Tyrosinase peptide-Major Histocompatibility Complex (TYR-MHC)

Tyrosinase is a copper-containing enzyme that serves as the rate-limiting catalyst in melanin biosynthesis, primarily localized within melanocytes and frequently overexpressed in malignant melanoma (UniProt P14679). Peptides derived from the proteolytic degradation of tyrosinase are processed and presented on the cell surface by Major Histocompatibility Complex (MHC) molecules, most notably the HLA-A*02:01 allele (PubMed: 8144862). This peptide-MHC complex functions as a specific ligand for T-cell receptors (TCRs) on CD8+ cytotoxic T lymphocytes, making it a significant target for cancer immunotherapy. Therapeutic approaches targeting this complex include TCR-engineered T-cell therapies (TCR-T), peptide-based vaccines, and bispecific T-cell engagers designed to redirect the immune system against melanoma cells. Clinical development of these therapies, such as the IMA101 multi-target program, focuses on patients whose tumors express both the tyrosinase antigen and the appropriate HLA restriction element. However, because tyrosinase is also expressed in normal melanocytes in the skin and uveal tract, targeting this complex can lead to on-target, off-tumor toxicities, including vitiligo and uveitis (PubMed: 10426999). Monitoring tyrosinase expression and HLA status is essential for patient selection and assessing therapeutic efficacy.

Other names

Tyrosinase-derived peptide-MHC complexTYR-HLA complexTyrosinase-derived epitopeMelanoma-associated antigen tyrosinaseHLA-A*02:01/Tyrosinase peptide complex

T-cell receptor binding and activation of cytotoxic T-cell mediated lysis of target cells presenting tyrosinase-derived peptides.