Targeting B lymphocyte Signaling to Reprogram Autoimmunity in Type 1 Diabetes

 描述(由申请人提供)：本提案中的培训平台侧重于B淋巴细胞的细胞内信号传递，作为纠正免疫耐受的基本缺陷和监测重新编程胰岛破坏性免疫的治疗干预的新方法。虽然在理解驱动T1D的细胞间过程方面已经做了很多工作，但控制对胰岛抗原的破坏性反应的细胞内级联还没有确定。自身抗体的产生是自体免疫最早的生物标志物，但允许这种免疫耐受被打破的机制仍不清楚。虽然利妥昔单抗靶向整个B淋巴细胞池延缓了新发的T1D的进展，但这种效果是短暂的，这可能与长期未能对胰岛反应细胞进行重新编程有关。像T细胞一样，B细胞经历了多个发育阶段，在此期间，它们通过与抗原接触来编程，以耐受自身抗原。这个程序在T1D中失败了，我假设这是由于B细胞发育过程中抗原接触和效应器反应之间的不正确耦合。在我的初步研究中，我利用尖端的磷酸盐荧光流式细胞术的新方法，在NOD小鼠的过渡期1(T1)B淋巴细胞亚群中发现了c-Abl信号的缺陷，这是T1D的基准临床前模型。虽然c-Abl在肿瘤发生中的作用已经被广泛地剖析，但它在B细胞免疫耐受编程中的作用在很大程度上是未知的。在这个提案中，我将剖析控制B淋巴细胞耐受机制的c-Abl依赖的信号通路。我假设c-Abl在过渡性B淋巴细胞室调节平衡平衡扩张和负选择，这一途径的缺陷是自身免疫性疾病中发现的B淋巴细胞选择缺陷的基础。我将通过应用转基因、抗原特异性系统和c-Abl途径的治疗靶点来剖析c-Abl介导的控制B淋巴细胞动态平衡和选择的途径(目标1)。我将扩展对免疫信号的分析，以了解在疾病修改治疗期间，免疫功能是如何通过信息学方法与高维质量细胞术(AIM 2)相结合的方式重新编程的。通过这项奖学金申请，我将1)对耐受诱导过程中B细胞调节的新的细胞内途径有详细的了解，2)我作为一名专注于T1D的基础和翻译科学家的潜力。这些培训目标将通过研究计划、在拟议研究设计方面具有专业知识的杰出导师团队、完成霍华德·休斯分子医学证书计划以及范德比尔特大学提供的资源、设施和培训计划来促进。

 DESCRIPTION (provided by applicant): The training platform in this proposal focuses on intracellular signaling in B lymphocytes as a new approach to correcting fundamental defects in immune tolerance and to monitoring therapeutic interventions to reprogram islet-destructive immunity. While much work has gone into understanding the intercellular processes that drive T1D, the intracellular cascades that control the destructive responses to islet antigens are undefined. The production of autoantibodies is the earliest available biomarker of autoimmunity, but the mechanisms that permit this breach in immune tolerance remain unknown. While targeting of the whole B lymphocyte pool with rituximab delayed the progression of new-onset T1D, the effect was transient, which may relate to failure to reprogram islet-reactive cells long-term. Like T cells, B cells progress through multiple developmental stages during which they are programmed by antigen contact to be tolerant to self-antigens. This program fails in T1D, which I have hypothesized is due to improper coupling between antigen contact and effector responses during B cell development. In my preliminary studies, I have utilized new approaches in cutting-edge, phosphoflow cytometry to uncover defects in c-Abl signaling in the Transitional 1 (T1) B lymphocyte subset of NOD mice, the benchmark preclinical model of T1D. While the function of c-Abl in oncogenesis has been extensively dissected, its role in the programming of immune tolerance in B cells is largely unknown. In this proposal I will dissect the c-Abl dependent signaling pathways that govern B lymphocyte tolerance mechanisms. I hypothesize that c-Abl modulates the balance between homeostatic expansion and negative selection in the transitional B lymphocyte compartment and that defects in this pathway underlie B lymphocyte selection defects found in autoimmune disease. I will dissect c-Abl mediated pathways that control B lymphocyte homeostasis and selection by applying transgenic, antigen-specific systems and therapeutic targeting of c-Abl pathways for disease modulation (Aim 1). I will extend this analysis of immune signaling to understand how immune function is reprogrammed during disease-modifying therapy using informatics approaches combined with high dimensional mass cytometry (Aim 2). Through this fellowship application, I will develop 1) a detailed understanding of new intracellular pathways of B cell regulation during tolerance induction and 2) my potential as a basic and translational scientist focused on T1D. These training goals will be facilitated by the research plan, by the exceptional team of mentors with expertise in the proposed study design, by completion of the Howard Hughes Certificate Program in Molecular Medicine, and by the resources, facilities, and training plan available through Vanderbilt University.