Transcription factor A mitochondria in SLE pathogenesis

项目摘要/摘要 系统性红斑狼疮(SLE)是一种自身免疫性疾病，以无菌炎症和高 针对自身抗原的效价抗体。尽管系统性红斑狼疮的病因尚不清楚，但累积的证据表明 干扰素(IFN)可能在疾病的发病机制中发挥关键作用，很可能I型干扰素(IFN-I)是 占主导地位的调解人。虽然不同的机制可能会失调系统性红斑狼疮患者干扰素-I的产生，但对 在过去的20年里，人们一直在研究含有基因组DNA和RNA-蛋白质(RNP)的免疫复合体(IC)。 复合体在血浆细胞样树突状细胞(PDCs)激活TLR和诱导干扰素-I的过程中起关键作用。 然而，最近的范式转换数据表明，线粒体是产生干扰素的重要来源 SLE中的信号。特别是，在TLR7激动剂自身抗体激活后，SLE中性粒细胞释放氧化 (OX)线粒体DNA(MtDNA)与转录因子A线粒体(TFAM)的复合体，它们一起 具有通过激活TLR9激活pDC以产生干扰素-I的非凡能力。然而，这种机制 在系统性红斑狼疮中，Ox-mtDNA/TFAM复合体对TLR9内体转运的调控作用尚不完全清楚。 有趣的是，我们的初步研究首次表明，SLE患者具有自身抗体。 TFAM。基于这一前提，我们推测抗TFAM抗体可能促进TFAM的内化和 PDC对Ox-mtDNA/TFAM复合体的干扰性反应，可能影响SLE的疾病活动性。 这项提议的主要目的是进一步洞察这些新假设的潜在意义。 以及在SLE发病机制方面的初步发现。在目标1中，我们将确定流行率和 抗TFAM抗体的临床相关性及其与干扰素标志物的关系 系统性红斑狼疮患者的观察队列，有广泛的临床和血清学数据，以及 干扰素诱导的基因表达分析。在目标2中，我们将从单个细胞中制备抗TFAM的单抗 SLE抗TFAM记忆B细胞以确定其自身反应起源[例如V(D)J使用，体细胞超突变 和抗原识别的决定因素]，以及它们激活复合体中pDC的能力和机制 用Ox-mtDNA/TFAM。总之，这些研究试图增强我们对自我免疫原性的理解。 系统性红斑狼疮无菌炎症和干扰素产生的潜在途径。这项工作的最终目标是获得新的 对疾病机制的洞察，从而为探索新的治疗方法奠定了基础。

PROJECT SUMMARY/ABSTRACT Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by sterile inflammation and high titer antibodies against self-antigens. Although the etiology of SLE is still unknown, cumulative evidence suggest that interferons (IFNs) might play a critical role in disease pathogenesis, likely with type I IFN (IFN-I) as the dominant mediator. While different mechanisms may dysregulate the production of IFN-I in SLE, studies for the last 20 years have been focused on immune complexes (ICs) containing genomic DNA and RNA–protein (RNP) complexes as critical players in TLR activation and the induction of IFN-I by plasmacytoid dendritic cells (pDCs). Recent paradigm shifting data, however, suggest that the mitochondria is an important source of interferogenic signals in SLE. In particular, upon activation with TLR7-agonist autoantibodies, SLE neutrophils release oxidized (Ox) mitochondrial DNA (mtDNA) in complex with transcription factor A mitochondria (TFAM), which together have an exceptional capacity to activate pDCs to produce IFN-I via TLR9 activation. Yet, mechanisms that modulate the delivery of Ox-mtDNA/TFAM complexes into TLR9 endosomes in SLE are not fully understood. Interestingly, our preliminary studies demonstrate for the first time that patients with SLE have autoantibodies to TFAM. Based on this premise, we hypothesize that anti-TFAM antibodies may facilitate the internalization and interferogenic response to Ox-mtDNA/TFAM complexes by pDCs, which may influence disease activity in SLE. The major goal of this proposal is to gain further insights into the potential significance of these novel hypotheses and preliminary findings in the context of SLE pathogenesis. In Aim 1, we will determine the prevalence and clinical associations of antibodies to TFAM and their relationship to the IFN-signature in a prospective observational cohort of patients with SLE, for which extensive clinical and serologic data is available, as well as IFN-induced gene expression analysis. In Aim 2, we will generate anti-TFAM monoclonal antibodies from single SLE anti-TFAM memory B cells to define their autoreactive origin [e.g. V(D)J usage, somatic hypermutations and determinants of antigen recognition], as well as their capacity and mechanism to activate pDCs in complex with Ox-mtDNA/TFAM. Together, these studies seek to enhance our understanding of self-immunogenic pathways underlying sterile inflammation and IFN production in SLE. The final goal of this work is to gain new insights into disease mechanisms, thus laying the foundation to explore novel therapies.