Melanoma-associated antigen recognized by T cells 1 (MART-1) peptide–HLA-A*0201 complex (MART-1/Melan-A–HLA-A*0201)

The MART-1/Melan-A peptide–HLA-A*0201 complex is a specific peptide-major histocompatibility complex (pMHC) that plays a central role in the immune system's recognition of melanoma (Kawakami et al., 1994). MART-1 (Melanoma-associated antigen recognized by T cells 1) is a melanocyte differentiation antigen that is overexpressed in most melanoma tumors (UniProt Q16655). The specific decamer peptide, typically MART-1 26-35, is presented by the HLA-A*0201 molecule, a common MHC class I allele, on the surface of both tumor cells and dendritic cells (Sliz et al., 2001). On dendritic cells, this complex is vital for the activation and clonal expansion of MART-1-specific CD8+ cytotoxic T lymphocytes (CTLs) (PubMed: 15150594). Therapeutic interventions, such as TCR-engineered T-cell therapies and peptide-based vaccines, specifically target this complex to direct the immune system to destroy melanoma cells (Rosenberg et al., 2011). However, because MART-1 is also expressed in healthy melanocytes, such therapies can result in "on-target, off-tumor" toxicities, including vitiligo and uveitis (Johnson et al., 2009). Monitoring for HLA-A*0201 status and MART-1 expression is essential for patient selection in these targeted clinical approaches (ClinicalTrials.gov). This complex serves as a primary model for understanding antigen-specific T-cell responses in human cancer immunotherapy.

Other names

MART-1/HLA-A2 complexMelan-A/HLA-A*02:01 complexMART-1(26-35)/HLA-A2MART-1(27-35)/HLA-A2Melanoma antigen recognized by T cells 1 peptide–HLA-A*0201 complexMART-1/Melan-A peptide–HLA-A*0201 complex on dendritic cells

Recognition by specific T-cell receptors (TCRs) on CD8+ T cells, triggering the release of cytotoxic granules such as perforin and granzymes to induce apoptosis in target cells presenting the complex.