Frequency Of Th17 Cells Research Articles

Effects of Probiotic Strains on Disease Activity and Enteric Permeability in Psoriatic Arthritis-A Pilot Open-Label Study.

(1) Background: Psoriatic Arthritis (PsA) is a painful disease of the joints and spine. Recent reports observed distinct enteric dysbiosis in PsA; intake of probiotic strains is considered to ameliorate enteric dysbiosis. If probiotics are effective in PsA is elusive. (2) Methods: In this pilot open-label study we enrolled 10 PsA patients with low to medium disease activity who received probiotics for 12 weeks. Analysis of faecal zonulin, α1-antitrypsin and calprotectin, as well as peripheral immune phenotyping was performed at baseline, after 12 weeks and 12 weeks after termination of probiotic intake. (3) Results: All patients showed increased levels of the enteric permeability marker zonulin which correlated with the frequency of peripheral Th17 cells. Calprotectin, a marker for intestinal inflammation was elevated in 6 out of 10 patients. Probiotic intake resulted in a reduction of disease activity and gut permeability. These effects, however, were not sustained beyond termination of probiotic intake. (4) Conclusions: PsA patients suffer from enhanced enteric permeability and inflammation. Probiotics may ameliorate disease activity in PsA by targeting these alterations.

To study the role of T regulatory cells in developing asthma in a birth cohort of babies with family history of allergies

Asthma is known to be correlated with TH2 immune response. There is evidence that T-regulatory cells are important to prevent allergic diseases like asthma. There are few studies based on the role of Treg cell in birth cohort babies with family history of allergy. Fifty children with asthma and respiratory allergy (study group), 20 children born with a positive family history and being followed up as a birth cohort (cohort group) and a group of 10 healthy children with no history of allergy in the family were considered to be satisfactory (Control group) were recruited in this study. Total IgE level, pulmonary function test (PFT) was assessed. The levels of TH1, TH2, TH17 and CD4+ CD25high FoxP3+ Treg cells expression were determined by Flow cytometry [FACSCanto (Becton Dickinson, Mountain View, CA, USA) with FACS DivaTM software]. The Ethics Committee of PGIMER approved this study (Micro / 2006 / 754 / 8th May 2006). The average level of total IgE in the studied group was 316.8±189.8 IU/mL and significantly higher than cohort (124±28.5 IU/mL, p<0.0001) and control (50±17.5 IU/mL, p<0.0001). The frequency of TH17 cells and culture supernatant level of IL-17 were 12.09±8.67 pg/ml and significantly higher in study group than corresponding level in cohort [5.91±3.56 pg/mL, p<0.001] and control group [2.01±1.27 pg/mL, p<0.001], whereas the frequency of Foxp3 level were significantly lower in study group [(49.00±13.47) %] and cohort group [(68.22±8.55) %] compare to the control group [(95.91±2.63) %]. The total serum IgE level is negatively correlated with FoxP3 level (r= -0.5273 p<0.0001). The FoxP3 expression is negatively correlated with the IL-17 levels (r= -0.5631, p< 0.0001) and IL-4 levels (r= -0.2836 p=0.0460). Imbalance in TH17/Treg was found in patients with allergic asthma. Elevated IL-17 and IL-4 cytokine response and down regulation of FoxP3 were associated with asthma. We also found that T regulatory cells expression decreases as asthma progression.

Association of Pathogenic Th17 Cells with the Disease Severity and Its Potential Implication for Biological Treatment Selection in Psoriasis Patients.

Psoriasis is an inflammatory autoimmune disease characterized by cutaneous lesions in plaques. It has been proposed that the immune response has a key role in the disease progression. Particularly, the Th17 cells through IL-17 can contribute to maintain the inflammatory process. The pathogenic Th17 phenotype has been described in human diseases and associated with high severity in inflammatory experimental models. However, it is not clear if the pathogenic phenotype could be present in the skin and peripheral blood as well as its possible association to severity in psoriasis. In the lesional skin, we found high infiltration of Th17 cells and the pathogenic phenotype, finding a correlation between the frequency of Th17 cells and the Psoriasis Area and Severity Index (PASI) score. In peripheral blood, we observed a pool of Th17 lymphocytes with potential to acquire pathogenic features. Interestingly, the percentage of pathogenic Th17 cells (CD4+ RORγt+ IFN-γ+) correlates with disease severity. Moreover, we distinguished three groups of patients based on their IL-17/IFN-γ production by Th17 lymphocytes, which seems to be related with a dynamic or stable potential to express these cytokines. Remarkably, we evaluated the cytokine production by Th17 cells as an immunological marker for the adequate selection of biologic therapy. We found that patients analyzed by this immunological approach and treated with antibodies against IL-17 and TNFα showed great improvement depicted by reduction in PASI and Dermatology Life Quality Index (DLQI) score as well as the percentage of Body Surface Area (BSA). Altogether, our results highlight the importance of the assessment of the pathogenic phenotype in Th17 cells as an immune personalized analysis with the potential to support the therapy choice in the clinical practice.

Increased AHR Transcripts Correlate With Pro-inflammatory T-Helper Lymphocytes Polarization in Both Metabolically Healthy Obesity and Type 2 Diabetic Patients

Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor whose transcription activity is regulated by small compounds provided by diet, xenobiotics, and metabolism. It has been proven to be involved in energy homeostasis and inflammation in most recent years. Epidemiologically, exposure to xenobiotic AHR ligands contributes to obesity and type 2 diabetes (T2D). AHR is also the critical transcription factor determining the lineage commitment of pro-inflammatory Th17 and Th22 cells from naïve CD4+ T lymphocytes. It has been well-illustrated in animal models that IL-22, the major effector cytokine of Th17 and Th22 cells, played a major role in the interaction of metabolism and gut microbiota. But there were still missing links between gut microbiota, IL-22, and metabolism in humans. Our previous findings indicated that elevated circulating levels of IL-22 and frequencies of Th22 cells were associated with insulin resistance in both patients with obesity and T2D. Additionally, the hyperactive Th17 and Th22 cells phenotype also correlate with islets β-cell dysfunction in T2D. In this study, we made efforts to determine AHR expressions in peripheral blood mononuclear cells (PBMCs) from patients with T2D and metabolically healthy obesity (MHO). Correlation analyses were conducted to assess the possible link between AHR and the metabolic and inflammatory context. We revealed that mRNA expression of AHR was up-regulated and correlated with the percentage of Th17, Th22 as well as Th1 cells. Elevated plasma levels of IL-22 and IL-17 also correlated with increased AHR transcripts in PBMCs from both MHO and T2D patients. The transcription factor AHR may thus have a plausible role in the interaction between metabolism and pro-inflammatory status of patients in the development of obesity and T2D.

High salt diet may promote progression of breast tumor through eliciting immune response

ObjectiveDietary patterns are believed to regulate tumor progression by altering the tumor microenvironment. Of note, a high salt diet is a risk factor for various diseases. However, the role of high salt intake in the progression of cancers remains unknown. MethodsWe constructed an in vivo high salt diet model in MMTV-PyVT mice with spontaneous tumor-forming properties to explore the role of a high salt diet in the progression of breast cancer as well as the modulation of the tumor microenvironment. Also, in vitro experiments were performed to understand the mechanism. ResultsHigh salt diet accelerated the development (P < 0.05) and lung metastasis (P < 0.05) of breast cancer in MMTV-PyVT mice, compared to the normal diet model. Moreover, higher frequency of Th17 cells in circulation, tumor tissue and draining lymph node tissue were observed in the high salt diet model (P < 0.05 for all). In vitro, co-culture with Th17 cells facilitated the proliferation, migration and invasion of MCF-7 human breast cancer cells, while these enhanced aggressive behaviors could be reversed by application of 1,25-vitamin D3 which could inhibit the differentiation of Th17 cells (P < 0.001 for all). In vitro, co-culture with Th17 cells activated MAPK signaling in MCF-7 cells (P < 0.001 for all). Consistently, activated MAPK/ERK signaling was observed by immunohistochemistry in breast cancer cell nodes in the high salt diet model (P < 0.05 for all). Mechanistically, higher level of IL-17F could be detected in breast tumors and serum from the high salt diet model through qRT-PCR and ELISA (P < 0.05 for all). IL-17F treatment facilitated the proliferation, migration and invasion of MCF-7 human breast cancer cells and activated MAPK/ERK signaling in MCF-7 cells (P < 0.001 for all). Moreover, the tumor-promoting function induced by Th17 cells and IL-17F could be inhibited by the administration of ERK inhibitor (sch772894) (P < 0.001 for all). Lastly, high concentration NaCl-induced Th17 cells promoted the proliferation, migration and invasion of MCF-7 human breast cancer cells and activated MAPK/ERK signaling in MCF-7 cells which could be inhibited by neutralizing anti-IL-17F (P < 0.001 for all). ConclusionHigh salt intake accelerates the growth of breast cancer and facilitates lung metastasis, as well as increases the level of Th17 cells. Increased Th17 cells might promote the growth of breast cancer via the secretion of IL-17F to activate the MAPK signaling pathway in breast cancer cells.

Soluble IL-2R\u03b1 correlates with imbalances of Th1/Th2 and Tc1/Tc2 cells in patients with acute brucellosis

BackgroundPrevious studies showed that soluble IL-2Rα is an important marker of cellular immune activation and might be a marker of treatment efficacy for children with brucellosis. However, data regarding adult patients with brucellosis were unknown. The aim of study was to explore the potential role of serum sIL-2Rα evaluating treatment responses in adult patients with brucellosis, and T cell immune status was also examined.MethodsDuring January 2016–April 2017, 30 patients with acute brucellosis from the Third People’s Hospital of Linfen in Shanxi Province and Beijing Di Tan Hospital, and 28 healthy controls were included in this study. Peripheral blood samples were collected before and after six weeks of antibiotic treatment. Serum sIL-2Rα levels were measured by enzyme-linked immunosorbent assay, and the percentage of Th1, Th2, Tc1, Tc2, and Tregs was detected by flow cytometry after intracellular staining for cytokines (interferon-γ and interleukin-4) and Foxp3 in T lymphocytes from peripheral blood. The obtained data were analyzed with Wilcoxon ranked sum tests for paired values, Mann-Whitney U-tests for comparisons between patients and healthy controls, and Spearman rank tests for correlation analyses.ResultsSerum sIL-2Rα levels were significantly higher in patients than in controls (P = 0.001). A significant decline was observed in patients after the cessation of treatment (P < 0.001) and return to normal (P > 0.05). Th1, Tc1, Th2, and Tc2 cell frequencies were higher in patients than in healthy subjects (P < 0.05), while the Th1/Th2 and Tc1/Tc2 ratios were significantly lower (P = 0.0305 and 0.0005, respectively) and returned to normal levels after treatment. In patients with acute brucellosis, serum sIL-2Rα levels were negatively correlated with the Th1/Th2 ratio (r = − 0.478, P = 0.028), Tc1/Tc2 ratio (r = − 0.677, P = 0.001), and Tc1 percentage (r = − 0.516, P = 0.017). Serum sIL-2Rα and Tc2 percentages were positively correlated (r = 0.442, P = 0.045).ConclusionsBased on the correlations with Th1/Th2 and Tc1/Tc2 ratios, serum sIL-2Rα levels may reflect the immune response status. sIL-2Rα may be a marker for therapeutic efficacy in acute brucellosis.

Intrahepatic T helper 17 cells recruited by hepatitis B virus X antigen-activated hepatic stellate cells exacerbate the progression of chronic hepatitis B virus infection.

Immunopathological injury induced by persistent hepatitis B virus (HBV) infection contributes to the progression from chronic hepatitis B (CHB) to hepatic cirrhosis and hepatocellular carcinoma (HCC). Regulatory T cells (Tregs), CD4+ T helper (Th) cells, and hepatic stellate cells (HSCs) are considered to be the pivotal factors during this progression. In this study, our aim was to investigate the molecular mechanisms of liver immunopathological injury associated with Tregs, CD4+ Th cells, and HSCs. Liver tissues were collected to assay the cytokines and distribution and frequencies of CD4+ Th cells and Tregs. The chemotaxis of Th17 cells towards the liver and the interactions between IL-22, IL-17A, and HSCs were explored. The data showed the frequencies of Th17 cells, and their effector molecules IL-22 and IL-17A were increased along with the severity of chronic liver diseases. However, the frequencies of Tregs were decreased in HBV-associated cirrhotic tissues compared with those in CHB tissues and HCC tissues. hepatitis B virus X antigen (HBxAg)-activated HSCs recruited more Th17 cells into the liver and conduced to the secretion of IL-17A and IL-22 that could in turn stimulate the proliferation and fibrotic marker secretion of the HSCs. Therefore, we suggest that the interactions between Th17 cells, IL-17A, IL-22, and HSCs form a positive feedback loop that aggravated the progression of chronic liver disease with HBV infection through the phosphoinositide-3-kinase/protein kinase B (PI3K/AKT) signalling pathway. Our findings indicated the IL-17A/IL-22 pathway might become a new treatment target for liver cirrhosis and HCC.

Mechanisms behind the Immunoregulatory Dialogue between Mesenchymal Stem Cells and Th17 Cells.

Mesenchymal stem cells (MSCs) exhibit potent immunoregulatory abilities by interacting with cells of the adaptive and innate immune system. In vitro, MSCs inhibit the differentiation of T cells into T helper 17 (Th17) cells and repress their proliferation. In vivo, the administration of MSCs to treat various experimental inflammatory and autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes, multiple sclerosis, systemic lupus erythematosus, and bowel disease showed promising therapeutic results. These therapeutic properties mediated by MSCs are associated with an attenuated immune response characterized by a reduced frequency of Th17 cells and the generation of regulatory T cells. In this manuscript, we review how MSC and Th17 cells interact, communicate, and exchange information through different ways such as cell-to-cell contact, secretion of soluble factors, and organelle transfer. Moreover, we discuss the consequences of this dynamic dialogue between MSC and Th17 well described by their phenotypic and functional plasticity.

Lipocalin-2 Exacerbates Lupus Nephritis by Promoting Th1 Cell Differentiation.

Lipocalin-2 (LCN2) is an indicator of the severity of lupus nephritis (LN) and plays a pivotal role in immune responses, but it is not known if its effect on LN pathogenesis derives from regulating the immune imbalance of T lymphocyte subsets. The expression of LCN2 in T cells and kidneys was assessed in renal biopsies from patients with LN. We investigated the relationship between LCN2 levels and development of LN and systemic illness by injecting anti-LCN2 antibodies into MRL/lpr mice and analyzing pristane-treated LCN2-/- mice. LCN2 is highly expressed in CD4+ T cells and in renal tissues, and is associated with severe renal damage in patients with LN and in mice with experimental lupus. LCN2 promotes IFN-γ overexpression in CD4+ T cells through the IL-12/STAT4 pathway in an autocrine or paracrine manner. Both neutralization of LCN2 in MRL/lpr mice and genetic depletion of LCN2 in pristane-induced lupus mice greatly ameliorate nephritis. The frequency and number of splenic and renal Th1 cells decrease in proportion to LN disease activity. Conversely, administration of LCN2 exacerbates the disease with significantly higher renal activity scores and increased numbers of Th1 cells. LCN2 plays a crucial role in Th1 cell differentiation, and may present a potential therapeutic target for LN.

Virologic and Immunologic Features of Simian Immunodeficiency Virus Control Post-ART Interruption in Rhesus Macaques.

Antiretroviral therapy (ART) cannot eradicate human immunodeficiency virus (HIV) and a rapid rebound of virus replication follows analytical treatment interruption (ATI) in the vast majority of HIV-infected individuals. Sustained control of HIV replication without ART has been documented in a subset of individuals, defined as posttreatment controllers (PTCs). The key determinants of post-ART viral control remain largely unclear. Here, we identified 7 SIVmac239-infected rhesus macaques (RMs), defined as PTCs, who started ART 8 weeks postinfection, continued ART for >7 months, and controlled plasma viremia at <104 copies/ml for up to 8 months after ATI and <200 copies/ml at the latest time point. We characterized immunologic and virologic features associated with post-ART SIV control in blood, lymph node (LN), and colorectal (RB) biopsy samples compared to 15 noncontroller (NC) RMs. Before ART initiation, PTCs had higher CD4 T cell counts, lower plasma viremia, and SIV-DNA content in blood and LN compared to NCs, but had similar CD8 T cell function. While levels of intestinal CD4 T cells were similar, PTCs had higher frequencies of Th17 cells. On ART, PTCs had significantly lower levels of residual plasma viremia and SIV-DNA content in blood and tissues. After ATI, SIV-DNA content rapidly increased in NCs, while it remained stable or even decreased in PTCs. Finally, PTCs showed immunologic benefits of viral control after ATI, including higher CD4 T cell levels and reduced immune activation. Overall, lower plasma viremia, reduced cell-associated SIV-DNA, and preserved Th17 homeostasis, including at pre-ART, are the main features associated with sustained viral control after ATI in SIV-infected RMs.IMPORTANCE While effective, antiretroviral therapy is not a cure for HIV infection. Therefore, there is great interest in achieving viral remission in the absence of antiretroviral therapy. Posttreatment controllers represent a small subset of individuals who are able to control HIV after cessation of antiretroviral therapy, but characteristics associated with these individuals have been largely limited to peripheral blood analysis. Here, we identified 7 SIV-infected rhesus macaques that mirrored the human posttreatment controller phenotype and performed immunologic and virologic analysis of blood, lymph node, and colorectal biopsy samples to further understand the characteristics that distinguish them from noncontrollers. Lower viral burden and preservation of immune homeostasis, including intestinal Th17 cells, both before and after ART, were shown to be two major factors associated with the ability to achieve posttreatment control. Overall, these results move the field further toward understanding of important characteristics of viral control in the absence of antiretroviral therapy.

A recombinant protein rLZ-8, originally extracted from Ganoderma lucidum, ameliorates OVA-induced lung inflammation by regulating Th17/Treg balance.

Asthma is one of the most common chronic and inflammatory respiratory diseases, which is estimated to affect 1-10% of the population in different regions across the world. Previous studies have shown that recombinant Ling-Zhi 8 (rLZ-8), an immunoregulatory protein originally extracted from Ganoderma lucidum, plays multiple roles in regulating murine immune cells, including T cells. Here, we examined whether rLZ-8 would ameliorate pulmonary inflammation in a model of asthma-like mice. We found that rLZ-8 significantly inhibited the lung inflammation and reduced infiltration of inflammatory cells, including dendritic cells and eosinophils, in OVA-induced asthmatic mice. It also deceased IL-17A level but increased IL-10 level in bronchoalveolar lavage fluid (BALF) while reducing RORγt mRNA expression and enhancing Foxp3 mRNA level in the lung tissue. Flow cytometry studies demonstrated that rLZ-8 remarkably down-regulated Th17 cells but upregulated Foxp3+ regulatory T (Treg) cells, rather than influencing Th1 versus Th2 cells. Experiments in vitro also showed that rLZ-8 suppressed murine CD3+ T cell proliferation and reduced the frequency of Th17 cells while promoting the differentiation of CD4+ Foxp3+ Tregs. Moreover, rIL-8 similarly altered human Th17/Treg generation or their balance in vitro. Finally, we found that rLZ-8 suppressed signaling pathways of both STAT3 and NF-κB (P100/P52) in murine lung tissue as well as cultured T cells. Thus, we have demonstrated that rLZ-8 attenuates pulmonary inflammation through regulating the balance of Th17/Treg cells in OVA-induced asthmatic mice and that rLZ-8 may be a potential therapeutic agent for the treatment of asthma in clinic.

Functional analysis of two STAT1 gain-of-function mutations in two Iranian families with autosomal dominant chronic mucocutaneous candidiasis.

Candidiasis is characterized by susceptibility to recurrent or persistent infections caused by Candida spp., typically Candida albicans, of cutaneous and mucosal surfaces. In this report, function and frequency of Th17 cells as well as genetics of patients susceptible to mucocutaneous candidiasis were studied. For patients, T-cell proliferation tests in response to Candida antigen, Th17 cell proportions, and STAT1 phosphorylation were evaluated through flow cytometry. Expression of IL17A, IL17F and IL22 genes were measured by real-time quantitative PCR. At the same time, whole exome sequencing was performed for all patients. We identified two heterozygous substitutions, one: c.821G>A (p. R274Q) was found in a multiplex family with three individuals affected, the second one: c.812A>C (p. Q271P) was found in a sporadic case. Both mutations are located in the coiled-coil domain (CCD) of STAT1. The frequency of Th17 cells, IL17A, IL17F, and IL22 gene expression in patients' peripheral blood mononuclear cells (PBMCs), and T-cell proliferation to Candida antigens were significantly reduced in the patients as compared to healthy controls. An increased STAT1 phosphorylation was observed in patients' PBMCs upon interferon (IFN)-γ stimulation as compared to healthy controls. We report two different but neighboring heterozygous mutations, located in exon 10 of the STAT1 gene, in four Iranian patients with CMC, one of whom also had hypothyroidism. These mutations were associated with impaired T cell proliferation to Candida antigen, low Th17 cell proportions, and increased STAT1 phosphorylation upon IFN-γ. We suggest that interfering with STAT1 phosphorylation might be a promising way for potential therapeutic measurements for such patients.

Immunomodulatory effects of platelets on the severity of hand, foot, and mouth disease infected with enterovirus 71

BackgroundEnterovirus 71 (EV71) infection contributes to hand, foot, and mouth disease (HFMD) with severe neurogenic complications, leading to higher morbidity. In addition to their typical roles in coagulation, platelets could serve as essential immune regulatory cells to play a key role in the pathogenesis of this viral infection.MethodsPlatelet parameters were measured using an automatic hematology analyzer. T-helper type 1 (Th1) and Th2 cells were analyzed by flow cytometry. The levels of cytokines and key transcription factors were determined.ResultsThe levels of platelet count and plateletcrit were positively associated with the severity of HFMD. Th1 and Th2 cells as well as their corresponding cytokines were increased in the severe group compared to the healthy volunteers. Moreover, the levels of platelets were negatively correlated with the level of interferon-γ (IFN-γ), but positively correlated with the frequency of Th1 cells. Coculture of platelets and naive CD4+ T cells showed that platelets from mild patients promote Th1 cell differentiation and IFN-γ secretion.ConclusionsOur study has shown for the first time that the distinct roles of platelets are responsible for the regulation of pathogenic CD4+ T cell differentiation and function in the pathogenesis of HFMD caused by EV71.ImpactOur study has shown for the first time that the distinct roles of platelets are responsible for the regulation of pathogenic CD4+ T cell differentiation and function in the pathogenesis of HFMD caused by EV71.For the first time, we have discovered the role of platelets in children’s HFMD caused by EV71 infection, which may provide a better treatment for HFMD in the future.This article describes new discoveries in platelet immunity.

Th17 cell frequency and IL-17A production in peripheral blood of patients with non-small-cell lung cancer.

ObjectiveThis study investigated the frequency of T-helper (Th)17 lymphocytes and production of cytokine interleukin (IL)-17 in peripheral blood of patients with non-small-cell lung cancer (NSCLC) and their use as a marker of clinical value.MethodsSixty patients with NSCLC and 60 healthy volunteers were enrolled in the study. Flow cytometry was used to detect the frequency of Th17 lymphocytes in peripheral blood, and enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of IL-17. We analyzed the association of Th17 lymphocytes and IL-17 levels in the peripheral blood of patients with their clinicopathological features.ResultsFrequency of Th17 lymphocytes and production of IL-17 were significantly higher in the NSCLC group than in the control group and were higher in patients with a smoking history compared with non-smokers. Moreover, Th17 lymphocyte and IL-17 expression levels were higher in patients with squamous cell carcinoma than in patients with adenocarcinoma, and significantly higher in patients with stage III and IV cancers than in patients at stage I or II.ConclusionTh17 lymphocytes and IL-17 play an important role in the development of NSCLC in patients and may have clinical value as markers for treatment of NSCLC.

P0419AUTOANTIGEN-SPECIFIC TH17 AND TH22 INFLAME THE KIDNEY IN ANCA-VASCULITIS

Abstract Background and Aims Anti-neutrophil-cytoplasmic-antibody (ANCA)-associated-vasculitis (AAV) is an autoimmune small-vessel-vasculitis. T-cells play a pivotal role in pathogenesis as drivers of autoantibody formation and vasculitic damage. However, the involvement of T-cells in renal vasculitis is understood poorly. IL-17C is secreted by epithelial parenchymal cells enhancing the pathogenicity of Th17 cells. Furthermore, IL-17C is a chemotactic factor for Th17 cells. The aim of this study was to assess the role of Th17 cells and IL-17C in the pathogenesis of ANCA-vasculitis in an animal model of AAV. Method Wistar-Kyoto-rats were immunized with myeloperoxidase (MPO) in Freunds Adjuvant to induce AAV. Control rats were immunized with Freunds Adjuvant only. Albuminuria was determined weekly and rats were culled after two, four and six weeks. At the time of harvest, renal T-cells were isolated and characterized by flow cytometry. Antigen-specificity was determined by ELiSPOT. Petechial bleedings on the lung surface reflecting pulmonary vasculitis were quantified after harvest. Gene expression in spleen, kidneys and lungs was studied by PCR and is expressed as fold change over controls. IL-17C levels were measured in sera by ELISA. Results MPO-rats developed detectable titres of anti-MPO by week two. By week six, all MPO-animals developed renal vasculitis with significant albuminuria and pulmonary vasculitis. Accordingly, MPO animals showed significant crescent formation as compared to the controls (% of affected glomeruli: 11.4 ±10.5% vs. 0.4 ±0.7%, p&amp;lt;0.005). The petechial bleeding score on the lung surface was higher in MPO-immunized rats than in controls at week six (68 ±13 vs. 2 ±1, p&amp;lt;0.05). From week two on, Th17 and Th22 cells inflamed the kidney as determined by PCR and/or flow cytometry in MPO-rats. The Th17 and Th22 infiltrate was heaviest at week six post-immunization. The intra-renal T-cell response was skewed towards Th17 as compared to the frequency of splenic Th17 cells in MPO-rats (9.1 ±4.3% vs. 1.9 ±0.6%, p&amp;lt;0.005). The majority of intra-renal Th17 and Th22 cells was MPO-specific. Control rats did not show renal T-cell infiltration. Renal transcripts for IL-17C were slightly decreased in week 2 (0.88 ±0.1 fold), unchanged in week four (1.0 ±0.2) and slightly increased in week six after immunization (1.7 ±0.7 fold). Pulmonary IL-17C mRNA transcripts were decreased during weeks two and four after disease induction as compared to controls (0.29 ±0.07 fold, 0.98 ±0.2 fold). During week six, pulmonary IL-17C mRNA transcripts were slightly increased over controls (1.9 ±0.4 fold). Serum levels of IL17C were unchanged during weeks two to six after disease induction comparing MPO-immunized rats and controls. Conclusion Th17 and Th22 cells are drivers of renal inflammation in ANCA-vasculitis. The role of IL-17C in this cascade needs to be determined.

Biological and clinical significance of T helper 17 cell deficiency: insight into monogenic defects.

T helper 17 (Th17) are a CD4+ T subpopulation cells which are involved in the host protection against microbes such as extracellular and intracellular bacteria, parasites, fungi, and viruses. Monogenic defects including those mutations in some genes such as the signal transducer and activator of transcription (STAT)1 and 3, dedicator of cytokinesis 8 (DOCK8), autoimmune regulator (AIRE), and interleukin 17 receptor A (IL-17RA) can lead to impairment in Th17 cell development and function along with the concomitant increased risk for chronic mucocutaneous candidiasis (CMC). The immunologic abnormalities in these patients include low frequency of Th17 cells; defective cutaneous or in vitro T cell response to Candida species, and/or autoantibodies against relevant cytokines. This review outlines the biological characteristics and functionality of Th17 cells, as well as the clinical features of individuals with genetic defects associated with Th17 deficiency.

Elevated levels of IL-17A and IL-35 in plasma and bronchoalveolar lavage fluid are associated with checkpoint inhibitor pneumonitis in patients with non-small cell lung cancer.

Advances in the immunology have identified that interleukin (IL)-17 and IL-35 are cytokines with diverse functions, serving important roles in autoimmune diseases and chronic inflammation. Checkpoint inhibitor pneumonitis (CIP) is focal or diffuse lung inflammation induced by immune checkpoint inhibitors and the underlying pathogenesis has not been fully explored. The aim of the present study was to investigate the roles of IL-17A and IL-35, and the correlation between their levels and different T cell subsets in CIP. The levels of IL-17A and IL-35 in peripheral blood and bronchoalveolar lavage fluid (BALF) were measured in patients with non-small cell lung cancer (NSCLC) with CIP, and the corresponding controls. The percentages of helper T lymphocyte (Th)1, Th2 and Th17 cells, and regulatory T cells (Tregs) in the peripheral blood were synchronically detected. Serum levels of IL-17A and IL-35 were significantly increased at the time of CIP diagnosis compared with the baseline, and significantly decreased upon clinical recovery or improvement. IL-17A and IL-35 were also increased in the BALF during the development of CIP compared with the baseline. Serum levels of IL-17A were positively correlated with the percentages of Th1 and Th17 cells as well as the ratio of Th17 to Tregs, but negatively associated with the frequency of Tregs in CIP. Serum levels of IL-35 were positively correlated with the percentages of Th1 and Tregs, and with the ratio of Th1 to Th2 cells in CIP. A higher frequency of Th1 and Th17 cells, as well as higher ratios of Th17 to Tregs and Th1 to Th2 cells were detected upon development of CIP comparing with the baseline. These data suggested that the activation of Th1 and Th17 cells, as well as Treg inhibition contributed to the imbalanced ratios of Th1 to Th2 and Th17 to Tregs, which resulted in increased secretion of IL-17A and IL-35 in the plasma and BALF; this may present a valuable index to monitor the development and severity of CIP in patients with NSCLC receiving immunotherapy.

High abundance of genus Prevotella is associated with dysregulation of IFN-I and T cell response in HIV-1-infected patients.

HIV-1-associated dysbiosis is most commonly characterized by overall decreased diversity, with abundance of the genus Prevotella, recently related to inflammatory responses. A pilot study including 10 antiretroviral therapy-treated HIV-1-infected men and 50 uninfected controls was performed to identify the main gut dysbiosis determinants (e.g. Prevotella enrichment), that may affect mucosal antiviral defenses and T cell immunity in HIV-1-infected individuals. 16rRNA gene sequencing was applied to the HIV-1-infected individuals' fecal microbiota and compared with controls. Measurements of CD4 and CD8 T cell activation [CD38, human leukocyte antigen (HLA)-DR, CD38 HLA-DR] and frequencies of Th17, obtained from lamina propria lymphocytes isolated from five different intestinal sites, were performed by flow cytometry. IFNβ, IFNAR1 and MxA gene expression level was evaluated by real-time PCR in lamina propria lymphocytes. Nonparametric t tests were used for statistical analysis. HIV-1-infected men had a significant fecal microbial communities' imbalance, including different levels of genera Faecalibacterium, Prevotella, Alistipes and Bacteroides, compared with controls. Notably, Prevotella abundance positively correlated with frequencies of CD4 T cells expressing CD38 or HLA-DR and coexpressing CD38 and HLA-DR (P < 0.05 for all these measures). The same trend was observed for the activated CD8 T cells. Moreover, Prevotella levels were inversely correlated with IFN-I genes (P < 0.05 for IFNβ, IFNAR1 and MxA genes) and the frequencies of Th17 cells (P < 0.05). By contrast, no statistically significant correlations were observed for the remaining bacterial genera. Our findings suggest that Prevotella enrichment might affect gut mucosal IFN-I pathways and T cell response in HIV-1-infected patients, thus contributing to immune dysfunction.

Evaluation of regulatory immune cells that favor engraftment following haploidentical peripheral blood stem cell transplantation for sickle cell disease

Abstract Haploidentical hematopoietic stem cell transplantation is one of the most widely available curative options for patients with sickle cell disease (SCD). Our previous non-myeloablative haploidentical peripheral blood stem cell transplantation (PBSCT) trial showed improved engraftment with post-transplant cyclophosphamide, but with a high incidence of allograft rejection. Here, our aim was to evaluate mechanisms of engraftment in SCD patients who underwent PBSCT. We analyzed and compared the following cells (Treg, Tr1, Th1, Th17, NK, Breg, pmnMDSCs, mMDSCs, eMDSCs, mDCs, and pDCs) in peripheral blood samples obtained from 20 transplanted patients at baseline (BSL), post-transplant day (PT-D) 30, 60, 100, and 180 using flow cytometry. Because we previously showed that 20% donor myeloid chimerism (DMC) is sufficient to reverse SCD, we classified patients at each time point as engrafted (DMC ≥20%) and rejected (DMC&amp;lt; 20%). Early MDSC frequencies were significantly elevated in engrafted patients (PT-D30). Patients were also evaluated based on engrafted/rejected at the end of study and mMDSC and Th17 cell frequencies were significantly elevated at PT-D30 and PT-D60 respectively in engrafted patients. All other cell populations were not statistically different. Tregs showed an elevated trend in engrafted patients and exhibited direct proportionality in patients with varying DMC levels. Our results reveal that eMDSC and mMDSC frequencies were elevated in engrafted patients and decreasing Tregs were associated with decreasing DMC. Taken together, eMDSCs, mMDSCs and Tregs may have a synergistic association in favoring the development of a tolerogenic immune milieu that promotes stable mixed chimerism after PBSCT in SCD patients.

Understanding human Crohn’s disease: T cell immunoprofiling and in vitro primary intestinal epithelial monolayer models

Abstract Crohn’s disease (CD) is a type of inflammatory bowel disease caused by uncontrolled inflammation and is associated with loss of tolerance to commensal bacteria. There is no current consensus on how CD forms; however, four susceptibility criteria are required for disease: a microbial presence, an immune response, an environmental trigger, and genetic susceptibility. We investigated the peripheral and intestinal immune response of people with CD compared to healthy people. CD peripheral blood (PBMC) contained higher baseline frequencies of pro-inflammatory Th17 cells compared to those from healthy controls, and regulatory T cells from CD patients increased in frequency in response to the commensal Faecalibacterium prausnitzii, whereas those from healthy controls did not. CD patient PBMCs secreted higher concentrations of the pro-inflammatory cytokines: IL-6, TNF, and IL-17A, compared to healthy controls. We developed a human 2-dimensional large intestine organoid monolayer transwell model that replicates the in vivo intestinal epithelial barrier as the cells of the epithelial monolayer are arranged into a selectively semi-permeable polarised membrane, separating the apical and basal regions of the system, emulating the luminal and lamina propria intestinal regions. Co-culture of CD patient-derived monolayers with patient PBMCs and heat-killed F. prausnitzii caused disruption of monolayer integrity, whereas control patient monolayers were unaffected. IL-6 was present in control monolayer supernatants but not those from CD patients. We hypothesise that CD patient PBMCs have inherent abnormal responses to commensal bacteria, and in the context of this model, IL-6 may be required for maintenance of monolayer integrity.