Role of Gene-Microbial Interactions in the Development of Crohn's Disease-like Colitis

基因-微生物相互作用在克罗恩病样结肠炎发展中的作用

基本信息

批准号：
10642900
负责人：
Gabriel Nunez
金额：
$ 42.37万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
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：
2019-09-20 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10642900
关键词：
Adult Affect Animal Model Applications Grants Automobile Driving Bacteria Breast Feeding CYBA gene Cell Lineage Cells Characteristics Childhood Chronic Chronic Granulomatous Disease Colitis Colon Complex Crohn&apos s disease Development Diet Digestive System Disorders Disease Enterobacteriaceae Environmental Risk Factor Exhibits Fiber Gastrointestinal Diseases Gastrointestinal tract structure Genes Genetic Genetic Polymorphism Gnotobiotic Gram-Negative Anaerobic Bacteria Heterozygote House mice Human Immune Immune response Immunoglobulins Impairment Individual Inflammation Inflammatory Inflammatory Bowel Diseases Intestines Invaded Knock-in Mouse Location Microbe Mucosal Immune Responses Mucous body substance Mus Mutant Strains Mice Mutation NADP NADPH Oxidase Natural Immunity Neutrophil Infiltration Oxidases Pathogenesis Pathologic Pathology Patients Phagocytes Play Predisposition Proteins Regulation Relapse Respiratory Burst Role Secondary to Testing Variant disorder control dysbiosis early onset genetic risk factor germ free condition gut inflammation gut microbiota high risk loss of function loss of function mutation microbiota microorganism interaction neutrophil pathobiont patient subsets prevent

项目摘要

ABSTRACT Crohn’s disease (CD), one of the major forms of Inflammatory Bowel Disease (IBD), is a complex disorder marked by chronic relapsing inflammation driven by CD4+ T helper 1 (TH1) cells that can affect any part of the gastrointestinal tract. CD is thought to result from an inappropriate mucosal immune response to the intestinal microbiota in genetically susceptible individuals. Consistent with this notion, CD patients harbor a dysbiotic microbiota. However, it remains unclear if the CD-associated dysbiosis plays a casual role or is secondary to inflammation. More than 100 loci predispose to CD of which polymorphisms in NOD2 are the strongest known genetic risk factor for disease development in adult and pediatric onset CD. However, the great majority of individuals homozygous for NOD2 CD-associated variants do not develop CD and no spontaneous intestinal inflammation mimicking CD occurs in Nod2−/− mice or knockin mice homozygous for the CD-associated L1007insC NOD2 variant. These findings suggest that additional genetic and/or environmental factors are critical for disease development. We found that combined, but not single deficiency, of NOD2 and phagocyte NAPDH oxidase activity triggers early-onset spontaneous TH1-type intestinal inflammation in mice with the pathological and immune hallmarks of CD. Development of disease required the presence of Mucispirillum schaedleri, a Gram-negative anaerobic bacterium that is an inhabitant of the colonic mucus layer of normal mice. The absence of NOD2 and CYBB led to marked accumulation of Mucispirillum in the gut which was associated with impaired recruitment of neutrophils and killing of the bacterium by luminal neutrophils. Mutant mice were protected from disease by maternal immunoglobulins against Mucispirillum during breastfeeding. These results indicate that a specific intestinal microbe can trigger CD-like disease in the presence of impaired clearance of the bacterium by innate immunity. We hypothesize that NOD2 and the NAPDH oxidase regulate the susceptibility to CD by controlling the abundance and local invasion of specific pathobionts such as Mucispirillum. We further hypothesize that killing of specific microbes by neutrophils regulated via NOD2 and NAPDH oxidase is important to prevent the development of CD-like disease. Finally, we hypothesize that targeting colitis-causing pathobionts such as Mucispirillum using diet could be an approach to treat CD-like colitis. In this grant application, we propose three specific Aims to understand the role of NOD2 and phagocyte NAPDH oxidase in the regulation of the microbiota and induction of colitis using a new animal model that exhibit pathology and immune alterations characteristic of CD.

抽象的克罗恩病 (CD) 是炎症性肠病 (IBD) 的主要形式之一，是一种复杂的疾病其特点是由 CD4+ T 辅助 1 (TH1) 细胞驱动的慢性复发性炎症，可影响全身的任何部位 CD被认为是由肠道粘膜免疫反应不当引起的。与这一观点一致的是，CD 患者体内存在菌群失调。然而，目前尚不清楚 CD 相关的菌群失调是偶然的还是继发的。超过 100 个位点易患 CD，其中 NOD2 的多态性已知最强。成人和儿童 CD 发病的遗传危险因素绝大多数。 NOD2 CD 相关变异纯合子个体不会发展为 CD，也不会出现自发性肠病炎症模拟 CD 发生在 Nod2−/− 小鼠中，敲入小鼠与 CD 相关的纯合子 L1007insC NOD2 变异体。这些发现表明额外的遗传和/或环境因素。我们发现 NOD2 和吞噬细胞的联合缺陷而非单一缺陷。 NAPDH 氧化酶活性引发小鼠早发自发性 TH1 型肠道炎症 CD 的病理和免疫特征是疾病的发展需要粘螺菌的存在。 schaedleri，一种革兰氏阴性厌氧细菌，是正常结肠粘液层的居民 NOD2 和 CYBB 的缺失导致粘螺菌在小鼠肠道中显着积聚。与中性粒细胞募集受损和突变型中性粒细胞杀死细菌有关。在母乳喂养期间，母体针对粘螺菌的免疫球蛋白可以保护小鼠免受疾病的侵害。这些结果表明，在存在受损的肠道微生物的情况下，特定的肠道微生物可以引发 CD 样疾病。我们认为 NOD2 和 NAPDH 氧化酶可以调节细菌的清除。通过控制特定病原体的丰度和局部侵袭来降低 CD 的易感性，例如我们进一步研究了通过 NOD2 调节的中性粒细胞对特定微生物的杀灭作用。 NAPDH 氧化酶对于预防 CD 样疾病的发展非常重要。使用饮食来靶向引起结肠炎的病原体（例如粘螺菌）可能是治疗 CD 样疾病的一种方法在这项拨款申请中，我们提出了三个具体目标来了解 NOD2 和吞噬细胞的作用。 NAPDH 氧化酶在调节微生物群和诱导结肠炎中使用新的动物模型表现出 CD 的病理学和免疫改变特征。