THE IMMUNOLOGICAL STUDY OF GULUTAMIC ACID DECARBOXYLASE SPECIFIC T LYMPHOCYTES IN THE ETIOLOGY OF JUBENILE DIABETES

I型糖尿病被认为是一种由T淋巴细胞对抗胰腺β细胞介导的自身免疫性疾病。近年来，谷氨酸脱羧酶（glutamic acid decarboxylase， GAD）被确定为1型糖尿病患者抗体的主要自身抗原。在这项研究中，我们重点研究了T淋巴细胞对日本1型糖尿病患者GAD的作用。将外周血分离的t淋巴细胞与胰岛素、大鼠胰岛素瘤细胞（RIN）匀浆或GAD在含RPMI培养基的10% AB型人血清中培养7天。在第7天，测量^ 3h -胸苷的摄取。1型糖尿病患者对GAD的T淋巴细胞反应明显强于健康对照组。未观察到对胰岛素的显著反应。对RIN的反应在患者中有较高的趋势，但不显著。采用ELISA法检测上清液中细胞因子的分泌情况。结果淋巴细胞分泌γ -干扰素，但白细胞介素4。我们曾尝试制作GAD特异性T细胞克隆，但目前尚未成功，但成功制作了GAD特异性T细胞系。流式细胞术分析显示，这些细胞系由CD4^+ t淋巴细胞和CD8^+ t淋巴细胞组成。这些结果表明，1型糖尿病患者外周血中存在GAD特异性CD4^+和CD8^+ T淋巴细胞。抗广泛性焦虑症的细胞免疫可能在1型糖尿病的发病机制中起作用。

Type I diabetes is thought to be an autoimmune disease mediated by T lymphocytes against pancreatic beta cells. Recently, glutamic acid decarboxylase (GAD) was identified as a major autoanitigen of antibody existing in Type 1 diabetes patients. In this study, we focused on the T lymphocytes against GAD in Japanese Type 1 diabetes.Tlymphocytes isolated from peripheral blood were cultured with insulin, rat insulinoma cell (RIN) homogenate, or GAD in 10% AB type human serum contained RPMI medium for 7 days. At 7days, ^3H-Thymidine uptake was measured. T lymphocyte response against GAD in Type 1 diabetes patients was significantly stronger than that in healthy controls. The significant response against insulin was not observed. The response against RIN showed higher tendency in the patients but not significant. The secretion of cytokines in the supernatant during the response against GAD were measured by ELISA.In results, the lymphocytes secreted gamma-interferon but interleukin 4.We tried to make the GAD specific T cell clones but failed at the present time, but succeeded to make the GAD specific T cell lines. The flow cytometry analysis revealed that these cell lines were composed of CD4^+ Tlymphocytes and CD8^+ Tlymphocytes.These results indicated that GAD specific CD4^+ and CD8^+ T lymphocytes exist in the peripheral blood of Type diabetes I patients. The cellular immunity against GAD may play a role in the pathogenesis of Type 1 diabetes.