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During sepsis, disturbed gastrointestinal motility and increased mucosal permeability can aggravate sepsis due to the increased risk of bacterial translocation. To help identify new therapeutic targets, there is a need for animal models that mimic the immunological changes in the gastrointestinal tract as observed during human sepsis. We therefore characterized in detail the gastrointestinal neuroimmune environment in the cecal ligation and puncture (CLP) model, which is the gold standard animal model of microbial sepsis. Mice were sacrificed at day 2 and day 7, during which gastrointestinal motility was assessed and cytokines were measured in the serum and the colon. In the spleen, lymph nodes, ileum, and colon, subsets of leukocyte populations were identified by flow cytometry. Septic animals displayed an impaired gastrointestinal motility at day 2 and day 7. Two days post-CLP, increased serum and colonic levels of proinflammatory cytokines were measured. Flow cytometry revealed an influx of neutrophils in the colon and ileum, increased numbers of macrophages in the spleen and mesenteric lymph nodes, and an enhanced number of mast cells in all tissues. At day 7 post-CLP, lymphocyte depletion was observed in all tissues coinciding with increased IL-10 and TGF- β levels, as well as increased colonic levels of IL-17A and IFN- γ . Thus, CLP-induced sepsis in mice results in simultaneous activation of pro- and anti-inflammatory players at day 2 and day 7 in different tissues, mimicking human sepsis.

Background and Aims: Inflammatory mediators that cross-talk in different metabolically active organs are thought to play a crucial role in the pathogenesis of Nonalcoholic Steatohepatitis (NASH). This study was aimed at investigating the CD4+RORγt+ T-helper cells and their counterpart, the CD4+CD25+FOXP3+ regulatory T cells in the liver, subcutaneous adipose tissue (SAT), and abdominal adipose tissue (AAT) in a high fat diet (HFD) mouse model., Methods: C57BL6 mice were fed a HFD or a normal diet (ND). Liver enzymes, metabolic parameters, and liver histology were assessed. The expression of CD4+RORγt+ cells and regulatory T cells in different organs (blood, liver, AAT, and SAT) were analyzed by flow cytometry. Cytokine and adipokine tissue expression were studied by RT-PCR., Results: Mice fed a HFD developed NASH and metabolic alterations compared to normal diet. CD4+RORγt++ cells were significantly increased in the liver and the AAT while an increase of regulatory T cells was observed in the SAT of mice fed HFD compared to ND. Inflammatory cytokines were also upregulated., Conclusions: CD4+RORγt++ cells and regulatory T cells are altered in NASH with a site-specific pattern and correlate with the severity of the disease. These site-specific differences are associated with increased cytokine expression.