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The role of a Clostridioides difficile P-type ATPase in ferrosome formation and its impact on cellular physiology and pathogenesis

艰难梭菌 P 型 ATP 酶在铁体形成中的作用及其对细胞生理学和发病机制的影响

基本信息

批准号：
10894965
负责人：
Hualiang Pi
金额：
$ 24.9万
依托单位：
YALE UNIVERSITY
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：
2022-08-15 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10894965
关键词：
ATP phosphohydrolase Affect Anaerobic Bacteria Antibiotic Therapy Antibiotics Bacillus subtilis Bacterial Physiology Binding Biochemical Biological Assay Biological Process Cell physiology Cells Chemistry Clostridium difficile Co-Immunoprecipitations Consumption Cytoplasmic Granules Data Drug Metabolic Detoxication Environment Equilibrium Exhibits Fluorescent in Situ Hybridization Fractionation Gastrointestinal tract structure Genes Genetic Gram-Positive Bacteria Growth Homeostasis In Vitro Infection Integration Host Factors Iron Iron Overload Kinetics Lactoferrin Leukocyte L1 Antigen Complex Life Life Style Maps Mediating Metals Minerals Molecular Names Nutrient Nutritional Immunity Outcome Oxidative Stress Pathogenesis Patients Peptide Nucleic Acids Physiological Predisposition Process Property Proteins Proteomics Reproduction spores Role Stains Staphylococcus aureus Structure Substrate Specificity System Techniques Testing Therapeutic Time Toxic effect antimicrobial biomineralization combat defined contribution enteric infection experimental study ferryl iron gut colonization gut inflammation gut microbiota in vivo insight iron deficiency iron oxide microbial microbiota mutant pathogen pathogenic bacteria prevent transposon sequencing trend uptake young adult

项目摘要

SUMMARY Clostridioides difficile is a Gram-positive, spore-forming anaerobic pathogen, and the leading cause of nosocomial and antibiotic-associated intestinal infections. Susceptibility to C. difficile infection (CDI) often follows antibiotic treatment and subsequent disruption of the resident intestinal microbiota, however the rise of infections in healthy young adults suggests that additional bacterial and host factors make important contributions to CDI. To colonize the gastrointestinal tract, C. difficile must compete with host metal sequestrating proteins that withhold nutrient metals to restrict microbial growth in a process termed nutritional immunity. Iron is the most well studied metal in the host-pathogen interface and is withheld by host iron-sequestering proteins such as calprotectin and lactoferrin. However, it is unknown how calprotectin and lactoferrin affect metal availability in the gastrointestinal tract and impact the outcome of CDI. It is also unclear how C. difficile adapts to metal limitation mediated by these two proteins and circumvents nutritional immunity during CDI. Thus, we set out to interrogate the iron homeostatic systems in C. difficile and examine their physiological function. Our preliminary data demonstrate that C. difficile undergoes an intracellular iron biomineralization process and produces faceted iron oxide granules (ferrosomes) to maintain iron balance during transient iron overload. We also discovered that a P1B6-ATPase transporter (which we have named FezB), regulated by both iron and the ferric uptake regulator Fur, is required for ferrosome formation. Additionally, ferrosomes isolated from C. difficile cells exhibit a highly ordered crystalline lattice structure that is distinct from any known iron oxide minerals. In this application, we hypothesize that (i) FezB transports iron into ferrosomes and interacts with other factors during ferrosome formation, (ii) ferrosomes serve as an important iron storage strategy and alleviate iron overload and oxidative stress, (iii) stored iron in ferrosomes is released through a specific mechanism to support growth under iron limitation, (iv) ferrosomes are produced within the vertebrate host to combat host iron sequestration, and (v) this ferrosome system is activated in the inflamed gut and required for bacterial colonization and survival during CDI. Experiments described in this proposal will test these hypotheses, elucidate the underlying mechanism of FezB- dependent ferrosome formation, define the structural features of the ferrosome, and determine its impact on cellular physiology and C. difficile pathogenesis. Furthermore, the findings from this application will determine the significance of host-mediated iron sequestration during CDI and create a framework for developing effective antimicrobial therapeutics to combat this important infection.

总结