Epigenetic instruction of memory B cell function and reactivation

记忆 B 细胞功能和重新激活的表观遗传指令

• 批准号: 10308049
• 负责人: Christopher D Scharer
• 金额: $ 38.7万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-12 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10308049
• 关键词: ATAC-seq; Antigens; Architecture; Autoimmune Diseases; B-Cell Activation; B-Lymphocyte Subsets; B-Lymphocytes; Binding Sites; Bioinformatics; Biological Assay; Cell division; Cell physiology; Cells; Cellular Assay; Chromatin; Chromatin Structure; DNA; DNA Methylation; Data; Deposition; Disease; EZH2 gene; Enhancers; Enzymes; Epigenetic Process; Equilibrium; Gene Expression; Gene Expression Profiling; Generations; Genetic; Genetic Transcription; Goals; Heritability; Histone H3; Homeostasis; Humoral Immunities; Immune response; Immunity; Immunoglobulin A; Immunoglobulin Class Switching; Immunoglobulin G; Immunoglobulin M; Immunologic Memory; Immunotherapeutic agent; Influenza; Instruction; Lupus; Lysine; Maps; Mediating; Memory; Memory B-Lymphocyte; Metabolic; Metabolism; Molecular; Mouse Strains; Mus; Nature; Outcome; Pathway interactions; Patients; Phenotype; Plasma Cells; Population; Process; Property; Protocols documentation; Reaction; Regulatory Element; Role; Series; Stimulus; Structure of germinal center of lymph node; T-Lymphocyte; Tamoxifen; Vaccine Design; Work; bioinformatics pipeline; design; differentiation protocol; epigenetic profiling; gene network; genetic signature; histone modification; improved; in vivo; influenza infection; plasma cell differentiation; programs; promoter; response; shared memory; targeted treatment; therapeutic target; therapy development; tool; transcription factor; transcriptome; transcriptome sequencing; vaccine strategy

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.

项目概要/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，因为它们具有多能性并且能够迅速实现多元化 BCR 库与终末分化浆细胞和初始 B 细胞进行比较。 MBC 代表具有不同子集的异质细胞群，可以快速启动 产生浆细胞或形成次级生发中心。此外，MBC 可能出现在 对各种刺激的反应，包括独立于生发中心的刺激 潜在的滤泡外途径。虽然所有 MBC 似乎都具有增强的召回特性，但 不知道 MBC 表型是如何在不同子集中编程的，也不知道 MBC 编程是什么 是否依赖GC？表观遗传机制是指导细胞命运的遗传程序 决策并确定潜在的表型。鉴于 MBC 的细胞本质 特性，我们假设 MBC 具有独特的表观遗传编程，可作为 先前状态的分子记忆并指导细胞命运决定和增强功能 记起。我们小组最近的工作表明，非典型记忆 B 细胞 在狼疮等自身免疫性疾病患者中得到扩展，显示出表观遗传特征 滤泡外激活途径。因此，充分了解 MBC 特性至关重要 设计疫苗策略，最大限度地发挥 MBC 潜力并开发针对目标的疗法 MBC 为组成部分的疾病。阐明表观遗传机制 MBC 表型，我们提出两个目标，旨在 1) 定义顺式监管格局， 转录因子网络和流感特异性 MBC 子集的代谢 源自或独立于生发中心； 2）了解表观遗传如何 阻遏蛋白 EZH2 控制 MBC 子集的形成和回忆反应。为了完成 这些目标我们建立了一系列表观遗传和转录分析方案 生物信息学方法；组装了一系列基因小鼠品系，使 有条件删除EZH2；并开发了一种离体 MBC 测定法来精细绘制分子图谱 回忆反应期间的变化。最终我们的研究将提供一个表观遗传学路线图 MBC 的形成和功能以及可以帮助操纵免疫的平台 MBC 介导的疾病的记忆和治疗靶点。