Tyrosinase-derived peptide–Major Histocompatibility Complex Class I (Tyr-MHC I complex)

Tyrosinase-derived peptide–Major Histocompatibility Complex Class I (MHC I) complexes on plasmacytoid dendritic cells (pDCs) represent a specialized immunological target for melanoma immunotherapy. Tyrosinase is a rate-limiting enzyme in melanin production that is highly expressed in melanocytes and overexpressed in most melanoma cases, making its derived peptides (such as Tyr368-376) potent tumor-associated antigens (Tel et al., 2013, Cancer Research). When these peptides are processed and presented on the surface of pDCs via MHC I molecules, they serve as the primary signal for the activation and expansion of antigen-specific CD8+ cytotoxic T lymphocytes. Unlike conventional myeloid dendritic cells, pDCs are unique in their ability to produce high levels of Type I interferons, which further enhances the anti-tumor immune environment (Westdorp et al., 2014, Expert Review of Clinical Immunology). Therapeutic strategies targeting this complex often involve the administration of autologous pDCs loaded ex vivo with tyrosinase peptides to bypass tumor-induced immunosuppression and trigger a robust systemic immune response (Banchereau & Palucka, 2005, Nature Reviews Immunology). Clinical trials have demonstrated that vaccination with these complexes can lead to measurable T-cell responses and, in some cases, clinical regression of tumors. However, a notable safety concern is the development of vitiligo, an autoimmune condition where the immune system attacks healthy melanocytes expressing the same tyrosinase-MHC complexes.

Other names

Tyrosinase peptide-HLA-A*02:01 complexTyr-MHC I complexpDC-presented tyrosinase antigenTyrosinase-derived peptide–MHC complexes on plasmacytoid dendritic cells

Presentation of tumor-associated antigens to CD8+ T cells to induce a cytotoxic immune response against melanoma cells.