Interplay of Innate and Adaptive Immunity in Lupus Pathogenesis

先天免疫和适应性免疫在狼疮发病机制中的相互作用

基本信息

批准号：
8662168
负责人：
Michelle L. Hermiston
金额：
$ 38.24万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-06-01 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8662168
关键词：
Adjuvant Amino Acid Substitution Antibodies Antigen-Antibody Complex Autoantibodies Autoimmune Diseases Autoimmunity B-Lymphocytes Backcrossings Biochemical Bone Marrow Candidate Disease Gene Cells Cessation of life Chimera organism Chromosomes, Human, Pair 9 Chronic Clinical Complex Computer Simulation Congenic Mice DNA Data Development Disease Genes Genetic Genetic Polymorphism Genetic Screening Glomerulonephritis Goals Homeostasis Human Hybrids Immune Immune System Diseases Immune system Inbred BALB C Mice Individual Leucine-Rich Repeat Ligand Binding Domain Ligands Lupus Lymphoproliferative Disorders Malignant lymphoid neoplasm Maps Mediating Modeling Molecular Molecular Models Mus Mutation Natural Immunity Organ PTPRC gene Pathogenesis Patients Peripheral Phenotype Phosphoric Monoester Hydrolases Process Production Relative (related person)Research Signal Pathway Signal Transduction System Systemic Lupus Erythematosus T-Lymphocyte TLR9 gene Testing Therapeutic Intervention Toll-like receptors Vaccines adaptive immunity anti-dsDNA antibodies arm autoreactivity defined contribution ds-DNA insight interest molecular modeling mouse model novel premature programs receptor response src-Family Kinases trafficking

项目摘要

DESCRIPTION (provided by applicant): Systemic Lupus Erythematosus (SLE) is a complex, polygenic disease. The delayed onset and variable pentetrance of SLE support the hypothesis that disease pathogenesis is a multi-step process. The highly variable clinical presentation of human SLE makes the study of this process difficult in patients. Here, we take advantage of a tractable and simplified genetic system, the CD45E613R mouse, to interrogate SLE pathogenesis. These mice express a single amino acid substitution that results in constitutive CD45 phosphatase activity. Mirroring the variable presentation of human SLE, the CD45E613R phenotype is extremely sensitive to genetic background. On a hybrid 129-C57Bl/6 (B6) background, CD45E613R mice develop anti-dsDNA antibodies and immune complex-mediated glomerulonephritis (GN). However, on a B6 genetic background mice lack autoantibodies despite biochemical hyper-responsiveness to receptor stimulation while BALB/c CD45E613R mice develop high-titer anti-dsDNA but no GN. We have taken advantage of the genetic separation of cellular hyper-responsiveness, autoantibody production, and end-organ damage to search for genetic modifiers required for disease. Here, we focus on the mechanisms governing the first two steps in SLE pathogenesis: Loss of tolerance to self and peripheral amplification of this autoreactivity. The goal of Aim 1 is to define the contributions of two novel loci we recently identified, Wam1 and Wam2, to autoantibody production. Congenic mice will be generated to test how these loci regulate the threshold for tolerance in the context of hyperactive CD45 phosphatase activity. In Aim 2, we evaluate the contributions of a promising candidate gene in Wam1, Toll Like Receptor (TLR) 9, to disease pathogenesis. Molecular modeling of the TLR9 polymorphisms indicate they map to leucine rich repeats in the DNA ligand binding domain. Our preliminary data indicate differential responses to TLR9 stimulation between B6 and BALB/c mice. These differences are further modulated by the CD45E613R mutation, indicating a novel interaction between CD45 and TLR9 signaling networks. We will use genetic and mixed bone-marrow chimera approaches to define the impact of TLR9 on autoantibody production and identify the cellular compartments in which it must function in CD45E613R mice. The focus of Aim 3 is to interrogate the cellular and molecular mechanisms by which the TLR9 polymorphisms and the CD45E613R mutation regulate tolerance. We will evaluate whether the observed differences are due to altered interaction with ligand, perturbations in intracellular trafficking, and/or altered signal transduction networks. Results of these studies will not only help elucidate the mechanisms governing tolerance, but should provide new insights into how the adaptive and innate arms of the immune system interact in systemic autoimmunity. This is a topic of significant importance in the pathogenesis of autoimmune disease in humans and has broad impact given the growing interest in targeting TLRs in the treatment of autoimmune disease and as an adjuvant in vaccine strategies.

描述（由申请人提供）：系统性红斑狼疮（SLE）是一种复杂的多基因疾病。 SLE 的延迟发病和可变的五分率支持疾病发病机制是一个多步骤过程的假设。人类系统性红斑狼疮临床表现的高度可变性使得在患者中研究这一过程变得困难。在这里，我们利用易于处理且简化的遗传系统 CD45E613R 小鼠来探究 SLE 发病机制。这些小鼠表达单个氨基酸取代，从而产生组成型 CD45 磷酸酶活性。 CD45E613R 表型反映了人类 SLE 的可变表现，对遗传背景极其敏感。在杂交 129-C57Bl/6 (B6) 背景下，CD45E613R 小鼠产生抗 dsDNA 抗体和免疫复合物介导的肾小球肾炎 (GN)。然而，B6 遗传背景的小鼠尽管对受体刺激具有生化高反应性，但缺乏自身抗体，而 BALB/c CD45E613R 小鼠产生高滴度的抗 dsDNA，但没有 GN。我们利用细胞高反应性、自身抗体产生和终末器官损伤的遗传分离来寻找疾病所需的遗传修饰剂。在这里，我们重点关注控制 SLE 发病机制前两个步骤的机制：自身耐受性丧失和自身反应性的外周放大。目标 1 的目标是确定我们最近确定的两个新位点 Wam1 和 Wam2 对自身抗体产生的贡献。将生成同类小鼠来测试这些基因座如何在 CD45 磷酸酶活性过度活跃的情况下调节耐受阈值。在目标 2 中，我们评估了 Wam1 中一个有前途的候选基因 Toll 样受体 (TLR) 9 对疾病发病机制的贡献。 TLR9 多态性的分子模型表明它们映射到 DNA 配体结合域中富含亮氨酸的重复序列。我们的初步数据表明 B6 和 BALB/c 小鼠对 TLR9 刺激的反应存在差异。这些差异进一步受到 CD45E613R 突变的调节，表明 CD45 和 TLR9 信号网络之间存在新的相互作用。我们将使用遗传和混合骨髓嵌合体方法来确定 TLR9 对自身抗体产生的影响，并确定 TLR9 在 CD45E613R 小鼠中必须发挥作用的细胞区室。目标 3 的重点是探究 TLR9 多态性和 CD45E613R 突变调节耐受性的细胞和分子机制。我们将评估观察到的差异是否是由于与配体相互作用的改变、细胞内运输的扰动和/或信号转导网络的改变所致。这些研究的结果不仅有助于阐明控制耐受性的机制，而且应该为免疫系统的适应性和先天性臂如何在系统性自身免疫中相互作用提供新的见解。这是人类自身免疫性疾病发病机制中一个非常重要的话题，并且鉴于人们对靶向 TLR 来治疗自身免疫性疾病以及作为疫苗策略的佐剂的兴趣日益浓厚，因此具有广泛的影响。