title: Vaccination with a co-expression DNA plasmid containing GAD65 fragment gene and IL-10 gene induces regulatory CD4(+) T cells that prevent experimental autoimmune diabetes.
abstract: The non-obese diabetic (NOD) mouse is a commonly used animal model for studying type 1 diabetes (T1D). The aims of our study were to explore the diabetes-preventive effect in NOD mice and the potential mechanisms of an optimized co-expression DNA vaccine containing GAD65 fragment gene with the IL-10 gene (SGAD65190-315 /IL-10).
  
  
  
  Female NOD mice at the age of 3-4 weeks old were randomly divided into two groups and received intra-muscular injection of either blank pBudCE4.l vector (n = 34) or pBudCE4.l carrying the SGAD65190-315 /IL-10 (n = 32). The incidence of diabetes was monitored up to 30 weeks of age. The severity of insulitis, apoptosis rate of β cells and relevant mechanisms were examined.
  
  
  
  Administration with SGAD65190-315 /IL-10 blocked the onset of autoimmune diabetes in NOD mice, significantly suppressed islet inflammation, inhibited the apoptosis of islet β cells, induced immune tolerance to autoantigen GAD65 and proinsulin and shifted the Th1/Th2 balance towards Th2. More importantly, the frequencies of CD4(+) CD25(+) Foxp3(+) regulatory T cells (Tregs) in the spleen and pancreatic lymph nodes in vaccine-immunized mice were significantly increased, and these Tregs were GAD65-reactive. In addition, Treg depletion by anti-CD25 mAb administration abolished the protective effects of SGAD65190-315 /IL-10 on diabetes and insulitis. Moreover, depletion of CD4(+) CD25(+) T cells using magnetic-activated cell sorting impaired the protective effect of SGAD65190-315 /IL-10 vaccination on adoptive transfer of diabetes.
  
  
  
  Our data suggested that SGAD65190-315 /IL-10 DNA vaccine had protective effects on T1D by upregulating autoantigen-reactive Tregs. Our findings may provide a novel preventive therapy for T1D. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha, Hunan, China, 410011.
authors.forename: Xinyuan
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha, Hunan, China, 410011.
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha, Hunan, China, 410011.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha, Hunan, China, 410011.
authors.forename: Peilin
authors.identifier: 0000-0002-4712-4903
authors.initials: P
authors.lastname: Zheng
authors.affiliation: Department of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha, Hunan, China, 410011.
authors.forename: Fang
authors.initials: F
authors.lastname: Hu
authors.affiliation: Department of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha, Hunan, China, 410011.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology* / Q000517:prevention & control; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000276:immunology* / Q000517:prevention & control; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D005968:Glutamate Decarboxylase / Q000235:genetics*; D006801:Humans; D007108:Immune Tolerance; D016753:Interleukin-10 / Q000235:genetics*; D008213:Lymphocyte Activation; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D010957:Plasmids / Q000008:administration & dosage*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D014611:Vaccination; D019444:Vaccines, DNA / Q000008:administration & dosage
chemical_list: D051858:Forkhead Transcription Factors; C556062:IL10 protein, mouse; D019444:Vaccines, DNA; D016753:Interleukin-10; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2
keywords: DNA vaccine; GAD65; regulatory T cells; type 1 diabetes