A bacterial biosensor for intracellular metal availability in the gut

用于肠道内细胞内金属可用性的细菌生物传感器

基本信息

批准号：
10764453
负责人：
Leigh Knodler
金额：
$ 19.04万
依托单位：
UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-22 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10764453
关键词：
Address Adopted Affect Affinity Anatomy Back Bacteria Bacterial Infections Binding Binding Proteins Biosensor Cattle Cell surface Cells Cessation of life Clinical Colon Communicable Diseases Complex Cytosol Defense Mechanisms Disease Divalent Cations Effectiveness Enteral Epithelial Cells Epithelium Extracellular Space Family Family member Fluorescence Microscopy Gastroenteritis Gene Expression Genes Genetic Transcription Goals Growth Homeostasis Homologous Gene Host Defense Host Defense Mechanism Human Immune Immunocompromised Host Individual Infection Ingestion Intestinal Mucosa Intestines Invaded Ions Iron Iron Chelating Agents Iron Chelation Knowledge Lamina Propria Life Life Style Ligation Macrophage Mammalian Cell Mammals Manganese Maps Mediating Membrane Messenger RNA Metabolism Metals Microbe Micronutrients Modeling Mus Mutation Myelogenous Myeloid Cells Neutrophil Infiltration Nutrient Nutritional Immunity Organism Outcome Parasites Parasitic infection Pathogenicity Phagocytes Phagosomes Play Predisposition Prevention Protein Family Protein Isoforms Protozoa Regional Anatomy Reporter Role SLC11A2 gene Salmonella Salmonella enterica Salmonella infections Salmonella typhimurium Siderophores Starvation Time Toxic effect Transition Elements Vacuole Virulence Factors Virus Diseases War Work Zinc antimicrobial apical membrane arms race burden of illness cell type defined contribution deprivation divalent metal efflux pump enteric infection enteritis experience experimental study extracellular fighting foodborne foodborne illness fungus gastrointestinal epithelium gut colonization intestinal epithelium iron deficiency knock-down man microbial microorganism mouse model natural resistance-associated macrophage protein 1 neutrophil new therapeutic target non-typhoidal Salmonella outcome prediction pathogen prevent response spatiotemporal uptake virulence gene

项目摘要

PROJECT SUMMARY Of the foodborne bacterial, protozoal and viral diseases, non-typhoidal Salmonella enterica cause the largest burden of illness and death worldwide. The most common human clinical isolates are Salmonella enterica serovars Typhimurium (S. Typhimurium, STm) and Enteriditis (S. Enteriditis). Infection can cause either a self- limiting gastroenteritis or a life-threatening, invasive disease in immunocompromised individuals. During enteric infection, STm adopts both extracellular and intracellular lifestyles, colonizing the intestinal lumen as well epithelial cells and phagocytes in the intestinal mucosa. Here we will study how host-mediated restriction of transition metals, known as nutritional immunity, affects STm colonization of the gut. The NRAMP family of proteins are “promiscuous” transporters of divalent cations that play a major role in metal ion homeostasis from bacteria to man. In mammals, there are two NRAMP genes, SLC11A1 and SLC11A2 in humans and Slc11a1 and Slc11a2 in mice. Slc11a1 is restricted to the myeloid lineage whereas Slc11a2 is ubiquitously expressed. Whilst the role of Slc11a1 in controlling intracellular bacterial and parasitic infections in macrophages and mice is undisputed, whether Slc11a2 also contributes to antimicrobial functions is unknown. Our general hypothesis is that intracellular metal ion availability differs in epithelial cells and phagocytes in the gut due to the distinct cell-type expression of SLC11A1 and SLC11A2. First, we will use microbial biosensors of metal ion concentrations to infect bovine ligated ileal loops, a highly relevant model of enteric salmonellosis in humans, and map the spatiotemporal distribution of metal ion deprivation in the gut. Second, we will define whether SLC11A2, the sole NRAMP family member expressed in intestinal epithelial cells, defends against invading pathogens via metal nutrient limitation. Completion of this proposal will close a significant knowledge gap about host-microbe competition for metal ions in the gut during enteric infection.

项目概要在食源性细菌、原虫和病毒性疾病中，非伤寒沙门氏菌引起的疾病最多全世界最常见的人类临床分离株是肠道沙门氏菌。鼠伤寒沙门氏菌 (S. Typhimurium, STm) 和肠炎 (S. Enteriditis) 血清型可引起自身感染。限制免疫功能低下个体的胃肠炎或危及生命的侵袭性疾病。感染后，STm 采用细胞外和细胞内的生活方式，也在肠腔内定殖在这里，我们将研究宿主介导的限制性肠粘膜上皮细胞和吞噬细胞。过渡金属，称为营养免疫，影响肠道中 NRAMP 家族的 STm 定植。蛋白质是二价阳离子的“混杂”转运蛋白，在金属离子稳态中发挥着重要作用从细菌到人类，有两个 NRAMP 基因，人类有 SLC11A1 和 SLC11A2，而人类有 SLC11a1。在小鼠中，Slc11a1 仅限于骨髓谱系，而 Slc11a2 则广泛表达。而Slc11a1在控制巨噬细胞和小鼠细胞内细菌和寄生虫感染中的作用毫无争议，Slc11a2是否也有助于抗菌功能尚不清楚。肠道中的上皮细胞和吞噬细胞的细胞内金属离子可用性不同，这是由于不同的 SLC11A1和SLC11A2的细胞型表达首先，我们将使用金属离子的微生物生物传感器。感染牛结扎回肠环的浓度，这是人类肠道沙门氏菌病的高度相关模型，并绘制肠道中金属离子剥夺的时空分布图其次，我们将定义是否。 SLC11A2 是肠上皮细胞中表达的唯一 NRAMP 家族成员，可防御入侵该提案的完成将弥补有关金属营养限制的重大知识空白。肠道感染期间宿主与微生物对肠道中金属离子的竞争。