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Background & Aims Priming of T cells by dendritic cells (DCs) in the intestinal mucosa and associated lymphoid tissues helps maintain mucosal tolerance but also contributes to the development of chronic intestinal inflammation. Chemokines regulate the intestinal immune response and can contribute to pathogenesis of inflammatory bowel diseases. We investigated the role of the chemokine CCL17, which is expressed by conventional DCs in the intestine and is up-regulated during colitis. Methods Colitis was induced by administration of dextran sodium sulfate (DSS) to mice or transfer of T cells to lymphopenic mice. Colitis activity was monitored by body weight assessment, histologic scoring, and cytokine profile analysis. The direct effects of CCL17 on DCs and the indirect effects on differentiation of T helper (Th) cells were determined in vitro and ex vivo. Results Mice that lacked CCL17 ( Ccl17 E/E mice) were protected from induction of severe colitis by DSS or T-cell transfer. Colonic mucosa and mesenteric lymph nodes from Ccl17 -deficient mice produced lower levels of proinflammatory cytokines. The population of Foxp3 + regulatory T cells (Tregs) was expanded in Ccl17 E/E mice and required for long-term protection from colitis. CCR4 expression by transferred T cells was not required for induction of colitis, but CCR4 expression by the recipients was required. CCL17 promoted Toll-like receptor–induced secretion of interleukin-12 and interleukin-23 by DCs in an autocrine manner, promoted differentiation of Th1 and Th17 cells, and reduced induction of Foxp3 + Treg cells. Conclusions The chemokine CCL17 is required for induction of intestinal inflammation in mice. CCL17 has an autocrine effect on DCs that promotes production of inflammatory cytokines and activation of Th1 and Th17 cells and reduces expansion of Treg cells.

Background & Aims Recent studies have described a major impact of genetic variations near the IL28B gene on the natural course and outcome of antiviral therapy in chronic hepatitis C. We therefore, aimed to explore the impact of donor and recipient genotypes of these polymorphisms on hepatitis C virus (HCV) liver graft reinfection. Methods Donor and recipient genotypes of IL28B rs12979860C>T single nucleotide polymorphism were determined in 91 patients with HCV liver graft reinfection, 47 of whom were treated with pegylated interferon-α (PEG-IFN-α) and ribavirin. IL28B genetic polymorphisms were correlated with the natural course and treatment outcome of recurrent hepatitis C. Results Patients requiring liver transplantation due to end-stage chronic hepatitis C appeared to be selected toward the adverse genotypes rs12979860 CT/TT compared to non-transplanted HCV-infected patients ( p =0.046). Patients with the donor genotype rs12979860 CC had higher peak ALT and HCV RNA serum concentrations than those with CT/TT ( p =0.04 and 0.06, respectively). No association was observed between ALT/HCV RNA serum concentrations and recipient genotypes ( p >0.3). More important, donor IL28B rs12979860 CC vs . CT/TT genotypes were associated with rapid, complete early, and sustained virologic response (RVR, cEVR, SVR) to treatment with PEG-IFN-α and ribavirin ( p =0.003, 0.0012, 0.008, respectively), but weaker associations of recipient genotypes with RVR, cEVR, and SVR were observed as well ( p =0.0046, 0.115, 0.118, respectively). Conclusions We provide evidence for a dominant, but not exclusive impact of the donor rather than the recipient IL28B genetic background on the natural course and treatment outcome of HCV liver graft reinfection.

Photodynamic therapy (PDT) with Visudyne acts by direct cellular phototoxicity and/or by an indirect vascular-mediated effect. Here, we demonstrate that the vessel integrity interruption by PDT can promote the extravasation of a macromolecular agent in normal tissue. To obtain extravasation in normal tissue PDT conditions were one order of magnitude more intensive than the ones in tissue containing neovessels reported in the literature. Fluorescein isothiocyanate dextran (FITC-D, 2000 kDa), a macromolecular agent, was intravenously injected 10 min before (LK0 group, n=14) or 2h (LK2 group, n=16) after Visudyne-mediated PDT in nude mice bearing a dorsal skin fold chamber. Control animals had no PDT (CTRL group, n=8). The extravasation of FITC-D from blood vessels in striated muscle tissue was observed in both groups in real-time for up to 2500 s after injection. We also monitored PDT-induced leukocyte rolling in vivo and assessed, by histology, the corresponding inflammatory reaction score in the dorsal skin fold chambers. In all animals, at the applied PDT conditions, FITC-D extravasation was significantly enhanced in the PDT-treated areas as compared to the surrounding non-treated areas (p

The mechanisms by which CD4(+)CD25(+)Foxp3(+) T (Treg) cells regulate effector T cells in a transplantation setting and their in vivo homeostasis still remain to be clarified. Using a mouse adoptive transfer model, we analyzed the in vivo expansion, trafficking, and effector function of alloreactive T cells and donor-specific Treg cells, in response to a full-thickness skin allograft. Fluorescent-labeled CD4(+)CD25(-) and antigen-specific Treg cells were transferred alone or co-injected into syngeneic BALB/c-Nude recipients transplanted with skins from (C57BL/6 x BALB/c) F1 donors. Treg cells divided in vivo, migrated and accumulated in the allograft draining lymph nodes as well as within the graft. The co-transfer of Treg cells did not modify the early activation and homing of CD4(+)CD25(-) T cells in secondary lymphoid organs. However, in the presence of Treg cells, alloreactive CD4(+)CD25(-) T cells produced significantly less IFN-gamma and were present in reduced numbers in the secondary lymphoid organs. Furthermore, time-course studies showed that Treg cells were recruited into the allograft at a very early stage after transplantation and effectively prevented the infiltration of effector T cells. In conclusion, suppression of rejection requires the early recruitment to the site of antigenic challenge of donor-specific Treg cells, which then mainly regulate the effector arm of T cell alloresponses.

a Central Laboratory Animal Facility b Institute of Clinical Chemistry and Laboratory Medicine c Institute of Medical Microbiology and Hygiene, Johannes Gutenberg University, Mainz, Germany d Klinik fur Gefaschirurgie und Nierentransplantation, Heinrich Heine Universitatsklinik, Dusseldorf, Germany e Zentrum fur Medizin und Biowissenschaften, Forschungszentrum, Borstel, Germany f Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland g Department of Molecular Pathology, Graduate School of Medicine and Engineering, University of Yamanashi, Japan

Members of the transforming growth factor beta (TGF-beta) superfamily of signaling molecules are involved in the regulation of many developmental processes that involve the interaction between mesenchymal and epithelial tissues. Smad7 is a potent inhibitor of many members of the TGF-beta family, notably TGF-beta and activin. In this study, we show that embryonic overexpression of Smad7 in stratified epithelia using a keratin 5 promoter, results in severe morphogenetic defects in skin and teeth and leads to embryonic and perinatal lethality. To further analyze the functions of Smad7 in epithelial tissues of adult mice, we used an expression system that allowed a controlled overexpression of Smad7 in terms of both space and time. Skin defects in adult mice overexpressing Smad7 were characterized by hyper-proliferation and missing expression of early markers of keratinocyte differentiation. Upon Smad7-mediated blockade of TGF-beta superfamily signaling, ameloblasts failed to produce an enamel layer in incisor teeth. In addition, TGF-beta blockade in adult mice altered the pattern of thymic T cell differentiation and the number of thymic T cells was significantly reduced. This study shows that TGF-beta superfamily signaling is essential for development of hair, tooth and T-cells as well as differentiation and proliferation control in adult tissues.

This study tested the hypothesis that GLUT-1 is a marker of radioresistance in oral squamous cell carcinomas (OSCC). A GLUT-1 labeling index (LI) was determined by immunohistochemistry in 40 pretreatment OSCC biopsies. Radiation responses were categorized by histopathology of the resection specimens. Associations between the LI and radiation response, Kaplan-Meier survival estimates and Cox regression analysis for the variables GLUT-1, T-stage, N-stage and chemotherapy were examined. The median LI was 64.2% (range 14-100%). Tumors with65% of GLUT-1+cells were more resistant to radiation (p=0.023). Overall survival was higher (p=0.044) for subjects with low LI (median value) than those with high LI (median value). The Cox regression analysis confirmed the prognostic significance of GLUT-1. Our results indicate that pre-treatment GLUT-1 expression in the tumor is a marker of radioresistance in OSCC, with high expression being associated with poor radiation response and shorter survival.

Objective The purpose of the study was to assess the feasibility of intraoperative sentinel node (SN) detection using injection of patent blue dye and radioactive tracer beneath the tumor of patients with endometrial carcinoma. Methods Hysteroscopy was used for injection of 2 ml of patent-V blue, followed by 20–50 MBq technetium-99 m-labelled nanocolloids into the subendometrial layer underlying the tumor of 60 patients with endometrial cancer. Then SN biopsy, pelvic and paraaortic lymphadenectomy, hysterectomy and bilateral salpingo-oophorectomy were carried out through laparotomy or laparoscopy. Results Sixty patients aged 43 years to 87 years (median age 65 years) were enrolled in this study. Sentinel nodes were identified in 49 of 60 patients (82%). The mean number of SN retrieved was 3.7 per patient (range, 1 to 8). Sixteen patients (33%) had SN in both pelvic and paraaortic areas. No patient had SN only at the paraaortic level. Metastatic disease was found in 9 patients (15%). In 8 of them at least one SN was positive. Conclusion Intraoperative sentinel node detection is feasible in patients with endometrial carcinoma using hysteroscopy for injection of blue dye and technetium-99 m beneath the tumor. This technique may actually enhance the chances of detecting metastatic disease, while reducing the extent of the surgery.

Microvascular ischemia-reperfusion (I/R) injury is characterized by failure of capillary perfusion ("no-reflow") and reoxygenation-associated phenomena ("reflow-paradox"), including activation of leukocyte-endothelium interaction with cytotoxic mediator-induced loss of endothelial integrity. The objectives of this study were to elucidate the impact of both prostaglandins E(1) (PGE(1)) and I(2) (PGI(2)) in microvascular reperfusion injury, with special focus on the distinct pathophysiology of no-reflow- and reflow-paradox phenomena.By use of the hamster dorsal skinfold preparation and in vivo fluorescence microscopy, the microcirculation of a striated skin muscle was assessed before 4 h of pressure-induced ischemia and 0.5, 2, and 24 h after onset of reperfusion.I/R was characterized by enhanced leukocyte-endothelium interaction in postcapillary venules, increase of macromolecular leakage, and reduction of functional capillary perfusion (P0.05). Intravenous 2-h infusion of PGE(1), starting with onset of reperfusion, reduced leukocyte adhesion and macromolecular leakage in postcapillary venules during early reperfusion (P0.05), while 6-h infusion, given during ischemia and early reperfusion, showed no significant effects. PGI(2) infusion also attenuated postischemic leukocyte adhesion, which was significant by a 6-h prolonged administration (P0.05), but did not influence the increase of microvascular permeability. Both prostaglandins were unable to prevent the postischemic failure of capillary perfusion (no-reflow).Both prostaglandins did not significantly influence postischemic no-reflow phenomena, but appeared as potent inhibitors of reflow-paradox under the experimental circumstances of this study.

Background & Aims: The microflora plays a crucial role in inflammatory bowel diseases (IBDs). Specific pathogen-free (SPF), but not germ-free, interleukin (IL)-2-deficient (IL-2−/−) mice develop colitis. The colitogenicity of commensal bacteria was determined. Methods: Gnotobiotic IL-2−/− and IL-2+/+ mice were colonized with Escherichia coli mpk, Bacteroides vulgatus mpk, or both bacterial strains, or with E. coli strain Nissle 1917. DNA arrays were used to characterize E. coli mpk. Colitis was analyzed by histology and real-time reverse-transcription polymerase chain reaction (RT-PCR) for interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-10, and CD14 messenger RNA (mRNA) expression. Bacterial numbers in feces and bacterial localization in the colon was determined by culture and fluorescence in situ hybridization (FISH). Results: IL-2−/− but not IL-2+/+ mice monocolonized with E. coli mpk developed colitis, whereas mono-association with B. vulgatus mpk, or E. coli Nissle, or co-colonization with E. coli mpk and B. vulgatus mpk, did not induce colitis. DNA array experiments and cellular studies revealed that E. coli mpk is a nonpathogenic strain. FISH and culture methods revealed that the anticolitogenic effect of B. vulgatus mpk on E. coli mpk cannot be explained by a significant reduction in numbers of E. coli in the colon. E. coli mpk-induced colitis was associated with increased IFN-γ, TNF-α, CD14, and IL-10 mRNA expression in the colon. Conclusions: In IL-2−/− mice, B. vulgatus mpk protects against E. coli mpk-triggered colitis by an unknown mechanism. E. coli Nissle does not induce colitis. Various bacterial species common to the microflora differ in their ability to trigger IBD.

Background: Aortocoronary bypass graft disease is responsible for long-term failure of autologous vein grafts. The analyses of proliferation and cell type characterisation in human bypass grafts harvested during re-do surgery make it possible to investigate the cellular processes leading to bypass graft failure. Methods: 30 stenotic vein grafts and 25 control veins were explantated during re-do heart surgery procedures. The total area and cell count of the neointima, media and adventitia were calculated computer-assisted. Actively proliferating cells were identified using antibody to Ki-67 and positive cells were determined by double-label immunocytochemistry with SMC α-actin, CD 31 (endothelial cells), CD 68 (macrophages) and CD 45 (T-lymphocytes). Results: Active proliferation was detected in different cell types with an average proliferation index of 0.15%, 0.18% and 0.086% for neointima, media and adventitia. Only 9% of proliferating cells in the neointima were SMC (not identified cells 40%); correspondingly, 14% SMC (not identified cells 33%) were detected in the media. Endothelial cells turned out to be the predominant proliferating cell type in all sections of the vessel wall. Conclusion: Proliferation in our series of stenotic vein grafts occurred at a low level, but was significantly higher compared to native control veins. While proliferation may play an important role in early lesions, our data clearly show low proliferation activity in advanced graft lesions. The identification of proliferating macrophages and T-lymphocytes implicate an additional inflammatory component in the development of human bypass graft disease. Summary: To clarify the role of cellular proliferation in human aortocoronary bypass grafts, we characterized the cellular composition and proliferation index in 30 stenotic saphenous vein grafts in comparison to 25 native veins. Proliferation in our series of stenotic vein grafts occurred at a low level, but was significantly higher compared to native control veins.

Background & Aims: In addition to acting as a regulator of food intake and energy expenditure, leptin can also modulate immune and inflammatory responses. The role of leptin in intestinal inflammation is the focus of the present study. Methods: Acute and chronic colitis were induced in leptin-deficient ob/ob or wild-type (WT) mice using dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS). The severity of colitis was evaluated, and possible mechanisms were studied. Results: Leptin directly stimulates intraepithelial lymphocytes (IELs) and lamina propria mononuclear cells (LPMCs). In the DSS acute model, ob/ob mice exhibited a 72% reduction of colitis severity and spontaneous release of proinflammatory cytokines from the colon compared with WT mice. Replacement of leptin in ob/ob mice converted disease resistance to susceptibility, indicating that leptin deficiency, not obesity, accounts for the resistance to acute DSS-induced colitis. During chronic DSS-induced colitis and TNBS-induced colitis, in addition to reduced disease severity, ob/ob mice exhibited a significant attenuation in intestinal inflammation, accompanied by reduced production of cytokines and chemokines. When compared with WT mice, CD8 + IELs of ob/ob mice were reduced in number as well as in their ability to synthesize interferon gamma. In addition, LPMCs of ob/ob mice showed increased apoptosis in untreated as well as DSS- or TNBS-treated mice. Phosphorylation of signal transducer and activator of transcription 3 and induction of cyclooxygenase 2 were absent in the colon of DSS-fed ob/ob mice. Conclusions: These results show that leptin represents a functional link between the endocrine and immune systems. GASTROENTEROLOGY 2002;122:2011-2025

Background & Aims GATA3 is a transcription factor that regulates T-cell production of cytokines. We investigated the role of GATA3 in development of colitis in mice. Methods We performed quantitative polymerase chain reaction and immunofluorescence analyses of colon tissues from patients with Crohn's disease (n = 61) or ulcerative colitis (UC, n = 74) or from patients without inflammatory bowel diseases (n = 22), to measure levels of GATA3. Colitis was induced by administration of oxazolone or 2,4,6-trinitrobenzenesulfonic acid to control mice, mice with T-cell−specific deletion of GATA3, and mice with deletion of tumor necrosis factor receptor (TNFR) 1 and TNFR2 (TNFR double knockouts); some mice were given a GATA3-specific DNAzyme (hgd40) or a control DNAzyme via intrarectal administration, or systemic injections of an antibody to TNF before or during sensitization and challenge phase of colitis induction. Colon tissues were collected and immunofluorescence and histochemical analyses were performed. Lamina propria mononuclear cells and T cells were isolated and analyzed by flow cytometry or cytokine assays. Colonic distribution of labeled DNAzyme and inflammation were monitored by in vivo imaging (endoscopy) of mice. Results Levels of GATA3 messenger RNA were higher in colon tissues from patients with UC, but not ileal Crohn's disease, than control tissues; levels of GATA3 correlated with levels of inflammatory cytokines (interleukin [IL] 9, IL17A, IL6, IL5, IL4, IL13, and TNF). We observed increased expression of GATA3 by lamina propria T cells from mice with colitis compared with controls. Mice with T-cell−specific deletion of GATA3 did not develop colitis and their colonic tissues did not produce inflammatory cytokines (IL6, IL9, or IL13). The DNAzyme hgd40 inhibited expression of GATA3 messenger RNA by unstimulated and stimulated T cells, and distributed throughout the inflamed colons of mice with colitis. Colon tissues from mice given hgd40 had reduced expression of GATA3 messenger RNA, compared with mice given a control DNAzyme. Mice given hgd40 did not develop colitis after administration of oxazolone or 2,4,6-trinitrobenzenesulfonic acid; lamina propria cells from these mice expressed lower levels of IL6, IL9, and IL13 than cells from mice given the control DNAzyme. Mini-endoscopic images revealed that hgd40 and anti-TNF reduced colon inflammation over 3 days; hgd40 reduced colitis in TNFR double-knockout mice. Conclusions Levels of GATA3 are increased in patients with UC and correlate with production of inflammatory cytokines in mice and humans. A DNAzyme that prevents expression of GATA3 reduces colitis in mice, independently of TNF, and reduces levels of cytokines in the colon. This DNAzyme might be developed for treatment of patients with UC.

Systemic and local delivery on the photosensitive drug Photofrin polyporphyrin was investigated in normal porcine arteries (n = 192). A macroporous balloon and a novel needle injection catheter were used for local drug delivery and compared with systemic delivery. Fluorescence microscopy combined with digital image analysis was used to quantify the drug-related fluorescence. Systemic delivery showed a maximum in the intima at 4 hours. Application with the porous balloon revealed maximum indicator-related fluorescence intensity in the intima after 5 minutes; delivery with the needle injection catheter resulted in a several-fold enhanced maximum in adventitia after 30 minutes compared with the maximum achieved with either systemic injection or porous balloon application. After 21 days fluorescence was detectable in arteries treated with the new needle injection catheter. Local drug delivery is feasible with either system, but prolonged delivery was achieved only with the needle injection catheter.

Plasma membrane fluidity of intact peripheral blood lymphocytes (PBL) of phenytoin-treated nonepileptic patients and phenytoin-treated CD4 + lymphoid cells H9 and K37 was determined by fluorescence anisotropy measurements. Anisotropy values of the membrane probe 6-(9-anthroyloxy) stearic acid were decreased in all cell types as compared with controls, indicating increased plasma membrane fluidity of phenytoin-treated cells. Specific binding of 125 I-labeled vasoactive intestinal peptide (VIP) to its cellular receptor CD4 on PBL was decreased in PBL of phenytoin-treated patients as compared with untreated, healthy subjects. Adsorption of a different ligand to the CD4 receptor on PBL, the human immunodeficiency virus type 1 (HIV-1), was likewise abolished to PBL of phenytoin-treated patients and phenytoin-treated CD4 + H9 and K37 cells, as assessed by indirect immunofluorescence. Subsequent HIV-1 infection of phenytoin-treated H9 and K37 cells was reduced as measured by indirect immunofluorescence and p24 antigen production. These data indicate that CD4 receptor availability for VIP and HIV-1 was reduced in phenytoin-treated cells. Using the DNA-specific dye Hoechst 33258, we examined cell cycle phase distributions of HIV-1 adsorbing and nonadsorbing H9 cells, as separated by flow cytometry. The majority of HIV-1 adsorbing cells were found to be in the G 2 /M phase, while nonadsorbing cells were mainly in the G 0 G 1 phase, during which plasma membrane fluidity is supposed to be increased. This study indicates that plasma membrane fluidization by phenytoin may serve to disrupt CD4 receptor function and emphasizes the impact of plasma membrane properties on HIV-1 adsorption and infection.

Introduction: Interleukin 9 is a pleiotropic pro-inflammatory cytokine mainly produced by T cells, beside B cells and mast cells. Mounting evidence suggests that there may be a specialized subset of T cells dedicated to produce IL-9 which are so called Th9 cells. In these cells the IL-9 gene is regulated by transcription factors like PU.1 and IRF4. Also many cytokines have been investigated so far in experimental models of chronic intestinal inflammation, the role of IL-9 is largely unidentified. But high concentrations of IL-9 in the colon tissue during colitis reveal the important role of this cytokine. Methods: For the analysis of IL-9 in the development of chronic intestinal inflammation IL-9 deficient mice were used in oxazolone-colitis model. Miniendoscopic analysis has been done to monitor the manifestation of the colitis. The inflamed colon was isolated and histological sections were taken for immunohistofluorescent staining and real-time PCR analysis. For therapeutically treatment wildtype mice were given 40μg of specific anti IL-9 antibody to prevent the emergence of colitis. Results: In the experimental oxazolone-colitis model the IL-9KO mice were protected. This became evident in the miniendoscopic analysis and in the HE staining. Immunofluorescence staining shows a decrease of the IL-9 regulating transcription factor PU.1 in the IL-9 deficient mice, indicating the involvement of PU.1 in the IL-9 production. This is consistent with the fact that PU.1 is higher expressed in human biopsies of colitis patients, which illustrates the pro-inflammatory role of IL-9 in patients suffering from inflammatory bowel disease. Double staining of CD4+ and PU.1 and EPCAM and PU.1 respectively suggests that there are specialized T cells expressing the transcription factor PU.1 implying a role of Th9 cells in colitis. Further analysis of the pro-inflammatory effect of IL-9 showed that the blockage of high IL-9 concentrations with a specific anti IL-9 antibody in wildtype mice lead to a protection in oxazolone-colitis model. Conclusion: Here, we have identified a central pathogenic role for Th9 cells in chronic intestinal inflammation. This is based on the fact that IL-9 is increased in inflamed colon tissue and IL-9KO mice are protected in the experimental oxazolone-colitis model. Furthermore, administration of a blocking anti IL-9 antibody before the manifestation of colitis has a protective effect. Thus IL-9 emerges as a potentially new therapeutic target for inflammatory bowel diseases.

Reference EPFL-CONF-185611View record in Web of Science Record created on 2013-03-28, modified on 2017-05-12

BACKGROUND: The specific inhibition of phosphodiesterase (PDE)4 and dual inhibition of PDE3 and PDE4 has been shown to decrease inflammation by suppression of proinflammatory cytokine synthesis In Vivo and In Vitro. We examined the effect of roflumilast, a selective PDE4 inhibitor marketed for severe COPD, and the investigational compound pumafentrine, a dual PDE3/PDE4 inhibitor, in the preventive dextran sodium sulfate (DSS)induced colitis model. METHODS: The clinical score, colon length, histologic score and colon cytokine production from mice with DSS-induced colitis (3.5% DSS in drinking water for 11 days) receiving either roflumilast (1 or 5 mg/kg body weight/d p.o.) or pumafentrine (1.5, 5 or 20 mg/kg/d p.o.) were determined and compared to vehicle treated control mice. In the pumafentrine-treated animals, splenocytes were analyzed for interferon-γ (IFNγ) production and CD69 expression. RESULTS: Roflumilast treatment resulted in dose-dependent improvements of clinical score (weight loss, stool consistency and bleeding), colon length, and tumor necrosis factor-α (TNF) production in the colonic tissue. These findings, however, were not associated with an improvement of the histologic score. Administration of pumafentrine at 5 mg/kg/d alleviated the clinical score, the colon length shortening, and local TNF-production. In Vitro stimulated splenocytes after In Vivo treatment with pumafentrine showed a significantly lower state of activation and production of IFNγ compared to no treatment In Vivo. CONCLUSIONS: These series of experiments document the anti-inflammatory effect of roflumilast and pumafentrine in the prevention of experimental colitis in mice. The selective inhibition of PDE4 or the selective combined inhibition of PDE3/ PDE4 represent promising novel approaches for the therapy of inflammatory bowel disease.

Background The transcriptional regulation of cytokines released and controlled by memory T cells is not well understood. Defective IFN-γ production in allergic asthma correlates in human beings with the risk of wheezing in childhood. Objective To understand the role of the transcription factor nuclear factor of activated T cells 2 (NFATc2) in memory and effector T cells in the airways in experimental allergic asthma. Methods We used murine models of allergic asthma and adoptive cell transfer of fluorescence-activated sorted cells in a disease model. Results Mice lacking NFATc2 developed an increase in airway hyperresponsiveness (AHR), remodeling, and serum IgE levels on ovalbumin sensitization. This phenotype was associated with CD8 + CD122 − T cells deficient in IFN-γ production in the airways. The origin of this phenotype in NFATc2 (−/−) mice was related to an expanded population of lung CD8 + CD122 + (IL-2Rβ chain) CD127 hi (IL-7 receptor [R] α chain + ) long-lived memory cells. Adoptive transfer of ovalbumin-specific CD8 + NFATc2 (−/−) T cells enhanced the AHR generated by NFATc2 (−/−) CD4 + T cells in immunodeficient mice, increased IL-17, and reduced IFN-γ production in the reconstituted mice. Depletion of the memory CD8 + CD122 + IL-7R high T-cell population corrected the defect in IFN-γ production by lung NFATc2 (−/−) CD8 + CD122 − cells and abrogated the increased AHR observed in NFATc2 (−/−) CD8 + T-cell–reconstituted mice with a severe combined immunodeficiency disorder. Conclusion Taken together, our results suggest that NFATc2 expression in long-lived memory CD8 + T cells controls IL-2 and IFN-γ production in lung CD8 + T cells, which then limits T H 17 and T H 2 development in the airways during allergen challenge.

Backround: Leptin deficient ob/ob mice exhibit an obese phenotype and develop a tarty liver disease. These mice are more sensitive against LPS.qNF mediated liver injury. Here we compare the sensitivity of tatty and normal livers against CEN5 induced apoptosis Material/Methods: Agonistic anti-CD95-antibodies (clone ]o2) were injected i.v. m 6-8 weeks old ob/ob mice and ob/? control animals (0.1 mg/kg). 8h after Jo2 challenge mice were killed, blood was taken and parts of the livers were stored in liquid nitrogen or formalin. ALT/ AST from blood serum was measured in the clinical chemistry, laborato D, at the University of Mainz. Histological analysis of liver sections was done after hematoxylme/eosine staining and apoptotic cells were identified by" TUNEL assay. Caspase 3 acticity was measured trom cytosofic extracts of fiver tissue Results: 8 h after Jo2 injection ALT/AST were significantly more elevated in ob/ob mice in comparison with ob/? control miee. Liver sections of ob/ob mice showed a severe apoptotic liver damage, while ob~ mice revealed only slight pathological changes atier Jo2 administration in accordance with these findings TUNEL assays of ob/ ob liver sections showed many hepatocy~es with DNA breakages after Jo2 injection, whereas only a few positive cells were detected in oh/? mice. Mter Jo2 injection Caspase 3 activity was sigudicantly more elevated m the livers of ob/ob mice in comparison with control mice D*cseussion: The results indicate an increased sensitivity of fatty liver against CD95 mediated apoptosis, Fatty degeneration of bepatocyles results m morpfiological and functional changes of the mitochondria, so a strong activation of the mitochondria[ apoptotic signaling pathway would be a possible explanation tor the increased hver iqury after administration of Jo2-antibodies.

Background: TNF-~plays an essential role in the pathogenesis of inflammatory bowel disease. Among the agents known to inhibit TNF-~production, attention has focused on cAMP-elevating agents such as phosphodiesterase (PDE) inhibitors. Mesopram (Dinter et al, J Neuroimmunol 2000,108,136-46) is a specific inhibitor of PDE IV the predominant isoenzyme in monocytes, which are the main source of TNF-,~. In the present study we investigated the effect of systemic mesopram in DeS-induced murine colitis. Methods: For induction of colitis Balb/c mice received 3.5 % DSS dissolved in sterile, distilled water for 10 days as drinking supply. Mesopram (10 mg/kg body weight/day) was applied twice daily intraperitoneally and orally, respectively. The clinical score was calculated daily by weight loss, stool consistency and bleeding (0 healthy, to 4 severely ill). At day 11 mice were sacrificed and colon length was assessed as an indirect parameter for the degree of inflammation. Further, a histologic score was determined, which was composed by the degree of inflammation (0 no changes to 6 extensive cell infiltration and tissue damage). The content of IFN--tin colon tissue was quantified in the eluate of homogenized parts of the colons by ELISA. Results: First, i.p.-mesopram (p