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IL-22 is produced by activated T cells and signals through a receptor complex consisting of IL-22R1 and IL-10R2. The aim of this study was to analyze IL-22 receptor expression, signal transduction, and specific biological functions of this cytokine system in intestinal epithelial cells (IEC). Expression studies were performed by RT-PCR. Signal transduction was analyzed by Western blot experiments, cell proliferation by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl) -2H-tetrazolium assay and Fas-induced apoptosis by flow cytometry. IEC migration was studied in wounding assays. The IEC lines Caco-2, DLD-1, SW480, HCT116, and HT-29 express both IL-22 receptor subunits IL-22R1 and IL-10R2. Stimulation with TNF-[alpha], IL-1[beta], and LPS significantly upregulated IL-22R1 without affecting IL-10R2 mRNA expression. IL-22 binding to its receptor complex activates STAT1/3, Akt, ERK1/2, and SAPK/JNK MAP kinases. IL-22 significantly increased cell proliferation (P = 0.002) and phosphatidylinsitol 3-kinase-dependent IEC cell migration (P < 0.00001) as well as mRNA expression of TNF-[alpha], IL-8, and human [beta]-defensin-2. IL-22 had no effect on Fas-induced apoptosis. IL-22 mRNA expression was increased in inflamed colonic lesions of patients with Crohn's disease and correlated highly with the IL-8 expression in these lesions (r = 0.840). Moreover, IL-22 expression was increased in murine dextran sulfate sodium-induced colitis. IEC express functional receptors for IL-22, which increases the expression of proinflammatory cytokines and promotes the innate immune response by increased defensin expression. Moreover, our data indicate intestinal barrier functions for this cytokine-promoting IEC migration, which suggests an important function in intestinal inflammation and wound healing. IL-22 is increased in active Crohn's disease and promotes proinflammatory gene expression and IEC migration. interleukin-10-like cytokines; interleukin-22; defensin

Human cytomegalovirus virus (CMV) is a major cause of morbidity and mortality in immunocompromised individuals. Recently, a novel group of cytokines [interleukin (IL)-28A/B and IL-29, also termed interferon (IFN)-[lambda]s] has been described. Here, we demonstrate that intestinal epithelial cell (IEC) lines as well as murine and human colonic tissue express the IFN-[lambda] receptor subunits IL-28R and IL-10R2. IL-28A and IL-29 binding to their receptor complex activates ERK-1/2 and stress-activated protein kinase/c-Jun N[H.sub.2]-terminal kinase MAPKs and Akt, resulting in increased IL-8 protein expression. IFN-[lambda] also induce phosphorylation of signal transducer and activator of transcription 1 and significantly increase mRNA expression of suppressor of cytokine signaling 3 and the antiviral proteins myxovirus resistance A and 2',5'-oligoadenylate synthetase. These signals result in an up to 83% reduction of cells positive for human CMV immediate-early protein after human CMV infection. In mice, IL-28A mRNA expression is upregulated after infection with murine CMV in vivo. Both IL-28A and IL-29 significantly decrease cell proliferation but have no effect on Fas-induced apoptosis. In conclusion, IECs express functional receptors for IFN-[lambda]s, which mediate antiviral and antiproliferative signals in IECs, suggesting a potential for therapeutic use in certain viral infections and as (antiproliferative) anticancer therapy. interleukin-10-like cytokines; interferon-[lambda]; interleukin-28A; interleukin-29; suppressor of cytokine signaling 3; signal transducer and activator of transcription 1; cytomegalovirus; human cytomegalovirus; murine cytomegalovirus

Otte, Jan-Michel, and Daniel K. Podolsky. Functional modulation of enterocytes by gram-positive and gram-negative microorganisms. Am J Physiol Gastrointest Liver Physiol 286: G613-G626, 2004; 10.1152/ajpgi.00341.2003.--Clinical studies have suggested that so-called probiotic bacteria may be effective as therapy in inflammatory bowel disease. However, the molecular mechanisms of their interaction with the intestinal surface remain undefined. The influence of whole probiotic bacteria [Escherichia coli Nissle 1917 (EcN); probiotic mixture VSL#3 (PM)], bacterial cell lysates, and conditioned media on transepithelial resistance (TER), IL-8 secretion, mucin gene expression, and tight junction proteins were determined in T84 and HT-29 intestinal epithelial cells (IEC). In addition, effects on pathogen (Salmonella dublin)-induced alterations were analyzed. EcN as well as debris and cell extracts induced IL-8 secretion from IEC, whereas no such effect was observed following incubation with the PM. The PM and soluble protein(s) released from the PM increased TER, prevented pathogen-induced decrease in TER, and were shown to stabilize tight junctions. The PM induced expression of mucins in IEC, and these organisms as well as EcN diminished S. dublin-induced cell death. Inhibition of MAPKs with PD-98059 or SB-203580 significantly decreased alterations in IL-8 synthesis and mucin expression and affected the regulation of TER. Probiotics and protein(s) released by these organisms may functionally modulate the intestinal epithelium of the host by different mechanisms, including the competition of whole organisms for contact with the epithelial surface as well as stabilization of the cytoskeleton and barrier function and the induction of mucin expression. Gram-negative and gram-positive organisms differ in the mechanisms activated, and a combination of organisms might be more effective than the application of a single strain. probiotics; Escherichia coli Nissle 1917; probiotic mixture VSL#3; intestinal epithelial cell lines; interleukin-8; transepithelial resistance; zonula occludens- 1; mucins

Abstract Background Adenoviral vectors have provided effective methods for in vivo gene delivery in therapeutic applications. However, these vectors can induce immune responses that may severely affect the ability of vector re-application. There is limited information about the mechanisms and signal transduction pathways involved in adenoviral recognition. For optimization of cutaneous gene therapy it is necessary to investigate molecular mechanisms of virus recognition in epidermal cells. The aim of this study was to investigate the signal transduction of the innate immunity after adenoviral DNA internalization in keratinocytes. Methods In vitro, keratinocytes were transfected with DNA, in the presence and absence of inhibitors for signalling molecules. In vivo, immunocompetent and athymic mice (n = 3 per group) were twice transduced with an Ad-vector. Results The results show an acute induction of type-I-interferon after in vitro transfection. Inhibition of PI3K, p38 MAPK, JNK and NFkappaB resulted in a decreased expression of type-I-interferon. In contrast to immunocompetent mice, athymic mice demonstrated a constant transgene expression and reduced inflammatory response in vivo. Conclusion The results suggest an induction of the innate immunity triggered by cytoplasm localised DNA which is mediated by PI3K-, p38 MAPK-, JNK-, NFkappaB-, JAK/STAT- and ERK1/2-dependent pathways. A stable transgene expression and a reduced inflammatory response in immunodeficient mice have been observed. These results provide potential for an effective adenoviral gene delivery into immunosupressed skin.

Environmental triggers acting at the intestinal barrier are thought to contribute to the initiation of autoimmune disorders. The transforming growth factor beta inhibitor Smad7 determines the phenotype of CD4+ T cells. We hypothesized that Smad7 in intestinal CD4+ T cells controls initiation of opticospinal encephalomyelitis (OSE), a murine model of multiple sclerosis (MS), depending on the presence of gut microbiota. Smad7 was overexpressed or deleted in OSE CD4+ T cells to determine the effect on clinical progression, T cell differentiation, and T cell migration from the intestine to the central nervous system (CNS). Smad7 overexpression worsened the clinical course of OSE and increased CNS inflammation and demyelination. It favored expansion of intestinal CD4+ T cells toward an inflammatory phenotype and migration of intestinal CD4+ T cells to the CNS. Intestinal biopsies from MS patients revealed decreased transforming growth factor beta signaling with a shift toward inflammatory T cell subtypes. Smad7 in intestinal T cells might represent a valuable therapeutic target for MS to achieve immunologic tolerance in the intestine and suppress CNS inflammation. [ABSTRACT FROM AUTHOR]

Although the expression of CCK2 receptors is widely reported in human colorectal cancers, little is known on its role in mediating the proliferative effects of mature amidated gastrin (G17 amide) on colorectal cancers. The purpose of the present study was to determine the effects of G17 amide on tyrosine phosphorylation of focal adhesion kinase (FAK), paxillin, and p130 Crk-associated substrate (p130Cas) in Colo 320 cells, a human colorectal cancer cell line which expresses CCK2 receptors. By immunoprecipitation and immunoblotting, an increase in tyrosine phosphorylation of FAK (tyrosine-397), paxillin (tyrosine-31), and p130Cas was detected in a time- and dose-dependent manner. Overexpression of CCK2 receptors in Colo 320 cells (Colo 320 WT) by stable transfection with the human CCK2 receptor cDNA resulted in an increased tyrosine phosphorylation of FAK, paxillin, and p130Cas. After incubation with 1 μM L-365,260, a specific CCK2 receptor antagonist, this increase was completely inhibited. Our results demonstrate that in human colon cancer cells, gastrin caused a rapid tyrosine phosphorylation of FAK, paxillin, and p130Cas by activation of CCK2 receptor. The phosphorylation of these proteins might be important in mediating gastrin effects on proliferation, apoptosis, and metastasis. [Copyright &y& Elsevier]

Background: Since the turn of the millennium there has been an alarming increase in the incidence and severity of clostridium difficile infections. Stopping medication with the triggering antibiotic and switching to a recommended antibiotic leads to healing up in 80%. However, patients who relapse have a 40% risk of an additional relapse and those with 2 or more episodes face a 60% risk. Fecal microbiota transplantation (FMT) is a new therapeutic option. Up to now there only exist two randomized studies (University of Amsterdam and the Massachusetts General Hospital in Boston)., Method: Data from 16 patients with recurrent clostridium difficile infection who had undergone FMT at a local hospital in the city of Bremen, Germany, were reviewed and compared to the results of the 2 randomized studies., Results: 11 out of 16 patients got cured after the first FMT (68.75%). The remaining 5 patients received a second FMT, with cure in 3 patients. The overall response rate was 14 from 16 patients (87.5%)., Conclusions: In comparison to the response rates of the University of Amsterdam (81.3% after the first and 93.8% after the second FMT) and of the Massachusetts General Hospital in Boston (70% after the first and 90% after the second FMT) we received slightly worse results. But, treatment of notably older patients and intensive care patients in our group explain these findings well. Therefore, we advocate a wide use of FMT for the treatment of recurrent clostridium difficile colitis in non-university hospitals.

Background: Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with increased expression in inflammatory bowel disease. The aim of the study was to analyze the role of the MIF -173G/C single nucleotide polymorphism in Crohn's disease (CD)., Methods: Using restriction fragment length polymorphism analysis, genomic DNA of 198 patients with CD and 159 unrelated controls was analyzed for the -173G/C SNP in the MIF promoter region. Colonic MIF mRNA expression was measured by quantitative polymerase chain reaction (PCR), serum MIF levels by enzyme-linked immunosorbent assay (ELISA)., Results: Thirty-six of the 146 G/G wildtype carriers (24.7%) but only 3 of the 45 G/C heterozygotes (6.7%) and only 1 of the C/C homozygotes (14.3%) were diagnosed with upper gastrointestinal tract involvement (P = 0.009, odds ratio [OR] = 0.22, 95% confidence interval [CI], 0.06-0.75 for wildtype versus hetero- and homozygous carriers). This result was confirmed in a second prospective study, in which all patients diagnosed with upper gastrointestinal involvement (n = 13) were G/G wildtype carriers (P = 0.01 versus controls). All patients (n = 12; 100%) with a Crohn's disease activity index (CDAI) > 300 were G/G wildtype carriers compared to only 65.6% wildtype carriers in the group with a CDAI < 150 (P = 0.016). MIF is expressed in the colonic mucosa of CD patients and intestinal epithelial cells but its mRNA expression does not correlate with the degree of inflammation and is not upregulated by proinflammatory cytokines. In CD, MIF serum levels are not influenced by the MIF -173G/C polymorphism., Conclusions: The MIF -173G/C polymorphism appears to be a factor contributing to a particular CD phenotype characterized by protection against upper gastrointestinal tract involvement and severe disease activity.