CCR8-overexpressing BaF3 recombinant cell line was used to detect the chemotaxis blocking effect of the antibody on the ligand CCL1.

The gene encoding the full-length human CCR8 was cloned into a mammalian cell expression vector, and HEK293T cells were co-transfected with three plasmids: pVSV-G, pCMV-dR8.91 and pCDH-human CCR8 ( CRL-11268) to package the virus. 48 hours after transfection, the virus-infected Ba/F3 cells (Nanjing Kebai, CBP60474) were collected. After two weeks of pressure screening, the cells were subcloned, and high-expression human CCR8 was obtained through FACS detection. Protein recombinant cell line human CCR8-Ba/F3.

Both CCL1 (R&D, Cat#272-I-050/CF) and antibodies were prepared in RPMI1640 complete medium (GE SH30809.01), and human CCR8-Ba/F3 cells were prepared in RPMI1640+10%FBS+10ng/mL mIL3 (Peprotech , Cat#213-13)+4μg/mL puromycin (puromycin) culture. On the day of the experiment, resuspend the cells in complete culture medium, and adjust the cell density to 8×10 ⁶ /mL after counting. Mix cells and prepared antibodies at a ratio of 1:1 and incubate in culture medium at 37°C for 30 minutes. Then open the upper cover of the Chemotaxis System (Neuron Probe Cat#106-8), uncover the filter membrane, add 20ng/mL CCL1 protein into the lower chamber, 30 μL per well; cover the filter membrane gently, and add cells on the membrane Antibody mixture, 50 μL/well; cover with the upper lid, place in an incubator (37°C, 5% CO ₂ ), and incubate for 2 hours. Then use a clean paper towel to absorb the liquid on the filter membrane, open the filter membrane, add 30 μL Cell Titer-Glo solution (Promega Cat#G7573) to each well in the lower chamber, and incubate at room temperature in the dark for 5 minutes. The liquid was transferred to a 96-well white bottom plate into which 40 μL of Cell Titer-Glo solution had been added, and the plate was read using the chemiluminescence method using a microplate reader (PerkinElmer, Vector3). The experimental data were processed with Graphpad, and the IC ₅₀ of the antibody's chemotaxis blocking experiment on BaF3 cells was calculated, as shown in Table 12.

Table 12. Chemotaxis inhibitory effects of antibodies on human CCR8-Ba/F3 cells

Conclusion: The disclosed antibodies have strong ligand blocking effect.

Test Example 5. Determination of the killing effect of antibody-induced PBMC on CCR8-expressing cells

HEK293 recombinant cells overexpressing hCCR8 and Luc-GFP were used to detect antibody-induced killing. The full-length genes encoding human CCR8 and Luc-GFP were cloned into mammalian cell expression vectors, and HEK293T cells were co-transfected with four plasmids: pVSV-G, pCMV-dR8.91, pCDH-human CCR8 and pCDH-Luc-GFP ( CRL-11268) packaging virus. 48 hours after transfection, virus-infected HEK293 (ATCC, CRL-1573) cells were collected. After two weeks of selection by pressure, cell subcloning was performed. Recombinant cells with different expression levels of CCR8 were obtained through FACS detection. Among them, HEK293-hCCR8/Luc-GFP clone 1 is a high-expression human CCR8 cell line; HEK293-hCCR8/Luc-GFP clone 11 is a low-expression human CCR8 cell line. CCR8 expression of clone 11 The amount is equivalent to the expression amount of CCR8 on Treg cells in PBMC.

HEK293-hCCR8/Luc-GFP clone 1 (high expression of CCR8) and clone 11 (low expression of CCR8) cells were spread into a white transparent bottom 96-well plate at 5000 cells/well. After the fresh PBMC cells were centrifuged, the density was adjusted to 0.6×10 ⁶ /mL with RPMI1640 complete medium, and then 50 μL of cell suspension was added to the well plate so that there were 30,000 effector cells in each well (E:T ratio= 6:1). Add 50 μL of RPMI1640 complete medium to the control well without effector cells. Take 10 μL of the prepared antibody and add it to the 96-well plate so that the initial concentration of the antibody in the cells is 10 nM. Add 10 μL of RPMI1640 complete medium to the no-antibody control well. Negative controls are medium and target cells only, and controls with target cells and effector cells but no antibodies. Place the well plate in a 37°C cell culture incubator and incubate for 24 hours. The number of viable target cells was then quantified using ONE-Glo reagent (Promega, E6120). After removing the well plate, add 50 μL of the prepared ONE-Glo reagent to each well and incubate at room temperature for 10 minutes. Place a white sticker on the bottom of the well plate, and then use a Wallac Victor 3 microplate reader to measure the luminescence fluorescence signal value. Taking the antibody concentration as the abscissa and the measured luminescence signal value as the ordinate, use GraphPad Prism9 software to draw a dose-response curve and calculate the EC ₅₀ value of each antibody. The results are shown in Table 13 and Table 14.

Table 13. Killing effect of antibodies on CCR8 high-expressing cell clone 1 cell line

Table 14. Emax% of the killing effect of antibodies on CCR8 low-expressing cell clone 11 cell line

Table 13 shows that PBMC induced by the two antibodies of the present disclosure have strong ADCC killing ability against the cell line clone 1 with high expression of CCR8. For the ADCC-enhanced fucose-free antibodies of the present disclosure, the ADCC killing ability of induced PBMCs against the high-expressing cell line clone 1 was enhanced.

Table 14 shows that all antibodies or their enhanced defucose forms did not show obvious ADCC killing effect on clone11 cells with low CCR8 expression, and Emax was relatively low, making it difficult to calculate EC ₅₀ by fitting.

In summary, the disclosed antibody can induce a significant killing effect of PBMC on cells with high CCR8 expression (clone 1), but has no obvious killing effect on cells with low CCR8 expression (clone 11). It shows that the antibody has obvious differential killing ability against cells with different CCR8 expression levels.

Test Example 6. Determination of the killing effect of antibodies on Tregs with low expression of CCR8 in normal PBMCs

Fluorescence amplification ligand BATDA (bis(acetoxymethyl)2,2':6',2″-terpyridine-6,6″-dicarboxylic acid) and target cells (HEK293-hCCR8/Luc-GFP clone 1 or Treg cells) were incubated together. BATDA can quickly enter target cells and form hydrophilic TDA (2,2':6',2"-tripyridine-6,6"-dicarboxylic acid) under hydrolysis to remain in the cells. When the antibodies of the present disclosure ADCC on target cells in PBMC, the target cells cleave to release TDA. The released TDA combines with a solution containing the lanthanide element europium (DELIFA Eu reagent) to form strong fluorescence. The stronger the fluorescence signal indicates the stronger ADCC effect of the antibody.

This experiment used DELFIA EUTDA kit ( EuTDA Cytotoxicity Reagents, PerkinElmer, Cat. No. AD0116) detects the ADCC killing effect of the antibody to be tested on different target cells (HEK293-hCCR8/Luc-GFP clone 1 or Treg cells). Read time-resolved fluorometer on Victor3. Calculate % lysis according to the kit instructions.

The antibodies to be tested include h28-3-Defuc and hCP11-7-Defuc, which are prepared in RPMI1640 complete medium (GE SH30809.01) at final concentrations of 10000pM, 250pM and 6.25pM. C25-hlgG1-Defuc is a negative control.

The test results are as follows:

Table 15. Treg cell lysis rate %

Table 16. HEK293-hCCR8/Luc-GFP clone 1 lysis rate %

Conclusion: Table 15 demonstrates that the two ADCC-enhanced defucose forms of the antibodies of the present disclosure are effective against Treg cells in PBMC have no obvious killing effect. The killing effect is the same as that of the irrelevant antibody C25, and the lysis% is lower than 10.

Table 16 shows that for the HEK293-hCCR8/Luc-GFP clone 1 with high CCR8 expression, the two defucose-free forms of the antibodies of the present invention both showed significant killing effects, and the lysis % was significantly higher than the irrelevant antibody C25. This experiment further proves that the antibody of the present invention can differentially kill cells with high CCR8 expression (HEK293-hCCR8-Luc-GFP clone 1) through ADCC, but has no significant killing effect on Treg cells with low CCR8 expression in normal PBMC. .

Test Example 7. Determining the binding site of antibody to CCR8

In order to determine the binding site of CCR8 antibodies to CCR8, we constructed a series of recombinant cell lines by mutating the amino acids at the N-terminus of CCR8 and constructing chimeric antigens of CCR8 and CCR4, and added a V5 tag at the N-terminus to facilitate detection. Antibody anti-V5 tag (sinobiology, catalog number: 100378-MM04) is a positive control.

The N-terminus of CCR8 was replaced with the N-terminus of CCR4 to obtain the chimeric protein plasmid P2746. Loop 2 of CCR8 was replaced with loop 2 of CCR4 to obtain chimeric protein plasmid P2748. The chimeric protein plasmid P2749 was obtained by replacing loop 3 of CCR8 with loop 3 of CCR4. The chimeric protein genes encoding human CCR8 and human CCR4 were cloned into the mammalian cell expression vector pCDH, and HEK293T cells were co-transfected with three plasmids: pVSV-G, pCMV-dR8.91 and the chimeric protein plasmid ( CRL-11268) to package the virus. 48 hours after transfection, the virus was collected to infect CHO-K1 (ATCC, CCL-61) cells. After two weeks of pressure screening, the cells were subcloned and high-expression chimeric cells were obtained through FACS detection. Recombinant cell lines for antigens.

The amino acid sequence of the chimeric protein particle is as follows:

Note: The underlined wavy line represents V5tag, the single underline represents the N-terminus, and the double underline represents the extracellular region of loop 1, loop 2, and loop 3.

Loop 2 sequence of CCR8:

Loop 3 sequence of CCR8:

In the same manner as in Test Example 1, FACS was used to detect the binding ability of the antibody to these recombinant cell lines. The results are shown in Table 17 below:

Table 17. Binding ability of antibodies to various cell lines

Note: The data in the table are the average fluorescence intensity of binding

Conclusion: All antibodies do not bind to CHOK1 wild-type cell lines, and the average fluorescence intensity is lower than 300. However, the anti-V5 tag antibody binds to all cell lines expressing CCR8 fragments, and the average fluorescence intensity is greater than 600, indicating that we have constructed These recombinant cell lines can be used for testing.

If we replace the N-terminus of CCR8 with the N-terminus of CCR4 (P2746), all the antibodies to be tested will not bind, indicating that the binding of the antibodies to be tested to CCR8 requires the N-terminus of CCR8.

At the same time, if loop 2 and loop 3 of CCR4 are used to replace loop 2 (P2748) and loop 3 (P2749) of CCR8 respectively, both positive antibodies can bind to the P2748 and P2749 cell lines, indicating that the two positive antibodies bind to the CCR8 Binding does not require the participation of loop 2 and loop 3, and mainly binds to the N-terminus of CCR8.

When loop 2 of CCR8 was replaced with loop 2 of CCR4 (P2748), hCP11-7 did not bind at all. At the same time, when loop 3 of CCR8 was replaced with loop 3 of CCR4 (P2749), the binding of hCP11-7 was also significantly reduced, indicating that the binding of hCP11-7 to CCR8 requires the participation of loop 2 and loop 3 of CCR8, so HCP11-7 mainly Binds to the spatial conformation composed of the N-terminal and loop 2 and loop 3 of CCR8.

At the same time, loop 2 and loop 3 of human and monkey CCR8 are highly conserved in amino acid sequence, while the N-terminal amino acid sequence similarity of human and monkey CCR8 is not high. hCP11-7 binds to the spatial conformation of CCR8 N-terminal, loop 2, and loop 3. , so it has good monkey CCR8 cross-activity, while the two positive antibodies mainly bind to the N-terminus of CCR8, so the binding activity to monkey CCR8 is very weak or no.

Test Example 8. Evaluation of the efficacy of antibodies on the B-hCCR8 mouse MC38 cell tumor-bearing model

In this experiment, human CCR8 transgenic mice of the C57BL/6N strain (B-hCCR8 female mice, purchased from Biocytogen Laboratory Animal Co., Ltd.) were used to inoculate MC38 mouse colon cancer cells. ^After the tumors had grown to an average size of about 118 mm, they were randomly Group the patients and give them antibody treatment. By comparing the size of tumors after treatment with different antibodies, the effect of drugs on tumor growth in tumor-bearing mice was evaluated. Because CCR8 antibodies mainly work through ADCC to eliminate Tregs with high CCR8 expression in tumor TILs, the antibodies used in this experiment were all mIgG2a antibodies.

MC38 cells were subcutaneously inoculated into the right ribs of B-hCCR8 mice at an inoculation volume of 5 × 10 ⁵ /100 μL/mouse; when the average tumor volume reached approximately ~118 mm ³ , 56 mice were selected based on tumor volume and randomly Divided into 7 groups of 8 animals each. Intraperitoneal administration (ip) was started on the day of grouping (D0), and the frequency of administration was twice a week (BIW). Tumor volume and mouse body weight were measured twice weekly. During the entire treatment process, there was no abnormality in the body weight of each group compared with the blank group.

The calculation formula of tumor volume (V) is: V=1/2×length× ^width2

Relative tumor proliferation rate T/C%=(T-T0)/(C-C0)×100%

Tumor inhibition rate TGI%=1-T/C%

Among them, C0 and T0 are the tumor volumes of the blank control group and the experimental group at the beginning of the experiment, respectively. C and T are the tumor volumes of the blank control and experimental groups at the end of the experiment, respectively.

The tumor inhibition results are shown in Table 18.

Table 18. Antitumor effects of drugs on MC38 tumor-bearing mice

Conclusion: The disclosed antibodies have good anti-tumor effect.

Although the above invention has been described in detail by means of the drawings and examples for the purpose of clear understanding, the description and examples should not be construed as limiting the scope of the present disclosure. The disclosures of all patent and scientific documents cited herein are expressly incorporated by reference in their entirety.

Claims

An anti-CCR8 antibody comprising a heavy chain variable region and a light chain variable region, wherein:

(a) The heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 as set forth in SEQ ID NOs: 14, 15 and 16 respectively, and the light chain variable region comprises SEQ ID NOs: 17, 18 and 16 respectively. LCDR1, LCDR2 and LCDR3 shown in 19; or

(b) The heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 as set forth in SEQ ID NOs: 20, 21 and 22 respectively, and the light chain variable region comprises SEQ ID NOs: 23, 24 and 22 respectively. LCDR1, LCDR2 and LCDR3 shown in 25; or

(c) The heavy chain variable region includes HCDR1, HCDR2 and HCDR3 as shown in SEQ ID NO: 20, 21 and 22 respectively, and the light chain variable region includes SEQ ID NO: 34, 35 and 22 respectively. LCDR1, LCDR2 and LCDR3 shown in 36; or

(d) The heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 as set forth in SEQ ID NOs: 33, 21 and 22 respectively, and the light chain variable region comprises SEQ ID NOs: 34, 35 and 22 respectively. LCDR1, LCDR2 and LCDR3 shown in 36.
The anti-CCR8 antibody according to claim 1, which is a murine antibody, a chimeric antibody or a humanized antibody, preferably a humanized antibody.
The anti-CCR8 antibody according to claim 1, which comprises the framework region of a human antibody;

Preferably, the framework region includes FR1, FR2, FR3 of human IGHV2-26*01 or IGHV4-30-4*01, and FR4 of IGHJ6*01I as a heavy chain framework region template; and human IGKV6-21*01, FR1, FR2, FR3 of IGKV1-39*01 or IGKV3-20*02, and FR4 of IGKJ4*01 serve as the light chain framework region template; or

The framework region includes FR1, FR2, FR3 of human IGHV3-72*01, IGHV3-66*01, IGHV3-23*01 or IGHV7-4-1*01, and the FR4 region of IGHJ6*01 as the heavy chain framework region Template; and FR1, FR2, FR3 of human IGKV2-28*01, IGKV3-11*01 or IGKV1-39*01, and FR4 of IGKJ4*01 as the light chain framework region template;

More preferably, the anti-CCR8 antibody comprises SEQ ID NO: 27, 26 or 28, or a heavy chain variable region sequence having at least 80% sequence identity with SEQ ID NO: 27, 26 or 28, and SEQ ID NO: 31, 29, 30 or 32, or a light chain variable region sequence having at least 80% sequence identity with SEQ ID NO: 31, 29, 30 or 32; or

The anti-CCR8 antibody comprises SEQ ID NO: 37, 38, 39 or 40, or a heavy chain variable region sequence having at least 80% sequence identity with SEQ ID NO: 37, 38, 39 or 40, and SEQ ID NO: 43, 41 or 42, or a light chain variable region sequence having at least 80% sequence identity with SEQ ID NO: 43, 41 or 42;

Preferably, the anti-CCR8 antibody includes:

i) The heavy chain variable region as set forth in SEQ ID NO: 27, and the light chain variable region as set forth in SEQ ID NO: 31; or

ii) a heavy chain variable region as set forth in SEQ ID NO: 37, and a light chain variable region as set forth in SEQ ID NO: 43.
The anti-CCR8 antibody according to any one of claims 1 to 3, wherein the anti-CCR8 antibody is a full-length antibody or an antibody fragment thereof; preferably, the antibody fragment is Fab, Fab', F(ab ') 2 , Fd, Fv, scFv, dsFv or dAb.
The anti-CCR8 antibody according to any one of claims 1 to 4, wherein the anti-CCR8 antibody comprises a heavy chain constant region and a light chain constant region;

Preferably, the heavy chain constant region is derived from human IgG1, IgG2, IgG3 and IgG4 constant regions, and the light chain constant region is derived from human kappa and lambda chain constant regions;

More preferably, the heavy chain constant region comprises the amino acid sequence of SEQ ID NO: 44, and/or the light chain constant region comprises the amino acid sequence of SEQ ID NO: 45.
The anti-CCR8 antibody according to any one of claims 1 to 5, comprising a heavy chain and a light chain, wherein:

The heavy chain comprises an amino acid sequence having at least 85% sequence identity with SEQ ID NO: 46, and the light chain comprises an amino acid sequence having at least 85% sequence identity with SEQ ID NO: 47; or

The heavy chain comprises an amino acid sequence having at least 85% sequence identity with SEQ ID NO: 48, and the light chain comprises an amino acid sequence having at least 85% sequence identity with SEQ ID NO: 49;

Preferably,

The heavy chain comprises the amino acid sequence of SEQ ID NO: 46, and the light chain comprises the amino acid sequence of SEQ ID NO: 47; or

The heavy chain includes the amino acid sequence of SEQ ID NO: 48, and the light chain includes the amino acid sequence of SEQ ID NO: 49.
The anti-CCR8 antibody according to any one of claims 1 to 6, having one or more of the following properties:

A. The anti-CCR8 antibody has cross-binding activity with monkey CCR8; preferably, the EC 50 value of binding to the monkey CCR8 protein on the cell surface is less than 1 nM; more preferably, the EC 50 value of binding to the monkey CCR8 protein on the cell surface is less than 0.5nM;

B. The anti-CCR8 antibody binds to loop 2 of human CCR8 as set forth in SEQ ID NO: 65; and

C. The anti-CCR8 antibody binds to loop 3 of human CCR8 as shown in SEQ ID NO:66.
A pharmaceutical composition comprising the anti-CCR8 antibody of any one of claims 1 to 7 and one or more pharmaceutically acceptable carriers, diluents or excipients.
An immunoconjugate comprising: the anti-CCR8 antibody of any one of claims 1 to 7 and an effector molecule, wherein the effector molecule is coupled to the anti-CCR8 antibody; preferably, the effector Molecules are selected from antineoplastic agents, immunomodulators, biological response modifiers, lectins, cytotoxic drugs, chromophores, fluorophores, chemiluminescent compounds, enzymes, metal ions, and any combination thereof.
Nucleic acid molecule encoding the anti-CCR8 antibody of any one of claims 1 to 7.
A host cell containing the nucleic acid molecule of claim 10.
The anti-CCR8 antibody according to any one of claims 1 to 7, or the pharmaceutical composition according to claim 8, or the immunoconjugate according to claim 9, when prepared for the treatment of CCR8-related diseases or conditions uses in medicines.
The anti-CCR8 antibody according to any one of claims 1 to 7, or the pharmaceutical composition according to claim 8, or the immunoconjugate according to claim 9, when prepared for the treatment of cancer or tumors, inflammatory Use in medicines for diseases and viral infections; preferably, the cancer or tumor is selected from prostate cancer, bladder cancer, ovarian cancer, lung cancer, liver cancer, gastric cancer, colon cancer, kidney cancer, dermatofibrosarcoma, osteosarcoma, Cervical cancer, esophageal cancer, rectal cancer, head and neck squamous cell carcinoma, breast cancer, multiple myeloma, lymphoma and melanoma.
A method of treating a CCR8-related disease or disorder, the method comprising administering to a patient in need the anti-CCR8 antibody of any one of claims 1 to 7, the pharmaceutical composition of claim 8, or the The immunoconjugate of claim 9; wherein the CCR8-related disease or disorder is selected from cancer or tumor, inflammatory disease and viral infection; preferably, the cancer or tumor is selected from prostate cancer, bladder cancer, ovary Cancer, lung cancer, liver cancer, stomach cancer, colon cancer, kidney cancer, dermatofibrosarcoma, osteosarcoma, cervical cancer, esophageal cancer, rectal cancer, head and neck squamous cell carcinoma, breast cancer, multiple myeloma, lymphoma and Melanoma.