Tumor-associated antigen peptide-MHC class I complex (TAA-pMHC-I)

Tumor-associated antigen (TAA) peptide-MHC class I complexes are critical targets in cancer immunotherapy, representing the presentation of intracellular protein fragments on the cell surface for immune recognition. These complexes consist of a short peptide, typically 8 to 11 amino acids in length, derived from mutated, overexpressed, or lineage-specific proteins, which is bound within the groove of a Major Histocompatibility Complex (MHC) class I molecule [3, 4]. This presentation mechanism allows CD8+ cytotoxic T lymphocytes to monitor the internal proteome of a cell and eliminate those displaying abnormal or foreign signatures. In clinical practice, these complexes are targeted by advanced modalities such as T-cell receptor (TCR) engineered T-cells and bispecific T-cell engagers like Tebentafusp, which specifically binds the gp100 peptide presented by HLA-A*02:01 [1, 2]. Because MHC molecules are highly polymorphic, these therapies are often restricted to patients with specific human leukocyte antigen (HLA) types. While highly effective at directing the immune system to solid tumors, challenges include the potential for off-target cross-reactivity with similar peptides in healthy tissues and the ability of tumors to evade detection by downregulating MHC expression [4].

Other names

Tumor-associated antigenspMHC class I complexCancer-testis antigen peptide-MHCNeoantigen-MHC complexTumor-specific antigen peptide-MHCHLA-peptide complex

Engagement of T-cell receptors (TCRs) or TCR-mimetic antibodies to induce cytotoxic T-lymphocyte (CTL) mediated lysis of tumor cells; induction of adaptive immune response via peptide vaccination.