Regulation of Migration of Autoreactive Germinal Centers and Precursor B Cells

描述（由申请人提供）： 抽象的。本提案的总体目标是确定IFN 1和IL-17以协调方式起作用以启动发展系统性红斑狼疮（狼疮或SLE）的人和小鼠中自身抗体（autoAb）形成B细胞的发展的机制。通过对IFN 1 R缺陷型和IL-17 R缺陷型BXD 2小鼠的分析，IL-17 R和IFN 1 R信号传导均与狼疮BXD 2小鼠模型中自发生发中心（GC）的形成有关。BXD 2小鼠的边缘窦中存在大量浆细胞样DC，可产生局部高水平的IFN 1。IFN 1似乎通过促进CD 21 hiIgMhi CD 23 hi B细胞群从边缘区（MZ）迁移到卵泡（FO）来影响GC的形成。这些B细胞被称为CD 23 hiAPChi B细胞，因为它们具有非常高的抗原（Ag）呈递能力和诱导比常规FO B细胞强得多的TH-17极化应答的能力。平行分析表明，IL-17通过上调B细胞中G蛋白信号传导（Rgs）13和Rgs 16的调节剂，促进BXD 2小鼠中GC的形成和稳定，然后促进APChi B细胞在FO区域中的保留。我们假设IFN α促进CD 23 hiAPChi B细胞从MZ释放，然后IL-17将这些细胞定位在CD 4 T细胞所在的FO中。由于这些CD 23 hiAPChi B细胞具有增加的APC和共刺激功能，它们促进TH-17细胞的产生/维持和自发GC的形成。本研究将探讨三个主要问题：（1）IFN 1诱导的CD 23 hiAPChi B细胞内流是否启动了BXD 2小鼠GC的发育？(2)CD 23 hiAPChi B细胞是否对IL-17产生应答并促进TH-17细胞的极化，从而导致BXD 2小鼠中自身抗体的产生？IFN α和IL-17能否调节狼疮患者APChi B细胞的迁移行为？我们将使用共聚焦显微镜和流式细胞仪分析体内APChi B细胞对CD 4 T细胞的Ag捕获、转运和呈递。IL-17和IFNa调节趋化性的能力将在体外确定，并通过使用来自BXD 2-Il-17 r-/-、BXD 2-Ifnar-/-、BXD 2-Rgs 13-/-和BXD 2-Rgs 16-/-小鼠的B细胞分析GFP阳性APChi B细胞的归巢来在体内确认。通过分析从狼疮患者的外周血获得的B细胞以分析IFN 1和IL-17对APChi B细胞的发育和迁移的影响，来评估这种自身免疫发展模型的临床相关性。重要性：这些研究应该确定关键的迁移信号和上游介质，促进自身免疫回路的发展，导致高亲和力致病性autoAb的产生。因此，他们有可能确定新的候选治疗靶点，并建议更有效的治疗干预autoAb介导的自身免疫性疾病。 公共卫生相关性： 自身抗体在自身免疫性疾病如类风湿性关节炎和系统性红斑狼疮的发展中起着关键作用。一段时间以来，人们已经知道干扰素-1和白细胞介素-17都在自身免疫的发展中发挥作用。在这个项目中，我们建议测试一个模型，该模型表明这些药物如何协调在脾脏中捕获自身抗原的淋巴细胞的迁移，从而促进对致病性自身抗体产生至关重要的淋巴细胞的相互作用。我们将在小鼠模型中使用最先进的体内技术并使用狼疮患者的外周血来测试该模型。研究结果将有助于确定新的治疗干预措施，并提出更好的方法来使用目前可用的疗法。

DESCRIPTION (provided by applicant): Abstract. The overall goal of this proposal is to identify the mechanisms by which IFN1 and IL-17 act in a coordinated fashion to initiate the development of autoantibody (autoAb)-forming B cells in both human and mouse that develop systemic lupus erythematosus (lupus or SLE). Both IL-17R and IFN1R signaling have been implicated in the formation of spontaneous germinal centers (GCs) in the BXD2 mouse model of lupus through analysis of IFN1R-deficient and IL-17R-deficient BXD2 mice. There are high numbers of plasmacytoid DCs in the marginal sinus of the BXD2 mice that produce locally high levels of IFN1. IFN1 appears to influence the formation of GCs by promoting the migration of a population of CD21hiIgMhiCD23hi B cells from the marginal zone (MZ) to the follicle (FO). These B cells were referred to as CD23hiAPChi B cells as they have a very high capacity for antigen (Ag) presentation and the ability to induce a much stronger TH-17 polarization response than the conventional FO B cells. Parallel analyses indicate that IL-17 promotes the formation and stabilization of the GCs in the BXD2 mice through upregulation of regulators of G-protein signaling (Rgs)13 and Rgs16 in the B cells, which then promote the retention of APChi B cells in the FO area. We hypothesize that IFNa facilitates the release of the CD23hiAPChi B cells from the MZ and that IL-17 then localizes these cells in the FO where the CD4 T cells reside. As these CD23hiAPChi B cells have increased APC and costimulatory functions, they promote the generation/maintenance of TH-17 cells and the formation of spontaneous GCs. Three major questions will be addressed: (1) Does the IFN1-induced influx of the CD23hiAPChi B cells initiate the development of GCs in BXD2 mice? (2) Do the CD23hiAPChi B cells respond to IL-17 and promote polarization of TH-17 cells leading to the production of autoAbs in the BXD2 mice? And (3) Can IFNa and IL-17 regulate the migration behavior of APChi B cells in lupus patients? We will analyze Ag capture, transportation and presentation by APChi B cells to CD4 T cells in vivo using confocal microscopy and FACS analysis. The ability of IL-17 and IFNa to regulate chemotaxis will be determined in vitro, and confirmed in vivo by analysis of homing of GFP-positive APChi B cells using B cells from BXD2-Il-17r-/-, BXD2-Ifnar-/-, BXD2-Rgs13-/- and BXD2-Rgs16-/- mice. The clinical relevance of this model of the development of autoimmunity will be assessed by that analysis of B cells obtained from the peripheral blood of lupus patients for the analysis of the effects of IFN1 and IL-17 on the development and migration of APChi B cells. SIGNIFICANCE: These studies should identify critical migratory signals and upstream mediators that facilitate the development of an autoimmune circuit that leads to the production of high affinity pathogenic autoAbs. Thus, they have the potential to identify novel candidate therapeutic targets and to suggest more effective therapeutic interventions in autoAb-mediated autoimmune diseases. PUBLIC HEALTH RELEVANCE: Short Narrative Autoantibodies play a critical role in the development of autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. It has been known for some time that both interferon-1 and interleukin-17 play a role in the development of autoimmunity. In this project, we propose to test a model that suggests how these agents can coordinate the migration of lymphocytes that have trapped self-antigens in the spleen, thereby promoting the interactions of the lymphocytes that are critical to the production of pathogenic autoantibodies. We will test this model using state-of-the-art in vivo techniques in a mouse model and using peripheral blood from lupus patients. The results will help to identify novel therapeutic interventions as well as suggesting better approaches to the use of currently available therapies.