Patient-specific neoantigen peptide–Major Histocompatibility Complex (Neoantigen-pMHC)

Patient-specific neoantigen peptide–Major Histocompatibility Complex (pMHC) complexes are unique molecular targets formed when somatic mutations in a patient's tumor create novel, "non-self" peptides that are subsequently presented on the cell surface by MHC molecules (Nature Reviews Cancer, 2017). Unlike shared tumor-associated antigens, these neoantigens are entirely absent from the healthy proteome, providing a high degree of tumor specificity and reducing the risk of central tolerance or autoimmune toxicity (Frontiers in Immunology, 2020). These complexes serve as the primary recognition signal for the adaptive immune system, specifically for CD8+ and CD4+ T-cells via their T-cell receptors (TCRs). Therapeutic interventions targeting these pMHCs include personalized mRNA or peptide vaccines designed to expand endogenous neoantigen-specific T-cells, as well as adoptive cell therapies using TCR-engineered T-cells (Nature, 2023). The clinical utility of these targets is highly dependent on the tumor's mutational burden and the efficiency of the cellular antigen processing machinery (Nature Reviews Drug Discovery, 2021). Despite their promise, challenges include the requirement for sophisticated bioinformatic pipelines to predict immunogenic neoepitopes and the potential for tumor escape through the loss of HLA expression (Science, 2017).

Other names

Tumor-specific neoantigen-HLA complexNeoepitope-MHC complexMutation-derived antigen-MHC complexTSA-MHC complexPersonalized neoantigen-pMHC

Activation of the adaptive immune system through the interaction of T-cell receptors (TCRs) with tumor-specific mutated peptides presented by MHC molecules, leading to the expansion of cytotoxic T-lymphocytes and selective lysis of tumor cells.