Role of Innate Immunity and Stat3 Activation in Colitis Mouse Model

先天免疫和 Stat3 激活在结肠炎小鼠模型中的作用

基本信息

批准号：
8077402
负责人：
Shervin Rabizadeh
金额：
$ 17.01万
依托单位：
CEDARS-SINAI MEDICAL CENTER
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：
2010-07-01 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8077402
关键词：
Acetylmuramyl-Alanyl-Isoglutamine Acute Address Adoptive Transfer Adult Affect American Anaerobic Bacteria Bacteria Bacteroides fragilis Binding Bone Marrow Bone Marrow Transplantation C57BL/6 Mouse CD4 Positive T Lymphocytes Caspase Cell Lineage Cells Chronic Colitis Colon Colorectal Cancer Crohn&apos s disease Data Defect Diagnostic Procedure Disease Enterobacteriaceae Epithelial Epithelial Cells Exhibits Family member Gastrointestinal tract structure Gene Mutation Genes Genotype Hematopoietic Hour Human Immune Immune response Immune system Immunohistochemistry Immunologics Immunology procedure In Vitro Individual Inflammation Inflammatory Inflammatory Bowel Diseases Interleukin-17 Intestines Investigation Knockout Mice Laboratories Life Light Link Metalloproteases Methods Modeling Molecular Morbidity - disease rate Mus Natural Immunity Nucleotides Outcome Pathogenesis Pathway interactions Patients Permeability Phenotype Play Proteins Public Health RIPK2 gene RNA analysis Receptor Signaling Regulation Relative (related person)Research Research Project Grants Resistance Rodent Role Secondary to Signal Pathway Signal Transduction Single Nucleotide Polymorphism Stat3 protein Structure Testing Time Toll-like receptors Toxin Ulcerative Colitis Virulence Factors Work Zinc base cytokine data modeling genome wide association study human disease improved in vivo insight interest mouse model novel novel diagnostics novel therapeutics pathogen public health relevance research study response transcription factor

项目摘要

DESCRIPTION (provided by applicant): Inflammatory bowel disease (IBD), Crohn's disease or ulcerative colitis, affects an estimated 1.4 million Americans and is manifested by chronic inflammation of the gastrointestinal tract with significant morbidity and, at times, life-threatening complications. IBD is proposed to result from a dysregulated mucosal immune (innate and adaptive) response to the colonic flora in genetically susceptible individuals. Bacteroides fragilis is a common human commensal residing in the colon. A subset of B. fragilis, enterotoxigenic B. fragilis (ETBF), has been associated with inflammatory diarrheal disease, IBD, and colorectal cancer. Our ETBF murine model data shows that colonization with ETBF leads to a proinflammatory response exhibiting a predominant Th17 (interleukin 17-secreting) CD4+ T cell infiltrate promoted by signal transducer and activator of transcription-3 (Stat3) in C57BL/6 mice. The presence of activated Stat3 as well as colitis is evident within hours of orogastric inoculation with ETBF. However, there have been no investigations to date regarding the role of the innate immune system in ETBF colitis. IL-17 skewing has been recently demonstrated in a different infectious model involving downstream products of the Nucleotide-binding oligomerization domain containing (NOD) innate immune pathway. There is a strong association of NOD2 gene mutations and Crohn's disease. Hence, this data supports that innate immune factors and signal transducer and activator of transcription 3 (Stat3) plays a major role in the ETBF mouse model of colitis providing insight into the genesis of Inflammatory Bowel Disease. The objective of this research project is to address the role of the innate immune signaling pathways, in particular the NOD/Rip2 and toll like receptor (TLR)/MyD88, in the ETBF-induced colitis model. We will test the hypothesis that MyD88-/- and Rip2-/- mice will exhibit enhanced ETBF-induced colitis and Stat3 activation. To that end, the following Specific Aims are proposed: Specific Aim 1: To evaluate the role of NOD/Rip2 and TLR/MyD88 innate immune pathways in response of ETBF induced colitis using various genetically manipulated mice; Specific Aim 2: To define the role of Stat3 activation in the pathogenesis of ETBF-induced colitis in the NOD/Rip2- and TLR/MyD88- deficient mice; Specific Aim 3: To determine the role of TLR/MyD88 and NOD/Rip2 deficiency in hematopoietic versus non-hematopoietic derived cells on Stat3 activation and the pathogenesis of ETBF-induced colitis by creating and utilizing chimeric mice derived via bone marrow (BM) transplantation. The project will use the murine (C57BL/6) model of ETBF-induced colitis and various immunologic assays, knock-out mice, bone marrow transplantation, immunohistochemistry, flow cytometery, cytokine and RNA analysis. The significance of this research is that it will allow insight into the dysregulated immune response to colonic bacteria associated with IBD, a disorder with substantial morbidity, with hopes for new therapeutic insights to this prevalent disease. PUBLIC HEALTH RELEVANCE: This study examines the role of innate immune system, specifically TLR and NOD receptor signaling pathways, and the role of signal transducer and activator of transcription 3 (Stat3) in a bacteria induced colitis mouse model. Information obtained from this study will allow insight into the dysregulated immune response associated with IBD, a disorder with substantial morbidity.

描述（由申请人提供）：炎症性肠病 (IBD)、克罗恩病或溃疡性结肠炎影响了大约 140 万美国人，其表现为胃肠道慢性炎症，发病率很高，有时还会出现危及生命的并发症。 IBD 被认为是由遗传易感个体对结肠菌群的粘膜免疫（先天性和适应性）反应失调引起的。脆弱拟杆菌是一种存在于结肠中的常见人类共生菌。脆弱拟杆菌的一个亚群，产肠毒素脆弱拟杆菌 (ETBF)，与炎症性腹泻病、IBD 和结直肠癌有关。我们的 ETBF 小鼠模型数据显示，ETBF 定植会导致促炎反应，在 C57BL/6 小鼠中表现出主要的 Th17（分泌白细胞介素 17）CD4+ T 细胞浸润，并由信号转导器和转录 3 激活剂 (Stat3) 促进。口胃接种 ETBF 后数小时内，活化的 Stat3 和结肠炎的存在就很明显。然而，迄今为止还没有关于先天免疫系统在 ETBF 结肠炎中的作用的研究。最近在涉及包含核苷酸结合寡聚化结构域 (NOD) 先天免疫途径下游产物的不同感染模型中证明了 IL-17 倾斜。 NOD2 基因突变与克罗恩病密切相关。因此，该数据支持先天免疫因子和信号转导子和转录激活子 3 (Stat3) 在 ETBF 小鼠结肠炎模型中发挥着重要作用，为深入了解炎症性肠病的起源提供了依据。该研究项目的目的是探讨先天免疫信号通路的作用，特别是 NOD/Rip2 和 Toll 样受体 (TLR)/MyD88 在 ETBF 诱导的结肠炎模型中的作用。我们将测试 MyD88-/- 和 Rip2-/- 小鼠将表现出增强的 ETBF 诱导的结肠炎和 Stat3 激活的假设。为此，提出以下具体目标：具体目标 1：使用各种基因操作小鼠评估 NOD/Rip2 和 TLR/MyD88 先天免疫途径在 ETBF 诱导的结肠炎反应中的作用；具体目标 2：确定 Stat3 激活在 NOD/Rip2 和 TLR/MyD88 缺陷小鼠中 ETBF 诱导的结肠炎发病机制中的作用；具体目标 3：通过创建和利用通过骨髓 (BM) 移植衍生的嵌合小鼠，确定造血细胞与非造血来源细胞中 TLR/MyD88 和 NOD/Rip2 缺陷对 Stat3 激活的作用以及 ETBF 诱导的结肠炎的发病机制。该项目将使用ETBF诱导的结肠炎小鼠（C57BL/6）模型和各种免疫测定、基因敲除小鼠、骨髓移植、免疫组织化学、流式细胞术、细胞因子和RNA分析。这项研究的意义在于，它将有助于深入了解与IBD（一种发病率很高的疾病）相关的结肠细菌免疫反应失调，并有望为这种流行疾病提供新的治疗见解。公共卫生相关性：本研究探讨了先天免疫系统的作用，特别是 TLR 和 NOD 受体信号通路，以及信号转导器和转录激活剂 3 (Stat3) 在细菌诱导的结肠炎小鼠模型中的作用。从这项研究中获得的信息将有助于深入了解与炎症性肠病（一种发病率很高的疾病）相关的免疫反应失调。