bluuebunny/crossref_metadata_2025_split huggingface dataset:
P019 GS-1069518 is a potent and selective small molecule α4β7 inhibitor
Authors: Wang Y , Zhou J , Chang C , Roedder S , Bonne-Annee S , Marchand B , Hung K , Currie K , Clarke A 
Published: January 2022

Abstract

Background
The interaction between the adhesion molecule MAdCAM-1 and the α4β7 integrin heterodimer enables the trafficking of gut-antigen specific lymphocytes to the small and large intestines and to gut-associated lymphoid tissues. The role of the α4β7 integrin in the pathophysiology of IBD has been clinically demonstrated, and targeted therapeutics have been shown to mitigate inflammation and mucosal damage mediated by α4β7+ lymphocytes. The purpose of this study was to determine the potency and selectivity of the small molecule α4β7 inhibitor GS-1069518.

Methods
The selectivity of GS-1069518 and relevant reference molecules was determined using in vitro cell capture assays with natural integrin ligands and by measuring receptor occupancy in human and cynomolgus monkey whole blood. The number of RPMI-8866 cells binding to MAdCAM-1-coated surfaces (a natural α4β7 ligand) and Jurkat cells binding to VCAM-1-coated surfaces (a natural α4β1 ligand) were quantified with high content imaging. Receptor occupancy on CD3+CD4+CD45RO+β7+ (human) or CD3+CD4+CD45RA-β7+ (cynomolgus monkey) and CD3+CD4+CD45RO+α4+β1+β7- (human) or CD3+CD4+CD45RA-α4+β1+β7- (cynomolgus monkey) memory T cells was measured by flow cytometry with fluorescent probes that detect occupancy in the ligand-binding sites.

Results
In a MAdCAM-1 cell capture assay, the EC50 of GS-1069518 was 0.034 nM, with 71-fold and &gt;10,000-fold selectivity over α4β1 and αLβ2, respectively. In α4β7 receptor occupancy assays the EC50 of GS-1069518 was 0.36 nM in human whole blood and 0.4 nM in cynomolgus monkey whole blood. GS-1069518 was 482-fold selective for α4β7 over α4β1 in human whole blood and 119-fold selective for α4β7 in cynomolgus monkey blood.

Conclusion
GS-1069518 is a highly potent and selective small molecule inhibitor of the α4β7-MAdCAM-1 ligand binding interaction.
P026 Inflammatory bowel disease does not preclude the presence of environmental enteropathy in Zambian adults
Authors: Hodges P , Mulenga C , Banda R , Kelly P 
Published: January 2022

Abstract

Background
Although data is scarce, inflammatory bowel disease (IBD) seems to be increasing in incidence in newly industrialised countries.(1) The environmental factors driving this change are not entirely clear, although it seems likely that changing diet and improving hygiene and sanitation are involved. In China, incidence of IBD is positively associated with gross domestic product.(2)
Environmental enteropathy (EE) is a lesion of the small bowel with villous blunting, chronic inflammation and increased gut permeability seen in people living in insanitary conditions in resource-limited settings. We set out to examine whether EE would be present in patients with IBD in Zambia, as these individuals are likely to come from higher socioeconomic strata hence would be expected to live in more sanitised environments. Here we report preliminary data.

Methods
IBD cases were recruited at time of diagnosis or follow-up. Two groups of controls were recruited: individuals of higher socioeconomic status attending the GI clinic for investigation of symptoms of dyspepsia who had normal upper GI endoscopy were recruited to control group A, and healthy individuals from Misisi compound where studies on EE have been conducted over the past two decades to control group B (low socioeconomic status). All participants gave informed consent and underwent upper GI endoscopy and collection of duodenal biopsies. Haematoxylin- and eosin-stained sections of paraffin-embedded formalin-fixed biopsies were imaged on an Olympus VS120 scanning microscope then assessed for villous height, crypt depth, and epithelial surface area. Demographic information was collected via questionnaire.

Results
Biopsies were collected from 13 cases, 7 controls in group A and 10 controls in group B. Demographics are shown in Table 1. Cases and controls in group A had a higher number of rooms in the house than controls in group B but there was no significant difference in other environmental factors. Other than crypt depth, which was greater in controls from the lower socioeconomic group, there was no significant difference in morphometric parameters between IBD cases and controls (Table 2). The most severe enteropathy is seen in the biopsy from control group B (Figure 1c) which is made up of participants recruited a socioeconomically deprived district of Lusaka.

Figure 1

Conclusion
EE can coexist alongside IBD, suggesting that immunological drivers of these conditions are not distinct, and do not support the hygiene hypothesis. There is evidence of some degree of EE in small bowel biopsies from all cases and controls. Normal villous height to crypt depth ratio is likely to be between 3 and 5 (3) whereas medians for villous height:crypt depth in all groups in this study were less than 2.
P044 Enteric dopaminergic pathways in mouse and human intestinal inflammation
Authors: Cerantola S , Faggin S , Caputi V , Cortese V , Bosi A , Banfi D , Rambaldo A , Porzionato A , Giaroni C , Savarino E V , Giron M C 
Published: January 2022

Abstract

Background
Changes in dopamine beta-hydroxylase (DBH) and anomalies in dopaminergic machinery have been shown in inflammatory bowel disease (IBD) patients and related animal models. Thus, we aimed to evaluate the dopaminergic pathways in IBD patients as well as in a mouse model of dextran sodium sulphate (DSS)-induced ileitis.

Methods
Colon biopsies (CB) obtained from healthy volunteers (N=3) and matched-IBD patients (N=3), were used to evaluate DBH immunoreactivity by confocal microscopy. Male C57/Bl6 (8±2 weeks old; N=16 mice) received 1.5% DSS in drinking water for 5 days, then switched to regular drinking water for 3 days. Inflammatory cytokines (IL-1β, TNFα, IL-6) were measured to assess ileitis severity. Changes in ileal muscle tension were isometrically recorded following 30 μM dopamine or 30 μM SKF38393 (a dopamine receptor 1 (D1R) agonist) or 30 μM bromocriptine (a D2R agonist). Immunofluorescence distribution of Iba1 (a macrophage specific marker), D1R, DBH and dopamine transporter (DAT) were determined in longitudinal muscle-myenteric plexus whole-mount preparations (LMMPs) by confocal microscopy. D1R and D2R mRNA transcripts were evaluated by qRT-PCR.

Results
CB from IBD patients and LMMPs from DSS mice showed a significant increase of DBH immunoreactivity compared to healthy patients and sham mice (+25% [p&lt;0.01], +20% [p&lt;0.01], respectively). DSS treatment caused a significant increase of DAT and D1R immunoreactivity as well as D1R mRNA levels (+27% [p&lt;0.05], +24% [p&lt;0.05], +6-fold [p&lt;0.05], respectively), accompanied by a significant reduction of dopamine-mediated relaxation (-27% [p&lt;0.01]). SKF38393 determined a marked inhibitory response in ileal preparations from DSS mice compared to sham mice (+73% [p&lt;0.01]), suggesting that dopamine responses are mainly mediated through D1R. A 2-fold increase of resident Iba1+ macrophages was observed in the myenteric plexus of DSS mice associated with a 2.9- and 1.5-fold enhancement of IL-6 and IL-1β mRNA levels, respectively.

Conclusion
Human colitis and mouse ileitis affect dopamine machinery in the enteric nervous system. Experimentally induced ileitis impairs dopaminergic neurotransmission altering D1R-mediated responses. These findings provide novel information on the involvement of dopaminergic pathways in IBD.
P045 TIGIT expression differentiates regulatory from inflammatory Th1* gut-homing effector CD4+ T cells in inflammatory bowel disease patients
Authors: Heredia M , Costes L M M , Tindemans I , Aardoom M A , Klomberg R C W , Kemos P , Joosse M E , van Haaften D H , Tuk B , Ruemmele F , Croft N M , Escher J C , de Ridder L , Samsom J N 
Published: January 2022

Abstract

Background
Crohn’s disease (CD) and ulcerative colitis (UC) are characterized by intestinal infiltration of pathogenic effector CD4+ T cells. The defects driving loss of T-cell regulation vary between patients and remain undefined. Previously, we have shown that in human intestine, 20–40% of effector (CD62LnegCD4+) T cells express TIGIT (T cell immunoglobulin and ITIM domain), an inhibitory receptor modulating dendritic cell and T-cell function. TIGIT expression is enriched in circulating gut-homing CD38+ effector T cells in healthy controls while in a subgroup of IBD patients with active intestinal inflammation, frequencies of inhibitory TIGIT+CD38+ effector T cells are decreased and associated with earlier relapse of disease. Here we hypothesized that gut-homing effector T cells lacking TIGIT (TIGITneg) are pathogenic mediators of intestinal inflammation in IBD and assessed whether patients with low frequencies have a distinctive disease immunotype.

Methods
In the Rotterdam PIBD-SETQuality cohort of newly diagnosed pediatric IBD patients (CD: n=50; UC: n=25), patients with suspicion of IBD but negative diagnosis (n=17) and age-matched healthy controls (HC: n=22), we monitored TIGIT+ and TIGITnegCD38+ effector T cells in peripheral blood, collected plasma at diagnosis and during therapy and phenotyped intestinal T cells.

Results
At diagnosis, 50% of CD patients had strongly reduced frequencies of inhibitory TIGIT+CD38+ effector T cells compared to UC patients and HC. CD patients with reduced frequencies of inhibitory TIGIT+CD38+ effector T cells had higher plasma IFN-γ concentrations and 53% of them experienced a disease relapse by 1 year versus 25% for CD patients with normal TIGIT+CD38+effector frequencies. In keeping with our hypothesis that TIGITneg gut-homing effector T cells are pathogenic, absence of TIGIT expression identified CD38+ effector T cells enriched in recent proliferation and having high expression of chemokine receptors associated with inflammatory non-classical T helper-1 IFNγ highIL-17Alow producing (Th1*) cells. Moreover, intestinal TIGITnegCD4+ T cells of CD patients contained higher frequencies of IFNγ and IL-17A producing cells than TIGIT+CD4+ T cells. In order to identify the factors that drive differentiation of the pathogenic Th1* cells, inhibitory TIGIT+CD38+ effector T cells from HC were exposed to an array of IBD-associated cytokines in vitro. Only IL-12p70, a known driver of IFNγ, could convert inhibitory TIGIT+CD38+ effector T cells into their TIGITneg proinflammatory counterpart.

Conclusion
We identify TIGITneg gut-homing effector T cells, enriched in Th1* cells, as potential drivers of intestinal inflammation in a subgroup of CD, but not UC patients, with a more severe disease course.
P061 Circulating inflammatory protein and cellular profiles at time of diagnosis classify inflammatory bowel disease patients according to their underlying immune response and clinical disease course
Authors: Heredia M , Charrout M , Klomberg R C W , Aardoom M A , Jongsma M M E , Kemos P , van Haaften D H , Tuk B , van Berkel L A , Bley Folly B , Mahfouz A , Reinders M J T , Ruemmele F , Croft N , Escher J C , de Ridder L , Samsom J N 
Published: January 2022

Abstract

Background
Chronicity of inflammatory bowel disease (IBD) is driven by reactivation of inflammatory memory CD4+ T helper (Th) cells which activate an inflammatory cascade involving innate immune cells and structural intestinal tissue cells. Because of disease heterogeneity, novel treatment strategies tailored to more precisely target the patient’s individual immune defect are required to prevent disease reactivation. We hypothesize that analysis of changes in circulating inflammatory protein abundance combined with phenotyping of circulating Th cells allow to dissect underlying immune pathogenesis and aim to stratify pediatric IBD patients accordingly.

Methods
We performed plasma analysis of 92 inflammatory proteins in a cohort of pediatric IBD patients (CD: n=62; UC/IBD-U: n=20), patients with suspicion of IBD but negative diagnosis (n=13) and age-matched healthy controls (HC: n=30). Peripheral blood was obtained at diagnosis and after induction treatment (t=10–14 weeks). Plasma protein concentrations were assessed with Olink Proximity Extension Assay technology® and Th cells were analyzed with flow cytometry.

Results
Thirty-six plasma proteins discriminated pediatric IBD patients from HC. CD and UC/IBD-U patients shared increased abundance of 17 proteins amongst which interleukin-6 and oncostatin-M. Increased abundance of the Th1 cytokine interferon-γ was strictly associated with CD while Th17-associated interleukin-17A was significantly more abundant in UC/IBD-U. Hierarchical clustering of plasma protein profiles discriminated 2 clusters of UC patients with different clinical disease activity and disease extent. In CD, three patient clusters were identified. CD#3 patients had lower clinical disease activity, lower C-reactive protein and higher blood albumin concentrations, while clusters CD#1 and CD#2 had comparable clinical parameters. CD#1 patients had higher abundance of 14 proteins associated with neutrophil function and interferon-γ signaling while CD#2 patients had a marked increase in frequencies of activated (HLA-DR+) memory Th cells. The three CD clusters responded differently to therapy with CD#1 patients exhibiting more modulated proteins and greater fold changes, CD#2 patients showing intermediate modulation and CD#3 patients exhibiting only a few changes.

Conclusion
Combined plasma immune protein and circulating Th cell profiling combined with in depth clinical monitoring discriminates subgroups of pediatric IBD patients during active disease which differ in their response to induction therapy.
Abbreviations: CD: Crohn’s disease; UC: ulcerative colitis; IBD-U: IBD-unclassified.
P073 Eosinophil depletion partially protects from colonic inflammation, but increases colonic collagen deposition in a DSS colitis model
Authors: Jacobs I , Deleu S , Cremer J , Guedelha Sabino J , Ferrante M , Vermeire S , Breynaert C , Verstockt B , Vanuytsel T 
Published: January 2022

Abstract

Background
The role of eosinophils in intestinal inflammation and fibrosis in inflammatory bowel disease (IBD) is largely unknown. Therefore, we assessed the functional role of eosinophils in a chronic murine model of colitis and associated fibrosis via anti-CCR3 mediated eosinophil depletion.

Methods
6-8-week-old C57BL/6 RAG-/- mice received three cycles of dextran sodium sulphate (DSS) (1.75% - 2.25% - 2.25%) each interspersed with 14 days of recovery. Twice weekly, anti-CCR3 antibody (n=8), isotype (n=8) or saline injections (n=8) were given intraperitoneally. At the same timepoints, the disease activity index (DAI; mouse weight, stool consistency and presence of blood) was determined. At sacrifice, colonic damage was scored macroscopically (presence of hyperaemia, adhesions and length and degree of colon affected by inflammation). Colonic single cells were isolated and stained for flow cytometry, where eosinophils were characterized as CD45+ CD11b+ Siglec-F+ CD117- cells. Intestinal fibrosis was scored via colon weight/length, collagen deposition (using a colorimetric hydroxyproline assay) and COL1A1 expression by PCR.

Results
Anti-CCR3 mediated eosinophil depletion resulted in decreased disease activity compared to the other DSS treated groups injected with saline or isotype, determined by the area under the curve of the DAI (74.6±18.4 vs. 127.5±42.9 and 136.9±33.6, p=0.01 and p=0.0008 respectively) (figure 1). The macroscopic damage score also suggested eosinophil depleted mice to be partially protected from colonic inflammation compared to the saline and isotype injected mice that received DSS (1.1±1.0 vs. 2.1±1.2 and 3.0±0.7, p=0.09 and p=0.001 respectively) (figure 1). Colon weight/length and hydroxyproline assay showed a trend towards increased fibrosis in the anti-CCR3 injected group compared to saline (p=0.03 and 0.07, respectively) but not isotype (p=0.3 and 0.1, respectively) injected groups (figure 2). However, COL1A1 expression levels were significantly increased in the eosinophil depleted mice compared to the saline and isotype injected mice receiving DSS (43.2±11.4 vs. 23.3±8.7 and 30.1±11.0, p=0.002 and 0.04 respectively) (figure 2), indicating increased collagen deposition.

Conclusion
Eosinophil depletion via intraperitoneal anti-CCR3 injections resulted in partial protection against colonic inflammation, but was associated with increased collagen production. Caution is therefore needed when designing therapeutic interventions targeting eosinophils.
P082 The profibrogenic role of neutrophil extracellular traps in stenotic Crohn’s disease: a new antifibrotic target?
Authors: Dragoni G , Ke B J , Verstockt B , Abdurahiman S , Innocenti T , Giudici F , De Hertogh G , Milla M , Bagnoli S , Picariello L , Galli A , Matteoli G , Vermeire S 
Published: January 2022

Abstract

Background
Neutrophil extracellular traps (NETs) are structures constituted of DNA filaments and protein granules, extruded by neutrophils after various insults, such as chronic inflammation. Their formation is dependent on the citrullination of histone H3 (H3cit) in the nucleus by peptidylarginine deiminase 4 (PAD4). The pathogenic effect of NETs in Crohn’s disease (CD) has been poorly addressed so far. Recently, a profibrogenic role of NETs has been proposed in the lung.
The aim of the present study was to assess whether NETs may trigger the fibrotic process in patients with CD.

Methods
Multiplex immunofluorescence (M-IF) for PAD4, myeloperoxidase, neutrophil elastase, H3cit, vimentin and alpha-SMA were performed in unaffected, inflamed and fibrotic ileum of patients operated for stricturing CD. From the same patients, primary intestinal fibroblasts (PIF) were cultured from unaffected ileum.
NETs were obtained from healthy volunteers’ neutrophils, incubated with 50 nM phorbol myristate acetate for 3.5 hours. Subconfluent PIF were stimulated in vitro with NETs for 6 hours and RNA extracted for sequencing (RNAseq). Cell culture medium was collected for soluble collagen analysis, using SIRCOL®. Experiments were replicated in 5 patients.
CCD-18Co cell line was used to test the migratory activity of fibroblasts with a scratch test and to confirm the expression of profibrogenic proteins, such as fibroblast activation protein (FAP) and collagen 3A1.
M-IF was interpreted using computational analysis. Statistics was performed with Kruskal-Wallis Test for collagen quantification, with p &lt; 0.05. For RNAseq, Poisson distribution and DESeq2 were used, with significance set at Q &lt; 0.05; the resulting gene list was then analysed with ClueGo® software.

Results
M-IF showed that NETs were primarily found in inflamed areas, with clusters of these traps located close to intestinal myofibroblasts in the deeper submucosa layer (Figure 1).
The gene ontology of RNAseq (Figure 2) showed significant upregulation of profibrogenic pathways of TGFB1/SMAD and p38/MAPK in the group of PIF co-cultured with NETs.
NETs stimulation determined a higher release of collagen in the medium (p = 0.003), and an increase in the protein expression of FAP and collagen 3A1 in PIF. Accordingly, NETs profibrotic effect resulted also in a slower migratory ability of activated fibroblasts.

Conclusion
Our data show that NETs are produced during active inflammation of CD and their colocalisation with intestinal myofibroblasts suggests that they may represent an early trigger of fibroblast activation. Clinically, the inhibition of PAD4 might result in both contrasting inflammation and fibrogenesis. An in vivo chronic model of colitis on PAD4-KO mice is ongoing to confirm these findings.
P098 Mucosal Microbiota Composition Predicts Infliximab Response in Inflammatory Bowel Diseases
Authors: Gazouli M , Dovrolis N , Kolios G 
Published: January 2022

Abstract

Background
The inflammatory bowel disease (iBD) etiology remain elusive and both genetic and environmental factors have been implicated in the establishment of systemic inflammatory reactions that typify IBD. A basic, modifiable environmental factor is the gut microbiota and dysbiosis seems to be a key factor in IBD pathogenesis. Nowadays, it is well known that anti-TNF therapy significantly improves the rates of remission in patients with inflammatory bowel disease (IBD), however, there is a subgroup of patients who do not respond to treatment. The aim of the present study is to profile changes in the mucosal gut microbiome before and after anti-TNF therapy and investigate its possibility to predict patient response at baseline.

Methods
Mucosal biopsy samples from IBD patients [14 Crohn’s disease patients (CD), 6 ulcerative colitis (UC) patients] and healthy controls (HC) were examined for differences in microbiota composition (16S rRNA gene sequencing) at baseline and upon completion of anti-TNF treatment, accordingly, via an in silico pipeline.

Results
Although no statistically significant differences at phylum level were noted, a relative reduction in Bacteroidetes and an increase in Actinobacteria, Fusobacteria and Chloroflexi were detected in IBD versus HC biopsies, however the microbiomes of UC, CD and HC display qualitative differences at the OTU level. At genus level, statistically significant differential abundance between the HC and IBD groups was observed. The genera Parabacteroides, Barnesiella, Butyricimonas, Ruminococcus_1, Ruminococcaceae_UCG013, Phascolarctobacterium, Ruminoclostridium_6, Paraprevotella as well as members of the Eubacterium_ruminantium group appear reduced in IBD, whereas Dialister abundance is increased. The genus Collinsella exhibits an induction during UC versus both HC and CD. Regarding anti-TNF treatment on the microbiome, Alpha-diversity is reduced after anti-TNF treatment. Beta-diversity indicates differences before and after treatment as well as between responders and non-responders. By using the biomarker discovery tool LEfSe, we identified microbial genera associated mainly with anti-TNF responders.

Conclusion
In the present study, we showed that the response to anti-TNF therapy is related to specific microbiota profiles in the gut mucosa. Correlation analysis between these parameters of response at baseline showed that the assessment of microbial taxa can further distinguish responders from non-responders.