NY-ESO-1 peptide–major histocompatibility complex class I complex

The **NY-ESO-1 peptide–major histocompatibility complex (MHC) class I complex** refers to a molecular structure where a peptide fragment derived from the cancer/testis antigen NY-ESO-1 (commonly NY-ESO-1 157–165 peptide, sequence SLLMWITQC) is bound and presented by the peptide-binding groove of a human MHC class I molecule (typically HLA-A*02:01)[2][3][6]. This complex is displayed on the surface of tumor cells, where it is recognized by cytotoxic CD8+ T cells through their T cell receptors, initiating immune-mediated killing of the presenting cell[5][6]. The NY-ESO-1 antigen is notable for its restricted expression in normal tissues (testis and placenta) but frequent re-expression in a wide range of cancers, making the NY-ESO-1 peptide–MHC complex a prominent target for immunotherapy approaches, including TCR-engineered T cells, peptide vaccines, and bispecific engagers[1][3][5]. Mechanistically, drugs targeting this complex enable highly specific immunological recognition and elimination of tumor cells expressing both the antigen and the relevant HLA allele; however, issues such as antigen/HLA loss or limited tumor specificity can create challenges for therapy efficacy and safety[4][5].

Other names

NY-ESO-1 pMHC complexNY-ESO-1 peptide–MHC complexHLA-A2/NY-ESO-1(157–165) complexNY-ESO-1/HLA-A*0201 complexNY-ESO-1 cancer/testis antigen 1B peptide–MHC complexCTAG1B peptide–MHC

Presentation of NY-ESO-1–derived peptide by MHC class I enables recognition by specific cytotoxic T lymphocytes, leading to targeted tumor cell killing[1][3][5]. Therapeutic TCRs or BiTEs bind to the peptide–MHC complex, redirecting immune activity toward cancer cells displaying this epitope[1][5].