Patient-specific tumor neoantigen–MHC complex (pMHC)

Patient-specific tumor neoantigen–MHC complexes are personalized therapeutic targets formed by the association of unique, mutation-derived peptides (neoantigens) with a patient's own Major Histocompatibility Complex (MHC) molecules. These complexes are presented on the surface of tumor cells, where they serve as non-self signals that can be recognized by the T-cell receptor (TCR) of cytotoxic CD8+ T cells (MHC Class I) or helper CD4+ T cells (MHC Class II) [1.2.1, 1.3.4]. In the context of immunotherapy, these complexes are also presented by professional antigen-presenting cells, such as dendritic cells, to prime and activate the patient's immune system against the tumor [1.5.2, 1.5.3]. Because neoantigens arise from somatic mutations unique to the cancer, they are absent from healthy tissues, minimizing the risk of central tolerance and off-target toxicity [1.2.2, 1.3.3]. Therapeutic strategies targeting these complexes include personalized neoantigen vaccines (mRNA, DNA, or peptide-based), which aim to expand the neoantigen-specific T-cell repertoire, and adoptive cell therapies like TCR-engineered T cells (TCR-T) [1.2.1, 1.3.4]. Despite their high specificity, challenges include the accurate prediction of immunogenic neoepitopes, the immunosuppressive tumor microenvironment, and potential tumor escape through the downregulation of MHC molecules [1.4.1, 1.5.2].

Other names

pMHC complexNeoepitope-MHC complexTumor-specific neoantigen-HLA complexPersonalized tumor neoantigenNeoAg-MHC complexTumor-specific antigen (TSA)-MHC complex

Induction of T cell-mediated anti-tumor immunity through the presentation of patient-specific mutated peptides on MHC Class I and II molecules, leading to the priming of CD8+ and CD4+ T cells and subsequent recognition and lysis of tumor cells [1.2.1, 1.3.4, 1.5.2].