Peptide–Major Histocompatibility Complex class I (pMHC-I) presenting oncogene-derived tumor-associated antigens (pMHC-I complexes)

Peptide–Major Histocompatibility Complex class I (pMHC-I) complexes presenting oncogene-derived tumor-associated antigens are specialized molecular assemblies on the surface of malignant cells that display intracellular protein fragments to the immune system. These complexes consist of a polymorphic HLA heavy chain, β2-microglobulin, and a short peptide derived from mutated oncogenes (neoantigens) or overexpressed proteins like MAGE-A4 or NY-ESO-1 [3][5]. In the context of oncology, they function as critical 'flags' that allow the immune system to distinguish between healthy and cancerous cells. Because these peptides are often derived from proteins essential for tumor survival or specific to the tumor's genetic mutations, they represent highly specific therapeutic targets [2][4]. Modern immunotherapies, including TCR-engineered T-cells and bispecific T-cell engagers, are designed to recognize these specific pMHC-I configurations to direct a potent immune response against the tumor [1][6]. However, the effectiveness of these therapies is often limited by the requirement for specific patient HLA types and the potential for tumors to evade detection by downregulating their antigen-presentation machinery [4][5].

Other names

HLA-peptide complexesTumor-specific antigen-MHC complexesNeoantigen-MHC complexespMHC complexesOncogene-derived peptide-HLA complexes

These complexes serve as the primary recognition site for T-cell receptors (TCRs) or TCR-mimic antibodies. Therapeutic agents such as TCR-engineered T-cells (TCR-T) or bispecific T-cell engagers (e.g., ImmTACs) bind specifically to the peptide-HLA interface, triggering the activation of cytotoxic T lymphocytes to induce apoptosis in the target tumor cell [1][3].