Project description:Previous experiments have shown that hexuronates regulate EHEC virulence, here we look at glucuronic acid effect on citrobacter rodentium
Project description:IBD is a complex autoimmune disease characterized by dysregulated interactions between host immune responses and microbiome at the intestinal epithelium interface. Here we identified shared protein alterations in intestinal epithelial differentiation and function between IBD and Citrobacter rodentium infected FVB mice. We discovered that prophylactic treatment with the mucosal healing therapy IL-22.Fc in the infected FVB mice reduced disease severity and rescued the mice from lethality. Notably, we observed an emergence of intermediate undifferentiated intestinal epithelial cells upon infection, with disrupted expression of the solute transporter machinery as well as components critical for intestinal barrier integrity. Multi-omics analyses revealed that with IL-22.Fc treatment several disease associated changes were prevented (including disruption of the solute transporter machinery), and proper physiological homeostatic functions of the intestine was restored. Taken together, we unveiled the disease relevance of the C. rodentium induced colitis model to IBD and demonstrated the protective role of the mucosal healing therapy IL-22.Fc in ameliorating the epithelial dysfunction.
Project description:Previous experiments have shown that hexuronates regulate EHEC virulence, here we look at glucuronic acid effect on citrobacter rodentium
Project description:Opioids analgesics are frequently prescribed in the United States and worldwide. However, serious side effects such as addiction, immunosuppression and gastrointestinal symptoms limit their use. It has been recently demonstrated that morphine treatment results in significant disruption in gut barrier function leading to increased translocation of gut commensal bacteria. Further study indicated distinct alterations in the gut microbiome and metabolome following morphine treatment, contributing to the negative consequences associated with opioid use. However, it is unclear how opioids modulate gut homeostasis in the context of a hospital acquired bacterial infection. In the current study, a mouse model of C. rodentium infection was used to investigate the role of morphine in the modulation of gut homeostasis in the context of a hospital acquired bacterial infection. Citrobacter rodentium is a natural mouse pathogen that models intestinal infection by enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) and causes attaching and effacing lesions and colonic hyperplasia. Morphine treatment resulted in 1) the promotion of C. rodentium systemic dissemination, 2) increase in virulence factors expression with C. rodentium colonization in intestinal contents, 3) altered gut microbiome, 4) damaged integrity of gut epithelial barrier function, 5) inhibition of C. rodentium-induced increase in goblet cells, and 6) dysregulated IL-17A immune response. This is the first study to demonstrate that morphine promotes pathogen dissemination in the context of intestinal C. rodentium infection, indicating morphine modulates virulence factor-mediated adhesion of pathogenic bacteria and induces disruption of mucosal host defense during C. rodentium intestinal infection in mice. This study demonstrates and further validates a positive correlation between opioid drug use/abuse and increased risk of infections, suggesting over-prescription of opioids may increase the risk in the emergence of pathogenic strains and should be used cautiously. Therapeutics directed at maintaining gut homeostasis during opioid use may reduce the comorbidities associated with opioid use for pain management.
Project description:To explore the regulatory mechanism of intestinal flora in Citrobacter rodentium -induced intestinal infection by transcriptome analysis at miRNA molecular level.
Project description:It is crucial to decipher the host-microbiota interactions as they are involved in intestinal homeostasis and diseases. Caspase Recruitment Domain 9 (Card9) is an inflammatory bowel disease (IBD) susceptibility gene coding for an adapter protein for innate immunity toward many microorganisms. Card9-/- mice are more susceptible to colitis induced by Citrobacter rodentium as a result of impaired of the IL-22 pathway. C. rodentium is a natural mouse pathogen widely used to model human infections with Enteropathogenic Escherichia coli and Enterohaemorrhagic E. coli. To explore the role of the gut microbiota in the susceptibility of Card9-/- mice to C. rodentium infection, we colonized WT germ-free (GF) mice with the microbiota of WT (WT-->GF) or Card9-/- (Card9-/- -->GF) mice and challenged them with C. rodentium. Card9-/- -->GF mice were more susceptible than WT-->GF mice to C. rodentium. To examine the mechanisms responsible for this defect, we compared the cecum transcriptomes of WT -->GF and Card9-/- -->GF mice before and during C. rodentium-induced colitis. The number of down-regulated and up-regulated genes on day 12 after C. rodentium infection was lower in Card9-/- -->GF mice than WT-->GF mice. Card9-/- -->GF mice showed a significant down-regulation of gut morphogenesis and wound healing pathways suggesting that recovery is impaired in Card9-/- -->GF mice after C. rodentium infection. Immune response and cell division pathways were up-regulated in WT-->GF mice but not in Card9-/- -->GF confirming the defect of global response to infection when only the Card9-/- microbiota was transferred. The most induced and differentially expressed genes between Card9-/- -->GF and WT-->GF mice on day 4 after C. rodentium infection were Reg3g (encoding REGIIIγ) and Reg3b (encoding REGIIIβ).
Project description:To further understand immune mechanims involved in regulating intestinal inflammation, we employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential of regulating inflammation in the absence of IL-10. Whole colon tissue from IL-10-deficient and C57BL/6 (wild-type) mice was collected 2 weeks after Citrobacter rodentium infection and from uninfected controls. Consistent with the histological and cellular analysis, expression levels of many chemokines and cytokines involved in recruiting leukocytes and promoting inflammation were, on average, lower in IL-10 deficient compared to wild-type mice after infection. An exception to this general trend was IL-27, a cytokine with both pro- and anti-inflammatory properties. Two weeks after Citrobacter rodentium challenge, total RNA was extracted and analyzed from whole colon tissue of infected IL-10-deficient and wild-type mice, and compared to uninfected controls. Each sample contained equal amounts of total RNA from 4-5 female mice which were pooled and used in the experiment.
Project description:Whole genome trancription study of Citrobacter rodentium grown in rich media. Publication Title: Citrobacter rodentium is an Unstable Pathogen Showing Evidence of Significant Genomic Flux Publication Author List: Nicola K. Petty, Theresa Feltwell, Derek Pickard, Simon Clare, Ana L. Toribio, Maria Fookes, Kevin Roberts, Rita Monson, Satheesh Nair, Robert A. Kingsley, Richard Bulgin, Siouxsie Wiles, David Goulding, Craig Corton, Nicola Lennard, David Harris, David Willey, Richard Rance, Lu Yu, Jyoti S. Choudhary, Carol Churcher, Michael A. Quail, Julian Parkhill, Gad Frankel, Gordon Dougan, George P.C. Salmond, Nicholas R. Thomson ArrayExpress Release Date: 2011-02-12 Person Roles: investigator Person Last Name: Thomson Person First Name: Nicholas Person Mid Initials: Person Email: nrt@sanger.ac.uk Person Phone: Person Address: Wellcome Trust Genome Campus, Hinxton, Cambridge, UK Person Affiliation: Wellcome Trust Sanger Institute Person Roles: submitter Person Last Name: Service Person First Name: Submission Person Mid Initials: Person Email: datahose@sanger.ac.uk Person Phone: Person Address: The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, United Kingdom Person Affiliation: Wellcome Trust Sanger Institute