Loss of interleukin-10 signaling and infantile inflammatory bowel disease: implications for diagnosis and therapy

The global stress response regulator oxyS in an adherent-invasive Escherichia coli strain attenuates experimental colitis

Crohn's disease and ulcerative colitis in humans and experimental immune-mediated colitis in mice are likely due in part to overactive immune responses to resident intestinal bacteria, including certain strains of adherent-invasive Escherichia coli (E. coli) such as E. coli NC101. We have previously shown that specific E. coli NC101 stress responses are upregulated during experimental colitis and attenuate inflammation. However, the roles of broader stress response pathways in E. coli NC101 during experimental colitis are unknown. We hypothesize that the global stress response regulator in E. coli, oxyS, also reduces experimental colitis. We show that intestinal E. coli NC101 upregulate oxyS expression during colitis in monocolonized interleukin-10 deficient mice. Furthermore, we demonstrate that oxyS-sufficient E. coli NC101 have decreased motility and biofilm formation in vitro and attenuated intestinal translocation and colitogenic potential in vivo compared with oxyS-deficient E. coli. These data suggest that activation of a generalized E. coli stress response, oxyS, reduces experimental colitis and may be a potential therapeutic target.

Treatment of IL-10RA deficiency of pediatric patients with very early onset inflammatory bowel disease by allogeneic haematopoietic stem cell transplantation

Very early onset inflammatory bowel disease (VEO-IBD) with interleukin-10 receptor-A (IL-10RA) defects is characterised by severe and unmanageable intestinal inflammation, perianal lesions, and a high mortality rate, with the onset of the disease occurring at a very early age. Currently, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is one of the most effective treatments for VEO-IBD patients with IL-10 signaling deficiency. The objective of this study was to evaluate the clinical effectiveness of allo-HSCT in the treatment of children with VEO-IBD and IL-10RA deficiency, and to provide further clinical insights. A retrospective analysis and summary of the clinical data of seven patients with VEO-IBD and IL-10RA deficiency from January 2021 to December 2023 was performed. These patients subsequently underwent allo-HSCT after receiving a reduced-intensity conditioning regimen followed by a cyclosporine-based regimen for the prevention of graft versus host disease (GVHD). Hematopoietic reconstruction was performed on seven children with VEO-IBD combined with IL-10RA deficiency. Four patients developed grade I-II GVHD, while three patients developed grade III-IV GVHD after undergoing allo-HSCT. At a median follow-up of 518 days after allo-HSCT (range: 210-1072 days), six patients were alive, while one patient died 16 months after the procedure because of chronic GVHD and severe infections. The 3-year cumulative overall survival (OS) probability rate was 80.0% (95% CI: 44.7-100.0). All VEO-IBD patients demonstrated weight gain following HSCT, with substantial improvements observed in severe malnutrition and growth retardation associated with IL-10RA deficiency post-transplantation. Allo-HSCT is thus identified as the optimal curative therapy for VEO-IBD patients with IL10-RA deficiency. The importance of early multidisciplinary intervention and co-management of VEO-IBD is paramount in improving HSCT outcomes.

Quality management, ethical considerations, and emerging challenges in genomics and biobanking: A comprehensive review

The integration of genomics into personalized medicine has the potential to transform healthcare by customizing treatments according to individual genetic profiles. This paper examines the diverse applications of genomics, including the identification of disease susceptibility, improvement of diagnostic methods, optimization of drug therapies, and monitoring of treatment responses. It also explores the expanding global market for genetic testing and the increasing implementation of whole-genome sequencing in clinical practice, with a focus on pilot programs that are advancing comprehensive genomic analysis. Despite challenges such as high costs, data interpretation complexities, and ethical concerns, significant efforts are being made to address these issues. Additionally, the creation of biobanks as vital resources for preserving high-quality biosamples and supporting research highlights the critical need for infrastructure development in genomics. By fostering interdisciplinary collaboration and establishing robust ethical and regulatory frameworks, personalized medicine can ensure equitable access to tailored therapies and enhance health outcomes for everyone. This abstract provides an overview of the transformative potential of genomics and personalized medicine in ushering in a new era of precision healthcare.

The genetics of hyper IgE syndromes

Hyper IgE syndromes (HIES) form a rare group of primary immunodeficiency disorders (PIDs) distinguished by persistent skin abscesses, dermatitis, allergies, and infections, in addition to their characteristic high serum IgE levels. Autosomal dominant (AD) and autosomal recessive (AR) genetic defects have been reported in HIES. From a clinical perspective, AD-HIES cases generally exhibit several non-immunologic features, including connective tissue, dental and skeletal abnormalities, whilst AR-HIES conditions have a higher incidence of neurologic complications and cutaneous viral infections. Genetic defects associated with HIES lead to impaired immune signaling, affecting pathways crucial for immune cell development, function, and immune response to pathogens/allergens. As a result, HIES patients are predisposed to recurrent bacterial and/or fungal infections, as well as atopic allergic responses. In many cases, the exact biological mechanisms responsible for the variations observed in the clinical phenotypes between the two inherited forms of HIES are still unclear. In this review, we describe the genetic basis of HIES with a distinction between the AR-HIES and AD-HIES forms, to better comprehend the different underlying molecular mechanisms, a distinction which is imperative for the accurate diagnosis, management, and development of targeted therapies for HIES patients.

Immunohistochemistry Analysis in Inflammatory Bowel Disease-Should We Bring to Light Interleukin-10?

Background/Objectives: Inflammatory bowel diseases (IBDs) are chronic intestinal disorders with an unpredictable course. In parallel with the advent of new biologic therapies targeting specific interleukin pathways, end-point targets have become more stringent, aiming for mucosal and even histologic healing. Methods: We conducted a prospective study assessing immunohistochemical (IHC) parameters in 46 IBD patients treated with biologic therapy. A similar IHC analysis was performed for comparison with a cohort of 10 "non-IBD" patients. Results: The highest integrated optical density (IOD) of TNF-α was observed in patients with dysplasia, abscesses, mucin depletion and basal plasmacytosis. Non-responders had higher pre- and post-treatment TNF-α expression in both UC and CD compared to responders. On the contrary, the same analysis conducted in the subpopulation treated with anti-TNF-α therapy (Infliximab and Adalimumab) did not reveal a substantial difference in TNF-α expression between responders and non-responders. High pre-treatment interleukin-10 expression was associated with biologic therapy failure, histological inflammatory activity and longer disease duration. Conclusions: Pre-treatment assessment of IL-10 might be a useful tool for identifying a high-risk subset of IBD patients and determining a more aggressive therapy and intensive monitoring strategy.

Risk factors for stoma and incision complications of enterostomy in children with very early-onset inflammatory bowel disease: a prospective cohort study

Enterostomy is utilized to mitigate severe clinical symptoms in children with very early-onset inflammatory bowel disease (VEO-IBD) and to provide a window for stem cell transplantation. Nevertheless, the incidence of postoperative complications is significant, and there is currently a lack of research exploring the risk factors associated with complications related to the stoma and incision following the procedure. The objective of this study is to investigate the risk factors for stoma and incision complications after enterostomy in patients with VEO-IBD. From January 2015 to December 2023, 49 children with VEO-IBD who underwent enterostomy were enrolled in the study. Demographic characteristics, blood biochemical indices, weighted Pediatric Crohn's Disease Activity Index (wPCDAI), and enterostomy-related information were prospectively collected. Multivariate logistic regression was employed to identify the risk factors for ostomy and incision-related complications. All 49 included VEO-IBD children had interleukin-10 (IL-10) signaling defects, with 27 (55.1%) having stomal-related complications and 10 (20.4%) had incision complications after enterostomy. Univariate analysis revealed that wPCDAI (OR, 1.03; 95% CI, 1.00-1.07; P = 0.05) showed a tendency towards statistical significance in the occurrence of ostomy complications. Weight-for-age Z-score (WAZ) (OR, 0.57; 95% CI, 0.39-0.84; P = 0.004), height-for-age Z-score (HAZ) (OR, 0.57; 95% CI, 0.37-0.88; P = 0.01), type of surgery (OR, 0.12; 95% CI, 0.03-0.56, P = 0.007), C-reactive protein (CRP) (OR, 1.02; 95% CI, 1.01-1.04; P = 0.007), and wPCDAI (OR, 1.08; 95% CI, 1.01-1.14; P = 0.009) demonstrated statistical significance in the occurrence of incision complications. However, multivariate binary logistic regression did not reveal any statistically significant factors.

CONCLUSION

Although emergency surgery is unavoidable, our study suggests that improving nutritional status, reducing CRP levels, and increasing preoperative wPCDAI scores may help reduce post-enterostomy stoma and incision complications in VEO-IBD children with interleukin-10 (IL-10) signaling defects. Further large-scale studies are needed to confirm these findings.

WHAT IS KNOWN

• Enterostomy is commonly used to manage severe symptoms in children with VEO-IBD and to provide a window for stem cell transplantation. • The incidence of postoperative complications, including stoma and incision-related issues, is significant in these patients.

WHAT IS NEW

• This study identifies potential risk factors for stoma and incision complications following enterostomy in children with VEO-IBD, particularly those with IL-10 signaling defects. • Factors such as nutritional status (WAZ and HAZ), CRP levels, type of surgery, and the wPCDAI were found to be associated with stoma and incision complications in univariate analysis, although multivariate analysis did not show statistical significance for these factors.

Unveiling and validating biomarkers related to the IL-10 family in chronic sinusitis with nasal polyps: insights from transcriptomics and single-cell RNA sequencing analysis

Introduction

Extensive efforts have been made to explore members of the IL-10 family as potential therapeutic strategies for various diseases; however, their biological role in chronic rhinosinusitis with nasal polyps (CRSwNP) remains underexplored.

Methods

Gene expression datasets GSE136825, GSE179265, and GSE196169 were retrieved from the Gene Expression Omnibus (GEO) for analysis. Candidate genes were identified by intersecting differentially expressed genes (DEGs) between the CRSwNP and control groups (DEGsall) with those between the high- and low-score groups within the CRSwNP cohort (DEGsNP). Biomarker selection was performed using the Least Absolute Shrinkage and Selection Operator (LASSO), Support Vector Machine Recursive Feature Elimination (SVM-RFE), and the Boruta algorithm. Further refinement of biomarkers was carried out using receiver operating characteristic (ROC) analysis, with genes demonstrating an area under the curve (AUC) greater than 0.7 being considered significant. Genes exhibiting consistent expression trends and significant differences across both GSE136825 and GSE179265 were selected as potential biomarkers. Cell-type annotation was performed on GSE196169, and the expression profiles of the biomarkers across various cell types were analyzed. A competing endogenous RNA (ceRNA) network and a biomarker-drug interaction network were also established. Additionally, the mRNALocater database was utilized to determine the cellular localization of the identified biomarkers.

Results

The intersection of 1817 DEGsall and 24 DEGsNP yielded 15 candidate genes. Further filtering through LASSO, SVM-RFE, and Boruta led to the identification of seven candidate biomarkers: PRB3, KRT16, MUC6, SPAG4, FGFBP1, NR4A1, and GSTA2. Six of these genes demonstrated strong diagnostic performance in GSE179265, while four biomarkers, showing both significant differences and consistent expression trends, were validated in both GSE179265 and GSE136825. Single-cell sequencing analysis of GSE196169 revealed seven distinct cell types, including endothelial cells, with the biomarkers predominantly expressed in epithelial cells. The ceRNA network comprised nine nodes and eleven edges, with only FGFBP1 exhibiting a complete lncRNA-miRNA-mRNA interaction.

Discussion

This study identifies several novel biomarkers and their associated drugs for CRSwNP therapy, as well as potential therapeutic targets, such as spiperone and arnenous acid, identified through molecular docking. Ultimately, this work underscores the identification of four IL-10 family-related biomarkers, providing a theoretical foundation for future clinical research in CRSwNP.

Translational characterization of immune pathways in inflammatory bowel disease: insights for targeted treatments

INTRODUCTION

The pathogenesis of inflammatory bowel disease (IBD) involves the dysregulation of multiple inflammatory pathways. The understanding of these mechanisms allows their selective targeting for therapeutic purposes. The discovery of Tumor Necrosis Factor-alpha's (TNF-α) role in mucosal inflammation ushered an exciting new era of drug development which now comprises agents targeting multiple pro-inflammatory signaling pathways, integrins, and leukocyte trafficking regulators.

AREA COVERED

This review provides an overview of the main molecular players of IBD, their translation into therapeutic targets and the successful development of the advanced agents modulating them. We combine basic science with clinical trials data to present a critical review of both the successful and failed drug development programs. A PubMed literature search was conducted to delve into the available literature and clinical trials.

EXPERT OPINION

The treatment landscape for IBD has rapidly expanded, particularly with the development of biologics targeting TNF-α, integrins, and S1P modulators, as well as newer agents such as IL-12/IL-23 inhibitors and JAK inhibitors, offering robust efficacy and safety profiles. However, challenges persist in understanding and effectively treating difficult-to-treat IBD, highlighting the need for continued research to uncover novel therapeutic targets and optimize patient outcomes.

Matched Unrelated Donor Hematopoietic Stem Cell Transplant as Successful Curative Therapy for IL10RB Mutation-Associated Very Early Onset IBD

BACKGROUND

Inflammatory bowel diseases are complex chronic disorders with a relapsing-remitting course that affect the gut due to dysregulated immune response. The incidence of these disorders is increasing globally along with an increase in the incidence in pediatric population. Very early onset inflammatory bowel diseases are seen in children with age less than 6 years, where monogenic causes predominate. With the advent of next-generation sequencing methods, these disorders are being diagnosed more. Interleukin-10 receptor mutation-associated inflammatory bowel diseases is one such monogenic disorder where immunosuppression shows poor response.

METHODS

We report the case of an 8-month-old child of Indian origin who presented with severe enterocolitis and rectovaginal fistulas. She was evaluated on lines of a very early onset inflammatory bowel disease. She was found to have a mutation in the interleukin-10 receptor causing severe enterocolitis. She underwent a diversion colostomy. She was admitted at 25 months of age for the hematopoietic-stem-cell-transplant (HSCT). The conditioning regimen used consisted of busulfan, fludarabine, and anti-thymocyte-globulin (ATG). The child received a 10/10 human leukocyte antigen (HLA) matched from a matched-unrelated adult female donor with bone marrow stem cell product at a dose of 5.6 million CD34+ cells per kg.

RESULTS

She was treated successfully by a matched unrelated donor HSCT. At present, she is 2 years and 4 months posttransplant and is cured.

CONCLUSIONS

Early recognition and prompt genetic testing can help in diagnosing and establishing the cause of a very early onset inflammatory bowel disease. Very early onset inflammatory bowel disease caused due to interleukin-10 receptor mutations can be cured by HSCT.

Considerations in Paediatric and Adolescent Inflammatory Bowel Disease

The incidence of inflammatory bowel disease [IBD] is rising most rapidly among children and adolescents. Paediatric-onset IBD is associated with a more extensive and severe disease course compared to adult-onset IBD. At a young age, screening for underlying genetic and immunological disorders is important and may impact treatment management. Early and effective treatment is crucial to reach disease remission and prevent complications of ongoing active disease. In children with Crohn's disease, exclusive enteral nutrition is an effective induction therapy. Other promising dietary therapies, such as the Crohn's disease exclusion diet, are emerging. Within paediatric IBD, anti-tumour necrosis factor therapy is the only approved biological thus far and additional treatment options are crucially needed. Other biological therapies, such as vedolizumab and ustekinumab, are currently prescribed off-label in this population. A specific challenge in paediatric IBD is the unacceptable and major delay in approval of drugs for children with IBD. A guided transfer period of paediatric patients to adult care is associated with improved disease outcomes and is required. Major knowledge gaps and challenges within paediatric IBD include the aetiology, diagnostics, and monitoring of disease, tailoring of treatment, and both understanding and coping with the physical and psychological consequences of living with IBD. Challenges and research gaps in paediatrics should be addressed without any delay in comparison with the adult field, in order to ensure a high quality of care for all patients with IBD, irrespective of the age of onset.

Successful Allogeneic Hematopoietic Cell Transplantation for Patients with IL10RA Deficiency in Japan

BACKGROUND

IL10RA (IL10 receptor subunit alpha) deficiency is an autosomal recessive disease that causes inflammatory bowel disease during early infancy. Its clinical course is often fatal and the only curative treatment is allogeneic hematopoietic cell transplantation (HCT). In Japan, only case reports are available, and there are no comprehensive reports of treatment outcomes.

METHODS

We retrospectively analyzed patients with IL10RA deficiency in Japan.

RESULTS

Two newly identified and five previously reported patients were included in this study. Five patients underwent HCT; one untransplanted patient survived to age 14, and one died of influenza encephalopathy before transplantation. All five HCT recipients underwent HCT at the age before 2 years. They all were conditioned with fludarabine/busulfan- or fludarabine /melphalan-based regimens. The donor source was human leukocyte antigen haploidentical donor bone marrow (BM) for two patients and unrelated umbilical cord blood (CB) for two patients. One patient experienced graft failure with unrelated CB and required a second transplant with unrelated BM. All patients who underwent HCT survived and demonstrated an improved performance status.

CONCLUSION

In cases of IL10RA deficiency, the need for transplantation should be promptly assessed, and early transplantation should be considered. (190/250).

Gastrointestinal system involvement in patients with primary immunodeficiency: a single center experience

AIM

Primary immunodeficiencies (PIDs) are a heterogeneous disorder group characterized by an impaired immune system, leading to an increased susceptibility to infections and a wide range of clinical manifestations, including gastrointestinal (GI) complications. This study aimed to assess the GI manifestations of PID patients and highlight the significance of atypical gastrointestinal symptoms in the early diagnosis of these patients.

METHODS

A retrospective analysis was conducted on pediatric patients diagnosed with PIDs at Selcuk University Medical Faculty from 2011 to 2021. The study focused on demographic data, clinical presentation, genetic mutations, and GI manifestations, including endoscopic evaluation. Patients were categorized according to the International Union of Immunological Societies (IUIS) PID classifications. Statistical analyses were performed to identify significant associations between PID types and GI manifestations.

RESULTS

The cohort comprised 101 patients, with 46% presenting with GI symptoms, including malnutrition and chronic diarrhea, as the most common findings. Primary antibody deficiency (PAD) emerged as the most prevalent PID with GI involvement, followed by combined immunodeficiencies (CID) with associated or syndromic features. Endoscopic evaluations revealed inflammatory bowel disease (IBD)-like colitis in a significant subgroup of patients. The analysis showed that some GI symptoms were more common in specific PID categories, highlighting the importance of early gastroenterological assessment in PID patients.

CONCLUSION

Recognition of common GI symptoms in pediatric patients with PIDs may facilitate early diagnosis and prompt multidisciplinary management, potentially improving patient outcomes. The study highlights the necessity of considering PIDs in diagnosing persistent or severe GI symptoms in children.

Early Onset Inflammatory Bowel Disease Due to Immunodeficiency as a Result of ICOS Gene Homozygous Mutation

INTRODUCTION

Inflammatory bowel disease (IBD) is classified as very early-onset IBD (VEO-IBD) if it occurs before age six. VEO-IBD may progress with more severe and resistant inflammation findings in the gastrointestinal and non-gastrointestinal systems.

CASE REPORT

We describe the clinical presentation of a 4-year-old female presenting with recurring episodes of bloody diarrhea, vomiting, abdominal pain, fever, arthritis, erysipelas, and bilateral ankle pain. Monogenic primary immunodeficiency (PID) was suspected due to her age, different clinical findings and the presence of atypical gastroscopic findings and deep transmural ulcerations resembling Crohn's disease. The gene analysis showed a homozygous mutation in the inducible T cell co-stimulator (ICOS) deficiency genes.

DISCUSSION/CONCLUSION

This case presentation shares our clinical experience and demonstrates the link between IBD progression and ICOS deficiency.

Neutralizing Autoantibodies against Interleukin-10 in Inflammatory Bowel Disease

We discovered high-titer neutralizing autoantibodies against interleukin-10 in a child with infantile-onset inflammatory bowel disease (IBD), a phenocopy of inborn errors of interleukin-10 signaling. After B-cell-depletion therapy and an associated decrease in the anti-interleukin-10 titer, conventional IBD therapy could be withdrawn. A second child with neutralizing anti-interleukin-10 autoantibodies had a milder course of IBD and has been treated without B-cell depletion. We conclude that neutralizing anti-interleukin-10 autoantibodies may be a causative or modifying factor in IBD, with potential implications for therapy. (Funded by the National Institute for Health and Care Research and others.).

The landscape of rare genetic variation associated with inflammatory bowel disease and Parkinson's disease comorbidity

BACKGROUND

Inflammatory bowel disease (IBD) and Parkinson's disease (PD) are chronic disorders that have been suggested to share common pathophysiological processes. LRRK2 has been implicated as playing a role in both diseases. Exploring the genetic basis of the IBD-PD comorbidity through studying high-impact rare genetic variants can facilitate the identification of the novel shared genetic factors underlying this comorbidity.

METHODS

We analyzed whole exomes from the BioMe BioBank and UK Biobank, and whole genomes from a cohort of 67 European patients diagnosed with both IBD and PD to examine the effects of LRRK2 missense variants on IBD, PD and their co-occurrence (IBD-PD). We performed optimized sequence kernel association test (SKAT-O) and network-based heterogeneity clustering (NHC) analyses using high-impact rare variants in the IBD-PD cohort to identify novel candidate genes, which we further prioritized by biological relatedness approaches. We conducted phenome-wide association studies (PheWAS) employing BioMe BioBank and UK Biobank whole exomes to estimate the genetic relevance of the 14 prioritized genes to IBD-PD.

RESULTS

The analysis of LRRK2 missense variants revealed significant associations of the G2019S and N2081D variants with IBD-PD in addition to several other variants as potential contributors to increased or decreased IBD-PD risk. SKAT-O identified two significant genes, LRRK2 and IL10RA, and NHC identified 6 significant gene clusters that are biologically relevant to IBD-PD. We observed prominent overlaps between the enriched pathways in the known IBD, PD, and candidate IBD-PD gene sets. Additionally, we detected significantly enriched pathways unique to the IBD-PD, including MAPK signaling, LPS/IL-1 mediated inhibition of RXR function, and NAD signaling. Fourteen final candidate IBD-PD genes were prioritized by biological relatedness methods. The biological importance scores estimated by protein-protein interaction networks and pathway and ontology enrichment analyses indicated the involvement of genes related to immunity, inflammation, and autophagy in IBD-PD. Additionally, PheWAS provided support for the associations of candidate genes with IBD and PD.

CONCLUSIONS

Our study confirms and uncovers new LRRK2 associations in IBD-PD. The identification of novel inflammation and autophagy-related genes supports and expands previous findings related to IBD-PD pathogenesis, and underscores the significance of therapeutic interventions for reducing systemic inflammation.

Clinical and cellular phenotypes resulting from a founder mutation in IL10RB

Inborn errors of immunity are a group of rare genetically determined diseases that impair immune system development or function. Many of these diseases include immune dysregulation, autoimmunity, or autoinflammation as prominent clinical features. In some children diagnosed with very early onset inflammatory bowel disease (VEOIBD), monogenic inborn errors of immune dysregulation underlie disease. We report a case of VEOIBD caused by a novel homozygous loss of function mutation in IL10RB. We use cytometry by time-of-flight with a broad panel of antibodies to interrogate the immunophenotype of this patient and detect reduced frequencies of CD4 and CD8 T cells with additional defects in some populations of T helper cells, innate-like T cells, and memory B cells. Finally, we identify the patient's mutation as a founder allele in an isolated indigenous population and estimate the age of this variant by studying the shared ancestral haplotype.

The trajectory of human B-cell function, immune deficiency, and allergy revealed by inborn errors of immunity

The essential role of B cells is to produce protective immunoglobulins (Ig) that recognize, neutralize, and clear invading pathogens. This results from the integration of signals provided by pathogens or vaccines and the stimulatory microenvironment within sites of immune activation, such as secondary lymphoid tissues, that drive mature B cells to differentiate into memory B cells and antibody (Ab)-secreting plasma cells. In this context, B cells undergo several molecular events including Ig class switching and somatic hypermutation that results in the production of high-affinity Ag-specific Abs of different classes, enabling effective pathogen neutralization and long-lived humoral immunity. However, perturbations to these key signaling pathways underpin immune dyscrasias including immune deficiency and autoimmunity or allergy. Inborn errors of immunity that disrupt critical immune pathways have identified non-redundant requirements for eliciting and maintaining humoral immune memory but concomitantly prevent immune dysregulation. Here, we will discuss our studies on human B cells, and how our investigation of cytokine signaling in B cells have identified fundamental requirements for memory B-cell formation, Ab production as well as regulating Ig class switching in the context of protective versus allergic immune responses.

Understanding very early onset inflammatory bowel disease (VEOIBD) in relation to inborn errors of immunity

Inflammatory bowel diseases (IBD) are multifactorial diseases which are caused by the combination of genetic predisposition, exposure factors (environmental and dietary), immune status, and dysbiosis. IBD is a disease which presents at any age, ranging from newborns to the elderly. The youngest of the pediatric IBD population have a more unique presentation and clinical course and may have a different etiology. Very early onset IBD (VEOIBD) patients, designated as those diagnosed prior the age of 6, have distinct features which are more frequent in this patient population including increased incidence of monogenetic causes for IBD (0%-33% depending on the study). This proportion is increased in the youngest subsets, which is diagnosed prior to the age of 2. To date, there are approximately 80 monogenic causes of VEOIBD that have been identified and published. Many of these monogenic causes are inborn errors of immunity yet the majority of VEOIBD patients do not have an identifiable genetic cause for their disease. In this review, we will focus on the clinical presentation, evaluation, and monogenic categories which have been associated with VEOIBD including (1) Epithelial cell defects (2) Adaptive immune defects, (3) Innate Immune/Bacterial Clearance and Recognition defects, and (4) Hyperinflammatory and autoinflammatory disorders. We will highlight differential diagnosis of VEOIBD presentations, as well as evaluation and treatment, which will be helpful for those who study and care for VEOIBD patients outside of the pediatric gastroenterology field. This is a fast-moving field of research which has grown significantly based on knowledge that we gain from our patients. These scientific findings have identified novel mucosal biology pathways and will continue to inform our understanding of gastrointestinal biology.

Identification of a Novel NLRP12 Frameshift Mutation (Val730Glyfs∗41) by Whole-Exome Sequencing in Patients with Crohn’s Disease

NLRP12 encodes the nucleotide-binding leucine-rich repeat-containing receptor 12 protein and has been linked to familial cold autoinflammatory syndrome 2 (FCAS2). Previous studies have reported that NLRP12 protein can dampen inflammatory responses in DSS-induced mice colitis. To date, only four alterations in the NLRP12 gene have been associated with Crohn’s disease (CD). Here, we reported a novel heterozygous NLRP12 frameshift mutation (c.2188dupG, p.Val730Glyfs${}^{\ast }$41) identified by whole-exome sequencing in the proband with CD. The Sanger sequencing confirmed that his sister and father also carried this NLRP12 mutation, which cosegregated well with the CD phenotype. In silico analysis predicted this mutation to be disease-causing. Patients heterozygous for this mutation exhibited decreased NLRP12 protein levels in the peripheral blood and colon. Functional assays showed that mutant NLRP12 plasmid-transfected HEK293T cells exhibited significantly lower NLRP12 mRNA and protein levels than wild-type plasmid-transfected cells. The nonsense-mediated decay inhibitor NMDI14 significantly increased NLRP12 mRNA and protein levels in mutant plasmid-transfected cells. Overall, our results demonstrated that this heterozygous NLRP12 mutation (c.2188dupG) resulted in decreased NLRP12 expression, which might contribute to the mechanism underlying CD.

Cord Blood Transplantation for Very Early-Onset Inflammatory Bowel Disease Caused by Interleukin-10 Receptor Deficiency

PURPOSE

Interleukin-10 receptor (IL-10R) deficiency can result in life-threatening very early-onset inflammatory bowel disease (VEO-IBD). Umbilical cord blood transplantation (UCBT) is a curative therapy for patients with IL-10R deficiency. This study aimed to investigate the efficacy of UCBT in treating IL-10R deficiency and develop a predictive model based on pre-transplant factors.

METHODS

Eighty patients with IL-10R deficiency who underwent UCBT between July 2015 and April 2023 were retrospectively analyzed. Cox proportional hazards regression and random survival forest were used to develop a predictive model.

RESULTS

Median age at transplant was 13.0 months (interquartile range [IQR], 8.8-25.3 months). With a median follow-up time of 29.4 months (IQR, 3.2-57.1 months), the overall survival (OS) rate was 65.0% (95% confidence interval [CI], 55.3%-76.3%). The engraftment rate was 85% (95% CI, 77%-93%). The cumulative incidences of acute and chronic graft-versus-host disease were 48.2% (95% CI, 37.1%-59.4%) and 12.2% (95% CI, 4.7%-19.8%), respectively. VEO-IBD-associated clinical symptoms were resolved in all survivors. The multivariate analysis showed that IL-6 and stool occult blood were independent prognostic risk factors. The multivariate Cox proportional hazards regression model with stool occult blood, length- or height-for-age Z-score, medical history of sepsis, and cord blood total nucleated cells showed good discrimination ability, with a bootstrap concordance index of 0.767-0.775 in predicting OS.

CONCLUSION

Better inflammation control before transplantation and higher cord blood total nucleated cell levels can improve patient prognosis. The nomogram can successfully predict OS in patients with IL-10R deficiency undergoing UCBT.

Berberine alleviates inflammation and suppresses PLA2-COX-2-PGE2-EP2 pathway through targeting gut microbiota in DSS-induced ulcerative colitis

Berberine, isolated from Coptis chinensis and Phellodendron amurense, can attenuate colonic injury and modulate gut microbiota disorders in ulcerative colitis (UC). However, the mechanism and causal relationship between gut microbiota and the efficacy of Berberine on UC are still unclear, which were investigated by pseudo-germ-free (PGF) mice, 16S rRNA gene analysis and transcriptome analysis in this study. The results demonstrated that Berberine improved gut microbiota disorders, colon damage, tight-junction proteins, inflammatory and anti-inflammatory cytokines in DSS-induced colitis mice with intact gut microbiota but not in PGF mice. Besides, immune-related and inflammation-related pathways were closely related to the efficacy that Berberine alleviated colitis by regulating gut microbiota. Furthermore, Berberine reduced PGE2, PLA2, COX-2, Ptges, EP2 and p-Stat3 only in colitis mice with intact gut microbiota. In summary, our study confirms that Berberine inhibits PLA2-COX-2-PGE2-EP2 pathway in UC through gut microbiota, leading to the alleviation of inflammation in colon, which further elucidates the underlying mechanism and promotes the application of Berberine in UC.

A novel biallelic 19-bp deletion in the IL10RB gene caused infant-onset inflammatory bowel disease in a consanguineous family: a molecular docking simulation study and literature review

BACKGROUND

Infantile-onset inflammatory bowel disease (IOIBD) is a gastrointestinal inflammatory condition often associated with monogenic disorders and is frequently caused by Interleukin-10 deficiencies. This study aimed to identify the mutation responsible for IBD in an 8-year-old patient from an Iranian family with consanguineous parents.

METHODS

Whole-exome sequencing (WES) was employed to identify disease-causing variations. Furthermore, we utilized integrated experimental data of HADDOCK molecular docking platform, including NMR spectroscopy, to characterize the mutant protein and elucidate the underlying functional mechanism of the identified mutation's pathogenicity.

RESULTS

Our findings revealed a novel 19-bp deletion mutation (c.25_43del, p.Leu9CysfsTer15) in the IL10RB gene. Sanger sequencing confirmed that this variant was inherited in homozygous state within this family, marking the first mutation identified in exon 1 of this gene. Molecular docking simulation demonstrated that the mutant form of IL10RB exhibited reduced affinity for binding to the Interleukin-10 ligand, leading to disruptions in downstream cellular signaling pathways.

CONCLUSIONS

The identification of this novel genetic variant as a causative factor for IOIBD highlights the clinical value of utilizing genetic testing, such as WES, as a reliable diagnostic approach for patients affected by this condition.

Long-term outcomes after enterostomy for very early-onset inflammatory bowel disease with interleukin-10 signaling deficiency

BACKGROUND

Very early-onset inflammatory bowel disease (VEOIBD) with interleukin-10 (IL10R) signaling deficiency usually requires enterostomy in patients who are refractory to traditional treatment. This study aimed to evaluate long-term outcomes after enterostomy for VEOIBD patients with IL10R signaling deficiency.

METHODS

The medical records of all patients undergoing enterostomy for signaling deficiency were retrospectively assessed during 2012.1-2022.7 in a tertiary teaching hospital, Children's Hospital of Fudan University, Shanghai, China. Data on disease history, diagnosis and details of enterostomy and stoma closure and follow-up were collected. Univariate and multivariate logistic regression analyses were used to evaluate the risk factors associated with the long-term outcome of delayed stoma closure.

RESULTS

A total of 46 patients underwent an enterostomy, 19 who required emergency enterostomy and 27 with selective enterostomy. After ten years of follow-up, 35 patients underwent hematopoietic stem cell transplantation (HSCT), and 25 patients were alive after HSCT. The median timeframe between HSCT and stoma closure was 19.6 [15.9,26.2] months. Nineteen patients underwent stoma closure and had an average age of 3.9 ± 1.5 years; 6 patients were waiting for stoma closure. Based on a univariate logistic model, risk factors significantly associated with late stoma closure were age at enterostomy and age at HSCT. However, multivariate logistic regression showed no statistically significant factor associated with late stoma closure. There was no significant difference between the stoma closure group and delay closure group in the z scores of weight for age at follow up.

CONCLUSIONS

This study determined the long-term outcomes after enterostomy for VEOIBD with interleukin-10 signaling deficiency. The appropriate time point of enterostomy and HSCT may improve quality of life in the long term.

Evaluation of oxidative stress in an experimental model of Crohn's disease treated with hyperbaric oxygen therapy

INTRODUCTION

Treatments of Inflammatory Bowel Disease (IBD) are able to control symptoms in most cases, however, a fraction of patients do not improve or have a loss of response to treatments, making it important to explore new therapeutic strategies. Hyperbaric oxygen therapy (HBO) may represent one of them. The aim of this study was to evaluate the effects of HBO therapy in an experimental model of IBD.

METHODS

Sixty male BALBc mice were divided into six groups. Group 1 was colitis-induced with trinitrobenzene sulfonic acid (TNBS) + ethanol, group 2 received TNBS + ethanol plus HBO, group 3 received only ethanol, group 4 received ethanol plus HBO, group 5 received saline solution, and group 6 received saline solution plus HBO. HBO was performed for four days, subsequently, the mice were evaluated daily. At the end of the study, samples from the intestine were collected for histological analysis as well as for measurement of antioxidant enzymes and cytokine levels.

RESULTS

HBO significantly improved the clinical and histological status of the animals. Treatment with HBO increased the activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in all of the groups; moreover, the difference was only significant between the TNBS and TNBS + HBO groups and treatments promoted a reduction in the proinflammatory cytokines IFN-γ, IL-12, IL-17 and TNF-α and increased the anti-inflammatory cytokines IL-4 and IL-10, with no changes in IL-13.

CONCLUSION

HBO effectively treats TNBS-induced colitis by increasing the activity of antioxidant enzymes and modulating cytokine profiles.

Deletion of Endogenous Neuregulin-4 Limits Adaptive Immunity During Interleukin-10 Receptor-Neutralizing Colitis

BACKGROUND

Growth factors are essential for maintenance of intestinal health. We previously showed that exogenous neuregulin-4 (NRG4) promotes colonocyte survival during cytokine challenge and is protective against acute models of intestinal inflammation. However, the function(s) of endogenous NRG4 are not well understood. Using NRG4-/- mice, we tested the role of endogenous NRG4 in models of colitis skewed toward either adaptive (interleukin-10 receptor [IL-10R] neutralization) or innate (dextran sulfate sodium [DSS]) immune responses.

METHODS

NRG4-/- and wild-type cage mate mice were subjected to chronic IL-10R neutralization colitis and acute DSS colitis. Disease was assessed by histological examination, inflammatory cytokine levels, fecal lipocalin-2 levels, and single cell mass cytometry immune cell profiling. Homeostatic gene alterations were evaluated by RNA sequencing analysis from colonic homogenates, with real-time quantitative polymerase chain reaction confirmation in both tissue and isolated epithelium.

RESULTS

During IL-10R neutralization colitis, NRG4-/- mice had reduced colonic inflammatory cytokine expression, histological damage, and colonic CD8+ T cell numbers vs wild-type cage mates. Conversely, in DSS colitis, NRG4-/- mice had elevated cytokine expression, fecal lipocalin-2 levels, and impaired weight recovery. RNA sequencing showed a loss of St3gal4, a sialyltransferase involved in immune cell trafficking, in NRG4-null colons, which was verified in both tissue and isolated epithelium. The regulation of St3gal4 by NRG4 was confirmed with ex vivo epithelial colon organoid cultures from NRG4-/- mice and by induction of St3gal4 in vivo following NRG4 treatment.

CONCLUSIONS

NRG4 regulates colonic epithelial ST3GAL4 and thus may allow for robust recruitment of CD8+ T cells during adaptive immune responses in colitis. On the other hand, NRG4 loss exacerbates injury driven by innate immune responses.

Development of functional resident macrophages in human pluripotent stem cell-derived colonic organoids and human fetal colon

Most organs have tissue-resident immune cells. Human organoids lack these immune cells, which limits their utility in modeling many normal and disease processes. Here, we describe that pluripotent stem cell-derived human colonic organoids (HCOs) co-develop a diverse population of immune cells, including hemogenic endothelium (HE)-like cells and erythromyeloid progenitors that undergo stereotypical steps in differentiation, resulting in the generation of functional macrophages. HCO macrophages acquired a transcriptional signature resembling human fetal small and large intestine tissue-resident macrophages. HCO macrophages modulate cytokine secretion in response to pro- and anti-inflammatory signals and were able to phagocytose and mount a robust response to pathogenic bacteria. When transplanted into mice, HCO macrophages were maintained within the colonic organoid tissue, established a close association with the colonic epithelium, and were not displaced by the host bone-marrow-derived macrophages. These studies suggest that HE in HCOs gives rise to multipotent hematopoietic progenitors and functional tissue-resident macrophages.

Genetic Defects in Early-Onset Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) represents a spectrum of disease, which is characterized by chronic gastrointestinal inflammation. Monogenic mutations driving IBD pathogenesis are more highly represented in early-onset compared to adult-onset disease. The pathogenic genes which dysregulate host immune responses in monogenic IBD affect both the innate (ie, intestinal barrier, phagocytes) and adaptive immune systems (ie, T cells, B cells). Advanced genomic and targeted functional testing can improve clinical decision making and present increased opportunities for precision medicine approaches in this important patient population.

Too much of a good thing: a review of primary immune regulatory disorders

Primary immune regulatory disorders (PIRDs) are inborn errors of immunity caused by a loss in the regulatory mechanism of the inflammatory or immune response, leading to impaired immunological tolerance or an exuberant inflammatory response to various stimuli due to loss or gain of function mutations. Whilst PIRDs may feature susceptibility to recurrent, severe, or opportunistic infection in their phenotype, this group of syndromes has broadened the spectrum of disease caused by defects in immunity-related genes to include autoimmunity, autoinflammation, lymphoproliferation, malignancy, and allergy; increasing focus on PIRDs has thus redefined the classical 'primary immunodeficiency' as one aspect of an overarching group of inborn errors of immunity. The growing number of genetic defects associated with PIRDs has expanded our understanding of immune tolerance mechanisms and prompted identification of molecular targets for therapy. However, PIRDs remain difficult to recognize due to incomplete penetrance of their diverse phenotype, which may cross organ systems and present to multiple clinical specialists prior to review by an immunologist. Control of immune dysregulation with immunosuppressive therapies must be balanced against the enhanced infective risk posed by the underlying defect and accumulated end-organ damage, posing a challenge to clinicians. Whilst allogeneic hematopoietic stem cell transplantation may correct the underlying immune defect, identification of appropriate patients and timing of transplant is difficult. The relatively recent description of many PIRDs and rarity of individual genetic entities that comprise this group means data on natural history, clinical progression, and treatment are limited, and so international collaboration will be needed to better delineate phenotypes and the impact of existing and potential therapies. This review explores pathophysiology, clinical features, current therapeutic strategies for PIRDs including cellular platforms, and future directions for research.

Interleukin-10 in cancer immunotherapy: from bench to bedside

Interleukin (IL)-10 was one of the first cytokines to be recognized. However, its functionality in promoting antitumor immunity was described more recently. Context- and concentration-dependent biological effects are the hallmarks of the pleiotropic role of IL-10. Despite reducing tumor-promoting inflammation, IL-10 may have a role in rejuvenating exhausted tumor-resident T cells. Contrary to the assumption that IL-10 produces an immunosuppressive tumor microenvironment (TME), it promotes activation of tumor-resident CD8+ T cells, which aids tumor rejection. Emerging data from published early-Phase trials have shown mixed results in different tumor types. In this review, we summarize the biological effects of IL-10 and highlight the clinical experience using pegilodecakin.

Under the influence: environmental factors as modulators of neuroinflammation through the IL-10/IL-10R axis

The IL-10/IL-10 receptor (IL-10R) axis plays an important role in attenuating neuroinflammation in animal models of Multiple Sclerosis (MS) and increased IL-10 has been associated with a positive response to MS disease modifying therapy. Because environmental factors play an important role in MS susceptibility and disease course, identification of environmental factors that impact the IL-10/IL-10R axis has therapeutic potential. In this review, we provide historical and updated perspectives of how IL-10R signaling impacts neuroinflammation, discuss environmental factors and intestinal microbes with known impacts on the IL-10/IL-10R axis, and provide a hypothetical model for how B cells, via their production of IL-10, may be important in conveying environmental "information" to the inflamed central nervous system.

Multiomics Strategy Reveals the Mechanism of Action and Ameliorating Effect of Deer Velvet Antler Water Extracts on DSS-Induced Colitis

Velvet antler is a precious traditional Chinese medicine used for thousands of years. This study investigated the anti-colitis effects of water extracts of Formosan sambar deer (SVAE) and red deer (RVAE) to identify the possible mechanisms and the bioactive compounds using a dextran sulfate sodium (DSS)-induced colitis mouse model. The mechanism of action and the ameliorating effects of SVAE and RVAE on DSS-induced colitis were evaluated using a mouse model. Ultra-high performance liquid chromatography-mass/mass and gas chromatography-mass/mass were applied to identify the bioactive components of the SVAE and RVAE water extracts. The results revealed that both high-dose SVAE and RVAE could ameliorate the symptoms of colitis due to reduced systemic inflammatory responses, enhanced intestinal barrier integrity by restoration of tight junction proteins, and improved gut dysbiosis. The potentially bioactive components of SVAE and RVAE were identified as small molecules (<3 kDa). Further identification by untargeted metabolomics analysis suggested that l-carnitine, hypoxanthine, adrenic acid, creatinine, gamma-aminobutyric-lysine, oleic acid, glycine, poly-γ-glutamic acid, and eicosapentaenoic acid in VAWEs might be involved in ameliorating the symptoms of colitis. This study provided evidence for the potential usage of SVAE and RVAE as anti-colitis agents.

Human inherited complete STAT2 deficiency underlies inflammatory viral diseases

STAT2 is a transcription factor activated by type I and III IFNs. We report 23 patients with loss-of-function variants causing autosomal recessive (AR) complete STAT2 deficiency. Both cells transfected with mutant STAT2 alleles and the patients' cells displayed impaired expression of IFN-stimulated genes and impaired control of in vitro viral infections. Clinical manifestations from early childhood onward included severe adverse reaction to live attenuated viral vaccines (LAV) and severe viral infections, particularly critical influenza pneumonia, critical COVID-19 pneumonia, and herpes simplex virus type 1 (HSV-1) encephalitis. The patients displayed various types of hyperinflammation, often triggered by viral infection or after LAV administration, which probably attested to unresolved viral infection in the absence of STAT2-dependent types I and III IFN immunity. Transcriptomic analysis revealed that circulating monocytes, neutrophils, and CD8+ memory T cells contributed to this inflammation. Several patients died from viral infection or heart failure during a febrile illness with no identified etiology. Notably, the highest mortality occurred during early childhood. These findings show that AR complete STAT2 deficiency underlay severe viral diseases and substantially impacts survival.

Clinical Features and Genetic Analysis of Taiwanese Primary Immunodeficiency Patients with Prolonged Diarrhea and Monogenetic Inflammatory Bowel Disease

PURPOSE

Diarrhea lasting longer than 14 days which fails to respond to conventional management is defined as severe and protracted diarrhea and might overlap with inflammatory bowel disease (IBD).

METHODS

The prevalence, associated pathogens, and prognosis of severe and protracted diarrhea without IBD (SD) and with monogenetic IBD (mono-IBD) in primary immunodeficiency patients (PID) were investigated in Taiwan.

RESULTS

A total of 301 patients were enrolled between 2003 and 2022, with predominantly pediatric-onset PID. Of these, 24 PID patients developed the SD phenotype before prophylactic treatment, including Btk (six), IL2RG (four), WASP, CD40L, gp91 (three each), gp47, RAG1 (one each), CVID (two), and SCID (one) without identified mutations. The most detectable pathogens were pseudomonas and salmonella (six each), and all patients improved after approximately 2 weeks of antibiotic and/or IVIG treatments. Six (25.0%) mortalities without HSCT implementation were due to respiratory failure from interstitial pneumonia (3 SCID and 1 CGD), intracranial hemorrhage (WAS), and lymphoma (HIGM). In the mono-IBD group, seventeen patients with mutant TTC7A (2), FOXP3 (2), NEMO (2), XIAP (2), LRBA (1), TTC37 (3), IL10RA (1), STAT1 (1), ZAP70 (1), PIK3CD (1), and PIK3R1 (1) genes failed to respond to aggressive treatments. Nine mono-IBD patients with TTC7A (2), FOXP3 (2), NEMO (2), XIAP (2), and LRBA (1) mutations were fatal in the absence of HSCT. The mono-IBD group had a significantly earlier age of diarrhea onset (1.7 vs 33.3 months, p = 0.0056), a longer TPN duration (34.2 vs 7.0 months, p < 0.0001), a shorter follow-up period (41.6 vs 132.6 months, p = 0.007), and a higher mortality rate (58.9 vs 25.0%, p = 0.012) compared with the SD group.

CONCLUSION

When compared to those with the SD phenotype, the mono-IBD patients had significant early-onset and poor responses to empiric antibiotics, IVIG, and steroids. Anti-inflammatory biologics and suitable HSCT still have the potential to control or even cure the mono-IBD phenotype.

Stem Cell Therapy in Inflammatory Bowel Disease: A Review of Achievements and Challenges

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a group of chronic inflammatory diseases of the gastrointestinal tract. Repeated inflammation can lead to complications, such as intestinal fistula, obstruction, perforation, and bleeding. Unfortunately, achieving durable remission and mucosal healing (MH) with current treatments is difficult. Stem cells (SCs) have the potential to modulate immunity, suppress inflammation, and have anti-apoptotic and pro-angiogenic effects, making them an ideal therapeutic strategy to target chronic inflammation and intestinal damage in IBD. In recent years, hematopoietic stem cells (HSCs) and adult mesenchymal stem cells (MSCs) have shown efficacy in treating IBD. In addition, numerous clinical trials have evaluated the efficiency of MSCs in treating the disease. This review summarizes the current research progress on the safety and efficacy of SC-based therapy for IBD in both preclinical models and clinical trials. We discuss potential mechanisms of SC therapy, including tissue repair, paracrine effects, and the promotion of angiogenesis, immune regulation, and anti-inflammatory effects. We also summarize current SC engineering strategies aimed at enhancing the immunosuppressive and regenerative capabilities of SCs for treating intestinal diseases. Additionally, we highlight current limitations and future perspectives of SC-related therapy for IBD.

Hematopoietic stem cell Transplantation in Children with very Early Onset Inflammatory Bowel Disease Secondary to Monogenic Disorders of immune-dysregulation

Background: Very early-onset inflammatory bowel disease (VEOIBD) is defined as IBD in children under six years of age. We present outcome data of hematopoietic stem cell transplantation (HSCT) in the above children. Patients and methods: We performed a retrospective study in children under six years of age who underwent HSCT for VEOIBD with an identified monogenic disorder from December 2012 to December 2020. Results: Of the 25 children included, the underlying diagnosis was IL10R deficiency (n = 4), Wiskott-Aldrich syndrome (n = 4), Leukocyte adhesion defect (n = 4), Hyper IgM syndrome (n = 3), Chronic granulomatous disease (n = 2), and one each with XIAP deficiency, severe congenital neutropenia, Omenn syndrome, Hyper IgE syndrome, Griscelli syndrome, MHC Class II deficiency, LRBA deficiency, and IPEX syndrome. Donors included a matched family donor in 10(40%); a matched unrelated donor in 8 (32%), haploidentical in 7 (28%) (T depleted 16%, T replete with post-transplant cyclophosphamide12%). Conditioning was myeloablative in 84% ofHSCTs. We documented engraftment in 22 (88%) children, primary graft failure in 2 children (8%), mixed chimerism in 6 (24%) children with mortality in 4/6 children. Children with a sustained chimerism of > 95% did not have recurrence of any features of IBD. Overall survival was 64%, with a median follow-up of 55 months. Mixed chimerism was associated with a significantly increased risk of mortality (p-value = 0.001). Conclusions: VEOIBD caused by monogenic disorders can be offered HSCT. Early recognition, optimal supportive care, and complete chimerism are essential components to achieving survival.

Cytokine-mediated STAT-dependent pathways underpinning human B-cell differentiation and function

B cells are fundamental to host defence against infectious diseases; indeed, the ability of humans to elicit robust antibody responses following exposure to foreign antigens underpins long-lived humoral immunity and serological memory, as well as the success of most currently administered vaccines. However, B cells also have a dark side - they can cause myriad diseases, including autoimmunity, atopy, allergy and malignancy. Thus, it is critical to understand the molecular requirements for generating effective, high-affinity, specific immune responses following natural infection or vaccination, as well as for constraining B-cell function to mitigate B-cell-mediated immune dyscrasias. In this review, we discuss recent developments that have been derived from the identification and detailed analysis of individuals with inborn errors of immunity that disrupt cytokine signalling, resulting in immune dysregulatory conditions. These studies have defined fundamental cytokine/cytokine receptor/signal transducer and activator of transcription (STAT) signalling pathways that are critical for the generation and maintenance of human memory B-cell and plasma cell subsets during host defence, as well as revealed mechanisms of disease pathogenesis causing immune deficiency, autoimmunity and atopy. More importantly, these studies have identified molecules that could be targeted to either enhance humoral immunity in the settings of infection or vaccination, or attenuate humoral immunity that contributes to antibody-mediated autoimmunity or allergy.

Pharmacologic Management of Monogenic and Very Early Onset Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is treated with a variety of immunomodulating and immunosuppressive therapies; however, for the majority of cases, these therapies are not targeted for specific disease phenotypes. Monogenic IBD with causative genetic defect is the exception and represents a disease cohort where precision therapeutics can be applied. With the advent of rapid genetic sequencing platforms, these monogenic immunodeficiencies that cause inflammatory bowel disease are increasingly being identified. This subpopulation of IBD called very early onset inflammatory bowel disease (VEO-IBD) is defined by an age of onset of less than six years of age. Twenty percent of VEO-IBDs have an identifiable monogenic defect. The culprit genes are often involved in pro-inflammatory immune pathways, which represent potential avenues for targeted pharmacologic treatments. This review will provide an overview of the current state of disease-specific targeted therapies, as well as empiric treatment for undifferentiated causes of VEO-IBD.

Treatment Effects of Natural Products on Inflammatory Bowel Disease In Vivo and Their Mechanisms: Based on Animal Experiments

Inflammatory bowel disease (IBD) is a chronic, non-specific inflammatory disease of the intestine that can be classified as ulcerative colitis (UC) and Crohn's disease (CD). Currently, the incidence of IBD is still increasing in developing countries. However, current treatments for IBD have limitations and do not fully meet the needs of patients. There is a growing demand for new, safe, and highly effective alternative drugs for IBD patients. Natural products (NPs) are used in drug development and disease treatment because of their broad biological activity, low toxicity, and low side effects. Numerous studies have shown that some NPs have strong therapeutic effects on IBD. In this paper, we first reviewed the pathogenesis of IBD as well as current therapeutic approaches and drugs. Further, we summarized the therapeutic effects of 170 different sources of NPs on IBD and generalized their modes of action and therapeutic effects. Finally, we analyzed the potential mechanisms of NPs for the treatment of IBD. The aim of our review is to provide a systematic and credible summary, thus supporting the research on NPs for the treatment of IBD and providing a theoretical basis for the development and application of NPs in drugs and functional foods.

Bio-Guided Isolation of Compounds from Fraxinus excelsior Leaves with Anti-Inflammatory Activity

Inflammation is the first physiological defence mechanism against external and internal stimuli. The prolonged or inappropriate response of the immune system may lead to the persistent inflammatory response that can potentially become a basis for chronic diseases e.g., asthma, type II diabetes or cancer. An important role in the alleviation of inflammatory processes, as an adjunct to traditional pharmacological therapy, is attributed to phytotherapy, especially to raw materials with a long tradition of use, e.g., ash leaves. Despite their long-term use in phytotherapy, the specific mechanisms of action have not been confirmed in a sufficient number of biological or clinical studies. The aim of the study is a detailed phytochemical analysis of infusion and its fractions, isolation of pure compounds from the leaves of Fraxinus excelsior and evaluation of their effect on the secretion of anti-inflammatory cytokines (TNF-α, IL-6) and IL-10 receptor expression in an in vitro model of monocyte/macrophage cells isolated from peripheral blood. Methods: Phytochemical analysis was carried out by the UHPLC-DAD-ESI-MS/MS method. Monocytes/macrophages were isolated from human peripheral blood using density gradient centrifugation on Pancoll. After 24 h incubation with tested fractions/subfractions and pure compounds, cells or their supernatants were studied, respectively, on IL-10 receptor expression by flow cytometry and IL-6, TNF-α, IL-1β secretion by the ELISA test. Results were presented with respect to Lipopolysaccharide (LPS) control and positive control with dexamethasone. Results: The infusion, 20% and 50% methanolic fractions and their subfractions, as well as their dominating compounds, e.g., ligstroside, formoside and oleoacteoside isolated from the leaves, show the ability to increase the IL-10 receptor expression on the surface of monocyte/macrophage cells, stimulated by LPS, and to decrease the secretion of pro-inflammatory cytokines, e.g., TNF-α, IL-6.

Pathogenic Interleukin-10 Receptor Alpha Variants in Humans - Balancing Natural Selection and Clinical Implications

Balancing natural selection is a process by which genetic variants arise in populations that are beneficial to heterozygous carriers, but pathogenic when homozygous. We systematically investigated the prevalence, structural, and functional consequences of pathogenic IL10RA variants that are associated with monogenic inflammatory bowel disease. We identify 36 non-synonymous and non-sense variants in the IL10RA gene. Since the majority of these IL10RA variants have not been functionally characterized, we performed a systematic screening of their impact on STAT3 phosphorylation upon IL-10 stimulation. Based on the geographic accumulation of confirmed pathogenic IL10RA variants in East Asia and in Northeast China, the distribution of infectious disorders worldwide, and the functional evidence of IL-10 signaling in the pathogenesis, we identify Schistosoma japonicum infection as plausible selection pressure driving variation in IL10RA. Consistent with this is a partially augmented IL-10 response in peripheral blood mononuclear cells from heterozygous variant carriers. A parasite-driven heterozygote advantage through reduced IL-10 signaling has implications for health care utilization in regions with high allele frequencies and potentially indicates pathogen eradication strategies that target IL-10 signaling.

Fulminant Viral Hepatitis in Two Siblings with Inherited IL-10RB Deficiency

Fulminant viral hepatitis (FVH) caused by hepatitis A virus (HAV) is a life-threatening disease that typically strikes otherwise healthy individuals. The only known genetic etiology of FVH is inherited IL-18BP deficiency, which unleashes IL-18-dependent lymphocyte cytotoxicity and IFN-γ production. We studied two siblings who died from a combination of early-onset inflammatory bowel disease (EOIBD) and FVH due to HAV. The sibling tested was homozygous for the W100G variant of IL10RB previously described in an unrelated patient with EOIBD. We show here that the out-of-frame IL10RB variants seen in other EOIBD patients disrupt cellular responses to IL-10, IL-22, IL-26, and IFN-λs in overexpression conditions and in homozygous cells. By contrast, the impact of in-frame disease-causing variants varies between cases. When overexpressed, the W100G variant impairs cellular responses to IL-10, but not to IL-22, IL-26, or IFN-λ1, whereas cells homozygous for W100G do not respond to IL-10, IL-22, IL-26, or IFN-λ1. As IL-10 is a potent antagonist of IFN-γ in phagocytes, these findings suggest that the molecular basis of FVH in patients with IL-18BP or IL-10RB deficiency may involve excessive IFN-γ activity during HAV infections of the liver. Inherited IL-10RB deficiency, and possibly inherited IL-10 and IL-10RA deficiencies, confer a predisposition to FVH, and patients with these deficiencies should be vaccinated against HAV and other liver-tropic viruses.

Pathophysiology of Inflammatory Bowel Disease: Innate Immune System

Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), is a heterogeneous state of chronic intestinal inflammation with no exact known cause. Intestinal innate immunity is enacted by neutrophils, monocytes, macrophages, and dendritic cells (DCs), and innate lymphoid cells and NK cells, characterized by their capacity to produce a rapid and nonspecific reaction as a first-line response. Innate immune cells (IIC) defend against pathogens and excessive entry of intestinal microorganisms, while preserving immune tolerance to resident intestinal microbiota. Changes to this equilibrium are linked to intestinal inflammation in the gut and IBD. IICs mediate host defense responses, inflammation, and tissue healing by producing cytokines and chemokines, activating the complement cascade and phagocytosis, or presenting antigens to activate the adaptive immune response. IICs exert important functions that promote or ameliorate the cellular and molecular mechanisms that underlie and sustain IBD. A comprehensive understanding of the mechanisms underlying these clinical manifestations will be important for developing therapies targeting the innate immune system in IBD patients. This review examines the complex roles of and interactions among IICs, and their interactions with other immune and non-immune cells in homeostasis and pathological conditions.

Dysregulated inflammasome activity in intestinal inflammation - Insights from patients with very early onset IBD

Inflammatory bowel disease (IBD) is a multifactorial disorder triggered by imbalances of the microbiome and immune dysregulations in genetically susceptible individuals. Several mouse and human studies have demonstrated that multimeric inflammasomes are critical regulators of host defense and gut homeostasis by modulating immune responses to pathogen- or damage-associated molecular patterns. In the context of IBD, excessive production of pro-inflammatory Interleukin-1β has been detected in patient-derived intestinal tissues and correlated with the disease severity or failure to respond to anti-tumor necrosis factor therapy. Correspondingly, genome-wide association studies have suggested that single nucleotide polymorphisms in inflammasome components might be associated with risk of IBD development. The relevance of inflammasomes in controlling human intestinal homeostasis has been further exemplified by the discovery of very early onset IBD (VEO-IBD) patients with monogenic defects affecting different molecules in the complex regulatory network of inflammasome activity. This review provides an overview of known causative monogenic entities of VEO-IBD associated with altered inflammasome activity. A better understanding of the molecular mechanisms controlling inflammasomes in monogenic VEO-IBD may open novel therapeutic avenues for rare and common inflammatory diseases.

A high salt diet protects interleukin 10-deficient mice against chronic colitis by improving the mucosal barrier function

A high salt diet (HSD) is often associated with a high risk for a variety of diseases, such as obesity and cardiovascular disease. Previous studies have demonstrated that an HSD enhances Th17 responses and increases the severity of autoimmune diseases. In this study, we investigated the effects of HSD (4% NaCl w/w) on colitis in IL-10^-/- mice by comparing it with IL-10^-/- mice on a normal salt diet (NSD, 1% NaCl w/w). The colonic epithelial barrier integrity in IL-10^-/- mice, as well as differentiated Caco-2 cells exposed to high NaCl and proinflammatory cytokines, was also evaluated. Surprisingly, an HSD significantly ameliorated macroscopic colitis, improved the intestinal permeability of FITC-dextran, and decreased multiple proinflammatory cytokines in the colonic mucosa of IL-10^-/- mice. While occludin and claudin-1, two major tight-junction proteins, were markedly down-regulated in IL-10^-/- mice, HSD effectively restored their expressions. In Caco-2 cells, proinflammatory cytokines (TNF-α and IL-1β) potently decreased the expression of occludin and claudin-1 regardless of salt conditions [0.9% (standard), 1.2%, or 1.5% NaCl]. Under high salt conditions (1.5% NaCl), transepithelial electrical resistance (TEER) was elevated, while the addition of IL-10 further downregulated occludin and claudin-1 expressions by ~50% and lowered TEER. These findings suggest that, in the absence of IL-10, HSD promotes intestinal epithelial integrity and exerts an anti-inflammatory role as demonstrated by alleviated colitis in IL-10^-/- mice. Moreover, Caco-2 data indicate that, in an inflammatory environment and under high NaCl conditions, IL-10 may play a proinflammatory role by disrupting colonic epithelial integrity and thus further promoting inflammation.

Stem Cell-Based Therapies for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic, relapsing disease that severely affects patients' quality of life. The exact cause of IBD is uncertain, but current studies suggest that abnormal activation of the immune system, genetic susceptibility, and altered intestinal flora due to mucosal barrier defects may play an essential role in the pathogenesis of IBD. Unfortunately, IBD is currently difficult to be wholly cured. Thus, more treatment options are needed for different patients. Stem cell therapy, mainly including hematopoietic stem cell therapy and mesenchymal stem cell therapy, has shown the potential to improve the clinical disease activity of patients when conventional treatments are not effective. Stem cell therapy, an emerging therapy for IBD, can alleviate mucosal inflammation through mechanisms such as immunomodulation and colonization repair. Clinical studies have confirmed the effectiveness of stem cell transplantation in refractory IBD and the ability to maintain long-term remission in some patients. However, stem cell therapy is still in the research stage, and its safety and long-term efficacy remain to be further evaluated. This article reviews the upcoming stem cell transplantation methods for clinical application and the results of ongoing clinical trials to provide ideas for the clinical use of stem cell transplantation as a potential treatment for IBD.

Haematopoietic stem cell transplantation for severe autoimmune diseases in children: A review of current literature, registry activity and future directions on behalf of the autoimmune diseases and paediatric diseases working parties of the European Society for Blood and Marrow Transplantation

Although modern clinical management strategies have improved the outcome of paediatric patients with severe autoimmune and inflammatory diseases over recent decades, a proportion will experience ongoing or recurrent/relapsing disease activity despite multiple therapies often leading to irreversible organ damage, and compromised quality of life, growth/development and long-term survival. Autologous and allogeneic haematopoietic stem cell transplantation (HSCT) have been used successfully to induce disease control and often apparent cure of severe treatment-refractory autoimmune diseases (ADs) in children. However, transplant-related outcomes are disease-dependent and long-term outcome data are limited in respect to efficacy and safety. Moreover, balancing risks of HSCT against AD prognosis with continually evolving non-transplant options is challenging. This review appraises published literature on HSCT strategies and outcomes in individual paediatric ADs. We also provide a summary of the European Society for Blood and Marrow Transplantation (EBMT) Registry, where 343 HSCT procedures (176 autologous and 167 allogeneic) have been reported in 326 children (<18 years) for a range of AD indications. HSCT is a promising treatment modality, with potential long-term disease control or cure, but therapy-related morbidity and mortality need to be reduced. Further research is warranted to establish the position of HSCT in paediatric ADs via registries and prospective clinical studies to support evidence-based interspeciality guidelines and recommendations.

The clinical, molecular, and therapeutic features of patients with IL10/IL10R deficiency: a systematic review

Interleukin10 (IL10) and IL10 receptor (IL10R) deficiencies are monogenic inborn errors of immunity (IEI) causing early-onset inflammatory bowel diseases (IBD). In this report, we systematically reviewed articles that included related keywords using PubMed, Web of Science, and Scopus databases. The articles were screened for eligibility criteria before data extraction. We assessed 286 patients (44.5% female) with IL10 and/or IL10R deficiencies who were predominantly from China (40.7%), Italy (13.9%), and South Korea (8.5%). The median age of onset was 1.0 (0.3-4.0) months with a median age of genetic diagnosis at 16.0 (7.4-81.0) months. Consanguinity was reported in all evaluable patients with IL10 deficiency and in 38.2% of patients with IL10R deficiency (22.9% of patients with IL10RA, and 79.4% of patients with IL10RB deficiency). The most prevalent mutations in IL10RA were c.301C>T (p.R101W) and c.537G>A (p.T179T), those in IL10RB were c.139A>G (p.K47E) and c.611G>A (p.W204X). Auto-inflammation and enteropathy were present in all cases. The first presentation of both groups was protracted diarrhea (45.7%), bloody diarrhea (17.8%), and colitis (15.5%). Patients with IL10R deficiency had a high frequency of dermatologic manifestations (50.5%) and failure to thrive (60.5%), while IL10-deficient patients lacked those complications. In the majority of patients, the basic immunologic parameters were in normal ranges. Of the entire publications, 30.7% underwent hemopoietic stem cell transplantation, 57.5% surgery, and 86.6% immunosuppressive treatment. The 10-year survival rate was higher in patients with IL10 deficiency than in patients with IL10R deficiency. In conclusion, IL10/IL10R deficiency predominantly presents with treatment-resistant, early-onset IBD within the first months of life. We detected no clear correlation between the phenotype of patients carrying the same variant. The high prevalence of distinct clinical manifestations reported in IL10RA- and IL10RB-deficient patients might be attributable to the interactions between the target tissue and cytokines other than IL10 capable of binding to IL10RB. These results gain translational significance by contributing to earlier diagnosis, adequate therapy, and avoiding delay in the diagnosis and unfavorable outcomes.

IL‑10/IL‑10 receptor 1 pathway promotes the viability and collagen synthesis of pulmonary fibroblasts originated from interstitial pneumonia tissues

Interstitial pneumonia is a pulmonary interstitial inflammatory and fibrosis disease with a variety of causes that causes respiratory disorders and threatens the lives of patients. The present study aimed to investigate the expression of interleukin (IL)-10 in peripheral blood of patients with interstitial pneumonia and its biological functions in pulmonary fibroblasts. A total of 42 patients with idiopathic pulmonary fibrosis (IPF) and 20 healthy subjects were included. ELISA was used to determine IL-10 concentration in serum from the patients and healthy subjects. Primary fibroblasts were isolated from lung tissue successfully and determined by morphology. The CCK-8 assay was performed to determine the effect of IL-10 expression on cell viability. Western blotting was used to determine COL1a1, COL1a2 and IL-10R1 protein expression. Flow cytometry was used for cell cycle analysis and to determine the number of IL-10⁺ cells. Expression of IL-10 in serum from IPF patients was higher compared to that from healthy subjects. IL-10 promoted the viability and collagen synthesis and secretion of MRC-5 cells and primary pulmonary fibroblasts. IL-10 and IL-10 receptor (R) 1 served regulatory roles in the viability and collagen synthesis of MRC-5 cells. The ratio of peripheral mononuclear lymphocytes with positive expression of IL-10 was elevated in peripheral blood from patients with IPF. The present study demonstrated that IL-10 expression in peripheral blood of patients with IPF is increased significantly compared with healthy subjects. Activation of the IL-10/IL-10R1 signaling pathway promoted the viability and collagen synthesis and secretion of pulmonary fibroblasts, leading to pulmonary fibrosis. The present study provided experimental basis for further understanding the development mechanism of pulmonary fibrosis.

Clinical outcome of infantile-onset inflammatory bowel disease in 102 patients with interleukin-10 signalling deficiency

BACKGROUND

Infantile-onset inflammatory bowel disease can be caused by defects in interleukin-10 signalling. The natural history and clinical outcomes of allogeneic haematopoietic stem cell transplantation, medical treatment and surgery have not been thoroughly described.

AIMS

This study evaluates disease progression and clinical outcome in patients with interleukin-10 signalling deficiency.

METHODS

One hundred and nine patients with interleukin-10 signalling deficiency were retrospectively reviewed from a single tertiary centre. The Kaplan-Meier method was applied to calculate probabilities of survival and interval between transplant and stoma closure.

RESULTS

One hundred and nine patients were reviewed, and 102 patients were included in the survival analysis. One hundred and eight patients were identified with IL10RA mutations, and one patient harboured IL10RB mutation. Seventy-three patients received haematopoietic stem cell transplantation. The overall survival after transplantation was 64.2% (95% confidence interval, 52.8 to 75.6), and without transplantation, it was 47.5% (95% confidence interval, 14.8 to 80.2, P = 0.47). The median timeframe between transplant and stoma closure was 19.6 months. The probability of survival was significantly lower in patients with perforation (P < 0.001), ileus (P = 0.038) and without thalidomide treatment (P < 0.001) among patients who did not receive haematopoietic stem cell transplantation. The survival probability was not associated with timeframe between transplant and onset, graft source and genotypes.

CONCLUSIONS

The survival probability was not significantly different between patients with transplantation and the non-transplanted patients.