Gnotobiotic IL-10; NF-κB Mice Develop Rapid and Severe Colitis Following Campylobacter jejuni Infection

Department of Medicine and Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
PLoS ONE (Impact Factor: 3.23). 10/2009; 4(10):e7413. DOI: 10.1371/journal.pone.0007413
Source: PubMed

ABSTRACT Limited information is available on the molecular mechanisms associated with Campylobacter jejuni (C. jejuni) induced food-borne diarrheal illnesses. In this study, we investigated the function of TLR/NF-kappaB signaling in C. jejuni induced pathogenesis using gnotobiotic IL-10(-/-); NF-kappaB(EGFP) mice. In vitro analysis showed that C. jejuni induced IkappaB phosphorylation, followed by enhanced NF-kappaB transcriptional activity and increased IL-6, MIP-2alpha and NOD2 mRNA accumulation in infected-mouse colonic epithelial cells CMT93. Importantly, these events were blocked by molecular delivery of an IkappaB inhibitor (Ad5IkappaBAA). NF-kappaB signalling was also important for C.jejuni-induced cytokine gene expression in bone marrow-derived dendritic cells. Importantly, C. jejuni associated IL-10(-/-); NF-kappaB(EGFP) mice developed mild (day 5) and severe (day 14) ulcerating colonic inflammation and bloody diarrhea as assessed by colonoscopy and histological analysis. Macroscopic analysis showed elevated EGFP expression indicating NF-kappaB activation throughout the colon of C. jejuni associated IL-10(-/-); NF-kappaB(EGFP) mice, while fluorescence microscopy revealed EGFP positive cells to be exclusively located in lamina propria mononuclear cells. Pharmacological NF-kappaB inhibition using Bay 11-7085 did not ameliorate C. jejuni induced colonic inflammation. Our findings indicate that C. jejuni induces rapid and severe intestinal inflammation in a susceptible host that correlates with enhanced NF-kappaB activity from lamina propria immune cells.

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    • "The development of acute disease caused by C. jejuni has been studied in multiple animal models, however the IL-10−/− germ-free mouse model has emerged as a reproducible and reliable model system for the study of campylobacteriosis.39,40 We used bacterial invasion of the spleen as an indicator of C. jejuni disease.41,42 "
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    ABSTRACT: Campylobacter jejuni is a gram-negative, curved and rod-shaped bacterium that causes human gastroenteritis. Acute disease is associated with C. jejuni invasion of the intestinal epithelium. Epithelial cells infected with C. jejuni strains containing mutations in the FlpA and CadF fibronectin (Fn)-binding proteins exhibit reduced invasion of host cells and a C. jejuni CadF FlpA double mutant is impaired in the activation of epidermal growth factor receptor (EGFR) and Rho GTPase Rac1. Although these observations establish a role for Fn-binding proteins during C. jejuni invasion, their mechanistic contributions to invasion-associated signaling are unclear. We examined FlpA, a C. jejuni Fn-binding protein composed of three FNIII-like repeats D1, D2 and D3, to identify the interactions required for cellular adherence on pathogen-induced host cell signaling. We report that FlpA binds the Fn gelatin-binding domain via a motif within the D2 repeat. Epithelial cells infected with a flpA mutant exhibited decreased Rac1 activation and reduced membrane ruffling that coincided with impaired delivery of the secreted Cia proteins and reduced cell association. Phosphorylation of the Erk1/2 kinase, a downstream effector of EGFR signaling, was specifically associated with FlpA-mediated activation of β1-integrin and EGFR signaling. In vivo experiments revealed that FlpA is necessary for C. jejuni disease based on bacterial dissemination to the spleen of IL-10−/− germ-free mice. Thus, a novel Fn-binding motif within FlpA potentiates activation of Erk1/2 signaling via β1-integrin during C. jejuni infection.
    Emerging Microbes and Infections 10/2013; 2(e65). DOI:10.1038/emi.2013.65 · 2.26 Impact Factor
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    • "Whereas Mansfield and colleagues demonstrated that enteritis developed after more than 28 days upon C. jejuni infection in IL-10−/− mice housed under specific pathogen free conditions (and depending on their genetic background) [37], [38], in our study, C. jejuni induced a rapid ulcerative colitis in gnotobiotic IL-10−/− mice. Using germfree IL-10−/− NF-κBEGFP mice raised under isolator-conditions, Lippert et al. highlighted the role of NF-κB in C. jejuni induced pathogenesis [39]. Following infection, germfree IL-10−/− NF-κBEGFP mice displayed mild symptoms at day 5 and ulcerative colitis at day 14 following C. jejuni strain 81–176 infection. "
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    ABSTRACT: Campylobacter jejuni is a leading cause of foodborne bacterial enterocolitis worldwide. Investigation of immunopathology is hampered by a lack of suitable vertebrate models. We have recently shown that gnotobiotic mice as well as conventional IL-10(-/-) animals are susceptible to C. jejuni infection and develop intestinal immune responses. However, clinical symptoms of C. jejuni infection were rather subtle and did not reflect acute bloody diarrhea seen in human campylobacteriosis. In order to overcome these limitations we generated gnotobiotic IL-10(-/-) mice by quintuple antibiotic treatment starting right after weaning. The early treatment was essential to prevent these animals from chronic colitis. Following oral infection C. jejuni colonized the gastrointestinal tract at high levels and induced acute enterocolitis within 7 days as indicated by bloody diarrhea and pronounced histopathological changes of the colonic mucosa. Immunopathology was further characterized by increased numbers of apoptotic cells, regulatory T-cells, T- and B-lymphocytes as well as elevated TNF-α, IFN-γ, and MCP-1 concentrations in the inflamed colon. The induction of enterocolitis was specific for C. jejuni given that control animals infected with a commensal E. coli strain did not display any signs of disease. Most strikingly, intestinal immunopathology was ameliorated in mice lacking Toll-like-receptors-2 or -4 indicating that C. jejuni lipoproteins and lipooligosaccharide are essential for induction and progression of immunopathology. Gnotobiotic IL-10(-/-) mice develop acute enterocolitis following C. jejuni infection mimicking severe episodes of human campylobacteriosis and are thus well suited to further dissect mechanisms underlying Campylobacter infections in vivo.
    PLoS ONE 07/2012; 7(7):e40761. DOI:10.1371/journal.pone.0040761 · 3.23 Impact Factor
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    ABSTRACT: To observe the expression of nucleotide-binding oligomerization domain 2 (NOD2) in rats with acute pancreatitis (AP). Sprague-Dawley rats were randomly divided into sham operation (SO) groups and AP groups. Acute pancreatitis was induced with retrograde infusion of sodium taurocholate into the biliopancreatic duct. They were then killed at 3, 6, 12, 24, and 48 hours after induction of AP. Blood biochemical indicators were detected with automatic biochemistry analyzer. Nuclear factor-κB (NF-κB) was measured by immunohistochemistry. The NOD2 was detected by real-time quantitative polymerase chain reaction and Western blot. Tumor necrosis factor-α (TNF-α) was determined by enzyme-linked immunosorbent assay. Compared with the SO group, the level of messenger RNA and protein of NOD2 in pancreatic tissue and peritoneal white blood cells (PWBCs) in the AP groups significantly declined (P < 0.05). The messenger RNA level of NOD2 in the AP groups was correlated positively with amylase (P < 0.05) and negatively with TNF-α (P < 0.05); TNF-α significantly decreased in the AP groups, whereas NF-κB significantly increased (P < 0.05). The NOD2 may play an important role in the up-regulation and activation of NF-κB during inflammation reactions in AP.
    Pancreas 04/2010; 39(7):1034-40. DOI:10.1097/MPA.0b013e3181da0f1d · 2.96 Impact Factor
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