H-2 class I histocompatibility antigen, D-B alpha chain complexed with gp100 (25-33) peptide (H-2Db/gp100(25-33))

The H-2Db/gp100(25-33) peptide–MHC complex is a molecular assembly consisting of the mouse MHC class I molecule H-2Db and a 9-amino acid epitope (EGSRNQDWL) derived from the melanocyte-specific protein gp100, also known as PMEL (Restifo et al., 2012, Nature Reviews Immunology). This complex is a cornerstone of preclinical melanoma research, particularly in the B16 mouse model, where it serves as the primary target for the Pmel-1 TCR-transgenic T cell system. Its biological function is to present intracellularly processed tumor antigens to the immune system, specifically to CD8+ cytotoxic T lymphocytes. In therapeutic contexts, this complex is targeted by TCR-engineered T cells and various vaccine modalities designed to break immune tolerance against melanoma. Recognition of the complex by specific T-cell receptors triggers the activation and expansion of cytotoxic T cells, leading to the targeted destruction of melanoma cells. However, because gp100 is also expressed in healthy melanocytes, targeting this complex often results in 'on-target, off-tumor' effects, such as vitiligo or uveitis (Palmer et al., 2008, J Immunol). This target remains a vital tool for understanding T-cell exhaustion, memory formation, and the development of next-generation immunotherapies in murine models.

Other names

H-2Db/PMEL(25-33)H-2Db/EGSRNQDWLMHC-peptide complex H-2Db-gp100pMHC H-2Db/gp100H-2Db/gp10025-33

The complex acts as a specific ligand for T-cell receptors (TCRs), such as the Pmel-1 TCR, on CD8+ cytotoxic T lymphocytes. Binding triggers TCR signaling and the formation of an immunological synapse, leading to the release of cytotoxic granules (perforin and granzymes) that induce apoptosis in the target cell presenting the complex (Overwijk et al., 2003, J Exp Med).