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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.

项目总结