不同剂量谷氨酸脱羧酶对非肥胖型糖尿病小鼠发生1型糖尿病的影响

目的不同剂量谷氨酸脱羧酶(GAD)对非肥胖型糖尿病小鼠(NOD)糖尿病免疫干预效果的影响。方法将3周龄40只体重(10.0±0.9)g雌性NOD小鼠分为4组分别腹腔注射GAD0.3mU和不完全弗氏佐剂(IFA)50μL、GAD3mU+IFA50μL、GAD0.03mU+IFA50μL、IFA50μL。8周龄时注射环磷酰胺200mg/kg加速糖尿病,定期检测血糖,眼内眦取血分离血清检测细胞因子白细胞介素(IL)4和干扰素(IFNγ)的变化,动态观察各组糖尿病发生发展的过程。28周时,全部处死,取脾、胸腺作淋巴细胞亚群测定,胰腺作病理组织学观察。结果GAD3mU+IFA50μL组小鼠无一只发生糖尿病,28周时血糖为(5.0+1.1)mmol/L;胰岛个数最多(8.2+2.3)个/张(P<0.01),胰岛炎评分最低(0.33+0.12)(P<0.01);血清中IL4的水平最高为(80+6)ng/L(P<0.01),IFNγ水平最低为(327±48)ng/L;CD8+/CD4+比值最大(P<0.01),在脾脏中为0.524±0.133,胸腺中为0.428±0.021。结论NOD小鼠在3周龄时腹腔注射CAD3mU+IFA50μL混合物比其他剂量组免疫调节效果好,较好地通过调节胸腺,脾淋巴细胞亚群分类,并通过淋巴细胞分泌Th1类因子和Th2类因子来调节Th0细胞的转化,从而抑制NOD小鼠胰岛炎,胰岛β细胞破坏减少,GAD3mU剂量组免疫干预NOD小鼠糖尿病的发生效果最好。

Different doses of glutamate decarboxylase to effect the incidence of diabetes in NOD mice

Objective Different doses of glutamate decarboxylase (GAD) effect the incidence of diabetes in NOD mice,the paper is to survey the immunoregulatory effect.Methods Forty female NOD mice of three week old were divided into 4 groups at random.In group 1 mice were given GAD 0.3 mU+incomplete Freund′s adjuvant (IFA) 50μL;in group 2 mice were given GAD 3 mU+IFA 50 μL;in group 3 mice were given GAD 3 mU+IFA 50 μL;in group 4 mice were given IFA 50 μL as control group.Blood glucose and the serum levels of IL 4 and IFN γ were measured at regular intervals.At the age of 28 weeks,mice were killed and the subsets of T cell in spleen and in thymus were determined by two clolor fluorescence activated cell sorting (FACS) analysis.Pancreatic histopathologic studies were performed by hematoxylin eosin staining.Results Group 2 got the lowest incidence of diabetes.In group 2,mice that were given GAD 3 mU+IFA 50 μL had kept balanced level of blood glucose.The serum levels of IL 4 were increased significantly,and IFN γ increased slowly.The lymphocytic inflammation of pancreatic islets in group 2,and the insulitis score decreased markedly (P<0 01).A strong proliferative response of CD8 + subsets in splenocytes occurred in group 2,and CD8 +/CD4 + ratio was the largest among all the groups (P<0 01).Conclusion GAD 3 mU+IFA 50 μL group is the best among the all groups to prevent the onset of type 1 diabetes and to reduce the risk of insulitis in female NOD mice.Its mechanism may be that lymphocytes secrete Th1 and Th2 which regulate Th0 cell′s transformation,thus inhibiting the NOD mice′s insulitis and reducing islet β cell injuries.The group GAD 3 mU showed the best immunointervention effect on the diabetic onset in NOD mice.