Research Article Identification of Candidate Tolerogenic CD8 + T Cell Epitopes for Therapy of Type 1 Diabetes in the NOD Mouse Model Cailin Yu, 1 Jeremy C. Burns, 1 William H. Robinson, 2,3 Paul J. Utz, 2 Peggy P. Ho, 4 Lawrence Steinman, 4 and Alan B. Frey 1 1 Department of Cell Biology, New York University Langone School of Medicine, 550 First Avenue, New York, NY 10016, USA 2 Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA 3 Geriatric Research Education and Clinical Center, Veterans Affairs, Palo Alto Health Care System, Palo Alto, CA 94304, USA 4 Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA Correspondence should be addressed to Alan B. Frey; alan.frey@nyumc.org Received 20 January 2016; Accepted 16 February 2016 Academic Editor: Georgia Fousteri Copyright © 2016 Cailin Yu et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Type 1 diabetes is an autoimmune disease in which insulin-producing pancreatic islet  cells are the target of self-reactive B and T cells. T cells reactive with epitopes derived from insulin and/or IGRP are critical for the initiation and maintenance of disease, but T cells reactive with other islet antigens likely have an essential role in disease progression. We sought to identify candidate CD8 + T cell epitopes that are pathogenic in type 1 diabetes. Proteins that elicit autoantibodies in human type 1 diabetes were analyzed by predictive algorithms for candidate epitopes. Using several different tolerizing regimes using synthetic peptides, two new predicted tolerogenic CD8 + T cell epitopes were identified in the murine homolog of the major human islet autoantigen zinc transporter ZnT8 (aa 158–166 and 282–290) and one in a non- cell protein, dopamine -hydroxylase (aa 233–241). Tolerizing vaccination of NOD mice with a cDNA plasmid expressing full-length proinsulin prevented diabetes, whereas plasmids encoding ZnT8 and DH did not. However, tolerizing vaccination of NOD mice with the proinsulin plasmid in combination with plasmids expressing ZnT8 and DH decreased insulitis and enhanced prevention of disease compared to vaccination with the plasmid encoding proinsulin alone. 1. Introduction Several dozen autoantigens related to type 1 diabetes have been described [1] engendering interest in developing an immunotherapeutic treatment. Phase III clinical trials in newly diagnosed patients using noncomplement fixing anti- CD3 Ab failed to achieve primary endpoints [2]. Together with heightened risks to patients receiving any type of systemic immunosuppression, this setback for nonspecific immunological control of disease progression in patients emphasizes the impetus to explore optimization of antigen- specific immunotherapy for prevention and treatment of type 1 diabetes [3–5]. Experimental immunotherapies that target individual antigens have been tested [6] but which have also proven disappointing; phase III GAD vaccination trials failed [7, 8] and preclinical studies targeting Hsp60 (p277) showed some disease protection [9] but a late stage clinical trial study was retracted [10]. More promisingly, preclinical [11] and phase I/II [12] trials using tolerogenic DNA plasmids encoding proinsulin showed encouraging improvement in subject C-peptide levels. Since CD8 + T cells play a causal role in diabetogene- sis [13] an important goal in development of an effective immunotherapy is identification of specific epitopes that elicit diabetogenic CD8 + T cells. A substantial number of candidate MHC Class I epitopes have been identified in both the NOD mouse [14] and patients [1] including multiple peptides derived from  cell antigens that elicit robust Ab response in patients as well as other candidate antigens not exclu- sively expressed in  cells [15, 16]. Humoral responses are successfully used clinically to forecast disease susceptibility [13, 17], and since adaptive B cell response usually requires T Hindawi Publishing Corporation Journal of Diabetes Research Volume 2016, Article ID 9083103, 12 pages http://dx.doi.org/10.1155/2016/9083103