Dysbacteriosis of intestinal microflora induces altered immune responses and results in disease susceptibility. Z-VAD-FMK ic50 Dendritic cells (DCs), the professional antigen-presenting cells, have gained increasing attention because they connect innate and adaptive immunity. They generate both immunity in response to stimulation by pathogenic bacteria and immune tolerance in the presence of commensal bacteria. However, few studies have examined the effects of intestinal dysbacteriosis on DCs. In this study, changes of DCs in the small intestine of mice under the condition of dysbacteriosis induced by ceftriaxone sodium were investigated. It was found that intragastric
administration of ceftriaxone sodium caused severe dysteriosis in mice. Compared with controls, numbers of DCs in mice with dysbacteriosis increased significantly (P = 0.0001). However, the maturity and antigen-presenting ability of DCs were greatly reduced. In addition, there was a significant difference in secretion of IL-10 and IL-12 between DCs from mice with dysbacteriosis and controls. To conclude,
ICG-001 ceftriaxone-induced intestinal dysbacteriosis strongly affected the numbers and functions of DCs. The present data suggest that intestinal microflora plays an important role in inducing and maintaining the functions of DCs and thus is essential for the connection between innate and adaptive immune responses. “
“Laboratory of Mucosal Immunology, Department of Medicine, University of California, La Jolla, CA,
USA Thymic stromal lymphopoietin (TSLP) is constitutively secreted by intestinal epithelial cells. It regulates gut DCs, therefore, contributing to the maintenance of immune tolerance. In the present report, we describe the regulation of TSLP expression in intestinal epithelial cells and characterize the role of several NF-κB binding sites present on the TSLP promoter. TSLP expression can Casein kinase 1 be stimulated by different compounds through activation of p38, protein kinase A, and finally the NF-κB pathway. We describe a new NF-κB binding element located at position –0.37 kb of the promoter that is crucial for the NF-κB-dependent regulation of TSLP. We showed that mutation of this proximal NF-κB site abrogates the IL-1β-mediated transcriptional activation of human TSLP in several epithelial cell lines. We also demonstrated that both p65 and p50 subunits are able to bind this new NF-κB binding site. The present work provides new insight into epithelial cell-specific TSLP regulation. A single layer of columnar intestinal epithelial cells (IECs) physically separates the intestinal lumen from the underlying mucosal immune cells and defects in their barrier function are associated with inflammatory bowel diseases [1, 2].