Peptide–major histocompatibility complex complex on tumor cell (pMHC complex)

Peptide–MHC complexes on tumor cells refer to cell-surface complexes formed when tumor-cell–derived peptides (including tumor antigens and neoepitopes) are presented by major histocompatibility complex (MHC) molecules, predominantly class I (MHC-I), to cytotoxic T lymphocytes (CD8+ T cells)[2][3][6][7]. These complexes play a central role in tumor immunosurveillance: they allow T cells to recognize and kill tumor cells displaying non-self or mutated peptides, a process fundamental to adaptive immune responses and also exploited by many cancer immunotherapies (such as TCR-T cell therapy, cancer vaccines, and TCR mimic antibodies)[3][5][6]. The specificity and immunogenicity of tumor pMHC complexes determine their effectiveness as targets. Tumors can evade immune responses by downregulating MHC expression or altering antigen processing components, making the understanding of these complexes critical for cancer therapy design[4][7]. Certain pMHC complexes have been specifically targeted in therapy (e.g., NY-ESO-1/HLA-A*02:01), and their expression can serve as both therapeutic targets and biomarkers for patient selection and monitoring[5][6].

Other names

peptide–MHC complexpMHCpeptide–major histocompatibility complex complex

Recognition of tumor cell–associated peptides by cytotoxic T lymphocytes via TCR engagement of peptide–MHC class I complexes, leading to tumor cell killing[2][3][6]. Therapeutic agents may block, mimic, or redirect TCR recognition of tumor-specific pMHC complexes[5][6].