Epigenetic instruction of memory B cell function and reactivation

项目摘要/摘要 保护性体液免疫由长寿记忆B细胞(MBC)和血浆共同介导 细胞。MBC是唯一重要的，因为它们是多能的，可以迅速使其 Bcr谱系与终末分化浆细胞和幼稚B细胞的比较。MBC 表示具有不同子集的异质细胞群体 产生浆细胞或形成次级生发中心。此外，MBC可在 对多种刺激的响应，包括独立于生发中心通过 潜在的卵泡外途径。虽然所有的MBC似乎都有增强的召回特性，但事实是 不知道MBC表型在不同的子集中是如何编程的，或者是什么MBC编程 依赖于GC吗？表观遗传机制是指导细胞命运的可遗传程序 决定和确定潜在的表型。鉴于MBC的细胞固有性质 属性，我们假设MBC包含一个不同的表观遗传编程，作为一个 分子记忆先前的状态，并指示细胞命运决定和增强的功能 召回。我们小组最近的研究表明，非典型记忆B细胞，即 在狼疮等自身免疫性疾病患者中扩大，显示出表观遗传特征 卵泡外激活途径。因此，充分了解MBC属性是至关重要的 设计疫苗策略，最大限度地发挥MBC潜力，并开发针对以下目标的疗法 以单核细胞为组成部分的疾病。阐明表观遗传机制 MBC表型，我们提出了两个目标，旨在1)定义顺式调控格局， 转录因子网络和流感特异性MBC亚群的新陈代谢 源自生发中心或独立于生发中心；以及2)了解表观遗传学 抑制子EZH2控制MBC亚群的形成和召回反应。要完成 为了达到这些目标，我们已经建立了一系列表观遗传学和转录图谱分析方案 生物信息学方法；组装了一系列遗传小鼠品系，使 有条件地删除EZH2；并建立了一种体外MBC实验来精细定位分子 召回响应过程中的变化。最终，我们的研究将提供表观遗传学路线图 MBC的形成和功能以及协助操作免疫的平台 记忆与单核细胞介导的疾病的治疗靶点。

Project Summary/Abstract Protective humoral immunity is mediated by both long-lived memory B cells (MBC) and plasma cells. MBC are uniquely important because they are multipotent and can rapidly diversify their BCR repertoire compared to both terminally differentiated plasma cells and naïve B cells. MBC represent a heterogenous population of cells with different subsets primed to either rapidly generate plasma cells or form secondary germinal centers. Additionally, MBC can arise in response to a diverse array of stimuli including independently of a germinal center through a potential extrafollicular pathway. While all MBC seem to have enhanced recall properties, it is not known how MBC phenotypes are programed in different subsets or what MBC programming is dependent on GC? Epigenetic mechanisms are heritable programs that act to guide cell fate decisions and determine potential phenotypes. Given the cell intrinsic nature of MBC properties, we hypothesize that MBC harbor a distinct epigenetic programming that serves as a molecular memory of prior states and instructs cell fate decisions and enhanced function during recall. Recent work from our group has shown that atypical memory B cells, which are expanded in patients with autoimmune diseases such as Lupus, show an epigenetic signature of extrafollicular activation pathways. Thus, a full understanding of MBC properties is essential to design vaccine strategies that maximize MBC potential and develop therapies that target diseases where MBC are a component. To elucidate the epigenetic mechanisms governing MBC phenotypes, we propose two aims designed to 1) define the cis-regulatory landscape, transcription factor networks, and metabolism of influenza specific MBC subsets that are derived from or independently of a germinal center; and 2) understand how the epigenetic repressor EZH2 controls the formation of MBC subsets and recall responses. To accomplish these aims we have established a series epigenetic and transcriptional profiling protocols and bioinformatic approaches; assembled a series of genetic mouse strains that allow the conditional deletion of EZH2; and developed an ex vivo MBC assay to fine map the molecular changes during recall responses. Ultimately our studies will provide an epigenetic road map to MBC formation and function and a platform that could aid in the manipulation of immune memory and therapeutic targets for MBC mediated diseases.