Premelanosome protein (PMEL)-derived peptide–Histocompatibility 2, D region locus b (H2-Db) complex (gp100/H2-Db)

The Premelanosome protein (PMEL)-derived peptide–Histocompatibility 2, D region locus b (H2-Db) complex is a murine peptide-major histocompatibility complex (pMHC) that serves as a critical target in preclinical melanoma research (Overwijk et al., 2003 [2]). It is composed of a specific epitope, typically the gp100_25-33 peptide (EGSRNQDWL), derived from the premelanosome protein (PMEL, also known as gp100) bound to the H2-Db MHC class I molecule (UniProt Q60696 [1]). PMEL is a lineage-specific protein involved in the maturation of melanosomes and is highly expressed in both normal melanocytes and melanoma cells (Restifo et al., 2004 [3]). This complex is the cognate antigen for the Pmel-1 T-cell receptor (TCR), making it the standard model for studying adoptive T-cell therapy and cancer vaccines in C57BL/6 mice (Overwijk et al., 2003 [2]). Therapeutic strategies targeting this complex aim to induce a potent cytotoxic T-lymphocyte (CTL) response against tumor cells (NIH NCI [4]). Recognition of this complex by specific TCRs triggers a signaling cascade leading to the release of perforin and granzymes, resulting in the apoptosis of the target cell. However, because the target is also present in healthy pigmented tissues, treatment can lead to autoimmune side effects such as vitiligo and ocular inflammation (Restifo et al., 2004 [3]).

Other names

gp100:H2-Db complexPMEL:H2-Db complexgp100(25-33)/H-2DbpPMEL:H2-DbMelanocyte protein PMEL peptide-MHC complex

The complex is recognized by the T-cell receptor (TCR) of CD8+ T cells, specifically the Pmel-1 TCR, which triggers a signaling cascade leading to the release of perforin and granzymes, resulting in the apoptosis of the target cell (Overwijk et al., 2003 [2]).