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32 result(s) for "Th-17"
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Advances in Understanding the Immunological Pathways in Psoriasis
Psoriasis vulgaris is a chronic, immune-mediated, inflammatory, polygenic skin disorder affecting approximately 2% of the population. It has a great impact on quality of life; patients often experience depression, anxiety, stigma as well as suicidal behavior. Even though psoriasis is one of the most studied dermatological conditions, the pathogenesis of the disease is still not completely elucidated. The complex interactions between keratinocytes, dendritic cells, T-lymphocytes, neutrophils and mast cells are responsible for the histopathological changes seen in psoriasis. The pathogenic model leading to the formation of psoriatic plaques has however evolved a lot over the years. There is now enough evidence to support the role of interleukin (IL) -23, IL-17, IL-22, T helper (Th) -17 cells, Th-22 cells, T regulatory cells, transforming growth factor (TGF)-β1 and IL-10 in the pathogenesis of the disease. Moreover, several inflammatory and anti-inflammatory molecules are currently being investigated, some of them showing promising results. The aim of this paper is to look over the most recent advances in the immunological pathways involved in the pathogenesis of psoriasis vulgaris.
The IL-17 pathway as a target in giant cell arteritis
The network of IL-17 cytokines is considered a key component of autoimmune and inflammatory processes. Blocking IL-17 showed great success in psoriasis as well as psoriatic arthritis, and in patients with axial spondyloarthritis. Secukinumab is one of the approved IL-17A inhibitors for these diseases and is now routinely used. In giant cell arteritis, a large vessel vasculitis, there is accumulating evidence for a pathogenic role of IL-17 and Th17 cells, which are part of the CD4 + T-cell subset. Giant cell arteritis occurs in individuals over 50 years of age and many have relative contraindications to glucocorticoid therapy, which today still represents the mainstay therapy. Despite the approval of tocilizumab, which targets the IL-6 receptor, a high demand for glucocorticoid-sparing agents remains that combine the effective suppression of the acute inflammation observed in giant cell arteritis with a safety profile that matches the needs of an older patient population. The first results from a phase II proof-of-principle study (TitAIN) support an optimistic outlook on a potential new treatment option with secukinumab in giant cell arteritis.
The interplay between alterations in esophageal microbiota associated with Th17 immune response and impaired LC20 phosphorylation in achalasia
Background Achalasia is an esophageal motility disorder with an unknown etiology. We aimed to determine the pathogenesis of achalasia by studying alterations in esophageal smooth muscle contraction and the associated inflammatory response, and evaluate the role of esophageal microbiota in achalasia development. Methods We analyzed esophageal mucosa and lower esophageal sphincter (LES) samples, obtained from patients with type II achalasia who underwent peroral endoscopic myotomy. Esophageal conditioned media obtained from patients were transferred into the mouse esophagus to determine whether the esophageal intraluminal environment is associated with achalasia. Results Approximately 30% of 20-kDa myosin light chains (LC 20 ) was phosphorylated in LES from the control group under resting and stimulated conditions, whereas less than 10% of LC 20 phosphorylation was detected in achalasia under all conditions. The hypophosphorylation of LC 20 in achalasia was associated with the downregulation of the myosin phosphatase-inhibitor protein CPI-17. Th17-related cytokines, including IL-17A, IL-17F, IL-22, and IL-23A, were significantly upregulated in achalasia. α-Diversity index of esophageal microbiota and the proportion of several microbes, including Actinomyces and Dialister , increased in achalasia. Actinomyces levels positively correlated with IL-23A levels, whereas Dialister levels were positively associated with IL-17A, IL-17F, and IL-22 levels. Esophageal IL-17F levels increased in mice after oral administration of the conditioned media. Conclusions In LES of patients with achalasia, hypophosphorylation of LC 20 , a possible cause of impaired contractility, was associated with CPI-17 downregulation and an increased Th17-related immune response. The esophageal intraluminal environment, represented by the esophageal microbiota, could be associated with the development and exacerbation of achalasia.
Role of Natural Autoantibodies and Natural IgM Anti-Leucocyte Autoantibodies in Health and Disease
We review how polyreactive natural IgM autoantibodies (IgM-NAA) protect the host from invading micro-organisms and host neo-antigens that are constantly being produced by oxidation mechanisms and cell apoptosis. Second, we discuss how IgM-NAA and IgM anti-leukocyte antibodies (IgM-ALA) inhibits autoimmune inflammation by anti-idiotypic mechanisms, enhancing removal of apoptotic cells, masking neo-antigens, and regulating the function of dendritic cells (DC) and effector cells. Third, we review how natural IgM prevents autoimmune disorders arising from pathogenic IgG autoantibodies, triggered by genetic mechanisms (e.g., SLE) or micro-organisms, as well as by autoreactive B and T cells that have escaped tolerance mechanisms. Studies in IgM knockout mice have clearly demonstrated that regulatory B and T cells require IgM to effectively regulate inflammation mediated by innate, adaptive, and autoimmune mechanisms. It is, therefore, not surprising why the host positively selects such autoreactive B1 cells that generate IgM-NAA, which are also evolutionarily conserved. Fourth, we show that IgM-ALA levels and their repertoire can vary in normal humans and disease states and this variation may partly explain the observed differences in the inflammatory response after infection, ischemic injury, or after a transplant. We also show how protective IgM-NAA can be rendered pathogenic under non-physiological conditions. We also review IgG-NAA that are more abundant than IgM-NAA in plasma. However, we need to understand if the (Fab)(2) region of IgG-NAA has physiological relevance in non-disease states, as in plasma, their functional activity is blocked by IgM-NAA having anti-idiotypic activity. Some IgG-NAA are produced by B2 cells that have escaped tolerance mechanisms and we show how such pathogenic IgG-NAA are regulated to prevent autoimmune disease. The Fc region of IgG-NAA can influence inflammation and B cell function in vivo by binding to activating and inhibitory FcγR. IgM-NAA has therapeutic potential. Polyclonal IgM infusions can be used to abrogate on-going inflammation. Additionally, inflammation arising after ischemic kidney injury, e.g., during high-risk elective cardiac surgery or after allograft transplantation, can be prevented by pre-emptively infusing polyclonal IgM or DC pretreated ex vivo with IgM or by increasing in vivo IgM with a vaccine approach. Cell therapy is appealing as less IgM will be required.
Association of sarcoidosis and vitiligo − sharing the autoimmune pathogenesis
The coexistence of vitiligo and sarcoidosis, although uncommon, has been reported rarely, suggesting the role of plasmacytoid dendritic cells in generating abnormal immune responses by Th1 and Th17-released cytokines. Our case is an interesting one, describing the co-existence of vitiligo and sarcoidosis. This further strengthens the growing amount of data supporting the hypothesis that Th1 and Th17 cells both have a role in causing autoimmune disorders and broadens the list of diseases with which sarcoidosis is associated.
Correlation of changes in inflammatory and collagen biomarkers with durable guselkumab efficacy through 2 years in participants with active psoriatic arthritis: results from a phase III randomized controlled trial
Background: Guselkumab (human monoclonal antibody) selectively inhibits the interleukin (IL)-23p19 subunit. Objectives: Assess the longer-term pharmacodynamic effects of guselkumab and explore associations between such effects and clinical responses in patients with active psoriatic arthritis (PsA). Design: DISCOVER-2 randomized 739 biologic-naïve patients with active PsA (swollen/tender joint counts each ⩾5, C-reactive protein (CRP) ⩾0.6 mg/dL) to guselkumab (100 mg every 4 weeks (Q4W) or at Weeks 0, 4, and then Q8W) or placebo. Guselkumab-randomized participants with available serum biomarker data (randomly selected to reflect demographic and disease characteristics of the DISCOVER-2 population) comprised inflammatory (N = 100) and collagen (N = 178) biomarker cohorts. Methods: Pharmacodynamic effects of guselkumab through 2 years on inflammatory and collagen biomarker levels (general linear model) and associations between biomarkers and improvements in composite measures of joint, skin, and overall disease activity (Spearman linear regression) through 2 years were assessed. The relationship between the pharmacodynamic effects of guselkumab and achieving ⩾50% improvement in the American College of Rheumatology response criteria (ACR50) was assessed using a general linear model. Results: With guselkumab, pharmacodynamic effects on inflammatory (CRP, IL-6, serum amyloid A (SAA), IL-17A, IL-17F, IL-22, and beta-defensin 2 (BD-2)) and collagen (matrix metalloproteinase-degradation type I, III, IV, and VI collagen (C1M, C3M, C4M, and C6M)) biomarker levels were sustained or enhanced through Week 100. Throughout follow-up timepoints (Week 24/52/100), decreases in CRP, IL-6, C1M, and C6M levels correlated (r = 0.26–0.30; p < 0.05) with improved joint disease activity (Disease Activity in Psoriatic Arthritis); decreases in IL-17A, IL-17F, IL-22, and BD-2 levels correlated (r = 0.34–0.58; p < 0.05) with improved skin disease (Psoriasis Area and Severity Index); and decreases in C1M, C3M, C4M, and C6M correlated (r = 0.27–0.31; p < 0.05) with improved overall disease activity (Psoriatic Arthritis Disease Activity Score). Significantly (p < 0.05) greater reductions from baseline at Week 100 in CRP, IL-6, SAA, and C1M levels were observed in participants improving from Week 24 ACR50 nonresponse to Week 100 ACR50 response and were accompanied by a significant decrease in C1M from Week 24 to Week 100 versus nonresponders at both Weeks 24 and 100. Conclusion: In biologic-naïve participants with active PsA, guselkumab elicited substantial and enduring reductions in biomarkers that were associated with durable improvements in joint, skin, and overall disease activity through 2 years of DISCOVER-2. Trial registration: NCT03158285 (clinicaltrials.gov identifier).
Cytokine Changes in Gingival Crevicular Fluid and Serum After Non-Surgical Periodontal Therapy in Patients with Periodontitis: A Systematic Review and Narrative Synthesis
Objective: We aimed to synthesize paired pre/post human evidence on how Th17-axis cytokines (IL-17A, IL-21, IL-22, IL-23 and related markers) change after non-surgical periodontal therapy (NSPT) by biospecimen (gingival crevicular fluid [GCF], saliva, serum) and time window. Material and methods: We performed a PRISMA-guided systematic review of non-randomized pre/post cohorts and clinical trials. Databases (PubMed, Embase, Scopus, Cochrane) were searched; two reviewers performed selection, data extraction, ROBINS-I risk-of-bias appraisal, and GRADE certainty assessment. Due to heterogeneity in sampling/assays and incomplete variance reporting, a qualitative direction-of-effect synthesis was prespecified for ≤4 weeks, ~6–8 weeks, and ~3–6 months. Results: Twelve studies (total n = 897) met inclusion (8 GCF; 5 blood-derived (serum/plasma) cohorts; one saliva). Most GCF cohorts reported decreases in IL-17A within ~6–8 weeks post-NSPT (≥4 cohorts), with one early 4-week cohort showing a concentration increase but an unchanged total amount due to reduced GCF volume. IL-23 generally declined locally and declined by ~3 months systemically in aggressive periodontitis. Serum IL-17A changes were smaller/variable (two cohorts reported decreases within 1–6 months), and one cohort showed a reduced IL-17A:IL-17E ratio at ~25 weeks. Heterogeneity precluded meta-analysis; we undertook a direction-of-effect synthesis. Conclusions: NSPT is likely associated with the early local down-regulation of Th17-axis activity (notably GCF IL-17A), when systemic signals are smaller and delayed. Given moderate–serious risk of bias and pre-analytical heterogeneity, the certainty of evidence is low to very low; Th17-axis biomarkers are not yet suitable for clinical decision-making.
Glucocorticoid Receptor-Beta Up-Regulation and Steroid Resistance Induction by IL-17 and IL-23 Cytokine Stimulation in Peripheral Mononuclear Cells
Purpose Most asthmatic patients have well controlled symptoms with regular treatment, but some require much higher doses of inhaled and oral corticosteroids, or in rare cases fail to respond; these patients may present Th-17 cell infiltration and associated cytokines (IL-17A and -F) in the airways, sputum and peripheral blood. Because glucocorticoid receptor-beta (GR-beta) is associated with corticosteroid resistance, we investigated whether Th-17 associated cytokines induce steroid insensitivity in PBMCs via GR-beta up-regulation. Methods GR-alpha, GR-beta, GILZ and IL-6 expression were analyzed in PBMCs stimulated with IL-2/IL-4, IL-17A/IL-17F and IL-23 cytokines by quantitative RT-PCR. Dexamethasone-inhibition of PHA-induced proliferation and Dexamethasone-induced apoptosis were determined by either 3 H-thymidine or CFSE-labelled cells and by Annexin-V staining and flow cytometry. Results IL-17 and IL-23 cytokines significantly increased GR-beta expression. IL-2/IL-4 significantly decreased GR-alpha expression without affecting GR-beta. IL17, IL-23 and IL2 + 4 stimulations significantly hampered Dexamethasone-inhibition of proliferation (Dex EC 50 for: IL-17A + F = 251 nM; IL-23 = 435 nM; IL2 + 4 = 950 nM; Medium = 90 nM). IL2 + 4 and IL17A + F but not IL-23, significantly hampered Dexamethasone-induced apoptosis (1400 and 320 nM Dex, respectively). Dexamethasone’s trans-activation of GILZ and trans-repression of NF-kB-driven IL-6 expression were both inhibited by IL2 + 4; IL17 + IL23 antagonized Dex trans-repression in PBMC from asthmatics. Conclusions GR-beta up-regulation by IL-17/IL-23 cytokines is associated with induced steroid insensitivity in PBMCs, observed as diminished Dexamethasone’s effects on cell proliferation, apoptosis and gene regulation. Steroid resistance induced by IL-2/IL-4 was associated with decreased GR-alpha expression. This study supports the possibility that Th-17 lymphocytes and associated cytokines play a role in the mechanism of steroid hypo-responsiveness in severe asthmatics.
A Traditional Chinese Medicine Formula Danshen Baibixiao Ameliorates Imiquimod-Induced Psoriasis-Like Inflammation in Mice
Background: Danshen Baibixiao (DB) is a traditional Chinese medicine formula, which has been used to treat psoriasis for decades. Although DB shows good efficacy in clinical practice, the pharmacological effects and underlying mechanisms of DB remain elusive. This study aimed to evaluate the anti-psoriatic effects of DB and explore its underlying mechanisms in an imiquimod (IMQ)-induced psoriasis-like mouse model. Materials and methods: DB was orally administered on IMQ-induced psoriatic mice. Psoriasis area severity index (PASI) was used to evaluate the severity of the inflammation in skin, and histological changes were evaluated by hematoxylin and eosin (H and E) staining. Levels of inflammatory cytokines, such as tumor necrosis factor α (TNF-α), interleukin (IL)-17A, IL-23, IL-6, IL-1 β and IL-22 in serum were assessed by enzyme-linked immunosorbent assay (ELISA). mRNA expressions of IL-17A, IL-23, IL-6 and IL-22 were determined by real-time polymerase chain reaction (PCR). Expression levels of proteins related to NF-κB, STAT3 and MAPKs signaling pathways were measured by western blotting (WB). Results: DB significantly ameliorated the psoriatic symptoms in IMQ-induced mice. The serum levels of inflammatory cytokines (TNF-α, IL-17A, IL-23, IL-6, IL-1β and IL-22) were decreased, and mRNA expressions of IL-17A, IL-23, IL-6 and IL-22 in skin tissues were down-regulated. Moreover, WB analysis indicated that DB inhibited the activation of NF-κB, STAT3 and MAPKs signaling pathways. Conclusion: This study confirms the anti-psoriatic activity of DB in IMQ-induced psoriasis-like mice. The possible mechanism may relate to the activities of regulating the IL-23/TH-17 axis and suppressing the activation of NF-κB, STAT3 and MAPKs signaling pathways.