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IL-10
Kinds of IL-10 Terms modified by IL-10 Selected AbstractsRegulation of nickel-induced T-cell responsiveness by CD4+CD25+cells in contact allergic patients and healthy individualsCONTACT DERMATITIS, Issue 2 2005H. Moed In this study, we investigated the capacity of CD4+CD25+ regulatory T cells to suppress nickel-specific effector T cells, both in nickel-allergic patients and healthy controls. CD4+ cells isolated from allergic patients showed an increased proliferative response to nickel, whereas CD4+ cells from negative controls did not respond to allergen. When CD4+CD25+ cells were depleted, nickel-specific responsiveness was strongly increased both in allergic and in non-allergic individuals, with the most pronounced effect in allergic patients. These regulatory T cells were anergic to nickel but inhibited nickel-specific CD4+CD25, effector T cells in coculture experiments. CD4+CD25+ cells from nickel-allergic patients showed only a limited capacity to suppress effector T-cell responsiveness, because an increased nickel reactivity could still be detected in these cocultures. None of the isolated CD4+CD25+ cells, either isolated from healthy controls or allergic patients, produced IL-10 in response to nickel. Overall, these results support the view that CD4+CD25+ cells can control the activation of nickel-specific effector T cells in non-allergic individuals, whereas this regulatory capacity is impaired in allergic patients. To investigate the presence of allergen-specific regulatory T cells in truly naïve, non-sensitized individuals, T-cell reactivity should also be studied with non-environmental contact allergens, such as para-phenylenediamine. [source] Adenosine infusion attenuates soluble RAGE in endotoxin-induced inflammation in human volunteersACTA PHYSIOLOGICA, Issue 1 2009A. Soop Abstract Aim:, To evaluate possible anti-inflammatory effects of pre-treatment with adenosine in a human experimental inflammatory model. Methods:, The study design was double-blind, crossover, placebo-controlled and randomized. In the Intensive Care Unit of a university hospital, 16 healthy male volunteers were treated for 5.5 h with infusions of adenosine 40 ,g kg,1 min,1 or placebo. Thirty minutes after the start of adenosine or placebo, 2 ng kg,1E-Coli endotoxin was administered. Heart rate, body temperature, blood pressure, plasma cytokines (TNF-,, IL-6 and IL-10), soluble RAGE and resistin, exhaled nitric oxide and nitrite/nitrate in urine were determined. Results:, Endotoxin elicited the expected clinical signs of an inflammatory reaction (tachycardia, fever) and led to prominent release of the cytokines studied (P < 0.001). Resistin in plasma increased after endotoxin (P < 0.001). After placebo treatment, soluble RAGE (sRAGE) in plasma increased 5 h after the endotoxin challenge (P < 0.001) but not after adenosine. After placebo, orally exhaled NO increased with a peak at 4 h (P < 0.001), although there was no statistically significant difference between the two treatments. Nitrite/nitrate in urine (n = 11) did not differ between adenosine and placebo treatments. Conclusion:, In conclusion, adenosine infusion starting before endotoxin challenge in humans attenuated sRAGE significantly but otherwise had no clear anti-inflammatory effect. Adenosine as a potential anti-inflammatory treatment in humans needs further study, including use of higher doses. The mechanism underlying the effect of adenosines on sRAGE remains unknown. [source] Interleukin-10 is associated with resistance to febrile seizures: Genetic association and experimental animal studiesEPILEPSIA, Issue 4 2009Yoshito Ishizaki Summary Purpose:, Febrile seizures (FS) are the most common form of childhood convulsions. Many reports have shown that a proinflammatory cytokine, interleukin-1 (IL-1) ,, may have a facilitatory effect on the development of FS. We have previously shown that the IL1B -511C/T single nucleotide polymorphism (SNP) is associated with simple FS of sporadic occurrence. The balance between pro- and antiinflammatory cytokines influences the regulation of infections and could, therefore, play a role in the pathogenesis of FS. Here, to determine whether pro- and antiinflammatory cytokine genes are responsible for the susceptibility to FS, we have performed an association study on functional SNPs of cytokine genes in FS patients and controls. Methods:, The promoter SNPs of four inflammatory cytokine genes (IL6 -572C/G, IL8 -251A/T, IL10 -592A/C and TNFA -1037C/T) were examined in 249 patients with FS (186 simple and 63 complex FS) and 225 controls. Because the IL10 -592 SNP showed a positive association with FS, two additional SNPs (IL10 -1082A/G and -819T/C) were subjected to haplotype analysis. Furthermore, we examined the in vivo role of IL-10 in hyperthermia-induced seizures using immature animal models. Results:, The frequencies of the IL10 -592C allele and -1082A/-819C/-592C haplotype were significantly decreased in FS as compared with in controls (p = 0.014 and 0.013, respectively). The seizure threshold temperature in the IL-10,administered rats was significantly higher than that in the saline-treated control ones (p = 0.027). Conclusions:, The present study suggests that IL-10 is genetically associated with FS and, contrary to IL-1,, confers resistance to FS. [source] Cytomegalovirus hyperimmunoglobulin: mechanisms in allo-immune response in vitroEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2007K. Hoetzenecker Abstract Background Cytomegalovirus hyperimmunoglobulin (CMVIg) containing drugs are routinely administered in cardiac transplantation for prophylaxis against CMV disease. Yet little is known about their influence on transplant relevant immune functions. The aim of this study was to evaluate the effect of CMVIg on cellular immunity in in vitro experiments and to define their role in tolerance inducing mechanisms. Materials and methods/results CMVIg reduces proliferation in mixed lymphocyte reactions and anti-CD3 blastogenesis assays and is related to decreased production of immune modulating cytokines interleukin (IL)-2, interferonr (IFN,), IL-10. This antiproliferative effect is associated with a cell-cycle arrest in the G0/G1 phase and induction of apoptosis in CD8+ and natural killer cells. Co-incubation with CMVIg causes down-regulation of cell bound immunoglobulin and Fc,RIII surface expression on natural killer cells and leads to attenuation of antibody dependent cellular cytotoxicity effector functions. Conclusions We conclude that CMVIg induces immunological features on leukocytes in vitro that are known to be related to tolerance induction. Our observations extend the current concept of CMVIg as passive CMV prophylaxis to a therapeutic drug compound capable of reducing allogeneic immune response. [source] 22-ene-25-oxa-vitamin D: a new vitamin D analogue with profound immunosuppressive capacitiesEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 5 2005C. Daniel Abstract Background, The biologic role of 1,25-dihydroxyvitamin D3, such as anti-inflammatory functions, reduction of cytokine production by T cells and immunoglobulin production by B cells, is well established. However, its clinical use as an immunosuppressive agent is limited because of the hypercalcemic toxicity occurring after systemic application. The purpose of this study was to investigate the immunmodulatory effects of 22-ene-25-oxa-vitamin D (ZK156979), a novel low calcemic vitamin D analogue. Materials and methods, Human peripheral blood mononuclear cells (PBMCs) from healthy donors were isolated using the Ficoll Hypaque technique, cultured for 24 h and treated with different concentrations of ZK156979 ranging from 10,5 to 10,10 mol L,1 compared with 1,25-dihydroxyvitamin D3[10,5,10,10 mol L,1] following phytohaemagglutinin (PHA) stimulation. Interferon gamma (IFN,), tumour necrosis factor alpha (TNF,), interleukin 1 beta (IL-1,), interleukin 10 (IL-10) and interleukin 4 (IL-4) secretion in supernatants were measured by ELISA. Results, ZK156979 inhibited the PHA-induced Th1-response (IFN, and TNF, levels) and the macrophage-product IL-1, in a concentration-dependent manner (10,10,10,5 mol L,1) with the efficiency on cytokine expression compared with 1,25-dihydroxyvitamin D3 being slightly reduced. In contrast, ZK156979 and 1,25-dihydroxyvitamin D3 both affected the Th2 response, leading to significantly increased IL-10- and IL-4 secretion. Conclusions, ZK156979 is a member of novel vitamin D analogues revealing prominent immunomodulatory and suppressive characteristics with distinctive inhibition of Th1-cytokines whereas the Th2 compartment is augmented, thus providing a considerable therapeutic potential in T-cell -mediated diseases. [source] Procoagulant and inflammatory response of virus-infected monocytesEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2002J. J. M. Bouwman Abstract Background Monocytes play a prominent role in inflammation, coagulation and atherosclerosis by their ability to produce tissue factor (TF) and cytokines. The aim of the present study was to establish whether virus-infected monocytes initiate coagulation. In addition, the production of cytokines by monocytes may accelerate the chronic process of atherosclerosis and may contribute to coronary syndromes by eliciting plaque instability. Materials and methods Monocytes were isolated by Vacutainer®, BD Biosciences, Alphen aan den Rijn, Netherlands and subsequent magnetic cell sorting (MACS®, Milteny Biotec, Bergish Gladbach, Germany). Coagulation times in normal pooled plasma and Factor VII-deficient plasma were measured after infection with cytomegalovirus (CMV), Chlamydia pneumoniae (Cp) and influenza A\H1N1. Anti-TF antibodies were added to neutralize TF expressed on monocytes. Interleukins (IL) 6, 8 and 10 were measured in the supernatants. Results Chlamydia pneumoniae- and CMV-infected monocytes decreased the clotting time by 60%, and influenza-infected monocytes by 19%, as compared to uninfected monocytes. Procoagulant activity was absent when Factor VII-deficient plasma or anti-TF antibodies were used. Monocytes produced both IL-6 and IL-8 after infection with CMV (317 pg mL,1 and 250 pg mL,1) or Cp (733 pg mL,1 and 268 pg mL,1). Similar results were obtained for influenza virus-infected monocytes, but the levels of both cytokines were 3,5-fold higher (1797 pg mL,1 and 725 pg mL,1). Interleukin-10 was not produced by infected monocytes. Conclusion The procoagulant activity of virus-infected monocytes is TF-dependent. Although influenza infection did not generate a significant reduction in clotting time, the pronounced expression of IL-6 and IL-8 may induce local and/or systemic inflammatory reactions, which may be associated with plaque rupture and atherosclerosis. The lack of production of the anti-inflammatory cytokine IL-10 may even accelerate these processes. [source] Interferon-, in healthy subjects: selective modulation of inflammatory mediatorsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2001J. De Metz Background It is suggested that interferon-, (IFN-,), like other cytokines, is a mediator in the host inflammatory response, which could be of importance in the pathophysiology of sepsis. The role of IFN-, in human host inflammatory responses, however, has not been studied. Design In a placebo-controlled trial we studied the acute effects of IFN-, administration on host inflammatory mediators in healthy men: i.e. the cytokine/chemokine cascade system, acute-phase proteins, activation markers of the innate cellular immunity and coagulation/fibrinolysis parameters. Results IFN-, increased plasma levels of interleukin-6 (IL-6), IL-8 and IFN-,-inducible protein-10 (IP-10) (P < 0·05), but did not affect plasma levels of other cytokines (IL-4, IL-10, tumour necrosis factor-,, IL-12p40/p70). Plasma concentrations of C-reactive protein and secretory phospholipase A2 both increased (P < 0·05). Plasma levels of the leucocyte activation marker elastase-,1,antitrypsin complexes increased after IFN-, administration (P < 0·05), IFN-, increased the percentage of high-affinity Fc,-receptor (Fc,RI) -positive neutrophils (P < 0·05), but did not affect the mean fluorescence intensity of Fc,RI on neutrophils. Procoagulant and profibrinolytic effects of IFN-, were evidenced by increased plasma levels of prothrombin fragment F1 + F2, tissue-plasminogen activator and plasmin-,2,antiplasmin complexes (P < 0·05). Conclusion We conclude that IFN-, selectively affects host inflammatory mediators in humans. [source] Transforming growth factor-beta1 affects interleukin-10 production in the bone marrow of patients with chronic idiopathic neutropeniaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2007Katerina Pyrovolaki Abstract Background:, Chronic idiopathic neutropenia (CIN) is a bone marrow (BM) failure syndrome characterized by accelerated apoptosis of myeloid progenitor cells because of a local imbalance between pro-inflammatory and anti-inflammatory cytokines. In this study, we investigated the interplay among transforming growth factor-beta1 (TGF-,1), interleukin-10 (IL-10), and soluble flt-3 ligand (sFL) within the BM of CIN patients and probed the role of these cytokines in the pathophysiology of CIN. Design:, We used long-term BM cultures (LTBMC) to evaluate TGF-,1, IL-10, and sFL levels in CIN patients (n = 70) and healthy subjects (n = 35). Cytokine levels in LTBMC supernatants were correlated with the number of circulating neutrophils and the proportion of BM CD34+/CD33+ myeloid progenitor cells. Results:, CIN patients had increased TGF-,1 and sFL levels in LTBMCs compared with controls and individual cytokine values were found to be correlated inversely with the number of neutrophils and the proportion of CD34+/CD33+ cells. Patients displayed low supernatant IL-10 levels compared with controls and cytokine values were found to be correlated positively with the number of neutrophils and the proportion of CD34+/CD33+ cells. The levels of TGF-,1 were found to be inversely correlated with IL-10 and positively with sFL values in LTBMC, supernatants suggesting a possible interplay among these cytokines in CIN BM. Neutralization of TGF-,1 in LTBMCs increased IL-10 levels significantly in patients but not in controls, while neutralization had no effect on sFL levels. Conclusion:, Excessive production of TGF-,1 within the BM microenvironment of CIN patients results in downregulation of IL-10 and reduction of myeloid progenitor cells. Overexpression of sFL probably represents a compensatory mechanism to the low myeloid progenitor cells. [source] Long-term effects of idiotype vaccination on the specific T-cell response in peripheral blood and bone marrow of multiple myeloma patientsEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2007Amir Osman Abdalla Abstract Objectives:, To elucidate long-term effects of idiotype (Id) vaccination on Id-specific T cells of multiple myeloma (MM) patients and compare Id-specific T-cell responses of peripheral blood with those of bone marrow (BM). Materials and methods:, Id-specific T-cell responses of peripheral blood mononuclear cells (PBMC) were compared with those of BM mononuclear cells (BMMC) in 10 MM patients vaccinated with the Id protein at a median time of 41 months since the last immunization. The PBMC responses at late follow-up were also compared with those during active immunization. The responses were assessed by a proliferation assay, enzyme-linked immunospot (ELISPOT) (,-interferon), cytometric bead array (CBA) for secreted cytokines and quantitative real-time polymerase chain reaction (QRT-PCR) for cytokine gene expression. Results:, At the late testing time, an Id-specific response was detected in PBMC of five patients (ELISPOT, CBA, QRT-PCR) and in BMMC of four patients (CBA, QRT-PCR). A response in both compartments was noted only in three patients. The cytokines gene profile was consistent with a predominance of Th2 cells [interleukin (IL)-4, IL-5, IL-10]. Comparison of the Id-specific responses of PBMC during active immunization with those at the late follow-up showed that the frequency and magnitude of the responses had decreased significantly by time (proliferation/ELISPOT) (P < 0.02) and shifted at the gene level from a Th1 to a Th2 profile (P < 0.05). Conclusion:, Id-specific T cells may decline overtime and shift toward a Th2 response and may be found at a similar frequency of patients in blood and BM. [source] What are regulatory B cells?EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2010David Gray Abstract B cells are now acknowledged to play multiple roles in the immune response, in addition to making antibodies. Their role in regulating T-cell responses during inflammation has come into focus recently. Thus, IL-10 production by B cells has been shown to be important in limiting auto-reactive and pathogen-driven immune pathology; however, the exact identity of the regulatory B cells remains elusive; do they belong to a committed subset or can all B cells regulate given the appropriate inducing stimuli? A study in this issue of the European Journal of Immunology provides insight into the IL-10-producing B cells in humans, suggesting that many B cells have the capacity to make IL-10 when optimally stimulated via the BCR and TLR9. Despite producing significant amounts of inflammatory cytokines as well, these B cells suppress T-cell proliferation. This Commentary places this study in the context of what we think we know about regulatory B cells and more importantly highlights the questions we still need to answer. [source] Targeting of LcrV virulence protein from Yersinia pestis to dendritic cells protects mice against pneumonic plagueEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2010Yoonkyung Do Abstract To help design needed new vaccines for pneumonic plague, we targeted the Yersinia pestis LcrV protein directly to CD8,+ DEC-205+ or CD8,, DCIR2+ DC along with a clinically feasible adjuvant, poly IC. By studying Y. pestis in mice, we could evaluate the capacity of this targeting approach to protect against a human pathogen. The DEC-targeted LcrV induced polarized Th1 immunity, whereas DCIR2-targeted LcrV induced fewer CD4+ T cells secreting IFN-,, but higher IL-4, IL-5, IL-10, and IL-13 production. DCIR-2 targeting elicited higher anti-LcrV Ab titers than DEC targeting, which were comparable to a protein vaccine given in alhydrogel adjuvant, but the latter did not induce detectable T-cell immunity. When DEC- and DCIR2-targeted and F1-V+ alhydrogel-vaccinated mice were challenged 6,wk after vaccination with the virulent CO92 Y. pestis, the protection level and Ab titers induced by DCIR2 targeting were similar to those induced by F1-V protein with alhydrogel vaccination. Therefore, LcrV targeting to DC elicits combined humoral and cellular immunity, and for the first time with this approach, also induces protection in a mouse model for a human pathogen. [source] Memory B cells from a subset of treatment-naïve relapsing-remitting multiple sclerosis patients elicit CD4+ T-cell proliferation and IFN-, production in response to myelin basic protein and myelin oligodendrocyte glycoproteinEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2010Christopher T. Harp Abstract Recent evidence suggests that B- and T-cell interactions may be paramount in relapsing-remitting MS (RRMS) disease pathogenesis. We hypothesized that memory B-cell pools from RRMS patients may specifically harbor a subset of potent neuro-APC that support neuro-Ag reactive T-cell proliferation and cytokine secretion. To test this hypothesis, we compared CD80 and HLA-DR expression, IL-10 and lymphotoxin-, secretion, neuro-Ag binding capacity, and neuro-Ag presentation by memory B cells from RRMS patients to naïve B cells from RRMS patients and to memory and naïve B cells from healthy donors (HD). We identified memory B cells from some RRMS patients that elicited CD4+ T-cell proliferation and IFN-, secretion in response to myelin basic protein and myelin oligodendrocyte glycoprotein. Notwithstanding the fact that the phenotypic parameters that promote efficient Ag presentation were observed to be similar between RRMS and HD memory B cells, a corresponding capability to elicit CD4+ T-cell proliferation in response to myelin basic protein and myelin oligodendrocyte glycoprotein was not observed in HD memory B cells. Our results demonstrate for the first time that the memory B-cell pool in RRMS harbors neuro-Ag specific B cells that can activate T cells. [source] Tumor expression of CD200 inhibits IL-10 production by tumor-associated myeloid cells and prevents tumor immune evasion of CTL therapyEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2010Lixin Wang Abstract CD200 is a cell-surface glycoprotein that functions through interaction with the CD200 receptor on myeloid lineage cells to regulate myeloid cell functions. Expression of CD200 has been implicated in multiple types of human cancer; however, the impact of tumor expression of CD200 on tumor immunity remains poorly understood. To evaluate this issue, we generated CD200-positive mouse plasmacytoma J558 and mastocytoma P815 cells. We found that established CD200-positive tumors were often completely rejected by adoptively transferred CTL without tumor recurrence; in contrast, CD200-negative tumors were initially rejected by adoptively transferred CTL but the majority of tumors recurred. Tumor expression of CD200 significantly inhibited suppressive activity and IL-10 production by tumor-associated myeloid cells (TAMC), and as a result, more CTL accumulated in the tumor and exhibited a greater capacity to produce IFN-, in CD200-positive tumors than in CD200-negative tumors. Neutralization of IL-10 significantly inhibited the suppressor activity of TAMC, and IL-10-deficiency allowed TAMC to kill cancer cells and their antigenic variants, which prevented tumor recurrence during CTL therapy. Thus, tumor expression of CD200 prevents tumor recurrence via inhibiting IL-10 production by TAMC. [source] Multiple functions of human T cells generated by experimental malaria challengeEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2009Stephen M. Todryk Abstract Protective immunity generated following malaria infection may be comprised of Ab or T cells against malaria Ag of different stages; however, the short-lived immunity that is observed suggests deficiency in immune memory or regulatory activity. In this study, cellular immune responses were investigated in individuals receiving Plasmodium falciparum sporozoite challenge by the natural (mosquito bite) route as part of a malaria vaccine efficacy trial. Parasitemia, monitored by blood film microscopy and PCR, was subsequently cleared with drugs. All individuals demonstrated stable IFN-,, IL-2 and IL-4 ex vivo ELISPOT effector responses against P. falciparum -infected RBC (iRBC) Ag, 28 and 90,days after challenge. However, infected RBC-specific central memory responses, as measured by IFN-, cultured ELISPOT, were low and unstable over time, despite CD4+ T cells being highly proliferative by CFSE dilution, and showed an inverse relationship to parasite density. In support of the observation of poor memory, co-culture experiments showed reduced responses to common recall Ag, indicating malaria-specific regulatory activity. This activity could not be accounted for by the expression of IL-10, TGF-,, FOXP3 or CTLA-4, but proliferating T cells expressed high levels of CD95, indicating a pro-apoptotic phenotype. Lastly, there was an inverse relationship between FOXP3 expression, when measured 10 days after challenge, and ex vivo IFN-, measured more than 100 days later. This study shows that malaria infection elicits specific Th1 and Th2 effector cells, but concomitant weak central memory and regulatory activity, which may help to explain the short-lived immunity observed. [source] Curcumin induces the tolerogenic dendritic cell that promotes differentiation of intestine-protective regulatory T cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2009Yingzi Cong Abstract The gut is home to a large number of Treg, with both CD4+ CD25+ Treg and bacterial antigen-specific Tr1 cells present in normal mouse intestinal lamina propria. It has been shown recently that intestinal mucosal DC are able to induce Foxp3+ Treg through production of TGF-, plus retinoic acid (RA). However, the factors instructing DC toward this mucosal phenotype are currently unknown. Curcumin has been shown to possess a number of biologic activities including the inhibition of NF-,B signaling. We asked whether curcumin could modulate DC to be tolerogenic whose function could mimic mucosal DC. We report here that curcumin modulated BM-derived DC to express ALDH1a and IL-10. These curcumin-treated DC induced differentiation of naïve CD4+ T cells into Treg resembling Treg in the intestine, including both CD4+CD25+ Foxp3+ Treg and IL-10-producing Tr1 cells. Such Treg induction required IL-10, TGF-, and retinoic acid produced by curcumin-modulated DC. Cell contact as well as IL-10 and TGF-, production were involved in the function of such induced Treg. More importantly, these Treg inhibited antigen-specific T-cell activation in vitro and inhibited colitis due to antigen-specific pathogenic T cells in vivo. [source] T-bet protects against exacerbation of schistosome egg-induced immunopathology by regulating Th17-mediated inflammationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2009Laura I. Rutitzky Abstract C57BL/6 mice infected with Schistosoma mansoni naturally develop mild CD4+ T-cell-mediated immunopathology characterized by small hepatic granulomas around parasite eggs. However, immunization with soluble egg Ag in CFA markedly exacerbates the lesions by inducing a potent proinflammatory environment with high levels of IFN-, and IL-17, which are signature cytokines of distinct Th1- versus Th17-cell lineages. To determine the relative role of these subsets in disease exacerbation, we examined mice deficient in T-bet (T-bet,/,), which is required for Th1 differentiation and IFN-, production. We now report that immunization with soluble egg Ag in CFA caused a significantly greater enhancement of egg-induced hepatic immunopathology in T-bet,/, mice compared with WT controls, and analysis of their granulomas disclosed a higher proportion of activated DC and CD4+ T cells, as well as a marked influx of neutrophils. The absence of IFN-, in the T-bet,/, mice correlated with a marked increase in IL-23p19, IL-17 and TNF-, in granulomas and MLN. In contrast, T-bet,/, mice had lower levels of IL-4, IL-5 and IL-10 and a reduction in FIZZ1 and FoxP3 expression, suggesting diminished regulatory activity, respectively, by alternatively activated macrophages and Treg. These findings demonstrate that T-bet-dependent signaling negatively regulates Th17-mediated immunopathology in severe schistosomiasis. [source] T-cell-specific deletion of gp130 renders the highly susceptible IL-10-deficient mouse resistant to intestinal nematode infectionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2009Nicolas Fasnacht Abstract Gp130 is the common receptor of the IL-6 family of cytokines and is involved in many biological processes, including acute phase response, inflammation and immune reactions. To investigate the role of gp130 under inflammatory conditions, T-cell-specific conditional gp130 mice were first bred to the IL-10-deficient background and were then infected with the gastrointestinal nematode Trichuris muris. While IL-10,/, mice were highly susceptible to T. muris, developed a mixed Th1/Th17 response and displayed severe inflammation of the caecum, infection of mice with an additional T-cell-specific deletion of gp130 signalling completely reversed the phenotype. These mice showed an accelerated worm expulsion that was associated with the rapid generation of a strong Th2 immune response and a significant increase in Foxp3-expressing Treg. Therefore, gp130 signalling in T cells regulates a switch between proinflammatory and pathogenic Th1/Th17 cells and regulatory Th2/Treg in vivo. Taken together, the data demonstrate that gp130 signalling in T cells is a positive regulator of inflammatory processes, favouring the Th1/Th17 axis. [source] Interleukin-10-secreting T cells define a suppressive subset within the HIV-1-specific T-cell populationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2009Eirik A. Torheim Abstract Recent studies have indicated that Treg contribute to the HIV type 1 (HIV-1)-related immune pathogenesis. However, it is not clear whether T cells with suppressive properties reside within the HIV-1-specific T-cell population. Here, PBMC from HIV-1-infected individuals were stimulated with a 15-mer Gag peptide pool, and HIV-1-specific T cells were enriched by virtue of their secretion of IL-10 or IFN-, using immunomagnetic cell-sorting. Neither the IL-10-secreting cells nor the IFN-,-secreting cells expressed the Treg marker FOXP3, yet the IL-10-secreting cells potently suppressed anti-CD3/CD28-induced CD4+ as well as CD8+ T-cell proliferative responses. As shown by intracellular cytokine staining, IL-10- and IFN-,-producing T cells represent distinct subsets of the HIV-1-specific T cells. Our data collectively suggest that functionally defined HIV-1-specific T-cell subsets harbor potent immunoregulatory properties that may contribute to HIV-1-associated T-cell dysfunction. [source] Nramp1 -functionality increases iNOS expression via repression of IL-10 formationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2008Gernot Fritsche Abstract In mice, resistance to certain intracellular microbes depends on the expression of a late phagosomal protein termed natural-resistance associated macrophage protein 1 (Nramp1, Slc11a1). Nramp1- functionality is associated with alterations of cellular iron homeostasis and a sustained pro-inflammatory immune response, including the formation of the antimicrobial effector molecule NO. To investigate the underlying mechanism we used RAW-264.7 murine macrophage cells stably transfected with a functional Nramp1 allele (RAW-37) or Nramp1 non-functional controls (RAW-21). We found that the production of and signalling by the anti-inflammatory cytokine IL-10 was significantly enhanced in macrophages lacking functional Nramp1. Upon infection of macrophages with Salmonella typhimurium pathogen survival was significantly better in RAW-21 than in RAW-37, which inversely correlated to NO and TNF-, formation. Addition of a neutralising anti-IL-10 antibody to RAW-21 cells led to a significantly reduced survival of S. typhimurium within these cells and enhanced formation of NO and TNF-, reaching levels comparable to that observed in cells bearing functional Nramp1. Oppositely, supplementation of iron to RAW-21 cells further increased IL-10 formation. Thus, Nramp1 mediates effective host defence in part via suppression of excessive IL-10 production which may relate to Nramp1- mediated reduction of cellular iron pools, thus strengthening antimicrobial effector mechanisms. [source] A Griscelli syndrome type 2 murine model of hemophagocytic lymphohistiocytosis (HLH)EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2008Jana Pachlopnik Schmid Abstract Griscelli syndrome type 2 is caused by mutations in the RAB27A gene and is a rare and potentially fatal immune disorder associated with hemophagocytic lymphohistiocytosis (HLH). Animal models could provide assistance for better understanding the mechanisms and finding new treatments. Rab27a-deficient (ashen) mice do not spontaneously develop HLH. When injected with lymphocytic choriomeningitis virus (LCMV) strain WE, Rab27a-deficient C57BL/6 mice developed wasting disease, hypothermia, splenomegaly, cytopenia (anemia, neutropenia and thrombocytopenia), hypertriglyceridemia and increased levels of IFN-,, TNF-,, GM-CSF, IL-12, CCL5 and IL-10. Activated macrophages with hemophagocytosis were found in liver sections of these mice. Compared with perforin-deficient mice, LCMV-infected Rab27a-deficient mice showed a substantially better survival rate and slightly higher viral doses were needed to trigger HLH in Rab27a-deficient mice. This study demonstrates that LCMV-infected Rab27a-deficient C57BL/6 mice develop features consistent with HLH and, therefore, represent a murine model of HLH in human Griscelli syndrome type 2. [source] Pulmonary stromal cells induce the generation of regulatory DC attenuating T-cell-mediated lung inflammationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2008Qian Li Abstract The tissue microenvironment may affect the development and function of immune cells such as DC. Whether and how the pulmonary stromal microenvironment can affect the development and function of lung DC need to be investigated. Regulatory DC (DCreg) can regulate T-cell response. We wondered whether such regulatory DC exist in the lung and what is the effect of the pulmonary stromal microenvironment on the generation of DCreg. Here we demonstrate that murine pulmonary stromal cells can drive immature DC, which are regarded as being widely distributed in the lung, to proliferate and differentiate into a distinct subset of DCreg, which express high levels of CD11b but low levels of MHC class II (I-A), CD11c, secrete high amounts of IL-10, NO and prostaglandin E2 (PGE2) and suppress T-cell proliferation. The natural counterpart of DCreg in the lung with similar phenotype and regulatory function has been identified. Pulmonary stroma-derived TGF-, is responsible for the differentiation of immature DC to DCreg, and DCreg-derived PGE2 contributes to their suppression of T-cell proliferation. Moreover, DCreg can induce the generation of CD4+CD25+Foxp3+ Treg. Importantly, infusion with DCreg attenuates T-cell-mediated eosinophilic airway inflammation in vivo. Therefore, the pulmonary microenvironment may drive the generation of DCreg, thus contributing to the maintenance of immune homoeostasis and the control of inflammation in the lung. [source] IL-2 induces in vivo suppression by CD4+CD25+Foxp3+ regulatory T cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2008Susan Brandenburg Abstract Interleukin-2 (IL-2) treatment is currently used to enhance T cell-mediated immune responses against tumors or in viral infections. At the same time, IL-2 is essential for the peripheral homeostasis of CD4+CD25+Foxp3+ regulatory T cells (Treg). In our study, we show that IL-2 is also an important activator of Treg suppressive activity in vivo. IL-2 treatment induces Treg expansion as well as IL-10 production and increases their suppressive potential in vitro. Importantly, in vivo application of IL-2 via gene-gun vaccination using IL-2 encoding DNA plasmids (pIL-2) inhibited naive antigen-specific T cell proliferation as well as a Th1-induced delayed type hypersensitivity response. The suppressive effect can be transferred onto naive animals by Treg from IL-2-treated mice and the suppression depends on the synergistic action of IL-10 and TGF-,. These data highlight that during therapeutic treatment with IL-2 the concomitant activation of Treg may indeed counteract the intended activation of cellular immunity. [source] Dendritic cells derived from TBP-2-deficient mice are defective in inducing T cell responsesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2008Aoi Son Abstract Thioredoxin-binding protein-2 (TBP-2), also known as vitamin,D3-up-regulated protein,1 (VDUP1), was identified as an endogenous molecule interacting with thioredoxin (TRX). Here, we show that dendritic cells (DC) derived from TBP-2-deficient mice are defective in the function of T cell activation. To compare TBP-2,/, DC function with wild-type (WT) DC, we stimulated DC with lipopolysaccharide (LPS). Although TBP-2,/, DC and WT DC expressed comparable levels of MHC class,II and costimulatory molecules such as CD40, CD80 and CD86, the IL-12p40, IL-12p70 and IL-6 productions of TBP-2,/, DC were attenuated. In a mixed leukocyte reaction (MLR), the concentrations of IL-2, IFN-,, IL-4 and IL-10 in the culture supernatant of MLR with TBP-2,/, DC were significantly lower than those in the cultures with WT DC. In MLR also, as with LPS stimulation, IL-12p40 and IL-12p70 production from TBP-2,/, DC was less than that from WT DC. Proliferation of T cells cultured with TBP-2,/, DC was poorer than that with WT DC. Invivo delayed-type hypersensitivity responses in TBP-2,/, mice immunized with ovalbumin were significantly reduced compared to WT mice. These results indicate that TBP-2 plays a crucial role in DC to induce T cell responses. [source] Intradermal NKT cell activation during DNA priming in heterologous prime-boost vaccination enhances T cell responses and protection against LeishmaniaEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2008Blaise Dondji Abstract Heterologous prime-boost vaccination employing DNA-vaccinia virus (VACV) modality using the Leishmania homologue of receptors for activated C,kinase (LACK) (p36) antigen has been shown to elicit protective immunity against both murine cutaneous and visceral leishmaniasis. However, DNA priming is known to have limited efficacy; therefore in the current study the effect of NKT cell activation using ,-galactosyl-ceramide (,GalCer) during intradermal DNAp36 priming was examined. Vaccinated mice receiving ,GalCer,+ DNAp36 followed by a boost with VVp36 appeared to be resolving their lesions and had at ten- to 20-fold higher reductions in parasite burdens. NKT cell activation during ,GalCer,+ DNAp36 priming resulted in higher numbers of antigen-reactive effector CD4+ and CD8+ T cells producing granzyme and IFN-,, with lower levels of IL-10. Although immunodepletion studies indicate that both CD4 and CD8 T cells provide protection in the vaccinated mice, the contribution of CD4+ T cells was significantly increased in mice primed with DNAp36 together with ,GalCer. Notably 5,months after boosting, mice vaccinated with DNAp36,+ ,GalCer continued to show sustained and heightened T cell immune responses. Thus, heterologous prime-boost vaccination using ,GalCer during priming is highly protective against murine cutaneous leishmaniasis, resulting in the heightened activation and development of CD4 and CD8 T cells (effector and memory T cells). [source] Polypropylene glycol is a selective binding inhibitor for LTA and other structurally related TLR2 agonistsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2008Christian Draing Abstract Polypropylene glycol (PPG) is commonly added to bacterial cultures to avoid foaming. However, lipoteichoic acid (LTA) from bacteria grown with PPG lacked cytokine-inducing potency in human blood. We tested the blocking efficacy of several glycols on the cytokine response to staphylococcal LTA in human blood. PPG 1200 was the most potent inhibitor tested, shown for TNF, IL-1,, IL-6, IL-8, IL-10 and TGF-, induction, and displayed no cytotoxic effects. TNF induction by Staphylococcus aureus or by Toll-like receptor (TLR)2 agonists (di- and triacylated lipopeptides and LTA) was also inhibited by PPG 1200, but not that induced by Escherichia,coli or TLR4 agonists. In flow cytometric studies, PPG-carrying nanobeads bound more rhodamine-labeled LTA than those with glycerol. Additionally, the methyl group peak in the 1H-NMR of LTA shifted after incubation with increasing PPG 1200 concentrations. Sequential incubation of polystyrene plates with LTA, then PPG 1200 and then blood, with washing steps in between, showed that LTA-induced TNF release was inhibited. But when PPG 1200 was pre-incubated with blood that was washed before LTA was added, TNF induction was not repressed, demonstrating that PPG binds LTA and not cellular structures. In summary, PPG 1200 is a novel inhibitor of cytokine induction by TLR2 agonists, which interferes directly with the ligands. [source] Notch signaling is activated by TLR stimulation and regulates macrophage functionsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 1 2008Tanapat Palaga Dr. Abstract Notch signaling is a well-conserved pathway involved in cell fate decisions, proliferation and apoptosis. We report on the involvement of Notch signaling in regulating gene expression in activated macrophages. Toll-like receptors (TLR) agonists such as bacterial lipopeptide, polyI:C, lipopolysaccharide and unmethylated CpG DNA all induced up-regulation of Notch1 in primary and macrophage-like cell lines. Notch1 up-regulation was dependent on the MyD88 pathway when stimulated through TLR2, but not TLR4. Activated Notch1 and expression of the Notch target genes, Hes1 and Deltex, were detected in activated macrophages, suggesting that Notch signaling was activated upon stimulation. Inhibiting processing of Notch receptor by ,-secretase using a ,-secretase inhibitor (GSI), the expression of Notch1 was down-regulated to basal levels. This treatment significantly modulated expression of TNF-,, IL-6, and IL-10. In addition, the amount of nitric oxide produced was significantly lower and the expression of MHC class II was up-regulated in GSI-treated cells. Treatment with GSI or silencing Notch1 resulted in decreased translocation of NF-,Bp50 into nucleus upon stimulation. Taken together, stimulation of macrophages through the TLR signaling cascade triggered activation of Notch signaling, which in turn regulated gene expression patterns involved in pro-inflammatory responses, through activation of NF-,B. [source] IL-35 is a novel cytokine with therapeutic effects against collagen-induced arthritis through the expansion of regulatory T cells and suppression of Th17 cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2007Wanda Niedbala Abstract Epstein-Barr virus-induced gene,3 (EBI3) and the p35 subunit of IL-12 have been reported to form a heterodimeric hematopoietin in human and mouse. We have constructed a heterodimeric protein covalently linking EBI3 and p35, to form a novel cytokine which we now call IL-35. The Fc fusion protein of IL-35 induced proliferation of murine CD4+CD25+ and CD4+CD25, T cells when stimulated with immobilized anti-CD3 and anti-CD28 antibodies in vitro. The IL-35-expanded CD4+CD25+ T cell population expressed Foxp3 and produced elevated levels of IL-10, whereas the IL-35-induced CD4+CD25, T cells produced IFN-, but not IL-4. The in vitro expanded CD4+CD25+ T cells retained their suppressive functions against CD4+CD25, effector cells. Furthermore, when cultured with soluble anti-CD3 antibody and antigen-presenting cells, IL-35 suppressed the proliferation of CD4+CD25, effector cells. Moreover, IL-35 inhibited the differentiation of Th17 cells in vitro. In vivo, IL-35 effectively attenuated established collagen-induced arthritis in mice, with concomitant suppression of IL-17 production but enhanced IFN-, synthesis. Thus, IL-35 is a novel anti-inflammatory cytokine suppressing the immune response through the expansion of regulatory T cells and suppression of Th17 cell development. [source] IL-10 modulates cytokine gene transcription by protein synthesis-independent and dependent mechanisms in lipopolysaccharide-treated neutrophilsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2007Marzia Rossato Abstract We have recently reported that the ability of IL-10 to rapidly exert its anti-inflammatory effects on human neutrophils is dependent upon exposure of these cells to LPS for at least 3,4,h. Here, we demonstrate that, in neutrophils "preconditioned" by LPS, IL-10 primarily targets the transcription of TNF-,, CXCL8 and IL-1ra genes, as revealed by primary transcript real-time RT-PCR. We also show that IL-10-induced transcriptional repression of TNF-, and CXCL8 genes consists of two distinct phases: an early one, occurring rapidly and in a protein synthesis-independent manner, followed by a second phase, more delayed and dependent on protein synthesis. Interestingly, the protein synthesis dependence of the latter phase coincides with a reduced ability of IL-10 to induce STAT3 tyrosine phosphorylation. Importantly, inhibition of IL-10-induced STAT3 activation and IL-10-suppressive action by a prolonged exposure to cycloheximide (CHX) was observed to occur also in human monocytes and was caused by a defective IL-10-mediated activation of Jak1 and Tyk2 kinases. Taken together, our findings suggest that CHX interferes with the IL-10-mediated intracellular signaling pathway by interrupting events upstream of STAT3 activation. These data question the concept of the requirement of an IL-10-induced mediator as the unique mechanism to execute IL-10 anti-inflammatory program. [source] Syk-dependent ERK activation regulates IL-2 and IL-10 production by DC stimulated with zymosanEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2007Abstract Zymosan is a particulate yeast preparation that elicits high levels of IL-2 and IL-10 from dendritic cells (DC) and engages multiple innate receptors, including the Syk-coupled receptor dectin-1 and the MyD88-coupled receptor TLR2. Here, we show that induction of IL-2 and IL-10 by zymosan requires activation of ERK MAP kinase in murine DC. Surprisingly, ERK activation in response to zymosan is completely blocked in Syk-deficient DC and unaffected by MyD88 deficiency. Conversely, ERK activation in response to the TLR2 agonist Pam3Cys is completely MyD88 dependent and unaffected by Syk deficiency. The inability of TLR2 ligands in zymosan to couple to ERK may explain the Syk dependence of the IL-2 and IL-10 response in DC and emphasises the importance of Syk-coupled pattern recognition receptors such as dectin-1 in the detection of yeasts. Furthermore, the lack of receptor compensation observed here suggests that responses induced by complex innate stimuli cannot always be predicted by the signalling pathways downstream of individual receptors. [source] Lung CD11c+ cells from mice deficient in Epstein-Barr virus-induced gene,3 (EBI-3) prevent airway hyper-responsiveness in experimental asthmaEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2007Michael Hausding Abstract Epstein-Barr virus-induced gene (EBI)-3 codes for a soluble type,1 cytokine receptor homologous to the p40 subunit of IL-12 that is expressed by antigen-presenting cells following activation. Here, we analyzed the functional role of EBI-3 in a murine model of asthma associated with airway hyper-responsiveness (AHR) in ovalbumin-sensitized mice. Upon allergen challenge, EBI-3,/, mice showed less severe AHR, decreased numbers and degranulation of eosinophils and a significantly reduced number of VCAM-1+ cells in the lungs as compared to wild-type littermates. We thus analyzed lung CD11c+ cells before and after allergen challenge in these mice and found that before allergen challenge, lung CD11c+ cells isolated from EBI-3,/, mice express markers of a more plasmacytoid phenotype without releasing IFN-, as compared to those from wild-type littermates. Moreover, allergen challenge induced the development of myeloid CD11c+ cells in the lungs of EBI-3,/, mice, which released increased amounts of IL-10 and IL-12 while not expressing IFN-,. Finally, inhibition of EBI-3 expression in lung DC could prevent AHR in adoptive transfer studies by suppressing mediator release of effector cells into the airways. These results indicate a novel role for EBI-3 in controlling local immune responses in the lungs in experimental asthma. [source] | ||||||||||||||||||||||||||||||||||||||||