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Background and aims: Administration of interferon (IFN)-β may represent a rational approach to the treatment of ulcerative colitis through its immunomodulatory and anti-inflammatory effects. The present study was performed to [...]

Background: Increased expression of proinflammatory cytokines, including tumour necrosis factor α, interleukin 6, and interferon γ, as well as activation of proinflammatory signalling molecules such as nuclear factor kappa B, [...]

Objective: Vedolizumab, a monoclonal antibody directed against the integrin heterodimer α4β7, is approved for the treatment of Crohn's disease and ulcerative colitis. The efficacy of vedolizumab has been suggested to result from inhibition of intestinal T cell trafficking although human data to support this conclusion are scarce. We therefore performed a comprehensive analysis of vedolizumab-induced alterations in mucosal and systemic immunity in patients with inflammatory bowel disease (IBD), using anti-inflammatory therapy with the TNFα antibody infliximab as control., Design: Immunophenotyping, immunohistochemistry, T cell receptor profiling and RNA sequencing were performed using blood and colonic biopsies from patients with IBD before and during treatment with vedolizumab (n=18) or, as control, the anti-TNFα antibody infliximab (n=20). Leucocyte trafficking in vivo was assessed using single photon emission computed tomography and endomicroscopy., Results: Vedolizumab was not associated with alterations in the abundance or phenotype of lamina propria T cells and did not affect the mucosal T cell repertoire or leucocyte trafficking in vivo. Surprisingly, however, α4β7 antibody treatment was associated with substantial effects on innate immunity including changes in macrophage populations and pronounced alterations in the expression of molecules involved in microbial sensing, chemoattraction and regulation of the innate effector response. These effects were specific to vedolizumab, not observed in response to the TNFα antibody infliximab, and associated with inhibition of intestinal inflammation., Conclusion: Our findings suggest that modulation of innate immunity contributes to the therapeutic efficacy of vedolizumab in IBD., Trial Registration Number: NCT02694588., Competing Interests: Competing interests: SZ: consulting fees: Biogen, Ferring, Janssen-Cilag, Takeda; Lecture fees: Abbvie, Falk, Ferring, MSD, Roche, Takeda. KA: grant support: Pfizer. AA: consulting fees: Boston Scientific; lecture fees: Boston Scientific. SS: consulting fees: AbbVie, Boehringer, Merck, Janssen, Pfizer, Takeda; lecture fees: AbbVie, Boehringer, Merck, Janssen, Pfizer, Takeda., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2019. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Objective: An inadequate host response to the intestinal microbiota likely contributes to the manifestation and progression of human inflammatory bowel disease (IBD). However, molecular approaches to unravelling the nature of the defective crosstalk and its consequences for intestinal metabolic and immunological networks are lacking. We assessed the mucosal transcript levels, splicing architecture and mucosa-attached microbial communities of patients with IBD to obtain a comprehensive view of the underlying, hitherto poorly characterised interactions, and how these are altered in IBD., Design: Mucosal biopsies from Crohn's disease and patients with UC, disease controls and healthy individuals (n=63) were subjected to microbiome, transcriptome and splicing analysis, employing next-generation sequencing. The three data levels were integrated by different bioinformatic approaches, including systems biology-inspired network and pathway analysis., Results: Microbiota, host transcript levels and host splicing patterns were influenced most strongly by tissue differences, followed by the effect of inflammation. Both factors point towards a substantial disease-related alteration of metabolic processes. We also observed a strong enrichment of splicing events in inflamed tissues, accompanied by an alteration of the mucosa-attached bacterial taxa. Finally, we noted a striking uncoupling of the three molecular entities when moving from healthy individuals via disease controls to patients with IBD., Conclusions: Our results provide strong evidence that the interplay between microbiome and host transcriptome, which normally characterises a state of intestinal homeostasis, is drastically perturbed in Crohn's disease and UC. Consequently, integrating multiple OMICs levels appears to be a promising approach to further disentangle the complexity of IBD., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Objective: Mechanisms of action (MoA) of anti-tumour necrosis factor α (TNFα) therapies in Crohn's disease (CD) may critically involve induction of immune cell apoptosis via membrane-bound TNFα (mTNFα) binding. Certolizumab pegol (CZP), which is effective in induction and maintenance of remission in CD lacks the ability to induce apoptosis. The aim of this study was to analyse transcriptomal responses of reverse signalling induced by the TNFα binding agents infliximab (IFX) and CZP in myelomonocytic cells., Design: Induction of transcriptional patterns upon anti-TNFα stimulation was assessed using oligonucleotide microarrays. mRNA expression of GDF-1/ LASS1, which was identified as a shared target, was studied in inflammatory bowel disease by real-time PCR, while signalling pathways induced by growth and differentiation factor 1 (GDF-1) were investigated using western blots and ELISA., Results: IFX and CZP induced a common signature of 20 transcripts that could be categorised into control of cell cycle, transcription activation and pre-mRNA processing. We selected GDF-1/LASS1 for functional follow-up, which was found to be upregulated in inflamed CD tissues. We show that downregulation of GDF-1/LASS1 depends on autocrine release of transforming growth factor β after mTNFα ligation. We demonstrate that GDF-1 itself acts as a novel proinflammatory factor via induction of interleukin 6 and signal transducer and activator of transcription 3 and is downregulated after IFX treatment., Conclusion: Commonalities in the MoA of IFX and CZP comprise modulation of non-apoptotic pathways through downregulation of proinflammatory GDF-1. Further characterisation of the molecular role of GDF-1 in complex inflammatory processes in vivo is warranted to decide whether this proinflammatory molecule is a promising therapeutic target in patients with CD.

Background: and aims: Administration of interferon (IFN)-beta may represent a rational approach to the treatment of ulcerative colitis through its immunomodulatory and anti-inflammatory effects. The present study was performed to evaluate the efficacy and tolerability of IFN-beta-1a., Methods: Patients (n=18) with moderately active ulcerative colitis were randomised to receive IFN-beta-1a or placebo. IFN-beta-1a was started at a dose of 22 micro g three times a week subcutaneously, and the dose was increased at two week intervals to 44 micro g and then to 88 micro g if no response was observed. The maximum duration of treatment was eight weeks. End points were clinical treatment response, defined as a decrease of at least 3 points from baseline in the ulcerative colitis scoring system (UCSS) symptoms score and induction of endoscopically confirmed remission., Results: Baseline characteristics and disease severity were similar in both groups. Data from 17 patients are included in this report (10 patients in the IFN-beta-1a group and seven patients in the placebo group). Clinical response was achieved in five patients (50%) in the IFN-beta-1a group and in one (14%) in the placebo group (P=0.14). Remission was achieved in three patients in the IFN-beta-1a group and in none in the placebo group (p=0.02). Most adverse reactions associated with IFN-beta-1a were influenza-like symptoms or injection site reactions, and were mild or moderate in severity., Conclusions: IFN-beta-1a may represent a promising novel treatment approach in ulcerative colitis.

Background: Expression of pro-inflammatory cytokines is increased in the intestinal lamina propria of patients with inflammatory bowel disease (IBD). Nuclear factor kappa B (NF kappa B) controls transcription of inflammation genes. On activation, NF kappa B is rapidly released from its cytoplasmic inhibitor (I kappa B), transmigrates into the nucleus, and binds to DNA response elements in gene promoter regions., Aims: To investigate whether increased activation of NF kappa B is important in IBD and may be down-regulated by anti-inflammatory treatment., Methods: Activation of NF kappa B was determined by western blot assessment and electrophoretic mobility shift assay in nuclear extracts of colonic biopsy samples as well as lamina propria mononuclear cells., Results: Nuclear levels of NF kappa B p65 are increased in lamina propria biopsy specimens from patients with Crohn's disease in comparison with patients with ulcerative colitis and controls. Increased activation of NF kappa B was detected in lamina propria mononuclear cells from patients with active IBD. Corticosteroids strongly inhibit intestinal NF kappa B activation in IBD in vivo and in vitro by stabilising the cytosolic inhibitor I kappa B alpha against activation induced degradation., Conclusions: In both IBDs, but particularly Crohn's disease, increased activation of NF kappa B may be involved in the regulation of the inflammatory response. Inhibition of NF kappa B activation may represent a mechanism by which steroids exert an anti-inflammatory effect in IBD.