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  1. EGFR regulates macrophage activation and function in bacterial infection.

    PubMed

    Hardbower, Dana M; Singh, Kshipra; Asim, Mohammad; Verriere, Thomas G; Olivares-Villagómez, Danyvid; Barry, Daniel P; Allaman, Margaret M; Washington, M Kay; Peek, Richard M; Piazuelo, M Blanca; Wilson, Keith T

    2016-09-01

    EGFR signaling regulates macrophage function, but its role in bacterial infection has not been investigated. Here, we assessed the role of macrophage EGFR signaling during infection with Helicobacter pylori, a bacterial pathogen that causes persistent inflammation and gastric cancer. EGFR was phosphorylated in murine and human macrophages during H. pylori infection. In human gastric tissues, elevated levels of phosphorylated EGFR were observed throughout the histologic cascade from gastritis to carcinoma. Deleting Egfr in myeloid cells attenuated gastritis and increased H. pylori burden in infected mice. EGFR deficiency also led to a global defect in macrophage activation that was associated with decreased cytokine, chemokine, and NO production. We observed similar alterations in macrophage activation and disease phenotype in the Citrobacter rodentium model of murine infectious colitis. Mechanistically, EGFR signaling activated NF-κB and MAPK1/3 pathways to induce cytokine production and macrophage activation. Although deletion of Egfr had no effect on DC function, EGFR-deficient macrophages displayed impaired Th1 and Th17 adaptive immune responses to H. pylori, which contributed to decreased chronic inflammation in infected mice. Together, these results indicate that EGFR signaling is central to macrophage function in response to enteric bacterial pathogens and is a potential therapeutic target for infection-induced inflammation and associated carcinogenesis.

  2. EGFR regulates macrophage activation and function in bacterial infection.

    PubMed

    Hardbower, Dana M; Singh, Kshipra; Asim, Mohammad; Verriere, Thomas G; Olivares-Villagómez, Danyvid; Barry, Daniel P; Allaman, Margaret M; Washington, M Kay; Peek, Richard M; Piazuelo, M Blanca; Wilson, Keith T

    2016-09-01

    EGFR signaling regulates macrophage function, but its role in bacterial infection has not been investigated. Here, we assessed the role of macrophage EGFR signaling during infection with Helicobacter pylori, a bacterial pathogen that causes persistent inflammation and gastric cancer. EGFR was phosphorylated in murine and human macrophages during H. pylori infection. In human gastric tissues, elevated levels of phosphorylated EGFR were observed throughout the histologic cascade from gastritis to carcinoma. Deleting Egfr in myeloid cells attenuated gastritis and increased H. pylori burden in infected mice. EGFR deficiency also led to a global defect in macrophage activation that was associated with decreased cytokine, chemokine, and NO production. We observed similar alterations in macrophage activation and disease phenotype in the Citrobacter rodentium model of murine infectious colitis. Mechanistically, EGFR signaling activated NF-κB and MAPK1/3 pathways to induce cytokine production and macrophage activation. Although deletion of Egfr had no effect on DC function, EGFR-deficient macrophages displayed impaired Th1 and Th17 adaptive immune responses to H. pylori, which contributed to decreased chronic inflammation in infected mice. Together, these results indicate that EGFR signaling is central to macrophage function in response to enteric bacterial pathogens and is a potential therapeutic target for infection-induced inflammation and associated carcinogenesis. PMID:27482886

  3. Macrophage Activation by Ursolic and Oleanolic Acids during Mycobacterial Infection.

    PubMed

    López-García, Sonia; Castañeda-Sanchez, Jorge Ismael; Jiménez-Arellanes, Adelina; Domínguez-López, Lilia; Castro-Mussot, Maria Eugenia; Hernández-Sanchéz, Javier; Luna-Herrera, Julieta

    2015-08-06

    Oleanolic (OA) and ursolic acids (UA) are triterpenes that are abundant in vegetables, fruits and medicinal plants. They have been described as active moieties in medicinal plants used for the treatment of tuberculosis. In this study, we analyzed the effects of these triterpenes on macrophages infected in vitro with Mycobacterium tuberculosis (MTB). We evaluated production of nitric oxide (NO), reactive oxygen species (ROS), and cytokines (TNF-α and TGF-β) as well as expression of cell membrane receptors (TGR5 and CD36) in MTB-infected macrophages following treatment with OA and UA. Triterpenes caused reduced MTB growth in macrophages, stimulated production of NO and ROS in the early phase, stimulated TNF-α, suppressed TGF-β and caused over-expression of CD36 and TGR5 receptors. Thus, our data suggest immunomodulatory properties of OA and UA on MTB infected macrophages. In conclusion, antimycobacterial effects induced by these triterpenes may be attributable to the conversion of macrophages from stage M2 (alternatively activated) to M1 (classically activated).

  4. Macrophage Activation by Ursolic and Oleanolic Acids during Mycobacterial Infection.

    PubMed

    López-García, Sonia; Castañeda-Sanchez, Jorge Ismael; Jiménez-Arellanes, Adelina; Domínguez-López, Lilia; Castro-Mussot, Maria Eugenia; Hernández-Sanchéz, Javier; Luna-Herrera, Julieta

    2015-01-01

    Oleanolic (OA) and ursolic acids (UA) are triterpenes that are abundant in vegetables, fruits and medicinal plants. They have been described as active moieties in medicinal plants used for the treatment of tuberculosis. In this study, we analyzed the effects of these triterpenes on macrophages infected in vitro with Mycobacterium tuberculosis (MTB). We evaluated production of nitric oxide (NO), reactive oxygen species (ROS), and cytokines (TNF-α and TGF-β) as well as expression of cell membrane receptors (TGR5 and CD36) in MTB-infected macrophages following treatment with OA and UA. Triterpenes caused reduced MTB growth in macrophages, stimulated production of NO and ROS in the early phase, stimulated TNF-α, suppressed TGF-β and caused over-expression of CD36 and TGR5 receptors. Thus, our data suggest immunomodulatory properties of OA and UA on MTB infected macrophages. In conclusion, antimycobacterial effects induced by these triterpenes may be attributable to the conversion of macrophages from stage M2 (alternatively activated) to M1 (classically activated). PMID:26287131

  5. LL-37 immunomodulatory activity during Mycobacterium tuberculosis infection in macrophages.

    PubMed

    Torres-Juarez, Flor; Cardenas-Vargas, Albertina; Montoya-Rosales, Alejandra; González-Curiel, Irma; Garcia-Hernandez, Mariana H; Enciso-Moreno, Jose A; Hancock, Robert E W; Rivas-Santiago, Bruno

    2015-12-01

    Tuberculosis is one of the most important infectious diseases worldwide. The susceptibility to this disease depends to a great extent on the innate immune response against mycobacteria. Host defense peptides (HDP) are one of the first barriers to counteract infection. Cathelicidin (LL-37) is an HDP that has many immunomodulatory effects besides its weak antimicrobial activity. Despite advances in the study of the innate immune response in tuberculosis, the immunological role of LL-37 during M. tuberculosis infection has not been clarified. Monocyte-derived macrophages were infected with M. tuberculosis strain H37Rv and then treated with 1, 5, or 15 μg/ml of exogenous LL-37 for 4, 8, and 24 h. Exogenous LL-37 decreased tumor necrosis factor alpha (TNF-α) and interleukin-17 (IL-17) while inducing anti-inflammatory IL-10 and transforming growth factor β (TGF-β) production. Interestingly, the decreased production of anti-inflammatory cytokines did not reduce antimycobacterial activity. These results are consistent with the concept that LL-37 can modulate the expression of cytokines during mycobacterial infection and this activity was independent of the P2X7 receptor. Thus, LL-37 modulates the response of macrophages during infection, controlling the expression of proinflammatory and anti-inflammatory cytokines.

  6. LL-37 Immunomodulatory Activity during Mycobacterium tuberculosis Infection in Macrophages

    PubMed Central

    Torres-Juarez, Flor; Cardenas-Vargas, Albertina; Montoya-Rosales, Alejandra; González-Curiel, Irma; Garcia-Hernandez, Mariana H.; Enciso-Moreno, Jose A.; Hancock, Robert E. W.

    2015-01-01

    Tuberculosis is one of the most important infectious diseases worldwide. The susceptibility to this disease depends to a great extent on the innate immune response against mycobacteria. Host defense peptides (HDP) are one of the first barriers to counteract infection. Cathelicidin (LL-37) is an HDP that has many immunomodulatory effects besides its weak antimicrobial activity. Despite advances in the study of the innate immune response in tuberculosis, the immunological role of LL-37 during M. tuberculosis infection has not been clarified. Monocyte-derived macrophages were infected with M. tuberculosis strain H37Rv and then treated with 1, 5, or 15 μg/ml of exogenous LL-37 for 4, 8, and 24 h. Exogenous LL-37 decreased tumor necrosis factor alpha (TNF-α) and interleukin-17 (IL-17) while inducing anti-inflammatory IL-10 and transforming growth factor β (TGF-β) production. Interestingly, the decreased production of anti-inflammatory cytokines did not reduce antimycobacterial activity. These results are consistent with the concept that LL-37 can modulate the expression of cytokines during mycobacterial infection and this activity was independent of the P2X7 receptor. Thus, LL-37 modulates the response of macrophages during infection, controlling the expression of proinflammatory and anti-inflammatory cytokines. PMID:26351280

  7. Macrophage activation and human immunodeficiency virus infection: HIV replication directs macrophages towards a pro-inflammatory phenotype while previous activation modulates macrophage susceptibility to infection and viral production.

    PubMed

    Porcheray, Fabrice; Samah, Boubekeur; Léone, Cathie; Dereuddre-Bosquet, Nathalie; Gras, Gabriel

    2006-05-25

    Macrophages are pivotal for the regulation of immune and inflammatory responses, but whether their role in HIV infection is protective or deleterious remains unclear. In this study, we investigated the effect of pro- and anti-inflammatory stimuli on macrophage sensitivity to two different aspects of HIV infection: their susceptibility to infection stricto sensu, which we measured by endpoint titration method, and their ability to support virus spread, which we measured by using an RT activity assay in infection kinetics. We show a partially protective role for pro-inflammatory agents as well as for IL-4. We also illustrate that various different stimuli display differential effects on macrophage susceptibility to HIV and on virus replication that occurs thereafter. On the other hand, HIV replication strongly repressed CD206 and CD163 expression, thus clearly orientating macrophages towards a pro-inflammatory phenotype, but independently of TNF. Taken together, our results emphasize that HIV infection of macrophages sets up inflammation at the cell level but through unexpected mechanisms. This may limit target susceptibility and participate in virus clearance but may also result in tissue damage.

  8. Macrophage Activation Redirects Yersinia-Infected Host Cell Death from Apoptosis to Caspase-1-Dependent Pyroptosis

    PubMed Central

    Bergsbaken, Tessa; Cookson, Brad T

    2007-01-01

    Infection of macrophages by Yersinia species results in YopJ-dependent apoptosis, and naïve macrophages are highly susceptible to this form of cell death. Previous studies have demonstrated that macrophages activated with lipopolysaccharide (LPS) prior to infection are resistant to YopJ-dependent cell death; we found this simultaneously renders macrophages susceptible to killing by YopJ− Yersinia pseudotuberculosis (Yptb). YopJ− Yptb-induced macrophage death was dependent on caspase-1 activation, resulting in rapid permeability to small molecules, followed by membrane breakdown and DNA damage, and accompanied by cleavage and release of proinflammatory interleukin-18. Induction of caspase-1-dependent death, or pyroptosis, required the bacterial type III translocon but none of its known translocated proteins. Wild-type Yptb infection also triggered pyroptosis: YopJ-dependent activation of proapoptotic caspase-3 was significantly delayed in activated macrophages and resulted in caspase-1-dependent pyroptosis. The transition to susceptibility was not limited to LPS activation; it was also seen in macrophages activated with other Toll-like receptor (TLR) ligands and intact nonviable bacteria. Yptb infection triggered macrophage activation and activation of caspase-1 in vivo. Y. pestis infection of activated macrophages also stimulated caspase-1 activation. These results indicate that host signaling triggered by TLR and other activating ligands during the course of Yersinia infection redirects both the mechanism of host cell death and the downstream consequences of death by shifting from noninflammatory apoptosis to inflammatory pyroptosis. PMID:17983266

  9. Localization and activity of various lysosomal proteases in Leishmania amazonensis-infected macrophages.

    PubMed Central

    Prina, E; Antoine, J C; Wiederanders, B; Kirschke, H

    1990-01-01

    In mammalian hosts, Leishmania amastigotes are obligatory intracellular parasites of macrophages and multiply within parasitophorous vacuoles of phagolysosomal origin. To understand how they escape the harmful strategies developed by macrophages to kill ingested microorganisms, it is important to obtain information on the functional state of parasitophorous vacuole. For this purpose, we studied the intracellular distribution and activity of host lysosomal proteases in rat bone marrow-derived macrophages infected with Leishmania amazonensis amastigotes. Localization of cathepsins B, H, L, and D was investigated by using specific immunoglobulins. In uninfected macrophages, these enzymes were located in perinuclear granules (most of them were probably secondary lysosomes) which, after infection, disappeared progressively. In infected macrophages, cathepsins were detected mainly in the parasitophorous vacuoles, suggesting that the missing secondary lysosomes had fused with these organelles. Biochemical assays of various proteases (cathepsins B, H, and D and dipeptidyl peptidases I and II) showed that infection was accompanied by a progressive increase of all activities tested, except that of dipeptidyl peptidase II, which remained constant. No more than 1 to 10% of these activities could be attributed to amastigotes. These data indicate that (i) Leishmania infection is followed by an increased synthesis and/or a reduced catabolism of host lysosomal proteases, and (ii) amastigotes grow in a compartment rich in apparently fully active proteases. Unexpectedly, it was found that infected and uninfected macrophages degraded endocytosed proteins similarly. The lack of correlation in infected macrophages between increase of protease activities and catabolism of exogenous proteins could be linked to the huge increase in volume of the lysosomal compartment. Images PMID:2187806

  10. Macrophage activation associated with chronic murine cytomegalovirus infection results in more severe experimental choroidal neovascularization.

    PubMed

    Cousins, Scott W; Espinosa-Heidmann, Diego G; Miller, Daniel M; Pereira-Simon, Simone; Hernandez, Eleut P; Chien, Hsin; Meier-Jewett, Courtney; Dix, Richard D

    2012-01-01

    The neovascular (wet) form of age-related macular degeneration (AMD) leads to vision loss due to choroidal neovascularization (CNV). Since macrophages are important in CNV development, and cytomegalovirus (CMV)-specific IgG serum titers in patients with wet AMD are elevated, we hypothesized that chronic CMV infection contributes to wet AMD, possibly by pro-angiogenic macrophage activation. This hypothesis was tested using an established mouse model of experimental CNV. At 6 days, 6 weeks, or 12 weeks after infection with murine CMV (MCMV), laser-induced CNV was performed, and CNV severity was determined 4 weeks later by analysis of choroidal flatmounts. Although all MCMV-infected mice exhibited more severe CNV when compared with control mice, the most severe CNV developed in mice with chronic infection, a time when MCMV-specific gene sequences could not be detected within choroidal tissues. Splenic macrophages collected from mice with chronic MCMV infection, however, expressed significantly greater levels of TNF-α, COX-2, MMP-9, and, most significantly, VEGF transcripts by quantitative RT-PCR assay when compared to splenic macrophages from control mice. Direct MCMV infection of monolayers of IC-21 mouse macrophages confirmed significant stimulation of VEGF mRNA and VEGF protein as determined by quantitative RT-PCR assay, ELISA, and immunostaining. Stimulation of VEGF production in vivo and in vitro was sensitive to the antiviral ganciclovir. These studies suggest that chronic CMV infection may serve as a heretofore unrecognized risk factor in the pathogenesis of wet AMD. One mechanism by which chronic CMV infection might promote increased CNV severity is via stimulation of macrophages to make pro-angiogenic factors (VEGF), an outcome that requires active virus replication. PMID:22570607

  11. Macrophage Activation Associated with Chronic Murine Cytomegalovirus Infection Results in More Severe Experimental Choroidal Neovascularization

    PubMed Central

    Cousins, Scott W.; Espinosa-Heidmann, Diego G.; Miller, Daniel M.; Pereira-Simon, Simone; Hernandez, Eleut P.; Chien, Hsin; Meier-Jewett, Courtney; Dix, Richard D.

    2012-01-01

    The neovascular (wet) form of age-related macular degeneration (AMD) leads to vision loss due to choroidal neovascularization (CNV). Since macrophages are important in CNV development, and cytomegalovirus (CMV)-specific IgG serum titers in patients with wet AMD are elevated, we hypothesized that chronic CMV infection contributes to wet AMD, possibly by pro-angiogenic macrophage activation. This hypothesis was tested using an established mouse model of experimental CNV. At 6 days, 6 weeks, or 12 weeks after infection with murine CMV (MCMV), laser-induced CNV was performed, and CNV severity was determined 4 weeks later by analysis of choroidal flatmounts. Although all MCMV-infected mice exhibited more severe CNV when compared with control mice, the most severe CNV developed in mice with chronic infection, a time when MCMV-specific gene sequences could not be detected within choroidal tissues. Splenic macrophages collected from mice with chronic MCMV infection, however, expressed significantly greater levels of TNF-α, COX-2, MMP-9, and, most significantly, VEGF transcripts by quantitative RT-PCR assay when compared to splenic macrophages from control mice. Direct MCMV infection of monolayers of IC-21 mouse macrophages confirmed significant stimulation of VEGF mRNA and VEGF protein as determined by quantitative RT-PCR assay, ELISA, and immunostaining. Stimulation of VEGF production in vivo and in vitro was sensitive to the antiviral ganciclovir. These studies suggest that chronic CMV infection may serve as a heretofore unrecognized risk factor in the pathogenesis of wet AMD. One mechanism by which chronic CMV infection might promote increased CNV severity is via stimulation of macrophages to make pro-angiogenic factors (VEGF), an outcome that requires active virus replication. PMID:22570607

  12. Enhanced resistance against Listeria monocytogenes at an early phase of primary infection in pregnant mice: activation of macrophages during pregnancy.

    PubMed Central

    Watanabe, Y; Mitsuyama, M; Sano, M; Nakano, H; Nomoto, K

    1986-01-01

    We investigated the pregnancy-induced changes in macrophage activity which are important in the expression of host defense against infections. Several macrophage functions were examined by using Listeria monocytogenes. In pregnant mice, prolonged survival and enhanced in vivo elimination of bacteria were observed in the early phase of primary infection. Functions of peritoneal macrophages, including in vitro phagocytosis intracellular killing, glucose consumption, generation of superoxide anion, and intracellular beta-glucuronidase activity were shown to be enhanced in pregnant mice. These findings indicate that pregnancy enhances macrophage functions qualitatively. Possible mechanisms for this enhancement and the significance of macrophage activation for pregnant hosts are discussed. PMID:3011673

  13. Inhibition of ecto-ATPase activities impairs HIV-1 infection of macrophages.

    PubMed

    Schachter, Julieta; Delgado, Kelly Valcárcel; Barreto-de-Souza, Victor; Bou-Habib, Dumith Chequer; Persechini, Pedro Muanis; Meyer-Fernandes, José Roberto

    2015-05-01

    Nucleotides and nucleosides are secreted into extracellular media at different concentrations as a consequence of different physiologic and pathological conditions. Ecto-nucleotidases, enzymes present on the surface of most cells, hydrolyze these extracellular nucleotides and reduce the concentration of them, thus affecting the activation of different nucleotide and nucleoside receptors. Also, ecto-nucleotidases are present in a number of microorganisms and play important roles in host-pathogen interactions. Here, we characterized the ecto-ATPase activities present on the surface of HIV-1 particle and human macrophages as well. We found that the kinetic properties of HIV-1 and macrophage ecto-ATPases are similar, suggesting that the enzyme is the same. This ecto-ATPase activity was increased in macrophages infected in vitro with HIV-1. Using three different non-related ecto-ATPase inhibitors-POM-1, ARL67156 and BG0-we showed that the inhibition of these macrophage and viral ecto-ATPase activities impairs HIV-1 infection. In addition, we also found that elevated extracellular concentrations of ATP inhibit HIV-1 production by infected macrophages.

  14. Induction of alternatively activated macrophages enhances pathogenesis during severe acute respiratory syndrome coronavirus infection.

    PubMed

    Page, Carly; Goicochea, Lindsay; Matthews, Krystal; Zhang, Yong; Klover, Peter; Holtzman, Michael J; Hennighausen, Lothar; Frieman, Matthew

    2012-12-01

    Infection with severe acute respiratory syndrome coronavirus (SARS-CoV) causes acute lung injury (ALI) that often leads to severe lung disease. A mouse model of acute SARS-CoV infection has been helpful in understanding the host response to infection; however, there are still unanswered questions concerning SARS-CoV pathogenesis. We have shown that STAT1 plays an important role in the severity of SARS-CoV pathogenesis and that it is independent of the role of STAT1 in interferon signaling. Mice lacking STAT1 have greater weight loss, severe lung pathology with pre-pulmonary-fibrosis-like lesions, and an altered immune response following infection with SARS-CoV. We hypothesized that STAT1 plays a role in the polarization of the immune response, specifically in macrophages, resulting in a worsened outcome. To test this, we created bone marrow chimeras and cell-type-specific knockouts of STAT1 to identify which cell type(s) is critical to protection from severe lung disease after SARS-CoV infection. Bone marrow chimera experiments demonstrated that hematopoietic cells are responsible for the pathogenesis in STAT1(-/-) mice, and because of an induction of alternatively activated (AA) macrophages after infection, we hypothesized that the AA macrophages were critical for disease severity. Mice with STAT1 in either monocytes and macrophages (LysM/STAT1) or ciliated lung epithelial cells (FoxJ1/STAT1) deleted were created. Following infection, LysM/STAT1 mice display severe lung pathology, while FoxJ1/STAT1 mice display normal lung pathology. We hypothesized that AA macrophages were responsible for this STAT1-dependent pathology and therefore created STAT1/STAT6(-/-) double-knockout mice. STAT6 is essential for the development of AA macrophages. Infection of the double-knockout mice displayed a lack of lung disease and prefibrotic lesions, suggesting that AA macrophage production may be the cause of STAT1-dependent lung disease. We propose that the control of AA

  15. Regulation of macrophage-mediated larvicidal activity in Echinococcus granulosus and Mesocestoides corti (Cestoda) infection in mice.

    PubMed

    Jenkins, P; Dixon, J B; Rakha, N K; Carter, S D

    1990-04-01

    Killing of metacestodes by normal or post-infection macrophages and the regulation of this activity by cytokines were studied in vitro. The protoscolecidal activity of normal macrophages against Echinococcus granulosus was inhibited by a product of naive T-enriched lymphocytes co-cultured with protoscoleces (PSC). By contrast, supernates from co-cultures of Mesocestoides corti tetrathyridia (MCT) and T-enriched or B-enriched normal lymphocytes increased killing of MCT by normal macrophages. Larvicidal activity (against both PSC and MCT) was enhanced by high concentrations of macrophage-activating factors produced by Con A-stimulated rat lymphocytes (Con A-LK), but was reduced by low concentrations of these factors. Activation by synergism between Con A-LK and recombinant interferon-gamma(r. IFN-gamma) was demonstrated in macrophage-mediated killing of MCT at high effector to target ratio. Cytokine-activation of normal or post-MCT infection macrophages was compared. Macrophages from both 8 and 20 week post-infection mice were refractory to lymphokines from lymphocyte-MCT cultures and displayed greatly reduced killing of MCT. Macrophage activation by Con A-LK and r.IFN-gamma was also impaired, implying a general defect in the ability of these post-infection macrophages to respond to macrophage activating signals. The data indicate that two different mechanisms may exist by which metacestodes regulate potentially larvicidal effector mechanisms. E. granulosus can elicit the production of lymphokines suppressive for PSC killing, whereas M. corti appears directly to induce a refractory state in effector macrophages.

  16. PPARγ-mediated increase in glucose availability sustains chronic Brucella abortus infection in alternatively activated macrophages

    PubMed Central

    Xavier, Mariana N.; Winter, Maria G.; Spees, Alanna M.; den Hartigh, Andreas B.; Nguyen, Kim; Roux, Christelle M.; Silva, Teane M. A.; Atluri, Vidya L.; Kerrinnes, Tobias; Keestra, A. Marijke; Monack, Denise M.; Luciw, Paul A.; Eigenheer, Richard A.; Bäumler, Andreas J.; Santos, Renato L.; Tsolis, Renée M.

    2013-01-01

    SUMMARY Eradication of persistent intracellular bacterial pathogens with antibiotic therapy is often slow or incomplete. However, strategies to augment antibiotics are hampered by our poor understanding of the nutritional environment that sustains chronic infection. Here we show that the intracellular pathogen Brucella abortus survives and replicates preferentially in alternatively activated macrophages (AAM), which are more abundant during chronic infection. A metabolic shift induced by peroxisome proliferator activated receptor γ (PPARγ), which increases intracellular glucose availability, is identified as a causal mechanism promoting enhanced bacterial survival in AAM. Glucose uptake was crucial for increased replication of B. abortus in AAM, and chronic infection, as inactivation of the bacterial glucose transporter gluP reduced both intracellular survival in AAM and persistence in mice. Thus, a shift in intracellular nutrient availability induced by PPARγ promotes chronic persistence of B. abortus within AAM and targeting this pathway may aid in eradicating chronic infection. PMID:23954155

  17. PPARγ-mediated increase in glucose availability sustains chronic Brucella abortus infection in alternatively activated macrophages.

    PubMed

    Xavier, Mariana N; Winter, Maria G; Spees, Alanna M; den Hartigh, Andreas B; Nguyen, Kim; Roux, Christelle M; Silva, Teane M A; Atluri, Vidya L; Kerrinnes, Tobias; Keestra, A Marijke; Monack, Denise M; Luciw, Paul A; Eigenheer, Richard A; Bäumler, Andreas J; Santos, Renato L; Tsolis, Renée M

    2013-08-14

    Eradication of persistent intracellular bacterial pathogens with antibiotic therapy is often slow or incomplete. However, strategies to augment antibiotics are hampered by our poor understanding of the nutritional environment that sustains chronic infection. Here we show that the intracellular pathogen Brucella abortus survives and replicates preferentially in alternatively activated macrophages (AAMs), which are more abundant during chronic infection. A metabolic shift induced by peroxisome proliferator-activated receptor γ (PPARγ), which increases intracellular glucose availability, is identified as a causal mechanism promoting enhanced bacterial survival in AAMs. Glucose uptake was crucial for increased replication of B. abortus in AAMs, and for chronic infection, as inactivation of the bacterial glucose transporter gluP reduced both intracellular survival in AAMs and persistence in mice. Thus, a shift in intracellular nutrient availability induced by PPARγ promotes chronic persistence of B. abortus within AAMs, and targeting this pathway may aid in eradicating chronic infection. PMID:23954155

  18. Caspase-1 activation in macrophages infected with Yersinia pestis KIM requires the type III secretion system effector YopJ.

    PubMed

    Lilo, Sarit; Zheng, Ying; Bliska, James B

    2008-09-01

    Pathogenic Yersinia species utilize a type III secretion system (T3SS) to translocate effectors called Yersinia outer proteins (Yops) into infected host cells. Previous studies demonstrated a role for effector Yops in the inhibition of caspase-1-mediated cell death and secretion of interleukin-1beta (IL-1beta) in naïve macrophages infected with Yersinia enterocolitica. Naïve murine macrophages were infected with a panel of different Yersinia pestis and Yersinia pseudotuberculosis strains to determine whether Yops of these species inhibit caspase-1 activation. Cell death was measured by release of lactate dehydrogenase (LDH), and enzyme-linked immunosorbent assay for secreted IL-1beta was used to measure caspase-1 activation. Surprisingly, isolates derived from the Y. pestis KIM strain (e.g., KIM5) displayed an unusual ability to activate caspase-1 and kill infected macrophages compared to other Y. pestis and Y. pseudotuberculosis strains tested. Secretion of IL-1beta following KIM5 infection was reduced in caspase-1-deficient macrophages compared to wild-type macrophages. However, release of LDH was not reduced in caspase-1-deficient macrophages, indicating that cell death occurred independently of caspase-1. Analysis of KIM-derived strains defective for production of functional effector or translocator Yops indicated that translocation of catalytically active YopJ into macrophages was required for caspase-1 activation and cell death. Release of LDH and secretion of IL-1beta were not reduced when actin polymerization was inhibited in KIM5-infected macrophages, indicating that extracellular bacteria translocating YopJ could trigger cell death and caspase-1 activation. This study uncovered a novel role for YopJ in the activation of caspase-1 in macrophages.

  19. Caspase-1 Activation in Macrophages Infected with Yersinia pestis KIM Requires the Type III Secretion System Effector YopJ▿

    PubMed Central

    Lilo, Sarit; Zheng, Ying; Bliska, James B.

    2008-01-01

    Pathogenic Yersinia species utilize a type III secretion system (T3SS) to translocate effectors called Yersinia outer proteins (Yops) into infected host cells. Previous studies demonstrated a role for effector Yops in the inhibition of caspase-1-mediated cell death and secretion of interleukin-1β (IL-1β) in naïve macrophages infected with Yersinia enterocolitica. Naïve murine macrophages were infected with a panel of different Yersinia pestis and Yersinia pseudotuberculosis strains to determine whether Yops of these species inhibit caspase-1 activation. Cell death was measured by release of lactate dehydrogenase (LDH), and enzyme-linked immunosorbent assay for secreted IL-1β was used to measure caspase-1 activation. Surprisingly, isolates derived from the Y. pestis KIM strain (e.g., KIM5) displayed an unusual ability to activate caspase-1 and kill infected macrophages compared to other Y. pestis and Y. pseudotuberculosis strains tested. Secretion of IL-1β following KIM5 infection was reduced in caspase-1-deficient macrophages compared to wild-type macrophages. However, release of LDH was not reduced in caspase-1-deficient macrophages, indicating that cell death occurred independently of caspase-1. Analysis of KIM-derived strains defective for production of functional effector or translocator Yops indicated that translocation of catalytically active YopJ into macrophages was required for caspase-1 activation and cell death. Release of LDH and secretion of IL-1β were not reduced when actin polymerization was inhibited in KIM5-infected macrophages, indicating that extracellular bacteria translocating YopJ could trigger cell death and caspase-1 activation. This study uncovered a novel role for YopJ in the activation of caspase-1 in macrophages. PMID:18559430

  20. Ursolic Acid Activates Intracellular Killing Effect of Macrophages During Mycobacterium tuberculosis Infection.

    PubMed

    Podder, Biswajit; Jang, Woong Sik; Nam, Kung-Woo; Lee, Byung-Eui; Song, Ho-Yeon

    2015-05-01

    Tuberculosis is one of the most threatening infectious diseases to public health all over the world, for which Mycobacterium tuberculosis (MTB) is the etiological agent of pathogenesis. Ursolic acid (UA) has immunomodulatory function and exhibits antimycobacterial activity. However, the intracellular killing effect of UA has yet to be elucidated. The aim of this study was to evaluate the intracellular killing effect of UA during mycobacterial infection. The intracellular killing activity of UA was evaluated in the macrophage cell line THP-1 by the MGIT 960 system as well as by CFU count. The production of reactive oxygen species (ROS) and the level of nitric oxide (NO) were measured using DCF-DA and Griess reagent, respectively. Phagocytosis was observed by a fluorescence-based staining method, and the colony forming units were enumerated on 7H11 agar medium following infection. In addition, MRP8 mRNA expression was measured by qRT-PCR. UA significantly decreased the number of intracellular Mycobacterium through generation of ROS and NO. In addition, it profoundly activated the phagocytosis process of THP-1 cells during MTB-infection. Furthermore, our data demonstrated that UA activated the phagocytosis process in human monocyte cells through MRP8 induction. These data suggest that UA firmly contributes to the intracellular killing effect of macrophages during mycobacterial infection.

  1. Guanylate binding proteins enable rapid activation of canonical and noncanonical inflammasomes in Chlamydia-infected macrophages.

    PubMed

    Finethy, Ryan; Jorgensen, Ine; Haldar, Arun K; de Zoete, Marcel R; Strowig, Till; Flavell, Richard A; Yamamoto, Masahiro; Nagarajan, Uma M; Miao, Edward A; Coers, Jörn

    2015-12-01

    Interferon (IFN)-inducible guanylate binding proteins (GBPs) mediate cell-autonomous host resistance to bacterial pathogens and promote inflammasome activation. The prevailing model postulates that these two GBP-controlled activities are directly linked through GBP-dependent vacuolar lysis. It was proposed that the rupture of pathogen-containing vacuoles (PVs) by GBPs destroyed the microbial refuge and simultaneously contaminated the host cell cytosol with microbial activators of inflammasomes. Here, we demonstrate that GBP-mediated host resistance and GBP-mediated inflammatory responses can be uncoupled. We show that PVs formed by the rodent pathogen Chlamydia muridarum, so-called inclusions, remain free of GBPs and that C. muridarum is impervious to GBP-mediated restrictions on bacterial growth. Although GBPs neither bind to C. muridarum inclusions nor restrict C. muridarum growth, we find that GBPs promote inflammasome activation in C. muridarum-infected macrophages. We demonstrate that C. muridarum infections induce GBP-dependent pyroptosis through both caspase-11-dependent noncanonical and caspase-1-dependent canonical inflammasomes. Among canonical inflammasomes, we find that C. muridarum and the human pathogen Chlamydia trachomatis activate not only NLRP3 but also AIM2. Our data show that GBPs support fast-kinetics processing and secretion of interleukin-1β (IL-1β) and IL-18 by the NLRP3 inflammasome but are dispensable for the secretion of the same cytokines at later times postinfection. Because IFN-γ fails to induce IL-1β transcription, GBP-dependent fast-kinetics inflammasome activation can drive the preferential processing of constitutively expressed IL-18 in IFN-γ-primed macrophages in the absence of prior Toll-like receptor stimulation. Together, our results reveal that GBPs control the kinetics of inflammasome activation and thereby shape macrophage responses to Chlamydia infections.

  2. Guanylate Binding Proteins Enable Rapid Activation of Canonical and Noncanonical Inflammasomes in Chlamydia-Infected Macrophages

    PubMed Central

    Finethy, Ryan; Jorgensen, Ine; Haldar, Arun K.; de Zoete, Marcel R.; Strowig, Till; Flavell, Richard A.; Yamamoto, Masahiro; Nagarajan, Uma M.; Miao, Edward A.

    2015-01-01

    Interferon (IFN)-inducible guanylate binding proteins (GBPs) mediate cell-autonomous host resistance to bacterial pathogens and promote inflammasome activation. The prevailing model postulates that these two GBP-controlled activities are directly linked through GBP-dependent vacuolar lysis. It was proposed that the rupture of pathogen-containing vacuoles (PVs) by GBPs destroyed the microbial refuge and simultaneously contaminated the host cell cytosol with microbial activators of inflammasomes. Here, we demonstrate that GBP-mediated host resistance and GBP-mediated inflammatory responses can be uncoupled. We show that PVs formed by the rodent pathogen Chlamydia muridarum, so-called inclusions, remain free of GBPs and that C. muridarum is impervious to GBP-mediated restrictions on bacterial growth. Although GBPs neither bind to C. muridarum inclusions nor restrict C. muridarum growth, we find that GBPs promote inflammasome activation in C. muridarum-infected macrophages. We demonstrate that C. muridarum infections induce GBP-dependent pyroptosis through both caspase-11-dependent noncanonical and caspase-1-dependent canonical inflammasomes. Among canonical inflammasomes, we find that C. muridarum and the human pathogen Chlamydia trachomatis activate not only NLRP3 but also AIM2. Our data show that GBPs support fast-kinetics processing and secretion of interleukin-1β (IL-1β) and IL-18 by the NLRP3 inflammasome but are dispensable for the secretion of the same cytokines at later times postinfection. Because IFN-γ fails to induce IL-1β transcription, GBP-dependent fast-kinetics inflammasome activation can drive the preferential processing of constitutively expressed IL-18 in IFN-γ-primed macrophages in the absence of prior Toll-like receptor stimulation. Together, our results reveal that GBPs control the kinetics of inflammasome activation and thereby shape macrophage responses to Chlamydia infections. PMID:26416908

  3. Triple trouble--macrophage activation syndrome in a case of severe leptospirosis and scrub typhus co-infection.

    PubMed

    Diwan, A G; Shewale, Rahul; Iyer, Shivakumar; Nisal, Amit; Agrawa, Prakhar

    2014-01-01

    Macrophage activation syndrome is a potentially life threatening phenomenon characterised by aggressive proliferation of macrophages and T lymphocytes leading to haemophagocytosis of other blood cells and multi organ failure. Here we present a very unusual combination of leptospirosis and scrub typhus infection leading to macrophage activation syndrome. Scrub typhus associated with macrophage activation syndrome has rarely been reported in India. A 40 year old female presented with high grade fever, seizures, bodyache, arthralgia and severe breathlessness. Investigations revealed persistent thrombocytopenia, impaired liver function tests, renal dysfunction, leptospiral IgM ELISA positive and a positive Weil Felix test. There was evidence of haemophagocytosis in bone marrow. Macrophage activation syndrome if left untreated has been associated with rapidly fatal outcome and early treatment can help us save that one precious thing..called life..! PMID:25327097

  4. Immune Activity of BCG Infected Mouse Macrophages Treated with a Novel Recombinant Mouse Lactoferrin.

    PubMed

    O'Shea, Kelly M; Hwang, Shen-An; Actor, Jeffrey K

    2015-01-01

    Lactoferrin has been investigated for its adjuvant action to boost the BCG vaccine. Previous studies demonstrated that lactoferrin (LF) enhanced efficacy of the Bacillus Calmette-Guérin (BCG) vaccine to protect mice against the virulent Erdman Mycobacterium tuberculosis challenge. The studies here investigate the hypothesis that a novel CHO-derived recombinant mouse LF can modify cytokine production and antigen presentation molecules on macrophages. The mouse LF (rmLF) was examined for effects on bone marrow derived macrophage (BMM) activities when cultured with BCG. Comparisons were made to CHO-derived recombinant human LF (rhLF). Inflammatory cytokine responses were investigated, as were antigen presentation and associated co-stimulatory molecules. Cytokine responses were subsequently measured when these cells were co-cultured with naïve or BCG sensitized CD4+ lymphocytes. While overall responses were similar between mouse, human, and bovine forms, the homologous rmLF treated infected BMMs showed unique activation patterns of cytokine production. These results indicate that species-specific LF can have different effects on mouse macrophages exposed to BCG, thus potentially affecting adjuvant activity when used in models of vaccination in mice.

  5. Intracellular activity of tedizolid phosphate and ACH-702 versus Mycobacterium tuberculosis infected macrophages

    PubMed Central

    2014-01-01

    Background Due to the emergency of multidrug-resistant strains of Mycobacterium tuberculosis, is necessary the evaluation of new compounds. Findings Tedizolid, a novel oxazolidinone, and ACH-702, a new isothiazoloquinolone, were tested against M. tuberculosis infected THP-1 macrophages. These two compounds significantly decreased the number of intracellular mycobacteria at 0.25X, 1X, 4X and 16X the MIC value. The drugs were tested either in nanoparticules or in free solution. Conclusion Tedizolid and ACH-702 have a good intracellular killing activity comparable to that of rifampin or moxifloxacin. PMID:24708819

  6. Mycobacterium avium serovars 2 and 8 infections elicit unique activation of the host macrophage immune responses.

    PubMed

    Cebula, B R; Rocco, J M; Maslow, J N; Irani, V R

    2012-12-01

    Mycobacterium avium is an opportunistic pathogen whose pathogenesis is attributed to its serovar-specific glycopeptidolipid (ssGPL), which varies among its 31 serovars. To determine if the presence and type of ssGPLs contribute to M. avium pathogenesis, we infected murine macrophages (mφs) with two M. avium wild type (wt) serovars (2 and 8) and their serovar-null strains. We examined the influence of ssGPL (presence and type) on cytokine production in non-activated (-IFN-γ) and activated (+IFN-γ) mφs, and the bacterial intra-mφ survival over a 6-day infection process. Serovar-2 infections activated TNF-α production that increased over the 6 day period and was capable of controlling the intra-mφ serovar-2 null strain. In contrast, the serovar-8 infection stimulated a strong pro-inflammatory response, but was incapable of removing the invading pathogen, maybe through IL-10 production. It was clear that the intracellular growth of serovar-null in contrast to the wt M. avium strains was easily controlled. Based on our findings and the undisputed fact that M. avium ssGPL is key to its pathogenesis, we conclude that it is not appropriate to dissect the pathogenesis of one M. avium serovar and apply those findings to other serovars. PMID:22991047

  7. Immunotherapy of HIV-infected patients with Gc protein-derived macrophage activating factor (GcMAF).

    PubMed

    Yamamoto, Nobuto; Ushijima, Naofumi; Koga, Yoshihiko

    2009-01-01

    Serum Gc protein (known as vitamin D3-binding protein) is the precursor for the principal macrophage activating factor (MAF). The MAF precursor activity of serum Gc protein of HIV-infected patients was lost or reduced because Gc protein is deglycosylated by alpha-N-acetylgalactosaminidase (Nagalase) secreted from HIV-infected cells. Therefore, macrophages of HIV-infected patients having deglycosylated Gc protein cannot be activated, leading to immunosuppression. Since Nagalase is the intrinsic component of the envelope protein gp120, serum Nagalase activity is the sum of enzyme activities carried by both HIV virions and envelope proteins. These Nagalase carriers were already complexed with anti-HIV immunoglobulin G (IgG) but retained Nagalase activity that is required for infectivity. Stepwise treatment of purified Gc protein with immobilized beta-galactosidase and sialidase generated the most potent macrophage activating factor (termed GcMAF), which produces no side effects in humans. Macrophages activated by administration of 100 ng GcMAF develop a large amount of Fc-receptors as well as an enormous variation of receptors that recognize IgG-bound and unbound HIV virions. Since latently HIV-infected cells are unstable and constantly release HIV virions, the activated macrophages rapidly intercept the released HIV virions to prevent reinfection resulting in exhaustion of infected cells. After less than 18 weekly administrations of 100 ng GcMAF for nonanemic patients, they exhibited low serum Nagalase activities equivalent to healthy controls, indicating eradication of HIV-infection, which was also confirmed by no infectious center formation by provirus inducing agent-treated patient PBMCs. No recurrence occurred and their healthy CD + cell counts were maintained for 7 years. PMID:19031451

  8. Tim-3 induces Th2-biased immunity and alternative macrophage activation during Schistosoma japonicum infection.

    PubMed

    Hou, Nan; Piao, Xianyu; Liu, Shuai; Wu, Chuang; Chen, Qijun

    2015-08-01

    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 with Schistosoma 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 against S. japonicum infection. 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 of S. 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 numbers in vitro and in 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.

  9. The predominance of alternatively activated macrophages following challenge with cell wall peptide-polysaccharide after prior infection with Sporothrix schenckii.

    PubMed

    Alegranci, Pamela; de Abreu Ribeiro, Livia Carolina; Ferreira, Lucas Souza; Negrini, Thais de Cássia; Maia, Danielle Cardoso Geraldo; Tansini, Aline; Gonçalves, Amanda Costa; Placeres, Marisa Campos Polesi; Carlos, Iracilda Zeppone

    2013-08-01

    Sporotrichosis is a subcutaneous mycosis that is caused by the dimorphic fungus Sporothrix schenckii. This disease generally occurs within the skin and subcutaneous tissues, causing lesions that can spread through adjacent lymphatic vessels and sometimes leading to systemic diseases in immunocompromised patients. Macrophages are crucial for proper immune responses against a variety of pathogens. Furthermore, macrophages can play different roles in response to different microorganisms and forms of activation, and they can be divided into "classic" or "alternatively" activated populations, as also known as M1 and M2 macrophages. M1 cells can lead to tissue injury and contribute to pathogenesis, whereas M2 cells promote angiogenesis, tissue remodeling, and repair. The aim of this study was to investigate the roles of M1 and M2 macrophages in a sporotrichosis model. Toward this end, we performed phenotyping of peritoneal exudate cells and evaluated the concomitant production of several immunomediators, including IL-12, IL-10, TGF-β, nitric oxide, and arginase-I activity, which were stimulated ex vivo with cell wall peptide-polysaccharide. Our results showed the predominance of the M2 macrophage population, indicated by peaks of arginase-I activity as well as IL-10 and TGF-β production during the 6th and 8th weeks after infection. These results were consistent with cellular phenotyping that revealed increases in CD206-positive cells over this period. This is the first report of the participation of M2 macrophages in sporotrichosis infections.

  10. Antiviral activity of derivatized dextrans on HIV-1 infection of primary macrophages and blood lymphocytes.

    PubMed

    Seddiki, N; Mbemba, E; Letourneur, D; Ylisastigui, L; Benjouad, A; Saffar, L; Gluckman, J C; Jozefonvicz, J; Gattegno, L

    1997-11-28

    The present study demonstrates at the molecular level that dextran derivatives carboxymethyl dextran benzylamine (CMDB) and carboxymethyl dextran benzylamine sulfonate (CMDBS), characterized by a statistical distribution of anionic carboxylic groups, hydrophobic benzylamide units, and/or sulfonate moieties, interact with HIV-1 LAI gp120 and V3 consensus clades B domain. Only limited interaction was observed with carboxy-methyl dextran (CMD) or dextran (D) under the same conditions. CMDBS and CMDB (1 microM) strongly inhibited HIV-1 infection of primary macrophages and primary CD4+ lymphocytes by macrophage-tropic and T lymphocyte-tropic strains, respectively, while D or CMD had more limited effects on M-tropic infection of primary macrophages and exert no inhibitory effect on M- or T-tropic infection of primary lymphocytes. CMDBS and CMDB (1 microM) had limited but significant effect on oligomerized soluble recombinant gp120 binding to primary macrophages while they clearly inhibit (> 50%) such binding to primary lymphocytes. In conclusion, the inhibitory effect of CMDB and the CMDBS, is observed for HIV M- and T-tropic strain infections of primary lymphocytes and macrophages which indicates that these compounds interfere with steps of HIV replicative cycle which neither depend on the virus nor on the cell.

  11. Enhanced allergic responsiveness after early childhood infection with respiratory viruses: Are long-lived alternatively activated macrophages the missing link?

    PubMed

    Keegan, Achsah D; Shirey, Kari Ann; Bagdure, Dayanand; Blanco, Jorge; Viscardi, Rose M; Vogel, Stefanie N

    2016-07-01

    Early childhood infection with respiratory viruses, including human rhinovirus, respiratory syncytial virus (RSV) and influenza, is associated with an increased risk of allergic asthma and severe exacerbation of ongoing disease. Despite the long recognition of this relationship, the mechanism linking viral infection and later susceptibility to allergic lung inflammation is still poorly understood. We discuss the literature and provide new evidence demonstrating that these viruses induce the alternative activation of macrophages. Alternatively activated macrophages (AAM) induced by RSV or influenza infection persisted in the lungs of mice up to 90 days after initial viral infection. Several studies suggest that AAM contribute to allergic inflammatory responses, although their mechanism of action is unclear. In this commentary, we propose that virus-induced AAM provide a link between viral infection and enhanced responses to inhaled allergens. PMID:27178560

  12. Infectious bursal disease virus infection induces macrophage activation via p38 MAPK and NF-kappaB pathways.

    PubMed

    Khatri, Mahesh; Sharma, Jagdev M

    2006-06-01

    In the present study, we show that infection with infectious bursal disease virus (IBDV) causes activation of macrophages, the key cells involved in inflammatory and immune-regulatory functions. Exposure of cultured spleen macrophages (SM) from SPF chickens to IBDV resulted in the production of nitric oxide (NO). In addition, there was upregulation of mRNA expression of inducible nitric oxide synthase (iNOS), IL-8 and cyclooxygenase-2 (COX-2). The signal transduction pathways involved in macrophage activation were examined. The role of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-kappaB) was tested by using specific pharmacological inhibitors. Addition of p38 MAPK inhibitor, SB-203580 and NF-kappaB inhibitor Bay 11-7082, suppressed IBDV-induced NO production and mRNA expression of iNOS, IL-8 and COX-2. The results suggest that IBDV uses cellular signal transduction machinery, in particular the p38 MAPK and NF-kappaB pathways, to elicit macrophage activation. The increased production of NO, IL-8 and COX-2 by macrophages may contribute to bursa inflammatory responses commonly seen during the acute IBDV infection.

  13. Canine leishmaniasis in Southern Italy: a role for nitric oxide released from activated macrophages in asymptomatic infection?

    PubMed Central

    Panaro, Maria A; Brandonisio, Olga; de Caprariis, Donato; Cavallo, Pasqua; Cianciulli, Antonia; Mitolo, Vincenzo; Otranto, Domenico

    2008-01-01

    Background Human and canine leishmaniasis (CanL) by Leishmania infantum is endemic in Italy, with a high percentage of infected asymptomatic animals. However, the immune response mechanisms underlying the clinical presentation of CanL have not been fully investigated. Among leishmanicidal molecules produced by activated macrophages, nitric oxide (NO) produced by an inducible NO synthase seems to play an important protective role, but no conclusive data are available. Therefore, NO released by cultured macrophages from dogs with natural Leishmania infection living in an endemic area for CanL was evaluated. Methods On the basis of one year's clinical and laboratory follow-up, 22 dogs infected by Leishmania infantum were identified and grouped as: asymptomatic dogs (n = 13) and dogs with symptoms of leishmaniasis (n = 9). Each animal was bled twice at 4-month intervals and macrophage and lymphocyte cultures were obtained from peripheral blood mononuclear cells. Supernatants of L. infantum-infected macrophage cultures, with or without addition of autologous lymphocytes, were assayed for NO production by Griess reaction for nitrites. Results In the first months of the infection the levels of NO in supernatants of Leishmania-infected macrophages were higher in symptomatic than in asymptomatic dogs, but they were significantly increased in the latter group eight months after the diagnosis of infection. Furthermore, NO release significantly decreased in the presence of autologous lymphocytes in both groups of animals. Conclusion These results suggest that NO may be involved in the long-term protection of dogs against natural Leishmania infection and in the clinical presentation of canine leishmaniasis in the Mediterranean area. PMID:18471289

  14. Mycobacterium avium subspecies paratuberculosis infection of cattle does not diminish peripheral blood-derived macrophage mycobactericidal activity.

    PubMed

    Hostetter, J; Zhang, W; Simutis, F

    2006-09-15

    Ruminants infected with Mycobacterium avium subspecies paratuberculosis consistently develop a multibacillary form of disease that is centered on the ileum. Mechanisms responsible for failure of macrophage function during multibacillary disease are incompletely characterized. Our data suggest that mycobactericidal functions are present, and potentially enhanced, in monocyte-derived macrophages from M. avium subsp. paratuberculosis infected cattle. Addition of CD4(+) T cells from infected animals to autologous in vitro infected macrophages did not increase bacterial killing. In contrast, CD4(+) T cells from non-infected animals did increase bacterial killing in autologous macrophages. In macrophages from both infected and non-infected cattle, bacterial killing appeared to be independent of interferon-gamma (IFN-gamma) and nitric oxide production.

  15. Electroacupuncture at the ST36 acupoint increases interleukin-4 responsiveness in macrophages, generation of alternatively activated macrophages and susceptibility to Leishmania major infection

    PubMed Central

    2012-01-01

    Background Electroacupuncture (EA) has been used to treat inflammatory diseases. Alternatively activated macrophages (AAMo) stimulated by cytokines such as interleukin (IL)-4, IL-10 and IL-13 are anti-inflammatory and mildly microbicidal. This study aimed to evaluate whether EA at the Zusanli acupoint (ST36) would change the profile of healthy murine macrophages, particularly the generation of AAMo and susceptibility to Leishmania major infection. Methods BALB/c mice were treated with EA (15/30 Hz) at the ST36 acupoint for 20 min/d for 5 d. After the final EA session, the mice were euthanized and their peritoneal cells were harvested and counted for determination of arginase activity, nitric oxide (NO) production and microbicidal activity after culture in the presence or absence of IL-4, interferon-γ (IFNγ) or lipopolysaccharide (LPS) or both IFNγ and LPS. Twelve mice were infected with L. major promastigotes into the footpads after the final EA session and the infection course was monitored. Results Peritoneal cells freshly obtained from EA-treated mice had similar arginase and microbicidal activities to cells from sham-treated mice. After culture with IL-4, cells from EA-treated mice exhibited significant increases in the arginase activity (sham: 58 ± 11.3 vs. EA: 80.7 ± 4.6%, P = 0.025) and number of parasites/infected cell (sham: 2.5 ± 0.4 vs. EA: 4.3 ± 0.8 cells, P = 0.007). The NO production was lower in cells from EA-treated mice cultured in the presence of a combination of IFNγ and LPS (sham: 31.6 ± 6.5 vs. EA: 22.3 ± 2.1 μM, P = 0.025). The lesion size in mice infected with L. major promastigotes was larger in EA-treated mice (sham: 3.26 ± 0.29 vs. EA: 2.23 ± 0.4 mm, P = 0.039). Conclusion EA at the ST36 acupoint increases IL-4 responsiveness in macrophages, Generation of AAMo and susceptibility to L. major infection PMID:22838729

  16. Viral and host factors induce macrophage activation and loss of Toll Like Receptor tolerance in chronic HCV infection

    PubMed Central

    Dolganiuc, Angela; Norkina, Oxana; Kodys, Karen; Catalano, Donna; Bakis, Gennadiy; Marshall, Christopher; Mandrekar, Pranoti; Szabo, Gyongyi

    2007-01-01

    Background&Aims Persistent inflammation contributes to progression of liver damage in chronic HCV (cHCV) infection. Repeated exposure to Toll like receptor (TLR) ligands results in tolerance, a protective mechanism aimed at limiting inflammation. Methods Monocytes/macrophages were repeatedly stimulated via pro-inflammatory cytokine-inducing TLRs and evaluated for activation markers. Results Unlike monocytes (Mo) of controls or patients with non-alcoholic steatohepatitis, the Mo of cHCV patients were hyper-responsive and failed to show homo- or hetero-tolerance to TLR ligands, manifested by elevated TNFα production. Serum levels of IFNγ, endotoxin (TLR4 ligand) and HCV core protein (TLR2 ligand) were elevated in cHCV patients suggesting potential mechanisms for in vivo monocyte pre-activation. Treatment of normal monocytes with IFNγ resulted in loss of tolerance to LPS or HCV core protein. Further, we found increased levels of MyD88-IRAK1 complexes and NFκB activity both in monocytes of cHCV patients and in normal monocytes that lost TLR tolerance after IFNγ+LPS pretreatment. In vitro differentiation of TLR tolerant cHCV monocytes into macrophages restored their capacity to exhibit TLR tolerance to LPS and HCV core protein and this could be reversed by administration of IFNγ. cHCV patients exhibited increased TNFα in the circulation and in the liver. In cHCV livers we found Kupffer cell/macrophage activation indicated by increased CD163 and CD33 expression. Conclusions We identified that host-derived factors (IFNγ and endotoxin) and viral factors (HCV core protein) act in tandem to induce and maintain monocyte/macrophage activation, thus favoring persistent inflammation in patients with cHCV infection. PMID:17916356

  17. Acute cysticercosis favours rapid and more severe lesions caused by Leishmania major and Leishmania mexicana infection, a role for alternatively activated macrophages.

    PubMed

    Rodríguez-Sosa, Miriam; Rivera-Montoya, Irma; Espinoza, Arlett; Romero-Grijalva, Miriam; López-Flores, Roberto; González, Jorge; Terrazas, Luis I

    2006-08-01

    Parasitic helminths have developed complex mechanisms to modulate host immunity. In the present study we found that previous infection of mice with the cestode Taenia crassiceps favours parasitemia and induces larger cutaneous lesions during both Leishmania major and Leishmania mexicana co-infections. Analysis of cytokine responses into draining lymph nodes indicated that co-infection of T. crassiceps-Leishmania did not inhibit IFN-gamma production in response to Leishmania antigens, but significantly increased IL-4 production. Additionally, anti-Leishmania-specific IgG1 antibodies and total IgE increased in co-infected mice, whereas, IgG2a titers remained similar. Macrophages from Taenia-infected mice displayed increased mRNA transcripts of arginase-1, Ym1, and Mannose Receptor, as well as greater production of urea (all markers for an alternate activation state) compared to macrophages from Leishmania-infected mice. In contrast, lower mRNA transcripts for IL-12p35, IL-12p40, IL-23p19, and iNOS were detected in macrophages obtained from cestode-infected mice compared to uninfected and Leishmania-infected mice after LPS stimulation. The presence of cestode also generated impaired macrophage anti-leishmanicidal activity in vitro, as evidenced by the inability of these macrophages to prevent Leishmania growth compared to macrophages from uninfected mice. This was observed despite the fact that both groups of cells were exposed to IFN-gamma. Flow cytometry showed high IFN-gammaR expression on Taenia-induced macrophages. Thus, lack of response to IFN-gamma is not associated with the absence of its receptor. Our data suggest that cestode infection may favour Leishmania installation by inducing alternatively activated macrophages rather than inhibiting Th1-type responses.

  18. Antibodies Against Glycolipids Enhance Antifungal Activity of Macrophages and Reduce Fungal Burden After Infection with Paracoccidioides brasiliensis

    PubMed Central

    Bueno, Renata A.; Thomaz, Luciana; Muñoz, Julian E.; da Silva, Cássia J.; Nosanchuk, Joshua D.; Pinto, Márcia R.; Travassos, Luiz R.; Taborda, Carlos P.

    2016-01-01

    Paracoccidioidomycosis is a fungal disease endemic in Latin America. Polyclonal antibodies to acidic glycosphingolipids (GSLs) from Paracoccidioides brasiliensis opsonized yeast forms in vitro increasing phagocytosis and reduced the fungal burden of infected animals. Antibodies to GSL were active in both prophylactic and therapeutic protocols using a murine intratracheal infection model. Pathological examination of the lungs of animals treated with antibodies to GSL showed well-organized granulomas and minimally damaged parenchyma compared to the untreated control. Murine peritoneal macrophages activated by IFN-γ and incubated with antibodies against acidic GSLs more effectively phagocytosed and killed P. brasiliensis yeast cells as well as produced more nitric oxide compared to controls. The present work discloses a novel target of protective antibodies against P. brasiliensis adding to other well-studied mediators of the immune response to this fungus. PMID:26870028

  19. Alendronate augments interleukin-1{beta} release from macrophages infected with periodontal pathogenic bacteria through activation of caspase-1

    SciTech Connect

    Deng Xue; Tamai, Riyoko; Endo, Yasuo; Kiyoura, Yusuke

    2009-02-15

    Nitrogen-containing bisphosphonates (NBPs) are anti-bone-resorptive drugs with inflammatory side effects that include osteomyelitis and osteonecrosis of the jaw. Oral bacteria have been considered to be a trigger for these NBP-associated jaw bone diseases. The present study examined the effects of alendronate (a typical NBP) and clodronate (a non-NBP) on the production of proinflammatory cytokines by macrophages infected with Porphyromonas gingivalis and Tannerella forsythia, which are important pathogens of periodontal diseases. Pretreatment with alendronate augmented IL-1{beta}, but not TNF{alpha}, production by macrophages infected with P. gingivalis or T. forsythia. This augmentation of IL-1{beta} production was inhibited by clodronate. Furthermore, caspase-1, a promoter of IL-1{beta} production, was activated by treatment with alendronate, and caspase-1 inhibitor reduced the production of IL-1{beta} induced by alendronate and P. gingivalis. These results suggest that NBPs augment periodontal pathogenic bacteria-induced IL-1{beta} release via caspase-1 activation, and this phenomenon may contribute to the development of NBP-associated inflammatory side effects including jaw osteomyelitis. Co-treatment with clodronate may prevent and/or reduce these inflammatory effects induced by NBPs.

  20. Secretion of multi-protein migratory complex induced by Toxoplasma gondii infection in macrophages involves the uPA/uPAR activation system.

    PubMed

    Schuindt, Sara Hellen Santos; Oliveira, Bruno Cabral de Lima; Pimentel, Pollyana Maria de Oliveira; Resende, Thatiane Lacerda; Retamal, Cláudio A; DaMatta, Renato A; Seipel, Daniele; Arnholdt, Andrea Cristina Vetö

    2012-05-25

    Toxoplasmosis is a world wide spread zoonosis caused by Toxoplasma gondii, an obligate intracellular parasite that is able to disseminate into deep tissues and cross biological barriers, reaching immunoprivileged sites such as the brain and retina. The parasite is able to infect macrophages and dendritic cells for dispersal throughout the body. However, the molecular mechanisms or outcomes of the subversion of the host cell are largely unknown. Recently our group established that metalloproteinases are involved in migration of infected macrophages. Herein, we evaluated the recruitment of host invasive machinery components in T. gondii infected murine macrophages. We showed by immunoprecipitation assays that MMP-9, CD44 TIMP-1 and uPAR were secreted as a multi-protein complex by infected macrophages. Zymographic analysis revealed that MMP-9 was present in its pro- and active form. Moreover, inhibition of uPA/uPAR pathway by PAI-1 decreased secretion of MMP-9 active forms, as well those associated to uPAR and TIMP-1, but not to CD44. Data presented here suggest that MMP-9 is secreted as a multiprotein complex by T. gondii infected macrophages, similar to that observed in metastatic cells. We further speculate that uPA/uPAR system is involved in the expression/secretion of complexes containing active MMP-9 forms.

  1. YopJ-Induced Caspase-1 Activation in Yersinia-Infected Macrophages: Independent of Apoptosis, Linked to Necrosis, Dispensable for Innate Host Defense

    PubMed Central

    Zheng, Ying; Lilo, Sarit; Mena, Patricio; Bliska, James B.

    2012-01-01

    Yersinia outer protein J (YopJ) is a type III secretion system (T3SS) effector of pathogenic Yersinia (Yersinia pestis, Yersinia enterocolitica and Yersinia pseudotuberculosis) that is secreted into host cells. YopJ inhibits survival response pathways in macrophages, causing cell death. Allelic variation of YopJ is responsible for differential cytotoxicity in Yersinia strains. YopJ isoforms in Y. enterocolitica O:8 (YopP) and Y. pestis KIM (YopJKIM) strains have high cytotoxic activity. In addition, YopJKIM-induced macrophage death is associated with caspase-1 activation and interleukin-1β (IL-1β secretion. Here, the mechanism of YopJKIM-induced cell death, caspase-1 activation, and IL-1β secretion in primary murine macrophages was examined. Caspase-3/7 activity was low and the caspase-3 substrate poly (ADP-ribose) polymerase (PARP) was not cleaved in Y. pestis KIM5-infected macrophages. In addition, cytotoxicity and IL-1β secretion were not reduced in the presence of a caspase-8 inhibitor, or in B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 homologous antagonist/killer (Bak) knockout macrophages, showing that YopJKIM-mediated cell death and caspase-1 activation occur independent of mitochondrial-directed apoptosis. KIM5-infected macrophages released high mobility group protein B1 (HMGB1), a marker of necrosis, and microscopic analysis revealed that necrotic cells contained active caspase-1, indicating that caspase-1 activation is associated with necrosis. Inhibitor studies showed that receptor interacting protein 1 (RIP1) kinase and reactive oxygen species (ROS) were not required for cytotoxicity or IL-β release in KIM5-infected macrophages. IL-1β secretion was reduced in the presence of cathepsin B inhibitors, suggesting that activation of caspase-1 requires cathepsin B activity. Ectopically-expressed YopP caused higher cytotoxicity and secretion of IL-1β in Y. pseudotuberculosis-infected macrophages than YopJKIM. Wild-type and congenic

  2. YopJ-induced caspase-1 activation in Yersinia-infected macrophages: independent of apoptosis, linked to necrosis, dispensable for innate host defense.

    PubMed

    Zheng, Ying; Lilo, Sarit; Mena, Patricio; Bliska, James B

    2012-01-01

    Yersinia outer protein J (YopJ) is a type III secretion system (T3SS) effector of pathogenic Yersinia (Yersinia pestis, Yersinia enterocolitica and Yersinia pseudotuberculosis) that is secreted into host cells. YopJ inhibits survival response pathways in macrophages, causing cell death. Allelic variation of YopJ is responsible for differential cytotoxicity in Yersinia strains. YopJ isoforms in Y. enterocolitica O:8 (YopP) and Y. pestis KIM (YopJ(KIM)) strains have high cytotoxic activity. In addition, YopJ(KIM)-induced macrophage death is associated with caspase-1 activation and interleukin-1β (IL-1β secretion. Here, the mechanism of YopJ(KIM)-induced cell death, caspase-1 activation, and IL-1β secretion in primary murine macrophages was examined. Caspase-3/7 activity was low and the caspase-3 substrate poly (ADP-ribose) polymerase (PARP) was not cleaved in Y. pestis KIM5-infected macrophages. In addition, cytotoxicity and IL-1β secretion were not reduced in the presence of a caspase-8 inhibitor, or in B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 homologous antagonist/killer (Bak) knockout macrophages, showing that YopJ(KIM)-mediated cell death and caspase-1 activation occur independent of mitochondrial-directed apoptosis. KIM5-infected macrophages released high mobility group protein B1 (HMGB1), a marker of necrosis, and microscopic analysis revealed that necrotic cells contained active caspase-1, indicating that caspase-1 activation is associated with necrosis. Inhibitor studies showed that receptor interacting protein 1 (RIP1) kinase and reactive oxygen species (ROS) were not required for cytotoxicity or IL-β release in KIM5-infected macrophages. IL-1β secretion was reduced in the presence of cathepsin B inhibitors, suggesting that activation of caspase-1 requires cathepsin B activity. Ectopically-expressed YopP caused higher cytotoxicity and secretion of IL-1β in Y. pseudotuberculosis-infected macrophages than YopJ(KIM). Wild-type and

  3. Suppression of Protective Responses upon Activation of L-Type Voltage Gated Calcium Channel in Macrophages during Mycobacterium bovis BCG Infection

    PubMed Central

    Sharma, Deepika; Tiwari, Brijendra Kumar; Mehto, Subhash; Antony, Cecil; Kak, Gunjan; Singh, Yogendra; Natarajan, Krishnamurthy

    2016-01-01

    The prevalence of Mycobacterium tuberculosis (M. tb) strains eliciting drug resistance has necessitated the need for understanding the complexities of host pathogen interactions. The regulation of calcium homeostasis by Voltage Gated Calcium Channel (VGCCs) upon M. tb infection has recently assumed importance in this area. We previously showed a suppressor role of VGCC during M. tb infections and recently reported the mechanisms of its regulation by M. tb. Here in this report, we further characterize the role of VGCC in mediating defence responses of macrophages during mycobacterial infection. We report that activation of VGCC during infection synergistically downmodulates the generation of oxidative burst (ROS) by macrophages. This attenuation of ROS is regulated in a manner which is dependent on Toll like Receptor (TLR) and also on the route of calcium influx, Protein Kinase C (PKC) and by Mitogen Activation Protein Kinase (MAPK) pathways. VGCC activation during infection increases cell survival and downmodulates autophagy. Concomitantly, pro-inflammatory responses such as IL-12 and IFN-γ secretion and the levels of their receptors on cell surface are inhibited. Finally, the ability of phagosomes to fuse with lysosomes in M. bovis BCG and M. tb H37Rv infected macrophages is also compromised when VGCC activation occurs during infection. The results point towards a well-orchestrated strategy adopted by mycobacteria to supress protective responses mounted by the host. This begins with the increase in the surface levels of VGCCs by mycobacteria and their antigens by well-controlled and regulated mechanisms. Subsequent activation of the upregulated VGCC following tweaking of calcium levels by molecular sensors in turn mediates suppressor responses and prepare the macrophages for long term persistent infection. PMID:27723836

  4. Prostaglandins from Cytosolic Phospholipase A2α/Cyclooxygenase-1 Pathway and Mitogen-activated Protein Kinases Regulate Gene Expression in Candida albicans-infected Macrophages.

    PubMed

    Yun, Bogeon; Lee, HeeJung; Jayaraja, Sabarirajan; Suram, Saritha; Murphy, Robert C; Leslie, Christina C

    2016-03-25

    In Candida albicans-infected resident peritoneal macrophages, activation of group IVA cytosolic phospholipase A2(cPLA2α) by calcium- and mitogen-activated protein kinases triggers the rapid production of prostaglandins I2 and E2 through cyclooxygenase (COX)-1 and regulates gene expression by increasing cAMP. InC. albicans-infected cPLA2α(-/-)or COX-1(-/-)macrophages, expression ofI l10,Nr4a2, and Ptgs2 was lower, and expression ofTnfα was higher, than in wild type macrophages. Expression was reconstituted with 8-bromo-cAMP, the PKA activator 6-benzoyl-cAMP, and agonists for prostaglandin receptors IP, EP2, and EP4 in infected but not uninfected cPLA2α(-/-)or COX-1(-/-)macrophages. InC. albicans-infected cPLA2α(+/+)macrophages, COX-2 expression was blocked by IP, EP2, and EP4 receptor antagonists, indicating a role for both prostaglandin I2 and E2 Activation of ERKs and p38, but not JNKs, by C. albicansacted synergistically with prostaglandins to induce expression of Il10,Nr4a2, and Ptgs2. Tnfα expression required activation of ERKs and p38 but was suppressed by cAMP. Results using cAMP analogues that activate PKA or Epacs suggested that cAMP regulates gene expression through PKA. However, phosphorylation of cAMP-response element-binding protein (CREB), the cAMP-regulated transcription factor involved inIl10,Nr4a2,Ptgs2, andTnfα expression, was not mediated by cAMP/PKA because it was similar inC. albicans-infected wild type and cPLA2α(-/-)or COX-1(-/-)macrophages. CREB phosphorylation was blocked by p38 inhibitors and induced by the p38 activator anisomycin but not by the PKA activator 6-benzoyl-cAMP. Therefore, MAPK activation inC. albicans-infected macrophages plays a dual role by promoting the cPLA2α/prostaglandin/cAMP/PKA pathway and CREB phosphorylation that coordinately regulate immediate early gene expression.

  5. Listeriolysin O-dependent bacterial entry into the cytoplasm is required for calpain activation and interleukin-1 alpha secretion in macrophages infected with Listeria monocytogenes.

    PubMed

    Dewamitta, Sita R; Nomura, Takamasa; Kawamura, Ikuo; Hara, Hideki; Tsuchiya, Kohsuke; Kurenuma, Takeshi; Shen, Yanna; Daim, Sylvia; Yamamoto, Takeshi; Qu, Huixin; Sakai, Shunsuke; Xu, Yanting; Mitsuyama, Masao

    2010-05-01

    Listeriolysin O (LLO), an hly-encoded cytolysin of Listeria monocytogenes, plays an essential role in the entry of L. monocytogenes into the host cell cytoplasm. L. monocytogenes-infected macrophages produce various proinflammatory cytokines, including interleukin-1 alpha (IL-1 alpha), that contribute to the host immune response. In this study, we have examined IL-1 alpha production in macrophages infected with wild-type L. monocytogenes or a nonescaping mutant strain deficient for LLO (Delta hly). Expression of IL-1 alpha mRNA and accumulation of pro-IL-1 alpha in the cytoplasm were induced by both strains. In contrast, the secretion of the mature form of IL-1 alpha from infected macrophages was observed in infection with wild-type L. monocytogenes but not with the Delta hly mutant. A recovery of the ability to induce IL-1 alpha secretion was shown in a mutant strain complemented with the hly gene. The Toll-like receptor (TLR)/MyD88 signaling pathway was exclusively required for the expression of pro-IL-1 alpha, independently of LLO-mediated cytoplasmic entry of L. monocytogenes. The LLO-dependent secretion of mature IL-1 alpha was abolished by addition of calcium chelators, and only LLO-producing L. monocytogenes strains were able to induce elevation of the intracellular calcium level in infected macrophages. A calcium-dependent protease, calpain, was implicated in the maturation and secretion of IL-1 alpha induced by LLO-producing L. monocytogenes strains based on the effect of calpain inhibitor. Functional activation of calpain was detected in macrophages infected with LLO-producing L. monocytogenes strains but not with a mutant strain lacking LLO. These results clearly indicated that LLO-mediated cytoplasmic entry of bacteria could induce the activation of intracellular calcium signaling, which is essential for maturation and secretion of IL-1 alpha in macrophages during L. monocytogenes infection through activation of a calcium-dependent calpain protease. In

  6. Activity-Based Proteomic Profiling of Deubiquitinating Enzymes in Salmonella-Infected Macrophages Leads to Identification of Putative Function of UCH-L5 in Inflammasome Regulation.

    PubMed

    Kummari, Evangel; Alugubelly, Navatha; Hsu, Chuan-Yu; Dong, Brittany; Nanduri, Bindu; Edelmann, Mariola J

    2015-01-01

    Although protein ubiquitination has been shown to regulate multiple processes during host response to Salmonella enterica serovar Typhimurium infection, specific functions of host deubiquitinating enzymes remain unknown in this bacterial infection. By using chemical proteomics approach, in which deubiquitinating enzymes were labeled by an active-site probe and analyzed by quantitative proteomics, we identified novel deubiquitinases in chicken macrophages based on their reactivity with the probe. Also, we detected down-regulation of UCH-L3, and USP4 as well as up-regulation of USP5 and UCH-L5 deubiquitinating enzymes in macrophages infected with Salmonella Typhimurium. We showed that decrease in either UCH-L5 activity, or in UCH-L5 protein amount in chicken and human macrophages infected or stimulated with LPS/nigericin, led to decreased IL-1β release. These data point towards a putative role of UCH-L5 in inflammasome regulation during Salmonella infection. Because inflammasome activation is important in innate resistance to these bacteria, one would expect that naturally occurring or therapeutically induced alteration in UCH-L5 activation would influence disease outcome and could represent a target for new therapeutic approaches.

  7. Attenuated Leishmania induce pro-inflammatory mediators and influence leishmanicidal activity by p38 MAPK dependent phagosome maturation in Leishmania donovani co-infected macrophages.

    PubMed

    Banerjee, Somenath; Bose, Dipayan; Chatterjee, Nabanita; Das, Subhadip; Chakraborty, Sreeparna; Das, Tanya; Saha, Krishna Das

    2016-01-01

    Promastigote form of Leishmania, an intracellular pathogen, delays phagosome maturation and resides inside macrophages. But till date limited study has been done to manipulate the phagosomal machinery of macrophages to restrict Leishmania growth. Attenuated Leishmania strain exposed RAW 264.7 cells showed a respiratory burst and enhanced production of pro-inflammatory mediators. The augmentation of pro-inflammatory activity is mostly attributed to p38 MAPK and p44/42 MAPK. In our study, these activated macrophages are found to induce phagosome maturation when infected with pathogenic Leishmania donovani. Increased co-localization of carboxyfluorescein succinimidyl ester labeled pathogenic L. donovani with Lysosome was found. Moreover, increased co-localization was observed between pathogenic L. donovani and late phagosomal markers viz. Rab7, Lysosomal Associated Membrane Protein 1, Cathepsin D, Rab9, and V-ATPase which indicate phagosome maturation. It was also observed that inhibition of V-type ATPase caused significant hindrance in attenuated Leishmania induced phagosome maturation. Finally, it was confirmed that p38 MAPK is the key player in acidification and maturation of phagosome in attenuated Leishmania strain pre-exposed macrophages. To our knowledge, this study for the first time reported an approach to induce phagosome maturation in L. donovani infected macrophages which could potentiate short-term prophylactic response in future. PMID:26928472

  8. Attenuated Leishmania induce pro-inflammatory mediators and influence leishmanicidal activity by p38 MAPK dependent phagosome maturation in Leishmania donovani co-infected macrophages

    PubMed Central

    Banerjee, Somenath; Bose, Dipayan; Chatterjee, Nabanita; Das, Subhadip; Chakraborty, Sreeparna; Das, Tanya; Saha, Krishna Das

    2016-01-01

    Promastigote form of Leishmania, an intracellular pathogen, delays phagosome maturation and resides inside macrophages. But till date limited study has been done to manipulate the phagosomal machinery of macrophages to restrict Leishmania growth. Attenuated Leishmania strain exposed RAW 264.7 cells showed a respiratory burst and enhanced production of pro-inflammatory mediators. The augmentation of pro-inflammatory activity is mostly attributed to p38 MAPK and p44/42 MAPK. In our study, these activated macrophages are found to induce phagosome maturation when infected with pathogenic Leishmania donovani. Increased co-localization of carboxyfluorescein succinimidyl ester labeled pathogenic L. donovani with Lysosome was found. Moreover, increased co-localization was observed between pathogenic L. donovani and late phagosomal markers viz. Rab7, Lysosomal Associated Membrane Protein 1, Cathepsin D, Rab9, and V-ATPase which indicate phagosome maturation. It was also observed that inhibition of V-type ATPase caused significant hindrance in attenuated Leishmania induced phagosome maturation. Finally, it was confirmed that p38 MAPK is the key player in acidification and maturation of phagosome in attenuated Leishmania strain pre-exposed macrophages. To our knowledge, this study for the first time reported an approach to induce phagosome maturation in L. donovani infected macrophages which could potentiate short-term prophylactic response in future. PMID:26928472

  9. Activation of PI3K/Akt signaling has a dominant negative effect on IL-12 production by macrophages infected with Leishmania amazonensis promastigotes

    PubMed Central

    Ruhland, Aaron; Kima, Peter E.

    2009-01-01

    Infection of macrophages with Leishmania parasites does not result in the production of IL-12. In addition, infection with Leishmania suppresses IL-12 production elicited by otherwise potent activators of IL-12. We provide evidence that engagement of phosphatidyl inositol-3 kinase (PI3K) signaling during Leishmania amazonensis infection leads to the prevention of IL-12 p70 production at the level of transcription of its p40 subunit in bone marrow derived macrophages (BMDMϕ). Inhibition of PI3K signaling with specific inhibitors of PI3K or the downstream kinase Akt, reverses the IL-12 blockade. Although the MAP kinase ERK (p44 and p42) was transiently activated by infection with L. amazonensis, inhibition of MEK, the kinase upstream of ERK, with PD98059, did not reverse the blockade of IL-12. Furthermore, inhibition of the other MAP kinases JNK and p38 as well as treatment of cells with pertussis toxin that blocks G protein mediated signaling, did not reverse the prevention of IL-12 production by Leishmania infection. Interestingly, activation of PI3K/Akt signaling had differential effects on ERK and p38 activation. Taken together we propose that infection of BMDMϕ with Leishmania promastigotes activates both positive and negative signaling pathways that control IL-12 production. PI3K signaling activated by the infection is the negative signaling pathway that prevents IL-12 production. PMID:19186178

  10. Activation of PI3K/Akt signaling has a dominant negative effect on IL-12 production by macrophages infected with Leishmania amazonensis promastigotes.

    PubMed

    Ruhland, Aaron; Kima, Peter E

    2009-05-01

    Infection of macrophages with Leishmania parasites does not result in the production of IL-12. In addition, infection with Leishmania suppresses IL-12 production elicited by otherwise potent activators of IL-12. We provide evidence that engagement of phosphatidyl inositol-3 kinase (PI3K) signaling during Leishmania amazonensis infection leads to the prevention of IL-12 p70 production at the level of transcription of its p40 subunit in bone marrow derived macrophages (BMDMPhi). Inhibition of PI3K signaling with specific inhibitors of PI3K or the downstream kinase Akt, reverses the IL-12 blockade. Although the MAP kinase ERK (p44 and p42) was transiently activated by infection with L. amazonensis, inhibition of MEK, the kinase upstream of ERK, with PD98059, did not reverse the blockade of IL-12. Furthermore, inhibition of the other MAP kinases JNK and p38 as well as treatment of cells with pertussis toxin that blocks G protein mediated signaling, did not reverse the prevention of IL-12 production by Leishmania infection. Interestingly, activation of PI3K/Akt signaling had differential effects on ERK and p38 activation. Taken together we propose that infection of BMDMPhi with Leishmania promastigotes activates both positive and negative signaling pathways that control IL-12 production. PI3K signaling activated by the infection is the negative signaling pathway that prevents IL-12 production.

  11. Brief Report: Macrophage Activation in HIV-2-Infected Patients Is Less Affected by Antiretroviral Treatment-sCD163 in HIV-1, HIV-2, and HIV-1/2 Dually Infected Patients.

    PubMed

    Hønge, Bo L; Andersen, Morten N; Jespersen, Sanne; Medina, Candida; Correira, Faustino G; Jakobsen, Martin R; Laursen, Alex; Erikstrup, Christian; Møller, Holger J; Wejse, Christian

    2016-07-01

    The course of disease among HIV-2, HIV-1, and HIV-1/2 dually infected patients is different. We investigated the macrophage activation marker soluble CD163 (sCD163) dynamics in 212 HIV-1, HIV-2, and HIV-1/2 dually infected patients. There were no differences in sCD163 levels at baseline or during follow-up without antiretroviral therapy (ART). At follow-up on ART, median sCD163 levels were decreased for HIV-1-infected patients (P < 0.001), but not among HIV-2 (P = 0.093) or HIV-1/2 dually infected patients (P = 0.145). The larger decrease in sCD163 levels among HIV-1-infected patients during ART may indicate an HIV type-dependent differential effect of ART on macrophage activation during HIV infection. PMID:26825178

  12. Macrophage proliferation, provenance, and plasticity in macroparasite infection

    PubMed Central

    Rückerl, Dominik; Allen, Judith E

    2014-01-01

    Summary: Macrophages have long been center stage in the host response to microbial infection, but only in the past 10–15 years has there been a growing appreciation for their role in helminth infection and the associated type 2 response. Through the actions of the IL-4 receptor α (IL-4Rα), type 2 cytokines result in the accumulation of macrophages with a distinctive activation phenotype. Although our knowledge of IL-4Rα-induced genes is growing rapidly, the specific functions of these macrophages have yet to be established in most disease settings. Understanding the interplay between IL-4Rα-activated macrophages and the other cellular players is confounded by the enormous transcriptional heterogeneity within the macrophage population and by their highly plastic nature. Another level of complexity is added by the new knowledge that tissue macrophages can be derived either from a resident prenatal population or from blood monocyte recruitment and that IL-4 can increase macrophage numbers through proliferative expansion. Here, we review current knowledge on the contribution of macrophages to helminth killing and wound repair, with specific attention paid to distinct cellular origins and plasticity potential. PMID:25319331

  13. Macrophage polarization drives granuloma outcome during Mycobacterium tuberculosis infection.

    PubMed

    Marino, Simeone; Cilfone, Nicholas A; Mattila, Joshua T; Linderman, Jennifer J; Flynn, JoAnne L; Kirschner, Denise E

    2015-01-01

    Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), induces formation of granulomas, structures in which immune cells and bacteria colocalize. Macrophages are among the most abundant cell types in granulomas and have been shown to serve as both critical bactericidal cells and targets for M. tuberculosis infection and proliferation throughout the course of infection. Very little is known about how these processes are regulated, what controls macrophage microenvironment-specific polarization and plasticity, or why some granulomas control bacteria and others permit bacterial dissemination. We take a computational-biology approach to investigate mechanisms that drive macrophage polarization, function, and bacterial control in granulomas. We define a "macrophage polarization ratio" as a metric to understand how cytokine signaling translates into polarization of single macrophages in a granuloma, which in turn modulates cellular functions, including antimicrobial activity and cytokine production. Ultimately, we extend this macrophage ratio to the tissue scale and define a "granuloma polarization ratio" describing mean polarization measures for entire granulomas. Here we coupled experimental data from nonhuman primate TB granulomas to our computational model, and we predict two novel and testable hypotheses regarding macrophage profiles in TB outcomes. First, the temporal dynamics of granuloma polarization ratios are predictive of granuloma outcome. Second, stable necrotic granulomas with low CFU counts and limited inflammation are characterized by short NF-κB signal activation intervals. These results suggest that the dynamics of NF-κB signaling is a viable therapeutic target to promote M1 polarization early during infection and to improve outcome.

  14. Macrophage cell death upon intracellular bacterial infection

    PubMed Central

    Lai, Xin-He; Xu, Yunsheng; Chen, Xiao-Ming; Ren, Yi

    2015-01-01

    Macrophage-pathogen interaction is a complex process and the outcome of this tag-of-war for both sides is to live or die. Without attempting to be comprehensive, this review will discuss the complexity and significance of the interaction outcomes between macrophages and some facultative intracellular bacterial pathogens as exemplified by Francisella, Salmonella, Shigella and Yersinia. Upon bacterial infection, macrophages can die by a variety of ways, such as apoptosis, autophagic cell death, necrosis, necroptosis, oncosis, pyronecrosis, pyroptosis etc, which is the focus of this review. PMID:26690967

  15. Failure of antigen-stimulated gammadelta T cells and CD4+ T cells from sensitized cattle to upregulate nitric oxide and mycobactericidal activity of autologous Mycobacterium avium subsp. paratuberculosis-infected macrophages.

    PubMed

    Simutis, Frank J; Jones, Douglas E; Hostetter, Jesse M

    2007-03-15

    The function of gammadelta T cells during ruminant paratuberculosis (Johne's disease) is presently unknown. An ex vivo system was used to test the hypothesis that gammadelta T cells are capable of activating Mycobacterium avium subsp. paratuberculosis-(M. paratuberculosis)-infected macrophages. Peripheral blood-derived macrophages were infected in vitro with live M. paratuberculosis, and autologous LN-derived gammadelta T cells or CD4+ T cells were co-cultured with infected macrophages for 48h, at which time bacterial survival as well as production of nitrites and IFN-gamma was evaluated. Incubation of M. paratuberculosis-infected macrophages with autologous gammadelta T cells did not result in reduced intracellular bacterial viability compared to infected macrophage cultures without added T cells. IFN-gamma production by-infected cultures containing added gammadelta T cells was not enhanced compared to that of infected macrophages alone. Although infection of macrophage cultures caused increased production of nitrites at both post-infection day (PID) 0 and PID 60, the addition of gammadelta T cells did not further increase nitrite production. In contrast, addition of PPD-stimulated CD4+ T cells obtained at PID 60 to M. paratuberculosis-infected macrophages resulted in significantly increased IFN-gamma production compared to cultures without added T cells or cultures containing unstimulated CD4+ T cells or unstimulated or antigen-stimulated gammadelta T cells. However, the increased production of IFN-gamma by co-cultures containing PPD-stimulated CD4+ T cells did not result in increased bacterial killing or increased production of nitrites compared to cultures without added T cells. In additional in vitro experiments, M. paratuberculosis-infected macrophages, but not uninfected macrophages, were unable to increase nitrite production when stimulated with recombinant IFN-gamma. Taken together, the data suggest that (1) gammadelta T cells do not produce significant

  16. Macrophage-activating T-cell factor(s) produced in an early phase of Legionella pneumophila infection in guinea pigs.

    PubMed Central

    Nikaido, Y; Yoshida, S; Goto, Y; Mizuguchi, Y; Kuroiwa, A

    1989-01-01

    Protective immunity of guinea pigs against Legionella pneumophila was studied by infecting the animals with a sublethal dose (about 2 x 10(4) CFU) of the organism. The bacteria multiplied in the liver, spleen, and lungs up to day 4 after the intraperitoneal infection. The live bacteria in these organs decreased quickly thereafter and were eliminated by day 7. A delayed-type skin reaction and lymphoproliferation of spleen cells to Formalin-killed L. pneumophila were detected from days 5 and 6, respectively, after infection. Peritoneal macrophages obtained from guinea pigs infected 6 days previously inhibited the intracellular growth of L. pneumophila. Antigen-stimulated spleen cell factor prepared from infected guinea pigs inhibited the intracellular growth of the organism in macrophages obtained from uninfected animals. Antigen-stimulated spleen cell factor prepared from spleen cells treated with anti-guinea pig T-cell monoclonal antibody did not inhibit growth. The activity of antigen-stimulated spleen cell factor was labile to pH 2 treatment, and the factor could not be absorbed by L. pneumophila antigen, suggesting that it contains gamma interferon. Our data show that T-cell-mediated immunity begins to work from an early period of infection with L. pneumophila in guinea pigs. PMID:2807531

  17. Antiorthostatic suspension stimulates profiles of macrophage activation in mice

    NASA Technical Reports Server (NTRS)

    Miller, E. S.; Bates, R. A.; Koebel, D. A.; Sonnenfeld, G.

    1999-01-01

    The antiorthostatic suspension model simulates certain physiological effects of spaceflight. We have previously reported BDF1 mice suspended by the tail in the antiorthostatic orientation for 4 days express high levels of resistance to virulent Listeria monocytogenesinfection. In the present study, we examined whether the increased resistance to this organism correlates with profiles of macrophage activation, given the role of the macrophage in killing this pathogen in vivo. We infected BDF1 mice with a lethal dose of virulent L. monocytogenes on day 4 of antiorthostatic suspension and 24 h later constructed profiles of macrophage activation. Viable listeria could not be detected in mice suspended in the antiorthostatic orientation 24 h after infection. Flow cytometric analysis revealed the numbers of granulocytes and mononuclear phagocytes in the spleen of infected mice were not significantly altered as a result of antiorthostatic suspension. Splenocytes from antiorthostatically suspended infected mice produced increased titers of IL-1. Serum levels of neopterin, a nucleotide metabolite secreted by activated macrophages, were enhanced in mice infected during antiorthostatic suspension, but not in antiorthostatically suspended naive mice. Splenic macrophages from mice infected on day 4 of suspension produced enhanced levels of lysozyme. In contrast to the results from antiorthostatically suspended infected mice, macrophages from antiorthostatically suspended uninfected mice did not express enhanced bactericidal activities. The collective results indicate that antiorthostatic suspension can stimulate profiles of macrophage activation which correlate with increased resistance to infection by certain classes of pathogenic bacteria.

  18. Dynamin inhibition interferes with inflammasome activation and cytokine gene expression in Streptococcus pyogenes-infected human macrophages

    PubMed Central

    Latvala, S; Mäkelä, S M; Miettinen, M; Charpentier, E; Julkunen, I

    2014-01-01

    In the present study, we have analysed the ability of Streptococcus pyogenes [Group A streptococcus (GAS)] to activate the NACHT-domain-, leucine-rich repeat- and PYD-containing protein 3 (NALP3) inflammasome complex in human monocyte-derived macrophages and the molecules and signalling pathways involved in GAS-induced inflammatory responses. We focused upon analysing the impact of dynamin-dependent endocytosis and the role of major streptococcal virulence factors streptolysin O (SLO) and streptolysin S (SLS) in the immune responses induced by GAS. These virulence factors are involved in immune evasion by forming pores in host cell membranes, and aid the bacteria to escape from the endosome–lysosome pathway. We analysed cytokine gene expression in human primary macrophages after stimulation with live or inactivated wild-type GAS as well as with live SLO and SLS defective bacteria. Interleukin (IL)-1β, IL-10, tumour necrosis factor (TNF)-α and chemokine (C-X-C motif) ligand (CXCL)-10 cytokines were produced after bacterial stimulation in a dose-dependent manner and no differences in cytokine levels were seen between live, inactivated or mutant bacteria. These data suggest that streptolysins or other secreted bacterial products are not required for the inflammatory responses induced by GAS. Our data indicate that inhibition of dynamin-dependent endocytosis in macrophages attenuates the induction of IL-1β, TNF-α, interferon (IFN)-β and CXCL-10 mRNAs. We also observed that pro-IL-1β protein was expressed and efficiently cleaved into mature-IL-1β via inflammasome activation after bacterial stimulation. Furthermore, we demonstrate that multiple signalling pathways are involved in GAS-stimulated inflammatory responses in human macrophages. PMID:25079511

  19. The interferon-induced gene Ifi27l2a is active in lung macrophages and lymphocytes after influenza A infection but deletion of Ifi27l2a in mice does not increase susceptibility to infection.

    PubMed

    Tantawy, Mohamed A; Hatesuer, Bastian; Wilk, Esther; Dengler, Leonie; Kasnitz, Nadine; Weiß, Siegfried; Schughart, Klaus

    2014-01-01

    Interferons represent one of the first and essential host defense mechanisms after infection, and the activation of the IFN-pathway results in the transcriptional activation of hundreds of interferon-stimulated genes. The alpha-inducible protein 27 like 2A (Ifi27l2a) gene (human synonym: ISG12) is strongly up-regulated in the lung after influenza A infection in mice and has been shown in gene expression studies to be highly correlated to other activated genes. Therefore, we investigated the role of Ifi27l2a for the host defense to influenza A infections in more detail. RT-PCR analyses in non-infected mice demonstrated that Ifi27l2a was expressed in several tissues, including the lung. Detailed analyses of reporter gene expression in lungs from Ifi27l2a-LacZ mice revealed that Ifi27l2a was expressed in macrophages and lymphocytes but not in alveolar cells or bronchiolar epithelium cells. The number of macrophages and lymphocyte strongly increased in the lung after infection, but no significant increase in expression levels of the LacZ reporter gene was found within individual immune cells. Also, no reporter gene expression was found in bronchiolar epithelial cells, alveolar cells or infiltrating neutrophils after infection. Thus, up-regulation of Ifi27l2a in infected lungs is mainly due to the infiltration of macrophages and lymphocytes. Most surprisingly, deletion of Ifi27l2a in mouse knock-out lines did not result in increased susceptibility to infections with H1N1 or H7N7 influenza A virus compared to wild type C57BL/6N mice, suggesting a less important role of the gene for the host response to influenza infections than for bacterial infections. PMID:25184786

  20. Depletion of alveolar macrophages prolongs survival in response to acute pneumovirus infection

    PubMed Central

    Rigaux, Peter; Killoran, Kristin E.; Qiu, Zhijun; Rosenberg, Helene F.

    2011-01-01

    Alveolar macrophages are immunoregulatory effector cells that interact directly with respiratory virus pathogens in vivo. We examined the role of alveolar macrophages in acute infection with pneumonia virus of mice (PVM), a rodent pneumovirus that replicates the clinical sequelae of severe human respiratory syncytial virus disease. We show that PVM replicates in primary mouse macrophage culture, releasing infectious virions and proinflammatory cytokines. Alveolar macrophages isolated from PVM-infected mice express activation markers Clec43 and CD86, cytokines TNFα, IL-1, IL-6, and numerous CC and CXC chemokines. Alveolar macrophage depletion prior to PVM infection results in small but statistically significant increases in virus recovery but paradoxically prolonged survival. In parallel, macrophage depleted PVM-infected mice exhibit enhanced NK cell recruitment and increased production of IFNγ by NK, CD4+ and CD8+ T cells. These results suggest a protective, immunomodulatory role for IFNγ, as overproduction secondary to macrophage depletion may promote survival despite increased virus recovery. PMID:22129848

  1. Matrine displayed antiviral activity in porcine alveolar macrophages co-infected by porcine reproductive and respiratory syndrome virus and porcine circovirus type 2.

    PubMed

    Sun, Na; Sun, Panpan; Lv, Haipeng; Sun, Yaogui; Guo, Jianhua; Wang, Zhirui; Luo, Tiantian; Wang, Shaoyu; Li, Hongquan

    2016-01-01

    The co-infection of porcine reproductive respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) is quite common in clinical settings and no effective treatment to the co-infection is available. In this study, we established the porcine alveolar macrophages (PAM) cells model co-infected with PRRSV/PCV2 with modification in vitro, and investigated the antiviral activity of Matrine on this cell model and further evaluated the effect of Matrine on virus-induced TLR3,4/NF-κB/TNF-α pathway. The results demonstrated PAM cells inoculated with PRRSV followed by PCV2 2 h later enhanced PRRSV and PCV2 replications. Matrine treatment suppressed both PRRSV and PCV2 infection at 12 h post infection. Furthermore, PRRSV/PCV2 co- infection induced IκBα degradation and phosphorylation as well as the translocation of NF-κB from the cytoplasm to the nucleus indicating that PRRSV/PCV2 co-infection induced NF-κB activation. Matrine treatment significantly down-regulated the expression of TLR3, TLR4 and TNF-α although it, to some extent, suppressed p-IκBα expression, suggesting that TLR3,4/NF-κB/TNF-α pathway play an important role of Matrine in combating PRRSV/PCV2 co-infection. It is concluded that Matrine possesses activity against PRRSV/PCV2 co-infection in vitro and suppression of the TLR3,4/NF-κB/TNF-α pathway as an important underlying molecular mechanism. These findings warrant Matrine to be further explored for its antiviral activity in clinical settings. PMID:27080155

  2. Matrine displayed antiviral activity in porcine alveolar macrophages co-infected by porcine reproductive and respiratory syndrome virus and porcine circovirus type 2.

    PubMed

    Sun, Na; Sun, Panpan; Lv, Haipeng; Sun, Yaogui; Guo, Jianhua; Wang, Zhirui; Luo, Tiantian; Wang, Shaoyu; Li, Hongquan

    2016-04-15

    The co-infection of porcine reproductive respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) is quite common in clinical settings and no effective treatment to the co-infection is available. In this study, we established the porcine alveolar macrophages (PAM) cells model co-infected with PRRSV/PCV2 with modification in vitro, and investigated the antiviral activity of Matrine on this cell model and further evaluated the effect of Matrine on virus-induced TLR3,4/NF-κB/TNF-α pathway. The results demonstrated PAM cells inoculated with PRRSV followed by PCV2 2 h later enhanced PRRSV and PCV2 replications. Matrine treatment suppressed both PRRSV and PCV2 infection at 12 h post infection. Furthermore, PRRSV/PCV2 co- infection induced IκBα degradation and phosphorylation as well as the translocation of NF-κB from the cytoplasm to the nucleus indicating that PRRSV/PCV2 co-infection induced NF-κB activation. Matrine treatment significantly down-regulated the expression of TLR3, TLR4 and TNF-α although it, to some extent, suppressed p-IκBα expression, suggesting that TLR3,4/NF-κB/TNF-α pathway play an important role of Matrine in combating PRRSV/PCV2 co-infection. It is concluded that Matrine possesses activity against PRRSV/PCV2 co-infection in vitro and suppression of the TLR3,4/NF-κB/TNF-α pathway as an important underlying molecular mechanism. These findings warrant Matrine to be further explored for its antiviral activity in clinical settings.

  3. Matrine displayed antiviral activity in porcine alveolar macrophages co-infected by porcine reproductive and respiratory syndrome virus and porcine circovirus type 2

    PubMed Central

    Sun, Na; Sun, Panpan; Lv, Haipeng; Sun, Yaogui; Guo, Jianhua; Wang, Zhirui; Luo, Tiantian; Wang, Shaoyu; Li, Hongquan

    2016-01-01

    The co-infection of porcine reproductive respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) is quite common in clinical settings and no effective treatment to the co-infection is available. In this study, we established the porcine alveolar macrophages (PAM) cells model co-infected with PRRSV/PCV2 with modification in vitro, and investigated the antiviral activity of Matrine on this cell model and further evaluated the effect of Matrine on virus-induced TLR3,4/NF-κB/TNF-α pathway. The results demonstrated PAM cells inoculated with PRRSV followed by PCV2 2 h later enhanced PRRSV and PCV2 replications. Matrine treatment suppressed both PRRSV and PCV2 infection at 12 h post infection. Furthermore, PRRSV/PCV2 co- infection induced IκBα degradation and phosphorylation as well as the translocation of NF-κB from the cytoplasm to the nucleus indicating that PRRSV/PCV2 co-infection induced NF-κB activation. Matrine treatment significantly down-regulated the expression of TLR3, TLR4 and TNF-α although it, to some extent, suppressed p-IκBα expression, suggesting that TLR3,4/NF-κB/TNF-α pathway play an important role of Matrine in combating PRRSV/PCV2 co-infection. It is concluded that Matrine possesses activity against PRRSV/PCV2 co-infection in vitro and suppression of the TLR3,4/NF-κB/TNF-α pathway as an important underlying molecular mechanism. These findings warrant Matrine to be further explored for its antiviral activity in clinical settings. PMID:27080155

  4. Extraintestinal Helminth Infection Limits Pathology and Proinflammatory Cytokine Expression during DSS-Induced Ulcerative Colitis: A Role for Alternatively Activated Macrophages and Prostaglandins.

    PubMed

    Ledesma-Soto, Yadira; Callejas, Blanca E; Terrazas, César A; Reyes, Jose L; Espinoza-Jiménez, Arlett; González, Marisol I; León-Cabrera, Sonia; Morales, Rosario; Olguín, Jonadab E; Saavedra, Rafael; Oghumu, Steve; Satoskar, Abhay R; Terrazas, Luis I

    2015-01-01

    Chronic inflammation of the intestinal mucosa is characteristic of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. Helminth parasites have developed immunomodulatory strategies that may impact the outcome of several inflammatory diseases. Therefore, we investigated whether Taenia crassiceps infection is able to decrease the inflammatory effects of dextran sulfate sodium- (DSS-) induced ulcerative colitis in BALB/c and C57BL/6 mice. Preinfection significantly reduced the manifestations of DSS-induced colitis, as weight loss and shortened colon length, and decreased the disease activity index independently of the genetic background of the mice. Taenia infection decreased systemic levels of proinflammatory cytokines while increasing levels of IL-4 and IL-10, and the inflammatory infiltrate into the colon was also markedly reduced. RT-PCR assays from colon showed that T. crassiceps-infected mice displayed increased expression of Arginase-1 but decreased expression of iNOS compared to DSS-treated uninfected mice. The percentages of T regulatory cells were not increased. The adoptive transfer of alternatively activated macrophages (AAMФs) from infected mice into mice with DSS-induced colitis reduced the severity of colon inflammation. Administration of indomethacin abrogated the anticolitic effect of Taenia. Thus, T. crassiceps infection limits the pathology of ulcerative colitis by suppressing inflammatory responses mechanistically associated with AAMФs and prostaglandins.

  5. Extraintestinal Helminth Infection Limits Pathology and Proinflammatory Cytokine Expression during DSS-Induced Ulcerative Colitis: A Role for Alternatively Activated Macrophages and Prostaglandins

    PubMed Central

    Ledesma-Soto, Yadira; Callejas, Blanca E.; Terrazas, César A.; Reyes, Jose L.; Espinoza-Jiménez, Arlett; González, Marisol I.; León-Cabrera, Sonia; Morales, Rosario; Olguín, Jonadab E.; Saavedra, Rafael; Oghumu, Steve; Satoskar, Abhay R.; Terrazas, Luis I.

    2015-01-01

    Chronic inflammation of the intestinal mucosa is characteristic of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. Helminth parasites have developed immunomodulatory strategies that may impact the outcome of several inflammatory diseases. Therefore, we investigated whether Taenia crassiceps infection is able to decrease the inflammatory effects of dextran sulfate sodium- (DSS-) induced ulcerative colitis in BALB/c and C57BL/6 mice. Preinfection significantly reduced the manifestations of DSS-induced colitis, as weight loss and shortened colon length, and decreased the disease activity index independently of the genetic background of the mice. Taenia infection decreased systemic levels of proinflammatory cytokines while increasing levels of IL-4 and IL-10, and the inflammatory infiltrate into the colon was also markedly reduced. RT-PCR assays from colon showed that T. crassiceps-infected mice displayed increased expression of Arginase-1 but decreased expression of iNOS compared to DSS-treated uninfected mice. The percentages of T regulatory cells were not increased. The adoptive transfer of alternatively activated macrophages (AAMФs) from infected mice into mice with DSS-induced colitis reduced the severity of colon inflammation. Administration of indomethacin abrogated the anticolitic effect of Taenia. Thus, T. crassiceps infection limits the pathology of ulcerative colitis by suppressing inflammatory responses mechanistically associated with AAMФs and prostaglandins. PMID:26090422

  6. Macrophage signalling upon mycobacterial infection: the MAP kinases lead the way.

    PubMed

    Schorey, Jeffrey S; Cooper, Andrea M

    2003-03-01

    Mycobacteria activate a series of macrophage signalling pathways upon engaging host cell receptors and during the invasion process. These signals initiate a cascade of events leading to the production of immune effector molecules including cytokines, chemokines and reactive nitrogen intermediates. This response by the macrophage is critical for the control of the mycobacterial infection and, not surprisingly, pathogenic mycobacteria have evolved mechanisms to limit this macrophage activation. Recent data has suggested that macrophages infected with pathogenic compared to non-pathogenic mycobacteria are restricted in their activation of the mitogen activated protein kinase (MAPK) pathways. Mitogen activated protein kinase activation in macrophages appears to play an important role in promoting antimycobacterial activity and in the production of various effector molecules following a mycobacterial infection. Therefore, the ability of pathogenic mycobacteria to limit MAPK activity is likely an important virulence mechanism and may be a potential therapeutic target.

  7. Effect of Cocaine on HIV Infection and Inflammasome Gene Expression Profile in HIV Infected Macrophages

    PubMed Central

    Atluri, Venkata Subba Rao; Pilakka-Kanthikeel, Sudheesh; Garcia, Gabriella; Jayant, Rahul Dev; Sagar, Vidya; Samikkannu, Thangavel; Yndart, Adriana; Nair, Madhavan

    2016-01-01

    We have observed significantly increased HIV infection in HIV infected macrophages in the presence of cocaine that could be due to the downregulation of BST2 restriction factor in these cells. In human inflammasome PCR array, among different involved in inflammasome formation, in HIV infected macrophages in the presence of cocaine, we have observed significant upregulation of NLRP3, AIM2 genes and downstream genes IL-1β and PTGS2. Whereas negative regulatory gene MEFV was upregulated, CD40LG and PYDC1 were significantly downregulated. Among various NOD like receptors, NOD2 was significantly upregulated in both HIV alone and HIV plus cocaine treated cells. In the downstream genes, chemokine (C-C motif) ligand 2 (CCL2), CCL7 and IL-6 were significantly up regulated in HIV plus cocaine treated macrophages. We have also observed significant ROS production (in HIV and/or cocaine treated cells) which is one of the indirect-activators of inflammasomes formation. Further, we have observed early apoptosis in HIV alone and HIV plus cocaine treated macrophages which may be resultant of inflammasome formation and cspase-1 activation. These results indicate that in case of HIV infected macrophages exposed to cocaine, increased ROS production and IL-1β transcription serve as an activators for the formation of NLRP3 and AIM2 mediated inflammasomes that leads to caspase 1 mediated apoptosis. PMID:27321752

  8. Sulforaphane Inhibits HIV Infection of Macrophages through Nrf2

    PubMed Central

    Furuya, Andrea Kinga Marias; Sharifi, Hamayun J.; Jellinger, Robert M.; Cristofano, Paul; Shi, Binshan; de Noronha, Carlos M. C.

    2016-01-01

    Marburg virus, the Kaposi's sarcoma-associated herpesvirus (KSHV) and Dengue virus all activate, and benefit from, expression of the transcription regulator nuclear erythroid 2-related factor 2 (Nrf2). The impact of Nrf2 activation on human immunodeficiency virus (HIV) infection has not been tested. Sulforaphane (SFN), produced in cruciferous vegetables after mechanical damage, mobilizes Nrf2 to potently reprogram cellular gene expression. Here we show for the first time that SFN blocks HIV infection in primary macrophages but not in primary T cells. Similarly SFN blocks infection in PMA-differentiated promonocytic cell lines, but not in other cell lines tested. siRNA-mediated depletion of Nrf2 boosted HIV infectivity in primary macrophages and reduced the anti-viral effects of SFN treatment. This supports a model in which anti-viral activity is mediated through Nrf2 after it is mobilized by SFN. We further found that, like the type I interferon-induced cellular anti-viral proteins SAMHD1 and MX2, SFN treatment blocks infection after entry, but before formation of 2-LTR circles. Interestingly however, neither SAMHD1 nor MX2 were upregulated. This shows for the first time that Nrf2 action can potently block HIV infection and highlights a novel way to trigger this inhibition. PMID:27093399

  9. Sulforaphane Inhibits HIV Infection of Macrophages through Nrf2.

    PubMed

    Furuya, Andrea Kinga Marias; Sharifi, Hamayun J; Jellinger, Robert M; Cristofano, Paul; Shi, Binshan; de Noronha, Carlos M C

    2016-04-01

    Marburg virus, the Kaposi's sarcoma-associated herpesvirus (KSHV) and Dengue virus all activate, and benefit from, expression of the transcription regulator nuclear erythroid 2-related factor 2 (Nrf2). The impact of Nrf2 activation on human immunodeficiency virus (HIV) infection has not been tested. Sulforaphane (SFN), produced in cruciferous vegetables after mechanical damage, mobilizes Nrf2 to potently reprogram cellular gene expression. Here we show for the first time that SFN blocks HIV infection in primary macrophages but not in primary T cells. Similarly SFN blocks infection in PMA-differentiated promonocytic cell lines, but not in other cell lines tested. siRNA-mediated depletion of Nrf2 boosted HIV infectivity in primary macrophages and reduced the anti-viral effects of SFN treatment. This supports a model in which anti-viral activity is mediated through Nrf2 after it is mobilized by SFN. We further found that, like the type I interferon-induced cellular anti-viral proteins SAMHD1 and MX2, SFN treatment blocks infection after entry, but before formation of 2-LTR circles. Interestingly however, neither SAMHD1 nor MX2 were upregulated. This shows for the first time that Nrf2 action can potently block HIV infection and highlights a novel way to trigger this inhibition. PMID:27093399

  10. Zika Virus Infects Human Placental Macrophages.

    PubMed

    Quicke, Kendra M; Bowen, James R; Johnson, Erica L; McDonald, Circe E; Ma, Huailiang; O'Neal, Justin T; Rajakumar, Augustine; Wrammert, Jens; Rimawi, Bassam H; Pulendran, Bali; Schinazi, Raymond F; Chakraborty, Rana; Suthar, Mehul S

    2016-07-13

    The recent Zika virus (ZIKV) outbreak in Brazil has been directly linked to increased cases of microcephaly in newborns. Current evidence indicates that ZIKV is transmitted vertically from mother to fetus. However, the mechanism of intrauterine transmission and the cell types involved remain unknown. We demonstrate that the contemporary ZIKV strain PRVABC59 (PR 2015) infects and replicates in primary human placental macrophages, called Hofbauer cells, and to a lesser extent in cytotrophoblasts, isolated from villous tissue of full-term placentae. Viral replication coincides with induction of type I interferon (IFN), pro-inflammatory cytokines, and antiviral gene expression, but with minimal cell death. Our results suggest a mechanism for intrauterine transmission in which ZIKV gains access to the fetal compartment by directly infecting placental cells and disrupting the placental barrier. PMID:27247001

  11. Zika Virus Infects Human Placental Macrophages.

    PubMed

    Quicke, Kendra M; Bowen, James R; Johnson, Erica L; McDonald, Circe E; Ma, Huailiang; O'Neal, Justin T; Rajakumar, Augustine; Wrammert, Jens; Rimawi, Bassam H; Pulendran, Bali; Schinazi, Raymond F; Chakraborty, Rana; Suthar, Mehul S

    2016-07-13

    The recent Zika virus (ZIKV) outbreak in Brazil has been directly linked to increased cases of microcephaly in newborns. Current evidence indicates that ZIKV is transmitted vertically from mother to fetus. However, the mechanism of intrauterine transmission and the cell types involved remain unknown. We demonstrate that the contemporary ZIKV strain PRVABC59 (PR 2015) infects and replicates in primary human placental macrophages, called Hofbauer cells, and to a lesser extent in cytotrophoblasts, isolated from villous tissue of full-term placentae. Viral replication coincides with induction of type I interferon (IFN), pro-inflammatory cytokines, and antiviral gene expression, but with minimal cell death. Our results suggest a mechanism for intrauterine transmission in which ZIKV gains access to the fetal compartment by directly infecting placental cells and disrupting the placental barrier.

  12. In Vitro Study of Cytophysiological Characteristics of Multinuclear Macrophages from Intact and BCG-Infected Mice.

    PubMed

    Il'in, D A; Arkhipov, S A; Shkurupy, V A

    2016-03-01

    Peritoneal macrophages were isolated from intact and BCG-infected BALB/c mice and explanted in vitro. Multinuclear macrophages formed in these cultures differed by the number of nuclei, expression of apoptosis inductors and regulators (TNF-α, p53 protein, caspase 3, and Bcl-2 protein), and cytophysiological characteristics (phagocytic activity, ROS generation, and antimycobacterial properties). Our results indicate that the formation of multinuclear macrophages is accompanied by induction of apoptosis (p53 signaling pathway) and appearance of multinuclear macrophage-derived cells characterized by high phagocytic and antimycobacterial activity. PMID:27021088

  13. Alternative activation modifies macrophage resistance to Mycobacterium bovis.

    PubMed

    Castillo-Velázquez, Uziel; Aranday-Cortés, Elihú; Gutiérrez-Pabello, José A

    2011-07-01

    The aim of this study was to evaluate the influence of macrophage alternative activation in the intracellular pathogen natural disease resistance phenotype of the host. Macrophage monolayers from resistant (R) (3) or susceptible (S) (3) cattle donors were treated with 10 ng/ml of bovine recombinant IL-4 (rbIL-4), and infected with virulent and avirulent Mycobacterium bovis (MOI 10:1). Bactericidal assays were performed to assess the bacterial phagocytic index and intracellular survival. Total RNA was reverse transcribed and used to analyze the relative changes in gene expression of IL-10, IL-12, IL-18 IL-1β, TNF-α, MCP-1, MCP-2, IL-6, MIP-1, MIP-3, iNOS, ARGII and SLAM by real time PCR. Cell supernatants were collected and nitric oxide and arginase production was assessed. Apoptosis induction was measured by TUNEL. IL-4 treatment increased the phagocytic index in both R and S macrophages; however intracellular survival was augmented mainly in S macrophages. Alternative activation decreased gene expression of pro-inflammatory cytokines, nitric oxide production and DNA fragmentation mainly in R macrophages. On the other hand, arginase production was not different between R and S macrophages. Alternative activation modifies the macrophage response against M. bovis. IL-4 treatment minimized the functional differences that exist between R and S macrophages.

  14. Apoptotic CD8 T-lymphocytes disable macrophage-mediated immunity to Trypanosoma cruzi infection

    PubMed Central

    Cabral-Piccin, M P; Guillermo, L V C; Vellozo, N S; Filardy, A A; Pereira-Marques, S T; Rigoni, T S; Pereira-Manfro, W F; DosReis, G A; Lopes, M F

    2016-01-01

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. CD8 T-lymphocytes help to control infection, but apoptosis of CD8 T cells disrupts immunity and efferocytosis can enhance parasite infection within macrophages. Here, we investigate how apoptosis of activated CD8 T cells affects M1 and M2 macrophage phenotypes. First, we found that CD8 T-lymphocytes and inflammatory monocytes/macrophages infiltrate peritoneum during acute T. cruzi infection. We show that treatment with anti-Fas ligand (FasL) prevents lymphocyte apoptosis, upregulates type-1 responses to parasite antigens, and reduces infection in macrophages cocultured with activated CD8 T cells. Anti-FasL skews mixed M1/M2 macrophage profiles into polarized M1 phenotype, both in vitro and following injection in infected mice. Moreover, inhibition of T-cell apoptosis induces a broad reprogramming of cytokine responses and improves macrophage-mediated immunity to T. cruzi. The results indicate that disposal of apoptotic CD8 T cells increases M2-macrophage differentiation and contributes to parasite persistence. PMID:27195678

  15. Apoptotic CD8 T-lymphocytes disable macrophage-mediated immunity to Trypanosoma cruzi infection.

    PubMed

    Cabral-Piccin, M P; Guillermo, L V C; Vellozo, N S; Filardy, A A; Pereira-Marques, S T; Rigoni, T S; Pereira-Manfro, W F; DosReis, G A; Lopes, M F

    2016-05-19

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. CD8 T-lymphocytes help to control infection, but apoptosis of CD8 T cells disrupts immunity and efferocytosis can enhance parasite infection within macrophages. Here, we investigate how apoptosis of activated CD8 T cells affects M1 and M2 macrophage phenotypes. First, we found that CD8 T-lymphocytes and inflammatory monocytes/macrophages infiltrate peritoneum during acute T. cruzi infection. We show that treatment with anti-Fas ligand (FasL) prevents lymphocyte apoptosis, upregulates type-1 responses to parasite antigens, and reduces infection in macrophages cocultured with activated CD8 T cells. Anti-FasL skews mixed M1/M2 macrophage profiles into polarized M1 phenotype, both in vitro and following injection in infected mice. Moreover, inhibition of T-cell apoptosis induces a broad reprogramming of cytokine responses and improves macrophage-mediated immunity to T. cruzi. The results indicate that disposal of apoptotic CD8 T cells increases M2-macrophage differentiation and contributes to parasite persistence.

  16. Mycobacterium tuberculosis- induced neutrophil extracellular traps activate human macrophages.

    PubMed

    Braian, Clara; Hogea, Valentin; Stendahl, Olle

    2013-01-01

    Neutrophils activated by Mycobacterium tuberculosis (Mtb) form neutrophil extracellular traps (NETs), containing DNA and several biologically active cytosolic and granular proteins. These NETs may assist in the innate immune defense against different pathogens. We investigated whether the NET-forming neutrophils mediate an activating signal to macrophages during the early multicellular inflammatory reaction and granuloma formation. Mtb-induced NETs were found to be reactive oxygen species dependent and phagocytosis dependent. A neutrophil elastase inhibitor also delayed NET formation. However, NET formation occurred independently of Mtb-induced apoptosis. We observed close interactions between macrophages and Mtb-activated neutrophils, where macrophages bound and phagocytosed NETs. Significant secretion of the cytokines interleukin (IL)-6, tumor necrosis factor-α, IL-1β and IL-10 were detected from macrophages cocultured with NETs from Mtb-activated but not phorbol myristate acetate-activated neutrophils. NETs binding heat shock protein 72 (Hsp72) or recombinant Hsp72 were able to trigger cytokine release from macrophages. Only Mtb-induced NETs contained Hsp72, suggesting that these NETs can transfer this danger signal to adjacent macrophages. We propose that Hsp72 sequestered in NETs plays an important role in the interaction between neutrophils and macrophages during the early innate immune phase of an Mtb infection. The immunomodulatory role of NETs and proteins derived from them may influence not only chronic inflammation during tuberculosis but also immune regulation and autoimmunity.

  17. Macrophages as effector cells of protective immunity in murine schistosomiasis: macrophage activation in mice vaccinated with radiation-attenuated cercariae.

    PubMed Central

    James, S L; Natovitz, P C; Farrar, W L; Leonard, E J

    1984-01-01

    Cell-mediated immune responses contributing to macrophage activation were compared in mice that demonstrated partial resistance to challenge Schistosoma mansoni infection as a result of vaccination with radiation-attenuated cercariae or of ongoing low-grade primary infection. Vaccinated mice developed significant delayed hypersensitivity reactions to soluble schistosome antigens in vivo. Splenocytes from vaccinated animals responded to in vitro culture with various specific antigens (soluble adult worm extract, living or disrupted schistosomula) by proliferation and production of macrophage-activating lymphokines as did lymphocytes from S. mansoni-infected animals. Macrophage-activating factors produced by spleen cells from vaccinated mice upon specific antigen stimulation eluted as a single peak on Sephadex G-100 with a molecular weight of approximately 50,000 and contained gamma interferon activity. Moreover, peritoneal macrophages with larvicidal and tumoricidal activity were recovered from vaccinated mice after intraperitoneal challenge with soluble schistosome antigens, a procedure also observed to elicit activated macrophages in S. mansoni-infected animals. These observations demonstrate that vaccination with irradiated cercariae stimulates many of the same cellular responses observed after primary S. mansoni infection, and suggest that lymphokine-activated macrophages may participate in the effector mechanism of vaccine-induced and concomitant immunity to challenge schistosome infection. This is the first demonstration of a potential immune effector mechanism in the irradiated vaccine model. PMID:6609885

  18. [Molecular mechanisms regulating the activity of macrophages].

    PubMed

    Onoprienko, L V

    2011-01-01

    This article reviews modern concepts of the most common types of macrophage activation: classical, alternative, and type II. Molecular mechanisms of induction and regulation of these three types of activation are discussed. Any population of macrophages was shown to change its properties depending on its microenvironment and concrete biological situation (the "functional plasticity of macrophages"). Many intermediate states of macrophages were described along with the most pronounced and well-known activation types (classical activation, alternative activation, and type II activation). These intermediate states are characterized by a variety of combinations of their biological properties, including elements of the three afore mentioned types of activation. Macrophage activity is regulated by a complex network of interrelated cascade mechanisms.

  19. Hemophagocytic Macrophages Harbor Salmonella enterica during Persistent Infection

    PubMed Central

    Nix, Rebecca N; Altschuler, Sarah E; Henson, Peter M; Detweiler, Corrella S

    2007-01-01

    Salmonella enterica subspecies can establish persistent, systemic infections in mammals, including human typhoid fever. Persistent S. enterica disease is characterized by an initial acute infection that develops into an asymptomatic chronic infection. During both the acute and persistent stages, the bacteria generally reside within professional phagocytes, usually macrophages. It is unclear how salmonellae can survive within macrophages, cells that evolved, in part, to destroy pathogens. Evidence is presented that during the establishment of persistent murine infection, macrophages that contain S. enterica serotype Typhimurium are hemophagocytic. Hemophagocytic macrophages are characterized by the ingestion of non-apoptotic cells of the hematopoietic lineage and are a clinical marker of typhoid fever as well as certain other infectious and genetic diseases. Cell culture assays were developed to evaluate bacterial survival in hemophagocytic macrophages. S. Typhimurium preferentially replicated in macrophages that pre-phagocytosed viable cells, but the bacteria were killed in macrophages that pre-phagocytosed beads or dead cells. These data suggest that during persistent infection hemophagocytic macrophages may provide S. Typhimurium with a survival niche. PMID:18085823

  20. Acute heart inflammation: ultrastructural and functional aspects of macrophages elicited by Trypanosoma cruzi infection

    PubMed Central

    Melo, Rossana C N

    2009-01-01

    Abstract The heart is the main target organ of the parasite Trypanosoma cruzi, the causal agent of Chagas' disease, a significant public health issue and still a major cause of morbidity and mortality in Latin America. During the acute disease, tissue damage in the heart is related to the intense myocardium parasitism. To control parasite multiplication, cells of the monocytic lineage are highly mobilized. In response to inflammatory and immune stimulation, an intense migration and extravasation of monocytes occurs from the bloodstream into heart. Monocyte differentiation leads to the formation of tissue phagocytosing macrophages, which are strongly activated and direct host defence. Newly elicited monocyte-derived macrophages both undergo profound physiological changes and display morphological heterogeneity that greatly differs from originally non-inflammatory macrophages, and underlie their functional activities as potent inflammatory cells. Thus, activated macrophages play a critical role in the outcome of parasite infection. This review covers functional and ultrastructural aspects of heart inflammatory macrophages triggered by the acute Chagas' disease, including recent discoveries on morphologically distinct, inflammation-related organelles, termed lipid bodies, which are actively formed in vivo within macrophages in response to T. cruzi infection. These findings are defining a broader role for lipid bodies as key markers of macrophage activation during innate immune responses to infectious diseases and attractive targets for novel anti-inflammatory therapies. Modulation of macrophage activation may be central in providing therapeutic benefits for Chagas' disease control. PMID:18624767

  1. Zika virus productively infects primary human placenta-specific macrophages

    PubMed Central

    Jurado, Kellie Ann; Simoni, Michael K.; Tang, Zhonghua; Uraki, Ryuta; Hwang, Jesse; Householder, Sarah; Wu, Mingjie; Lindenbach, Brett D.; Abrahams, Vikki M.; Guller, Seth

    2016-01-01

    The strong association of Zika virus infection with congenital defects has led to questions of how a flavivirus is capable of crossing the placental barrier to reach the fetal brain. Here, we demonstrate permissive Zika virus infection of primary human placental macrophages, commonly referred to as Hofbauer cells, and placental villous fibroblasts. We also demonstrate Zika virus infection of Hofbauer cells within the context of the tissue ex vivo using term placental villous explants. In addition to amplifying infectious virus within a usually inaccessible area, the putative migratory activities of Hofbauer cells may aid in dissemination of Zika virus to the fetal brain. Understanding the susceptibility of placenta-specific cell types will aid future work around and understanding of Zika virus–associated pregnancy complications. PMID:27595140

  2. Zika virus productively infects primary human placenta-specific macrophages

    PubMed Central

    Jurado, Kellie Ann; Simoni, Michael K.; Tang, Zhonghua; Uraki, Ryuta; Hwang, Jesse; Householder, Sarah; Wu, Mingjie; Lindenbach, Brett D.; Abrahams, Vikki M.; Guller, Seth; Fikrig, Erol

    2016-01-01

    The strong association of Zika virus infection with congenital defects has led to questions of how a flavivirus is capable of crossing the placental barrier to reach the fetal brain. Here, we demonstrate permissive Zika virus infection of primary human placental macrophages, commonly referred to as Hofbauer cells, and placental villous fibroblasts. We also demonstrate Zika virus infection of Hofbauer cells within the context of the tissue ex vivo using term placental villous explants. In addition to amplifying infectious virus within a usually inaccessible area, the putative migratory activities of Hofbauer cells may aid in dissemination of Zika virus to the fetal brain. Understanding the susceptibility of placenta-specific cell types will aid future work around and understanding of Zika virus–associated pregnancy complications.

  3. Glutamate metabolism in HIV-1 infected macrophages: Role of HIV-1 Vpr.

    PubMed

    Datta, Prasun K; Deshmane, Satish; Khalili, Kamel; Merali, Salim; Gordon, John C; Fecchio, Chiara; Barrero, Carlos A

    2016-09-01

    HIV-1 infected macrophages play a significant role in the neuropathogenesis of AIDS. HIV-1 viral protein R (Vpr) not only facilitates HIV-1 infection but also contribute to long-lived persistence in macrophages. Our previous studies using SILAC-based proteomic analysis showed that the expression of critical metabolic enzymes in the glycolytic pathway and tricarboxylic acid (TCA) cycle were altered in response to Vpr expression in macrophages. We hypothesized that Vpr-induced modulation of glycolysis and TCA cycle regulates glutamate metabolism and release in HIV-1 infected macrophages. We assessed the amount of specific metabolites induced by Vpr and HIV-1 in macrophages at the intracellular and extracellular level in a time-dependent manner utilizing multiple reaction monitoring (MRM) targeted metabolomics. In addition, stable isotope-labeled glucose and an MRM targeted metabolomics assay were used to evaluate the de novo synthesis and release of glutamate in Vpr overexpressing macrophages and HIV-1 infected macrophages, throughout the metabolic flux of glycolytic pathway and TCA cycle activation. The metabolic flux studies demonstrated an increase in glucose uptake, glutamate release and accumulation of α-ketoglutarate (α-KG) and glutamine in the extracellular milieu in Vpr expressing and HIV-1 infected macrophages. Interestingly, glutamate pools and other intracellular intermediates (glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), citrate, malate, α-KG, and glutamine) showed a decreased trend except for fumarate, in contrast to the glutamine accumulation observed in the extracellular space in Vpr overexpressing macrophages. Our studies demonstrate that dysregulation of mitochondrial glutamate metabolism induced by Vpr in HIV-1 infected macrophages commonly seen, may contribute to neurodegeneration via excitotoxic mechanisms in the context of NeuroAIDS. PMID:27245560

  4. Chronic Opisthorchis viverrini Infection and Associated Hepatobiliary Disease Is Associated with Iron Loaded M2-like Macrophages

    PubMed Central

    Sripa, Banchob

    2014-01-01

    Chronic Opisthorchis viverrini-induced hepatobiliary disease is associated with significant leukocyte infiltration, including activated macrophages; however, the polarization of infiltrating macrophages remains to be fully characterized. In this study, we characterized macrophage polarization and phenotype in chronic O. viverrini-induced hepatobiliary disease in humans and hamsters using gene expression and histochemical analysis. Chronic O. viverrini infection and associated hepatobiliary diseases were associated with iron loaded M2-like macrophages in both humans and hamsters. This study provides suggestive evidence that iron loaded M2-like macrophages promote hepatobiliary disease in chronic O. viverrini infection. PMID:25548425

  5. p47 GTPases Regulate Toxoplasma gondii Survival in Activated Macrophages

    PubMed Central

    Butcher, Barbara A.; Greene, Robert I.; Henry, Stanley C.; Annecharico, Kimberly L.; Weinberg, J. Brice; Denkers, Eric Y.; Sher, Alan; Taylor, Gregory A.

    2005-01-01

    The cytokine gamma interferon (IFN-γ) is critical for resistance to Toxoplasma gondii. IFN-γ strongly activates macrophages and nonphagocytic host cells to limit intracellular growth of T. gondii; however, the cellular factors that are required for this effect are largely unknown. We have shown previously that IGTP and LRG-47, members of the IFN-γ-regulated family of p47 GTPases, are required for resistance to acute T. gondii infections in vivo. In contrast, IRG-47, another member of this family, is not required. In the present work, we addressed whether these GTPases are required for IFN-γ-induced suppression of T. gondii growth in macrophages in vitro. Bone marrow macrophages that lacked IGTP or LRG-47 displayed greatly attenuated IFN-γ-induced inhibition of T. gondii growth, while macrophages that lacked IRG-47 displayed normal inhibition. Thus, the ability of the p47 GTPases to limit acute infection in vivo correlated with their ability to suppress intracellular growth in macrophages in vitro. Using confocal microscopy and sucrose density fractionation, we demonstrated that IGTP largely colocalizes with endoplasmic reticulum markers, while LRG-47 was mainly restricted to the Golgi. Although both IGTP and LRG-47 localized to vacuoles containing latex beads, neither protein localized to vacuoles containing live T. gondii. These results suggest that IGTP and LRG-47 are able to regulate host resistance to acute T. gondii infections through their ability to inhibit parasite growth within the macrophage. PMID:15908352

  6. Akt inhibitors as an HIV-1 infected macrophage-specific anti-viral therapy

    PubMed Central

    Chugh, Pauline; Bradel-Tretheway, Birgit; Monteiro-Filho, Carlos MR; Planelles, Vicente; Maggirwar, Sanjay B; Dewhurst, Stephen; Kim, Baek

    2008-01-01

    Background Unlike CD4+ T cells, HIV-1 infected macrophages exhibit extended life span even upon stress, consistent with their in vivo role as long-lived HIV-1 reservoirs. Results Here, we demonstrate that PI3K/Akt inhibitors, including clinically available Miltefosine, dramatically reduced HIV-1 production from long-living virus-infected macrophages. These PI3K/Akt inhibitors hyper-sensitize infected macrophages to extracellular stresses that they are normally exposed to, and eventually lead to cell death of infected macrophages without harming uninfected cells. Based on the data from these Akt inhibitors, we were able to further investigate how HIV-1 infection utilizes the PI3K/Akt pathway to establish the cytoprotective effect of HIV-1 infection, which extends the lifespan of infected macrophages, a key viral reservoir. First, we found that HIV-1 infection activates the well characterized pro-survival PI3K/Akt pathway in primary human macrophages, as reflected by decreased PTEN protein expression and increased Akt kinase activity. Interestingly, the expression of HIV-1 or SIV Tat is sufficient to mediate this cytoprotective effect, which is dependent on the basic domain of Tat – a region that has previously been shown to bind p53. Next, we observed that this interaction appears to contribute to the downregulation of PTEN expression, since HIV-1 Tat was found to compete with PTEN for p53 binding; this is known to result in p53 destabilization, with a consequent reduction in PTEN protein production. Conclusion Since HIV-1 infected macrophages display highly elevated Akt activity, our results collectively show that PI3K/Akt inhibitors may be a novel therapy for interfering with the establishment of long-living HIV-1 infected reservoirs. PMID:18237430

  7. Delineation of Diverse Macrophage Activation Programs in Response to Intracellular Parasites and Cytokines

    PubMed Central

    Zhang, Shuyi; Kim, Charles C.; Batra, Sajeev; McKerrow, James H.; Loke, P'ng

    2010-01-01

    Background The ability to reside and proliferate in macrophages is characteristic of several infectious agents that are of major importance to public health, including the intracellular parasites Trypanosoma cruzi (the etiological agent of Chagas disease) and Leishmania species (etiological agents of Kala-Azar and cutaneous leishmaniasis). Although recent studies have elucidated some of the ways macrophages respond to these pathogens, the relationships between activation programs elicited by these pathogens and the macrophage activation programs elicited by bacterial pathogens and cytokines have not been delineated. Methodology/Principal Findings To provide a global perspective on the relationships between macrophage activation programs and to understand how certain pathogens circumvent them, we used transcriptional profiling by genome-wide microarray analysis to compare the responses of mouse macrophages following exposure to the intracellular parasites T. cruzi and Leishmania mexicana, the bacterial product lipopolysaccharide (LPS), and the cytokines IFNG, TNF, IFNB, IL-4, IL-10, and IL-17. We found that LPS induced a classical activation state that resembled macrophage stimulation by the Th1 cytokines IFNG and TNF. However, infection by the protozoan pathogen L. mexicana produced so few transcriptional changes that the infected macrophages were almost indistinguishable from uninfected cells. T. cruzi activated macrophages produced a transcriptional signature characterized by the induction of interferon-stimulated genes by 24 h post-infection. Despite this delayed IFN response by T. cruzi, the transcriptional response of macrophages infected by the kinetoplastid pathogens more closely resembled the transcriptional response of macrophages stimulated by the cytokines IL-4, IL-10, and IL-17 than macrophages stimulated by Th1 cytokines. Conclusions/Significance This study provides global gene expression data for a diverse set of biologically significant pathogens and

  8. Weight loss in obese mice persistently infected with lymphocytic choriomeningitis virus is not associated with elevated tumor necrosis factor/cachectin activity in peritoneal macrophages.

    PubMed Central

    Lathey, J. L.; Oldstone, M. B.

    1988-01-01

    C57BL/6 ob/ob (C57 ob/ob) mice infected persistently with lymphocytic choriomeningitis virus (LCMV) show cachexia as judged by a weight loss of greater than 20%. Virus persists in a subset of macrophages. Because a cachexic state occurs in several chronic debilitating diseases of humans, often accompanied by persistent microbial infections with macrophage/monocytic involvement and tumor necrosis factor (TNF) cachectin production, the role of TNF in the weightloss of ob/ob mice infected persistently with LCMV was investigated. TNF mRNA expression was not increased in peritoneal cells from such persistently-infected mice, nor did their serum levels of TNF rise above those in uninfected litter-mates. Furthermore, in vitro LCMV infection of adherent peritoneal cells from these C57 ob/ob mice did not enhance TNF mRNA or protein expression. Therefore, the cachexia-like weight loss observed in C57 ob/ob mice during a persistent LCMV infection is apparently not associated with a measurable increase in TNF. Images Figure 2 Figure 3 Figure 4 PMID:3414785

  9. Anti-infective activities of Pelargonium sidoides (EPS® 7630): effects of induced NO production on Leishmania major in infected macrophages and antiviral effects as assessed in a fibroblast-virus protection assay.

    PubMed

    Thäle, Carsten; Kiderlen, Albrecht Ferdinand; Kolodziej, Herbert

    2011-05-01

    EPs® 7630 is an aqueous-ethanolic extract of the roots of Pelargonium sidoides, employed in the treatment of upper respiratory tract infections. Its anti-infective activity is supposed to be associated with the activation of the nonspecific immune system. Using Leishmania major GFP-infected murine BMMΦ, the NO production of EPs® 7630-activated macrophages was correlated with the reduction of the GFP signal measured at single cell levels using flow cytometry. The anti-infectious effect of EPs® 7630 (3-10 µg/mL) on its own (NO production: 4-13 µM; signal reduction: 25-73 %) was less prominent than that in combination with IFN- γ (100 U/mL) (NO production: 20-27 µM; signal reduction: 35-78 %). Furthermore, supernatants of EPs® 7630-stimulated BMMΦ (10 µg/mL) significantly reduced the cytopathic effect of EMCV on L929 fibroblasts (antiviral activity 80 U/mL) when compared with an IFN- γ standard (100 U/mL). Direct addition of EPs® 7630 to L929 did not mediate cytoprotective effects. The antiviral components induced in BMMΦ by EPs® 7630 remain to be identified. Detection of any IFNs by ELISA was unsuccessful, which may be due to their very low concentrations in cell supernatants. The current data provide convincing support for the induction of anti-infectious responses by EPs® 7630.

  10. A comparison of two distinct murine macrophage gene expression profiles in response to Leishmania amazonensis infection

    PubMed Central

    2012-01-01

    Background The experimental murine model of leishmaniasis has been widely used to characterize the immune response against Leishmania. CBA mice develop severe lesions, while C57BL/6 present small chronic lesions under L. amazonensis infection. Employing a transcriptomic approach combined with biological network analysis, the gene expression profiles of C57BL/6 and CBA macrophages, before and after L. amazonensis infection in vitro, were compared. These strains were selected due to their different degrees of susceptibility to this parasite. Results The genes expressed by C57BL/6 and CBA macrophages, before and after infection, differ greatly, both with respect to absolute number as well as cell function. Uninfected C57BL/6 macrophages express genes involved in the deactivation pathway of macrophages at lower levels, while genes related to the activation of the host immune inflammatory response, including apoptosis and phagocytosis, have elevated expression levels. Several genes that participate in the apoptosis process were also observed to be up-regulated in C57BL/6 macrophages infected with L. amazonensis, which is very likely related to the capacity of these cells to control parasite infection. By contrast, genes involved in lipid metabolism were found to be up-regulated in CBA macrophages in response to infection, which supports the notion that L. amazonensis probably modulates parasitophorous vacuoles in order to survive and multiply in host cells. Conclusion The transcriptomic profiles of C57BL/6 macrophages, before and after infection, were shown to be involved in the macrophage pathway of activation, which may aid in the control of L. amazonensis infection, in contrast to the profiles of CBA cells. PMID:22321871

  11. Virulent Coxiella burnetii pathotypes productively infect primary human alveolar macrophages.

    PubMed

    Graham, Joseph G; MacDonald, Laura J; Hussain, S Kauser; Sharma, Uma M; Kurten, Richard C; Voth, Daniel E

    2013-06-01

    The intracellular bacterial pathogen Coxiella burnetii is a category B select agent that causes human Q fever. In vivo, C. burnetii targets alveolar macrophages wherein the pathogen replicates in a lysosome-like parasitophorous vacuole (PV). In vitro, C. burnetii infects a variety of cultured cell lines that have collectively been used to model the pathogen's infectious cycle. However, differences in the cellular response to infection have been observed, and virulent C. burnetii isolate infection of host cells has not been well defined. Because alveolar macrophages are routinely implicated in disease, we established primary human alveolar macrophages (hAMs) as an in vitro model of C. burnetii-host cell interactions. C. burnetii pathotypes, including acute disease and endocarditis isolates, replicated in hAMs, albeit with unique PV properties. Each isolate replicated in large, typical PV and small, non-fused vacuoles, and lipid droplets were present in avirulent C. burnetii PV. Interestingly, a subset of small vacuoles harboured single organisms undergoing degradation. Prototypical PV formation and bacterial growth in hAMs required a functional type IV secretion system, indicating C. burnetii secretes effector proteins that control macrophage functions. Avirulent C. burnetii promoted sustained activation of Akt and Erk1/2 pro-survival kinases and short-termphosphorylation of stress-related p38. Avirulent organisms also triggered a robust, early pro-inflammatory response characterized by increased secretion of TNF-α and IL-6, while virulent isolates elicited substantially reduced secretion of these cytokines. A corresponding increase in pro- and mature IL-1β occurred in hAMs infected with avirulent C. burnetii, while little accumulation was observed following infection with virulent isolates. Finally, treatment of hAMs with IFN-γ controlled intracellular replication, supporting a role for this antibacterial insult in the host response to C

  12. Bacterial Membrane Vesicles Mediate the Release of Mycobacterium tuberculosis Lipoglycans and Lipoproteins from Infected Macrophages.

    PubMed

    Athman, Jaffre J; Wang, Ying; McDonald, David J; Boom, W Henry; Harding, Clifford V; Wearsch, Pamela A

    2015-08-01

    Mycobacterium tuberculosis is an intracellular pathogen that infects lung macrophages and releases microbial factors that regulate host defense. M. tuberculosis lipoproteins and lipoglycans block phagosome maturation, inhibit class II MHC Ag presentation, and modulate TLR2-dependent cytokine production, but the mechanisms for their release during infection are poorly defined. Furthermore, these molecules are thought to be incorporated into host membranes and released from infected macrophages within exosomes, 40-150-nm extracellular vesicles that derive from multivesicular endosomes. However, our studies revealed that extracellular vesicles released from infected macrophages include two distinct, largely nonoverlapping populations: one containing host cell markers of exosomes (CD9, CD63) and the other containing M. tuberculosis molecules (lipoglycans, lipoproteins). These vesicle populations are similar in size but have distinct densities, as determined by separation on sucrose gradients. Release of lipoglycans and lipoproteins from infected macrophages was dependent on bacterial viability, implicating active bacterial mechanisms in their secretion. Consistent with recent reports of extracellular vesicle production by bacteria (including M. tuberculosis), we propose that bacterial membrane vesicles are secreted by M. tuberculosis within infected macrophages and subsequently are released into the extracellular environment. Furthermore, extracellular vesicles released from M. tuberculosis-infected cells activate TLR2 and induce cytokine responses by uninfected macrophages. We demonstrate that these activities derive from the bacterial membrane vesicles rather than exosomes. Our findings suggest that bacterial membrane vesicles are the primary means by which M. tuberculosis exports lipoglycans and lipoproteins to impair effector functions of infected macrophages and circulate bacterial components beyond the site of infection to regulate immune responses by uninfected

  13. Bacterial membrane vesicles mediate the release of Mycobacterium tuberculosis lipoglycans and lipoproteins from infected macrophages

    PubMed Central

    Athman, Jaffre J.; Wang, Ying; McDonald, David J.; Boom, W. Henry; Harding, Clifford V.; Wearsch, Pamela A.

    2015-01-01

    Mycobacterium tuberculosis (Mtb) is an intracellular pathogen that infects lung macrophages and releases microbial factors that regulate host defense. Mtb lipoproteins and lipoglycans block phagosome maturation, inhibit MHC-II antigen presentation, and modulate TLR2-dependent cytokine production, but the mechanisms for their release during infection are poorly defined. Furthermore, these molecules are thought to be incorporated into host membranes and released from infected macrophages within exosomes, 40-150 nm extracellular vesicles that derive from multivesicular endosomes. However, our studies revealed that extracellular vesicles released from Mtb-infected macrophages include two distinct, largely non-overlapping populations, one containing host cell markers of exosomes (CD9, CD63) and the other containing Mtb molecules (lipoglycans, lipoproteins). These vesicle populations are similar in size, but have distinct densities as determined by separation on sucrose gradients. Release of Mtb lipoglycans and lipoproteins from infected macrophages was dependent on bacterial viability, implicating active bacterial mechanisms in their genesis. Consistent with recent reports of extracellular vesicle production by bacteria (including Mtb), we propose that bacterial membrane vesicles are secreted by Mtb within infected macrophages and subsequently released into the extracellular environment. Extracellular vesicles released from Mtb-infected cells activate TLR2 and induce cytokine responses by uninfected macrophages. We demonstrate that these activities derive from the bacterial membrane vesicles rather than exosomes. Our findings suggest that bacterial membrane vesicles are the primary means by which Mtb exports lipoglycans and lipoproteins to impair effector functions within infected macrophages and circulate bacterial components beyond the site of infection to regulate immune responses by uninfected cells. PMID:26109643

  14. The Role of Prostate Apoptosis Response-4 (Par-4) in Mycobacterium tuberculosis Infected Macrophages

    PubMed Central

    Han, Ji-Ye; Lim, Yun-Ji; Choi, Ji-Ae; Lee, Jung-hwan; Jo, Sung-Hee; Oh, Sung-Man; Song, Chang-Hwa

    2016-01-01

    Prostate apoptosis response-4 (Par-4) is a tumor suppressor protein that forms a complex with glucose-regulated protein 78 (GRP78) to induce apoptosis. Previously, we reported that ER stress-induced apoptosis is a critical host defense mechanism against Mycobacterium tuberculosis (Mtb). We sought to understand the role of Par-4 during ER stress-induced apoptosis in response to mycobacterial infection. Par-4 and GRP78 protein levels increased in response Mtb (strain: H37Ra) infection. Furthermore, Par-4 and GRP78 translocate to the surface of Mtb H37Ra-infected macrophages and induce apoptosis via caspase activation. NF-κB activation, Mtb-mediated ER stress, and Par-4 production were significantly diminished in macrophages with inhibited ROS production. To test Par-4 function during mycobacterial infection, we analyzed intracellular survival of Mtb H37Ra in macrophages with Par-4 overexpression or knockdown. Mtb H37Ra growth was significantly reduced in Par-4 overexpressing macrophages and increased in knockdown macrophages. We also observed increased Par-4, GRP78, and caspases activation in Bacillus Calmette-Guérin (BCG)-infected prostate cancer cells. Our data demonstrate that Par-4 is associated with ER stress-induced apoptosis resulting in reduced intracellular survival of mycobacteria. BCG treatment increases Par-4-dependent caspase activation in prostate cancer cells. These results suggest ER stress-induced Par-4 acts as an important defense mechanism against mycobacterial infection and regulates cancer. PMID:27552917

  15. Long-term HIV-1 infection induces an antiviral state in primary macrophages.

    PubMed

    Pujantell, Maria; Badia, Roger; Ramirez, Cristina; Puig, Teresa; Clotet, Bonaventura; Ballana, Ester; Esté, José A; Riveira-Muñoz, Eva

    2016-09-01

    HIV-1 infection is thought to impair type I interferon (IFN-I) production in macrophages, a cell type that is also relatively resistant to HIV-1 cytotoxic effects. Here, we show that monocyte differentiation into macrophages by M-CSF led to cell proliferation and susceptibility to HIV-1 infection that induced cell cycle arrest and increased cell death. Established HIV-1 infection of monocyte-derived macrophages induced the upregulation of the pattern recognition receptors MDA5 and Rig-I that serve as virus sensors; production of interferon-β, and transcription of interferon-stimulated genes including CXCL10. Infected macrophages showed increased expression of p21 and subsequent inactivation of cyclin-CDK2 activity leading to a hypo-phosphorylated active retinoblastoma protein (pRb) and deactivation of E2F1-dependent transcription and CDK1 downregulation. Additionally, HIV-1 infection limited deoxynucleotide pool by downregulation of the ribonucleotide reductase subunit R2 (RNR2) and reactivation of the HIV-1 restriction factor SAMHD1 together with increased cell death. In conclusion, HIV-1 induced an innate antiviral mechanism associated to IFN-I production, interferon stimulated gene activation, and p21-mediated G2/M arrest leading to elevated levels of cell death in monocyte derived macrophages. Upregulation of MDA5 and Rig-I may serve as targets for the development of antiviral strategies leading to the elimination of HIV-1 infected cells. PMID:27510577

  16. Toxoplasma gondii Chitinase Induces Macrophage Activation

    PubMed Central

    Almeida, Fausto; Sardinha-Silva, Aline; da Silva, Thiago Aparecido; Pessoni, André Moreira; Pinzan, Camila Figueiredo; Alegre-Maller, Ana Claudia Paiva; Cecílio, Nerry Tatiana; Moretti, Nilmar Silvio; Damásio, André Ricardo Lima; Pedersoli, Wellington Ramos; Mineo, José Roberto; Silva, Roberto Nascimento; Roque-Barreira, Maria Cristina

    2015-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite found worldwide that is able to chronically infect almost all vertebrate species, especially birds and mammalians. Chitinases are essential to various biological processes, and some pathogens rely on chitinases for successful parasitization. Here, we purified and characterized a chitinase from T. gondii. The enzyme, provisionally named Tg_chitinase, has a molecular mass of 13.7 kDa and exhibits a Km of 0.34 mM and a Vmax of 2.64. The optimal environmental conditions for enzymatic function were at pH 4.0 and 50°C. Tg_chitinase was immunolocalized in the cytoplasm of highly virulent T. gondii RH strain tachyzoites, mainly at the apical extremity. Tg_chitinase induced macrophage activation as manifested by the production of high levels of pro-inflammatory cytokines, a pathogenic hallmark of T. gondii infection. In conclusion, to our knowledge, we describe for the first time a chitinase of T. gondii tachyzoites and provide evidence that this enzyme might influence the pathogenesis of T. gondii infection. PMID:26659253

  17. Inhibition of herpes simplex virus multiplication by activated macrophages: a role for arginase?

    PubMed Central

    Wildy, P; Gell, P G; Rhodes, J; Newton, A

    1982-01-01

    Proteose-peptone-activated mouse macrophages can prevent productive infection by herpes simplex virus in neighboring cells in vitro whether or not those cells belong to the same animal species. The effect does not require contact between the macrophages and the infected cells, may be prevented by adding extra arginine to the medium, and may be reversed when extra arginine is added 24 h after the macrophages. Arginase activity was found both intracellularly and released from the macrophages. The extracellular enzyme is quite stable; 64% activity was found after 48 h of incubation at 37 degrees C in tissue culture medium. No evidence was found that the inefficiency of virus replication in macrophages was due to self-starvation by arginase. As might be predicted macrophages can, by the same mechanism, limit productive infection by vaccinia virus. PMID:6286497

  18. Micro RNA in Exosomes from HIV-Infected Macrophages.

    PubMed

    Roth, William W; Huang, Ming Bo; Addae Konadu, Kateena; Powell, Michael D; Bond, Vincent C

    2015-12-22

    Exosomes are small membrane-bound vesicles secreted by cells that function to shuttle RNA and proteins between cells. To examine the role of exosomal micro RNA (miRNA) during the early stage of HIV-1 infection we characterized miRNA in exosomes from HIV-infected macrophages, compared with exosomes from non-infected macrophages. Primary human monocytes from uninfected donors were differentiated to macrophages (MDM) which were either mock-infected or infected with the macrophage-tropic HIV-1 BaL strain. Exosomes were recovered from culture media and separated from virus particles by centrifugation on iodixanol density gradients. The low molecular weight RNA fraction was prepared from purified exosomes. After pre-amplification, RNA was hybridized to microarrays containing probes for 1200 miRNA species of known and unknown function. We observed 48 miRNA species in both infected and uninfected MDM exosomes. Additionally, 38 miRNAs were present in infected-cell exosomes but not uninfected-cell exosomes. Of these, 13 miRNAs were upregulated in exosomes from HIV-infected cells, including 4 miRNA species that were increased by more than 10-fold. Though numerous miRNA species have been identified in HIV-infected cells, relatively little is known about miRNA content in exosomes from these cells. In the future, we plan to investigate whether the upregulated miRNA species we identified are increased in exosomes from HIV-1-positive patients.

  19. Extracellular calcium influx promotes antibacterial autophagy in Escherichia coli infected murine macrophages via CaMKKβ dependent activation of ERK1/2, AMPK and FoxO1.

    PubMed

    Liu, Xin; Wang, Ning; Zhu, Yuanfeng; Yang, Yongjun; Chen, Xiaoli; Chen, Qian; Zhou, Hong; Zheng, Jiang

    2016-01-15

    Autophagy induction has been found as an alternative mechanism for ultimate elimination of invaded bacteria in innate immune cells. However, underlying mechanisms for the regulation of antibacterial autophagy require further elucidation. The present study mainly explores calcium dependent regulation of autophagy and its contribution to bactericidal activity in Escherichia coli (E. coli) infected murine macrophages. In this study, E. coli was shown to increase cellular calcium levels by triggering extracellular calcium influx in murine bone marrow derived macrophages. The elevated calcium was required for autophagy and bactericidal activity against E. coli, as extracellular calcium depletion or inhibition of calcium influx suppressed E. coli induced Beclin1 and LC3B expression, dampened LC3B puncta or LC3I to LC3II conversion and impaired intracellular E. coli degradation. Then CaMKKβ was identified as activated by E. coli induced calcium influx and chemical inhibition or RNAi knockdown of CaMKKβ abolished calcium mediated antibacterial autophagy. CaMKKβ was demonstrated to activate signaling pathways involving ERK, AMPK and FoxO1 and RNAi knockdown of these molecules also dampened the antibacterial autophagy against E. coli. In summary, we demonstrate a new mechanism of calcium dependent antibacterial strategy in E. coli infected macrophages, which requires autophagy enhancement mediated by activation of CaMKKβ, ERK, AMPK and FoxO1.

  20. Low-oxygen tensions found in Salmonella-infected gut tissue boost Salmonella replication in macrophages by impairing antimicrobial activity and augmenting Salmonella virulence.

    PubMed

    Jennewein, Jonas; Matuszak, Jasmin; Walter, Steffi; Felmy, Boas; Gendera, Kathrin; Schatz, Valentin; Nowottny, Monika; Liebsch, Gregor; Hensel, Michael; Hardt, Wolf-Dietrich; Gerlach, Roman G; Jantsch, Jonathan

    2015-12-01

    In Salmonella infection, the Salmonella pathogenicity island-2 (SPI-2)-encoded type three secretion system (T3SS2) is of key importance for systemic disease and survival in host cells. For instance, in the streptomycin-pretreated mouse model SPI-2-dependent Salmonella replication in lamina propria CD11c(-)CXCR1(-) monocytic phagocytes/macrophages (MΦ) is required for the development of colitis. In addition, containment of intracellular Salmonella in the gut critically depends on the antimicrobial effects of the phagocyte NADPH oxidase (PHOX), and possibly type 2 nitric oxide synthase (NOS2). For both antimicrobial enzyme complexes, oxygen is an essential substrate. However, the amount of available oxygen upon enteroinvasive Salmonella infection in the gut tissue and its impact on Salmonella-MΦ interactions was unknown. Therefore, we measured the gut tissue oxygen levels in a model of Salmonella enterocolitis using luminescence two-dimensional in vivo oxygen imaging. We found that gut tissue oxygen levels dropped from ∼78 Torr (∼11% O2) to values of ∼16 Torr (∼2% O2) during infection. Because in vivo virulence of Salmonella depends on the Salmonella survival in MΦ, Salmonella-MΦ interaction was analysed under such low oxygen values. These experiments revealed an increased intracellular replication and survival of wild-type and t3ss2 non-expressing Salmonella. These findings were paralleled by blunted nitric oxide and reactive oxygen species (ROS) production and reduced Salmonella ROS perception. In addition, hypoxia enhanced SPI-2 transcription and translocation of SPI-2-encoded virulence protein. Neither pharmacological blockade of PHOX and NOS2 nor impairment of T3SS2 virulence function alone mimicked the effect of hypoxia on Salmonella replication under normoxic conditions. However, if t3ss2 non-expressing Salmonella were used, hypoxia did not further enhance Salmonella recovery in a PHOX and NOS2-deficient situation. Hence, these data suggest that

  1. CD4 Depletion in SIV-Infected Macaques Results in Macrophage and Microglia Infection with Rapid Turnover of Infected Cells

    PubMed Central

    Ortiz, Alexandra M.; Ryan, Emily S.; McGary, Colleen S.; Deleage, Claire; McAtee, Brigitte B.; He, Tianyu; Apetrei, Cristian; Easley, Kirk; Pahwa, Savita; Collman, Ronald G.; Derdeyn, Cynthia A.; Davenport, Miles P.; Estes, Jacob D.; Silvestri, Guido; Lackner, Andrew A.; Paiardini, Mirko

    2014-01-01

    In rhesus macaques (RMs), experimental depletion of CD4+ T-cells prior to SIV infection results in higher viremia and emergence of CD4-independent SIV-envelopes. In this study we used the rhesus recombinant anti-CD4 antibody CD4R1 to deplete RM CD4+ T-cells prior to SIVmac251 infection and investigate the sources of the increased viral burden and the lifespan of productively infected cells. CD4-depleted animals showed (i) set-point viral load two-logs higher than controls; (ii) macrophages constituting 80% of all SIV vRNA+ cells in lymph node and mucosal tissues; (iii) substantial expansion of pro-inflammatory monocytes; (iv) aberrant activation and infection of microglial cells; and (v) lifespan of productively infected cells significantly longer in comparison to controls, but markedly shorter than previously estimated for macrophages. The net effect of CD4+ T-cell depletion is an inability to control SIV replication and a shift in the tropism of infected cells to macrophages, microglia, and, potentially, other CD4-low cells which all appear to have a shortened in vivo lifespan. We believe these findings have important implications for HIV eradication studies. PMID:25356757

  2. Intracellular Macrophage Infections with E. coli under Nitrosative Stress

    PubMed Central

    Bateman, Stacey L.; Seed, Patrick

    2016-01-01

    Escherichia coli (E. coli) produces disseminated infections of the urinary tract, blood, and central nervous system where it encounters professional phagocytes such as macrophages, which utilize reactive nitrogen intermediates (RNI) to arrest bacteria. In vitro, extraintestinal pathogenic E. coli (ExPEC) can survive within bone marrow-derived macrophages for greater than 24 h post-infection within a LAMP1+ vesicular compartment, and ExPEC strains, in particular, are better adapted to intracellular macrophage survival than commensal strains (Bokil et al., 2011). This protocol details an intracellular murine macrophage-like cell infection, including modulation of the host nitrosative stress response, to model this host-pathogen interaction in vitro. To accomplish this, RAW 264.7 murine macrophage-like cells are pre-incubated with either L-arginine, an NO precursor, or IFNγ to yield a high nitric oxide (NO) physiological state, or L-NAME, an inducible NO synthase (iNOS)-specific inhibitor, to yield a low NO physiological state. This protocol has been successfully utilized to assess the contribution of a novel ExPEC regulator to intracellular survival and the nitrosative stress response during macrophage infections (Bateman and Seed, 2012), but can be adapted for use with a variety of E. coli strains or isogenic deletions.

  3. Adoptive transfer of macrophages from adult mice reduces mortality in mice infected with human enterovirus 71.

    PubMed

    Liu, Jiangning; Li, Xiaoying; Fan, Xiaoxu; Ma, Chunmei; Qin, Chuan; Zhang, Lianfeng

    2013-02-01

    Human enterovirus 71 (EV71) causes hand, foot and mouth disease in children under 6 years of age, and the neurological complications of this virus can lead to death. Until now, no vaccines or drugs have been available for the clinical control of this epidemic. Macrophages can engulf pathogens and mediate a series of host immune responses that play a role in the defence against infectious diseases. Using immunohistochemistry, we observed the localizations of virus in muscle tissues of EV71-infected mice. The macrophages isolated from the adult mice could kill the virus gradually in vitro, as shown using quantitative real-time PCR (qRT-PCR) and virus titration. Co-localisation of lysosomes and virus within macrophages suggested that the lysosomes were possibly responsible for the phagocytosis of EV71. Activation of the macrophages in the peritoneal cavity of mice four days pre-infection reduced the mortality of mice upon lethal EV71 infection. The adoptive transfer of macrophages from adult mice inhibited virus replication in the muscle tissues of infected mice, and this was followed by a relief of symptoms and a significant reduction of mortality, which suggested that the adoptive transfer of macrophages from adult humans represents a potential strategy to treat EV71-infected patients.

  4. Role of Macrophages in the Repair Process during the Tissue Migrating and Resident Helminth Infections

    PubMed Central

    Faz-López, Berenice

    2016-01-01

    The Th1/Th2/Th17 balance is a fundamental feature in the regulation of the inflammatory microenvironment during helminth infections, and an imbalance in this paradigm greatly contributes to inflammatory disorders. In some cases of helminthiasis, an initial Th1 response could occur during the early phases of infection (acute), followed by a Th2 response that prevails in chronic infections. During the late phase of infection, alternatively activated macrophages (AAMs) are important to counteract the inflammation caused by the Th1/Th17 response and larval migration, limiting damage and repairing the tissue affected. Macrophages are the archetype of phagocytic cells, with the primary role of pathogen destruction and antigen presentation. Nevertheless, other subtypes of macrophages have been described with important roles in tissue repair and immune regulation. These types of macrophages challenge the classical view of macrophages activated by an inflammatory response. The role of these subtypes of macrophages during helminthiasis is a controversial topic in immunoparasitology. Here, we analyze some of the studies regarding the role of AAMs in tissue repair during the tissue migration of helminths.

  5. Role of Macrophages in the Repair Process during the Tissue Migrating and Resident Helminth Infections.

    PubMed

    Faz-López, Berenice; Morales-Montor, Jorge; Terrazas, Luis I

    2016-01-01

    The Th1/Th2/Th17 balance is a fundamental feature in the regulation of the inflammatory microenvironment during helminth infections, and an imbalance in this paradigm greatly contributes to inflammatory disorders. In some cases of helminthiasis, an initial Th1 response could occur during the early phases of infection (acute), followed by a Th2 response that prevails in chronic infections. During the late phase of infection, alternatively activated macrophages (AAMs) are important to counteract the inflammation caused by the Th1/Th17 response and larval migration, limiting damage and repairing the tissue affected. Macrophages are the archetype of phagocytic cells, with the primary role of pathogen destruction and antigen presentation. Nevertheless, other subtypes of macrophages have been described with important roles in tissue repair and immune regulation. These types of macrophages challenge the classical view of macrophages activated by an inflammatory response. The role of these subtypes of macrophages during helminthiasis is a controversial topic in immunoparasitology. Here, we analyze some of the studies regarding the role of AAMs in tissue repair during the tissue migration of helminths. PMID:27648452

  6. Role of Macrophages in the Repair Process during the Tissue Migrating and Resident Helminth Infections

    PubMed Central

    Faz-López, Berenice

    2016-01-01

    The Th1/Th2/Th17 balance is a fundamental feature in the regulation of the inflammatory microenvironment during helminth infections, and an imbalance in this paradigm greatly contributes to inflammatory disorders. In some cases of helminthiasis, an initial Th1 response could occur during the early phases of infection (acute), followed by a Th2 response that prevails in chronic infections. During the late phase of infection, alternatively activated macrophages (AAMs) are important to counteract the inflammation caused by the Th1/Th17 response and larval migration, limiting damage and repairing the tissue affected. Macrophages are the archetype of phagocytic cells, with the primary role of pathogen destruction and antigen presentation. Nevertheless, other subtypes of macrophages have been described with important roles in tissue repair and immune regulation. These types of macrophages challenge the classical view of macrophages activated by an inflammatory response. The role of these subtypes of macrophages during helminthiasis is a controversial topic in immunoparasitology. Here, we analyze some of the studies regarding the role of AAMs in tissue repair during the tissue migration of helminths. PMID:27648452

  7. Nitric oxide inhibition after Toxoplasma gondii infection of chicken macrophage cell lines.

    PubMed

    Guillermo, L V C; DaMatta, R A

    2004-05-01

    Toxoplasma gondii infects many warm-blooded animals, including chickens. However, little is known about how this protozoan behaves within chicken macrophages. Thus, the microbicidal biology of HD11 and MQ-NCSU (available chicken macrophage cell lines) and the escaping mechanism of T. gondii were investigated. After infection, both cell lines were activated with lipopolysaccharide (LPS) and nitric oxide (NO), and reactive oxygen intermediates (ROI) were evaluated. T. gondii infected both cell lines, and 30 and 60% inhibition of NO production was detected in MQ-NCSU and HD11, respectively. In HD11, NO inhibition was not dependent on cyclooxygenase products. Although NO was partially inhibited, it did control T. gondii multiplication, showing the importance of this microbicidal molecule. Production of ROI was not detected in either cell line after T. gondii or yeast interaction. NADPH diaphorase (NADPH-d) activity, a histochemical marker of inducible NO synthase (iNOS), was detected at various levels in the HD11 population activated with LPS. The HD11 population infected with T. gondii showed a decrease in NADPH-d, indicating that NO production inhibition was related to iNOS disappearance in infected macrophages. These results demonstrate that in chicken macrophages T. gondii can also inhibit NO production, which suggests that an iNOS suppression mechanism might be used for better survival in macrophages.

  8. Maternal immune activation leads to activated inflammatory macrophages in offspring

    PubMed Central

    Onore, Charity E.; Schwartzer, Jared J.; Careaga, Milo; Bennan, Robert F.; Ashwood, Paul

    2015-01-01

    Several epidemiological studies have shown an association between infection or inflammation during pregnancy and increased risk of autism in the child. In addition, animal models have illustrated that maternal inflammation during gestation can cause autism-relevant behaviors in the offspring; so called maternal immune activation (MIA) models. More recently, permanent changes in T cell cytokine responses were reported in children with autism and in offspring of MIA mice; however, the cytokine responses of other immune cell populations have not been thoroughly investigated in these MIA models. Similar to changes in T cell function, we hypothesized that following MIA, offspring will have long-term changes in macrophage function. To test this theory, we utilized the poly (I:C) MIA mouse model in C57BL/6J mice and examined macrophage cytokine production in adult offspring. Pregnant dams were given either a single injection of 20 mg/kg polyinosinic–polycytidylic acid, poly (I:C), or saline delivered intraperitoneally on gestational day 12.5. When offspring of poly (I:C) treated dams reached 10 weeks of age, femurs were collected and bone marrow-derived macrophages were generated. Cytokine production was measured in bone marrow-derived macrophages incubated for 24 h in either growth media alone, LPS, IL-4/LPS, or IFN-γ/LPS. Following stimulation with LPS alone, or the combination of IFN-γ/LPS, macrophages from offspring of poly (I:C) treated dams produced higher levels of IL-12(p40) (p < 0.04) suggesting an increased M1 polarization. In addition, even without the presence of a polarizing cytokine or LPS stimulus, macrophages from offspring of poly (I:C) treated dams exhibited a higher production of CCL3 (p = 0.05). Moreover, CCL3 levels were further increased when stimulated with LPS, or polarized with either IL-4/LPS or IFN-γ/LPS (p < 0.05) suggesting a general increase in production of this chemokine. Collectively, these data suggest that MIA can produce lasting

  9. The Many Alternative Faces of Macrophage Activation

    PubMed Central

    Hume, David A.

    2015-01-01

    Monocytes and macrophages provide the first line of defense against pathogens. They also initiate acquired immunity by processing and presenting antigens and provide the downstream effector functions. Analysis of large gene expression datasets from multiple cells and tissues reveals sets of genes that are co-regulated with the transcription factors that regulate them. In macrophages, the gene clusters include lineage-specific genes, interferon-responsive genes, early inflammatory genes, and genes required for endocytosis and lysosome function. Macrophages enter tissues and alter their function to deal with a wide range of challenges related to development and organogenesis, tissue injury, malignancy, sterile, or pathogenic inflammatory stimuli. These stimuli alter the gene expression to produce “activated macrophages” that are better equipped to eliminate the cause of their influx and to restore homeostasis. Activation or polarization states of macrophages have been classified as “classical” and “alternative” or M1 and M2. These proposed states of cells are not supported by large-scale transcriptomic data, including macrophage-associated signatures from large cancer tissue datasets, where the supposed markers do not correlate with other. Individual macrophage cells differ markedly from each other, and change their functions in response to doses and combinations of agonists and time. The most studied macrophage activation response is the transcriptional cascade initiated by the TLR4 agonist lipopolysaccharide. This response is reviewed herein. The network topology is conserved across species, but genes within the transcriptional network evolve rapidly and differ between mouse and human. There is also considerable divergence in the sets of target genes between mouse strains, between individuals, and in other species such as pigs. The deluge of complex information related to macrophage activation can be accessed with new analytical tools and new databases

  10. HIV-1-infected macrophages induce astrogliosis by SDF-1{alpha} and matrix metalloproteinases

    SciTech Connect

    Okamoto, Mika; Wang, Xin; Baba, Masanori . E-mail: baba@m.kufm.kagoshima-u.ac.jp

    2005-11-04

    Brain macrophages/microglia and astrocytes are known to be involved in the pathogenesis of HIV-1-associated dementia (HAD). To clarify their interaction and contribution to the pathogenesis, HIV-1-infected or uninfected macrophages were used as a model of brain macrophages/microglia, and their effects on human astrocytes in vitro were examined. The culture supernatants of HIV-1-infected or uninfected macrophages induced significant astrocyte proliferation, which was annihilated with a neutralizing antibody to stromal cell-derived factor (SDF)-1{alpha} or a matrix metalloproteinase (MMP) inhibitor. In these astrocytes, CXCR4, MMP, and tissue inhibitors of matrix metalloproteinase mRNA expression and SDF-1{alpha} production were significantly up-regulated. The supernatants of infected macrophages were always more effective than those of uninfected cells. Moreover, the enhanced production of SDF-1{alpha} was suppressed by the MMP inhibitor. These results indicate that the activated and HIV-1-infected macrophages can indirectly induce astrocyte proliferation through up-regulating SDF-1{alpha} and MMP production, which implies a mechanism of astrogliosis in HAD.

  11. Chlamydia muridarum Infection of Macrophages Elicits Bactericidal Nitric Oxide Production via Reactive Oxygen Species and Cathepsin B

    PubMed Central

    Rajaram, Krithika

    2015-01-01

    The ability of certain species of Chlamydia to inhibit the biogenesis of phagolysosomes permits their survival and replication within macrophages. The survival of macrophage-adapted chlamydiae correlates with the multiplicity of infection (MOI), and optimal chlamydial growth occurs in macrophages infected at an MOI of ≤1. In this study, we examined the replicative capacity of Chlamydia muridarum in the RAW 264.7 murine macrophage cell line at different MOIs. C. muridarum productively infected these macrophages at low MOIs but yielded few viable elementary bodies (EBs) when macrophages were infected at a moderate (10) or high (100) MOI. While high MOIs caused cytotoxicity and irreversible host cell death, macrophages infected at a moderate MOI did not show signs of cytotoxicity until late in the infectious cycle. Inhibition of host protein synthesis rescued C. muridarum in macrophages infected at a moderate MOI, implying that chlamydial growth was blocked by activated defense mechanisms. Conditioned medium from these macrophages was antichlamydial and contained elevated levels of interleukin 1β (IL-1β), IL-6, IL-10, and beta interferon (IFN-β). Macrophage activation depended on Toll-like receptor 2 (TLR2) signaling, and cytokine production required live, transcriptionally active chlamydiae. A hydroxyl radical scavenger and inhibitors of inducible nitric oxide synthase (iNOS) and cathepsin B also reversed chlamydial killing. High levels of reactive oxygen species (ROS) led to an increase in cathepsin B activity, and pharmacological inhibition of ROS and cathepsin B reduced iNOS expression. Our data demonstrate that MOI-dependent TLR2 activation of macrophages results in iNOS induction via a novel ROS- and cathepsin-dependent mechanism to facilitate C. muridarum clearance. PMID:26015483

  12. Perivascular macrophages mediate neutrophil recruitment during bacterial skin infection

    PubMed Central

    Abtin, Arby; Jain, Rohit; Mitchell, Andrew J.; Roediger, Ben; Brzoska, Anthony J.; Tikoo, Shweta; Cheng, Qiang; Ng, Lai Guan; Cavanagh, Lois L.; von Andrian, Ulrich H.; Hickey, Michael J.; Firth, Neville; Weninger, Wolfgang

    2014-01-01

    Transendothelial migration of neutrophils in post-capillary venules is a key event in the inflammatory response against pathogens and tissue damage. The precise regulation of this process is incompletely understood. We report that perivascular macrophages are critical for neutrophil migration into skin infected with the pathogen Staphylococcus aureus. Using multiphoton intravital microscopy we show that neutrophils extravasate from inflamed dermal venules in close proximity to perivascular macrophages, which are a major source of neutrophil chemoattractants. The virulence factor alpha-hemolysin lyses perivascular macrophages leading to decreased neutrophil transmigration. Our data illustrate a previously unrecognized role for perivascular macrophages in neutrophil recruitment to inflamed skin, and indicate that Staphylococcus aureus uses hemolysin-dependent killing of these cells as an immune evasion strategy. PMID:24270515

  13. Perivascular macrophages mediate neutrophil recruitment during bacterial skin infection.

    PubMed

    Abtin, Arby; Jain, Rohit; Mitchell, Andrew J; Roediger, Ben; Brzoska, Anthony J; Tikoo, Shweta; Cheng, Qiang; Ng, Lai Guan; Cavanagh, Lois L; von Andrian, Ulrich H; Hickey, Michael J; Firth, Neville; Weninger, Wolfgang

    2014-01-01

    Transendothelial migration of neutrophils in postcapillary venules is a key event in the inflammatory response against pathogens and tissue damage. The precise regulation of this process is incompletely understood. We report that perivascular macrophages are critical for neutrophil migration into skin infected with the pathogen Staphylococcus aureus. Using multiphoton intravital microscopy we showed that neutrophils extravasate from inflamed dermal venules in close proximity to perivascular macrophages, which are a major source of neutrophil chemoattractants. The virulence factor α-hemolysin produced by S. aureus lyses perivascular macrophages, which leads to decreased neutrophil transmigration. Our data illustrate a previously unrecognized role for perivascular macrophages in neutrophil recruitment to inflamed skin and indicate that S. aureus uses hemolysin-dependent killing of these cells as an immune evasion strategy. PMID:24270515

  14. Quantitation of Productively Infected Monocytes and Macrophages of Simian Immunodeficiency Virus-Infected Macaques

    PubMed Central

    Avalos, Claudia R.; Price, Sarah L.; Forsyth, Ellen R.; Pin, Julia N.; Shirk, Erin N.; Bullock, Brandon T.; Queen, Suzanne E.; Li, Ming; Gellerup, Dane; O'Connor, Shelby L.; Zink, M. Christine; Mankowski, Joseph L.; Gama, Lucio

    2016-01-01

    ABSTRACT Despite the success of combined antiretroviral therapy (ART), human immunodeficiency virus (HIV) infection remains a lifelong infection because of latent viral reservoirs in infected patients. The contribution of CD4+ T cells to infection and disease progression has been extensively studied. However, during early HIV infection, macrophages in brain and other tissues are infected and contribute to tissue-specific diseases, such as encephalitis and dementia in brain and pneumonia in lung. The extent of infection of monocytes and macrophages has not been rigorously assessed with assays comparable to those used to study infection of CD4+ T cells and to evaluate the number of CD4+ T cells that harbor infectious viral genomes. To assess the contribution of productively infected monocytes and macrophages to HIV- and simian immunodeficiency virus (SIV)-infected cells in vivo, we developed a quantitative virus outgrowth assay (QVOA) based on similar assays used to quantitate CD4+ T cell latent reservoirs in HIV- and SIV-infected individuals in whom the infection is suppressed by ART. Myeloid cells expressing CD11b were serially diluted and cocultured with susceptible cells to amplify virus. T cell receptor β RNA was measured as a control to assess the potential contribution of CD4+ T cells in the assay. Virus production in the supernatant was quantitated by quantitative reverse transcription-PCR. Productively infected myeloid cells were detected in blood, bronchoalveolar lavage fluid, lungs, spleen, and brain, demonstrating that these cells persist throughout SIV infection and have the potential to contribute to the viral reservoir during ART. IMPORTANCE Infection of CD4+ T cells and their role as latent reservoirs have been rigorously assessed; however, the frequency of productively infected monocytes and macrophages in vivo has not been similarly studied. Myeloid cells, unlike lymphocytes, are resistant to the cytopathic effects of HIV. Moreover, tissue

  15. STAT1 Signaling within Macrophages Is Required for Antifungal Activity against Cryptococcus neoformans

    PubMed Central

    Leopold Wager, Chrissy M.; Hole, Camaron R.; Wozniak, Karen L.; Olszewski, Michal A.; Mueller, Mathias

    2015-01-01

    Cryptococcus neoformans, the predominant etiological agent of cryptococcosis, is an opportunistic fungal pathogen that primarily affects AIDS patients and patients undergoing immunosuppressive therapy. In immunocompromised individuals, C. neoformans can lead to life-threatening meningoencephalitis. Studies using a virulent strain of C. neoformans engineered to produce gamma interferon (IFN-γ), denoted H99γ, demonstrated that protection against pulmonary C. neoformans infection is associated with the generation of a T helper 1 (Th1)-type immune response and signal transducer and activator of transcription 1 (STAT1)-mediated classical (M1) macrophage activation. However, the critical mechanism by which M1 macrophages mediate their anti-C. neoformans activity remains unknown. The current studies demonstrate that infection with C. neoformans strain H99γ in mice with macrophage-specific STAT1 ablation resulted in severely increased inflammation of the pulmonary tissue, a dysregulated Th1/Th2-type immune response, increased fungal burden, deficient M1 macrophage activation, and loss of protection. STAT1-deficient macrophages produced significantly less nitric oxide (NO) than STAT1-sufficient macrophages, correlating with an inability to control intracellular cryptococcal proliferation, even in the presence of reactive oxygen species (ROS). Furthermore, macrophages from inducible nitric oxide synthase knockout mice, which had intact ROS production, were deficient in anticryptococcal activity. These data indicate that STAT1 activation within macrophages is required for M1 macrophage activation and anti-C. neoformans activity via the production of NO. PMID:26351277

  16. Changes in lymphocyte and macrophage subsets due to morphine and ethanol treatment during a retrovirus infection causing murine AIDS

    SciTech Connect

    Watson, R.R.; Prabhala, R.H.; Darban, H.R.; Yahya, M.D.; Smith, T.L.

    1988-01-01

    The number of lymphocytes of various subsets were not significantly changed by the ethanol exposure except those showing activation markers which were reduced. The percentage of peripheral blood cells showing markers for macrophage functions and their activation were significantly reduced after binge use of ethanol. Ethanol retarded suppression of cells by retroviral infection. However by 25 weeks of infection there was a 8.6% survival in the ethanol fed mice infected with retrovirus which was much less than virally infected controls. Morphine treatment also increased the percentage of cells with markers for macrophages and activated macrophages in virally infected mice, while suppressing them in uninfected mice. The second and third morphine injection series suppressed lymphocyte T-helper and T-suppressor cells, but not total T cells. However, suppression by morphine was significantly less during retroviral disease than suppression caused by the virus only. At 25 weeks of infection 44.8% of morphine treated, infected mice survived.

  17. Asc-Dependent and Independent Mechanisms Contribute to Restriction of Legionella Pneumophila Infection in Murine Macrophages

    PubMed Central

    Abdelaziz, Dalia H. A.; Gavrilin, Mikhail A.; Akhter, Anwari; Caution, Kyle; Kotrange, Sheetal; Khweek, Arwa Abu; Abdulrahman, Basant A.; Hassan, Zeinab A.; El-Sharkawi, Fathia Z.; Bedi, Simranjit S.; Ladner, Katherine; Gonzalez-Mejia, M. Elba; Doseff, Andrea I.; Mostafa, Mahmoud; Kanneganti, Thirumala-Devi; Guttridge, Dennis; Marsh, Clay B.; Wewers, Mark D.; Amer, Amal O.

    2010-01-01

    The apoptosis-associated speck-like protein containing a caspase recruitment domain (Asc) is an adaptor molecule that mediates inflammatory and apoptotic signals. Legionella pneumophila is an intracellular bacterium and the causative agent of Legionnaire's pneumonia. L. pneumophila is able to cause pneumonia in immuno-compromised humans but not in most inbred mice. Murine macrophages that lack the ability to activate caspase-1, such as caspase-1−/− and Nlrc4−/− allow L. pneumophila infection. This permissiveness is attributed mainly to the lack of active caspase-1 and the absence of its down stream substrates such as caspase-7. However, the role of Asc in control of L. pneumophila infection in mice is unclear. Here we show that caspase-1 is moderately activated in Asc−/− macrophages and that this limited activation is required and sufficient to restrict L. pneumophila growth. Moreover, Asc-independent activation of caspase-1 requires bacterial flagellin and is mainly detected in cellular extracts but not in culture supernatants. We also demonstrate that the depletion of Asc from permissive macrophages enhances bacterial growth by promoting L. pneumophila-mediated activation of the NF-κB pathway and decreasing caspase-3 activation. Taken together, our data demonstrate that L. pneumophila infection in murine macrophages is controlled by several mechanisms: Asc-independent activation of caspase-1 and Asc-dependent regulation of NF-κB and caspase-3 activation. PMID:21713115

  18. Dysregulation of Macrophage Activation Profiles by Engineered Nanoparticles

    SciTech Connect

    Kodali, Vamsi; Littke, Matthew H.; Tilton, Susan C.; Teeguarden, Justin G.; Shi, Liang; Frevert, Charles W.; Wang, Wei; Pounds, Joel G.; Thrall, Brian D.

    2013-08-27

    Although the potential human health impacts from exposure to engineered nanoparticles (ENPs) are uncertain, past epidemiological studies have established correlations between exposure to ambient air pollution particulates and the incidence of pneumonia and lung infections. Using amorphous silica and superparamagnetic iron oxide (SPIO) as model high production volume ENPs, we examined how macrophage activation by bacterial lipopolysaccharide (LPS) or the lung pathogen Streptococcus pneumoniae is altered by ENP pretreatment. Neither silica nor SPIO treatment elicited direct cytotoxic or pro-inflammatory effects in bone marrow-derived macrophages. However, pretreatment of macrophages with SPIO caused extensive reprogramming of nearly 500 genes regulated in response to LPS challenge, hallmarked by exaggerated activation of oxidative stress response pathways and suppressed activation of both pro- and anti-inflammatory pathways. Silica pretreatment altered regulation of only 67 genes, but there was strong correlation with gene sets affected by SPIO. Macrophages exposed to SPIO displayed a phenotype suggesting an impaired ability to transition from an M1 to M2-like activation state, characterized by suppressed IL-10 induction, enhanced TNFα production, and diminished phagocytic activity toward S. pneumoniae. Studies in macrophages deficient in scavenger receptor A (SR-A) showed SR-A participates in cell uptake of both the ENPs and S. pneumonia and co-regulates the anti-inflammatory IL-10 pathway. Thus, mechanisms for dysregulation of innate immunity exist by virtue that common receptor recognition pathways are used by some ENPs and pathogenic bacteria, although the extent of transcriptional reprogramming of macrophage function depends on the physicochemical properties of the ENP after internalization. Our results also illustrate that biological effects of ENPs may be indirectly manifested only after challenging normal cell function. Finally, nanotoxicology screening

  19. Role of macrophages in the altered epithelial function during a type 2 immune response induced by enteric nematode infection.

    PubMed

    Notari, Luigi; Riera, Diana C; Sun, Rex; Bohl, Jennifer A; McLean, Leon P; Madden, Kathleen B; van Rooijen, Nico; Vanuytsel, Tim; Urban, Joseph F; Zhao, Aiping; Shea-Donohue, Terez

    2014-01-01

    Parasitic enteric nematodes induce a type 2 immune response characterized by increased production of Th2 cytokines, IL-4 and IL-13, and recruitment of alternatively activated macrophages (M2) to the site of infection. Nematode infection is associated with changes in epithelial permeability and inhibition of sodium-linked glucose absorption, but the role of M2 in these effects is unknown. Clodronate-containing liposomes were administered prior to and during nematode infection to deplete macrophages and prevent the development of M2 in response to infection with Nippostrongylus brasiliensis. The inhibition of epithelial glucose absorption that is associated with nematode infection involved a macrophage-dependent reduction in SGLT1 activity, with no change in receptor expression, and a macrophage-independent down-regulation of GLUT2 expression. The reduced transport of glucose into the enterocyte is compensated partially by an up-regulation of the constitutive GLUT1 transporter consistent with stress-induced activation of HIF-1α. Thus, nematode infection results in a "lean" epithelial phenotype that features decreased SGLT1 activity, decreased expression of GLUT2 and an emergent dependence on GLUT1 for glucose uptake into the enterocyte. Macrophages do not play a role in enteric nematode infection-induced changes in epithelial barrier function. There is a greater contribution, however, of paracellular absorption of glucose to supply the energy demands of host resistance. These data provide further evidence of the ability of macrophages to alter glucose metabolism of neighboring cells.

  20. Leishmania-infected macrophages sequester endogenously synthesized parasite antigens from presentation to CD4+ T cells.

    PubMed

    Kima, P E; Soong, L; Chicharro, C; Ruddle, N H; McMahon-Pratt, D

    1996-12-01

    CD4+ T cell lines raised against the protective leishmanial antigens GP46 and P8 were used to study the presentation of endogenously synthesized Leishmania antigens by infected cells. Using two different sources of macrophages, the I4.07 macrophage cell line (H-2k) which constitutively expresses major histocompatibility complex (MHC) class II molecules, and elicited peritoneal exudate cells, we found that cells infected with Leishmania amastigotes presented little, if any endogenously synthesized parasite antigens to CD4+ T cells. In contrast, promastigote-infected macrophages did present endogenous parasite molecules to CD4+ T cells, although only for a limited time, with maximal presentation occurring within 24 h of infection and decreasing to minimal antigen presentation at 72 h post-infection. These observations suggest that once within the macrophage, Leishmania amastigote antigens are sequestered from the MHC class II pathway of antigen presentation. This allows live parasites to persist in infected hosts by evading the activation of CD4+ T cells, a major and critical anti-leishmanial component of the host immune system. Studies with drugs that modify fusion patterns of phagosomes suggest that the mechanism of this antigen sequestration includes targeted fusion of the parasitophorous vacuole with certain endocytic compartments.

  1. Susceptibility of mouse macrophage J774 to dengue virus infection.

    PubMed

    Moreno-Altamirano, María M B; Sánchez-García, F Javier; Legorreta-Herrera, Martha; Aguilar-Carmona, Israel

    2007-01-01

    The aim of this study was to investigate whether the J774 mouse macrophage cell line could be used as an in vitro model for dengue virus infection (DENV). After 3 days, infection in J774 cells was assessed by detecting dengue virus non-structural protein 1 (NSP-1) production either by dot blot or indirect immunofluorescence assay (IFA) of saponine-permeabilized J774 cells and then confirmed by RT-PCR (171 bp product, corresponding to the DENV-2 core). Based on the presence of NSP-1 in infected but not in non-infected cells by both IFA and dot blot, as well as the amplification of a 171-bp DENV-2-specific RT-PCR product exclusively in the infected cells, the J774 cell line was found to be permissive for dengue virus infection. As far as we know, this is the first report that the J774 mouse macrophage cell line is infected with dengue virus and, thus, that it can be used as an alternative in vitro model for dengue virus infection studies. This finding could help to further elucidate the mechanisms involved in dengue virus infection and pathogenesis. PMID:17356302

  2. Rickettsia australis Activates Inflammasome in Human and Murine Macrophages

    PubMed Central

    Smalley, Claire; Bechelli, Jeremy; Rockx-Brouwer, Dedeke; Saito, Tais; Azar, Sasha R.; Ismail, Nahed; Walker, David H.; Fang, Rong

    2016-01-01

    Rickettsiae actively escape from vacuoles and replicate free in the cytoplasm of host cells, where inflammasomes survey the invading pathogens. In the present study, we investigated the interactions of Rickettsia australis with the inflammasome in both mouse and human macrophages. R. australis induced a significant level of IL-1β secretion by human macrophages, which was significantly reduced upon treatment with an inhibitor of caspase-1 compared to untreated controls, suggesting caspase-1-dependent inflammasome activation. Rickettsia induced significant secretion of IL-1β and IL-18 in vitro by infected mouse bone marrow-derived macrophages (BMMs) as early as 8–12 h post infection (p.i.) in a dose-dependent manner. Secretion of these cytokines was accompanied by cleavage of caspase-1 and was completely abrogated in BMMs deficient in caspase-1/caspase-11 or apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), suggesting that R. australis activate the ASC-dependent inflammasome. Interestingly, in response to the same quantity of rickettsiae, NLRP3-/- BMMs significantly reduced the secretion level of IL-1β compared to wild type (WT) controls, suggesting that NLRP3 inflammasome contributes to cytosolic recognition of R. australis in vitro. Rickettsial load in spleen, but not liver and lung, of R. australis-infected NLRP3-/- mice was significantly greater compared to WT mice. These data suggest that NLRP3 inflammasome plays a role in host control of bacteria in vivo in a tissue-specific manner. Taken together, our data, for the first time, illustrate the activation of ASC-dependent inflammasome by R. australis in macrophages in which NLRP3 is involved. PMID:27362650

  3. Modulation of Stat-1 in Human Macrophages Infected with Different Species of Intracellular Pathogenic Bacteria

    PubMed Central

    Dominici, Sabrina; Rinaldi, Laura; Cangiano, Alfonsina Mariarosaria; Brandi, Giorgio; Magnani, Mauro

    2016-01-01

    The infection of human macrophages by pathogenic bacteria induces different signaling pathways depending on the type of cellular receptors involved in the microorganism entry and on their mechanism(s) of survival and replication in the host cell. It was reported that Stat proteins play an important role in this process. In the present study, we investigate the changes in Stat-1 activation (phosphorylation in p-tyr701) after uptake of two Gram-positive (Listeria monocytogenes and Staphylococcus aureus) and two Gram-negative bacteria (Salmonella typhimurium and Legionella pneumophila) characterized by their varying abilities to enter, survive, and replicate in human macrophages. Comparing the results obtained with Gram-negative and Gram-positive bacteria, Stat-1 activation in macrophages does not seem to be related to LPS content. The p-tyr701Stat-1 expression levels were found to be independent of the internalized bacterial number and IFN-γ release. On the contrary, Jak/Stat-1 pathway activation only occurs when an active infection has been established in the host macrophage, and it is plausible that the differences in the expression levels of p-tyr701Stat-1 could be due to different survival mechanisms or to differences in bacteria life cycles within macrophages. PMID:27437406

  4. Modulation of Stat-1 in Human Macrophages Infected with Different Species of Intracellular Pathogenic Bacteria.

    PubMed

    Schiavano, Giuditta Fiorella; Dominici, Sabrina; Rinaldi, Laura; Cangiano, Alfonsina Mariarosaria; Brandi, Giorgio; Magnani, Mauro

    2016-01-01

    The infection of human macrophages by pathogenic bacteria induces different signaling pathways depending on the type of cellular receptors involved in the microorganism entry and on their mechanism(s) of survival and replication in the host cell. It was reported that Stat proteins play an important role in this process. In the present study, we investigate the changes in Stat-1 activation (phosphorylation in p-tyr701) after uptake of two Gram-positive (Listeria monocytogenes and Staphylococcus aureus) and two Gram-negative bacteria (Salmonella typhimurium and Legionella pneumophila) characterized by their varying abilities to enter, survive, and replicate in human macrophages. Comparing the results obtained with Gram-negative and Gram-positive bacteria, Stat-1 activation in macrophages does not seem to be related to LPS content. The p-tyr701Stat-1 expression levels were found to be independent of the internalized bacterial number and IFN-γ release. On the contrary, Jak/Stat-1 pathway activation only occurs when an active infection has been established in the host macrophage, and it is plausible that the differences in the expression levels of p-tyr701Stat-1 could be due to different survival mechanisms or to differences in bacteria life cycles within macrophages. PMID:27437406

  5. Role of Macrophage Scavenger Receptors in Response to Listeria monocytogenes Infection in Mice

    PubMed Central

    Ishiguro, Takuro; Naito, Makoto; Yamamoto, Takashi; Hasegawa, Go; Gejyo, Fumitake; Mitsuyama, Masao; Suzuki, Hiroshi; Kodama, Tatsuhiko

    2001-01-01

    Type I and type II macrophage scavenger receptors (SR-A I/II) recognize a variety of polyanions including bacterial cell-wall products such as lipopolysaccharide, suggesting a role for SR-A I/II in immunity against bacterial infection. SR-A I/II-deficient (MSR-A−/−) mice were more susceptible to infection with listeriolysin-O (LLO)-producing Listeria monocytogenes. After infection, Kupffer cells in wild-type (MSR-A+/+) mice phagocytized larger numbers of Listeria than those in MSR-A−/− mice. The number and the diameter of hepatic granulomas were larger in MSR-A−/− mice than MSR-A+/+ mice. L. monocytogenes replicated at higher levels in the liver of MSR-A−/− mice compared with MSR-A+/+ mice, and macrophages from MSR-A−/− mice showed impaired ability to kill Listeria in vitro. However, macrophages from MSR-A+/+ and MSR-A−/− mice showed similar levels of listericidal activity against isogenic mutant L. monocytogenes with an inactivated LLO gene. The listerial phagocytic activities of MSR-A+/+ macrophages treated with an anti-SR-A I/II antibody (2F8) and MSR-A−/− macrophages were significantly impaired compared with untreated MSR-A+/+ macrophages, indicating that SR-A I/II function as a receptor for L. monocytogenes. Electron microscopy revealed that most L. monocytogenes had been eliminated from the lysosomes of MSR-A+/+ macrophages in vivo and in vitro. In contrast, L. monocytogenes rapidly lysed the phagosomal membrane and escaped to the cytosol in MSR-A−/− macrophages and in MSR-A+/+ macrophages treated with 2F8 before phagosome-lysosome fusion. These findings imply that SR-A I/II plays a crucial role in host defense against listerial infection not only by functioning as a receptor but also by mediating listericidal mechanisms through the regulation of LLO-dependent listerial escape from the macrophages. PMID:11141491

  6. Induction of Mycobacterium avium proteins upon infection of human macrophages.

    PubMed

    Brunori, Lara; Giannoni, Federico; Bini, Luca; Liberatori, Sabrina; Frota, Cristiane; Jenner, Peter; Thoresen, Ove Fredrik; Orefici, Graziella; Fattorini, Lanfranco

    2004-10-01

    Induction of Mycobacterium avium proteins labelled with [35S]methionine and mRNAs upon infection of the human macrophage cell line THP-1 was investigated by two-dimensional gel electrophoresis-mass spectrometry and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. M. avium overexpressed proteins within the macrophages that are involved in fatty acids metabolism (FadE2, FixA), cell wall synthesis (KasA), and protein synthesis (EF-tu). The correlation of differential protein and mRNA expression varied between good and no correlation. Overall, these four proteins may be involved in the adaptation and survival of M. avium within human macrophages. PMID:15378697

  7. Dysfunctional CFTR alters the bactericidal activity of human macrophages against Pseudomonas aeruginosa.

    PubMed

    Del Porto, Paola; Cifani, Noemi; Guarnieri, Simone; Di Domenico, Enea Gino; Mariggiò, Maria A; Spadaro, Francesca; Guglietta, Silvia; Anile, Marco; Venuta, Federico; Quattrucci, Serena; Ascenzioni, Fiorentina

    2011-01-01

    Chronic inflammation of the lung, as a consequence of persistent bacterial infections by several opportunistic pathogens represents the main cause of mortality and morbidity in cystic fibrosis (CF) patients. Mechanisms leading to increased susceptibility to bacterial infections in CF are not completely known, although the involvement of cystic fibrosis transmembrane conductance regulator (CFTR) in microbicidal functions of macrophages is emerging. Tissue macrophages differentiate in situ from infiltrating monocytes, additionally, mature macrophages from different tissues, although having a number of common activities, exhibit variation in some molecular and cellular functions. In order to highlight possible intrinsic macrophage defects due to CFTR dysfunction, we have focused our attention on in vitro differentiated macrophages from human peripheral blood monocytes. Here we report on the contribution of CFTR in the bactericidal activity against Pseudomonas aeruginosa of monocyte derived human macrophages. At first, by real time PCR, immunofluorescence and patch clamp recordings we demonstrated that CFTR is expressed and is mainly localized to surface plasma membranes of human monocyte derived macrophages (MDM) where it acts as a cAMP-dependent chloride channel. Next, we evaluated the bactericidal activity of P. aeruginosa infected macrophages from healthy donors and CF patients by antibiotic protection assays. Our results demonstrate that control and CF macrophages do not differ in the phagocytic activity when infected with P. aeruginosa. Rather, although a reduction of intracellular live bacteria was detected in both non-CF and CF cells, the percentage of surviving bacteria was significantly higher in CF cells. These findings further support the role of CFTR in the fundamental functions of innate immune cells including eradication of bacterial infections by macrophages.

  8. Bactericidal Activity of Human Macrophages: Analysis of Factors Influencing the Killing of Listeria monocytogenes

    PubMed Central

    Cline, Martin J.

    1970-01-01

    A technique is described for the measurement of listericidal activity of human macrophages grown from blood monocytes. Phagocytosis of Listeria monocytogenes was inhibited by a glycolytic poison (NaF) but was unaffected by anaerobic conditions, cyanide, or 2,4-dinitrophenol (DNP). Killing by macrophages was slower than that by neutrophils, and Listeria phagocytized by macrophages began to synthesize deoxyribonucleic acid within 3 hr of the time of ingestion. Differentiated macrophages ingested and killed more organisms per cell than newly isolated monocytes. Maximal killing of Listeria required oxygen but was unaffected by cyanide or DNP. Macrophages isolated from patients with chronic intracellular infection (leprosy, tuberculosis, fungal diseases) and from patients with active Hodgkin's disease were more bactericidal than macrophages from normal subjects. Images PMID:16557814

  9. Alternative activation deprives macrophages of a coordinated defense program to Mycobacterium tuberculosis.

    PubMed

    Kahnert, Antje; Seiler, Peter; Stein, Maik; Bandermann, Silke; Hahnke, Karin; Mollenkopf, Hans; Kaufmann, Stefan H E

    2006-03-01

    A potent Th1 immune response is critical to the control of tuberculosis. The impact of an additive Th2 response on the course of disease has so far been insufficiently characterized, despite increased morbidity after co-infection with Mycobacterium tuberculosis and Th2-eliciting helminths and possible involvement of Th2 polarization in reactivation of latent tuberculosis. Here, we describe the gene expression profile of murine bone marrow-derived macrophages alternatively activated by IL-4 in response to infection with M. tuberculosis. Comparison of transcriptional profiles of infected IL-4- and IFN-gamma-activated macrophages revealed delayed and partially diminished responses to intracellular bacteria in alternatively activated macrophages, characterized by reduced exposure to nitrosative stress and increased iron availability, respectively. Alternative activation of host macrophages correlated with elevated expression of the M. tuberculosis iron storage protein bacterioferritin as well as reduced expression of the mycobactin synthesis genes mbtI and mbtJ. The extracellular matrix-remodeling enzyme matrix metalloproteinase (MMP)-12 was induced in alternatively activated macrophages in vitro, and MMP-12-expressing macrophages were abundant at late, but not early, stages of tuberculosis in murine lungs. Our findings emphasize that alternative activation deprives macrophages of control mechanisms that limit mycobacterial growth in vivo, thus supporting intracellular persistence of M. tuberculosis. PMID:16479545

  10. NMAAP1 Expressed in BCG-Activated Macrophage Promotes M1 Macrophage Polarization.

    PubMed

    Liu, Qihui; Tian, Yuan; Zhao, Xiangfeng; Jing, Haifeng; Xie, Qi; Li, Peng; Li, Dong; Yan, Dongmei; Zhu, Xun

    2015-10-01

    Macrophages are divided into two subpopulations: classically activated macrophages (M1) and alternatively activated macrophages (M2). BCG (Bacilli Calmette-GuC)rin) activates disabled naC/ve macrophages to M1 macrophages, which act as inflammatory, microbicidal and tumoricidal cells through cell-cell contact and/or the release of soluble factors. Various transcription factors and signaling pathways are involved in the regulation of macrophage activation and polarization. We discovered that BCG-activated macrophages (BAM) expressed a new molecule, and we named it Novel Macrophage Activated Associated Protein 1 (NMAAP1). The current study found that the overexpression of NMAAP1 in macrophages results in M1 polarization with increased expression levels of M1 genes, such as inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-N1), Interleukin 6 (IL-6), Interleukin 12 (IL-12), Monocyte chemoattractant protein-1 (MCP-1) and Interleukin-1 beta (IL-1N2), and decreased expression of some M2 genes, such as Kruppel-like factor 4 (KLF4) and suppressor of cytokine signaling 1 (SOCS1), but not other M2 genes, including arginase-1 (Arg-1), Interleukin (IL-10), transforming growth factor beta (TGF-N2) and found in inflammatory zone 1 (Fizz1). Moreover, NMAAP1 overexpression in the RAW264.7 cell line increased cytotoxicity against MCA207 tumor cells, which depends on increased inflammatory cytokines rather than cell-cell contact. NMAAP1 also substantially enhanced the phagocytic ability of macrophages, which implies that NMAAP1 promoted macrophage adhesive and clearance activities. Our results indicate that NMAAP1 is an essential molecule that modulates macrophages phenotype and plays an important role in macrophage tumoricidal functions.

  11. Cholesteryl ester hydrolase activity is abolished in HSL-/- macrophages but unchanged in macrophages lacking KIAA1363.

    PubMed

    Buchebner, Marlene; Pfeifer, Thomas; Rathke, Nora; Chandak, Prakash G; Lass, Achim; Schreiber, Renate; Kratzer, Adelheid; Zimmermann, Robert; Sattler, Wolfgang; Koefeler, Harald; Fröhlich, Eleonore; Kostner, Gerhard M; Birner-Gruenberger, Ruth; Chiang, Kyle P; Haemmerle, Guenter; Zechner, Rudolf; Levak-Frank, Sanja; Cravatt, Benjamin; Kratky, Dagmar

    2010-10-01

    Cholesteryl ester (CE) accumulation in macrophages represents a crucial event during foam cell formation, a hallmark of atherogenesis. Here we investigated the role of two previously described CE hydrolases, hormone-sensitive lipase (HSL) and KIAA1363, in macrophage CE hydrolysis. HSL and KIAA1363 exhibited marked differences in their abilities to hydrolyze CE, triacylglycerol (TG), diacylglycerol (DG), and 2-acetyl monoalkylglycerol ether (AcMAGE), a precursor for biosynthesis of platelet-activating factor (PAF). HSL efficiently cleaved all four substrates, whereas KIAA1363 hydrolyzed only AcMAGE. This contradicts previous studies suggesting that KIAA1363 is a neutral CE hydrolase. Macrophages of KIAA1363(-/-) and wild-type mice exhibited identical neutral CE hydrolase activity, which was almost abolished in tissues and macrophages of HSL(-/-) mice. Conversely, AcMAGE hydrolase activity was diminished in macrophages and some tissues of KIAA1363(-/-) but unchanged in HSL(-/-) mice. CE turnover was unaffected in macrophages lacking KIAA1363 and HSL, whereas cAMP-dependent cholesterol efflux was influenced by HSL but not by KIAA1363. Despite decreased CE hydrolase activities, HSL(-/-) macrophages exhibited CE accumulation similar to wild-type (WT) macrophages. We conclude that additional enzymes must exist that cooperate with HSL to regulate CE levels in macrophages. KIAA1363 affects AcMAGE hydrolase activity but is of minor importance as a direct CE hydrolase in macrophages.

  12. MMP-10 Regulates Collagenolytic Activity of Alternatively Activated Resident Macrophages

    PubMed Central

    Rohani, Maryam G.; McMahan, Ryan S.; Razumova, Maria V.; Hertz, Angie L.; Cieslewicz, Maryelise; Pun, Suzie H.; Regnier, Michael; Wang, Ying; Birkland, Timothy P.; Parks, William C.

    2015-01-01

    MMP-10 is expressed by macrophages and epithelium in response to injury, but its functions in wound repair are unknown. We observed increased collagen deposition and skin stiffness in Mmp10−/− wounds with no difference in collagen expression or re-epithelialization. Increased collagen deposition in Mmp10−/− wounds was accompanied by less collagenolytic activity and reduced expression of specific metallocollagenases, particularly MMP-8 and MMP-13, where MMP-13 was the key collagenase. Ablation and adoptive transfer approaches and cell-based models demonstrated that the MMP-10-dependent collagenolytic activity was a product of alternatively activated (M2) resident macrophages. These data demonstrate a critical role for macrophage MMP-10 in controlling the tissue remodeling activity of macrophages and moderating scar formation during wound repair. PMID:25927164

  13. Distinct Macrophage Fates after in vitro Infection with Different Species of Leishmania: Induction of Apoptosis by Leishmania (Leishmania) amazonensis, but Not by Leishmania (Viannia) guyanensis

    PubMed Central

    DaMata, Jarina Pena; Mendes, Bárbara Pinheiro; Maciel-Lima, Kátia; Menezes, Cristiane Alves Silva; Dutra, Walderez Ornelas; Sousa, Lirlândia Pires; Horta, Maria Fátima

    2015-01-01

    Leishmania is an intracellular parasite in vertebrate hosts, including man. During infection, amastigotes replicate inside macrophages and are transmitted to healthy cells, leading to amplification of the infection. Although transfer of amastigotes from infected to healthy cells is a crucial step that may shape the outcome of the infection, it is not fully understood. Here we compare L. amazonensis and L. guyanensis infection in C57BL/6 and BALB/c mice and investigate the fate of macrophages when infected with these species of Leishmania in vitro. As previously shown, infection of mice results in distinct outcomes: L. amazonensis causes a chronic infection in both strains of mice (although milder in C57BL/6), whereas L. guyanensis does not cause them disease. In vitro, infection is persistent in L. amazonensis-infected macrophages whereas L. guyanensis growth is controlled by host cells from both strains of mice. We demonstrate that, in vitro, L. amazonensis induces apoptosis of both C57BL/6 and BALB/c macrophages, characterized by PS exposure, DNA cleavage into nucleosomal size fragments, and consequent hypodiploidy. None of these signs were seen in macrophages infected with L. guyanensis, which seem to die through necrosis, as indicated by increased PI-, but not Annexin V-, positive cells. L. amazonensis-induced macrophage apoptosis was associated to activation of caspases-3, -8 and -9 in both strains of mice. Considering these two species of Leishmania and strains of mice, macrophage apoptosis, induced at the initial moments of infection, correlates with chronic infection, regardless of its severity. We present evidence suggestive that macrophages phagocytize L. amazonensis-infected cells, which has not been verified so far. The ingestion of apoptotic infected macrophages by healthy macrophages could be a way of amastigote spreading, leading to the establishment of infection. PMID:26513474

  14. Distinct Macrophage Fates after in vitro Infection with Different Species of Leishmania: Induction of Apoptosis by Leishmania (Leishmania) amazonensis, but Not by Leishmania (Viannia) guyanensis.

    PubMed

    DaMata, Jarina Pena; Mendes, Bárbara Pinheiro; Maciel-Lima, Kátia; Menezes, Cristiane Alves Silva; Dutra, Walderez Ornelas; Sousa, Lirlândia Pires; Horta, Maria Fátima

    2015-01-01

    Leishmania is an intracellular parasite in vertebrate hosts, including man. During infection, amastigotes replicate inside macrophages and are transmitted to healthy cells, leading to amplification of the infection. Although transfer of amastigotes from infected to healthy cells is a crucial step that may shape the outcome of the infection, it is not fully understood. Here we compare L. amazonensis and L. guyanensis infection in C57BL/6 and BALB/c mice and investigate the fate of macrophages when infected with these species of Leishmania in vitro. As previously shown, infection of mice results in distinct outcomes: L. amazonensis causes a chronic infection in both strains of mice (although milder in C57BL/6), whereas L. guyanensis does not cause them disease. In vitro, infection is persistent in L. amazonensis-infected macrophages whereas L. guyanensis growth is controlled by host cells from both strains of mice. We demonstrate that, in vitro, L. amazonensis induces apoptosis of both C57BL/6 and BALB/c macrophages, characterized by PS exposure, DNA cleavage into nucleosomal size fragments, and consequent hypodiploidy. None of these signs were seen in macrophages infected with L. guyanensis, which seem to die through necrosis, as indicated by increased PI-, but not Annexin V-, positive cells. L. amazonensis-induced macrophage apoptosis was associated to activation of caspases-3, -8 and -9 in both strains of mice. Considering these two species of Leishmania and strains of mice, macrophage apoptosis, induced at the initial moments of infection, correlates with chronic infection, regardless of its severity. We present evidence suggestive that macrophages phagocytize L. amazonensis-infected cells, which has not been verified so far. The ingestion of apoptotic infected macrophages by healthy macrophages could be a way of amastigote spreading, leading to the establishment of infection. PMID:26513474

  15. Human cytomegalovirus and Epstein–Barr virus inhibit oral bacteria-induced macrophage activation and phagocytosis

    PubMed Central

    Lin, Y.-L.; Li, M.

    2016-01-01

    Introduction Periodontal disease is an inflammatory condition caused by periodontal microorganisms. Viruses such as human cytomegalovirus (HCMV) and Epstein–Barr virus (EBV) are associated with certain types of periodontal disease, but their roles in promoting the disease are unclear. Because both viruses infect human macrophages, cells which play key roles in the clearance of pathogenic bacteria, it is likely that the viruses alter the functional capacity of macrophages by inhibiting their defense mechanisms against invading pathogens. Methods Macrophages preinfected with HCMV or EBV were evaluated following stimulation by selected oral bacteria. Bacteria-induced macrophage activation was assayed by measuring the levels of tumor necrosis factor-α (TNF-α) produced in the media, and phagocytic activity was analysed by a phagocytosis assay with fluorescein isothiocyanate-labeled bacteria. The virus-infected macrophages were also subjected to semi-quantitative polymerase chain reaction to measure the expression of toll-like receptor 9, which is involved in the activation of phagocytosis-related pathways. Results Both HCMV and EBV significantly diminished the TNF-α production typically induced by oral bacteria, inhibited the phagocytic activity of macrophages, and downregulated the expression of toll-like receptor 9. Conclusion Infection by HCMV or EBV inhibits the functional ability of macrophages to respond to bacterial challenge, thereby suggesting their pathogenic role in the development of periodontal disease. PMID:19416455

  16. Adenosine triphosphate released from HIV-infected macrophages regulates glutamatergic tone and dendritic spine density on neurons

    PubMed Central

    Tovar-y-Romo, Luis B.; Kolson, Dennis L.; Bandaru, Veera Venkata Ratnam; Drewes, Julia; Graham, David R.; Haughey, Norman J.

    2013-01-01

    Despite wide spread use of combination antiretroviral therapy (cART) in developed countries, approximately half of HIV-infected patients will develop impairments in cognitive function. Accumulating evidence suggests that neuronal dysfunction can be precipitated by HIV-infection of macrophages by mechanisms that involve alterations in innate and adaptive immune responses. HIV-infection of macrophages is known to increase the release of soluble neurotoxins. However, the composition of products released from infected macrophages is complex and not fully known. In this study we provide evidence that ATP and other immuno-/neuromodulatory nucleotides are exported from HIV-infected macrophages and modify neuronal structure. Supernatants collected from HIV-infected macrophages (HIV/MDM) contained large amounts of ATP, ADP, AMP and small amounts of adenosine, in addition to glutamate. Dilutions of these supernatants that were sub-threshold for glutamate receptor activation evoked rapid calcium flux in neurons that were completely inhibited by the enzymatic degradation of ATP, or by blockade of calcium permeable purinergic receptors. Applications of these high-dilution HIV/MDM onto neuronal cultures increased the amount of extracellular glutamate by mechanisms dependent on purinergic receptor activation, and downregulated spine density on neurons by mechanisms dependent on purinergic and glutamate receptor activation. We conclude from these data that ATP released from HIV-infected macrophages downregulates dendritic spine density on neurons by a mechanism that involves purinergic receptor mediated modulation of glutamatergic tone. These data suggest that neuronal function may be depressed in HIV infected individuals by mechanisms that involve macrophage release of ATP that triggers secondary effects on glutamate handling. PMID:23686368

  17. Intrinsic resistance of feline peritoneal macrophages to coronavirus infection correlates with in vivo virulence.

    PubMed

    Stoddart, C A; Scott, F W

    1989-01-01

    Cats infected with virulent feline coronavirus strains develop feline infectious peritonitis, an invariably fatal, immunologically mediated disease; avirulent strains cause either clinically inapparent infection or mild enteritis. Four virulent coronavirus isolates and five avirulent isolates were assessed by immunofluorescence and virus titration for their ability to infect and replicate in feline peritoneal macrophages in vitro. The avirulent coronaviruses infected fewer macrophages, produced lower virus titers, were less able to sustain viral replication, and spread less efficiently to other susceptible macrophages than the virulent coronaviruses. Thus, the intrinsic resistance of feline macrophages may play a pivotal role in the outcome of coronavirus infection in vivo.

  18. In vitro expression of IL-1α, GM-CSF, and TNF-α by multinucleated macrophages from BCG-infected mice.

    PubMed

    Iljine, D A; Arkhipov, S A; Shkurupy, V A

    2013-09-01

    Peritoneal cells from intact and BCG-infected mice were explanted in vitro. In these cultures, multinucleated macrophages in different number of nuclei were formed. The intensity of multinucleated cell formation was higher in cultures from BCG-infected mice. Increasing role of amitosis in the formation of multinucleated macrophages with relatively high number of nuclei was noted with presumable domination of cell fusion mechanism. Relatively high level of IL-1α expression was noted only in the population of binucleated macrophages of BCG-infected mice in comparison with mononuclear cells. It was found macrophages from BCG-infected mice demonstrate a kind of "lineage commitment" towards multinucleated cells, which manifested in culture in initially high and increasing (with increasing the number of nuclei in cells) expression of granulocyte-macrophage CSF and TNF-α as well as initially high amitotic activity of macrophages.

  19. Vocal Fold Fibroblasts Immunoregulate Activated Macrophage Phenotype

    PubMed Central

    King, Suzanne N.; Chen, Fei; Jetté, Marie E.; Thibeault, Susan L.

    2012-01-01

    Recent evidence suggests that fibroblasts play a critical role in regulating inflammation during wound healing because they express several inflammatory mediators in response to bacteria. The objective of this study was to analyze the effects of lipopolysaccaride (LPS) on the immunomodulatory properties of vocal fold fibroblasts (VFF) derived from polyps, scar and normal tissue co-cultured with macrophages, to provide insight into their interactions during the inflammatory process. Fibroblasts were co-cultured with CD14+ monocytes and after 7 days, wells were treated with LPS for 24 and 72 hours. Culture supernatants were collected and concentrations of TNF-α, IL-6, IL-8, IL-10, IL-12, IL-1β, and MCP-1 were quantified by ELISA. Normal VFF and CD14+ monocultures were used as controls. Twenty-four hours after LPS activation, macrophages co-cultured with polyp VFF had significantly increased expression of TNF-α, IL-1β, IL-12, and IL-10 compared to controls (p<0.0001). In contrast, macrophages co-cultured with scar VFF had significantly lower expression of TNF-α, IL-1β and IL-12 with significantly higher IL-10 compared to control (p<0.0001). After 72 hours, macrophages co-cultured with polyp VFF increased expression of TNF-α, IL-1β, IL-10, IL-6, IL-8, MCP-1 and TGF-β (p<0.01) and macrophages co-cultured with scar VFF significantly decreased their expression of IL-1β and IL-12 compared to control (p<0.0001). Scar VFF at both time points produced significantly lower levels of IL-8, MCP-1, IL-6 and TGF-β compared to controls (p<0.05). Based on our findings, VFF and macrophages secrete several inflammatory mediators that modify their diverse functions. Polyp and scar VFF may play a role in regulating abnormal inflammatory responses, which could result in excessive ECM deposition that disrupts the function of the vocal folds. PMID:23123198

  20. Direct imaging of macrophage activation during PDT treatment

    NASA Astrophysics Data System (ADS)

    Song, Sheng; Zhou, Feifan; Chen, Wei R.; Xing, Da

    2011-11-01

    Mounting evidence describes a more complex progress of macrophage activation during photodynamic therapy (PDT), which performing distinct immunological functions and different physiologies on surrounding cells and tissues. Macrophage-targeted PDT has been applied in the selective killing of cells involved in inflammation and tumor. We have previously shown that PDT-mediated tumor cells apoptosis can induce a higher level immune response than necrosis, and enhance the macrophage activation. However, the molecular mechanism of macrophage activation during PDT-induced apoptotic cells (AC) still unclear. Here, we use confocal microscopy to image the phagocytosis of tumor cells by macrophages. We also observed that PDT-treated AC can activate Toll-like receptors (TLRs) which are present on macrophages surface. Besides, the increase in nitric oxide (NO) formation in macrophages was detected in real time by a laser scanning microscopy. This study provided more details for understanding the molecular mechanism of the immune response induced by PDT-treated AC.

  1. Direct imaging of macrophage activation during PDT treatment

    NASA Astrophysics Data System (ADS)

    Song, Sheng; Zhou, Feifan; Chen, Wei R.; Xing, Da

    2012-03-01

    Mounting evidence describes a more complex progress of macrophage activation during photodynamic therapy (PDT), which performing distinct immunological functions and different physiologies on surrounding cells and tissues. Macrophage-targeted PDT has been applied in the selective killing of cells involved in inflammation and tumor. We have previously shown that PDT-mediated tumor cells apoptosis can induce a higher level immune response than necrosis, and enhance the macrophage activation. However, the molecular mechanism of macrophage activation during PDT-induced apoptotic cells (AC) still unclear. Here, we use confocal microscopy to image the phagocytosis of tumor cells by macrophages. We also observed that PDT-treated AC can activate Toll-like receptors (TLRs) which are present on macrophages surface. Besides, the increase in nitric oxide (NO) formation in macrophages was detected in real time by a laser scanning microscopy. This study provided more details for understanding the molecular mechanism of the immune response induced by PDT-treated AC.

  2. Epstein-Barr virus-induced gene 3 suppresses T helper type 1, type 17 and type 2 immune responses after Trypanosoma cruzi infection and inhibits parasite replication by interfering with alternative macrophage activation.

    PubMed

    Böhme, Julia; Roßnagel, Caroline; Jacobs, Thomas; Behrends, Jochen; Hölscher, Christoph; Erdmann, Hanna

    2016-03-01

    The Epstein-Barr virus-induced gene 3 (EBI3) is a member of the interleukin-12 (IL)-12) family structurally related to the subunit p40 of IL-12 and forms a heterodimer either with the p28 subunit to build IL-27 or with p35 to form IL-35. Interleukin-27 is secreted by antigen-presenting cells whereas IL-35 appears to be produced mainly by regulatory T cells and regulatory B cells but both cytokines negatively regulate inflammatory immune responses. We here analysed the function of EBI3 during infection with the intracellular parasite Trypanosoma cruzi. Compared with C57BL/6 wild-type mice, EBI3-deficient (EBI3(-/-) ) mice showed a higher parasitaemia associated with an increased mortality rate. The EBI3(-/-) mice displayed an elevated inflammatory immune response with an increased production of T helper type 1 (Th1-), Th2- and Th17-derived cytokines. The increased Th2 immune response appears to have over-ridden the otherwise protective Th1 and Th17 immune responses by the induction of arginase-1-expressing alternatively activated macrophages in these mice. Hence, neutralization of IL-4 and arginase-1 activity partially restored protective immune responses in EBI3(-/-) mice. So far, our results demonstrate that EBI3 is an essential general regulator of inflammatory immune responses in experimental Chagas disease and is required for control of T. cruzi infection by inhibiting Th2-dependent alternative macrophage activation. Further studies are needed to dissect the underlying mechanisms and clarify whether EBI3 association with IL-27 or/and IL-35 accounts for its anti-inflammatory character in parasitic disease.

  3. Cathepsin L maturation and activity is impaired in macrophages harboring M. avium and M. tuberculosis.

    PubMed

    Nepal, Rajeev M; Mampe, Stephanie; Shaffer, Brian; Erickson, Ann H; Bryant, Paula

    2006-06-01

    Mycobacterium tuberculosis-infected macrophages demonstrate diminished capacity to present antigens via class II MHC molecules. Since successful class II MHC-restricted antigen presentation relies on the actions of endocytic proteases, we asked whether the activities of cathepsins (Cat) B, S and L-three major lysosomal cysteine proteases-are modulated in macrophages infected with pathogenic Mycobacterium spp. Infection of murine bone marrow-derived macrophages with either Mycobacterium avium or M. tuberculosis had no obvious effect on Cat B or Cat S activity. In contrast, the activity of Cat L was altered in infected cells. Specifically, whereas the 24-kDa two-chain mature form of active Cat L predominated in uninfected cells, we observed an increase in the steady-state activity of the precursor single-chain (30 kDa) and 25-kDa two-chain forms of the enzyme in cells infected with either M. avium or M. tuberculosis. Pulse-chase analyses revealed that maturation of nascent, single-chain Cat L into the 25-kDa two-chain form was impaired in infected macrophages, and that maturation into the 24-kDa two-chain form did not occur. Consistent with these data, M. avium infection inhibited the IFNgamma-induced secretion of active two-chain Cat L by macrophages. Viable bacilli were not required to disrupt Cat L maturation, suggesting that a constitutively expressed mycobacterial component was responsible. The absence of the major active form of lysosomal Cat L in M. avium- and M. tuberculosis-infected macrophages may influence the types of T cell epitopes generated in these antigen-presenting cells, and/or the rate of class II MHC peptide loading. PMID:16636015

  4. Intrinsic antibody-dependent enhancement of microbial infection in macrophages: disease regulation by immune complexes

    PubMed Central

    Halstead, Scott B; Mahalingam, Prof Suresh; Marovich, Mary A; Ubol, Sukathida; Mosser, Prof David M

    2011-01-01

    A wide range of microorganisms can replicate in macrophages, and cell entry of these pathogens via non-neutralising IgG antibody complexes can result in increased intracellular infection through idiosyncratic Fcγ-receptor signalling. The activation of Fcγ receptors usually leads to phagocytosis. Paradoxically, the ligation of monocyte or macrophage Fcγ receptors by IgG immune complexes, rather than aiding host defences, can suppress innate immunity, increase production of interleukin 10, and bias T-helper-1 (Th1) responses to Th2 responses, leading to increased infectious output by infected cells. This intrinsic antibody-dependent enhancement (ADE) of infection modulates the severity of diseases as disparate as dengue haemorrhagic fever and leishmaniasis. Intrinsic ADE is distinct from extrinsic ADE, whereby complexes of infectious agents with non-neutralising antibodies lead to an increased number of infected cells. Intrinsic ADE might be involved in many protozoan, bacterial, and viral infections. We review insights into intracellular mechanisms and implications of enhanced pathogenesis after ligation of macrophage Fcγ receptors by infectious immune complexes. PMID:20883967

  5. STAT3 Represses Nitric Oxide Synthesis in Human Macrophages upon Mycobacterium tuberculosis Infection

    PubMed Central

    Queval, Christophe J.; Song, Ok-Ryul; Deboosère, Nathalie; Delorme, Vincent; Debrie, Anne-Sophie; Iantomasi, Raffaella; Veyron-Churlet, Romain; Jouny, Samuel; Redhage, Keely; Deloison, Gaspard; Baulard, Alain; Chamaillard, Mathias; Locht, Camille; Brodin, Priscille

    2016-01-01

    Mycobacterium tuberculosis is a successful intracellular pathogen. Numerous host innate immune responses signaling pathways are induced upon mycobacterium invasion, however their impact on M. tuberculosis replication is not fully understood. Here we reinvestigate the role of STAT3 specifically inside human macrophages shortly after M. tuberculosis uptake. We first show that STAT3 activation is mediated by IL-10 and occurs in M. tuberculosis infected cells as well as in bystander non-colonized cells. STAT3 activation results in the inhibition of IL-6, TNF-α, IFN-γ and MIP-1β. We further demonstrate that STAT3 represses iNOS expression and NO synthesis. Accordingly, the inhibition of STAT3 is detrimental for M. tuberculosis intracellular replication. Our study thus points out STAT3 as a key host factor for M. tuberculosis intracellular establishment in the early stages of macrophage infection. PMID:27384401

  6. A potential target gene for the host-directed therapy of mycobacterial infection in murine macrophages.

    PubMed

    Bao, Zhang; Chen, Ran; Zhang, Pei; Lu, Shan; Chen, Xing; Yao, Yake; Jin, Xiaozheng; Sun, Yilan; Zhou, Jianying

    2016-09-01

    Mycobacterium tuberculosis (MTB), one of the major bacterial pathogens for lethal infectious diseases, is capable of surviving within the phagosomes of host alveolar macrophages; therefore, host genetic variations may alter the susceptibility to MTB. In this study, to identify host genes exploited by MTB during infection, genes were non-selectively inactivated using lentivirus-based antisense RNA methods in Raw264.7 macrophages, and the cells that survived virulent MTB infection were then screened. Following DNA sequencing of the surviving cell clones, 26 host genes affecting susceptibility to MTB were identified and their pathways were analyzed by bioinformatics analysis. In total, 9 of these genes were confirmed as positive regulators of collagen α-5(IV) chain (Col4a5) expression, a gene encoding a type IV collagen subunit present on the cell surface. The knockdown of Col4a5 consistently suppressed intracellular mycobacterial viability, promoting the survival of Raw264.7 macrophages following mycobacterial infection. Furthermore, Col4a5 deficiency lowered the pH levels of intracellular vesicles, including endosomes, lysosomes and phagosomes in the Raw264.7 cells. Finally, the knockdown of Col4a5 post-translationally increased microsomal vacuolar-type H+-ATPase activity in macrophages, leading to the acidification of intracellular vesicles. Our findings reveal a novel role for Col4a5 in the regulation of macrophage responses to mycobacterial infection and identify Col4a5 as a potential target for the host-directed anti-mycobacterial therapy. PMID:27432120

  7. A potential target gene for the host-directed therapy of mycobacterial infection in murine macrophages

    PubMed Central

    Bao, Zhang; Chen, Ran; Zhang, Pei; Lu, Shan; Chen, Xing; Yao, Yake; Jin, Xiaozheng; Sun, Yilan; Zhou, Jianying

    2016-01-01

    Mycobacterium tuberculosis (MTB), one of the major bacterial pathogens for lethal infectious diseases, is capable of surviving within the phagosomes of host alveolar macrophages; therefore, host genetic variations may alter the susceptibility to MTB. In this study, to identify host genes exploited by MTB during infection, genes were non-selectively inactivated using lentivirus-based antisense RNA methods in RAW264.7 macrophages, and the cells that survived virulent MTB infection were then screened. Following DNA sequencing of the surviving cell clones, 26 host genes affecting susceptibility to MTB were identified and their pathways were analyzed by bioinformatics analysis. In total, 9 of these genes were confirmed as positive regulators of collagen α-5(IV) chain (Col4a5) expression, a gene encoding a type IV collagen subunit present on the cell surface. The knockdown of Col4a5 consistently suppressed intracellular mycobacterial viability, promoting the survival of RAW264.7 macrophages following mycobacterial infection. Furthermore, Col4a5 deficiency lowered the pH levels of intracellular vesicles, including endosomes, lysosomes and phagosomes in the RAW264.7 cells. Finally, the knockdown of Col4a5 post-translationally increased microsomal vacuolar-type H+-ATPase activity in macrophages, leading to the acidification of intracellular vesicles. Our findings reveal a novel role for Col4a5 in the regulation of macrophage responses to mycobacterial infection and identify Col4a5 as a potential target for the host-directed anti-mycobacterial therapy. PMID:27432120

  8. Differential Induction of Apoptosis, Interferon Signaling, and Phagocytosis in Macrophages Infected with a Panel of Attenuated and Nonattenuated Poxviruses

    PubMed Central

    Royo, Sandra; Sainz, Bruno; Hernández-Jiménez, Enrique; Reyburn, Hugh; López-Collazo, Eduardo

    2014-01-01

    ABSTRACT Due to the essential role macrophages play in antiviral immunity, it is important to understand the intracellular and molecular processes that occur in macrophages following infection with various strains of vaccinia virus, particularly those used as vaccine vectors. Similarities as well as differences were found in macrophages infected with different poxvirus strains, particularly at the level of virus-induced apoptosis and the expression of immunomodulatory genes, as determined by microarray analyses. Interestingly, the attenuated modified vaccinia Ankara virus (MVA) was particularly efficient in triggering apoptosis and beta interferon (IFN-β) secretion and in inducing changes in the expression of genes associated with increased activation of innate immunity, setting it apart from the other five vaccinia virus strains tested. Taken together, these results increase our understanding of how these viruses interact with human macrophages, at the cellular and molecular levels, and suggest mechanisms that may underlie their utility as recombinant vaccine vectors. IMPORTANCE Our studies clearly demonstrate that there are substantial biological differences in the patterns of cellular gene expression between macrophages infected with different poxvirus strains and that these changes are due specifically to infection with the distinct viruses. For example, a clear induction in IFN-β mRNA was observed after infection with MVA but not with other poxviruses. Importantly, antiviral bioassays confirmed that MVA-infected macrophages secreted a high level of biologically active type I IFN. Similarly, the phagocytic capacity of macrophages was also specifically increased after infection with MVA. Although the main scope of this study was not to test the vaccine potential of MVA as there are several groups in the field working extensively on this aspect, the characteristics/phenotypes we observed at the in vitro level clearly highlight the inherent advantages that MVA

  9. Type I interferon induces necroptosis in macrophages during infection with Salmonella enterica serovar Typhimurium

    PubMed Central

    Robinson, Nirmal; McComb, Scott; Mulligan, Rebecca; Dudani, Renu; Krishnan, Lakshmi; Sad, Subash

    2014-01-01

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is a virulent pathogen that induces rapid host death. Here we observed that host survival after infection with S. Typhimurium was enhanced in the absence of type I interferon signaling, with improved survival of mice deficient in the receptor for type I interferons (Ifnar1−/− mice) that was attributed to macrophages. Although there was no impairment in cytokine expression or inflammasome activation in Ifnar1−/− macrophages, they were highly resistant to S. Typhimurium–induced cell death. Specific inhibition of the kinase RIP1or knockdown of the gene encoding the kinase RIP3 prevented the death of wild-type macrophages, which indicated that necroptosis was a mechanism of cell death. Finally, RIP3-deficient macrophages, which cannot undergo necroptosis, had similarly less death and enhanced control of S. Typhimurium in vivo. Thus, we propose that S. Typhimurium induces the production of type I interferon, which drives necroptosis of macrophages and allows them to evade the immune response. PMID:22922364

  10. Critical Role of Methylglyoxal and AGE in Mycobacteria-Induced Macrophage Apoptosis and Activation

    PubMed Central

    Rachman, Helmy; Kim, Nayoung; Ulrichs, Timo; Baumann, Sven; Pradl, Lydia; Eddine, Ali Nasser; Bild, Matthias; Rother, Marion; Kuban, Ralf-Jürgen; Lee, Jong Seok; Hurwitz, Robert; Brinkmann, Volker; Kosmiadi, George A.; Kaufmann, Stefan H.E.

    2006-01-01

    Apoptosis and activation of macrophages play an important role in the host response to mycobacterial infection involving TNF-α as a critical autocrine mediator. The underlying mechanisms are still ill-defined. Here, we demonstrate elevated levels of methylglyoxal (MG), a small and reactive molecule that is usually a physiological product of various metabolic pathways, and advanced glycation end products (AGE) during mycobacterial infection of macrophages, leading to apoptosis and activation of macrophages. Moreover, we demonstrate abundant AGE in pulmonary lesions of tuberculosis (TB) patients. Global gene expression profiling of MG-treated macrophages revealed a diverse spectrum of functions induced by MG, including apoptosis and immune response. Our results not only provide first evidence for the involvement of MG and AGE in TB, but also form a basis for novel intervention strategies against infectious diseases in which MG and AGE play critical roles. PMID:17183656

  11. Cytolytic activity against tumor cells by macrophage cell lines and augmentation by macrophage stimulants.

    PubMed

    Taniyama, T; Holden, H T

    1980-07-15

    Previous studies have shown that macrophage cell lines retained the ability to phagocytize, to secrete lysosomal enzymes, and to function as effector cells in antibody-dependent cellular cytoxicity. In this paper, the cytolytic activity of murine macrophage cell lines against tumor target cells was assessed using an 18-h 51Cr release assay. Of the macrophage cell lines tested, RAW 264, PU5-1.8 and IC-21 had intermediate to high levels of spontaneous cytolytic activity, P388D, and J774 had low to intermediate levels, while /WEHI-3 showed little or no cytolytic activity against RBL-5, MBL-2 and TU-5 target cells. Tumor-cell killing by macrophage cell lines could be augmented by the addition of macrophage stimulants, such as bacterial lipopolysaccharide and poly I:C, indicating that the activation of macrophages by these stimulants does not require the participation of other cell types. Treatment with interferon also augmented the tumor-cell killing by macrophage cell lines. Although the mechanism by which these cell lines exert their spontaneous or boosted cytotoxic activity is not clear, it does not appear to be due to depletion of nutrients since cell lines with high metabolic and proliferative activities, such as WEHI-3 and RBL-5, showed little or no cytotoxicity and supernatants from the macrophage cell lines did not exert any cytotoxic effects in their essay. Thus, it appears that the different macrophage cell lines represent different levels of activation and/or differentiation and may be useful for studying the development of these processes as well as providing a useful tool for analyzing the mechanisms of macrophage-mediated cytolysis. PMID:6165690

  12. Activation of macrophages for destruction of Francisella tularensis: identification of cytokines, effector cells, and effector molecules.

    PubMed Central

    Fortier, A H; Polsinelli, T; Green, S J; Nacy, C A

    1992-01-01

    Francisella tularensis live vaccine strain (LVS) was grown in culture with nonadherent resident, starch-elicited, or Proteose Peptone-elicited peritoneal cells. Numbers of bacteria increased 4 logs over the input inoculum in 48 to 72 h. Growth rates were faster in inflammatory cells than in resident cells: generation times for the bacterium were 3 h in inflammatory cells and 6 h in resident macrophages. LVS-infected macrophage cultures treated with lymphokines did not support growth of the bacterium, although lymphokines alone had no inhibitory effects on replication of LVS in culture medium devoid of cells. Removal of gamma interferon (IFN-gamma) by immunoaffinity precipitation rendered lymphokines ineffective for induction of macrophage anti-LVS activity, and recombinant IFN-gamma stimulated both resident and inflammatory macrophage populations to inhibit LVS growth in vitro. Inflammatory macrophages were more sensitive to effects of IFN-gamma: half-maximal activity was achieved at 5 U/ml for inflammatory macrophages and 20 U/ml for resident macrophages. IFN-gamma-induced anti-LVS activity correlated with the production of nitrite (NO2-), an oxidative end product of L-arginine-derived nitric oxide (NO). Anti-LVS activity and nitrite production were both completely inhibited by the addition of either the L-arginine analog NG-monomethyl-L-arginine or anti-tumor necrosis factor antibodies to activated macrophage cultures. Thus, macrophages can be activated by IFN-gamma to suppress the growth of F. tularensis by generation of toxic levels of NO, and inflammatory macrophages are substantially more sensitive to activation activities of IFN-gamma for this effector reaction than are more differentiated resident cells. PMID:1541555

  13. Development of ostrich thrombocytes and monocyte-derived macrophages in culture and the control of Toxoplasma gondii reproduction after macrophage activation.

    PubMed

    Miranda, Farlen J B; Damasceno-Sá, João Cláudio; DaMatta, Renato A

    2016-01-01

    Raising ostriches became an important economic activity after their products became commodities. The health of farm animals is of paramount importance, so assessing basic immunological responses is necessary to better understand health problems. We developed a method to obtain ostrich thrombocytes and macrophages. The thrombocytes died by apoptosis after 48 h in culture, and the macrophages expanded in size and increased the number of acidic compartments. Macrophages were activated by chicken interferon-γ, producing high levels of nitric oxide. Toxoplasma gondii was able to infect these macrophages, and activation controlled parasitic reproduction. T. gondii, however, persisted in these cells, and infection reduced the production of nitric oxide. These results are important for the future assessment of the basic cellular and immunobiology of ostriches and demonstrate T. gondii suppression of nitric oxide production. PMID:26794839

  14. Ultrastructural studies of the killing of schistosomula of Schistosoma mansoni by activated macrophages in vitro.

    PubMed

    McLaren, D J; James, S L

    1985-05-01

    Immunologically activated murine macrophages have been shown elsewhere to kill skin stage schistosomula of Schistosoma mansoni in vitro, in a manner analogous to the extracellular killing of tumour cell targets. In this study, the kinetics of the interaction between activated macrophages and larval targets and the resultant ultrastructural changes in parasite morphology that culminated in death have been analysed in detail. Unlike granulocyte-mediated schistosomular killing, macrophage-mediated cytotoxicity did not appear to be directed against the surface tissues of the parasite. Macrophages adhered only transiently following initiation of the cultures, yet changes in the subtegumental mitochondria and muscle cells of the larva were detected within the first hour of incubation. Progressive internal disorganisation followed rapidly, but the tegument and tegumental outer membrane remained intact, to form a 'shell' that maintained the general shape of the parasite. Such changes were recognised irrespective of whether the effector cell population comprised peritoneal macrophages activated by lymphokine treatment in vitro, or by infection with Mycobacterium bovis (strain BCG), or S. mansoni in vivo. That macrophages rather than contaminating granulocytes or lymphocytes, had mediated the observed damage was demonstrated by the use of a lymphokine treated macrophage cell line, IC-21. The observation that macrophage cytotoxicity is directed against internal organelles rather than the tegumental outer membrane of this multicellular target, may help to elucidate the general mechanism of extracellular killing by these cells. PMID:3892433

  15. Lipid Droplet Formation, Their Localization and Dynamics during Leishmania major Macrophage Infection

    PubMed Central

    Rabhi, Sameh; Rabhi, Imen; Trentin, Bernadette; Piquemal, David; Regnault, Béatrice; Goyard, Sophie; Lang, Thierry; Descoteaux, Albert; Enninga, Jost; Guizani-Tabbane, Lamia

    2016-01-01

    Leishmania, the causative agent of vector-borne diseases, known as leishmaniases, is an obligate intracellular parasite within mammalian hosts. The outcome of infection depends largely on the activation status of macrophages, the first line of mammalian defense and the major target cells for parasite replication. Understanding the strategies developed by the parasite to circumvent macrophage defense mechanisms and to survive within those cells help defining novel therapeutic approaches for leishmaniasis. We previously showed the formation of lipid droplets (LDs) in L. major infected macrophages. Here, we provide novel insights on the origin of the formed LDs by determining their cellular distribution and to what extent these high-energy sources are directed to the proximity of Leishmania parasites. We show that the ability of L. major to trigger macrophage LD accumulation is independent of parasite viability and uptake and can also be observed in non-infected cells through paracrine stimuli suggesting that LD formation is from cellular origin. The accumulation of LDs is demonstrated using confocal microscopy and live-cell imagin in parasite-free cytoplasmic region of the host cell, but also promptly recruited to the proximity of Leishmania parasites. Indeed LDs are observed inside parasitophorous vacuole and in parasite cytoplasm suggesting that Leishmania parasites besides producing their own LDs, may take advantage of these high energy sources. Otherwise, these LDs may help cells defending against parasitic infection. These metabolic changes, rising as common features during the last years, occur in host cells infected by a large number of pathogens and seem to play an important role in pathogenesis. Understanding how Leishmania parasites and different pathogens exploit this LD accumulation will help us define the common mechanism used by these different pathogens to manipulate and/or take advantage of this high-energy source. PMID:26871576

  16. Functional modifications of macrophage activity after sublethal irradiation. [Toxoplasma gondii

    SciTech Connect

    Swartz, R.P.

    1982-01-01

    The modifications of macrophage activity following sublethal irradiation, both in vivo and in vitro, were studied using spreading and C3b-receptor-mediated ingestion assays. Nonelicited peritoneal washout cells were examined for changes in activity and selected population characteristics. The cells from irradiated mice were from a resident peritoneal population and not immigrating cells. The macrophage population showed enhanced activity early with a refractory period (24-48) when the macrophages were unresponsive to stimulation by irradiated lymphocytes. The enhanced activity was inversely dose dependent on macrophage. The lymphocytes showed a regulatory function(s) on the time post irradiation at which they were examined. Early lymphocytes exhibited the ability to enhance the activity of normal macrophages while lymphocytes removed 24 hours post irradiation could suppress the activity of already activated macrophages. The effect(s) of the various lymphocyte populations were reproduced with cell-free supernatants which was indicative of the production of lymphokines. Separation on nylon wool columns indicated that the activity resided primarily in the T-cell population of lymphocytes. In vitro irradiation indicated that stimulation of the lymphocytes is macrophage dependent. Additional work indicated that sublethally irradiated macrophages did not inhibit replication of the coccidian protozoon Toxoplasma gondii although they did show increased phagocytosis. Examination of the serum from whole body irradiated mice showed the presence of a postirradiation substance which enhanced the phagocytosis of normal macrophages. It was not present in the serum of normal mice and was not endotoxin.

  17. E-NTPDase (ecto-nucleoside triphosphate diphosphohydrolase) of Leishmania amazonensis inhibits macrophage activation.

    PubMed

    Gomes, Rodrigo Saar; de Carvalho, Luana Cristina Faria; de Souza Vasconcellos, Raphael; Fietto, Juliana Lopes Rangel; Afonso, Luís Carlos Crocco

    2015-04-01

    Leishmania amazonensis, the causal agent of diffuse cutaneous leishmaniasis, is known for its ability to modulate the host immune response. Because a relationship between ectonucleotidase activity and the ability of Leishmania to generate injury in C57BL/6 mice has been demonstrated, in this study we evaluated the involvement of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) activity of L. amazonensis in the process of infection of J774-macrophages. Our results show that high-activity parasites show increased survival rate in LPS/IFN-γ-activated cells, by inhibiting the host-cell NO production. Conversely, inhibition of E-NTPDase activity reduces the parasite survival rates, an effect associated with increased macrophage NO production. E-NTPDase activity generates substrate for the production of extracellular adenosine, which binds to A2B receptors and reduces IL-12 and TNF-α produced by activated macrophages, thus inhibiting NO production. These results indicate that E-NTPDase activity is important for survival of L. amazonensis within macrophages, showing the role of the enzyme in modulating macrophage response and lower NO production, which ultimately favors infection. Our results point to a new mechanism of L. amazonensis infection that may pave the way for the development of new treatments for this neglected disease. PMID:25554487

  18. Modulation of macrophage activation and programming in immunity.

    PubMed

    Liu, Guangwei; Yang, Hui

    2013-03-01

    Macrophages are central mediators of the immune, contributing both to the initiation and the resolution of inflammation. The concept of macrophage activation and program has stimulated interest in its definition, and functional significance in homeostasis and diseases. It has been known that macrophages could be differently activated and programmed into different functional subtypes in response to different types of antigen stumuli or different kinds of cytokines present in the microenvironment and could thus profoundly influence immune responses, but little is known about the state and exact regulatory mechanism of macrophage activation and program from cell or molecular signaling level in immunity. In this review, we summarize the recent finding regarding the regulatory mechanism of macrophage activation and program toward M1 and M2, especially on M2 macrophages.

  19. High-Density Lipoprotein Binds to Mycobacterium avium and Affects the Infection of THP-1 Macrophages

    PubMed Central

    Ichimura, Naoya; Sato, Megumi; Yoshimoto, Akira; Yano, Kouji; Ohkawa, Ryunosuke; Kasama, Takeshi

    2016-01-01

    High-density lipoprotein (HDL) is involved in innate immunity toward various infectious diseases. Concerning bacteria, HDL is known to bind to lipopolysaccharide (LPS) and to neutralize its physiological activity. On the other hand, cholesterol is known to play an important role in mycobacterial entry into host cells and in survival in the intracellular environment. However, the pathogenicity of Mycobacterium avium (M. avium) infection, which tends to increase worldwide, remains poorly studied. Here we report that HDL indicated a stronger interaction with M. avium than that with other Gram-negative bacteria containing abundant LPS. A binding of apolipoprotein (apo) A-I, the main protein component of HDL, with a specific lipid of M. avium might participate in this interaction. HDL did not have a direct bactericidal activity toward M. avium but attenuated the engulfment of M. avium by THP-1 macrophages. HDL also did not affect bacterial killing after ingestion of live M. avium by THP-1 macrophage. Furthermore, HDL strongly promoted the formation of lipid droplets in M. avium-infected THP-1 macrophages. These observations provide new insights into the relationship between M. avium infection and host lipoproteins, especially HDL. Thus, HDL may help M. avium to escape from host innate immunity. PMID:27516907

  20. Molecular imaging of macrophage enzyme activity in cardiac inflammation

    PubMed Central

    Ali, Muhammad; Pulli, Benjamin; Chen, John W.

    2014-01-01

    Molecular imaging is highly advantageous as various insidious inflammatory events can be imaged in a serial and quantitative fashion. Combined with the conventional imaging modalities like computed tomography (CT), magnetic resonance (MR) and nuclear imaging, it helps us resolve the extent of ongoing pathology, quantify inflammation and predict outcome. Macrophages are increasingly gaining importance as an imaging biomarker in inflammatory cardiovascular diseases. Macrophages, recruited to the site of injury, internalize necrotic or foreign material. Along with phagocytosis, activated macrophages release proteolytic enzymes like matrix metalloproteinases (MMPs) and cathepsins into the extracellular environment. Pro-inflammatory monocytes and macrophages also induce tissue oxidative damage through the inflammatory enzyme myeloperoxidase (MPO). In this review we will highlight recent advances in molecular macrophage imaging. Particular stress will be given to macrophage functional and enzymatic activity imaging which targets phagocytosis, proteolysis and myeloperoxidase activity imaging. PMID:24729833

  1. Soluble CD40 Ligand in Sera of Subjects Exposed to Leishmania infantum Infection Reduces the Parasite Load in Macrophages

    PubMed Central

    de Oliveira, Fabrícia Alvisi; Barreto, Aline Silva; Bomfim, Lays G. S.; Leite, Talita Rebeca S.; dos Santos, Priscila Lima; de Almeida, Roque Pacheco; da Silva, Ângela Maria; Duthie, Malcolm S.; Reed, Steven G.

    2015-01-01

    Background While CD40L is typically a membrane glycoprotein expressed on activated T cells and platelets that binds and activates CD40 on the surface on antigen presenting cells, a soluble derivative (sCD40L) that appears to retain its biological activity after cleavage from cell membrane also exists. We recently reported that sCD40L is associated with clinical resolution of visceral leishmaniasis and protection against the disease. In the present study we investigated if this sCD40L is functional and exerts anti-parasitic effect in L. infantum-infected macrophages. Methodology/Principal Findings Macrophages from normal human donors were infected with L. infantum promastigotes and incubated with either sera from subjects exposed to L. infantum infection, monoclonal antibodies against human CD40L, or an isotype control antibody. We then evaluated infection by counting the number of infected cells and the number of parasites in each cell. We also measured a variety of immune modulatory cytokines in these macrophage culture supernatants by Luminex assay. The addition of sCD40L, either recombinant or from infected individuals’ serum, decreased both the number of infected macrophages and number of intracellular parasites. Moreover, this treatment increased the production of IL-12, IL-23, IL-27, IL-15, and IL1β such that negative correlations between the levels of these cytokines with both the infection ratio and number of intracellular parasites were observed. Conclusions/Significance sCD40L from sera of subjects exposed to L. infantum is functional and improves both the control of parasite and production of inflamatory cytokines of infected macrophages. Although the mechanisms involved in parasite killing are still unclear and require further exploration, these findings indicate a protective role of sCD40L in visceral leishmaniasis. PMID:26488744

  2. The tyrosine kinase inhibitor genistein blocks HIV-1 infection in primary human macrophages.

    PubMed

    Stantchev, Tzanko S; Markovic, Ingrid; Telford, William G; Clouse, Kathleen A; Broder, Christopher C

    2007-02-01

    Binding of HIV-1 envelope glycoprotein (Env) to its cellular receptors elicits a variety of signaling events, including the activation of select tyrosine kinases. To evaluate the potential role of such signaling, we examined the effects of the tyrosine kinase inhibitor, genistein, on HIV-1 entry and infection of human macrophages using a variety of assays. Without altering cell viability, cell surface expression of CD4 and CCR5 or their abilities to interact with Env, genistein inhibited infection of macrophages by reporter gene-encoding, beta-lactamase containing, or wild type virions, as well as Env-mediated cell-fusion. The observation that genistein blocked virus infection if applied before, during or immediately after the infection period, but not 24h later; coupled with a more pronounced inhibition of infection in the reporter gene assays as compared to both beta-lactamase and p24 particle entry assays, imply that genistein exerts its inhibitory effects on both entry and early post-entry steps. These findings suggest that other exploitable targets, or steps, of the HIV-1 infection process may exist and could serve as additional opportunities for the development of new therapeutics.

  3. Classical Swine Fever Virus Inhibits Nitric Oxide Production in Infected Macrophages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Classical swine fever virus (CSFV)-macrophage interactions during infection were analyzed by examining macrophage transcriptional responses via microarray. Eleven genes had increased mRNA levels (>2.5 fold, p<0.05) in infected cell cultures including arginase-1, an inhibitor of nitric oxide producti...

  4. SIV Vpx Is Essential for Macrophage Infection but Not for Development of AIDS

    PubMed Central

    Westmoreland, Susan V.; Converse, A. Peter; Hrecka, Kasia; Hurley, Mollie; Knight, Heather; Piatak, Michael; Lifson, Jeffrey; Mansfield, Keith G.; Skowronski, Jacek; Desrosiers, Ronald C.

    2014-01-01

    Analysis of rhesus macaques infected with a vpx deletion mutant virus of simian immunodeficiency virus mac239 (SIVΔvpx) demonstrates that Vpx is essential for efficient monocyte/macrophage infection in vivo but is not necessary for development of AIDS. To compare myeloid-lineage cell infection in monkeys infected with SIVΔvpx compared to SIVmac239, we analyzed lymphoid and gastrointestinal tissues from SIVΔvpx-infected rhesus (n = 5), SIVmac239-infected rhesus with SIV encephalitis (7 SIV239E), those without encephalitis (4 SIV239noE), and other SIV mutant viruses with low viral loads (4 SIVΔnef, 2 SIVΔ3). SIV+ macrophages and the percentage of total SIV+ cells that were macrophages in spleen and lymph nodes were significantly lower in rhesus infected with SIVΔvpx (2.2%) compared to those infected with SIV239E (22.7%), SIV239noE (8.2%), and SIV mutant viruses (10.1%). In colon, SIVΔvpx monkeys had fewer SIV+ cells, no SIV+ macrophages, and lower percentage of SIV+ cells that were macrophages than the other 3 groups. Only 2 SIVΔvpx monkeys exhibited detectable virus in the colon. We demonstrate that Vpx is essential for efficient macrophage infection in vivo and that simian AIDS and death can occur in the absence of detectable macrophage infection. PMID:24465411

  5. AKT mediated glycolytic shift regulates autophagy in classically activated macrophages.

    PubMed

    Matta, Sumit Kumar; Kumar, Dhiraj

    2015-09-01

    Autophagy is considered as an innate defense mechanism primarily due to its role in the targeting of intracellular pathogens for lysosomal degradation. Here we report inhibition of autophagy as an adaptive response in classically activated macrophages that helps achieve high cellular ROS production and cell death-another hallmark of innate mechanisms. We show prolonged classical activation of Raw 264.7 macrophages by treating them with IFN-γ and LPS inhibited autophagy. The inhibition of autophagy was dependent on nitric oxide (NO) production which activated the AKT-mTOR signaling, the known negative regulators of autophagy. Autophagy inhibition in these cells was accompanied with a shift to aerobic glycolysis along with a decline in the mitochondrial membrane potential (MOMP). The decline in MOMP coupled with autophagy inhibition led to increased mitochondrial content and considerably elevated cellular ROS, eventually causing cell death. Next, using specific siRNA mediated knockdowns we show AKT was responsible for the glycolytic shift and autophagy inhibition in activated macrophages. Surprisingly, AKT knockdown in activated macrophages also rescued them from cell death. Finally we show that AKT mediated autophagy inhibition in the activated macrophages correlated with the depletion of glucose from the extracellular medium, and glucose supplementation not only rescued autophagy levels and reversed other phenotypes of activated macrophages, but also inhibited cell death. Thus we report here a novel link between AKT mediated glycolytic metabolism and autophagy in the activated macrophages, and provide a possible mechanism for sustained macrophage activation in vivo.

  6. Immunoregulation by macrophages II. Separation of mouse peritoneal macrophages having tumoricidal and bactericidal activities and those secreting PGE and interleukin I

    SciTech Connect

    Hopper, K.E.; Cahill, J.M.

    1983-06-01

    Macrophage subpopulations having bactericidal or tumoricidal activities and secreting interleukin I (IL1) or prostaglandin E (PGE) were identified through primary or secondary infection with Salmonella enteritidis and separated by sedimentation velocity. Bactericidal activity was measured by (3H)-thymidine release from Listeria monocytogenes and tumoricidal activity by 51Cr-release from C-4 fibrosarcoma or P815 mastocytoma cells. Macrophages with bactericidal activity were distinguished from those with tumoricidal activity a) during secondary infection when cytolytic activity occurred only at days 1-4 post injection and bactericidal activity remained high throughout and b) after sedimentation velocity separation. Cytolysis was consistently greatest among adherent cells of low sedimentation velocity, whereas cells with bactericidal activity increased in size during the infection. Tumour cytostasis (inhibition and promotion of (3H)-thymidine uptake) differed from cytolysis in that the former was more prolonged during infection and was also detected among large cells. Secretion of immunoregulatory molecules PGE and IL1 occurred maximally among different macrophage subpopulations separated by sedimentation velocity and depending on the type of stimulus used in vitro. There was an inverse correlation between IL1 production and PGE production after stimulation with C3-zymosan or lipopolysaccharide (LPS). The development of immunity during infection may therefore be dependent upon the relative proportions of effector and regulatory macrophage subpopulations and the selective effects of environmental stimuli on these functions.

  7. Coxiella burnetii Infects Primary Bovine Macrophages and Limits Their Host Cell Response.

    PubMed

    Sobotta, Katharina; Hillarius, Kirstin; Mager, Marvin; Kerner, Katharina; Heydel, Carsten; Menge, Christian

    2016-06-01

    Although domestic ruminants have long been recognized as the main source of human Q fever, little is known about the lifestyle that the obligate intracellular Gram-negative bacterium Coxiella burnetii adopts in its animal host. Because macrophages are considered natural target cells of the pathogen, we established primary bovine monocyte-derived macrophages (MDM) as an in vitro infection model to study reservoir host-pathogen interactions at the cellular level. In addition, bovine alveolar macrophages were included to take cell type peculiarities at a host entry site into account. Cell cultures were inoculated with the virulent strain Nine Mile I (NMI; phase I) or the avirulent strain Nine Mile II (NMII; phase II). Macrophages from both sources internalized NMI and NMII. MDM were particularly permissive for NMI internalization, but NMI and NMII replicated with similar kinetics in these cells. MDM responded to inoculation with a general upregulation of Th1-related cytokines such as interleukin-1β (IL-1β), IL-12, and tumor necrosis factor alpha (TNF-α) early on (3 h postinfection). However, inflammatory responses rapidly declined when C. burnetii replication started. C. burnetii infection inhibited translation and release of IL-1β and vastly failed to stimulate increased expression of activation markers, such as CD40, CD80, CD86, and major histocompatibility complex (MHC) molecules. Such capability of limiting proinflammatory responses may help Coxiella to protect itself from clearance by the host immune system. The findings provide the first detailed insight into C. burnetii-macrophage interactions in ruminants and may serve as a basis for assessing the virulence and the host adaptation of C. burnetii strains. PMID:27021246

  8. Collagenase Production by Endotoxin-Activated Macrophages

    PubMed Central

    Wahl, Larry M.; Wahl, Sharon M.; Mergenhagen, Stephan E.; Martin, George R.

    1974-01-01

    Peritoneal exudate macrophages, when exposed to bacterial lipopolysaccharide in culture, were found to produce collagenase (EC 3.4.24.3). This enzyme was not detected in extracts of the macrophages or in media from nonstimulated macrophage cultures. Lipidcontaining fractions of the lipopolysaccharide, including a glycolipid from the rough mutant of Salmonella minnesota (R595) and lipid A, were potent stimulators of collagenase production. The lipid-free polysaccharide fraction had no effect. Cycloheximide prevented the production of collagenase by endotoxin-treated macrophages, suggesting that it was newly synthesized. Images PMID:4372628

  9. Enhancement of host resistance against Listeria infection by Lactobacillus casei: Role of macrophages

    SciTech Connect

    Sato, K.

    1984-05-01

    Among the 10 species of the genus Lactobacillus, L. casei showed the strongest protective action against Listeria monocytogenes infection in mice. The activity of L. casei differed with regard to the dose of administration. The anti-L. monocytogenes resistance in mice intravenously administered 5.5 X 10(7), 2.8 X 10(8), or 1.1 X 10(9) L. casei cells was most manifest at ca. 2, 2 and 13, and 3 to 21 days after its administration, respectively. The growth of L. monocytogenes in the liver of mice injected with L. casei (10(7), 10(8), or 10(9) cells) 48 h after infection was suppressed, particularly when 10(8) or 10(9) L. casei cells were given 2 or 13 days before the induced infection, respectively. This suppression of L. monocytogenes growth was overcome by carrageenan treatment or X-ray irradiation. (/sup 3/H)thymidine incorporation into the liver DNA increased 13 days after administration of L. casei, and augmentation of (/sup 3/H)thymidine incorporation during 6 to 48 h after infection was dependent on the dose of L. casei. Peritoneal macrophage accumulation observed 1 to 5 days after intraperitoneal injection of UV-killed L. monocytogenes was markedly enhanced when the mice were treated with L. casei cells 13 days before macrophage elicitation. Therefore, the enhanced host resistance by L. casei to L. monocytogenes infection may be mediated by macrophages migrating from the blood stream to the reticuloendothelial system in response to L. casei injection before or after L. monocytogenes infection.

  10. Enhancement of host resistance against Listeria infection by Lactobacillus casei: role of macrophages.

    PubMed Central

    Sato, K

    1984-01-01

    Among the 10 species of the genus Lactobacillus, L. casei showed the strongest protective action against Listeria monocytogenes infection in mice. The activity of L. casei differed with regard to the dose of administration. The anti-L. monocytogenes resistance in mice intravenously administered 5.5 X 10(7), 2.8 X 10(8), or 1.1 X 10(9) L. casei cells was most manifest at ca. 2, 2 and 13, and 3 to 21 days after its administration, respectively. The growth of L. monocytogenes in the liver of mice injected with L. casei (10(7), 10(8), or 10(9) cells) 48 h after infection was suppressed, particularly when 10(8) or 10(9) L. casei cells were given 2 or 13 days before the induced infection, respectively. This suppression of L. monocytogenes growth was overcome by carrageenan treatment or X-ray irradiation. [3H]thymidine incorporation into the liver DNA increased 13 days after administration of L. casei, and augmentation of [3H]thymidine incorporation during 6 to 48 h after infection was dependent on the dose of L. casei. Peritoneal macrophage accumulation observed 1 to 5 days after intraperitoneal injection of UV-killed L. monocytogenes was markedly enhanced when the mice were treated with L. casei cells 13 days before macrophage elicitation. Therefore, the enhanced host resistance by L. casei to L. monocytogenes infection may be mediated by macrophages migrating from the blood stream to the reticuloendothelial system in response to L. casei injection before or after L. monocytogenes infection. Images PMID:6425222

  11. Cellular and Molecular Mechanisms Underpinning Macrophage Activation during Remyelination

    PubMed Central

    Lloyd, Amy F.; Miron, Veronique E.

    2016-01-01

    Remyelination is an example of central nervous system (CNS) regeneration, whereby myelin is restored around demyelinated axons, re-establishing saltatory conduction and trophic/metabolic support. In progressive multiple sclerosis, remyelination is limited or fails altogether which is considered to contribute to axonal damage/loss and consequent disability. Macrophages have critical roles in both CNS damage and regeneration, such as remyelination. This diverse range in functions reflects the ability of macrophages to acquire tissue microenvironment-specific activation states. This activation is dynamically regulated during efficient regeneration, with a switch from pro-inflammatory to inflammation-resolution/pro-regenerative phenotypes. Although, some molecules and pathways have been implicated in the dynamic activation of macrophages, such as NFκB, the cellular and molecular mechanisms underpinning plasticity of macrophage activation are unclear. Identifying mechanisms regulating macrophage activation to pro-regenerative phenotypes may lead to novel therapeutic strategies to promote remyelination in multiple sclerosis. PMID:27446913

  12. CCL2 Mediates Neuron-Macrophage Interactions to Drive Proregenerative Macrophage Activation Following Preconditioning Injury.

    PubMed

    Kwon, Min Jung; Shin, Hae Young; Cui, Yuexian; Kim, Hyosil; Thi, Anh Hong Le; Choi, Jun Young; Kim, Eun Young; Hwang, Dong Hoon; Kim, Byung Gon

    2015-12-01

    CNS neurons in adult mammals do not spontaneously regenerate axons after spinal cord injury. Preconditioning peripheral nerve injury allows the dorsal root ganglia (DRG) sensory axons to regenerate beyond the injury site by promoting expression of regeneration-associated genes. We have previously shown that peripheral nerve injury increases the number of macrophages in the DRGs and that the activated macrophages are critical to the enhancement of intrinsic regeneration capacity. The present study identifies a novel chemokine signal mediated by CCL2 that links regenerating neurons with proregenerative macrophage activation. Neutralization of CCL2 abolished the neurite outgrowth activity of conditioned medium obtained from neuron-macrophage cocultures treated with cAMP. The neuron-macrophage interactions that produced outgrowth-promoting conditioned medium required CCL2 in neurons and CCR2/CCR4 in macrophages. The conditioning effects were abolished in CCL2-deficient mice at 3 and 7 d after sciatic nerve injury, but CCL2 was dispensable for the initial growth response and upregulation of GAP-43 at the 1 d time point. Intraganglionic injection of CCL2 mimicked conditioning injury by mobilizing M2-like macrophages. Finally, overexpression of CCL2 in DRGs promoted sensory axon regeneration in a rat spinal cord injury model without harmful side effects. Our data suggest that CCL2-mediated neuron-macrophage interaction plays a critical role for amplification and maintenance of enhanced regenerative capacity by preconditioning peripheral nerve injury. Manipulation of chemokine signaling mediating neuron-macrophage interactions may represent a novel therapeutic approach to promote axon regeneration after CNS injury.

  13. 17β-Estradiol Protects Primary Macrophages Against HIV Infection Through Induction of Interferon-Alpha

    PubMed Central

    Tasker, Carley; Ding, Jian; Schmolke, Mirco; Rivera-Medina, Amariliz; García-Sastre, Adolfo

    2014-01-01

    Abstract Estrogen has been shown to increase resistance to HIV/SIV transmission by increasing the thickness of the genital epithelium. The immunological role of estrogen in HIV infection of primary target cells is less well characterized. We have found that primary macrophages are a target for anti-HIV activity of 17β-estradiol (E2). E2 did not affect surface expression of CD4 and HIV co-receptors nor HIV attachment to monocyte-derived macrophages (MDMs). In addition, E2 treatment blocked infection by a co-receptor-independent HIV-1VSV-G pseudotyped virus. Quantitative polymerase chain reaction analysis of HIV reverse transcribed DNA products indicated that E2 blocked HIV reverse transcription. E2 upregulated gene expression of interferons (IFNs) in MDMs from multiple donors. However, induction of host restriction factors APOBEC3G, APOBEC3F, or SAMHD1 was not consistent, with exception of APOBEC3A. Anti-HIV activity of E2 was abolished in the presence of IFN-α neutralizing antibody, and was absent in bone marrow–derived macrophages from IFN-α receptor deficient mice. Interestingly, HIV overcame E2-mediated HIV inhibition by suppressing induction of IFNs when MDMs were exposed to HIV before E2 treatment. These results offer a new mechanism of E2 on HIV inhibition. Future studies on the interplay between HIV and E2-mediated innate immune responses will likely provide insights relevant for development of effective strategies for HIV prevention. PMID:24801776

  14. Exopolysaccharide from Trichoderma pseudokoningii induces macrophage activation.

    PubMed

    Wang, Guodong; Zhu, Lei; Yu, Bo; Chen, Ke; Liu, Bo; Liu, Jun; Qin, Guozheng; Liu, Chunyan; Liu, Huixia; Chen, Kaoshan

    2016-09-20

    In this study, we evaluated the immunomodulatory activity of an exopolysaccharide (EPS) derived from Trichoderma pseudokoningii and investigated the molecular mechanism of EPS-mediated activation of macrophages. Results revealed that EPS could significantly induce the production of nitric oxide (NO), tumor necrosis factor (TNF)-α and interleukin (IL)-1β and enhance phagocytic activity in RAW 264.7 cells. Immunofluorescence staining indicated that EPS promoted the nuclear translocation of nuclear factor (NF)-κB p65 subunit. Western blot analysis showed that EPS increased the expression of inducible nitric oxide synthase (iNOS) protein, the degradation of IκB-α and the phosphorylation of mitogen-activated protein kinases (MAPKs). Furthermore, pretreatment of RAW 264.7 cells with specific inhibitors of NF-κB and MAPKs significantly attenuated EPS-induced TNF-α and IL-1β production. EPS also induced the inhibition of cytokine secretion by special antibodies against Toll-like receptor-4 (TLR4) and Dectin-1. These data suggest that EPS from Trichoderma pseudokoningii activates RAW 264.7 cells through NF-κB and MAPKs signaling pathways via TLR4 and Dectin-1. PMID:27261736

  15. Cryptococcus neoformans Intracellular Proliferation and Capsule Size Determines Early Macrophage Control of Infection.

    PubMed

    Bojarczuk, Aleksandra; Miller, Katie A; Hotham, Richard; Lewis, Amy; Ogryzko, Nikolay V; Kamuyango, Alfred A; Frost, Helen; Gibson, Rory H; Stillman, Eleanor; May, Robin C; Renshaw, Stephen A; Johnston, Simon A

    2016-01-01

    Cryptococcus neoformans is a significant fungal pathogen of immunocompromised patients. Many questions remain regarding the function of macrophages in normal clearance of cryptococcal infection and the defects present in uncontrolled cryptococcosis. Two current limitations are: 1) The difficulties in interpreting studies using isolated macrophages in the context of the progression of infection, and 2) The use of high resolution imaging in understanding immune cell behavior during animal infection. Here we describe a high-content imaging method in a zebrafish model of cryptococcosis that permits the detailed analysis of macrophage interactions with C. neoformans during infection. Using this approach we demonstrate that, while macrophages are critical for control of C. neoformans, a failure of macrophage response is not the limiting defect in fatal infections. We find phagocytosis is restrained very early in infection and that increases in cryptococcal number are driven by intracellular proliferation. We show that macrophages preferentially phagocytose cryptococci with smaller polysaccharide capsules and that capsule size is greatly increased over twenty-four hours of infection, a change that is sufficient to severely limit further phagocytosis. Thus, high-content imaging of cryptococcal infection in vivo demonstrates how very early interactions between macrophages and cryptococci are critical in the outcome of cryptococcosis. PMID:26887656

  16. Cryptococcus neoformans Intracellular Proliferation and Capsule Size Determines Early Macrophage Control of Infection

    PubMed Central

    Bojarczuk, Aleksandra; Miller, Katie A.; Hotham, Richard; Lewis, Amy; Ogryzko, Nikolay V.; Kamuyango, Alfred A.; Frost, Helen; Gibson, Rory H.; Stillman, Eleanor; May, Robin C.; Renshaw, Stephen A.; Johnston, Simon A.

    2016-01-01

    Cryptococcus neoformans is a significant fungal pathogen of immunocompromised patients. Many questions remain regarding the function of macrophages in normal clearance of cryptococcal infection and the defects present in uncontrolled cryptococcosis. Two current limitations are: 1) The difficulties in interpreting studies using isolated macrophages in the context of the progression of infection, and 2) The use of high resolution imaging in understanding immune cell behavior during animal infection. Here we describe a high-content imaging method in a zebrafish model of cryptococcosis that permits the detailed analysis of macrophage interactions with C. neoformans during infection. Using this approach we demonstrate that, while macrophages are critical for control of C. neoformans, a failure of macrophage response is not the limiting defect in fatal infections. We find phagocytosis is restrained very early in infection and that increases in cryptococcal number are driven by intracellular proliferation. We show that macrophages preferentially phagocytose cryptococci with smaller polysaccharide capsules and that capsule size is greatly increased over twenty-four hours of infection, a change that is sufficient to severely limit further phagocytosis. Thus, high-content imaging of cryptococcal infection in vivo demonstrates how very early interactions between macrophages and cryptococci are critical in the outcome of cryptococcosis. PMID:26887656

  17. Sympathetic glial cells and macrophages develop different responses to Trypanosoma cruzi infection or lipopolysaccharide stimulation

    PubMed Central

    de Almeida-Leite, Camila Megale; Silva, Isabel Cristina Costa; Galvão, Lúcia Maria da Cunha; Arantes, Rosa Maria Esteves

    2014-01-01

    Nitric oxide (NO) participates in neuronal lesions in the digestive form of Chagas disease and the proximity of parasitised glial cells and neurons in damaged myenteric ganglia is a frequent finding. Glial cells have crucial roles in many neuropathological situations and are potential sources of NO. Here, we investigate peripheral glial cell response to Trypanosoma cruzi infection to clarify the role of these cells in the neuronal lesion pathogenesis of Chagas disease. We used primary glial cell cultures from superior cervical ganglion to investigate cell activation and NO production after T. cruzi infection or lipopolysaccharide (LPS) exposure in comparison to peritoneal macrophages. T. cruzi infection was greater in glial cells, despite similar levels of NO production in both cell types. Glial cells responded similarly to T. cruzi and LPS, but were less responsive to LPS than macrophages were. Our observations contribute to the understanding of Chagas disease pathogenesis, as based on the high susceptibility of autonomic glial cells to T. cruzi infection with subsequent NO production. Moreover, our findings will facilitate future research into the immune responses and activation mechanisms of peripheral glial cells, which are important for understanding the paradoxical responses of this cell type in neuronal lesions and neuroprotection. PMID:25075784

  18. Sympathetic glial cells and macrophages develop different responses to Trypanosoma cruzi infection or lipopolysaccharide stimulation.

    PubMed

    de Almeida-Leite, Camila Megale; Silva, Isabel Cristina Costa; Galvão, Lúcia Maria da Cunha; Arantes, Rosa Maria Esteves

    2014-07-01

    Nitric oxide (NO) participates in neuronal lesions in the digestive form of Chagas disease and the proximity of parasitised glial cells and neurons in damaged myenteric ganglia is a frequent finding. Glial cells have crucial roles in many neuropathological situations and are potential sources of NO. Here, we investigate peripheral glial cell response to Trypanosoma cruzi infection to clarify the role of these cells in the neuronal lesion pathogenesis of Chagas disease. We used primary glial cell cultures from superior cervical ganglion to investigate cell activation and NO production after T. cruzi infection or lipopolysaccharide (LPS) exposure in comparison to peritoneal macrophages. T. cruzi infection was greater in glial cells, despite similar levels of NO production in both cell types. Glial cells responded similarly to T. cruzi and LPS, but were less responsive to LPS than macrophages were. Our observations contribute to the understanding of Chagas disease pathogenesis, as based on the high susceptibility of autonomic glial cells to T. cruzi infection with subsequent NO production. Moreover, our findings will facilitate future research into the immune responses and activation mechanisms of peripheral glial cells, which are important for understanding the paradoxical responses of this cell type in neuronal lesions and neuroprotection.

  19. Human macrophage polarization in vitro: maturation and activation methods compared.

    PubMed

    Vogel, Daphne Y S; Glim, Judith E; Stavenuiter, Andrea W D; Breur, Marjolein; Heijnen, Priscilla; Amor, Sandra; Dijkstra, Christine D; Beelen, Robert H J

    2014-09-01

    Macrophages form a heterogeneous cell population displaying multiple functions, and can be polarized into pro- (M1) or anti-inflammatory (M2) macrophages, by environmental factors. Their activation status reflects a beneficial or detrimental role in various diseases. Currently several in vitro maturation and activation protocols are used to induce an M1 or M2 phenotype. Here, the impact of different maturation factors (NHS, M-CSF, or GM-CSF) and activation methods (IFN-γ/LPS, IL-4, dexamethason, IL-10) on the macrophage phenotype was determined. Regarding macrophage morphology, pro-inflammatory (M1) activation stimulated cell elongation, and anti-inflammatory (M2) activation induced a circular appearance. Activation with pro-inflammatory mediators led to increased CD40 and CD64 expression, whereas activation with anti-inflammatory factors resulted in increased levels of MR and CD163. Production of pro-inflammatory cytokines was induced by activation with IFN-γ/LPS, and TGF-β production was enhanced by the maturation factors M-CSF and GM-CSF. Our data demonstrate that macrophage marker expression and cytokine production in vitro is highly dependent on both maturation and activation methods. In vivo macrophage activation is far more complex, since a plethora of stimuli are present. Hence, defining the macrophage activation status ex vivo on a limited number of markers could be indecisive. From this study we conclude that maturation with M-CSF or GM-CSF induces a moderate anti- or pro-inflammatory state respectively, compared to maturation with NHS. CD40 and CD64 are the most distinctive makers for human M1 and CD163 and MR for M2 macrophage activation and therefore can be helpful in determining the activation status of human macrophages ex vivo.

  20. Macrophages sense and kill bacteria through carbon monoxide–dependent inflammasome activation

    PubMed Central

    Wegiel, Barbara; Larsen, Rasmus; Gallo, David; Chin, Beek Yoke; Harris, Clair; Mannam, Praveen; Kaczmarek, Elzbieta; Lee, Patty J.; Zuckerbraun, Brian S.; Flavell, Richard; Soares, Miguel P.; Otterbein, Leo E.

    2014-01-01

    Microbial clearance by eukaryotes relies on complex and coordinated processes that remain poorly understood. The gasotransmitter carbon monoxide (CO) is generated by the stress-responsive enzyme heme oxygenase-1 (HO-1, encoded by Hmox1), which is highly induced in macrophages in response to bacterial infection. HO-1 deficiency results in inadequate pathogen clearance, exaggerated tissue damage, and increased mortality. Here, we determined that macrophage-generated CO promotes ATP production and release by bacteria, which then activates the Nacht, LRR, and PYD domains-containing protein 3 (NALP3) inflammasome, intensifying bacterial killing. Bacterial killing defects in HO-1–deficient murine macrophages were restored by administration of CO. Moreover, increased CO levels enhanced the bacterial clearance capacity of human macrophages and WT murine macrophages. CO-dependent bacterial clearance required the NALP3 inflammasome, as CO did not increase bacterial killing in macrophages isolated from NALP3-deficient or caspase-1–deficient mice. IL-1β cleavage and secretion were impaired in HO-1–deficient macrophages, and CO-dependent processing of IL-1β required the presence of bacteria-derived ATP. We found that bacteria remained viable to generate and release ATP in response to CO. The ATP then bound to macrophage nucleotide P2 receptors, resulting in activation of the NALP3/IL-1β inflammasome to amplify bacterial phagocytosis by macrophages. Taken together, our results indicate that macrophage-derived CO permits efficient and coordinated regulation of the host innate response to invading microbes. PMID:25295542

  1. Monocytes/macrophages infected with Toxoplasma gondii do not increase co-stimulatory molecules while maintaining their migratory ability.

    PubMed

    Seipel, Daniele; Ribeiro-Gomes, Flavia Lima; Barcelos, Michelle Willmen; Ramalho, André Villaça; Kanashiro, Milton M; Kipnis, Thereza Liberman; Arnholdt, Andrea Cristina Veto

    2009-09-01

    Toxoplasma gondii is an obligate intracellular parasite that is able to disseminate into deep tissues and cross biological barriers, reaching immunoprivileged sites such as the brain and retina. The parasite is able to infect macrophages and dendritic cells and use them for dispersal throughout the body, but the activation state of those cells is unknown. We investigated the ability of human and murine cells from monocytic/macrophage lineages that had not previously been exposed to inflammatory cytokines to up-regulate co-stimulatory and adhesion molecules upon infection. Toxoplasma gondii-infected human monocytes (freshly isolated and THP1 lineage) were unable to up-regulate CD86, CD83, CD40 or CD1a. CD80 expression increased in infected cells but expression of l-selectin and beta2 integrin was unaltered. We evaluated the ability of infected macrophages from wild type C57/BL/6 or CD14(-/-) mice to migrate in 8 mum transwells. Infected cells from CD14(-/-) mice were more likely to de-adhere than infected cells from wild type mice but they did not show any increase in migratory ability. The non-stimulatory profile of these infected cells may contribute to parasite spread throughout the lymphatic circulation in the initial phases of infection.

  2. Elevated Numbers of CD163+ Macrophages in Hearts of Simian Immunodeficiency Virus-Infected Monkeys Correlate with Cardiac Pathology and Fibrosis

    PubMed Central

    Walker, Joshua A.; Sulciner, Megan L.; Nowicki, Katherine D.; Miller, Andrew D.; Burdo, Tricia H.

    2014-01-01

    Abstract The role of macrophage activation, traffic, and accumulation on cardiac pathology was examined in 23 animals. Seventeen animals were simian immunodeficiency virus (SIV) infected, 12 were CD8 lymphocyte depleted, and the remaining six were uninfected controls (two CD8 lymphocyte depleted, four nondepleted). None of the uninfected controls had cardiac pathology. One of five (20%) SIV-infected, non-CD8 lymphocyte-depleted animals had minor cardiac pathology with increased numbers of macrophages in ventricular tissue compared to controls. Seven of the 12 (58%) SIV-infected, CD8 lymphocyte-depleted animals had cardiac pathology in ventricular tissues, including macrophage infiltration and myocardial degeneration. The extent of fibrosis (measured as the percentage of collagen per tissue area) was increased 41% in SIV-infected, CD8 lymphocyte-depleted animals with cardiac pathology compared to animals without pathological abnormalities. The number of CD163+ macrophages increased significantly in SIV-infected, CD8 lymphocyte-depleted animals with cardiac pathology compared to ones without pathology (1.66-fold) and controls (5.42-fold). The percent of collagen (percentage of collagen per total tissue area) positively correlated with macrophage numbers in ventricular tissue in SIV-infected animals. There was an increase of BrdU+ monocytes in the heart during late SIV infection, regardless of pathology. These data implicate monocyte/macrophage activation and accumulation in the development of cardiac pathology with SIV infection. PMID:24524407

  3. Activation of TLR3/interferon signaling pathway by bluetongue virus results in HIV inhibition in macrophages.

    PubMed

    Dai, Ming; Wang, Xu; Li, Jie-Liang; Zhou, Yu; Sang, Ming; Liu, Jin-Biao; Wu, Jian-Guo; Ho, Wen-Zhe

    2015-12-01

    Bluetongue virus (BTV), a nonenveloped double-stranded RNA virus, is a potent inducer of type Ι interferons in multiple cell systems. In this study, we report that BTV16 treatment of primary human macrophages induced both type I and III IFN expression, resulting in the production of multiple antiviral factors, including myxovirus resistance protein A, 2',5'-oligoadenylate synthetase, and the IFN-stimulated gene 56. Additionally, BTV-treated macrophages expressed increased HIV restriction factors (apolipoprotein B mRNA-editing enzyme catalytic polypeptide 3 G/F/H) and CC chemokines (macrophage inflammatory protein 1-α, macrophage inflammatory protein 1-β, regulated on activation of normal T cell expressed and secreted), the ligands for HIV entry coreceptor CC chemokine receptor type 5. BTV16 also induced the expression of tetherin, which restricts HIV release from infected cells. Furthermore, TLR3 signaling of macrophages by BTV16 resulted in the induction of several anti-HIV microRNAs (miRNA-28, -29a, -125b, -150, -223, and -382). More importantly, the induction of antiviral responses by BTV resulted in significant suppression of HIV in macrophages. These findings demonstrate the potential of BTV-mediated TLR3 activation in macrophage innate immunity against HIV.

  4. Effect of macrophage classical (M1) activation on implant-adherent macrophage interactions with Staphylococcus epidermidis: A murine in vitro model system.

    PubMed

    Park, Kyung R; Bryers, James D

    2012-08-01

    A model in vitro system was developed for eliciting classical (M1) activation of surface-adherent murine macrophages, which was then used to study the interaction of the M1 macrophages with Staphylococcus epidermidis. Glass substrata were first covalently grafted with a mixture of methoxy- and biotin-terminated silanated polyethylene glycol. Interferon (IFN)-γ and/or lipopolysaccharide (LPS), ligands known to induce the highly microbicidal M1 activation state in macrophages, were biotinylated and immobilized by way of a streptavidin intermediate to the biotin-PEG base substratum. Assessment of mouse bone marrow-derived macrophage (BMDM) interleukin (IL)-12(p40) and nitric oxide response to the fabricated surfaces confirmed that the model system achieved activation of adherent macrophage: IFN-γ-presenting surfaces primed cells for M1 activation, LPS-presenting surfaces elicited innate activation, and surface presenting a combination of IFN-γ and LPS induced M1 activation. The phagocytic and microbicidal capacity of activated, surface-adherent BMDM was evaluated using S. epidermidis, a bacterial species prevalent in implant-associated infections. Results indicate that M1 activation of implant-adherent macrophages trends towards diminishing their phagocytic capacity, but enhances their microbicidal capacity for S. epidermidis.

  5. Importance of Endosomal Cathelicidin Degradation To Enhance DNA-Induced Chicken Macrophage Activation.

    PubMed

    Coorens, Maarten; van Dijk, Albert; Bikker, Floris; Veldhuizen, Edwin J A; Haagsman, Henk P

    2015-10-15

    Cathelicidins are essential in the protection against invading pathogens through both their direct antimicrobial activity and their immunomodulatory functions. Although cathelicidins are known to modulate activation by several TLR ligands, little is known about their influence on DNA-induced macrophage activation. In this study, we explored the effects of cathelicidins on DNA-induced activation of chicken macrophages and elucidated the intracellular processes underlying these effects. Our results show that chicken cathelicidin (CATH)-2 strongly enhances DNA-induced activation of both chicken and mammalian macrophages because of enhanced endocytosis of DNA-CATH-2 complexes. After endocytosis, DNA is liberated from the complex because of proteolytic breakdown of CATH-2, after which TLR21 is activated. This leads to increased cytokine expression and NO production. Through the interaction with DNA, CATH-2 can play an important role in modulating the immune response at sites of infection. These observations underline the importance of cathelicidins in sensing bacterial products and regulating immune responses.

  6. The macrophage response to bacteria. Modulation of macrophage functional activity by peptidoglycan from Moraxella (Branhamella) catarrhalis.

    PubMed Central

    Keller, R; Gustafson, J E; Keist, R

    1992-01-01

    Moraxella (Branhamella) catarrhalis organisms have been shown to be particularly efficient in inducing in a pure population of bone marrow-derived mononuclear phagocytes secretory and cellular activities. In the present study, the ability of peptidoglycan from this Gram-negative organism to trigger a macrophage response was compared with that elicited by peptidoglycan from Staphylococcus aureus and Bacillus subtilis. The results show that the three peptidoglycans were similarly active in triggering the secretion of tumour necrosis factor and tumouricidal activity but differed considerably in their ability to induce the generation of nitrite in macrophages; in this respect, peptidoglycan from M. catarrhalis was particularly potent. The impressive capacity of M. catarrhalis peptidoglycan to induce in low concentration the secretion of tumour necrosis factor and nitrite and tumouricidal activity may, in addition to its lipopolysaccharide, contribute to the extraordinary potential of this organism to trigger the functional activities of macrophages. PMID:1516255

  7. Trypanosoma cruzi Calreticulin Topographical Variations in Parasites Infecting Murine Macrophages

    PubMed Central

    González, Andrea; Valck, Carolina; Sánchez, Gittith; Härtel, Steffen; Mansilla, Jorge; Ramírez, Galia; Fernández, María Soledad; Arias, José Luis; Galanti, Norbel; Ferreira, Arturo

    2015-01-01

    Trypanosoma cruzi calreticulin (TcCRT), a 47-kDa chaperone, translocates from the endoplasmic reticulum to the area of flagellum emergence. There, it binds to complement components C1 and mannan-binding lectin (MBL), thus acting as a main virulence factor, and inhibits the classical and lectin pathways. The localization and functions of TcCRT, once the parasite is inside the host cell, are unknown. In parasites infecting murine macrophages, polyclonal anti-TcCRT antibodies detected TcCRT mainly in the parasite nucleus and kinetoplast. However, with a monoclonal antibody (E2G7), the resolution and specificity of the label markedly improved, and TcCRT was detected mainly in the parasite kinetoplast. Gold particles, bound to the respective antibodies, were used as probes in electron microscopy. This organelle may represent a stopover and accumulation site for TcCRT, previous its translocation to the area of flagellum emergence. Finally, early during T. cruzi infection and by unknown mechanisms, an important decrease in the number of MHC-I positive host cells was observed. PMID:25758653

  8. Tim-3 blocking rescue macrophage and T cell function against Mycobacterium tuberculosis infection in HIV+ patients

    PubMed Central

    Sada-Ovalle, Isabel; Ocaña-Guzman, Ranferi; Pérez-Patrigeón, Santiago; Chávez-Galán, Leslie; Sierra-Madero, Juan; Torre-Bouscoulet, Luis; Addo, Marylyn M.

    2015-01-01

    Introduction T cell immunoglobulin and mucin domain (Tim) 3 and programmed death 1 (PD-1) are co-inhibitory receptors involved in the so-called T cell exhaustion, and in vivo blockade of these molecules restores T cell dysfunction. High expression of Tim-3 and PD-1 is induced after chronic antigen-specific stimulation of T cells during HIV infection. We have previously demonstrated that the interaction of Tim-3 with its ligand galectin-9 induces macrophage activation and killing of Mycobacterium tuberculosis. Our aim in this study was to analyze the Tim-3 expression profile before and after six months of antiretroviral therapy and the impact of Tim-3 and PD-1 blocking on immunity against M. tuberculosis. Materials and methods HIV+ patients naïve to anti-retroviral therapy (ART) were followed up for six months. Peripheral immune-cell phenotype (CD38/HLA-DR/galectin-9/Tim-3 and PD-1) was assessed by flow cytometry. Supernatants were analyzed with a multiplex cytokine detection system (human Th1/Th2 cytokine Cytometric Bead Array) by flow cytometry. Control of bacterial growth was evaluated by using an in vitro experimental model in which virulent M. tuberculosis-infected macrophages were cultured with T cells in the presence or absence of Tim-3 and PD-1 blocking antibodies. Interleukin-1 beta treatment of infected macrophages was evaluated by enumerating colony-forming units. Results We showed that HIV+ patients had an increased expression of Tim-3 in T cells and were able to control bacterial growth before ART administration. By blocking Tim-3 and PD-1, macrophages and T cells recovered their functionality and had a higher ability to control bacterial growth; this result was partially dependent on the restitution of cytokine production. Conclusions In this study, we demonstrated that increased Tim-3 expression can limit the ability of the immune system to control the infection of intracellular bacteria such as M. tuberculosis. The use of ART and the in vitro

  9. MicroRNA-155 in exosomes secreted from helicobacter pylori infection macrophages immunomodulates inflammatory response

    PubMed Central

    Wang, Jianjun; Deng, Zhiyong; Wang, Zeyou; Wu, Jianhong; Gu, Tao; Jiang, Yibiao; Li, Guangxin

    2016-01-01

    Exosomes containing microRNA-155 act as molecule carriers during immune cell-cell communication and play an important role in the inflammatory response of H. pylori infection macrophages. Previous reports have found that miR-155 was over-expressed in H. pylori infection macrophages, but the significance of which is still unknown. In this study, we analyzed the impact of miR-155 loaded in exosomes derived from macrophages to the inflammatory response of H. pylori infection macrophages and possible mechanisms. We found that miR-155 promoted the expression of inflammatory cytokines including TNF-a, IL-6, IL-23, but also increased the expression of CD40, CD63, CD81, and MCH-I. Meanwhile, inflammatory signal pathways proteins, such as MyD88, NF-κB in H. pylori infection macrophages were down-regulated due to the over-expression of miR-155. Experiments in vitro or in vivo revealed that miR-155 promoted macrophages to inhibit or kill H. pylori by regulating the inflammatory response of cells to prevent the gastritis caused by H. pylori infection. These findings contribute to the understanding of miR-155 contained in exosomes in inflammatory responses of H. pylori infection macrophages. PMID:27725852

  10. Effects of lipopolysaccharide on the catabolic activity of macrophages

    SciTech Connect

    Cluff, C.; Ziegler, H.K.

    1986-03-05

    The ability of macrophages to degrade and catabolize antigens is of relevance both as a means to process complex antigens prior to presentation to T cells, as well as a way to down regulate immune responses by destroying the antigenicity of polypeptides. With these considerations, the authors have investigated the regulation of macrophage catabolic activity by lipopolysaccharide (LPS). Catabolic activity was quantitated by following the distribution and molecular form of /sup 125/-I labelled surface components of heat-killed Listeria monocytogenes (HKLM) subsequent to their uptake by macrophages. They have compared the catabolic activity of macrophages from peritoneal exudates of mice injected i.p. with saline or LPS and have found that LPS-elicited macrophages display a greatly enhanced (3 fold) rate of catabolism. This increase in catabolic activity peaks 3 days after LPS injection and steadily declines thereafter, approaching a baseline level after 3 weeks. The enhancement of catabolic activity is under LPS gene control. LPS-elicited macrophages rapidly destroy the antigenicity of bacterial antigens and function poorly as antigen presenting cells in vitro. These results suggest that LPS elicits a macrophage population specialized for antigen degradation functions with negative regulatory effects on the induction of specific immune responses.

  11. Phagosome Migration and Velocity Measured in Live Primary Human Macrophages Infected with HIV-1.

    PubMed

    Lê-Bury, Gabrielle; Deschamps, Chantal; Dumas, Audrey; Niedergang, Florence

    2016-01-01

    Macrophages are phagocytic cells that play a major role at the crossroads between innate and specific immunity. They can be infected by the human immunodeficiency virus (HIV)-1 and because of their resistance to its cytopathic effects they can be considered to be persistent viral reservoirs. In addition, HIV-infected macrophages exhibit defective functions that contribute to the development of opportunistic diseases. The exact mechanism by which HIV-1 impairs the phagocytic response of macrophages was unknown. We had previously shown that the uptake of various particulate material by macrophages was inhibited when they were infected with HIV-1. This inhibition was only partial and phagosomes did form within HIV-infected macrophages. Therefore, we focused on analyzing the fate of these phagosomes. Phagosome maturation is accompanied by migration of these compartments towards the cell center, where they fuse with lysosomes, generating phagolysosomes, responsible for degradation of the ingested material. We used IgG-opsonized Sheep Red Blood Cells as a target for phagocytosis. To measure the speed of centripetal movement of phagosomes in individual HIV-infected macrophages, we used a combination of bright field and fluorescence confocal microscopy. We established a method to calculate the distance of phagosomes towards the nucleus, and then to calculate the velocity of the phagosomes. HIV-infected cells were identified thanks to a GFP-expressing virus, but the method is applicable to non-infected cells or any type of infection or treatment. PMID:27684087

  12. Innate immune responses to rotavirus infection in macrophages depend on MAVS but involve neither the NLRP3 inflammasome nor JNK and p38 signaling pathways.

    PubMed

    Di Fiore, Izabel J M; Holloway, Gavan; Coulson, Barbara S

    2015-10-01

    Rotavirus infection is a major cause of life-threatening infantile gastroenteritis. The innate immune system provides an immediate mechanism of suppressing viral replication and is necessary for an effective adaptive immune response. Innate immunity involves host recognition of viral infection and establishment of a powerful antiviral state through the expression of pro-inflammatory cytokines such as type-1 interferon (IFN). Macrophages, the front-line cells of innate immunity, produce IFN and other cytokines in response to viral infection. However, the role of macrophages during rotavirus infection is not well defined. We demonstrate here that RRV rotavirus triggers the production of proinflammatory cytokines from mouse bone marrow-derived macrophages. IFN and antiviral cytokine production was abolished in rotavirus-infected MAVS (-/-) macrophages. This indicates that rotavirus triggers innate immunity in macrophages through RIG-I and/or MDA5 viral recognition, and MAVS signaling is essential for cytokine responses in macrophages. Rotavirus induced IFN expression in both wild type and MDA5 (-/-) macrophages, showing that MDA5 is not essential for IFN secretion following infection, and RIG-I and MDA5 may act redundantly in promoting rotavirus recognition. Interestingly, rotavirus neither stimulated mitogen-activated protein kinases p38 and JNK nor activated the NLRP3 inflammasome, demonstrating that these components might not be involved in innate responses to rotavirus infection in macrophages. Our results indicate that rotavirus elicits intracellular signaling in macrophages, resulting in the induction of IFN and antiviral cytokines, and advance our understanding of the involvement of these cells in innate responses against rotavirus.

  13. TRANSCRIPTIONAL RESPONSE OF CHICKEN MACROPHAGES TO SALMONELLA ENTERICA SEROVAR ENTERITIDIS INFECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The transcriptional profiles of chicken macrophages (HD11) infected with Salmonella enterica serovar Enteritidis (SE) were analyzed by using avian macrophage microarray and real time RT-PCR. Out of 4,906 array elements interrogated, 269 genes exhibited a 2-fold change (P < 0.001) over a 24-hour time...

  14. Virulent Mycobacterium bovis Beijing Strain Activates the NLRP7 Inflammasome in THP-1 Macrophages

    PubMed Central

    Zhou, Yang; Shah, Syed Zahid Ali; Yang, Lifeng; Zhang, Zhongqiu; Zhou, Xiangmei; Zhao, Deming

    2016-01-01

    Mycobacterium bovis is the causative agent of tuberculosis in a wide range of mammals, including humans. Macrophages are the first line of host defense. They secrete proinflammatory cytokines, such as interleukin-1 beta (IL-1β), in response to mycobacterial infection, but the underlying mechanisms by which human macrophages are activated and release IL-1β following M. bovis infection are poorly understood. Here we show that the ‘nucleotide binding and oligomerization of domain-like receptor (NLR) family pyrin domain containing 7 protein’ (NLRP7) inflammasome is involved in IL-1β secretion and caspase-1 activation induced by M. bovis infection in THP-1 macrophages. NLRP7 inflammasome activation promotes the induction of pyroptosis as well as the expression of tumor necrosis factor alpha (TNF-α), Chemokine (C-C motif) ligand 3 (CCL3) and IL-1β mRNAs. Thus, the NLRP7 inflammasome contributes to IL-1β secretion and induction of pyroptosis in response to M. bovis infection in THP-1 macrophages. PMID:27043315

  15. Integration is required for productive infection of monocyte-derived macrophages by human immunodeficiency virus type 1.

    PubMed Central

    Englund, G; Theodore, T S; Freed, E O; Engelman, A; Martin, M A

    1995-01-01

    Certain human immunodeficiency virus type 1 (HIV-1) isolates are able to productively infect nondividing cells of the monocyte/macrophage lineage. We have used a molecular genetic approach to construct two different HIV-1 integrase mutants that were studied in the context of an infectious, macrophage-tropic HIV-1 molecular clone. One mutant, HIV-1 delta D(35)E, containing a 37-residue deletion within the central, catalytic domain of integrase, was noninfectious in both peripheral blood mononuclear cells and monocyte-derived macrophages. The HIV-1 delta D(35)E mutant, however, exhibited defects in the assembly and/or release of progeny virions in transient transfection assays, as well as defects in entry and/or viral DNA synthesis during the early stages of monocyte-derived macrophage infection. The second mutant, HIV-1D116N/8, containing a single Asp-to-Asn substitution at the invariant Asp-116 residue of integrase, was also noninfectious in both peripheral blood mononuclear cells and monocyte-derived macrophages but, in contrast to HIV-1 delta D(35)E, was indistinguishable from wild-type virus in reverse transcriptase production. PCR analysis indicated that HIV-1D116N/8 entered monocyte-derived macrophages efficiently and reverse transcribed its RNA but was unable to complete its replication cycle because of a presumed block to integration. These data are consistent with the hypothesis that integration is an obligate step in productive HIV-1 infection of activated peripheral blood mononuclear cells and primary human macrophage cultures. PMID:7707554

  16. Dual Transcriptome Profiling of Leishmania-Infected Human Macrophages Reveals Distinct Reprogramming Signatures

    PubMed Central

    Fernandes, Maria Cecilia; Dillon, Laura A. L.; Belew, Ashton Trey; Bravo, Hector Corrada; Mosser, David M.

    2016-01-01

    ABSTRACT Macrophages are mononuclear phagocytes that constitute a first line of defense against pathogens. While lethal to many microbes, they are the primary host cells of Leishmania spp. parasites, the obligate intracellular pathogens that cause leishmaniasis. We conducted transcriptomic profiling of two Leishmania species and the human macrophage over the course of intracellular infection by using high-throughput RNA sequencing to characterize the global gene expression changes and reprogramming events that underlie the interactions between the pathogen and its host. A systematic exclusion of the generic effects of large-particle phagocytosis revealed a vigorous, parasite-specific response of the human macrophage early in the infection that was greatly tempered at later time points. An analogous temporal expression pattern was observed with the parasite, suggesting that much of the reprogramming that occurs as parasites transform into intracellular forms generally stabilizes shortly after entry. Following that, the parasite establishes an intracellular niche within macrophages, with minimal communication between the parasite and the host cell later during the infection. No significant difference was observed between parasite species transcriptomes or in the transcriptional response of macrophages infected with each species. Our comparative analysis of gene expression changes that occur as mouse and human macrophages are infected by Leishmania spp. points toward a general signature of the Leishmania-macrophage infectome. PMID:27165796

  17. The frequency and duration of Salmonella–macrophage adhesion events determines infection efficiency

    PubMed Central

    Achouri, Sarra; Wright, John A.; Evans, Lewis; Macleod, Charlotte; Fraser, Gillian; Cicuta, Pietro; Bryant, Clare E.

    2015-01-01

    Salmonella enterica causes a range of important diseases in humans and a in a variety of animal species. The ability of bacteria to adhere to, invade and survive within host cells plays an important role in the pathogenesis of Salmonella infections. In systemic salmonellosis, macrophages constitute a niche for the proliferation of bacteria within the host organism. Salmonella enterica serovar Typhimurium is flagellated and the frequency with which this bacterium collides with a cell is important for infection efficiency. We investigated how bacterial motility affects infection efficiency, using a combination of population-level macrophage infection experiments and direct imaging of single-cell infection events, comparing wild-type and motility mutants. Non-motile and aflagellate bacterial strains, in contrast to wild-type bacteria, collide less frequently with macrophages, are in contact with the cell for less time and infect less frequently. Run-biased Salmonella also collide less frequently with macrophages but maintain contact with macrophages for a longer period of time than wild-type strains and infect the cells more readily. Our results suggest that uptake of S. Typhimurium by macrophages is dependent upon the duration of contact time of the bacterium with the cell, in addition to the frequency with which the bacteria collide with the cell. PMID:25533091

  18. Macrophage polarization in inflammatory diseases.

    PubMed

    Liu, Yan-Cun; Zou, Xian-Biao; Chai, Yan-Fen; Yao, Yong-Ming

    2014-01-01

    Diversity and plasticity are two hallmarks of macrophages. M1 macrophages (classically activated macrophages) are pro-inflammatory and have a central role in host defense against infection, while M2 macrophages (alternatively activated macrophages) are associated with responses to anti-inflammatory reactions and tissue remodeling, and they represent two terminals of the full spectrum of macrophage activation. Transformation of different phenotypes of macrophages regulates the initiation, development, and cessation of inflammatory diseases. Here we reviewed the characters and functions of macrophage polarization in infection, atherosclerosis, obesity, tumor, asthma, and sepsis, and proposed that targeting macrophage polarization and skewing their phenotype to adapt to the microenvironment might hold great promise for the treatment of inflammatory diseases.

  19. Jacalin-Activated Macrophages Exhibit an Antitumor Phenotype

    PubMed Central

    Danella Polli, Cláudia; Pereira Ruas, Luciana; Chain Veronez, Luciana; Herrero Geraldino, Thais; Rossetto de Morais, Fabiana; Roque-Barreira, Maria Cristina; Pereira-da-Silva, Gabriela

    2016-01-01

    Tumor-associated macrophages (TAMs) have an ambiguous and complex role in the carcinogenic process, since these cells can be polarized into different phenotypes (proinflammatory, antitumor cells or anti-inflammatory, protumor cells) by the tumor microenvironment. Given that the interactions between tumor cells and TAMs involve several players, a better understanding of the function and regulation of TAMs is crucial to interfere with their differentiation in attempts to skew TAM polarization into cells with a proinflammatory antitumor phenotype. In this study, we investigated the modulation of macrophage tumoricidal activities by the lectin jacalin. Jacalin bound to macrophage surface and induced the expression and/or release of mainly proinflammatory cytokines via NF-κB signaling, as well as increased iNOS mRNA expression, suggesting that the lectin polarizes macrophages toward the antitumor phenotype. Therefore, tumoricidal activities of jacalin-stimulated macrophages were evaluated. High rates of tumor cell (human colon, HT-29, and breast, MCF-7, cells) apoptosis were observed upon incubation with supernatants from jacalin-stimulated macrophages. Taken together, these results indicate that jacalin, by exerting a proinflammatory activity, can direct macrophages to an antitumor phenotype. Deep knowledge of the regulation of TAM functions is essential for the development of innovative anticancer strategies. PMID:27119077

  20. The Macrophage-Specific Promoter mfap4 Allows Live, Long-Term Analysis of Macrophage Behavior during Mycobacterial Infection in Zebrafish.

    PubMed

    Walton, Eric M; Cronan, Mark R; Beerman, Rebecca W; Tobin, David M

    2015-01-01

    Transgenic labeling of innate immune cell lineages within the larval zebrafish allows for real-time, in vivo analyses of microbial pathogenesis within a vertebrate host. To date, labeling of zebrafish macrophages has been relatively limited, with the most specific expression coming from the mpeg1 promoter. However, mpeg1 transcription at both endogenous and transgenic loci becomes attenuated in the presence of intracellular pathogens, including Salmonella typhimurium and Mycobacterium marinum. Here, we describe mfap4 as a macrophage-specific promoter capable of producing transgenic lines in which transgene expression within larval macrophages remains stable throughout several days of infection. Additionally, we have developed a novel macrophage-specific Cre transgenic line under the control of mfap4, enabling macrophage-specific expression using existing floxed transgenic lines. These tools enrich the repertoire of transgenic lines and promoters available for studying zebrafish macrophage dynamics during infection and inflammation and add flexibility to the design of future macrophage-specific transgenic lines.

  1. From amoeba to macrophages: exploring the molecular mechanisms of Legionella pneumophila infection in both hosts.

    PubMed

    Escoll, Pedro; Rolando, Monica; Gomez-Valero, Laura; Buchrieser, Carmen

    2013-01-01

    Legionella pneumophila is a Gram-negative bacterium and the causative agent of Legionnaires' disease. It replicates within amoeba and infects accidentally human macrophages. Several similarities are seen in the L. pneumophila-infection cycle in both hosts, suggesting that the tools necessary for macrophage infection may have evolved during co-evolution of L. pneumophila and amoeba. The establishment of the Legionella-containing vacuole (LCV) within the host cytoplasm requires the remodeling of the LCV surface and the hijacking of vesicles and organelles. Then L. pneumophila replicates in a safe intracellular niche in amoeba and macrophages. In this review we will summarize the existing knowledge of the L. pneumophila infection cycle in both hosts at the molecular level and compare the factors involved within amoeba and macrophages. This knowledge will be discussed in the light of recent findings from the Acanthamoeba castellanii genome analyses suggesting the existence of a primitive immune-like system in amoeba.

  2. Vasodilator-Stimulated Phosphoprotein Activity Is Required for Coxiella burnetii Growth in Human Macrophages

    PubMed Central

    Colonne, Punsiri M.; Winchell, Caylin G.; Graham, Joseph G.; Onyilagha, Frances I.; MacDonald, Laura J.; Doeppler, Heike R.; Storz, Peter; Kurten, Richard C.; Beare, Paul A.; Voth, Daniel E.

    2016-01-01

    Coxiella burnetii is an intracellular bacterial pathogen that causes human Q fever, an acute flu-like illness that can progress to chronic endocarditis and liver and bone infections. Humans are typically infected by aerosol-mediated transmission, and C. burnetii initially targets alveolar macrophages wherein the pathogen replicates in a phagolysosome-like niche known as the parasitophorous vacuole (PV). C. burnetii manipulates host cAMP-dependent protein kinase (PKA) signaling to promote PV formation, cell survival, and bacterial replication. In this study, we identified the actin regulatory protein vasodilator-stimulated phosphoprotein (VASP) as a PKA substrate that is increasingly phosphorylated at S157 and S239 during C. burnetii infection. Avirulent and virulent C. burnetii triggered increased levels of phosphorylated VASP in macrophage-like THP-1 cells and primary human alveolar macrophages, and this event required the Cα subunit of PKA. VASP phosphorylation also required bacterial protein synthesis and secretion of effector proteins via a type IV secretion system, indicating the pathogen actively triggers prolonged VASP phosphorylation. Optimal PV formation and intracellular bacterial replication required VASP activity, as siRNA-mediated depletion of VASP reduced PV size and bacterial growth. Interestingly, ectopic expression of a phospho-mimetic VASP (S239E) mutant protein prevented optimal PV formation, whereas VASP (S157E) mutant expression had no effect. VASP (S239E) expression also prevented trafficking of bead-containing phagosomes to the PV, indicating proper VASP activity is critical for heterotypic fusion events that control PV expansion in macrophages. Finally, expression of dominant negative VASP (S157A) in C. burnetii-infected cells impaired PV formation, confirming importance of the protein for proper infection. This study provides the first evidence of VASP manipulation by an intravacuolar bacterial pathogen via activation of PKA in human

  3. Immunoprotective effect of lentinan in combination with miltefosine on Leishmania-infected J-774A.1 macrophages.

    PubMed

    Shivahare, R; Ali, W; Singh, U S; Natu, S M; Khattri, S; Puri, S K; Gupta, S

    2016-10-01

    Rejuvenation of deteriorated host immune functions is imperative for successful annihilation of Leishmania parasites. The use of immunomodulatory agents may have several advantages as they conquer immunosuppression and, when given in combination, improve current therapeutic regimens. We herein investigated the immunostimulatory potency of a β-glucan, lentinan either alone or in combination with short dose of standard drug, miltefosine on Leishmania-infected J-774A.1 macrophages. Our study shows that infected macrophages when stimulated with 2.5 μg/mL and above concentrations of lentinan secreted significant amount of host-protective molecules. The in vitro interaction between lentinan and miltefosine showed some synergy (mean sum of fractional inhibitory concentration [mean ∑FIC] 0.87) at IC50 level. Lentinan (2.5 μg/mL) plus low-dose miltefosine (2 μM) displayed heightened level of pro-inflammatory cytokines, IL-12 (13.6-fold) and TNF-α (6.8-fold) along with nitric oxide (7.2-fold higher) when compared with infected control. In combination group, we also observed remarkably (P<.001) suppressed levels of anti-inflammatory cytokines, IL-10 and TGF-β, than that of untreated macrophages. Additionally, in comparison with infected group, we observed significant induction in phagocytic activity of macrophages in combination with treated group. Collectively, these findings emphasize the immunostimulatory effect of lentinan alone and in combination with low dose of miltefosine against Leishmania donovani.

  4. Inhibition of nuclear factor-kappa B activation decreases survival of Mycobacterium tuberculosis in human macrophages.

    PubMed

    Bai, Xiyuan; Feldman, Nicole E; Chmura, Kathryn; Ovrutsky, Alida R; Su, Wen-Lin; Griffin, Laura; Pyeon, Dohun; McGibney, Mischa T; Strand, Matthew J; Numata, Mari; Murakami, Seiji; Gaido, Loretta; Honda, Jennifer R; Kinney, William H; Oberley-Deegan, Rebecca E; Voelker, Dennis R; Ordway, Diane J; Chan, Edward D

    2013-01-01

    Nuclear factor-kappa B (NFκB) is a ubiquitous transcription factor that mediates pro-inflammatory responses required for host control of many microbial pathogens; on the other hand, NFκB has been implicated in the pathogenesis of other inflammatory and infectious diseases. Mice with genetic disruption of the p50 subunit of NFκB are more likely to succumb to Mycobacterium tuberculosis (MTB). However, the role of NFκB in host defense in humans is not fully understood. We sought to examine the role of NFκB activation in the immune response of human macrophages to MTB. Targeted pharmacologic inhibition of NFκB activation using BAY 11-7082 (BAY, an inhibitor of IκBα kinase) or an adenovirus construct with a dominant-negative IκBα significantly decreased the number of viable intracellular mycobacteria recovered from THP-1 macrophages four and eight days after infection. The results with BAY were confirmed in primary human monocyte-derived macrophages and alveolar macrophages. NFκB inhibition was associated with increased macrophage apoptosis and autophagy, which are well-established killing mechanisms of intracellular MTB. Inhibition of the executioner protease caspase-3 or of the autophagic pathway significantly abrogated the effects of BAY. We conclude that NFκB inhibition decreases viability of intracellular MTB in human macrophages via induction of apoptosis and autophagy.

  5. Inhibition of nuclear factor-kappa B activation decreases survival of Mycobacterium tuberculosis in human macrophages.

    PubMed

    Bai, Xiyuan; Feldman, Nicole E; Chmura, Kathryn; Ovrutsky, Alida R; Su, Wen-Lin; Griffin, Laura; Pyeon, Dohun; McGibney, Mischa T; Strand, Matthew J; Numata, Mari; Murakami, Seiji; Gaido, Loretta; Honda, Jennifer R; Kinney, William H; Oberley-Deegan, Rebecca E; Voelker, Dennis R; Ordway, Diane J; Chan, Edward D

    2013-01-01

    Nuclear factor-kappa B (NFκB) is a ubiquitous transcription factor that mediates pro-inflammatory responses required for host control of many microbial pathogens; on the other hand, NFκB has been implicated in the pathogenesis of other inflammatory and infectious diseases. Mice with genetic disruption of the p50 subunit of NFκB are more likely to succumb to Mycobacterium tuberculosis (MTB). However, the role of NFκB in host defense in humans is not fully understood. We sought to examine the role of NFκB activation in the immune response of human macrophages to MTB. Targeted pharmacologic inhibition of NFκB activation using BAY 11-7082 (BAY, an inhibitor of IκBα kinase) or an adenovirus construct with a dominant-negative IκBα significantly decreased the number of viable intracellular mycobacteria recovered from THP-1 macrophages four and eight days after infection. The results with BAY were confirmed in primary human monocyte-derived macrophages and alveolar macrophages. NFκB inhibition was associated with increased macrophage apoptosis and autophagy, which are well-established killing mechanisms of intracellular MTB. Inhibition of the executioner protease caspase-3 or of the autophagic pathway significantly abrogated the effects of BAY. We conclude that NFκB inhibition decreases viability of intracellular MTB in human macrophages via induction of apoptosis and autophagy. PMID:23634218

  6. Inhibition of Nuclear Factor-Kappa B Activation Decreases Survival of Mycobacterium tuberculosis in Human Macrophages

    PubMed Central

    Chmura, Kathryn; Ovrutsky, Alida R.; Su, Wen-Lin; Griffin, Laura; Pyeon, Dohun; McGibney, Mischa T.; Strand, Matthew J.; Numata, Mari; Murakami, Seiji; Gaido, Loretta; Honda, Jennifer R.; Kinney, William H.; Oberley-Deegan, Rebecca E.; Voelker, Dennis R.; Ordway, Diane J.; Chan, Edward D.

    2013-01-01

    Nuclear factor-kappa B (NFκB) is a ubiquitous transcription factor that mediates pro-inflammatory responses required for host control of many microbial pathogens; on the other hand, NFκB has been implicated in the pathogenesis of other inflammatory and infectious diseases. Mice with genetic disruption of the p50 subunit of NFκB are more likely to succumb to Mycobacterium tuberculosis (MTB). However, the role of NFκB in host defense in humans is not fully understood. We sought to examine the role of NFκB activation in the immune response of human macrophages to MTB. Targeted pharmacologic inhibition of NFκB activation using BAY 11-7082 (BAY, an inhibitor of IκBα kinase) or an adenovirus construct with a dominant-negative IκBα significantly decreased the number of viable intracellular mycobacteria recovered from THP-1 macrophages four and eight days after infection. The results with BAY were confirmed in primary human monocyte-derived macrophages and alveolar macrophages. NFκB inhibition was associated with increased macrophage apoptosis and autophagy, which are well-established killing mechanisms of intracellular MTB. Inhibition of the executioner protease caspase-3 or of the autophagic pathway significantly abrogated the effects of BAY. We conclude that NFκB inhibition decreases viability of intracellular MTB in human macrophages via induction of apoptosis and autophagy. PMID:23634218

  7. Infection of white rat peritoneal macrophages with Toxoplasma gondii, (Coccidia: Sarcocystidae) after Trypanosoma lewisi (Kinetoplastida: Trypanosomatidae) infection.

    PubMed

    Catarinella, G; Chinchilla, M; Guerrero, O M; Castro, A

    1999-09-01

    Peritoneal macrophages from Wistar rats, inoculated and non-inoculated with 10(6) T. lewisi trypomastigotes, were cultured and infected with 10(6) T. gondii tachyzoites. Multiplication rates of this parasite were studied after 1, 24 and 48 h of infection but there were not significant differences between the number of parasites found inside of macrophages coming, either from T. lewisi infected or non infected rats. On the other hand, in vivo studies of Toxoplasma multiplication inside peritoneal macrophages, showed that there is an increase of parasite number in cells from T. lewisi infected rats, as compared with those macrophages from non infected rats. This effect was statistically significant and was more evident after four days of infection. Therefore, it has been demonstrated that in vivo, but not in vitro T. lewisi infections, causes an important decrease of the natural resistance to T. gondii of the white rats, which is manifested by the major invasion and multiplication of the parasite inside of peritoneal macrophages.

  8. CrATP interferes in the promastigote-macrophage interaction in Leishmania amazonensis infection.

    PubMed

    Ennes-Vidal, V; Castro, R O S; Britto, C; Barrabin, H; D'Avila-Levy, C M; Moreira, O C

    2011-07-01

    Recent have shown the relationship between Ecto-Nucleoside-Triphosphate-Diphosphohydrolases (Ecto-NTPDases or ecto-nucleotidases) and virulence and infectivity in trypanosomatids. In this work, the inhibition of the ecto-ATPase activities and promastigote growth of Leishmania amazonensis by CrATP was characterized. Furthermore, this compound was used to investigate the role of ecto-nucleotidase in the interaction of L. amazonensis with resident peritoneal macrophages obtained from BALB/c mice. CrATP partially inhibits the ecto-ATPase activity, presenting Ki values of 575·7±199·1 and 383·5±79·0 μm, in the presence or absence of 5 mm MgCl2, respectively. The apparent Kms for ATP (2·9±0·5 mm to Mg2+-dependent ecto-ATPase and 0·4±0·2 mm to Mg2+-independent ecto-ATPase activities) are not significantly altered by CrATP, suggesting a reversible non-competitive inhibition of both enzymes. When CrATP was added to the cultivation medium at 500 μm, it drastically inhibited the cellular growth. The interaction of promastigote forms of L. amazonensis with BALB/c peritoneal macrophages is strongly affected by CrATP. When the parasites were treated with 500 μm CrATP before interacting with macrophages, the adhesion and endocytic indices were strongly reduced to 53·0±14·8% and 39·8±1·1%, respectively. These results indicate that ecto-nucleotidase plays an important role in the infection process caused by Leishmania amazonensis. PMID:21679488

  9. INTERLEUKIN-4- AND INTERLEUKIN-13-MEDIATED ALTERNATIVELY ACTIVATED MACROPHAGES: ROLES IN HOMEOSTASIS AND DISEASE

    PubMed Central

    Van Dyken, Steven J.; Locksley, Richard M.

    2013-01-01

    The macrophage, a versatile cell type prominently involved in host defense and immunity, assumes a distinct state of alternative activation in the context of polarized type 2 immune responses such as allergic inflammation and helminth infection. This alternatively activated phenotype is induced by the canonical type 2 cytokines interleukin (IL)-4 and IL-13, which mediate expression of several characteristic markers along with a dramatic shift in macrophage metabolic pathways that influence surrounding cells and tissues. We discuss recent advances in the understanding of IL-4- and IL-13-mediated alternatively activated macrophages and type 2 immune responses; such advances have led to an expanded appreciation for functions of these cells beyond immunity, including maintenance of physiologic homeostasis and tissue repair. PMID:23298208

  10. Antibody-Dependent Enhancement of Dengue Virus Infection in Primary Human Macrophages; Balancing Higher Fusion against Antiviral Responses.

    PubMed

    Flipse, Jacky; Diosa-Toro, Mayra A; Hoornweg, Tabitha E; van de Pol, Denise P I; Urcuqui-Inchima, Silvio; Smit, Jolanda M

    2016-01-01

    The dogma is that the human immune system protects us against pathogens. Yet, several viruses, like dengue virus, antagonize the hosts' antibodies to enhance their viral load and disease severity; a phenomenon called antibody-dependent enhancement of infection. This study offers novel insights in the molecular mechanism of antibody-mediated enhancement (ADE) of dengue virus infection in primary human macrophages. No differences were observed in the number of bound and internalized DENV particles following infection in the absence and presence of enhancing concentrations of antibodies. Yet, we did find an increase in membrane fusion activity during ADE of DENV infection. The higher fusion activity is coupled to a low antiviral response early in infection and subsequently a higher infection efficiency. Apparently, subtle enhancements early in the viral life cycle cascades into strong effects on infection, virus production and immune response. Importantly, and in contrast to other studies, the antibody-opsonized virus particles do not trigger immune suppression and remain sensitive to interferon. Additionally, this study gives insight in how human macrophages interact and respond to viral infections and the tight regulation thereof under various conditions of infection. PMID:27380892

  11. Antibody-Dependent Enhancement of Dengue Virus Infection in Primary Human Macrophages; Balancing Higher Fusion against Antiviral Responses

    PubMed Central

    Flipse, Jacky; Diosa-Toro, Mayra A.; Hoornweg, Tabitha E.; van de Pol, Denise P. I.; Urcuqui-Inchima, Silvio; Smit, Jolanda M.

    2016-01-01

    The dogma is that the human immune system protects us against pathogens. Yet, several viruses, like dengue virus, antagonize the hosts’ antibodies to enhance their viral load and disease severity; a phenomenon called antibody-dependent enhancement of infection. This study offers novel insights in the molecular mechanism of antibody-mediated enhancement (ADE) of dengue virus infection in primary human macrophages. No differences were observed in the number of bound and internalized DENV particles following infection in the absence and presence of enhancing concentrations of antibodies. Yet, we did find an increase in membrane fusion activity during ADE of DENV infection. The higher fusion activity is coupled to a low antiviral response early in infection and subsequently a higher infection efficiency. Apparently, subtle enhancements early in the viral life cycle cascades into strong effects on infection, virus production and immune response. Importantly, and in contrast to other studies, the antibody-opsonized virus particles do not trigger immune suppression and remain sensitive to interferon. Additionally, this study gives insight in how human macrophages interact and respond to viral infections and the tight regulation thereof under various conditions of infection. PMID:27380892

  12. Aging Enhances the Production of Reactive Oxygen Species and Bactericidal Activity in Peritoneal Macrophages by Upregulating Classical Activation Pathways

    SciTech Connect

    Smallwood, Heather S.; López-Ferrer, Daniel; Squier, Thomas C.

    2011-10-07

    Maintenance of macrophages in their basal state and their rapid activation in response to pathogen detection are central to the innate immune system, acting to limit nonspecific oxidative damage and promote pathogen killing following infection. To identify possible age-related alterations in macrophage function, we have assayed the function of peritoneal macrophages from young (3–4 months) and aged (14–15 months) Balb/c mice. In agreement with prior suggestions, we observe age-dependent increases in the extent of recruitment of macrophages into the peritoneum, as well as ex vivo functional changes involving enhanced nitric oxide production under resting conditions that contribute to a reduction in the time needed for full activation of senescent macrophages following exposure to lipopolysaccharides (LPS). Further, we observe enhanced bactericidal activity following Salmonella uptake by macrophages isolated from aged Balb/c mice in comparison with those isolated from young animals. Pathways responsible for observed phenotypic changes were interrogated using tandem mass spectrometry, which identified age-dependent increases in levels of proteins linked to immune cell pathways under basal conditions and following LPS activation. Immune pathways upregulated in macrophages isolated from aged mice include proteins critical to the formation of the immunoproteasome. Detection of these latter proteins is dramatically enhanced following LPS exposure for macrophages isolated from aged animals; in comparison, the identification of immunoproteasome subunits is insensitive to LPS exposure for macrophages isolated from young animals. Consistent with observed global changes in the proteome, quantitative proteomic measurements indicate that there are age-dependent abundance changes involving specific proteins linked to immune cell function under basal conditions. LPS exposure selectively increases the levels of many proteins involved in immune cell function in aged Balb/c mice

  13. The Balance of Apoptotic and Necrotic Cell Death in Mycobacterium tuberculosis Infected Macrophages Is Not Dependent on Bacterial Virulence

    PubMed Central

    Butler, Rachel E.; Brodin, Priscille; Jang, Jichan; Jang, Mi-Seon; Robertson, Brian D.; Gicquel, Brigitte; Stewart, Graham R.

    2012-01-01

    Background An important mechanism of Mycobacterium tuberculosis pathogenesis is the ability to control cell death pathways in infected macrophages: apoptotic cell death is bactericidal, whereas necrotic cell death may facilitate bacterial dissemination and transmission. Methods We examine M.tuberculosis control of spontaneous and chemically induced macrophage cell death using automated confocal fluorescence microscopy, image analysis, flow cytometry, plate-reader based vitality assays, and M.tuberculosis strains including H37Rv, and isogenic virulent and avirulent strains of the Beijing lineage isolate GC1237. Results We show that bacterial virulence influences the dynamics of caspase activation and the total level of cytotoxicity. We show that the powerful ability of M.tuberculosis to inhibit exogenously stimulated apoptosis is abrogated by loss of virulence. However, loss of virulence did not influence the balance of macrophage apoptosis and necrosis – both virulent and avirulent isogenic strains of GC1237 induced predominantly necrotic cell death compared to H37Rv which induced a higher relative level of apoptosis. Conclusions This reveals that macrophage necrosis and apoptosis are independently regulated during M. tuberculosis infection of macrophages. Virulence affects the level of host cell death and ability to inhibit apoptosis but other strain-specific characteristics influence the ultimate mode of host cell death and alter the balance of apoptosis and necrosis. PMID:23118880

  14. Salmonella typhimurium infection triggers dendritic cells and macrophages to adopt distinct migration patterns in vivo.

    PubMed

    Zhao, Chunfang; Wood, Michael W; Galyov, Edouard E; Höpken, Uta E; Lipp, Martin; Bodmer, Helen C; Tough, David F; Carter, Robert W

    2006-11-01

    The presence of an anti-bacterial T cell response and evidence of bacterial products in inflamed joints of reactive arthritis patients suggests an antigen transportation role in this disease for macrophages and dendritic cells. We have investigated the functional properties and in vivo migration of macrophages and DC after infection with Salmonella enterica serovar Typhimurium (S. typhimurium). BM-derived macrophages and DC displayed enhanced expression of costimulatory molecules (CD40 and CD86) and increased production of pro-inflammatory cytokines (TNF-alpha, IL-6 and IL-12p40) and nitric oxide after infection. Upon adoptive transfer into mice, infected DC migrated to lymphoid tissues and induced an anti-Salmonella T cell response, whereas infected macrophages did not. Infection of DC with S. typhimurium was associated with strong up-regulation of the chemokine receptor CCR7 and acquisition of responsiveness to chemokines acting through this receptor. Moreover, S. typhimurium-infected CCR7-deficient DC were unable to migrate to lymph nodes after adoptive transfer, although they did reach the spleen. Our data demonstrate distinct roles for macrophages and DC as antigen transporters after S. typhimurium infection and a dependence on CCR7 for migration of DC to lymph nodes after bacterial infection. PMID:17048271

  15. Productive infection of Piscirickettsia salmonis in macrophages and monocyte-like cells from rainbow trout, a possible survival strategy.

    PubMed

    Rojas, Verónica; Galanti, Norbel; Bols, Niels C; Marshall, Sergio H

    2009-10-15

    Piscirickettsia salmonis is the etiologic agent of the salmonid rickettsial septicemia (SRS), an endemic disease which causes significant losses in salmon production. This intracellular bacterium is normally cultured in salmonid epithelial cell lines inducing characteristic cytopathic effects (CPEs). In this study we demonstrate that P. salmonis is able to infect, survive, replicate, and propagate in the macrophages/monocytes cell line RTS11 derived from rainbow trout spleen, without inducing the characteristic CPEs and the host cells showing the same expression levels as non-infected control cell. On the other hand, bacteria were capable of expressing specific proteins within infected cells. Infected macrophages cease proliferation and a fraction of them detached from the plate, transform to non-adhesive, monocyte-like cells with proliferative activity. Productive infection of P. salmonis into salmonid macrophage/monocyte cells in culture provides an excellent model for the study of host-pathogen interactions, almost unknown in the case of P. salmonis. Our results suggest that the infection of cells from the salmonid innate immune system without inducing an important cell death response should lead to the persistence of the bacteria and consequently their dissemination to other tissues, favoring the evasion of the first line of defense against pathogens.

  16. Viral respiratory infection increases alveolar macrophage cytoplasmic motility in rats: role of NO.

    PubMed

    Fukushima, T; Sekizawa, K; Yamaya, M; Okinaga, S; Satoh, M; Sasaki, H

    1995-03-01

    Ingested ferrimagnetic (Fe3O4) particles were used to estimate noninvasively the motion of organelles in alveolar macrophages (AM) in intact rats during viral respiratory infection by parainfluenza type 1 (Sendai) virus. Four days after instillation of Fe3O4 particles (3 mg/kg) into the lung, remnant field strength (RFS) was measured at the body surface immediately after magnetization of Fe3O4 particles by an externally applied magnetic field. RFS decreases with time, due to particle rotation (relaxation) which is related to cytoplasmic motility of AM. Viral infection increased the relaxation rate (lambda o per min), and increases in lambda o reached a maximum 3 days after nasal inoculation (day 3). Viral infection (day 3)-induced increases in lambda o were dose dependently inhibited by either the L-arginine analogue N-nitro-L-arginine or by methylene blue, an inhibitor of guanylate cyclase activity. Bronchoalveolar lavage fluid obtained from infected rats contained significantly higher levels of nitrite than that from control rats (P < 0.01). In in vitro experiments, AM from infected rats showed significantly higher lambda o, nitrite production, and intracellular guanosine 3',5'-cyclic monophosphate levels than those from control rats (P < 0.01). Sodium nitroprusside, known to release nitric oxide concentration dependently, increased lambda o of AM from noninfected rats in vitro. These results suggest that nitric oxide plays an important role in AM cytoplasmic motility during viral respiratory infection. PMID:7900821

  17. Macrophage Bactericidal Activities against Staphylococcus aureus Are Enhanced In Vivo by Selenium Supplementation in a Dose-Dependent Manner

    PubMed Central

    Aribi, Mourad; Meziane, Warda; Habi, Salim; Boulatika, Yasser

    2015-01-01

    Background Dietary selenium is of fundamental importance to maintain optimal immune function and enhance immunity during infection. To this end, we examined the effect of selenium on macrophage bactericidal activities against Staphylococcus aureus. Methods Assays were performed in golden Syrian hamsters and peritoneal macrophages cultured with S. aureus and different concentrations of selenium. Results Infected and selenium-supplemented animals have significantly decreased levels of serum nitric oxide (NO) production when compared with infected but non-selenium-supplemented animals at day 7 post-infection (p < 0.05). A low dose of 5 ng/mL selenium induced a significant decrease in macrophage NO production, but significant increase in hydrogen peroxide (H2O2) levels (respectively, p = 0.009, p < 0.001). The NO production and H2O2 levels were significantly increased with increasing concentrations of selenium; the optimal macrophage activity levels were reached at 20 ng/mL. The concentration of 5 ng/mL of selenium induced a significant decrease in the bacterial arginase activity but a significant increase in the macrophage arginase activity. The dose of 20 ng/mL selenium induced a significant decrease of bacterial growth (p < 0.0001) and a significant increase in macrophage phagocytic activity, NO production/arginase balance and S. aureus killing (for all comparisons, p < 0.001). Conclusions Selenium acts in a dose-dependent manner on macrophage activation, phagocytosis and bacterial killing suggesting that inadequate doses may cause a loss of macrophage bactericidal activities and that selenium supplementation could enhance the in vivo control of immune response to S. aureus. PMID:26340099

  18. Phenotypic changes in the brain of SIV-infected macaques exposed to methamphetamine parallel macrophage activation patterns induced by the common gamma-chain cytokine system

    PubMed Central

    Bortell, Nikki; Morsey, Brenda; Basova, Liana; Fox, Howard S.; Marcondes, Maria Cecilia Garibaldi

    2015-01-01

    One factor in the development of neuroAIDS is the increase in the migration of pro-inflammatory CD8 T cells across the blood–brain barrier. Typically these cells are involved with keeping the viral load down. However, the persistence of above average numbers of CD8 T cells in the brain, not necessarily specific to viral peptides, is facilitated by the upregulation of IL15 from astrocytes, in the absence of IL2, in the brain environment. Both IL15 and IL2 are common gamma chain (γc) cytokines. Here, using the non-human primate model of neuroAIDS, we have demonstrated that exposure to methamphetamine, a powerful illicit drug that has been associated with HIV exposure and neuroAIDS severity, can cause an increase in molecules of the γc system. Among these molecules, IL15, which is upregulated in astrocytes by methamphetamine, and that induces the proliferation of T cells, may also be involved in driving an inflammatory phenotype in innate immune cells of the brain. Therefore, methamphetamine and IL15 may be critical in the development and aggravation of central nervous system immune-mediated inflammatory pathology in HIV-infected drug abusers. PMID:26441851

  19. Macrophage Expression of Inflammatory Genes in Response to EMCV Infection

    PubMed Central

    Shaheen, Zachary R.; Corbett, John A.

    2015-01-01

    The expression and production of type 1 interferon is the classic cellular response to virus infection. In addition to this antiviral response, virus infection also stimulates the production of proinflammatory mediators. In this review, the pathways controlling the induction of inflammatory genes and the roles that these inflammatory mediators contribute to host defense against viral pathogens will be discussed. Specific focus will be on the role of the chemokine receptor CCR5, as a signaling receptor controlling the activation of pathways leading to virus-induced inflammatory gene expression. PMID:26295266

  20. MiR-16 regulates mouse peritoneal macrophage polarization and affects T-cell activation.

    PubMed

    Jia, Xiaoqin; Li, Xiaomin; Shen, Yating; Miao, Junjun; Liu, Hao; Li, Guoli; Wang, Zhengbing

    2016-10-01

    MiR-16 is a tumour suppressor that is down-regulated in certain human cancers. However, little is known on its activity in other cell types. In this study, we examined the biological significance and underlying mechanisms of miR-16 on macrophage polarization and subsequent T-cell activation. Mouse peritoneal macrophages were isolated and induced to undergo either M1 polarization with 100 ng/ml of interferon-γ and 20 ng/ml of lipopolysaccharide, or M2 polarization with 20 ng/ml of interleukin (IL)-4. The identity of polarized macrophages was determined by profiling cell-surface markers by flow cytometry and cytokine production by ELISA. Macrophages were infected with lentivirus-expressing miR-16 to assess the effects of miR-16. Effects on macrophage-T cell interactions were analysed by co-culturing purified CD4(+) T cells with miR-16-expressing peritoneal macrophages, and measuring activation marker CD69 by flow cytometry and cytokine secretion by ELISA. Bioinformatics analysis was applied to search for potential miR-16 targets and understand its underlying mechanisms. MiR-16-induced M1 differentiation of mouse peritoneal macrophages from either the basal M0- or M2-polarized state is indicated by the significant up-regulation of M1 marker CD16/32, repression of M2 marker CD206 and Dectin-1, and increased secretion of M1 cytokine IL-12 and nitric oxide. Consistently, miR-16-expressing macrophages stimulate the activation of purified CD4(+) T cells. Mechanistically, miR-16 significantly down-regulates the expression of PD-L1, a critical immune suppressor that controls macrophage-T cell interaction and T-cell activation. MiR-16 plays an important role in shifting macrophage polarization from M2 to M1 status, and functionally activating CD4(+) T cells. This effect is potentially mediated through the down-regulation of immune suppressor PD-L1.

  1. The macrophage galactose-type lectin-1 (MGL1) recognizes Taenia crassiceps antigens, triggers intracellular signaling, and is critical for resistance to this infection.

    PubMed

    Montero-Barrera, Daniel; Valderrama-Carvajal, Héctor; Terrazas, César A; Rojas-Hernández, Saúl; Ledesma-Soto, Yadira; Vera-Arias, Laura; Carrasco-Yépez, Maricela; Gómez-García, Lorena; Martínez-Saucedo, Diana; Becerra-Díaz, Mireya; Terrazas, Luis I

    2015-01-01

    C-type lectins are multifunctional sugar-binding molecules expressed on dendritic cells (DCs) and macrophages that internalize antigens for processing and presentation. Macrophage galactose-type lectin 1 (MGL1) recognizes glycoconjugates expressing Lewis X structures which contain galactose residues, and it is selectively expressed on immature DCs and macrophages. Helminth parasites contain large amounts of glycosylated components, which play a role in the immune regulation induced by such infections. Macrophages from MGL1(-/-) mice showed less binding ability toward parasite antigens than their wild-type (WT) counterparts. Exposure of WT macrophages to T. crassiceps antigens triggered tyrosine phosphorylation signaling activity, which was diminished in MGL1(-/-) macrophages. Following T. crassiceps infection, MGL1(-/-) mice failed to produce significant levels of inflammatory cytokines early in the infection compared to WT mice. In contrast, MGL1(-/-) mice developed a Th2-dominant immune response that was associated with significantly higher parasite loads, whereas WT mice were resistant. Flow cytometry and RT-PCR analyses showed overexpression of the mannose receptors, IL-4Rα, PDL2, arginase-1, Ym1, and RELM-α on MGL1(-/-) macrophages. These studies indicate that MGL1 is involved in T. crassiceps recognition and subsequent innate immune activation and resistance.

  2. The Macrophage Galactose-Type Lectin-1 (MGL1) Recognizes Taenia crassiceps Antigens, Triggers Intracellular Signaling, and Is Critical for Resistance to This Infection

    PubMed Central

    Montero-Barrera, Daniel; Valderrama-Carvajal, Héctor; Terrazas, César A.; Rojas-Hernández, Saúl; Ledesma-Soto, Yadira; Vera-Arias, Laura; Carrasco-Yépez, Maricela; Gómez-García, Lorena; Martínez-Saucedo, Diana; Becerra-Díaz, Mireya; Terrazas, Luis I.

    2015-01-01

    C-type lectins are multifunctional sugar-binding molecules expressed on dendritic cells (DCs) and macrophages that internalize antigens for processing and presentation. Macrophage galactose-type lectin 1 (MGL1) recognizes glycoconjugates expressing Lewis X structures which contain galactose residues, and it is selectively expressed on immature DCs and macrophages. Helminth parasites contain large amounts of glycosylated components, which play a role in the immune regulation induced by such infections. Macrophages from MGL1−/− mice showed less binding ability toward parasite antigens than their wild-type (WT) counterparts. Exposure of WT macrophages to T. crassiceps antigens triggered tyrosine phosphorylation signaling activity, which was diminished in MGL1−/− macrophages. Following T. crassiceps infection, MGL1−/− mice failed to produce significant levels of inflammatory cytokines early in the infection compared to WT mice. In contrast, MGL1−/− mice developed a Th2-dominant immune response that was associated with significantly higher parasite loads, whereas WT mice were resistant. Flow cytometry and RT-PCR analyses showed overexpression of the mannose receptors, IL-4Rα, PDL2, arginase-1, Ym1, and RELM-α on MGL1−/− macrophages. These studies indicate that MGL1 is involved in T. crassiceps recognition and subsequent innate immune activation and resistance. PMID:25664320

  3. Macrophages and lymphocytes differentially modulate the ability of RANTES to inhibit HIV-1 infection.

    PubMed

    Gross, Eleanore; Amella, Carol A; Pompucci, Lorena; Franchin, Giovanni; Sherry, Barbara; Schmidtmayerova, Helena

    2003-11-01

    The beta-chemokines MIP-1alpha, MIP-1beta, and RANTES inhibit HIV-1 infection of CD4+ T cells by inhibiting interactions between the virus and CCR5 receptors. However, while beta-chemokine-mediated inhibition of HIV-1 infection of primary lymphocytes is well documented, conflicting results have been obtained using primary macrophages as the virus target. Here, we show that the beta-chemokine RANTES inhibits virus entry into both cellular targets of the virus, lymphocytes and macrophages. However, while virus entry is inhibited at the moment of infection in both cell types, the amount of virus progeny is lowered only in lymphocytes. In macrophages, early-entry restriction is lost during long-term cultivation, and the amount of virus produced by RANTES-treated macrophages is similar to the untreated cultures, suggesting an enhanced virus replication. We further show that at least two distinct cellular responses to RANTES treatment in primary lymphocytes and macrophages contribute to this phenomenon. In lymphocytes, exposure to RANTES significantly increases the pool of inhibitory beta-chemokines through intracellular signals that result in increased production of MIP-1alpha and MIP-1beta, thereby amplifying the antiviral effects of RANTES. In macrophages this amplification step does not occur. In fact, RANTES added to the macrophages is efficiently cleared from the culture, without inducing synthesis of beta-chemokines. Our results demonstrate dichotomous effects of RANTES on HIV-1 entry at the moment of infection, and on production and spread of virus progeny in primary macrophages. Since macrophages serve as a reservoir of HIV-1, this may contribute to the failure of endogenous chemokines to successfully eradicate the virus.

  4. HCV core protein inhibits polarization and activity of both M1 and M2 macrophages through the TLR2 signaling pathway

    PubMed Central

    Zhang, Qianqian; Wang, Yang; Zhai, Naicui; Song, Hongxiao; Li, Haijun; Yang, Yang; Li, Tianyang; Guo, Xiaolin; Chi, Baorong; Niu, Junqi; Crispe, Ian Nicholas; Su, Lishan; Tu, Zhengkun

    2016-01-01

    Hepatitis C virus (HCV) establishes persistent infection in most infected patients, and eventually causes chronic hepatitis, cirrhosis, and hepatocellular carcinoma in some patients. Monocytes and macrophages provide the first line of defense against pathogens, but their roles in HCV infection remains unclear. We have reported that HCV core protein (HCVc) manipulates human blood-derived dendritic cell development. In the present study, we tested whether HCVc affects human blood-derived monocyte differentiating into macrophages. Results showed that HCVc inhibits monocyte differentiation to either M1 or M2 macrophages through TLR2, associated with impaired STATs signaling pathway. Moreover, HCVc inhibits phagocytosis activity of M1 and M2 macrophages, M1 macrophage-induced autologous and allogeneic CD4+ T cell activation, but promotes M2 macrophage-induced autologous and allogeneic CD4+ T cell activation. In conclusion, HCVc inhibits monocyte-derived macrophage polarization via TLR2 signaling, leading to dysfunctions of both M1 and M2 macrophages in chronic HCV infected patients. This may contribute to the mechanism of HCV persistent infection, and suggest that blockade of HCVc might be a novel therapeutic approach to treating HCV infection. PMID:27786268

  5. Update on the role of alternatively activated macrophages in asthma

    PubMed Central

    Jiang, Zhilong; Zhu, Lei

    2016-01-01

    Lung macrophages link innate and adaptive immune responses during allergic airway inflammatory responses. Alveolar macrophages (AMs) and interstitial macrophages are two different phenotypes that differentially exert immunological function under physiological and pathological conditions. Exposure to pathogen induces polarization of AM cells into classically activated macrophages (M1 cells) and alternatively activated macrophages (M2 cells). M1 cells dominantly express proinflammatory cytokines such as TNF-α and IL-1 β and induce lung inflammation and tissue damage. M2 cells are further divided into M2a and M2c subsets. M2a cells dominantly produce allergic cytokines IL-4 and IL-13, but M2c cells dominantly produce anti-inflammatory cytokine IL-10. M2a and M2c cells are differently involved in initiation, inflammation resolution, and tissue remodeling in the different stages of asthma. Microenvironment dynamically influences polarization of AM cells. Cytokines, chemokines, and immune-regulatory cells interplay and affect the balance between the polarization of M1 and M2 cells, subsequently influencing disease progression. Thus, modulation of AM phenotypes through molecular intervention has therapeutic potential in the treatment of asthma and other allergic inflammatory diseases. This review updated recent advances in polarization and functional specialization of these macrophage subtypes with emphasis on modulation of polarization of M2 cells in asthma of human subjects and animal models. PMID:27350756

  6. CDDO-Me Redirects Activation of Breast Tumor Associated Macrophages

    PubMed Central

    Ball, Michael S.; Shipman, Emilie P.; Kim, Hyunjung; Liby, Karen T.; Pioli, Patricia A.

    2016-01-01

    Tumor-associated macrophages can account for up to 50% of the tumor mass in breast cancer patients and high TAM density is associated with poor clinical prognosis. Because TAMs enhance tumor growth, development, and metastatic potential, redirection of TAM activation may have significant therapeutic benefit. Our studies in primary human macrophages and murine breast TAMs suggest that the synthetic oleanane triterpenoid CDDO-methyl ester (CDDO-Me) reprograms the activation profile of TAMs from tumor-promoting to tumor-inhibiting. We show that CDDO-Me treatment inhibits expression of IL-10 and VEGF in stimulated human M2 macrophages and TAMs but increases expression of TNF-α and IL-6. Surface expression of CD206 and CD163, which are characteristic of M2 activation, is significantly attenuated by CDDO-Me. In contrast, CDDO-Me up-regulates surface expression of HLA-DR and CD80, which are markers of M1 activation, and importantly potentiates macrophage activation of autologous T cells but inhibits endothelial cell vascularization. These results show for the first time that CDDO-Me redirects activation of M2 macrophages and TAMs from immune-suppressive to immune-stimulatory, and implicate a role for CDDO-Me as an immunotherapeutic in the treatment of breast and potentially other types of cancer. PMID:26918785

  7. Reduced inflammatory activity of RAW 264.7 macrophages on titania nanotube modified Ti surface.

    PubMed

    Neacsu, Patricia; Mazare, Anca; Cimpean, Anisoara; Park, Jung; Costache, Marieta; Schmuki, Patrik; Demetrescu, Ioana

    2014-10-01

    Macrophages play a pivotal role in the hosts response to biomaterials being considered as an essential cell type during both optimal tissue-implant integration and pathologic process of implant failure. Hence, understanding of their cellular activity on biomaterials is important for improving evaluation and design of biomaterials for biomedical applications. In the present study, we have comparatively investigated the interactions of titania nanotubes (78 nm diameter) and commercial pure Ti with RAW 264.7 macrophages in both standard and pro-inflammatory (stimulation with lipopolysaccharide, LPS) culture conditions. In vitro tests showed that TiO2 nanotubes exhibited significantly decreased inflammatory activity of macrophages with respect to cytokine and chemokine gene expression/protein secretion, induction of foreign body giant cells (FBGCs) and nitric oxide (NO) release thereby mitigating the inflammatory response induced by LPS as compared to flat Ti surface. Therefore, our results suggest a novel role of TiO2 nanotubes in modulating macrophage response in biomaterial-associated bacterial infections. Overall, the current study provides new insight into how TiO2 nanotubes can be involved in macrophage activation and supports the great promise of such surface modifications for biomedical applications.

  8. Active autophagy but not lipophagy in macrophages with defective lipolysis

    PubMed Central

    Schlager, Stefanie; Chandak, Prakash G.; Korbelius, Melanie; Gottschalk, Benjamin; Leopold, Christina; Obrowsky, Sascha; Rainer, Silvia; Doddapattar, Prakash; Aflaki, Elma; Wegscheider, Martin; Sachdev, Vinay; Graier, Wolfgang F.; Kolb, Dagmar; Radovic, Branislav; Kratky, Dagmar

    2015-01-01

    During autophagy, autophagosomes fuse with lysosomes to degrade damaged organelles and misfolded proteins. Breakdown products are released into the cytosol and contribute to energy and metabolic building block supply, especially during starvation. Lipophagy has been defined as the autophagy-mediated degradation of lipid droplets (LDs) by lysosomal acid lipase. Adipose triglyceride lipase (ATGL) is the major enzyme catalyzing the initial step of lipolysis by hydrolyzing triglycerides (TGs) in cytosolic LDs. Consequently, most organs and cells, including macrophages, lacking ATGL accumulate TGs, resulting in reduced intracellular free fatty acid concentrations. Macrophages deficient in hormone-sensitive lipase (H0) lack TG accumulation albeit reduced in vitro TG hydrolase activity. We hypothesized that autophagy is activated in lipase-deficient macrophages to counteract their energy deficit. We therefore generated mice lacking both ATGL and HSL (A0H0). Macrophages from A0H0 mice showed 73% reduced neutral TG hydrolase activity, resulting in TG-rich LD accumulation. Increased expression of cathepsin B, accumulation of LC3-II, reduced expression of p62 and increased DQ-BSA dequenching suggest intact autophagy and functional lysosomes in A0H0 macrophages. Markedly decreased acid TG hydrolase activity and lipid flux independent of bafilomycin A1 treatment, however, argue against effective lysosomal degradation of LDs in A0H0 macrophages. We conclude that autophagy of proteins and cell organelles but not of LDs is active as a compensatory mechanism to circumvent and balance the reduced availability of energy substrates in A0H0 macrophages. PMID:26143381

  9. Mast cell–macrophage dynamics in modulation of dengue virus infection in skin

    PubMed Central

    Chu, Ya-Ting; Wan, Shu-Wen; Anderson, Robert; Lin, Yee-Shin

    2015-01-01

    Dengue virus (DENV) infection causes dengue fever, dengue haemorrhagic fever, or dengue shock syndrome. Mast cells have been speculated to play a role in DENV disease although their precise roles are unclear. In this study, we used mast cell-deficient KitW-sh/W-sh mice to investigate the involvement of mast cells after intradermal DENV infection. An approximately two- to three-fold higher level of DENV NS3 antigen was detected at the skin inoculation site in DENV-infected KitW-sh/W-sh mice than in DENV-infected wild-type (WT) mice (using a dose of 1 × 109 plaque-forming units/mouse). Moreover, as an indicator of heightened pathogenesis, a more prolonged bleeding time was observed in DENV-infected KitW-sh/W-sh mice than in WT mice. Monocytes/macrophages are considered to be important targets for DENV infection, so we investigated the susceptibility and chemokine response of DENV-infected peritoneal macrophages from KitW-sh/W-sh and WT mice both ex vivo and in vivo. There was a tendency for higher DENV infection and higher secretion of CCL2 (MCP-1) from peritoneal macrophages isolated from KitW-sh/W-sh mice than those from WT mice. In vivo studies using intradermal inoculation of DENV showed about twofold higher levels of infiltrating macrophages and CCL2 (MCP-1) at the inoculation site in both mock control and DENV-inoculated KitW-sh/W-sh mice than in corresponding WT mice. In summary, compared with WT mice, KitW-sh/W-sh mice show enhanced DENV infection and macrophage infiltration at the skin inoculation site as well as increased DENV-associated bleeding time. The results indicate an intriguing interplay between mast cells and tissue macrophages to restrict DENV replication in the skin. PMID:26059780

  10. Mast cell-macrophage dynamics in modulation of dengue virus infection in skin.

    PubMed

    Chu, Ya-Ting; Wan, Shu-Wen; Anderson, Robert; Lin, Yee-Shin

    2015-09-01

    Dengue virus (DENV) infection causes dengue fever, dengue haemorrhagic fever, or dengue shock syndrome. Mast cells have been speculated to play a role in DENV disease although their precise roles are unclear. In this study, we used mast cell-deficient Kit(W-sh/W-sh) mice to investigate the involvement of mast cells after intradermal DENV infection. An approximately two- to three-fold higher level of DENV NS3 antigen was detected at the skin inoculation site in DENV-infected Kit(W-sh/W-sh) mice than in DENV-infected wild-type (WT) mice (using a dose of 1 × 10(9) plaque-forming units/mouse). Moreover, as an indicator of heightened pathogenesis, a more prolonged bleeding time was observed in DENV-infected Kit(W-sh/W-sh) mice than in WT mice. Monocytes/macrophages are considered to be important targets for DENV infection, so we investigated the susceptibility and chemokine response of DENV-infected peritoneal macrophages from Kit(W-sh/W-sh) and WT mice both ex vivo and in vivo. There was a tendency for higher DENV infection and higher secretion of CCL2 (MCP-1) from peritoneal macrophages isolated from Kit(W-sh/W-sh) mice than those from WT mice. In vivo studies using intradermal inoculation of DENV showed about twofold higher levels of infiltrating macrophages and CCL2 (MCP-1) at the inoculation site in both mock control and DENV-inoculated Kit(W-sh/W-sh) mice than in corresponding WT mice. In summary, compared with WT mice, Kit(W-sh/W-sh) mice show enhanced DENV infection and macrophage infiltration at the skin inoculation site as well as increased DENV-associated bleeding time. The results indicate an intriguing interplay between mast cells and tissue macrophages to restrict DENV replication in the skin.

  11. Francisella tularensis live vaccine strain folate metabolism and pseudouridine synthase gene mutants modulate macrophage caspase-1 activation.

    PubMed

    Ulland, Tyler K; Janowski, Ann M; Buchan, Blake W; Faron, Matthew; Cassel, Suzanne L; Jones, Bradley D; Sutterwala, Fayyaz S

    2013-01-01

    Francisella tularensis is a Gram-negative bacterium and the causative agent of the disease tularemia. Escape of F. tularensis from the phagosome into the cytosol of the macrophage triggers the activation of the AIM2 inflammasome through a mechanism that is not well understood. Activation of the AIM2 inflammasome results in autocatalytic cleavage of caspase-1, resulting in the processing and secretion of interleukin-1β (IL-1β) and IL-18, which play a crucial role in innate immune responses to F. tularensis. We have identified the 5-formyltetrahydrofolate cycloligase gene (FTL_0724) as being important for F. tularensis live vaccine strain (LVS) virulence. Infection of mice in vivo with a F. tularensis LVS FTL_0724 mutant resulted in diminished mortality compared to infection of mice with wild-type LVS. The FTL_0724 mutant also induced increased inflammasome-dependent IL-1β and IL-18 secretion and cytotoxicity in macrophages in vitro. In contrast, infection of macrophages with a F. tularensis LVS rluD pseudouridine synthase (FTL_0699) mutant resulted in diminished IL-1β and IL-18 secretion from macrophages in vitro compared to infection of macrophages with wild-type LVS. In addition, the FTL_0699 mutant was not attenuated in vivo. These findings further illustrate that F. tularensis LVS possesses numerous genes that influence its ability to activate the inflammasome, which is a key host strategy to control infection with this pathogen in vivo.

  12. Francisella tularensis Live Vaccine Strain Folate Metabolism and Pseudouridine Synthase Gene Mutants Modulate Macrophage Caspase-1 Activation

    PubMed Central

    Ulland, Tyler K.; Janowski, Ann M.; Buchan, Blake W.; Faron, Matthew; Cassel, Suzanne L.; Jones, Bradley D.

    2013-01-01

    Francisella tularensis is a Gram-negative bacterium and the causative agent of the disease tularemia. Escape of F. tularensis from the phagosome into the cytosol of the macrophage triggers the activation of the AIM2 inflammasome through a mechanism that is not well understood. Activation of the AIM2 inflammasome results in autocatalytic cleavage of caspase-1, resulting in the processing and secretion of interleukin-1β (IL-1β) and IL-18, which play a crucial role in innate immune responses to F. tularensis. We have identified the 5-formyltetrahydrofolate cycloligase gene (FTL_0724) as being important for F. tularensis live vaccine strain (LVS) virulence. Infection of mice in vivo with a F. tularensis LVS FTL_0724 mutant resulted in diminished mortality compared to infection of mice with wild-type LVS. The FTL_0724 mutant also induced increased inflammasome-dependent IL-1β and IL-18 secretion and cytotoxicity in macrophages in vitro. In contrast, infection of macrophages with a F. tularensis LVS rluD pseudouridine synthase (FTL_0699) mutant resulted in diminished IL-1β and IL-18 secretion from macrophages in vitro compared to infection of macrophages with wild-type LVS. In addition, the FTL_0699 mutant was not attenuated in vivo. These findings further illustrate that F. tularensis LVS possesses numerous genes that influence its ability to activate the inflammasome, which is a key host strategy to control infection with this pathogen in vivo. PMID:23115038

  13. Alveolar Macrophages Are a Prominent but Nonessential Target for Murine Cytomegalovirus Infecting the Lungs

    PubMed Central

    Farrell, Helen E.; Lawler, Clara; Oliveira, Martha T.; Davis-Poynter, Nick

    2015-01-01

    ABSTRACT Cytomegaloviruses (CMVs) infect the lungs and cause pathological damage there in immunocompromised hosts. How lung infection starts is unknown. Inhaled murine CMV (MCMV) directly infected alveolar macrophages (AMs) and type 2 alveolar epithelial cells (AEC2s) but not type 1 alveolar epithelial cells (AEC1s). In contrast, herpes simplex virus 1 infected AEC1s and murid herpesvirus 4 (MuHV-4) infected AEC1s via AMs. MCMV-infected AMs prominently expressed viral reporter genes from a human CMV IE1 promoter; but most IE1-positive cells were AEC2s, and CD11c-cre mice, which express cre in AMs, switched the fluorochrome expression of <5% of floxed MCMV in the lungs. In contrast, CD11C-cre mice exhibited fluorochrome switching in >90% of floxed MuHV-4 in the lungs and 50% of floxed MCMV in the blood. AM depletion increased MCMV titers in the lung during the acute phase of infection. Thus, the influence of AMs was more restrictive than permissive. Circulating monocytes entered infected lungs in large numbers and became infected, but not directly; infection occurred mainly via AEC2s. Mice infected with an MCMV mutant lacking its m131/m129 chemokine homolog, which promotes macrophage infection, showed levels of lung infection equivalent to those of wild-type MCMV-infected mice. The level of lung infiltration by Gr-1-positive cells infected with the MCMV m131/m129-null mutant was modestly different from that for wild-type MCMV-infected lungs. These results are consistent with myeloid cells mainly disseminating MCMV from the lungs, whereas AEC2s provide local amplification. IMPORTANCE Cytomegaloviruses (CMVs) chronically and systemically infect most mammals. Human CMV infection is usually asymptomatic but causes lung disease in people with poor immune function. As human infection is hard to analyze, studies with related animal viruses provide important insights. We show that murine CMV has two targets in the lungs: macrophages and surfactant-secreting epithelial cells

  14. Alternatively activated macrophages produce catecholamines to sustain adaptive thermogenesis

    PubMed Central

    Nguyen, Khoa D.; Qiu, Yifu; Cui, Xiaojin; Goh, Y.P. Sharon; Mwangi, Julia; David, Tovo; Mukundan, Lata; Brombacher, Frank; Locksley, Richard M.; Chawla, Ajay

    2011-01-01

    All homeotherms utilize thermogenesis to maintain core body temperature, ensuring that cellular functions and physiologic processes can ensue in cold environments1-3. In the prevailing model, when the hypothalamus senses cold temperatures, it triggers sympathetic discharge, resulting in the release of noradrenaline in brown adipose tissue (BAT) and white adipose tissue (WAT)4,5. Acting via the β3-adrenergic receptors, noradrenaline induces lipolysis in white adipocytes6, whereas it stimulates the expression of thermogenic genes, such as PPARγ coactivator 1a (Ppargc1a), uncoupling protein 1 (Ucp1), and acyl-CoA synthetase long-chain family member 1 (Acsl1), in brown adipocytes7-9. However, the precise nature of all the cell types involved in this efferent loop is not well established. Here we report an unexpected requirement for the interleukin 4 (IL4)-stimulated program of alternative macrophage activation in adaptive thermogenesis. Cold exposure rapidly promoted alternative activation of adipose tissue macrophages, which secrete catecholamines to induce thermogenic gene expression in BAT and lipolysis in WAT. Absence of alternatively activated macrophages impaired metabolic adaptations to cold, whereas administration of IL4 increased thermogenic gene expression, fatty acid mobilization, and energy expenditure, all in a macrophage-dependent manner. We have thus discovered a surprising role for alternatively activated macrophages in the orchestration of an important mammalian stress response, the response to cold. PMID:22101429

  15. An inducible transgene reports activation of macrophages in live zebrafish larvae.

    PubMed

    Sanderson, Leslie E; Chien, An-Tzu; Astin, Jonathan W; Crosier, Kathryn E; Crosier, Philip S; Hall, Christopher J

    2015-11-01

    Macrophages are the most functionally heterogenous cells of the hematopoietic system. Given many diseases are underpinned by inappropriate macrophage activation, macrophages have emerged as a therapeutic target to treat disease. A thorough understanding of what controls macrophage activation will likely reveal new pathways that can be manipulated for therapeutic benefit. Live imaging fluorescent macrophages within transgenic zebrafish larvae has provided a valuable window to investigate macrophage behavior in vivo. Here we describe the first transgenic zebrafish line that reports macrophage activation, as evidenced by induced expression of an immunoresponsive gene 1(irg1):EGFP transgene. When combined with existing reporter lines that constitutively mark macrophages, we reveal this unique transgenic line can be used to live image macrophage activation in response to the bacterial endotoxin lipopolysaccharide and xenografted human cancer cells. We anticipate the Tg(irg1:EGFP) line will provide a valuable tool to explore macrophage activation and plasticity in the context of different disease models.

  16. Dermal CD14(+) Dendritic Cell and Macrophage Infection by Dengue Virus Is Stimulated by Interleukin-4.

    PubMed

    Schaeffer, Evelyne; Flacher, Vincent; Papageorgiou, Vasiliki; Decossas, Marion; Fauny, Jean-Daniel; Krämer, Melanie; Mueller, Christopher G

    2015-07-01

    Dengue virus (DENV) is responsible for the most prevalent arthropod-borne viral infection in humans. Events decisive for disease development occur in the skin after virus inoculation by the mosquito. Yet, the role of human dermis-resident immune cells in dengue infection and disease remains elusive. Here we investigated how dermal dendritic cells (dDCs) and macrophages (dMs) react to DENV and impact on immunopathology. We show that both CD1c(+) and CD14(+) dDC subsets were infected, but viral load greatly increased in CD14(+) dDCs upon IL-4 stimulation, which correlated with upregulation of virus-binding lectins Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Nonintegrin (DC-SIGN/CD209) and mannose receptor (CD206). IL-4 also enhanced T-cell activation by dDCs, which was further increased upon dengue infection. dMs purified from digested dermis were initially poorly infected but actively replicated the virus and produced TNF-α upon lectin upregulation in response to IL-4. DC-SIGN(+) cells are abundant in inflammatory skin with scabies infection or Th2-type dermatitis, suggesting that skin reactions to mosquito bites heighten the risk of infection and subsequent immunopathology. Our data identify dDCs and dMs as primary arbovirus target cells in humans and suggest that dDCs initiate a potent virus-directed T-cell response, whereas dMs fuel the inflammatory cascade characteristic of dengue fever. PMID:25521455

  17. Transcriptomic analysis of responses to infectious salmon anemia virus infection in macrophage-like cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aquatic orthomyxovirus infectious salmon anemia virus (ISAV) is an important pathogen for salmonid aquaculture, however little is known about protective and pathological host responses to infection. We have investigated intracellular responses during cytopathic ISAV infection in the macrophage-l...

  18. Effect of lipopolysaccharide on protein accumulation by murine peritoneal macrophages: the correlation to activation for macrophage tumoricidal function

    SciTech Connect

    Tannenbaum, C.S.

    1987-01-01

    The protein synthetic patterns of tumoricidal murine peritoneal macrophage populations have been compared to those of non-tumoricidal populations utilizing two dimensional polyacrylamide gel electrophoresis (2D PAGE) of (/sup 35/S)-methionine-labeled proteins. While the protein synthetic patterns exhibited by resident, inflammatory and activated macrophages had numerous common features which distinguished them from the other normal non-macrophage cell types examined, unique proteins also distinguished each macrophage population from the others. Peritoneal macrophages elicited by treatment with heat killed Propionibacterium acnes, the live, attenuated Mycobacterium bovis strain BCG, Listeria monocytogenes and the protozoan flagellate Trypanosoma rhodesiense, all exhibited tumoricidal activity in 16h or 72h functional assays, and shared a common protein synthetic profile which differentiated them from the synthetic patterns characteristic of the non-tumoricidal resident and inflammatory macrophages.

  19. Integrated MicroRNA-mRNA-Analysis of Human Monocyte Derived Macrophages upon Mycobacterium avium subsp. hominissuis Infection

    PubMed Central

    Sharbati, Jutta; Lewin, Astrid; Kutz-Lohroff, Barbara; Kamal, Elisabeth; Einspanier, Ralf; Sharbati, Soroush

    2011-01-01

    Background Many efforts have been made to understand basal mechanisms of mycobacterial infections. Macrophages are the first line of host immune defence to encounter and eradicate mycobacteria. Pathogenic species have evolved different mechanisms to evade host response, e.g. by influencing macrophage apoptotic pathways. However, the underlying molecular regulation is not fully understood. A new layer of eukaryotic regulation of gene expression is constituted by microRNAs. Therefore, we present a comprehensive study for identification of these key regulators and their targets in the context of host macrophage response to mycobacterial infections. Methodology/Principal Findings We performed microRNA as well as mRNA expression analysis of human monocyte derived macrophages infected with several Mycobacterium avium hominissuis strains by means of microarrays as well as quantitative reverse transcription PCR (qRT-PCR). The data revealed the ability of all strains to inhibit apoptosis by transcriptional regulation of BCL2 family members. Accordingly, at 48 h after infection macrophages infected with all M. avium strains showed significantly decreased caspase 3 and 7 activities compared to the controls. Expression of let-7e, miR-29a and miR-886-5p were increased in response to mycobacterial infection at 48 h. The integrated analysis of microRNA and mRNA expression as well as target prediction pointed out regulative networks identifying caspase 3 and 7 as potential targets of let-7e and miR-29a, respectively. Consecutive reporter assays verified the regulation of caspase 3 and 7 by these microRNAs. Conclusions/Significance We show for the first time that mycobacterial infection of human macrophages causes a specific microRNA response. We furthermore outlined a regulatory network of potential interactions between microRNAs and mRNAs. This study provides a theoretical concept for unveiling how distinct mycobacteria could manipulate host cell response. In addition, functional

  20. Alternatively activated macrophages in helminth infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Helminthic parasites can trigger highly polarized immune responses typically associated with increased numbers of CD4+ Th2 cells, eosinophils, mast cells, and basophils. These cell populations are thought to coordinate an effective response ultimately leading to parasite expulsion, but they also pl...

  1. Nitric oxide-mediated regulation of ferroportin-1 controls macrophage iron homeostasis and immune function in Salmonella infection.

    PubMed

    Nairz, Manfred; Schleicher, Ulrike; Schroll, Andrea; Sonnweber, Thomas; Theurl, Igor; Ludwiczek, Susanne; Talasz, Heribert; Brandacher, Gerald; Moser, Patrizia L; Muckenthaler, Martina U; Fang, Ferric C; Bogdan, Christian; Weiss, Günter

    2013-05-01

    Nitric oxide (NO) generated by inducible NO synthase 2 (NOS2) affects cellular iron homeostasis, but the underlying molecular mechanisms and implications for NOS2-dependent pathogen control are incompletely understood. In this study, we found that NO up-regulated the expression of ferroportin-1 (Fpn1), the major cellular iron exporter, in mouse and human cells. Nos2(-/-) macrophages displayed increased iron content due to reduced Fpn1 expression and allowed for an enhanced iron acquisition by the intracellular bacterium Salmonella typhimurium. Nos2 gene disruption or inhibition of NOS2 activity led to an accumulation of iron in the spleen and splenic macrophages. Lack of NO formation resulted in impaired nuclear factor erythroid 2-related factor-2 (Nrf2) expression, resulting in reduced Fpn1 transcription and diminished cellular iron egress. After infection of Nos2(-/-) macrophages or mice with S. typhimurium, the increased iron accumulation was paralleled by a reduced cytokine (TNF, IL-12, and IFN-γ) expression and impaired pathogen control, all of which were restored upon administration of the iron chelator deferasirox or hyperexpression of Fpn1 or Nrf2. Thus, the accumulation of iron in Nos2(-/-) macrophages counteracts a proinflammatory host immune response, and the protective effect of NO appears to partially result from its ability to prevent iron overload in macrophages.

  2. Effect of cortisol and/or DHEA on THP1-derived macrophages infected with Mycobacterium tuberculosis.

    PubMed

    Bongiovanni, Bettina; Mata-Espinosa, Dulce; D'Attilio, Luciano; Leon-Contreras, Juan Carlos; Marquez-Velasco, Ricardo; Bottasso, Oscar; Hernandez-Pando, Rogelio; Bay, María Luisa

    2015-09-01

    Tuberculosis (TB) is a major health problem requiring an appropriate cell immune response to be controlled. Macrophages play a central role in the response against Mycobacterium tuberculosis (Mtb). Given our prior studies in which adrenal steroids were found to modify the cellular immune responses from TB patients, it was sensible to analyze the immunomodulatory capability of cortisol and DHEA on macrophages infected with Mtb. The human macrophage-like THP-1 cells were infected with the H37Rv strain of Mtb and treated with Cortisol and DHEA at different doses. We monitored phagocytosis, intracellular-bacterial growth, autophagosoma formation, as well as cytokine gene expression and production. Cultures exposed to cortisol showed a decreased production of IL-1β, TNF-α, with DHEA being unable to modify the pattern of cytokine production or to reverse the cortisol inhibitory effects. Interestingly the intra-macrophagic bacterial burden was found reduced by DHEA treatment. While this effect was not related to a different cytokine pattern, in terms their production or mRNA expression, DHEA treatment did promote autophagy in Mtb-infected macrophages, irrespective of Cortisol presence. In essence, the better control of Mtb load by DHEA-treated macrophages seems to be dependent on an autophagic mechanism. The present results are relevant for two reasons as autophagy is not only important for clearance of mycobacteria but also for the prevention of tissue damage.

  3. Macrophage activation syndrome induced by A/H1N1 influenza in cystic fibrosis.

    PubMed

    Casciaro, Rosaria; Cresta, Federico; Favilli, Federica; Naselli, Aldo; De Alessandri, Alessandra; Minicucci, Laura

    2014-02-01

    Bacterial respiratory infections have an important impact on the development and progression of pulmonary disease in cystic fibrosis (CF). Viral infections are possible triggers of acute deterioration in the clinical status of CF patients. Macrophage activation syndrome (MAS) is a life-threatening complication of rheumatic disease characterized by pancytopenia, hepatitis, hyperferritinemia, coagulopathy, and neurologic symptoms. This syndrome is thought to be caused by the activation and uncontrolled proliferation of T lymphocytes and well-differentiated macrophages, leading to widespread hemophagocytosis and cytokine overproduction. Here, we report the case of a boy affected by CF who developed MAS triggered by pandemic H1N1 influenza; good clinical response was obtained through high dose prednisone treatment. PMID:23401277

  4. The Warburg effect in mycobacterial granulomas is dependent on the recruitment and activation of macrophages by interferon-γ.

    PubMed

    Appelberg, Rui; Moreira, Diana; Barreira-Silva, Palmira; Borges, Margarida; Silva, Letícia; Dinis-Oliveira, Ricardo Jorge; Resende, Mariana; Correia-Neves, Margarida; Jordan, Michael B; Ferreira, Nuno C; Abrunhosa, Antero J; Silvestre, Ricardo

    2015-08-01

    Granulomas are the hallmark of mycobacterial disease. Here, we demonstrate that both the cell recruitment and the increased glucose consumption in granulomatous infiltrates during Mycobacterium avium infection are highly dependent on interferon-γ (IFN-γ). Mycobacterium avium-infected mice lacking IFN-γ signalling failed to developed significant inflammatory infiltrations and lacked the characteristic uptake of the glucose analogue fluorine-18-fluorodeoxyglucose (FDG). To assess the role of macrophages in glucose uptake we infected mice with a selective impairment of IFN-γ signalling in the macrophage lineage (MIIG mice). Although only a partial reduction of the granulomatous areas was observed in infected MIIG mice, the insensitivity of macrophages to IFN-γ reduced the accumulation of FDG. In vivo, ex vivo and in vitro assays showed that macrophage activated by IFN-γ displayed increased rates of glucose uptake and in vitro studies showed also that they had increased lactate production and increased expression of key glycolytic enzymes. Overall, our results show that the activation of macrophages by IFN-γ is responsible for the Warburg effect observed in organs infected with M. avium.

  5. Proteomic Investigation of the Time Course Responses of RAW 264.7 Macrophages to Infection with Salmonella enterica

    SciTech Connect

    Shi, Liang; Chowdhury, Saiful M.; Smallwood, Heather S.; Yoon, Hyunjin; Mottaz-Brewer, Heather M.; Norbeck, Angela D.; McDermott, Jason E.; Clauss, Therese RW; Heffron, Fred; Smith, Richard D.; Adkins, Joshua N.

    2009-08-01

    Macrophages plan important roles in controlling Salmonella-mediated systemic infection. To investigate the responses of macrophages to Salmonella infection, we infected RAW 264.7 macrophages with Salmonella enterica serovar Typhimurium (STM) and then performed a comparative liquid chromatography-tandem mass spectrometry [LC-MS(/MS)]-based proteomics analysis of the infected macrophages. A total of 1006 macrophage and 115 STM proteins were indentified from this study. Most of STM proteins were found at late stage of the time course of infection, consistent with the fact that STM proliferates inside RAW 264.7 macrophages. Majority of the identified macrophage proteins were house keeping-related, including cytoplasmic superoxide dismutase 1 (SOD1), whose peptide abundances were relatively constant during the time course of infection. Compared to those in no infection control, the peptide abundances of 244 macrophage proteins (or 24% of total indentified macrophage proteins) changed considerably after STM infection. The functions of these STM infection-affected macrophage proteins were diverse and ranged from production of antibacterial nitric oxide (i.e., inducible nitric oxide synthase or iNOS) or production of prostaglandin H2 (i.e., prostaglandin-endoperoxide synthase 2, also know as cyclooxygenase-2 or COX-2) to regulation of intracellular traffic (e.g., sorting nexin or SNX 5, 6 and 9), demonstrating a global impact of STM infection on macrophage proteome. Western-blot analysis not only confirmed the LC-MS(/MS) results of SOD1, COX-2 and iNOS, but also revealed that the protein abundances of mitochondrial SOD2 increased after STM infection, indicating an infection-induced oxidative stress in mitochondria.

  6. Influence of parasite encoded inhibitors of serine peptidases in early infection of macrophages with Leishmania major

    PubMed Central

    Eschenlauer, Sylvain C P; Faria, Marilia S; Morrison, Lesley S; Bland, Nicolas; Ribeiro-Gomes, Flavia L; DosReis, George A; Coombs, Graham H; Lima, Ana Paula C A; Mottram, Jeremy C

    2009-01-01

    Ecotin is a potent inhibitor of family S1A serine peptidases, enzymes lacking in the protozoan parasite Leishmania major. Nevertheless, L. major has three ecotin-like genes, termed inhibitor of serine peptidase (ISP). ISP1 is expressed in vector-borne procyclic and metacyclic promastigotes, whereas ISP2 is also expressed in the mammalian amastigote stage. Recombinant ISP2 inhibited neutrophil elastase, trypsin and chymotrypsin with Kis between 7.7 and 83 nM. L. major ISP2–ISP3 double null mutants (Δisp2/3) were created. These grew normally as promastigotes, but were internalized by macrophages more efficiently than wild-type parasites due to the upregulation of phagocytosis by a mechanism dependent on serine peptidase activity. Δisp2/3 promastigotes transformed to amastigotes, but failed to divide for 48 h. Intracellular multiplication of Δisp2/3 was similar to wild-type parasites when serine peptidase inhibitors were present, suggesting that defective intracellular growth results from the lack of serine peptidase inhibition during promastigote uptake. Δisp2/3 mutants were more infective than wild-type parasites to BALB/c mice at the early stages of infection, but became equivalent as the infection progressed. These data support the hypothesis that ISPs of L. major target host serine peptidases and influence the early stages of infection of the mammalian host. PMID:19016791

  7. Alveolar Macrophages Infected with Ames or Sterne Strain of Bacillus anthracis Elicit Differential Molecular Expression Patterns

    PubMed Central

    Lane, Douglas; Kenny, Tara; Ojeda, Jenifer F.; Zhong, Yang; Che, Jianwei; Zhou, Yingyao; Ribot, Wilson; Kota, Krishna P.; Bavari, Sina; Panchal, Rekha G.

    2014-01-01

    Alveolar macrophages (AMs) phagocytose Bacillus anthracis following inhalation and induce the production of pro-inflammatory cytokines and chemokines to mediate the activation of innate immunity. Ames, the virulent strain of B. anthracis, contains two plasmids that encode the antiphagocytic poly-γ-d-glutamic acid capsule and the lethal toxin. The attenuated Sterne strain of B. anthracis, which lacks the plasmid encoding capsule, is widely adapted as a vaccine strain. Although differences in the outcome of infection with the two strains may have originated from the presence or absence of an anti-phagocytic capsule, the disease pathogenesis following infection will be manifested via the host responses, which is not well understood. To gain understanding of the host responses at cellular level, a microarray analysis was performed using primary rhesus macaque AMs infected with either Ames or Sterne spores. Notably, 528 human orthologs were identified to be differentially expressed in AMs infected with either strain of the B. anthracis. Meta-analyses revealed genes differentially expressed in response to B. anthracis infection were also induced upon infections with multiple pathogens such as Francisella Novicida or Staphylococcus aureus. This suggests the existence of a common molecular signature in response to pathogen infections. Importantly, the microarray and protein expression data for certain cytokines, chemokines and host factors provide further insights on how cellular processes such as innate immune sensing pathways, anti-apoptosis versus apoptosis may be differentially modulated in response to the virulent or vaccine strain of B. anthracis. The reported differences may account for the marked difference in pathogenicity between these two strains. PMID:24516547

  8. CX3CR1hi Monocyte/Macrophages Support Bacterial Survival and Experimental Infection-Driven Bone Resorption.

    PubMed

    Steinmetz, Orit; Hoch, Shifra; Avniel-Polak, Shani; Gavish, Keren; Eli-Berchoer, Luba; Wilensky, Asaf; Nussbaum, Gabriel

    2016-05-01

    Porphyromonas gingivalis,an anaerobic bacterium strongly linked to infection-driven inflammatory bone erosion, thrives within a highly inflamed milieu and disseminates to distant sites, such as atherosclerotic plaque. We examined the role of monocyte/macrophages in determining the outcome of infection with P. gingivalis. Surprisingly, transient monocyte/macrophage depletion led to greatly improved clearance of P. gingivalis. The chemokine receptors CCR2 and CX3CR1 play a major role in monocyte recruitment and differentiation to Ly6C(hi) vs CX3CR1(hi) subsets, respectively. To determine the contribution of particular monocyte/macrophage subsets to bacterial survival, we challenged chemokine receptor knockout mice and found that P. gingivalis clearance is significantly improved in the absence of CX3CR1. CX3CR1(hi) monocyte/macrophages promote P. gingivalis survival by downregulating neutrophil phagocytosis. Furthermore, CX3CR1 knockout mice resist bone resorption in the oral cavity following challenge with P. gingivalis Our findings provide an explanation for bacterial coexistence alongside an activate neutrophil infiltrate. PMID:26704610

  9. Visualisation of nitric oxide generated by activated murine macrophages.

    PubMed

    Leone, A M; Furst, V W; Foxwell, N A; Cellek, S; Moncada, S

    1996-04-01

    We have visualised the release and approximate diffusion profile of nitric oxide (NO) from activated murine macrophages using a high transmission microscope coupled to a high sensitivity photon counting camera. The images generated by NO were cell-associated and spread over an area of approximately 175 micrometers from the activated macrophage. The signals obtained were dependent on the presence of exogenous L-arginine in the medium and followed a time course similar to that previously described for the generation of NO by the inducible form of NO synthase. The light signal was attenuated by the inhibitor of NO synthase, N omega-nitro-L-arginine methyl ester. Studies using superoxide-deficient macrophages further confirmed that the signals detected were generated by NO rather than reactive oxygen intermediates. PMID:8660339

  10. Activation of murine macrophages and lymphocytes by Ureaplasma diversum.

    PubMed Central

    Chelmonska-Soyta, A; Miller, R B; Ruhnke, L; Rosendal, S

    1994-01-01

    Ureaplasma diversum is a pathogen in the bovine reproductive tract. The objective of the research was to study interactions with macrophages and lymphocytes which might elucidate aspects of pathogenetic mechanisms of this organism. We studied the activation of murine macrophages of C3H/HeN (LPS-responder) and C3H/HeJ (LPS-low-responder) genotype for TNF-alpha, IL-6, IL-1 and nitric oxide production and blastogenic response of C3H/HeJ splenocytes after Ureaplasma diversum stimulation. Live and heat-killed U. diversum induced TNF-alpha, IL-6 and IL-1 in peritoneal macrophage cultures of both C3H/HeN and C3H/HeJ mice in a dose dependent manner. Interferon-gamma modulated the cytokine production, by increasing the production of TNF-alpha, IL-6 and nitric oxide, but IL-1 secretion was only enhanced in C3H/HeJ macrophages stimulated by live ureaplasmas. Supernatant of U. diversum sonicate was mitogenic for murine spleen lymphocytes. The blastogenic response was dose dependent, and stimulation with both U. diversum and Concanavalin A seemed to have an additive effect. These results suggest that U. diversum, similar to other mycoplasmas, activates murine macrophages and lymphoid cells. The studies should be repeated with bovine cells in order to elucidate pathogenetic aspects of inflammation in cattle caused by U. diversum. PMID:7889459

  11. Fine-tuning of macrophage activation using synthetic rocaglate derivatives

    PubMed Central

    Bhattacharya, Bidisha; Chatterjee, Sujoy; Devine, William G.; Kobzik, Lester; Beeler, Aaron B.; Porco, John A.; Kramnik, Igor

    2016-01-01

    Drug-resistant bacteria represent a significant global threat. Given the dearth of new antibiotics, host-directed therapies (HDTs) are especially desirable. As IFN-gamma (IFNγ) plays a central role in host resistance to intracellular bacteria, including Mycobacterium tuberculosis, we searched for small molecules to augment the IFNγ response in macrophages. Using an interferon-inducible nuclear protein Ipr1 as a biomarker of macrophage activation, we performed a high-throughput screen and identified molecules that synergized with low concentration of IFNγ. Several active compounds belonged to the flavagline (rocaglate) family. In primary macrophages a subset of rocaglates 1) synergized with low concentrations of IFNγ in stimulating expression of a subset of IFN-inducible genes, including a key regulator of the IFNγ network, Irf1; 2) suppressed the expression of inducible nitric oxide synthase and type I IFN and 3) induced autophagy. These compounds may represent a basis for macrophage-directed therapies that fine-tune macrophage effector functions to combat intracellular pathogens and reduce inflammatory tissue damage. These therapies would be especially relevant to fighting drug-resistant pathogens, where improving host immunity may prove to be the ultimate resource. PMID:27086720

  12. Inability of tumour cells to elicit the respiratory burst in cytotoxic, activated macrophages.

    PubMed Central

    Bryant, S M; Hill, H R

    1982-01-01

    Activated macrophages from Corynebacterium parvum-treated mice are cytotoxic to non-antibody-coated tumour cells and have an augmented respiratory burst potential when compared to resident macrophages. We have investigated the possible involvement of the respiratory burst as an effector mechanism in this type of tumour killing. Scavengers of toxic metabolites of oxygen such as catalase, superoxide dismutase, 2,3-dihydroxybenzoate, ethanol, and cytochrome c did not inhibit macrophage cytotoxicity in this system. To investigate whether or not neoplastic cells stimulate the macrophage respiratory burst, we exposed activated macrophages to viable tumour cells and monitored macrophage superoxide anion production, chemiluminescence, and hexose monophosphate shunt activity. None of these indicators of the macrophage respiratory burst was stimulated by the tumour cells towards which the macrophages were cytotoxic. The data suggest that the macrophages burst is not utilized as an effector mechanism in the non-antibody-mediated macrophage tumour cytotoxicity reaction. PMID:6277777

  13. Cutting Edge: Inflammasome Activation in Primary Human Macrophages Is Dependent on Flagellin

    PubMed Central

    Kortmann, Jens; Brubaker, Sky W.

    2015-01-01

    Murine NLR family, apoptosis inhibitory protein (Naip)1, Naip2, and Naip5/6 are host sensors that detect the cytosolic presence of needle and rod proteins from bacterial type III secretion systems and flagellin, respectively. Previous studies using human-derived macrophage-like cell lines indicate that human macrophages sense the cytosolic needle protein, but not bacterial flagellin. In this study, we show that primary human macrophages readily sense cytosolic flagellin. Infection of primary human macrophages with Salmonella elicits robust cell death and IL-1β secretion that is dependent on flagellin. We show that flagellin detection requires a full-length isoform of human Naip. This full-length Naip isoform is robustly expressed in primary macrophages from healthy human donors, but it is drastically reduced in monocytic tumor cells, THP-1, and U937, rendering them insensitive to cytosolic flagellin. However, ectopic expression of full-length Naip rescues the ability of U937 cells to sense flagellin. In conclusion, human Naip functions to activate the inflammasome in response to flagellin, similar to murine Naip5/6. PMID:26109648

  14. Escherichia coli and Candida albicans Induced Macrophage Extracellular Trap-Like Structures with Limited Microbicidal Activity

    PubMed Central

    Liao, Chengshui; Liu, Xiaolei; Du, Jing; Shi, Haining; Wang, Xuelin; Bai, Xue; Peng, Peng; Yu, Lu; Wang, Feng; Zhao, Ying; Liu, Mingyuan

    2014-01-01

    The formation of extracellular traps (ETs) has recently been recognized as a novel defense mechanism in several types of innate immune cells. It has been suggested that these structures are toxic to microbes and contribute significantly to killing several pathogens. However, the role of ETs formed by macrophages (METs) in defense against microbes remains little known. In this study, we demonstrated that a subset of murine J774A.1 macrophage cell line (8% to 17%) and peritoneal macrophages (8.5% to 15%) form METs-like structures (METs-LS) in response to Escherichia coli and Candida albicans challenge. We found only a portion of murine METs-LS, which are released by dying macrophages, showed detectable killing effects on trapped E. coli but not C. albicans. Fluorescence and scanning electron microscopy analyses revealed that, in vitro, both microorganisms were entrapped in J774A.1 METs-LS composed of DNA and microbicidal proteins such as histone, myeloperoxidase and lysozyme. DNA components of both nucleus and mitochondrion origins were detectable in these structures. Additionally, METs-LS formation occurred independently of ROS produced by NADPH oxidase, and this process did not result in cell lysis. In summary, our results emphasized that microbes induced METs-LS in murine macrophage cells and that the microbicidal activity of these METs-LS differs greatly. We propose the function of METs-LS is to contain invading microbes at the infection site, thereby preventing the systemic diffusion of them, rather than significantly killing them. PMID:24587206

  15. Cutting Edge: Inflammasome Activation in Primary Human Macrophages Is Dependent on Flagellin.

    PubMed

    Kortmann, Jens; Brubaker, Sky W; Monack, Denise M

    2015-08-01

    Murine NLR family, apoptosis inhibitory protein (Naip)1, Naip2, and Naip5/6 are host sensors that detect the cytosolic presence of needle and rod proteins from bacterial type III secretion systems and flagellin, respectively. Previous studies using human-derived macrophage-like cell lines indicate that human macrophages sense the cytosolic needle protein, but not bacterial flagellin. In this study, we show that primary human macrophages readily sense cytosolic flagellin. Infection of primary human macrophages with Salmonella elicits robust cell death and IL-1β secretion that is dependent on flagellin. We show that flagellin detection requires a full-length isoform of human Naip. This full-length Naip isoform is robustly expressed in primary macrophages from healthy human donors, but it is drastically reduced in monocytic tumor cells, THP-1, and U937, rendering them insensitive to cytosolic flagellin. However, ectopic expression of full-length Naip rescues the ability of U937 cells to sense flagellin. In conclusion, human Naip functions to activate the inflammasome in response to flagellin, similar to murine Naip5/6. PMID:26109648

  16. Lipoxin Inhibits Fungal Uptake by Macrophages and Reduces the Severity of Acute Pulmonary Infection Caused by Paracoccidioides brasiliensis.

    PubMed

    Ribeiro, Laura R R; Loures, Flávio V; de Araújo, Eliseu F; Feriotti, Cláudia; Costa, Tânia A; Serezani, Carlos Henrique; Jancar, Sonia; Calich, Vera L G

    2015-01-01

    Cysteinyl leukotrienes (CysLTs) and lipoxins (LXs) are lipid mediators that control inflammation, with the former inducing and the latter inhibiting this process. Because the role played by these mediators in paracoccidioidomycosis was not investigated, we aimed to characterize the role of CysLT in the pulmonary infection developed by resistant (A/J) and susceptible (B10.A) mice. 48 h after infection, elevated levels of pulmonary LTC4 and LXA4 were produced by both mouse strains, but higher levels were found in the lungs of susceptible mice. Blocking the CysLTs receptor by MTL reduced fungal loads in B10.A, but not in A/J mice. In susceptible mice, MLT treatment led to reduced influx of PMN leukocytes, increased recruitment of monocytes, predominant synthesis of anti-inflammatory cytokines, and augmented expression of 5- and 15-lipoxygenase mRNA, suggesting a prevalent LXA4 activity. In agreement, MTL-treated macrophages showed reduced fungal burdens associated with decreased ingestion of fungal cells. Furthermore, the addition of exogenous LX reduced, and the specific blockade of the LX receptor increased the fungal loads of B10.A macrophages. This study showed for the first time that inhibition of CysLTs signaling results in less severe pulmonary paracoccidioidomycosis that occurs in parallel with elevated LX activity and reduced infection of macrophages.

  17. Lipoxin Inhibits Fungal Uptake by Macrophages and Reduces the Severity of Acute Pulmonary Infection Caused by Paracoccidioides brasiliensis

    PubMed Central

    Ribeiro, Laura R. R.; Loures, Flávio V.; de Araújo, Eliseu F.; Feriotti, Cláudia; Costa, Tânia A.; Serezani, Carlos Henrique; Jancar, Sonia; Calich, Vera L. G.

    2015-01-01

    Cysteinyl leukotrienes (CysLTs) and lipoxins (LXs) are lipid mediators that control inflammation, with the former inducing and the latter inhibiting this process. Because the role played by these mediators in paracoccidioidomycosis was not investigated, we aimed to characterize the role of CysLT in the pulmonary infection developed by resistant (A/J) and susceptible (B10.A) mice. 48 h after infection, elevated levels of pulmonary LTC4 and LXA4 were produced by both mouse strains, but higher levels were found in the lungs of susceptible mice. Blocking the CysLTs receptor by MTL reduced fungal loads in B10.A, but not in A/J mice. In susceptible mice, MLT treatment led to reduced influx of PMN leukocytes, increased recruitment of monocytes, predominant synthesis of anti-inflammatory cytokines, and augmented expression of 5- and 15-lipoxygenase mRNA, suggesting a prevalent LXA4 activity. In agreement, MTL-treated macrophages showed reduced fungal burdens associated with decreased ingestion of fungal cells. Furthermore, the addition of exogenous LX reduced, and the specific blockade of the LX receptor increased the fungal loads of B10.A macrophages. This study showed for the first time that inhibition of CysLTs signaling results in less severe pulmonary paracoccidioidomycosis that occurs in parallel with elevated LX activity and reduced infection of macrophages. PMID:26635449

  18. Does khat chewing increases the risk of Mycobacterium tuberculosis infection by macrophage immune modulation?

    PubMed

    Alvi, Ayesha; Rizwan, Mohammed; Sunosi, Rashad A L; Bin Ali Jerah, Ahmed

    2014-06-01

    Drug abuse is a serious problem associated with different pathological outcomes including modulating the immune system. Drug abuse is rising in Saudi Arabia and so as TB, a disease of worldwide significance, caused by immunological modulation in the host system. Khat chewing is a common practice in Arabian Peninsula which is now gaining momentum in other parts of the world. It is considered as an addiction. It has been associated with different adverse outcomes such as periodontitis, oral leukoplakia and oral cancer and also has shown to promote apoptotic cell death through cysteine proteases. The active ingredient of khat, cathinone is shown to have immunomodulatory effect. In principle, this leads to enhanced susceptibility to various infections. The present study is designed to delineate the mechanism of immunomodulation produced by khat/cathinone in human/mouse macrophage. Further, this activity will be evaluated both in vivo and in vitro in response to infection with Mycobacterium smegmatis to get an insight if there exists a co relation between the Mycobacterium tuberculosis infection and khat chewing.

  19. The mechanism of cytoskeleton protein β-actin and cofilin-1 of macrophages infected by Mycobacterium avium

    PubMed Central

    Wang, Jianjun; Yao, Yongliang; Wu, Jianhong; Deng, Zhiyong; Gu, Tao; Tang, Xin; Cheng, Yang; Li, Guangxin

    2016-01-01

    Cytoskeleton proteins and their regulation proteins could be influenced seriously in Mycobacterium tuberculosis infection host cells leading to the apoptosis of host cells. Macrophages infected by Mycobacterium avium were detected from cell morphology and genome levels to analyze changes of the cytoskeleton of M. avium infection macrophages. Then the expression of β-actin, cofilin-1 proteins in M. avium infected macrophages were analyzed by western blotting, and the apoptosis of M. avium infection macrophages were tested by flow cytometry. Results indicated that the morphology and genomic DNA of M. avium infection macrophages were not damaged significantly. Meanwhile, β-actin gene and its proteins in M. avium infection macrophages were both decreased, but its regulatory protein cofilin-1 was expressed conversely. Furthermore, macrophages could be induced to apoptosis due to M. avium infection by cytoskeleton changes. These findings contributed us to understand that macrophages infected by M. avium could be lead to apoptosis by regulating cytoskeleton protein β-actin or its regulatory protein cofilin-1. PMID:27158391

  20. NOTCH reprograms mitochondrial metabolism for proinflammatory macrophage activation

    PubMed Central

    Xu, Jun; Chi, Feng; Guo, Tongsheng; Punj, Vasu; Lee, W.N. Paul; French, Samuel W.; Tsukamoto, Hidekazu

    2015-01-01

    Metabolic reprogramming is implicated in macrophage activation, but the underlying mechanisms are poorly understood. Here, we demonstrate that the NOTCH1 pathway dictates activation of M1 phenotypes in isolated mouse hepatic macrophages (HMacs) and in a murine macrophage cell line by coupling transcriptional upregulation of M1 genes with metabolic upregulation of mitochondrial oxidative phosphorylation and ROS (mtROS) to augment induction of M1 genes. Enhanced mitochondrial glucose oxidation was achieved by increased recruitment of the NOTCH1 intracellular domain (NICD1) to nuclear and mitochondrial genes that encode respiratory chain components and by NOTCH-dependent induction of pyruvate dehydrogenase phosphatase 1 (Pdp1) expression, pyruvate dehydrogenase activity, and glucose flux to the TCA cycle. As such, inhibition of the NOTCH pathway or Pdp1 knockdown abrogated glucose oxidation, mtROS, and M1 gene expression. Conditional NOTCH1 deficiency in the myeloid lineage attenuated HMac M1 activation and inflammation in a murine model of alcoholic steatohepatitis and markedly reduced lethality following endotoxin-mediated fulminant hepatitis in mice. In vivo monocyte tracking further demonstrated the requirement of NOTCH1 for the migration of blood monocytes into the liver and subsequent M1 differentiation. Together, these results reveal that NOTCH1 promotes reprogramming of mitochondrial metabolism for M1 macrophage activation. PMID:25798621

  1. Trypanosoma cruzi Needs a Signal Provided by Reactive Oxygen Species to Infect Macrophages

    PubMed Central

    Goes, Grazielle R.; Rocha, Peter S.; Diniz, Aline R. S.; Aguiar, Pedro H. N.; Machado, Carlos R.; Vieira, Leda Q.

    2016-01-01

    Background During Trypanosoma cruzi infection, macrophages produce reactive oxygen species (ROS) in a process called respiratory burst. Several works have aimed to elucidate the role of ROS during T. cruzi infection and the results obtained are sometimes contradictory. T. cruzi has a highly efficiently regulated antioxidant machinery to deal with the oxidative burst, but the parasite macromolecules, particularly DNA, may still suffer oxidative damage. Guanine (G) is the most vulnerable base and its oxidation results in formation of 8-oxoG, a cellular marker of oxidative stress. Methodology/Principal Findings In order to investigate the contribution of ROS in T. cruzi survival and infection, we utilized mice deficient in the gp91phox (Phox KO) subunit of NADPH oxidase and parasites that overexpress the enzyme EcMutT (from Escherichia coli) or TcMTH (from T. cruzi), which is responsible for removing 8-oxo-dGTP from the nucleotide pool. The modified parasites presented enhanced replication inside murine inflammatory macrophages from C57BL/6 WT mice when compared with control parasites. Interestingly, when Phox KO macrophages were infected with these parasites, we observed a decreased number of all parasites when compared with macrophages from C57BL/6 WT. Scavengers for ROS also decreased parasite growth in WT macrophages. In addition, treatment of macrophages or parasites with hydrogen peroxide increased parasite replication in Phox KO mice and in vivo. Conclusions Our results indicate a paradoxical role for ROS since modified parasites multiply better inside macrophages, but proliferation is significantly reduced when ROS is removed from the host cell. Our findings suggest that ROS can work like a signaling molecule, contributing to T. cruzi growth inside the cells. PMID:27035573

  2. Macrophage Migration Inhibitory Factor (MIF): A Key Player in Protozoan Infections

    PubMed Central

    de Dios Rosado, Juan; Rodriguez-Sosa, Miriam

    2011-01-01

    Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine produced by the pituitary gland and multiple cell types, including macrophages (Mø), dendritic cells (DC) and T-cells. Upon releases MIF modulates the expression of several inflammatory molecules, such as TNF-α, nitric oxide and cyclooxygenase 2 (COX-2). These important MIF characteristics have prompted investigators to study its role in parasite infections. Several reports have demonstrated that MIF plays either a protective or deleterious role in the immune response to different pathogens. Here, we review the role of MIF in the host defense response to some important protozoan infections. PMID:22110378

  3. Carbon nanohorns allow acceleration of osteoblast differentiation via macrophage activation

    NASA Astrophysics Data System (ADS)

    Hirata, Eri; Miyako, Eijiro; Hanagata, Nobutaka; Ushijima, Natsumi; Sakaguchi, Norihito; Russier, Julie; Yudasaka, Masako; Iijima, Sumio; Bianco, Alberto; Yokoyama, Atsuro

    2016-07-01

    Carbon nanohorns (CNHs), formed by a rolled graphene structure and terminating in a cone, are promising nanomaterials for the development of a variety of biological applications. Here we demonstrate that alkaline phosphatase activity is dramatically increased by coculture of human monocyte derived macrophages (hMDMs) and human mesenchymal stem cells (hMSCs) in the presence of CNHs. CNHs were mainly localized in the lysosome of macrophages more than in hMSCs during coculturing. At the same time, the amount of Oncostatin M (OSM) in the supernatant was also increased during incubation with CNHs. Oncostatin M (OSM) from activated macrophage has been reported to induce osteoblast differentiation and matrix mineralization through STAT3. These results suggest that the macrophages engulfed CNHs and accelerated the differentiation of mesenchymal stem cells into the osteoblast via OSM release. We expect that the proof-of-concept on the osteoblast differentiation capacity by CNHs will allow future studies focused on CNHs as ideal therapeutic materials for bone regeneration.Carbon nanohorns (CNHs), formed by a rolled graphene structure and terminating in a cone, are promising nanomaterials for the development of a variety of biological applications. Here we demonstrate that alkaline phosphatase activity is dramatically increased by coculture of human monocyte derived macrophages (hMDMs) and human mesenchymal stem cells (hMSCs) in the presence of CNHs. CNHs were mainly localized in the lysosome of macrophages more than in hMSCs during coculturing. At the same time, the amount of Oncostatin M (OSM) in the supernatant was also increased during incubation with CNHs. Oncostatin M (OSM) from activated macrophage has been reported to induce osteoblast differentiation and matrix mineralization through STAT3. These results suggest that the macrophages engulfed CNHs and accelerated the differentiation of mesenchymal stem cells into the osteoblast via OSM release. We expect that the

  4. Diet Modifies the Neuroimmune System by Influencing Macrophage Activation

    ERIC Educational Resources Information Center

    Sherry, Christina Lynn

    2009-01-01

    It has long been appreciated that adequate nutrition is required for proper immune function and it is now recognized that dietary components contribute to modulation of immune cells, subsequently impacting the whole body's response during an immune challenge. Macrophage activation plays a critical role in the immune system and directs the…

  5. Proteomic analysis of macrophage activated with salmonella lipopolysaccharide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macrophages play pivotal role in immunity. They are activated by many pathogen derived molecules such as lipopolysaccharides (LPS) which trigger the production of various proteins and peptides that drive and resolve inflammation. There are numerous studies on the effect of LPS at the genome level bu...

  6. PPAR Activation Induces M1 Macrophage Polarization via cPLA2-COX-2 Inhibition, Activating ROS Production against Leishmania mexicana

    PubMed Central

    Díaz-Gandarilla, J. A.; Osorio-Trujillo, C.; Hernández-Ramírez, V. I.; Talamás-Rohana, P.

    2013-01-01

    Defence against Leishmania depends upon Th1 inflammatory response and, a major problem in susceptible models, is the turnoff of the leishmanicidal activity of macrophages with IL-10, IL-4, and COX-2 upregulation, as well as immunosuppressive PGE2, all together inhibiting the respiratory burst. Peroxisome proliferator-activated receptors (PPAR) activation is responsible for macrophages polarization on Leishmania susceptible models where microbicide functions are deactivated. In this paper, we demonstrated that, at least for L. mexicana, PPAR activation, mainly PPARγ, induced macrophage activation through their polarization towards M1 profile with the increase of microbicide activity against intracellular pathogen L. mexicana. PPAR activation induced IL-10 downregulation, whereas the production of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6 remained high. Moreover, PPAR agonists treatment induced the deactivation of cPLA2-COX-2-prostaglandins pathway together with an increase in TLR4 expression, all of whose criteria meet the M1 macrophage profile. Finally, parasite burden, in treated macrophages, was lower than that in infected nontreated macrophages, most probably associated with the increase of respiratory burst in these treated cells. Based on the above data, we conclude that PPAR agonists used in this work induces M1 macrophages polarization via inhibition of cPLA2 and the increase of aggressive microbicidal activity via reactive oxygen species (ROS) production. PMID:23555077

  7. Granulocyte-macrophage colony-stimulating factor primes interleukin-13 production by macrophages via protease-activated receptor-2.

    PubMed

    Aoki, Manabu; Yamaguchi, Rui; Yamamoto, Takatoshi; Ishimaru, Yasuji; Ono, Tomomichi; Sakamoto, Arisa; Narahara, Shinji; Sugiuchi, Hiroyuki; Hirose, Eiji; Yamaguchi, Yasuo

    2015-04-01

    Chronic inflammation is often linked to the presence of type 2-polarized macrophages, which are induced by the T helper type 2 cytokines interleukin-4 and interleukin-13 (IL-13). IL-13 is a key mediator of tissue fibrosis caused by T helper type 2-based inflammation. Human neutrophil elastase (HNE) plays a pivotal role in the pathogenesis of pulmonary fibrosis. This study investigated the priming effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on IL-13 expression by macrophages stimulated with HNE. Adherent macrophages were obtained from primary cultures of human mononuclear cells. Expression of IL-13 mRNA and protein by GM-CSF-dependent macrophages was investigated after stimulation with HNE, using the polymerase chain reaction and enzyme-linked immunosorbent assay. GM-CSF had a priming effect on IL-13 mRNA and protein expression by macrophages stimulated with HNE, while this effect was not observed for various other cytokines. GM-CSF-dependent macrophages showed a significant increase in the expression of protease activated receptor-2 (PAR-2) mRNA and protein. The response of IL-13 mRNA to HNE was significantly decreased by pretreatment with alpha1-antitrypsin, a PAR-2 antibody (SAM11), or a PAR-2 antagonist (ENMD-1068). These findings suggest that stimulation with HNE can induce IL-13 production by macrophages, especially GM-CSF-dependent macrophages. Accordingly, neutrophil elastase may have a key role in fibrosis associated with chronic inflammation.

  8. Cross-tolerization between Nod1 and Nod2 signaling results in reduced refractoriness to bacterial infection in Nod2-deficient macrophages.

    PubMed

    Kim, Yun-Gi; Park, Jong-Hwan; Daignault, Stephanie; Fukase, Koichi; Núñez, Gabriel

    2008-09-15

    Nod2 is an intracellular innate immune receptor that plays a role in host defense and susceptibility to inflammatory disease. We show in this study that macrophages rendered refractory to TLR4 and Nod2 signaling by exposure to LPS and muramyl dipeptide (MDP) exhibit impaired TNF-alpha and IL-6 production in response to pathogenic Listeria monocytogenes and Yersinia pseudotuberculosis as well as commensal bacteria including Escherichia coli and Bacteroides fragilis. Surprisingly, Nod2 deficiency was associated with impaired tolerization in response to pathogenic and commensal bacteria. Mechanistically, reduced tolerization of Nod2-null macrophages was mediated by recognition of bacteria through Nod1 because it was abolished in macrophages deficient in Nod1 and Nod2. Consistently, Nod2-null macrophages tolerant to LPS and MDP showed enhanced production of TNF-alpha and IL-6 as well as increased NF-kappaB and MAPK activation in response to the dipeptide KF1B, the Nod1 agonist. Furthermore, reduced tolerization of Nod2-deficient macrophages in response to bacteria was abolished when mutant macrophages were also rendered tolerant to the Nod1 ligand. Finally, MDP stimulation induced refractoriness not only to MDP, but also to iE-DAP stimulation, providing a mechanism to explain the reduced tolerization of Nod2-deficient macrophages infected with bacteria. These results demonstrate that cross-tolerization between Nod1 and Nod2 leads to increase recognition of both pathogenic and commensal bacteria in Nod2-deficient macrophages pre-exposed to microbial ligands.

  9. NFATc1 releases BCL6-dependent repression of CCR2 agonist expression in peritoneal macrophages from Saccharomyces cerevisiae infected mice.

    PubMed

    Busch, Rhoda; Murti, Krisna; Liu, Jiming; Patra, Amiya K; Muhammad, Khalid; Knobeloch, Klaus-Peter; Lichtinger, Monika; Bonifer, Constanze; Wörtge, Simone; Waisman, Ari; Reifenberg, Kurt; Ellenrieder, Volker; Serfling, Edgar; Avots, Andris

    2016-03-01

    The link between the extensive usage of calcineurin (CN) inhibitors cyclosporin A and tacrolimus (FK506) in transplantation medicine and the increasing rate of opportunistic infections within this segment of patients is alarming. Currently, how peritoneal infections are favored by these drugs, which impair the activity of several signaling pathways including the Ca(++) /CN/NFAT, Ca(++) /CN/cofilin, Ca(++) /CN/BAD, and NF-κB networks, is unknown. Here, we show that Saccharomyces cerevisiae infection of peritoneal resident macrophages triggers the transient nuclear translocation of NFATc1β isoforms, resulting in a coordinated, CN-dependent induction of the Ccl2, Ccl7, and Ccl12 genes, all encoding CCR2 agonists. CN inhibitors block the CCR2-dependent recruitment of inflammatory monocytes (IM) to the peritoneal cavities of S. cerevisiae infected mice. In myeloid cells, NFATc1/β proteins represent the most prominent NFATc1 isoforms. NFATc1/β ablation leads to a decrease of CCR2 chemokines, impaired mobilization of IMs, and delayed clearance of infection. We show that, upon binding to a composite NFAT/BCL6 regulatory element within the Ccl2 promoter, NFATc1/β proteins release the BCL6-dependent repression of Ccl2 gene in macrophages. These findings suggest a novel CN-dependent cross-talk between NFAT and BCL6 transcription factors, which may affect the outcome of opportunistic fungal infections in immunocompromised patients. PMID:26631626

  10. Macrophages are required for dendritic cell uptake of respiratory syncytial virus from an infected epithelium.

    PubMed

    Ugonna, Kelechi; Bingle, Colin D; Plant, Karen; Wilson, Kirsty; Everard, Mark L

    2014-01-01

    We have previously shown that the respiratory syncytial virus [RSV] can productively infect monocyte derived dendritic cells [MoDC] and remain dormant within the same cells for prolonged periods. It is therefore possible that infected dendritic cells act as a reservoir within the airways of individuals between annual epidemics. In the present study we explored the possibility that sub-epithelial DCs can be infected with RSV from differentiated bronchial epithelium and that in turn RSV from DCs can infect the epithelium. A dual co-culture model was established in which a differentiated primary airway epithelium on an Air Liquid Interface (ALI) was cultured on a transwell insert and MoDCs were subsequently added to the basolateral membrane of the insert. Further experiments were undertaken using a triple co-culture model in which in which macrophages were added to the apical surface of the differentiated epithelium. A modified RSV [rr-RSV] expressing a red fluorescent protein marker of replication was used to infect either the MoDCs or the differentiated epithelium and infection of the reciprocal cell type was assessed using confocal microscopy. Our data shows that primary epithelium became infected when rr-RSV infected MoDCs were introduced onto the basal surface of the transwell insert. MoDCs located beneath the epithelium did not become infected with virus from infected epithelial cells in the dual co-culture model. However when macrophages were present on the apical surface of the primary epithelium infection of the basal MoDCs occurred. Our data suggests that RSV infected dendritic cells readily transmit infection to epithelial cells even when they are located beneath the basal layer. However macrophages appear to be necessary for the transmission of infection from epithelial cells to basal dendritic cells.

  11. Anti-α4 Integrin Antibody Blocks Monocyte/Macrophage Traffic to the Heart and Decreases Cardiac Pathology in a SIV Infection Model of AIDS

    PubMed Central

    Walker, Joshua A; Beck, Graham A; Campbell, Jennifer H; Miller, Andrew D; Burdo, Tricia H; Williams, Kenneth C

    2015-01-01

    Background Cardiovascular disease (CVD), myocarditis and fibrosis are comorbidities of HIV+ individuals on durable antiretroviral therapy (ART). Although mechanisms for these vary, monocytes/macrophages are increasingly demonstrated to be key players. Methods and Results We directly blocked monocyte/macrophage traffic to the heart in an SIV model of AIDS using an anti-alpha-4 integrin antibody (natalizumab). Nineteen Rhesus macaques were SIVmac251 infected and CD8-lymphocyte depleted for the development of rapid AIDS. Ten animals received natalizumab once a week, for 3 weeks, and were sacrificed 1 week later. Six animals began treatment at the time of infection (early) and the remaining 4 began treatment 28 days post-infection (late), a time point we have previously established when significant cardiac inflammation occurs. Nine animals were untreated controls; of these, 3 were sacrificed early and 6 were sacrificed late. At necropsy, we found decreased SIV-associated cardiac pathology in late natalizumab-treated animals, compared to untreated controls. Early and late treatment resulted in significant reductions in numbers of CD163+ and CD68+ macrophages in cardiac tissues, compared to untreated controls, and a trend in decreasing numbers of newly recruited MAC387+ and BrdU+ (recruited) monocytes/macrophages. In late treated animals, decreased macrophage numbers in cardiac tissues correlated with decreased fibrosis. Early and late treatment resulted in decreased cardiomyocyte damage. Conclusions These data demonstrate a role for macrophages in the development of cardiac inflammation and fibrosis, and suggest that blocking monocyte/macrophage traffic to the heart can alleviate HIV- and SIV-associated myocarditis and fibrosis. They underscore the importance of targeting macrophage activation and traffic as an adjunctive therapy in HIV infection. PMID:26185285

  12. Distinct innate immune responses in human macrophages and endothelial cells infected with shrew-borne hantaviruses.

    PubMed

    Shin, Ok Sarah; Yanagihara, Richard; Song, Jin-Won

    2012-12-01

    Although hantaviruses have been previously considered as rodent-borne pathogens, recent studies demonstrate genetically distinct hantaviruses in evolutionarily distant non-rodent reservoirs, including shrews, moles and bats. The immunological responses to these newfound hantaviruses in humans are unknown. We compared the innate immune responses to Imjin virus (MJNV) and Thottapalayam virus (TPMV), two shrew-borne hantaviruses, with that toward two rodent-borne hantaviruses, pathogenic Hantann virus (HTNV) and nonpathogenic Prospect Hill virus (PHV). Infection of human macrophages and endothelial cells with either HTNV or MJNV triggered productive viral replication and up-regulation of anti-viral responsive gene expression from day 1 to day 3 postinfection, compared with PHV and TPMV. Furthermore, HTNV, MJNV and TPMV infection led to prolonged increased production of pro-inflammatory cytokines from days 3 to 7 postinfection. By contrast, PHV infection failed to induce pro-inflammatory responses. Distinct patterns of innate immune activation caused by MJNV suggest that it might be pathogenic to humans. PMID:22944108

  13. Role of HDL in cholesteryl ester metabolism of lipopolysaccharide-activated P388D1 macrophages.

    PubMed

    Uda, Sabrina; Spolitu, Stefano; Angius, Fabrizio; Collu, Maria; Accossu, Simonetta; Banni, Sebastiano; Murru, Elisabetta; Sanna, Francesca; Batetta, Barbara

    2013-11-01

    Infections share with atherosclerosis similar lipid alterations, with accumulation of cholesteryl esters (CEs) in activated macrophages and concomitant decrease of cholesterol-HDL (C-HDL). Yet the precise role of HDL during microbial infection has not been fully elucidated. Activation of P388D1 by lipopolysaccharide (LPS) triggered an increase of CEs and neutral lipid contents, along with a remarkable enhancement in 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate-HDL uptake. Similar results were found in human monocyte-derived macrophages and monocytes cocultured with phytohemagglutinin-activated lymphocytes. Inhibition of cholesterol esterification with Sandoz-58035 resulted in 80% suppression of CE biosynthesis in P388D1. However, only a 35% decrease of CE content, together with increased scavenger receptor class B member 1 (SR-B1) protein expression, was found after 72 h and thereafter up to 16 passages of continuous ACAT suppression. Chronic inhibition blunted the effect of LPS treatment on cholesterol metabolism, increased the ratio of free cholesterol/CE content and enhanced interleukin 6 secretion. These results imply that, besides de novo biosynthesis and acquisition by LDL, HDL contributes probably through SR-B1 to the increased CE content in macrophages, partly explaining the low levels of C-HDL during their activation. Our data suggest that in those conditions where more CEs are required, HDL rather than removing, may supply CEs to the cells. PMID:23956443

  14. A Yersinia effector with enhanced inhibitory activity on the NF-κB pathway activates the NLRP3/ASC/caspase-1 inflammasome in macrophages.

    PubMed

    Zheng, Ying; Lilo, Sarit; Brodsky, Igor E; Zhang, Yue; Medzhitov, Ruslan; Marcu, Kenneth B; Bliska, James B

    2011-04-01

    A type III secretion system (T3SS) in pathogenic Yersinia species functions to translocate Yop effectors, which modulate cytokine production and regulate cell death in macrophages. Distinct pathways of T3SS-dependent cell death and caspase-1 activation occur in Yersinia-infected macrophages. One pathway of cell death and caspase-1 activation in macrophages requires the effector YopJ. YopJ is an acetyltransferase that inactivates MAPK kinases and IKKβ to cause TLR4-dependent apoptosis in naïve macrophages. A YopJ isoform in Y. pestis KIM (YopJ(KIM)) has two amino acid substitutions, F177L and K206E, not present in YopJ proteins of Y. pseudotuberculosis and Y. pestis CO92. As compared to other YopJ isoforms, YopJ(KIM) causes increased apoptosis, caspase-1 activation, and secretion of IL-1β in Yersinia-infected macrophages. The molecular basis for increased apoptosis and activation of caspase-1 by YopJ(KIM) in Yersinia-infected macrophages was studied. Site directed mutagenesis showed that the F177L and K206E substitutions in YopJ(KIM) were important for enhanced apoptosis, caspase-1 activation, and IL-1β secretion. As compared to YopJ(CO92), YopJ(KIM) displayed an enhanced capacity to inhibit phosphorylation of IκB-α in macrophages and to bind IKKβ in vitro. YopJ(KIM) also showed a moderately increased ability to inhibit phosphorylation of MAPKs. Increased caspase-1 cleavage and IL-1β secretion occurred in IKKβ-deficient macrophages infected with Y. pestis expressing YopJ(CO92), confirming that the NF-κB pathway can negatively regulate inflammasome activation. K+ efflux, NLRP3 and ASC were important for secretion of IL-1β in response to Y. pestis KIM infection as shown using macrophages lacking inflammasome components or by the addition of exogenous KCl. These data show that caspase-1 is activated in naïve macrophages in response to infection with a pathogen that inhibits IKKβ and MAPK kinases and induces TLR4-dependent apoptosis. This pro

  15. A Yersinia Effector with Enhanced Inhibitory Activity on the NF-κB Pathway Activates the NLRP3/ASC/Caspase-1 Inflammasome in Macrophages

    PubMed Central

    Brodsky, Igor E.; Zhang, Yue; Medzhitov, Ruslan; Marcu, Kenneth B.; Bliska, James B.

    2011-01-01

    A type III secretion system (T3SS) in pathogenic Yersinia species functions to translocate Yop effectors, which modulate cytokine production and regulate cell death in macrophages. Distinct pathways of T3SS-dependent cell death and caspase-1 activation occur in Yersinia-infected macrophages. One pathway of cell death and caspase-1 activation in macrophages requires the effector YopJ. YopJ is an acetyltransferase that inactivates MAPK kinases and IKKβ to cause TLR4-dependent apoptosis in naïve macrophages. A YopJ isoform in Y. pestis KIM (YopJKIM) has two amino acid substitutions, F177L and K206E, not present in YopJ proteins of Y. pseudotuberculosis and Y. pestis CO92. As compared to other YopJ isoforms, YopJKIM causes increased apoptosis, caspase-1 activation, and secretion of IL-1β in Yersinia-infected macrophages. The molecular basis for increased apoptosis and activation of caspase-1 by YopJKIM in Yersinia-infected macrophages was studied. Site directed mutagenesis showed that the F177L and K206E substitutions in YopJKIM were important for enhanced apoptosis, caspase-1 activation, and IL-1β secretion. As compared to YopJCO92, YopJKIM displayed an enhanced capacity to inhibit phosphorylation of IκB-α in macrophages and to bind IKKβ in vitro. YopJKIM also showed a moderately increased ability to inhibit phosphorylation of MAPKs. Increased caspase-1 cleavage and IL-1β secretion occurred in IKKβ-deficient macrophages infected with Y. pestis expressing YopJCO92, confirming that the NF-κB pathway can negatively regulate inflammasome activation. K+ efflux, NLRP3 and ASC were important for secretion of IL-1β in response to Y. pestis KIM infection as shown using macrophages lacking inflammasome components or by the addition of exogenous KCl. These data show that caspase-1 is activated in naïve macrophages in response to infection with a pathogen that inhibits IKKβ and MAPK kinases and induces TLR4-dependent apoptosis. This pro-inflammatory form of apoptosis

  16. Measuring glutathione redox potential of HIV-1-infected macrophages.

    PubMed

    Bhaskar, Ashima; Munshi, MohamedHusen; Khan, Sohrab Zafar; Fatima, Sadaf; Arya, Rahul; Jameel, Shahid; Singh, Amit

    2015-01-01

    Redox signaling plays a crucial role in the pathogenesis of human immunodeficiency virus type-1 (HIV-1). The majority of HIV redox research relies on measuring redox stress using invasive technologies, which are unreliable and do not provide information about the contributions of subcellular compartments. A major technological leap emerges from the development of genetically encoded redox-sensitive green fluorescent proteins (roGFPs), which provide sensitive and compartment-specific insights into redox homeostasis. Here, we exploited a roGFP-based specific bioprobe of glutathione redox potential (E(GSH); Grx1-roGFP2) and measured subcellular changes in E(GSH) during various phases of HIV-1 infection using U1 monocytic cells (latently infected U937 cells with HIV-1). We show that although U937 and U1 cells demonstrate significantly reduced cytosolic and mitochondrial E(GSH) (approximately -310 mV), active viral replication induces substantial oxidative stress (E(GSH) more than -240 mV). Furthermore, exposure to a physiologically relevant oxidant, hydrogen peroxide (H2O2), induces significant deviations in subcellular E(GSH) between U937 and U1, which distinctly modulates susceptibility to apoptosis. Using Grx1-roGFP2, we demonstrate that a marginal increase of about ∼25 mV in E(GSH) is sufficient to switch HIV-1 from latency to reactivation, raising the possibility of purging HIV-1 by redox modulators without triggering detrimental changes in cellular physiology. Importantly, we show that bioactive lipids synthesized by clinical drug-resistant isolates of Mycobacterium tuberculosis reactivate HIV-1 through modulation of intracellular E(GSH). Finally, the expression analysis of U1 and patient peripheral blood mononuclear cells demonstrated a major recalibration of cellular redox homeostatic pathways during persistence and active replication of HIV.

  17. Bactericidal activity of macrophages against Streptococcus uberis is different in mammary gland secretions of lactating and drying off cows.

    PubMed

    Denis, Michel; Parlane, Natalie A; Lacy-Hulbert, S Jane; Summers, Emma L; Buddle, Bryce M; Wedlock, D Neil

    2006-11-15

    to exert significant bactericidal activity against S. uberis. There were no significant differences in the bactericidal activity of milk macrophages obtained from lactating cows with low somatic cell counts (SCC; < 10(5) ml(-1)) compared with those with a mildly elevated SCC (> 10(5) ml(-1)) (P > 0.05). In contrast, mammary gland secretion macrophages isolated from the same cows in the mid-dry period killed a significant proportion of phagocytosed S. uberis (50-65% of ingested S. uberis killed, P < 0.01) although cytokine production in response to in vitro bacterial infection was low. We conclude that the bactericidal activity of mammary gland secretion macrophages against a virulent strain of S. uberis is low during the lactation period. In addition, our data indicate that S. uberis is not a strong inducer of NO and TNF-alpha in macrophages from the milk or mammary gland secretions of cows during the drying off period. Finally, IFN-gamma does not activate milk macrophages or macrophages from cows during the lactating period or mammary gland secretions during the drying off period.

  18. Immunoresponsive gene 1 augments bactericidal activity of macrophage-lineage cells by regulating β-oxidation-dependent mitochondrial ROS production.

    PubMed

    Hall, Christopher J; Boyle, Rachel H; Astin, Jonathan W; Flores, Maria Vega; Oehlers, Stefan H; Sanderson, Leslie E; Ellett, Felix; Lieschke, Graham J; Crosier, Kathryn E; Crosier, Philip S

    2013-08-01

    Evidence suggests the bactericidal activity of mitochondria-derived reactive oxygen species (mROS) directly contributes to killing phagocytozed bacteria. Infection-responsive components that regulate this process remain incompletely understood. We describe a role for the mitochondria-localizing enzyme encoded by Immunoresponsive gene 1 (IRG1) during the utilization of fatty acids as a fuel for oxidative phosphorylation (OXPHOS) and associated mROS production. In a zebrafish infection model, infection-responsive expression of zebrafish irg1 is specific to macrophage-lineage cells and is regulated cooperatively by glucocorticoid and JAK/STAT signaling pathways. Irg1-depleted macrophage-lineage cells are impaired in their ability to utilize fatty acids as an energy substrate for OXPHOS-derived mROS production resulting in defective bactericidal activity. Additionally, the requirement for fatty acid β-oxidation during infection-responsive mROS production and bactericidal activity toward intracellular bacteria is conserved in murine macrophages. These results reveal IRG1 as a key component of the immunometabolism axis, connecting infection, cellular metabolism, and macrophage effector function.

  19. In vivo selection of lymphocyte-tropic and macrophage-tropic variants of lymphocytic choriomeningitis virus during persistent infection.

    PubMed Central

    King, C C; de Fries, R; Kolhekar, S R; Ahmed, R

    1990-01-01

    This study demonstrates cell-specific selection of viral variants during persistent lymphocytic choriomeningitis virus infection in its natural host. We have analyzed viral isolates obtained from CD4+ T cells and macrophages of congenitally infected carrier mice and found that three types of variants are present in individual carrier mice: (i) macrophage-tropic, (ii) lymphotropic, and (iii) amphotropic. The majority of the isolates were amphotropic and exhibited enhanced growth in both lymphocytes and macrophages. However, some of the lymphocyte-derived isolates grew well in lymphocytes but poorly in macrophages, and a macrophage-derived isolate replicated well in macrophages but not in lymphocytes. In striking contrast, the original wild-type (wt) Armstrong strain of lymphocytic choriomeningitis virus that was used to initiate the chronic infection and from which the variants are derived grew poorly in both lymphocytes and macrophages. These three types of variants also differed from the parental virus in their ability to establish a chronic infection in immunocompetent hosts. Adult mice infected with the wt Armstrong strain cleared the infection within 2 weeks, whereas adult mice infected with the variants harbored virus for several months. These results suggest that the ability of the variants to persist in adult mice is due to enhanced replication in macrophages and/or lymphocytes. This conclusion is further strengthened by the finding that the variants and the parental wt virus grew equally well in mouse fibroblasts and that the observed growth differences were specific for cells of the immune system. Images PMID:1976825

  20. Identification of Francisella novicida mutants that fail to induce prostaglandin E2 synthesis by infected macrophages

    PubMed Central

    Woolard, Matthew D.; Barrigan, Lydia M.; Fuller, James R.; Buntzman, Adam S.; Bryan, Joshua; Manoil, Colin; Kawula, Thomas H.; Frelinger, Jeffrey A.

    2013-01-01

    Francisella tularensis is the causative agent of tularemia. We have previously shown that infection with F. tularensis Live Vaccine Strain (LVS) induces macrophages to synthesize prostaglandin E2 (PGE2). Synthesis of PGE2 by F. tularensis infected macrophages results in decreased T cell proliferation in vitro and increased bacterial survival in vivo. Although we understand some of the biological consequences of F. tularensis induced PGE2 synthesis by macrophages, we do not understand the cellular pathways (neither host nor bacterial) that result in up-regulation of the PGE2 biosynthetic pathway in F. tularensis infected macrophages. We took a genetic approach to begin to understand the molecular mechanisms of bacterial induction of PGE2 synthesis from infected macrophages. To identify F. tularensis genes necessary for the induction of PGE2 in primary macrophages, we infected cells with individual mutants from the closely related strain F. tularensis subspecies novicida U112 (U112) two allele mutant library. Twenty genes were identified that when disrupted resulted in U112 mutant strains unable to induce the synthesis of PGE2 by infected macrophages. Fourteen of the genes identified are located within the Francisella pathogenicity island (FPI). Genes in the FPI are required for F. tularensis to escape from the phagosome and replicate in the cytosol, which might account for the failure of U112 with transposon insertions within the FPI to induce PGE2. This implies that U112 mutant strains that do not grow intracellularly would also not induce PGE2. We found that U112 clpB::Tn grows within macrophages yet fails to induce PGE2, while U112 pdpA::Tn does not grow yet does induce PGE2. We also found that U112 iglC::Tn neither grows nor induces PGE2. These findings indicate that there is dissociation between intracellular growth and the ability of F. tularensis to induce PGE2 synthesis. These mutants provide a critical entrée into the pathways used in the host for PGE2

  1. Crosstalk between circadian rhythmicity, mitochondrial dynamics and macrophage bactericidal activity

    PubMed Central

    Oliva-Ramírez, Jacqueline; Moreno-Altamirano, María Maximina B; Pineda-Olvera, Benjamín; Cauich-Sánchez, Patricia; Sánchez-García, F Javier

    2014-01-01

    Biological functions show rhythmic fluctuations with 24-hr periodicity regulated by circadian proteins encoded by the so-called ‘clock’ genes. The absence or deregulation of circadian proteins in mice leads to metabolic disorders and in vitro models have shown that the synthesis of pro-inflammatory cytokines by macrophages follows a circadian rhythm so showing a link between circadian rhythmicity, metabolism and immunity. Recent evidence reveals that mitochondrial shape, position and size, collectively referred to as mitochondrial dynamics, are related to both cell metabolism and immune function. However, studies addressing the simultaneous crosstalk between circadian rhythm, mitochondrial dynamics and cell immune function are scarce. Here, by using an in vitro model of synchronized murine peritoneal macrophages, we present evidence that the mitochondrial dynamics and the mitochondrial membrane potential (Δψm) follow a circadian rhythmic pattern. In addition, it is shown that the fusion of mitochondria along with high Δψm, indicative of high mitochondrial activity, precede the highest phagocytic and bactericidal activity of macrophages on Salmonella typhimurium. Taken together, our results suggest a timely coordination between circadian rhythmicity, mitochondrial dynamics, and the bactericidal capacity of macrophages. PMID:24903615

  2. Metabolic profiling during HIV-1 and HIV-2 infection of primary human monocyte-derived macrophages.

    PubMed

    Hollenbaugh, Joseph A; Montero, Catherine; Schinazi, Raymond F; Munger, Joshua; Kim, Baek

    2016-04-01

    We evaluated cellular metabolism profiles of HIV-1 and HIV-2 infected primary human monocyte-derived macrophages (MDMs). First, HIV-2 GL-AN displays faster production kinetics and greater amounts of virus as compared to HIV-1s: YU-2, 89.6 and JR-CSF. Second, quantitative LC-MS/MS metabolomics analysis demonstrates very similar metabolic profiles in glycolysis and TCA cycle metabolic intermediates between HIV-1 and HIV-2 infected macrophages, with a few notable exceptions. The most striking metabolic change in MDMs infected with HIV-2 relative to HIV-1-infected MDMs was the increased levels of quinolinate, a metabolite in the tryptophan catabolism pathway that has been linked to HIV/AIDS pathogenesis. Third, both HIV-1 and HIV-2 infected MDMs showed elevated levels of ribose-5-phosphate, a key metabolic component in nucleotide biosynthesis. Finally, HIV-2 infected MDMs display increased dNTP concentrations as predicted by Vpx-mediated SAMHD1 degradation. Collectively, these data show differential metabolic changes during HIV-1 and HIV-2 infection of macrophages.

  3. Role of complement activation and antibody in the interaction between Mycobacterium tuberculosis and human macrophages.

    PubMed

    Manivannan, S; Rao, Narayan V; Ramanathan, V D

    2012-08-01

    Mycobacterium tuberculosis-specific antibodies possess immunomodulatory effects during tuberculosis infection. Prior sensitization to environmental mycobacteria is known to suppress immune responses against BCG and M. tuberculosis. Mycobacteria-induced antibodies can influence events such as complement activation and phagocytosis during infectious process. In the present study role of anti-M. tuberculosis IgG (anti-M. tb IgG) antibody during interaction between M. tuberculosis and human macrophages mediated through complement has been examined in vitro. Anti-M. tb IgG antibody significantly enhanced complement activation by M. tuberculosis. Phagocytosis of M. tuberculosis by macrophages increased significantly in the presence of complement and/or antibody. Moreover, antibody enhanced phagocytosis in the presence of complement. Addition of antibody alone or in combination with complement also augmented intracellular viability of bacilli within macrophages. Results of this study showed that anti-mycobacterial antibody enhances complement activation and anti-M. tb IgG antibody probably modulates effects of complement during early stages of tuberculosis infection.

  4. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis.

    PubMed

    Agnihothram, Sudhakar S; Basco, Maria D S; Mullis, Lisa; Foley, Steven L; Hart, Mark E; Sung, Kidon; Azevedo, Marli P

    2015-01-01

    Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV). We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP), caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together.

  5. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis

    PubMed Central

    Agnihothram, Sudhakar S.; Basco, Maria D. S.; Mullis, Lisa; Foley, Steven L.; Hart, Mark E.; Sung, Kidon; Azevedo, Marli P.

    2015-01-01

    Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV). We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP), caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together. PMID:26658916

  6. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis.

    PubMed

    Agnihothram, Sudhakar S; Basco, Maria D S; Mullis, Lisa; Foley, Steven L; Hart, Mark E; Sung, Kidon; Azevedo, Marli P

    2015-01-01

    Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV). We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP), caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together. PMID:26658916

  7. Dengue virus isolation by antibody-dependent enhancement of infectivity in macrophages.

    PubMed

    Cardosa, M J

    1987-01-24

    Acute-phase serum samples collected during an outbreak of dengue fever and dengue haemorrhagic fever in Penang, Malaysia, were tested by a method involving antibody-dependent enhancement of infectivity in the mouse macrophage-like cell line, P388D1. 58 of 71 (81.7%) serologically positive cases yielded virus.

  8. Heme oxygenase-1 induction alters chemokine regulation and ameliorates human immunodeficiency virus-type-1 infection in lipopolysaccharide-stimulated macrophages

    SciTech Connect

    Zhou, Zhao-Hua; Kumari, Namita; Nekhai, Sergei; Clouse, Kathleen A.; Wahl, Larry M.; Yamada, Kenneth M.; Dhawan, Subhash

    2013-06-07

    Highlights: •Lipopolysaccharide stimulation of heme oxygenase-1 (HO-1) ameliorated HIV-1 infection of primary human macrophages. •The partial protection by HO-1 against HIV infection was associated with induction of chemokines such as MIP1α and MIP1β. •This mechanism explains lipopolysaccharide-stimulated HO-1-mediated inhibition of HIV-1 infection of macrophages. -- Abstract: We have elucidated a putative mechanism for the host resistance against HIV-1 infection of primary human monocyte-derived macrophages (MDM) stimulated with lipopolysaccharide (LPS). We show that LPS-activated MDM both inhibited HIV-1 entry into the cells and were refractory to post-entry productive viral replication. LPS-treated cells were virtually negative for mature virions as revealed by transmission electron microscopy. LPS activation of MDM markedly enhanced the expression of heme oxygenase-1 (HO-1), a potent inducible cytoprotective enzyme. Increased HO-1 expression was accompanied by elevated production of macrophage inflammatory chemokines (MIP1α and MIP1β) by LPS-activated MDM, significantly decreased surface chemokine receptor-5 (CCR-5) expression, and substantially reduced virus replication. Treatment of cells with HO-1 inhibitor SnPP IX (tin protoporphyrin IX) attenuated the LPS-mediated responses, HIV-1 replication and secretion of MIP1α, MIP1β, and LD78β chemokines with little change in surface CCR-5 expression. These results identify a novel role for HO-1 in the modulation of host immune response against HIV infection of MDM.

  9. Yersinia pestis can bypass protective antibodies to LcrV and activation with gamma interferon to survive and induce apoptosis in murine macrophages.

    PubMed

    Noel, Betty L; Lilo, Sarit; Capurso, Daniel; Hill, Jim; Bliska, James B

    2009-10-01

    Yersinia pestis, the agent of plague, uses a type III secretion injectisome to deliver Yop proteins into macrophages to counteract phagocytosis and induce apoptosis. Additionally, internalized Y. pestis can survive in the phagosomes of naïve or gamma interferon (IFN-gamma)-activated macrophages by blocking vacuole acidification. The Y. pestis LcrV protein is a target of protective antibodies. The binding of antibodies to LcrV at the injectisome tip results in neutralization of the apoptosis of Y. pestis-infected macrophages and is used as an in vitro correlate of protective immunity. The cytokines IFN-gamma and tumor necrosis factor alpha can cooperate with anti-LcrV to promote protection against lethal Y. pestis infection in mice. It is not known if these phagocyte-activating cytokines cooperate with anti-LcrV to increase the killing of the pathogen and decrease apoptosis in macrophages. We investigated how anti-LcrV and IFN-gamma impact bacterial survival and apoptosis in cultured murine macrophages infected with Y. pestis KIM5. Y. pestis KIM5 opsonized with polyclonal or monoclonal anti-LcrV was used to infect macrophages treated with or without IFN-gamma. The phagocytosis and survival of KIM5 and the apoptosis of macrophages were measured at different time points postinfection. The results show that anti-LcrV reduced apoptosis at an early time point (5 h) but not at a later time point (24 h). Polyclonal anti-LcrV was unable to inhibit apoptosis at either time point in IFN-gamma-activated macrophages. Additionally, anti-LcrV was ineffective at promoting the killing of KIM5 in naïve or activated macrophages. We conclude that Y. pestis can bypass protective antibodies to LcrV and activation with IFN-gamma to survive and induce apoptosis in murine macrophages.

  10. Yersinia pestis Can Bypass Protective Antibodies to LcrV and Activation with Gamma Interferon To Survive and Induce Apoptosis in Murine Macrophages

    PubMed Central

    Noel, Betty L.; Lilo, Sarit; Capurso, Daniel; Hill, Jim; Bliska, James B.

    2009-01-01

    Yersinia pestis, the agent of plague, uses a type III secretion injectisome to deliver Yop proteins into macrophages to counteract phagocytosis and induce apoptosis. Additionally, internalized Y. pestis can survive in the phagosomes of naïve or gamma interferon (IFN-γ)-activated macrophages by blocking vacuole acidification. The Y. pestis LcrV protein is a target of protective antibodies. The binding of antibodies to LcrV at the injectisome tip results in neutralization of the apoptosis of Y. pestis-infected macrophages and is used as an in vitro correlate of protective immunity. The cytokines IFN-γ and tumor necrosis factor alpha can cooperate with anti-LcrV to promote protection against lethal Y. pestis infection in mice. It is not known if these phagocyte-activating cytokines cooperate with anti-LcrV to increase the killing of the pathogen and decrease apoptosis in macrophages. We investigated how anti-LcrV and IFN-γ impact bacterial survival and apoptosis in cultured murine macrophages infected with Y. pestis KIM5. Y. pestis KIM5 opsonized with polyclonal or monoclonal anti-LcrV was used to infect macrophages treated with or without IFN-γ. The phagocytosis and survival of KIM5 and the apoptosis of macrophages were measured at different time points postinfection. The results show that anti-LcrV reduced apoptosis at an early time point (5 h) but not at a later time point (24 h). Polyclonal anti-LcrV was unable to inhibit apoptosis at either time point in IFN-γ-activated macrophages. Additionally, anti-LcrV was ineffective at promoting the killing of KIM5 in naïve or activated macrophages. We conclude that Y. pestis can bypass protective antibodies to LcrV and activation with IFN-γ to survive and induce apoptosis in murine macrophages. PMID:19710295

  11. Macrophage activation syndrome as the initial manifestation of severe juvenile onset systemic lupus erythematosus. Favorable response to cyclophosphamide.

    PubMed

    Torres Jiménez, Alfonso; Solís Vallejo, Eunice; Zeferino Cruz, Maritza; Céspedes Cruz, Adriana; Sánchez Jara, Berenice

    2014-01-01

    The macrophage activation syndrome is a rare but potentially fatal complication of patients with autoimmune rheumatic diseases. This is a clinicopathological entity characterized by activation of histiocytes with prominent hemophagocytosis in the bone marrow and other reticuloendothelial systems. In patients with lupus it may mimic an exacerbation of the disease or infection. We report the case of a 7-year-old girl in whom the diagnosis of lupus erythematosus and macrophage activation syndrome was simultaneously made with response to the use of cyclophosphamide.

  12. East Coast Fever Caused by Theileria parva Is Characterized by Macrophage Activation Associated with Vasculitis and Respiratory Failure

    PubMed Central

    Schneider, David A.; Frevert, Charles W.; Nelson, Danielle D.; Morrison, W. Ivan; Knowles, Donald P.

    2016-01-01

    Respiratory failure and death in East Coast Fever (ECF), a clinical syndrome of African cattle caused by the apicomplexan parasite Theileria parva, has historically been attributed to pulmonary infiltration by infected lymphocytes. However, immunohistochemical staining of tissue from T. parva infected cattle revealed large numbers of CD3- and CD20-negative intralesional mononuclear cells. Due to this finding, we hypothesized that macrophages play an important role in Theileria parva disease pathogenesis. Data presented here demonstrates that terminal ECF in both Holstein and Boran cattle is largely due to multisystemic histiocytic responses and resultant tissue damage. Furthermore, the combination of these histologic changes with the clinical findings, including lymphadenopathy, prolonged pyrexia, multi-lineage leukopenia, and thrombocytopenia is consistent with macrophage activation syndrome. All animals that succumbed to infection exhibited lymphohistiocytic vasculitis of small to medium caliber blood and lymphatic vessels. In pulmonary, lymphoid, splenic and hepatic tissues from Holstein cattle, the majority of intralesional macrophages were positive for CD163, and often expressed large amounts of IL-17. These data define a terminal ECF pathogenesis in which parasite-driven lymphoproliferation leads to secondary systemic macrophage activation syndrome, mononuclear vasculitis, pulmonary edema, respiratory failure and death. The accompanying macrophage phenotype defined by CD163 and IL-17 is presented in the context of this pathogenesis. PMID:27195791

  13. East Coast Fever Caused by Theileria parva Is Characterized by Macrophage Activation Associated with Vasculitis and Respiratory Failure.

    PubMed

    Fry, Lindsay M; Schneider, David A; Frevert, Charles W; Nelson, Danielle D; Morrison, W Ivan; Knowles, Donald P

    2016-01-01

    Respiratory failure and death in East Coast Fever (ECF), a clinical syndrome of African cattle caused by the apicomplexan parasite Theileria parva, has historically been attributed to pulmonary infiltration by infected lymphocytes. However, immunohistochemical staining of tissue from T. parva infected cattle revealed large numbers of CD3- and CD20-negative intralesional mononuclear cells. Due to this finding, we hypothesized that macrophages play an important role in Theileria parva disease pathogenesis. Data presented here demonstrates that terminal ECF in both Holstein and Boran cattle is largely due to multisystemic histiocytic responses and resultant tissue damage. Furthermore, the combination of these histologic changes with the clinical findings, including lymphadenopathy, prolonged pyrexia, multi-lineage leukopenia, and thrombocytopenia is consistent with macrophage activation syndrome. All animals that succumbed to infection exhibited lymphohistiocytic vasculitis of small to medium caliber blood and lymphatic vessels. In pulmonary, lymphoid, splenic and hepatic tissues from Holstein cattle, the majority of intralesional macrophages were positive for CD163, and often expressed large amounts of IL-17. These data define a terminal ECF pathogenesis in which parasite-driven lymphoproliferation leads to secondary systemic macrophage activation syndrome, mononuclear vasculitis, pulmonary edema, respiratory failure and death. The accompanying macrophage phenotype defined by CD163 and IL-17 is presented in the context of this pathogenesis. PMID:27195791

  14. MicroRNA Response of Primary Human Macrophages to Arcobacter Butzleri Infection

    PubMed Central

    zur Bruegge, Jennifer; Backes, Christina; Gölz, Greta; Hemmrich-Stanisak, Georg; Scharek-Tedin, Lydia; Franke, Andre; Alter, Thomas; Einspanier, Ralf; Keller, Andreas; Sharbati, Soroush

    2016-01-01

    The role of microRNAs (miRNAs) in infectious diseases is becoming more and more apparent, and the use of miRNAs as a diagnostic tool and their therapeutic application has become the major focus of investigation. The aim of this study was to identify miRNAs involved in the immune signaling of macrophages in response to Arcobacter (A.) butzleri infection, an emerging foodborne pathogen causing gastroenteritis. Therefore, primary human macrophages were isolated and infected, and miRNA expression was studied by means of RNAseq. Analysis of the data revealed the expression of several miRNAs, which were previously associated with bacterial infections such as miR-155, miR-125, and miR-212. They were shown to play a key role in Toll-like receptor signaling where they act as fine-tuners to establish a balanced immune response. In addition, miRNAs which have yet not been identified during bacterial infections such as miR-3613, miR-2116, miR-671, miR-30d, and miR-629 were differentially regulated in A. butzleri-infected cells. Targets of these miRNAs accumulated in pathways such as apoptosis and endocytosis – processes that might be involved in A. butzleri pathogenesis. Our study contributes new findings about the interaction of A. butzleri with human innate immune cells helping to understand underlying regulatory mechanisms in macrophages during infection. PMID:27429792

  15. IRAK-M regulates the inhibition of TLR-mediated macrophage immune response during late in vitro Leishmania donovani infection.

    PubMed

    Srivastav, Supriya; Saha, Amrita; Barua, Jayita; Ukil, Anindita; Das, Pijush K

    2015-10-01

    Intramacrophage protozoan parasite Leishmania donovani, causative agent of visceral leishmaniasis, escapes Toll-like receptor (TLR) dependent early host immune response by inducing the deubiquitinating enzyme A20, which is sustained up to 6 h postinfection only. Therefore, Leishmania must apply other means to deactivate late host responses. Here, we elucidated the role of IL-1 receptor-associated kinase M (IRAK-M), a negative regulator of TLR signaling, in downregulating macrophage proinflammatory response during late hours of in vitro infection. Our data reveal a sharp decline in IRAK1 and IRAK4 phosphorylation at 24 h postinfection along with markedly reduced association of IRAK1-TNF receptor associated factor 6, which is mandatory for TLR activation. In contrast, IRAK-M was induced after A20 levels decreased and reached a maximum at 24 h postinfection. IRAK-M induction coincided with increased stimulation of TGF-β, a hallmark cytokine of visceral infection. TGF-β-dependent signaling-mediated induction of SMAD family of proteins, 2, 3, and 4 plays important roles in transcriptional upregulation of IRAK-M. In infected macrophages, siRNA-mediated silencing of IRAK-M displayed enhanced IRAK1 and IRAK4 phosphorylation with a concomitant increase in downstream NF-κB activity and reduced parasite survival. Taken together, the results suggest that IRAK-M may be targeted by L. donovani to inhibit TLR-mediated proinflammatory response late during in vitro infection.

  16. Alternatively activated macrophages derived from monocytes and tissue macrophages are phenotypically and functionally distinct

    PubMed Central

    Gundra, Uma Mahesh; Girgis, Natasha M.; Ruckerl, Dominik; Jenkins, Stephen; Ward, Lauren N.; Kurtz, Zachary D.; Wiens, Kirsten E.; Tang, Mei San; Basu-Roy, Upal; Mansukhani, Alka; Allen, Judith E.

    2014-01-01

    Macrophages adopt an alternatively activated phenotype (AAMs) when activated by the interleukin-4receptor(R)α. AAMs can be derived either from proliferation of tissue resident macrophages or recruited inflammatory monocytes, but it is not known whether these different sources generate AAMs that are phenotypically and functionally distinct. By transcriptional profiling analysis, we show here that, although both monocyte and tissue-derived AAMs expressed high levels of Arg1, Chi3l3, and Retnla, only monocyte-derived AAMs up-regulated Raldh2 and PD-L2. Monocyte-derived AAMs were also CX3CR1-green fluorescent protein (GFP)high and expressed CD206, whereas tissue-derived AAMs were CX3CR1-GFP and CD206 negative. Monocyte-derived AAMs had high levels of aldehyde dehydrogenase activity and promoted the differentiation of FoxP3+ cells from naïve CD4+ cells via production of retinoic acid. In contrast, tissue-derived AAMs expressed high levels of uncoupling protein 1. Hence monocyte-derived AAM have properties associated with immune regulation, and the different physiological properties associated with AAM function may depend on the distinct lineage of these cells. PMID:24695852

  17. Xylitol, an Anticaries Agent, Exhibits Potent Inhibition of Inflammatory Responses in Human THP-1-Derived Macrophages Infected With Porphyromonas gingivalis

    PubMed Central

    Park, Eunjoo; Na, Hee Sam; Kim, Sheon Min; Wallet, Shannon; Cha, Seunghee; Chung, Jin

    2016-01-01

    Background Xylitol is a well-known anticaries agent and has been used for the prevention and treatment of dental caries. In this study, the anti-inflammatory effects of xylitol are evaluated for possible use in the prevention and treatment of periodontal infections. Methods Cytokine expression was stimulated in THP-1 (human monocyte cell line)-derived macrophages by live Porphyromonas gingivalis, and enzyme-linked immunosorbent assay and a commercial multiplex assay kit were used to determine the effects of xylitol on live P. gingivalis–induced production of cytokine. The effects of xylitol on phagocytosis and the production of nitric oxide were determined using phagocytosis assay, viable cell count, and Griess reagent. The effects of xylitol on P. gingivalis adhesion were determined by immunostaining, and costimulatory molecule expression was examined by flow cytometry. Results Live P. gingivalis infection increased the production of representative proinflammatory cytokines, such as tumor necrosis factor-α and interleukin (IL)-1β, in a multiplicity of infection– and time-dependent manner. Live P. gingivalis also enhanced the release of cytokines and chemokines, such as IL-12 p40, eotaxin, interferon γ–induced protein 10, monocyte chemotactic protein-1, and macrophage inflammatory protein-1. The pretreatment of xylitol significantly inhibited the P. gingivalis– induced cytokines production and nitric oxide production. In addition, xylitol inhibited the attachment of live P. gingivalis on THP-1-derived macrophages. Furthermore, xylitol exerted anti-phagocytic activity against both Escherichia coli and P. gingivalis. Conclusion These findings suggest that xylitol acts as an antiinflammatory agent in THP-1-derived macrophages infected with live P. gingivalis, which supports its use in periodontitis. PMID:24592909

  18. The Macrophage-Specific Promoter mfap4 Allows Live, Long-Term Analysis of Macrophage Behavior during Mycobacterial Infection in Zebrafish

    PubMed Central

    Walton, Eric M.; Cronan, Mark R.; Beerman, Rebecca W.; Tobin, David M.

    2015-01-01

    Transgenic labeling of innate immune cell lineages within the larval zebrafish allows for real-time, in vivo analyses of microbial pathogenesis within a vertebrate host. To date, labeling of zebrafish macrophages has been relatively limited, with the most specific expression coming from the mpeg1 promoter. However, mpeg1 transcription at both endogenous and transgenic loci becomes attenuated in the presence of intracellular pathogens, including Salmonella typhimurium and Mycobacterium marinum. Here, we describe mfap4 as a macrophage-specific promoter capable of producing transgenic lines in which transgene expression within larval macrophages remains stable throughout several days of infection. Additionally, we have developed a novel macrophage-specific Cre transgenic line under the control of mfap4, enabling macrophage-specific expression using existing floxed transgenic lines. These tools enrich the repertoire of transgenic lines and promoters available for studying zebrafish macrophage dynamics during infection and inflammation and add flexibility to the design of future macrophage-specific transgenic lines. PMID:26445458

  19. Magnetometric measurements of macrophage activity in the liver after administration of different perfluorochemicals.

    PubMed

    Koester, M B; Lutz, J

    1994-01-01

    The activity of liver macrophages was evaluated using a magnetometric method after administration of different perfluorochemicals. Following treatment with perfluoroctylbromide a significant shorter time period of diminished macrophage activity was found compared with a mixture of perfluorodecalin and perfluorotripropylamine. Results obtained with the magnetometric method on liver macrophages were more sensitive compared with those of colloidal carbon clearance of total body RES.

  20. [Inclusion Bodies are Formed in SFTSV-infected Human Macrophages].

    PubMed

    Jin, Cong; Song, Jingdong; Han, Ying; Li, Chuan; Qiu, Peihong; Liang, Mifang

    2016-01-01

    The severe fever with thrombocytopenia syndrome virus (SFTSV) is a new member in the genus Phlebovirus of the family Bunyaviridae identified in China. The SFTSV is also the causative pathogen of an emerging infectious disease: severe fever with thrombocytopenia syndrome. Using immunofluorescent staining and confocal microscopy, the intracellular distribution of nucleocapsid protein (NP) in SFTSV-infected THP-1 cells was investigated with serial doses of SFTSV at different times after infection. Transmission electron microscopy was used to observe the ultrafine intracellular structure of SFTSV-infected THP-1 cells at different times after infection. SFTSV NP could form intracellular inclusion bodies in infected THP-1 cells. The association between NP-formed inclusion bodies and virus production was analyzed: the size of the inclusion body formed 3 days after infection was correlated with the viral load in supernatants collected 7 days after infection. These findings suggest that the inclusion bodies formed in SFTSV-infected THP-1 cells could be where the SFTSV uses host-cell proteins and intracellular organelles to produce new viral particles. PMID:27295879

  1. [Inclusion Bodies are Formed in SFTSV-infected Human Macrophages].

    PubMed

    Jin, Cong; Song, Jingdong; Han, Ying; Li, Chuan; Qiu, Peihong; Liang, Mifang

    2016-01-01

    The severe fever with thrombocytopenia syndrome virus (SFTSV) is a new member in the genus Phlebovirus of the family Bunyaviridae identified in China. The SFTSV is also the causative pathogen of an emerging infectious disease: severe fever with thrombocytopenia syndrome. Using immunofluorescent staining and confocal microscopy, the intracellular distribution of nucleocapsid protein (NP) in SFTSV-infected THP-1 cells was investigated with serial doses of SFTSV at different times after infection. Transmission electron microscopy was used to observe the ultrafine intracellular structure of SFTSV-infected THP-1 cells at different times after infection. SFTSV NP could form intracellular inclusion bodies in infected THP-1 cells. The association between NP-formed inclusion bodies and virus production was analyzed: the size of the inclusion body formed 3 days after infection was correlated with the viral load in supernatants collected 7 days after infection. These findings suggest that the inclusion bodies formed in SFTSV-infected THP-1 cells could be where the SFTSV uses host-cell proteins and intracellular organelles to produce new viral particles.

  2. Virus distribution and role of thymic macrophages during experimental infection with noncytopathogenic bovine viral diarrhea virus type 1.

    PubMed

    Raya, A I; Gomez-Villamandos, J C; Sánchez-Cordón, P J; Bautista, M J

    2012-09-01

    Thymic depletion, presence of viral antigen, and changes in distribution and cytokine production of thymic macrophages were investigated in calves experimentally infected with a noncytopathogenic bovine viral diarrhea virus type (BVDV) 1 strain. Ten clinically healthy colostrum-deprived calves were used. Eight calves were inoculated with the virus and two were used as uninfected controls. Calves were sedated and euthanized in batches between 3 and 14 days postinoculation. At necropsy, thymus samples were collected for structural, immunohistochemical, and ultrastructural study and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling). From 6 days postinoculation, the thymic cortex was multifocally depleted with increased frequency of pyknosis and karyorrhexis, suggestive of apoptosis and confirmed by the TUNEL technique. Although the onset of lymphoid depletion was coincident with the detection of viral antigen by immunohistochemistry, the number of infected lymphocytes was very low through the experiment. There was an increase in number of macrophages in cortex and medulla, accompanied by ultrastructural changes indicative of phagocyte activation, and a decrease in cells expressing tumor necrosis factor-alpha (TNF-α) and IL-1α. These results suggest that the increase in number of these cells could be related to phagocytosis of cell debris and apoptotic lymphocytes. Furthermore, the results imply that, in contrast to the situation with classical swine fever virus, the lymphocyte apoptosis resulting from bovine viral diarrhea virus infection is not mediated by TNF-α or interleukin-1 alpha (IL-1α) production by virus-infected macrophages. This is the first study that describes this decrease in the number of thymic cells expressing TNF-α and IL-1α in cattle experimentally infected with bovine viral diarrhea virus type 1.

  3. Toll-like receptor 4 is involved in the cell cycle modulation and required for effective human cytomegalovirus infection in THP-1 macrophages

    SciTech Connect

    Arcangeletti, Maria-Cristina; Germini, Diego; Rodighiero, Isabella; Mirandola, Prisco; De Conto, Flora; Medici, Maria-Cristina; Gatti, Rita; Chezzi, Carlo; Calderaro, Adriana

    2013-05-25

    Suitable host cell metabolic conditions are fundamental for the effective development of the human cytomegalovirus (HCMV) lytic cycle. Indeed, several studies have demonstrated the ability of this virus to interfere with cell cycle regulation, mainly by blocking proliferating cells in G1 or G1/S. In the present study, we demonstrate that HCMV deregulates the cell cycle of THP-1 macrophages (a cell line irreversibly arrested in G0) by pushing them into S and G2 phases. Moreover, we show that HCMV infection of THP-1 macrophages leads to Toll-like receptor 4 (TLR4) activation. Since various studies have indicated TLR4 to be involved in promoting cell proliferation, here we investigate the possible role of TLR4 in the observed HCMV-induced cell cycle perturbation. Our data strongly support TLR4 as a mediator of HCMV-triggered cell cycle activation in THP-1 macrophages favouring, in turn, the development of an efficient viral lytic cycle. - Highlights: ► We studied HCMV infection impact on THP-1 macrophage cell cycle. ► We analysed the role played by Toll-like receptor (TLR) 4 upon HCMV infection. ► HCMV pushes THP-1 macrophages (i.e. resting cells) to re-enter the cell cycle. ► TLR4 pathway inhibition strongly affects the effectiveness of HCMV replication. ► TLR4 pathway inhibition significantly decreases HCMV-induced cell cycle re-entry.

  4. Within-Host Models of High and Low Pathogenic Influenza Virus Infections: The Role of Macrophages

    PubMed Central

    Pawelek, Kasia A.; Dor, Daniel; Salmeron, Cristian; Handel, Andreas

    2016-01-01

    The World Health Organization identifies influenza as a major public health problem. While the strains commonly circulating in humans usually do not cause severe pathogenicity in healthy adults, some strains that have infected humans, such as H5N1, can cause high morbidity and mortality. Based on the severity of the disease, influenza viruses are sometimes categorized as either being highly pathogenic (HP) or having low pathogenicity (LP). The reasons why some strains are LP and others HP are not fully understood. While there are likely multiple mechanisms of interaction between the virus and the immune response that determine LP versus HP outcomes, we focus here on one component, namely macrophages (MP). There is some evidence that MP may both help fight the infection and become productively infected with HP influenza viruses. We developed mathematical models for influenza infections which explicitly included the dynamics and action of MP. We fit these models to viral load and macrophage count data from experimental infections of mice with LP and HP strains. Our results suggest that MP may not only help fight an influenza infection but may contribute to virus production in infections with HP viruses. We also explored the impact of combination therapies with antivirals and anti-inflammatory drugs on HP infections. Our study suggests a possible mechanism of MP in determining HP versus LP outcomes, and how different interventions might affect infection dynamics. PMID:26918620

  5. Alternative activation of macrophages and pulmonary fibrosis are modulated by scavenger receptor, macrophage receptor with collagenous structure.

    PubMed

    Murthy, Shubha; Larson-Casey, Jennifer L; Ryan, Alan J; He, Chao; Kobzik, Lester; Carter, A Brent

    2015-08-01

    Alternative activation of alveolar macrophages is linked to fibrosis following exposure to asbestos. The scavenger receptor, macrophage receptor with collagenous structure (MARCO), provides innate immune defense against inhaled particles and pathogens; however, a receptor for asbestos has not been identified. We hypothesized that MARCO acts as an initial signaling receptor for asbestos, polarizes macrophages to a profibrotic M2 phenotype, and is required for the development of asbestos-induced fibrosis. Compared with normal subjects, alveolar macrophages isolated from patients with asbestosis express higher amounts of MARCO and have greater profibrotic polarization. Arginase 1 (40-fold) and IL-10 (265-fold) were higher in patients. In vivo, the genetic deletion of MARCO attenuated the profibrotic environment and pulmonary fibrosis in mice exposed to chrysotile. Moreover, alveolar macrophages from MARCO(-/-) mice polarize to an M1 phenotype, whereas wild-type mice have higher Ym1 (>3.0-fold) and nearly 7-fold more active TGF-β1 in bronchoalveolar lavage (BAL) fluid (BALF). Arg(432) and Arg(434) in domain V of MARCO are required for the polarization of macrophages to a profibrotic phenotype as mutation of these residues reduced FIZZ1 expression (17-fold) compared with cells expressing MARCO. These observations demonstrate that a macrophage membrane protein regulates the fibrotic response to lung injury and suggest a novel target for therapeutic intervention.

  6. Essential role of hormone-sensitive lipase (HSL) in the maintenance of lipid storage in Mycobacterium leprae-infected macrophages.

    PubMed

    Tanigawa, Kazunari; Degang, Yang; Kawashima, Akira; Akama, Takeshi; Yoshihara, Aya; Ishido, Yuko; Makino, Masahiko; Ishii, Norihisa; Suzuki, Koichi

    2012-05-01

    Mycobacterium leprae (M. leprae), the causative agent of leprosy, parasitizes within the foamy or enlarged phagosome of macrophages where rich lipids accumulate. Although the mechanisms for lipid accumulation in the phagosome have been clarified, it is still unclear how such large amounts of lipids escape degradation. To further explore underlying mechanisms involved in lipid catabolism in M. leprae-infected host cells, we examined the expression of hormone-sensitive lipase (HSL), a key enzyme in fatty acid mobilization and lipolysis, in human macrophage THP-1 cells. We found that infection by live M. leprae significantly suppressed HSL expression levels. This suppression was not observed with dead M. leprae or latex beads. Macrophage activation by peptidoglycan (PGN), the ligand for toll-like receptor 2 (TLR2), increased HSL expression; however, live M. leprae suppressed this increase. HSL expression was abolished in the slit-skin smear specimens from patients with lepromatous and borderline leprosy. In addition, the recovery of HSL expression was observed in patients who experienced a lepra reaction, which is a cell-mediated, delayed-type hypersensitivity immune response, or in patients who were successfully treated with multi-drug therapy. These results suggest that M. leprae suppresses lipid degradation through inhibition of HSL expression, and that the monitoring of HSL mRNA levels in slit-skin smear specimens may be a useful indicator of patient prognosis.

  7. The role of IgG subclass of mouse monoclonal antibodies in antibody-dependent enhancement of feline infectious peritonitis virus infection of feline macrophages.

    PubMed

    Hohdatsu, T; Tokunaga, J; Koyama, H

    1994-01-01

    Antibody-dependent enhancement (ADE) of feline infectious peritonitis virus (FIPV) infection was studied in feline alveolar macrophages and human monocyte cell line U937 using mouse neutralizing monoclonal antibodies (MAbs) directed to the spike protein of FIPV. Even among the MAbs that have been shown to recognize the same antigenic site, IgG 2a MAbs enhanced FIPV infection strongly, whereas IgG 1 MAbs did not. These IgG 2a MAbs enhanced the infection even when macrophages pretreated with the MAb were washed and then inoculated with the virus. Immunofluorescence flow cytometric analysis of the macrophages treated with each of the MAbs showed that the IgG 2a MAbs but not the IgG 1 MAbs bound to feline alveolar macrophages. Treatment of the IgG 2a MAb with protein A decreased the binding to the macrophages and, in parallel, diminished the ADE activity. Although no infection was observed by inoculation of FIPV to human monocyte cell line U937 cells, FIPV complexed with either the IgG 2a MAb or the IgG 1 MAb caused infection in U937 cells which are shown to express Fc gamma receptor (Fc gamma R) I and II that can bind mouse IgG 2a and IgG 1, respectively. These results suggest that the enhancing activity of MAb is closely correlated with IgG subclass and that the correlation is involved in binding of MAb to Fc gamma R on feline macrophage.

  8. Pathogen vacuole purification from legionella-infected amoeba and macrophages.

    PubMed

    Hoffmann, Christine; Finsel, Ivo; Hilbi, Hubert

    2013-01-01

    Legionella pneumophila replicates intracellularly in environmental and immune phagocytes within a unique membrane-bound compartment, the Legionella-containing vacuole (LCV). Formation of LCVs is strictly dependent on the Icm/Dot type IV secretion system and the translocation of "effector" proteins into the cell. Some effector proteins decorate the LCV membrane and subvert host cell vesicle trafficking pathways. Here we describe a method to purify intact LCVs from Dictyostelium discoideum amoebae and RAW 264.7 murine macrophages. The method comprises a two-step protocol: first, LCVs are enriched by immuno-magnetic separation using an antibody against a bacterial effector protein specifically localizing to the LCV membrane, and second, the LCVs are further purified by density gradient centrifugation. The purified LCVs can be characterized by proteomics and other biochemical approaches.

  9. Uncovering an Important Role for YopJ in the Inhibition of Caspase-1 in Activated Macrophages and Promoting Yersinia pseudotuberculosis Virulence.

    PubMed

    Schoberle, Taylor J; Chung, Lawton K; McPhee, Joseph B; Bogin, Ben; Bliska, James B

    2016-04-01

    Pathogenic Yersinia species utilize a type III secretion system to translocate Yop effectors into infected host cells. Yop effectors inhibit innate immune responses in infected macrophages to promote Yersinia pathogenesis. In turn,Yersinia-infected macrophages respond to translocation of Yops by activating caspase-1, but different mechanisms of caspase-1 activation occur, depending on the bacterial genotype and the state of phagocyte activation. In macrophages activated with lipopolysaccharide (LPS) prior to Yersinia pseudotuberculosis infection, caspase-1 is activated by a rapid inflammasome-dependent mechanism that is inhibited by translocated YopM. The possibility that other effectors cooperate with YopM to inhibit caspase-1 activation in LPS-activated macrophages has not been investigated. Toward this aim, epistasis analysis was carried out in which the phenotype of aY. pseudotuberculosis yopM mutant was compared to that of a yopJ yopM, yopE yopM, yopH yopM, yopT yopM, or ypkA yopM mutant. Activation of caspase-1 was measured by cleavage of the enzyme, release of interleukin-1β (IL-1β), and pyroptosis in LPS-activated macrophages infected with wild-type or mutant Y. pseudotuberculosis strains. Results show enhanced activation of caspase-1 after infection with the yopJ yopM mutant relative to infection by any other single or double mutant. Similar results were obtained with the yopJ, yopM, and yopJ yopM mutants ofY ersinia pestis Following intravenous infection of mice, theY. pseudotuberculosis yopJ mutant was as virulent as the wild type, while the yopJ yopM mutant was significantly more attenuated than the yopM mutant. In summary, through epistasis analysis this work uncovered an important role for YopJ in inhibiting caspase-1 in activated macrophages and in promoting Yersinia virulence.

  10. Purinergic signaling during macrophage differentiation results in M2 alternative activated macrophages.

    PubMed

    Barberà-Cremades, Maria; Baroja-Mazo, Alberto; Pelegrín, Pablo

    2016-02-01

    Macrophages represent a highly heterogenic cell population of the innate immune system, with important roles in the initiation and resolution of the inflammatory response. Purinergic signaling regulates both M1 and M2 macrophage function at different levels by controlling the secretion of cytokines, phagocytosis, and the production of reactive oxygen species. We found that extracellular nucleotides arrest macrophage differentiation from bone marrow precursors via adenosine and P2 receptors. This results in a mature macrophage with increased expression of M2, but not M1, genes. Similar to adenosine and ATP, macrophage growth arrested with LPS treatment resulted in an increase of the M2-related marker Ym1. Recombinant Ym1 was able to affect macrophage proliferation and could, potentially, be involved in the arrest of macrophage growth during hematopoiesis.

  11. Neutrophil and Alveolar Macrophage-Mediated Innate Immune Control of Legionella pneumophila Lung Infection via TNF and ROS.

    PubMed

    Ziltener, Pascal; Reinheckel, Thomas; Oxenius, Annette

    2016-04-01

    Legionella pneumophila is a facultative intracellular bacterium that lives in aquatic environments where it parasitizes amoeba. However, upon inhalation of contaminated aerosols it can infect and replicate in human alveolar macrophages, which can result in Legionnaires' disease, a severe form of pneumonia. Upon experimental airway infection of mice, L. pneumophila is rapidly controlled by innate immune mechanisms. Here we identified, on a cell-type specific level, the key innate effector functions responsible for rapid control of infection. In addition to the well-characterized NLRC4-NAIP5 flagellin recognition pathway, tumor necrosis factor (TNF) and reactive oxygen species (ROS) are also essential for effective innate immune control of L. pneumophila. While ROS are essential for the bactericidal activity of neutrophils, alveolar macrophages (AM) rely on neutrophil and monocyte-derived TNF signaling via TNFR1 to restrict bacterial replication. This TNF-mediated antibacterial mechanism depends on the acidification of lysosomes and their fusion with L. pneumophila containing vacuoles (LCVs), as well as caspases with a minor contribution from cysteine-type cathepsins or calpains, and is independent of NLRC4, caspase-1, caspase-11 and NOX2. This study highlights the differential utilization of innate effector pathways to curtail intracellular bacterial replication in specific host cells upon L. pneumophila airway infection. PMID:27105352

  12. Neutrophil and Alveolar Macrophage-Mediated Innate Immune Control of Legionella pneumophila Lung Infection via TNF and ROS

    PubMed Central

    Ziltener, Pascal; Reinheckel, Thomas; Oxenius, Annette

    2016-01-01

    Legionella pneumophila is a facultative intracellular bacterium that lives in aquatic environments where it parasitizes amoeba. However, upon inhalation of contaminated aerosols it can infect and replicate in human alveolar macrophages, which can result in Legionnaires’ disease, a severe form of pneumonia. Upon experimental airway infection of mice, L. pneumophila is rapidly controlled by innate immune mechanisms. Here we identified, on a cell-type specific level, the key innate effector functions responsible for rapid control of infection. In addition to the well-characterized NLRC4-NAIP5 flagellin recognition pathway, tumor necrosis factor (TNF) and reactive oxygen species (ROS) are also essential for effective innate immune control of L. pneumophila. While ROS are essential for the bactericidal activity of neutrophils, alveolar macrophages (AM) rely on neutrophil and monocyte-derived TNF signaling via TNFR1 to restrict bacterial replication. This TNF-mediated antibacterial mechanism depends on the acidification of lysosomes and their fusion with L. pneumophila containing vacuoles (LCVs), as well as caspases with a minor contribution from cysteine-type cathepsins or calpains, and is independent of NLRC4, caspase-1, caspase-11 and NOX2. This study highlights the differential utilization of innate effector pathways to curtail intracellular bacterial replication in specific host cells upon L. pneumophila airway infection. PMID:27105352

  13. The macrophage IRF8/IRF1 regulome is required for protection against infections and is associated with chronic inflammation

    PubMed Central

    Langlais, David; Barreiro, Luis B.

    2016-01-01

    IRF8 and IRF1 are transcriptional regulators that play critical roles in the development and function of myeloid cells, including activation of macrophages by proinflammatory signals such as interferon-γ (IFN-γ). Loss of IRF8 or IRF1 function causes severe susceptibility to infections in mice and in humans. We used chromatin immunoprecipitation sequencing and RNA sequencing in wild type and in IRF8 and IRF1 mutant primary macrophages to systematically catalog all of the genes bound by (cistromes) and transcriptionally activated by (regulomes) IRF8, IRF1, PU.1, and STAT1, including modulation of epigenetic histone marks. Of the seven binding combinations identified, two (cluster 1 [IRF8/IRF1/STAT1/PU.1] and cluster 5 [IRF1/STAT1/PU.1]) were found to have a major role in controlling macrophage transcriptional programs both at the basal level and after IFN-γ activation. They direct the expression of a set of genes, the IRF8/IRF1 regulome, that play critical roles in host inflammatory and antimicrobial defenses in mouse models of neuroinflammation and of pulmonary tuberculosis, respectively. In addition, this IRF8/IRF1 regulome is enriched for genes mutated in human primary immunodeficiencies and with loci associated with several inflammatory diseases in humans. PMID:27001747

  14. The macrophage IRF8/IRF1 regulome is required for protection against infections and is associated with chronic inflammation.

    PubMed

    Langlais, David; Barreiro, Luis B; Gros, Philippe

    2016-04-01

    IRF8 and IRF1 are transcriptional regulators that play critical roles in the development and function of myeloid cells, including activation of macrophages by proinflammatory signals such as interferon-γ (IFN-γ). Loss of IRF8 or IRF1 function causes severe susceptibility to infections in mice and in humans. We used chromatin immunoprecipitation sequencing and RNA sequencing in wild type and inIRF8andIRF1mutant primary macrophages to systematically catalog all of the genes bound by (cistromes) and transcriptionally activated by (regulomes) IRF8, IRF1, PU.1, and STAT1, including modulation of epigenetic histone marks. Of the seven binding combinations identified, two (cluster 1 [IRF8/IRF1/STAT1/PU.1] and cluster 5 [IRF1/STAT1/PU.1]) were found to have a major role in controlling macrophage transcriptional programs both at the basal level and after IFN-γ activation. They direct the expression of a set of genes, the IRF8/IRF1 regulome, that play critical roles in host inflammatory and antimicrobial defenses in mouse models of neuroinflammation and of pulmonary tuberculosis, respectively. In addition, this IRF8/IRF1 regulome is enriched for genes mutated in human primary immunodeficiencies and with loci associated with several inflammatory diseases in humans. PMID:27001747

  15. Genome-Wide Analysis of Antiviral Signature Genes in Porcine Macrophages at Different Activation Statuses

    PubMed Central

    Sang, Yongming; Brichalli, Wyatt; Rowland, Raymond R. R.; Blecha, Frank

    2014-01-01

    Macrophages (MФs) can be polarized to various activation statuses, including classical (M1), alternative (M2), and antiviral states. To study the antiviral activation status of porcine MФs during porcine reproductive and respiratory syndrome virus (PRRSV) infection, we used RNA Sequencing (RNA-Seq) for transcriptomic analysis of differentially expressed genes (DEGs). Sequencing assessment and quality evaluation showed that our RNA-Seq data met the criteria for genome-wide transcriptomic analysis. Comparisons of any two activation statuses revealed more than 20,000 DEGs that were normalized to filter out 153–5,303 significant DEGs [false discovery rate (FDR) ≤0.001, fold change ≥2] in each comparison. The highest 5,303 significant DEGs were found between lipopolysaccharide- (LPS) and interferon (IFN)γ-stimulated M1 cells, whereas only 153 significant DEGs were detected between interleukin (IL)-10-polarized M2 cells and control mock-activated cells. To identify signature genes for antiviral regulation pertaining to each activation status, we identified a set of DEGs that showed significant up-regulation in only one activation state. In addition, pathway analyses defined the top 20–50 significantly regulated pathways at each activation status, and we further analyzed DEGs pertinent to pathways mediated by AMP kinase (AMPK) and epigenetic mechanisms. For the first time in porcine macrophages, our transcriptomic analyses not only compared family-wide differential expression of most known immune genes at different activation statuses, but also revealed transcription evidence of multiple gene families. These findings show that using RNA-Seq transcriptomic analyses in virus-infected and status-synchronized macrophages effectively profiled signature genes and gene response pathways for antiviral regulation, which may provide a framework for optimizing antiviral immunity and immune homeostasis. PMID:24505295

  16. Activation/proliferation and apoptosis of bystander goat lymphocytes induced by a macrophage-tropic chimeric caprine arthritis encephalitis virus expressing SIV Nef

    SciTech Connect

    Bouzar, Baya Amel; Rea, Angela; Hoc-Villet, Stephanie; Garnier, Celine; Guiguen, Francois; Jin Yuhuai; Narayan, Opendra; Chebloune, Yahia . E-mail: ychebloune@kumc.edu

    2007-08-01

    Caprine arthritis encephalitis virus (CAEV) is the natural lentivirus of goats, well known for its tropism for macrophages and its inability to cause infection in lymphocytes. The viral genome lacks nef, tat, vpu and vpx coding sequences. To test the hypothesis that when nef is expressed by the viral genome, the virus became toxic for lymphocytes during replication in macrophages, we inserted the SIVsmm PBj14 nef coding sequences into the genome of CAEV thereby generating CAEV-nef. This recombinant virus is not infectious for lymphocytes but is fully replication competent in goat macrophages in which it constitutively expresses the SIV Nef. We found that goat lymphocytes cocultured with CAEV-nef-infected macrophages became activated, showing increased expression of the interleukin-2 receptor (IL-2R). Activation correlated with increased proliferation of the cells. Interestingly, a dual effect in terms of apoptosis regulation was observed in exposed goat lymphocytes. Nef was found first to induce a protection of lymphocytes from apoptosis during the first few days following exposure to infected macrophages, but later it induced increased apoptosis in the activated lymphocytes. This new recombinant virus provides a model to study the functions of Nef in the context of infection of macrophages, but in absence of infection of T lymphocytes and brings new insights into the biological effects of Nef on lymphocytes.

  17. Presentation via the class I pathway by Leishmania amazonensis-infected macrophages of an endogenous leishmanial antigen to CD8+ T cells.

    PubMed

    Kima, P E; Ruddle, N H; McMahon-Pratt, D

    1997-08-15

    CD8+ T cells play a protective role in immunity to cutaneous leishmaniasis. However, it has been unclear how these cells execute this function, since results from several investigations attempting to demonstrate recognition of Leishmania-infected macrophages by CD8+ T cells have been contradictory. In this study, we report the generation of CD8+ T cell lines specific for GP46/M-2, a leishmanial Ag, previously shown to protectively immunize mice against a Leishmania amazonensis challenge. Using T cell cytolysis and IFN-gamma production to assess CD8+ T cell activation, we show that in addition to recognizing mammalian cells transfected with GP46/M-2, these CD8+ T cell lines also recognize macrophages infected with Leishmania amazonensis. MHC class I presentation of GP46/M-2 by infected macrophages can be blocked by treatment with brefeldin A and also by inhibitors of the cytosolic multicatalytic proteasome, N-acetyl-L-leucinyl-L-leucinal-L-norleucinal and N-acetyl-L-leucinyl-L-leucinylmethional. These results suggest that this leishmanial Ag is processed in the macrophage cytoplasm and is presented to CD8+ T cells via the classical pathway of MHC class I presentation. The relevance of these findings as they impact on our understanding of the biology of the parasite within the macrophage is discussed.

  18. Increases in Calmodulin Abundance and Stabilization of Activated iNOS Mediate Bacterial Killing in RAW 264.7 Macrophages

    SciTech Connect

    Smallwood, Heather S.; Shi, Liang; Squier, Thomas C.

    2006-08-01

    The rapid activation of macrophages in response to bacterial antigens is central to the innate immune system that permits the recognition and killing of pathogens to limit infection. To understand regulatory mechanisms underlying macrophage activation, we have investigated changes in the abundance of calmodulin (CaM) and iNOS in response to the bacterial cell wall component lipopolysaccharide (LPS) using RAW 264.7 macrophages. Critical to these measurements was the ability to differentiate free iNOS from the CaM-bound (active) form of iNOS associated with nitric oxide generation. We observe a rapid two-fold increase in CaM abundance during the first 30 minutes that is blocked by inhibition of NF?B nuclear translocation or protein synthesis. A similar two-fold increase in the abundance of the complex between CaM and iNOS is observed with the same time dependence. In contrast, there are no detectable increases in the CaM-free (i.e., inactive) form of iNOS within the first hour; it remains at a very low abundance during the initial phase of macrophage activation. Increasing cellular CaM levels in stably transfected cells results in a corresponding increase in the abundance of the CaM/iNOS complex that promotes effective bacterial killing following challenge by Salmonella typhimurium. Thus, LPS-dependent increases in CaM abundance function in the stabilization and activation of iNOS on the rapid time-scale associated with macrophage activation and bacterial killing. These results explain how CaM and iNOS coordinately function to form a stable complex that is part of a rapid host-response that functions within the first 30 minutes following bacterial infection to up-regulate the innate immune system involving macrophage activation.

  19. Expression and characterization of a parasite-specific antigen on macrophages after infection with Leishmania donovani.

    PubMed

    Basu, N; Kole, L; Ghosh, A; Das, P K

    1994-03-16

    A rabbit polyclonal antibody to crude soluble antigen of Leishmania donovani promastigotes recognized a determinant expressed on the surface membrane of mouse peritoneal macrophages and human monocyte derived macrophages infected in vitro. The determinant was recognized on infected macrophage surface only when F(ab')2 fragments of anti-leishmanial antiserum was employed in immunofluorescence. F(ab')2 fragments of human patient sera also could recognize the determinant. The expression of this antigen was not stage-specific for the parasite. Immunochemical analyses revealed this antigen to be of 51 kDa protein. Specific leaching of membrane proteins by trypsin showed three bands of expressed antigens of 26, 11 and 10 kDa, which in all likelihood might be arising from the 51 kDa antigen. The antigen was not expressed until 12 h of post infection, reached a maximum level at 24 h and thereafter attained a steady state level as studied upto 96 h of post infection. This type of antigen might have a great potential in immunodiagnostics and site-specific drug targeting. PMID:8078503

  20. Effects of inhibitors of tumoricidal activity upon schistosomulum killing by activated macrophages.

    PubMed

    James, S L; Glaven, J A

    1987-12-01

    Larvae of the helminth parasite Schistosoma mansoni are efficiently killed in vitro by lymphokine-activated macrophages, leading to the hypothesis that these cells may participate in the effector mechanism of protective immunity against schistosomiasis. Larvacidal activity has also been demonstrated in the IC-21 macrophage cell line in the absence of a demonstrable respiratory burst, indicating that macrophages possess nonoxidative mechanisms of schistosomulum killing. In this study, we demonstrated that IC-21 larval killing was most effective when contact was allowed between cells and target. Nonoxidative larvacidal activity was prevented by protein synthesis inhibitors, by the inhibition of microtubule polymerization, and by tosyllysylchloromethylketone but not by other inhibitors or substrates of tryptic or chymotryptic protease activity. The addition of excess iron to the culture also prevented IC-21-mediated larval killing, suggesting that the production of an iron-binding molecule may be involved. In contrast, the addition of excess thymidine or arginine did not reverse macrophage larvacidal activity, nor did lysosomotropic agents that depress the activity of acid hydrolases. Under appropriate conditions of activation and surface membrane stimulation, IC-21 cells could be induced to release soluble cytotoxic factors retaining larvacidal activity. These observations provide insight into the mechanism of macrophage-mediated schistosome killing, in comparison to the cytotoxic mechanisms described in the better-studied tumoricidal models, and supply a basis for further biochemical investigation of macrophage function against a multicellular target. PMID:3119500

  1. Effects of inhibitors of tumoricidal activity upon schistosomulum killing by activated macrophages.

    PubMed Central

    James, S L; Glaven, J A

    1987-01-01

    Larvae of the helminth parasite Schistosoma mansoni are efficiently killed in vitro by lymphokine-activated macrophages, leading to the hypothesis that these cells may participate in the effector mechanism of protective immunity against schistosomiasis. Larvacidal activity has also been demonstrated in the IC-21 macrophage cell line in the absence of a demonstrable respiratory burst, indicating that macrophages possess nonoxidative mechanisms of schistosomulum killing. In this study, we demonstrated that IC-21 larval killing was most effective when contact was allowed between cells and target. Nonoxidative larvacidal activity was prevented by protein synthesis inhibitors, by the inhibition of microtubule polymerization, and by tosyllysylchloromethylketone but not by other inhibitors or substrates of tryptic or chymotryptic protease activity. The addition of excess iron to the culture also prevented IC-21-mediated larval killing, suggesting that the production of an iron-binding molecule may be involved. In contrast, the addition of excess thymidine or arginine did not reverse macrophage larvacidal activity, nor did lysosomotropic agents that depress the activity of acid hydrolases. Under appropriate conditions of activation and surface membrane stimulation, IC-21 cells could be induced to release soluble cytotoxic factors retaining larvacidal activity. These observations provide insight into the mechanism of macrophage-mediated schistosome killing, in comparison to the cytotoxic mechanisms described in the better-studied tumoricidal models, and supply a basis for further biochemical investigation of macrophage function against a multicellular target. PMID:3119500

  2. Enhancement of macrophage candidacidal activity by interferon-gamma. Increased phagocytosis, killing, and calcium signal mediated by a decreased number of mannose receptors.

    PubMed Central

    Maródi, L; Schreiber, S; Anderson, D C; MacDermott, R P; Korchak, H M; Johnston, R B

    1993-01-01

    In contrast to its macrophage-activating capacity, IFN-gamma downregulates expression of the macrophage mannose receptor (MMR), which mediates uptake of Candida and other microorganisms. We found that IFN-gamma induced a concentration-dependent increase in the capacity of human monocyte-derived macrophages to ingest and kill both opsonized and unopsonized Candida albicans and to release superoxide anion upon stimulation with Candida. Mannan or mannosylated albumin inhibited this activated uptake of unopsonized Candida, but glucan did not. Addition of mAb to complement receptor (CR) 3 did not inhibit ingestion; macrophages that lacked CR3 (leukocyte adhesion defect) showed normal upregulation of ingestion by IFN-gamma. The increased candidacidal activity of IFN-gamma-activated macrophages was associated with reduced expression of MMR by a mean of 79% and decreased pinocytic uptake of 125I-mannosylated BSA by 73%; K(uptake) of pinocytosis was not changed. Exposure of resident macrophages to unopsonized Candida did not elicit a transient increase in intracellular free Ca2+ ([Ca2+]i); macrophages activated by IFN-gamma expressed a brisk increase in [Ca2+]i on exposure to Candida. These data suggest that macrophage activation by IFN-gamma can enhance resistance to C. albicans infection in spite of downregulation of the MMR, perhaps through enhanced coupling of the MMR to microbicidal functions. PMID:8390485

  3. Treatment of Mycobacterium tuberculosis-Infected Macrophages with Poly(Lactic-Co-Glycolic Acid) Microparticles Drives NFκB and Autophagy Dependent Bacillary Killing.

    PubMed

    Lawlor, Ciaran; O'Connor, Gemma; O'Leary, Seonadh; Gallagher, Paul J; Cryan, Sally-Ann; Keane, Joseph; O'Sullivan, Mary P

    2016-01-01

    The emergence of multiple-drug-resistant tuberculosis (MDR-TB) has pushed our available repertoire of anti-TB therapies to the limit of effectiveness. This has increased the urgency to develop novel treatment modalities, and inhalable microparticle (MP) formulations are a promising option to target the site of infection. We have engineered poly(lactic-co-glycolic acid) (PLGA) MPs which can carry a payload of anti-TB agents, and are successfully taken up by human alveolar macrophages. Even without a drug cargo, MPs can be potent immunogens; yet little is known about how they influence macrophage function in the setting of Mycobacterium tuberculosis (Mtb) infection. To address this issue we infected THP-1 macrophages with Mtb H37Ra or H37Rv and treated with MPs. In controlled experiments we saw a reproducible reduction in bacillary viability when THP-1 macrophages were treated with drug-free MPs. NFκB activity was increased in MP-treated macrophages, although cytokine secretion was unaltered. Confocal microscopy of immortalized murine bone marrow-derived macrophages expressing GFP-tagged LC3 demonstrated induction of autophagy. Inhibition of caspases did not influence the MP-induced restriction of bacillary growth, however, blockade of NFκB or autophagy with pharmacological inhibitors reversed this MP effect on macrophage function. These data support harnessing inhaled PLGA MP-drug delivery systems as an immunotherapeutic in addition to serving as a vehicle for targeted drug delivery. Such "added value" could be exploited in the generation of inhaled vaccines as well as inhaled MDR-TB therapeutics when used as an adjunct to existing treatments. PMID:26894562

  4. Treatment of Mycobacterium tuberculosis-Infected Macrophages with Poly(Lactic-Co-Glycolic Acid) Microparticles Drives NFκB and Autophagy Dependent Bacillary Killing

    PubMed Central

    Lawlor, Ciaran; O’Connor, Gemma; O’Leary, Seonadh; Gallagher, Paul J.

    2016-01-01

    The emergence of multiple-drug-resistant tuberculosis (MDR-TB) has pushed our available repertoire of anti-TB therapies to the limit of effectiveness. This has increased the urgency to develop novel treatment modalities, and inhalable microparticle (MP) formulations are a promising option to target the site of infection. We have engineered poly(lactic-co-glycolic acid) (PLGA) MPs which can carry a payload of anti-TB agents, and are successfully taken up by human alveolar macrophages. Even without a drug cargo, MPs can be potent immunogens; yet little is known about how they influence macrophage function in the setting of Mycobacterium tuberculosis (Mtb) infection. To address this issue we infected THP-1 macrophages with Mtb H37Ra or H37Rv and treated with MPs. In controlled experiments we saw a reproducible reduction in bacillary viability when THP-1 macrophages were treated with drug-free MPs. NFκB activity was increased in MP-treated macrophages, although cytokine secretion was unaltered. Confocal microscopy of immortalized murine bone marrow-derived macrophages expressing GFP-tagged LC3 demonstrated induction of autophagy. Inhibition of caspases did not influence the MP-induced restriction of bacillary growth, however, blockade of NFκB or autophagy with pharmacological inhibitors reversed this MP effect on macrophage function. These data support harnessing inhaled PLGA MP-drug delivery systems as an immunotherapeutic in addition to serving as a vehicle for targeted drug delivery. Such “added value” could be exploited in the generation of inhaled vaccines as well as inhaled MDR-TB therapeutics when used as an adjunct to existing treatments. PMID:26894562

  5. Treatment of Mycobacterium tuberculosis-Infected Macrophages with Poly(Lactic-Co-Glycolic Acid) Microparticles Drives NFκB and Autophagy Dependent Bacillary Killing.

    PubMed

    Lawlor, Ciaran; O'Connor, Gemma; O'Leary, Seonadh; Gallagher, Paul J; Cryan, Sally-Ann; Keane, Joseph; O'Sullivan, Mary P

    2016-01-01

    The emergence of multiple-drug-resistant tuberculosis (MDR-TB) has pushed our available repertoire of anti-TB therapies to the limit of effectiveness. This has increased the urgency to develop novel treatment modalities, and inhalable microparticle (MP) formulations are a promising option to target the site of infection. We have engineered poly(lactic-co-glycolic acid) (PLGA) MPs which can carry a payload of anti-TB agents, and are successfully taken up by human alveolar macrophages. Even without a drug cargo, MPs can be potent immunogens; yet little is known about how they influence macrophage function in the setting of Mycobacterium tuberculosis (Mtb) infection. To address this issue we infected THP-1 macrophages with Mtb H37Ra or H37Rv and treated with MPs. In controlled experiments we saw a reproducible reduction in bacillary viability when THP-1 macrophages were treated with drug-free MPs. NFκB activity was increased in MP-treated macrophages, although cytokine secretion was unaltered. Confocal microscopy of immortalized murine bone marrow-derived macrophages expressing GFP-tagged LC3 demonstrated induction of autophagy. Inhibition of caspases did not influence the MP-induced restriction of bacillary growth, however, blockade of NFκB or autophagy with pharmacological inhibitors reversed this MP effect on macrophage function. These data support harnessing inhaled PLGA MP-drug delivery systems as an immunotherapeutic in addition to serving as a vehicle for targeted drug delivery. Such "added value" could be exploited in the generation of inhaled vaccines as well as inhaled MDR-TB therapeutics when used as an adjunct to existing treatments.

  6. IL-1β production through the NLRP3 inflammasome by hepatic macrophages links hepatitis C virus infection with liver inflammation and disease.

    PubMed

    Negash, Amina A; Ramos, Hilario J; Crochet, Nanette; Lau, Daryl T Y; Doehle, Brian; Papic, Neven; Delker, Don A; Jo, Juandy; Bertoletti, Antonio; Hagedorn, Curt H; Gale, Michael

    2013-01-01

    Chronic hepatitis C virus (HCV) infection is a leading cause of liver disease. Liver inflammation underlies infection-induced fibrosis, cirrhosis and liver cancer but the processes that promote hepatic inflammation by HCV are not defined. We provide a systems biology analysis with multiple lines of evidence to indicate that interleukin-1β (IL-1β) production by intrahepatic macrophages confers liver inflammation through HCV-induced inflammasome signaling. Chronic hepatitis C patients exhibited elevated levels of serum IL-1β compared to healthy controls. Immunohistochemical analysis of healthy control and chronic hepatitis C liver sections revealed that Kupffer cells, resident hepatic macrophages, are the primary cellular source of hepatic IL-1β during HCV infection. Accordingly, we found that both blood monocyte-derived primary human macrophages, and Kupffer cells recovered from normal donor liver, produce IL-1β after HCV exposure. Using the THP-1 macrophage cell-culture model, we found that HCV drives a rapid but transient caspase-1 activation to stimulate IL-1β secretion. HCV can enter macrophages through non-CD81 mediated phagocytic uptake that is independent of productive infection. Viral RNA triggers MyD88-mediated TLR7 signaling to induce IL-1β mRNA expression. HCV uptake concomitantly induces a potassium efflux that activates the NLRP3 inflammasome for IL-1β processing and secretion. RNA sequencing analysis comparing THP1 cells and chronic hepatitis C patient liver demonstrates that viral engagement of the NLRP3 inflammasome stimulates IL-1β production to drive proinflammatory cytokine, chemokine, and immune-regulatory gene expression networks linked with HCV disease severity. These studies identify intrahepatic IL-1β production as a central feature of liver inflammation during HCV infection. Thus, strategies to suppress NLRP3 or IL-1β activity could offer therapeutic actions to reduce hepatic inflammation and mitigate disease.

  7. Prolonged-acting, multi-targeting gallium nanoparticles potently inhibit growth of both HIV and mycobacteria in co-infected human macrophages.

    PubMed

    Narayanasamy, Prabagaran; Switzer, Barbara L; Britigan, Bradley E

    2015-03-06

    Human immunodeficiency virus (HIV) infection and Mycobacterium tuberculosis (TB) are responsible for two of the major global human infectious diseases that result in significant morbidity, mortality and socioeconomic impact. Furthermore, severity and disease prevention of both infections is enhanced by co-infection. Parallel limitations also exist in access to effective drug therapy and the emergence of resistance. Furthermore, drug-drug interactions have proven problematic during treatment of co-incident HIV and TB infections. Thus, improvements in drug access and simplified treatment regimens are needed immediately. One of the key host cells infected by both HIV and TB is the mononuclear phagocyte (MP; monocyte, macrophage and dendritic cell). Therefore, we hypothesized that one way this can be achieved is through drug-targeting by a nanoformulated drug that ideally would be active against both HIV and TB. Accordingly, we validated macrophage targeted long acting (sustained drug release) gallium (Ga) nanoformulation against HIV-mycobacterium co-infection. The multi-targeted Ga nanoparticle agent inhibited growth of both HIV and TB in the macrophage. The Ga nanoparticles reduced the growth of mycobacterium and HIV for up to 15 days following single drug loading. These results provide a potential new approach to treat HIV-TB co-infection that could eventually lead to improved clinical outcomes.

  8. Prolonged-acting, Multi-targeting Gallium Nanoparticles Potently Inhibit Growth of Both HIV and Mycobacteria in Co-Infected Human Macrophages

    PubMed Central

    Narayanasamy, Prabagaran; Switzer, Barbara L.; Britigan, Bradley E.

    2015-01-01

    Human immunodeficiency virus (HIV) infection and Mycobacterium tuberculosis (TB) are responsible for two of the major global human infectious diseases that result in significant morbidity, mortality and socioeconomic impact. Furthermore, severity and disease prevention of both infections is enhanced by co-infection. Parallel limitations also exist in access to effective drug therapy and the emergence of resistance. Furthermore, drug-drug interactions have proven problematic during treatment of co-incident HIV and TB infections. Thus, improvements in drug access and simplified treatment regimens are needed immediately. One of the key host cells infected by both HIV and TB is the mononuclear phagocyte (MP; monocyte, macrophage and dendritic cell). Therefore, we hypothesized that one way this can be achieved is through drug-targeting by a nanoformulated drug that ideally would be active against both HIV and TB. Accordingly, we validated macrophage targeted long acting (sustained drug release) gallium (Ga) nanoformulation against HIV-mycobacterium co-infection. The multi-targeted Ga nanoparticle agent inhibited growth of both HIV and TB in the macrophage. The Ga nanoparticles reduced the growth of mycobacterium and HIV for up to 15 days following single drug loading. These results provide a potential new approach to treat HIV-TB co-infection that could eventually lead to improved clinical outcomes. PMID:25744727

  9. Lectin coated MgO nanoparticle: its toxicity, antileishmanial activity, and macrophage activation.

    PubMed

    Jebali, Ali; Hekmatimoghaddam, Seyedhossein; Kazemi, Bahram; Allaveisie, Azra; Masoudi, Alireza; Daliri, Karim; Sedighi, Najme; Ranjbari, Javad

    2014-10-01

    The purpose of this research was to evaluate toxicity of uncoated magnesium oxide nanoparticles (MgO NPs), MgO NPs coated with Peanut agglutinin (PNA) lectin, and PNA alone on the promastigotes of Leishmania major (L. major) and macrophages of BALB/c mice. On the other hand, antileishmanial property of uncoated MgO NPs, lectin coated MgO NPs, and PNA lectin alone was evaluated, and also macrophage activation was investigated after treatment with these materials by measurement of nitrite, H2O2, and some interleukins. This study showed that PNA lectin and lectin coated MgO NPs had approximately no toxicity on L. major and macrophages, but some toxic effects were observed for uncoated MgO NPs, especially at concentration of 500 µg/mL. Interestingly, lectin coated MgO NPs had the highest antileishmanial activity and macrophage activation, compared with uncoated MgO NPs and PNA lectin.

  10. New insights into the multidimensional concept of macrophage ontogeny, activation and function.

    PubMed

    Ginhoux, Florent; Schultze, Joachim L; Murray, Peter J; Ochando, Jordi; Biswas, Subhra K

    2016-01-01

    Macrophages have protective roles in immunity to pathogens, tissue development, homeostasis and repair following damage. Maladaptive immunity and inflammation provoke changes in macrophage function that are causative of disease. Despite a historical wealth of knowledge about macrophages, recent advances have revealed unknown aspects of their development and function. Following development, macrophages are activated by diverse signals. Such tissue microenvironmental signals together with epigenetic changes influence macrophage development, activation and functional diversity, with consequences in disease and homeostasis. We discuss here how recent discoveries in these areas have led to a multidimensional concept of macrophage ontogeny, activation and function. In connection with this, we also discuss how technical advances facilitate a new roadmap for the isolation and analysis of macrophages at high resolution.

  11. Monosodium urate activates Src/Pyk2/PI3 kinase and cathepsin dependent unconventional protein secretion from human primary macrophages.

    PubMed

    Välimäki, Elina; Miettinen, Juho J; Lietzén, Niina; Matikainen, Sampsa; Nyman, Tuula A

    2013-03-01

    Monosodium urate (MSU) is an endogenous danger signal that is crystallized from uric acid released from injured cells. MSU is known to activate inflammatory response in macrophages but the molecular mechanisms involved have remained uncharacterized. Activated macrophages start to secrete proteins to activate immune response and to recruit other immune cells to the site of infection and/or tissue damage. Secretome characterization after activation of innate immune system is essential to unravel the details of early phases of defense responses. Here, we have analyzed the secretome of human primary macrophages stimulated with MSU using quantitative two-dimensional gel electrophoresis based proteomics as well as high-throughput qualitative GeLC-MS/MS approach combining protein separation by SDS-PAGE and protein identification by liquid chromatography-MS/MS. Both methods showed that MSU stimulation induced robust protein secretion from lipopolysaccharide-primed human macrophages. Bioinformatic analysis of the secretome data showed that MSU stimulation strongly activates unconventional, vesicle mediated protein secretion. The unconventionally secreted proteins included pro-inflammatory cytokines like IL-1β and IL-18, interferon-induced proteins, and danger signal proteins. Also active forms of lysosomal proteases cathepsins were secreted on MSU stimulation, and cathepsin activity was essential for MSU-induced unconventional protein secretion. Additionally, proteins associated to phosphorylation events including Src family tyrosine kinases were increased in the secretome of MSU-stimulated cells. Our functional studies demonstrated that Src, Pyk2, and PI3 kinases act upstream of cathepsins to activate the overall protein secretion from macrophages. In conclusion, we provide the first comprehensive characterization of protein secretion pathways activated by MSU in human macrophages, and reveal a novel role for cathepsins and Src, Pyk2, PI3 kinases in the activation of

  12. Evidence for apoptosis of human macrophage-like HL-60 cells by Legionella pneumophila infection.

    PubMed Central

    Müller, A; Hacker, J; Brand, B C

    1996-01-01

    Legionella pneumophila, the causative agent of Legionnaires' disease and Pontiac fever, replicates within and eventually kills human macrophages. In this study, we show that L. pneumophila is cytotoxic to HL-60 cells, a macrophage-like cell line. We demonstrate that cell death mediated by L. pneumophila occurred at least in part through apoptosis, as shown by changes in nuclear morphology, an increase in the proportion of fragmented host cell DNA, and the typical ladder pattern of DNA fragmentation indicative of apoptosis. We further sought to determine whether potential virulence factors like the metalloprotease and the macrophage infectivity potentiator of L. pneumophila are involved in the induction of apoptosis. None of these factors are essential for the induction of apoptosis in HL-60 cells but may be involved in other cytotoxic mechanisms that lead to accidental cell death (necrosis). The ability of L. pneumophila to promote cell death may be important for the initiation of infection, bacterial survival, and escape from the host immune response. Alternatively, the triggering of apoptosis in response to bacterial infection may have evolved as a means of the host immune system to reduce or inhibit bacterial replication. PMID:8945524

  13. Human immunodeficiency virus type 1 endocytic trafficking through macrophage bridging conduits facilitates spread of infection.

    PubMed

    Kadiu, Irena; Gendelman, Howard E

    2011-12-01

    Bridging conduits (BC) sustain communication and homeostasis between distant tethered cells. These are also exploited commonly for direct cell-to-cell transfer of microbial agents. Conduits efficiently spread infection, effectively, at speeds faster than fluid phase exchange while shielding the microbe against otherwise effective humoral immunity. Our laboratory has sought to uncover the mechanism(s) for these events for human immunodeficiency virus type one (HIV-1) infection. Indeed, in our prior works HIV-1 Env and Gag antigen and fluorescent virus tracking were shown sequestered into endoplasmic reticulum-Golgi organelles but the outcomes for spreading viral infection remained poorly defined. Herein, we show that HIV-1 specifically traffics through endocytic compartments contained within BC and directing such macrophage-to-macrophage viral transfers. Following clathrin-dependent viral entry, HIV-1 constituents bypass degradation by differential sorting from early to Rab11(+) recycling endosomes and multivesicular bodies. Virus-containing endocytic viral cargoes propelled by myosin II through BC spread to neighboring uninfected cells. Disruption of endosomal motility with cytochalasin D, nocodasole and blebbistatin diminish intercellular viral spread. These data lead us to propose that HIV-1 hijacks macrophage endocytic and cytoskeletal machineries for high-speed cell-to-cell spread.

  14. Modeling the transcriptome of genital tract epithelial cells and macrophages in healthy mucosa versus mucosa inflamed by Chlamydia muridarum infection.

    PubMed

    Johnson, Raymond M; Kerr, Micah S

    2015-12-01

    Chlamydia trachomatis urogenital serovars are intracellular bacteria that parasitize human reproductive tract epithelium. As the principal cell type supporting bacterial replication, epithelial cells are central to Chlamydia immunobiology initially as sentries and innate defenders, and subsequently as collaborators in adaptive immunity-mediated bacterial clearance. In asymptomatic individuals who do not seek medical care a decisive struggle between C. trachomatis and host defenses occurs at the epithelial interface. For this study, we modeled the immunobiology of epithelial cells and macrophages lining healthy genital mucosa and inflamed/infected mucosa during the transition from innate to adaptive immunity. Upper reproductive tract epithelial cell line responses were compared to bone marrow-derived macrophages utilizing gene expression microarray technology. Those comparisons showed minor differences in the intrinsic innate defenses of macrophages and epithelial cells. Major lineage-specific differences in immunobiology relate to epithelial collaboration with adaptive immunity including an epithelial requirement for inflammatory cytokines to express MHC class II molecules, and a paucity and imbalance between costimulatory and coinhibitory ligands on epithelial cells that potentially limits sterilizing immunity (replication termination) to Chlamydia-specific T cells activated with limited or unconventional second signals.

  15. GM-CSF Promotes Macrophage Alternative Activation after Renal Ischemia/Reperfusion Injury

    PubMed Central

    Huynh, Larry; Marlier, Arnaud; Lee, Yashang; Moeckel, Gilbert W.; Cantley, Lloyd G.

    2015-01-01

    After kidney ischemia/reperfusion (I/R) injury, monocytes home to the kidney and differentiate into activated macrophages. Whereas proinflammatory macrophages contribute to the initial kidney damage, an alternatively activated phenotype can promote normal renal repair. The microenvironment of the kidney during the repair phase mediates the transition of macrophage activation from a proinflammatory to a reparative phenotype. In this study, we show that macrophages isolated from murine kidneys during the tubular repair phase after I/R exhibit an alternative activation gene profile that differs from the canonical alternative activation induced by IL-4–stimulated STAT6 signaling. This unique activation profile can be reproduced in vitro by stimulation of bone marrow-derived macrophages with conditioned media from serum-starved mouse proximal tubule cells. Secreted tubular factors were found to activate macrophage STAT3 and STAT5 but not STAT6, leading to induction of the unique alternative activation pattern. Using STAT3-deficient bone marrow-derived macrophages and pharmacologic inhibition of STAT5, we found that tubular cell-mediated macrophage alternative activation is regulated by STAT5 activation. Both in vitro and after renal I/R, tubular cells expressed GM-CSF, a known STAT5 activator, and this pathway was required for in vitro alternative activation of macrophages by tubular cells. Furthermore, administration of a neutralizing antibody against GM-CSF after renal I/R attenuated kidney macrophage alternative activation and suppressed tubular proliferation. Taken together, these data show that tubular cells can instruct macrophage activation by secreting GM-CSF, leading to a unique macrophage reparative phenotype that supports tubular proliferation after sterile ischemic injury. PMID:25388222

  16. Killing of Leishmania parasites in activated murine macrophages is based on an L-arginine-dependent process that produces nitrogen derivatives

    SciTech Connect

    Maul, J.R.; Ransijn, A.; Buchmueller-Rouiller, Y. )

    1991-01-01

    The experiments described in this report were aimed at determining whether L-arginine (L-arg)-derived nitrogen oxidation products (nitric oxide, nitrous acid, nitrites) are involved in the intracellular killing of Leishmania parasites by activated murine macrophages in vitro. Peritoneal or bone marrow-derived macrophages were infected with L. enriettii or L. major, then activated by exposure to recombinant murine interferon-gamma or to macrophage activating factor (MAF)-rich media in the presence of lipopolysaccharide. Activation of macrophages in regular (i.e., arginine-containing) culture medium led to complete destruction of the microorganisms within 24 h (L. enriettii) or 48 h (L. major), concomitant with accumulation of nitrites (NO2-) in the culture fluids. When macrophage activation was carried out in L-arg-free medium, however, neither parasite killing nor NO2- production was obtained. A similar inhibition of macrophage leishmanicidal activity and of NO2- release was observed using media treated with arginase (which converts L-arg to urea and ornithine), or supplemented with NG-monomethyl-L-arg or guanidine (which inhibit the conversion of L-arg to nitrogen oxidation products). In all these situations, an excellent correlation between the levels of NO2- production by macrophages and intracellular killing of Leishmania was observed, whereas no strict correlation was detectable between leishmanicidal activity and superoxide production. Intracellular parasite killing by activated macrophages could be prevented by addition of iron salts to the incubation fluids. Incubation of free parasites with NaNO2 at acid pH led to immobilisation, multiplication arrest, and morphological degeneration of the microorganisms. Similarly, exposure of infected cells to NaNO2 led to killing of the intracellular parasite without affecting macrophage viability.

  17. Vibrio cholerae porin OmpU mediates M1-polarization of macrophages/monocytes via TLR1/TLR2 activation.

    PubMed

    Khan, Junaid; Sharma, Praveen K; Mukhopadhaya, Arunika

    2015-11-01

    Polarization of the monocytes and macrophages toward the M1 and M2 states is important for hosts' defense against the pathogens. Moreover, it plays a crucial role to resolve the overwhelming inflammatory responses that can be harmful to the host. Polarization of macrophages/monocytes can be induced by pathogen-associated molecular patterns (PAMPs). PAMP-mediated monocyte/macrophage polarization is important during the infection, as pathogen can suppress host immune system by altering the polarization status of the macrophages/monocytes. OmpU, an outer membrane porin protein of Vibrio cholerae, possesses the ability to induce pro-inflammatory responses in monocytes/macrophages. It is also able to down-regulate the LPS-mediated activation of the monocytes/macrophages. Such observation leads us to believe that OmpU may induce a state that can be called as M1/M2-intermediate state. In the present study, we evaluated a set of M1 and M2 markers in RAW 264.7 murine macrophage cell line, and THP-1 human monocytic cell line, in response to the purified OmpU protein. We observed that OmpU, as a PAMP, induced M1-polarization by activating the Toll-like receptor (TLR) signaling pathway. OmpU induced formation of TLR1/TLR2-heterodimers. OmpU-mediated TLR-activation led to the MyD88 recruitment to the TLR1/TLR2 complex. MyD88, in turn, recruited IRAK1. Ultimately, OmpU-mediated signaling led to the activation and subsequent nuclear translocation of the NFκB p65 subunit. We also observed that blocking of the TLR1, TLR2, IRAK1, and NFκB affected OmpU-mediated production of M1-associated pro-inflammatory cytokines such as TNFα and IL-6.

  18. Kinetics of liver macrophages (Kupffer cells) in SIV-infected macaques

    SciTech Connect

    Ahsan, Muhammad H.; Gill, Amy F.; Alvarez, Xavier; Lackner, Andrew A.; Veazey, Ronald S.

    2013-11-15

    Since the liver drains antigens from the intestinal tract, and since the intestinal tract is a major site of viral replication, we examined the dynamics of liver macrophages (Kupffer cells) throughout SIV infection. Absolute numbers of Kupffer cells increased in the livers in acute infection, and in animals with AIDS. Significantly higher percentages of proliferating (BrdU+) Kupffer cells were detected in acute infection and in AIDS with similar trends in blood monocytes. Significantly higher percentages of apoptotic (AC3+) Kupffer cells were also found in acute and AIDS stages. However, productively infected cells were not detected in liver of 41/42 animals examined, despite abundant infected cells in gut and lymph nodes of all animals. Increased rates of Kupffer cell proliferation resulting in an increase in Kupffer cells without productive infection indicate SIV infection affects Kupffer cells, but the liver does not appear to be a major site of productive viral replication. - Highlights: • Kupffer cells increase in the liver of SIV-infected macaques. • Increased proliferation and apoptosis of Kupffer cells occurs in SIV infection. • Productively infected cells are rarely detected in the liver. • The liver is not a major site for SIV replication.

  19. Effect of low-level laser therapy on the modulation of the mitochondrial activity of macrophages

    PubMed Central

    Souza, Nadhia H. C.; Ferrari, Raquel A. M.; Silva, Daniela F. T.; Nunes, Fabio D.; Bussadori, Sandra K.; Fernandes, Kristianne P. S.

    2014-01-01

    BACKGROUND: Macrophages play a major role among the inflammatory cells that invade muscle tissue following an injury. Low-level laser therapy (LLLT) has long been used in clinical practice to accelerate the muscle repair process. However, little is known regarding its effect on macrophages. OBJECTIVE: This study evaluated the effect of LLLT on the mitochondrial activity (MA) of macrophages. METHOD: J774 macrophages were treated with lipopolysaccharide (LPS) and interferon - gamma (IFN-γ) (activation) for 24 h to simulate an inflammatory process, then irradiated with LLLT using two sets of parameters (780 nm; 70 mW; 3 J/cm2 and 660 nm; 15 mW; 7.5 J/cm2). Non-activated/non-irradiated cells composed the control group. MA was evaluated by the cell mitochondrial activity (MTT) assay (after 1, 3 and 5 days) in three independent experiments. The data were analyzed statistically. RESULTS: After 1 day of culture, activated and 780 nm irradiated macrophages showed lower MA than activated macrophages, but activated and 660 nm irradiated macrophages showed MA similar to activated cells. After 3 days, activated and irradiated (660 nm and 780 nm) macrophages showed greater MA than activated macrophages, and after 5 days, the activated and irradiated (660 nm and 780 nm) macrophages showed similar MA to the activated macrophages. CONCLUSIONS: These results show that 660 nm and 780 nm LLLT can modulate the cellular activation status of macrophages in inflammation, highlighting the importance of this resource and of the correct determination of its parameters in the repair process of skeletal muscle. PMID:25076002

  20. Sulfur compounds block MCP-1 production by Mycoplasma fermentans-infected macrophages through NF-κB inhibition

    PubMed Central

    2014-01-01

    Background and aims Hydrogen sulfide (H2S), together with nitric oxide (NO) and carbon monoxide (CO), belongs to a family of endogenous signaling mediators termed “gasotransmitters”. Recent studies suggest that H2S modulates many cellular processes and it has been recognized to play a central role in inflammation, in the cardiovascular and nervous systems. By infecting monocytes/macrophages with Mycoplasma fermentans (M.F.), a well-known pro-inflammatory agent, we evaluated the effects of H2S. Methods M.F.-infected cells were analyzed by ELISA and real time RT-PCR to detect the M.F. effects on MCP-1 and on MMP-12 expression. The role of two different H2S donors (NaHS and GYY4137) on MF-infected cells was determined by treating infected cells with H2S and then testing the culture supernatants for MCP-1 and on MMP-12 production by ELISA assay. In order to identify the pathway/s mediating H2S- anti-inflammatory activity, cells were also treated with specific pharmaceutical inhibitors. Cytoplasmic and nuclear accumulation of NF-κB heterodimers was analyzed. Results We show that H2S was able to reduce the production of pro-inflammatory cytokine MCP-1, that was induced in monocytes/macrophages during M.F. infection. Moreover, MCP-1 was induced by M.F. through Toll-like receptor (TLR)-mediated nuclear factor-κB (NF-κB) activation, as demonstrated by the fact that TLR inhibitors TIRAP and MyD88 and NF-κB inhibitor IKK were able to block the cytokine production. In contrast H2S treatment of M.F. infected macrophages reduced nuclear accumulation of NF-κB heterodimer p65/p52. Conclusions Our data demonstrate that under the present conditions H2S is effective in reducing Mycoplasma-induced inflammation by targeting the NF-κB pathway. This supports further studies for possible clinical applications. PMID:24886588

  1. LPS-inducible factor(s) from activated macrophages mediates cytolysis of Naegleria fowleri amoebae

    SciTech Connect

    Cleary, S.F.; Marciano-Cabral, F.

    1986-03-01

    Soluble cytolytic factors of macrophage origin have previously been described with respect to their tumoricidal activity. The purpose of this study was to investigate the mechanism and possible factor(s) responsible for cytolysis of the amoeba Naegleria fowleri by activated peritoneal macrophages from B6C3F1 mice. Macrophages or conditioned medium (CM) from macrophage cultures were incubated with /sup 3/H-Uridine labeled amoebae. Percent specific release of label served as an index of cytolysis. Bacille Calmette-Guerin (BCG) and Corynebacterium parvum macrophages demonstrated significant cytolysis of amoebae at 24 h with an effector to target ratio of 10:1. Treatment of macrophages with inhibitors of RNA or protein synthesis blocked amoebicidal activity. Interposition of a 1 ..mu..m pore membrane between macrophages and amoebae inhibited killing. Inhibition in the presence of the membrane was overcome by stimulating the macrophages with LPS. CM from SPS-stimulated, but not unstimulated, cultures of activated macrophages was cytotoxic for amoebae. The activity was heat sensitive and was recovered from ammonium sulfate precipitation of the CM. Results indicate that amoebicidal activity is mediated by a protein(s) of macrophage origin induced by target cell contact or stimulation with LPS.

  2. Macrophage-epithelial paracrine crosstalk inhibits lung edema clearance during influenza infection

    PubMed Central

    Peteranderl, Christin; Morales-Nebreda, Luisa; Lecuona, Emilia; Vadász, István; Morty, Rory E.; Schmoldt, Carole; Bespalowa, Julia; Pleschka, Stephan; Mayer, Konstantin; Gattenloehner, Stefan; Fink, Ludger; Lohmeyer, Juergen; Seeger, Werner; Sznajder, Jacob I.; Mutlu, Gökhan M.; Budinger, G.R. Scott

    2016-01-01

    Influenza A viruses (IAV) can cause lung injury and acute respiratory distress syndrome (ARDS), which is characterized by accumulation of excessive fluid (edema) in the alveolar airspaces and leads to hypoxemia and death if not corrected. Clearance of excess edema fluid is driven mostly by the alveolar epithelial Na,K-ATPase and is crucial for survival of patients with ARDS. We therefore investigated whether IAV infection alters Na,K-ATPase expression and function in alveolar epithelial cells (AECs) and the ability of the lung to clear edema. IAV infection reduced Na,K-ATPase in the plasma membrane of human and murine AECs and in distal lung epithelium of infected mice. Moreover, induced Na,K-ATPase improved alveolar fluid clearance (AFC) in IAV-infected mice. We identified a paracrine cell communication network between infected and noninfected AECs and alveolar macrophages that leads to decreased alveolar epithelial Na,K-ATPase function and plasma membrane abundance and inhibition of AFC. We determined that the IAV-induced reduction of Na,K-ATPase is mediated by a host signaling pathway that involves epithelial type I IFN and an IFN-dependent elevation of macrophage TNF-related apoptosis–inducing ligand (TRAIL). Our data reveal that interruption of this cellular crosstalk improves edema resolution, which is of biologic and clinical importance to patients with IAV-induced lung injury. PMID:26999599

  3. A Novel Polysaccharide in Insects Activates the Innate Immune System in Mouse Macrophage RAW264 Cells

    PubMed Central

    Ohta, Takashi; Ido, Atsushi; Kusano, Kie; Miura, Chiemi; Miura, Takeshi

    2014-01-01

    A novel water-soluble polysaccharide was identified in the pupae of the melon fly (Bactrocera cucurbitae) as a molecule that activates the mammalian innate immune response. We attempted to purify this innate immune activator using nitric oxide (NO) production in mouse RAW264 macrophages as an indicator of immunostimulatory activity. A novel acidic polysaccharide was identified, which we named “dipterose”, with a molecular weight of 1.01×106 and comprising nine monosaccharides. Dipterose was synthesized in the melon fly itself at the pupal stage. The NO-producing activity of dipterose was approximately equal to that of lipopolysaccharide, a potent immunostimulator. Inhibition of Toll-like receptor 4 (TLR4) led to the suppression of NO production by dipterose. Furthermore, dipterose induced the expression of proinflammatory cytokines and interferon β (IFNβ) and promoted the activation of nuclear factor kappa B (NF-κB) in macrophages, indicating that it stimulates the induction of various cytokines in RAW264 cells via the TLR4 signaling pathway. Our results thus suggest that dipterose activates the innate immune response against various pathogenic microorganisms and viral infections. This is the first identification of an innate immune-activating polysaccharide from an animal. PMID:25490773

  4. Importance of bacterial replication and alveolar macrophage-independent clearance mechanisms during early lung infection with Streptococcus pneumoniae.

    PubMed

    Camberlein, Emilie; Cohen, Jonathan M; José, Ricardo; Hyams, Catherine J; Callard, Robin; Chimalapati, Suneeta; Yuste, Jose; Edwards, Lindsey A; Marshall, Helina; van Rooijen, Nico; Noursadeghi, Mahdad; Brown, Jeremy S

    2015-03-01

    Although the importance of alveolar macrophages for host immunity during early Streptococcus pneumoniae lung infection is well established, the contribution and relative importance of other innate immunity mechanisms and of bacterial factors are less clear. We have used a murine model of S. pneumoniae early lung infection with wild-type, unencapsulated, and para-amino benzoic acid auxotroph mutant TIGR4 strains to assess the effects of inoculum size, bacterial replication, capsule, and alveolar macrophage-dependent and -independent clearance mechanisms on bacterial persistence within the lungs. Alveolar macrophage-dependent and -independent (calculated indirectly) clearance half-lives and bacterial replication doubling times were estimated using a mathematical model. In this model, after infection with a high-dose inoculum of encapsulated S. pneumoniae, alveolar macrophage-independent clearance mechanisms were dominant, with a clearance half-life of 24 min compared to 135 min for alveolar macrophage-dependent clearance. In addition, after a high-dose inoculum, successful lung infection required rapid bacterial replication, with an estimated S. pneumoniae doubling time of 16 min. The capsule had wide effects on early lung clearance mechanisms, with reduced half-lives of 14 min for alveolar macrophage-independent and 31 min for alveolar macrophage-dependent clearance of unencapsulated bacteria. In contrast, with a lower-dose inoculum, the bacterial doubling time increased to 56 min and the S. pneumoniae alveolar macrophage-dependent clearance half-life improved to 42 min and was largely unaffected by the capsule. These data demonstrate the large effects of bacterial factors (inoculum size, the capsule, and rapid replication) and alveolar macrophage-independent clearance mechanisms during early lung infection with S. pneumoniae. PMID:25583525

  5. Importance of bacterial replication and alveolar macrophage-independent clearance mechanisms during early lung infection with Streptococcus pneumoniae.

    PubMed

    Camberlein, Emilie; Cohen, Jonathan M; José, Ricardo; Hyams, Catherine J; Callard, Robin; Chimalapati, Suneeta; Yuste, Jose; Edwards, Lindsey A; Marshall, Helina; van Rooijen, Nico; Noursadeghi, Mahdad; Brown, Jeremy S

    2015-03-01

    Although the importance of alveolar macrophages for host immunity during early Streptococcus pneumoniae lung infection is well established, the contribution and relative importance of other innate immunity mechanisms and of bacterial factors are less clear. We have used a murine model of S. pneumoniae early lung infection with wild-type, unencapsulated, and para-amino benzoic acid auxotroph mutant TIGR4 strains to assess the effects of inoculum size, bacterial replication, capsule, and alveolar macrophage-dependent and -independent clearance mechanisms on bacterial persistence within the lungs. Alveolar macrophage-dependent and -independent (calculated indirectly) clearance half-lives and bacterial replication doubling times were estimated using a mathematical model. In this model, after infection with a high-dose inoculum of encapsulated S. pneumoniae, alveolar macrophage-independent clearance mechanisms were dominant, with a clearance half-life of 24 min compared to 135 min for alveolar macrophage-dependent clearance. In addition, after a high-dose inoculum, successful lung infection required rapid bacterial replication, with an estimated S. pneumoniae doubling time of 16 min. The capsule had wide effects on early lung clearance mechanisms, with reduced half-lives of 14 min for alveolar macrophage-independent and 31 min for alveolar macrophage-dependent clearance of unencapsulated bacteria. In contrast, with a lower-dose inoculum, the bacterial doubling time increased to 56 min and the S. pneumoniae alveolar macrophage-dependent clearance half-life improved to 42 min and was largely unaffected by the capsule. These data demonstrate the large effects of bacterial factors (inoculum size, the capsule, and rapid replication) and alveolar macrophage-independent clearance mechanisms during early lung infection with S. pneumoniae.

  6. Caspase-1 but Not Caspase-11 Is Required for NLRC4-Mediated Pyroptosis and Restriction of Infection by Flagellated Legionella Species in Mouse Macrophages and In Vivo.

    PubMed

    Cerqueira, Daiane M; Pereira, Marcelo S F; Silva, Alexandre L N; Cunha, Larissa D; Zamboni, Dario S

    2015-09-01

    Gram-negative bacteria from the Legionella genus are intracellular pathogens that cause a severe form of pneumonia called Legionnaires' disease. The bacteria replicate intracellularly in macrophages, and the restriction of bacterial replication by these cells is critical for host resistance. The activation of the NAIP5/NLRC4 inflammasome, which is readily triggered in response to bacterial flagellin, is essential for the restriction of bacterial replication in murine macrophages. Once activated, this inflammasome induces pore formation and pyroptosis and facilitates the restriction of bacterial replication in macrophages. Because investigations related to the NLRC4-mediated restriction of Legionella replication were performed using mice double deficient for caspase-1 and caspase-11, we assessed the participation of caspase-1 and caspase-11 in the functions of the NLRC4 inflammasome and the restriction of Legionella replication in macrophages and in vivo. By using several species of Legionella and mice singly deficient for caspase-1 or caspase-11, we demonstrated that caspase-1 but not caspase-11 was required for pore formation, pyroptosis, and restriction of Legionella replication in macrophages and in vivo. By generating F1 mice in a mixed 129 × C57BL/6 background deficient (129 × Casp-11(-/-) ) or sufficient (129 × C57BL/6) for caspase-11 expression, we found that caspase-11 was dispensable for the restriction of Legionella pneumophila replication in macrophages and in vivo. Thus, although caspase-11 participates in flagellin-independent noncanonical activation of the NLRP3 inflammasome, it is dispensable for the activities of the NLRC4 inflammasome. In contrast, functional caspase-1 is necessary and sufficient to trigger flagellin/NLRC4-mediated restriction of Legionella spp. infection in macrophages and in vivo.

  7. Characterization of Burkholderia pseudomallei Strains Using a Murine Intraperitoneal Infection Model and In Vitro Macrophage Assays

    PubMed Central

    Welkos, Susan L.; Klimko, Christopher P.; Kern, Steven J.; Bearss, Jeremy J.; Bozue, Joel A.; Bernhards, Robert C.; Trevino, Sylvia R.; Waag, David M.; Amemiya, Kei; Worsham, Patricia L.; Cote, Christopher K.

    2015-01-01

    Burkholderia pseudomallei, the etiologic agent of melioidosis, is a gram-negative facultative intracellular bacterium. This bacterium is endemic in Southeast Asia and Northern Australia and can infect humans and animals by several routes. It has also been estimated to present a considerable risk as a potential biothreat agent. There are currently no effective vaccines for B. pseudomallei, and antibiotic treatment can be hampered by nonspecific symptomology, the high incidence of naturally occurring antibiotic resistant strains, and disease chronicity. Accordingly, there is a concerted effort to better characterize B. pseudomallei and its associated disease. Before novel vaccines and therapeutics can be tested in vivo, a well characterized animal model is essential. Previous work has indicated that mice may be a useful animal model. In order to develop standardized animal models of melioidosis, different strains of bacteria must be isolated, propagated, and characterized. Using a murine intraperitoneal (IP) infection model, we tested the virulence of 11 B. pseudomallei strains. The IP route offers a reproducible way to rank virulence that can be readily reproduced by other laboratories. This infection route is also useful in distinguishing significant differences in strain virulence that may be masked by the exquisite susceptibility associated with other routes of infection (e.g., inhalational). Additionally, there were several pathologic lesions observed in mice following IP infection. These included varisized abscesses in the spleen, liver, and haired skin. This model indicated that commonly used laboratory strains of B. pseudomallei (i.e., K96243 and 1026b) were significantly less virulent as compared to more recently acquired clinical isolates. Additionally, we characterized in vitro strain-associated differences in virulence for macrophages and described a potential inverse relationship between virulence in the IP mouse model of some strains and in the

  8. Glycoconjugates isolated from Trypanosoma cruzi but not from Leishmania species membranes trigger nitric oxide synthesis as well as microbicidal activity in IFN-gamma-primed macrophages.

    PubMed

    Camargo, M M; Andrade, A C; Almeida, I C; Travassos, L R; Gazzinelli, R T

    1997-12-15

    In the present study, we investigated the role of glycosylphosphatidylinositol-anchored mucin-like glycoproteins (GPI-mucins) from Trypanosoma cruzi trypomastigotes in triggering the synthesis of nitric oxide as well as the microbicidal activity in murine macrophages. Our results show that GPI-mucins isolated from trypomastigote membranes are potent inducers of nitric oxide synthesis by IFN-gamma-primed macrophages, even at concentrations as low as 10 ng/ml. Our data also indicate the important role of glycosylphosphatidylinositol anchors from GPI-mucins as the second signal responsible for induction of nitric oxide synthesis by macrophages. To further investigate the role of these parasite molecules in inducing parasiticidal function, we cultured macrophages in the presence or absence of trypomastigote GPI-mucins and/or IFN-gamma and then infected these cells with either Leishmania spp. or T. cruzi. IFN-gamma was sufficient to induce microbial activity in macrophages infected with T. cruzi trypomastigotes. In contrast, killing of different species of Leishmania was further enhanced when macrophages exposed to IFN-gamma were also costimulated with trypomastigote-derived GPI-mucins. Our results also indicate that different glycolipids obtained from Leishmania major or Leishmania donovani (i.e., lipophosphoglycans or glycoinositolphospholipids) were unable to potentiate nitric oxide synthesis and/or microbicidal activity displayed by IFN-gamma-primed macrophages.

  9. The respiratory burst is not required for killing of intracellular and extracellular parasites by a lymphokine-activated macrophage cell line.

    PubMed

    Scott, P; James, S; Sher, A

    1985-06-01

    The macrophage cell line, IC-21, was found to be incapable of producing the oxygen products associated with the respiratory burst. However, IC-21 cells were activated by lymphokine (LK) to kill intracellular (Leishmania donovani amastigotes) and extracellular (Schistosoma mansoni larvae) parasites, as well as tumor cells. In each case, the cytotoxicity exhibited by activated IC-21 cells and activated peritoneal macrophages was indistinguishable. However, nonactivated IC-21 cells were unable to kill L. donovani log-growth phase promastigotes, while nonactivated peritoneal macrophages destroyed greater than 90% of the initial infection. These results indicate that amastigotes and schistosome larvae are susceptible to killing by nonoxidative cytotoxic mechanism induced by lymphokine activation but, on the other hand, support the concept that the killing of log-growth phase promastigotes by nonactivated cells is dependent upon the respiratory burst. We propose that the IC-21 cell line may be a useful model for studying nonoxidative killing functions of activated macrophages. PMID:2988973

  10. Macrophages migrate in an activation-dependent manner to chemokines involved in neuroinflammation

    PubMed Central

    2014-01-01

    Background In neuroinflammatory diseases, macrophages can play a dual role in the process of tissue damage, depending on their activation status (M1 / M2). M1 macrophages are considered to exert damaging effects to neurons, whereas M2 macrophages are reported to aid regeneration and repair of neurons. Their migration within the central nervous system may be of critical importance in the final outcome of neurodegeneration in neuroinflammatory diseases e.g. multiple sclerosis (MS). To provide insight into this process, we examined the migratory capacity of human monocyte-derived M1 and M2 polarised macrophages towards chemoattractants, relevant for neuroinflammatory diseases like MS. Methods Primary cultures of human monocyte-derived macrophages were exposed to interferon gamma and lipopolysaccharide (LPS) to evoke proinflammatory (M1) activation or IL-4 to evoke anti-inflammatory (M2) activation. In a TAXIScan assay, migration of M0, M1 and M2 towards chemoattractants was measured and quantified. Furthermore the adhesion capacity and the expression levels of integrins as well as chemokine receptors of M0, M1 and M2 were assessed. Alterations in cell morphology were analysed using fluorescent labelling of the cytoskeleton. Results Significant differences were observed between M1 and M2 macrophages in the migration towards chemoattractants. We show that M2 macrophages migrated over longer distances towards CCL2, CCL5, CXCL10, CXCL12 and C1q compared to non-activated (M0) and M1 macrophages. No differences were observed in the adhesion of M0, M1 and M2 macrophages to multiple matrix components, nor in the expression of integrins and chemokine receptors. Significant changes were observed in the cytoskeleton organization upon stimulation with CCL2, M0, M1 and M2 macrophages adopt a spherical morphology and the cytoskeleton is rapidly rearranged. M0 and M2 macrophages are able to form filopodia, whereas M1 macrophages only adapt a spherical morphology. Conclusions

  11. Some biochemical and functional characteristics of macrophages activated by Tetrahymena pyriformis.

    PubMed

    Makioka, A; Kobayashi, A

    1984-01-01

    Phagocytosis, enzyme activities and capacity to release hydrogen peroxide (H2O2) and superoxide anion (O2-) of peritoneal macrophages from mice inoculated with Tetrahymena pyriformis, a free-living ciliate, were examined in comparison with resident and BCG-activated macrophages. Fc receptor-mediated phagocytosis of sheep erythrocytes was markedly increased in Tetrahymena-activated macrophages to the same level as that seen in BCG-activated ones. Tetrahymena-activated macrophages showed an increased level of acid phosphatase (lysosomal enzyme) and a reduced level of alkaline phosphodiesterase I (plasma membrane ectoenzyme) as compared with resident macrophages. Similar changes in the activities of the two enzymes were also observed in BCG-activated macrophages. Both Tetrahymena- and BCG-activated macrophages exhibited more enhanced capacity to release H2O2 and O2- than resident macrophages when stimulated with phorbol myristate acetate. In the macrophages from mice inoculated with varying doses of Tetrahymena, a significant correlation was observed between the increased capacity of H2O2 and O2- release as observed in the present study, and the enhanced toxoplasmacidal activity as observed in a previous study, in a dose-dependent fashion.

  12. Stearoyl lysophosphatidylcholine enhances the phagocytic ability of macrophages through the AMP-activated protein kinase/p38 mitogen activated protein kinase pathway.

    PubMed

    Quan, Hui; Hur, Young-Hoe; Xin, Chun; Kim, Joung-Min; Choi, Jeong-Il; Kim, Man-Young; Bae, Hong-Beom

    2016-10-01

    A previous study showed that stearoyl lysophosphatidylcholine (sLPC) suppressed extracellular high mobility group box 1 translocation in macrophages stimulated with lipopolysaccharide through AMP-activated protein kinase (AMPK) activation. In the present study, we investigated whether sLPC-induced AMPK activation could enhance macrophages phagocytosis of bacteria. We found that sLPC increased phosphorylation of AMPK and acetyl-CoA carboxylase, a downstream target of AMPK, in a time- and dose-dependent manner in macrophages. Furthermore, sLPC increased the uptake of FITC-conjugated Escherichia coli by macrophages in a dose-dependent manner, and treatment with an AMPK inhibitor (compound C) or siRNA to AMPKα1 reversed this uptake. sLPC increased the phosphorylation of p38 mitogen-activated protein kinase (MAPK), but inhibition of AMPK activity with compound C or siRNA to AMPKα1 prevented the sLPC-induced increase in p38 MAPK phosphorylation. SB203580, a p38 MAPK inhibitor, decreased sLPC-induced phagocytosis. In vivo, systemic administration of sLPC to mice led to increased AMPK and p38 MAPK activity in the lung and to increased phagocytosis of fluorescent E. coli in bronchoalveolar lavage cells. These results suggest that sLPC increases macrophages phagocytosis through activation of the AMPK/p38 MAPK pathway. Therefore, sLPC is a candidate pharmacological agent for the treatment of bacterial infections in clinically relevant conditions. PMID:27517519

  13. Macrophage Activation Syndrome-Associated Markers in Severe Dengue

    PubMed Central

    Ab-Rahman, Hasliana Azrah; Rahim, Hafiz; AbuBakar, Sazaly; Wong, Pooi-Fong

    2016-01-01

    Hemophagocytosis, a phenomenon of which activated macrophages phagocytosed hematopoietic elements was reportedly observed in severe dengue patients. In the present study, we investigated whether markers of macrophage activation syndrome (MAS) can be used as differential diagnostic markers of severe dengue. Two hundred and eight confirmed dengue patients were recruited for the study. Sandwich ELISA was used to determine serum ferritin, soluble CD163 (sCD163), and soluble CD25 (sCD25) levels. The population of circulating CD163 (mCD163) monocytes was determined using flow cytometry. Receiver operating characteristic (ROC) analysis was plotted to determine the predictive validity of the biomarkers. Serum ferritin and sCD163 were found significantly increased in severe dengue patients compared to dengue fever patients (P = 0.003). A fair area under ROC curves (AUC) at 0.72 with a significant P value of 0.004 was observed for sCD163. sCD25 and mCD163 levels were not significantly different between severe dengue and dengue fever patients. Our findings suggest that in addition to serum ferritin, sCD163 can differentiate severe dengue from that of dengue fever patients. Hence, sCD163 level can be considered for use as a predictive marker for impending severe dengue. PMID:26941578

  14. Conditioned medium from alternatively activated macrophages induce mesangial cell apoptosis via the effect of Fas

    SciTech Connect

    Huang, Yuan; Luo, Fangjun; Li, Hui; Jiang, Tao; Zhang, Nong

    2013-11-15

    During inflammation in the glomerulus, the proliferation of myofiroblast-like mesangial cells is commonly associated with the pathological process. Macrophages play an important role in regulating the growth of resident mesangial cells in the glomeruli. Alternatively activated macrophage (M2 macrophage) is a subset of macrophages induced by IL-13/IL-4, which is shown to play a repair role in glomerulonephritis. Prompted by studies of development, we performed bone marrow derived macrophage and rat mesangial cell co-culture study. Conditioned medium from IL-4 primed M2 macrophages induced rat mesangial cell apoptosis. The pro-apoptotic effect of M2 macrophages was demonstrated by condensed nuclei stained with Hoechst 33258, increased apoptosis rates by flow cytometry analysis and enhanced caspase-3 activation by western blot. Fas protein was up-regulated in rat mesangial cells, and its neutralizing antibody ZB4 partly inhibited M2 macrophage-induced apoptosis. The up-regulated arginase-1 expression in M2 macrophage also contributed to this apoptotic effect. These results indicated that the process of apoptosis triggered by conditioned medium from M2 macrophages, at least is partly conducted through Fas in rat mesangial cells. Our findings provide compelling evidence that M2 macrophages control the growth of mesangial cells in renal inflammatory conditions. - Highlights: • Conditioned-medium from M2 macrophages induces rat mesangial cell (MsC) apoptosis. • M2 macrophage conditioned medium exerts its pro-apoptotic effects via Fas ligand. • Arginase-1 activity in M2 macrophages plays a role in inducing apoptosis in rat MsC.

  15. Mapping of Mycobacterium tuberculosis katG promoters and their differential expression in infected macrophages.

    PubMed

    Master, S; Zahrt, T C; Song, J; Deretic, V

    2001-07-01

    Intracellular pathogenic bacteria, including Mycobacterium tuberculosis, frequently have multitiered defense mechanisms ensuring their survival in host phagocytic cells. One such defense determinant in M. tuberculosis is the katG gene, which encodes an enzyme with catalase, peroxidase, and peroxynitritase activities. KatG is considered to be important for protection against reactive oxygen and nitrogen intermediates produced by phagocytic cells. However, KatG also activates the front-line antituberculosis drug isoniazid, hence rendering M. tuberculosis exquisitely sensitive to this compound. In this context, katG expression represents a double-edged sword, as it is an important virulence determinant but at the same time its activity levels determine sensitivity to INH. Thus, it is important to delineate the regulation and expression of katG, as this not only can aid understanding of how M. tuberculosis survives and persists in the host but also may provide information of relevance for better management of INH therapy. Here, we report the first extensive analysis of the katG promoter activity examined both in vitro and in vivo. Using S1 nuclease protection analysis, we mapped the katG mRNA 5' ends and demonstrated that two promoters, P(1)furA and P(1)katG, control transcription of katG. The furA and katG genes are cotranscribed from P(1)furA. Both P(1)furA and P(1)katG promoters show induction upon challenge with hydrogen peroxide and cumene hydroperoxide. Studies carried out using the transcriptional fusions P(1)furA-gfp, P(1)katG-gfp, and P(1)furA-P(1)katG-gfp confirmed the existence of two katG promoters. In addition, we showed that both promoters are expressed in vivo during intracellular growth of virulent M. tuberculosis H37Rv. P(1)furA is induced early upon infection, and P(1)katG becomes active only upon extended growth in macrophages. These studies delineate the transcriptional organization of the furA-katG region and indicate differential regulation in

  16. A defect in the inflammation-primed macrophage-activation cascade in osteopetrotic rats.

    PubMed

    Yamamoto, N; Lindsay, D D; Naraparaju, V R; Ireland, R A; Popoff, S N

    1994-05-15

    Macrophages were activated by administration of lysophosphatidylcholine (lyso-Pc) or dodecylglycerol (DDG) to wild-type rats but not in osteopetrotic (op) mutant rats. In vitro treatment of wild-type rat peritoneal cells with lyso-Pc or DDG efficiently activated macrophages whereas treatment of op mutant rat peritoneal cells with lyso-Pc or DDG did not activate macrophages. The inflammation-primed macrophage activation cascade in rats requires participation of B lymphocytes and vitamin D binding protein (DBP). Lyso-Pc-inducible beta-galactosidase of wild-type rat B lymphocytes can convert DBP to the macrophage-activating factor (MAF), whereas B lymphocytes of the op mutant rats were shown to be deficient in lyso-Pc-inducible beta-galactosidase. DBP is conserved among mammalian species. Treatment of human DBP (Gc1 protein) with commercial glycosidases yields an extremely high titrated MAF as assayed on mouse and rat macrophages. Because the enzymatically generated MAF (GcMAF) bypasses the role of lymphocytes in macrophage activation, the op mutant rat macrophages were efficiently activated by administration of a small quantity (100 pg/rat) of GcMAF. Likewise, in vitro treatment of op rat peritoneal cells with as little as 40 pg GcMAF/ml activated macrophages. PMID:8176226

  17. Activation of peritoneal macrophages to cytoxicity against B16 melanoma cells by Serratia marcescens polyribosome fractions

    SciTech Connect

    Hoover, S.K.

    1985-01-01

    Serratia marcescens polyribosomes (SMPR) have been shown to elicit an anti-tumor response in vivo. The in-vitro effects of SMPR on macrophages as the nonspecific mediators of the anti-tumor response have not previously been examined. The first objective of this research project is to corroborate and analyze the in-vivo results by the development and application of an in-vitro cytotoxicity assay. The second objective is to examine the effect of SMPR upon previously unstimulated peritoneal macrophages as representing the mechanism of cytotoxicity. The third objective is to identify the minimal effective component of SMPR responsible for an effect on macrophages. Results revealed that SMPR preparations exert a number of effects upon macrophages. Morphologic changes included increased spreading and increased perinuclear vacuolization. Macrophages were shown to be metabolically activate by two lines of evidence. SMPR-treated macrophages exhibited increased cellular metabolism by the increased uptake of /sup 3/H-thymidine and by the increased levels of secreted leucine aminopeptidase as compared to control macrophages. Results also showed that SMPR activates macrophages to cytotoxicity against syngeneic tumor target cells. Buoyant-density fractions were isolated and assayed for macrophage activating ability. Results showed 50S ribosomal subunits to be the smallest fraction effective for macrophage activation. Both the RNA and protein were necessary for complete effectiveness.

  18. Interaction of human leukocytes and Entamoeba histolytica. Killing of virulent amebae by the activated macrophage.

    PubMed Central

    Salata, R A; Pearson, R D; Ravdin, J I

    1985-01-01

    Capable effector mechanisms in the human immune response against the cytolytic, protozoan parasite Entamoeba histolytica have not been described. To identify a competent human effector cell, we studied the in vitro interactions of normal human polymorphonuclear neutrophils, peripheral blood mononuclear cells (PBMC), monocytes (MC), and MC-derived macrophages with virulent axenic amebae (strain HMI-IMSS). Amebae killed neutrophils, PBMC, MC, and MC-derived macrophages (P less than 0.001), without loss of parasite viability. The addition of heat-inactivated immune serum did not enable leukocytes to kill amebae, nor did it protect these host cells from amebae. MC-derived macrophages, activated with lymphokine elicited by the mitogens conconavalin A, phytohemagglutinin, or an amebic soluble protein preparation (strain HK9), killed 55% of amebae by 3 h in a trypan blue exclusion assay (P less than 0.001); during this time, 40% of the activated macrophages died. Lysis of amebae was confirmed using 111Indium oxine radiolabeled parasites and was antibody independent. Macrophage death appeared to be due to the deleterious effect of lysed amebae rather than the contact-dependent effector mechanisms of E. histolytica. Adherence between activated macrophages and amebae was greater than that between other leukocytes and amebae (P less than 0.001). Microscopic observations, kinetic analysis of the killing of amebae by activated macrophages, and suspension of amebae with adherent activated macrophages in a 10% dextran solution indicated that contact by activated macrophages was necessary to initiate the killing of amebae. Catalase but not superoxide dismutase inhibited the amebicidal capacity of activated macrophages (P less than 0.001). However, activated macrophages from an individual with chronic granulomatous disease were able to kill amebae, but not as effectively as normal cells (P less than 0.01). In summary, activated MC-derived macrophages killed virulent E. histolytica

  19. Interaction of human leukocytes and Entamoeba histolytica. Killing of virulent amebae by the activated macrophage.

    PubMed

    Salata, R A; Pearson, R D; Ravdin, J I

    1985-08-01

    Capable effector mechanisms in the human immune response against the cytolytic, protozoan parasite Entamoeba histolytica have not been described. To identify a competent human effector cell, we studied the in vitro interactions of normal human polymorphonuclear neutrophils, peripheral blood mononuclear cells (PBMC), monocytes (MC), and MC-derived macrophages with virulent axenic amebae (strain HMI-IMSS). Amebae killed neutrophils, PBMC, MC, and MC-derived macrophages (P less than 0.001), without loss of parasite viability. The addition of heat-inactivated immune serum did not enable leukocytes to kill amebae, nor did it protect these host cells from amebae. MC-derived macrophages, activated with lymphokine elicited by the mitogens conconavalin A, phytohemagglutinin, or an amebic soluble protein preparation (strain HK9), killed 55% of amebae by 3 h in a trypan blue exclusion assay (P less than 0.001); during this time, 40% of the activated macrophages died. Lysis of amebae was confirmed using 111Indium oxine radiolabeled parasites and was antibody independent. Macrophage death appeared to be due to the deleterious effect of lysed amebae rather than the contact-dependent effector mechanisms of E. histolytica. Adherence between activated macrophages and amebae was greater than that between other leukocytes and amebae (P less than 0.001). Microscopic observations, kinetic analysis of the killing of amebae by activated macrophages, and suspension of amebae with adherent activated macrophages in a 10% dextran solution indicated that contact by activated macrophages was necessary to initiate the killing of amebae. Catalase but not superoxide dismutase inhibited the amebicidal capacity of activated macrophages (P less than 0.001). However, activated macrophages from an individual with chronic granulomatous disease were able to kill amebae, but not as effectively as normal cells (P less than 0.01). In summary, activated MC-derived macrophages killed virulent E. histolytica

  20. An update on renal involvement in hemophagocytic syndrome (macrophage activation syndrome)

    PubMed Central

    Esmaili, Haydarali; Mostafidi, Elmira; Mehramuz, Bahareh; Ardalan, Mohammadreza; Mohajel-Shoja, Mohammadali

    2016-01-01

    Context: Hemophagocytic syndrome (HPS) is mainly characterized by massive infiltration of bone marrow by activated macrophages and often presents with pancytopenia. Thrombotic microangiopathy (TMA) is also present with thrombocytopenia and renal involvement. Both conditions could coexist with each other and complicate the condition. Evidence Acquisition: Directory of Open Access Journals (DOAJ), EMBASE, Google Scholar, PubMed, EBSCO, and Web of Science with keywords relevant to; Hemophagocytic syndrome, macrophage activation syndrome, interferon-gamma and thrombotic microangiopathy, have been searched. Results: Viral infection, rheumatologic disease and malignancies are the main underlying causes for secondary HPS. calcineurin inhibitors and viral infections are also the main underlying causes of TMA in transplant recipients. In this review, we discussed a 39-year-old male who presented with pancytopenia and renal allograft dysfunction. With the diagnosis of HPS induced TMA his renal condition and pancytopenia improved after receiving intravenous immunoglobulin (IVIG) and plasmapheresis therapy. Conclusions: HPS is an increasingly recognized disorder in the realm of different medical specialties. Renal involvement complicates the clinical picture of the disease, and this condition even is more complex in renal transplant recipients. We should consider the possibility of HPS in any renal transplant recipient with pancytopenia and allograft dysfunction. The combination of HPS with TMA future increases the complexity of the situation. PMID:27047804

  1. Cross-Regulation of Proinflammatory Cytokines by Interleukin-10 and miR-155 in Orientia tsutsugamushi-Infected Human Macrophages Prevents Cytokine Storm.

    PubMed

    Tsai, Ming-Hsien; Chang, Chung-Hsing; Tsai, Rong-Kung; Hong, Yi-Ren; Chuang, Tsung-Hsien; Fan, Kan-Tang; Peng, Chi-Wen; Wu, Ching-Ying; Hsu, Wen-Li; Wang, Lih-Shinn; Chen, Li-Kuang; Yu, Hsin-Su

    2016-07-01

    Scrub typhus is caused by the obligate intracellular bacterium Orientia tsutsugamushi. Macrophages are host cells for its replication and clearance. Severe complications in patients are mainly caused by a cytokine storm resulting from overproduction of proinflammatory cytokines; nevertheless, the molecular mechanism for the occurrence remains obscure. Herein, we investigate the interactive regulation of cytokines and micro-RNA (miR) in human macrophages infected with low and high doses of O. tsutsugamushi. During low dose infection, macrophages produce high levels of IL-10 through extracellular signal-regulated kinase activation, which inhibits proinflammatory cytokine production and facilitates pathogen replication. Increasing levels of pathogen results in reduced levels of IL-10, and macrophages begin to generate high levels of proinflammatory cytokines through NF-κB activation. However, during a high dose infection, macrophages produce high levels of miR-155 to slow the proinflammatory response. The extracellular signal-regulated kinase/IL-10 axis suppresses the NF-κB/tumor necrosis factor alpha axis via activation of signal transducer and activator of transcription 3. Both IL-10 and miR-155 inhibit the NF-κB signaling pathway. Furthermore, IL-10 is a potent inhibitor of miR-155. Patients susceptible to a cytokine storm, peripheral blood mononuclear cells showed significantly lower IL-10 and miR-155 responses to O. tsutsugamushi challenge. Thus, IL-10 and miR-155 operate inhibitory mechanisms to achieve a proper defense mechanism and prevent a cytokine storm.

  2. Treatment in vitro with PPARα and PPARγ ligands drives M1-to-M2 polarization of macrophages from T. cruzi-infected mice.

    PubMed

    Penas, Federico; Mirkin, Gerardo A; Vera, Marcela; Cevey, Ágata; González, Cintia D; Gómez, Marisa I; Sales, María Elena; Goren, Nora B

    2015-05-01

    Trypanosoma cruzi, the etiological agent of Chagas' disease, induces a persistent inflammatory response. Macrophages are a first line cell phenotype involved in the clearance of infection. Upon parasite uptake, these cells increase inflammatory mediators like NO, TNF-α, IL-1β and IL-6, leading to parasite killing. Although desired, inflammatory response perpetuation and exacerbation may lead to tissue damage. Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent nuclear transcription factors that, besides regulating lipid and carbohydrate metabolism, have a significant anti-inflammatory effect. This is mediated through the interaction of the receptors with their ligands. PPARγ, one of the PPAR isoforms, has been implicated in macrophage polarization from M1, the classically activated phenotype, to M2, the alternatively activated phenotype, in different models of metabolic disorders and infection. In this study, we show for the first time that, besides PPARγ, PPARα is also involved in the in vitro polarization of macrophages isolated from T. cruzi-infected mice. Polarization was evidenced by a decrease in the expression of NOS2 and proinflammatory cytokines and the increase in M2 markers like Arginase I, Ym1, mannose receptor and TGF-β. Besides, macrophage phagocytic activity was significantly enhanced, leading to increased parasite load. We suggest that modulation of the inflammatory response by both PPARs might be due, at least in part, to a change in the profile of inflammatory macrophages. The potential use of PPAR agonists as modulators of overt inflammatory response during the course of Chagas' disease deserves further investigation.

  3. Prostaglandin D2-loaded microspheres effectively activate macrophage effector functions.

    PubMed

    Pereira, Priscilla Aparecida Tartari; Bitencourt, Claudia da Silva; dos Santos, Daiane Fernanda; Nicolete, Roberto; Gelfuso, Guilherme Martins; Faccioli, Lúcia Helena

    2015-10-12

    Biodegradable lactic-co-glycolic acid (PLGA) microspheres (MS) improve the stability of biomolecules stability and allow enable their sustained release. Lipid mediators represent a strategy for improving host defense; however, most of these mediators, such as prostaglandin D2 (PGD2), have low water solubility and are unstable. The present study aimed to develop and characterize MS loaded with PGD2 (PGD2-MS) to obtain an innovative tool to activate macrophages. PGD2-MS were prepared using an oil-in-water emulsion solvent extraction-evaporation process, and the size, zeta potential, surface morphology and encapsulation efficiency were determined. It was also evaluated in vitro the phagocytic index, NF-κB activation, as well as nitric oxide and cytokine production by alveolar macrophages (AMs) in response to PGD2-MS. PGD2-MS were spherical with a diameter of 5.0±3.3 μm and regular surface, zeta potential of -13.4±5.6 mV, and 36% of encapsulation efficiency, with 16-26% release of entrapped PGD2 at 4 and 48 h, respectively. PGD2-MS were more efficiently internalized by AMs than unloaded-MS, and activated NF-κB more than free PGD2. Moreover, PGD2-MS stimulated the production of nitric oxide, TNF-α, IL-1β, and TGF-β, more than free PGD2, indicating that microencapsulation increased the activating effect of PGD2 on cells. In LPS-pre-treated AMs, PGD2-MS decreased the release of IL-6 but increased the production of nitric oxide and IL-1β. These results show that the morphological characteristics of PGD2-MS facilitated interaction with, and activation of phagocytic cells; moreover, PGD2-MS retained the biological activities of PGD2 to trigger effector mechanisms in AMs. It is suggested that PGD2-MS represent a strategy for therapeutic intervention in the lungs of immunocompromised subjects.

  4. Quantitative Proteomics and Lipidomics Analysis of Endoplasmic Reticulum of Macrophage Infected with Mycobacterium tuberculosis

    PubMed Central

    Saquib, Najmuddin Mohd; Jamwal, Shilpa; Midha, Mukul Kumar; Verma, Hirdya Narain; Manivel, Venkatasamy

    2015-01-01

    Even though endoplasmic reticulum (ER) stress associated with mycobacterial infection has been well studied, the molecular basis of ER as a crucial organelle to determine the fate of Mtb is yet to be established. Here, we have studied the ability of Mtb to manipulate the ultrastructural architecture of macrophage ER and found that the ER-phenotypes associated with virulent (H37Rv) and avirulent (H37Ra) strains were different: a rough ER (RER) with the former against a smooth ER (SER) with the later. Further, the functional attributes of these changes were probed by MS-based quantitative proteomics (133 ER proteins) and lipidomics (8 phospholipids). Our omics approaches not only revealed the host pathogen cross-talk but also emphasized how precisely Mtb uses proteins and lipids in combination to give rise to characteristic ER-phenotypes. H37Ra-infected macrophages increased the cytosolic Ca2+ levels by attenuating the ATP2A2 protein and simultaneous induction of PC/PE expression to facilitate apoptosis. However, H37Rv inhibited apoptosis and further controlled the expression of EST-1 and AMRP proteins to disturb cholesterol homeostasis resulting in sustained infection. This approach offers the potential to decipher the specific roles of ER in understanding the cell biology of mycobacterial infection with special reference to the impact of host response. PMID:25785198

  5. Macrophage M1/M2 polarization dynamically adapts to changes in cytokine microenvironments in Cryptococcus neoformans infection.

    PubMed

    Davis, Michael J; Tsang, Tiffany M; Qiu, Yafeng; Dayrit, Jeremy K; Freij, Joudeh B; Huffnagle, Gary B; Olszewski, Michal A

    2013-06-18

    The outcome of cryptococcal pneumonia correlates with local macrophage polarization status, as M1 and M2 polarization marks protective and nonprotective responses, respectively. Overall, pulmonary macrophage polarization status changes over time during a cryptococcal infection. This could have been caused by repolarization of individual macrophages or by a replacement of M2-polarized cells by new M1-polarized cells. To explore the ability of macrophages to change between polarization states, we conducted a series of experiments using in vitro macrophages. Coculture of macrophages with Cryptococcus neoformans resulted in development of a weak M1-like phenotype, with modestly increased inducible nitric oxide synthase (iNOS) but lacking interleukin 6 (IL-6) induction. The C. neoformans-induced M1-like polarization state was plastic, as macrophages stimulated first with C. neoformans and then with gamma interferon (IFN-γ) or IL-4 expressed mRNA polarization patterns similar to those stimulated with cytokines alone. To further evaluate macrophage polarization plasticity, cytokine stimulatory conditions were established which fully polarized macrophages. IFN-γ and IL-4 stimulation differentially induced complete M1 and M2 polarization, defined by differential expression of marker mRNA panels, surface marker expression, and tumor necrosis factor alpha (TNF-α) protein production. Switching IFN-γ- to IL-4-stimulating conditions, and vice versa, resulted in uniform changes in profiles of polarization marker genes consistent with the most recent cytokine environment. Furthermore, the ability of sequentially stimulated macrophages to inhibit C. neoformans reflected the most recent polarizing condition, independent of previous polarization. Collectively, these data indicate that M1/M2 macrophage polarization phenotypes are highly plastic to external signals, and interventions which therapeutically repolarize macrophages could be beneficial for treatment of cryptococcosis.

  6. Low-power laser irradiation enhance macrophage phagocytic capacity through Src activation

    NASA Astrophysics Data System (ADS)

    Wu, Shengnan; Zhou, Feifan; Xing, Da

    2012-03-01

    Phagocytosis and subsequent degradation of pathogens by macrophages play a pivotal role in host innate immunity in mammals. Laser irradiation has been found to produce photobiological effects with evidence of interference with organic functions. In this study, we focused our attention on the effects of He-Ne laser on the phagocytic activity of macrophages, the regulation mechanism of phagocytosis was also discussed. Our results indicated that Low-power laser irradiation can enhance the phagocytosis of macrophage through activation of Src.

  7. Innate interferon response in macrophage and epithelial cells infected with wild-type compared to DNA adenine methylase and flagellin mutant Salmonella enterica serovar Typhimurium.

    PubMed

    Simon, Raphael; Samuel, Charles E

    2007-04-01

    Salmonella enterica serovar Typhimurium is highly virulent and mediates robust interferon (IFN)-stimulated gene (ISG) induction, whereas bacterial mutants that lack the DNA adenine methylase (Dam) are attenuated, elicit a reduced ISG activation profile, and establish immunity to murine typhoid fever. We show here that in contrast to observations in mice, infection of macrophage cell cultures with either wild-type (WT) or dam(-) mutant Salmonella resulted in surprisingly similar kinetics and amplitudes of induction of IFN-beta, the type I IFN-alpha,beta beacon gene Mx, and the type II IFN-gamma beacon inducible nitric oxide synthase (iNOS). Likewise, activation of NF-kappaB-dependent gene expression in epithelial cells was comparable with WT and dam(-) mutant Salmonella. In contrast, the flagellin-deficient flhC(-) mutant did not activate NF-kappaB in epithelial cells but activated ISG expression comparable to that of WT Salmonella in macrophage cells. WT and dam(-) strains displayed a similar Toll-like receptor 5 (TLR5)-dependent NF-kappaB activation, whereas the flhC(-) mutant lacked this activity. UV-inactivated Salmonella elicited similar ISG induction to that of viable Salmonella in macrophages and mediated the establishment of a functional antiviral state but displayed decreased cytocidal activity. These results establish that the inherent IFN system-inducing capacities of dam(-) and WT Salmonella strains in cultured macrophage and epithelial cells, unlike the mouse, are indistinguishable.

  8. The generation of macrophages with anti-inflammatory activity in the absence of STAT6 signaling

    PubMed Central

    Fleming, Bryan D.; Chandrasekaran, Prabha; Dillon, Laura A. L.; Dalby, Elizabeth; Suresh, Rahul; Sarkar, Arup; El-Sayed, Najib M.; Mosser, David M.

    2015-01-01

    Macrophages readily change their phenotype in response to exogenous stimuli. In this work, macrophages were stimulated under a variety of experimental conditions, and phenotypic alterations were correlated with changes in gene expression. We identified 3 transcriptionally related populations of macrophages with immunoregulatory activity. They were generated by stimulating cells with TLR ligands in the presence of 3 different "reprogramming" signals: high-density ICs, PGE2, or Ado. All 3 of these cell populations produced high levels of transcripts for IL-10 and growth and angiogenic factors. They also secreted reduced levels of inflammatory cytokines IL-1β, IL-6, and IL-12. All 3 macrophage phenotypes could partially rescue mice from lethal endotoxemia, and therefore, we consider each to have anti-inflammatory activity. This ability to regulate innate-immune responses occurred equally well in macrophages from STAT6-deficient mice. The lack of STAT6 did not affect the ability of macrophages to change cytokine production reciprocally or to rescue mice from lethal endotoxemia. Furthermore, treatment of macrophages with IL-4 failed to induce similar phenotypic or transcriptional alterations. This work demonstrates that there are multiple ways to generate macrophages with immunoregulatory activity. These anti-inflammatory macrophages are transcriptionally and functionally related to each other and are quite distinct from macrophages treated with IL-4. PMID:26048978

  9. Macrophage-oriented cytotoxic activity of novel triterpene saponins extracted from roots of Securidaca inappendiculata.

    PubMed

    Yui, S; Ubukata, K; Hodono, K; Kitahara, M; Mimaki, Y; Kuroda, M; Sashida, Y; Yamazaki, M

    2001-10-01

    It is recognized that macrophages in peripheral tissues often proliferate under pathological conditions such as tumors, inflammation and atherosclerosis. Because the growth state of macrophages is believed to be a factor regulating the pathological process of the diseases, substances that regulate macrophage growth or survival may be useful for disease control. In this paper, we identified the activity inhibiting macrophage growth in a hot water extract of roots of Securidaca inappendiculata. The extract markedly inhibited macrophage colony-stimulating factor (M-CSF/CSF-1)-induced growth of macrophages, whereas it exerted a less potent effect on growth of Concanavalin A (Con A)-stimulated thymocytes or M-CSF-stimulated bone marrow cells. The inhibition of macrophage growth was caused by a cytotoxic effect rather than a cytostatic effect. Cell death was due to the induction of apoptosis, as judged by staining with terminal deoxynucleotidyl transferase-mediated d-UTP nick end labelling (TUNEL). The cytotoxic activity seemed to be specific to peripheral macrophages; it showed a weak effect on the growth and survival of tumor cell lines including a macrophage-like cell line, J-774.1. Moreover, the saponin fraction induced apoptotic cell death of macrophages only when they were stimulated by M-CSF; it did not affect the viability of macrophages cultured without M-CSF or with granulocyte/macrophage-CSF. We determined the structures of the two active triterpene saponin compounds in the fraction, named securioside A and securioside B having a 3,4-dimethoxycinnamic group which is essential for the cell death-inducing activity. They are believed to be the primary compounds of new drugs for the treatment of pathological states in which macrophage proliferation occurs. PMID:11606030

  10. Phagocyte respiratory burst activates macrophage erythropoietin signalling to promote acute inflammation resolution

    PubMed Central

    Luo, Bangwei; Wang, Jinsong; Liu, Zongwei; Shen, Zigang; Shi, Rongchen; Liu, Yu-Qi; Liu, Yu; Jiang, Man; Wu, Yuzhang; Zhang, Zhiren

    2016-01-01

    Inflammation resolution is an active process, the failure of which causes uncontrolled inflammation which underlies many chronic diseases. Therefore, endogenous pathways that regulate inflammation resolution are fundamental and of wide interest. Here, we demonstrate that phagocyte respiratory burst-induced hypoxia activates macrophage erythropoietin signalling to promote acute inflammation resolution. This signalling is activated following acute but not chronic inflammation. Pharmacological or genetical inhibition of the respiratory burst suppresses hypoxia and macrophage erythropoietin signalling. Macrophage-specific erythropoietin receptor-deficient mice and chronic granulomatous disease (CGD) mice, which lack the capacity for respiratory burst, display impaired inflammation resolution, and exogenous erythropoietin enhances this resolution in WT and CGD mice. Mechanistically, erythropoietin increases macrophage engulfment of apoptotic neutrophils via PPARγ, promotes macrophage removal of debris and enhances macrophage migration to draining lymph nodes. Together, our results provide evidences of an endogenous pathway that regulates inflammation resolution, with important implications for treating inflammatory conditions. PMID:27397585

  11. Phenylbutyrate Is Bacteriostatic against Mycobacterium tuberculosis and Regulates the Macrophage Response to Infection, Synergistically with 25-Hydroxy-Vitamin D₃

    PubMed Central

    Coussens, Anna K.; Wilkinson, Robert J.; Martineau, Adrian R.

    2015-01-01

    Adjunctive vitamin D treatment for pulmonary tuberculosis enhances resolution of inflammation but has modest effects on bacterial clearance. Sodium 4-phenylbutyrate (PBA) is in clinical use for a range of conditions and has been shown to synergise with vitamin D metabolites to upregulate cathelicidin antimicrobial peptide (CAMP) expression. We investigated whether clinically attainable plasma concentrations of PBA (0.4-4mM) directly affect Mycobacterium tuberculosis (Mtb) growth and human macrophage and PBMC response to infection. We also tested the ability of PBA to enhance the immunomodulatory actions of the vitamin D metabolite 25(OH)D3 during infection and synergistically inhibit intracellular Mtb growth. PBA inhibited Mtb growth in broth with an MIC99 of 1mM, which was reduced to 0.25mM by lowering pH. During human macrophage infection, PBA treatment restricted Mtb uptake, phagocytic receptor expression and intracellular growth in a dose-dependent manner. PBA independently regulated CCL chemokine secretion and induced expression of the antimicrobial LTF (lactoferrin), the anti-inflammatory PROC (protein C) and multiple genes within the NLRP3 inflammasome pathway. PBA co-treatment with 25(OH)D3 synergistically modulated expression of numerous vitamin D-response genes, including CAMP, CYP24A1, CXCL10 and IL-37. This synergistic effect was dependent on MAPK signalling, while the effect of PBA on LTF, PROC and NLRP3 was MAPK-independent. During PBA and 25(OH)D3 co-treatment of human macrophages, in the absence of exogenous proteinase 3 (PR3) to activate cathelicidin, Mtb growth restriction was dominated by the effect of PBA, while the addition of PR3 enhanced growth restriction by 25(OH)D3 and PBA co-treatment. This suggests that PBA augments vitamin D–mediated cathelicidin-dependent Mtb growth restriction by human macrophages and independently induces antimicrobial and anti-inflammatory action. Therefore through both host-directed and bacterial

  12. HIV-1 Nef Impairs Key Functional Activities in Human Macrophages through CD36 Downregulation

    PubMed Central

    Olivetta, Eleonora; Tirelli, Valentina; Chiozzini, Chiara; Scazzocchio, Beatrice; Romano, Ignazio; Arenaccio, Claudia; Sanchez, Massimo

    2014-01-01

    Monocytes and macrophages utilize the class A and B scavenger receptors to recognize and perform phagocytosis of invading microbes before a pathogen-specific immune response is generated. HIV-1 Nef protein affects the innate immune system impairing oxidative burst response and phagocytic capacity of macrophages. Our data show that exogenous recombinant myristoylated Nef protein induces a marked CD36 downregulation in monocytes from Peripheral Blood Mononuclear Cells, in Monocyte-Derived Macrophages (MDMs) differentiated by cytokines and in MDMs contained in a mixed culture obtained expanding PBMCs under Human Erythroid Massive Amplification condition. Under the latter culture condition we identify three main populations after 6 days of expansion: lymphocytes (37.8±14.7%), erythroblasts (46.7±6.1%) and MDMs (15.7±7.5%). The Nef addition to the cell culture significantly downregulates CD36 expression in MDMs, but not in erythroid cells. Furthermore, CD36 inhibition is highly specific since it does not modify the expression levels of other MDM markers such as CD14, CD11c, CD86, CD68, CD206, Toll-like Receptor 2 and Toll-like Receptor 4. Similar results were obtained in MDMs infected with VSV-G pseudotyped HIV-1-expressing Nef. The reduced CD36 membrane expression is associated with decrease of correspondent CD36 mRNA transcript. Furthermore, Nef-induced CD36 downregulation is linked to both impaired scavenger activity with reduced capability to take up oxidized lipoproteins and to significant decreased phagocytosis of fluorescent beads and GFP-expressing Salmonella tiphymurium. In addition we observed that Nef induces TNF-α release in MDMs. Although these data suggest a possible involvement of TNF-α in mediating Nef activity, our results exclude a possible relationship between Nef-induced TNF-α release and Nef-mediated CD36 downregulation. The present work shows that HIV-1 Nef protein may have a role in the strategies elaborated by HIV-1 to alter pathogen

  13. Cytokine responses in severe acute respiratory syndrome coronavirus-infected macrophages in vitro: possible relevance to pathogenesis.

    PubMed

    Cheung, Chung Y; Poon, Leo L M; Ng, Iris H Y; Luk, Winsie; Sia, Sin-Fun; Wu, Mavis H S; Chan, Kwok-Hung; Yuen, Kwok-Yung; Gordon, Siamon; Guan, Yi; Peiris, Joseph S M

    2005-06-01

    The pathogenesis of severe acute respiratory syndrome (SARS) remains unclear. Macrophages are key sentinel cells in the respiratory system, and it is therefore relevant to compare the responses of human macrophages to infections with the SARS coronavirus (SARS-CoV) and other respiratory viruses. Primary human monocyte-derived macrophages were infected with SARS-CoV in vitro. Virus replication was monitored by measuring the levels of positive- and negative-strand RNA, by immunofluorescence detection of the SARS-CoV nucleoprotein, and by titration of the infectious virus. The gene expression profiles of macrophages infected with SARS-CoV, human coronavirus 229E, and influenza A (H1N1) virus were compared by using microarrays and real-time quantitative reverse transcriptase PCR. Secreted cytokines were measured with an enzyme-linked immunosorbent assay. SARS-CoV initiated viral gene transcription and protein synthesis in macrophages, but replication was abortive and no infectious virus was produced. In contrast to the case with human coronavirus 229E and influenza A virus, there was little or no induction of beta interferon (IFN-beta) in SARS-CoV-infected macrophages. Furthermore, SARS-CoV induced the expression of chemokines such as CXCL10/IFN-gamma-inducible protein 10 and CCL2/monocyte chemotactic protein 1. The poor induction of IFN-beta, a key component of innate immunity, and the ability of the virus to induce chemokines could explain aspects of the pathogenesis of SARS.

  14. Activation of JAK2/STAT1-alpha-dependent signaling events during Mycobacterium tuberculosis-induced macrophage apoptosis.

    PubMed

    Rojas, Mauricio; Olivier, Martin; García, Luis F

    2002-01-01

    Induction of apoptosis by Mycobacterium tuberculosis in murine macrophage involves TNF-alpha and nitric oxide (NO) production and caspase cascade activation; however, the intracellular signaling pathways implicated remain to be established. Our results indicate that infection of the B10R murine macrophage line with M. tuberculosis induces apoptosis independent of mycobacterial phagocytosis and that M. tuberculosis induces protein tyrosine kinase (PTK) activity, JAK2/STAT1-alpha phosphorylation, and STAT1-alpha nuclear translocation. Inhibitors of PTK (AG-126), or JAK2 (AG-490) inhibited TNF-alpha and NO production, caspase 1 activation and apoptosis, suggesting that M. tuberculosis-induction of these events depends on JAK2/STAT1-alpha activation. In addition, we have obtained evidence that ManLAM capacity to inhibit M. tuberculosis-induced apoptosis involves the activation of the PTP SHP-1. The finding that M. tuberculosis infection activate JAK2/STAT1-alpha pathway suggests that M. tuberculosis might mimic macrophage-activating stimuli.

  15. Hypoxia-Mediated Impairment of the Mitochondrial Respiratory Chain Inhibits the Bactericidal Activity of Macrophages

    PubMed Central

    Wiese, Melanie; Gerlach, Roman G.; Popp, Isabel; Matuszak, Jasmin; Mahapatro, Mousumi; Castiglione, Kirstin; Chakravortty, Dipshikha; Willam, Carsten; Hensel, Michael; Bogdan, Christian

    2012-01-01

    In infected tissues oxygen tensions are low. As innate immune cells have to operate under these conditions, we analyzed the ability of macrophages (Mϕ) to kill Escherichia coli or Staphylococcus aureus in a hypoxic microenvironment. Oxygen restriction did not promote intracellular bacterial growth but did impair the bactericidal activity of the host cells against both pathogens. This correlated with a decreased production of reactive oxygen intermediates (ROI) and reactive nitrogen intermediates. Experiments with phagocyte NADPH oxidase (PHOX) and inducible NO synthase (NOS2) double-deficient Mϕ revealed that in E. coli- or S. aureus-infected cells the reduced antibacterial activity during hypoxia was either entirely or partially independent of the diminished PHOX and NOS2 activity. Hypoxia impaired the mitochondrial activity of infected Mϕ. Inhibition of the mitochondrial respiratory chain activity during normoxia (using rotenone or antimycin A) completely or partially mimicked the defective antibacterial activity observed in hypoxic E. coli- or S. aureus-infected wild-type Mϕ, respectively. Accordingly, inhibition of the respiratory chain of S. aureus-infected, normoxic PHOX−/− NOS2−/− Mϕ further raised the bacterial burden of the cells, which reached the level measured in hypoxic PHOX−/− NOS2−/− Mϕ cultures. Our data demonstrate that the reduced killing of S. aureus or E. coli during hypoxia is not simply due to a lack of PHOX and NOS2 activity but partially or completely results from an impaired mitochondrial antibacterial effector function. Since pharmacological inhibition of the respiratory chain raised the generation of ROI but nevertheless phenocopied the effect of hypoxia, ROI can be excluded as the mechanism underlying the antimicrobial activity of mitochondria. PMID:22252868

  16. Biosynthesis of nitric oxide activates iron regulatory factor in macrophages.

    PubMed

    Drapier, J C; Hirling, H; Wietzerbin, J; Kaldy, P; Kühn, L C

    1993-09-01

    Biosynthesis of nitric oxide (NO) from L-arginine modulates activity of iron-dependent enzymes, including mitochondrial acontiase, an [Fe-S] protein. We examined the effect of NO on the activity of iron regulatory factor (IRF), a cytoplasmic protein which modulates both ferritin mRNA translation and transferrin receptor mRNA stability by binding to specific mRNA sequences called iron responsive elements (IREs). Murine macrophages were activated with interferon-gamma and lipopolysaccharide to induce NO synthase activity and cultured in the presence or absence of NG-substituted analogues of L-arginine which served as selective inhibitors of NO synthesis. Measurement of the nitrite concentration in the culture medium was taken as an index of NO production. Mitochondria-free cytosols were then prepared and aconitase activity as well as IRE binding activity and induction of IRE binding activity were correlated and depended on NO synthesis after IFN-gamma and/or LPS stimulation. Authentic NO gas as well as the NO-generating compound 3-morpholinosydnonimine (SIN-1) also conversely modulated aconitase and IRE binding activities of purified recombinant IRF. These results provide evidence that endogenously produced NO may modulate the post-transcriptional regulation of genes involved in iron homeostasis and support the hypothesis that the [Fe-S] cluster of IRF mediates iron-dependent regulation. PMID:7504626

  17. A Novel Strategy for TNF-Alpha Production by 2-APB Induced Downregulated SOCE and Upregulated HSP70 in O. tsutsugamushi-Infected Human Macrophages

    PubMed Central

    Liang, Jui-Lin; Tsai, Ming-Hsien; Yen, Chia-Jung; Li, Hsiu-Wen; Chiu, Siou-Jin; Chang, Chung-Hsing; Huang, Yaw-Bin; Lin, Ming-Wei; Yoshioka, Tohru

    2016-01-01

    Orientia (O.) tsutsugamushi-induced scrub typhus is endemic across many regions of Asia and the Western Pacific, where an estimated 1 million cases occur each year; the majority of patients infected with O. tsutsugamushi end up with a cytokine storm from a severe inflammatory response. Previous reports have indicated that blocking tumor necrosis factor (TNF)-α reduced cell injury from a cytokine storm. Since TNF-α production is known to be associated with intracellular Ca2+ elevation, we examined the effect of store-operated Ca2+ entry (SOCE) inhibitors on TNF-α production in O. tsutsugamushi-infected macrophages. We found that 2-aminoethoxydiphenyl borate (2-APB), but not SKF96365, facilitates the suppression of Ca2+ mobilization via the interruption of Orai1 expression in O. tsutsugamushi-infected macrophages. Due to the decrease of Ca2+ elevation, the expression of TNF-α and its release from macrophages was repressed by 2-APB. In addition, a novel role of 2-APB was found in macrophages that causes the upregulation of heat shock protein 70 (HSP70) expression associated with ERK activation; upregulated TNF-α production in the case of knockdown HSP70 was inhibited with 2-APB treatment. Furthermore, elevated HSP70 formation unexpectedly did not help the cell survival of O. tsutsugamushi-infected macrophages. In conclusion, the parallelism between downregulated Ca2+ mobilization via SOCE and upregulated HSP70 after treatment with 2-APB against TNF-α production was found to efficiently attenuate an O. tsutsugamushi-induced severe inflammatory response. PMID:27472555

  18. A Novel Strategy for TNF-Alpha Production by 2-APB Induced Downregulated SOCE and Upregulated HSP70 in O. tsutsugamushi-Infected Human Macrophages.

    PubMed

    Wu, Ching-Ying; Hsu, Wen-Li; Wang, Chun-Hsiung; Liang, Jui-Lin; Tsai, Ming-Hsien; Yen, Chia-Jung; Li, Hsiu-Wen; Chiu, Siou-Jin; Chang, Chung-Hsing; Huang, Yaw-Bin; Lin, Ming-Wei; Yoshioka, Tohru

    2016-01-01

    Orientia (O.) tsutsugamushi-induced scrub typhus is endemic across many regions of Asia and the Western Pacific, where an estimated 1 million cases occur each year; the majority of patients infected with O. tsutsugamushi end up with a cytokine storm from a severe inflammatory response. Previous reports have indicated that blocking tumor necrosis factor (TNF)-α reduced cell injury from a cytokine storm. Since TNF-α production is known to be associated with intracellular Ca2+ elevation, we examined the effect of store-operated Ca2+ entry (SOCE) inhibitors on TNF-α production in O. tsutsugamushi-infected macrophages. We found that 2-aminoethoxydiphenyl borate (2-APB), but not SKF96365, facilitates the suppression of Ca2+ mobilization via the interruption of Orai1 expression in O. tsutsugamushi-infected macrophages. Due to the decrease of Ca2+ elevation, the expression of TNF-α and its release from macrophages was repressed by 2-APB. In addition, a novel role of 2-APB was found in macrophages that causes the upregulation of heat shock protein 70 (HSP70) expression associated with ERK activation; upregulated TNF-α production in the case of knockdown HSP70 was inhibited with 2-APB treatment. Furthermore, elevated HSP70 formation unexpectedly did not help the cell survival of O. tsutsugamushi-infected macrophages. In conclusion, the parallelism between downregulated Ca2+ mobilization via SOCE and upregulated HSP70 after treatment with 2-APB against TNF-α production was found to efficiently attenuate an O. tsutsugamushi-induced severe inflammatory response. PMID:27472555

  19. Interaction of Chlamydiae with human macrophages.

    PubMed

    Herweg, Jo-Ana; Rudel, Thomas

    2016-02-01

    The phylum Chlamydiae contains several members that are well-known human pathogens, like Chlamydia trachomatis and C. pneumoniae. Establishing a chronic bacterial infection requires the active evasion of the host immune response. A major arm of the innate immune defence is constituted by macrophages, which fight infections by removing bacteria and triggering an adaptive immune response. However, some pathogenic Chlamydia infect and survive in macrophages at least for a certain period of time. Therefore, macrophages can serve as vehicles for the dissemination of bacterial infections from the primary infection site via the urogenital or respiratory tract to distant sites in the body. The capacity to infect macrophages seems to depend on the chlamydial strain and the source of macrophages. In vitro infections of macrophages with C. trachomatis, C. psittaci and C. pneumoniae reveal low efficiency of infection and progeny formation, as well as failure to develop mature inclusions. In contrast, the emerging pathogen, Simkania negevensis, actively replicates in macrophages. Here we summarize the current knowledge of the intracellular and molecular key mechanisms of C. trachomatis, C. pneumoniae and S. negevensis infections in human macrophages. PMID:26613554

  20. Plasma Membrane Profiling Reveals Upregulation of ABCA1 by Infected Macrophages Leading to Restriction of Mycobacterial Growth

    PubMed Central

    Long, Jing; Basu Roy, Robindra; Zhang, Yanjia J.; Antrobus, Robin; Du, Yuxian; Smith, Duncan L.; Weekes, Michael P.; Javid, Babak

    2016-01-01

    The plasma membrane represents a critical interface between the internal and extracellular environments, and harbors multiple proteins key receptors and transporters that play important roles in restriction of intracellular infection. We applied plasma membrane profiling, a technique that combines quantitative mass spectrometry with selective cell surface aminooxy-biotinylation, to Bacille Calmette–Guérin (BCG)-infected THP-1 macrophages. We quantified 559 PM proteins in BCG-infected THP-1 cells. One significantly upregulated cell-surface protein was the cholesterol transporter ABCA1. We showed that ABCA1 was upregulated on the macrophage cell-surface following infection with pathogenic mycobacteria and knockdown of ABCA1 resulted in increased mycobacterial survival within macrophages, suggesting that it may be a novel mycobacterial host-restriction factor. PMID:27462310

  1. Ozone effect on respiratory syncytial virus infectivity and cytokine production by human alveolar macrophages

    SciTech Connect

    Soukup, J.; Koren, H.S.; Becker, S.

    1993-01-01

    The study was performed to evaluate the effect of ozone (O3) exposure at 1 ppm for 2 hr on the susceptibility/resistance of adult human alveolar macrophages (AM) to infection with respiratory syncytial virus (RSV) in vitro and on RSV-induced cytokine production by the AM. AM were first exposed to O3 or to filtered air and then infected with RSV at multiplicities of infection (m.o.i.) of 0.1 1.0 and 10. The percentage RSV-infected AM and the amount of infectious virus released by the cells were determined at Days 2 and 4 after infection. Interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF) levels in the supernatants were determined on Day 2. No difference in the percentage infected AM or in the amount of infectious RSV produced was found between control and O3-exposed cultures. However, O3-exposed AM infected with RSV at m.o.i. 1 produced less IL-1 in response to RSV infection than control AM:63.6 pg/ml compared with 98.5 pg/ml. No difference in IL-1 was seen with m.o.i. 10. IL-6 levels were also decreased, but only after infection with m.o.i. 0.1. At this level of infection 830 pg/ml was produced by control AM as compared to 468.2 pg/ml by O3-exposed AM. TNF production was unaffected by O3 at all multiplicities of infection. (Copyright (c) 1993 by Academic Press, Inc.)

  2. Phospholipid Ozonation Products Activate the 5-Lipoxygenase Pathway in Macrophages.

    PubMed

    Zemski Berry, Karin A; Murphy, Robert C

    2016-08-15

    Ozone is a highly reactive environmental toxicant that can react with the double bonds of lipids in pulmonary surfactant. This study was undertaken to investigate the proinflammatory properties of the major lipid-ozone product in pulmonary surfactant, 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (16:0/9al-PC), with respect to eicosanoid production. A dose-dependent increase in the formation of 5-lipoxygenase (5-LO) products was observed in murine resident peritoneal macrophages (RPM) and alveolar macrophages (AM) upon treatment with 16:0/9al-PC. In contrast, the production of cyclooxygenase (COX) derived eicosanoids did not change from basal levels in the presence of 16:0/9al-PC. When 16:0/9al-PC and the TLR2 ligand, zymosan, were added to RPM or AM, an enhancement of 5-LO product formation along with a concomitant decrease in COX product formation was observed. Neither intracellular calcium levels nor arachidonic acid release was influenced by the addition of 16:0/9al-PC to RPM. Results from mitogen-activated protein kinase (MAPK) inhibitor studies and direct measurement of phosphorylation of MAPKs revealed that 16:0/9al-PC activates the p38 MAPK pathway in RPM, which results in the activation of 5-LO. Our results indicate that 16:0/9al-PC has a profound effect on the eicosanoid pathway, which may have implications in inflammatory pulmonary disease states where eicosanoids have been shown to play a role. PMID:27448436

  3. Contrasting regulation of macrophage iron homeostasis in response to infection with Listeria monocytogenes depending on localization of bacteria.

    PubMed

    Haschka, David; Nairz, Manfred; Demetz, Egon; Wienerroither, Sebastian; Decker, Thomas; Weiss, Günter

    2015-06-01

    Due to its multiple roles for the proliferation and pathogenicity of many microbes on the one hand and via modulation of immune effector functions on the other hand the control over iron homeostasis is thought to play a decisive role in the course of infections. Diversion of cellular iron traffic is considered as an important defense mechanism of macrophages to reduce metal availability for intracellular bacteria residing in the phagosome. However, evidence is lacking whether such alterations of iron homeostasis also become evident upon infection with bacteria gaining access to the cytosol like Listeria monocytogenes. Here we show that infection of macrophages with L. monocytogenes triggers the expression of the major cellular iron exporter ferroportin1 and induces cellular iron egress. As the growth of Listeria within macrophages is promoted by iron, stimulation of ferroportin1 functionality limits the availability of the metal for Listeria residing in the cytoplasm, whereas ferroportin1 degradation upon hepcidin treatment increases intracellular bacterial growth. In parallel to an increase of ferroportin1 expression, infected macrophages induce anti-microbial immune effector mechanisms such as TNFα formation or NO expression which are aggravated upon iron deficiency. These adaptive changes of iron homeostasis and immune response pathways are only found in macrophages infected with Listeria which express listeriolysin O and are therefore able to escape from the phagosome to the cytoplasm. Listeriolysin O deficient Listeria which are restricted to the phagosome are even killed by excess iron which may be based on "iron intoxification" via macrophage radical formation, because iron supplementation in that setting is paralleled by increased ROS formation. Our results indicate that ferroportin1 mediated iron export is a nutritional immune effector pathway to control infection with Listeria residing in the cytoplasm, whereas a different strategy is observed in mutant

  4. A transient reversal of miRNA-mediated repression controls macrophage activation.

    PubMed

    Mazumder, Anup; Bose, Mainak; Chakraborty, Abhijit; Chakrabarti, Saikat; Bhattacharyya, Suvendra N

    2013-11-01

    In mammalian macrophages, the expression of a number of cytokines is regulated by miRNAs. Upon macrophage activation, proinflammatory cytokine mRNAs are translated, although the expression of miRNAs targeting these mRNAs remains largely unaltered. We show that there is a transient reversal of miRNA-mediated repression during the early phase of the inflammatory response in macrophages, which leads to the protection of cytokine mRNAs from miRNA-mediated repression. This derepression occurs through Ago2 phosphorylation, which results in its impaired binding to miRNAs and to the corresponding target mRNAs. Macrophages expressing a mutant, non-phosphorylatable AGO2--which remains bound to miRNAs during macrophage activation--have a weakened inflammatory response and fail to prevent parasite invasion. These findings highlight the relevance of the transient relief of miRNA repression for macrophage function.

  5. Monocyte/macrophage inflammatory response pathways to combat Francisella infection: possible therapeutic targets?

    PubMed Central

    Gillette, Devyn D.; Tridandapani, Susheela; Butchar, Jonathan P.

    2014-01-01

    Francisella tularensis can bypass and suppress host immune responses, even to the point of manipulating immune cell phenotypes and intercellular inflammatory networks. Strengthening these responses such that immune cells more readily identify and destroy the bacteria is likely to become a viable (and perhaps necessary) strategy for combating infections with Francisella, especially given the likelihood of antibiotic resistance in the foreseeable future. Monocytes and macrophages offer a niche wherein Francisella can invade and replicate, resulting in substantially higher bacterial load that can overcome the host. As such, understanding their responses to Francisella may uncover potential avenues of therapy that could promote a lowering of bacterial burden and clearance of infection. These response pathways include Toll-like Receptor 2 (TLR2), the caspase-1 inflammasome, Interferons, NADPH oxidase, Phosphatidylinositide 3-kinase (PI3K), and the Ras pathway. In this review we summarize the literature pertaining to the roles of these pathways during Francisella infection, with an emphasis on monocyte/macrophage responses. The therapeutic targeting of one or more such pathways may ultimately become a valuable tool for the treatment of tularemia, and several possibilities are discussed. PMID:24600590

  6. Modulation of macrophage cytokine profiles during solid tumor progression: susceptibility to Candida albicans infection

    PubMed Central

    2009-01-01

    Background In order to attain a better understanding of the interactions between opportunist fungi and their hosts, we investigated the cytokine profile associated with the inflammatory response to Candida albicans infection in mice with solid Ehrlich tumors of different degrees. Methods Groups of eight animals were inoculated intraperitoneally with 5 × 106 C. albicans 7, 14 or 21 days after tumor implantation. After 24 or 72 hours, the animals were euthanized and intraperitoneal lavage fluid was collected. Peritoneal macrophages were cultivated and the levels of IFN-γ, TNF-α, IL-12, IL-10 and IL-4 released into the supernatants were measured by ELISA. Kidney, liver and spleen samples were evaluated for fungal dissemination. Tumor-free animals and animals that had only been subjected to C. albicans infection were used as control groups. Results Our results demonstrated that the mice produced more IFN-γ and TNF-α and less IL-10, and also exhibited fungal clearance, at the beginning of tumor evolution. With the tumor progression, this picture changed: IL-10 production increased and IFN-γ and TNF-α release decreased; furthermore, there was extensive fungal dissemination. Conclusion Our results indicate that solid tumors can affect the production of macrophage cytokines and, in consequence, affect host resistance to opportunistic infections. PMID:19534779

  7. Induction of Heme Oxygenase-1 Deficiency and Associated Glutamate-Mediated Neurotoxicity Is a Highly Conserved HIV Phenotype of Chronic Macrophage Infection That Is Resistant to Antiretroviral Therapy

    PubMed Central

    Kovacsics, Colleen E.; Vance, Patricia J.; Collman, Ronald G.

    2015-01-01

    ABSTRACT Expression of the cytoprotective enzyme heme oxygenase-1 (HO-1) is significantly reduced in the brain prefrontal cortex of HIV-positive individuals with HIV-associated neurocognitive disorders (HAND). Furthermore, this HO-1 deficiency correlates with brain viral load, markers of macrophage activation, and type I interferon responses. In vitro, HIV replication in monocyte-derived macrophages (MDM) selectively reduces HO-1 protein and RNA expression and induces production of neurotoxic levels of glutamate; correction of this HO-1 deficiency reduces neurotoxic glutamate production without an effect on HIV replication. We now demonstrate that macrophage HO-1 deficiency, and the associated neurotoxin production, is a conserved feature of infection with macrophage-tropic HIV-1 strains that correlates closely with the extent of replication, and this feature extends to HIV-2 infection. We further demonstrate that this HO-1 deficiency does not depend specifically upon the HIV-1 accessory genes nef, vpr, or vpu but rather on HIV replication, even when markedly limited. Finally, antiretroviral therapy (ART) applied to MDM after HIV infection is established does not prevent HO-1 loss or the associated neurotoxin production. This work defines a predictable relationship between HIV replication, HO-1 loss, and neurotoxin production in MDM that likely reflects processes in place in the HIV-infected brains of individuals receiving ART. It further suggests that correcting this HO-1 deficiency in HIV-infected MDM could provide neuroprotection above that provided by current ART or proposed antiviral therapies directed at limiting Nef, Vpr, or Vpu functions. The ability of HIV-2 to reduce HO-1 expression suggests that this is a conserved phenotype among macrophage-tropic human immunodeficiency viruses that could contribute to neuropathogenesis. IMPORTANCE The continued prevalence of HIV-associated neurocognitive disorders (HAND) underscores the need for adjunctive therapy that

  8. Exercise effects on IFN-beta expression and viral replication in lung macrophages after HSV-1 infection.

    PubMed

    Kohut, M L; Davis, J M; Jackson, D A; Jani, P; Ghaffar, A; Mayer, E P; Essig, D A

    1998-12-01

    Mice exercised to fatigue and exposed to herpes simplex virus type 1 (HSV-1) exhibit greater mortality than control mice. In this study, we examined lung macrophage resistance to HSV-1 after exercise in terms of both viral replication and interferon (IFN)-beta production. We utilized the reverse transcriptase-rapid polymerase chain reaction to measure the IFN-beta mRNA content in alveolar macrophages. IFN release was measured with a bioassay, and viral replication within the macrophage was assessed by plaque titration. Exercised (Ex) mice ran on a treadmill until fatigue while control (Con) mice remained in lanes above the treadmill. After exercise, alveolar macrophages were removed and incubated with HSV-1. Alveolar macrophage IFN-beta mRNA was greater in Ex than in Con mice. Culture supernatant from infected macrophages showed a higher degree of IFN release and a higher number of infectious viral particles in Ex vs. Con mice. It is likely that the increase in IFN-beta mRNA occurs in response to a higher degree of viral replication. These results suggest that macrophages from Ex mice are less resistant to infection with HSV-1.

  9. Liver X receptor activation stimulates iron export in human alternative macrophages

    PubMed Central

    Bories, Gael; Colin, Sophie; Vanhoutte, Jonathan; Derudas, Bruno; Copin, Corinne; Fanchon, Melanie; Daoudi, Mehdi; Belloy, Loic; Haulon, Stephan; Zawadzki, Christophe; Jude, Brigitte; Staels, Bart; Chinetti-Gbaguidi, Giulia

    2013-01-01

    Rationale In atherosclerotic plaques, iron preferentially accumulates in macrophages where it can exert pro-oxidant activities. Objective The objective of this study is, first, to better characterize the iron distribution and metabolism in macrophage sub-populations in human atherosclerotic plaques and, second, to determine whether iron homeostasis is under the control of nuclear receptors, such as the Liver X Receptors (LXR). Methods and Results Here we report that iron depots accumulate in human atherosclerotic plaque areas enriched in CD68 and Mannose Receptor (MR) positive (CD68+MR+) alternative M2 macrophages. In vitro IL-4 polarization of human monocytes into M2 macrophages also resulted in a gene expression profile and phenotype favouring iron accumulation. However, upon iron exposure, M2 macrophages acquire a phenotype favouring iron release, through a strong increase in ferroportin expression, illustrated by a more avid oxidation of extra-cellular LDL by iron-loaded M2 macrophages. In line, in human atherosclerotic plaques, CD68+MR+ macrophages accumulate oxidized lipids, which activate Liver X Receptors (LXRα and LXRβ), resulting in the induction of ABCA1, ABCG1 and ApoE expression. Moreover, in iron-loaded M2 macrophages, LXR activation induces nuclear factor erythroid 2-like 2 (NRF2) expression, hence increasing ferroportin expression, which, together with a decrease of hepcidin mRNA levels, promotes iron export. Conclusions These data identify a role for M2 macrophages in iron handling, a process which is regulated by LXR activation. PMID:24036496

  10. Liver X Receptor (LXR) activation negatively regulates visfatin expression in macrophages

    SciTech Connect

    Mayi, Therese Hervee; Rigamonti, Elena; Pattou, Francois; Staels, Bart; Chinetti-Gbaguidi, Giulia

    2011-01-07

    Research highlights: {yields} Synthetic LXR ligands decreased visfatin expression in human macrophages. {yields} LXR activation leads to a modest and transient decrease of NAD{sup +} concentration. {yields} LXR activation decreased PPAR{gamma}-induced visfatin in human macrophages. -- Abstract: Adipose tissue macrophages (ATM) are the major source of visfatin, a visceral fat adipokine upregulated during obesity. Also known to play a role in B cell differentiation (pre-B cell colony-enhancing factor (PBEF)) and NAD biosynthesis (nicotinamide phosphoribosyl transferase (NAMPT)), visfatin has been suggested to play a role in inflammation. Liver X Receptor (LXR) and Peroxisome Proliferator-Activated Receptor (PPAR){gamma} are nuclear receptors expressed in macrophages controlling the inflammatory response. Recently, we reported visfatin as a PPAR{gamma} target gene in human macrophages. In this study, we examined whether LXR regulates macrophage visfatin expression. Synthetic LXR ligands decreased visfatin gene expression in a LXR-dependent manner in human and murine macrophages. The decrease of visfatin mRNA was paralleled by a decrease of protein secretion. Consequently, a modest and transient decrease of NAD{sup +} concentration was observed. Interestingly, LXR activation decreased the PPAR{gamma}-induced visfatin gene and protein secretion in human macrophages. Our results identify visfatin as a gene oppositely regulated by the LXR and PPAR{gamma} pathways in human macrophages.

  11. Peroxisome proliferator-activated receptor-gamma agonist rosiglitazone attenuates postincisional pain by regulating macrophage polarization

    SciTech Connect

    Hasegawa-Moriyama, Maiko; Ohnou, Tetsuya; Godai, Kohei; Kurimoto, Tae; Nakama, Mayo; Kanmura, Yuichi

    2012-09-14

    Highlights: Black-Right-Pointing-Pointer Rosiglitazone attenuated postincisional pain. Black-Right-Pointing-Pointer Rosiglitazone alters macrophage polarization to F4/80{sup +}CD206{sup +} M2 macrophages at the incisional sites. Black-Right-Pointing-Pointer Transplantation of rosiglitazone-treated macrophages produced analgesic effects. -- Abstract: Acute inflammation triggered by macrophage infiltration to injured tissue promotes wound repair and may induce pain hypersensitivity. Peroxisome proliferator-activated receptor {gamma} (PPAR){gamma} signaling is known to regulate heterogeneity of macrophages, which are often referred to as classically activated (M1) and alternatively activated (M2) macrophages. M1 macrophages have considerable antimicrobial activity and produce a wide variety of proinflammatory cytokines. In contrast, M2 macrophages are involved in anti-inflammatory and homeostatic functions linked to wound healing and tissue repair. Although it has been suggested that PPAR{gamma} agonists attenuate pain hypersensitivity, the molecular mechanism of macrophage-mediated effects of PPAR{gamma} signaling on pain development has not been explored. In this study, we investigated the link between the phenotype switching of macrophage polarization induced by PPAR{gamma} signaling and the development of acute pain hypersensitivity. Local administration of rosiglitazone significantly ameliorated hypersensitivity to heat and mechanical stimuli, and paw swelling. Consistent with the down-regulation of nuclear factor {kappa}B (NF{kappa}B) phosphorylation by rosiglitazone at the incisional sites, the number of F4/80{sup +}iNOS{sup +} M1 macrophages was decreased whereas numbers of F4/80{sup +}CD206{sup +} M2 macrophages were increased in rosiglitazone-treated incisional sites 24 h after the procedure. In addition, gene induction of anti-inflammatory M2-macrophage-associated markers such as arginase1, FIZZ1 and interleukin (IL)-10 were significantly increased, whereas

  12. Analysis of the Bovine Monocyte-Derived Macrophage Response to Mycobacterium avium Subspecies Paratuberculosis Infection Using RNA-seq

    PubMed Central

    Casey, Maura E.; Meade, Kieran G.; Nalpas, Nicolas C.; Taraktsoglou, Maria; Browne, John A.; Killick, Kate E.; Park, Stephen D. E.; Gormley, Eamonn; Hokamp, Karsten; Magee, David A.; MacHugh, David E.

    2015-01-01

    Johne’s disease, caused by infection with Mycobacterium avium subsp. paratuberculosis, (MAP), is a chronic intestinal disease of ruminants with serious economic consequences for cattle production in the United States and elsewhere. During infection, MAP bacilli are phagocytosed and subvert host macrophage processes, resulting in subclinical infections that can lead to immunopathology and dissemination of disease. Analysis of the host macrophage transcriptome during infection can therefore shed light on the molecular mechanisms and host-pathogen interplay associated with Johne’s disease. Here, we describe results of an in vitro study of the bovine monocyte-derived macrophage (MDM) transcriptome response during MAP infection using RNA-seq. MDM were obtained from seven age- and sex-matched Holstein-Friesian cattle and were infected with MAP across a 6-h infection time course with non-infected controls. We observed 245 and 574 differentially expressed (DE) genes in MAP-infected versus non-infected control samples (adjusted P value ≤0.05) at 2 and 6 h post-infection, respectively. Functional analyses of these DE genes, including biological pathway enrichment, highlighted potential functional roles for genes that have not been previously described in the host response to infection with MAP bacilli. In addition, differential expression of pro- and anti-inflammatory cytokine genes, such as those associated with the IL-10 signaling pathway, and other immune-related genes that encode proteins involved in the bovine macrophage response to MAP infection emphasize the balance between protective host immunity and bacilli survival and proliferation. Systematic comparisons of RNA-seq gene expression results with Affymetrix® microarray data generated from the same experimental samples also demonstrated that RNA-seq represents a superior technology for studying host transcriptional responses to intracellular infection. PMID:25699042

  13. Identification and Analysis of the Porcine MicroRNA in Porcine Cytomegalovirus-Infected Macrophages Using Deep Sequencing

    PubMed Central

    Liu, Xiao; Liao, Shan; Xu, Zhiwen; Zhu, Ling; Yang, Fan; Guo, Wanzhu

    2016-01-01

    Porcine cytomegalovirus (PCMV; genus Cytomegalovirus, subfamily Betaherpesvirinae, family Herpesviridae) is an immunosuppressive virus that mainly inhibits the immune function of T lymphocytes and macrophages, which has caused substantial damage in the farming industry. In this study, we obtained the miRNA expression profiles of PCMV-infected porcine macrophages via high-throughput sequencing. The comprehensive analysis of miRNA profiles showed that 239 miRNA database-annotated and 355 novel pig-encoded miRNAs were detected. Of these, 130 miRNAs showed significant differential expression between the PCMV-infected and uninfected porcine macrophages. The 10 differentially expressed pig-encoded miRNAs were further determined by stem-loop reverse-transcription polymerase chain reaction, and the results were consistent with the high-throughput sequencing. Gene Ontology analysis of the target genes of miRNAs in PCMV-infected porcine macrophages showed that the differentially expressed miRNAs are mainly involved in immune and metabolic processes. This is the first report of the miRNA transcriptome in porcine macrophages and an analysis of the miRNA regulatory mechanisms during PCMV infection. Further research into the regulatory mechanisms of miRNAs during immunosuppressive viral infections should contribute to the treatment and prevention of immunosuppressive viruses. PMID:26943793

  14. Mutation of the Theiler’s virus leader protein zinc-finger domain impairs apoptotic activity in murine macrophages

    PubMed Central

    Son, Kyung-No; Liang, Zhiguo; Lipton, Howard L.

    2014-01-01

    The Theiler’s murine encephalomyelitis virus (TMEV) leader (L) protein zinc-finger domain was mutated to study its role in cell death in infection of the murine macrophage cell line M1-D, revealing that an intact zinc-finger domain is required for full apoptotic activity. A functional L zinc-finger domain was also required for activation of p38 MAPK that results in phosphorylation and activation of p53, and in turn, alteration of the conformation of the anti-apoptotic proteins Puma and Mcl-1, leading to the release of pro-apoptotic Bax and apoptosis through the intrinsic pathway. TMEV infection also inhibits host protein synthesis, a stress shown by others to induce apoptosis. Since inhibition of host protein synthesis follows rather than precedes activation of MKK3/6 and p38, it seems less likely that it triggers of apoptosis in infected cells. Finally, we showed that the levels of reactive oxygen species following infection were consistent with apoptotic rather than necrotic cell death. Thus, these experiments support an important role for the TMEV L protein zinc-finger domain in apoptosis in an infected murine macrophage line. PMID:24036175

  15. Mutation of the Theiler's virus leader protein zinc-finger domain impairs apoptotic activity in murine macrophages.

    PubMed

    Son, Kyung-No; Liang, Zhiguo; Lipton, Howard L

    2013-11-01

    The Theiler's murine encephalomyelitis virus (TMEV) leader (L) protein zinc-finger domain was mutated to study its role in cell death in infection of the murine macrophage cell line M1-D, revealing that an intact zinc-finger domain is required for full apoptotic activity. A functional L zinc-finger domain was also required for activation of p38 MAPK that results in phosphorylation and activation of p53, and in turn, alteration of the conformation of the anti-apoptotic proteins Puma and Mcl-1, leading to the release of pro-apoptotic Bax and apoptosis through the intrinsic pathway. TMEV infection also inhibits host protein synthesis, a stress shown by others to induce apoptosis. Since inhibition of host protein synthesis follows rather than precedes activation of MKK3/6 and p38, it seems less likely that it triggers apoptosis in infected cells. Finally, we showed that the levels of reactive oxygen species following infection were consistent with apoptotic rather than necrotic cell death. Thus, these experiments support an important role for the TMEV L protein zinc-finger domain in apoptosis in an infected murine macrophage line.

  16. Induction of Macrophage Function in Human THP-1 Cells Is Associated with Rewiring of MAPK Signaling and Activation of MAP3K7 (TAK1) Protein Kinase

    PubMed Central

    Richter, Erik; Ventz, Katharina; Harms, Manuela; Mostertz, Jörg; Hochgräfe, Falko

    2016-01-01

    Macrophages represent the primary human host response to pathogen infection and link the immediate defense to the adaptive immune system. Mature tissue macrophages convert from circulating monocyte precursor cells by terminal differentiation in a process that is not fully understood. Here, we analyzed the protein kinases of the human monocytic cell line THP-1 before and after induction of macrophage differentiation by using kinomics and phosphoproteomics. When comparing the macrophage-like state with the monocytic precursor, 50% of the kinome was altered in expression and even 71% of covered kinase phosphorylation sites were affected. Kinome rearrangements are for example characterized by a shift of overrepresented cyclin-dependent kinases associated with cell cycle control in monocytes to calmodulin-dependent kinases and kinases involved in proinflammatory signaling. Eventually, we show that monocyte-to-macrophage differentiation is associated with major rewiring of mitogen-activated protein kinase signaling networks and demonstrate that protein kinase MAP3K7 (TAK1) acts as the key signaling hub in bacterial killing, chemokine production and differentiation. Our study proves the fundamental role of protein kinases and cellular signaling as major drivers of macrophage differentiation and function. The finding that MAP3K7 is central to macrophage function suggests MAP3K7 and its networking partners as promising targets in host-directed therapy for macrophage-associated disease. PMID:27066479

  17. Critical illness induces alternative activation of M2 macrophages in adipose tissue

    PubMed Central

    2011-01-01

    Introduction We recently reported macrophage accumulation in adipose tissue of critically ill patients. Classically activated macrophage accumulation in adipose tissue is a known feature of obesity, where it is linked with increasing insulin resistance. However, the characteristics of adipose tissue macrophage accumulation in critical illness remain unknown. Methods We studied macrophage markers with immunostaining and gene expression in visceral and subcutaneous adipose tissue from healthy control subjects (n = 20) and non-surviving prolonged critically ill patients (n = 61). For comparison, also subcutaneous in vivo adipose tissue biopsies were studied from 15 prolonged critically ill patients. Results Subcutaneous and visceral adipose tissue biopsies from non-surviving prolonged critically ill patients displayed a large increase in macrophage staining. This staining corresponded with elevated gene expression of "alternatively activated" M2 macrophage markers arginase-1, IL-10 and CD163 and low levels of the "classically activated" M1 macrophage markers tumor necrosis factor (TNF)-α and inducible nitric-oxide synthase (iNOS). Immunostaining for CD163 confirmed positive M2 macrophage staining in both visceral and subcutaneous adipose tissue biopsies from critically ill patients. Surprisingly, circulating levels and tissue gene expression of the alternative M2 activators IL-4 and IL-13 were low and not different from controls. In contrast, adipose tissue protein levels of peroxisome proliferator-activated receptor-γ (PPARγ), a nuclear receptor required for M2 differentiation and acting downstream of IL-4, was markedly elevated in illness. In subcutaneous abdominal adipose tissue biopsies from surviving critically ill patients, we could confirm positive macrophage staining with CD68 and CD163. We also could confirm elevated arginase-1 gene expression and elevated PPARγ protein levels. Conclusions Unlike obesity, critical illness evokes adipose tissue

  18. Neither Classical nor Alternative Macrophage Activation Is Required for Pneumocystis Clearance during Immune Reconstitution Inflammatory Syndrome

    PubMed Central

    Zhang, Zhuo-Qian; Wang, Jing; Hoy, Zachary; Keegan, Achsah; Bhagwat, Samir; Gigliotti, Francis

    2015-01-01

    Pneumocystis is a respiratory fungal pathogen that causes pneumonia (Pneumocystis pneumonia [PcP]) in immunocompromised patients. Alveolar macrophages are critical effectors for CD4+ T cell-dependent clearance of Pneumocystis, and previous studies found that alternative macrophage activation accelerates fungal clearance during PcP-related immune reconstitution inflammatory syndrome (IRIS). However, the requirement for either classically or alternatively activated macrophages for Pneumocystis clearance has not been determined. Therefore, RAG2−/− mice lacking either the interferon gamma (IFN-γ) receptor (IFN-γR) or interleukin 4 receptor alpha (IL-4Rα) were infected with Pneumocystis. These mice were then immune reconstituted with wild-type lymphocytes to preserve the normal T helper response while preventing downstream effects of Th1 or Th2 effector cytokines on macrophage polarization. As expected, RAG2−/− mice developed severe disease but effectively cleared Pneumocystis and resolved IRIS. Neither RAG/IFN-γR−/− nor RAG/IL-4Rα−/− mice displayed impaired Pneumocystis clearance. However, RAG/IFN-γR−/− mice developed a dysregulated immune response, with exacerbated IRIS and greater pulmonary function deficits than those in RAG2 and RAG/IL-4Rα−/− mice. RAG/IFN-γR−/− mice had elevated numbers of lung CD4+ T cells, neutrophils, eosinophils, and NK cells but severely depressed numbers of lung CD8+ T suppressor cells. Impaired lung CD8+ T cell responses in RAG/IFN-γR−/− mice were associated with elevated lung IFN-γ levels, and neutralization of IFN-γ restored the CD8 response. These data demonstrate that restricting the ability of macrophages to polarize in response to Th1 or Th2 cytokines does not impair Pneumocystis clearance. However, a cell type-specific IFN-γ/IFN-γR-dependent mechanism regulates CD8+ T suppressor cell recruitment, limits immunopathogenesis, preserves lung function, and enhances the resolution of Pc

  19. Activation effect of Ganoderma lucidum polysaccharides liposomes on murine peritoneal macrophages.

    PubMed

    Liu, Zhenguang; Xing, Jie; Huang, Yee; Bo, Ruonan; Zheng, Sisi; Luo, Li; Niu, Yale; Zhang, Yan; Hu, Yuanliang; Liu, Jiaguo; Wu, Yi; Wang, Deyun

    2016-01-01

    The activation of murine peritoneal macrophages by Ganoderma lucidum polysaccharides liposomes (GLPL) was investigated in vitro. After treatment with GLPL, the changes of the nitric oxide (NO) secretion and iNOS (inducible nitric oxide synthase) activity were evaluated. The results showed that NO production and iNOS activity of macrophages were enhanced compared to GLP and BL group. In addition, both the phagocytic activity and levels of cytokines IL-1β, TNF-α and IFN-γ were enhanced in the peritoneal macrophages of mice by stimulation of GLPL. The expression of the major histocompatibility complex class II molecule (MHC II) on the surface of peritoneal macrophages significantly increased. These indicated that GLPL could enhance the activation of peritoneal macrophages and their potential for use as a delivery system of GLP. PMID:26529190

  20. Activation effect of Ganoderma lucidum polysaccharides liposomes on murine peritoneal macrophages.

    PubMed

    Liu, Zhenguang; Xing, Jie; Huang, Yee; Bo, Ruonan; Zheng, Sisi; Luo, Li; Niu, Yale; Zhang, Yan; Hu, Yuanliang; Liu, Jiaguo; Wu, Yi; Wang, Deyun

    2016-01-01

    The activation of murine peritoneal macrophages by Ganoderma lucidum polysaccharides liposomes (GLPL) was investigated in vitro. After treatment with GLPL, the changes of the nitric oxide (NO) secretion and iNOS (inducible nitric oxide synthase) activity were evaluated. The results showed that NO production and iNOS activity of macrophages were enhanced compared to GLP and BL group. In addition, both the phagocytic activity and levels of cytokines IL-1β, TNF-α and IFN-γ were enhanced in the peritoneal macrophages of mice by stimulation of GLPL. The expression of the major histocompatibility complex class II molecule (MHC II) on the surface of peritoneal macrophages significantly increased. These indicated that GLPL could enhance the activation of peritoneal macrophages and their potential for use as a delivery system of GLP.

  1. Monocytes and macrophages, implications for breast cancer migration and stem cell-like activity and treatment

    PubMed Central

    Ward, Rebecca; Sims, Andrew H.; Lee, Alexander; Lo, Christina; Wynne, Luke; Yusuf, Humza; Gregson, Hannah; Lisanti, Michael P.; Sotgia, Federica; Landberg, Göran; Lamb, Rebecca

    2015-01-01

    Macrophages are a major cellular constituent of the tumour stroma and contribute to breast cancer prognosis. The precise role and treatment strategies to target macrophages remain elusive. As macrophage infiltration is associated with poor prognosis and high grade tumours we used the THP-1 cell line to model monocyte-macrophage differentiation in co-culture with four breast cancer cell lines (MCF7, T47D, MDA-MB-231, MDA-MB-468) to model in vivo cellular interactions. Polarisation into M1 and M2 subtypes was confirmed by specific cell marker expression of ROS and HLA-DR, respectively. Co-culture with all types of macrophage increased migration of ER-positive breast cancer cell lines, while M2-macrophages increased mammosphere formation, compared to M1-macrophages, in all breast cancer cells lines. Treatment of cells with Zoledronate in co-culture reduced the “pro-tumourigenic” effects (increased mammospheres/migration) exerted by macrophages. Direct treatment of breast cancer cells in homotypic culture was unable to reduce migration or mammosphere formation. Macrophages promote “pro-tumourigenic” cellular characteristics of breast cancer cell migration and stem cell activity. Zoledronate targets macrophages within the microenvironment which in turn, reduces the “pro-tumourigenic” characteristics of breast cancer cells. Zoledronate offers an exciting new treatment strategy for both primary and metastatic breast cancer. PMID:26008983

  2. Isoniazid (INH) treatment of INH-resistant Mycobacterium tuberculosis inhibits infected macrophage to produce TNF-alpha.

    PubMed

    Wibawa, Tri; Pangemanan, Lisa; Rachmawaty, Farida J; Rintiswati, Ning; Mustofa; Soesatyo, Marsetyawan H N E

    2014-09-01

    Macrophages undergo apoptosis after infected by Mycobacterium tuber- culosis (M.tb), which is regulated by tumor necrosis factor alpha (TNF-alpha) and has a direct correlation with killing of intracellular bacilli. In order to clarify the role of isoniazid (INH) in the modulation of macrophages apoptosis and intracellular bacilli replication, we performed the following studies using an INH-resistant clinical M.tb isolate (INHres). Macrophages derived from peripheral blood were infected with INHres and treated or not treated with INH. Apoptosis was measured using an Ag-capture ELISA for histone and fragmented DNA. Production of TNF-alpha by INHres infected was assayed using ELISA and viability of intracellular M.tb was determined using bacterial culture of macrophage lysates on Lowenstein-Jensen (LJ) medium. INH pre-treatment to INHres reduced macrophages apoptosis, production of TNF-alpha and intracellular INHres viability. This study indicated that INH affected TNF-alpha release resulting in reduction of the extent macrophages apoptosis and of intracellular INH-resistant M.tb viability.

  3. Macrophages in homeostatic immune function.

    PubMed

    Jantsch, Jonathan; Binger, Katrina J; Müller, Dominik N; Titze, Jens

    2014-01-01

    Macrophages are not only involved in inflammatory and anti-infective processes, but also play an important role in maintaining tissue homeostasis. In this review, we summarize recent evidence investigating the role of macrophages in controlling angiogenesis, metabolism as well as salt and water balance. Particularly, we summarize the importance of macrophage tonicity enhancer binding protein (TonEBP, also termed nuclear factor of activated T-cells 5 [NFAT5]) expression in the regulation of salt and water homeostasis. Further understanding of homeostatic macrophage function may lead to new therapeutic approaches to treat ischemia, hypertension and metabolic disorders. PMID:24847274

  4. Macrophages in homeostatic immune function

    PubMed Central

    Jantsch, Jonathan; Binger, Katrina J.; Müller, Dominik N.; Titze, Jens

    2014-01-01

    Macrophages are not only involved in inflammatory and anti-infective processes, but also play an important role in maintaining tissue homeostasis. In this review, we summarize recent evidence investigating the role of macrophages in controlling angiogenesis, metabolism as well as salt and water balance. Particularly, we summarize the importance of macrophage tonicity enhancer binding protein (TonEBP, also termed nuclear factor of activated T-cells 5 [NFAT5]) expression in the regulation of salt and water homeostasis. Further understanding of homeostatic macrophage function may lead to new therapeutic approaches to treat ischemia, hypertension and metabolic disorders. PMID:24847274

  5. SIRT1 Suppresses Activator Protein-1 Transcriptional Activity and Cyclooxygenase-2 Expression in Macrophages*

    PubMed Central

    Zhang, Ran; Chen, Hou-Zao; Liu, Jin-Jing; Jia, Yu-Yan; Zhang, Zhu-Qin; Yang, Rui-Feng; Zhang, Yuan; Xu, Jing; Wei, Yu-Sheng; Liu, De-Pei; Liang, Chih-Chuan

    2010-01-01

    SIRT1 (Sirtuin type 1), a mammalian orthologue of yeast SIR2 (silent information regulator 2), has been shown to mediate a variety of calorie restriction (CR)-induced physiological events, such as cell fate regulation via deacetylation of the substrate proteins. However, whether SIRT1 deacetylates activator protein-1 (AP-1) to influence its transcriptional activity and target gene expression is still unknown. Here we demonstrate that SIRT1 directly interacts with the basic leucine zipper domains of c-Fos and c-Jun, the major components of AP-1, by which SIRT1 suppressed the transcriptional activity of AP-1. This process requires the deacetylase activity of SIRT1. Notably, SIRT1 reduced the expression of COX-2, a typical AP-1 target gene, and decreased prostaglandin E2 (PGE2) production of peritoneal macrophages (pMΦs). pMΦs with SIRT1 overexpression displayed improved phagocytosis and tumoricidal functions, which are associated with depressed PGE2. Furthermore, SIRT1 protein level was up-regulated in CR mouse pMΦs, whereas elevated SIRT1 decreased COX-2 expression and improved PGE2-related macrophage functions that were reversed following inhibition of SIRT1 deacetylase activity. Thus, our results indicate that SIRT1 may be a mediator of CR-induced macrophage regulation, and its deacetylase activity contributes to the inhibition of AP-1 transcriptional activity and COX-2 expression leading to amelioration of macrophage function. PMID:20042607

  6. Activated prostaglandin D2 receptors on macrophages enhance neutrophil recruitment into the lung

    PubMed Central

    Jandl, Katharina; Stacher, Elvira; Bálint, Zoltán; Sturm, Eva Maria; Maric, Jovana; Peinhaupt, Miriam; Luschnig, Petra; Aringer, Ida; Fauland, Alexander; Konya, Viktoria; Dahlen, Sven-Erik; Wheelock, Craig E.; Kratky, Dagmar; Olschewski, Andrea; Marsche, Gunther; Schuligoi, Rufina; Heinemann, Akos

    2016-01-01

    Background Prostaglandin (PG) D2 is an early-phase mediator in inflammation, but its action and the roles of the 2 D-type prostanoid receptors (DPs) DP1 and DP2 (also called chemoattractant receptor–homologous molecule expressed on TH2 cells) in regulating macrophages have not been elucidated to date. Objective We investigated the role of PGD2 receptors on primary human macrophages, as well as primary murine lung macrophages, and their ability to influence neutrophil action in vitro and in vivo. Methods In vitro studies, including migration, Ca2+ flux, and cytokine secretion, were conducted with primary human monocyte-derived macrophages and neutrophils and freshly isolated murine alveolar and pulmonary interstitial macrophages. In vivo pulmonary inflammation was assessed in male BALB/c mice. Results Activation of DP1, DP2, or both receptors on human macrophages induced strong intracellular Ca2+ flux, cytokine release, and migration of macrophages. In a murine model of LPS-induced pulmonary inflammation, activation of each PGD2 receptor resulted in aggravated airway neutrophilia, tissue myeloperoxidase activity, cytokine contents, and decreased lung compliance. Selective depletion of alveolar macrophages abolished the PGD2-enhanced inflammatory response. Activation of PGD2 receptors on human macrophages enhanced the migratory capacity and prolonged the survival of neutrophils in vitro. In human lung tissue specimens both DP1 and DP2 receptors were located on alveolar macrophages along with hematopoietic PGD synthase, the rate-limiting enzyme of PGD2 synthesis. Conclusion For the first time, our results show that PGD2 markedly augments disease activity through its ability to enhance the proinflammatory actions of macrophages and subsequent neutrophil activation. PMID:26792210

  7. Macrophage Infiltration and Alternative Activation during Wound Healing Promote MEK1-Induced Skin Carcinogenesis.

    PubMed

    Weber, Christine; Telerman, Stephanie B; Reimer, Andreas S; Sequeira, Ines; Liakath-Ali, Kifayathullah; Arwert, Esther N; Watt, Fiona M

    2016-02-15

    Macrophages are essential for the progression and maintenance of many cancers, but their role during the earliest stages of tumor formation is unclear. To test this, we used a previously described transgenic mouse model of wound-induced skin tumorigenesis, in which expression of constitutively active MEK1 in differentiating epidermal cells results in chronic inflammation (InvEE mice). Upon wounding, the number of epidermal and dermal monocytes and macrophages increased in wild-type and InvEE skin, but the increase was greater, more rapid, and more sustained in InvEE skin. Macrophage ablation reduced tumor incidence. Furthermore, bioluminescent imaging in live mice to monitor macrophage flux at wound sites revealed that macrophage accumulation was predictive of tumor formation; wounds with the greatest number of macrophages at day 5 went on to develop tumors. Gene expression profiling of flow-sorted monocytes, macrophages, and T cells from InvEE and wild-type skin showed that as wound healing progressed, InvEE macrophages altered their phenotype. Throughout wound healing and after wound closure, InvEE macrophages demonstrated sustained upregulation of several markers implicated in alternative macrophage activation including arginase-1 (ARG1) and mannose receptor (CD206). Notably, inhibition of ARG1 activity significantly reduced tumor formation and epidermal proliferation in vivo, whereas addition of L-arginase to cultured keratinocytes stimulated proliferation. We conclude that macrophages play a key role in early, inflammation-mediated skin tumorigenesis, with mechanistic evidence suggesting that ARG1 secretion drives tumor development by stimulating epidermal cell proliferation. These findings highlight the importance of cancer immunotherapies aiming to polarize tumor-associated macrophages toward an antitumor phenotype. PMID:26754935

  8. Hypoxia inhibits Moloney murine leukemia virus expression in activated macrophages.

    PubMed

    Puppo, Maura; Bosco, Maria Carla; Federico, Maurizio; Pastorino, Sandra; Varesio, Luigi

    2007-02-01

    Hypoxia, a local decrease in oxygen tension, occurring in many pathological processes, modifies macrophage (Mphi) gene expression and function. Here, we provide the first evidence that hypoxia inhibits transgene expression driven by the Moloney murine leukemia virus-long terminal repeats (MoMLV-LTR) in IFN-gamma-activated Mphi. Hypoxia silenced the expression of several MoMLV-LTR-driven genes, including v-myc, enhanced green fluorescence protein, and env, and was effective in different mouse Mphi cell lines and on distinct MoMLV backbone-based viruses. Down-regulation of MoMLV mRNA occurred at the transcriptional level and was associated with decreased retrovirus production, as determined by titration experiments, suggesting that hypoxia may control MoMLV retroviral spread through the suppression of LTR activity. In contrast, genes driven by the CMV or the SV40 promoter were up-regulated or unchanged by hypoxia, indicating a selective inhibitory activity on the MoMLV promoter. It is interesting that hypoxia was ineffective in suppressing MoMLV-LTR-controlled gene expression in T or fibroblast cell lines, suggesting a Mphi lineage-selective action. Finally, we found that MoMLV-mediated gene expression in Mphi was also inhibited by picolinic acid, a tryptophan catabolite with hypoxia-like activity and Mphi-activating properties, suggesting a pathophysiological role of this molecule in viral resistance and its possible use as an antiviral agent.

  9. Cyclooxygenase-2 Generates the Endogenous Mutagen trans-4-Hydroxy-2-nonenal in Enterococcus faecalis-infected Macrophages

    PubMed Central

    Wang, Xingmin; Allen, Toby D.; Yang, Yonghong; Moore, Danny R.; Huycke, Mark M.

    2013-01-01

    Infection of macrophages by the human intestinal commensal Enterococcus faecalis generates DNA damage and chromosomal instability in mammalian cells through bystander effects. These effects are characterized by clastogenesis and damage to mitotic spindles in target cells and are mediated, in part, by trans-4-hydroxy-2-nonenal (4-HNE). In this study we investigated the role of cyclooxygenase (COX) and lipoxygenase (LOX) in producing this reactive aldehyde using E. faecalis-infected macrophages and interleukin-10 knockout mice colonized with this commensal. 4-HNE production by E. faecalis-infected macrophages was significantly reduced by COX and LOX inhibitors. The infection of macrophages led to decreased Cox1 and Alox5 expression while COX-2 and 4-HNE increased. Silencing Alox5 and Cox1 with gene-specific siRNAs had no effect on 4-HNE production. In contrast, silencing Cox2 significantly decreased 4-HNE production by E. faecalis-infected macrophages. Depleting intracellular glutathione increased 4-HNE production by these cells. Next, to confirm COX-2 as a source for 4-HNE, we assayed the products generated by recombinant human COX-2 and found 4-HNE in a concentration-dependent manner using arachidonic acid as a substrate. Finally, tissue macrophages in colon biopsies from interleukin-10 knockout mice colonized with E. faecalis were positive for COX-2 by immunohistochemical staining. This was associated with increased staining for 4-HNE-protein adducts in surrounding stroma. These data show that E. faecalis, a human intestinal commensal, can trigger macrophages to produce 4-HNE through COX-2. Importantly, it reinforces the concept of COX-2 as a procarcinogenic enzyme capable of damaging DNA in target cells through bystander effects that contribute to colorectal carcinogenesis. PMID:23321929

  10. The Effect of Aqueous Garlic Extract on Interleukin-12 and 10 Levels in Leishmania major (MRHO/IR/75/ER) Infected Macrophages

    PubMed Central

    Gharavi, MJ; Nobakht, M; Khademvatan, S; Fani, F; Bakhshayesh, M; Roozbehani, M

    2011-01-01

    Background The aim of the present study was to investigate the immunomodulation effects of aqueous garlic extract (AGE) in the cultured macrophages infected by Leishmania major. Methods: After J774 macrophages proliferation in RPMI1640 and incubation with Leishmania for 72 hours, AGE was added in doses of 9.25, 18.5, 37, 74 and 148 mg/ml for 18, 24 and 48 hours and cell culture supernatants were harvested. The Leishmania infected J774 cells to assess the cell viability was examined using trypan blue and methylthiazol tetrazolium assay (MTT). An enzyme-linked immunosorbent assay (ELISA) was performed on cell culture supernatants for measurement of interleukin IL-10 and IL-12. Results: Dose of 37 mg/ml for 48 hours of garlic extract was the most potent dose for activation of amastigotes infected macrophages. In addition, AGE increased the level of IL-12 in Leishmania infected cell lines significantly. Conclusions: AGE treated cell is effective against parasitic pathogens, and AGE induced IL-12 differentially affected the immune response to invading Leishmania parasites. PMID:23113109

  11. Macrophage activation of allogeneic lymphocyte proliferation in the guinea pig mixed leukocyte culture.

    PubMed

    Greineder, D K; Rosenthal, A S

    1975-05-01

    The role of the macrophage in the guinea pig mixed leukocyte culture was investigated. Macrophages obtained from oil-induced peritoneal exudates, peritoneal wash-out cells, spleen, and alveolar washings were found to be effective stimulators of allogeneic lymph node and splenic lymphocyte DNA synthesis. The stimulatory properties of macrophages proved radioresistant but viability dependent. Unfractionated lymph node cells or adherence column purified lymph node lymphocytes and thymocytes were only minimally active as stimulators, even in the presence of macrophages syngeneic to the responder lymphocytes. Allogeneic fibroblasts, polymorphonuclear leukocytes, L2C leukemia cells, and xenogeneic (murine) macrophages failed to simulate. These data provide evidence that the macrophage is the predominant stimulator of the mixed leukocyte culture in the guinea pig.

  12. Ozone-enhanced pulmonary infection with Streptococcus zooepidemicus in mice. The role of alveolar macrophage function and capsular virulence factors

    SciTech Connect

    Gilmour, M.I.; Park, P.; Selgrade, M.K. )

    1993-03-01

    Ozone exposure has been shown to increase the susceptibility of mice to pulmonary bacterial infection. We report here the differences in susceptibility of two strains of mice (C3H/HeJ and C57Bl/6) to pulmonary challenge with Streptococcus zooepidemicus, and demonstrate an association between O3 exposure, reduced alveolar macrophage (AM) function, and increased mortality to infection. After a 3-h exposure to air or to 0.4 or 0.8 ppm O3, mice received an infection of bacteria by aerosol. Subsequent mortality observed over a 20-day period for any given exposure concentration was greater in the C3H/HeJ mice than in the C57Bl/6 mice. Phagocytosis assays identified the AM from O3-exposed lungs as having an impaired ability to engulf the bacteria. Baseline phagocytic activity in C3H/HeJ mice was lower than that in C57Bl/6 mice. Microbiologic assessment of the lungs at various times after infection revealed that the streptococci proliferated rapidly in the lungs of O3-exposed mice, grew more quickly upon isolation, and displayed a mucoid colony appearance indicative of increased encapsulation. In vitro assays confirmed that the encapsulated isolates prevented binding of the bacteria to AM, and reinfection of nonexposed mice with the encapsulated isolate resulted in increased mortality compared with infection with similar numbers of the original unencapsulated bacteria. We have demonstrated that O3 inhalation impairs AM activity in the lung. The streptococci are then able to proliferate and more fully express virulence factors, in particular, the antiphagocytic capsule, which prohibits the ingestion of bacteria by pulmonary phagocytes and leads to increased severity of infection.

  13. Macrophages Contribute to the Cyclic Activation of Adult Hair Follicle Stem Cells

    PubMed Central

    Castellana, Donatello; Paus, Ralf; Perez-Moreno, Mirna

    2014-01-01

    Skin epithelial stem cells operate within a complex signaling milieu that orchestrates their lifetime regenerative properties. The question of whether and how immune cells impact on these stem cells within their niche is not well understood. Here we show that skin-resident macrophages decrease in number because of apoptosis before the onset of epithelial hair follicle stem cell activation during the murine hair cycle. This process is linked to distinct gene expression, including Wnt transcription. Interestingly, by mimicking this event through the selective induction of macrophage apoptosis in early telogen, we identify a novel involvement of macrophages in stem cell activation in vivo. Importantly, the macrophage-specific pharmacological inhibition of Wnt production delays hair follicle growth. Thus, perifollicular macrophages contribute to the activation of skin epithelial stem cells as a novel, additional cue that regulates their regenerative activity. This finding may have translational implications for skin repair, inflammatory skin diseases and cancer. PMID:25536657

  14. Cell Motility Is Decreased in Macrophages Activated by Cancer Cell-Conditioned Medium

    PubMed Central

    Go, Ahreum; Ryu, Yun-Kyoung; Lee, Jae-Wook; Moon, Eun-Yi

    2013-01-01

    Macrophages play a role in innate immune responses to various foreign antigens. Many products from primary tumors influence the activation and transmigration of macrophages. Here, we investigated a migration of macrophages stimulated with cancer cell culture-conditioned medium (CM). Macrophage activation by treatment with CM of B16F10 cells were judged by the increase in protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). The location where macrophages were at 4 h-incubation with control medium or CM was different from where they were at 5 h-incubation in culture dish. Percentage of superimposed macrophages at every 1 h interval was gradually increased by CM treatment as compared to control. Total coverage of migrated track expressed in coordinates was smaller and total distance of migration was shorter in CM-treated macrophages than that in control. Rac1 activity in CM-treated macrophages was also decreased as compared to that in control. When macrophages were treated with CM in the presence of dexamethasone (Dex), an increase in COX2 protein levels, and a decrease in Rac1 activity and total coverage of migration were reversed. In the meanwhile, biphasic changes were detected by Dex treatment in section distance of migration at each time interval, which was more decreased at early time and then increased at later time. Taken together, data demonstrate that macrophage motility could be reduced in accordance with activation in response to cancer cell products. It suggests that macrophage motility could be a novel marker to monitor cancer-associated inflammatory diseases and the efficacy of anti-inflammatory agents. PMID:24404340