Mechanisms by which TLR9-deficiency and FasL Promote Cutaneous Lupus

TLR9 缺陷和 FasL 促进皮肤狼疮的机制

基本信息

批准号：
9884735
负责人：
Ann Marshak-Rothstein
金额：
$ 20.94万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-03-05 至 2022-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9884735
关键词：
Address Animal Model Apoptosis Autoantibodies Autoimmune Diseases Autoimmunity Automobile Driving B-Lymphocytes Basement membrane Binding Biopsy CASP8 gene CCL8 gene Cell Death Cells Cessation of life Chimeric Proteins Clinical Cutaneous Data Dendritic Cells Deposition Dermal Dermatitis Development Disease Exhibits Flare Functional disorder Gene Expression Gene Targeting Generations Goals Hematopoietic Histologic Immunosuppressive Agents In Vitro Inflammation Inflammatory Interferon Type II Interleukin-17 Langerhans cell Ligands Lupus MHC Class II Genes Membrane Modeling Molecular Chaperones Mus Mutation Myeloid Cells Pathogenesis Pathway interactions Patients Process Production Psoriasis Radiation Chimera Recurrence Regulation Reproducibility Role Signal Pathway Signal Transduction Site Skin Structure of germinal center of lymph node System T-Lymphocyte TLR7 gene Th1 Cells Tissues Treatment Efficacy UV Radiation Exposure Up-Regulation Work chemokine cytokine draining lymph node effector T cell human disease in vivo insight keratinocyte lupus cutaneous lupus-like mouse model novel patient population prevent protein expression radioresistant response side effect skin lesion skin organogenesis small molecule inhibitor therapeutic target trafficking

Address Animal Model Apoptosis Autoantibodies Autoimmune Diseases Autoimmunity Automobile Driving B-Lymphocytes Basement membrane Binding Biopsy CASP8 gene CCL8 gene Cell Death Cells Cessation of life Chimeric Proteins Clinical Cutaneous Data Dendritic Cells Deposition Dermal Dermatitis Development Disease Exhibits Flare Functional disorder Gene Expression Gene Targeting Generations Goals Hematopoietic Histologic Immunosuppressive Agents In Vitro Inflammation Inflammatory Interferon Type II Interleukin-17 Langerhans cell Ligands Lupus MHC Class II Genes Membrane Modeling Molecular Chaperones Mus Mutation Myeloid Cells Pathogenesis Pathway interactions Patients Process Production Psoriasis Radiation Chimera Recurrence Regulation Reproducibility Role Signal Pathway Signal Transduction Site Skin Structure of germinal center of lymph node System T-Lymphocyte TLR7 gene Th1 Cells Tissues Treatment Efficacy UV Radiation Exposure Up-Regulation Work chemokine cytokine draining lymph node effector T cell human disease in vivo insight keratinocyte lupus cutaneous lupus-like mouse model novel patient population prevent protein expression radioresistant response side effect skin lesion skin organogenesis small molecule inhibitor therapeutic target trafficking

展开

项目摘要

ABSTRACT Common pathophysiological mechanisms are thought to promote the cutaneous and systemic manifestations of lupus. Thus a better understanding of the factors that promote CLE are likely to provide important insights as far as the pathogenesis of SLE. Nevertheless, it is also likely that tissue specific effector mechanisms account for the diverse clinical presentations exhibited by SLE patient populations. Since 75% of SLE patients exhibit skin lesions of some sort, and UV exposure of the skin is often associated with lupus flares, it is surprising that there have been relatively few mechanistic studies that address initiation, progression and recurrence of CLE. One reason for this gap is that murine models available for the study of CLE have been limited – despite the numerous murine models of SLE, models that accurately reflect the central features of CLE are much more limited. We have now develop an inducible model of lupus like skin inflammation (LLSI), initiated by T cell transfer, that recapitulates many of the features of CLE. These include a prominent role for skin-infiltrating IFNγ-producing Th1 cells, excessive keratinocyte death, autoantibody deposition at the dermal/epidermal border, increased expression of CxCL9, CxCL10, CxCL11, CCL8, and accumulation of pDCs in the skin. There are also mechanistic similarities between our LLSI model and other inducible as well as genetically programmed murine models of SLE; they all depend on the expression of TLR7 and are exacerbated by the absence of TLR9. Therefore our LLSI mice provide a novel, rapid and reproducible system for exploring the effector mechanisms responsible for the induction and regulation of cutaneous lupus. This application will focus on TLR9 and FasL. As mentioned, TLR9 negatively regulates the development of both cutaneous and systemic lupus, but whether TLR9 works passively by simply competing with TLR7 for access to the endosomal trafficking chaperone Unc93B1, or actively by inducing molecules dependent on a TLR9 signaling cascade that limit inflammation, has not been addressed. We have also recently shown that the development of skin lesions is completely dependent T cell FasL expression, but whether FasL promotes disease indirectly by inducing cell death and creating cell debris and/or directly by inducing the production of pro-inflammatory cytokines is unresolved. Interplay between TLR9 and FasL may be an important amplification loop in LLSI - TLR ligands induce upregulation of Fas and FasL generates cell debris that can activate endosomal TLRs. We propose to address the questions by using gene-targeted mice with discriminating mutations for both in vitro and in vivo (LLSI) studies. In Aim 1, we will use mice that express normal levels of a form of TLR9 that cannot engage MyD88, and in Aim 2, we will use mice that express a Caspase 8 mutation which removes the Caspase 8 autocleavage site and thereby prevents FasL-induced apoptosis but not chemokine production. Together, these studies should help identify the most effective therapeutic strategies for targeting TLR9 and FasL pathways to prevent or ameliorate the development of cutaneous lupus.

抽象的人们认为常见的病理生理机制可以促进皮肤和全身表现狼疮。更好地理解促进CLE的因素可能会提供重要的见解与SLE的发病机理无关。然而，组织特异性效应器机制也很可能说明对于SLE患者人群展示的潜水员临床演示。由于75％的SLE患者表现出来某种皮肤病变，皮肤的紫外线通常与狼疮耀斑有关，令人惊讶的是相对较少的机械研究解决了CLE的开始，进展和复发。此差距的原因之一是可用于研究CLE的鼠模型受到限制 - dospite 众多的SLE鼠模型，准确反映CLE的主要特征的模型更多有限的。现在，我们已经开发了狼疮的诱导型模型，例如皮肤感染（LLSI），由T细胞引发转移，这概括了CLE的许多特征。这些包括浸入皮肤的重要作用产生IFNγ的Th1细胞，过多的角质形成病死亡，皮肤/表皮上的自身抗体沉积边界，CXCL9，CXCL10，CXCL11，CCL8的表达增加，以及PDC在皮肤中的积累。那里我们的LLSI模型与其他诱导性以及一般的机械相似性也是 SLE的编程鼠模型；它们都取决于TLR7的表达，并因缺乏TLR9。因此，我们的LLSI小鼠提供了一种新颖，快速且可再现的系统，用于探索效应器机制，负责皮肤狼疮的诱导和调节。此应用程序将专注于TLR9和FASL。如前所述，TLR9对皮肤和系统性狼疮，但是TLR9是否通过简单地与TLR7竞争以访问该蛋内体运输伴侣UNC93B1，或通过诱导分子积极地取决于TLR9信号传导限制注入的级联尚未解决。我们最近还表明了发展皮肤病变的完全依赖性T细胞FASL表达，但FASL是否间接促进疾病通过摄入细胞死亡并创建细胞碎片和/或直接通过产生促炎性的产生细胞因子尚未解决。 TLR9和FASL之间的相互作用可能是LLSI - TLR配体诱导FAS和FASL的上调会产生可以激活内体TLR的细胞碎片。我们提议通过使用具有区分突变的基因靶向小鼠来解决问题和体内（LLSI）研究。在AIM 1中，我们将使用表达正常水平的TLR9形式的小鼠参与MyD88，在AIM 2中，我们将使用表达caspase 8突变的老鼠 caspase 8自身分解位点，从而防止FASL诱导的细胞凋亡，但不能防止趋化因子产生。这些研究共同帮助确定针对TLR9和的最有效的治疗策略防止或改善皮肤狼疮的发展的FASL途径。