Tumor-associated antigen peptide–human leukocyte antigen complex

A tumor-associated antigen peptide–human leukocyte antigen (HLA) complex consists of a short peptide (often derived from a tumor-specific antigen) presented on the cell surface by an HLA molecule, which is a product of the major histocompatibility complex (MHC). The complex can be recognized by T cell receptors (TCRs) on cytotoxic or helper T cells, leading to immune activation, tumor cell killing, or modulation of tolerance. These complexes form the molecular basis of several cancer immunotherapies, including peptide vaccines, adoptive T cell therapy, and antibody-based approaches. The immune response efficacy is highly dependent on the specific peptide sequence, HLA allele, conformational dynamics of the peptide–HLA binding groove, and potential modifications (e.g., phosphorylation). Tumor cells can evade this immune recognition by downregulating HLA expression or presenting altered peptides, posing significant challenges for therapeutic efficacy and patient safety.

Other names

Tumor antigen peptide–HLA complexTumor-associated peptide–MHC complexTumor-antigen/HLA complexPeptide/MHC complex

Specific cytotoxic T lymphocyte (CTL) recognition and cell lysis via TCR engagement with tumor antigen peptide–HLA class I complex; CD4+ T cell activation via peptide–HLA class II complexes; Induction of immune response leading to tumor cell killing or immune modulation