Expression Of Th17 Cells Research Articles

Decreased RORC-dependent silencing of prostaglandin receptor EP2 induces autoimmune Th17 cells.

Prostaglandin E2 (PGE2) promotes Th17 expansion while otherwise inhibiting other CD4+ T cell subsets. Here, we identified a PGE2-dependent pathway that induces pathogenic Th17 cells in autoimmune disease and is regulated by the transcription factor RORC. Compared with other CD4+ cell types from healthy subjects, there is a surprising lack of the prostaglandin receptor EP2 on Th17 cells; therefore, we examined the hypothesis that RORγt, which is highly expressed in Th17 cells, mediates EP2 downregulation. Chromatin immunoprecipitation followed by DNA sequencing revealed that RORγt binds directly to Ptger2 (the gene encoding EP2 receptor) in Th17 cells isolated from WT mice. In Th17 cells isolated from humans, RORC repressed EP2 by directly silencing PTGER2 transcription, and knock down of RORC restored EP2 expression in Th17 cells. Compared with Th17 cells from healthy individuals, Th17 cells from patients with MS exhibited reduced RORC binding to the PTGER2 promoter region, resulting in higher EP2 levels and increased expression of IFN-γ and GM-CSF. Finally, overexpression of EP2 in Th17 cells from healthy individuals induced a specific program of inflammatory gene transcription that produced a pathogenic Th17 cell phenotype. These findings reveal that RORC directly regulates the effects of PGE2 on Th17 cells, and dysfunction of this pathway induces a pathogenic Th17 cell phenotype.

Regulatory effect of nicotine on collagen-induced arthritis and on the induction and function of in vitro-cultured Th17 cells

Objectives. To determine the effect of nicotine stimulation on collagen-induced arthritis (CIA), especially on Th17 cells, and the influence of activated acetylcholine receptor signaling on the induction and function of in vitro-cultured Th17 cells.Methods. Mice were divided into control and experimental (nicotine) group, and PBS or nicotine-PBS was orally administered from Day 21 to Day 28. Phenotypic changes in spleen CD4+ cells were measured by flow cytometry. α7nAChR expression in Th17 cells was detected using flow cytometry, western blotting and real-time PCR. Purified Th17 cells were further stimulated with nicotine. The cytometric bead array (CBA) assay was employed to measure TNF-α levels in mice serum and IL-17A levels in the supernatants of nicotine-treated cell cultures.Results. Compared with their counterparts, mice receiving oral nicotine showed a delayed progress of arthritis and more attenuated signs of histological changes. Moreover, serum TNFα levels were lower in the nicotine-treated group. Spleen IL-17 level of nicotine-treated mice was lower than that of the control group, and the mRNA expression of pro-inflammatory cytokines (IL-17A and IL-6) in splenocytes were also lower than that of the control group. α7nAChR expression was detected on in vitro-cultured IL-17A+ cells. Cells treated with 10 − 6 M nicotine expressed lower IL-17A levels. Similarly, supernatants from nicotine-treated cell cultures also showed lower IL-17A levels.Conclusions. Nicotine stimulation attenuated signs and severity of arthritis in mice. Activation of nicotine acetylcholine receptors on in vitro-cultured Th17 cells decreased their pro-inflammatory function, which may play a potential role in alleviating arthritis in mice.

Changes of Th17 cells, Treg cells and Th17/Treg cell-associated cytokines in patients with tubercu-lous pleurisy and significance of the changes

Objective To investigate the significance of Th 17 cells, Treg cells and Th17/Treg cell-associated cytokines in the development of tuberculous pleurisy through detecting the expressions of Th 17 cells and Treg cells （CD4＋CD25＋Foxp3＋） in CD4＋T cells, analyzing concentrations of IL-17, IL-23, IL-6＆nbsp;and TGF-βin serum of patients with tuberculous pleurisy and healthy controls and measuring levels of IL -17, IL-23, IL-6 and TGF-βin hydrothorax of patients with tuberculous pleurisy .Methods Flow cytometry was used to detect expressions of Th 17 and Treg cells in peripheral blood of patients with tuberculous pleurisy and healthy controls.ELISA method was performed for quantitative detection of concentrations of IL -17, IL-23, IL-6 and TGF-βin serum and hydrothorax .Differences and correlations between the above measured data were analyzed by the statistical software SPSS 17.0.Results Compared with the healthy control group , the expressions of Th17 cells in peripheral blood of the patients were significantly increased （1.02%±0.20%vs.0.89%±0.13%, P=0.002〈0.05）, while the expressions of Treg cells were significantly decreased （4.64%±0.77%vs.5.10%±0.90%, P=0.000〈0.05）.Correspondingly, the ratio of Th17/Treg cells （0.25±0.07） in the patients were significantly higher than that in the healthy controls （0.17±0.05, P=0.000〈0.05）.Concentrations of IL-17, IL-23 and IL-6 in peripheral blood and in hydrothorax of the pa-tients were （17.49±3.94） ng/L, （90.42±23.06） ng/L, （4.54±1.02） ng/L and （26.13±5.98） ng/L, （122.26±31.71） ng/L, （5.31±0.74） ng/L respectively, which were remarkably higher than the levels of IL-17 （14.45±3.81） ng/L, IL-23 （77.55±20.26） ng/L and IL-6 （4.26±0.91） ng/L in control group. In tuberculous pleurisy group , concentrations of IL-17, IL-23 and IL-6 in hydrothorax were significantly higher than those in peripheral blood with P values of 0.000, 0.000 and 0.003.There was no difference be-tween IL-6 levels in peripheral blood from patients and IL-6 levels in peripheral blood from the healthy con-trols, P=0.274.In comparison with the control group , TGF-βlevels in peripheral blood and in hydrothorax of the patients were significantly decreased （3.95 ng/L±0.79 ng/L, 3.12 ng/L±0.77 ng/L vs.3.32 ng/L ±0.80 ng/L） .In tuberculous pleurisy patients , the expression of Th17 cells in peripheral blood was nega-tively correlated with Treg cells in peripheral blood （r=-0.684, P=0.000〈0.05）, but was positively relat-ed to the levels of IL-17, IL-23 and IL-6 （r=0.479, 0.441, 0.326, P=0.013, 0.015, 0.017）.TGF-βlevel had significantly positive correlations with Treg cells in the peripheral blood of the patients （r=0.297, P=0.024）, but no significant correlation with Th17 cells was found （r=0.091, P=0.659）.Conclusion Th17/Treg cell-associated cytokines might regulate the expressions of Th 17 and Treg cells and inflammatory reaction.Changes of Th17 cells, Treg cells and related cytokines might be important immunopathological mechanisms for tuberculous pleurisy . Key words: Th17 cell; Treg cell; Tuberculous pleurisy; Flow cytometry; Cytokine

Abstract 254: Chronic Ang II Hypertension Differentially Impacts the Renal T Cell Profile in Males and Females

T cells contribute to angiotensin (Ang) II hypertension in male animal models yet less is known in females. We previously showed that hypertensive female rats have more immuno-suppressive T regulatory cells (Tregs) and males have more pro-inflammatory Th17 cells in their kidneys. This study tested the hypothesis that Ang II results in greater expression of renal Tregs in females and Th17 cells in males. 12 wk old male and female Sprague Dawley rats (SD) were treated with Ang II (200 ng/kg/min) or vehicle for 2 wks; blood pressure (BP) was measured via tail cuff and renal T cell profiles were measured via flow cytometry. Ang II infusion increased BP in both sexes (mmHg: males: 130±2 to 152±2; females: 123±1 to 146±1; p<0.05). Females had lower CD3 + T cell counts at baseline vs. males (p<0.0001). Ang II significantly increased CD3 + T cells in both sexes (p<0.0001). Baseline CD4 + T cell counts were comparable between male and female SD. Ang II infusion increased CD4 + T cells in both sexes (p<0.0001), however, expression remained lower in females (p=0.04). Females had greater expression of Tregs (p<0.0001) at baseline. Ang II infusion increased Treg expression in females (p=0.004), with no effect in males. Males expressed more baseline Th17 cells than females (p<0.001). Though Ang II increased levels in both sexes (p<0.001), females maintained significantly reduced Th17 cell expression vs. males (p<0.001). Therefore, Ang II resulted in female SD having greater renal expression of Tregs and males having greater expression of Th17 cells. In conclusion, sex differences in the T cell profile may contribute to observed sex differences in BP control.

The Editor takes a closer look at some of this month's articles

Clinical & Experimental AllergyVolume 43, Issue 9 p. 977-977 Editor's ChoiceFree Access The Editor takes a closer look at some of this month's articles First published: 20 August 2013 https://doi.org/10.1111/cea.12174AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat T cells and asthma: complexity rather than duality The Th2 paradigm of asthma has gained considerable traction based largely on the allergen challenge model of asthma in mice which is a Th2 dominant. The mutual inhibition of Th1 and Th2 subsets led to a persuasive if in retrospect over-simplistic view of asthma as Th2 disease, where Th1 immune responses were suppressed. However, a more sophisticated awareness of the degree of heterogeneity in asthma together with the proliferation in the number of T cells subsets, their plasticity and complexity of interaction demands a re-evaluation of this concept 1. Seys et al. (pp. 1009-1017) contribute to this debate by demonstrating complex patterns of T cell associated cytokines in asthma based on measurement of sputum mRNA. Strikingly, they found in some subjects combined Th2 and Th17 related cytokines and this was associated with more severe disease. Studies such as this linking patterns of T cell activation with clinical phenotypes will allow us to describe endotypes of asthma with greater confidence 2. Sven Seys Radar plot representing the proportion of patients (%) with increased sputum mRNA of a particular cytokine [see Figure 1 in S. F. Seys et al. (pp. 1009-1017)]. T cells and asthma: how important are Th17 cells? Continuing the theme of T cells and asthma a subset that is gaining increasing attention in asthma are Th17 cells that release the cytokines IL-17A and IL-17F 3. Tsai et al. (pp. 1018-1026) have investigated expression of Th17 cells in childhood asthma of varying severity by measuring the number of Th17 cells in peripheral blood and serum IL-17 concentrations. They related this to production of exhaled nitric oxide (eNO) and severity of disease. They found an increased concentration of IL-17 in the serum in asthma as well as an increased percentage of Th17 cells, particularly in those with more severe disease. This correlated with eNO. This study provides further support for the idea that Th17 mediated inflammation is important in asthma. Dr. Jien-Wen Chien Associations between serum IL-17 and fractional exhaled nitric oxide [see Figure 2 in J.-W. Chien et al. (pp. 1018-1026)]. Nasal polyps: interaction between infection and vascular proliferation Nasal polyposis is a common and very unpleasant condition, the cause of which remains obscure. Nasal polyps are part of a group of conditions that cause chronic rhino sinusitis, and there is considerable interest in the interplay between sinus infection and the chronic inflammation, including the increased vascularity, that characterizes nasal polyps. Cho et al. (pp. 1038-1047) have studied this relationship in vitro by investigating the interaction between LPS and vascular endothelial growth factor (VEGF) production in nasal polyp fibroblasts. They show that LPS dramatically induced VEGF production via a TLR4-Akt-dependent pathway, providing evidence that bacterial infection can mediate the dramatic remodelling of the nasal mucosa seen in this disease. Professor Heun-Man Lee VEGF protein expression level was examined by immunofluorescence staining. [see Figure 3 in J.-S. Cho et al. (pp.1038-1047)]. References 1Poon AH, Eidelman DH, Martin JG, Laprise C, Hamid Q. Pathogenesis of severe asthma. Clin Exp Allergy 2012; 42: 625– 37. Wiley Online LibraryCASPubMedWeb of Science®Google Scholar 2Lotvall J, Akdis CA, Bacharier LB et al. Asthma endotypes: a new approach to classification of disease entities within the asthma syndrome. J Allergy Clin Immunol 2010; 127: 355– 60. CrossrefWeb of Science®Google Scholar 3Weaver CT, Elson CO, Fouser LA, Kolls JK. The Th17 pathway and inflammatory diseases of the intestines, lungs, and skin. Annu Rev Pathol 2013; 8: 477– 512. CrossrefCASPubMedWeb of Science®Google Scholar Caption to cover illustration: miRNA biogenesis. Following the transcription of the pri-miRNA transcript (1), the pre-miRNA is excised by Drosha (2) and transported by Exportin-5 into the cytoplasm (3). Splicing of the pre-miRNA by Dicer generates the miRNA duplex (4) that contains the mature miRNA strand, which together with several accessory proteins assembles into the RISC complex (5) to enable post-transcriptional regulation of target mRNA translation (6). [See figure 1 in M. Plank et al. (981-999)]. This logo highlights the Editor's Choice articles on the cover and the first page of each of the articles. Volume43, Issue9September 2013Pages 977-977 ReferencesRelatedInformation

Detection significance of Th17 cells in peripheral blood of patients with rheumatoid arthritis in clinical remission

To explore the significance and evaluate the early structural erosion through the expressions of Th17 cells in peripheral blood of patients with rheumatoid arthritis (RA) in clinical remission. A total of 41 active RA patients without structural erosion were selected. Intracelluar flow cytometric detection of Th17 cells in peripheral blood was performed. And the supernatant level of interleukin (IL)-17A was determined simultaneously in RA patients and control groups at baseline and endpoint of 24-month therapy. The correlations were analyzed between Th17 cells and RA disease activity index DAS28. They were classified into radiographic progression (P, n = 10) and radiographic non-progression groups (NP, n = 26) by the Sharp/van der Heijde score (SHS) at the endpoint. The differences of Th17 cells and IL-17A levels were analyzed between P (SHS > 0.5) and NP groups (SHS ≤ 0.5). The expression of Th17 cells in active RA patients was significantly higher than that of controls [(1.63 ± 0.45)% vs (0.91 ± 0.26)%, P < 0.01]. And the results of IL-17A level were similar [1510 ± 280) vs (320 ± 31) ng/L, P < 0.05]. The expression of Th17 cells was positively correlated with DAS28 score (r = 0.87, P < 0.01). Thirty-six RA patients were followed up at the endpoint and all of them stayed in clinical remission (DAS28 < 2.6). The peripheral blood expressions of Th17 cells of P group were significantly higher than those of NP group . At the same time, no differences of IL-17A levels existed between two groups. Structural erosion still progresses in some RA patients despite an apparent clinic remission. And a high-level peripheral expression of Th17 hints at structural erosion.

The CCR6/CCL20 Axis Mediates Th17 Cell Migration to the Ocular Surface in Dry Eye Disease

Th17 cells are believed to be the primary effector cells in the pathogenesis of dry eye disease (DED). However, the mechanisms by which Th17 cells migrate from the lymphoid tissues to the ocular surface are unknown. The purpose of this study was to investigate the role of the C-C chemokine receptor 6/C-C chemokine ligand 20 (CCR6/CCL20) chemokine axis in mediating Th17 cell migration in DED. DED was induced by housing C57BL/6 mice in a low-humidity environment supplemented with scopolamine treatment. Th17 cell expression of CCR6 was evaluated using flow cytometry and ocular surface expression of CCL20 was measured using PCR and ELISA assays. CCL20 neutralizing antibody was administered subconjunctivally to DED mice and disease severity, including the frequency of conjunctival Th17 cells, was evaluated. CCR6 is preferentially expressed by Th17 cells in both normal and DED mice and DED significantly upregulates ocular surface expression of CCL20. Disruption of CCR6/CCL20 binding with CCL20 neutralizing antibody decreases T-cell migration in vitro and reduces Th17 cell infiltration of the conjunctiva when administered in vivo, significantly improving clinical signs of DED. These changes were accompanied by a decrease in ocular surface inflammatory cytokine levels and corneal CD11b+ cell frequencies. Treatment also significantly reduced the generation of Th17 cells. Local neutralization of CCL20 decreases Th17 cell infiltration of the ocular surface in DED, leading to improvement in clinical signs of disease. This suggests that CCR6/CCL20 interactions direct Th17 cell migration in DED and that disruption of this axis may be a novel therapeutic approach to this condition.

STAT3 ActivatesmiR-155in Th17 Cells and Acts in Concert to Promote Experimental Autoimmune Uveitis

MicroRNA-155 (miR-155) and STAT3 are implicated in uveitis and pathogenic mechanisms of CNS autoimmune diseases. In our study, we used miR-155(-/-) mice and mice with targeted STAT3 deletion in T cells (CD4-STAT3KO) to investigate roles of miR-155 and STAT3 in the development of experimental autoimmune uveitis (EAU), a mouse model of human uveitis. We induced EAU in WT, miR-155(-/-), or CD4-STAT3KO mice by immunization with interphotoreceptor retinoid-binding protein/complete Freund's adjuvant (IRBP/CFA) or adoptive transfer of T cells. EAU was assessed by funduscopy and histology. RNA expression was analyzed by quantitative PCR (qPCR), while cytokine production was assessed by fluorescence-activated cell sorting (FACS). We used a combination of genomic and genetic tools to provide the first evidence that STAT3 binds directly to the miR-155 locus and that STAT3 is required for miR-155 expression. Furthermore, STAT3-dependent increase in miR-155 expression in vivo correlated temporally with onset of EAU, and miR-155(-/-) or CD4-STAT3KO mice did not suffer EAU. CD4(+) lymph node cells from IRBP-immunized WT mice transferred EAU to naïve wild-type (WT) and miR-155(-/-) mice, while miR-155(-/-) IRBP-specific T cells did not. Although miR-155 and STAT3 have been implicated in the etiology of multiple sclerosis (MS), uveitis, or rheumatoid arthritis, their exact roles in these diseases are unclear. We show here for the first time to our knowledge that STAT3 regulates miR-155 expression in Th17 cells. We show further that STAT3 and miR-155 form an axis that promotes the expansion of pathogenic Th17 cells that mediate uveitis. Thus, STAT3 and miR-155 may be therapeutic targets for treating uveitis and other Th17-mediated inflammatory disorders.

Regulation of the expression of Th17 cells and regulatory T cells by IL-27 in patients with unexplained early recurrent miscarriage

In normal pregnancy, tolerance of the maternal immune system with regard to the genetically incompatible fetus depends on the interactions of an array of cytokines secreted by maternal and fetal cells at the site of implantation. Earlier research indicating that altered immunity exists in unexplained recurrent miscarriage (RM) has been dominated by the Th1/Th2 hypothesis. Recently, the Th1/Th2 paradigm has been expanded into the Th1/Th2/Th17 and regulatory T cells paradigm. We recently demonstrated a prevalence of Th17 cells, an inverse relationship between Th17 cells and regulatory T cells and deregulation of Th17 cells by regulatory T cells in early pregnancy in unexplained RM patients. In this study, we investigated the expression of IL-27 and the role of the cytokine IL-27 in the regulation of Th17/Treg expression. Quantitative real-time RT-PCR and Western blot analyses were performed to evaluate IL-27 expression in deciduas from unexplained RM patients, spontaneous miscarriage (SM) patients and healthy women following elective abortion in the early stages of normal pregnancy (control). Regulation of IL-17, TGF-β and IL-10 expression in CD4+ T cells in unexplained RM patients by IL-27 was assessed using enzyme-linked immunosorbent assay (ELISA). Expression of IL-27 was lower in deciduas of patients with unexplained RM compared with SM and control subjects. IL-27 inhibited IL-17 expression and enhanced IL-10 expression in a dose-dependent manner. IL-27 had no effect on TGF-β expression. IL-27 regulates the expression of IL-17 and IL-10, which are predominantly secreted by Th17 cells and regulatory T cells in unexplained RM patients.

Twist1 impairs inflammatory cytokine production in T helper 17 cells (P1227)

Abstract Subsets of T helper cells are specialized for the production of specific cytokines, and this specificity is controlled by the function of transcription factors in each subset. Twist1, a basic helix-loop-helix (bHLH) transcription factor, is induced by STAT3-activating cytokines and inhibited by TGF-β in Th17 cells. Ectopic Twist1 expression in Th17 cells reduced IL-17A and IL-17F production while Twist1-deficient Th17 cells produced more IL-17A, IL-17F, and other inflammatory cytokines than wild type cells. In a myelin oligodendrocyte glycoprotein (MOGp35-55)-induced EAE disease model, Twist1-deficient mice manifest earlier onset of paralysis compared to wild type mice. Mechanistically, Twist1 controls cytokine production in Th17 cells by directly repressing Il6ra expression, limiting activation of the IL-6-STAT3 signaling pathway. Thus, Twist1 inhibits inflammatory cytokine production in Th17 cells, suggesting a central role for Twist1 in the regulatory network controlling autoimmune disease.

A novel function for FOXP3 in humans: intrinsic regulation of conventional T cells

AbstractThe role of forkhead box P3 (FOXP3) is well-established in T-regulatory cells, but the function of transient FOXP3 expression in activated human conventional T (Tconv) cells is unknown. In the present study, we used 2 approaches to determine the role of FOXP3 in human Tconv cells. First, we obtained Tconv clones from a female subject who is hemizygous for a null mutation in FOXP3, allowing the comparison of autologous T-cell clones that do or do not express FOXP3. Second, we knocked down activation-induced FOXP3 in Tconv cells from healthy donors with small interfering RNA against FOXP3. We found that FOXP3-deficient Tconv cells proliferate more and produce more cytokines than wild-type Tconv cells and have differential expression of 274 genes. We also investigated the role of FOXP3 in Th1 and Th17 cells and found that the expression of activation-induced FOXP3 was higher and more sustained in Th17 cells compared with Th1 cells. Knocking down FOXP3 expression in Th17 cells significantly increased the production of IFN-γ and decreased the expression of CCR4, but had no effect on IL-17 expression. These data reveal a novel function of FOXP3 in Tconv cells and suggest that expression of this protein is important in the function of multiple CD4+ T-cell lineages.

Interleukin-17 plays a critical role in the acute rejection of intestinal transplantation

To investigate the role of interleukin (IL)-17 in small bowel allograft rejection. We detected the expression of helper T cell 17 (Th17) cells in biopsy specimens from 3 cases of living small bowel transplantation in our department through immunofluorescence stain. We then established a rat heterotopic small bowel transplantation model. The rats were sacrificed on the 1(st), 2(nd), 3(rd), 5(th), and 7(th) d after small bowel transplantation. The degrees of transplantation rejection in rat intestine graft were examined through hematoxylin eosin (HE) stain, and the expression of Th17 cells in rat intestine graft were detected through immunofluorescence stain. In addition, the recipient rats undergoing intestinal transplantation were administrated with mouse-anti-rat IL-17 monoclonal antibody (mAb), and the survival of rats was analyzed. The recipient rats which received mouse-anti-rat IL-17 mAb treatment were sacrificed on the 1(st), 2(nd), 3(rd), 5(th), and 7(th) d after small bowel transplantation. The degrees of transplantation rejection and the expression of Th17 cells in rat intestine graft were detected through HE and immunofluorescence stain. The expression of IL-17, IL-1β, tumor necroses factor receptor-α (TNF-α), IL-6, and IL-8 in the intestine graft or serum were also detected. The expressions of Th17 cells ran parallel with the degree of acute rejection in human intestine grafts. The intestine graft rejection of rats was aggravated with prolonged duration after intestinal transplantation, and the expressions of Th17 cells were also correlated with the degree of acute rejection in rat intestine grafts. Administration of mouse-anti-rat IL-17 mAb prolonged the survival of rats after small bowel transplantation (P < 0.001). Furthermore, we found that the administration of mouse-anti-rat IL-17 mAb significantly decreased the intensity of CD4+IL-17+ Th17 cells in intestine grafts on the 2(nd), 3(rd), 5(th), and the 7(th) d (97.22 ± 4.05 vs 12.45 ± 2.02 on the 7(th) d, P < 0.0001), and suppressed the severity of acute rejection. The expression of IL-17 in the intestine graft declined after mouse-anti-rat IL-17 mAb administration on the 2(nd), 3(rd), 5(th), and the 7(th) d (0.88 ± 0.03 vs 0.35 ± 0.02 on the 7(th) d, P < 0.0001). We also detected the IL-17 serum level and found that the IL-17 level reduced from the 1(st) d to the 7(th) d (6.52 ± 0.18 ng/mL vs 2.04 ± 0.15 ng/mL on the 7(th) d, P < 0.0001). No significant difference in the level of IL-17 mRNA in the intestine graft was identified between the two groups. The levels of IL-1β, TNF-α, IL-6, and IL-8 mRNA in the intestine graft after the administration of mouse-anti-rat IL-17 mAb were also tested. We found that on the 3(rd), 5(th), and 7(th) d after intestinal transplantation, administration of mouse-anti-rat IL-17 mAb significantly inhibited the levels of IL-1β (12.11 ± 1.16 vs 1.27 ± 0.15 on the 7(th) d, P < 0.001), TNF-α (27.37 ± 2.60 vs 1.06 ± 0.26 on the 7(th) d, P < 0.001), IL-6 (21.43 ± 1.79 vs 1.90 ± 0.32 on the 7(th) d, P < 0.001), and IL-8 (20.44 ± 1.44 vs 1.34 ± 0.20 on the 7(th) d, P < 0.001) mRNA in the intestine graft. IL-17 may act as a promising and potent target for inhibiting acute rejection after small bowel transplantation.

Cordycepin Inhibits Differentiation of Th17 Cells and Promotes Generation of CD4+CD25+FoxP3+ Tregs In Vitro

Introduction: Recent evidences have demonstrated that Th17 cells are major contributors to autoimmune disease. In contrast, CD4+CD25+FoxP3+ T regulatory cells (Tregs) actively restrain the inflammatory response, suppress development of autoimmune diseases and dampen a wide spectrum of immune responses. Furthermore, Th17 contributes to the transplant rejection while Tregs exhibit protective effects. Cordycepin (Cs) is a known polyadenylation inhibitor with a large spectrum of biological activities, including anti-proliferative, pro-apoptotic and anti-inflammatory effects. In this study was to determine the effect of Cs on T lymphocytes proliferation and differentiation, further more, to explore the mechanism of Cs how to play its biological activities. Methods: Using MACS-purified mice spleen CD4+ T cells and stimulated with plate bound anti-CD3 Ab and soluble anti-CD28 Ab for 72h. The CD4+ T cells proliferation were analyzed by [3H]-Thymidine incorporation, the proportion of Th17 cells and Tregs were measured by flow cytometry, and the cytokines level was analyzed by ELISA. Results: Cs (80μg/mL) could better suppress CD4+ T cells proliferation (p< 0.05 vs control group: with out Cs), but with a less significant effect than ciclosporin A (CsA 100ng/mL) (p < 0.05). Further more, Cs not only induce the differentiation of CD4+ T cells toward to the CD4+CD25+FoxP3+ Treg cells (p< 0.05 vs control group and CsA group) but also inhibit the expression of Th17 cells (p< 0.01 vs control group), though less effectively than CsA (p< 0.05). Cs down-regulated the IL-2, TNF-α and IFN-γ, per contra the IL-10 and TGF-beta were up-regulated. Conclusion: Based on these observations, Cs could inhibits differentiation of Th17 cells and promotes generation of CD4+CD25+FoxP3+ Tregs in vitro and suggested that Cs may potentially be used as immunomodulatory agents in the treatment of transplant rejection and inflammatory disease.

Sarcoidosis Th17 Cells are ESAT-6 Antigen Specific but Demonstrate Reduced IFN-γ Expression

Sarcoidosis is a granulomatous disease of unknown etiology. Many patients with sarcoidosis demonstrate antigen-specific immunity to mycobacterial virulence factors. Th-17 cells are crucial to the immune response in granulomatous inflammation, and have recently been shown to be present in greater numbers in the peripheral blood and bronchoalveolar lavage (BAL) fluid (BALF) of sarcoidosis patients than healthy controls. It is unclear whether Th-17 cells in sarcoidosis are specific for mycobacterial antigens, or whether they have similar functionality to control Th-17 cells. Flow cytometry was used to determine the numbers of Th-17 cells present in the peripheral blood and BALF of patients with sarcoidosis, the percentage of Th-17 cells that were specific to the mycobacterial virulence factor ESAT-6, and as well as to assess IFN-γ expression in Th-17 cells following polyclonal stimulation. Patients with sarcoidosis had greater numbers of Th-17 cells in the peripheral blood and BALF than controls and produced significantly more extracellular IL-17A (p = 0.03 and p = 0.02, respectively). ESAT-6 specific Th-17 cells were present in both peripheral blood and BALF of sarcoidosis patients (p < 0.001 and p = 0.03, respectively). After polyclonal stimulation, Th-17 cells from sarcoidosis patients produced less IFN-γ than healthy controls. Patients with sarcoidosis have mycobacterial antigen-specific Th-17 cells peripherally and in sites of active sarcoidosis involvement. Despite the Th1 immunophenotype of sarcoidosis immunology, the Th-17 cells have reduced IFN-γ expression, compared to healthy controls. This reduction in immunity may contribute to sarcoidosis pathogenesis.

Conserved Intergenic Elements and DNA Methylation Cooperate to Regulate Transcription at the il17 Locus

Naive CD4(+) T cells can differentiate into distinct lineages with unique immune functions. The cytokines TGFβ and IL-6 promote the development of Th17 cells that produce IL-17, an inflammatory cytokine not expressed by other T helper lineages. To further understand how IL-17 production is controlled, we studied an ~120-kb genomic region containing the murine il17a and il17f genes and seven evolutionarily conserved, intergenic noncoding sequences. We show that the +28-kb noncoding sequence cooperates with STAT3, RORγt, and Runx1 to enhance transcription from both il17a and il17f promoters. This enhancer and both promoters exhibited Th17 lineage-specific DNA demethylation, accompanied by demethylation of lysine 27 of histone H3 (H3K27) and increased H3K4 methylation. Loss of DNA methylation tended to occur at STAT3 consensus elements, and we show that methylation of one of these elements in the il17a promoter directly inhibits STAT3 binding and transcriptional activity. These results demonstrate that TGFβ and IL-6 synergize to epigenetically poise the il17 loci for expression in Th17 cells, and suggest a general mechanism by which active STAT3 may be epigenetically excluded from STAT3-responsive genes in non-Th17 lineages.

Deficiency of Id3 (inhibitor of DNA binding 3) results in Inflammation in salivary glands and gamma-delta (gd) T cell lymphoma (71.11)

Abstract Id3-/- mice have been shown to develop a T cell-dependent autoimmune-like sjogren’s syndrome(SS). The dysregulated differentiation between Foxp3+ Tregs and Th17+ T cells in Id3-/- CD4+ T cells promoted us to study whether the autoimmune-like SS in Id3-/- mice was associated with the abnormal expression of Th17 cells in the target organs. We focused on the salivary glands and lachrymal glands, as they are main target tissues involving in SS. 50% of Id3-/- started to show proinflammatory CD4+ infiltrating cells in the salivary glands. Significantly higher frequency of Th1 and Th17 cells were observed in Id3-/- salivary glands, and higher frequency of Th17 and lower frequency of Tregs were observed in Id3-/- spleen. Notably, 26% mice Id3-/- mice developed gd T cell lymphoma. The gd T lymphoma cells were characterized by dysregulated IL-17 production and high expression of an oncogene, c-myc. Adoptive transfer of Id3-/- gd T lymphoma cells to Rag1-/- mice resulted in gd T lymphoma, suggesting that Id3 may regulates gd T cell tumor development.

Expression and significance of Th17 and Treg cells in peripheral blood of patients with systemic lupus erythematosus

To explore the expression and significance of Th17 and Treg cells in peripheral blood of patients with systemic lupus erythematosus (SLE). Thirty active SLE patients (including 17 SLE patients with lupus nephritis), 20 inactive SLE patients and 20 healthy controls were enrolled. The expressions of Th17 cells and CD4+CD25+Foxp3+Treg cells in peripheral blood mononuclear cells (PBMC) were evaluated by flow cytometry. The correlations between the expression of Th17 cells, CD4+CD25+Foxp3+Treg cells and disease activity (SLEDAI), as well as the ratios of Th17 cells and Treg cells (Th17/Treg) in SLE patients and healthy controls were analyzed respectively. The expression of Th17 cells in PBMC of SLE patients was higher than that in healthy controls [(1.39 ± 0.60)% vs (0.80 ± 0.33)%, P < 0.01] while the expression of CD4+CD25+Foxp3+Treg cells decreased in SLE patients [(3.09 ± 1.54)% vs (6.04 ± 1.49)%, P < 0.01]. The increased expression of Th17 cells and reduced CD4+CD25+Foxp3+Treg cells in PBMC were positively correlated with SLEDAI and negatively correlated with complements C3 and C4. There were increased expression of Th17 cells and reduced CD4+CD25+Foxp3+Treg cells in PBMC of lupus nephritis versus SLE patients without nephritis. There is an abnormal elevation of Th17 cells and decrease of CD4+CD25+Foxp3+Treg cells in PBMC of SLE patients. The imbalance between Th17 and Treg cells may play a critical role in the pathogenesis of SLE.

Th17 Cells in Multiple Sclerosis Express Higher Levels of JAK2, Which Increases Their Surface Expression of IFN-γR2

IFN-β inhibits the expansion of Th17 cells in active multiple sclerosis (AMS), and this might contribute to improve the clinical symptoms. The effectiveness of this inhibition, however, requires intact IFN-γ signaling in T cells. In this study, we report that both mRNA and cell surface expression of the signaling chain of the IFN-γ receptor (IFN-γR2) and its cognate tyrosine kinase JAK2 are enhanced in peripheral blood Th17 cells and clones from patients with AMS compared with those with inactive multiple sclerosis (IMS) or healthy subjects (HS). IFN-γ decreased the frequency of Th17 peripheral cells and proliferation of Th17 clones from AMS patients. Stimulation of PBMCs from HS in Th17-polarizing conditions resulted in the enhancement of JAK2 expression and accumulation of cell surface IFN-γR2. The role of JAK2 in the modulation of IFN-γR2 was demonstrated as its transduction prevented rapid internalization and degradation of IFN-γR2 in JAK2-deficient γ2A cells. In conclusion, these data identify JAK2 as a critical factor that stabilizes IFN-γR2 surface expression in Th17 cells from AMS patients, making them sensitive to IFN-γ. These data may have clinical implications for a better use of IFNs in multiple sclerosis and possibly other inflammatory diseases.

The role of IL-22 in the pathogenesis of skin diseases

IL-22 is an IL-10 family cytokine that acts mainly on epithelial cells. It is produced by immune cell subsets, including CD4⁺ T cells, natural killer cells, and natural killer T cells. In the skin, IL-22 mediates keratinocyte proliferation and epidermal hyperplasia, inhibits terminal differentiation of keratinocytes, and induces the production of antimicrobial proteins. Although IL-22 production was initially linked with IL-17 expression in Th17 cells, IL-22 production can also occur in an apparently unique subset of cells that lacks the production of IL-17 and IFN-γ (Th22). Interestingly, Th22 cells express skin homing chemokine receptors CCR4 and CCR10. Indeed, Th22 cells reside in the normal skin and are shown to be enriched in the lesional skin of inflammatory skin diseases, indicating the importance of IL-22 in skin homeostasis and pathogenesis of skin diseases. Although psoriasis is the first example of an organ-specific immune disorder for which the role of IL-22 has been comprehensively studied, a growing body of evidence indicates that this cytokine also plays a critical role in the pathogenesis of atopic dermatitis. In this review, we discuss the role of IL-22 in the pathogenesis of skin diseases, particularly focusing on psoriasis and atopic dermatitis. Targeting IL-22 may have promise as a potential therapeutic for various skin diseases.

Crosstalk between Nitric Oxide and T helper cells

Crosstalk between Nitric Oxide and T helper cells