Tyrosinase peptide–HLA class I complex (TYR-HLA-I complex)

Tyrosinase peptide–HLA class I complexes are specialized molecular targets found on the surface of melanoma cells, formed when the intracellular enzyme tyrosinase is processed into short peptides and presented by Human Leukocyte Antigen (HLA) molecules. Tyrosinase is a rate-limiting enzyme in melanin synthesis and is highly overexpressed in the melanocyte lineage, particularly in malignant melanoma, making these complexes ideal neoantigen-like targets for immunotherapy (PMID: 25108441). Because the peptide is presented within the groove of an HLA molecule (most commonly HLA-A*02:01), it can be specifically recognized by the T-cell receptors (TCRs) of cytotoxic T lymphocytes. Therapeutic interventions targeting these complexes include TCR-engineered T-cell (TCR-T) therapies and bispecific T-cell engagers designed to bypass traditional immune checkpoints and directly induce tumor cell lysis (PMID: 30104343). However, since tyrosinase is also expressed in healthy melanocytes, clinical use of these therapies carries a risk of on-target, off-tumor toxicities such as vitiligo or ocular inflammation. Despite these challenges, the high specificity and prevalence of these complexes in melanoma patients make them a cornerstone of modern adoptive cell therapy research (PMID: 21422470).

Other names

Tyrosinase-derived peptide-MHC complexTYR-MHC class I complexTyrosinase-HLA-A*02:01 complexpMHC complex (Tyrosinase)

T-cell receptor (TCR) mediated recognition of the peptide-HLA complex leading to T-cell activation and cytotoxic lysis of the target tumor cell.