Explore the vast range of titles available.

Research on IBDs has identified disrupted immune responses in the gastrointestinal mucosa and putative disruptions in the gut microbiome as causative agents. This work has led to better therapeutic control of IBDs with the use of various antiinflammatory agents.

Inflammation promotes regeneration of injured tissues through poorly understood mechanisms, some of which involve interleukin (IL)-6 family members, the expression of which is elevated in many diseases including inflammatory bowel diseases and colorectal cancer. Here we show in mice and human cells that gp130, a co-receptor for IL-6 cytokines, triggers activation of YAP and Notch, transcriptional regulators that control tissue growth and regeneration, independently of the gp130 effector STAT3. Through YAP and Notch, intestinal gp130 signalling stimulates epithelial cell proliferation, causes aberrant differentiation and confers resistance to mucosal erosion. gp130 associates with the related tyrosine kinases Src and Yes, which are activated on receptor engagement to phosphorylate YAP and induce its stabilization and nuclear translocation. This signalling module is strongly activated upon mucosal injury to promote healing and maintain barrier function. This study demonstrates the activation of a STAT3-independent healing pathway in response to mucosal injury which involves the co-receptor for IL-6 cytokines gp130 and downstream effectors Src, Yes, YAP and Notch. Beneficial effects of inflammation As well as activating innate and adaptive immunity, inflammation triggers tissue repair and regeneration through mechanisms that are largely unknown. This study demonstrates the activation of a STAT3-independent healing pathway in a mouse model of experimental colitis through a process involving gp130 (a co-receptor for interleukin-6 family cytokines) and the downstream effectors Src, Yes, YAP and Notch.

During a microbial infection, responding CD8 + T cells give rise to effector cells that provide acute host defense and memory cells that provide sustained protection. An alternative outcome is exhaustion, a state of T cell dysfunction that occurs in the context of chronic infections and cancer. Although it is evident that exhausted CD8 + T (T EX ) cells are phenotypically and molecularly distinct from effector and memory CD8 + T cells, the factors regulating the earliest events in the differentiation process of T EX cells remain incompletely understood. Here, we performed single-cell RNA-sequencing and single-cell ATAC-sequencing of CD8 + T cells responding to LCMV-Armstrong (LCMV-Arm) or LCMV-Clone 13 (LCMV-Cl13), which result in acute or chronic infections, respectively. Compared to CD8 + T cells that had undergone their first division in response to LCMV-Arm (Div1 ARM ) cells, CD8 + T cells that had undergone their first division in response to LCMV-Cl13 (Div1 CL13 ) expressed higher levels of genes encoding transcription factors previously associated with exhaustion, along with higher levels of Ezh2, the catalytic component of the Polycomb Repressive Complex 2 (PRC2) complex, which mediates epigenetic silencing. Modulation of Ezh2 resulted in altered expression of exhaustion-associated molecules by CD8 + T cells responding to LCMV-Cl13, though the specific cellular and infectious contexts, rather than simply the level of Ezh2 expression, likely determine the eventual outcome. Taken together, these findings suggest that the differentiation paths of CD8 + T cells responding to acute versus chronic infections may diverge earlier than previously appreciated.

We assessed the real-world effectiveness and safety of vedolizumab (VDZ) in moderate-severe Crohn's disease (CD). Retrospective cohort study of seven medical centers, from May 2014 to December 2015. Adults with moderate-severe CD treated with VDZ, with follow-up after initiation of therapy, were included. Using the multivariable Cox proportional hazard analyses, we identified independent predictors of clinical remission or mucosal healing with VDZ. Rates of serious infection (requiring antibiotics, resulting in discontinuation of VDZ, hospitalization or death) and serious adverse events (discontinuation of VDZ, hospitalization or death) were described quantitatively. We included 212 patients with moderate-severe CD (median age 34 years; 40% male; 90% tumor necrosis factor (TNF)-antagonist exposed) with a median follow-up (IQR) of 39 weeks (25-53). Twelve-month cumulative rates of clinical remission, mucosal healing, and deep remission (clinical remission+mucosal healing) were 35%, 63%, and 26%, respectively. Individuals with prior TNF-antagonist exposure (hazard ratio (HR) 0.40; 95% confidence interval (CI): 0.20-0.81), smoking history (HR 0.47; 95% CI: 0.25-0.89), active perianal disease (HR 0.49; 95% CI: 0.27-0.88), and severe disease activity (HR 0.54; 95% CI: 0.31-0.95) were less likely to achieve clinical remission. Those with prior TNF-antagonist exposure (HR 0.29; 95% CI: 0.12-0.73), and severe disease activity (HR 0.54; 95% CI: 0.31-0.95) were less likely to achieve mucosal healing. During 160 patient years of follow-up (PYF) and 1,433 VDZ infusions, 5 patients developed infusion reactions (3.5 per 1,000 infusions), 21 developed serious infections (13 per 100 PYF), and 17 developed serious adverse events (10 per 100 PYF). A minority of adverse events required discontinuation of therapy (6 per 100 PYF). VDZ is a safe and effective treatment option for moderate-severe CD in routine practice. Clinical remission and deep remission (clinical remission and mucosal healing) can be achieved in 1/3 of individuals, and a minority of individuals require discontinuation of therapy due to adverse events.

Modeling human diseases as networks simplify complex multi-cellular processes, helps understand patterns in noisy data that humans cannot find, and thereby improves precision in prediction. Using Inflammatory Bowel Disease (IBD) as an example, here we outline an unbiased AI-assisted approach for target identification and validation. A network was built in which clusters of genes are connected by directed edges that highlight asymmetric Boolean relationships. Using machine-learning, a path of continuum states was pinpointed, which most effectively predicted disease outcome. This path was enriched in gene-clusters that maintain the integrity of the gut epithelial barrier. We exploit this insight to prioritize one target, choose appropriate pre-clinical murine models for target validation and design patient-derived organoid models. Potential for treatment efficacy is confirmed in patient-derived organoids using multivariate analyses. This AI-assisted approach identifies a first-in-class gut barrier-protective agent in IBD and predicted Phase-III success of candidate agents. Traditional drug discovery process use differential, Bayesian and other network based approaches. We developed a Boolean approach for building disease maps and prioritizing pre-clinical models to discover a first-in-class therapy to restore and protect the leaky gut barrier in inflammatory bowel disease.

Tamoxifen is a selective oestrogen receptor modulator widely used for the treatment of breast cancer. In addition to its activity as an oestrogen receptor agonist/antagonist, tamoxifen also modulates sphingolipid biosynthesis, which has been shown to play an important role in the regulation of neutrophil activity. Here, we find that tamoxifen stimulation enhances several pro-inflammatory pathways in human neutrophils, including chemotaxis, phagocytosis and neutrophil extracellular trap (NET) formation. The enhancement of NET production occurs via a ceramide/PKCζ-mediated pathway, and treatment with synthetic ceramide is sufficient to promote NET formation. Pretreatment of human neutrophils with tamoxifen boosts neutrophil bactericidal capacity against a variety of pathogens in vitro and enhances clearance of the leading human pathogen methicillin-resistant Staphylococcus aureus in vivo . Our results suggest that tamoxifen, and the lipid signalling pathways it modulates, merit further exploration as targets for boosting host innate immune function. Tamoxifen, widely used to modulate oestrogen receptor activity in breast cancer treatment, also regulates sphingolipid metabolism. Here the authors show that the latter activity of tamoxifen stimulates pro-inflammatory and antibacterial activities of human neutrophils.

Intestinal epithelial cell (IEC) death is a common feature of inflammatory bowel disease (IBD) that triggers inflammation by compromising barrier integrity. In many patients with IBD, epithelial damage and inflammation are TNF-dependent. Elevated TNF production in IBD is accompanied by increased expression of the TNFAIP3 gene, which encodes A20, a negative feedback regulator of NF-κB. A20 in intestinal epithelium from patients with IBD coincided with the presence of cleaved caspase-3, and A20 transgenic (Tg) mice, in which A20 is expressed from an IEC-specific promoter, were highly susceptible to TNF-induced IEC death, intestinal damage, and shock. A20-expressing intestinal organoids were also susceptible to TNF-induced death, demonstrating that enhanced TNF-induced apoptosis was a cell-autonomous property of A20. This effect was dependent on Receptor Interacting Protein Kinase 1 (RIPK1) activity, and A20 was found to associate with the Ripoptosome complex, potentiating its ability to activate caspase-8. A20-potentiated RIPK1-dependent apoptosis did not require the A20 deubiquitinase (DUB) domain and zinc finger 4 (ZnF4), which mediate NF-κB inhibition in fibroblasts, but was strictly dependent on ZnF7 and A20 dimerization. We suggest that A20 dimers bind linear ubiquitin to stabilize the Ripoptosome and potentiate its apoptosis-inducing activity.

Transcription factors (TFs) are crucial for regulating cell differentiation during the development of the immune system. However, the key TFs for orchestrating the specification of distinct immune cells are not fully understood. Here, we integrated the transcriptomic and epigenomic measurements in 73 mouse and 61 human primary cell types, respectively, that span the immune cell differentiation pathways. We constructed the cell-type-specific transcriptional regulatory network and assessed the global importance of TFs based on the Taiji framework, which is a method we have previously developed that can infer the global impact of TFs using integrated transcriptomic and epigenetic data. Integrative analysis across cell types revealed putative driver TFs in cell lineage-specific differentiation in both mouse and human systems. We have also identified TF combinations that play important roles in specific developmental stages. Furthermore, we validated the functions of predicted novel TFs in murine CD8 + T cell differentiation and showed the importance of Elf1 and Prdm9 in the effector versus memory T cell fate specification and Kdm2b and Tet3 in promoting differentiation of CD8 + tissue resident memory (Trm) cells, validating the approach. Thus, we have developed a bioinformatic approach that provides a global picture of the regulatory mechanisms that govern cellular differentiation in the immune system and aids the discovery of novel mechanisms in cell fate decisions.

BACKGROUNDHyperbaric oxygen therapy (HBOT) markedly increases tissue oxygen delivery. Case series suggest it may have a potential therapeutic benefit in ulcerative colitis (UC). We investigated the therapeutic potential of HBOT as an adjunct to steroids for UC flares requiring hospitalization.METHODSThe study was terminated early due to poor recruitment with 18 of the planned 70 patients enrolled. UC patients hospitalized for moderate–severe flares (Mayo score ≥6, endoscopic sub-score ≥2) were block randomized to steroids + daily HBOT (n = 10) or steroids + daily sham hyperbaric air (n = 8). Patients were blinded to study assignment, and assessments were performed by a blinded gastroenterologist. Primary outcome was the clinical remission rate at study day 5 (partial Mayo score ≤2 with no sub-score >1). Key secondary outcomes were: clinical response (reduction in partial Mayo score ≥2, rectal bleeding sub-score of 0–1) and progression to second-line therapy (colectomy or biologic therapy) during the hospitalization.RESULTSA significantly higher proportion of HBOT-treated patients achieved clinical remission at study day 5 and 10 (50 vs. 0%, p = 0.04). HBOT-treated patients less often required progression to second-line therapy during the hospitalization (10 vs. 63%, p = 0.04). The proportion requiring in-hospital colectomy specifically as second-line therapy for medically refractory UC was lower in the HBOT group compared to sham (0 vs. 38%, p = 0.07). There were no serious adverse events.CONCLUSIONIn this small, proof-of-concept, phase 2A trial, the use of HBOT as an adjunctive therapy to steroids for UC patients hospitalized for moderate–severe flares resulted in higher rates of clinical remission, and a reduction in rates of progression to second-line therapy during the hospitalization. Larger well-powered trials are needed, however, to provided definitive evidence of therapeutic benefit.

The utility of spatial omics in leveraging cellular interactions in normal and diseased states for precision medicine is hampered by a lack of strategies for matching disease states with spatial heterogeneity-guided cellular annotations. Here we use a spatial context-dependent approach that matches spatial pattern detection to cell annotation. Using this approach in existing datasets from ulcerative colitis patient colonic biopsies, we identified architectural complexities and associated difficult-to-detect rare cell types in ulcerative colitis germinal-center B cell follicles. Our approach deepens our understanding of health and disease pathogenesis, illustrates a strategy for automating nested architecture detection for highly multiplexed spatial biology data, and informs precision diagnosis and therapeutic strategies.