Epigenetic instruction of memory B cell function and reactivation

项目总结/摘要 保护性体液免疫由长寿命记忆B细胞（MBC）和血浆介导 细胞MBC具有独特的重要性，因为它们是多能的，可以迅速使其多样化。 与终末分化浆细胞和幼稚B细胞相比的BCR库。MBC 代表具有不同亚群的异源细胞群， 产生浆细胞或形成次级生发中心。此外，MBC可能会出现在 对各种刺激的反应，包括独立于脑电中心， 潜在的卵泡外途径。虽然所有MBC似乎都具有增强的回忆属性，但它确实是 不知道MBC表型如何在不同子集中编程或MBC编程 是否依赖于GC？表观遗传机制是可遗传的程序，其作用是引导细胞命运 决定和确定潜在的表型。鉴于MBC的细胞内在性质 属性，我们假设MBC具有独特的表观遗传编程，作为一个 先前状态的分子记忆，并指导细胞命运决定和增强功能， 记得了我们小组最近的工作表明，非典型记忆B细胞，即 在狼疮等自身免疫性疾病患者中的扩展，显示出表观遗传特征， 卵泡外激活途径的一种。因此，充分了解MBC的性质是必不可少的 设计疫苗策略，最大限度地发挥MBC潜力，并开发针对 MBC是一种成分的疾病。为了阐明表观遗传机制 MBC表型，我们提出了两个目标，旨在1）定义顺式调控景观， 转录因子网络和流感特异性MBC亚群的代谢， 源自或独立于生殖中心; 2）了解表观遗传如何 阻遏物EZH 2控制MBC亚群的形成和回忆反应。完成 为了这些目的，我们建立了一系列表观遗传和转录谱分析方案， 生物信息学方法;组装了一系列遗传小鼠品系， EZH 2的条件性缺失;并开发了一种离体MBC测定法，以精细绘制EZH 2的分子图谱。 在召回响应期间发生变化。最终，我们的研究将提供一个表观遗传路线图， MBC的形成和功能以及可以帮助操纵免疫调节的平台。 记忆和MBC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.