KLRB1 binding agents and methods of use thereof
KLRB1 binding agents (in particular anti-KLRB1-antibodies and antigen binding portion thereof) with increased humanness and compositions thereof, as well as therapeutic methods of using the agents, e.g., for depleting cells or inhibiting cells or activating cells, (in particular, Th17, Th17.1, ex-Th17, Tc17, MAIT, iNKT, peTh2, ILC2, ILC3, NK cells, and/or neoplastic T or NK cells in vivo), for the treatment of autoimmune disease, allergic diseases, transplant rejection, hematologic malignancies, and cancer.
1 . An antibody that specifically binds to killer cell lectin-like receptor subfamily B, member 1 (KLRB1), the antibody comprising:
a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 68, and
a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 65.
2 . The antibody of claim 1 , wherein the antibody comprises an afucosylated Fc region.
3 . The antibody of claim 2 , wherein the antibody binds to Fc gamma receptor (FcγR) and induces antibody dependent cell-mediated cytotoxicity.
4 . The antibody of claim 2 , wherein the antibody binds to C1q and induces complement dependent cytotoxicity.
5 . The antibody of claim 1 , wherein the antibody is a full-length antibody, a Fab fragment, or a single-chain variable fragment (scFv).
6 . The antibody of claim 1 , wherein the antibody is of the class IgG, IgA, IgM, or IgE.
7 . The antibody of claim 1 , wherein the antibody comprises a heavy chain (HC) constant region.
8 . The antibody of claim 7 , wherein the HC constant region is a constant region of human IgG1.
9 . The antibody of claim 7 , wherein the HC constant region comprises the amino acid sequence of SEQ ID NO: 4.
10 . The antibody of claim 1 , wherein the antibody comprises a light chain (LC) constant region.
11 . The antibody of claim 10 , wherein the LC constant region is a constant region of human Igκ.
12 . The antibody of claim 10 , wherein the LC constant region comprises the amino acid sequence of SEQ ID NO: 7.
13 . The antibody of claim 1 , wherein the antibody comprises a HC comprising the amino acid sequence of SEQ ID NO: 98, and a LC comprising the amino acid sequence of SEQ ID NO: 102.
14 . The antibody of claim 1 , wherein the antibody binds to and depletes Th17 cells, Th17.1 cells, ex-Th17 cells, Tc17 cells, mucosal-associated invariant T (MAIT) cells, innate lymphoid cells type 2 (ILC2), innate lymphoid cells type 3 (ILC3), pathogenic effector Th2 (peTh2) cells, or NK cells expressing KLRB1.
15 . The antibody of claim 1 , wherein the antibody binds to and depletes neoplastic T cells or neoplastic NK cells expressing KLRB1.
16 . The antibody of claim 1 , wherein the antibody binds to and depletes invariant NK-T (iNKT) cells expressing KLRB1.