Frequency Of Th17 Cells Research Articles

Respiratory syncytial virus disease severity is associated with distinct CD8+ T cell profiles

Abstract Most infants are infected with RSV by their second birthday. Despite known risk factors such as prematurity or congenital heart disease, most hospitalized infants are previously healthy. The mechanisms underlying the immunopathology of severe disease is incompletely understood. Our objective was to compare T cell profiles in nasal aspirates between infants with moderate and severe RSV disease hospitalized without immune deficiencies or congenital heart disease, during 2014–2017. Infants requiring intensive care were categorized as having severe disease, while infants maintained in the general ward were categorized as having moderate disease. The T cell profile in nasal aspirates collected 7 days after hospitalization (median 11 days after first symptom onset) was determined by flow cytometry. Nasal aspirates from patients with severe disease were characterized by a higher proportion of CD8+ T cells expressing IL-4 (Tc2) (P=0.024) and a lower proportion of CD8+ T cells expressing IFNγ (Tc1) (P=0.019) compared to patients with moderate disease. Patients with reduced frequencies of Tc1, Tc17, or Th17 cells had shorter durations of hospitalization (P=0.0023, P=0.0188, P=0.0437, respectively). Additionally, patients with severe disease had lower concentrations of IL-17 in nasal aspirates compared to patients with moderate disease (P=0.0133). These results suggest that RSV disease severity is associated with a specific T cell profile, and that Tc2 cells may play an underappreciated role in the development of RSV immunopathology.

Dopamine Receptor D3 Expression Is Altered in CD4+ T-Cells From Parkinson's Disease Patients and Its Pharmacologic Inhibition Attenuates the Motor Impairment in a Mouse Model.

Neuroinflammation constitutes a fundamental process involved in Parkinson's disease (PD). Microglial cells play a central role in the outcome of neuroinflammation and consequent neurodegeneration of dopaminergic neurons in the substantia nigra. Current evidence indicates that CD4+ T-cells infiltrate the brain in PD, where they play a critical role determining the functional phenotype of microglia, thus regulating the progression of the disease. We previously demonstrated that mice bearing dopamine receptor D3 (DRD3)-deficient CD4+ T-cells are completely refractory to neuroinflammation and consequent neurodegeneration induced by the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In this study we aimed to determine whether DRD3-signalling is altered in peripheral blood CD4+ T-cells obtained from PD patients in comparison to healthy controls (HC). Furthermore, we evaluated the therapeutic potential of targeting DRD3 confined to CD4+ T-cells by inducing the pharmacologic antagonism or the transcriptional inhibition of DRD3-signalling in a mouse model of PD induced by the chronic administration of MPTP and probenecid (MPTPp). In vitro analyses performed in human cells showed that the frequency of peripheral blood Th1 and Th17 cells, two phenotypes favoured by DRD3-signalling, were significantly increased in PD patients. Moreover, naïve CD4+ T-cells obtained from PD patients displayed a significant higher Th1-biased differentiation in comparison with those naïve CD4+ T-cells obtained from HC. Nevertheless, DRD3 expression was selectively reduced in CD4+ T-cells obtained from PD patients. The results obtained from in vivo experiments performed in mice show that the transference of CD4+ T-cells treated ex vivo with the DRD3-selective antagonist PG01037 into MPTPp-mice resulted in a significant reduction of motor impairment, although without significant effect in neurodegeneration. Conversely, the transference of CD4+ T-cells transduced ex vivo with retroviral particles codifying for an shRNA for DRD3 into MPTPp-mice had no effects neither in motor impairment nor in neurodegeneration. Notably, the systemic antagonism of DRD3 significantly reduced both motor impairment and neurodegeneration in MPTPp mice. Our findings show a selective alteration of DRD3-signalling in CD4+ T-cells from PD patients and indicate that the selective DRD3-antagonism in this subset of lymphocytes exerts a therapeutic effect in parkinsonian animals dampening motor impairment.

Expression of the Butyrate/niacin Receptor, GPR109a on T cells Plays an Important Role in a Mouse Model of Graft Versus Host Disease

Abstract The intestinal microbiota is essential for the fermentation of dietary fibers into metabolites, notably the short-chain fatty acids (SCFA) butyrate, acetate and propionate. SCFA can bind to G-protein-coupled receptors such as GPR109a to activate downstream anti-inflammatory effects. GPR109a is the main butyrate receptor and we have previously demonstrated that butyrate can ameliorate gastrointestinal injury during graft versus host disease (GVHD). Therefore, we hypothesized that GPR109a is important in the pathophysiology of intestinal GVHD. Using a MHC-mismatched model of GVHD, we demonstrated a lower incidence of disease when mice received wild type (WT) bone marrow (BM) and T cells from a GPR109a−/− mouse. It is known that GPR109a is highly expressed on myeloid cell populations such as dendritic cells and macrophages; however, expression on T cells is not entirely resolved. At baseline, we observed low expression of GPR109a on T cells, which increases upon T-cell receptor stimulation. T cell development in GPR109a−/− mice appears normal, however, 7 days after transplant, we found significantly fewer CD4+ and CD8+ T cells in the intestines of mice that received WT BM and GPR109a−/− T cells. While frequency of Th1 and Th17 cells were similar between the groups, we saw significantly more regulatory T cells in the intestines and spleen of GPR109a−/−T cell recipients. This reduction of GVHD was accompanied by maintenance of the gut commensal Clostridium and increased butyrate, which is known to protect the intestinal epithelium and increases the regulatory T cell pool. Thus, we propose a novel role for GPR109a in the expansion and activation of T cells during GVHD.

Sox9 deletion in the intestinal epithelium increases house dust mite induced allergic asthma symptoms in mice

Abstract Paneth cells regulate many key aspects of gastrointestinal health through the antimicrobial products and cytokines they produce. Loss or defective Paneth cell functions leads to dysbiosis and is one of the causes of Inflammatory Bowel Disease (IBD). Mice with Sox9 gene deletion within the intestinal epithelium (Sox9 ΔIEC mice) lack Paneth cells making these mice a great model for the study or IBD and other consequences of dysbiosis. Our separate studies have shown that dysbiosis of the gut microbiota could enhance allergic sensitization in the gut and subsequent allergic responses to nasal allergen challenge. We investigated whether dysbiosis caused by a Sox9 deletion in the intestinal epithelium of mice could affect allergic sensitization in the airway and development of asthma responses. For this purpose, control wild-type and Sox9 ΔIEC mice were sensitized tohouse dust mite (HDM) by daily intranasal administration over two weeks period. Upon nasal HDM challenge, Sox9 ΔIEC mice showed more severe signs of allergic asthma than wild-type C57 BL/6 mice as indicated by their higher hypothermia. We also established that the increased allergic symptoms in Sox9 ΔIEC mice correlated with higherIgE levels in serum and bronchoalveolar lavage fluid, and higher frequency of HDM-specific Th2 cells but no difference in Th1 or Th17 responses. These results further illustrate that the gut immune homeostasis plays an important role in allergic responses at distant mucosal sites.

Cytokine profile, Treg/Th17 cell frequency changes during different posttransplantational time points in patients undergoing renal transplantation.

Renal transplantation is the best therapeutic approach for end stage renal dysfunction patients. There are direct relationships between proportions of Treg cells, Treg/Th17 cells ratio and secreted immunosuppressive cytokines with increased survival rate of the transplanted organ. The aim of this study was the measurement of Treg and Th17 cells frequency and their secreted cytokines. Ninety renal-transplanted patients were divided in three groups based on times after transplantation (1-6 month, 6-36 month, and more than 3 years). Treg and Th17 cells frequency, expression level of their transcription factors and cytokines, and their secreted cytokines level were measured in these groups. Higher expression level of Interleukin (IL)-10 and FoxP3 mRNA were observed in patients who had longer posttransplantation time. In contrast, lower mRNA expressions of IL-6, IL-17, IL-23, and TGF-β were observed in this group. Receptor γt showed no significant changes in studied groups. In addition IL-10 level was increased and IL-6, IL-17, IL-23, and TGF-β level were decreased in patients who had longer posttransplantation time. Treg cells frequency was raised in mentioned group whereas no remarkable changes were observed in Th17 cell frequency. The present study declared that in stable renal transplantation, over time, the percentage of Treg cells and Treg/Th17 ration is increased. This increase in ratio induces a change in cytokine profile, resulting in an increased immunosuppressive cytokines such as IL-10 leading to increase in the survival rate of the transplanted organ.

Interleukin-35 modulates the balance between viral specific CD4+CD25+CD127dim/- regulatory T cells and T helper 17 cells in chronic hepatitis B virus infection

BackgroundInterleukin (IL)-35 regulates imbalance between regulatory T cells (Tregs) and T helper (Th) 17 cells, leading to an important modulator in autoimmune disorder, cancer, and infectious diseases. Our previous study revealed an immunosuppressive activity of IL-35 in chronic hepatitis B virus (HBV) infection. Thus, the aim of the current study was to investigate the role of regulatory function of IL-35 to viral specific Tregs/Th17 cells balance in chronic HBV infection.MethodsA total of 44 HLA-A2 restricted chronic HBV infected patients, including 21 of chronic hepatitis B (CHB) and 23 of asymptomatic HBV carriers (ASC) were enrolled. Purified CD4+ T cells or CD4+CD25+CD127dim/− Tregs were stimulated with recombinant IL-35. HBV core antigen specific Tregs and Th17 cells were determined by flow cytometry. FoxP3 and RORγt mRNA was measured by real-time PCR. Cytokines production (IL-10 and IL-17) was investigated by ELISA.ResultsPeripheral viral specific Tregs was comparable between CHB and ASC. However, increased percentage of viral specific Th17 cells was found in CHB, leading to the reduction of Tregs/Th17 ratio in CHB patients. IL-35 stimulation elevated viral specific Tregs, but not Th17 cells frequency, in both CHB and ASC, resulting in the elevation of Tregs/Th17 ratio in both groups. This process was accompanied by increased expression of FoxP3 mRNA and IL-10 production, and decreased IL-17 secretion and STAT3 phosphorylation in purified CD4+ T cells. Moreover, IL-35 stimulation inhibited viral specific Th17-like phenotype differentiation from Tregs in CHB patients. Effective anti-HBV therapy did not affect viral specific Tregs/Th17 cells frequency or IL-35 expression in CHB patients, however, reduced responsiveness of CD4+ T cells or Tregs to IL-35 stimulation in vitro.ConclusionOur findings indicated that IL-35 regulation to viral specific Tregs/Th17 balance may contribute to viral persistence in chronic HBV infection.

From the Editor’s desk…: May 2019

From the Editor’s desk…: May 2019

Decreased Frequencies of Th17 and Tc17 Cells in Patients Infected with Avian Influenza A (H7N9) Virus.

The outbreak of avian influenza A (H7N9) virus infection, with a high mortality rate, has caused concern worldwide. Although interleukin-17- (IL-17-) secreting CD4+ T (Th17) and CD8+ T (Tc17) cells have been proven to play crucial roles in influenza virus infection, the changes and roles of Th17 and Tc17 cells in immune responses to H7N9 infection remain controversial. In this study, we found that the frequencies of Th17 and Tc17 cells among human peripheral blood mononuclear cells (PBMCs) as well as IL-17A protein and mRNA levels were markedly decreased in patients with acute H7N9 virus infection. A positive correlation was found between the serum IL-17A level and the frequency of these two cell groups. In vitro infection experiments revealed decreased Th17 and Tc17 cell frequency and IL-17A levels at various time points postinfection. In addition, Th17 cells were the predominant sources of IL-17A in PBMCs of patients infected with H7N9 virus. Taken together, our results indicate immune disorder in acute H7N9 infection and a restored Th17 and Tc17 cell frequency might serve as a biomarker for predicting recovery in patients infected with this virus.

Transplantation of dental tissue-derived mesenchymal stem cells ameliorates nephritis in lupus mice.

Recently, clinical studies have suggested that transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) were able to alleviate clinical symptoms of refractory systemic lupus erythematosus (SLE). Although dental tissue derived MSCs, including dental pulp stem cells (DPSCs) and periodontal ligament stem cell (PDLSCs), have been reported to possess immunomodulatory functions, whether they can ameliorate SLE symptoms as UC-MSCs remains to be elucidated. We assessed the abilities of DPSCs and PDLSCs to treat SLE, cells were transferred intravenously to 28-week old B6/lpr mice. Ten weeks later, mice were sacrificed. Serum anti-dsDNA antibodies and anti-nuclear antibodies (ANA) were measured by ELISA. Renal pathology was analyzed by H&E, PAS and MASSON staining. Aggregation of IgG and IgM in the glomerulus was examined by immunofluorescence. Frequencies of Th1, Th2, Treg, Th17, Tfh, and plasma cells were determined by surface and intracellular staining. Serum IL-6, IL-10, IL-17 and MCP-1 were measured by Milliplex® MAP technology. Same as UC-MSCs, both DPSCs and PDLSCs could efficiently downregulate 24-h proteinuria, anti-dsDNA antibodies and glomerular IgG/IgM in B6/lpr mice. However, DPSCs but not PDLSCs could ameliorate the glomerular lesion in B6/lpr mice. Compared to the phosphate buffered saline (PBS) group, percentages of Th1 (CD4+IFNγ+) cells and plasma (B220-CD138+) cells in the spleen were significantly decreased in DPSCs and PDLSCs groups. There was no significant difference in Th2 (CD4+IL4+), Th17 (CD4+IL17+), Tfh (CD4+PD-1+CXCR5+) and Treg (CD4+CD25+Foxp3+) cells. Serum IL-6, IL-10, IL-17 and MCP-1 levels didn't change after MSCs transplantation. Our results show that both DPSCs and PDLSCs can alleviate the disease symptoms of lupus-prone B6/lpr mice. DPSCs are also effective in reducing kidney glomerular lesion and perivascular inflammation infiltration as well as UC-MSCs, suggesting that DPSCs might be another choice for SLE treatment.

α-Difluoromethylornithine suppresses inflammatory arthritis by impairing myeloid-derived suppressor cells

ObjectivesThe chemopreventive drug α-difluoromethylornithine (DFMO) has been shown to have an antinociceptive effect on mechanical allodynia in inflammatory arthritis by directly inhibiting ornithine decarboxylase (ODC) and decreasing polyamine production in inflammatory sites. However, little is known about the effect of DFMO on the immune system of inflammatory arthritis. Here, we investigated the effect of DFMO in a well-established collagen-induced arthritis (CIA) mouse model and explored its effect on the immune system. MethodsThe effect of DFMO on the frequency of myeloid-derived suppressor cells (MDSCs) in the spleens of CIA mice and their associations with disease severity, tissue inflammation and the levels of proinflammatory T-helper (Th) 17 cells in lymphoid tissues were investigated. The effects of DFMO on disease severity and Th17 cells were compared with those of antibody depletion of MDSCs. The arthritis severity was also evaluated by adoptive transfer of MDSCs derived from DFMO- or dH2O-treated mice. ResultsIn this study, we showed that both MDSCs and Th17 cells were significantly expanded in CIA mice. Treatment by DFMO at the onset of CIA suppressed the development of arthritis and decreased the frequency of MDSCs and Th17 cells. MDSC depletion by anti-Gr-1 mAb achieved a similar result, while combination treatment of both methods did not achieve a significant difference compared to either of the single treatments. In addition, the adoptive transfer of MDSCs derived from dH2O-treated mice with CIA restored the arthritis severity of CIA in mice treated with anti-Gr-1 mAb, while the transfer of MDSCs from DFMO-treated mice did not have such an effect. ConclusionsOur results identified DFMO as a potential therapeutic drug for the treatment of inflammatory arthritis.

Tim-3 regulates inflammatory cytokine expression and Th17 cell response induced by monocytes from patients with chronic hepatitis B.

Tim-3 is expressed on monocytes/macrophages and is involved in the regulation of inflammatory responses. The aim of this study was to determine the effect of Tim-3 on inflammatory response triggered by peripheral monocytes from patients with chronic hepatitis B (CHB). Tim-3 expression on peripheral monocytes and frequency of Th17 cells in peripheral blood mononuclear cells (PBMCs) derived from CHB patients were detected. Followed by lipopolysaccharides (LPS) activation of circulating monocytes from CHB patients, expression of inflammatory cytokines including TNF-α，IL-1β and IL-6 were examined in the presence and absence of Galectin-9 which is the ligand for Tim-3. Subsequently, after purified CD4+T cells were cocultured with LPS-activated monocytes from CHB patients in the presence of anti-Tim-3 antibody, percentage of Th17 cells and production of IL-17 were measured. Tim-3 expression was significantly upregulated and closely correlated to the frequency of Th17 cells in patients with CHB. Expression of TNF-α，IL-1β and IL-6 increased significantly in monocytes stimulated with LPS and Galectin-9, compared to LPS stimulation alone. LPS-activated monocytes from CHB patients could drive differentiation of memory CD4+T cells to Th17 cells. However, under the blockade of Tim-3 signalling by anti-Tim-3 antibody, percentage of Th17 cells and production of IL-17 decreased significantly. Our results demonstrate that upregulated expression of Tim-3 on circulating monocytes accelerates inflammatory response by promoting production of inflammatory cytokines and Th17 responses in CHB.

Effector Functions of CD4+ T Cells at the Site of Local Autoimmune Inflammation-Lessons From Rheumatoid Arthritis.

Infiltration of memory CD4+ T cells in synovial joints of Rheumatoid Arthritis (RA) patients has been reported since decades. Moreover, several genome wide association studies (GWAS) pinpointing a key genetic association between the HLA-DR locus and RA have led to the generally agreed hypothesis that CD4+ T cells are directly implicated in the disease. Still, RA is a heterogeneous disease and much effort has been made to understand its different facets. T cell differentiation is driven by mechanisms including antigen stimulation, co-stimulatory signals and cytokine milieu, all of which are abundant in the rheumatic joint, implying that any T cells migrating into the joint may be further affected locally. In parallel to the characterization and classification of T-cell subsets, the contribution of different effector T cells to RA has been investigated in numerous studies though sometimes with contradictory results. In particular, the frequency of Th1 and Th17 cells has been assessed in the synovial joints with various results that could, at least partly, be explained by the stage of the disease. For regulatory T cells, it is largely accepted that they accumulate in RA synovial fluid and that the equilibrium between regulatory T cells and effector cells is a key factor in controlling inflammation processes involved in RA. Recent phenotypic studies describe the possible implication of a novel subset of peripheral T helper cells (Tph) important for T-B cell cross talk and plasma cell differentiation in the RA joint of ACPA+ (autoantibodies against citrullinated proteins) RA patients. Finally, cytotoxic CD4+ T cells, historically described as increased in the peripheral blood of RA patients have attracted new attention in the last years. In view of the recently identified peripheral T-cell subsets, we will integrate immunological data as well as information on genetic variants and therapeutic strategy outcomes into our current understanding of the width of effector T cells. We will also integrate tissue-resident memory T cell aspects, and discuss similarities and differences with inflammatory conditions in skin (psoriasis) and mucosal organs (Crohn's disease).

Adoptive transfer of regulatory T cells stimulated by Allogeneic Hepatic Stellate Cells mitigates liver injury in mice with concanavalin A-induced autoimmune hepatitis

Regulatory T cell (Treg)-based therapy can effectively control autoimmune hepatitis (AIH). Hepatic stellate cells (HSC) can selectively stimulate allogeneic Treg proliferation following liver transplantation. This study tested the therapeutic effect and potential mechanisms underlying the action of HSC-stimulated Tregs on AIH in a mouse model of Concanavalin A (ConA)-induced AIH. HSC were isolated from BALB/c mice and characterized. Splenic CD4+CD25+ Tregs were isolated from C57BL/6 mice by immunomagnetic beads. The cells were co-cultured with primary (HSC-0), the second generation of HSC (HSC-2) for 72 h. The proliferation of Tregs was determined by flow cytometry. Similarly, the Tregs were co-cultured with HSC in transwell plates to determine the potential cell-cell contact dependent. The CD4+CD25− effector T cells (CFSE-Teffs) were co-cultured with Teff or Tregs in the presence or absence of HSC to determine the suppressive capacity of Tregs. The effects of Tregs or HSC-stimulated Tregs on AIH severity and the frequency of splenic Tregs and Th17 cells were examined in mice. Co-culture with HSC-2 significantly promoted Treg proliferation in a dose- and cell-cell contact-dependent manner, and allogeneic HSC enhanced the suppressive activity of Tregs to inhibit the proliferation of Teff in vitro. Adoptive transfer of Tregs, particularly of HSC-stimulated Tregs, significantly reduced liver injury, inflammation and Ishak modified histology activity index in AIH mice, which were associated with improving the balance of Treg and Th17 cell responses. Our data indicated that mature HSC stimulated allogeneic Treg proliferation in a dose and cell-cell contact-dependent manner, and HSC enhanced the suppressive activity of Tregs to inhibit the proliferation of Teff. Adoptive transfer of HSC-stimulated Tregs significantly reduced liver injury in AIH mice by modulating the balance of Treg and Th17 cell responses.

Altered Th17/Treg Ratio in Peripheral Blood of Systemic Lupus Erythematosus but Not Primary Antiphospholipid Syndrome.

Introduction: The role of the immune response in the pathogenesis of antiphospholipid syndrome (APS) remains elusive. It is possible that differences in the frequencies of Th17 cells and/or defects in the immunoregulatory mechanisms are involved in the pathogenesis of APS. Our aim was to determine the peripheral blood Th cells phenotype and the circulating cytokine profile in patients with primary APS (pAPS) and compare it with systemic lupus erythemathosus (SLE) as disease control group.Methods: The frequencies of circulating regulatory T cells (Tregs) were determined in PBMCs from 36 patients with pAPS by flow cytometry. As control groups we included 21 age- and gender-matched healthy controls (HC) and 11 patients with SLE. The suppressive capacity of Tregs was evaluated in vitro by coculture assay. On the other hand, intracellular cytokine production was assessed in Th1, Th2, and Th17 cells and circulating IL-6, IL-10, and IL-35 were measured by Cytometric Bead Array and ELISA. The quantification of Th master gene expression levels was performed by real time quantitative PCR.Results: pAPS patients and SLE patients did not show differences in the percentage or number of Tregs compared to HC. The suppressive capacity of Tregs was also similar in the three study group. Instead, we found higher FoxP3·mRNA expression levels in pAPS patients and HC than SLE patients. Regarding the Th17 response, patients with pAPS and HC showed a significantly lower frequency of circulating Th17 cells than SLE. However, no differences were observed in the Th1 response between patients and controls. Thus, increased Th17/Th1 and Th17/Treg ratios were found in SLE patients but not in pAPS patients. pAPS and SLE patients had higher serum IL-6 levels than HC but there was not difference between both disease groups. Besides, a significant increase in the immunosuppressive cytokine levels was observed only in pAPS as compared to HC.Conclusions: Our data demonstrate an increased inflammatory profile of peripheral blood CD4+ T cells from SLE as compared with pAPS mostly due to an increased Th17 response. In conclusion, there seems not to be a direct pathogenic role for Th cells in pAPS but in SLE.

Amlexanox attenuates experimental autoimmune encephalomyelitis by inhibiting dendritic cell maturation and reprogramming effector and regulatory T cell responses

BackgroundAmlexanox (ALX), a TBK1 inhibitor, can modulate immune responses and has anti-inflammatory properties. To investigate its role in regulating the progression of experimental autoimmune encephalomyelitis (EAE), we studied the effect of ALX on the maturation of dendritic cells (DCs) and the responses of effector and regulatory T cells (Tregs).MethodsIn vitro, bone marrow-derived DCs (BMDCs) were cultured and treated with ALX. Their proliferation, maturation, and their stimulatory function to induce T cells responses were detected. In vivo, the development of EAE from different groups was recorded. At the peak stage of disease, HE, LFB, and electronic microscope (EM) were used to evaluate inflammation and demyelination. Maturation of splenic DC and Th1/Th17/Treg response in the CNS and peripheral were also detected. To further explore the mechanism underlying the action of ALX in DC maturation, the activation of TBK1, IRF3, and AKT was analyzed.ResultsOur data indicated that ALX significantly inhibited the proliferation and maturation of BMDCs, characterized by the reduced MHCII, a co-stimulatory molecule, IL12, and IL-23 expression, along with morphological alterations. Co-culture of ALX-treated BMDCs inhibited allogeneic T cell proliferation and MOG-specific T cell response. In EAE mice, ALX significantly attenuated the EAE development by decreasing inflammatory infiltration and demyelination in the spinal cords, accompanied by reduced frequency of splenic pathogenic Th1 and Th17 cells and increased Tregs. Moreover, ALX treatment decreased Th1 and Th17 cytokines, but increased Treg cytokines in the CNS and spleen. Notably, ALX treatment reduced the frequency and expression of CD80 and CD86 on splenic DCs and lowered IL-12 and IL-23 secretion, further supporting an impaired maturation of splenic DCs. In addition, ALX potently reduced the phosphorylation of IRF3 and AKT in BMDC and splenic DCs, both of which are substrates of TBK1 and associated with DC maturation.ConclusionsALX, a TBK1 inhibitor, mitigated EAE development by inhibiting DC maturation and subsequent pathogenic Th1 and Th17 responses while increasing Treg responses through attenuating the TBK1/AKT and TBK1/IRF3 signaling.

Nanocurcumin: A novel strategy in treating ankylosing spondylitis by modulating Th17 cells frequency and function.

Ankylosing spondylitis (AS) is a chronic rheumatic disease which mainly affects the axial skeleton and sacroiliac joints. T-helper 17 (Th17) cells have been reportedly involved in AS pathogenesis. Nanocurcumin is considered to be beneficial, as an anti-inflammatory compound, in AS patients treatment. In this study, Th17-related immunological parameters were evaluated in AS patients. Transcription factors messenger RNA (mRNA) expression level, cytokines, and related microRNAs (miRNAs) were measured by real-time polymerase chain reaction. Additionally, Th17 frequency and cytokines secretion were evaluated by flow cytometry and enzyme-linked immunosorbent assay tests, respectively. The frequency of Th17 was higher in AS patients. Gained data from nanocurcumin group also demonstrated that retinoic acid-related orphan receptor γ (RORγt) and interleukin-17 (IL-17) mRNA expression levels were significantly decreased (P = 0.0001 and0.0006, respectively), as the decrease also happened in Th17-associated miRNAs including miR-141, miR-155, and miR-200 ( P = 0.04, P = 0.02, and P < 0.0001, respectively). Posttreatment data of miR-155 and miR-200 in the nanocurcumin and placebo groups also showed a higher expression level in the placebo group compared with nanocurcumin-treated patients. Some clinical symptoms of AS patients were also improved at the end of the treatment process. The results of this study showed the potential ability of nanocurcumin to regulate Th17 cells activity in AS patients. This study provided further evidence on the function and underlying mechanism of nanocurcumin helping better treatment of AS.

Protection from EAE in DOCK8 mutant mice occurs despite increased Th17 cell frequencies in the periphery.

Mutation of Dedicator of cytokinesis 8 (DOCK8) has previously been reported to provide resistance to the Th17 cell dependent EAE in mice. Contrary to expectation, we observed an elevation of Th17 cells in two different DOCK8 mutant mouse strains in the steady state. This was specific for Th17 cells with no change in Th1 or Th2 cell populations. In vitro Th cell differentiation assays revealed that the elevated Th17 cell population was not due to a T cell intrinsic differentiation bias. Challenging these mutant mice in the EAE model, we confirmed a resistance to this autoimmune disease with Th17 cells remaining elevated systemically while cellular infiltration in the CNS was reduced. Infiltrating T cells lost the bias toward Th17 cells indicating a relative reduction of Th17 cells in the CNS and a Th17 cell specific migration disadvantage. Adoptive transfers of Th1 and Th17 cells in EAE-affected mice further supported the Th17 cell-specific migration defect, however, DOCK8-deficient Th17 cells expressed normal Th17 cell-specific CCR6 levels and migrated toward chemokine gradients in transwell assays. This study shows that resistance to EAE in DOCK8 mutant mice is achieved despite a systemic Th17 bias.

Metabolic syndrome mediates proinflammatory responses of inflammatory cells in preeclampsia.

To investigate whether metabolic syndrome (MetS) is associated with exacerbation of inflammatory responses in preeclamptic (PE) patients, the dynamic changes of Th17 and Treg cells, monocytes, cytokines, and transcription pattern of inflammasome-related genes were analyzed in 35 women with PE suffering from MetS in comparison to 38 PE women without MetS and healthy pregnant women. Expression of inflammasome-related genes, cytokines, and also TLR4 was measured using real-time PCR. Serum and medium supernatant cytokines levels of PBMCs and serum levels of HMGB1 and Caspase-1 were also evaluated by ELISA. Monocytes, Th17, and Treg cells frequency were also determined by flow cytometry. PE women with MetS exhibited increased percentage of non-classical and intermediate monocytes and Th17 cells (P=0.025). Furthermore, decreased Treg cells frequency was also observed in PE women with MetS compared to PE women (P=0.019). The mRNA expression of inflammasome-related genes (Caspase-1, NLRP3, HMGB1), TLR4, IL-1β, IL-6, IL-17, IL-18, and TNF-α was significantly higher in PE patients with MetS than that of the healthy pregnant individuals (P<0.0001) and PE patients (P<0.0001). Serum levels of TGF-β and TNF-α in PE patients with MetS were increased compared to other two groups, while IL-10 levels were significantly reduced. A significant sFlt (P=0.016), Caspase-1 (P=0.012), HMGB1 (P=0.016) upregulation, and VEGF (P=0.023) downregulation were also observed in the serum of PE women having MetS compared to PE women. MetS is closely related to the exacerbation of inflammatory reactions in PE. This study indicates that, in order to diminish the systemic features of PE, prior to conceive and start a pregnancy, MetS should be severely considered and managed.

Protection against Staphylococcus aureus bacteremia-induced mortality depends on ILC2s and eosinophils.

The dysregulated, unbalanced immune response of sepsis results in a mortality exceeding 20%, yet recent findings by our group indicate that patients with allergic, type 2-mediated immune diseases are protected from developing sepsis. We evaluated CD4+ Th cell polarization among patients with Staphylococcus aureus bacteremia and confirmed that survivors had a higher percentage of circulating Th2 cells but lower frequencies of Th17 cells and neutrophils early in the course of infection. To establish the mechanism of this protection, we used a mouse model of lethal S. aureus bacteremia and found that intratracheal pretreatment with the type 2-initiating cytokine IL-33 activated pulmonary type 2 innate lymphoid cells (ILC2s) and promoted eosinophilia. In addition, stimulation of type 2 immunity before lethal infection suppressed the pulmonary neutrophilic response to S. aureus. Mice lacking functional ILC2s did not respond to IL-33 and were not protected from lethal bacteremia, but treatment of these mice with the type 2 cytokines IL-5 and IL-13 rescued them from death. Depletion of eosinophils abrogated IL-33-mediated protection, indicating that eosinophilia is also necessary for the survival benefit. Thus, we have identified a potentially novel mechanism by which type 2 immunity can balance dysregulated septic inflammatory responses, thereby clarifying the protective benefit of type 2 immune diseases on sepsis mortality.

Effects of vitamin D supplements on frequency of CD4+ T-cell subsets in women with Hashimoto's thyroiditis: a double-blind placebo-controlled study.

Vitamin D is a modulator of immune functions. Investigations on the mechanisms of vitamin D action and pathogenesis of Hashimoto's thyroiditis (HT) have revealed that vitamin D can reduce damages to thyroid cells caused by autoreactive immune cells. Totally, 48 female patients with HT disease were introduced to the study by endocrinologists. Patients were divided into two major groups of 24 individuals and treated weekly with 50,000 IU of cholecalciferol (vitamin D group) or placebo (placebo group) using oral administration for 3 months. Eventually, 17 of the 24 patients in each group finished the study. Before and after supplementation, frequencies of Th1, Th17, Th2 and Tr1 cells and mean fluorescent intensity (MFI) of the associated cytokines, including IFN-γ, IL-17, IL-4 and IL-10, were assessed using flow cytometry. Furthermore, gene expression of IL-10 was assessed using real-time PCR. Results of this study showed that cholecalciferol supplementation caused a significant decrease in Th17/Tr1 ratio. The proportion and MFI of Th1, Th2, Tr1 and Th17 cells included no significant changes in vitamin D group, compared to those in placebo group. Expression rate and MFI of IL-10 increased in both groups. This increase was higher in vitamin D group than placebo group with no significance. In this novel preliminary clinical trial study, supplementation with cholecalciferol in HT patients for 3 months changed the balance of CD4+ T-cell subsets to improve the disease control. However, further studies are necessary to investigate effects of vitamin D on immune functions in HT patients.