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Introduction: The therapeutic interest of targeting B-cell activating factor (BAFF) in Sjögren's disease (SjD) can be suspected from the results of two phase II clinical trials but has not been evaluated in an animal model of the disease. We aimed to evaluate the therapeutic efficacy of this strategy on dryness and salivary gland (SG) infiltrates in the NOD mouse model of SjD., Material and Methods: Female NOD mice between ages 10 and 18 weeks were treated with a BAFF-blocking monoclonal antibody, Sandy-2 or an isotype control. Dryness was measured by the stimulated salivary flow. Salivary lymphocytic infiltrates were assessed by immunohistochemistry. Blood, SGs, spleen and lymph-node lymphocyte subpopulations were analysed by flow cytometry. SG mRNA expression was analysed by transcriptomic analysis., Results: BAFF inhibition significantly decreased SG lymphocytic infiltrates, which was inversely correlated with salivary flow. The treatment markedly decreased B-cell number in SGs, blood, lymph nodes and spleen and increased Foxp3 + regulatory and CD3 + CD4 - CD8 - double negative T-cell numbers in SGs., Conclusion: A monoclonal antibody blocking BAFF and depleting B cells had therapeutic effectiveness in the NOD mouse model of SjD. The increase in regulatory T-lymphocyte populations might underlie the efficacy of this treatment., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: - Janus Kinase inhibitors (JAKi) are a new class of drugs available for pediatric rheumatic diseases. This study aimed to describe the safety and effectiveness of JAKi in these diseases, with a focus on longitudinal interferon-stimulated genes (ISG) assessment., Methods: - We present a single-center retrospective study of children with refractory pediatric rheumatic diseases including connective tissue diseases, monogenic type I interferonopathies or juvenile idiopathic arthritis, receiving JAKi. According to physicians' assessment, treatment effectiveness was classified at 12 months as a complete response in the total absence of disease activity, partial response in case of significant (>50%) but incomplete improvement or no response in the case of non-response or improvement of less than 50% of the clinical and biological parameters. ISG were monitored longitudinally using Nanostring technology., Results: - 22 children were retrospectively included in this study, treated either by baricitinib or ruxolitinib. Complete response was achieved at 12 months in 9/22 (41%) patients. 6/22 (27%) patients were non-responders and treatment had been discontinued in five of them. Within the interferon (IFN)-related diseases group, ISG-score was significantly reduced 12 months after JAKi onset (p = 0.0068). At 12 months, daily glucocorticoid doses had been reduced with a median dose of 0.16 mg/kg/day (IQR 0.11; 0.33) (p = 0.0425). 7/22 (32%) patients had experienced side effects, infections being the most common. Increase of the body mass index was also recorded in children in the first 6 months of treatment., Conclusion: - JAKi represent a promising treatment of immune-mediated pediatric diseases, enabling to decrease type-I IFN transcriptomic signature in responding patients, especially in the context of juvenile dermatomyositis. JAKi represent steroid-sparing drugs but they induce metabolic changes linked to weight gain, posing a concern in the treatment of young patients and teenagers. More data are required to define the efficacy and safety of JAKi in the management of refractory pediatric rheumatic diseases., Competing Interests: Declaration of Competing Interest AB has received grant support from Boehringer Ingelheim, Merck Serono, and consultant fees from Novartis, RocheChugai, GSK., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

An European Alliance of Associations for Rheumatology task force recently recommended specific points to consider for exploring type I interferon pathway in patients, highlighting the lack of analytical assays validated for clinical routine. We report here the French experience on a type I interferon pathway assay that has been set up and used routinely since 2018 in Lyon, France., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Insulin-dependent or type 1 diabetes (T1D) is a polygenic autoimmune disease. In humans, more than 60 loci carrying common variants that confer disease susceptibility have been identified by genome-wide association studies, with a low individual risk contribution for most variants excepting those of the major histocompatibility complex (MHC) region (40 to 50% of risk); hence the importance of missing heritability due in part to rare variants. Nonobese diabetic (NOD) mice recapitulate major features of the human disease including genetic aspects with a key role for the MHC haplotype and a series of Idd loci. Here we mapped in NOD mice rare variants arising from genetic drift and significantly impacting disease risk. To that aim we established by selective breeding two sublines of NOD mice from our inbred NOD/Nck colony exhibiting a significant difference in T1D incidence. Whole-genome sequencing of high (H)- and low (L)-incidence sublines (NOD/Nck H and NOD/Nck L ) revealed a limited number of subline-specific variants. Treating age of diabetes onset as a quantitative trait in automated meiotic mapping (AMM), enhanced susceptibility in NOD/Nck H mice was unambiguously attributed to a recessive missense mutation of Dusp10 , which encodes a dual specificity phosphatase. The causative effect of the mutation was verified by targeting Dusp10 with CRISPR-Cas9 in NOD/Nck L mice, a manipulation that significantly increased disease incidence. The Dusp10 mutation resulted in islet cell down-regulation of type I interferon signature genes, which may exert protective effects against autoimmune aggression. De novo mutations akin to rare human susceptibility variants can alter the T1D phenotype., Competing Interests: The authors declare no competing interest.

Allergic asthma is characterized by airway inflammation with a Th2-type cytokine profile, hyper-IgE production, mucus hypersecretion, and airway hyperreactivity (AHR). It is increasingly recognized that asthma is a heterogeneous disease implicating complex immune mechanisms resulting in distinct endotypes observed in patients. In this study, we showed that non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, undergo more severe allergic asthma airway inflammation and AHR than pro-Th2 BALB/c mice upon house dust mite (HDM) sensitization and challenge. The use of IL-4-deficient NOD mice and the in vivo neutralization of IL-17 demonstrated that both IL-4 and IL-17 are responsible by the exacerbated airway inflammation and AHR observed in NOD mice. Overall, our findings indicate that autoimmune diabetes-prone NOD mice might become useful as a new HDM-induced asthma model to elucidate allergic dysimmune mechanisms involving Th2 and Th17 responses that could better mimic some asthmatic endoytpes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Foray, Dietrich, Pecquet, Machavoine, Chatenoud and Leite-de-Moraes.)

Background: Chronic disseminated candidiasis (CDC) is a rare disease that mostly occurs after chemotherapy-induced prolonged neutropenia in patients with hematological malignancies. It is believed to ensue from Candida colonization, breach of the intestinal epithelial barrier, and venous translocation to organs. Fungal blood or liver biopsy cultures are generally negative, suggesting the absence of an ongoing invasive fungal disease., Methods: To unravel the contribution of the immune system to CDC pathogenesis, we undertook a prospective multicentric exploratory study in 44 CDC patients at diagnosis and 44 matched controls., Results: Analysis of Candida-specific T-cell responses using enzyme-linked immunospot assays revealed higher numbers of interferon (IFN)γ-producing T cells reactive to mp65 or candidin in 27 CDC cases compared with 33 controls. Increased plasma levels of soluble CD25, interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and IL-10 and lower levels of IL-2 were observed in CDC patients versus controls. Neutrophilia and higher levels of CD4 and CD8 T-cell activation were found in CDC patients as well as increased proportions of CXCR3-expressing TCRγδ +Vδ2+ cells., Conclusions: The expansion of Candida-specific IFNγ-producing T cells together with features of T-cell activation and systemic inflammation identified here support the view that CDC belongs to the broad spectrum of fungal-associated immune reconstitution inflammatory syndromes., (© The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Insulin-dependent or type 1 diabetes is a prototypic autoimmune disease whose incidence steadily increased over the past decades in industrialized countries. Recent evidence suggests the importance of the gut microbiota to explain this trend. Here, non-obese diabetic (NOD) mice that spontaneously develop autoimmune type 1 diabetes were treated with different antibiotics to explore the influence of a targeted intestinal dysbiosis in the progression of the disease. A mixture of wide spectrum antibiotics (i.e. streptomycin, colistin and ampicillin) or vancomycin alone were administered orally from the moment of conception, treating breeding pairs, and during the postnatal and adult life until the end of follow-up at 40 weeks. Diabetes incidence significantly and similarly increased in male mice following treatment with these two antibiotic regimens. In NOD females a slight yet not significant trend towards an increase in disease incidence was observed. Changes in gut microbiota composition were assessed by sequencing the V3 region of bacterial 16S rRNA genes. Administration of the antibiotic mixture resulted in near complete ablation of the gut microbiota. Vancomycin treatment led to increased Escherichia, Lactobacillus and Sutterella genera and decreased members of the Clostridiales order and Lachnospiraceae, Prevotellaceae and Rikenellaceae families, as compared to control mice. Massive elimination of IL-17-producing cells, both CD4+TCRαβ+ and TCRγδ+ T cells was observed in the lamina propria of the ileum and the colon of vancomycin-treated mice. These results show that a directed even partial ablation of the gut microbiota, as induced by vancomycin, significantly increases type 1 diabetes incidence in male NOD mice thus prompting for caution in the use of antibiotics in pregnant women and newborns.

Background: Cow's milk allergy (CMA) is a frequent food allergy in young children. The oral food challenge is the gold standard for diagnosis, and there is currently no reliable biological test. Our aim was to evaluate the diagnostic potential of a functional assay quantifying allergen-specific Th2 cells in CMA children., Methods: A total of 29 children aged 2.8-10.5 years underwent a double-blind, placebo-controlled food challenge (DBPCFC) to cow's milk. Blood was collected before performing the DBPCFC, and peripheral mononuclear cells were cultured in an 18-h ELISpot assay with casein, α-lactalbumin, or β-lactoglobulin. Numbers of antigen-specific IL-4- and IL-13-secreting lymphocytes and serum-specific IgE, IgG4, and total IgE levels were assessed. Receiver operating characteristic (ROC) curves were generated., Results: A total of 17 (59%) children reacted to cow's milk and were therefore considered as allergic to cow's milk (CMA). The mean number of casein-specific IL-4- and IL-13-secreting T cells was higher in CMA than in non-CMA children (P = 0.009, 0.004, respectively). Moreover, it was inversely correlated with the cumulative dose of cow's milk tolerated (P = 0.003, 0.0009, respectively). ROC curve of combined IL-4 and IL-13 analysis showed an area under the curve of 0.98 (95% CI 0.90-1.06). For a cutoff of 10 IL-4- and 12 IL-13-secreting T cells, sensitivity and negative predictive value were 100%., Conclusions: Enumeration of casein-specific IL-4- and IL-13-secreting T cells appears a promising tool to improve diagnosis and, if confirmed in larger studies, could permit less frequent use of the oral food challenge., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Sepsis-induced immunosuppression is a new paradigm in sepsis pathophysiology. This up-to-date review integrates recent facts in the field. It focuses on immune dysfunctions described so far in septic patients (especially regarding T lymphocytes), on the mechanisms sustaining this immune failure, on the monitoring of the pro-/anti-inflammatory balance rapidly changing over time and on new promising therapeutic avenues emerging from those recent findings. Of them, the case of interleukin-7 is more specifically envisaged., (© 2014 médecine/sciences – Inserm.)

Objective: Systemic lupus erythematosus (SLE) is a prototype autoimmune disease that is assumed to occur via a complex interplay of environmental and genetic factors. Rare causes of monogenic SLE have been described, providing unique insights into fundamental mechanisms of immune tolerance. The aim of this study was to identify the cause of an autosomal-recessive form of SLE., Methods: We studied 3 siblings with juvenile-onset SLE from 1 consanguineous kindred and used next-generation sequencing to identify mutations in the disease-associated gene. We performed extensive biochemical, immunologic, and functional assays to assess the impact of the identified mutations on B cell biology., Results: We identified a homozygous missense mutation in PRKCD, encoding protein kinase δ (PKCδ), in all 3 affected siblings. Mutation of PRKCD resulted in reduced expression and activity of the encoded protein PKCδ (involved in the deletion of autoreactive B cells), leading to resistance to B cell receptor- and calcium-dependent apoptosis and increased B cell proliferation. Thus, as for mice deficient in PKCδ, which exhibit an SLE phenotype and B cell expansion, we observed an increased number of immature B cells in the affected family members and a developmental shift toward naive B cells with an immature phenotype., Conclusion: Our findings indicate that PKCδ is crucial in regulating B cell tolerance and preventing self-reactivity in humans, and that PKCδ deficiency represents a novel genetic defect of apoptosis leading to SLE., (Copyright © 2013 by the American College of Rheumatology.)

Septic syndrome is the leading cause of mortality for critically ill patients worldwide. Patients develop lymphocyte dysfunctions associated with increased risk of death and nosocomial infections. In this study, we performed preclinical experiments testing the potential of recombinant human IL-7 (rhIL-7) as a lymphostimulating therapy in sepsis. Circulating IL-7 and soluble IL-7 receptor α-chain (soluble CD127) concentrations were measured in plasma, whereas cellular CD127 expression was evaluated on circulating CD4(+) and CD8(+) lymphocytes from septic shock patients and healthy volunteers. Lymphocyte proliferation, IFN-γ production, STAT5 phosphorylation, and B cell lymphoma 2 induction were measured ex vivo in response to T cell stimulation in the presence or not of rhIL-7. We show that IL-7 pathway (plasmatic IL-7 concentration and cellular and soluble CD127 expressions) is not overtly altered and remains activable in septic patients. Most importantly ex vivo treatment of patients' cells with rhIL-7 significantly improves lymphocyte functionality (CD4(+) and CD8(+) lymphocyte proliferations, IFN-γ production, STAT5 phosphorylation, and B cell lymphoma 2 induction after stimulation). To our knowledge, this constitutes the first report of rhIL-7 ability to restore normal lymphocyte functions in septic patients. These results support the rational for initiating a clinical trial testing rhIL-7 in septic shock.