Patient-specific tumor neoantigen peptides presented on MHC molecules (Neoantigen-MHC complex) (Neoantigen-MHC complex)

Patient-specific tumor neoantigen peptides presented on MHC molecules are unique protein fragments derived from somatic mutations—such as single nucleotide variants, insertions, or frameshifts—that occur exclusively within a patient's tumor cells (Schumacher & Schreiber, 2015, Science). These mutated sequences are processed by the cellular machinery and displayed on the cell surface by Major Histocompatibility Complex (MHC) class I or II molecules, where they serve as highly specific markers of malignancy (Sahin & Türeci, 2018, Science). Because these neoantigens are absent from the normal human proteome, they are recognized as foreign by the immune system, allowing for the induction of potent T-cell responses without the constraints of central thymic tolerance (Blass & Ott, 2021, Nature Reviews Clinical Oncology). This high degree of specificity makes them ideal targets for personalized immunotherapies, including mRNA-based vaccines, synthetic peptide vaccines, and adoptive T-cell receptor (TCR) therapies (Ott et al., 2017, Nature). In clinical practice, these targets are identified through whole-exome sequencing and bioinformatic algorithms that predict peptide-MHC binding affinity and immunogenicity (Hu et al., 2021, Nature Reviews Cancer). However, the effectiveness of targeting these complexes can be limited by tumor heterogeneity and the potential for tumors to escape immune detection through the downregulation of MHC molecules (Gubin et al., 2015, Journal of Clinical Investigation).

Other names

Tumor-specific antigensNeoepitopesMHC-restricted neoantigensPersonalized neoantigensTSAsTumor neoantigens

Induction of antigen-specific T-cell responses through T-cell receptor (TCR) recognition of the peptide-MHC complex, leading to the targeted destruction of tumor cells expressing the specific neoantigen.