Tumor-associated antigen peptide–HLA-A2 complex (null)

Tumor-associated antigen peptide–HLA-A2 complex refers to a molecular structure formed when a peptide derived from a tumor-associated antigen (TAA) is presented at the cell surface in the peptide-binding groove of the HLA-A2 class I major histocompatibility complex (MHC) molecule. These complexes are recognized by T-cell receptors (TCRs) on cytotoxic T lymphocytes (CTLs), enabling the immune system to discriminate and target tumor cells. Their surface exposure and essential immunological role make them key therapeutic targets in cancer immunotherapy, for both engineered T cells and TCR-mimic antibodies. The nature and conformation of the peptide bound in the HLA-A2 groove can impact TCR recognition and immunogenicity, often requiring precise structural characterization for optimal therapeutic design[1][2][3][4]. Each complex is specific to the peptide sequence and the presenting HLA-A2 allele, and only some peptide/HLA-A2 combinations serve as clinically actionable targets.

Other names

pHLA-A2 complexTumor antigen/HLA-A2 complexPeptide/MHC class I (HLA-A2) complexTumor peptide-HLA-A*02:01 complex (for allele-specificity)

Direct recognition and killing by cytotoxic T lymphocytes (CTLs) whose TCRs recognize specific tumor antigen peptides bound to HLA-A2[1][2][3][4] Targeting by TCR-mimic antibodies, which bind the specific pHLA-A2 complex on tumor cells to mediate immune cell killing or deliver cytotoxic payloads[4] Immunization (peptide vaccines) to stimulate an endogenous T-cell response against tumor cells expressing the target[1][2]