Described herein are interleukin-10 receptor-2 peptides, antibodies that bind the peptides, compositions including the peptides and antibodies and methods of use of the peptides and antibodies. The interleukin-10 receptor-2 peptide consists of an 8-15 amino acid sequence that includes TABLE-US-00001 SEQIDNO:1 ((I/V)P(P/K/V/E)P(E/K/R/Q)N(A/V)R), SEQIDNO:2 ((S/L/V)PAF(A/P)(K/Q)(G/T/E)(N/T/D)),or SEQIDNO:3 (PP(G/T/Q/V)(V/T/A)(R/H/T/S)(GN/NHP/SAA)).

A ligand includes each of the complementary-determining regions (CDRs) set forth in SEQ ID No. 1, SEQ ID No. 2, SEQ ID No. 3 SEQ ID No. 4, SEQ ID No. 5 and SEQ ID No. 6 or any sequence having either number of substituted aminoacids within said sequences as indicated in the following, from 0 to 3 in CDR1 (SEQ ID No.1), from 0 to 2 in CDR2 (SEQ ID No.2), from 0 to 2 in CDR3 (SEQ ID No.3), from 0 to 1 in CDR4 (SEQ ID No.4), from 0 to 4 in CDR5 (SEQ ID No.5), from 0 to 2 in CDR6 (SEQ ID No.6), or aminoacids substituted with other aminoacids having equivalent chemical functions and properties, within said sequences SEQ ID No. 1 to SEQ ID No. 6.

The invention relates to peptides, proteins, nucleic acids, and cells for use in immunotherapeutic methods. In particular, the invention relates to the immunotherapy of cancer. The invention provides T cell receptors (TCRs), tumor infiltrating lymphocytes (TILs), and vaccines that recognize HERV-K. The invention provides TCR sequences generated from tumor infiltrating lymphocytes that recognize HERV-K antigens as peptides bound to the Major Histocompatibility Complex (MHC), resulting in an interaction between the HLA-peptide complex and the CDS TCR. Peptides bound to molecules of the MHC, or peptides as such, can also be targets of antibodies, soluble TCRs, and other binding molecules.

The disclosure provides recombinant polypeptides that specifically bind to an envelope epitope of HERV-K HML-2, wherein such engineered polypeptides may be single-domain antibodies or immunoglobulin variable domains. The disclosure also provides CAR comprising such recombinant polypeptides. The disclosure further provides nucleic acid molecules that encode such recombinant polypeptides or CARs, and methods of making such recombinant polypeptides or CARs. The disclosure further provides pharmaceutical compositions that comprise such recombinant polypeptides or CARs, and methods of treatment using such recombinant polypeptides or CARs.