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Pogonka T.,Humboldt University of Berlin | Schelzke K.,Humboldt University of Berlin | Stange J.,Humboldt University of Berlin | Papadakis K.,Humboldt University of Berlin | And 3 more authors.
Microbes and Infection | Year: 2010

We investigated cellular immune responses of mice infected with the apicomplexan parasite Eimeria falciformis in order to characterise protective immune mechanisms and effector functions. Adoptive transfer experiments with mesenterial lymph node cells (MLNC) from immune donor mice were performed, and the oocyst output monitored after challenge infection. Phenotypical analysis by fluorescence cytometry and T cell proliferation assay showed that already from day four post infection E. falciformis-specific lymphocytes were present in the MLN. The frequency of parasite-specific, IFN-γ producing CD4+ and CD8+ cells increased in this period by 9.8% and 16.4%, respectively. Infection experiments with IFN-γ deficient mice revealed that IFN-γ is involved in resistance to primary and secondary infection. Transfer of total MLNC from immune donors reduced the oocyst output by 65-74%, as compared to the oocyst output of animals transferred with cells from naïve donors. Transfer of CD8+ cells inhibited parasite development resulting in a reduction of oocyst numbers by 42-64%, whereas CD4+ cells showed no influence on resistance to reinfection. © 2009 Elsevier Masson SAS. All rights reserved.


Brueckner C.S.,Charite - Medical University of Berlin | Becker M.O.,Charite - Medical University of Berlin | Kroencke T.,Charite - Medical University of Berlin | Huscher D.,German Rheumatology Research Center | And 4 more authors.
Annals of the Rheumatic Diseases | Year: 2010

Objective: In this pilot study, the effect of sildenafil on digital ulcer (DU) healing and related clinical symptoms was analysed. Methods: A total of 19 patients with systemic sclerosis (SSc) were treated with maximally tolerated sildenafil doses up to 6 months. Primary outcome was the healing of DUs. Changes in other clinical symptoms were also evaluated. Results: In all, 49 DUs were present at baseline; this decreased to 17 ulcers (p<0.001) at the end of sildenafil treatment. Furthermore, the visual analogue scale (VAS) score for Raynaud's phenomenon (RP), pain and activity improved (p=0.003, p=0.002 and p=0.05, respectively). A total of 9 patients developed 12 new DUs during sildenafil treatment. Conclusions: This study indicates an effect of sildenafil on DU healing in patients with SSc and an improvement of RP and associated symptoms that should be validated in controlled studies.


Martinez-Gamboa L.,Charite - Medical University of Berlin | Lesemann K.,Charite - Medical University of Berlin | Kuckelkorn U.,Charite - Medical University of Berlin | Scheffler S.,Charite - Medical University of Berlin | And 13 more authors.
Journal of Rheumatology | Year: 2013

Objective. Dysregulation of proteasome subunit β1i expression has been shown in total blood mononuclear cells (PBMC) from patients with primary Sjögren syndrome (pSS), a B cell-driven systemic autoimmune disorder. Methods. Proteasome activation was investigated in sorted blood cells from patients with pSS and controls by measuring transcript levels of constitutive (β1/β2/β5) and corresponding immunoproteasome catalytic subunits (β1i/β2i/β5i) using real-time PCR. At protein level, β1i protein expression was analyzed by immunoblotting. Functional effects of proteasome inhibition on proteolytic activity and induction of apoptosis were also evaluated in cellular subsets. Results. The proteasome was found to be activated in pSS, with upregulation of gene expression of catalytic proteasome subunits. Western blot analysis revealed decreased β1i protein expression in pSS B lymphocytes, with decreased protein despite increased messenger RNA (mRNA) levels. After proteasome inhibition in vitro, proteolytic activity was less reduced and resistance to apoptosis was increased in B lymphocytes compared to other cells. Conclusion. In pSS, catalytic subunits of the proteasome are upregulated at the mRNA level, while dysregulation of subunit β1i is attributed to B lymphocytes. B cell resistance after proteasome inhibition differs from the classical concept of increased susceptibility toward inhibition in activated cells, supporting the novel notion that susceptibility depends on cellular intrinsic factors and on proteasome activation. The Journal of Rheumatology Copyright © 2013. All rights reserved.


Seidel D.,Charite - Medical University of Berlin | Eickmeier I.,Charite - Medical University of Berlin | Kuhl A.A.,Charite - Medical University of Berlin | Hamann A.,German Rheumatology Research Center | And 2 more authors.
Hepatology | Year: 2014

The pathogenesis of primary sclerosing cholangitis (PSC) remains poorly understood. Since PSC predominantly occurs in patients with inflammatory bowel disease, autoimmunity triggered by activated T cells migrating from the gut to the liver is a possible mechanism. We hypothesized that T cells primed in the gut-associated lymphoid tissue (GALT) by a specific antigen migrate to the liver and cause cholangitis when they recognize the same antigen on cholangiocytes. We induced ovalbumin-dependent colitis in mice that express ovalbumin in biliary epithelia (ASBT-OVA mice) and crossed ASBT-OVA mice with mice that express ovalbumin in enterocytes (iFABP-OVA mice). We analyzed T-cell activation in the GALT and crossreactivity to the same antigen in the liver as well as the effects of colitis per se on antigen-presentation and T-cell activation in the liver. Intrarectal application of ovalbumin followed by transfer of CD8 OT-I T cells led to antigen-dependent colitis. CD8 T cells primed in the GALT acquired effector function and the capability to migrate to the liver, where they caused cholangitis in a strictly antigen-dependent manner. Likewise, cholangitis developed in mice expressing ovalbumin simultaneously in biliary epithelia and enterocytes after transfer of OT-I T cells. Dextran sodium sulfate colitis led to increased levels of inflammatory cytokines in the portal venous blood, induced activation of resident liver dendritic cells, and promoted the induction of T-cell-dependent cholangitis. Conclusion: Our data strengthen the notion that immune-mediated cholangitis is caused by T cells primed in the GALT and provide the first link between colitis and cholangitis in an antigen-dependent mouse model. © 2013 by the American Association for the Study of Liver Diseases.


Felson D.T.,Boston University | Felson D.T.,University of Manchester | Smolen J.S.,Medical University of Vienna | Wells G.,University of Ottawa | And 42 more authors.
Annals of the Rheumatic Diseases | Year: 2011

Objective: Remission in rheumatoid arthritis (RA) is an increasingly attainable goal, but there is no widely used definition of remission that is stringent but achievable and could be applied uniformly as an outcome measure in clinical trials. This work was undertaken to develop such a definition. Methods: A committee consisting of members of the American College of Rheumatology, the European League Against Rheumatism, and the Outcome Measures in Rheumatology Initiative met to guide the process and review prespecified analyses from RA clinical trials. The committee requested a stringent definition (little, if any, active disease) and decided to use core set measures including, as a minimum, joint counts and levels of an acute-phase reactant to define remission. Members were surveyed to select the level of each core set measure that would be consistent with remission. Candidate definitions of remission were tested, including those that constituted a number of individual measures of remission (Boolean approach) as well as definitions using disease activity indexes. To select a definition of remission, trial data were analysed to examine the added contribution of patient-reported outcomes and the ability of candidate measures to predict later good radiographic and functional outcomes. Results: Survey results for the definition of remission suggested indexes at published thresholds and a count of core set measures, with each measure scored as 1 or less (eg, tender and swollen joint counts, C reactive protein (CRP) level, and global assessments on a 0-10 scale). Analyses suggested the need to include a patient-reported measure. Examination of 2-year follow-up data suggested that many candidate definitions performed comparably in terms of predicting later good radiographic and functional outcomes, although 28-joint Disease Activity Score-based measures of remission did not predict good radiographic outcomes as well as the other candidate definitions did. Given these and other considerations, we propose that a patient's RA can be defined as being in remission based on one of two definitions:(1) when scores on the tender joint count, swollen joint count, CRP (in mg/dl), and patient global assessment (0-10 scale) are all ≤1, or (2) when the score on the Simplified Disease Activity Index is ≤3.3. Conclusion: We propose two new definitions of remission, both of which can be uniformly applied and widely used in RA clinical trials. The authors recommend that one of these be selected as an outcome measure in each trial and that the results on both be reported for each trial.

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