Patient-specific tumor neoantigen peptides presented on MHC class I and II molecules (NeoAg-MHC)

Patient-specific tumor neoantigen peptides are unique protein fragments derived from somatic mutations, such as single nucleotide variants, insertions, or deletions, that occur exclusively within a patient's tumor cells. These peptides are processed and presented on the cell surface by Major Histocompatibility Complex (MHC) class I and II molecules, where they serve as highly specific targets for the adaptive immune system (Nature Reviews Cancer, 2021). Because these neoantigens are not present in the normal human proteome, they are recognized as foreign by T cells, bypassing central tolerance and reducing the risk of autoimmune reactions compared to traditional tumor-associated antigens (NEJM, 2017). In modern oncology, these complexes are the foundation for personalized immunotherapy, including mRNA-based vaccines and engineered TCR-T cell therapies, which are designed to prime the immune system to recognize and eliminate the patient's specific tumor profile. The identification of these targets requires advanced genomic sequencing and bioinformatic algorithms to predict which mutations will result in peptides with high binding affinity for the patient's specific HLA alleles (Cell, 2019). Consequently, they represent a cornerstone of precision medicine, offering a path toward highly individualized and potent cancer treatments.

Other names

NeoepitopesTumor-specific antigens (TSAs)Mutation-derived antigensMHC-restricted neoantigensPersonalized tumor antigens

Therapeutic agents such as personalized vaccines or TCR-T cell therapies aim to induce or expand a population of CD8+ cytotoxic T cells and CD4+ helper T cells that specifically recognize these mutated peptide-MHC complexes, leading to the selective lysis of tumor cells while sparing healthy tissue (Nature, 2017; Science, 2015).