Viral infections and celiac disease pathogenesis

项目总结/摘要 拟议研究的中心目标是确定病毒感染导致细胞丧失的机制。 耐受性（LOT）和诱导乳糜泻（CD），并设计策略，以防止病毒- 诱导LOT和CD发作。病毒感染越来越被认为是导致 自身免疫性炎症性疾病的发病机制。然而，人们对这种生物学特征知之甚少， 使病毒能够引起炎性组织损伤。CD是一种T细胞介导的肠道疾病， 一种自身免疫成分，其特征是发生炎症性抗麸质免疫反应， 仅在具有HLA DQ 2或DQ 8等位基因的麸质暴露者中。大约45%的美国 人群表达DQ 2或DQ 8，但只有1%的人群发生疾病，表明 其他因素也有助于疾病的诱发。呼肠孤病毒是最近与CD相关的人dsRNA病毒。 这些病毒感染小鼠肠道，并且可以通过遗传操作来鉴定病毒决定簇， 自身免疫宿主反应。我们发现呼肠孤病毒株T1 L消除了对饮食抗原的耐受性， 包括使用依赖于IRF 1的途径的谷蛋白，而菌株T3 D-RV不依赖于IRF 1。诱导保护性 对T1 L免疫通过与免疫病理学所需不同的机制发生。我们建议 增强对病毒如何影响自身免疫性炎症发展的理解 通过鉴定影响LOT对饮食抗原的病毒和宿主因素， 并确定阻断病毒诱导的LOT和CD发展的策略。为了实现这一目标，我们 设计了三个完整的具体目标。在具体目标1中，我们将定义病毒决定因素， 负责使用T1 L x T3 D-RV重组病毒和工程化病毒进行LOT的相关宿主途径 突变体以定义负责LOT的蛋白产物的功能结构域。我们将阐明 使用缺乏IRF 1或IRF 1诱导的小鼠在呼肠孤病毒感染后的潜在IRF 1介导的TH 1免疫 特定细胞类型的因子。在具体目标2中，我们将定义T1 L和T3 D-RV感染对 微生物群落的组成。我们还将确定肠道微生物群的贡献， 通过在有和没有定义的免疫缺陷病毒治疗和无菌小鼠中评估LOT来评估呼肠孤病毒诱导的LOT 微生物群在具体目标3中，我们将定义T1 L感染和面筋引入的时间关系 使用经工程改造以表达人DQ 8风险等位基因的小鼠进行LOT。我们将测试是否接种 在谷蛋白引入之前灭活或减毒的呼肠孤病毒防止由T1 L介导的LOT。这个项目 扩展了国际公认的PI与CD互补专业知识的富有成效的合作， 粘膜免疫学和病毒学。通过这些努力获得的知识将增进对 病毒感染如何导致胃肠道炎症性疾病的发展， 在遗传易感人群中预防CD的策略。

PROJECT SUMMARY/ABSTRACT The central goal of the proposed research is to determine mechanisms by which viral infections lead to loss of tolerance (LOT) to oral antigen and induce celiac disease (CD) and to design strategies to prevent virus- induced LOT and CD onset. Viral infections are increasingly recognized as contributing factors in the pathogenesis of autoimmune inflammatory diseases. However, little is known about the biological features that enable a virus to provoke inflammatory tissue injury. CD is a T cell-mediated intestinal disorder with an autoimmune component characterized by an inflammatory anti-gluten immune response that occurs exclusively in gluten-exposed persons with HLA DQ2 or DQ8 alleles. Approximately 45% of the U.S. population expresses DQ2 or DQ8, yet only 1% of the population develops the disease, indicating that additional factors contribute to disease induction. Reoviruses are human dsRNA viruses recently linked to CD. These viruses infect the murine intestine and can be genetically manipulated to identify viral determinants of autoimmune host responses. We discovered that reovirus strain T1L abrogates tolerance to dietary antigens including gluten using a pathway dependent on IRF1, whereas strain T3D-RV does not. Induction of protective immunity to T1L occurs by a mechanism distinct from that required for immunopathology. We propose to enhance an understanding of how viruses influence the development of autoimmune inflammatory disorders and prevent CD by identifying virus and host factors that influence LOT to dietary antigen and defining strategies to block virus-induced LOT and CD development. To achieve this goal, we have designed three well-integrated specific aims. In Specific Aim 1, we will define the viral determinants and associated host pathways responsible for LOT using T1L x T3D-RV reassortant viruses and engineered viral mutants to define functional domains of protein products responsible for LOT. We will elucidate mechanisms underlying IRF1-mediated TH1 immunity following reovirus infection using mice lacking IRF1 or IRF1-inducing factors in specific cell types. In Specific Aim 2, we will define the effect of T1L and T3D-RV infection on the composition of microbial communities. We will also determine the contribution of the intestinal microbiota to reovirus-induced LOT by assessing LOT in antibiotic-treated and germ-free mice with and without defined microbiota. In Specific Aim 3, we will define the temporal relationship of T1L infection and gluten introduction on LOT using mice engineered to express the human DQ8 risk allele. We will test whether inoculation with inactivated or attenuated reovirus prior to gluten introduction prevents LOT mediated by T1L. This project extends a productive collaboration of internationally recognized PIs with complementary expertise in CD, mucosal immunology, and virology. Knowledge gained through these efforts will enhance an understanding of how viral infections lead to the development of gastrointestinal inflammatory disorders and foster new strategies to prevent CD in genetically vulnerable individuals.