Entry of antigen-presenting B cells into the follicle directed by IFNa and IL-17

抗原呈递 B 细胞在 IFNa 和 IL-17 的引导下进入滤泡

• 批准号: 8187350
• 负责人: HUI-CHEN HSU
• 金额: $ 36.63万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8187350
• 关键词: Address; Affinity; Antibody Formation; Antigens; Area; Autoantibodies; Autoimmune Diseases; Autoimmune Process; Autoimmunity; B-Cell Development; B-Lymphocytes; Behavior; Biological Response Modifiers; CD4 Positive T Lymphocytes; CXCL12 gene; CXCL13 gene; Cells; Chemotaxis; Clinical; Data; Development; Event; Exhibits; Feasibility Studies; Figs - dietary; Follicular Dendritic Cells; GTP-Binding Protein Regulators; Generations; Genes; Goals; Grant; Hen Egg Lysozyme; Homing; Image Analysis; In Vitro; Interferon-alpha; Interferons; Interleukin-17; Knowledge; Letters; Light; Lupus; Lymphoid; Manuscripts; Mediating; Mediator of activation protein; Modeling; Mus; National Institute of Allergy and Infectious Disease; Organ; Ovalbumin; Population; Principal Investigator; Process; Production; Publications; RGS Family Gene; Reaction; Reagent; Receptors, Antigen, B-Cell; Research Personnel; Rheumatoid Arthritis; Series; Signal Transduction; Sinus; Spleen; Structure of germinal center of lymph node; T-Cell Receptor; Testing; Therapeutic; Therapeutic Intervention; Transgenes; Transportation; Universities; Up-Regulation; base; cell motility; cytokine; improved; in vivo; insight; migration; novel; novel therapeutic intervention; precursor cell; prevent; response

DESCRIPTION (provided by applicant): The overall goal of this revised proposal is to identify the mechanisms by which IL-17 and IFN1 act in concert to initiate the development of B cells that produce autoantibodies in the BXD2 model of autoimmunity. We have found that both IL-17 and IFN1 are required for the formation of germinal centers (GCs) that enable the production of pathogenic autoantibodies in autoimmune BXD2 mice, i.e., a deficiency of either of these cytokines abrogates GC formation, autoantibody formation, and autoimmune disease in these mice. Analysis of the effects of IL-17 on GC formation in the BXD2 mice suggest that IL-17 facilitates the interaction of CD4 T cells and B cells thereby enhancing the formation and stabilization of spontaneous germinal centers (GCs), and that this effect is mediated by upregulation of regulators of G-protein signaling (Rgs)13 and Rgs16 in the B cells. The principal investigator's most recent results indicate that there is an increased number of plasmacytoid DCs (pDCs) in the marginal sinus in BXD2 mice and that these pDCs exhibit significantly elevated expression of IFN1. Notably, there is a robust marginal zone precursor B cell population (MZP) that exhibits an enhanced ability to transport antigen (Ag) directly into a GC light zone area. Based on our accumulated preliminary data, we have formulated a hypothetical model in which IL-17 and IFNa act in a coordinated manner to facilitate the spontaneous GC response through regulating the migration behavior of Ag-transporting MZP B cells. We propose to test this hypothetical model by addressing two of its essential components: (1) Does IFNa regulate influx and IL-17 regulate the retention of MZP in the GC LZ area? (2) Do IFNa and IL-17 regulate Ag transport by MZP B cells leading to GC development? To answer the first question, the ability of IL-17 and IFNa to regulate chemotaxis will be determined in vitro using a transwell chamber, and in vivo by analyzing homing of GFP+ MZP B cells in BXD2 mice in which IL-17R, IFNaR, or Rgs genes has been modulated. This will be achieved by using B cells obtained from BXD2-Il-17r-/-, BXD2-Ifnar-/-, BXD2-Rgs13-/- and BXD2-Rgs16-/- mice. To answer the second question, in vivo Ag capture and transportation by MZP B cells will be determined by FACS and confocal imaging analyses. The Ag transport function of MZP B cells will be studied using the hen egg lysozyme (HEL) or HEL-ovalbumin (OVA) conjugate strategies in combination with BXD2 mice that express the MD4 B-cell receptor transgene and the OVA T-cell receptor transgene. RELEVANCE: Successful accomplishment of the project will help to identify critical migratory signals and upstream mediators that facilitate the transportation of Ag to initiate a GC response. The results will provide new insights into the mechanisms of action of currently used therapies based on modulation of IFN1 as well as the proposed targeting of Th17 cells in autoimmune disease as well as suggesting novel targets for therapeutic intervention. PUBLIC HEALTH RELEVANCE: In this project, we propose that local production of immune mediators in the secondary lymphoid organ facilitates specialized B cells that transport antigens into the antibody formation area called germinal centers in autoimmune BXD2 mice. The combination of these events results in the initiation of the chain reaction that leads to the production of pathogenic autoantibodies. An understanding of this process will help to identify a novel therapeutic intervention to prevent the generation of pathogenic autoantibodies as well as suggesting more effective utilization of currently available therapeutic strategies for various autoimmune diseases including lupus and rheumatoid arthritis.

描述（由申请人提供）：本修订提案的总体目标是确定 IL-17 和 IFN1 协同作用以启动在 BXD2 自身免疫模型中产生自身抗体的 B 细胞发育的机制。我们发现 IL-17 和 IFN1 都是生发中心 (GC) 形成所必需的，GC 能够在自身免疫 BXD2 小鼠中产生致病性自身抗体，即，这些细胞因子中任何一种的缺乏都会消除这些小鼠中的 GC 形成、自身抗体形成和自身免疫性疾病。 IL-17 对 BXD2 小鼠 GC 形成的影响分析表明，IL-17 促进 CD4 T 细胞和 B 细胞的相互作用，从而增强自发生发中心 (GC) 的形成和稳定，并且这种作用是通过 B 细胞中 G 蛋白信号传导 (Rgs)13 和 Rgs16 调节因子的上调介导的。主要研究者的最新结果表明，BXD2 小鼠边缘窦中的浆细胞样 DC (pDC) 数量增加，并且这些 pDC 的 IFN1 表达显着升高。值得注意的是，有一个强大的边缘区前体 B 细胞群 (MZP)，其将抗原 (Ag) 直接转运到 GC 光区区域的能力增强。基于我们积累的初步数据，我们制定了一个假设模型，其中 IL-17 和 IFNa 以协调方式发挥作用，通过调节 Ag ​​转运 MZP B 细胞的迁移行为来促进自发性 GC 反应。我们建议通过解决其两个基本组成部分来测试这个假设模型：(1) IFNa 是否调节流入，IL-17 是否调节 MZP 在 GC LZ 区域的保留？ (2) IFNa 和 IL-17 是否调节 MZP B 细胞的 Ag 转运导致 GC 发展？为了回答第一个问题，将使用 Transwell 小室在体外测定 IL-17 和 IFNa 调节趋化性的能力，并在体内通过分析 BXD2 小鼠中 GFP+ MZP B 细胞的归巢来测定，其中 IL-17R、IFNaR 或 Rgs 基因已被调节。这将通过使用从 BXD2-Il-17r-/-、BXD2-Ifnar-/-、BXD2-Rgs13-/- 和 BXD2-Rgs16-/- 小鼠获得的 B 细胞来实现。为了回答第二个问题，MZP B 细胞体内 Ag 的捕获和运输将通过 FACS 和共聚焦成像分析来确定。将使用鸡蛋溶菌酶 (HEL) 或 HEL-卵清蛋白 (OVA) 缀合物策略，结合表达 MD4 B 细胞受体转基因和 OVA T 细胞受体转基因的 BXD2 小鼠，研究 MZP B 细胞的 Ag 转运功能。相关性：该项目的成功完成将有助于识别关键的迁移信号和上游介体，以促进 Ag 的运输以启动 GC 响应。这些结果将为当前使用的基于 IFN1 调节的疗法的作用机制提供新的见解，以及拟议的针对自身免疫性疾病的 Th17 细胞的靶向，并提出治疗干预的新靶标。 公共健康相关性：在这个项目中，我们提出，次级淋巴器官中免疫介质的局部产生有助于将抗原转运到自身免疫 BXD2 小鼠中称为生发中心的抗体形成区域。这些事件的结合导致连锁反应的启动，从而导致致病性自身抗体的产生。了解这一过程将有助于确定一种新的治疗干预措施，以防止致病性自身抗体的产生，并建议更有效地利用目前可用的治疗策略来治疗包括狼疮和类风湿性关节炎在内的各种自身免疫性疾病。