scholarly journals Early MyD88-Dependent Induction of Interleukin-17A Expression during Salmonella Colitis

2011 ◽  
Vol 79 (8) ◽  
pp. 3131-3140 ◽  
Author(s):  
A. Marijke Keestra ◽  
Ivan Godinez ◽  
Mariana N. Xavier ◽  
Maria G. Winter ◽  
Sebastian E. Winter ◽  
...  
Keyword(s):  
T Cells ◽  
Inflammatory Responses ◽  
Primary Response ◽  
Neutrophil Recruitment ◽  
T Helper 17 ◽  
Content Type ◽  
Interleukin 17A ◽  
Colitis Model ◽  
Cecal Mucosa

ABSTRACTThe development of T helper 17 (TH17) cells is a well-established adaptive mechanism for the production of interleukin-17A (IL-17A), a cytokine involved in neutrophil recruitment. However, pathways contributing to mucosal expression of IL-17A during the initial phase of a bacterial infection have received less attention. Here we used the mouse colitis model ofSalmonella entericaserotype Typhimurium infection to investigate the contribution of myeloid differentiation primary response protein 88 (MyD88) to inflammation and mucosal IL-17A expression. Expression of IL-23 in the cecal mucosa duringS.Typhimurium colitis was dependent on the presence of MyD88. Furthermore, initial expression of IL-17A at 24 h afterS.Typhimurium infection was dependent on MyD88 and the receptor for IL-1β. IL-23 and IL-1β synergized in inducing expression of IL-17A in splenic T cellsin vitro. In the intestinal mucosa, IL-17A was produced by three distinct T cell populations, including δγ T cells, TH17 cells, and CD4−CD8−T cells. The absence of IL-1β signaling or IL-17 signaling reduced CXC chemokine expression but did not alter the overall severity of pathological lesions in the cecal mucosa. In contrast, cecal pathology and neutrophil recruitment were markedly reduced in Myd88-deficient mice during the initial phases ofS.Typhimurium infection. Collectively, these data demonstrate that MyD88-dependent mechanisms, including an initial expression of IL-17A, are important for orchestrating early inflammatory responses duringS.Typhimurium colitis.

scholarly journals Microbial Amyloids Induce Interleukin 17A (IL-17A) and IL-22 Responses via Toll-Like Receptor 2 Activation in the Intestinal Mucosa

2012 ◽  
Vol 80 (12) ◽  
pp. 4398-4408 ◽  
Author(s):  
Jessalyn H. Nishimori ◽  
Tiffanny N. Newman ◽  
Gertrude O. Oppong ◽  
Glenn J. Rapsinski ◽  
Jui-Hung Yen ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Intestinal Mucosa ◽  
Amyloid Fibrils ◽  
Inflammatory Responses ◽  
Toll Like Receptor ◽  
T Helper ◽  
Content Type ◽  
Interleukin 17A ◽  
Toll Like Receptor 2

ABSTRACTThe Toll-like receptor 2 (TLR2)/TLR1 receptor complex responds to amyloid fibrils, a common component of biofilm material produced by members of the phylaFirmicutes,Bacteroidetes, andProteobacteria. To determine whether this TLR2/TLR1 ligand stimulates inflammatory responses when bacteria enter intestinal tissue, we investigated whether expression of curli amyloid fibrils by the invasive enteric pathogenSalmonella entericaserotype Typhimurium contributes to T helper 1 and T helper 17 responses by measuring cytokine production in the mouse colitis model. AcsgBAmutant, deficient in curli production, elicited decreased expression of interleukin 17A (IL-17A) and IL-22 in the cecal mucosa compared to theS. Typhimurium wild type. In TLR2-deficient mice, IL-17A and IL-22 expression was blunted duringS. Typhimurium infection, suggesting that activation of the TLR2 signaling pathway contributes to the expression of these cytokines. T cells incubated with supernatants from bone marrow-derived dendritic cells (BMDCs) treated with curli fibrils released IL-17A in a TLR2-dependent mannerin vitro. Lower levels of IL-6 and IL-23 production were detected in the supernatants of the TLR2-deficient BMDCs treated with curli fibrils. Consistent with this, three distinct T-cell populations—CD4+T helper cells, cytotoxic CD8+T cells, and γδ T cells—produced IL-17A in response to curli fibrils in the intestinal mucosa duringS. Typhimurium infection. Notably, decreased IL-6 expression by the dendritic cells and decreased IL-23 expression by the dendritic cells and macrophages were observed in the cecal mucosa of mice infected with the curli mutant. We conclude that TLR2 recognition of bacterial amyloid fibrils in the intestinal mucosa represents a novel mechanism of immunoregulation, which contributes to the generation of inflammatory responses, including production of IL-17A and IL-22, in response to bacterial entry into the intestinal mucosa.

scholarly journals Interleukin-17A as a Biomarker for Bovine Tuberculosis

2015 ◽  
Vol 23 (2) ◽  
pp. 168-180 ◽  
Author(s):  
W. Ray Waters ◽  
Mayara F. Maggioli ◽  
Mitchell V. Palmer ◽  
Tyler C. Thacker ◽  
Jodi L. McGill ◽  
...  
Keyword(s):  
Immune Responses ◽  
Bovine Tuberculosis ◽  
Mononuclear Cells ◽  
Inflammatory Responses ◽  
Interleukin 17 ◽  
T Helper 17 ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Interleukin 17A ◽  
Highly Correlated

ABSTRACTT helper 17 (Th17)-associated cytokines are integral to the immune responses to tuberculosis, initiating both protective and harmful inflammatory responses. The aim of the present study was to evaluate applied aspects of interleukin-17 (IL-17) biology in the context ofMycobacterium bovisinfection of cattle. Using transcriptome sequencing (RNA-Seq), numerous Th17-associated cytokine genes (including IL-17A, IL-17F, IL-22, IL-19, and IL-27) were upregulated >9-fold in response to purified protein derivative stimulation of peripheral blood mononuclear cells from experimentallyM. bovis-infected cattle. Protective vaccines elicited IL-17A, IL-17F, IL-22, and IL-27 responses. Reduced IL-17A responses by vaccine recipients, compared to nonvaccinated animals, at 2.5 weeks afterM. bovischallenge correlated with reduced disease burdens. Additionally, IL-17A and interferon gamma (IFN-γ) responses were highly correlated and exhibited similar diagnostic capacities. The present findings support the use of Th17-associated cytokines as biomarkers of infection and protection in the immune responses to bovine tuberculosis.

scholarly journals Enhancing the Nrf2 Antioxidant Signaling Provides Protection Against Trichloroethene-mediated Inflammation and Autoimmune Response

2020 ◽  
Vol 175 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Nivedita Banerjee ◽  
Hui Wang ◽  
Gangduo Wang ◽  
M Firoze Khan
Keyword(s):  
Oxidative Stress ◽  
T Cells ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Autoimmune Response ◽  
Mediated Effects ◽  
Antioxidant Gene Expression ◽  
Responsive Element

Abstract Trichloroethene (trichloroethylene, TCE) and one of its reactive metabolites dichloroacetyl chloride (DCAC) are associated with the induction of autoimmunity in MRL+/+ mice. Although oxidative stress plays a major role in TCE-/DCAC-mediated autoimmunity, the underlying molecular mechanisms still need to be delineated. Nuclear factor (erythroid-derived 2)-like2 (Nrf2) is an oxidative stress-responsive transcription factor that binds to antioxidant responsive element (ARE) and provides protection by regulating cytoprotective and antioxidant gene expression. However, the potential of Nrf2 in the regulation of TCE-/DCAC-mediated autoimmunity is not known. This study thus focused on establishing the role of Nrf2 and consequent inflammatory responses in TCE-/DCAC-mediated autoimmunity. To achieve this, we pretreated Kupffer cells (KCs) or T cells with/without tert-butylhydroquinone (tBHQ) followed by treatment with DCAC. In both KCs and T cells, DCAC treatment significantly downregulated Nrf2 and HO-1 expression along with induction of Keap-1 and caspase-3, NF-κB (p65), TNF-α, and iNOS, whereas pretreatment of these cells with tBHQ attenuated these responses. The in vitro findings were further verified in vivo by treating female MRL+/+ mice with TCE along with/without sulforaphane. TCE exposure in mice also led to reduction in Nrf2 and HO-1 but increased phospho-NF-κB (p-p65) and iNOS along with increased anti-dsDNA antibodies. Interestingly, sulforaphane treatment led to amelioration of TCE-mediated effects, resulting in Nrf2 activation and reduction in inflammatory and autoimmune responses. Our results show that TCE/DCAC mediates an impairment in Nrf2 regulation. Attenuation of TCE-mediated autoimmunity via activation of Nrf2 supports that antioxidants sulforaphane/tBHQ could be potential therapeutic agents for autoimmune diseases.

scholarly journals A Salmonella Virulence Factor Activates the NOD1/NOD2 Signaling Pathway

mBio ◽  
2011 ◽  
Vol 2 (6) ◽  
Author(s):  
A. Marijke Keestra ◽  
Maria G. Winter ◽  
Daisy Klein-Douwel ◽  
Mariana N. Xavier ◽  
Sebastian E. Winter ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Content Type ◽  
Type Iii

ABSTRACTThe invasion-associated type III secretion system (T3SS-1) ofSalmonella entericaserotype Typhimurium (S. Typhimurium) activates the transcription factor NF-κB in tissue culture cells and induces inflammatory responses in animal models through unknown mechanisms. Here we show that bacterial delivery or ectopic expression of SipA, a T3SS-1-translocated protein, led to the activation of the NOD1/NOD2 signaling pathway and consequent RIP2-mediated induction of NF-κB-dependent inflammatory responses. SipA-mediated activation of NOD1/NOD2 signaling was independent of bacterial invasionin vitrobut required an intact T3SS-1. In the mouse colitis model, SipA triggered mucosal inflammation in wild-type mice but not in NOD1/NOD2-deficient mice. These findings implicate SipA-driven activation of the NOD1/NOD2 signaling pathway as a mechanism by which the T3SS-1 induces inflammatory responsesin vitroandin vivo.IMPORTANCESalmonella entericaserotype Typhimurium (S. Typhimurium) deploys a type III secretion system (T3SS-1) to induce intestinal inflammation and benefits from the ensuing host response, which enhances growth of the pathogen in the intestinal lumen. However, the mechanisms by which the T3SS-1 triggers inflammatory responses have not been resolved. Here we show that the T3SS-1 effector protein SipA induces NF-κB activation and intestinal inflammation by activating the NOD1/NOD2 signaling pathway. These data suggest that the T3SS-1 escalates innate responses through a SipA-mediated activation of pattern recognition receptors in the host cell cytosol.

scholarly journals Regulatory T Cells Contribute to Resistance against Lyme Arthritis

2020 ◽  
Vol 88 (11) ◽  
Author(s):  
Emily M. Siebers ◽  
Elizabeth S. Liedhegner ◽  
Michael W. Lawlor ◽  
Ronald F. Schell ◽  
Dean T. Nardelli
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lyme Disease ◽  
Regulatory T Cells ◽  
Regulatory T Cell ◽  
Interleukin 10 ◽  
Lyme Arthritis ◽  
Interleukin 17 ◽  
Content Type

ABSTRACT The symptoms of Lyme disease are caused by inflammation induced by species of the Borrelia burgdorferi sensu lato complex. The various presentations of Lyme disease in the population suggest that differences exist in the intensity and regulation of the host response to the spirochete. Previous work has described correlations between the presence of regulatory T cells and recovery from Lyme arthritis. However, the effects of Foxp3-expressing CD4+ T cells existing prior to, and during, B. burgdorferi infection have not been well characterized. Here, we used C57BL/6 “depletion of regulatory T cell” mice to assess the effects these cells have on the arthritis-resistant phenotype characteristic of this mouse strain. We showed that depletion of regulatory T cells prior to infection with B. burgdorferi resulted in sustained swelling, as well as histopathological changes, of the tibiotarsal joints that were not observed in infected control mice. Additionally, in vitro stimulation of splenocytes from these regulatory T cell-depleted mice resulted in increases in gamma interferon and interleukin-17 production and decreases in interleukin-10 production that were not evident among splenocytes of infected mice in which Treg cells were not depleted. Depletion of regulatory T cells at various times after infection also induced rapid joint swelling. Collectively, these findings provide evidence that regulatory T cells existing at the time of, and possibly after, B. burgdorferi infection may play an important role in limiting the development of arthritis.

scholarly journals Oleuropein modulates over-proliferation of keratinocytes in mice with imiquimodmediated psoriasis and inhibits differentiation of TH17 cells through the JAK3/STAT3 axis

2020 ◽  
Author(s):  
Quan Shi ◽  
Qi He ◽  
Weiming Chen ◽  
Jianwen Long ◽  
Bo Zhang
Keyword(s):  
T Cells ◽  
In Silico ◽  
Th17 Cells ◽  
Skin Lesions ◽  
Docking Studies ◽  
Inflammatory Disorder ◽  
T Helper 17 ◽  
In Silico Docking

IntroductionOleuropein (OLP) is polyphenol obtained from olive oil; it is proved in Chinese traditional medicine for its use in disorders including autoimmune and inflammatory disorders. Psoriasis (PSR) is an autoimmune and inflammatory disorder triggered by T-helper-17 (Th17) cells.Material and methodsWe developed an imiquimod (IMQ)-mediated PSR model in mice to study the anti-inflammatory role of OLP in psoriasis. The mice were given 50 mg/kg and 100 mg/kg dose of OLP. Histology was done to assess the inflammation of lesions. Western blot analysis was done for JAK3/STAT3 in isolated T cells, expression of RORgt was done by RT-PCR. The In silico molecular docking studies were done for interaction of OLP with target protein STAT3 and JAK3.ResultsTreatment of OLP attenuated proliferation in IMQ-mediated keratinocytes, improved infiltration of CD3+ cells in the skin lesions and in CD4+ and CD8+ T cells and also ameliorated the levels of cytokines. In in vitro studies in isolated T cells, OLP blocked the differentiation of Th17 cells and also the levels of IL-17 and the JAK3/STAT3 pathway. The in silico docking showed that OLP had potential binding affinity with JAK3 and STAT3 which was parallel to in vivo and in vitro findings.ConclusionsOLP ameliorates psoriasis skin lesions by blocking Th17-mediated inflammation. OLP may be an interesting molecule for treating autoimmunity in psoriasis.

scholarly journals Tim-3 Induces Th2-Biased Immunity and Alternative Macrophage Activation during Schistosoma japonicum Infection

2015 ◽  
Vol 83 (8) ◽  
pp. 3074-3082 ◽  
Author(s):  
Nan Hou ◽  
Xianyu Piao ◽  
Shuai Liu ◽  
Chuang Wu ◽  
Qijun Chen
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Schistosoma Japonicum ◽  
Immune Cell ◽  
Nk Cell ◽  
Alternative Activation ◽  
Interleukin 12 ◽  
Content Type

T cell immunoglobulin- and mucin-domain-containing molecule 3 (Tim-3) has been regarded as an important regulatory factor in both adaptive and innate immunity. Recently, Tim-3 was reported to be involved in Th2-biased immune responses in mice infected withSchistosoma japonicum, but the exact mechanism behind the involvement of Tim-3 remains unknown. The present study aims to understand the role of Tim-3 in the immune response againstS. japonicuminfection. Tim-3 expression was determined by flow cytometry, and increased Tim-3 expression was observed on CD4+and CD8+T cells, NK1.1+cells, and CD11b+cells from the livers ofS. japonicum-infected mice. However, the increased level of Tim-3 was lower in the spleen than in the liver, and no increase in Tim-3 expression was observed on splenic CD8+T cells or CD11b+cells. The schistosome-induced upregulation of Tim-3 on natural killer (NK) cells was accompanied by reduced NK cell numbersin vitroandin vivo. Tim-3 antibody blockade led to upregulation of inducible nitric oxide synthase and interleukin-12 (IL-12) mRNA in CD11b+cells cocultured with soluble egg antigen and downregulation of Arg1 and IL-10, which are markers of M2 macrophages. In summary, we observed schistosome-induced expression of Tim-3 on critical immune cell populations, which may be involved in the Th2-biased immune response and alternative activation of macrophages during infection.

scholarly journals Protective effect of Lactobacillus reuteri DSM 17938 against experimental necrotizing enterocolitis is mediated by Toll-like receptor 2

2018 ◽  
Vol 315 (2) ◽  
pp. G231-G240 ◽  
Author(s):  
Thomas K. Hoang ◽  
Baokun He ◽  
Ting Wang ◽  
Dat Q. Tran ◽  
J. Marc Rhoads ◽  
...  
Keyword(s):  
T Cells ◽  
Necrotizing Enterocolitis ◽  
Immune Modulation ◽  
Lactobacillus Reuteri ◽  
Inflammatory Responses ◽  
Cow Milk ◽  
Toll Like Receptor ◽  
Toll Like Receptor 2 ◽  
Anti Inflammatory

Lactobacillus reuteri DSM 17938 (LR 17938) has been shown to reduce the incidence and severity of necrotizing enterocolitis (NEC). It is unclear if preventing NEC by LR 17938 is mediated by Toll-like receptor 2 (TLR2), which is known to mediate proinflammatory responses to bacterial cell wall components. NEC was induced in newborn TLR2−/− or wild-type (WT) mice by the combination of gavage-feeding cow milk-based formula and exposure to hypoxia and cold stress. Treatment groups were administered formula supplemented with LR 17938 or placebo (deMan-Rogosa-Sharpe media). We observed that LR 17938 significantly reduced the incidence of NEC and reduced the percentage of activated effector CD4+T cells, while increasing Foxp3+ regulatory T cells in the intestinal mucosa of WT mice with NEC, but not in TLR2−/− mice. Dendritic cell (DC) activation by LR 17938 was mediated by TLR2. The percentage of tolerogenic DC in the intestine of WT mice was increased by LR 17938 treatment during NEC, a finding not observed in TLR2−/− mice. Furthermore, gut levels of proinflammatory cytokines IL-1β and IFN-γ were decreased after treatment with LR 17938 in WT mice but not in TLR2−/− mice. In conclusion, the combined in vivo and in vitro findings suggest that TLR2 receptors are involved in DC recognition and DC-priming of T cells to protect against NEC after oral administration of LR 17938. Our studies further clarify a major mechanism of probiotic LR 17938 action in preventing NEC by showing that neonatal immune modulation of LR 17938 is mediated by a mechanism requiring TLR2. NEW & NOTEWORTHY Lactobacillus reuteri DSM 17938 (LR 17938) has been shown to protect against necrotizing enterocolitis (NEC) in neonates and in neonatal animal models. The role of Toll-like receptor 2 (TLR2) as a sensor for gram-positive probiotics, activating downstream anti-inflammatory responses is unclear. Our current studies examined TLR2 −/− mice subjected to experimental NEC and demonstrated that the anti-inflammatory effects of LR 17938 are mediated via a mechanism requiring TLR2.

scholarly journals TRAF6 inhibits Th17 differentiation and TGF-β–mediated suppression of IL-2

Blood ◽  
2010 ◽  
Vol 115 (23) ◽  
pp. 4750-4757 ◽  
Author(s):  
Pedro J. Cejas ◽  
Matthew C. Walsh ◽  
Erika L. Pearce ◽  
Daehee Han ◽  
Gretchen M. Harms ◽  
...  
Keyword(s):  
T Cells ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Transforming Growth Factor Β ◽  
Main Function ◽  
Normal Numbers ◽  
T Helper 17 ◽  
Th17 Differentiation

Abstract Transforming growth factor-β (TGF-β) has an essential role in the generation of inducible regulatory T (iTreg) and T helper 17 (Th17) cells. However, little is known about the TGF-β–triggered pathways that drive the early differentiation of these cell populations. Here, we report that CD4+ T cells lacking the molecular adaptor tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) exhibit a specific increase in Th17 differentiation in vivo and in vitro. We show that TRAF6 deficiency renders T cells more sensitive to TGF-β–induced Smad2/3 activation and proliferation arrest. Consistent with this, in TRAF6-deficient T cells, TGF-β more effectively down-regulates interleukin-2 (IL-2), a known inhibitor of Th17 differentiation. Remarkably, TRAF6-deficient cells generate normal numbers of Foxp3-expressing cells in iTreg differentiation conditions where exogenous IL-2 is supplied. These findings show an unexpected role for the adaptor molecule TRAF6 in Smad-mediated TGF-β signaling and Th17 differentiation. Importantly, the data also suggest that a main function of TGF-β in early Th17 differentiation may be the inhibition of autocrine and paracrine IL-2–mediated suppression of Th17 cell generation.

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