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INTRODUCTION Despite enormous efforts during the past decades, pancreatic adenocarcinoma (PAC) remains one of the most deleterious cancer entities. A useful biomarker for early detection or prognosis of PAC does not yet exist. The goal of our study was the characterization of β6-integrin (ITGB6) as a novel serum tumor marker for refined diagnosis and prognosis of PAC. Serum ITGB6 levels were analyzed in 3 independent PAC cohorts consisting of retrospectively and prospectively collected serum and/or (metastatic) PAC tissue specimens. METHODS Using 2 independent cohorts, we measured serum ITGB6 concentrations in 10 chronic pancreatitis patients, 10 controls, as well as in 27 (cohort 1) and 24 (cohort 2) patients with PAC, respectively. In these patients, we investigated whether ITGB6 serum levels correlate with known clinical and prognostic markers for PAC and whether they might differ between patients with PAC or benign inflammatory diseases of the pancreas. RESULTS We found that elevated serum ITGB6 levels (≥0.100 ng/mL) in patients suffering from metastasizing PAC presented an unfavorable prognostic outcome. By correlating the ITGB6 tissue expression in primary and metastatic PAC with clinical parameters, we found that positive ITGB6 expression in the tumor tissue is linked to increased serum ITGB6 levels in nonmetastatic PAC and correlates with carbohydrate antigen 19-9 and clinical outcome. DISCUSSION Our findings suggest that ITGB6 might serve as a novel serum biomarker for early diagnosis and prognosis of PAC. Given the limited specificity and sensitivity of currently used carbohydrate antigen 19-9-based assays, ITGB6 may have the potential to improve the diagnostic accuracy for PAC.

Colorectal cancers (CRCs) remain one of the most common and challenging neoplasia in the Western world. The response rate of immunotherapeutic treatment approaches in a subset of advanced CRCs is remarkable and has sustainably changed treatment regimens. Unfortunately, currently available immunotherapeutics only displayed significant antitumoral activity – in terms of progression free survival (PFS) and objective response rate (ORR) – in microsatellite instability-high (MSI-H)/DNA mismatch repair deficient (dMMR) CRCs. Subsequently, these remarkable results had led to the US Food and Drug Administration’s approval of both immune checkpoint inhibitors (ICIs) pembrolizumab and nivolumab in the treatment of advanced MSI-H/dMMR CRCs. However, in microsatellite stable (MSS)/DNA mismatch repair proficient (pMMR) CRCs, ICIs have clearly failed to meet their expectations and are therefore not considered effective. As the vast majority of CRCs display a molecular MSS/pMMR profile, current treatment approaches endeavor to improve tumor immunogenicity that consecutively leads to increased proinflammatory cytokine levels as well as tumor infiltrating T-cells, which in turn may be targeted by various immunotherapeutic agents. Therefore, ongoing studies are investigating novel synergistic therapy modalities and approaches to overcome a “cold” to “hot” tumor conversion in MSS/pMMR CRCs. In this review, we summarize the efficacy and possible immune-related adverse events as well as novel therapeutic approaches of ICIs in the treatment of MSI-H/dMMR and MSS/pMMR CRCs.

Inflammatory bowel diseases [IBD] are a heterogeneous spectrum with two extreme phenotypes, Crohn's disease [CD] and ulcerative colitis [UC], which both represent numerous phenotypical variations. Hence, we should no longer approach all IBD patients similarly, but rather aim to rethink clinical classifications and modify treatment algorithms to usher in a new era of precision medicine in IBD. This scientific ECCO workshop aims to provide a state-of-the-art overview on prognostic and predictive markers, shed light on key questions in biomarker development, propose best practices in IBD biomarker development [including trial design], and discuss the potential for multi-omic data integration to help drive further advances to make precision medicine a reality in IBD. ispartof: JOURNAL OF CROHNS & COLITIS vol:15 issue:9 pages:1431-1442 ispartof: location:England status: published

Background Fistulas represent a frequent and severe complication in patients with Crohn disease (CD). Tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta, and interleukin (IL)-13 are known to trigger epithelial-mesenchymal transition (EMT), promoting fistula formation. Here, we investigated the role of T-lymphocytes (T cells) in fistula pathogenesis. Methods CD3+CD8-, CD3+CD8+, or CD45+CD3- cells from healthy volunteers, patients with CD, and patients with CD with perianal fistula were co-cultured with HT-29 cells. The EMT, cytokine production, and mRNA expression were analyzed. Perianal CD fistula specimens were immunohistochemically stained for cytokines and their receptors. The effect of cytokines on EMT induction was investigated using an EMT spheroid model. Results Patients with CD with fistula revealed more CD3+CD8- and less CD3+CD8+ T cells in blood than healthy control patients and patients with CD without fistula. In perianal fistula specimens, CD4+ cells—and to a lesser extent CD8+ cells—were highly present around fistula tracts. When co-cultured with HT-29 cells, both cell subsets promoted EMT-related gene expression and TNF-α production in a time-dependent manner. The CD3+CD8- T cells from patients with CD with fistula also produced higher amounts of IL-13 than cells from healthy control patients or patients with CD without a fistula. We found that IL-22 and IL-22Rα1 were highly expressed in perianal CD fistula specimens and that IL-22 cotreatment potentiated TNF-α-induced EMT in HT-29 spheroids. Conclusions Our data indicate that both CD3+CD8- and CD3+CD8+ T cells play an important role in the pathogenesis of perianal CD fistulas by the secretion of TNF-α. Our data support clinical evidence indicating that anti-TNF-α therapy is effective in fistula treatment and identify IL-13 and IL-22 as possible novel therapeutic targets for fistula therapy.

Scope The aim of this study is to test whether the choice of the lipid emulsion in total parenteral nutrition (TPN), that is, n‐3 fatty acid‐based Omegaven versus n‐6 fatty acid‐based Intralipid, determines inflammation in the liver, the incretin profile, and insulin resistance. Methods and results Jugular vein catheters (JVC) are placed in C57BL/6 mice and used for TPN for 7 days. Mice are randomized into a saline group (saline infusion with oral chow), an Intralipid group (IL‐TPN, no chow), an Omegaven group (OV‐TPN, no chow), or a chow only group (without JVC). Both TPN elicite higher abundance of lipopolysaccharide binding protein in the liver, but only IL‐TPN increases interleukin‐6 and interferon‐γ, while OV‐TPN reduces interleukin‐4, monocyte chemoattractant protein‐1, and interleukin‐1α. Insulin plasma concentrations are higher in both TPN, while glucagon and glucagon‐like peptide‐1 (GLP‐1) were higher in IL‐TPN. Gluconeogenesis is increased in IL‐TPN and the nuclear profile of key metabolic transcription factors shows a liver‐protective phenotype in OV‐TPN. OV‐TPN increases insulin sensitivity in the liver and skeletal muscle. Conclusion OV‐TPN as opposed to IL‐TPN mitigates inflammation in the liver and reduces the negative metabolic effects of hyperinsulinemia and hyperglucagonemia by “re‐sensitizing” the liver and skeletal muscle to insulin. © 2020 Wiley-VCH GmbH. ISSN:1613-4125 ISSN:1613-4133

Background and Aims: Antibodies targeting tumor necrosis factor-alpha [TNF-alpha] are a mainstay in the treatment of inflammatory bowel disease. However, they fail to demonstrate efficacy in a considerable proportion of patients. On the other hand, glycosylation of antibodies might influence not only their immunogenicity but also their structure and function. We investigated whether specific glycosylation patterns of the Fc-fragment would affect the immunogenicity of anti-TNF-alpha antibody in monocyte-derived dendritic cells. Methods: The effect of a specific Fc-glycosylation pattern on antibody uptake by monocyte-derived dendritic cells [mo-DCs] and how this process shapes the immunologic profile of mo-DCs was investigated. Three N-glycoforms of the anti-TNF-alpha antibody adalimumab, that differed in the content of fucose or sialic acid, were tested: [1] mock treated Humira, abbreviated ‘Fuc-G0’, where the N-glycan mainly consist of fucose and N-acetylglucosamine [GlcNAc], without sialic acid; [2] ‘Fuc-G2S1/G2S2’ with fucose and alpha 2,6 linked sialic acid; and [3] ‘G2S1/G2S2’ with alpha 2,6 linked sialic acid, without fucose. Results: Our data demonstrated that neither fucosylation nor sialylation of anti-TNF-Abs [Fuc-G0, FucG2S1/G2S2, G2S1/G2S2] influence their uptake by mo-DCs. Additionally, none of the differentially glycosylated antibodies altered CD80, CD86, CD273, CD274 levels on mo-DCs stimulated in with lipopolysaccharide in the presence of antibodies. Next, we evaluated the levels of cytokines in the supernatant of mo-DCs stimulated with lipopolysaccharide in the presence of Fuc-G0, Fuc-G2S1/G2S2 or G2S1/G2S2-glycosylated anti-TNF antibodies. Only IL-2 and IL-17 levels were downregulated, and IL-5 production was upregulated by uptake of Fuc-G0 antibodies, as compared to control without antibodies. Conclusions: The specific modification in the Fc-glycosylation pattern of anti-TNF-alpha Abs does not affect their immunogenicity under the tested conditions. As this study was limited to mo-DCs, further investigation is required to clarify whether Ab uptake into mo-DCs might change the immunological profile of T- and B-cells, in order to ultimately reduce the formation of anti-drug antibodies and to improve the patient care.

We lack a holistic understanding of the genetic programs orchestrating embryonic colon morphogenesis and governing damage response in the adult. A window into these programs is the transcriptomes of the epithelial and mesenchymal cell populations in the colon. Performing unbiased single-cell transcriptomic analyses of the developing mouse colon at different embryonic stages (embryonic day 14.5 [E14.5], E15.5, and E18.5), we capture cellular and molecular profiles of the stages before, during, and after the appearance of crypt structures, as well as in a model of adult colitis. The data suggest most adult lineages are established by E18.5. We find embryonic-specific gene expression profiles and cell populations that reappear in response to tissue damage. Comparison of the datasets from mice and human colitis suggests the processes are conserved. In this study, we provide a comprehensive single-cell atlas of the developing mouse colon and evidence for the reactivation of embryonic genes in disease.

BACKGROUND AND AIMS Extraintestinal manifestations are reported to occur in up to 45% of inflammatory bowel disease (IBD) patients during the course of disease. It is unknown whether colectomy reduces the rate of de novo extraintestinal manifestations (EIMs) or impacts on severity of EIMs following a parallel versus independent disease course from underlying IBD. METHODS Using data from the Swiss Inflammatory Bowel Disease Cohort Study we aimed to analyse the course of EIMs in ulcerative colitis (UC) and Crohn's disease (CD) patients undergoing colectomy during the cohort's prospective follow-up. RESULTS One hundred and twenty-one IBD patients (33 CD, 81 UC and seven unclassified) underwent colectomy during prospective follow-up in the Swiss Inflammatory Bowel Disease Cohort Study. Within the 114 patients with UC or CD any EIM was reported in 40 (nine CD and 31 UC) patients. Activity of EIMs ceased entirely after colectomy in 21 patients (52.5%). Complete cessation of EIM after colectomy was higher in patients with UC versus CD with 58.1% versus 33.3%. After colectomy, 29 out of the 114 patients (25.4%) experienced any EIM. Two thirds of these (19 patients) represented persisting EIMs, while in one third (10 patients) EIM represented a de-novo event after colectomy. Overall, 13.5% of IBD patients developed a de-novo EIM after colectomy. CONCLUSIONS In IBD patients undergoing colectomy, EIMs present prior to surgery will persist in about half of patients. Complete cessation of EIM after colectomy may be less common in CD than in UC. In patients who never experienced EIMs prior to colectomy de-novo manifestations thereafter should be expected in up to one in seven patients.

Environmental and genetic factors have been demonstrated to contribute to the development of inflammatory bowel disease (IBD). Recent studies suggested that the food additive, titanium dioxide (TiO2) might play a causative role in the disease. Therefore, in the present study we aimed to explore the interaction between the food additive TiO2 and the well-characterized IBD risk gene protein tyrosine phosphatase non-receptor type 2 (Ptpn2) and their role in the development of intestinal inflammation. Dextran sodium sulphate (DSS)-induced acute colitis was performed in mice lacking the expression of Ptpn2 in myeloid cells (Ptpn2LysMCre) or their wild type littermates (Ptpn2fl/fl) and exposed to the microparticle TiO2. The impact of Ptpn2 on TiO2 signalling pathways and TiO2-induced IL-1&beta, and IL-10 levels were studied using bone marrow-derived macrophages (BMDMs). Ptpn2LysMCre exposed to TiO2 exhibited more severe intestinal inflammation than their wild type counterparts. This effect was likely due to the impact of TiO2 on the differentiation of intestinal macrophages, suppressing the number of anti-inflammatory macrophages in Ptpn2 deficient mice. Moreover, we also found that TiO2 was able to induce the secretion of IL-1&beta, via mitogen-activated proteins kinases (MAPKs) and to repress the expression of IL-10 in bone marrow-derived macrophages via MAPK-independent pathways. This is the first evidence of the cooperation between the genetic risk factor Ptpn2 and the environmental factor TiO2 in the regulation of intestinal inflammation. The results presented here suggest that the ingestion of certain industrial compounds should be taken into account, especially in individuals with increased genetic risk

Protein tyrosine phosphatase nonreceptor type 2 (PTPN2) recently emerged as a promising cancer immunotherapy target. We set out to investigate the functional role of PTPN2 in the pathogenesis of human colorectal carcinoma (CRC), as its role in immune-silent solid tumors is poorly understood. We demonstrate that in human CRC, increased PTPN2 expression and activity correlated with disease progression and decreased immune responses in tumor tissues. In particular, stage II and III tumors displayed enhanced PTPN2 protein expression in tumor-infiltrating T cells, and increased PTPN2 levels negatively correlated with expression of PD-1, CTLA4, STAT1, and granzyme A. In vivo, T cell– and DC-specific PTPN2 deletion reduced tumor burden in several CRC models by promoting CD44(+) effector/memory T cells, as well as CD8(+) T cell infiltration and cytotoxicity in the tumor. In direct relevance to CRC treatment, T cell–specific PTPN2 deletion potentiated anti–PD-1 efficacy and induced antitumor memory formation upon tumor rechallenge in vivo. Our data suggest a role for PTPN2 in suppressing antitumor immunity and promoting tumor development in patients with CRC. Our in vivo results identify PTPN2 as a key player in controlling the immunogenicity of CRC, with the strong potential to be exploited for cancer immunotherapy.

Many patients suffering from inflammatory bowel disease (IBD) follow restrictive diets, as many respective recommendations circulate. Efforts are made to evaluate and summarize the published information, for example, in a recent consensus manuscript by the International Organization for the Study of IBD (IOIBD). However, the standards that should be applied to make claims about dietary effects are poorly defined. In this manuscript, the scientific basis of recommendations for nutritional interventions in IBD is analyzed. Epidemiological evidence on diet in IBD is always biased by numerous factors, and the number of robust dietary intervention studies is limited due to methodological difficulties. Therefore, animal models are used to test hypotheses with respect to dietary factors and intestinal inflammation. Naturally, animal models have limitations, and knowledge of key characteristics of colitis animal models is crucial to understand their advantages and disadvantages. In recent years the important role of the microbiota for IBD and dietary factors has been discovered. Microbiota data are added to many publications on IBD and nutrition. The quality of those data varies largely. Subsequently, quality standards for microbiota analyses also are discussed. Finally, quality requirements to be applied on recommendations for dietary changes in patients with IBD are suggested.

INTRODUCTION : The introduction and broad use of new immunosuppressive agents, including biologic agents and JAK inhibitors, have revolutionised treatment of inflammatory bowel disease [IBD] in recent decades. With such immunosuppression, the potential for opportunistic infection is a key safety concern. [...]

Gut microbiota appears to be involved in the pathogenesis of primary sclerosing cholangitis (PSC). The protein tyrosine phosphatase nonreceptor 2 (PTPN2) gene risk variant rs1893217 is associated with gut dysbiosis in inflammatory bowel disease (IBD), and PTPN2 was mentioned as a possible risk gene for PSC. This study assessed the microbial profile of ulcerative colitis (UC) patients with PSC and without PSC (non-PSC). Additionally, effects of the PTPN2 risk variant were assessed. In total, 216 mucosal samples from ileum, colon, and rectum were collected from 7 PSC and 42 non-PSC patients, as well as 28 control subjects (non-IBD). The microbial composition was derived from 16S rRNA sequencing data. Overall, bacterial richness was highest in PSC patients, who also had a higher relative abundance of the genus Roseburia compared to non-PSC, as well as Haemophilus, Fusobacterium, Bifidobacterium, and Actinobacillus compared to non-IBD, as well as a lower relative abundance of Bacteroides compared to non-PSC and non-IBD, respectively. After exclusion of patients with the PTPN2 risk variant, Brachyspira was higher in PSC compared to non-PSC, while, solely in colon samples, Eubacterium and Tepidimonas were higher in PSC vs. non-IBD. In conclusion, this study underlines the presence of gut mucosa-associated microbiome changes in PSC patients and rather weakens the role of PTPN2 as a PSC risk gene.

Summary Background Eosinophilic esophagitis is a chronic inflammatory gastrointestinal disease with a high prevalence in younger, atopic males. In our clinical practice, we observed a striking preponderance of patients having a high educational background. The purposes of this study were first to assess the level of education of eosinophilic esophagitis patients and second to compare the findings to patients with inflammatory bowel disease, another chronic immune-mediated condition of the gastrointestinal tract, and with the Swiss general population. Methods Using a questionnaire, we assessed the educational level of adult patients who have attended Swiss Eosinophilic Esophagitis Clinics in the past. In addition, the educational level of the parents was assessed as well. We calculated the proportions of patients and parents who have obtained a higher educational level. Data from the Swiss Inflammatory Bowel Disease Cohort Study and from the Swiss general population served as confirmation and as comparison, respectively. Results A total of 277 successfully contacted patients (response rate 69.1%; mean age 51.1 years, 73% male) participated. A significantly higher proportion of surveyed eosinophilic esophagitis patients had a high International Standard Classification of Education level (66.8%, P Conclusion Our analysis confirms the clinical observation that eosinophilic esophagitis patients have a significantly higher educational level compared with the general population and to patients with other chronic inflammatory diseases of the gastrointestinal tract. As a limitation, this impressive finding remains on a purely descriptive level.

Only a fraction of patients benefits from immune checkpoint inhibitors (ICI). Tumor cells exhibit a distinct glycosylation pattern and supplementation of glycans has the potential to promote response and overcome resistance to ICI, thus addressing an urgent clinical need. Using a subcutaneous tumor mouse model, we investigated whether two glycopeptide-based test items reduce tumor burden when orally administered alone or in combination with ICI. C57/BL6 mice were supplemented with 3% GNU-201 (n=10) or 3% GNU-101 (n=10) in the drinking water starting 14 days prior to tumor cell injection (d-14), while control mice (n=10) received normal drinking water. On day 0, all mice were injected subcutaneously with YUMM1.7 melanoma cells in each flank. On days 6, 9 and 12, mice in each group received anti-PD1 antibody or an isotype control. Tumor size was measured every 3rd day. On day 15, the mice were sacrificed to analyze tumor weight and tumor infiltrating immune cells. 16S rDNA sequencing of fecal samples was performed on days -14, 0 and 14. GNU-201 and GNU-101 supplementation was well tolerated, no difference in water consumption and no abnormal behavior were detected that would indicate adverse effects of the products. While anti-PD1 on its own had no effect on tumor growth, we observed reduced tumor growth in the GNU-201+anti-PD1, GNU-101 and GNU-101+anti-PD1-treated groups, resulting in a significantly reduced tumor volume in these three groups on day 15. Administration of the two test items had a clear effect on anti-tumor T cell responses. In combination with anti-PD1, GNU-201 promoted the overall abundance of T cells, and among those the proportion of CD8+ T cells and IFNγ producing CD4+ T cells. Even in absence of anti-PD1, GNU-201 promoted the number of IFNγ+ CD8+ T cells, indicating that GNU-201 did not only promote tumor infiltration but also activation of CD8+ T cells, which are known to directly kill tumor cells. Finally, GNU-201+anti-PD1 resulted in significantly increased levels of Perforin and TNFα producing CD8+ T cells. With GNU-101 there was a trend towards elevated numbers of T cells and TNFα+ CD4 T cells. In mice that received GNU-101 with anti-PD1, we observed significantly elevated levels of TNFα+ CD8+ T cells and a trend towards higher numbers of IFNγ+ CD8+ T cells. GNU-201 and GNU-101 induced a significant modulation of the gut microbiota. In particular, the products promoted the growth of Akkermansia spp., a genus previously associated with anti-tumor immunity. In conclusion, GNU-201 and GNU-101 are both able to boost an anti-tumor immune response upon PD1 inhibition and GNU-101 shows moderate anti-tumor effects on its own. The response is linked with tumor-infiltration and activation of T cells and seems to be associated with changes in the gut microbiome. This study highlights a potential therapeutic role for glycopeptides in boosting anti-tumor immunity in response to ICI therapy. Citation Format: Marianne R. Spalinger, Romain Wyss, Sara Vidal, Yong Miao, Michael Scharl, Yemi Adesokan. Glycopeptides promote anti-cancer immune response against solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5600.

2565 Background: Only a minority of colorectal cancer (CRC) patients benefit from immune checkpoint inhibitors (ICI), with less than half of eligible patients responding to the treatment. Abnormal glycosylation of tumor cells is a signature of cancer development. Here, we described novel immunomodulatory molecules, named GLAAD (glycopeptides with adjuvant and tumor-associated antigen delivery). We hypothesized that GLAAD, by sharing similarities with aberrant glycans expressed in many cancers, may be a safe and effective treatment strategy to promote response and overcome resistance to ICI, thus addressing an urgent clinical need. Using a CRC mouse model, we tested whether two GLAAD candidates reduce tumor burden when orally administered alone or in combination with ICI. Methods: C57/BL6J mice were supplemented with 3% GNU-201 or 3% GNU-101 in the drinking water starting 14 days prior to tumor cell injection (d-14), while control mice received normal drinking water. On day 0, all mice were injected subcutaneously with MC38 CRC cells in each flank. On days 6, 9, 12, and 15, mice in each group received anti-PD1 antibody (aPD1) or an isotype control. Tumor size was measured every 3rd day. On day 18, the mice were sacrificed. Results: The aPD1 therapy alone showed a limited anti-tumor efficacy overall. Groups treated with GNU-201, GNU-101, GNU-201+aPD1 or GNU-101+aPD1 exhibited reduced growth, resulting in a significantly reduced tumor volume vs control on day 18. In contrast, GLAAD candidates alone significantly reduced tumor volume compared with control and led to a numerically larger decrease than aPD1 treatment alone, suggesting a higher efficacy. When analyzing tumor infiltrating myeloid cells on day 18, no differences were seen for neutrophils or dendritic cells but the proportion of macrophages was decreased in mice receiving GNU-201 or GNU-101. GNU-101 resulted in reduced serum levels of IL-10, a molecule participating in the suppression of antitumor immune responses. The tested GLAAD candidates stimulated robust anti-tumor T cell responses. GNU-201 and GNU-101 supplementation alone or in combination with aPD1 increased the proportion of T cells and among those CD8+ T cells, IFNγ producing CD4+ T cells, IFNγ+ and perforin+ CD8+ T cells. GNU-101 and GNU-201 elicited memory T cell responses after priming of the mice, measured as the ex vivo recall response (CD69 expression) of CD8+ T cells isolated from the tumor. Conclusions: GNU-201 and GNU-101 as standalone treatment induce a strong anti-tumor response that is as good as or even better than aPD1 alone. The therapeutic efficacy is associated with increased tumor infiltration and activation of T cells, in particular CD8+ T cells, highlighting the role of these GLAAD candidates as potent adjuvants in supporting specific tumor-associated antigen recognition by the immune system.

Coronavirus disease (COVID-19), caused by SARS-CoV-2, has affected over 65 million individuals and killed over 1.5 million persons (December 8, 2020;www.who.int)1. While fatality rates are higher among the elderly and those with underlying comorbidities2, host factors that promote susceptibility to SARS-CoV-2 infection and severe disease are poorly understood. Although individuals with certain autoimmune/inflammatory disorders show increased susceptibility to viral infections, there is incomplete knowledge of SARS-CoV-2 susceptibility in these diseases.3–7We report that the autoimmunePTPN2risk variant rs1893217 promotes expression of the SARS-CoV-2 receptor, ACE2, and increases cellular entry mediated by SARS-CoV-2 spike protein. Elevated ACE2 expression and viral entry were mediated by increased JAK-STAT signalling, and were reversed by the JAK inhibitor, tofacitinib. Collectively, our findings uncover a novel risk biomarker for increased expression of the SARS-CoV-2 receptor and viral entry, and identify a clinically approved therapeutic agent to mitigate this risk.

Background: Crohn’s disease (CD) may progress from an inflammatory to a stricturing or penetrating disease phenotype. The aim of our study was to identify single nucleotide polymorphisms (SNPs) that predict disease progression in patients of the Swiss IBD Cohort Study (SIBDCS). Methods: We applied a multi-state Markov model for progression behavior of CD with three behavioral states according to the Montreal classification. The model considered transition from B1 to B2/B3 or from B2 to B3 stage. Model dynamics were summarized with transition intensities by including the effect of SNPs and calculating transition intensities for each SNP. Results: We included 1276 CD patients [669 (52.4%) B1, 248 (19.4%) B2, 359 (28.1%) B3 patients] with a median follow-up of 6.8 (interquartile range = 3.6–9.1; range 0–11.6) years. Probability for a B1 patient to develop a stenosis (B1 to B2, q = 0.033) was twice as much as compared to developing a penetrating complication (B3) during the disease course. In contrast, the probability of entering B3 stage was similar regardless of whether antecedent stricture was present (B2 to B3, q = 0.016) or not (B1 to B3, q = 0.016). We identified SNPs within the gene loci encoding ZMIZ1, LOC105373831 and KSR1 as carrying the highest risk for progression to B3, while the presence of SNPs within gene loci TNFSF15 and CEBPB-PTPN1 protected from progression to B2 or B3. Conclusion: We identified new genetic risk factors that can predict disease course in CD patients. A closer understanding on the functional impact of these genetic variations might improve our treatment options finally to prevent disease progression in CD patients.

BackgroundThe rise in the prevalence of inflammatory bowel diseases in the past decades coincides with changes in nutritional habits, such as adaptation of a Western diet. However, it is largely unknown how certain nutritional habits, such as energy drink consumption, affect intestinal inflammation. Here, we assessed the effect of energy drink supplementation on the development of intestinal inflammation in vitro and in vivo.MethodsHT-29 and T84 intestinal epithelial cells and THP-1 monocytic cells were treated with IFNγ in presence or absence of different concentrations of an energy drink. Colitis was induced in C57BL/6 mice by addition of dextran sodium sulfate (DSS) to drinking water with or without supplementation of the energy drink.ResultsEnergy drink supplementation caused a dose-dependent decrease in IFNγ-induced epithelial barrier permeability, which was accompanied by upregulation of the pore-forming protein claudin-2. Administration of the energy drink reduced secretion of the pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-α from HT-29, T84, and THP-1 cells. In vivo, energy drink administration reduced clinical symptoms of DSS-induced colitis and epithelial barrier permeability. Endoscopic and histologic colitis scores and expression of pro-inflammatory cytokines were significantly reduced by energy drink co-administration.ConclusionEnergy drink consumption seems to exert an unexpected anti-inflammatory effect in vitro and in vivo in our experimental setting. However, our experimental approach focuses on intestinal inflammation and neglects additional effects of energy drink consumption on the body (eg, on metabolism or sleep). Therefore, the translation of our findings into the human situation must be taken with caution.

Background and Aims Loss-of-function variants in protein tyrosine phosphatase non-receptor type-2 [PTPN2] promote susceptibility to inflammatory bowel diseases [IBD]. PTPN2 regulates Janus-kinase [JAK] and signal transducer and activator of transcription [STAT] signalling, while protecting the intestinal epithelium from inflammation-induced barrier disruption. The pan-JAK inhibitor tofacitinib is approved to treat ulcerative colitis, but its effects on intestinal epithelial cell-macrophage interactions and on barrier properties are unknown. We aimed to determine if tofacitinib can rescue disrupted epithelial-macrophage interaction and barrier function upon loss of PTPN2. Methods Human Caco-2BBe intestinal epithelial cells [IECs] and THP-1 macrophages expressing control or PTPN2-specific shRNA were co-cultured with tofacitinib or vehicle. Transepithelial electrical resistance and 4 kDa fluorescein-dextran flux were measured to assess barrier function. Ptpn2fl/fl and Ptpn2-LysMCre mice, which lack Ptpn2 in myeloid cells, were treated orally with tofacitinib citrate twice daily to assess the in vivo effect on the intestinal epithelial barrier. Colitis was induced via administration of 1.5% dextran sulphate sodium [DSS] in drinking water. Results Tofacitinib corrected compromised barrier function upon PTPN2 loss in macrophages and/or IECs via normalisation of: [i] tight junction protein expression; [ii] excessive STAT3 signalling; and [iii] IL-6 and IL-22 secretion. In Ptpn2-LysMCre mice, tofacitinib reduced colonic pro-inflammatory macrophages, corrected underlying permeability defects, and prevented the increased susceptibility to DSS colitis. Conclusions PTPN2 loss in IECs or macrophages compromises IEC-macrophage interactions and reduces epithelial barrier integrity. Both of these events were corrected by tofacitinib in vitro and in vivo. Tofacitinib may have greater therapeutic efficacy in IBD patients harbouring PTPN2 loss-of-function mutations.

While the long-term evolution of disease behavior in Crohn's disease has been well described in the pre-anti-TNF era, our knowledge thereon remains scarce after the introduction of anti-TNF.Our investigation examined the long-term evolution of disease concerning Montreal classification's B-stages over time in patients enrolled into the Swiss IBD Cohort Study between 2006 and 2017.We analyzed prospectively collected SIBDCS data using a Markov model and multivariate testing for effects of treatment and other confounders on B-stage migration over time. The primary outcome was a transition in disease behavior from B1 to either B2 or pB3, or from B2 to pB3, respectively.The 10- and 15-year probability of remaining in B1 was 0.61 and 0.48, as opposed to a probability to migrate to B2 or B3 of 0.25 or 0.14, and 0.32 or 0.2, after 10 and 15 years, respectively. In multivariate testing, the hazard ratio for migrating from B1 to pB3 (HR 0.27) and from B2 to pB3 (HR 0.12) was lower in patients 40 years compared to patients 17 years. We found that immunosuppression (HR 0.38) and treatment with anti-TNF for 1 year (HR 0.30) were associated with a decreased likelihood of transitioning from stage B1 to pB3.While in the anti-TNF era most patients with Crohn's disease will eventually develop stricturing and/or penetrating complications, our data indicate that immunosuppressive and anti-TNF treatment for more than 1 year reduce the risk of transitioning from stage B1 to pB3 in the long-term run.

Activity of the NLRP3 inflammasome, a critical mediator of inflammation, is controlled by accessory proteins, posttranslational modifications, cellular localization, and oligomerization. How these factors relate is unclear. We show that a well-established drug target, Bruton’s tyrosine kinase (BTK), affects several levels of NLRP3 regulation. BTK directly interacts with NLRP3 in immune cells and phosphorylates four conserved tyrosine residues upon inflammasome activation, in vitro and in vivo. Furthermore, BTK promotes NLRP3 relocalization, oligomerization, ASC polymerization, and full inflammasome assembly, probably by charge neutralization, upon modification of a polybasic linker known to direct NLRP3 Golgi association and inflammasome nucleation. As NLRP3 tyrosine modification by BTK also positively regulates IL-1β release, we propose BTK as a multifunctional positive regulator of NLRP3 regulation and BTK phosphorylation of NLRP3 as a novel and therapeutically tractable step in the control of inflammation.

Inflammasomes are multi-protein complexes that mediate the activation and secretion of the inflammatory cytokines IL-1β and IL-18. More than half a decade ago, it has been shown that the inflammasome adaptor molecule, ASC requires tyrosine phosphorylation to allow effective inflammasome assembly and sustained IL-1β/IL-18 release. This finding provided evidence that the tyrosine phosphorylation status of inflammasome components affects inflammasome assembly and that inflammasomes are subjected to regulation via kinases and phosphatases. In the subsequent years, it was reported that activation of the inflammasome receptor molecule, NLRP3, is modulated via tyrosine phosphorylation as well, and that NLRP3 de-phosphorylation at specific tyrosine residues was required for inflammasome assembly and sustained IL-1β/IL-18 release. These findings demonstrated the importance of tyrosine phosphorylation as a key modulator of inflammasome activity. Following these initial reports, additional work elucidated that the activity of several inflammasome components is dictated via their phosphorylation status. Particularly, the action of specific tyrosine kinases and phosphatases are of critical importance for the regulation of inflammasome assembly and activity. By summarizing the currently available literature on the interaction of tyrosine phosphatases with inflammasome components we here provide an overview how tyrosine phosphatases affect the activation status of inflammasomes.

Up till now, research on inflammatory bowel disease [IBD] has mainly been focused on the immune cells present in the gastrointestinal tract. However, recent insights indicate that stromal cells also play an important and significant role in IBD pathogenesis. Stromal cells in the intestines regulate both intestinal epithelial and immune cell homeostasis. Different subsets of stromal cells have been found to play a role in other inflammatory diseases [e.g. rheumatoid arthritis], and these various stromal subsets now appear to carry out also specific functions in the inflamed gut in IBD. Novel potential therapies for IBD utilize, as well as target, these pathogenic stromal cells. Injection of mesenchymal stromal cells [MSCs] into fistula tracts of Crohn’s disease patients is already approved and used in clinical settings. In this review we discuss the current knowledge of the role of stromal cells in IBD pathogenesis. We further outline recent attempts to modify the stromal compartment in IBD with agents that target or replace the pathogenic stroma.

Very-early-onset inflammatory bowel disease (VEO-IBD) is a heterogeneous phenotype associated with a spectrum of rare Mendelian disorders. Here, we perform whole-exome-sequencing and genome-wide genotyping in 145 patients (median age-at-diagnosis of 3.5 years), in whom no Mendelian disorders were clinically suspected. In five patients we detect a primary immunodeficiency or enteropathy, with clinical consequences (XIAP, CYBA, SH2D1A, PCSK1). We also present a case study of a VEO-IBD patient with a mosaic de novo, pathogenic allele in CYBB. The mutation is present in ~70% of phagocytes and sufficient to result in defective bacterial handling but not life-threatening infections. Finally, we show that VEO-IBD patients have, on average, higher IBD polygenic risk scores than population controls (99 patients and 18,780 controls; P, Adult forms of inflammatory bowel disease (IBD) are of a polygenic nature, but paediatric and very early onset (VEO) IBD also occur as monogenic forms. Here, using whole exome sequencing, the authors explore both the monogenic and polygenic contribution to VEO-IBD and characterize a rare somatic mosaic VEO-IBD patient.

Background The single nucleotide polymorphism (SNP) rs1893217 within the gene locus encoding PTPN2 represents a risk factor for inflammatory bowel disease (IBD). Our previous work demonstrated reduced PTPN2 activity and subsequently increased inflammatory signaling upon presence of SNP rs1893217. The naturally occurring polyamine spermidine reduces pro-inflammatory signaling via induction of PTPN2 activity; however, the effect of SNP rs1893217 on the anti-inflammatory potential of spermidine is still unknown. Here, we investigated how presence of SNP rs1893217 affects treatment efficacy of spermidine and whether it might serve as a potential biomarker for spermidine treatment. Methods Human T84 (wild-type [WT] for PTPN2 SNP rs1893217) and HT29 (heterozygous for PTPN2 SNP rs1893217) intestinal epithelial cells (IECs) were treated with several polyamines from the putrescine-spermidine pathway. T84 and HT29 IECs, THP-1 monocytes (WT and transfected with a lentiviral vector expressing PTPN2 SNP rs1893217) and genotyped, patient-derived peripheral blood mononuclear cells were challenged with IFN-γ and/or spermidine. Results Among the analyzed polyamines, spermidine was the most efficient activator of PTPN2 phosphatase activity, regardless of the PTPN2 genotype. Spermidine suppressed IFN-γ-induced STAT1 and STAT3 phosphorylation, along with decreased mRNA expression of ICAM-1, NOD2, and IFNG in IECs and monocytes. Of note, these effects were clearly more pronounced when the disease-associated PTPN2 C-variant in SNP rs1893217 was present. Conclusions Our data demonstrate that spermidine is the most potent polyamine in the putrescine-spermine axis for inducing PTPN2 enzymatic activity. The anti-inflammatory effect of spermidine is potentiated in the presence of SNP rs1893217, and this SNP might thus be a useful biomarker for possible spermidine-treatment in IBD patients.

Introduction: The pathophysiology of inflammatory bowel disease (IBD) is incompletely understood. Current concepts imply that environmental factors (EFs) trigger disease onset as well as flares in genetically susceptible individuals. Objective: The objective of this study is to analyze the association between IBD and various EFs, which may influence the pathogenesis of the disease. Methods: 2,294 patients from the Swiss IBD Cohort Study (SIBDCS) received a questionnaire regarding EF including mode of delivery, breastfeeding, animals in household, and place of residence. The control group comprised patients’ childhood friends, who grew up in a similar environment (“friends cohort”). Results: A total of 1,111 questionnaires were returned from SIBDCS patients (response rate: 48.4%). Breastfeeding for p = 0.006). IBD patients reported less pet animals in the household than the control group (p = 0.004). The presence of cats or dogs (OR: 0.688, p = 0.015) and pet rodents (OR: 0.598, p = 0.001) in the household before the age of 20 was inversely associated with the risk for UC/IC. Conclusion: The present study underlines the importance of EFs in the pathogenesis of IBD. Overall, the development of UC/IC seems to be more affected from environmental influences than from Crohn’s disease. Our results imply a protective effect of possessing pet animals in household and short breastfeeding regarding the onset of UC/IC.

Background/Aims: Among the severe immune-related adverse events (irAEs) that occur with immune checkpoint inhibitor (ICI) therapy, colitis is the most frequent one. This study aimed at describing the experience from the largest gastroenterology unit in Switzerland with immune checkpoint inhibitor-associated colitis (ICIAC), its clinical presentation, management, and outcomes. Methods: We performed a retrospective review of patients who were referred for the evaluation of ICIAC between January 2011 and October 2018 to the Division of Gastroenterology and Hepatology, University Hospital Zurich. Results: Thirty-three patients with immune-related colitis grade 3 or 4 met the inclusion criteria and were analyzed in detail: All patients had diarrhea, 64% had abdominal pain, 42% had bloody stool, 27% had emesis, and 18% developed fever. In total, 33% were successfully treated with corticosteroids alone; 66% were steroid-refractory and treated with infliximab or vedolizumab. Two of these patients developed severe complications requiring surgery. All patients reached complete remission of ICIAC and its symptoms. At colonoscopy, ulcerations were seen in 37% of steroid-refractory versus 63% of steroid-responsive cases. Deep histological ulcerations invading the submucosa were only present in steroid-refractory cases. Conclusion: ICIAC is a severe irAE which frequently requires high-dose steroids and a close follow-up due to deleterious complications. The detection of histologically diagnosed deep ulcerations may predict a steroid-refractory course and may warrant early application of infliximab. However, larger studies are required to confirm our findings.

Background and Aims Epithelial-mesenchymal transition [EMT] has been related to fibrosis and fistula formation, common complications associated with Crohn´s disease [CD]. The WNT signalling pathway mediates EMT, and specific WNT/FZD interactions have been related to the activation of this process in several diseases. We aim to analyse the relevance of EMT and WNT ligands and receptors in the penetrating behaviour of CD. Methods Intestinal surgical resections were obtained from control and CD patients with a stenotic or penetrating behaviour. Fibrosis was determined by the histological analysis of collagen deposition and EMT by confocal microscopy. The expression of WNT ligands, inhibitors, and FZD receptors was analysed by RT-PCR, WB, IH, and IF studies. The effects of WNT2b and the role of FZD4 in EMT were analysed in HT29 epithelial cells. Results Fibrosis and expression of EMT markers were detected in samples from CD patients irrespective of the clinical behaviour. However, an increased colocalisation of E-CADHERIN and VIMENTIN, an increased number of cells expressing WNT2b, and a higher expression of FZD4 and WNT2b/FZD4 interaction, were detected in intestinal tissue from the penetrating compared with the stenotic CD behaviour. WNT2b induced EMT in HT29 cells through FZD4 activation. Conclusions An increased EMT, associated with increased WNT2b/FZD4 interaction, was detected in intestinal tissue from CD patients with a penetrating behaviour. WNT2b, through FZD4 activation, induces EMT in vitro which points to a novel pharmacological target to prevent intestinal penetrating complications of CD.

Self-inserted foreign rectal bodies are an infrequent occurrence, however they present a serious dilemma to the surgeon, due to the variety of objects, and the difficulty of extraction. The purpose of this study is to give a comprehensive review of the literature regarding the epidemiology, diagnostic tools and therapeutic approaches of foreign rectal body insertion.A comprehensive systematic literature review on Pubmed/ Medline and Google for 'foreign bodies' was performed on January 14th 2018. A meta-analysis was carried out to evaluate the epidemiology, diagnostics and therapeutic techniques. 1,551 abstracts were identified, of which 54 articles were included.The motivation of foreign rectal body insertion is mostly sexual stimulation. Patients are typically young and predominantly male, with a male to female ratio of 6:1. Sexual devices (35.7%, n=108) and glass objects (17.5%, n=53) are the most commonly self-inserted rectal foreign bodies. Patient history should be taken sensitively after diagnostic evaluation and identification of the object. Removal was performed under general anesthesia in 45.2% (n=95) and sedation in 29.0% (n=61). The total complication rate was described to be 30.4%.Diagnostics must be performed with caution in order to rule out perforation and establish a treatment algorithm. Manual transanal extraction under sedation or general anesthesia may be performed in conjunction with cautious abdominal compression. Because of the variety of objects, i.e. in form and material, each case must be treated individually. Sometimes creativity and surgeon imagination may be required, although different algorithms have been established.

© The Author(s) 2020. Published by Oxford University Press on behalf of European Crohn’s and Colitis Organisation. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)., Currently, the main targets of drug therapy for ulcerative colitis [UC] are endoscopic and clinical remission. However, there is active discussion about the additional advantages of including histological remission as a target. Accumulating evidence indicates that microscopic activity persists in endoscopically quiescent UC, that histological changes may lag behind clinical remission after treatment, and that absence of histological activity predicts lower rates of relapse, hospitalization, surgery and subsequent neoplasia. Obtaining useful information from mucosal biopsies in this setting depends on accurate and consistent evaluation of histological features. However, there is no standardization of biopsy procedures, histological sample processing technique or histological scoring systems, and there is no agreement on the definitions of histological remission, response or activity. Accordingly, a consensus expert panel convened by the European Crohn's and Colitis Organisation [ECCO] reviewed the literature and agreed a number of position statements regarding harmonization of UC histopathology. The objective was to provide evidence-based guidance for the standardization and harmonization of procedures, definitions and scoring systems for histology in UC, and to reach expert consensus where possible. We propose the absence of intraepithelial neutrophils, erosion and ulceration as a minimum requirement for the definition of histological remission. For randomized control trials we recommend the use of the Robarts histopathology index [RHI] or the Nancy index [NI]. For observational studies or in clinical practice we recommend the use of the NI. To predict the risk of future neoplasia in UC, cumulative histological scores over time are more useful than single scores.

Local extracellular acidification occurs at sites of inflammation. Proton-sensing ovarian cancer G-protein-coupled receptor 1 (OGR1, also known as GPR68) responds to decreases in extracellular pH. Our previous studies show a role for OGR1 in the pathogenesis of mucosal inflammation, suggesting a link between tissue pH and immune responses. Additionally, pH-dependent signalling is associated with the progression of intestinal fibrosis. In this study, we aimed to investigate OGR1 expression and OGR1-mediated signalling in patients with inflammatory bowel disease (IBD). Our results show that OGR1 expression significantly increased in patients with IBD compared to non-IBD patients, as demonstrated by qPCR and immunohistochemistry (IHC). Paired samples from non-inflamed and inflamed intestinal areas of IBD patients showed stronger OGR1 IHC staining in inflamed mucosal segments compared to non-inflamed mucosa. IHC of human surgical samples revealed OGR1 expression in macrophages, granulocytes, endothelial cells, and fibroblasts. OGR1-dependent inositol phosphate (IP) production was significantly increased in CD14+ monocytes from IBD patients compared to healthy subjects. Primary human and murine fibroblasts exhibited OGR1-dependent IP formation, RhoA activation, F-actin, and stress fibre formation upon an acidic pH shift. OGR1 expression and signalling increases with IBD disease activity, suggesting an active role of OGR1 in the pathogenesis of IBD.

Background Tissue inflammation in inflammatory bowel diseases [IBD] is associated with local acidification. Genetic variants in the pH-sensing G protein-coupled receptor 65, also known as T cell death-associated gene 8 [TDAG8], have been implicated in IBD and other autoimmune diseases. Since the role of TDAG8 in intestinal inflammation remains unclear, we investigated the function of TDAG8 using murine colitis models. Methods The effects of TDAG8 deficiency were assessed in dextran sodium sulphate [DSS], IL-10-/-, and T cell transfer colitis murine models. RNA sequencing of acidosis-activated TDAG8-/- and wild-type [WT] peritoneal macrophages [MΦs] was performed. Results mRNA expression of IFN-γ, TNF, IL-6, and iNOS in TDAG8-/- mice increased significantly in colonic lymphoid patches and in colonic tissue in acute and chronic DSS colitis, respectively. In transfer colitis, there was a trend towards increased IFN-γ, iNOS, and IL-6 expression in mice receiving TDAG8-/- T cells. However, absence of TDAG8 did not lead to changes in clinical scores in the models tested. Increased numbers of infiltrating MΦs and neutrophils, but not CD3+ T cells, were observed in DSS-treated TDAG8-/- mice. No differences in infiltrating CD3+ T cells were observed between mice receiving TDAG8-/- or WT naive T cells in transfer colitis. RNA sequencing showed that acidosis activation of TDAG8 in MΦs modulated the expression of immune response genes. Conclusions TDAG8 deficiency triggers colonic MΦ and neutrophil infiltration, and expression of pro-inflammatory mediators in DSS colitis models. In transfer colitis, mice receiving TDAG8-/- T cells presented a significantly higher spleen weight and a tendency towards increased expression of pro-inflammatory markers of monocyte/MΦ activity.

Background & Aims: Hypoxia-associated pathways influence the development of inflammatory bowel disease. Adaptive responses to hypoxia are mediated through hypoxia-inducible factors, which are regulated by iron-dependent hydroxylases. Signals reflecting oxygen tension and iron levels in enterocytes regulate iron metabolism. Conversely, iron availability modulates responses to hypoxia. In the present study we sought to elucidate how iron influences the responses to hypoxia in the intestinal epithelium. Methods: Human subjects were exposed to hypoxia, and colonic biopsy specimens and serum samples were collected. HT-29, Caco-2, and T84 cells were subjected to normoxia or hypoxia in the presence of iron or the iron chelator deferoxamine. Changes in inflammatory gene expression and signaling were assessed by quantitative polymerase chain reaction and Western blot. Chromatin immunoprecipitation was performed using antibodies against nuclear factor (NF)-κB and primers for the promoter of tumor necrosis factor (TNF) and interleukin (IL)1β. Results: Human subjects presented reduced levels of ferritin in the intestinal epithelium after hypoxia. Hypoxia reduced iron deprivation–associated TNF and IL1β expression in HT-29 cells through the induction of autophagy. Contrarily, hypoxia triggered TNF and IL1β expression, and NF-κB activation in Caco-2 and T84 cells. Iron blocked autophagy in Caco-2 cells, while reducing hypoxia-associated TNF and IL1β expression through the inhibition of NF-κB binding to the promoter of TNF and IL1β. Conclusions: Hypoxia promotes iron mobilization from the intestinal epithelium. Hypoxia-associated autophagy reduces inflammatory processes in HT-29 cells. In Caco-2 cells, iron uptake is essential to counteract hypoxia-induced inflammation. Iron mobilization into enterocytes may be a vital protective mechanism in the hypoxic inflamed mucosa. Keywords: Inflammatory Bowel Disease, Autophagy, Deferoxamine, Caco-2

Summary: Variants in the gene locus encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) are associated with inflammatory disorders, including inflammatory bowel diseases, rheumatoid arthritis, and type 1 diabetes. The anti-inflammatory role of PTPN2 is highlighted by the fact that PTPN2-deficient mice die a few weeks after birth because of systemic inflammation and severe colitis. However, the tissues, cells, and molecular mechanisms that contribute to this phenotype remain unclear. Here, we demonstrate that myeloid cell-specific deletion of PTPN2 in mice (PTPN2-LysMCre) promotes intestinal inflammation but protects from colitis-associated tumor formation in an IL-1β-dependent manner. Elevated levels of mature IL-1β production in PTPN2-LysMCre mice are a consequence of increased inflammasome assembly due to elevated phosphorylation of the inflammasome adaptor molecule ASC. Thus, we have identified a dual role for myeloid PTPN2 in directly regulating inflammasome activation and IL-1β production to suppress pro-inflammatory responses during colitis but promote intestinal tumor development.

Summary Despite overall success, T cell checkpoint inhibitors for cancer treatment are still only efficient in a minority of patients. Recently, intestinal microbiota was found to critically modulate anti-cancer immunity and therapy response. Here, we identify Clostridiales members of the gut microbiota associated with a lower tumor burden in mouse models of colorectal cancer (CRC). Interestingly, these commensal species are also significantly reduced in CRC patients compared with healthy controls. Oral application of a mix of four Clostridiales strains (CC4) in mice prevented and even successfully treated CRC as stand-alone therapy. This effect depended on intratumoral infiltration and activation of CD8+ T cells. Single application of Roseburia intestinalis or Anaerostipes caccae was even more effective than CC4. In a direct comparison, the CC4 mix supplementation outperformed anti-PD-1 therapy in mouse models of CRC and melanoma. Our findings provide a strong preclinical foundation for exploring gut bacteria as novel stand-alone therapy against solid tumors.

Background Pathogenesis of cutaneous extraintestinal manifestations (EIM) in inflammatory bowel disease (IBD) remains elusive. Efficacy of anti-TNF agents suggests TNF-dependent mechanisms. The role of other biologics such as anti-integrins or JAK-inhibitors is not yet clear. Methods We performed immunohistochemistry for TNFα, NFκB, STAT1/STAT3, MAdCAM1, CD20/68, caspase 3/9, IFNγ, Hsp-27/70 on 240 intestinal (55 controls, 185 IBD) and 64 skin biopsies (11 controls, 18 Erythema nodosum (EN), 13 Pyoderma gangenosum (PG), 22 psoriasis). A semiquantitative score (0-100%) was used for evaluation. Results TNFα was upregulated in intestinal biopsies from active Crohn`s disease (CD) vs. controls (36.2 vs. 12.1, p

A variant within the gene locus encoding PTPN22 (protein tyrosine phosphatase, non-receptor type 22) emerged as an important risk factor for auto-inflammatory disorders, including rheumatoid arthritis, systemic lupus erythematosus and type 1 diabetes, but at the same time protects from Crohn disease, one of the 2 main forms of inflammatory bowel diseases. We have previously shown that loss of PTPN22 results in decreased NLRP3 (NLR family pyrin domain containing 3) activation and that this effect is mediated via enhanced NLRP3 phosphorylation. However, it is unclear how phosphorylation of NLRP3 mediates its inhibition. Here, we demonstrate that loss of macroautophagy/autophagy abrogates the inhibitory effect on NLRP3 activation observed upon loss of PTPN22. Phosphorylated, but not nonphosphorylated NLRP3 is found in autophagosomes, indicating that NLRP3 phosphorylation mediates its inactivation via promoting sequestration into phagophores, the precursors to autophagosomes. This finding shows that autophagy and NLRP3 inflammasome activation are connected, and that PTPN22 plays a key role in the regulation of those 2 pathways. Given its role in inflammatory disorders, PTPN22 might be an attractive therapeutic target, and understanding the cellular mechanisms modulated by PTPN22 is of crucial importance.

An acute sigmoid volvulus is due to the torsion of the sigmoid colon around its mesenteric axis. It mainly occurs in elderly patients and represents an abdominal emergency requiring urgent treatment. A 53-year-old male patient with severe craniocerebral injury and traumatic subarachnoidal bleeding 3 weeks prior presented on the ward with distended abdomen without abdominal pain, muscular defense, or resistances. He featured large volume diarrhea within the last few hours without signs of bleeding. A plain abdominal X-ray demonstrated a coffee bean sign indicating a sigmoid volvulus. A consequent CT scan of the abdomen revealed a deep outlet obstruction with massively dilated, elongated and twisted loop of the sigmoid colon and no signs of perforation. We performed emergency colonoscopy under the assumption of an acute sigmoid volvulus. After careful insertion of the endoscope completely refraining from insufflation of air or CO2, endoscopic reposition of the sigma could be achieved and a colonic drainage was placed over an inserted guide wire up to the proximal transverse colon. No relapse occurred and a diagnostic colonoscopy after 4 weeks revealed no tumor or polyps. Our report describes a classic case of acute sigmoid volvulus and undermines the potential of colonoscopy as conservative primary treatment of choice.

Background: Long-term data of certolizumab pegol (CZP) in Crohn's disease (CD) from pivotal registry trials are limited. We therefore aimed to evaluate the long-term efficacy of CZP in clinical practice in Switzerland. Methods: In the First Approved Certolizumab Therapeutic Experience in Switzerland-III phase IV multicenter cohort, patients receiving CZP were prospectively included all over Switzerland in (non-) academic hospitals and private practice. Results: We included 104 CD patients (52 male; only 22.1% anti-tumor necrosis factor (TNF) naïve, CZP as third anti-TNF agent in 46.2%) with follow-up time between 6 weeks up to 5 years. During treatment with CZP, we observed a significant decrease of the Harvey Bradshaw Index from a median of 7 at baseline (interquartile range 4-11) to 4, 5, 4, 3, 3, and 2 at weeks 6, 26, 52, 78, 104, and 156, respectively. While anti-TNF naïve patients showed a significantly better response at the end of induction, during CZP maintenance therapy response was similar as compared to anti-TNF experienced patients as well as between patients with a short (0-5 years) vs. long duration of disease (>5 years). Conclusions: CZP is an effective long-term treatment option, including CD patients with long disease duration and prior treatment with 1 or 2 anti-TNF agents.

Background Several large genome wide association studies have identified an increasing number of IBD risk loci with currently more than 240 established loci and generated robust data on disease association. However, knowledge remains limited on distinctive associations to specific clinical characteristics. The Swiss IBD Cohort Study (SIBDCS) represents a large prospective cohort study with clinically and phenotypically sound data collection since 2006 including genotyping. In this study, we aimed to determine individual associations of known risk loci with clinical features of patients in the SIBDCS, as well as their combined effect on clinical outcomes. Methods Based on 158 analysed SNPs, we investigated the numerical distribution of risk alleles and determined an individual SNP risk score (defined as percentage of risk alleles; i.e. number of risk alleles divided by twice the number of given SNPs multiplied with 100). We then performed linear regression modelling to investigate, whether relevant clinical disease characteristics associate with this SNP risk score. Further, for each given clinical outcome, a model was run with all SNPs as potential predictors, and the number of significant associations per SNP counted. Results In a total of 2304 genotyped patients, we observed a median number of risk alleles of 167, 168 and 167 for IBD overall, CD and UC/IC, respectively with a narrow inter quartile range [11 (q25 = 162, q75 = 173) for IBD and CD; 12 (q25 = 161, q75 = 173) for UC/IC]. A higher SNP risk score was significantly associated with any complications (defined as a composite of any or more of colorectal cancer, colon dysplasia, intestinal lymphoma, osteopenia/-porosis, anaemia, deep venous thrombosis, pulmonary embolism, nephro- or cholelithiasis, malabsorption syndrome, massive haemorrhage, perforation/peritonitis, pouchitis), stenosis in CD patients; pancolitis, conversion to CD, female sex in UC patients; higher clinical disease activity in both CD & UC. Regarding individual SNPs, we identified substantial differences in terms of the frequency of associations to disease-related outcomes with up to 11 for rs4899554 in CD and 7 for rs9557195 in UC, respectively. Conclusion In our large population of IBD patients there is high per patient frequency of hetero- and homozygous SNP risk alleles. The association of higher SNP risk score with several disease-related outcomes indicates a potential interplay of per patient given SNP risk alleles.

Background Extraintestinal manifestations (EIM) are reported to occur in a highly variable frequency of between 6% and up to 47% of patient with IBD during the course of disease and may substantially contribute to the overall disease burden. Little is known on the impact of colectomy in UC or CD patients on the course of EIM, neither regarding pre-existing vs. de novo EIM occurring after colectomy nor regarding potential differences between EIM typically known to follow a parallel vs. independent course of activity to disease activity of underlying IBD. Methods Using data from the Swiss IBD Cohort Study (SIBDCS) we aimed to analyze the course of EIM in UC and CD patients undergoing colectomy during the prospective SIBDCS follow-up. Results Amongst a total of 3620 IBD patients (53.6% CD, 42.8% UC, 3.6% IBD unclassified), 115 IBD patients (33 CD and 82 UC) underwent colectomy. One or more EIM had been present at any time antecedent to colectomy in 35.7% of these patients (27.3% and 39% in CD and UC patients, respectively). Within the 115 IBD patients undergoing colectomy any EIM was present only before colectomy in 21 patients (18.3% of all patients undergoing colectomy), i.e. entirely ceased thereafter in 51.2% of patients with any EIM prior to colectomy. After colectomy, overall 30 out of the 115 patients (26.1%) suffered from any EIM after colectomy. Out of these, two thirds (20 patients) already had any EIM prior to colectomy, while in one third (10 patients) occurrence of EIM represented a de-novo event after colectomy. Overall, amongst all patient with no EIM prior to undergoing colectomy 13.5% of patients developed a de-novo EIM after colectomy. The fraction of patients with complete cessation of EIM after colectomy was numerically higher in patients with UC vs. CD with 56.3% vs. 33.3% of patients with EIM prior to colectomy, respectively (51.2% in IBD patients overall). An overview over the frequency of EIM overall and individual EIM is provided in Figure 1. Conclusion In IBD patients with undergoing colectomy, any EIM present prior to surgical intervention will persist in about half of patients. Although our results are based on a limited number of patients our findings indicate, that complete cessation of EIM after colectomy may be less common in CD than in UC patients. Absence of EIM prior to colectomy does not equal freedom from any EIM thereafter as up to one in seven IBD patients may develop de-novo EIM after colectomy.

Total parenteral nutrition (TPN) is a life‐saving therapy administered to millions of patients. However, it is associated with significant adverse effects, namely liver injury, risk of infections, and metabolic derangements. In this review, the underlying causes of TPN‐associated adverse effects, specifically gut atrophy, dysbiosis of the intestinal microbiome, leakage of the epithelial barrier with bacterial invasion, and inflammation are first described. The role of the bile acid receptors farnesoid X receptor and Takeda G protein‐coupled receptor, of pleiotropic hormones, and growth factors is highlighted, and the mechanisms of insulin resistance, namely the lack of insulinotropic and insulinomimetic signaling of gut‐originating incretins as well as the potentially toxicity of phytosterols and pro‐inflammatory fatty acids mainly released from soybean oil‐based lipid emulsions, are discussed. Finally, novel approaches in the design of next generation lipid delivery systems are proposed. Propositions include modifying the physicochemical properties of lipid emulsions, the use of lipid emulsions generated from sustainable oils with favorable ratios of anti‐inflammatory n‐3 to pro‐inflammatory n‐6 fatty acids, beneficial adjuncts to TPN, and concomitant pharmacotherapies to mitigate TPN‐associated adverse effects. ISSN:1613-4125 ISSN:1613-4133

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers and leading cause of cancer-related deaths worldwide. In recent years, there has been a growing realisation that lifestyle plays a major role for CRC development and that intestinal microbiota, which are shaped by lifestyle and nutrition habits, may be critically involved in the pathogenesis of CRC. Although the precise mechanisms for how the microbiota contribute to CRC development and progression remain elusive, increasing evidence suggests a direct causative role for the intestinal microbiota in modulating signalling pathways, anti-tumour immune responses and cell proliferation. Recent advances in understanding host-microbe interactions have shed light onto the putative use of intestinal microbiota as a powerful tool in CRC diagnosis and therapy. Here, we will discuss the role of the intestinal microbiota in CRC pathogenesis, their potential utility as diagnostic markers, and consider how microbes could be used in therapeutic approaches for the treatment of CRC. Keywords: Colorectal cancer (CRC), Intestinal microbiota, Nutrition, Pathogenesis, Diagnosis, Therapy

Reactive oxygen species such as H2O2are believed to play a prominent role in the injury and loss of transport function that affect the intestinal epithelium in inflammatory conditions such as inflammatory bowel diseases. Defects in intestinal epithelial ion transport regulation contribute to dysbiosis and inflammatory phenotypes. We previously showed that H2O2inhibits Ca2+-dependent Cl−secretion across intestinal epithelial cells (IECs) via a phosphatidylinositol 3-kinase (PI3K)- and extracellular signal-regulated kinase (ERK)-dependent mechanism that occurs, at least in part, through inhibition of the basolateral Na+-K+-2Cl−cotransporter NKCC1. NKCC1 governs Cl−entry into crypt IECs and thus plays a critical role in maintaining the driving force for Cl−secretion. Electrolyte transport consumes large amounts of cellular energy, and direct pharmacological activation of the cellular energy sensor AMP-activated protein kinase (AMPK) has been shown to inhibit a number of ion transport proteins. Here, we show that H2O2activates AMPK in human IEC lines and ex vivo human colon. Moreover, we demonstrate that the inhibitory effect of H2O2on Ca2+-dependent Cl−secretion and NKCC1 activity is AMPK-dependent. This inhibitory effect is associated with a physical interaction between AMPK and NKCC1, as well as increased phosphorylation (Thr212,217) of NKCC1, without causing NKCC1 internalization. These data identify a key role for AMPK-NKCC1 interaction as a point of convergence for suppression of colonic epithelial ion transport by inflammatory reactive oxygen species.NEW & NOTEWORTHY H2O2inhibition of intestinal epithelial Ca2+-dependent Cl−secretion involves recruitment of AMP-activated protein kinase (AMPK) downstream of ERK and phosphatidylinositol 3-kinase signaling pathways, physical interaction of AMPK with the Na+-K+-2Cl−cotransporter NKCC1, and AMPK-dependent suppression of NKCC1-mediated electrolyte influx without causing NKCC1 internalization. It is intriguing that, in human intestinal epithelial cell lines and human colon, H2O2activation of AMPK increased phosphorylation of NKCC1 residues required for promoting, not inhibiting, NKCC1 activity. These data identify an elevated complexity of AMPK regulation of NKCC1 in the setting of an inflammatory stimulus.

Background Patients with Crohn’s disease (CD) responding to anti–tumor necrosis factor (anti-TNF) show great variability in serum drug levels, even within the therapeutic range. We aimed at exploring the role of inflammatory, genetic, and bacterial variables in relation to anti-TNF through levels in CD patients. Methods Consecutive CD patients receiving stable doses of infliximab or adalimumab were included. Clinical and analytical parameters were recorded. Cytokine response, bacterial DNA translocation, and several immune-related genes’ genotypes were evaluated, along with serum through anti-TNF drug levels. A linear regression analysis controlled by weight and drug regimen was performed. Results One hundred nineteen patients were initially considered. Five patients on infliximab and 2 on adalimumab showed antidrug antibodies in serum and were excluded. One hundred twelve patients were finally included (62 on infliximab, 50 on adalimumab). Fourteen patients on infliximab and 15 on adalimumab (22.6% vs 30%, P = 0.37) were receiving an intensified drug regimen. C-reactive protein (CRP), fecal calprotectin, Crohn’s Disease Activity Index, leukocyte count, and albumin levels in plasma were not significantly associated with infliximab or adalimumab levels in the multivariate analysis. Serum interleukin-10 (IL-10) levels were directly related to infliximab (Beta = 0.097, P < 0.0001) and adalimumab levels (Beta = 0.069, P = 0.0241). The best multivariate regression model explaining the variability of serum infliximab and adalimumab levels included IL-10. Predicted drug levels by this model robustly fitted with actual drug levels (R2 = 0.841 for infliximab, R2 = 0.733 for adalimumab). Conclusion Serum IL-10 is significantly related to serum anti-TNF levels in CD patients, showing how the disposition of anti-TNF drugs is significantly influenced by the degree of immunological activation.

Background: Inflammatory bowel disease (IBD) is a chronic inflammatory disorder, primarily of, but not restricted to, the gut. Association between IBD and cancer has been clearly established and is uniformly accepted. Summary: IBD patients are at particular risk for intestinal and extraintestinal cancers. There are 2 underlying mechanisms: (1) IBD-related inflammation triggers initiation and progression of tumor formation. This particularly results in the development of colorectal cancer, small bowel adenocarcinoma, intestinal lymphoma, anal cancer, and cholangiocarcinoma. (2) Immunosuppressive drugs exhibit carcinogenic properties such as shown for azathioprine and anti-TNF promoting lymphoproliferative malignancies and melanoma and nonmelanoma skin cancer. However, within the last years, IBD-related cancer incidence and prevalence have been decreasing, which might be attributed to better treatment options and surveillance strategies. Moreover, novel biological drugs have been introduced in clinical practice and have dramatically changed long-term IBD management. Therefore, we sought to summarize up-to-date knowledge about (1) overall cancer risk; (2) risk and protective factors for cancer development; and (3) inflammation- and immunosuppression-related malignancies in the current anti-TNF era of IBD. Key Messages: Recent studies and meta-analyses questioned the excess rates of cancer in IBD patients. However, IBD still is associated with cancer development due to ongoing intestinal inflammation and the use of potential carcinogenic drugs. Patients should be educated about the increased risk of cancer with IBD and IBD drugs. However, they should also be informed that most malignancy subtypes are possibly preventable by controlling intestinal inflammation and by using adequate screening strategies.

Background and aims Enteric fistulas represent a severe and medically challenging comorbidity commonly affecting Crohn's disease [CD] patients. Gut fistulas do not develop in animal models of the disease. We have used transplantation of the human fetal gut into mice as a novel platform for studying inflammatory enterocutaneous fistulas. Methods Human fetal gut segments were transplanted subcutaneously into mature SCID mice, where they grew and fully developed over the course of several months. We first analysed the resident immune cells and inflammatory response elicited by systemic lipopolysaccharide [LPS] in normal, fully developed human gut xenografts. Thereafter, we used immunostaining to analyse fully developed xenografts that spontaneously developed enterocutaneous fistulas. Results Resident human innate and adaptive immune cells were demonstrated in gut xenografts during steady state and inflammation. The expression of human IL-8, IL-1β, IL-6, TNF-α, A20, and IkBα was significantly elevated in response to LPS, with no change in IL-10 gene expression. Approximately 17% [19/110] of fully developed subcutaneous human gut xenografts spontaneously developed enterocutaneous fistulas, revealing striking histopathological similarities with CD fistula specimens. Immunohistochemical analyses of fistulating xenografts revealed transmural lymphocytic enteritis associated with massive expansion of resident human CD4+ lymphocytes and their migration into the intraepithelial compartment. Regionally, mucosal epithelial cells assumed spindle-shaped mesenchymal morphology and formed fistulous tracts towards chronic non-healing wounds in the host mouse skin overlying the transplants. Conclusions Inflammation and fistulas developed in human gut xenografts lacking IL-10 gene response. This novel model system will enable systematic studies of the inflamed and fistulating human gut in live animals.

The gut microbiota is crucial for our health, and well-balanced interactions between the host's immune system and the microbiota are essential to prevent chronic intestinal inflammation, as observed in inflammatory bowel diseases (IBD). A variant in protein tyrosine phosphatase non-receptor type 22 (PTPN22) is associated with reduced risk of developing IBD, but promotes the onset of autoimmune disorders. While the role of PTPN22 in modulating molecular pathways involved in IBD pathogenesis is well studied, its impact on shaping the intestinal microbiota has not been addressed in depth. Here, we demonstrate that mice carrying the PTPN22 variant (619W mice) were protected from acute dextran sulfate sodium (DSS) colitis, but suffered from pronounced inflammation upon chronic DSS treatment. The basal microbiota composition was distinct between genotypes, and DSS-induced dysbiosis was milder in 619W mice than in WT littermates. Transfer of microbiota from 619W mice after the first DSS cycle into treatment-naive 619W mice promoted colitis, indicating that changes in microbial composition enhanced chronic colitis in those animals. This indicates that presence of the PTPN22 variant affects intestinal inflammation by modulating the host's response to the intestinal microbiota.