Analysis of MyD88-mediated immune activation in Sjogren's syndrome pathogenesis

项目总结/摘要 干燥综合征（SS）是一种自身免疫性疾病，其外分泌组织受损，导致泪液丢失 和唾液分泌。SS的诊断是具有挑战性的，患者经常经历多年的症状 在他们被诊断之前。一旦确诊，没有SS特异性治愈性治疗选择; 而SS的治疗是姑息性的。因此，迫切需要确定病因学事件， SS的早期诊断和减轻或消除这种使人衰弱的疾病的进展。即使 免疫系统是SS的驱动因素，但有关SS发生机制的研究报道较少。 对狼疮（一种相关的自身免疫性疾病）的研究表明， 反应蛋白88（MyD 88）是疾病发展的关键。MyD 88是一种衔接分子， Toll样受体（TLR）广泛表达，是大多数TLR信号传导所必需的。值得注意的是， 局部（唾液组织）和SS患者的外周血细胞中，表明TLR信号传导有助于SS 发病机制令人惊讶的是，MyD 88和TLR信号转导的作用尚未在SS中进行深入评估。我们 中心假设是MyD 88在唾液组织和免疫细胞中的表达对于SS的起始至关重要 以及TLR信号通过MyD 88驱动SS发病机制。我们的目标是评估 MyD 88介导的信号传导有助于SS的方式，并鉴定激活TLR的特异性因子 SS中的信号通路。我们将使用SS小鼠模型（NOD.B10）和我们最近开发的敲除品系 NOD.B10小鼠缺乏MyD 88。这些小鼠提供了检查MyD 88在SS中的作用的机会。我们 我们将通过以下具体目的来检验我们的假设：（1）确定MyD 88是否表达。 造血细胞是SS发病所必需的。这些实验将检查自身抗体的产生， 唾液功能，以确定造血内在MyD 88表达是否对特定SS疾病至关重要 表现。(2)探讨MyD 88在SS自身抗体产生及致病中的作用。 这些结果将确定MyD 88在SS自身抗体发展中的作用，并将确定是否 来源于MyD 88-/- NOD.B10小鼠的抗体在体内的致病性降低。(3)调查的作用 SS中MyD 88依赖性TLR 2/4活化。我们将确定唾液组织中是否通过TLR 2/4信号传导 以MyD 88依赖的方式促进SS。我们还将过度表达一种特定的损伤相关基因， 以MyD 88依赖的方式激活TLR 2/4的分子模式，以确定这是否加速SS。 最后，我们将评估TLR 2和TLR 4阻断SS，以确定这些是否减轻疾病。本研究 它的创新之处在于它将采用一种新的小鼠模型来评估MyD 88的作用，MyD 88是一种关键的免疫信号传导， 分子，以SS计。该提案意义重大，因为它将提供有关MyD 88作用的新知识， TLR 2/4信号在SS发生和发展中的作用这项工作将奠定基础，为今后的研究，以确定 针对TLR/MyD 88相关通路的SS和其他自身免疫性疾病患者的治疗剂。

Project Summary/ Abstract Sjögren's syndrome (SS) is an autoimmune disease in which exocrine tissue is damaged, resulting in loss of tears and saliva production. The diagnosis of SS is challenging and patients often experience symptoms for years before they are diagnosed. Once diagnosis is achieved, no SS-specific curative treatment options are available; rather treatments for SS are palliative. Thus, there is a critical need to identify etiologic events that will facilitate earlier diagnosis of SS and mitigate or abrogate the progression of this debilitating disease. Even though the immune system drives SS, few mechanistic studies of the seminal factors responsible for SS are reported. Studies in lupus, a related autoimmune disease, demonstrated that Myeloid Differentiation Factor Primary Response Protein 88 (MyD88) is critical for disease development. MyD88 is an adaptor molecule that is expressed ubiquitously and is required for most Toll-like receptor (TLR) signaling. Notably, TLRs are elevated locally (in salivary tissue) and in peripheral blood cells of SS patients, suggesting TLR signaling contributes to SS pathogenesis. Surprisingly, the role of MyD88 and TLR signaling has not been evaluated in depth in SS. Our central HYPOTHESES are that MyD88 expression in salivary tissue and in immune cells is crucial for SS initiation and progression and that TLR signals via MyD88 drive SS pathogenesis. Our OBJECTIVE is to evaluate the means by which MyD88-mediated signaling contributes to SS and to identify specific factors that activate TLR signaling pathways in SS. We will use a SS mouse model (NOD.B10) and our recently developed knockout strain of NOD.B10 mice that lack MyD88. These mice provide the opportunity to examine the role of MyD88 in SS. We will test our hypotheses through the following Specific Aims: (1) To determine whether MyD88 expression by hematopoietic cells is required for SS pathogenesis. These experiments will examine autoantibody production and salivary function to determine whether hematopoietic-intrinsic MyD88 expression is crucial for specific SS disease manifestations. (2) To evaluate the role of MyD88 in the generation and pathogenicity of autoantibodies in SS. These results will identify the role of MyD88 in the development of autoantibodies in SS, and will establish whether antibodies derived from MyD88-/- NOD.B10 mice have reduced pathogenicity in vivo. (3) To investigate the role of MyD88-dependent TLR2/4 activation in SS. We will determine whether signaling via TLR2/4 in salivary tissue contributes to SS in a MyD88-dependent manner. We will also overexpress a specific damage-associated molecular pattern that activates TLR2/4 in a MyD88-dependent manner to determine whether this accelerates SS. Finally, we will assess TLR2 and TLR4 blockade in SS to determine whether these attenuate disease. This study is innovative in that it will employ a novel mouse model to evaluate the role of MyD88, a key immune signaling molecule, in SS. The proposal is significant, as it will provide new knowledge regarding the role of MyD88 and TLR2/4 signaling in SS initiation and progression. This work will lay the foundation for future studies to identify therapeutics for patients with SS and other autoimmune diseases that target TLR/MyD88-related pathways.