scholarly journals Possible Role for Toll-Like Receptors in Interaction of Fasciola hepatica Excretory/Secretory Products with Bovine Macrophages

2007 ◽  
Vol 76 (2) ◽  
pp. 678-684 ◽  
Author(s):  
Robin J. Flynn ◽  
Grace Mulcahy

ABSTRACT Alternative activation of macrophages (Mφ) during helminth infection is a characteristic feature of the host immune response. Alternatively activated macrophages (AAMφ) are distinguished from others by high arginase 1 (Arg-1) activity, low nitric oxide (NO), and high interleukin 10 (IL-10) production. In murine models, these cells have been shown to possess anti-inflammatory properties. They have also been implicated in exacerbating a subsequent infection with a secondary pathogen. In this study we used cattle experimentally infected with Fasciola hepatica to monitor the kinetics of IL-4 and IL-10 over the course of infection. Using naïve Mφ in vitro, we examined the effects of exposure to F. hepatica excretory/secretory products (FhepES) alone or in combination with IL-4. Our results suggest that FhepES may work in combination with IL-4 to produce AAMφ. The effects of FhepES on the subsequent responses to lipopolysaccharide (LPS) and purified protein derivative from Mycobacterium bovis (PPD-B), which are bovine Toll-like receptor 4 (TLR4) and TLR2 antagonists, respectively, were also examined. We found that Mφ stimulated with FhepES together with LPS or PPD-B have reduced NO or gamma interferon production, respectively. The ability of FhepES to produce AAMφ was found to be heat labile and partially dependent on glycan residues. A possible role for TLR recognition is discussed.

2005 ◽  
Vol 73 (1) ◽  
pp. 166-173 ◽  
Author(s):  
Sheila Donnelly ◽  
Sandra M. O'Neill ◽  
Mary Sekiya ◽  
Grace Mulcahy ◽  
John P. Dalton

ABSTRACT Alternatively activated macrophages (AAMφ) are primarily associated with the chronic stages of parasitic infections and the development of a polarized Th2 response. We have shown that Fasciola hepatica infection of BALB/c mice induces a polarized Th2 response during both the latent and chronic stage of disease. The activation status of macrophages was analyzed in this model of helminth infection by evaluating the expression of genetic markers of alternative activation, namely, Fizz1, Ym1, and Arg1. AAMφ were recruited to the peritoneum of mice within 24 h of F. hepatica infection and after intraperitoneal injection of parasite excretory-secretory (ES) products. Administration of a recombinant antioxidant thioredoxin peroxidase (TPx), which is contained within the ES products, also induced the recruitment of AAMφ to the peritoneum. In vitro studies showed that this recombinant TPx directly converts RAW 264.7 macrophages to an alternatively activated phenotype characterized by the production of high levels of interleukin-10 (IL-10), prostaglandin E2, corresponding with low levels of IL-12. Our data suggest that the Th2 responses induced by the helminth F. hepatica are mediated through the secretion of molecules, one of which is TPx, that induce the recruitment and alternative activation of macrophages.


2016 ◽  
Vol 291 (33) ◽  
pp. 17450-17466 ◽  
Author(s):  
Yongfang Yao ◽  
Qian Shi ◽  
Bing Chen ◽  
Qingsong Wang ◽  
Xinda Li ◽  
...  

Alternatively activated macrophages (AAMs) play essential roles in the promotion of tissue remodeling, vasculogenesis, and tumor progression; however, the detailed mechanisms underlying the activation of AAMs remain largely unknown. Here, by using quantitative proteomic analysis, we identified 62 proteins that were up-regulated in IL-4-induced macrophages. Among these, Caspase-6 was increased significantly. Caspase-6 is important in the apoptotic signaling pathway; however, its role in non-apoptosis is also reported. Here, we first examined the non-apoptotic role of Caspase-6 in the alternative activation of macrophages after administration of IL-4, 4T1 tumor conditional medium, or co-culture with 4T1 cells. Both treatments promoted alternative activation of RAW264.7 cells and primary macrophages, whereas disruption of caspase-6 expression and activity could markedly suppress the biomarker levels of AAMs. Overexpression of Caspase-6 could significantly promote the activation of AAMs. Importantly, we further present evidence that caspase-6 could regulate breast cancer cell invasion by modulating MMP-2 and MMP-9 expression in 4T1 tumor-associated macrophages, as ablation of protein levels or activity of caspase-6 suppressed tumor cell invasion in vitro. In conclusion, the observed results markedly expanded our views of the dynamic changes in protein composition during alternative activation of macrophages, and they revealed a critical new role of caspase-6 in regulating this cellular biological process, which suggested that caspase-6 might be a key nod molecule to regulate immunological steady-state and be a therapeutic candidate for tumor immunotherapy.


2021 ◽  
Author(s):  
Lei Shi ◽  
Koby Kidder ◽  
Zhen Bian ◽  
Samantha Kuon Ting Chiang ◽  
Corbett Ouellette ◽  
...  

The Th2 cytokines IL-4 and IL-13 through activation of their shared receptor IL-4Rα direct macrophage alternative activation to promote immunosuppression and wound healing. However, the mechanisms that control macrophage responses to IL-4/13 are not fully understood. Apart from driving JAK-STAT and PI3K-Akt pathways to polarize macrophages toward the alternative phenotype, the activated IL-4/13 receptors recruit negative regulators SHP-1 and SHP-2, which dephosphorylate IL-4Rα and decrease its signaling. Here we report that SIRPα spatially restricts SHP-2 and, by such, promotes IL-4/13 signaling and macrophage alternative activation. SIRPα executes this regulation via its cytoplasmic ITIMs/ITSMs that undergo phosphorylation by IL-4/13-induced, Src kinase-activated Brutons tyrosine kinase (Btk), resulting in recruitment of SHP-2 and preclusion of SHP-2 from binding to and inhibiting IL-4/13 receptors. Despite that this regulation occurs independent of CD47, extracellular CD47 ligation of SIRPα facilitates its cytoplasmic phosphorylation and SHP-2 sequestration, leading to stronger IL-4/13 signaling and enhanced macrophage expression of IL-10, TGFβ, CD206, arginase-1, etc. Conversely, deficiency of SIRPα allows SHP-2 to freely bind to γC or IL-13Rα1 and through which dephosphorylate IL-4Rα, dampening its signaling. Consistent with these findings, impaired wound healing in Sirpα-/- mice under experimental colitis correlated with a deficit of immunosuppressive macrophages in the colon, a condition that was corrected by transfusion of ex vivo-produced SIRPαhigh alternatively activated macrophages.


Parasitology ◽  
2011 ◽  
Vol 138 (10) ◽  
pp. 1259-1271 ◽  
Author(s):  
DEYONG CHU ◽  
MINGZHAN DU ◽  
XIANGYANG HU ◽  
QIANG WU ◽  
JILONG SHEN

SUMMARYInterleukin (IL)-13 and alternatively activated macrophages (AAMs) play an important role in liver granuloma and fibrosis of schistosomiasis. Paeoniflorin (PAE, C23H28O11) has been reported to have an anti-hepatic fibrosis effect in schistosomiasis; however, the mechanism has not been fully elucidated. In this study, we measured serum hyaluronic acid (HA) concentrations, liver granuloma diameter and volume density, fibrosis degree and expressions of IL-13, arginase-1 (ARG-1), nitric oxide synthase-2 (NOS-2), and phosphorylated signal transducer and activator of transcription 6 (p-STAT6) in mice liver of schistosomiasis. Then we detected expressions of specific biomarkers of AAMs and activity of Arg-1 in Kupffer cells (KCs) from infected and PAE-treated mice, or in KCs from uninfected mice, but exposed to rIL-13in vitro. Finally, we observed expression of IL-13 signalling molecules in KCs and secretion of IL-13 from lymphocytes of infected and PAE-treated mice. Our results showed that during schistosomiasis, IL-13 expression and secretion increased with liver macrophages activated alternatively. PAE not only directly inhibited alternative activation of macrophages via reducing the phosphorylations of janus-activated kinase 2 (JAK2) and/or STAT6, leading to reduction of AAMs-related markers and Arg-1 activity, but also indirectly suppressed alternative activation of macrophages through decreasing secretion of IL-13. PAE might be a promising prophylactic agent for hepatic granuloma and fibrosis of schistosomiasis japonica.


2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Cinthia C. Stempin ◽  
Laura R. Dulgerian ◽  
Vanina V. Garrido ◽  
Fabio M. Cerban

A type 1 cytokine-dependent proinflammatory response inducing classically activated macrophages (CaMϕs) is crucial for parasite control during protozoan infections but can also contribute to the development of immunopathological disease symptoms. Type 2 cytokines such as IL-4 and IL-13 antagonize CaMϕs inducing alternatively activated macrophages (AaMϕs) that upregulate arginase-1 expression. During several infections, induction of arginase-1-macrophages was showed to have a detrimental role by limiting CaMϕ-dependent parasite clearance and promoting parasite proliferation. Additionally, the role of arginase-1 in T cell suppression has been explored recently. Arginase-1 can also be induced by IL-10 and transforming growth factor-β(TGF-β) or even directly by parasites or parasite components. Therefore, generation of alternative activation states of macrophages could limit collateral tissue damage because of excessive type 1 inflammation. However, they affect disease outcome by promoting parasite survival and proliferation. Thus, modulation of macrophage activation may be instrumental in allowing parasite persistence and long-term host survival.


2002 ◽  
Vol 9 (3) ◽  
pp. 151-159 ◽  
Author(s):  
Geert Raes ◽  
Wim Noël ◽  
Alain Beschin ◽  
Lea Brys ◽  
Patrick de Baetselier ◽  
...  

Although it is well-established that macrophages can occur in distinct activation states, the molecular characteristics of differentially activated macrophages, and particularly those of alternatively activated macrophages (aaMφ), are still poorly unraveled. Recently, we demonstrated that the expression of FIZZ1 and Ym is induced in aaMφ as compared with classically activated macrophages (caMφ), elicitedin vitroor developedin vivoduring infection withTrypanosoma brucei brucei. In the present study, we analyzed the expression of FIZZ1 and Ym in caMφ and aaMφ elicited duringTrypanosoma congolenseinfection and show that the use of FIZZ1 and Ym for the identification of aaMφ is not limited toT. b. bruceiinfection and is independent of the organ sources from which macrophages are obtained. We also demonstrate that FIZZ1 can be used to discriminate between different populations of aaMφ. Furthermore, we studied the effects of various stimuli, and combinations thereof, on the expression of FIZZ1 and Ym in macrophages from different mouse strains and demonstrate that regulation of the expression of FIZZ1 and Ym in macrophages is not dependent on the mouse strain. Finally, we show that these genes can be used to monitor the macrophage activation status without the need to obtain pure macrophage populations.


2021 ◽  
Author(s):  
Eric V. Dang ◽  
Susan Lei ◽  
Atanas Radkov ◽  
Hiten Madhani

How deadly fungal pathogens overcome mammalian innate immunity is largely unknown. Cryptococcus neoformans, the most common cause of fungal meningitis, induces a pathogenic type 2 response characterized by pulmonary eosinophilia and alternatively activated macrophages. Using forward genetics, we identified a fungal secreted protein, Cpl1, necessary and sufficient to enhance alternative activation of primary macrophages in vitro. Cpl1-enhanced polarization requires Toll-like receptor 4, a known mediator of allergen-induced type 2 responses. Cpl1 is essential for virulence, drives polarization of interstitial macrophages in vivo, and requires type 2 cytokine signaling for its impact on infectivity. C. neoformans selectively associates with polarized interstitial macrophages during infection, supporting a direct host-pathogen interaction. This work identifies a secreted effector produced by a human fungal pathogen that reprograms innate immunity to enable tissue infection.


2019 ◽  
Vol 54 (3) ◽  
pp. 1900154 ◽  
Author(s):  
Anna Birnhuber ◽  
Slaven Crnkovic ◽  
Valentina Biasin ◽  
Leigh M. Marsh ◽  
Balazs Odler ◽  
...  

The interleukin (IL)-1 family of cytokines is strongly associated with systemic sclerosis (SSc) and pulmonary involvement, but the molecular mechanisms are poorly understood. The aim of this study was to assess the role of IL-1α and IL-1β in pulmonary vascular and interstitial remodelling in a mouse model of SSc.IL-1α and IL-1β were localised in lungs of SSc patients and in the fos-related antigen-2 (Fra-2) transgenic (TG) mouse model of SSc. Lung function, haemodynamic parameters and pulmonary inflammation were measured in Fra-2 TG mice with or without 8 weeks of treatment with the IL-1 receptor antagonist anakinra (25 mg·kg−1·day−1). Direct effects of IL-1 on pulmonary arterial smooth muscle cells (PASMCs) and parenchymal fibroblasts were investigated in vitro.Fra-2 TG mice exhibited increased collagen deposition in the lung, restrictive lung function and enhanced muscularisation of the vasculature with concomitant pulmonary hypertension reminiscent of the changes in SSc patients. Immunoreactivity of IL-1α and IL-1β was increased in Fra-2 TG mice and in patients with SSc. IL-1 stimulation reduced collagen expression in PASMCs and parenchymal fibroblasts via distinct signalling pathways. Blocking IL-1 signalling in Fra-2 TG worsened pulmonary fibrosis and restriction, enhanced T-helper cell type 2 (Th2) inflammation, and increased the number of pro-fibrotic, alternatively activated macrophages.Our data suggest that blocking IL-1 signalling as currently investigated in several clinical studies might aggravate pulmonary fibrosis in specific patient subsets due to Th2 skewing of immune responses and formation of alternatively activated pro-fibrogenic macrophages.


Blood ◽  
1980 ◽  
Vol 55 (3) ◽  
pp. 489-493 ◽  
Author(s):  
SH Bartelmez ◽  
WH Dodge ◽  
DA Bass

Abstract Nonadherent spleen cells of mice infected with Trichinella spiralis released growth stimulatory factors (GSFs) in vitro when challenged with excretory/secretory products of muscle stage larvae. The assay of GSF was based on proliferation of normal, nonadherent syngeneic marrow cells in liquid tube cultures. Media conditioned for 1 day by challenged spleen cells stimulated eosinophil production but failed to stimulate production of other cell types. In contrast, media conditioned for 5 days supported eosinophil, neutrophil, and macrophage production. The kinetics of cell production were also different. Eosinophil production started within 1 day, reached a peak at day 2, and was down to control levels by day 4. In contrast, neutrophil/macrophage production began between 2 and 4 days and reached a peak at 6--8 days. The short duration of eosinophil production was evidently due to depletion of growth-factor-responsive cells.


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