Diabetes 56:2551-2560, 2007 DOI: 10.2337/db07-0332 © 2007 by the American Diabetes Association
In Vivo Cytotoxicity of Insulin-Specific CD8+ T-Cells in HLA-A*0201 Transgenic NOD Mice
1 Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York Address correspondence and reprint requests to Teresa P. DiLorenzo, PhD, Albert Einstein College of Medicine, Microbiology and Immunology, 1300 Morris Park Ave., Bronx, NY 10461. E-mail: dilorenz{at}aecom.yu.edu
Abbreviations:
CFSE, carboxyfluorescein diacetate succinimidyl ester; ELISPOT, enzyme-linked immunospot; IFN, interferon; IGRP, islet-specific glucose-6-phosphatase catalytic subunit-related protein; MHC, major histocompatibility complex
OBJECTIVE—CD8+ T-cells specific for islet antigens are essential for the development of type 1 diabetes in the NOD mouse model of the disease. Such T-cells can also be detected in the blood of type 1 diabetic patients, suggesting their importance in the pathogenesis of the human disease as well. The development of peptide-based therapeutic reagents that target islet-reactive CD8+ T-cells will require the identification of disease-relevant epitopes.
RESEARCH DESIGN AND METHODS—We used islet-infiltrating CD8+ T-cells from HLA-A*0201 transgenic NOD mice in an interferon- RESULTS—We found that HLA-A*0201-restricted T-cells isolated from the islets of the transgenic mice were specific for Ins1 L3–11, Ins1 B5–14, and Ins1/2 A2–10. Insulin-reactive T-cells were present in the islets of mice as young as 5 weeks of age, suggesting an important function for these specificities early in the pathogenic process. Although there was individual variation in peptide reactivity, Ins1 B5–14 and Ins1/2 A2–10 were the immunodominant epitopes. Notably, in vivo cytotoxicity to cells bearing these peptides was observed, further confirming them as important targets of the pathogenic process. CONCLUSIONS—The human versions of B5–14 and A2–10, differing from the murine peptides by only a single residue, represent excellent candidates to explore as CD8+ T-cell targets in HLA-A*0201–positive type 1 diabetic patients.
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