Regulation of Migration of Autoreactive Germinal Centers and Precursor B Cells

抽象的。这项建议的总体目标是确定干扰素和IL-17在急性白血病中的作用机制。 以协同方式启动形成自身抗体的B细胞在两人体内的发展 以及发生系统性红斑狼疮(狼疮或SLE)的小鼠。IL-17R和干扰素受体信号转导 与Bxd2小鼠模型中自发生发中心(GC)的形成有关 通过对干扰素受体缺陷和IL-17R缺陷的Bxd2小鼠进行分析，得出狼疮的诊断标准。有大量的 Bxd2小鼠边缘窦中产生局部高水平干扰素的浆细胞样树突状细胞。干扰素？ 似乎通过促进人口的迁移来影响GC的形成 CD21hiIgMhiCD23hi B细胞从边缘带(MZ)到卵泡(FO)。这些B细胞是指 作为CD23hiAPCHI B细胞，因为它们具有非常高的抗原(Ag)提呈能力和 诱导比常规FO B细胞更强的TH-17极化反应。平行分析 提示IL-17通过促进Bxd2小鼠GCs的形成和稳定 上调B细胞中G蛋白信号转导(RGS)13和RGS16的调节因子，从而促进 APCHI B细胞在FO区的滞留。我们假设IFNA有助于释放 CD23hiAPCHI B细胞来自MZ和IL-17，然后将这些细胞定位在FO中，其中CD4 T细胞驻留在。由于这些CD23hiAPCHI B细胞增加了APC和共刺激功能， 它们促进TH-17细胞的生成/维持和自发GC的形成。 将解决三个主要问题：(1)干扰素β诱导的CD23hiAPCHI B细胞是否内流 启动Bxd2小鼠GCs的发育？(2)CD23hiAPCHI B细胞对IL-17和 促进TH-17细胞极化导致Bxd2小鼠产生自身抗体？和(3)可以 IFNA和IL-17对狼疮患者APCHI B细胞迁移行为的调节？我们将分析银 共聚焦显微镜下APCHI B细胞对CD4T细胞的捕获、转运和呈递 和FACS分析。IL-17和IFNA调节趋化的能力将在体外确定，以及 通过Bxd2-Il-17r-/-B细胞对GFP阳性APCHI B细胞归巢的分析在体内得到证实， Bxd2-Ifnar-/-、Bxd2-Rgs13-/-和Bxd2-Rgs16-/-小鼠。该模型的临床应用价值 自身免疫的发展将通过分析从外周血中获得的B细胞来评估 狼疮患者外周血中干扰素和白介素17对其发生和迁移的影响 APCHI B细胞。意义：这些研究应该确定关键的迁徙信号和上游 促进自身免疫回路发展的介质，从而导致高水平的 亲和力致病自体抗体。因此，它们有可能确定新的候选治疗靶点。 并对自身抗体介导的自身免疫性疾病提出更有效的治疗干预措施。

Abstract. The overall goal of this proposal is to identify the mechanisms by which IFN¿ 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 IFN¿R signaling have been implicated in the formation of spontaneous germinal centers (GCs) in the BXD2 mouse model of lupus through analysis of IFN¿R-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 IFN¿. IFN¿ 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 IFN¿-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 IFN¿ 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.