Patient-specific tumor neoantigen peptide-MHC class I complex (NeoAg-MHC I complex)

Patient-specific tumor neoantigen peptides presented on MHC class I molecules are unique protein fragments derived from somatic mutations within a patient's tumor cells [1]. These peptides are processed intracellularly and displayed on the cell surface by Major Histocompatibility Complex (MHC) class I molecules, where they serve as "non-self" signals to the immune system [2]. Their primary biological function in the context of immunotherapy is to act as targets for CD8+ cytotoxic T lymphocytes, which recognize the mutant peptide-MHC complex via specific T-cell receptors (TCRs) [3]. Because these neoantigens are absent from normal tissues, they provide a high degree of tumor specificity, reducing the likelihood of off-target autoimmune toxicity compared to shared tumor-associated antigens [4]. In disease states, tumors often evolve mechanisms to evade detection by downregulating MHC expression or losing the specific neoantigen [1]. Therapeutic interventions targeting these complexes include personalized vaccines (mRNA, DNA, or peptide-based) and adoptive cell therapies, such as TCR-engineered T cells [1,3]. These treatments aim to expand the repertoire of neoantigen-specific T cells to achieve durable anti-tumor responses [2]. The identification and selection of these targets require advanced genomic sequencing and predictive algorithms to determine peptide binding affinity and immunogenicity [4].

Other names

Tumor-specific neoantigen (TSA)Neoepitope-MHC I complexPersonalized tumor antigenMutant peptide-HLA class I complexpMHC I complexTumor-specific antigen (TSA) presented on MHC I

Induction of neoantigen-specific cytotoxic T lymphocyte (CTL) responses through the presentation of tumor-specific mutant peptides to T-cell receptors (TCRs).