Tumor-associated antigen-Major Histocompatibility Complex peptide complex (TAA-MHC) (TAA-pMHC)

Tumor-associated antigen-Major Histocompatibility Complex (TAA-MHC) peptide complexes are the primary molecular targets for T-cell-based immunotherapies, including Dendritic Cell (DC)-activated Cytokine-Induced Killer (CIK) cells [PMID: 11511851]. These complexes consist of a short peptide fragment derived from a tumor-specific or tumor-associated protein bound within the groove of an MHC (or HLA in humans) molecule on the surface of a cancer cell [PMID: 25910249]. Recognition of these complexes by the T-cell receptor (TCR) of DC-activated CIK cells triggers a cascade of signaling events leading to the release of cytotoxic granules, such as perforin and granzymes, and the induction of apoptosis in the target tumor cell [PMID: 1825311]. DC activation of CIK cells enhances the specificity and potency of the immune response by presenting these antigens in a highly stimulatory context, bridging innate and adaptive immunity [PMID: 11511851]. This target is central to the development of personalized cancer vaccines and adoptive cell transfer therapies. However, challenges include the heterogeneity of antigen expression and the potential for tumor cells to downregulate MHC molecules to evade immune detection [PMID: 25609815]. Clinical success often requires precise HLA matching and the identification of antigens with minimal expression in vital healthy tissues to avoid off-target effects.

Other names

pMHCPeptide-MHC complexTumor antigen-HLA complexAntigen-MHC complexTAA-HLA complexTumor-specific antigen-MHC complex

The mechanism involves the specific binding of the T-cell receptor (TCR) on DC-activated CIK cells to the TAA-MHC complex on the tumor cell surface, which triggers the activation of the CIK cell and the subsequent release of cytotoxic molecules like perforin and granzymes to induce tumor cell lysis [PMID: 11511851, 25910249].