Antibody targeting Ly6G6D and application thereof

Abstract

The invention provides an antibody targeting Ly6G6D and application of the antibody, particularly provides an anti-Ly6G6D (lymphocyte antigen 6 complex and locus G61) antibody and an antibody fragment, and further provides application of the antibody or the antibody fragment in preparation of drugs for treating Ly6G6D positive cancers.

Description

Technical Field

[0001] The present invention belongs to the field of antibody engineering. Specifically, the present invention relates to an antibody, and particularly to an antibody targeting Ly6G6D and its use for preparing a drug. Background Art

[0002] Colorectal cancer is a malignant tumor that occurs in the mucosa epithelium and glands of the colon and rectum, and its incidence rate ranks second only to gastric cancer and esophageal cancer among digestive tract malignant tumors. In recent years, due to the changes in eating habits and dietary structure and the aging of the population, the incidence and mortality rates of colorectal cancer in China have both shown an increasing trend.

[0003] Lymphocyte antigen 6 family member G6D (Ly6G6D) is a leukocyte antigen cluster located in the major histocompatibility complex (MHC) class III region of chromosome 6, encoding a protein of 133 amino acid residues with a molecular weight of approximately 13.7 kDa. Like most family members, Ly6G6D is attached to the cell membrane through a glycosylphosphatidylinositol (GPI) anchor. Multiple studies have shown that lymphocyte antigen 6 family members are very important for regulating the functions of the immune system, nervous system, and complement. Especially in cancer, many lymphocyte antigen 6 family members play key roles in many types of cancers, such as gastric cancer, cervical cancer, breast cancer, ovarian cancer, lung cancer, and bladder cancer. Therefore, the lymphocyte antigen 6 gene family may play an important role in clinical practice, not only as a marker for disease prognosis but also as an important target for developing new drugs. In-depth study of their biological functions will be of great significance for clarifying the functions of the lymphocyte antigen 6 family, analyzing the protein-protein interactions in their structures, exploring the pathogenesis of diseases, and discovering new therapeutic targets. As a new member of the lymphocyte antigen 6 gene family, Ly6G6D has been successively reported to play an important role in the occurrence of diseases such as colorectal cancer. Currently, there is already a bispecific antibody based on Ly6G6D used for the treatment of colorectal cancer, which indicates that Ly6G6D is expected to become a potential target for antibody-based therapy. Summary of the Invention

[0004] The present invention provides a fully human anti-Ly6G6D antibody, which has a high affinity for the human recombinant Ly6G6D protein, and has better low immunogenicity and safety compared with the currently commonly used rabbit or mouse anti-Ly6G6D antibodies, and even has better effects, and has good application prospects.

[0005] Specifically, on the one hand, the present invention provides an anti-Ly6G6D antibody or antigen-binding fragment, the antibody or antigen-binding fragment binds to Ly6G6D, the antibody comprises a heavy chain and a light chain, wherein the heavy chain comprises a heavy chain variable region, and the heavy chain variable region comprises complementarity-determining regions: H-CDR1, H-CDR2, and H-CDR3; wherein,

[0006] (1) H-CDR1 has the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:7, SEQ ID NO:13, SEQ ID NO:18, SEQ ID NO:22, SEQ ID NO:28, SEQ ID NO:34, SEQ ID NO:42, SEQ ID NO:46, SEQ ID NO:52, SEQ ID NO:56, SEQ ID NO:61, or SEQ ID NO:71; and

[0007] (2) H-CDR2 has the amino acid sequence shown in SEQ ID NO:2, SEQ ID NO:8, SEQ ID NO:14, SEQ ID NO:19, SEQ ID NO:23, SEQ ID NO:29, SEQ ID NO:35, SEQ ID NO:43, SEQ ID NO:47, SEQ ID NO:53, SEQ ID NO:57, or SEQ ID NO:72; and

[0008] (3) H-CDR3 has the amino acid sequence shown in SEQ ID NO:3, SEQ ID NO:9, SEQ ID NO:15, SEQ ID NO:20, SEQ ID NO:24, SEQ ID NO:30, SEQ ID NO:36, SEQ ID NO:40, SEQ ID NO:44, SEQ ID NO:48, SEQ ID NO:54, SEQ ID NO:58, SEQ ID NO:62, SEQ ID NO:66, or SEQ ID NO:73; and

[0009] wherein the light chain comprises a light chain variable region, and the light chain variable region comprises complementarity-determining regions: L-CDR1, L-CDR2, and L-CDR3; wherein,

[0010] (1) L-CDR1 has an amino acid sequence shown in SEQ ID NO:4, SEQ ID NO:10, SEQ ID NO:25, SEQ ID NO:31, SEQ ID NO:37, SEQ ID NO:49, SEQ ID NO:59, SEQ ID NO:63, SEQ ID NO:68 or SEQ ID NO:74; and

[0011] (2) L-CDR2 has an amino acid sequence shown in SEQ ID NO:5, SEQ ID NO:11, SEQ ID NO:16, SEQ ID NO:26, SEQ ID NO:32, SEQ ID NO:38, SEQ ID NO:50, SEQ ID NO:60, SEQ ID NO:64, SEQ ID NO:67, SEQ ID NO:69 or SEQ ID NO:75; and

[0012] (3) L-CDR3 has an amino acid sequence shown in SEQ ID NO:6, SEQ ID NO:12, SEQ ID NO:17, SEQ ID NO:21, SEQ ID NO:27, SEQ ID NO:33, SEQ ID NO:39, SEQ ID NO:41, SEQ ID NO:45, SEQ ID NO:51, SEQ ID NO:55, SEQ ID NO:65, SEQ ID NO:70 or SEQ ID NO:76.

[0013] In some embodiments, the heavy chain variable region of the present invention comprises complementary determining regions: H-CDR1, H-CDR2 and H-CDR3; wherein,

[0014] (1) H-CDR1 has an amino acid sequence shown in SEQ ID NO:1, H-CDR2 has an amino acid sequence shown in SEQ ID NO:2 and H-CDR3 has an amino acid sequence shown in SEQ ID NO:3; or

[0015] (2) H-CDR1 has an amino acid sequence shown in SEQ ID NO:7, H-CDR2 has an amino acid sequence shown in SEQ ID NO:8 and H-CDR3 has an amino acid sequence shown in SEQ ID NO:9; or

[0016] (3) H-CDR1 has an amino acid sequence shown in SEQ ID NO:13, H-CDR2 has an amino acid sequence shown in SEQ ID NO:14 and H-CDR3 has an amino acid sequence shown in SEQ ID NO:15; or

[0017] (4) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 19, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 20; or

[0018] (5) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 22, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 23, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 24; or

[0019] (6) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 28, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 30; or

[0020] (7) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 34, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 35, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 36; or

[0021] (8) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 40; or

[0022] (9) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 42, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 43, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 44; or

[0023] (10) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 46, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 47, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 48; or

[0024] (11) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 52, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 53, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 54; or

[0025] (12) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 56, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 57, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 58; or

[0026] (13) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 61, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 62; or

[0027] (14) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 66; or

[0028] (15) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 62; or

[0029] (16) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 71, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 72, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 73.

[0030] In some embodiments, the light chain variable region of the present invention comprises complementarity determining regions: L-CDR1, L-CDR2, and L-CDR3; wherein,

[0031] (1) The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 4, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 5, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 6; or

[0032] (2) The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 10, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 11, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 12; or

[0033] (3) The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 4, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 16, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 17; or

[0034] (4) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:4, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:16, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:21; or

[0035] (5) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:25, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:26, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:27; or

[0036] (6) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:31, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:32, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:33; or

[0037] (7) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:38, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:39; or

[0038] (8) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:38, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:41; or

[0039] (9) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:38, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:45; or

[0040] (10) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:49, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:50, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:51; or

[0041] (11) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:38, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:55; or

[0042] (12) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:59, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:60, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:51; or

[0043] (13) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:63, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:64, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:65; or

[0044] (14) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:67, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:41; or

[0045] (15) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:68, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:69, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:70; or

[0046] (16) The L-CDR1 has the amino acid sequence shown in SEQ ID NO:74, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:75, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:76.

[0047] In some embodiments, the heavy chain variable region of the present invention comprises complementarity determining regions: H-CDR1, H-CDR2, and H-CDR3; and the light chain variable region of the present invention comprises complementarity determining regions: L-CDR1, L-CDR2, and L-CDR3; wherein,

[0048] (1) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:1, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:2, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:3; and

[0049] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:4, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:5, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:6; or

[0050] (2) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:7, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:8, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:9; and

[0051] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:10, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:11, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:12; or

[0052] (3) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:13, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:14, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:15; and

[0053] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:4, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:16, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:17; or

[0054] (4) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:18, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:19, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:20; and

[0055] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:4, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:16, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:21; or

[0056] (5) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:22, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:23, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:24; and

[0057] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:25, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:26, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:27; or

[0058] (6) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:28, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:30; and

[0059] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:31, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:32, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:33; or

[0060] (7) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:34, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:35, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:36; and

[0061] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:38, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:39; or

[0062] (8) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:18, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:40; and

[0063] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:38, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:41; or

[0064] (9) The H-CDR1 has the amino acid sequence shown in SEQ ID NO:42, the H-CDR2 has the amino acid sequence shown in SEQ ID NO:43, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO:44; and

[0065] The L-CDR1 has the amino acid sequence shown in SEQ ID NO:37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO:38, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO:45; or

[0066] The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 46, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 47, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 48; and

[0067] The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 49, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 50, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 51; or

[0068] (11) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 52, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 53, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 54; and

[0069] The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 38, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 55; or

[0070] (12) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 56, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 57, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 58; and

[0071] The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 59, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 60, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 51; or

[0072] (13) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 61, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 62; and

[0073] The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 63, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 64, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 65; or

[0074] The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 66; and

[0075] The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 37, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 67, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 41; or

[0076] (15) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 62; and

[0077] The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 68, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 69, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 70; or

[0078] (16) The H-CDR1 has the amino acid sequence shown in SEQ ID NO: 71, the H-CDR2 has the amino acid sequence shown in SEQ ID NO: 72, and the H-CDR3 has the amino acid sequence shown in SEQ ID NO: 73; and

[0079] The L-CDR1 has the amino acid sequence shown in SEQ ID NO: 74, the L-CDR2 has the amino acid sequence shown in SEQ ID NO: 75, and the L-CDR3 has the amino acid sequence shown in SEQ ID NO: 76.

[0080] In some embodiments, the CDR sequences of the present invention are defined with reference to the Kabat nomenclature system.

[0081] NYAMH (SEQ ID NO: 1).

[0082] VISYDGSKKYYADSVKG (SEQ ID NO: 2). PAGSTSGFDY (SEQ ID NO: 3).

[0083] TGTSSDVGGYNYVS (SEQ ID NO: 4). DVSNRPS (SEQ ID NO: 5).

[0084] SSYTSSSTLVV (SEQ ID NO: 6).

[0085] DYGMS (SEQ ID NO:7).

[0086] GINWNGGSTGYADSVKG (SEQ ID NO:8). SSVKHY (SEQ ID NO:9).

[0087] SGSSSNIGTNTVN (SEQ ID NO:10). RNDLRPS (SEQ ID NO:11).

[0088] AAWDDSLNGVV (SEQ ID NO:12). NYGIT (SEQ ID NO:13).

[0089] WISPYNGHTIYAQKVQG (SEQ ID NO:14). GLNSRLQY (SEQ ID NO:15).

[0090] DVSKRPS (SEQ ID NO:16).

[0091] SSYTSSSTDV (SEQ ID NO:17).

[0092] GYYMH (SEQ ID NO:18).

[0093] WINPVSGGTNYAQKFQG (SEQ ID NO:19). DPFDI (SEQ ID NO:20).

[0094] SSYTSRSTPGYV (SEQ ID NO:21).

[0095] NYGFS (SEQ ID NO:22).

[0096] WISSYNGNTKYAQKFRG (SEQ ID NO:23). GGDWPADY (SEQ ID NO:24).

[0097] GLSSGSVSNNYYPS (SEQ ID NO:25). STNTRSS (SEQ ID NO:26).

[0098] VVYMGSGIWV (SEQ ID NO:27).

[0099] SYGIS (SEQ ID NO:28).

[0100] WINPNSGGTNYAQKFQG (SEQ ID NO:29). AGDLRDYYYYGMDV (SEQ ID NO:30). TGSSSNIGAGYDVH (SEQ ID NO:31). GNSNRPS (SEQ ID NO:32).

[0101] QSYDSSLSGWV (SEQ ID NO:33).

[0102] RYPIH (SEQ ID NO:34).

[0103] WINTNTGNPTYAQGFTG (SEQ ID NO:35). SGELGGALDI (SEQ ID NO:36).

[0104] RSSQSLLHSNGYNYLD (SEQ ID NO:37). LGSNRAS (SEQ ID NO:38).

[0105] MQPLQTPLT (SEQ ID NO:39).

[0106] VGHYYYGMDV (SEQ ID NO:40).

[0107] MQALQTPPT (SEQ ID NO:41).

[0108] NHFIH (SEQ ID NO:42).

[0109] WISANSGNTDYAQKFQG (SEQ ID NO:43). DLATVDGFDI (SEQ ID NO:44).

[0110] MQALQTPLT (SEQ ID NO:45).

[0111] SYSVS (SEQ ID NO:46).

[0112] GIIPTFGRTNYAQKFQG (SEQ ID NO:47). VRKPYYGMDV (SEQ ID NO:48).

[0113] RASQSIGRFLN (SEQ ID NO:49).

[0114] GASRLQG (SEQ ID NO:50).

[0115] QQSYSTPPT (SEQ ID NO:51).

[0116] SYGIN (SEQ ID NO:52).

[0117] WINTKTGNPTYVQGFTG (SEQ ID NO:53). DRNPYGMDV (SEQ ID NO:54).

[0118] MQPLQALYT (SEQ ID NO:55).

[0119] SYAIS (SEQ ID NO:56).

[0120] GIIPIFGTANYAQKFQG (SEQ ID NO:57). TGGDYYYYGMDV (SEQ ID NO:58). RASQTISTYLN (SEQ ID NO:59).

[0121] GASSLQT (SEQ ID NO:60).

[0122] DYFLH (SEQ ID NO:61).

[0123] DPFDY (SEQ ID NO:62).

[0124] RSSQSLVHSDGNTYLS (SEQ ID NO:63).

[0125] KISNRFS (SEQ ID NO:64).

[0126] MQATQFPIT (SEQ ID NO:65).

[0127] VGGSYYGGFDY (SEQ ID NO:66).

[0128] LSSNRAS (SEQ ID NO:67).

[0129] RSSQSLVYSDGNTYLS (SEQ ID NO:68).

[0130] KVSNRFS (SEQ ID NO:69).

[0131] MQATQYPLA (SEQ ID NO:70).

[0132] NYWIG (SEQ ID NO:71).

[0133] IIYPGDSDTRYSPSFQG (SEQ ID NO:72).

[0134] PQGAFDI (SEQ ID NO:73).

[0135] RSSQSLVYSDGNTYLN (SEQ ID NO:74).

[0136] KVSNRDS (SEQ ID NO:75).

[0137] MQGTHWPLT (SEQ ID NO:76).

[0138] In some embodiments, the antibody of the present invention comprises at least one of a heavy chain framework region sequence and a light chain framework region sequence, and at least a part of at least one of the heavy chain framework region sequence and the light chain framework region sequence is derived from at least one of a murine antibody, a human antibody, a primate antibody or a mutant thereof.

[0139] In some embodiments, the heavy chain variable region of the antibody of the present invention comprises an amino acid sequence having at least 85%, at least 90%, at least 95% or at least 99% sequence identity with any one of SEQ ID NOs: 77 - 92.

[0140] In some embodiments, the heavy chain variable region of the antibody comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity with any one of SEQ ID NOs: 77 - 92.

[0141] In some embodiments, the light chain variable region of the antibody of the present invention comprises an amino acid sequence having at least 85%, at least 90%, at least 95% or at least 99% sequence identity with any one of SEQ ID NOs: 93 - 108.

[0142] In some embodiments, the light chain variable region of the antibody of the present invention comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity with any one of SEQ ID NOs: 93 - 108.

[0143] In some embodiments, the heavy chain variable region of the antibody of the present invention comprises the amino acid sequence shown in SEQ ID NO:77 and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO:93.

[0144] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:77 and the light chain variable region shown in SEQ ID NO:93 is numbered: 2E7.

[0145] In some embodiments, the heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:78 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:94.

[0146] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:78 and the light chain variable region shown in SEQ ID NO:94 is numbered: 2G10.

[0147] The heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:79 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:95.

[0148] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:79 and the light chain variable region shown in SEQ ID NO:95 is numbered: 5C12.

[0149] The heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:80 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:96.

[0150] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:80 and the light chain variable region shown in SEQ ID NO:96 is numbered: 6C1.

[0151] The heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:81 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:97.

[0152] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:81 and the light chain variable region shown in SEQ ID NO:97 is numbered: 7B1.

[0153] The heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:82 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:98.

[0154] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:82 and the light chain variable region shown in SEQ ID NO:98 is numbered: 12A1.

[0155] The heavy chain variable region of the antibody of the present invention comprises the amino acid sequence shown in SEQ ID NO: 83, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 99.

[0156] In the present invention, the antibody comprising the heavy chain variable region shown in SEQ ID NO: 83 and the light chain variable region shown in SEQ ID NO: 99 was cloned, and the number is: 13A10.

[0157] The heavy chain variable region of the antibody of the present invention comprises the amino acid sequence shown in SEQ ID NO: 84, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 100.

[0158] In the present invention, the antibody comprising the heavy chain variable region shown in SEQ ID NO: 84 and the light chain variable region shown in SEQ ID NO: 100 was cloned, and the number is: 14A2.

[0159] The heavy chain variable region of the antibody of the present invention comprises the amino acid sequence shown in SEQ ID NO: 85, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 101.

[0160] In the present invention, the antibody comprising the heavy chain variable region shown in SEQ ID NO: 85 and the light chain variable region shown in SEQ ID NO: 101 was cloned, and the number is: 14B5.

[0161] The heavy chain variable region of the antibody of the present invention comprises the amino acid sequence shown in SEQ ID NO: 86, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 102.

[0162] In the present invention, the antibody comprising the heavy chain variable region shown in SEQ ID NO: 86 and the light chain variable region shown in SEQ ID NO: 102 was cloned, and the number is: 14G2.

[0163] The heavy chain variable region of the antibody of the present invention comprises the amino acid sequence shown in SEQ ID NO: 87, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 103.

[0164] In the present invention, the antibody comprising the heavy chain variable region shown in SEQ ID NO: 87 and the light chain variable region shown in SEQ ID NO: 103 was cloned, and the number is: 16H6.

[0165] The heavy chain variable region of the antibody of the present invention comprises the amino acid sequence shown in SEQ ID NO: 88, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 104.

[0166] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:88 and the light chain variable region shown in SEQ ID NO:104 was numbered: 17A11.

[0167] The heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:89 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:105.

[0168] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:89 and the light chain variable region shown in SEQ ID NO:105 was numbered: 18A11.

[0169] The heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:90 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:106.

[0170] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:90 and the light chain variable region shown in SEQ ID NO:106 was numbered: 19A4.

[0171] The heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:91 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:107.

[0172] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:91 and the light chain variable region shown in SEQ ID NO:107 was numbered: 20E2.

[0173] The heavy chain variable region of the antibody of the present invention contains the amino acid sequence shown in SEQ ID NO:92 and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:108.

[0174] In the present invention, the antibody clone containing the heavy chain variable region shown in SEQ ID NO:92 and the light chain variable region shown in SEQ ID NO:108 was numbered: 22A6.

[0175] EVHLVESGGGVVQPGRSLRLSCAASGFTFSNYAMHWVRQAPGKGLEWVAVISYDGSK

[0176] KYYADSVKGRFTISRDDSKNTLYLQMNSLRAEDTAVYYCAKPAGSTSGFDYWGQGTLVTVSS(SEQ IDNO:77).

[0177] QSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSNRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSSTLVVFGGGTKLTVL(SEQ ID NO:93).

[0178] QVQLVQSGGGVVRPGGSLRLSCAASGFTFDDYGMSWVRQAPGKGLEWVSGINWNGG

[0179] STGYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCATSSVKHYWGQGTLVTVSS(SEQ IDNO:78).

[0180] QPVLTQPPSASATPGQRVTISCSGSSSNIGTNTVNWYQQVPGTAPKVLIYRNDLRPSGVPDRFSGSKSGTSASLAISGLQSDDEADYYCAAWDDSLNGVVFGGGTKVTVL(SEQ ID NO:94).

[0181] QVQLVQSGPEMKKPGASVKVACKTSGYIFINYGITWVRQAPGQGLEWMGWISPYNGH

[0182] TIYAQKVQGRGTMTTETPTSTAYLDLTNLTPDDTAIYYCATGLNSRLQYWGQGALVTVSS(SEQ IDNO:79).

[0183] QPVLTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSKRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSSTDVFGTGTKVTVL(SEQ ID NO:95).

[0184] EVQLVQSGAEVKKPGASMKVSCKASGYTFTGYYMHWVRQAPGQGLEWMGWINPVS

[0185] GGTNYAQKFQGRVTMTRDTSIGTAYMELTGLRSDDTAVYYCAADPFDIWGQGTMVTVSS(SEQ IDNO:80).

[0186] QSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSKRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSRSTPGYVFGTGTKLTVL(SEQ ID NO:96)。

[0187] QVQLVQSGAEVKKPGASVKVSCKASGYTFTNYGFSWVRQAPGQGLEWMGWISSYNG

[0188] NTKYAQKFRGRVTMTTDTSTSTGYMELRSLRSDDTAVYYCARGGDWPADYWGQGTLVTVSS(SEQ IDNO:81)。

[0189] QAVVTQEPSFSVSPGGTVTLTCGLSSGSVSNNYYPSWYQQIPGQAPRTLIYSTNTRSSGVPDRFSGSILGNKAALTITGAQADDEADYYCVVYMGSGIWVFGGGTKLTVL(SEQ ID NO:97)。

[0190] QVQLVQSGAEVKKPGASVKVSCKASGYTFTSYGISWVRQAPGQGLEWMGWINPNSGG

[0191] TNYAQKFQGRVTMTRDTSISTAYMELSRLRSDDTAVYYCARAGDLRDYYYYGMDVWGQGTTVTVSS(SEQ ID NO:82)。

[0192] QSVLTQPPSVSGAPGQRVTISCTGSSSNIGAGYDVHWYQQLPGTAPKLLIYGNSNRPSGVPDRFSGSKSGTSASLAITGLQAEDEADYYCQSYDSSLSGWVFGGGTQLTAL(SEQ ID NO:98)。

[0193] EVQLVQSGSELKNPGASVKVSCKASGYPFSRYPIHWVRQAPGQGLEWMGWINTNTGN

[0194] PTYAQGFTGRFVFSLDTSVSTAYLQISSLKAEDSAVYYCARSGELGGALDIWGQGTTVTVSS(SEQ IDNO:83)。

[0195] EIVLTQSPLSLSVTPGEPASFSCRSSQSLLHSNGYNYLDWYVQKPGQSPQLLIYLGSNRASGVPDRFSGSGSGTDFTLKISRVEAEDVGIYYCMQPLQTPLTFGGGTKVEIK(SEQ ID NO:99).

[0196] QVQLVQSGAEVKKPGASVKVSCKASGYTFTGYYMHWVRQAPGQGLEWMGWINPNS

[0197] GGTNYAQKFQGRVTMTRDTSISTAYMELSRLRSDDTAVYYCARVGHYYYGMDVWGQGTTVTVSS(SEQID NO:84).

[0198] EIVLTQSPLSLPVTPGEPASISCRSSQSLLHSNGYNYLDWYLQKPGQSPQLLIYLGSNRASGVPDRFSGSGSGTDFTLKISRVEAEDVGVYYCMQALQTPPTFGQGTKLEIK(SEQ ID NO:100).

[0199] QVQLVQSGAEVKKPGASVKVSCKASGYTFTNHFIHWVRQAPGQGLEWMGWISANSG

[0200] NTDYAQKFQGRVTMTTDTSTSTAYMELRSLRYDDTAVYYCARDLATVDGFDIWGQGTMVTVSS(SEQID NO:85).

[0201] DVVMTQSPLSLPVTPGEPASISCRSSQSLLHSNGYNYLDWYLQKPGQSPQLLIYLGSNRASGVPDRFSGSGSGTDFTLKISRVEAEDVGVYYCMQALQTPLTFGPGTKVDIK(SEQ ID NO:101).

[0202] EVQLVQSGSEVKKPGSSVKVSCKAPGGTFSSYSVSWVRQAPGQGLEWMGGIIPTFGRT

[0203] NYAQKFQGRVTISAHESTGTAYMELSSLRSEDTAVYYCASVRKPYYGMDVWGQGTMVTVSS(SEQ IDNO:86).

[0204] DIQMTQSPSSLSASVGDRVTITCRASQSIGRFLNWYQQKPGTAPKLLISGASRLQGGIPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPPTFGQGTKVEIK (SEQ ID NO:102).

[0205] QVQLVQSGSELKKPGASVKISCKASGYTLTSYGINWVRQAPGKGLELMGWINTKTGNP

[0206] TYVQGFTGQVVFSFDTSVNTAYLQINNLKSDDTAVYFCARDRNPYGMDVWGQGTTVTVSS (SEQ ID NO:87).

[0207] EIVLTQSPLSLPVTPGEPASISCRSSQSLLHSNGYNYLDWYLQKPGQSPQLLIYLGSNRASGVPDRFSGSGSGTDFTLKISRVEAEDVGVYYCMQPLQALYTFGQGTKVEIK (SEQ ID NO:103).

[0208] QVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTAN

[0209] YAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARTGGDYYYYGMDVWGQGTTVTVSS (SEQ ID NO:88).

[0210] DIQMTQSPSSLSASVGDRVTITCRASQTISTYLNWYQQKPGKAPKLLIYGASSLQTGVPS RFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPPTFGQGTKLEIK (SEQ ID NO:104).

[0211] EVQLVESGAEVKKPGASVKVSCKASGYTFTDYFLHWVRQAPGQGLEWMGWINPNSG

[0212] GTNYAQKFQGWVTMTRDTSISTAYLELSSLTSDDTAVYYCAVDPFDYWGQGTLVTVSS(SEQ ID NO:89).

[0213] DVVMTQSPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLHQRPGQPPRLLIHKISNRFS GVPDRFSGSGAGTDFTLKISRVEAEDVGVFYCMQATQFPITFGQGTRLEIK(SEQ ID NO:105).

[0214] QVQLVQSGAEVKKPGASVKVSCKASGYTFTGYYMHWVRQAPGQGLEWMGWINPNS

[0215] GGTNYAQKFQGRVTMTRDTSISTAYMELSRLRSDDTAVYYCARVGGSYYGGFDYWGQGTL VTVSS(SEQ ID NO:90).

[0216] EIVLTQSPLSLPVTPGEPASISCRSSQSLLHSNGYNYLDWYLQKPGQSPQLLMYLSSNRA SGVPDRFSGSGSGRDFTLKISRVEAEDVGLYYCMQALQTPPTFGQGTRLEIK(SEQ ID NO:106).

[0217] QVQLVQSGAEVKKPGASVKVSCKASGYTFTGYYMHWVRQAPGQGLEWMGWINPNS

[0218] GGTNYAQKFQGRVTMTRDTSISTAYMELSRLRSDDTAVYYCASDPFDYWGQGTLVTVSS(SEQ IDNO:91).

[0219] DVVMTQSPLSSPVTLGQPASISCRSSQSLVYSDGNTYLSWLQQRPGQPPRLLIYKVSNRF SGVPDRFSGSGAGTDFTLTISRVEAEDVGVYYCMQATQYPLAFGGGTKLEIK(SEQ ID NO:107).

[0220] QVQLVQSGAEVKKPGESLKISCKGSGYSFTNYWIGWVRQMPGKGLEWMGIIYPGDSDT

[0221] RYSPSFQGQVTISADKSISTAYLQWSSLKASDTAMYYCARPQGAFDIWGQGTMVTVSS(SEQ ID NO:92).

[0222] EIVMTQTPLSLPVTLGQPASISCRSSQSLVYSDGNTYLNWFQQRPGQSPRRLIYKVSNRD SGVPDRFSGSGSGTDFTLKISRVEAEDVGVYYCMQGTHWPLTFGQGTKVEIK(SEQ ID NO:108).

[0223] In some embodiments, the antibody of the present invention comprises at least one of a heavy chain constant region and a light chain constant region, and at least a part of at least one of the heavy chain constant region and the light chain constant region is derived from at least one of a murine antibody, a human antibody, a primate antibody, or a mutant thereof.

[0224] In some embodiments, both the heavy chain constant region and the light chain constant region of the antibody of the present invention are derived from a human IgG antibody or a mutant thereof.

[0225] In some embodiments, the heavy chain constant region of the antibody of the present invention is derived from a human IgG1 or IgG4 antibody or a mutant thereof.

[0226] In some embodiments, the light chain constant region of the antibody of the present invention is derived from a human IgGκ or IgGλ constant region.

[0227] In some embodiments, the heavy chain constant region of the antibody of the present invention comprises the full-length sequence of the constant region, and the light chain constant region of the antibody comprises the full-length sequence of the constant region.

[0228] In some embodiments, the heavy chain of the antibody of the present invention comprises a heavy chain variable region and a constant region; the heavy chain variable region comprises an amino acid sequence having at least 85%, at least 90%, at least 95%, or at least 99% sequence identity with any one of SEQ ID NOs: 77-92.

[0229] In some embodiments, the heavy chain of the antibody of the present invention comprises a heavy chain variable region and a constant region; the heavy chain variable region comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with any one of SEQ ID NOs: 77-92.

[0230] In some embodiments, the light chain of the antibody of the present invention comprises a light chain variable region and a constant region; the light chain variable region comprises an amino acid sequence having at least 85%, at least 90%, at least 95% or at least 99% sequence identity with any one of SEQ ID NOs: 93-108.

[0231] In some embodiments, the light chain of the antibody of the present invention comprises a light chain variable region and a constant region; the light chain variable region comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity with any one of SEQ ID NOs: 93-108.

[0232] In some embodiments, the antibody of the present invention is a monoclonal antibody.

[0233] In some embodiments, the antibody of the present invention is a monoclonal human antibody.

[0234] In some embodiments, the antigen-binding fragment of the antibody of the present invention is selected from: Fab, Fab'-SH, Fv and (Fab')2 fragments.

[0235] In some embodiments, the antibody of the present invention is a native intact antibody, a single-chain antibody (scFv), a single-chain Fv-Fc antibody (scFv-Fc), a scFv dimer, and a dimer of scFv-Fc antibody. Among them, the dimer includes a homodimer and a heterodimer.

[0236] The single-chain antibody (scFv) as described above comprises a heavy chain variable region of the amino acid sequence shown in any one of SEQ ID NOs: 77-92 and a light chain variable region of the amino acid sequence shown in any one of SEQ ID NOs: 93-108, wherein the C-terminus of the heavy chain variable region is connected to the N-terminus of the light chain variable region through a linker peptide Linker, or the C-terminus of the variable region is connected to the N-terminus of the heavy chain variable region through a linker peptide Linker. It should be noted that the "linker peptide Linker" of the single-chain antibody of the present invention is used to connect the heavy chain variable region and the light chain variable region of the antibody, which can be a commonly used linker peptide Linker for preparing single-chain antibodies, or a linker peptide Linker modified by scientific researchers. Examples of the amino acid sequence of the linker peptide Linker are: (GnS)m, n is a natural number from 3 to 5, n is preferably 4, m is a natural number from 1 to 5, and m is preferably 3.

[0237] GGGS (SEQ ID NO: 109).

[0238] GGGGS (SEQ ID NO:110).

[0239] GGGGSGGGGS (SEQ ID NO:111).

[0240] GGGGSGGGGSGGGGS (SEQ ID NO:112).

[0241] Specific example, the single-chain antibody (scFv) of the present invention comprises the amino acid sequence shown in SEQ ID NO:113.

[0242] EVHLVESGGGVVQPGRSLRLSCAASGFTFSNYAMHWVRQAPGKGLEWVAVISYDGSKKYYADSVKGRFTISRDDSKNTLYLQMNSLRAEDTAVYYCAKPAGSTSGFDYWGQGTLVTVSSGGGGSGGGGSGGGGSQSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSNRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSSTLVVFGGGTKLTVL (SEQ ID NO:113).

[0243] In the amino acid sequence shown in SEQ ID NO:113, the bold part is the linker peptide Linker.

[0244] The single-chain antibodies of the present invention can all be constructed with reference to the specific examples described above.

[0245] The single-chain Fv-Fc antibody (scFv-Fc) described above comprises an scFv and an Fc fragment, and the Fc fragment refers to a fragment of the constant region of the heavy chain of an antibody comprising at least a hinge region, CH2 and CH3 domains; the scFv is as described above, and the scFv is directly connected to the Fc fragment or connected through a linker peptide Linker (specific examples of the linker peptide Linker are GGGGSGGGGSGGGGS). In some embodiments, the scFv in the present invention is directly connected to the Fc fragment through a hinge region.

[0246] The Fc fragment as described above is derived from a heavy chain constant region selected, for example, from human IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgD, and IgE; particularly selected from the heavy chain constant regions of, for example, human IgG1, IgG2, IgG3, and IgG4, and more particularly from the heavy chain constant region of human IgG1 or IgG4; and, the Fc fragment has one or more amino acid substitutions, deletions, or additions compared to its native sequence (e.g., up to 20, up to 15, up to 10, up to 5, up to 3, or up to 1 substitution, deletion, or addition).

[0247] Specifically, the Fc in the single-chain Fv-Fc antibody (scFv-Fc) of the present invention has the amino acid sequence shown in SEQ ID NO: 114.

[0248] EPKSADKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 114).

[0249] In some embodiments, the antibody of the present invention is a monospecific antibody, bispecific antibody, or multispecific antibody.

[0250] On the other hand, the present invention provides an isolated nucleic acid molecule that comprises a nucleotide sequence encoding the antibody or antigen-binding fragment of the present invention.

[0251] In some embodiments, the nucleic acid molecule of the present invention is DNA.

[0252] On yet another hand, the present invention provides a nucleic acid construct that comprises the nucleic acid molecule of the present invention; further, the nucleic acid construct comprises one or more control sequences operably linked to the nucleic acid molecule, and the one or more control sequences direct the production of the antibody or its antigen-binding fragment of the present invention in a suitable host cell, and the one or more control sequences are selected from: promoters, enhancers, stop signals, signal peptides, leader sequences, transcription terminators, and any combination thereof.

[0253] On the other hand, the present invention provides an expression vector, which carries the nucleic acid molecule of the present invention.

[0254] In some embodiments, the expression vector of the present invention is selected from: plasmids, cosmids, viruses, minichromosomes, and artificial chromosomes.

[0255] In some embodiments, the expression vector of the present invention is a eukaryotic expression vector.

[0256] In some embodiments, the eukaryotic expression vector of the present invention is selected from: pCRII, pCR3, and pcDNA3.4, pBSII, pET 15, pGEX, pEGFP-N1, pETL, pDSR-α, and pFastBacDual, etc.

[0257] On the other hand, the present invention provides a host cell, which contains the nucleic acid molecule of the present invention or the expression vector of the present invention.

[0258] In some embodiments, the host cell of the present invention is Escherichia coli, yeast, or a eukaryotic cell.

[0259] In some embodiments, the host cell of the present invention is a eukaryotic host cell.

[0260] In some embodiments, the eukaryotic host cell of the present invention is selected from: Chinese hamster ovary cells CHO, monkey kidney cells COS cells, human embryonic kidney cells HEK-293, human cervical cancer cells HELA, etc.

[0261] In some embodiments, the host cell is a mammalian host cell.

[0262] On the other hand, the present invention provides a pharmaceutical composition, which contains the antibody or antigen-binding fragment of the present invention, the nucleic acid molecule of the present invention, the expression vector of the present invention, or the host cell of the present invention and a pharmaceutically acceptable carrier.

[0263] On the other hand, the present invention provides the use of the antibody or antigen-binding fragment of the present invention, the nucleic acid molecule of the present invention, the expression vector of the present invention, the host cell of the present invention, or the pharmaceutical composition of the present invention in the preparation of a drug for treating a cell proliferative disease or delaying the progression of a cell proliferative disease.

[0264] On the other hand, the present invention provides a method for treating a cell proliferative disease or delaying the progression of a cell proliferative disease, the method comprising administering to a patient in need thereof an effective amount of the antibody or antigen-binding fragment of the present invention, the nucleic acid molecule of the present invention, the expression vector of the present invention, the host cell of the present invention, or the pharmaceutical composition of the present invention.

[0265] On the other hand, the present invention provides a method for treating cancer, the method comprising administering to a patient in need thereof an effective amount of the antibody or antigen-binding fragment of the present invention, the nucleic acid molecule of the present invention, the expression vector of the present invention, the host cell of the present invention, or the pharmaceutical composition of the present invention.

[0266] In some embodiments, the administration of the present invention is by oral, nasal, intravenous, subcutaneous, sublingual, or intramuscular administration.

[0267] In some embodiments, the cell proliferative disease of the present invention is cancer.

[0268] In some embodiments, the cancer of the present invention is a Ly6G6D-positive cancer.

[0269] In some embodiments, the Ly6G6D-positive cancer of the present invention is colorectal cancer, head and neck cancer, ovarian cancer, cervical cancer, melanoma, gastric cancer, esophageal cancer, small intestine cancer, large intestine cancer, or adenocarcinoma, etc.

[0270] In some embodiments, the adenocarcinoma of the present invention is colorectal adenocarcinoma, gastric adenocarcinoma, or pancreatic adenocarcinoma.

[0271] On the other hand, the present invention provides an antibody-drug conjugate, the antibody-conjugate comprising the antibody or antigen-binding fragment of the present invention.

[0272] In some embodiments, the drug conjugate of the present invention is preferably a small molecule drug, and the antibody in the antibody-drug conjugate targets the small molecule drug to the treatment target through specific binding.

[0273] On the other hand, the present invention provides a kit for detecting Ly6G6D, the kit of the present invention comprising the antibody or antigen-binding fragment of the present invention.

[0274] In some embodiments, the kit of the present invention further includes a container, an instruction manual, a buffer, etc. In the kit of the present invention, the antibody of the present invention can be immobilized on a detection plate.

[0275] Term Definitions

[0276] In the present invention, unless otherwise specified, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Also, the operating steps such as cell culture, molecular biology, biochemistry, nucleic acid chemistry, immunology, etc. used herein are all conventional steps widely used in the relevant fields. Meanwhile, to better understand the present invention, the definitions and explanations of relevant terms are provided below.

[0277] When the terms "such as", "for example", "such as", "including", "comprising" or their variants are used herein, these terms will not be considered as restrictive terms and will be interpreted as meaning "but not limited to" or "not limited to".

[0278] Unless otherwise specified herein or clearly contradictory according to the context, the terms "a", "an" and "the" and similar referents in the context of describing the present invention (especially in the context of the following claims) should be construed to cover both the singular and the plural.

[0279] The terms "anti-Ly6G6D antibody" and "antibody that binds Ly6G6D" refer to an antibody that is capable of binding Ly6G6D with sufficient affinity such that the antibody can be used as a diagnostic and / or therapeutic agent targeting Ly6G6D.

[0280] The term "antibody" is used in the broadest sense and encompasses various antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies) and antibody fragments (e.g., bisFab), as long as they exhibit the required antigen-binding activity.

[0281] The term "complementary determining region" or "CDR" refers to the amino acid residues in the variable region of an antibody that are responsible for antigen binding. Nanobodies contain three CDRs, named CDR1, CDR2, and CDR3. The precise boundaries of these CDRs can be defined according to various numbering systems known in the art, such as the Kabat numbering system (Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md., 1991), the Chothia numbering system (Chothia & Lesk (1987) J. Mol. Biol. 196:901-917; Chothia et al. (1989) Nature 342:878-883), or the IMGT numbering system (Lefranc et al., Dev. Comparat. Immunol. 27:55-77, 2003). For a given nanobody, those skilled in the art will readily identify the CDRs defined by each numbering system. Also, the correspondence between different numbering systems is well known to those skilled in the art (e.g., see Lefranc et al., Dev. Comparat. Immunol. 27:55-77, 2003).

[0282] The term "framework region" or "FR" residues refers to those amino acid residues in the variable region of an antibody other than the CDR residues defined as above. The FR of the variable domain typically consists of the following four FR domains: FR1, FR2, FR3, and FR4.

[0283] The term "specifically binds" refers to a non-random binding reaction between two molecules, such as the reaction between an antibody and the antigen it targets. The strength or affinity of a specific binding interaction can be expressed by the equilibrium dissociation constant (KD) of that interaction. In the present invention, the term "KD" refers to the dissociation equilibrium constant of a specific antibody-antigen interaction, which is used to describe the binding affinity between an antibody and an antigen. The smaller the equilibrium dissociation constant, the tighter the antibody-antigen binding and the higher the affinity between the antibody and the antigen.

[0284] The term "affinity" refers to the strength of the sum of non-covalent interactions between a single binding site of a molecule (e.g., an antibody) and its binding partner (e.g., an antigen). Unless otherwise specified, as used herein, "binding affinity" refers to the intrinsic binding affinity, which reflects the 1:1 interaction between the members of a binding pair (e.g., an antibody and an antigen). The affinity of molecule X for its partner Y is generally represented by the dissociation constant (KD). Affinity can be measured by conventional methods known in the art, including those described herein.

[0285] 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 containing an Fc region as defined herein.

[0286] The term "native antibody" refers to naturally occurring immunoglobulin molecules having different structures. For example, a native IgG antibody is a heterotetrameric glycoprotein of approximately 150,000 daltons, composed of two identical light chains and two identical heavy chains linked by disulfide bonds. From the N-terminus to the C-terminus, each heavy chain has a variable region (VH), also known as the variable heavy chain domain or heavy chain variable domain, followed by three constant domains (CH1, CH2, and CH3). Similarly, from the N-terminus to the C-terminus, each light chain has a variable region (VL), also known as the variable light chain domain or light chain variable domain, followed by a constant light chain (CL) domain. The light chains of an antibody can be assigned to one of two types based on the amino acid sequence of their constant domains, and these two types are called kappa (κ) and lambda (λ).

[0287] The terms "antibody fragment" and "antigen-binding fragment" are used interchangeably and refer to a molecule other than a full antibody that contains a portion of a full antibody and binds to an antigen to which the full antibody binds. Examples of antibody fragments include, but are not limited to: bisFab; Fv; Fab; Fab, Fab'-SH; F(ab')2; single-chain antibody molecules (e.g., scFv, ScFab); and multispecific antibodies formed from antibody fragments.

[0288] The Fab fragment is an antigen-binding fragment produced by pepsin digestion of an antibody and consists of the entire light chain and the variable domain of the heavy chain (VH) and the first constant domain of one heavy chain (CH1). Pepsin digestion of an antibody produces two identical Fab fragments. Pepsin treatment of an antibody produces a single large F(ab')2 fragment, which is roughly equivalent to two Fab fragments joined by a disulfide bond and having divalent antigen-binding activity and still being able to cross-link antigens. The Fab' fragment differs from the Fab fragment in that the Fab' fragment has some residues added at the carboxyl terminus of the CH1 domain, and these residues contain one or more cysteines from the antibody hinge region. Fab'-SH is the nomenclature used herein for Fab' in which the cysteine residue of the constant domain bears a free thiol group. The F(ab')2 antibody fragment was originally produced as a pair of Fab' fragments with hinge cysteines in between. Other chemical couplings of antibody fragments are also known.

[0289] "Fv" consists of a tightly, non-covalently associated dimer of a heavy-chain variable domain and a light-chain variable domain. The folding of these two domains gives rise to six hypervariable loops (3 loops are produced by each of the H chain and the L chain), and these loops contribute amino acid residues for antigen binding and confer antigen-binding specificity on the antibody. However, even a single variable domain (or half of the Fv, containing only three CDRs specific for the antigen) has the ability to recognize and bind antigens, although its affinity is often lower than that of the complete binding site.

[0290] The term "Fc region" is used to define the C-terminal region of an immunoglobulin heavy chain, which includes the native sequence Fc region and variant Fc regions. Although the boundaries of the Fc region of an immunoglobulin heavy chain may vary, the Fc region of a human IgG heavy chain is generally defined as extending from the amino acid residue at position Cys226 or from Pro230 to the carboxyl terminus of the heavy chain. The C-terminal lysine of the Fc region (residue 447 according to the EU numbering system) can be removed, for example, during the production or purification of an antibody or by recombinant engineering of the nucleic acid encoding the antibody heavy chain. Thus, the composition of a complete antibody can include a population of antibodies in which all Lys447 residues have been removed, a population of antibodies in which the Lys447 residues have not been removed, and a population of antibodies having a mixture of antibodies with and without Lys447 residues.

[0291] Light chains (LCs) derived from any vertebrate can be assigned to one of two distinct types based on the amino acid sequence of their constant domains, which are called κ and λ, respectively. Immunoglobulins can be assigned to different classes or isotypes based on the amino acid sequence of their heavy chain constant domains (CH). There are five classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, which have heavy chains called α, δ, γ, ε, and μ, respectively. The γ and α classes are further divided into subclasses based on relatively minor differences in CH sequence and function. For example, humans express the following subclasses: IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2.

[0292] The term "chimeric" antibody refers to an antibody in which a portion of the heavy and / or light chain is derived from a particular source or species, while the remainder of the heavy and / or light chain is derived from a different source or species.

[0293] The term "human antibody" refers to an antibody that has an amino acid sequence corresponding to that of an antibody produced by a human or a human cell, or an amino acid sequence of an antibody derived from a non-human source that utilizes a human antibody library or other human antibody-encoding sequences. This definition of a human antibody specifically excludes humanized antibodies that contain non-human antigen-binding residues.

[0294] The term "humanized" antibody refers to a chimeric antibody that contains amino acid residues from non-human HVRs and amino acid residues from human FRs. In some aspects, a humanized antibody will generally contain all of at least one, and usually two, variable domains, in which all or substantially all of the HVRs (e.g., CDRs) correspond to the HVRs of a non-human antibody, and all or substantially all of the FRs correspond to the FRs of a human antibody. In some aspects in which all or substantially all of the FRs of a humanized antibody correspond to the FRs of a human antibody, any FR of the humanized antibody may contain one or more amino acid residues from a non-human FR (e.g., one or more germline position residues of the FR). A humanized antibody optionally may contain at least a portion of an antibody constant region derived from a human antibody. An antibody in a "humanized form", e.g., a non-human antibody, refers to an antibody that has been humanized.

[0295] The terms "variable region" or "variable domain" refer to the domain of an antibody heavy or light chain that is involved in binding of the antibody to antigen. The variable domains of the heavy and light chains of a native antibody (VH and VL, respectively) generally have similar structures, each domain comprising four conserved framework regions (FRs) and three hypervariable regions (HVRs). (See, e.g., Kindt et al., Kuby Immunology, 6th ed., W.H. Freeman and Co., p. 91 (2007).) A single VH or VL domain may be sufficient to confer antigen-binding specificity. Moreover, antibodies that bind a particular antigen can be isolated using, respectively, the VH or VL domain from an antibody that binds that antigen to screen a library for a complementary VL or VH domain. See, e.g., Portolano et al. J. Immunol. 150:880-887, 1993; Clarkson et al. Nature 352:624-628, 1991.

[0296] The term "hypervariable region" or "HVR" refers to each of the regions within the variable domain of an antibody that are hypervariable in sequence (complementary determining regions or CDRs). Typically, an antibody comprises six CDRs; three in VH (H-CDR1, H-CDR2, H-CDR3), and three in VL (L-CDR1, L-CDR2, L-CDR3).

[0297] The term "single-chain Fv" also abbreviated "sFv" or "scFv", is an antibody fragment that comprises the VH and VL antibody domains joined in a single polypeptide chain. Preferably, the scFv polypeptide further comprises a polypeptide linker between the VH and VL domains, enabling the scFv to form the desired antigen-binding structure.

[0298] The term "monoclonal antibody" refers to an antibody obtained from a substantially homogeneous population of antibodies, i.e., each antibody of the population is identical and / or binds the same epitope, except for possible variant antibodies (e.g., containing naturally occurring mutations or arising during the production of the monoclonal antibody preparation, such variants are typically present in minor amounts). In contrast to polyclonal antibody preparations, which generally include different antibodies directed against different determinants (epitopes), each monoclonal antibody in a monoclonal antibody preparation is directed against a single determinant on an antigen. Thus, the modifier "monoclonal" indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies and is not to be construed as requiring production of the antibody by any particular method. For example, monoclonal antibodies useful in accordance with the present invention can be prepared by a variety of techniques, including but not limited to the hybridoma method, recombinant DNA methods, phage display methods, and methods utilizing transgenic animals containing all or part of the human immunoglobulin locus, such methods and other exemplary methods for preparing monoclonal antibodies are described herein.

[0299] The term "bispecific" antibody refers to an artificial antibody or antigen-binding fragment that has origins from two different monoclonal antibodies and is capable of binding to two different epitopes. The two epitopes may be present on the same antigen, or they may be present on two different antigens.

[0300] The term "multispecific antibody" is used in the broadest sense and specifically encompasses antibodies with multi-epitope specificity. In one aspect, a multispecific antibody binds to two different targets (e.g., a bispecific antibody). Such multispecific antibodies include, but are not limited to, antibodies comprising heavy chain variable domains (VH) and light chain variable domains (VL), where the VH / VL unit has multi-epitope specificity; antibodies having two or more VL and VH domains, where each VH / VL unit binds to a different epitope; antibodies having two or more single variable domains, where each single variable domain binds to a different epitope; full-length antibodies; antibody fragments such as Fab, Fv, dsFv, scFv, diabodies, bispecific diabodies, and triabodies; covalently or non-covalently linked antibody fragments.

[0301] The term "tumor" refers to all neoplastic cell growth and proliferation, whether malignant or benign, and all precancerous and cancerous cells and tissues. The terms "cancer", "cancerous", "cell proliferative disorder", "cell proliferative disease", "proliferative disorder", and "tumor" are not mutually exclusive in this context.

[0302] The terms "cancer" and "cancerous" refer to or describe a physiological condition in mammals that is typically characterized by uncontrolled cell growth / proliferation. Aspects of cancer include solid tumor cancers and non-solid tumor cancers. Solid cancer tumors include, but are not limited to, colorectal cancer, melanoma, breast cancer, lung cancer, head and neck cancer, bladder cancer, kidney cancer, ovarian cancer, pancreatic cancer, or prostate cancer, or metastatic forms thereof. Cancer may be LY6G6D-positive cancer.

[0303] In some aspects, the cancer is colorectal cancer. As used herein, the terms "colorectal cancer", "CRC", "colon cancer", or "bowel cancer" refer to cancer that develops from the large intestine, such as the colon or rectum.

[0304] "Effector function" refers to those biological activities that are attributable to the Fc region of an antibody and vary with the antibody isotype. Examples of antibody effector functions include: C1q binding and complement-dependent cytotoxicity (CDC); Fc receptor binding; antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; downregulation of cell surface receptors (e.g., B cell receptors); and B cell activation.

[0305] "Complement-dependent cytotoxicity" or "CDC" refers to the lysis of target cells in the presence of complement. Activation of the classical complement pathway begins with the binding of the first component of the complement system (C1q) to an antibody (appropriate subclass) that has bound to its cognate antigen.

[0306] "Antibody-dependent cell-mediated cytotoxicity" or "ADCC" refers to a form of cytotoxicity in which secreted Ig binds to Fc receptors (FcR) present on certain cytotoxic cells (e.g., natural killer (NK) cells, neutrophils, and macrophages), enabling these cytotoxic effector cells to specifically bind to antigen-bearing target cells, followed by killing of the target cells with cytotoxic agents. The antibody "arms" the cytotoxic cells and is required for such killing. The major cell mediating ADCC, the NK cell, expresses only FcγRIII, while monocytes express FcγRI, FcγRII, and FcγRIII.

[0307] The term "antibody-drug conjugate (ADC)" refers to the conjugation of the antibody with the effector molecule, and preferably a chemical conjugation. Wherein, the effector molecule is preferably a drug with therapeutic activity, such as one or more of a toxin protein, a chemotherapeutic drug, a small molecule drug, or a radionuclide.

[0308] As used herein, "delayed progression" of a disorder or disease means delaying, hindering, slowing, retarding, stabilizing, and / or postponing the development of a disease or disorder (e.g., a cell proliferative disorder, such as cancer). This delay can have different time lengths, depending on the medical history and / or the individual to be treated. It will be apparent to those skilled in the art that sufficient or significant delay can actually encompass prevention, since the individual will not develop the disease. For example, the development of advanced cancer, such as metastasis, may be delayed.

[0309] The term "treatment" (and its grammatical variants such as "treat" or "treating") refers to a clinical intervention that attempts to alter the natural course of the individual being treated and can be for prophylaxis 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, attenuating any direct or indirect pathological consequences of the disease, preventing metastasis, reducing the rate of disease progression, improving or alleviating the disease state, and relieving or improving the prognosis. In some aspects, the antibodies of the invention (e.g., the anti-LY6G6D antibodies of the invention) are used to delay the development of a disease or slow the progression of a disease.

[0310] An "effective amount" of a compound (e.g., an anti-LY6G6D antibody of the invention) or a composition thereof (e.g., a pharmaceutical composition) is at least the minimum amount required to obtain the desired therapeutic or prophylactic result, such as a measurable improvement or prevention of a particular disorder (e.g., a cell proliferative disorder, e.g., cancer). The effective amount herein can vary depending on factors such as the disease state, age, sex, and weight of the patient, as well as the ability of the antibody to elicit the desired response in an individual. The effective amount is also the amount at which the therapeutic beneficial effects exceed any toxic or detrimental effects of the treatment. For prophylactic use, beneficial or desired results include, for example, eliminating or reducing the risk, alleviating the severity, or delaying the onset of a disease, which includes the biochemical, histological, and / or behavioral symptoms of the disease, its complications, and intermediate pathological phenotypes that arise during the development of the disease. For therapeutic use, beneficial or desired results include clinical outcomes such as reducing one or more symptoms caused by the disease, improving the quality of life of the sufferer, reducing the dosage of other medications required to treat the disease, enhancing the effectiveness of other medications (such as by targeting, delaying disease progression, and / or prolonging survival). In the case of cancer or a tumor, an effective amount of a drug may reduce the number of cancer cells; reduce the tumor size; inhibit (i.e., slow down to some extent and hopefully stop) the invasion of cancer cells into surrounding organs; inhibit (i.e., slow down to some extent and hopefully stop) tumor metastasis; inhibit the growth of the tumor to some extent; and / or alleviate one or more symptoms associated with the condition to some extent. The effective amount can be administered in one or more doses. For the purposes of the present invention, an effective amount of a drug, compound, or pharmaceutical composition is an amount sufficient to directly or indirectly effect prophylaxis or treatment. As understood in a clinical context, a drug, compound, or pharmaceutical composition may or may not achieve an effective amount when combined with another drug, compound, or pharmaceutical composition. Thus, an "effective amount" can be considered in the context of administering one or more therapeutic agents, and a single agent can be considered to be administered in an effective amount if the desired result can be obtained or achieved when combined with one or more other agents.

[0311] A "purified" protein or peptide is a protein or peptide that has been separated from the components of its natural environment. In some aspects, the protein or peptide is purified to greater than 95% or 99% purity as determined, for example, by electrophoresis (e.g., SDS-PAGE, isoelectric focusing (IEF), capillary electrophoresis) or chromatography (e.g., ion exchange or reverse phase HPLC). A "purified" nucleic acid refers to a nucleic acid molecule that has been separated from the components of its natural environment. Purified nucleic acids include nucleic acid molecules that are contained in a cell that normally contains the nucleic acid molecule, but the nucleic acid molecule is present extrachromosomally or at a chromosomal location different from its natural chromosomal location.

[0312] The term "expression vector" refers to a nucleic acid vehicle into which a polynucleotide can be inserted. When the vector enables the expression of the protein encoded by the inserted polynucleotide, the vector is called an expression vector. The vector can be introduced into a host cell by transformation, transduction, or transfection, so that the genetic material elements carried by it can be expressed in the host cell. Vectors are well known to those skilled in the art and include, but are not limited to: plasmids; phagemids; cosmids; artificial chromosomes, such as yeast artificial chromosomes (YACs), bacterial artificial chromosomes (BACs), or P1-derived artificial chromosomes (PACs); phages such as lambda phage or M13 phage, and animal viruses, etc. Animal viruses that can be used as vectors include, but are not limited to, retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpesviruses (such as herpes simplex virus), poxviruses, baculoviruses, papillomaviruses, polyomaviruses (such as SV40). A vector can contain a variety of elements that control expression, including, but not limited to, promoter sequences, transcription initiation sequences, enhancer sequences, selection elements, and reporter genes. In addition, the vector can also contain an origin of replication.

[0313] The term "nucleic acid molecule" is intended to include DNA molecules and RNA molecules. The nucleic acid molecule can be single-stranded or double-stranded and can be cDNA.

[0314] The term "host cell" refers to a cell that can be used to introduce a vector, including, but not limited to, prokaryotic cells such as Escherichia coli or Bacillus subtilis, fungal cells such as yeast cells or Aspergillus, insect cells such as Drosophila S2 cells or Sf9, or animal cells such as fibroblast cells, CHO cells, COS cells, NSO cells, HeLa cells, BHK cells, HEK 293 cells, or human cells. The host cell can include a single cell or a cell population.

[0315] The terms "identity" or "sequence identity" are used to refer to the sequence match between two polypeptides or between two nucleic acids. When a position in both of the two sequences being compared is occupied by the same base or amino acid monomer subunit (e.g., a position in each of two DNA molecules is occupied by adenine, or a position in each of two polypeptides is occupied by lysine), then the molecules are identical at that position. The "percent identity" between two sequences is a function of the number of matching positions shared by the two sequences divided by the number of positions compared × 100. For example, if 6 of 10 positions in two sequences match, then the two sequences have 60% identity. Typically, the comparison is made when the two sequences are aligned to yield maximum identity. Such alignment can be achieved by using, for example, the method of Needleman et al. (1970) J. Mol. Biol. 48:443-453, which can be conveniently performed by computer programs such as the Align program (DNAstar, Inc.). The algorithm of E. Meyers and W. Miller (Comput. Appl. Biosci., 4:11-17 (1988)), incorporated into the ALIGN program (version 2.0), can also be used, with a PAM120 weight residue table, a gap length penalty of 12, and a gap penalty of 4, to determine the percent identity between two amino acid sequences. In addition, the algorithm of Needleman and Wunsch (J Mol Biol. 48:444-453 (1970)) incorporated into the GAP program in the GCG software package (available at www.gcg.com) can be used, with a Blossum 62 matrix or a PAM250 matrix, and gap weights of 16, 14, 12, 10, 8, 6, or 4 and length weights of 1, 2, 3, 4, 5, or 6, to determine the percent identity between two amino acid sequences.

[0316] The term "pharmaceutically acceptable carrier" refers to a carrier that is pharmacologically and / or physiologically compatible with the subject and the active ingredient, which is well known in the art (see, for example, Remington's Pharmaceutical Sciences. Edited by Gennaro AR, 19th ed. Pennsylvania: Mack Publishing Company, 1995), and includes but is not limited to: pH regulators, surfactants, adjuvants, ionic strength enhancers, diluents, osmotic pressure maintaining reagents, absorption delaying reagents, preservatives. For example, pH regulators include but are not limited to phosphate buffers. Surfactants include but are not limited to cationic, anionic or non-ionic surfactants, such as Tween-80. Ionic strength enhancers include but are not limited to sodium chloride. Preservatives include but are not limited to various antibacterial and antifungal agents, such as parabens, chlorobutanol, phenol, sorbic acid, etc. Osmotic pressure maintaining reagents include but are not limited to sugars, NaCl and its analogues. Absorption delaying reagents include but are not limited to monostearates and gelatin. Diluents include but are not limited to water, aqueous buffers (such as buffered saline), alcohols and polyols (such as glycerol), etc. Preservatives include but are not limited to various antibacterial and antifungal agents, such as thimerosal, 2-phenoxyethanol, parabens, chlorobutanol, phenol, sorbic acid, etc. Stabilizers have the meaning commonly understood by those skilled in the art, and can stabilize the desired activity of the active ingredient in the drug, including but not limited to sodium glutamate, gelatin, SPGA, sugars (such as sorbitol, mannitol, starch, sucrose, lactose, dextran, or glucose), amino acids (such as glutamic acid, glycine), proteins (such as dried whey, albumin or casein) or their degradation products (such as lactalbumin hydrolysate), etc. In certain exemplary embodiments, the pharmaceutically acceptable carrier includes a sterile injectable liquid (such as an aqueous or non-aqueous suspension or solution). In some exemplary embodiments, such sterile injectable liquids are selected from water for injection (WFI), bacteriostatic water for injection (BWFI), sodium chloride solution (such as 0.9% (w / v) NaCl), glucose solution (such as 5% glucose), solution containing a surfactant (such as 0.01% polysorbate 20), pH buffer solution (such as phosphate buffer solution), Ringer's solution and any combination thereof.

[0317] The term "subject" refers to a mammal, such as a primate mammal, such as a human. In some embodiments, the subject (such as a human) suffers from a disease related to Ly6G6D.

[0318] The term "administer" means a method of delivering a dose of a compound (e.g., an anti-LY6G6D antibody of the present invention) to a subject. In some aspects, the compositions used in the methods herein are administered intravenously. The compositions used in the methods described herein can be administered, for example, intramuscularly, intravenously, intradermally, transdermally, intraarterially, intraperitoneally, intralesionally, intracranially, intraarticularly, intraprostatically, intrapleurally, intratracheally, intranasally, intravitreally, intravaginally, rectally, topically, intratumorally, intraperitoneally, subcutaneously, subconjunctivally, intracapsularly, mucosally, pericardially, periumbilically, intraocularly, orally, topically, locally, by inhalation, by injection, by infusion, by continuous infusion, by direct lavage of target cells by local perfusion, by catheter, by lavage, in the form of an emulsion or a lipid composition. The method of administration can vary depending on a variety of factors (e.g., the compound or composition to be administered and the severity of the condition, disease, or disorder to be treated).

[0319] The embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings and examples. However, those skilled in the art will understand that the following drawings and examples are only for illustrating the present invention and not for limiting the scope of the present invention. According to the following detailed description of the drawings and preferred embodiments, various objects and advantageous aspects of the present invention will become practicable to those skilled in the art. Brief Description of the Drawings

[0320] Figure 1 It is a graph showing the binding result of a candidate antibody to the hLY6G6D antigen confirmed by ELISA;

[0321] Figure 2 It is a graph showing the binding result of a candidate antibody to the cynoLY6G6D antigen confirmed by ELISA;

[0322] Figure 3 It is a graph showing the binding result of HEK23T cells highly expressing hLY6G6D and a candidate antibody detected by flow cytometry;

[0323] Figure 4 It is a graph showing the binding result of HEK23T cells highly expressing cynoLY6G6D and a candidate antibody detected by flow cytometry;

[0324] Figure 5 It is a graph showing the result of evaluating the ADCC activity of a candidate molecule by the Jurkat-NFAT-Luc2-CD16 cell model. Detailed Description of the Embodiments

[0325] The solution of the present invention will be explained below in conjunction with embodiments. Those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. For those without specific technical or conditions noted in the embodiments, the techniques or conditions described in the literature in the art or according to the product specifications are followed. The reagents or instruments used without indicating the manufacturer can all be obtained through commercial purchase as conventional products.

[0326] Unless otherwise specified, the molecular biology experimental methods and immunoassay methods used in the present invention are basically carried out according to the methods described in J. Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Edition, Cold Spring Harbor Laboratory Press, 1989, and F.M. Ausubel et al., Current Protocols in Molecular Biology, 3rd Edition, John Wiley & Sons, Inc., 1995. Those skilled in the art know that the embodiments describe the present invention by way of example and are not intended to limit the scope claimed by the present invention.

[0327] Example 1: Screening of monoclonal antibodies against LY6G6D by phage display technology and flow cytometry

[0328] Monoclonal phages that can highly bind to LY6G6D at the molecular level were screened by panning a natural fully human phage display library in combination with ELISA method. The extracellular region coding genes of HumanLY6G6D and cynoLY6G6D proteins were designed using Uniprot and NCBI databases and constructed into a mammalian eukaryotic expression system. The extracellular regions of HumanLY6G6D and cynoLY6G6D proteins were expressed and used for screening the natural human antibody library. The heavy and light chain variable region sequences of the antibody were amplified from human PBMC, and the heavy and light chain gene fragments were linked by a Linker (specific example, the Linker has the amino acid sequence shown in SEQ ID NO: 112) to establish a natural human antibody phage library. The library was panned with HumanLY6G6D protein. After 4 rounds of panning, monoclonal phages that could bind to HumanLY6G6D were screened by the ELSIA method. The binding results of 16 candidate phages to HumanLY6G6D are shown in Table 1 below. From the results in Table 1, it can be seen that all 16 candidate phages of the present invention have good binding to HumanLY6G6D.

[0329] Table 1

[0330] Number 2E7 2G10 5C12 6C1 7B1 12A1 13A10 14A2 OD450 1.248 2.269 2.237 1.244 1.257 1.879 0.963 1.452 Number 14G2 14B5 16H6 17A11 18A11 19A4 20E2 22A6 OD450 1.254 0.838 1.16 1.19 1.551 1.425 0.989 1.412

[0331] Example 2: Expression and purification of antibodies

[0332] The 16 candidate phages obtained in Example 1 were sequenced to obtain the variable region sequences of the heavy and light chains encoding the antibody candidates. The single-chain antibody (VH-Linker1-VL-Linker2-Fc) gene coding sequence was synthesized by whole gene synthesis means, where VH has the amino acid sequence shown in any one of SEQ ID NOs: 77-92, VL has the amino acid sequence shown in any one of SEQ ID NOs: 93-108, Linker1 and Linker2 have the amino acid sequence shown in SEQ ID NO: 112, and Fc has the amino acid sequence shown in SEQ ID NO: 114. A series of antibody expression vectors were constructed by molecular cloning methods and recombinantly expressed in the 293F expression system. After resuscitating and culturing the 293F host cells with Optimem medium, when the cell density was about 3*10 6 cell / mL, the cells were collected and transfected with PEI reagent. On the second day of culture, feeding and adding glucose were performed until the culture concentration reached 8 g / L. On the 6th day of culture, the cell culture medium was collected.

[0333] A series of candidate antibodies were detected at the translational level. The collected cell culture medium was purified using a Protein A chromatography column, and the absorption peak was collected for mass spectrometry detection. The molecular weight of a series of candidate antibodies scFv-Fc was about 100 KDa, which was consistent with the theoretical molecular weight and was in the form of a dimer. At the same time, the collected samples were detected by 10% SDS-PAGE electrophoresis after reduction and non-reduction. The reduced SDS-PAGE electrophoresis pattern of the candidate antibody scFv-Fc showed a band at about 50 KDa, and the non-reduced SDS-PAGE electrophoresis pattern showed a single band at about 100 KDa. The size of the electrophoresis pattern band was consistent with the theory. The purified sample was dialyzed overnight at 4°C using 0.02 M PBS buffer at pH 7.4.

[0334] Example 3: Detection of the binding characteristics of the antibody to the antigen

[0335] The binding of the candidate antibodies obtained in Example 2 to the hLY6G6D antigen was confirmed by ELISA. The ELISA plate was coated with 100 ng / well of hLY6G6D and placed in an electrothermal constant temperature incubator at 37°C for 2 h, and then the non-specific binding sites were blocked overnight at 4°C with 5% skim milk powder. Different concentrations of mAb were incubated for 1 h, washed 3 times with 0.1% PBST, HRP-mouse anti-human IgG1 Fc was added to detect the bound mAb, then washed 5 times with 0.1% PBST, TMB substrate (Yunqiao Biotech) was added, the reaction was terminated after color development, and the absorbance was read at 450 nm. The results are as Figure 1 and Table 2-3 show, where Figure 1 A corresponds to Table 2, Figure 1B corresponds to Table 3. The affinity of the candidate antibody is comparable to that of the positive antibody 20A12, and among them, the antigen-binding activities of 17A11, 19A4, 20E2 and hLY6G6D are superior to those of the positive antibody 20A12. The positive control antibody 20A12 is from patent CN202080086360.1. The heavy chain of antibody 20A12 contains the amino acid sequence shown in SEQ ID NO:115, and the light chain of antibody 20A12 contains the amino acid sequence shown in SEQ ID NO:116;

[0336] EVQLLESGGGLVQPGGSLRLSCAASGFDFVNNAMIWVRQAPGKGLEWVSALSFADNTAYYATWASGRFTISRDSSKTTVYLQMNSLRAEDTAVYYCMRGDLWGPGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK(SEQ IDNO:115),

[0337] DIQMTQSPSTLSASVGDRVTITCQASESITRYLNWYQQKPGKAPKLLIYDASKLPSGVPSRFSGSGSGTEFTLTISSLQPDDFATYYCQSTSFRGRSYQNTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC(SEQ ID NO:116).

[0338] Table 2

[0339] Number 2E7 2G10 5C12 6C1 14B5 14G2 16H6 20A12 EC50 (nM) 14.27 1.605 10.78 8.882 4.383 1.667 2.873 7.89

[0340] Table 3

[0341] Number 7B1 12A1 17A11 18A11 19A4 20E2 22A6 20A12 EC50 (nM) 3.086 2.094 2.885 6.281 2.356 5.399 4.601 7.89

[0342] Example 4: Detection of the Binding Characteristics between Antibody and Antigen

[0343] Cross-reactivity detection with monkeys: The binding of the expressed candidate antibody (obtained from Example 2) to cynoLY6G6D antigen was confirmed by ELISA. Information on the positive control antibody 20A12 is shown in Example 3. ELISA plates were coated with 100 ng / well of cynoLY6G6D and placed in an electrothermal constant temperature incubator at 37 °C for 2 h, then non-specific binding sites were blocked with 5% skim milk overnight at 4 °C. Different concentrations of mAb were incubated for 1 h, washed 3 times with 0.1% PBST, HRP-mouse anti-human IgG1Fc was added to detect the bound mAb, then washed 5 times with 0.1% PBST, TMB substrate (Yunqiao Biotech) was added, the reaction was terminated after color development, and readings were taken at 450 nm. The results are as Figure 2 shown in Table 4-5, Figure 2 A corresponds to Table 4, Figure 2 B corresponds to Table 5. The candidate antibody 14B5 did not bind to cynoLY6G6D, while the other candidate antibodies and the positive antibody all bound to cynoLY6G6D.

[0344] Table 4

[0345] Number 2E7 7B1 12A1 14G2 17A11 19A4 20E2 20A12 EC50 (nM) 13.66 3.388 1.332 2.213 3.206 2.86 14.6 4.975

[0346] Table 5

[0347] Number 2G10 5C12 6C1 14B5 16H6 18A11 22A6 20A12 EC50 (nM) 0.4541 22.53 10.23 0.0204 86.34 31.53 2.047 4.975

[0348] Example 5: Detection of the Binding Characteristics between Antibody and Antigen

[0349] Flow cytometry was used to detect the binding of HEK23T cells highly expressing hLY6G6D to the candidate antibody (obtained from Example 2). Information on the positive control antibody 20A12 is shown in Example 3. 2×10 5 cells were resuspended in 96-well plates, incubated with different concentrations of mAb for 1 h, then the cells were washed 2 times in PBS. PE-Goat anti-human IgG Fc (Jackson ImmunoResearch) was diluted 1:500 and incubated at 4 °C for 30 min to detect the bound candidate antibodies, then the cells were washed 2 times in PBS and analyzed on FACS (beckman). The results are as Figure 3 shown in Table 6-7, Figure 3 A corresponds to Table 6, Figure 3Table 7 shows that the affinity of the candidate antibodies is comparable to that of the positive anti-20A12, and the binding activities of 19A4, 20E2, and hLY6G6D to positive HEK293T cells are better than those of the positive antibody 20A12.

[0350] Table 6

[0351] Number 2E7 2G10 5C12 6C1 7B1 13A10 14A2 18A11 20A12 EC50 (nM) 5.195 6.508 19.85 6.517 6.795 3.007 3.909 1.885 6.711

[0352] Table 7

[0353]

[0354]

[0355] Example 6: Detection of the Binding Characteristics between Antibodies and Antigens

[0356] Cross-reactivity detection with monkeys: Flow cytometry was used to detect the binding of HEK23T cells highly expressing cynoLY6G6D to the candidate antibodies (obtained from Example 2). Information on the positive control antibody 20A12 can be found in Example 3. 2×10 5 cells were resuspended in a 96-well plate, incubated with different concentrations of mAb for 1 h, then the cells were washed twice in PBS. PE-Goat anti-human IgG Fc (Jackson ImmunoResearch) was diluted 1:500 and incubated at 4 °C for 30 min to detect the bound antibodies. Then the cells were washed twice in PBS and analyzed on a FACS (beckman). The results are shown as follows. The candidate antibody 14B5 did not bind to cynoLY6G6D, while the other candidate antibodies and the positive antibody all bound to cynoLY6G6D. Figure 4 as shown. The candidate antibody 14B5 did not bind to cynoLY6G6D, while the other candidate antibodies and the positive antibody all bound to cynoLY6G6D.

[0357] Example 7: Evaluation of the ADCC Activity of Candidate Molecules Using the Jurkat-NFAT-Luc2-CD16 Cell Model

[0358] The Jurkat-NFAT-Luc2-CD16 reporter gene cell model was constructed by stably transfecting jurkat cells with the FcγRIIIa receptor and NFAT (nuclear factor of activated T cells) to evaluate the ADCC activity of candidate molecules.

[0359] Using the constructed hLY6G6D-HEK293T cells as target cells and Jurkat-NFAT-Luc2-CD16 cells as effector cells, seed the effector cells and target cells in a 384-well plate, with 5000 cells seeded in each well. Information on the positive control antibody 20A12 can be found in Example 3. Add dilutions of antibodies at different concentrations (obtained from Example 2) to the 384-well plate, and co-culture the effector cells and target cells in an incubator at 37°C and 5% carbon dioxide for 14 h. The antibody can specifically bind to hLY6G6D on the surface of the target cells, and the Fc end of the antibody can bind to the FcγRIIIa receptor on the surface of the effector cells, thereby forming a target cell-antibody-effector cell complex, activating the NFAT-Luc signaling pathway in the effector cells, so that the effector cells produce luciferase. Add the luciferase detection substrate, react for 3 min, and use a multifunctional microplate reader to read the luminescence values of each well. The results are as Figure 5 shown in Table 8-9, Figure 5 A corresponds to Table 8, Figure 5 B corresponds to Table 9. The ADCC activity of the candidate antibodies is comparable to that of the positive antibody 20A12, and the ADCC activities of 17A11 and 20E2 are superior to that of the positive antibody.

[0360] Table 8

[0361] Number 7B1 12A1 14B5 16H6 19A4 22A6 20A12 EC50 (nM) 0.0208 0.01893 0.02252 0.01525 0.02603 0.01231 0.01213

[0362] Table 9

[0363] Number 2E7 2G10 5C12 6C1 17A11 18A11 20E2 20A12 EC50 (nM) 0.005627 0.02368 0.08249 0.01506 0.007523 0.0265 0.007653 0.01213

[0364] In the description of this specification, the description referring to terms such as "some embodiments", "an embodiment", "some embodiments", "examples", "specific examples" or "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0365] Although the specific embodiments of the present invention have been described in detail, those skilled in the art will understand that: according to all the teachings that have been published, various modifications and changes can be made to the details, and these changes are within the protection scope of the present invention. The entire scope of the present invention is given by the appended claims and any equivalents thereof.

Claims

1. An anti-Ly6G6D antibody or antigen-binding fragment, characterized in that: The antibody or antigen-binding fragment binds to Ly6G6D, the antibody comprises a heavy chain and a light chain, wherein the heavy chain comprises a heavy chain variable region, and the heavy chain variable region comprises complementary determining regions: H-CDR1, H-CDR2 and H-CDR3; wherein, (1) H-CDR1 has the amino acid sequence shown in SEQ ID NO: 1, SEQ ID NO: 7, SEQ ID NO: 13, SEQ ID NO: 18, SEQ ID NO: 22, SEQ ID NO: 28, SEQ ID NO: 34, SEQ ID NO: 42, SEQ ID NO: 46, SEQ ID NO: 52, SEQ ID NO: 56, SEQ ID NO: 61 or SEQ ID NO: 71; and (2) H-CDR2 has the amino acid sequence shown in SEQ ID NO:2, SEQ ID NO:8, SEQ ID NO:14, SEQ ID NO:19, SEQ ID NO:23, SEQ ID NO:29, SEQ ID NO:35, SEQ ID NO:43, SEQ ID NO:47, SEQ ID NO:53, SEQ ID NO:57 or SEQ ID NO:72; and (3) H-CDR3 has the amino acid sequence shown in SEQ ID NO:3, SEQ ID NO:9, SEQ ID NO:15, SEQ ID NO:20, SEQ ID NO:24, SEQ ID NO:30, SEQ ID NO:36, SEQ ID NO:40, SEQ ID NO:44, SEQ ID NO:48, SEQ ID NO:54, SEQ ID NO:58, SEQ ID NO:62, SEQ ID NO:66 or SEQ ID NO:73; and Wherein, the light chain comprises a light chain variable region, and the light chain variable region comprises complementary determining regions: L-CDR1, L-CDR2 and L-CDR3; wherein, (1) L-CDR1 has the amino acid sequence shown in SEQ ID NO:4, SEQ ID NO:10, SEQ ID NO:25, SEQ ID NO:31, SEQ ID NO:37, SEQ ID NO:49, SEQ ID NO:59, SEQ ID NO:63, SEQ ID NO:68 or SEQ ID NO:74; and (2) L-CDR2 has the amino acid sequence shown in SEQ ID NO:5, SEQ ID NO:11, SEQ ID NO:16, SEQ ID NO:26, SEQ ID NO:32, SEQ ID NO:38, SEQ ID NO:50, SEQ ID NO:60, SEQ ID NO:64, SEQ ID NO:67, SEQ ID NO:69 or SEQ ID NO:75; and (3) L-CDR3 has the amino acid sequence shown in SEQ ID NO:6, SEQ ID NO:12, SEQ ID NO:17, SEQ ID NO:21, SEQ ID NO:27, SEQ ID NO:33, SEQ ID NO:39, SEQ ID NO:41, SEQ ID NO:45, SEQ ID NO:51, SEQ ID NO:55, SEQ ID NO:65, SEQ ID NO:70 or SEQ ID NO:

76.

2. The antibody or antigen-binding fragment according to claim 1, characterized in that The heavy chain variable region comprises complementarity determining regions: H-CDR1, H-CDR2 and H-CDR3; wherein, (1) H-CDR1 has the amino acid sequence shown in SEQ ID NO: 1, H-CDR2 has the amino acid sequence shown in SEQ ID NO: 2, and H-CDR3 has the amino acid sequence shown in SEQ ID NO: 3; or (2) H-CDR1 has the amino acid sequence shown in SEQ ID NO:7, H-CDR2 has the amino acid sequence shown in SEQ ID NO:8, and H-CDR3 has the amino acid sequence shown in SEQ ID NO:9; or (3) H-CDR1 has the amino acid sequence shown in SEQ ID NO: 13, H-CDR2 has the amino acid sequence shown in SEQ ID NO: 14, and H-CDR3 has the amino acid sequence shown in SEQ ID NO: 15; or (4) H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, H-CDR2 has the amino acid sequence shown in SEQ ID NO: 19, and H-CDR3 has the amino acid sequence shown in SEQ ID NO: 20; or (5) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:22, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:23, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:24; or (6) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:28, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:29, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:30; or (7) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:34, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:35, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:36; or (8) H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and H-CDR3 has the amino acid sequence shown in SEQ ID NO: 40; or (9) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:42, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:43, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:44; or (10) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:46, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:47, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:48; or (11) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:52, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:53, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:54; or (12) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:56, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:57, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:58; or (13) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:61, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:29, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:62; or (14) H-CDR1 has the amino acid sequence shown in SEQ ID NO: 18, H-CDR2 has the amino acid sequence shown in SEQ ID NO: 29, and H-CDR3 has the amino acid sequence shown in SEQ ID NO: 66; or (15) H-CDR1 has the amino acid sequence set forth in SEQ ID NO:18, H-CDR2 has the amino acid sequence set forth in SEQ ID NO:29, and H-CDR3 has the amino acid sequence set forth in SEQ ID NO:62; or (16) H-CDR1 has the amino acid sequence shown in SEQ ID NO:71, H-CDR2 has the amino acid sequence shown in SEQ ID NO:72, and H-CDR3 has the amino acid sequence shown in SEQ ID NO:

73.

3. The antibody or antigen-binding fragment according to claim 1, characterized in that The light chain variable region comprises complementarity determining regions: L-CDR1, L-CDR2 and L-CDR3; wherein, (1) L-CDR1 has the amino acid sequence shown in SEQ ID NO:4, L-CDR2 has the amino acid sequence shown in SEQ ID NO:5, and L-CDR3 has the amino acid sequence shown in SEQ ID NO:6; or (2) L-CDR1 has the amino acid sequence shown in SEQ ID NO: 10, L-CDR2 has the amino acid sequence shown in SEQ ID NO: 11, and L-CDR3 has the amino acid sequence shown in SEQ ID NO: 12; or (3) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:4, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:16, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:17; or (4) L-CDR1 has the amino acid sequence shown in SEQ ID NO:4, L-CDR2 has the amino acid sequence shown in SEQ ID NO:16, and L-CDR3 has the amino acid sequence shown in SEQ ID NO:21; or (5) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:25, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:26, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:27; or (6) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:31, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:32, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:33; or (7) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:37, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:38, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:39; or (8) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:37, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:38, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:41; or (9) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:37, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:38, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:45; or (10) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:49, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:50, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:51; or (11) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:37, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:38, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:55; or (12) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:59, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:60, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:51; or (13) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:63, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:64, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:65; or (14) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:37, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:67, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:41; or (15) L-CDR1 has the amino acid sequence set forth in SEQ ID NO:68, L-CDR2 has the amino acid sequence set forth in SEQ ID NO:69, and L-CDR3 has the amino acid sequence set forth in SEQ ID NO:70; or (16) L-CDR1 has the amino acid sequence shown in SEQ ID NO:74, L-CDR2 has the amino acid sequence shown in SEQ ID NO:75, and L-CDR3 has the amino acid sequence shown in SEQ ID NO:

76.

4. The antibody or antigen-binding fragment according to any one of claims 1 to 3, characterized in that: The antibody comprises at least one of a heavy chain framework region sequence and a light chain framework region sequence, and at least a portion of at least one of the heavy chain framework region sequence and the light chain framework region sequence is derived from at least one of a murine antibody, a human antibody, a primate antibody or a mutant thereof.

5. The antibody or antigen-binding fragment according to any one of claims 1 to 3, characterized in that: The antibody heavy chain variable region comprises an amino acid sequence having at least 85%, at least 90%, at least 95% or at least 99% sequence identity to any one of SEQ ID NOs: 77-92.

6. The antibody or antigen-binding fragment according to any one of claims 1 to 4, characterized in that: The antibody light chain variable region comprises an amino acid sequence having at least 85%, at least 90%, at least 95% or at least 99% sequence identity to any one of SEQ ID NOs: 93-108.

7. The antibody or antigen-binding fragment according to any one of claims 1 to 6, characterized in that: The antibody comprises at least one of a heavy chain constant region and a light chain constant region, at least a portion of at least one of the heavy chain constant region and the light chain constant region is derived from at least one of a murine antibody, a human antibody, a primate antibody or a mutant thereof; Preferably, the antibody heavy chain constant region and light chain constant region are both derived from human IgG antibody or a mutant thereof; More preferably, the antibody heavy chain constant region is from a human IgG1 or IgG4 antibody or a mutant thereof; More preferably, the antibody light chain constant region is derived from a human IgGκ or IgGλ constant region.

8. The antibody or antigen-binding fragment according to any one of claims 1 to 7, characterized in that: The antibody heavy chain comprises a heavy chain variable region and a constant region; the heavy chain variable region comprises an amino acid sequence having at least 85%, at least 90%, at least 95% or at least 99% sequence identity with any one of SEQ ID NOs: 77-92.

9. The antibody or antigen-binding fragment according to any one of claims 1 to 8, characterized in that: The antibody light chain comprises a light chain variable region and a constant region; the light chain variable region comprises an amino acid sequence having at least 85%, at least 90%, at least 95% or at least 99% sequence identity with any one of SEQ ID NOs: 93-108.

10. The antibody or antigen-binding fragment according to any one of claims 1 to 9, characterized in that: The antibody is a monoclonal antibody.

11. The antibody or antigen-binding fragment according to any one of claims 1 to 10, characterized in that: The antigen-binding fragment of the antibody is selected from the group consisting of: Fab, Fab'-SH, Fv and (Fab')2 fragments.

12. The antibody or antigen-binding fragment according to any one of claims 1 to 11, characterized in that: The antibody is a monospecific antibody, a bispecific antibody or a multispecific antibody.

13. An isolated nucleic acid molecule, characterized in that The nucleic acid molecule comprises a nucleotide sequence encoding the antibody or antigen-binding fragment of any one of claims 1-12.

14. An expression vector, characterized in that: The expression vector carries the nucleic acid molecule of claim 13.

15. A host cell, characterized in that The host cell comprises the nucleic acid molecule of claim 13 or the expression vector of claim 14.

16. A pharmaceutical composition, characterized in that The pharmaceutical composition comprises the antibody or antigen-binding fragment of any one of claims 1 to 12, the nucleic acid molecule of claim 13, the expression vector of claim 14 or the host cell of claim 15, and a pharmaceutically acceptable carrier.

17. Use of the antibody or antigen-binding fragment of any one of claims 1 to 12, the nucleic acid molecule of claim 13, the expression vector of claim 14, the host cell of claim 15 or the pharmaceutical composition of claim 16 in the preparation of a drug for treating a cell proliferative disease or delaying the progression of a cell proliferative disease.

18. The use according to claim 17, characterized in that The cell proliferative disorder is cancer.

19. The use according to claim 18, characterized in that The cancer is a Ly6G6D-positive cancer.

20. The use according to claim 19, characterized in that The Ly6G6D-positive cancer is colorectal cancer, head and neck cancer, ovarian cancer, cervical cancer, melanoma, gastric cancer, esophageal cancer, small intestine cancer, colon cancer or adenocarcinoma, etc.

21. An antibody-drug conjugate, characterized in that: The antibody-conjugate comprises the antibody or antigen-binding fragment of any one of claims 1-12.

22. A kit for detecting Ly6G6D, characterized in that: The kit comprises the antibody or antigen-binding fragment according to any one of claims 1 to 12.

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