Ou D, Mitchell L A, Metzger D L, Gillam S, Tingle A J
Department of Paediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Diabetologia. 2000 Jun;43(6):750-62. doi: 10.1007/s001250051373.
AIMS/HYPOTHESIS: To examine the cross-reaction between viral and beta-cell protein determinants and to further understand the potential role of this mechanism in Type I (insuline-dependent) diabetes mellitus.
Immune responses to a panel of 28 viral and beta-cell protein peptides representing selected sequences of rubella virus (RV), Coxsackie virus, human 38 KDa31G and glutamic acid decarboxylase (GAD 65 and 67) proteins in proliferation or cytotoxicity assays have been studied using uncloned and cloned T-cell cohorts from a group of 60 Type I diabetic patients.
Peptide GAD65(252-266) induced the responses of patients with recent onset diabetes in proliferation assays at the highest frequency (77%), whereas GAD67(212-226) stimulated the cellular responses at the highest rate (61%) in patients with late-onset diabetes. RVE1(157-176) was recognised by all groups of patients at the highest frequency and the largest amplitude among the viral peptides tested. T-cell clones specific to GAD65(252-266), GAD65(274-286) or GAD67(212-226) were tested in cytotoxicity assays for their responses to rubella virus peptides. Each of these T-cell clones cross-reacted with two to four rubella virus peptides, including RVE1(157-176) and RVE2(87-107). Analysis of the sequences of cross-reactive viral and glutamic acid decarboxylase antigens showed that these epitopes shared similar peptide binding motifs to HLA DR3/DR4. There is a statistically significant correlation between the response amplitude of patient's peripheral blood mononuclear cells to RVE1(157-176), RVE2(87-107) and GAD65(274-286) in patients with recent onset diabetes, and to RVE1(157-176) and GAD67(212-226) in patients with late onset diabetes.
CONCLUSION/INTERPRETATION: Cross-reactive glutamic acid decarboxylase and rubella virus determinants identified by T-cell clones were also recognised at high frequencies by general T-cell populations of Type I diabetic patients.
目的/假设：研究病毒蛋白决定簇与β细胞蛋白决定簇之间的交叉反应，进一步了解该机制在I型（胰岛素依赖型）糖尿病中的潜在作用。
使用来自60例I型糖尿病患者的未克隆和克隆T细胞群体，在增殖或细胞毒性试验中研究了对一组28种病毒和β细胞蛋白肽的免疫反应，这些肽代表风疹病毒（RV）、柯萨奇病毒、人38KDa31G和谷氨酸脱羧酶（GAD 65和67）蛋白的选定序列。
在增殖试验中，肽GAD65(252 - 266)诱导近期发病糖尿病患者的反应频率最高（77%），而GAD67(212 - 226)在晚期发病糖尿病患者中刺激细胞反应的速率最高（61%）。在所有测试的病毒肽中，RVE1(157 - 176)被所有患者组识别的频率最高且幅度最大。对GAD65(252 - 266)、GAD65(274 - 286)或GAD67(212 - 226)特异的T细胞克隆在细胞毒性试验中测试了它们对风疹病毒肽的反应。这些T细胞克隆中的每一个都与两到四种风疹病毒肽发生交叉反应，包括RVE1(157 - 176)和RVE2(87 - 107)。对交叉反应性病毒和谷氨酸脱羧酶抗原的序列分析表明，这些表位与HLA DR3/DR4共享相似的肽结合基序。近期发病糖尿病患者外周血单个核细胞对RVE1(157 - 176)、RVE2(87 - 107)和GAD65(274 - 286)的反应幅度，与晚期发病糖尿病患者对RVE1(157 - 176)和GAD67(212 - 226)的反应幅度之间存在统计学显著相关性。
结论/解读：T细胞克隆鉴定出的交叉反应性谷氨酸脱羧酶和风疹病毒决定簇在I型糖尿病患者的普通T细胞群体中也被高频率识别。
