IL-10–producing B cells, also known as regulatory B cells (Bregs), play a key role in controlling autoimmunity. In this study, we report that chimeric mice specifically lacking IL-10–producing B cells (IL-10−/−B cell) developed an exacerbated arthritis compared with chimeric wild-type (WT) B cell mice. A significant decrease in the absolute numbers of Foxp3 regulatory T cells (Tregs), in their expression level of Foxp3, and a marked increase in inflammatory Th1 and Th17 cells were detected in IL-10−/− B cell mice compared with WT B cell mice. Reconstitution of arthritic B cell deficient (μMT) mice with different B cell subsets revealed that the ability to modulate Treg frequencies in vivo is exclusively restricted to transitional 2 marginal zone precursor Bregs. Moreover, transfer of WT transitional 2 marginal zone precursor Bregs to arthritic IL-10−/− mice increased Foxp3+ Tregs and reduced Th1 and Th17 cell frequencies to levels measured in arthritic WT mice and inhibited inflammation. In vitro, IL-10+/+ B cells established longer contact times with arthritogenic CD4+CD25− T cells compared with IL-10−/− B cells in response to Ag stimulation, and using the same culture conditions, we observed upregulation of Foxp3 on CD4+ T cells. Thus, IL-10–producing B cells restrain inflammation by promoting differentiation of immunoregulatory over proinflammatory T cells.

ObjectiveGluten-free diet (GFD) is the only management for coeliac disease (CD). Available methods to assess GFD compliance are insufficiently sensitive to detect occasional dietary transgressions that may cause gut mucosal damage. We aimed to develop a method to determine gluten intake and monitor GFD compliance in patients with CD and to evaluate its correlation with mucosal damage.DesignUrine samples of 76 healthy subjects and 58 patients with CD subjected to different gluten dietary conditions were collected. A lateral flow test (LFT) with the highly sensitive and specific G12 monoclonal antibody for the most dominant gluten immunogenic peptides (GIP) and a LFT reader were used to quantify GIP in solid-phase extracted urines.ResultsGIP were detectable in concentrated urines from healthy individuals previously subjected to GFD as early as 4–6 h after single gluten intake, and remained detectable for 1–2 days. The urine assay revealed infringement of the GFD in about 50% of the patients. Analysis of duodenal biopsies revealed that most of patients with CD (89%) with no villous atrophy had no detectable GIP in urine, while all patients with quantifiable GIP in urine showed incomplete intestinal mucosa recovery.ConclusionGIP are detected in urine after gluten consumption, enabling a new and non-invasive method to monitor GFD compliance and transgressions. The method was sensitive, specific and simple enough to be convenient for clinical monitoring of patients with CD as well as for basic and clinical research applications including drug development.Trial registration numberNCT02344758.

Antigen-presenting molecules vary between individuals of the same species, making it more difficult for pathogens to evade immune recognition and spread through the whole population. As a result of this genetic diversity, transplants between individuals are recognized as foreign and are rejected. This alloreactivity turns placental viviparity into a major immunological challenge. The maternal immune system has to balance the opposing needs of maintaining robust immune reactivity to protect both mother and fetus from invading pathogens, while at the same time tolerating highly immunogenic paternal alloantigens in order to sustain fetal integrity. Regulatory T cells are responsible for the establishment of tolerance by modulating the immune response, and uterine natural killer cells direct placentation by controlling trophoblast invasion. A variety of other cell types, including decidual stromal cells, dendritic cells, and immunomodulatory multipotent mesenchymal stromal cells, are found at the fetal-maternal interface. These cells conspire to establish a suitable environment for fetal development without compromising systemic immunity. Defects in any of these components can lead to gestational failure despite successful fertilization.

Objectives:Treatment for celiac disease (CD) is a lifelong strict gluten-free diet (GFD). Patients should be followed-up with dietary interviews and serology as CD markers to ensure adherence to the diet. However, none of these methods offer an accurate measure of dietary compliance. Our aim was to evaluate the measurement of gluten immunogenic peptides (GIP) in stools as a marker of GFD adherence in CD patients and compare it with traditional methods of GFD monitoring.Methods:We performed a prospective, nonrandomized, multicenter study including 188 CD patients on GFD and 84 healthy controls. Subjects were given a dietary questionnaire and fecal GIP quantified by enzyme-linked immunosorbent assay (ELISA). Serological anti-tissue transglutaminase (anti-tTG) IgA and anti-deamidated gliadin peptide (anti-DGP) IgA antibodies were measured simultaneously.Results:Of the 188 celiac patients, 56 (29.8%) had detectable GIP levels in stools. There was significant association between age and GIP in stools that revealed increasing dietary transgressions with advancing age (39.2% in subjects ≥13 years old) and with gender in certain age groups (60% in men ≥13 years old). No association was found between fecal GIP and dietary questionnaire or anti-tTG antibodies. However, association was detected between GIP and anti-DGP antibodies, although 46 of the 53 GIP stool-positive patients were negative for anti-DGP.Conclusions:Detection of gluten peptides in stools reveals limitations of traditional methods for monitoring GFD in celiac patients. The GIP ELISA enables direct and quantitative assessment of gluten exposure early after ingestion and could aid in the diagnosis and clinical management of nonresponsive CD and refractory CD. Trial registration number NCT02711397.

BACKGROUNDLife-long removal of gluten from the diet is currently the only way to manage celiac disease (CeD). Until now, no objective test has proven useful to objectively detect ingested gluten in clinical practice. Recently, tests that determine consumption of gluten by assessing excretion of gluten immunogenic peptides (GIP) in stool and urine have been developed. Their utility, in comparison with conventional dietary and analytical follow-up strategies, has not been fully established.AIMTo assess the performance of enzyme-linked immunosorbent assay (ELISA) and point-of-care tests (PoCTs) for GIP excretion in CeD patients on gluten-free diet (GFD).METHODSWe conducted an observational, prospective, cross-sectional study in patients following a GFD for at least two years. Using the Gastrointestinal Symptom Rating Scale questionnaire, patients were classified at enrollment as asymptomatic or symptomatic. Gluten consumption was assessed twice by 3-d dietary recall and GIP excretion (by ELISA in stool and PoCTs (commercial kits for stool and urine) in two consecutive samples. These samples and dietary reports were obtained 10 day apart one from the other. Patients were encouraged to follow their usual GFD during the study period.RESULTSForty-four patients were enrolled, of which 19 (43.2%) were symptomatic despite being on a GFD. Overall, 83 sets of stool and/or urine samples were collected. Eleven out of 44 patients (25.0%) had at least one positive GIP test. The occurrence of at least one positive test was 32% in asymptomatic patients compared with 15.8% in symptomatic patients. GIP was concordant with dietary reports in 65.9% of cases (Cohen´s kappa: 0.317). PoCT detected dietary indiscretions. Both ELISA and PoCT in stool were concordant (concomitantly positive or negative) in 67 out of 74 (90.5%) samples. Excretion of GIP was detected in 7 (8.4%) stool and/or urine samples from patients considered to be strictly compliant with the GFD by dietary reports.CONCLUSIONGIP detects dietary transgressions in patients on long-term GFD, irrespective of the presence of symptoms. PoCT for GIP detection constitutes a simple home-based method for self-assessment of dietary indiscretions.

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Hepatitis C virus (HCV) infection is the main cause for chronic hepatitis, leading to cirrhosis and hepatic carcinoma. Virally induced immune dysfunction has been called as the cause for viral persistence. Previous results demonstrate that CD4 Jurkat cells stably expressing the HCV core protein show an increased activation of NFAT transcription factor and an impaired IL-2 promoter activity, affecting intracellular signaling pathways in a manner that mimics clonal anergy. We had shown previously that NFAT activates a transcriptional program, ensuing in immunological tolerance. In the present work, we have engineered lentiviral vectors expressing the HCV core to analyze the events, which unfold in the initial phase of HCV core-induced anergy. We show that genes initially described to be up-regulated by ionomycin-induced anergy in mice are also up-regulated in humans, not only by ionomycin but also by HCV core expression. We also show that HCV core is sufficient to cause NFAT nuclear translocation and a slow-down in cell-cycle progression, and using whole genome microarrays, we identify novel genes up-regulated in Jurkat cells expressing HCV core. The relevance of our results is highlighted by the presence of HCV in CD4 T cells from HCV chronically infected patients.

Pregnancy frequently has a beneficial effect on the autoimmune disease Rheumatoid Arthritis, ranging from improvement in clinical symptoms to complete remission. Despite decades of study, a mechanistic explanation remains elusive. Here, we demonstrate that an analogous pregnancy-induced remission can be observed in a mouse model of arthritis. We demonstrate that during pregnancy mice are protected from collagen-induced arthritis, but are still capable of launching normal immune responses to influenza infections. We examine the role of regulatory T (TR) cells in this beneficial effect. TR cells are essential for many aspects of immune tolerance, including the suppression of autoimmune responses. Remarkably, transfer of regulatory T cells from pregnant ‘protected’ mice was sufficient to confer protection to non-pregnant mice. These results suggest that regulatory T cells are responsible for the pregnancy-induced amelioration of arthritis.