IRGM-Mediated Autoplay in Human Intestinal Epithelial Cells

IRGM 介导的人肠上皮细胞自动发挥作用

• 批准号: 7678717
• 负责人: Jeannette Sophia Messer
• 金额: $ 7.54万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7678717
• 关键词: Affect; American; Automobile Driving; Autophagocytosis; Autophagosome; Bacteria; Binding; Cell Line; Cells; Chronic; Clinical; Complement; Complex; Crohn' s disease; Data; Defect; Disease; Environmental Risk Factor; Epithelial Cells; Functional disorder; Gastrointestinal tract structure; Gene Mutation; Gene Targeting; Generations; Genes; Genetic; Genomics; Goals; Guanosine Triphosphate Phosphohydrolases; Hela Cells; Human; Immune; Immune response; Immunity; Immunosuppressive Agents; Infection; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Intestines; Investigation; Knock-in Mouse; Lead; Ligands; Light; Mediating; Membrane; Microtubules; Modeling; Mus; Mutation; Natural Immunity; Pathogenesis; Patients; Pharmaceutical Preparations; Phosphatidylethanolamine; Process; Proteins; Role; Salmonella typhimurium; Screening procedure; Single Nucleotide Polymorphism; Stimulus; Testing; cytokine; genome wide association study; immune function; improved; macrophage; microbial; mouse model; mutant; phosphatidylethanolamine; protein complex; protein protein interaction; response; small hairpin RNA; theories

DESCRIPTION (provided by applicant): Crohn's disease is a type of inflammatory bowel disease that affects hundreds of thousands of Americans. The pathophysiology of this disease is not well understood and current therapies largely consist of immunosuppressive medications to control clinical signs. Recent genomic screening studies have identified single nucleotide polymorphisms (SNPs) associated with Crohn's disease. Two of these SNPs are in the ATG16 autophagy related 16-like (ATG16L1) and immunity-related GTPase M (IRGM) genes, genes known to be involved in autophagy and clearance of intracellular bacteria. The association between Crohn's disease, ATG16L1, and IRGM suggests that immune responses to bacteria could be driving the inflammation seen in the gastrointestinal tract, an idea in keeping with current theories of Crohn's disease pathogenesis. To date, the role of ATG16L1 and IRGM in intestinal epithelial cell (IEC) autophagy and defense against intracelllular bacteria have not been examined. The goal of this study is to determine whether alterations in autophagy genes lead to aberrant intestinal innate immune responses to bacteria. We hypothesize that ATG16L1 and IRGM are essential for autophagy of intracellular bacteria in IEC and mutation or loss of either protein compromises the ability of IEC to autophagocytose and clear intracellular bacteria. We propose to test this hypothesis using human IEC lines that express the ATG16L1 T300A mutation or are deficient in ATG16L1 or IRGM. These cells will be treated with an inflammatory cytokine, microbial ligands, or infected with Salmonella typhimurium to evaluate autophagy and bacterial clearance (Aim1). We will also evaluate the role of ATG16L1 and IRGM in protein-protein interactions during autophagy to attempt to elucidate a mechanism for autophagic defects seen in cells deficient in ATG16L1 or IRGM (Aim2). Human intestinal epithelial cells are constantly in contact with bacteria in the gastrointestinal tract. Appropriate responses to these bacteria lead to control of inflammation and tolerance to the intestinal microbiota. If responses such as autophagy are altered, it could lead to generation of aberrant inflammation in the gastrointestinal tract, like that seen with Crohn's disease. The data generated in this study could lead to a better understanding of the functional consequences of the Crohn's associated autophagy gene mutations and an improved model of the pathophysiology of Crohn's disease.

描述（由申请人提供）：克罗恩病是一种影响数十万美国人的炎症性肠病。这种疾病的病理生理学尚不清楚，目前的治疗主要包括控制临床症状的免疫抑制药物。最近的基因组筛选研究已经确定了与克罗恩病相关的单核苷酸多态性 (SNP)。其中两个 SNP 位于 ATG16 自噬相关 16-like (ATG16L1) 和免疫相关 GTPase M (IRGM) 基因中，这些基因已知参与细胞内细菌的自噬和清除。克罗恩病、ATG16L1 和 IRGM 之间的关联表明，对细菌的免疫反应可能会导致胃肠道炎症，这一想法与克罗恩病发病机制的当前理论一致。迄今为止，ATG16L1 和 IRGM 在肠上皮细胞 (IEC) 自噬和细胞内细菌防御中的作用尚未得到研究。本研究的目的是确定自噬基因的改变是否会导致肠道对细菌的先天免疫反应异常。我们假设 ATG16L1 和 IRGM 对于 IEC 中细胞内细菌的自噬至关重要，并且任一蛋白质的突变或丢失都会损害 IEC 自噬和清除细胞内细菌的能力。我们建议使用表达 ATG16L1 T300A 突变或 ATG16L1 或 IRGM 缺陷的人类 IEC 系来检验这一假设。这些细胞将用炎症细胞因子、微生物配体处理，或用鼠伤寒沙门氏菌感染，以评估自噬和细菌清除（Aim1）。我们还将评估 ATG16L1 和 IRGM 在自噬过程中蛋白质-蛋白质相互作用中的作用，以试图阐明在 ATG16L1 或 IRGM 缺陷的细胞中观察到的自噬缺陷的机制 (Aim2)。人体肠上皮细胞不断与胃肠道中的细菌接触。对这些细菌的适当反应可以控制炎症并提高对肠道微生物群的耐受性。如果自噬等反应发生改变，可能会导致胃肠道产生异常炎症，就像克罗恩病那样。这项研究产生的数据可以帮助人们更好地了解克罗恩病相关自噬基因突变的功能后果，并改进克罗恩病的病理生理学模型。