scholarly journals Schistosoma mansoni Hemozoin Modulates Alternative Activation of Macrophages via Specific Suppression of Retnla Expression and Secretion

2012 ◽  
Vol 81 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Martha Truscott ◽  
D. Andrew Evans ◽  
Matt Gunn ◽  
Karl F. Hoffmann
Keyword(s):  
Schistosoma Mansoni ◽  
Macrophage Activation ◽  
Inflammatory Responses ◽  
Interleukin 4 ◽  
Alternative Activation ◽  
Content Type ◽  
Hepatic Expression ◽  
Life Years ◽  
Alternatively Activated

The trematodeSchistosoma mansoniis one of the etiological agents of schistosomiasis, a key neglected tropical disease responsible for an estimated annual loss of 70 million disability-adjusted life years. Hematophagy represents the primary nutrient acquisition pathway of this parasite, but digestion of hemoglobin also liberates toxic heme. Schistosomes detoxify heme via crystallization into hemozoin, which is subsequently regurgitated into the host's circulation. Here we demonstrate that during experimental schistosomiasis, hemozoin accumulating in the mouse liver is taken up by phagocytes at a time coincident with the development of the egg-induced T-helper 2 (Th2) granulomatous immune response. Furthermore, the uptake of hemozoin also coincides with the hepatic expression of markers of alternative macrophage activation. Alternatively activated macrophages are a key effector cell population associated with protection against schistosomiasis, making hemozoin well placed to play an important immunomodulatory role in this disease. To systematically explore this hypothesis,S. mansonihemozoin was purified and added toin vitrobone marrow-derived macrophage cultures concurrently exposed to cytokines chosen to reflect the shifting state of macrophage activationin vivo. Macrophages undergoing interleukin-4 (IL-4)-induced alternative activation in the presence of hemozoin developed a phenotype specifically lacking inRetnla, a characteristic alternatively activated macrophage product associated with regulation of Th2 inflammatory responses. As such, in addition to its important detoxification role during hematophagy, we propose that schistosome hemozoin also provides a potent immunomodulatory function in the coevolved network of host-parasite relationships during schistosomiasis.

scholarly journals CD14 Influences Host Immune Responses and Alternative Activation of Macrophages during Schistosoma mansoni Infection

2014 ◽  
Vol 82 (8) ◽  
pp. 3240-3251 ◽  
Author(s):  
Smanla Tundup ◽  
Leena Srivastava ◽  
Tamas Nagy ◽  
Donald Harn
Keyword(s):  
Schistosoma Mansoni ◽  
Metabolic Diseases ◽  
Macrophage Polarization ◽  
Interleukin 4 ◽  
Alternative Activation ◽  
M2 Macrophages ◽  
Content Type ◽  
Host Immune Responses ◽  
Th Cell

ABSTRACTAntigen-presenting cell (APC) plasticity is critical for controlling inflammation in metabolic diseases and infections. The roles that pattern recognition receptors (PRRs) play in regulating APC phenotypes are just now being defined. We evaluated the expression of PRRs on APCs in mice infected with the helminth parasiteSchistosoma mansoniand observed an upregulation of CD14 expression on macrophages. Schistosome-infectedCd14−/−mice showed significantly increased alternative activation of (M2) macrophages in the livers compared to infected wild-type (wt) mice. In addition, splenocytes from infectedCd14−/−mice exhibited increased production of CD4+-specific interleukin-4 (IL-4), IL-5, and IL-13 and CD4+Foxp3+IL-10+regulatory T cells compared to cells from infected wt mice.S. mansoni-infectedCd14−/−mice also presented with smaller liver egg granulomas associated with increased collagen deposition compared to granulomas in infected wt mice. The highest expression of CD14 was found on liver macrophages in infected mice. To determine if theCd14−/−phenotype was in part due to increased M2 macrophages, we adoptively transferred wt macrophages intoCd14−/−mice and normalized the M2 and CD4+Th cell balance close to that observed in infected wt mice. Finally, we demonstrated that CD14 regulates STAT6 activation, asCd14−/−mice had increased STAT6 activationin vivo, suggesting that lack of CD14 impacts the IL-4Rα-STAT6 pathway, altering macrophage polarization during parasite infection. Collectively, these data identify a previously unrecognized role for CD14 in regulating macrophage plasticity and CD4+T cell biasing during helminth infection.

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 Foxp3+ T Regulatory Cells as a Potential Target for Immunotherapy against Primary Infection with Echinococcus multilocularis Eggs

2018 ◽  
Vol 86 (10) ◽  
Author(s):  
Junhua Wang ◽  
Rita Cardoso ◽  
Nelson Marreros ◽  
Norbert Müller ◽  
Britta Lundström-Stadelmann ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Echinococcus Multilocularis ◽  
Transforming Growth Factor ◽  
Early Stage ◽  
Expression Profiles ◽  
Growth Potential ◽  
Interleukin 4 ◽  
Content Type ◽  
Hepatic Expression ◽  
Th2 Immune Response

ABSTRACT Alveolar echinococcosis (AE) is a lethal disease caused by infection with the metacestode stage of the helminth Echinococcus multilocularis, which develops into a tumorlike mass in susceptible intermediate hosts. The growth potential of this parasite stage is directly linked to the nature of the surrounding periparasitic immune-mediated processes. In a first step (experiment 1), mice were orally infected with E. multilocularis eggs, to be used for assessing the hepatic expression profiles of 15 selected cytokine and chemokine genes related to acquired immunity from 21 to 120 days postinfection. The early stage of infection in immunocompetent animals was marked by a mixed Th1/Th2 immune response, as characterized by the concomitant presence of gamma interferon (IFN-γ) and interleukin-4 (IL-4) and their related chemokines. At the late stage of AE, the profile extended to a combined tolerogenic mode including Foxp3, IL-10, and transforming growth factor beta (TGF-β) as key components. In a second step (experiment 2), the effect of T regulatory cell (Treg) deficiency on metacestode growth was assessed in E. multilocularis-infected DEREG (depletion of regulatory T cells) mice upon induction of Treg deficiency with diphtheria toxin (DT). The parasite lesions were significantly smaller in the livers of treated mice than in corresponding control groups. Foxp3+ Tregs appear to be one of the key players in immune-regulatory processes favoring metacestode survival by affecting antigen presentation and suppressing Th1-type immune responses. For these reasons, we suggest that affecting Foxp3+ Tregs could offer an attractive target in the development of an immunotherapy against AE.

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 Interleukin-4 Signaling Plays a Major Role in Urogenital Schistosomiasis-Associated Bladder Pathogenesis

2019 ◽  
Vol 88 (3) ◽  
Author(s):  
Evaristus C. Mbanefo ◽  
Chi-Ling Fu ◽  
Christina P. Ho ◽  
Loc Le ◽  
Kenji Ishida ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Signaling Pathway ◽  
Ex Vivo ◽  
Bladder Wall ◽  
Interleukin 4 ◽  
Wild Type ◽  
Urogenital Schistosomiasis ◽  
Content Type ◽  
Helminth Infections

ABSTRACT Interleukin-4 (IL-4) is crucial in many helminth infections, but its role in urogenital schistosomiasis, infection with Schistosoma haematobium worms, remains poorly understood due to a historical lack of animal models. The bladder pathology of urogenital schistosomiasis is caused by immune responses to eggs deposited in the bladder wall. A range of pathology occurs, including urothelial hyperplasia and cancer, but associated mechanisms and links to IL-4 are largely unknown. We modeled urogenital schistosomiasis by injecting the bladder walls of IL-4 receptor-alpha knockout (Il4ra−/−) and wild-type mice with S. haematobium eggs. Readouts included bladder histology and ex vivo assessments of urothelial proliferation, cell cycle, and ploidy status. We also quantified the effects of exogenous IL-4 on urothelial cell proliferation in vitro, including cell cycle status and phosphorylation patterns of major downstream regulators in the IL-4 signaling pathway. There was a significant decrease in the intensity of granulomatous responses to bladder-wall-injected S. haematobium eggs in Il4ra−/− versus wild-type mice. S. haematobium egg injection triggered significant urothelial proliferation, including evidence of urothelial hyper-diploidy and cell cycle skewing in wild-type but not Il4ra−/− mice. Urothelial exposure to IL-4 in vitro led to cell cycle polarization and increased phosphorylation of AKT. Our results show that IL-4 signaling is required for key pathogenic features of urogenital schistosomiasis and that particular aspects of this signaling pathway may exert these effects directly on the urothelium. These findings point to potential mechanisms by which urogenital schistosomiasis promotes bladder carcinogenesis.

scholarly journals Human Monocyte Subsets at Homeostasis and Their Perturbation in Numbers and Function in Filarial Infection

2014 ◽  
Vol 82 (11) ◽  
pp. 4438-4446 ◽  
Author(s):  
Roshanak Tolouei Semnani ◽  
Vanessa Moore ◽  
Sasisekhar Bennuru ◽  
Renee McDonald-Fleming ◽  
Sundar Ganesan ◽  
...  
Keyword(s):  
Wuchereria Bancrofti ◽  
Human Monocyte ◽  
Interleukin 10 ◽  
Alternative Activation ◽  
Helminth Parasites ◽  
Monocyte Subsets ◽  
Filarial Infection ◽  
Content Type ◽  
And Function

ABSTRACTTo characterize the function and plasticity of the major human circulating monocyte populations and to explore their role in systemic helminth infection, highly purified (by flow-based sorting) human monocyte subsets (CD14hi/CD16neg[classical], CD14+ or hi/CD16med[intermediate], and CD14neg/CD16hi[nonclassical]) were examined at homeostasis and after activation. Among these three subsets the classical and intermediate subsets were found to be the major sources of inflammatory and regulatory cytokines, as well as cytokines/chemokines associated with alternative activation, whereas the nonclassical and classical populations demonstrated an ability to transmigrate through endothelial monolayers. Moreover, it was primarily the classical subset that was the most efficient in promoting autologous T cell proliferation. The distribution of these subsets changed in the context of a systemic helminth (Wuchereria bancrofti) infection such that patent infection altered the frequency and distribution of these monocyte subsets with the nonclassical monocytes being expanded (almost 2-fold) in filarial infection. To understand further the filarial/monocyte interface,in vitromodeling demonstrated that the classical subset internalized filarial antigens more efficiently than the other two subsets but that the parasite-driven regulatory cytokine interleukin-10 was exclusively coming from the intermediate subset. Our data suggest that monocyte subsets have a differential function at homeostasis and in response to helminth parasites.

scholarly journals The Surface-Associated Exopolysaccharide of Bifidobacterium longum 35624 Plays an Essential Role in Dampening Host Proinflammatory Responses and Repressing Local TH17 Responses

2016 ◽  
Vol 82 (24) ◽  
pp. 7185-7196 ◽  
Author(s):  
Elisa Schiavi ◽  
Marita Gleinser ◽  
Evelyn Molloy ◽  
David Groeger ◽  
Remo Frei ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Cells ◽  
Essential Role ◽  
Inflammatory Responses ◽  
Bifidobacterium Longum ◽  
Molecular Characteristics ◽  
Interleukin 17 ◽  
Content Type ◽  
Exopolysaccharide Production

ABSTRACTThe immune-modulating properties of certain bifidobacterial strains, such asBifidobacterium longumsubsp.longum35624 (B. longum35624), have been well described, although the strain-specific molecular characteristics associated with such immune-regulatory activity are not well defined. It has previously been demonstrated thatB. longum35624 produces a cell surface exopolysaccharide (sEPS), and in this study, we investigated the role played by this exopolysaccharide in influencing the host immune response.B. longum35624 induced relatively low levels of cytokine secretion from human dendritic cells, whereas an isogenic exopolysaccharide-negative mutant derivative (termed sEPSneg) induced vastly more cytokines, including interleukin-17 (IL-17), and this response was reversed when exopolysaccharide production was restored in sEPSnegby genetic complementation. Administration ofB. longum35624 to mice of the T cell transfer colitis model prevented disease symptoms, whereas sEPSnegdid not protect against the development of colitis, with associated enhanced recruitment of IL-17+lymphocytes to the gut. Moreover, intranasal administration of sEPSnegalso resulted in enhanced recruitment of IL-17+lymphocytes to the murine lung. These data demonstrate that the particular exopolysaccharide produced byB. longum35624 plays an essential role in dampening proinflammatory host responses to the strain and that loss of exopolysaccharide production results in the induction of local TH17 responses.IMPORTANCEParticular gut commensals, such asB. longum35624, are known to contribute positively to the development of mucosal immune cells, resulting in protection from inflammatory diseases. However, the molecular basis and mechanisms for these commensal-host interactions are poorly described. In this report, an exopolysaccharide was shown to be decisive in influencing the immune response to the bacterium. We generated an isogenic mutant unable to produce exopolysaccharide and observed that this mutation caused a dramatic change in the response of human immune cellsin vitro. In addition, the use of mouse models confirmed that lack of exopolysaccharide production induces inflammatory responses to the bacterium. These results implicate the surface-associated exopolysaccharide of theB. longum35624 cell envelope in the prevention of aberrant inflammatory responses.

Factor XIII-A is involved in the regulation of gene expression in alternatively activated human macrophages

2010 ◽  
Vol 104 (10) ◽  
pp. 709-717 ◽  
Author(s):  
Dániel Töröcsik ◽  
Lajos Széles ◽  
György Paragh ◽  
Zsuzsa Rákosy ◽  
Helga Bárdos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Factor Xiii ◽  
Gene Expression Regulation ◽  
Regulation Of Gene Expression ◽  
Wound Response ◽  
Interleukin 4 ◽  
Alternative Activation ◽  
Wild Type ◽  
Functional Clustering ◽  
Alternatively Activated

SummaryFactor XIII subunit A (FXIII-A) is one of the most overrepresented genes that is expressed during the alternative activation of macrophages. Based on its substrate profile and its cellular localisation, FXIII-A is thought to function as an intracellular/intranuclear transglutaminase. Our aim was to find role for the intracellular FXIII-A by comparing the microarray profiles of alternatively activated monocyte-derived macrophages. Microarray analyses of FXIII-A-deficient patients and healthy controls were evaluated, followed by functional clustering of the differentially expressed genes. After a 48-hour differentiation in the presence of interleukin 4 (IL4), 1,017 probes out of the 24,398 expressed in macrophages from FXIII-A- deficient samples were IL4 sensitive, while only 596 probes were IL4 sensitive in wild-type samples. Of these genes, 307 were induced in both the deficient and the wild-type macrophages. Our results revealed that FXIII-A has important role(s) in mediating gene expression changes in macrophages during alternative activation. Functional clustering of the target genes carried out using Cytoscape/BiNGO and Ingenuity Pathways Analysis programs showed that, in the absence of FXIII-A, the most prominent differences are related to immune functions and to wound response. Our findings suggest that functional impairment of macrophages at the level of gene expression regulation plays a role in the wound healing defects of FXIII-A-deficient patients.

scholarly journals Peroxisome proliferator-activated receptor α and γ agonists differently regulate classical and alternative macrophage activation

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Erja-Leena Paukkeri ◽  
Antti Pekurinen ◽  
Eeva Moilanen
Keyword(s):  
Macrophage Activation ◽  
Inflammatory Responses ◽  
Therapeutic Potential ◽  
Alternative Activation ◽  
Peroxisome Proliferator ◽  
Activation Markers ◽  
Peroxisome Proliferator Activated Receptor ◽  
Arginase 1 ◽  
Pparγ Agonist ◽  
Ppar Agonists

AbstractPeroxisome proliferator-activated receptor (PPAR) agonists, fibrates and thiazolidinediones, are commonly used drugs in the treatment of dyslipidemia and diabetes. Their targets, PPARα and PPARγ, have also been shown to have a role in the regulation of inflammatory responses linking metabolism and inflammation. In the present study we investigated the effects of PPAR agonists on macrophage activation. In addition to the proinflammatory classical activation, we also focused on interleukin (IL) 4 and 13 -induced alternative activation which is a significant macrophage phenotype in tissue repairing processes and in fibrosing diseases. PPARα agonists GW7647 and fenofibrate as well as PPARγ agonist GW1929 inhibited lipopolysaccharide-induced classical macrophage activation and production of the characteristic biomarkers of this phenotype, i.e. IL-6 and nitric oxide, in murine J774 macrophages. Remarkably, the PPARα agonists also inhibited IL-4 and IL-13 –induced expression of alternative activation markers arginase-1, fizz1 and mannose receptor 1 whereas the PPARγ agonist GW1929 enhanced their expression in J774 macrophages. The PPARα agonists GW7647 and fenofibrate also attenuated the production of alternative activation markers chemokine (C-C motif) ligand 13 and plateletderived growth factor in human THP-1 macrophages. The present findings show that PPARα and PPARγ agonists differently regulate classical and alternative macrophage phenotypes. Furthermore, PPARα activation was introduced as a novel concept to down-regulate alternative macrophage activation indicating that PPARα agonists have therapeutic potential in conditions associated with aberrant alternative macrophage activation such as fibrosing diseases.

scholarly journals Mechanisms Involved in Type II Macrophage Activation and Effector Functions

2021 ◽  
Author(s):  
◽  
Marie Clare Lydia Kharkrang
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Surface Marker ◽  
Alternative Activation ◽  
Type Ii ◽  
Activated Macrophages ◽  
Phenotypic Properties ◽  
Anti Inflammatory ◽  
The Impact

<p>Autoimmunities are extremely difficult to treat and involved in their pathogenesis are pro-inflammatory immune responses redirected against one's own tissues. Studies in our lab have shown macrophages that are induced to become type II macrophages protect against an animal model of MS, experimental autoimmune encephalomyelitis (EAE), with protection due to immune deviation. Another way to deviate immune responses away from inflammation is by infection with the parasitic helminth Schistosoma mansoni, which also protects against EAE. The contribution of type II macrophages in this protection is unknown, as are the mechanisms involved in promoting the phenotype induced by type II activation. This project investigates key mechanisms involved in type II activation, while also elucidating the possible effect of schistosome exposure on the induction of this activation state. Using a validated model of type II activation in vitro, we compared the effects of schistosome immune complexes on various macrophage properties such as cytokine, surface marker and enzymatic profiles. This thesis identified that exposure to schistosome complexes induces a macrophage state with characteristics of two distinct activation states (type II and alternative activation), as well as completely novel characteristics. This activation state shows many phenotypic properties associated with immune regulation, and may have important consequences for understanding mechanisms involved in protection against inflammatory illnesses. We also investigated key mechanisms involved in the anti-inflammatory responses induced by type II activation. Cytokine, chemokine and surface marker profiles of macrophages were assessed in response to type II activation in vitro, with the main emphasis on determining the effects of IL-10 and CD40 on the type II activation phenotype and function. This investigation found that type II activated macrophages depend on low levels of CD40/CD40L signalling to polarise Th2 development, as the expression of receptors for Th2-inducing cytokines are significantly impaired in the absence of this interaction. This suggests an important role for the low but maintained levels of CD40 on type II activated macrophages, in aiding the deviation of immune responses, while maintaining Th2 polarization. We also suggest a suppressive role of CD40/CD40L in IL-10 production, which is a novel find. The requirement of new treatments for MS is escalating as more people are affected each year. The impact of MS on the quality of life is severe and long lasting. Having a greater understanding of the mechanisms involved in deviating pro-inflammatory or anti-inflammatory responses will enable the development of much more effective treatments and therapies in the future.</p>

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