Antigens Targeted by Prevalent Pathogennic T Cells in Type 1 Diabetes and Uses Thereof

摘要

The present invention is based on the identification of a predominant ligand of CD8+ T cells that are responsible eq for type 1 diabetes. That ligand is islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP). Several CD8+ T cell-binding peptides from IGRP are identified, including the peptide comprising amino acids 206-214 of the IGRP sequence, which has high avidity to the most prevalent T cell receptor of pathogenic CD8+ T cells in autoimmune diabetes. The invention thus provides oligopeptide and polypeptide compositions comprising YLKTN/A/I/L/V)FL, FLWSVFWLI, (T/A)YY/G/T)FLNFM, LR(LV)(F/L)(G/N)IDLL, KWCANPDWI, and SFCKSASIP. Also provided are oligopeptide compositions 8-10 amino acids in length and completely homologous with a mammalian IGRP, where the oligopeptide is capable of binding a human MHC class I molecule. Additionally, various methods of treating a mammal using the above compositions are provided, where the mammal is at risk for or has type 1 diabetes. Also provided are methods of preventing a CD8+ T cell that is cytotoxic to pancreatic islet β-cells from destroying a mammalian β-cell, where the methods also use the above compositions. Further provided are methods for determining whether a mammal is at risk for or has type 1 diabetes, where the methods use the above compositions.