Characterizing autoimmunity in NOD mouse islets, PLN and 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。对抗原耐受的转基因NOD小鼠的研究表明，不同的自身抗原在引发导致1型糖尿病（T1 D）的自身免疫中起首要作用。然而，基于我们对T细胞耐受性诱导的知识的理论考虑预测，β细胞自身免疫性最初应该同时丧失于许多β细胞抗原，但几乎没有实验证据支持这种情况。我们已经开发了一种改良的ELISPOT测定法，其能够表征胰腺淋巴结（PLN）内的自身反应性T细胞和胰岛浸润T细胞群体。我们的初步数据表明，抗原特异性和表型的自身反应性T细胞内的靶组织是完全不同的，从目前的图片，通过分析在NOD小鼠外周的T细胞群。我们期望我们对PLN、胰岛和脾脏中自身反应性CD 4+和CD 8 + T细胞应答的进一步纵向表征将导致NOD小鼠中自身免疫过程的新概念化。我们对PLN和胰岛中早期T细胞自身反应性的功能亲和力的分析将提供一条独立的证据线来支持T细胞自身免疫发展的“分层”或“同时”模型。经验教训将支持/反驳的假设，即自身免疫可以规避个人的“启动”靶抗原的耐受性。我们的研究还将阐明外周T细胞反应与靶组织中T细胞反应之间的关系。由于只有PBMC可从人类获得，因此了解外周和靶组织中T细胞自身反应性之间的关系对于评估使用基于T细胞的标志物监测疾病进展的可行性、干预性治疗的疗效和移植胰岛的状态是重要的。外行：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（PLN，其中自身免疫被认为首先出现）和胰岛浸润T细胞群内的自身反应性T细胞的能力，这在此之前是不可行的。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对潜在治疗方法的思考，以及基于外周T细胞反应的生物标志物的实用性。

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.