Gut microbes modulate immune pathways in intestinal stem cells to influence their lineage

肠道微生物调节肠道干细胞的免疫途径以影响其谱系

• 批准号: 10409676
• 负责人: Nicolas Buchon
• 金额: $ 57.7万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-12 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10409676
• 关键词: Address; Affect; Animal Model; Bacteria; Biological Models; Cell Differentiation process; Cell Lineage; Cells; Characteristics; Development; Disease; Disease Progression; Drosophila genus; Drosophila melanogaster; Enterocytes; Environment; Epithelial; Equilibrium; Etiology; Exposure to; Face; Feedback; Food; Future; Gastrointestinal tract structure; Genes; Genetic; Genetic Models; Goals; Health; Homologous Gene; Immune; Immune response; Immune signaling; Indigenous; Infection; Inflammatory; Ingestion; Intestinal Diseases; Intestines; Janus kinase; Mediating; Microbe; Molecular; Mus; Oral; Outcomes Research; Pathogenicity; Pathology; Pathway interactions; Pattern; Peptide Initiation Factors; Physiology; Play; Process; Role; Shapes; Signal Pathway; Signal Transduction; Structure; Testing; Tissues; Transducers; Virulence; Work; Xenobiotics; base; cell behavior; cell type; epidemiology study; gastrointestinal epithelium; gene network; gut homeostasis; gut microbes; gut microbiota; immunogenicity; improved; insight; intestinal epithelium; intestinal homeostasis; knock-down; microbial; microbial host; microbiome; microbiota; novel therapeutics; pathogen; pathogenic microbe; progenitor; response; stem cell differentiation; stem cell fate; stem cell proliferation; stem cells; transcriptomics; translational study

An increasing number of epidemiological studies suggest that intestinal microbes are not only central to maintaining host health, but also constitute etiological factors for the initiation and progression of diseases of the intestinal tract. However, the mechanisms by which microbes affect intestinal health remain largely unknown. Using a powerful genetic model organism, Drosophila melanogaster, we have recently shown that microbes not only alter intestinal stem cell (ISC) proliferation, but also modulate the relative proportions of differentiated cell types in the epithelium. Importantly, we found that pathogens promote an enteroendocrine (EE) fate while non- pathogenic microbes promote an enterocyte (EC) fate, suggesting that pathogenic and non-pathogenic microbes influence ISC lineage in an opposing manner. Based on these results, and from our previous studies, we hypothesize that gut microbes modulate immune signaling pathways in ISCs to influence their lineage decisions. To test this hypothesis, we propose the following specific aims: Aim 1: We will determine the microbial characteristics (immunogenicity, virulence/damage) that modulate the cellular composition of the gut epithelium in both Drosophila and murine enteroids. In parallel, we will determine the relative contributions of cell loss, ISC proliferation and differentiation to this process. Aim 2: We will characterize how a classical immune pathway, the Imd/Relish pathway (NFκB homologue), acts in Drosophila ISCs and murine enteroids to influence differentiation in response to gut microbes. We will first identify ISC-specific Relish target genes using a combination of cell type-specific transcriptomics and targeted DamID (TaDa). We will then analyze how the Imd/Relish pathway interacts with other gene networks known to control ISC differentiation. Our studies will therefore demonstrate a new role for Imd/Relish that goes beyond the control of immune effectors and provide mechanistic insight into how this pathway alters stem cell lineage and epithelial composition. Aim 3: We will investigate how activation of the Janus kinase (JAK)-signal transducer of activator (STAT) pathway triggers EE fate commitment in Drosophila ISCs and murine enteroids. We will identify direct and indirect target genes of STAT in order to characterize downstream mechanisms and delineate the impact that JAK-STAT signaling has on ISC differentiation. Finally, we aim to clarify how the interaction between the JAK-STAT and Imd/Relish pathways determines the opposite ISC fates produced in the gut by pathogenic and non-pathogenic microbes. Outcomes of this research will improve our understanding of how the microbiota alters intestinal homeostasis in health and disease and demonstrate that different gut microbes (pathogenic vs non-pathogenic) alter gut epithelial composition by differentially modulating ISC differentiation. We will also identify a new role for pathways classically defined as immune pathways in affecting ISC differentiation, providing new mechanistic insight into how ISCs respond to their microbial environment. The mechanistic principles identified in our study will therefore pave the way to a better understanding of diseases of gut origin and potentiate the development of new therapies.

越来越多的流行病学研究表明，肠道微生物不仅是 维持宿主健康，但也是宿主疾病发生和进展的病因因素 然而，微生物影响肠道健康的机制仍然很大程度上未知。 使用强大的遗传模型生物——黑腹果蝇，我们最近证明微生物不 不仅改变肠干细胞（ISC）增殖，还调节分化细胞的相对比例 重要的是，我们发现病原体促进肠内分泌（EE）命运，而不是促进肠内分泌（EE）命运。 病原微生物促进肠上皮细胞（EC）的命运，这表明病原微生物和非病原微生物 以相反的方式影响 ISC 谱系 根据这些结果以及我们之前的研究，我们 肠道微生物调节 ISC 中的免疫信号通路，从而影响其谱系 为了检验这一假设，我们提出以下具体目标： 目标 1：我们将确定 调节肠道细胞组成的微生物特征（免疫原性、毒力/损伤） 同时，我们将确定果蝇和小鼠肠样细胞的相对贡献。 目标 2：我们将描述经典免疫的特征。 Imd/Relish 通路（NFκB 同源物）作用于果蝇 ISC 和鼠肠类，影响 我们将首先使用 ISC 特异性 Relish 靶基因进行分化。 然后我们将分析细胞类型特异性转录组学和靶向 DamID (TaDa) 的结合。 Imd/Relish 通路与已知控制 ISC 分化的其他基因网络相互作用。 因此证明了 Imd/Relish 的新作用超越了免疫效应器的控制并提供 深入了解该途径如何改变干细胞谱系和上皮组成 目标 3：我们将。 研究 Janus 激酶 (JAK)-激活剂信号转导器 (STAT) 通路的激活如何触发 EE 我们将确定果蝇 ISC 和小鼠肠类中的命运承诺的直接和间接目标基因。 STAT 来表征下游机制并描述 JAK-STAT 信号传导的影响 最后，我们的目的是阐明 JAK-STAT 和 Imd/Relish 之间的相互作用。 途径决定了致病性和非致病性微生物在肠道中产生相反的 ISC 命运。 这项研究的结果将提高我们对微生物群如何改变肠道稳态的理解 健康和疾病，并证明不同的肠道微生物（致病性与非致病性）会改变肠道 我们还将确定通路的新作用。 经典地定义为影响 ISC 分化的免疫途径，提供了新的机制见解 因此，ISC 如何应对其微生物环境。 为更好地了解肠道疾病并促进新疗法的开发铺平道路。