Tumor-specific neoantigen-MHC class I complex (NeoAg-MHC-I)

Tumor-specific neoantigen-MHC class I complexes are molecular structures on the surface of malignant cells consisting of a somatic mutation-derived peptide bound to a Major Histocompatibility Complex (MHC) class I molecule [1]. These complexes are the fundamental units of recognition for the adaptive immune system, specifically for CD8+ cytotoxic T cells via their T-cell receptors (TCRs) [2]. Because neoantigens are derived from non-synonymous mutations unique to the tumor genome, these complexes are absent from healthy tissues, making them ideal targets for highly specific immunotherapy with minimal off-target effects [1, 3]. Therapeutic approaches include personalized neoantigen vaccines (mRNA, DNA, or peptide-based) that prime the patient's immune system to recognize these complexes, as well as adoptive cell therapies using TCR-engineered T cells (TCR-T) [3, 4]. Additionally, next-generation biologics such as bispecific T-cell engagers (BiTEs) and soluble TCRs are being developed to bridge T cells directly to these peptide-MHC targets [4]. Challenges in targeting these complexes include the high degree of HLA polymorphism among patients, the necessity for sophisticated bioinformatic pipelines to predict peptide binding, and tumor-mediated immune evasion through the downregulation of MHC expression [1, 2]. Despite these hurdles, targeting these complexes remains a cornerstone of precision oncology, offering a path toward truly individualized cancer treatment [3].

Other names

Patient-specific tumor antigens presented as peptide–MHC-I complexesNeoantigen-MHC complexTumor-specific antigen (TSA) complexpHLA-I complexNeoepitope-MHC complexPersonalized tumor-specific antigen-MHC complex

Induction of neoantigen-specific CD8+ T-cell responses or direct engagement of the complex by engineered receptors to mediate tumor cell lysis [2, 3].