Basic Science S89 the early diagnosis, prognosis prediction and treatment of colorectal tumors and inflammatory bowel disease. P063 Identification of novel non-transcriptionally acting glucocorticoid receptor ligands that suppress T cell activation but lack adipogenic activity A. Verhaar 1 *, R. Dvorsky 2 , M. Wildenberg 3 , M. L¨ owenberg 1 , M. Peppelenbosch 4 , D.W. Hommes 5 , G. van den Brink 1 . 1 Academic Medical Center, Gastroenterology & Hepatology, Amsterdam, Netherlands, 2 Max Planck Institute of Molecular Physiology, Structural Biology, Dortmund, Germany, 3 Academic Medical Center, Tytgat Institute for Liver and Intestinal Research, Amsterdam, Netherlands, 4 Erasmus MC, Gastroenterology and Hepatology, Rotterdam, Netherlands, 5 University of California Los Angeles, Center for Inflammatory Bowel Diseases, Los Angeles, United States Background: The use of glucocorticoids as immunosuppressives is limited by important side effects such as loss of bone mass, muscle atrophy and adipogenesis. Glucocorticoids bind to the glucocorticoid receptor (GR) that translocates from the cytosol to the nucleus and regulates transcription of target genes. In addition to this transcriptional regulation, there are also more rapid, non-transcriptionally mediated effects of glucocorticoids. We have previously shown that the GR is part of the T cell receptor (TCR) complex and that ligand binding results in dissociation of the GR from this complex and inhibition of canonical TCR signalling through LCK-PLCg. The dissociation of this complex appears to play an important role in glucocorticoid mediated inhibition of T cell activation as we found that stimuli that bypass LCK-PLCg signalling render T lymphocytes glucocorticoid resistant. Here we aimed to develop a GR ligand that inactivates LCK-PLCg signalling without resulting in transcriptional regulation. We examined if this approach could separate the anti-inflammatory effects of glucocorticoids from some of their side effects. Methods: Potential steroidal and nonsteroidal candidates were identified using an in silico docking assay to predict GR affinity. Selected compounds where screened in in vitro for gluco- corticoid response element (GRE) mediated transcriptional regulation and their capacity to inhibit phytohemagglutinin (PHA) or Staphylococcus aureus enterotoxin B induced T cell activation. Two lead compounds were examined for GR binding, their capacity to inhibit canonical LCK-PLCg-mediated TCR signalling and ability to induce adipogenesis and muscle fiber atrophy. Results: In the first in silico screening round, we screened 9.2 million compounds and selected 20,000 steroidal and non- steroidal compounds based on similarity to the structure of cortisol. In the second round these compounds were virtually docked in the binding pocket of the GR in two conformations and assigned a score that reflected their predicted affinity. The top 100 compounds were further screened for their capacity to inhibit T cell proliferation. This approach led to the discovery of compounds S3.1 and S3.4, which lack a generic cortisol structure but bind the GR in T lymphocytes and inhibit LCK-PLCg dependent T cell proliferation without causing transcriptional modulation of GR target genes. In contrast to classical glucocorticoids, S3.1 and S3.4 do not induce adipogenesis or cause muscle cell atrophy in vitro. Conclusions: Our data show that it is possible to develop nonsteroidal GR ligands that dissociate transcriptional from non-transcriptional effects and may have reduced side effects. P064 Identification of inflammatory mediators in Crohn’s disease patients who are unresponsive to anti-TNF therapy A transcriptional analysis of intestinal mucosa R.F. Leal 1 *, N. Planell 2 , R. Kajekar 3 , J.J. Lozano 2 , I. Ord´ as 4 , I. Dotti 1 , M. Esteller 1 , M.C. Masamunt 1 , H. Parmar 3 , E. Ricart 4 , J. Pan´ es 1 , A. Salas 1 . 1 IDIBAPS, Hospital Clínic, CIBERehd, Department of Gastroenterology, Barcelona, Spain, 2 IDIBAPS, CIBERehd, Bioinformatics Platform, Barcelona, Spain, 3 Hoffmann-La Roche, Nutley, New Jersey, United States, 4 Hospital Clínic Barcelona, Department of Gastroenterology, Barcelona, Spain Background: Crohn’s disease (CD) is a chronic inflammatory disease with a relapsing course. Its clinical treatment has greatly improved with the introduction of antibodies such as anti-tumor necrosis factor (TNF)-a. Nonetheless, over time up to 40% of patients become unresponsive to anti-TNF-a treatment. Aim: To identify the molecular mechanisms underlying the persistence of mucosal lesions in patients who do not respond to anti-TNF-a therapy. Methods: Whole genome-transcriptional analysis was carried out using intestinal biopsies from CD patients before and after anti-TNF-a therapy. The transcriptional signature of responders was compared to that of non-responders after anti-TNF-a therapy. Non-inflammatory bowel disease (non-IBD) controls were also used for comparisons. Genes of interest were validated by real-time RT-PCR in an independent cohort of individuals. For statistical analysis, the non-parametric Wilcoxon test was performed and the Benjamini-Hochberg procedure was used for multiple testing corrections. A p-value of <0.05 was considered statistically significant. Pearson’s product moment correlation was used to test for any associations between paired data. All analyses were performed using R statistical environment (V.2.15.0). The study was performed in accordance with the Declaration of Helsinki and was approved by the Institutional Ethics Committee of the Hospital Clinic of Barcelona (Spain). Results: The response to anti-TNF-a was accompanied by significant regulation of a large number of genes. Expression of a subset of these genes (i.e. IL-1B, S100A8, CXCL1, etc.) correlated with endoscopic activity and C-reactive protein. Remarkably, patients that failed to respond to anti-TNF-a showed a mixed signature, maintaining up-regulation of IL-1B, IL-17 and S100A8, while exhibiting significant down-regulation of other genes commonly up-regulated in active CD, including IL-6 and IL-23p19. Conclusions: Anti-TNF-a therapy significantly down-regulates a subset of inflammatory genes even in patients that do not achieve endoscopic remission, suggesting that these genes may not be responsible for driving inflammation in non-responders. On the other hand, IL-1B and IL-17 were identified as genes that remained altered in non-responders, which suggests the existence of more relevant targets to modulate mucosal damage in this set of refractory patients. P065 IL-33/ST2 axis modulates epithelial repair and gut mucosal wound healing in DSS-colitic mice L.R. Lopetuso 1,2 *, C. De Salvo 2 , H. Senkfor 2 , X.-M. Wang 2 , D.W. Abbott 2 , F. Scaldaferri 1 , A. Gasbarrini 1 , T.T. Pizarro 2 . 1 Catholic University of Sacred Heart, Internal Medicine and Gastroenterology, Rome, Italy, 2 Case Western Reserve University, Pathology, Cleveland, OH, United States Background: IL-33 and its receptor, ST2, are important factors in IBD. However, animal studies have yielded ambiguous results, reporting both pathogenic and protective functions. The aim was to characterize and functionally evaluate the precise role