中文摘要：

目的：观察皮下注射胰岛素免疫干预对非肥胖糖尿病（non-obese diabetic，NOD）鼠胰岛炎、B细胞凋亡和糖尿病的影响，并探讨其诱导免疫耐受的机制。方法：60只NOD雌鼠随机分为胰岛素处理组（n=34）和磷酸盐缓冲液（phosphate buffered saline，PBS）对照组（n=28），分别于4周、12周、20周、28周皮下注射中效胰岛素优泌林N（Humulin N）6U（60μL）＋不完全弗氏佐剂（incomplete Freund＇s adjuvant，IFA）60μL，对照组予PBS（60μL）＋IFA（60μL）。于12周龄观察胰岛炎和胰岛B细胞凋亡；检测胰岛Fas和FasL的表达；测定血清IL-4和IFN-γ浓度，以及胰岛内I-Aβ^x7，IL-1β，IFN-γ，Fas，IL-4 mRNA的表达水平。结果：NOD鼠皮下注射胰岛素加IFA组30周龄和52周龄时发病率仅为21．4％和28．6％，而皮下PBS加IFA组为71．4％和85．7％（P〈0．05）。胰岛素组胰岛炎积分比对照组低，但差异无统计学意义（P〉0．05）。胰岛素组胰岛Fas抗原表达和B细胞凋亡率均比PBS对照组低（均P〈0．05）。胰岛素组胰岛内I-Aβ^x7，IFN-γ，IL-1β，FasmRNA表达较PBS对照组低（均P〈0．05），而IL-4mRNA表达较对照组高（P〈0．05）；胰岛素组血清IL-4比PBS组高，IFN-γ比PBS组低（均P〈0．05）。结论：皮下注射胰岛素能诱导NOD鼠的免疫耐受而预防糖尿病的发生，但不能阻断胰岛炎的进展。皮下注射胰岛素能诱导调节性T细胞产生，使全身和胰岛局部T细胞由，Th1向Th2转型，从而抑制Fas介导的B细胞凋亡而预防糖尿病。

英文摘要：

Objective To investigate the effects of subcutaneous administration of insulin on insulitis, 13 cell apoptosis and diabetes in non-obese diabetic （ NOD ） mice, and to explore the mechanism of immune tolerance induced by insulin. Methods Sixty female NOD mice were randomly divided into insulin group （n = 32 ） and phosphate buffered saline （PBS） group （ PBS group, n = 28）. Insulin was subcutaneously injected with humulin N （60μL, 6 U） ＋ IFA （60μL） at 4, 12, 20, and 28 weeks respectively, while the PBS group received PBS（60μL） ＋ IFA （60μL）. Insulitis and β cell apoptosis of islets were observed at 12 weeks. IL-4 and IFN-γ in the sera were measured by enzyme linked immunosorbent assay （ ELISA ） . The expression levels of I-Aβ^g7 , IL-4, IFN-γ, IL-1β, and Fas mRNA of islets were measured by reverse transcription-polymerase chain reaction （RT-PCR） at 12 weeks. Results The incidences in the insulin group were significantly lower than those in the PBS group （21.4% vs 71.4% at 30 weeks, 28.6% vs 85.7% at 52 weeks, P 〈0.05 ）. The insulitis scores in the insulin group were lower than those in the PBS group, but there was no statistical significance. Fas expresson on islets and apoptotic β cell rates in the insulin group were lower than those in the PBS group （P〈 0. 05 ）. In the insulin group, serum IL-4 levels were higher, but IFN-γ levels were lower than thdse in the PBS group （ P 〈0. 05 ）. The levels of I-Aβ^g7, IFN-γ, IL-1β and Fas mRNA transcription in islets were lower in insulin group, but IL-4 mRNA levels were higher than those in the PBS group （ P 〈 0.05 ）. Conclusion The specific autoantigen insulin may induce immune tolerance and prevent diabetes in NOD mice, but it can ＇ t block the progression of insulitis. Subcutaneous administration of insulin can induce the regulatory T cells, and make Thl to Th2 cytokine shifts in system and islets, thus preventing the Fas- mediated β-cell apoptosis and diabetes.