bluuebunny/crossref_metadata_2025 huggingface dataset:
Common and distinct patterns underlying different linguistic tasks: multivariate disconnectome symptom mapping in poststroke patients
Authors: Jiang Yaya , Gong Gaolang
Published: January 2024

Numerous studies have been devoted to neural mechanisms of a variety of linguistic tasks (e.g. speech comprehension and production). To date, however, whether and how the neural patterns underlying different linguistic tasks are similar or differ remains elusive. In this study, we compared the neural patterns underlying 3 linguistic tasks mainly concerning speech comprehension and production. To address this, multivariate regression approaches with lesion/disconnection symptom mapping were applied to data from 216 stroke patients with damage to the left hemisphere. The results showed that lesion/disconnection patterns could predict both poststroke scores of speech comprehension and production tasks; these patterns exhibited shared regions on the temporal pole of the left hemisphere as well as unique regions contributing to the prediction for each domain. Lower scores in speech comprehension tasks were associated with lesions/abnormalities in the superior temporal gyrus and middle temporal gyrus, while lower scores in speech production tasks were associated with lesions/abnormalities in the left inferior parietal lobe and frontal lobe. These results suggested an important role of the ventral and dorsal stream pathways in speech comprehension and production (i.e. supporting the dual stream model) and highlighted the applicability of the novel multivariate disconnectome-based symptom mapping in cognitive neuroscience research.
OP05 Primary efficacy and safety of mirikizumab in moderate to severe Crohn’s Disease: results of the treat-through VIVID 1 study
Authors: Ferrante M , Danese S , Chen M , D'Haens G , Ghosh S , Hisamatsu T , Jairath V , Kierkus J , Peyrin-Biroulet L , Siegmund B , Bragg S M , Crandall W , Hunter Gibble T , Lin Z , Ugolini Lopes M , Morris N , Carlier H , Sands B
Published: January 2024

Background

Mirikizumab (miri) is a selective IL23p19 monoclonal antibody approved for the treatment of ulcerative colitis. The primary focus of the VIVID-1 trial (NCT03926130) was to demonstrate the efficacy and safety of mirikizumab (miri) compared to placebo (PBO) in patients (pts) with moderate-to-severe Crohn’s disease. Here we present primary efficacy and safety of miri compared to placebo (PBO) up to Week 52 (W52) from the Phase 3, randomised, double-blind, double-dummy, active- and PBO-controlled, treat-through VIVID-1 study.

Methods

Adult pts (N=1065) were randomized 6:3:2 to miri (N=579) 900mg intravenously (IV) at W0, W4, and W8, then 300mg subcutaneously (SC) every 4 weeks (Q4W) from W12 to W52, placebo (PBO) (N=199), or ustekinumab (N=287) ~6mg/kg IV at W0 and SC dose of 90mg Q8W from W8 to W48. At W12, PBO responders continued PBO to W52; PBO non-responders received the same blinded miri regimen (IV then SC) as described above. The co-primary endpoints assessing superiority of miri over PBO were composite endpoints: 1) PRO clinical response at W12 and endoscopic response at W52, and 2) PRO clinical response at W12 and clinical remission by Crohn’s Disease Activity Index (CDAI) at W52. The adjusted risk differences were calculated, and the comparison was performed by CMH test. Nonresponder imputation was used.

Results

Baseline characteristics were similar across treatment groups. 48.7% of pts in the PBO, and 48.5% in the miri, group previously failed at least one biologic. 15.6% and 18.3% of the PBO and miri groups respectively failed more than one biologic. Both co-primary endpoints (Figure 1A, 1C, all p<.000001) and all key secondary endpoints (Figure 1E, all p<.000001 except endoscopic remission at W12: p<.001 and W12 clinical remission by CDAI: p=0.001) were achieved. Robust and consistent efficacy at W52 was also demonstrated with similar response rates and treatment effect in patients with and without prior biologic failure (Figure 1B, 1D, all p<.0001). Overall safety was consistent with the known safety profile of miri (Table 1).

Conclusion

In this phase 3 CD study, miri demonstrated statistically significant and clinically meaningful improvements vs PBO in both co-primary composite endpoints and all key secondary endpoints, with an acceptable safety profile.
OP06 Risankizumab Maintenance Therapy in Patients With Moderately to Severely Active Ulcerative Colitis: Efficacy and Safety in the Randomised Phase 3 COMMAND Study
Authors: Louis E , Panaccione R , Parkes G , Peyrin-Biroulet L , Ferrante M , Hisamatsu T , Siegmund B , Kalabic J , Levine P , Neimark E , Wallace K , Chen S , Cheng L , Duan W R , Armuzzi A , Biederman L , Loftus E , Melmed G , Schreiber S
Published: January 2024

Background

Risankizumab (RZB), a monoclonal antibody targeting interleukin-23 p19, was evaluated for maintenance therapy in patients with moderately to severely active ulcerative colitis (UC) and clinical response to RZB intravenous (IV) induction treatment in a phase 3 double-blind, placebo (PBO)-controlled withdrawal (WD) maintenance study, COMMAND (NCT03398135).

Methods

Patients with moderately to severely active UC who achieved a clinical response per Adapted Mayo score after 12 or 24 weeks (wks) of RZB IV treatment in the phase 2b and phase 3 INSPIRE induction studies (NCT03398148)1 were randomized 1:1:1 in COMMAND to RZB 180 mg (RZB180), 360 mg (RZB360), or PBO (RZB withdrawal) subcutaneous (SC) treatment every 8 wks for 52 wks. The efficacy analysis included responders to 12 wk of RZB IV, while the safety analysis included responders to 12 or 24 wk of RZB IV. The primary endpoint was clinical remission per Adapted Mayo score at wk 52. Key secondary endpoints included endoscopic improvement, HEMI, endoscopic remission, steroid-free clinical remission, maintenance of clinical remission, no bowel urgency, and no abdominal pain at wk 52.

Results

At baseline of induction, demographics and disease characteristics were similar between treatment groups; 75% of 548 patients had history of inadequate response or intolerance to ≥ 1 advanced therapy (AT). Patients receiving RZB180 (40.2%) and RZB360 (37.6%) achieved significantly higher rates of clinical remission vs WD (25.1%) (adjusted treatment difference vs WD: 16.3% and 14.2%, respectively; P ≤ .01) (Fig. 1A). Greater proportions of patients achieved endoscopic improvement, HEMI, endoscopic remission, steroid-free clinical remission, maintenance of clinical remission, no bowel urgency, and no abdominal pain with RZB180 and RZB360 vs WD (Fig. 1B). The overall rates of adverse events (AEs), and serious infections were similar among treatment groups (Table 1). Serious (presented as events/100 patient-years [E/100 PY]) (RZB180: 5.9; RZB360: 6.3; WD: 11.4) and severe AEs (RZB180: 1.6; RZB360: 4.0; WD: 8.0) were lower in the RZB arms vs WD. No active tuberculosis, adjudicated anaphylaxis, serious hypersensitivity, or adjudicated major adverse cardiovascular events were reported in any treatment group.

Conclusion

In patients with moderately to severely active UC responding to 12-week RZB induction therapy, RZB maintenance dosing with 180 mg and 360 mg SC was superior to placebo in achieving clinical remission as well as other key clinical, endoscopic, and histological-endoscopic endpoints. RZB was well-tolerated, with no new safety concerns observed.
OP17 IBD ulcers are characterized by bioactive interleukin-1 and transcriptomic hallmarks of stromal cell state reprogramming
Authors: Mitsialis V , Losa M , Field M , Collen L , Barends J , Ringel A , Bresnahan M , Yang J , Tumminkatti R , Sveen M , Bearup R , Kotlarz D , Klein C , Argmann C , Schadt E , Muise A , Thiagarajah J , Eran A , Horwitz B , Snapper S
Published: January 2024

Background

The programs that perpetuate the inflammation and prevent epithelial repair in Inflammatory Bowel Disease (IBD) remain unclear. Interleukin (IL)-1 plays a role in the maintenance of mucosal homeostasis but also in IBD. Expansion of IL-1 expressing myeloid cells is a hallmark of IBD tissue, including severe and anti-TNF unresponsive disease, and IL-1 expression is highly localized to ulcer beds. However, little is known about the presence of bioactive IL-1 proteins in the cell-free mucosal environment of IBD, nor whether IL-1-driven programs affect epithelial regeneration in IBD ulcers.

Methods

We established a highly sensitive assay (~500-fold greater than ELISA) to assess bioactive extracellular IL-1 from previously cryopreserved IBD biopsies. We assessed a cohort of Crohn’s Disease (CD, n=23), Ulcerative Colitis (UC, n=18) and non-IBD (n=17) patients, with biopsies from paired inflamed/uninflamed regions (primarily colon but also ileal). We assessed IL-1 bioactivity, including IL-1α vs IL-1β contributions, and performed RNA-seq of samples’ matched cellular compartments. An ulcer-associated gene signature was interrogated in a single-cell (sc)RNA-seq cohort (n=42) of very early onset (VEO)IBD including monogenic disorders, as well as publicly available IBD bulk RNA-seq datasets and scRNA-seq of mouse models of colitis.

Results

IL-1α and IL-1β bioactivity corresponded with disease and ulcer severity in CD and UC. The most extreme signals were seen in select CD patients with deep ulceration. IL-1α was the predominant contributor to total IL-1 bioactivity in most patients although several with ulcers displayed IL-1β predominance. IL-1 bioactivity correlated with IL-1 transcripts in matched RNA-seq, and weighted gene co-expression network analysis revealed a compelling ulcer-specific module. This module contained transcription factors and genes related to cell state, validated in publicly available datasets (e.g. RISK cohort of ileal CD and scRNA-seq of murine DSS colitis), that when interrogated in a scRNA-seq dataset of VEOIBD (including patients with IL-10RA mutations characterized by deep ulcers), suggests an orchestrated IL-1-driven myeloid/stromal response to epithelial ulceration involving cell state reprogramming and loss of key myofibroblast populations.

Conclusion

Mucosal ulceration in IBD is associated with bioactive IL-1α and IL-1β proteins, and transcriptomic evaluation of the same correlates with bioactive signal. An ulcer-associated gene module, validated in other datasets, sheds light on IL-1 biology in intestinal epithelial repair. Results strongly suggest the IL-1 signaling pathway being an attractive and precision-based therapeutic target in subsets of IBD patients.
OP39 Vedolizumab response in ulcerative colitis associates with reduced IgG+ plasma cells and FcγR signaling
Authors: Canales-Herrerias P , Uzzan M , Al-taie Z , Seki A , Verstockt B , Livanos A , Tankelevich M , Ganjian D , Cossarini F , Jha D , Taylor M D , Rosenstein A , Cerutti A , Petralia F , Argmann C , Suarez-Farinas M , Polydorides A D , Colombel J F , Mehandru S
Published: January 2024

Background

Vedolizumab (VDZ) targets the gut-homing receptor α4β7. Despite its widespread use as a frontline therapy for ulcerative colitis (UC), its mode of action (MOA) remains unclear. Previously, we documented that response to VDZ is associated with size loss of gut-associated lymphoid tissues (GALT). To further understand drug MOA, here we aimed at defining the relationship between GALT attrition and resolution of inflammation.

Methods

Tissue immunofluorescence (IF) was performed on two independent UC cohorts (n=60, n=21) studied longitudinally pre- and post-VDZ. Peripheral blood mononuclear cells from UC patients (n=56) were examined at week 0 (pre-VDZ) and 14 (post-VDZ) by flow cytometry, while intestinal biopsies were analyzed in a subset of patients. Transcriptomic analyses were performed in a third cohort of 401 UC patients and 243 controls where bulk RNA-sequencing was performed on intestinal biopsies. Finally, data from a fourth validation cohort (n=31) was examined pre- and post-VDZ.

Results

Using IF, we examined follicular naïve B (FB) cells (IgD+), germinal center (GC) B cells (BCL6+CD3-) and total T cells (CD3+), and identified three GALT types: organized aggregates (demarcated B/T cell zones) with GC, organized aggregates without GC, and poorly organized aggregates (Fig1A). When comparing pre- and post-VDZ, Responders (R) had a significant reduction in GALT organization, while no change was seen in Non-Responders (NR). The number of FB cells was significantly reduced post-VDZ in R but not in NR (Fig1B), with no change in T cells (Fig1C). The reduction in FB was validated using transcriptomic data (Fig1D). To explore potential consequences of GALT attrition, we analyzed circulating β7+ (GALT-generated) and β7- plasmablasts (PB). The frequencies of β7+IgG+ and β7+IgA+ PB were significantly reduced post-VDZ in R, but not in NR (Fig1E). No change was observed in β7- PB post-VDZ (Fig1F). Among β7+ PB, there was a greater reduction in IgG+ compared to IgA+ (Fig1G). Furthermore, colonic IgG+ plasma cells (PC) were significantly reduced post-VDZ in R but not in NR (Fig1H). To evaluate IgG-mediated proinflammatory function, we studied the expression of FcγR-pathway genes in colonic biopsies. Importantly, the FcγR-pathway was enhanced in inflamed tissues of UC patients (Fig1I-J) and was significantly reduced in R (but not in NR) post-VDZ (Fig1K).

Conclusion

Our work demonstrates a novel effect of anti-α4β7 blockade that results in intestinal lymphoid aggregate attrition through impaired recruitment of naïve B cells, leading to the suppression of IgG-driven immune responses and proinflammatory FcγR signaling. These data highlight the targeting of GALT as a novel therapeutic paradigm in IBD.
DOP40 Inflammatory Bowel Disease single cell atlas construction to enable cell type-specific target identification
Authors: De Baets G , D'Rozario J , Gehrman U , Mattsson J , Castiblanco D , Kaymak I , Moldoveanu A L , Giorgio C , Prandi F , Jawale C , Honsa P , Ruppova K , Valny M , Macuchova E , Freinkman E , Sponarova J , Platt A , Ort T , Corridoni D
Published: January 2024

Background

Advances in single-cell technologies enable the unbiased study of cellular heterogeneity. Recently, single-cell RNA sequencing (scRNA-seq) has been utilised on intestinal and blood samples from patients with inflammatory bowel disease (IBD) and healthy individuals, often in conjunction with cell surface proteome and TCR repertoire analyses. These individual studies revealed novel cell subpopulations of immune, mesenchymal, and epithelial cells in UC and CD, but are not sufficiently powered to consistently identify granular cell subsets or establish their association with disease status and response to treatment. Integration of these studies into a unified IBD single-cell atlas would provide a more robust data foundation for therapeutic target discovery. Here, we constructed a comprehensive, multi-modal single-cell atlas of human IBD tissue, combining a large breadth of meta-analysis with the depth of single-cell resolution.

Methods

Raw data from 20 public datasets were curated and reprocessed to generate a harmonised data foundation to support downstream discovery efforts. Low-quality cells and doublets were removed using thresholds for gene number, gene count, and percentage of counts originating from mitochondrial genes, and the resulting data were normalised and adjusted for batch effects. Published clinical metadata from each study were re-annotated with controlled vocabularies. Associations between clinical metadata and cellular/molecular features were discovered using computational and ML approaches.

Results

We generated a large-scale integrated single-cell atlas for IBD comprising >500 tissue samples from >200 IBD patients and relevant controls, with harmonised clinical metadata including treatment history and response. This tissue atlas comprises >990k high-quality cells with granular annotations of 129 cell types/states. IBD inflammation and non-response to anti-TNF treatment were associated with unique transcriptional signatures in specific mononuclear phagocyte, CD4 T cell, and fibroblast subpopulations. Further prioritisation and validation of genes comprising these signatures may yield future therapeutic targets for IBD.

Conclusion

This atlas integrates single-cell data across the largest available collection of IBD patient-derived tissue samples. Leveraging high-resolution cell type annotations and harmonised clinical metadata, meta-analyses of this data foundation will broaden the understanding of IBD biology to identify novel targets and pathways for drug discovery.
DOP55 High diagnostic accuracy of 4-probe methylation biomarkers in paediatric Inflammatory Bowel Disease by epigenome-wide analysis
Authors: Noble A , Adams A T , Nayak K M , Kalla R , Ventham N , Cheng G , Ashton J J , Hansen R , Croft N , Wilson D C , Ennis S , Zilbauer M , Uhlig H H , Satsangi J
Published: January 2024

Background

The application of -omics technology offers important opportunities for biomarker discovery to personalise management of patients with inflammatory bowel disease (IBD). In previous work, we reported a characteristic profile of genome-wide DNA methylation in peripheral blood leucocytes from children with paediatric IBD (pIBD) at diagnosis defining the IBD methylome. This characteristic pattern of genome-wide alterations was replicated in inception cohorts of adult patients in UK and Scandinavia.

Methods

Whole blood DNA methylation profiling was performed using the Illumina EPIC array on 86 pIBD patients and 30 non-IBD controls. Patients had a median age of 12 y and were prospectively recruited from gastroenterology clinics in Oxford and Cambridge, UK. In modelling, we utilised the paediatric BISCUIT and PICTS study cohorts from Scotland as our training data. Publicly available data from the RISK paediatric CD cohort from North America was accessed (GSE11261) to further assess accuracy of the model. The model was then subjected to further testing in an Oxford-based paediatric coeliac cohort and adult cohorts with IBD, and rheumatoid arthritis (RA)(Table 1).

Results

Genome-wide methylation changes in the Oxford/Cambridge cohort were highly consistent with the index BISCUIT and PICTS cohorts. Four single methylation sites were selected to make up a diagnostic model involving the genes, RPS6KA2, VMP1, CF1 and ARHGEF3 (Figure 1) in the index cohort and validated in the Oxford/Cambridge cohort. Following receiver operating characteristic (ROC) area under the curve (AUC) analyses the model demonstrated an AUC of 0.912 (95% CI: 0.86-0.96) (Table 1). To further validate our model, we compared pIBD who were CRP-positive (>5 mg/l) and CRP-negative (<5 mg/l) at presentation against non-IBD children. In the CRP-positive group, we found an AUC of 0.99 (95% CI: 0.99-1). Within the CRP-negative group an AUC of 0.90 was observed against controls (95% CI: 0.83-0.96). The model was further validated using methylation data at the baseline timepoint in the RISK cohort, with an AUC of 0.93 (95% CI: 0.90-0.96). In further analyses, we demonstrated specificity for IBD compared with paediatric coeliac disease; and accuracy higher in childhood-onset AUC than adult-onset disease AUC; the model is not accurate in diagnosis of RA.

Conclusion

We confirm a characteristic pattern of DNA methylation changes in childhood-onset IBD; and derive and validate a 4-probe model for diagnosis with high accuracy in both Europe and North America. The model is specific for pIBD compared with symptomatic children with no demonstrable pathology; and children with coeliac disease; and may provide an alternative to current markers in blood and stool, including calprotectin.
DOP62 A core molecular resistome characterised by extracellular matrix dysregulation and neutrophil degranulation predicts resistance to multiple therapies in Ulcerative Colitis
Authors: Saifuddin A , Cozzetto D , Pavlidis P , Hart A , Powell N
Published: January 2024

Background

Several transcript signatures have been published that predict anti-TNF resistance in ulcerative colitis (UC). However, clinical translation is hampered by suboptimal validation performance, partly because of insufficient emphasis on potential pathophysiology. Moreover, predictors of ustekinumab response are lacking. We interrogated transcriptomic datasets and anti-TNF predictive signatures to investigate resistance mechanisms and applicability to ustekinumab.

Methods

Transcript profiles of colonic biopsies taken before treatment for moderate-to-severe UC were analysed from Gene Expression Omnibus. Patients were then treated with infliximab (n = 24 and n = 22), golimumab (n = 84) or ustekinumab (n = 358). Molecular pathways from the Reactome database that were differentially enriched between mucosal healing responders and non-responders post-induction were found, along with shared pathways between cohorts. The largest cohort was used to calculate enrichment of published resistance signatures in actively inflamed mucosa using Spearman correlation. Hierarchical clustering was undertaken for non-responders. Analyses were performed using R 4.2.2 (Vienna, Austria).

Results

Many biological pathways were associated with resistance across the cohorts (1079 pathways, adjusted p value<0.01). Sixty pathways were shared between 3 or 4 datasets. Those relating to extracellular matrix (ECM) activity, neutrophil degranulation and interleukin signalling were most prominent. Network analyses revealed that proteins forming these pathways interact in vivo, forming a discrete functional module. The enrichment of published transcript signatures correlated highly. For instance, correlation between enrichment of UC1 (Czarnewski et al, 2019) and M5 (Friedrich et al 2021) was 0.96. Over-representation analyses showed that these signatures represent processes such as interleukin signalling and neutrophil activity. Hierarchical clustering of non-responders revealed two distinct groups, including those with high (NRhi) and low (NRlo) signature enrichment (Figure 1). Cellular deconvolution analyses showed that neutrophils are more prevalent in NRhi compared to NRlo and that eosinophils may be more frequent in NRlo than NRhi.

Conclusion

ECM dysregulation and neutrophil activity may underlie a core ‘resistome’ that heralds poor treatment outcomes to anti-TNFs and ustekinumab. Supporting this, the enrichment scores of published transcript signatures in inflamed tissue correlate highly, suggesting that many of these represent shared, or similar, molecular mechanisms of resistance. However, there is a separate resistant cohort with different molecular drivers. These findings have implications for precision medicine approaches in UC.
DOP77 Mesenchymal stem cell therapy for refractory Crohn’s perianal fistulas: a case series
Authors: Pronk A , Beek K J , Wildenberg M E , Bemelman W A , Stoker J , Buskens C J
Published: January 2024

Background

Nearly one-third of patients with Crohn’s disease will develop one or multiple perianal fistulas within the first two decades after diagnosis, with the majority being complex. Treatment options are limited with high recurrence rates after both medical and surgical approaches. It has been demonstrated that a completely fibrotic tract on Magnetic Resonance Imaging (MRI) with a MAGNIFI-CD <6 is the best predictor for long-term clinical closure. Mesenchymal stem cell treatment (MST) has emerged as a new therapeutic strategy for these fistulas. The aim of the current study was to analyse the effectiveness of MST for complex Crohn’s perianal fistulas based on MRI.

Methods

Consecutive patients with complex Crohn’s perianal fistulas, previously failing both anti-TNF treatment and surgical closure, that underwent surgical closure of the internal opening with MST between December 2019 and March 2023 were included. All patients underwent a MRI preoperatively and between three to six months after MST. For the current study, MRI’s were read by an senior radiologist. The primary endpoint was radiological remission of the fistula(s) defined as a MAGNIFI-CD <6 on MRI. Secondary endpoints were clinical closure (defined as closure of the external opening(s)), recurrence rate, change of MAGNIFI-CD over time, quality of life based on the perianal disease activity index (PDAI), and serious adverse events (SAE).

Results

In total, 30 patients (16 females) with 48 fistula tracts were included with a median clinical follow-up of 20 months. Radiological remission was achieved in thirteen patients (43.3%) after a median follow-up of 5.0 months (IQR 3.0-6.0). The median MAGNIFI-CD at baseline was 15.0 (IQR 7.0-20.0) which decreased significantly to 8.0 (IQR 3.0-15.0) after treatment (p= 0.001). Clinical closure of the fistula(s) was achieved in 21 patients (70.0%). Three patients (14.3%) developed a recurrence during long-term FU. All three patients had clinically closed fistula(s), but no radiological remission. The median PDAI decreased significantly from 10.5 (IQR 7.0-14.0) to 4.0 (IQR 0.0-7.3) (p= 0.001). Overall, in this patient group one SAE occurred requiring multiple reinterventions and temporary stoma.

Conclusion

Closure of the internal fistula opening with MST is a promising treatment strategy for therapy refractory Crohn’s perianal fistulas, resulting in >40% radiological remission and clinical closure in 70%. No recurrences were seen in patients with radiological remission. MST was also associated with a significant increase in quality of life. Further research is needed to gain insight in which patients MST is most likely to induce radiological remission.
P012 Intestinal epithelial cells as targets of thiopurines in Inflammatory Bowel Disease paediatric patients-derived organoids
Authors: Muzzo A , Lucafò M , Bramuzzo M , Zudeh G , Franzin M , Hofmann U , Lazzari E , Meroni G , Schwab M , Decorti G , Stocco G
Published: January 2024

Background

Thiopurines, azathioprine (AZA) and mercaptopurine (MP), are immunomodulators used to maintain remission in patients with inflammatory bowel disease (IBD). Intestinal epithelial cells play a key role in the pathogenesis of IBD, however, their role as target cells for thiopurines has not been elucidated. The aim of the project is to establish an in vitro IBD model using organoids starting from intestinal biopsies of IBD paediatric patients to investigate thiopurine effects on intestinal epithelium.

Methods

Forty-four IBD patients (mean age 14.4 years, 21 males) were enrolled. Intestinal biopsies were used to isolate crypts and generate adult stem cell-derived organoids. The cytotoxicity of thiopurines (0.2-200 µM for 72 hours) was evaluated by CellTiter-Glo 3D assay. Gene expression was evaluated using TaqMan assays. Thiopurine metabolites were quantified by LC-MS/MS analysis. Proteomic profiles were analyzed by Q-Exactive Plus mass spectrometer, western blot and REACTOME pathway software. Statistical analysis was performed using GraphPad and R software.

Results

IBD patients-derived organoids were sensitive to thiopurine treatment in a dose-dependent manner with a high interpatient variability (Two-way ANOVA p-value<0.0001; IC50 2.24 µM for AZA (95% CI: 1.28–5.53 µM) and 2.65 µM for MP (95% CI: 1.43–8.27 µM)).A significant negative correlation was observed between the viability after thiopurine exposure and mRNA expression of candidate genes involved in thiopurine pharmacokinetics (ITPA, TPMT, PACSIN2 and NUDT15). The most abundant thiopurine metabolite measured on organoids treated with IC50 of MP was MeTIMP, with a concentration correlated with cell viability after MP exposure (p=0.0056, ρ=-0.99). Proteomic analysis on organoids treated with IC20 of thiopurines (0.2 μM) showed 45 differentially expressed proteins in common between AZA and MP (p<0.05). REACTOME enrichment analysis revealed as the most altered pathways: vesicular traffic, autophagy, protein ubiquitination and interferon signalling, while no proteins related to apoptosis were induced. Among these proteins, TRIM32, a ubiquitin ligase involved in STING activity, a key regulator of both interferon I expression and NF-kB activation, resulted downregulated by the treatment (t-test AZA: p=0.0006; MP: p=0.014) and its basal levels negatively correlated with viability rates after thiopurine exposure (AZA: p=0.006, ρ=-0.85; MP: p=0.002, ρ=-0.88). Organoid exposure to thiopurines also decreased p-STING/STING ratio, particularly after MP treatment (t-test p=0.025), and increased autophagy, assessed as LC3-II levels (t-test AZA: p=0.0006; MP: p=0.014).

Conclusion

Organoid cultures provide new insights on the mechanism of action of thiopurines in the intestinal epithelium.
P014 First-time-in-human visualisation of CCR9 expression in the gut by positron emission tomography
Authors: MacKay J , Jucaite A , Cselényi Z , Johnström P , Dahl K , Schou M , Stenkrona P , Sousa V , Cortes Gonzalez M , Giffen P , Bouma G , Nys J , Brülls M , Duncan M , Larsson J , Lundahl A , Les K , Bergare J , Elmore C , Kiraga J , Blé F X , Fowler A , Belvisi M , Marks D
Published: January 2024

Background

CCR9/CCL25 is the key axis for recruiting lymphocytes to the small intestine and represents a potential treatment target in Crohn’s disease (CD). AZD7798 is a first-in-class monoclonal antibody for CD that depletes CCR9+ lymphocytes. Monitoring CCR9+ cell depletion and repletion in the blood is straightforward, but difficult in the primary tissues of interest (small bowel, mesenteric lymph nodes) which require invasive procedures to access. For AZD7798, an understanding of pharmacodynamics in gut is crucial to guide further clinical development. To address this need, we have developed a CCR9-specific PET tracer based on the small molecule CCR9 antagonist vercirnon.

Methods

Specific binding of [3H]vercirnon was assessed in-vitro using autoradiography. Specific binding and dosimetry of [11C]vercirnon was assessed in-vivo in cynomolgus monkeys.

Subsequently, a first-time-in-human study (NCT05818514) was performed in healthy volunteers to assess the biodistribution, binding to CCR9 in abdominal regions of interest, and safety of [11C]vercirnon, administered intravenously at microdoses (<10μg). Two PET-CT examinations were performed 14 days apart to assess reproducibility.

Results

In-vitro specific binding of [3H]vercirnon to CCR9 was confirmed in human thymus sections and CCR9-expressing cell pellets.

In-vivo specific binding of [11C]vercirnon to CCR9 was putatively demonstrated in the gut of non-human primates (NHPs) in pre-treatment/displacement studies with excess unlabelled vercirnon (20mg/kg).

8 healthy volunteers (5 male) were enrolled in the FTIH study. Detectable intestinal uptake of [11C]vercirnon was demonstrated in all participants (Figure 1) with mean±SD standardised uptake value ratio (SUVR) 1.4±0.6 (reference abdominal aorta), and a proximal to distal gradient (SUVR jejunum 1.8±0.7/ileum 0.9±0.4/colon 0.6±0.2) consistent with CCR9 gene expression data. Test-retest variability of intestinal uptake was 9.6% (intraclass correlation coefficient 0.96), in line with values for other clinically useful PET tracers.

Mean±SD injected radioactivity per PET examination was 351±105 MBq, corresponding to a radiation exposure of 1.4 mSv. This low radiation exposure (c.f. conventional FDG PET ~9 mSv) allows multiple PET examinations per participant. Administration of [11C]vercirnon was well-tolerated with no serious adverse events.

Conclusion

We have developed a CCR9-specific PET tracer which potentially enables repeatable quantification of CCR9 expression in the gut. Ongoing studies will assess the effects of AZD7798 on CCR9+ cell depletion/repletion in the gut, providing critical data to support the clinical development programme.
P027 Involvement of PD-L1 in myenteric plexitis associated with postoperative recurrence of Crohn's disease
Authors: Le Berre C , Durand T , Clavreul M , Neunlist M , Bourreille A , Neveu I , Naveilhan P
Published: January 2024

Background

Despite a growing therapeutic armamentarium, post-operative recurrence (POR) in Crohn’s disease (CD) remains frequent. The presence of myenteric plexitis at the proximal margin of ileocolonic resection has been recognized as a risk factor for early POR. They are defined by the accumulation of immune cells in contact with the ganglia of the myenteric plexus.

In preliminary work, we have shown an increase in the number of T lymphocytes (TL) in contact with enteric glial cells (EGC) in patients with CD depending on ICAM-1/LFA-1 pathway. As CD is classically associated with a Th1 immune response, the aim of this work was to study the impact of EGC/CD4+ TL contacts on Th1-type cytokine production (IFNγ and its transcription factor Tbet) and to identify molecules that may be involved in these regulations.

Methods

In vitro in rats, the impact of EGC/CD4+ TL co-culture on IFNγ production was studied by ELISA and qPCR of the transcription factor Tbet. The expression and regulation of PD-L1, a candidate molecule, was then analyzed in murine and human EGC by qPCR and immunohisto/cytochemistry.

Results

While EGC alone produced only a small amount of IFNγ, there was a significant reduction in IFNγ production in EGC/CD4+ TL co-cultures compared with CD4+ TL alone. Yet the proportion of CD4+ TL cells capable of producing IFNγ was significantly increased in contact with EGC, as was their survival. In parallel, Tbet was downregulated in CD4+ TL in contact with EGC. These results suggested the involvement of PD-L1, a molecule known to negatively regulate cytokine production (notably IFNγ) and Tbet expression.

Expression of PD-L1 mRNA and its protein was demonstrated in murine and human EGC and was upregulated under pro-inflammatory conditions. Analysis of transmural sections at the proximal margin of ileocolonic resection from patients (n=15 controls, n=14 CD without POR, n=15 CD with POR) showed PD-L1 expression in myenteric ganglia that was restricted to EGC (no neuronal expression) (Figure 1A). PD-L1 fluorescence intensity in myenteric ganglia at the proximal resection margin was significantly lower in CD patients with POR than in controls (∆13.5%; p=0.012) (Figure 1B).

Conclusion

Lower IFNγ production in EGC/CD4+ TL co-cultures associated with reduced Tbet expression by TL in contact with EGC suggest a role of PD-L1 in myenteric plexitis. PD-L1 expression has been demonstrated in murine and human EGC, with significantly lower expression in myenteric ganglia located at the proximal resection margin of CD patients with POR compared with controls. Blocking the ICAM-1/LFA-1 pathway and/or restoring the PD-1/PD-L1 loop could be of interest for developing strategies to prevent and/or treat POR in CD patients.
P035 3D bioprinting of gelatin derivatives: towards novel small intestinal in vitro models
Authors: Maes L , Szabó A , Van Haevermaete J , Geurs I , Dewettinck K , Van Vlierberghe S , Laukens D
Published: January 2024

Background

Despite significant progress achieved in the field of inflammatory bowel disease research, the precise cause of the disease has yet to be elucidated. Intestinal in vitro models can provide a fast and inexpensive alternative for in vivo studies. Nonetheless, many in vitro models lack the crypt or crypt-villus architecture as seen in the large and small intestine respectively and therefore fail to mimic the complexity of the gut. In this study, we aim to improve the physiology of small intestinal in vitro models by the development of hydrogels that mirror the villi and crypts of the digestive tract.

Methods

This study focused on the development of gelatin-methacryloyl-aminoethyl-methacrylate (gel-MA-AEMA)-, and gelatin-methacryloyl-norbornene (gel-MA-NB)-based biomaterial inks to fabricate 3D constructs, mimicking villi or a combination of villi and crypts, with digital light processing. The constructs were mechanically and morphologically evaluated with parallel plate rheology and cryo-scanning electron microscopy respectively. To assess the biocompatibility of the 3D constructs, a Caco-2/HT29-MTX co-culture in a 9:1 ratio was maintained for 21 days and confluency was confirmed with immunofluorescence. Gene expression, transepithelial electrical resistance (TEER) and paracellular permeability of the cells cultured on the constructs were compared to cells cultured on flat gel-MA-AEMA and gel-MA-NB hydrogels, a collagen type I coating or uncoated tissue culture plastic.

Results

Both gel-MA-AEMA and gel-MA-NB hydrogels exhibited physiologically relevant stiffness (1.9 ± 0.63 kPa and 1.64 ± 0.63 kPa respectively), but only the gel-MA-AEMA based biomaterial ink could be successfully utilized for printing constructs with villi and crypts. On all construct designs, confluency was reached and paracellular permeability of small sized marker molecules in combination with TEER measurements suggested the formation of a functional barrier over time, which was further confirmed by immunofluorescence and increased gene expression of tight junction proteins, occludin and ZO-1. The gene expression of enterocyte differentiation markers, villin-1, sucrase isomaltase and alkaline phosphatase, suggested the superior differentiation of Caco-2 cells on the ‘only villi’ and ‘villi and crypts’ constructs compared to flat hydrogels, collagen type I coating or uncoated tissue culture plastic.

Conclusion

Although both hydrogels promoted functional barrier formation and enterocyte differentiation, gel-MA-AEMA was more suited for DLP than gel-MA-NB. In addition, culturing intestinal epithelial cells on the 3D constructs ameliorated cell differentiation compared to conventional 2D setups.
P051 Diets enriched in fat and sugar and sex-dependant response to colitis in a mouse model
Authors: Touly N , Arnone D , Caron B , Kökten T , Umoret R , Peyrin-Biroulet L , Boudaud M
Published: January 2024

Background

Inflammatory bowel diseases (IBD) are chronic diseases characterized by inflammation of the mucosa linked to an alteration of the intestinal microbiota and overreaction of the immune system. The prevalence of IBD is increasing in industrialized countries where we find a “Western Diet” rich in refined sugars and saturated fats but low in fiber and essential unsaturated fatty acids1. Thus, nutrition seems to be an important environmental factor involved in the occurrence of IBD, however, underlying biological mechanisms are still poorly understood2. Additionally, most studies on colitis focused on males, yet diets effects are often very different according to sex. The aim of this study was therefore to study the sex-dependent effect of a diet enriched in sugar (sucrose) and a diet rich in fat in a mouse model of colitis.

Methods

Male and female, 9-weeks old C57BL/6 mice were fed 3 diets for 8 weeks: control diet (C), high-fat diet (HF), and high-fat/high-sucrose diet (HFHS). Then, colitis was induced using 3% Dextran sodium sulfate (DSS) for 5 days and kept 5 more days without DSS. The animals were monitored and weighed daily to establish a disease activity index (DAI). Blood and stools were collected monthly from the start of feeding. At the end of the protocol, a colonoscopy was carried out for each group before sacrifice and intestinal tissues were collected.

Results

DSS-induced colitis was earlier and more severe in both males and females fed high-caloric diets (both HF and HFHS). However, the HFHS diet accelerated DSS-induced colitis in males compared to the HF diet, while the HF diet led to more severe DSS-induced colitis than the HFHS diet in females. Males and females had similar weight gain following the high-caloric diets.

Conclusion

This difference in response to DSS after consumption of high-caloric diets between males and females indicates that the inflammatory mechanisms seem to differ depending on sex. Recent work reports the same sex-dependent effect in the Il10-/- mouse model3, suggesting that the sex has an impact on the pathophysiology of colitis and is essential to consider when studying IBD.

References

1. Arnone D, et al. Sugars and Gastrointestinal Health. Clin Gastroenterol Hepatol. 2022 Sep;20(9):1912-1924.e7.

2. Arnone D, et al. Long-Term Overconsumption of Fat and Sugar Causes a Partially Reversible Pre-inflammatory Bowel Disease State. Front Nutr. 2021 Nov 18;8:758518.

3. Maite CB, et al. The Effect of Sex-Specific Differences on IL-10-/- Mouse Colitis Phenotype and Microbiota. Int J Mol Sci. 2023 Jun 20;24(12):10364.
P058 The identification of three linear epitopes on infliximab all map to complementarity-determining regions
Authors: Tun G , Ramage W , Hufton S E , Lobo A J
Published: January 2024

Background

Infliximab (IFX) is a mainstay of treatment for inflammatory bowel disease (IBD). Its use is limited by the development of anti-drug antibodies (ADA), which can cause loss of response and adverse drug reactions. The antigenic epitopes have not been clearly defined, and large antigenic areas suggested. The aim of this study was to identify clinically relevant distinct epitopes in IBD patients treated with IFX with ADA and different clinical outcomes.

Methods

Sera were pooled from 8 ADA positive IBD patients (ADA >10 AU/mL; IDKmonitor® Infliximab total ADA) treated with CT -P13 (Remsima® Celltrion Inc., Korea) exhibiting: loss of response, response with therapeutic drug levels, response with subtherapeutic drug levels and adverse drug reactions. A novel whole gene fragment library (GFL) was synthesised using pools of overlapping synthetic oligonucleotides covering the IFX heavy chain and light chain (Twist Bioscience, California, United States). This was cloned into a phage display vector to generate a library >106 clones. Three rounds of selection of the GFL were performed using pooled sera. DNA from the selection outputs were analysed by next generation sequencing (NGS) (Illumina, San Diego, United States). Outputs from one round of selection using individual sera were also analysed by NGS.

Results

ADA ranged 17->600 AU/mL. 23,383 gene sequences analysed from the GFL showed complete coverage of the IFX gene. After three rounds of selection, DNA sequencing showed the enrichment of three peptides – all overlapping the IFX complementary-determining regions (CDR)- Figure 1. The three peptides enriched: heavy chain peptide 1 included heavy chain CDR 1, light chain peptide 2 overlap light chain CDR 1 and light chain peptide 3 overlap light chain CDR 2. NGS assessment of the outputs from round 1-3 using pooled ADA positive sera confirmed enrichment of the three peptides. NGS analysis of the selections on individual sera showed differences in enrichment profile of the three peptides.

Conclusion

Using ADA positive sera from IBD patients treated with IFX with differing clinical outcomes, three linear epitopes were identified from a novel whole IFX-GFL. All epitopes overlapped with CDRs which is consistent with being potential sites for neutralising ADA. NGS has suggested that individual ADA positive sera have differing recognition profiles for the selected epitopes. Identifying distinct epitopes may lead to the identification of a biomarker for loss of response to infliximab.
P061 The macrophage-specific role of PTPN23 in Acute and Chronic Colitis
Authors: Linzmeier L , Matus V , Determann M , Wilmink M , Schwarzfischer M , Sanchez Alvarez R , Pöhlmann D , Scharl M , Spalinger M
Published: January 2024

Background

Single nucleotide polymorphisms within the gene locus encoding PTPN2, are associated with Crohn’s disease and ulcerative colitis. We have previously shown that, deletion of PTPN2 results in PTPN23 upregulation in intestinal epithelial cells (IEC) in vivo. PTPN23 is known to be involved in endosomal sorting and responsible for epidermal growth factor receptor (EGFR) internalization from the cell surface and thus negatively controls EGFR signalling in epithelial cells. Though PTPN23 is highly expressed in IEC and intestinal macrophages, nothing is known about its function in myeloid cells and its role in intestinal inflammation.

Methods

Experimental colitis was induced in PTPN23fl/flLysMCre+/- (KO) and PTPN23fl/flLysMCre-/- (WT) littermates by administration of 2% DSS in drinking water for 7 days (acute colitis) or for 4 cycles of 1.5% DSS for 7 days followed by 10 days recovery, each (chronic colitis). Immune cells were isolated from spleen and colon lamina propria from KO and WT mice and PTPN23 expression was detected by qPCR of RNA isolated after cell sorting with flow cytometry.

Results

The mRNA expression of PTPN23 in untreated WT mice was significantly higher in macrophages isolated from the lamina propria of the colon than in those isolated from spleen (p=0.0279).

PTPN23fl/flLysMCre+/- (KO) mice were protected from DSS-induced acute colitis when compared to their WT littermates. This was apparent by a lack of DSS-induced weight loss (p=0.02); longer colon length (p=0.01), reduced endoscopic colitis scores (p=0.0016) and lower spleen weights (p=0.0063) in KO mice. In HE staining of colon tissue, the loss of crypts was less pronounced in KO mice. On mRNA level a lower expression of the pro-inflammatory cytokines interleukin 6 (IL-6) (p=0.0117) and tumour necrosis factor α (TNFα) (p=0.0024) was observed in KO compared to WT mice, supporting a reduced inflammatory response.

In chronic colitis the same trends was observed, however the effects were less pronounced. WT mice lost more weight during the DSS cycles compared to KO mice, whereas no difference in weight development was detected between the genotypes in water control groups. Higher MEICSs scores were observed in WT compared to KO mice (p<0.0001) and loss of colonic crypts was more pronounced in HE stained colon samples in WT mice than KO mice.

Conclusion

PTPN23 deletion in myeloid cells results in protection from DSS-induced acute and chronic colitis. Additionally, a higher expression in intestinal macrophages compared to macrophages isolated from the spleen suggest a specific role in the intestinal immune system.