MC38-derived neoantigen–Major Histocompatibility Complex class I complex (MC38 neoantigen-MHC-I)

MC38-derived neoantigen–MHC class I complexes are molecular assemblies consisting of mutated peptides derived from the MC38 murine colon adenocarcinoma cell line bound to Major Histocompatibility Complex (MHC) class I molecules, specifically H-2Kb or H-2Db. These complexes serve as the primary signal for CD8+ cytotoxic T cells to identify and eliminate tumor cells, acting as highly specific markers of malignancy (Gubin et al., Nature, 2014). Common neoantigens presented in this model include mutated versions of proteins like Adpgk and Dpagt1, which are generated through somatic mutations and processed via the endogenous antigen presentation pathway (Yadav et al., Nature, 2014). In therapeutic contexts, these complexes are the focal point for personalized immunotherapy, including neoantigen-based vaccines and TCR-engineered T-cell therapies designed to amplify the immune system's natural anti-tumor capacity (Schumacher & Schreiber, Science, 2015). The presence and density of these pMHC complexes on the cell surface are critical determinants of the efficacy of immune checkpoint inhibitors, which work by reinvigorating T cells that recognize these specific targets. However, tumors may evolve to escape detection by downregulating MHC expression or losing the expression of the neoantigen itself, posing a significant challenge for sustained therapeutic success.

Other names

MC38 tumor-specific neoantigen-MHC complexMC38 neoepitope-H-2 complexMC38 pMHC-IMutated peptide-MHC class I complex

The complex acts as a specific ligand for T-cell receptors (TCRs) on CD8+ cytotoxic T lymphocytes; binding triggers the formation of an immunological synapse, leading to the release of cytotoxic granules (perforin and granzymes) and the subsequent apoptosis of the tumor cell.