Patient-specific tumor-associated antigen peptide–Major Histocompatibility Complex class I (pTAA-MHC-I)

Patient-specific tumor-associated antigen peptide–MHC class I complexes are molecular assemblies on the surface of cancer cells that present intracellular protein fragments to the immune system. These complexes are composed of a peptide derived from a tumor-specific mutation (neoantigen) or an overexpressed tumor-associated antigen (TAA) bound to a Major Histocompatibility Complex (MHC) class I molecule (Ott et al., 2017). In metastatic melanoma, these complexes are critical for the recognition and elimination of malignant cells by CD8+ cytotoxic T lymphocytes. Therapeutic interventions, such as personalized neoantigen vaccines (e.g., mRNA-4157) and TCR-engineered T-cell therapies, are designed to enhance the immune system's ability to identify these specific complexes (Sahin & Türeci, 2018). While highly specific, the efficacy of targeting these complexes can be limited by tumor-mediated immune evasion, such as the loss of MHC expression or the emergence of antigen-negative clones (Blass & Ott, 2021). Understanding the landscape of these complexes is essential for developing precision immunotherapies tailored to the unique mutational profile of an individual patient's tumor. These targets represent the pinnacle of personalized medicine, as they allow for the redirection of the host immune system against the specific genetic signature of the malignancy.

Other names

Neoantigen-MHC complexTumor-specific antigen-HLA complexpMHC complexPersonalized tumor antigen-MHC complexHLA-peptide complexHLA-restricted tumor antigen

Recognition by T-cell receptors (TCRs) on CD8+ T cells, triggering cytotoxic activity and apoptosis of the target tumor cell (Sahin & Türeci, 2018).