Characterizing autoimmunity NOD mouse islets, PLN/spleen

描述（由申请人提供）：科学摘要：我们缺乏对自发性自身免疫性疾病如何发生的基本了解。对抗原耐受转基因NOD小鼠的研究表明，不同的自身抗原在启动导致1型糖尿病（T1D）的自身免疫中起主要作用。然而，基于我们对T细胞耐受诱导知识的理论考虑预测，β细胞自身免疫最初应该同时失去许多β细胞抗原，但很少有实验证据支持这一设想。我们开发了一种改进的ELISPOT检测方法，能够表征胰腺淋巴结（PLN）和胰岛浸润T细胞群中的自身反应性T细胞。我们的初步数据表明，靶组织内自身反应性T细胞的抗原特异性和表型与通过分析NOD小鼠周围T细胞群获得的当前图像有很大不同。我们期望对PLN、胰岛和脾脏中自身反应性CD4+和CD8+ T细胞反应的进一步纵向表征将导致NOD小鼠自身免疫过程的新概念。我们对PLN和胰岛早期T细胞自身反应功能的分析将提供一条独立的证据线，以支持T细胞自身免疫发展的“分层”或“同步”模型。吸取的经验教训将支持/驳斥这样一种假设，即允许个体“启动”目标抗原来规避自身免疫。我们的研究还将阐明外周T细胞反应与靶组织中的T细胞反应之间的关系。由于人类只有PBMC，了解T细胞自身反应性与靶组织之间的关系对于评估使用基于T细胞的标记物监测疾病进展、介入治疗的疗效和移植胰岛状态的可行性非常重要。外行人：我们缺乏对自发性自身免疫性疾病如何发生的基本了解。我们已经建立了直接表征胰腺淋巴结内自身反应性T细胞（PLN，其中自身免疫被认为首先出现）和胰岛浸润性T细胞群的能力，这在以前是不可实现的。我们期望这一建议的结果将导致NOD小鼠自身免疫过程的新概念。同样的基本过程也可能发生在人类器官特异性自身免疫性疾病中。这些结果将有助于指导我们思考潜在的治疗方法，以及基于外周T细胞反应的生物标志物的效用。

DESCRIPTION (provided by applicant): Scientific Abstract: We lack a basic understanding how spontaneous autoimmune disease arises. Studies of antigen-tolerized transgenic NOD mice have suggested the primacy of different autoantigens in initiating the autoimmunity that leads to type 1 diabetes (T1D). However, theoretical considerations based on our knowledge of T cell tolerance induction predict that beta-cell autoimmunity should be initially lost to many beta-cell antigens simultaneously but there is little experimental evidence in support of this scenario. We have developed a modified ELISPOT assay that enables the characterization of autoreactive T cells within the pancreatic lymph nodes (PLN) and islet-infiltrating T cell population. Our preliminary data indicate that antigen-specificity and phenotype of autoreactive T cells within the target tissue is quite different from the current picture that was obtained through analysis of T cell populations in the periphery of NOD mice. We expect that our further longitudinal characterization of autoreactive CD4+ and CD8+ T cell responses in the PLN, islets and spleen will lead to a new conceptualization of the autoimmune processes in NOD mice. Our analysis of the functional avidity of early T cell autoreactivity in the PLN and islets will provide an independent line of evidence to support either the "hierarchal" or the "simultaneous" model of the development of T cell autoimmunity. The lessons learned will support/refute the hypothesis that autoimmunity can be circumvented by tolerizing individuals to "initiating" target antigens. Our studies will also elucidate the relationship between peripheral T cell responses and those in the target tissue. As only PBMC are available from humans, understanding the relationship between T cell autoreactivities in the periphery and target tissue is important to assess the feasibility of using T cell-based markers to monitor disease progression, the efficacy of interventive therapies, and the status of transplanted islets. Laypersons: We lack a basic understanding how spontaneous autoimmune disease arises. We have established the ability to directly characterize autoreactive T cells within the pancreatic lymph nodes (PLN, wherein autoimmunity is thought to first arise) and the islet-infiltrating T cell population, which heretofore has not been feasible. We expect that the results of this proposal will lead to a new conceptualization of the autoimmune process in NOD mice. The same basic processes may also occur in human organ-specific autoimmune diseases. The results will help guide our thinking on potential therapeutic approaches, as well as the utility of biomarkers based on peripheral T cell responses.