Patient-specific tumor-associated antigen presented on peptide–MHC complex (pMHC)

Patient-specific tumor-associated antigens (TAAs) and neoantigens presented on peptide–MHC (pMHC) complexes are critical targets in personalized cancer immunotherapy (Nature Reviews Drug Discovery, 2021). These targets consist of short peptide fragments, derived from mutated or overexpressed proteins, displayed on the cell surface by Major Histocompatibility Complex molecules to be recognized by T-cell receptors (Science, 2019). Unlike standard antibody targets, pMHC complexes allow the immune system to detect intracellular oncogenic transformations, making them highly specific to the tumor's unique genetic profile (Journal of Hematology & Oncology, 2023). Therapeutic approaches include personalized vaccines that prime the patient's own immune system and adoptive T-cell therapies (TCR-T) that provide pre-engineered recognition of these complexes (Nature, 2022). These therapies are designed to trigger a robust cytotoxic T-lymphocyte response specifically against the malignant cells while sparing healthy tissue. While highly promising for precision medicine, the effectiveness of targeting pMHC is often challenged by tumor heterogeneity and the potential for the cancer to hide by downregulating its antigen presentation machinery (Frontiers in Immunology, 2020). Furthermore, the risk of off-target toxicity remains a concern if the targeted peptide shares structural similarity with self-antigens found in vital organs.

Other names

NeoantigenTumor-specific antigenTSATumor-associated antigenTAACancer-specific epitopeMutated self-antigenpMHC complex

Induction of antigen-specific T-cell responses via active immunization or direct targeting of the complex using engineered T-cell receptors (TCRs) and bispecific antibodies.