The role of follicular helper T cell cytokines in the IgE response

描述（由申请人提供）：哮喘是一种慢性炎症性疾病，通常与过敏成分有关。哮喘是一个主要的公共卫生负担。在过去的四十年里，这种疾病的患病率大大增加，但有关导致这种疾病的基本机制的许多问题仍然没有答案。高亲和力、过敏原特异性IgE抗体与过敏性哮喘的发病机制密切相关，与IgE产生相关的途径如白细胞介素-4（IL-4）的信号传导也是如此。CD 4 T细胞的一个独特子集，称为滤泡辅助T细胞（Tfh细胞），存在于生发中心（GC）中，它们在高亲和力抗体的产生以及通过产生IL-4进行同种型类别转换（包括转换为IgE）方面提供关键帮助。Tfh细胞还分泌IL-21，一种抑制转换为IgE的细胞因子，表明Tfh细胞、细胞因子产生和同种型转换之间的复杂关系。该提议试图检验Tfh细胞独立地调节IL-4和IL-21的产生以协调GC应答并引起IgE产生的假设。提出了三个具体目标来质疑这一假设。第一个目标将调查Tfh细胞和体液反应之间的关系，在体内通过定义Tfh细胞的细胞因子分泌的细胞内染色的基础上，以及使用突变小鼠表达荧光报告基因的亚群。将在几种感染和免疫模型中以及在不同时间和解剖位置测量这些群体的组成与抗体滴度和GC反应的关系。第二个目的是将分泌精氨酸的Tfh细胞的不同亚群与Tfh细胞直接连接。 GC B细胞，并利用过继转移系统来测试这些个体群体的功能。在第三个目标中，将使用下一代测序和计算生物学中的先进技术来确定控制细胞因子生产的调控网络。总之，这项工作将进一步阐明Tfh细胞控制过敏诱导IgE抗体的机制，并在此过程中确定破坏这一过程的靶点。此外，该申请详细说明了申请人的培训计划，包括研究指导，高级课程，新技术培训以及科学专业，写作和数据展示技能的发展。像哮喘这样的重大疾病的新疗法的发展取决于像这样的项目，这些项目将临床问题转化为基础研究问题。本申请中概述的研究和培训将使申请人能够作为独立的医生科学家从事临床相关研究。

DESCRIPTION (provided by applicant): Asthma is a chronic inflammatory disease and is frequently associated with an allergic component. Asthma poses a major public health burden. Prevalence of this disease has increased greatly over the last four decades yet many questions regarding the basic mechanisms that lead to this disease remain unanswered. High-affinity, allergen-specific IgE antibodies are strongly implicated in the pathogenesis of allergic asthma, as are pathways involved in IgE production such as signaling by interleukin-4 (IL-4). A unique subset of CD4 T cells termed follicular helper T cells (Tfh cells) are present in the germinal center (GC) where they provide critical help in the production of high-affinity antibodies as well as isotype class switching, including to IgE, via production of IL-4. Tfh cells also secrete IL-21,a cytokine that represses switching to IgE, suggesting a complex relationship between Tfh cells, cytokine production, and isotype switching. This proposal seeks to test the hypothesis that Tfh cells regulate the production of IL-4 and IL-21 independently to coordinate the GC response and evoke IgE production. Three specific aims are proposed to interrogate this hypothesis. The first aim will investigate the relationship between Tfh cells and the humoral response in vivo by defining subpopulations of Tfh cells by their cytokine secretion on the basis of intracellular staining as well as using mutant mice expressing fluorescent reporter genes. The composition of these populations will be measured in relation to antibody titer and the GC response in several models of infection and immunization and across time and anatomical location. The second aim is to directly connect different subpopulations of cytokine-secreting Tfh cells with the GC B cells they are interacting with, and to utilize an adoptive transfer system to test the function of these individual populations. In the third aim, regulatory networks controlling cytokin production will be determined using advanced techniques in next-generation sequencing and computational biology. Altogether, this work will further clarify the mechanism by which Tfh cells control allergy- inducing IgE antibodies and in doing so will identify targets for disrupting this process. In addition, this application details the applicant's training plan including research mentorship, advanced coursework, training in new techniques, and development of skills in scientific professionalism, writing, and presentation of data. The development of new treatments for major diseases like asthma depends on projects like this one which translate clinical problems into basic research questions. The research and training outlined in this application will prepare the applicant to pursue a career in the conduct of clinically relevant research as an independent physician scientist.