Tissue-Specific Self-Peptides Bound by Major Histocompatibility Complex Class I Molecules of a Human Pancreatic β-cell Line

The process of β-cell destruction in IDDM is mediated, in part, by CD8⁺ T-cells. Structural characterization of HLA-I-bound self-peptides presented by the human β-cell line HP-62 was performed to identify possible tissue-specific autoantigens in the context of CD8⁺ T-cell/HLA-I interactions. The sequences of the β-cell line HLA-I-bound peptides were compared with sequence databases. Six of the obtained sequences showed homology to known precursor proteins, three of which—GLUT2 receptor, phosphatidylinositol-glycan-specific phospholipase D, and 5-hydroxytryptamine-1F receptor—have a limited, tissue-specific expression. These HLA-bound self-peptides may be part of a pool of autoantigens recognized by β-cell reactive cytotoxic T-cells.