Mechanisms of immune tolerance in autoimmune diabetes

建议书摘要 1型糖尿病(T1D)由自身免疫T淋巴细胞介导的胰岛素破坏所致 在胰腺中产生β细胞。每日多次注射胰岛素是糖尿病患者的救命疗法 病人，他们不是治愈的方法。为了治愈T1D，我们必须首先识别自我反应性T细胞，其次 我们必须除掉他们。直到最近，识别细胞一直是一项非常困难的任务。然而，最近 多肽-MHC四聚体技术的进步使我们能够识别、跟踪和审问个人 1型糖尿病小鼠模型和人类中的CD4+T淋巴细胞克隆。通过拥有工具和 技术研究疾病期间的抗原特异性T细胞，我们将能够评估在 外周耐受性和检查治疗效果以选择性地清除或沉默这些自身反应性T细胞 作为靶向治疗的细胞。我们最近修改了一种敏感的四聚体富集法，允许 一种特殊的多肽：MHCII复合体的罕见的CD4+T细胞的鉴定和表型。我们 假设第二类MHC：肽四聚体和浓缩技术将提供一种灵敏和稳健的 临床检测胰岛抗原特异性CD4+T细胞数量及活化状态的方法 来自T1D患者的可行样本。我们进一步假设胰岛抗原特异性的CD4T的特征 使用这种方法的细胞将为T1D诊断和疾病分期提供有用的生物标志物试剂。vbl.使用 这项技术我们将确定糖尿病患者和胰岛β细胞肽是否会失去外周耐受性 表位成为免疫系统的主要靶点。我们预测，新发的T1D患者将 有更多的β细胞肽：具有活化表型的MHCII特异性CD4+T细胞比非糖尿病患者更多 个人。随着对β细胞靶点的更好的了解，我们将能够开发出抗原特异性的 选择性消除自杀性T细胞治疗糖尿病的方法。

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.