Interferon beta-1a for the maintenance of remission in patients with Crohn's disease: results of a phase II dose-finding study

Treatment of autoimmunity: The impact of disease-modifying therapies in multiple sclerosis and comorbid autoimmune disorders

More than 10 disease-modifying therapies (DMT) are approved by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for the treatment of multiple sclerosis (MS) and new therapeutic options are on the horizon. Due to different underlying therapeutic mechanisms, a more individualized selection of DMTs in MS is possible, taking into account the patient's current situation. Therefore, concomitant treatment of various comorbid conditions, including autoimmune mediated disorders such as rheumatoid arthritis, should be considered in MS patients. Because the pathomechanisms of autoimmunity partially overlap, DMT could also treat concomitant inflammatory diseases and simplify the patient's treatment. In contrast, the exacerbation and even new occurrence of several autoimmune diseases have been reported as a result of immunomodulatory treatment of MS. To simplify treatment and avoid disease exacerbation, knowledge of the beneficial and adverse effects of DMT in other autoimmune disorders is critical. Therefore, we conducted a literature search and described the beneficial and adverse effects of approved and currently studied DMT in a large number of comorbid autoimmune diseases, including rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel diseases, cutaneous disorders including psoriasis, Sjögren´s syndrome, systemic lupus erythematosus, systemic vasculitis, autoimmune hepatitis, and ocular autoimmune disorders. Our review aims to facilitate the selection of an appropriate DMT in patients with MS and comorbid autoimmune diseases.

Exposing the Two Contrasting Faces of STAT2 in Inflammation

Inflammation is a natural immune defense mechanism of the body's response to injury, infection, and other damaging triggers. Uncontrolled inflammation may become chronic and contribute to a range of chronic inflammatory diseases. Signal transducer and activator of transcription 2 (STAT2) is an essential transcription factor exclusive to type I and type III interferon (IFN) signaling pathways. Both pathways are involved in multiple biological processes, including powering the immune system as a means of controlling infection that must be tightly regulated to offset the development of persistent inflammation. While studies depict STAT2 as protective in promoting host defense, new evidence is accumulating that exposes the deleterious side of STAT2 when inappropriately regulated, thus prompting its reevaluation as a signaling molecule with detrimental effects in human disease. This review aims to provide a comprehensive summary of the findings based on literature regarding the inflammatory behavior of STAT2 in microbial infections, cancer, autoimmune, and inflammatory diseases. In conveying the extent of our knowledge of STAT2 as a proinflammatory mediator, the aim of this review is to stimulate further investigations into the role of STAT2 in diseases characterized by deregulated inflammation and the mechanisms responsible for triggering severe responses.

IL-23 Monoclonal Antibodies for IBD: So Many, So Different?

Interleukin [IL]-23 is a member of the IL-12 family of cytokines and has been implicated in multiple inflammatory disorders including psoriasis, psoriatic arthritis, and the inflammatory bowel diseases [IBDs]. Blockade of both IL-12 and IL-23 using an antibody that targets a shared subunit is highly effective in treating psoriasis, and recent data suggest similar efficacy in IBD with minimal adverse events. In this review, we summarise published data on the efficacy of anti-IL-12/23 therapies in IBD as well as emerging data on more selective anti-IL-23 specific therapies. Last, we discuss novel therapeutics under development which target the IL-23 pathway in unique ways and suggest that a biomarker-driven approach will soon guide clinicians to prescribe anti-IL-23 therapies to the patients most likely to respond to them.

Loss of Nckx3 Exacerbates Experimental DSS-Induced Colitis in Mice through p53/NF-κB Pathway

Inflammatory bowel diseases (IBDs) comprises a range of chronic inflammatory conditions of the intestinal tract. The incidence and prevalence of IBDs are increasing worldwide, but the precise etiology of these diseases is not completely understood. Calcium signaling plays a regulatory role in cellular proliferation. Nckx3, a potassium-dependent Na⁺/Ca²⁺ exchanger, is not only expressed in the brain but also in the aortic, uterine, and intestinal tissues, which contain abundant smooth muscle cells. This study investigated the role of Nckx3 in intestinal inflammation. Microarray analyses revealed the upregulation of the innate immune response-associated genes in the duodenum of Nckx3 knockout (KO) mice. The Nckx3 KO mice also showed an increase in IBD- and tumorigenesis-related genes. Using dextran sodium sulfate (DSS)-induced experimental colitis mice models, the Nckx3 KO mice showed severe colitis. Furthermore, the pathways involving p53 and NF-κB signaling were significantly upregulated by the absence of Nckx3. Overall, Nckx3 plays a critical role in the innate immune and immune response and may be central to the pathogenesis of IBD.

Interferons at the crossroad of cell death pathways during gastrointestinal inflammation and infection

Interferons (IFNs) are pleiotropic immune-modulatory cytokines that are well known for their essential role in host defense against viruses, bacteria, and other pathogenic microorganisms. They can exert both, protective or destructive functions depending on the microorganism, the targeted tissue and the cellular context. Interferon signaling results in the induction of IFN-stimulated genes (ISGs) influencing different cellular pathways including direct anti-viral/anti-bacterial response, immune-modulation or cell death. Multiple pathways leading to host cell death have been described, and it is becoming clear that depending on the cellular context, IFN-induced cell death can be beneficial for both: host and pathogen. Accordingly, activation or repression of corresponding signaling mechanisms occurs during various types of infection but is also an important pathway for gastrointestinal inflammation and tissue damage. In this review, we summarize the role of interferons at the crossroad of various cell death pathways in the gut during inflammation and infection.

Intestinal Stem Cells and Immune Cell Relationships: Potential Therapeutic Targets for Inflammatory Bowel Diseases

The mammalian intestine is the largest immune organ that contains the intestinal stem cells (ISC), differentiated epithelial cells (enterocytes, Paneth cells, goblet cells, tuft cells, etc.), and gut resident-immune cells (T cells, B cells, dendritic cells, innate lymphoid cell, etc.). Inflammatory bowel disease (IBD), a chronic inflammatory disease characterized by mucosa damage and inflammation, threatens the integrity of the intestine. The continuous renewal and repair of intestinal mucosal epithelium after injury depend on ISCs. Inflamed mucosa healing could be a new target for the improvement of clinical symptoms, disease recurrence, and resection-free survival in IBD treated patients. The knowledge about the connections between ISC and immune cells is expanding with the development of in vitro intestinal organoid culture and single-cell RNA sequencing technology. Recent findings implicate that immune cells such as T cells, ILCs, dendritic cells, and macrophages and cytokines secreted by these cells are critical in the regeneration of ISCs and intestinal epithelium. Transplantation of ISC to the inflamed mucosa may be a new therapeutic approach to reconstruct the epithelial barrier in IBD. Considering the links between ISC and immune cells, we predict that the integration of biological agents and ISC transplantation will revolutionize the future therapy of IBD patients.

Contradictory Effects of NLRP3 Inflammasome Regulatory Mechanisms in Colitis

The inflammasome is an intracellular molecular complex, which is mainly involved in innate immunity. Inflammasomes are formed in response to danger signals, associated with infection and injury, and mainly regulate the secretion of interleukin-1β and interleukin-18. Inflammasome dysregulation is known to be associated with various diseases and conditions, and its regulatory mechanisms have become of great interest in recent years. In the colon, inflammasomes have been reported to be associated with autophagy and the microbiota, and their dysregulation contributes to colitis and. However, the detailed role of inflammasomes in inflammatory bowel disease is still under debate because the mechanisms that regulate the inflammasome are complex and the inflammasome components and cytokines show seemingly contradictory multiple effects. Herein, we comprehensively review the literature on inflammasome functioning in the colon and describe the complex interactions of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome components with inflammatory cytokines, autophagy, and the microbiota in experimental colitis models and patients with inflammatory bowel disease.

Interventions for fatigue in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is an umbrella term used to describe a group of chronic, progressive inflammatory disorders of the digestive tract. Crohn's disease and ulcerative colitis are the two main types. Fatigue is a common, debilitating and burdensome symptom experienced by individuals with IBD. The subjective, complex nature of fatigue can often hamper its management. The efficacy and safety of pharmacological or non-pharmacological treatments for fatigue in IBD is not yet established through systematic review of studies.

OBJECTIVES

To assess the efficacy and safety of pharmacological and non-pharmacological interventions for managing fatigue in IBD compared to no treatment, placebo or active comparator.

SEARCH METHODS

A systematic search of the databases Embase, MEDLINE, Cochrane Library, CINAHL, PsycINFO was undertaken from inception to July 2018. A top-up search was run in October 2019. We also searched the Cochrane IBD Group Specialized Register, the Cochrane Central Register of Controlled Trials, ongoing trials and research registers, conference abstracts and reference lists for potentially eligible studies.

SELECTION CRITERIA

Randomised controlled trials of pharmacological and non-pharmacological interventions in children or adults with IBD, where fatigue was assessed as a primary or secondary outcome using a generic or disease-specific fatigue measure, a subscale of a larger quality of life scale or as a single-item measure, were included.

DATA COLLECTION AND ANALYSIS

Two authors independently screened search results and four authors extracted and assessed bias independently using the Cochrane 'Risk of bias' tool. The primary outcome was fatigue and the secondary outcomes included quality of life, adverse events (AEs), serious AEs and withdrawal due to AEs. Standard methodological procedures were used.

MAIN RESULTS

We included 14 studies (3741 participants): nine trials of pharmacological interventions and five trials of non-pharmacological interventions. Thirty ongoing studies were identified, and five studies are awaiting classification. Data on fatigue were available from nine trials (1344 participants). In only four trials was managing fatigue the primary intention of the intervention (electroacupuncture, physical activity advice, cognitive behavioural therapy and solution-focused therapy). Electroacupuncture Fatigue was measured with Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F) (scores range from 0 to 52). The FACIT-F score at week eight was 8.00 points higher (better) in participants receiving electroacupuncture compared with no treatment (mean difference (MD) 8.00, 95% CI 6.45 to 9.55; 1 RCT; 27 participants; low-certainty evidence). Results at week 16 could not be calculated. FACIT-F scores were also higher with electroacupuncture compared to sham electroacupuncture at week eight (MD 5.10, 95% CI 3.49 to 6.71; 1 RCT; 30 participants; low-certainty evidence) but not at week 16 (MD 2.60, 95% CI 0.74 to 4.46; 1 RCT; 30 participants; low-certainty evidence). No adverse events were reported, except for one adverse event in the sham electroacupuncture group. Cognitive behavioural therapy (CBT) and solution-focused therapy Compared with a fatigue information leaflet, the effects of CBT on fatigue are very uncertain (Inflammatory Bowel Disease-Fatigue (IBD-F) section I: MD -2.16, 95% CI -6.13 to 1.81; IBD-F section II: MD -21.62, 95% CI -45.02 to 1.78; 1 RCT, 18 participants, very low-certainty evidence). The efficacy of solution-focused therapy on fatigue is also very uncertain, because standard summary data were not reported (1 RCT, 98 participants). Physical activity advice One 2 x 2 factorial trial (45 participants) found physical activity advice may reduce fatigue but the evidence is very uncertain. At week 12, compared to a control group receiving no physical activity advice plus omega 3 capsules, FACIT-F scores were higher (better) in the physical activity advice plus omega 3 group (FACIT-F MD 6.40, 95% CI -1.80 to 14.60, very low-certainty evidence) and the physical activity advice plus placebo group (FACIT-F MD 9.00, 95% CI 1.64 to 16.36, very low-certainty evidence). Adverse events were predominantly gastrointestinal and similar across physical activity groups, although more adverse events were reported in the no physical activity advice plus omega 3 group. Pharmacological interventions Compared with placebo, adalimumab 40 mg, administered every other week ('eow') (only for those known to respond to adalimumab induction therapy), may reduce fatigue in patients with moderately-to-severely active Crohn's disease, but the evidence is very uncertain (FACIT-F MD 4.30, 95% CI 1.75 to 6.85; very low-certainty evidence). The adalimumab 40 mg eow group was less likely to experience serious adverse events (OR 0.56, 95% CI 0.33 to 0.96; 521 participants; moderate-certainty evidence) and withdrawal due to adverse events (OR 0.48, 95%CI 0.26 to 0.87; 521 participants; moderate-certainty evidence). Ferric maltol may result in a slight increase in fatigue, with better SF-36 vitality scores reported in the placebo group compared to the treatment group following 12 weeks of treatment (MD -9.31, 95% CI -17.15 to -1.47; 118 participants; low-certainty evidence). There may be little or no difference in adverse events (OR 0.55, 95% CI 0.26 to 1.18; 120 participants; low-certainty evidence) AUTHORS' CONCLUSIONS: The effects of interventions for the management of fatigue in IBD are uncertain. No firm conclusions regarding the efficacy and safety of interventions can be drawn. Further high-quality studies, with a larger number of participants, are required to assess the potential benefits and harms of therapies. Future studies should assess interventions specifically designed for fatigue management, targeted at selected IBD populations, and measure fatigue as the primary outcome.

Inflammatory bowel disease pathobiology: the role of the interferon signature

The pathogenesis of inflammatory bowel disease (IBD) is still unclear, but includes both inflammatory and autoimmune reactions. Current methodological approaches could better elucidate the cytokine pathways and the genetics involved in the etiopathogenesis of this disease. Interferons (IFNs) are cytokines that play a key role in autoimmune/inflammatory disorders because of their pro- and anti-inflammatory properties as well as their immunoregulatory functions. An increased expression of IFN-regulated genes, widely known as an IFN signature, has been reported in blood and tissue from patients with autoimmune disorders. In this review, we present the function as well as the clinical and therapeutic potential of the IFN signature. Current data demonstrate that the IFN signature can be used as a biomarker that defines disease activity in autoimmune diseases, although this has not been thoroughly studied in IBD. Consequently, further investigation of the IFN signature in IBD would be essential for a better understanding of its actions.

Repurposing multiple sclerosis drugs: a review of studies in neurological and psychiatric conditions

Treatment options for multiple sclerosis (MS) have improved in the past 20 years, with new oral disease-modifying drugs and monoclonal antibodies becoming available. The success seen with these drugs in MS, and their various mechanisms of action, has led to them being investigated in other neurological and psychiatric disorders. This review article summarises the ongoing and completed studies of MS drugs in neurological and psychiatric conditions other than MS. The most promising results are for interferon beta in human T cell leukaemia virus 1 associated myelopathy/tropical spastic paraparesis and glioma, and for fingolimod in acute ischaemic stroke and intracerebral haemorrhage. The coming years could see the arrival of exciting new therapies for disorders that neurologists have historically found difficult to treat and that represent a significant unmet clinical need.

Systematic review: outcomes and adverse events from randomised trials in Crohn's disease

BACKGROUND

The suitability of disease activity indices has been challenged, with growing interest in objective measures of inflammation.

AIM

To undertake a systematic review of efficacy and safety outcomes in placebo-controlled randomised controlled trials (RCTs) of patients with Crohn's disease.

METHODS

MEDLINE, EMBASE, CINAHL and Cochrane Library were searched until November 2015, for RCTs of adult Crohn's disease patients treated with medical or surgical therapies. Data on efficacy and safety outcomes, end-point definitions, and measurement instruments were extracted and stratified by publication date (pre-2009 and 2009 onwards).

RESULTS

One hundred and eighty-one RCTs (110 induction and 71 maintenance) were identified, including 23 850 patients. About 92.3% reported clinical efficacy endpoints. The Crohn's Disease Activity Index (CDAI) dominated, defining clinical response or remission in 63.5% of trials (35 definitions of response or remission). CDAI < 150 was the commonest endpoint, but reporting reduced between periods (46.4%-41.1%), whilst use of CDAI100 increased (16.8%-30.4%). Fistula studies most commonly reported fistula closure (9, 90.0%). Reporting of biomarker, endoscopy and histology endpoints increased overall (33.3%-40.6%, 14.4%-30.4% and 3.2%-12.5%, respectively), but were heterogeneous and rarely reported in fistula trials. Patient-reported outcome measures were reported in 41.4% of trials and safety endpoints in 35.4%. Many of the common adverse events relate to disease exacerbation or treatment failure.

CONCLUSIONS

Trial endpoints vary across studies, over time and are distinct in fistula studies. Despite growth in reporting of objective measures of inflammation and in patient-reported outcome measures, there is a lack of standardisation. This confirms the need for a core outcome set for comparative effectiveness research in Crohn's disease.

Cell type-specific gene expression patterns associated with posttraumatic stress disorder in World Trade Center responders

Posttraumatic stress disorder (PTSD), a chronic disorder resulting from severe trauma, has been linked to immunologic dysregulation. Gene expression profiling has emerged as a promising tool for understanding the pathophysiology of PTSD. However, to date, all but one gene expression study was based on whole blood or unsorted peripheral blood mononuclear cell (PBMC), a complex tissue consisting of several populations of cells. The objective of this study was to utilize RNA sequencing to simultaneously profile the gene expression of four immune cell subpopulations (CD4T, CD8T, B cells, and monocytes) in 39 World Trade Center responders (20 with and 19 without PTSD) to determine which immune subsets play a role in the transcriptomic changes found in whole blood. Transcriptome-wide analyses identified cell-specific and shared differentially expressed genes across the four cell types. FKBP5 and PI4KAP1 genes were consistently upregulated across all cell types. Notably, REST and SEPT4, genes linked to neurodegeneration, were among the top differentially expressed genes in monocytes. Pathway analyses identified differentially expressed gene sets involved in mast cell activation and regulation in CD4T, interferon-beta production in CD8T, and neutrophil-related gene sets in monocytes. These findings suggest that gene expression indicative of immune dysregulation is common across several immune cell populations in PTSD. Furthermore, given notable differences between cell subpopulations in gene expression associated with PTSD, the results also indicate that it may be valuable to analyze different cell populations separately. Monocytes may constitute a key cell type to target in research on gene expression profile of PTSD.

Bacteria-related Events and the Immunological Response of Onset and Relapse Adult Crohn's Disease Patients

BACKGROUND AND AIMS

Crohn's disease [CD] is a chronic, systemic inflammatory disease characterised by periods of remission and flare-ups. It has been associated with a disturbed gastrointestinal barrier function, an increase in the transport of luminal contents into the tissue, and lower immune tolerance.

METHODS

Peripheral blood samples were collected from healthy controls and 33 adult active flare-up CD patients. We classified patients as onset or relapse flare-up subjects, according to the days of disease evolution. Plasma levels of lipopolysaccharide-binding protein [LBP], fatty acid-binding proteins [FABP], and antibodies against bacterial lysates, interferons [IFN] and interleukin-6 [IL6] were measured by enzyme-linked immunosorbent assay [ELISA] in each group of patients.

RESULTS

Onset CD patients had higher plasma levels of LBP [57.32 ± 38.86 vs 30.22 ± 9.80 µg/ml] and IFNα [1.25 ± 0.23 vs 0.95 ± 0.36 log10pg/ml] and lower levels of immunoglobulins G and A [IgG and IgA] antibodies against bacterial lysates than relapse CD patients. We also observed a subgroup of onset patients with the highest levels of LBP. In this subgroup, LBP correlated negatively with C-reactive protein [CRP]. Onset and relapse CD patients had similar levels of FABP6 and FABP2, though LBP and FABP6 correlated positively only in relapse patients. In relapse patients, anti-E coli IgG antibodies correlated positively with systemic IL6 and IFNα levels.

CONCLUSIONS

Our findings suggest that onset and relapse flare-ups in adult CD patients are related to different systemic immune-related bacterial events. Characterising these differences may provide insights into the aetiology of Crohn's disease, and would help in the selection of appropriate therapies.

Heterogeneity in Definitions of Efficacy and Safety Endpoints for Clinical Trials of Crohn's Disease: A Systematic Review

BACKGROUND & AIMS

Endpoints in randomized controlled trials (RCTs) of Crohn's disease (CD) are changing. We performed a systematic review of efficacy and safety outcomes reported in placebo-controlled RCTs of patients with CD.

METHODS

We searched the MEDLINE, EMBASE, and the Cochrane Library through March 1, 2017 for placebo-controlled RCTs of adult patients with CD treated with aminosalicylates, immunomodulators, corticosteroids, biologics, and oral small molecules. Efficacy and safety outcomes, definitions, and measurement tools were collected and stratified by decade of publication.

RESULTS

Our final analysis included 116 RCTs (81 induction, 44 maintenance, 7 postoperative prevention trials, comprising 27,263 patients). Clinical efficacy endpoints were reported in all trials; the most common endpoint was CD activity index score. We identified 38 unique definitions of clinical response or remission and 32 definitions of loss of response. Definitions of endoscopic response, remission, and endoscopic healing were also heterogeneous, evaluated using the CD endoscopic index of severity, the simple endoscopic score for CD, ulcer resolution, and Rutgeerts' Score for postoperative endoscopic appearance. Histologic outcomes were reported in 11.1% of induction trials, 2.3% of maintenance trials, and 14.3% of postoperative prevention trials. Biomarker outcomes were reported in 81.5% induction trials, 68.2% of maintenance trials, and 42.9% of postoperative prevention trials. Safety outcomes were reported in 93.8% of induction trials, 97.7% of maintenance trials, and 85.7% of postoperative prevention trials.

CONCLUSIONS

In this systematic review, we demonstrate heterogeneity in definitions of response and remission, and changes in outcomes reported in RCTs of CD. It is a priority to select a core set of outcomes to standardize efficacy and safety evaluation in trials of patients with CD.

mTOR inhibitor INK128 attenuates dextran sodium sulfate-induced colitis by promotion of MDSCs on Treg cell expansion

Accumulating evidence has shown that mammalian target of rapamycin (mTOR) pathway and myeloid-derived suppressor cells (MDSCs) are involved in pathogenesis of inflammatory bowel diseases (IBDs). INK128 is a novel mTOR kinase inhibitor in clinical development. However, the exact roles of MDSCs and INK128 in IBD are unclear. Here, we showed that the INK128 treatment enhanced the resistance of mice to dextran sodium sulfate (DSS)-induced colitis and inhibited the differentiation of MDSCs into macrophages. Moreover, interferon (IFN)-α level was elevated in INK128-treated colitis mice. When stimulated with IFN-α in vitro, MDSCs showed a superior immunosuppression activity. Of note, the regulatory T cells (Tregs) increased but Th1 cells decreased in INK128-treated colitis mice. These results indicate that mTOR inhibitor INK128 attenuates DSS-induced colitis via Treg expansion promoted by MDSCs. Our work provides a new evidence that INK128 is potential to be a therapeutic drug on DSS-induced colitis via regulating MDSCs as well as maintaining Treg expansion.

Gp96 Peptide Antagonist gp96-II Confers Therapeutic Effects in Murine Intestinal Inflammation

Background

The expression of heat shock protein gp96 is strongly correlated with the degree of tissue inflammation in ulcerative colitis and Crohn’s disease, thereby leading us to the hypothesis that inhibition of expression via gp96-II peptide prevents intestinal inflammation.

Methods

We employed daily injections of gp96-II peptide in two murine models of intestinal inflammation, the first resulting from five daily injections of IL-12/IL-18, the second via a single intrarectal application of TNBS (2,4,6-trinitrobenzenesulfonic acid). We also assessed the effectiveness of gp96-II peptide in murine and human primary cell culture.

Results

In the IL-12/IL-18 model, all gp96-II peptide-treated animals survived until day 5, whereas 80% of placebo-injected animals died. gp96-II peptide reduced IL-12/IL-18-induced plasma IFNγ by 89%, IL-1β by 63%, IL-6 by 43% and tumor necrosis factor (TNF) by 70% compared to controls. The clinical assessment Disease Activity Index of intestinal inflammation severity was found to be significantly lower in the gp96-II-treated animals when compared to vehicle-injected mice. gp96-II peptide treatment in the TNBS model limited weight loss to 5% on day 7 compared with prednisolone treatment, whereas placebo-treated animals suffered a 20% weight loss. Histological disease severity was reduced equally by prednisolone (by 40%) and gp96-II peptide (35%). Mice treated with either gp96-II peptide or prednisolone exhibited improved endoscopic scores compared with vehicle-treated control mice: vascularity, fibrin, granularity, and translucency scores were reduced by up to 49% by prednisolone and by up to 30% by gp96-II peptide. In vitro, gp96-II peptide reduced TLR2-, TLR4- and IL-12/IL-18-induced cytokine expression in murine splenocytes, with declines in constitutive IL-6 (54%), lipopolysaccharide-induced TNF (48%), IL-6 (81%) and in Staphylococcus epidermidis-induced TNF (67%) and IL-6 (81%), as well as IL-12/IL-18-induced IFNγ (75%). gp96-II peptide reduced IL–1β, IL-6, TNF and GM-CSF in human peripheral blood mononuclear cells to a similar degree without affecting cell viability, whereas RANTES, IL-25 and MIF were twofold to threefold increased.

Conclusion

gp96-II peptide protects against murine intestinal inflammation by regulating inflammation in vivo and in vitro, pointing to its promise as a novel treatment for inflammatory bowel disease.

Genetic polymorphism in ATG16L1 gene is associated with adalimumab use in inflammatory bowel disease

Background

The role of single nucleotide polymorphisms (SNPs) associated with inflammatory bowel disease (IBD) is gaining interest. With the advent of novel therapies, personalized treatment in IBD is a future goal. We wondered whether IBD-associated SNPs are able to predict response to anti-TNFα treatment.

Methods

Data on treatment use and primary response, loss of response and side effects to anti-TNFα treatments were retrieved for 570 IBD patients. rs13361189 (IRGM), rs10210302 (ATG16L1), rs2066844, rs2066845, rs2066847 (NOD2), rs35873774 (XBP1), rs11175593 (LRRK2), rs11465804 (IL23R), rs2301436 (CCR6), rs744166 (STAT3) and rs4821544 (NCF4) SNP status were determined.

Results

No associations were found between genetic variants of the LRRK2, CCR6, IL23R and NCF4 genes and response to anti-TNFα. For NOD2 and XBP1 associations were found, however, these associations were not strong enough to survive multiple testing corrections. Strikingly, patients carrying the ATG16L1 T300A variant were more likely to be treated with adalimumab, even after correction for disease phenotype, disease behavior and age (p = 0.004, OR 2.8, CI 1.6–5.0).

Conclusions

Genetic polymorphisms in the known IBD-associated gene ATG16L1 correlate with requirement of treatment, suggesting a different IBD disease phenotype in these patients. Further investigation will need to elucidate the implications of these findings and identify the underlying disease characteristics.

Electronic supplementary material

The online version of this article (10.1186/s12967-017-1355-9) contains supplementary material, which is available to authorized users.

Activation of NLRP3 Inflammasome in Inflammatory Bowel Disease: Differences Between Crohn's Disease and Ulcerative Colitis

BACKGROUND

NLRP3 inflammasome is a multimolecular cytosol complex that, when activated, contributes to the cleavage of pro-interleukin (IL)-1β to IL-1β.

AIMS

To investigate NLRP3 inflammasome activation in inflammatory bowel disease.

METHODS

Peripheral blood mononuclear cells from Crohn's disease (CD), ulcerative colitis (UC) patients and controls were stimulated with LPS in the absence or presence of MSU. After incubation, concentrations of IL-1β, IL-6, and TNFα were measured in cell supernatants and concentration of pro-IL-1β was measured in cell lysates. NLRP3 activation was defined as more than 30% increase in IL-1β production after MSU addition. In separate experiments, PBMCs were lysed for RNA isolation transcripts of IL-1β, TNFα, NLRP3, and CASP1 were measured by RT-PCR. DNA was isolated from CD patients for ATG16L1 gene genotyping.

RESULTS

NLRP3 inflammasome was activated in 60% of CD patients compared to 28.6% of controls (p = 0.042); no significant difference was detected between UC and controls. Among UC patients, NLRP3 activation was associated (p = 0.008) with long-standing disease (>1.5 years). IL-1β levels were significantly higher in CD patents in comparison with controls (p = 0.032). No difference was detected in the levels of IL-6, TNFα, pro-IL-1β and in the numbers IL-1β, TNFα, NLRP3, and CASP1 transcripts among groups. IL-1β production was similar between carriers of wild-type and of SNP alleles of the rs2241880.

CONCLUSIONS

NLRP3 inflammasome is activated in CD patients and in UC patients with long-standing disease.

The Protective Role of Type I Interferons in the Gastrointestinal Tract

The immune system of the gastrointestinal (GI) tract manages the significant task of recognizing and eliminating pathogens while maintaining tolerance of commensal bacteria. Dysregulation of this delicate balance can be detrimental, resulting in severe inflammation, intestinal injury, and cancer. Therefore, mechanisms to relay important signals regulating cell growth and immune reactivity must be in place to support GI homeostasis. Type I interferons (IFN-I) are a family of pleiotropic cytokines, which exert a wide range of biological effects including promotion of both pro- and anti-inflammatory activities. Using animal models of colitis, investigations into the regulation of intestinal epithelium inflammation highlight the role of IFN-I signaling during fine modulation of the immune system. The intestinal epithelium of the gut guides the immune system to differentiate between commensal and pathogenic microbiota, which relies on intimate links with the IFN-I signal-transduction pathway. The current paradigm depicts an IFN-I-induced antiproliferative state in the intestinal epithelium enabling cell differentiation, cell maturation, and proper intestinal barrier function, strongly supporting its role in maintaining baseline immune activity and clearance of damaged epithelia or pathogens. In this review, we will highlight the importance of IFN-I in intestinal homeostasis by discussing its function in inflammation, immunity, and cancer.

Systematic review with meta-analysis: placebo rates in induction and maintenance trials of Crohn's disease

BACKGROUND

Minimising placebo response is essential for drug development.

AIM

To conduct a meta-analysis to determine placebo response and remission rates in trials and identify the factors affecting these rates.

METHODS

MEDLINE, EMBASE and CENTRAL were searched from inception to April 2014 for placebo-controlled trials of pharmacological interventions for Crohn's disease. Placebo response and remission rates for induction and maintenance trials were pooled by random-effects and mixed-effects meta-regression models to evaluate effects of study-level characteristics on these rates.

RESULTS

In 100 studies containing 67 induction and 40 maintenance phases and 7638 participants, pooled placebo remission and response rates for induction trials were 18% [95% confidence interval (CI) 16-21%] and 28% (95% CI 24-32%), respectively. Corresponding values for maintenance trials were 32% (95% CI 25-39%) and 26% (95% CI 19-35%), respectively. For remission, trials enrolling patients with more severe disease activity, longer disease duration and more study centres were associated with lower placebo rates, whereas more study visits and longer study duration was associated with higher placebo rates. For response, findings were opposite such that trials enrolling patients with less severe disease activity and longer study duration were associated with lower placebo rates. Placebo rates varied by drug class and route of administration, with the highest placebo response rates observed for biologics.

CONCLUSIONS

Placebo rates vary according to whether trials are designed for induction or maintenance and the factors influencing them differ for the endpoints of remission and response. These findings have important implications for clinical trial design in Crohn's disease.

Type I and III Interferon in the Gut: Tight Balance between Host Protection and Immunopathology

The intestinal mucosa forms an active interface to the outside word, facilitating nutrient and water uptake and at the same time acts as a barrier toward the highly colonized intestinal lumen. A tight balance of the mucosal immune system is essential to tolerate harmless antigens derived from food or commensals and to effectively defend against potentially dangerous pathogens. Interferons (IFN) provide a first line of host defense when cells detect an invading organism. Whereas type I IFN were discovered almost 60 years ago, type III IFN were only identified in the early 2000s. It was initially thought that type I IFN and type III IFN performed largely redundant functions. However, it is becoming increasingly clear that type III IFN exert distinct and non-redundant functions compared to type I IFN, especially in mucosal tissues. Here, we review recent progress made in unraveling the role of type I/III IFN in intestinal mucosal tissue in the steady state, in response to mucosal pathogens and during inflammation.

Type I IFN induces protein ISGylation to enhance cytokine expression and augments colonic inflammation

Type I IFNs have broad activity in tissue inflammation and malignant progression that depends on the expression of IFN-stimulated genes (ISGs). ISG15, one such ISG, can form covalent conjugates to many cellular proteins, a process termed "protein ISGylation." Although type I IFNs are involved in multiple inflammatory disorders, the role of protein ISGylation during inflammation has not been evaluated. Here we report that protein ISGylation exacerbates intestinal inflammation and colitis-associated colon cancer in mice. Mechanistically, we demonstrate that protein ISGylation negatively regulates the ubiquitin-proteasome system, leading to increased production of IFN-induced reactive oxygen species (ROS). The increased cellular ROS then enhances LPS-induced activation of p38 MAP kinase and the expression of inflammation-related cytokines in macrophages. Thus our studies reveal a regulatory role for protein ISGylation in colonic inflammation and its related malignant progression, indicating that targeting ubiquitin-activating enzyme E1 homolog has therapeutic potential in treating inflammatory diseases.

Current stage in inflammatory bowel disease: What is next?

In recent years, the incidence of inflammatory bowel disease (IBD) has been on the rise, extending to countries where it was infrequent in the past. As a result, the gap between high and low incidence countries is decreasing. The disease, therefore, has an important economic impact on the healthcare system. Advances in recent years in pharmacogenetics and clinical pharmacology have allowed for the development of treatment strategies adjusted to the patient profile. Concurrently, new drugs aimed at inflammatory targets have been developed that may expand future treatment options. This review examines advances in the optimization of existing drug treatments and the development of novel treatment options for IBD.

The role of type I interferons in intestinal infection, homeostasis, and inflammation

Type I interferons are a widely expressed family of effector cytokines that promote innate antiviral and antibacterial immunity. Paradoxically, they can also suppress immune responses by driving production of anti-inflammatory cytokines, and dysregulation of these cytokines can contribute to host-mediated immunopathology and disease progression. Recent studies describe their anti-inflammatory role in intestinal inflammation and the locus containing IFNAR, a heterodimeric receptor for the type I interferons has been identified as a susceptibility region for human inflammatory bowel disease. This review focuses on the role of type I IFNs in the intestine in health and disease and their emerging role as immune modulators. Clear understanding of type I IFN-mediated immune responses may provide avenues for fine-tuning existing IFN treatment for infection and intestinal inflammation.

Therapeutic peptides in inflammatory bowel disease

INTRODUCTION

Therapeutic peptides in inflammatory bowel diseases essentially comprise cytokines affecting immune response, growth factors and monoclonal antibodies directed against key targets of mucosal inflammation, in particular, tumor necrosis factor-a (TNF-a). The latter have revolutionized standard medical treatment which previously was restricted to mesalamine, corticosteroids or classical immunosuppressants.

AREAS COVERED

We review current evidence of the use of the so-called biologicals, including the well-established TNF-a antagonists and novel peptides and monoclonal antibodies developed for these diseases. The focus is on controlled clinical trials and meta-analyses, if available. Limitations and biases of these studies are important but tend to be ignored. Safety is also an important issue with opportunistic infections and lymphoma as relevant risks. There is significant heterogeneity between different countries, guidelines and opinions within the scientific community regarding clinical indications, even apart from pharmacoeconomics and reimbursement.

EXPERT OPINION

TNF blockers have greatly extended medical options in inflammatory bowel diseases. Their more or less extensive use in nearly all patients or only a few selected indications is a matter of debate. It proved difficult to reproduce this success with other antibody targets as well as with immunomodulatory cytokines and growth factors. The most promising novel peptide is vedolizumab, an antibody against α4β7 integrin.

The value of experimental models of colitis in predicting efficacy of biological therapies for inflammatory bowel diseases

During the last decade, biological therapies have an increasing share in the modern therapeutics of various diseases including inflammatory bowel diseases (IBD). Animal models of IBD have often been used to identify the targets of biological therapies, to test their relevance to disease pathogenesis, to assess their therapeutic efficacy in vivo, and to check for drug toxicity. In the field of inflammatory diseases the majority of biologics under development have failed to reach the clinic. This review examines the ability of preclinical data from animal models of IBD to predict success or failure of biologics in human IBD. Specifically, it describes the murine models of IBD, the mechanism of disease induction, the phenotype of the disease, its relevance to human IBD, and the specific immunological features of disease pathogenesis in each model and mainly compares the results of the phase II and III trials of biologics in IBD with preclinical data obtained from studies in animal models. Finally, it examines the possible reasons for low success in translation from bench to bedside and offers some suggestions to improve translation rates.

New insights into an autoimmune mechanism, pharmacological treatment and relationship between multiple sclerosis and inflammatory bowel disease

Inflammatory bowel disease (IBD) and multiple sclerosis (MS) are autoimmune diseases with a close relationship to their disease pattern and immunologic cascade with considerable morbidity and mortality. This article provides insight of why tumor necrosis factor blockers couldn't work in multiple sclerosis and why interferon-beta doesn't work in inflammatory bowel disease. In this article, we provide a detailed review of the linkage and potential interchangeable medication between IBD and MS in addition to Natalizumab, Trichuris suis egg therapy and vitamin D. Different treatment strategies may have potential in treating both diseases in the future.

Type I IFNs regulate effector and regulatory T cell accumulation and anti-inflammatory cytokine production during T cell-mediated colitis

We explored the function of endogenous type I IFNs (IFN-1) in the colon using the T cell adoptive transfer model of colitis. Colon mononuclear phagocytes (MPs) constitutively produced IFN-1 in a Toll/IL-1R domain-containing adapter-inducing IFN-β-dependent manner. Transfer of CD4(+)CD45RB(hi) T cells from wild-type (WT) or IFN-α/β receptor subunit 1 knockout (IFNAR1(-/-)) mice into RAG(-/-) hosts resulted in similar onset and severity of colitis. In contrast, RAG(-/-) × IFNAR1(-/-) double knockout (DKO) mice developed accelerated severe colitis compared with RAG(-/-) hosts when transferred with WT CD4(+)CD45RB(hi) T cells. IFNAR signaling on host hematopoietic cells was required to delay colitis development. MPs isolated from the colon lamina propria of IFNAR1(-/-) mice produced less IL-10, IL-1R antagonist, and IL-27 compared with WT MPs. Accelerated colitis development in DKO mice was characterized by early T cell proliferation and accumulation of CD11b(+)CD103(-) dendritic cells in the mesenteric lymph nodes, both of which could be reversed by systemic administration of IL-1R antagonist (anakinra). Cotransfer of CD4(+)CD25(+) regulatory T cells (Tregs) from WT or IFNAR1(-/-) mice prevented disease caused by CD4(+)CD45RB(hi) T cells. However, WT CD4(+)CD25(+)Foxp3(GFP+) Tregs cotransferred with CD4(+)CD45RB(hi) T cells into DKO hosts failed to expand or maintain Foxp3 expression and gained effector functions in the colon. To our knowledge, these data are the first to demonstrate an essential role for IFN-1 in the production of anti-inflammatory cytokines by gut MPs and the indirect maintenance of intestinal T cell homeostasis by both limiting effector T cell expansion and promoting Treg stability.

IFNα converts IL-22 into a cytokine efficiently activating STAT1 and its downstream targets

Besides their antiviral activity, type I Interferons (IFN) display context-specific immunomodulation. In contrast to long-known IFNα/β, Interleukin (IL)-22 is an anti-bacterial, largely tissue protective cytokine that recently gained attention. Herein, cellular IFNα/IL-22 interactions are investigated. We report that pre-conditioning of epithelial cells with IFNα initiated dramatic changes in IL-22 signaling normally dominated by signal transducer and activator of transcription (STAT)-3. Specifically, by using human DLD1 colon epithelial/carcinoma cells we demonstrate that, upon IFNα, IL-22 converts into a cytokine robustly activating STAT1 and its downstream pro-inflammatory targets CXCL9, CXCL10, and inducible nitric oxide synthase (iNOS). Accordingly, only after IFNα pre-incubation was IL-22-induced STAT1 binding to the CXCL10 promoter detectable. Using the viral mimic polyinosinic:polycytidylic acid and the IFNα/β antagonist B18R we furthermore demonstrate the capability of endogenous IFN to promote IL-22-induced STAT1 activation and expression of CXCL10. IL-22-induced STAT1 activation subsequent to IFNα priming became likewise apparent in human Caco2 colon epithelial/carcinoma cells, HepG2 hepatoma cells, and primary keratinocytes. Current observations may relate to characteristics of IFNα/β in clinical therapy and expose margins of tissue protection by IL-22 application.

Type I interferons in regulation of mucosal immunity

The mucosal system is the first line of defense against many pathogens. It is continuously exposed to dietary and microbial antigens, and thus the host must maintain a homeostatic environment between commensal microbiota and pathogenic infections. Following infections and inflammatory events, a rapid innate immune response is evoked to dampen the inflammatory processes. Type I interferons, a family of pleiotropic cytokines and major products of the innate immune response, have a key role in these early immune events at the mucosa, as reviewed here. With the emergence of new discoveries of immune cell types in mucosal tissues and their reactions to commensal and pathogenic organisms, we also review the opportunities for exciting research in this field.

Immunomodulatory functions of type I interferons

Interferon-α (IFNα) and IFNβ, collectively known as type I IFNs, are the major effector cytokines of the host immune response against viral infections. However, the production of type I IFNs is also induced in response to bacterial ligands of innate immune receptors and/or bacterial infections, indicating a broader physiological role for these cytokines in host defence and homeostasis than was originally assumed. The main focus of this Review is the underappreciated immunomodulatory functions of type I IFNs in health and disease. We discuss their function in the regulation of innate and adaptive immune responses, the response to bacterial ligands, inflammasome activation, intestinal homeostasis and inflammatory and autoimmune diseases.

Current and emerging drugs for the treatment of inflammatory bowel disease

During the last decade a large number of biological agents against tumor necrosis factor-α (TNF-α), as well as many biochemical substances and molecules specifically for the medical treatment of patients with inflammatory bowel disease (IBD), have been developed. This enormous progress was a consequence of the significant advances in biotechnology along with the increased knowledge of the underlying pathophysiological mechanisms involved in the pathogenesis of IBD. However, conventional therapies remain the cornerstone of treatment for most patients. During recent years conventional and biologic IBD therapies have been optimized. Newer mesalazine formulations with a reduced pill size and only one dose per day demonstrate similar efficacy to older formulations. New corticosteroids retain the efficacy of older corticosteroids while exhibiting a higher safety profile. The role of antibiotics and probiotics has been further clarified. Significant progress in understanding thiopurine metabolism has improved the effective dose along with adjunctive therapies. Quite a large number of substances and therapies, including biologic agents other than TNF-α inhibitors, unfractionated or low-molecular-weight heparin, omega-3 polyunsaturated fatty acids, microbes and microbial products, leukocytapheresis, and other substances under investigation, could offer important benefits to our patients. In this paper we review the established and emerging therapeutic strategies in patients with Crohn’s disease and ulcerative colitis.