Mechanisms of immune tolerance in autoimmune diabetes

提案摘要 1型糖尿病（T1 D）是由自身免疫性T淋巴细胞介导的对胰岛素的破坏引起的。 在胰腺中产生β细胞。每天多次注射胰岛素是糖尿病患者的救命疗法 病人，他们不是一个治愈。为了治愈T1 D，我们必须首先识别自身反应性T细胞，其次是 我们必须把他们赶走。直到最近，识别细胞一直是一项非常困难的任务。但最近的 肽-MHC四聚体技术的进步使我们能够识别、跟踪和询问个体 1型糖尿病小鼠模型和人类中的CD 4 + T淋巴细胞克隆。通过拥有工具和 研究疾病期间抗原特异性T细胞的技术，我们将能够评估 外周耐受性，并检查治疗效果，以选择性地去除或沉默这些自身反应性T细胞。 细胞作为靶向治疗。我们最近采用了一种敏感的四聚体富集方案， 特异性肽：MHCII复合物的极其罕见的CD 4 + T细胞的鉴定和表型分析。我们 假设II类MHC：肽四聚体和富集技术将提供灵敏和稳健 临床上测定胰岛Ag特异性CD 4 + T细胞数量和活化状态的方法 T1 D患者的可行样本。我们进一步假设胰岛抗原特异性CD 4 T细胞的特征 使用这种方法的细胞将为T1 D诊断和疾病分期提供有用的生物标志物试剂。使用 这项技术，我们将确定是否外周耐受性丧失糖尿病患者和胰岛β细胞肽 表位成为免疫系统的主要目标。我们预测，新发T1 D患者将 具有比非糖尿病患者更多的具有活化表型的β细胞肽：MHCII特异性CD 4 + T细胞 个体随着对β细胞靶点的更好理解，我们将能够开发抗原特异性 选择性消除自我破坏性T细胞以治愈糖尿病的方法。

Proposal Summary Type 1 diabetes (T1D) results from the autoimmune T lymphocyte mediated destruction of the insulin producing beta cells in the pancreas. Multiple daily insulin injections are a lifesaving therapy for diabetic patients, they are not a cure. In order to cure T1D we must first identify the self-reactive T cells, and secondly we must remove them. Until recently identifying the cells has been a very difficult task. However, recent advances in peptide-MHC tetramer technology have allowed us to identify, track and interrogate individual CD4+ T lymphocyte clones in both mouse models and humans with type 1 diabetes. By having the tools and technology to study antigen specific T cells during disease, we will be able to assess the breakdown in peripheral tolerance and examine therapeutic efficacy to selectively remove or silence these self-reactive T cells as a targeted cure. We have recently adapted a sensitive tetramer enrichment protocol allowing the identification and phenotyping of exceedingly rare CD4+ T cells of a specific peptide:MHCII complex. We hypothesize that class II MHC:peptide tetramer and enrichment techniques will provide a sensitive and robust method for determining the number and activation status of islet Ag-specific CD4+ T cells using clinically feasible samples from T1D patients. We further hypothesize that characterization of islet Ag-specific CD4 T cells using this approach will provide a useful biomarker reagent for T1D diagnosis and disease staging. Using this technology we will determine if peripheral tolerance is lost in diabetic patients and islet beta cell peptide epitopes become major targets of the immune system. We predict that individuals with new onset T1D will have more beta cell peptide:MHCII specific CD4+ T cells with an activated phenotype than non-diabetic individuals. With a better understanding of beta cell targets, we will be able to develop antigen specific approaches to selectively eliminate self-destructive T cells to cure diabetes.