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Sample records for immune cells macrophages

  1. Metabolic reprogramming in macrophages and dendritic cells in innate immunity

    PubMed Central

    Kelly, Beth; O'Neill, Luke AJ

    2015-01-01

    Activation of macrophages and dendritic cells (DCs) by pro-inflammatory stimuli causes them to undergo a metabolic switch towards glycolysis and away from oxidative phosphorylation (OXPHOS), similar to the Warburg effect in tumors. However, it is only recently that the mechanisms responsible for this metabolic reprogramming have been elucidated in more detail. The transcription factor hypoxia-inducible factor-1α (HIF-1α) plays an important role under conditions of both hypoxia and normoxia. The withdrawal of citrate from the tricarboxylic acid (TCA) cycle has been shown to be critical for lipid biosynthesis in both macrophages and DCs. Interference with this process actually abolishes the ability of DCs to activate T cells. Another TCA cycle intermediate, succinate, activates HIF-1α and promotes inflammatory gene expression. These new insights are providing us with a deeper understanding of the role of metabolic reprogramming in innate immunity. PMID:26045163

  2. Polymicrobial Sepsis Enhances Clearance of Apoptotic Immune Cells by Splenic Macrophages

    PubMed Central

    Swan, Ryan; Chung, Chun-Shiang; Albina, Jorge; Cioffi, William; Perl, Mario; Ayala, Alfred

    2007-01-01

    Background Macrophage phagocytosis of apoptotic cells induces an anti-inflammatory macrophage phenotype. Immune cell apoptosis is widespread in sepsis; however, it is unknown whether sepsis alters the capacity of macrophages to clear this expanded population. We hypothesize that sepsis will enhance splenic macrophage phagocytosis of apoptotic immune cells, potentially contributing to immunosuppression. Methods Sepsis was induced in C57BL/6J mice by cecal ligation and puncture (CLP). Apoptosis was induced in mouse thymocytes by dexamethasone incubation. At multiple time points following CLP/sham, splenic and peritoneal macrophages were isolated, plated on glass coverslips, co-incubated with apoptotic thymocytes, fixed, and the coverslips were then Giemsa stained. Splenic macrophages were also isolated 48 hours after CLP/sham, stained with the red fluorescent dye PKH26, co-incubated with green fluorescent dye CFSE-stained apoptotic thymocytes and then coverslips were fixed and counterstained with DAPI. The macrophage phagocytic index (PI) was calculated for both staining methods. Results The PI of CLP splenic macrophages was significantly higher than sham by 24 hours, and this difference was sustained through 48 hours. Conclusions Studies suggest that apoptotic cell clearance leads to an anti-inflammatory macrophage condition, which together with our findings in septic macrophages, may point at a process that contributes to septic immune suppression. PMID:17689693

  3. Phenotypic and functional plasticity of cells of innate immunity: macrophages, mast cells and neutrophils

    PubMed Central

    Galli, Stephen J; Borregaard, Niels; Wynn, Thomas A

    2012-01-01

    Hematopoietic cells, including lymphoid and myeloid cells, can develop into phenotypically distinct subpopulations with different functions. However, evidence indicates that some of these subpopulations can manifest substantial plasticity (that is, undergo changes in their phenotype and function). Here we focus on the occurrence of phenotypically distinct subpopulations in three lineages of myeloid cells with important roles in innate and acquired immunity: macrophages, mast cells and neutrophils. Cytokine signals, epigenetic modifications and other microenvironmental factors can substantially and, in some cases, rapidly and reversibly alter the phenotype of these cells and influence their function. This suggests that regulation of the phenotype and function of differentiated hematopoietic cells by microenvironmental factors, including those generated during immune responses, represents a common mechanism for modulating innate or adaptive immunity. PMID:22012443

  4. Glioblastoma-infiltrated innate immune cells resemble M0 macrophage phenotype

    PubMed Central

    Gabrusiewicz, Konrad; Rodriguez, Benjamin; Wei, Jun; Hashimoto, Yuuri; Healy, Luke M.; Maiti, Sourindra N.; Thomas, Ginu; Zhou, Shouhao; Wang, Qianghu; Elakkad, Ahmed; Liebelt, Brandon D.; Yaghi, Nasser K.; Ezhilarasan, Ravesanker; Huang, Neal; Weinberg, Jeffrey S.; Prabhu, Sujit S.; Rao, Ganesh; Sawaya, Raymond; Langford, Lauren A.; Bruner, Janet M.; Fuller, Gregory N.; Bar-Or, Amit; Li, Wei; Colen, Rivka R.; Curran, Michael A.; Bhat, Krishna P.; Antel, Jack P.; Cooper, Laurence J.; Sulman, Erik P.; Heimberger, Amy B.

    2016-01-01

    Glioblastomas are highly infiltrated by diverse immune cells, including microglia, macrophages, and myeloid-derived suppressor cells (MDSCs). Understanding the mechanisms by which glioblastoma-associated myeloid cells (GAMs) undergo metamorphosis into tumor-supportive cells, characterizing the heterogeneity of immune cell phenotypes within glioblastoma subtypes, and discovering new targets can help the design of new efficient immunotherapies. In this study, we performed a comprehensive battery of immune phenotyping, whole-genome microarray analysis, and microRNA expression profiling of GAMs with matched blood monocytes, healthy donor monocytes, normal brain microglia, nonpolarized M0 macrophages, and polarized M1, M2a, M2c macrophages. Glioblastoma patients had an elevated number of monocytes relative to healthy donors. Among CD11b+ cells, microglia and MDSCs constituted a higher percentage of GAMs than did macrophages. GAM profiling using flow cytometry studies revealed a continuum between the M1- and M2-like phenotype. Contrary to current dogma, GAMs exhibited distinct immunological functions, with the former aligned close to nonpolarized M0 macrophages. PMID:26973881

  5. Monocytes and Macrophages Regulate Immunity through Dynamic Networks of Survival and Cell Death

    PubMed Central

    Parihar, Arti; Eubank, Timothy D.; Doseff, Andrea I.

    2010-01-01

    Monocytes and macrophages are central cells of the innate immune system, responsible for defending against diverse pathogens. While they originate from a common myeloid precursor and share functions in innate immunity, each has a very distinct life span finely tuned by the apoptotic caspases. Normally, circulating monocytes are short-lived and undergo spontaneous apoptosis on a daily basis. Macrophages, however, have a longer life span. In chronic inflammatory diseases and, as recently recognized, in the tumor microenvironment, the inhibition of the apoptotic program promotes monocyte survival contributing to the accumulation of macrophages and the persistence of an inflammatory milieu. A complex network of differentiation factors and inflammatory stimuli determine monocyte/macrophage life span by blocking the apoptotic pathway and activating a myriad of survival pathways. Our understanding of apoptosis has flourished over the last decade, and its relevance in the regulation of the immune system is now indisputable. Nevertheless, how the complicated networks of survival and apoptotic regulators are integrated to determine cellular life span remains elusive. This review summarizes the contribution of the caspases and their regulators in monocyte/macrophage cell fate and discusses how these molecules orchestrate the initiation, maintenance, and resolution of inflammation. More provocatively, we discuss possible strategies to control inflammation by manipulating leukocyte life span. PMID:20375558

  6. MicroRNA-33-dependent regulation of macrophage metabolism directs immune cell polarization in atherosclerosis.

    PubMed

    Ouimet, Mireille; Ediriweera, Hasini N; Gundra, U Mahesh; Sheedy, Frederick J; Ramkhelawon, Bhama; Hutchison, Susan B; Rinehold, Kaitlyn; van Solingen, Coen; Fullerton, Morgan D; Cecchini, Katharine; Rayner, Katey J; Steinberg, Gregory R; Zamore, Phillip D; Fisher, Edward A; Loke, P'ng; Moore, Kathryn J

    2015-12-01

    Cellular metabolism is increasingly recognized as a controller of immune cell fate and function. MicroRNA-33 (miR-33) regulates cellular lipid metabolism and represses genes involved in cholesterol efflux, HDL biogenesis, and fatty acid oxidation. Here, we determined that miR-33-mediated disruption of the balance of aerobic glycolysis and mitochondrial oxidative phosphorylation instructs macrophage inflammatory polarization and shapes innate and adaptive immune responses. Macrophage-specific Mir33 deletion increased oxidative respiration, enhanced spare respiratory capacity, and induced an M2 macrophage polarization-associated gene profile. Furthermore, miR-33-mediated M2 polarization required miR-33 targeting of the energy sensor AMP-activated protein kinase (AMPK), but not cholesterol efflux. Notably, miR-33 inhibition increased macrophage expression of the retinoic acid-producing enzyme aldehyde dehydrogenase family 1, subfamily A2 (ALDH1A2) and retinal dehydrogenase activity both in vitro and in a mouse model. Consistent with the ability of retinoic acid to foster inducible Tregs, miR-33-depleted macrophages had an enhanced capacity to induce forkhead box P3 (FOXP3) expression in naive CD4(+) T cells. Finally, treatment of hypercholesterolemic mice with miR-33 inhibitors for 8 weeks resulted in accumulation of inflammation-suppressing M2 macrophages and FOXP3(+) Tregs in plaques and reduced atherosclerosis progression. Collectively, these results reveal that miR-33 regulates macrophage inflammation and demonstrate that miR-33 antagonism is atheroprotective, in part, by reducing plaque inflammation by promoting M2 macrophage polarization and Treg induction. PMID:26517695

  7. Macrophages and immune cells in atherosclerosis: recent advances and novel concepts.

    PubMed

    Cochain, Clment; Zernecke, Alma

    2015-01-01

    Atherosclerotic lesion-related thrombosis is the major cause of myocardial infarction and stroke, which together constitute the leading cause of mortality worldwide. The inflammatory response is considered as a predominant driving force in atherosclerotic plaque formation, growth and progression towards instability and rupture. Notably, accumulation of macrophages in the intima and emergence of a pro-inflammatory milieu are a characteristic feature of plaque progression, and these processes can be modulated by adaptive immune responses. Recently, novel evidences of onsite proliferation of macrophages in lesions and transdifferentiation of smooth muscle cells to macrophages have challenged the prevalent paradigm that macrophage accumulation mostly relies on recruitment of circulating monocytes to plaques. Furthermore, previously unrecognized roles of inflammatory cell subsets such as plasmacytoid dendritic cells, innate response activator B cells or CD8(+) T cells in atherosclerosis have emerged, as well as novel mechanisms by which regulatory T cells or natural killer T cells contribute to lesion formation. Here, we review and discuss these recent advances in our understanding of inflammatory processes in atherosclerosis. PMID:25947006

  8. Marginal zone macrophages suppress innate and adaptive immunity to apoptotic cells in the spleen.

    PubMed

    McGaha, Tracy L; Chen, Yunying; Ravishankar, Buvana; van Rooijen, Nico; Karlsson, Mikael C I

    2011-05-19

    Marginal zone macrophages (MZMs) are a small subset of specialized splenic macrophages known to interact with apoptotic material entering the spleen from circulation. To evaluate whether MZMs regulate immunity to apoptotic material we depleted MZMs and assessed innate and adaptive immune responses to apoptotic cells administered systemically. MZM depletion altered the spatial localization of apoptotic cells, which accumulated in T-cell areas of the lymphoid follicles. MZM depletion also enhanced phagocytosis of apoptotic cells by red pulp (CD68(+)F4/80(+)) macrophages, which expressed increased CD86, MHCII, and CCR7. MZM depletion led to increased production of proinflammatory cytokines and enhanced lymphocyte responsiveness to apoptotic cell antigens. Furthermore, we found that MZM depletion accelerated autoimmune disease progression in mice genetically prone to systemic lupus erythematosus and caused significant mortality in wild-type mice repeatedly exposed to exogenous apoptotic thymocytes. These findings support the hypothesis that MZMs are central in the clearance of apoptotic cells to minimize the immunogenicity of autoantigens. PMID:21444914

  9. Presence of a macrophage-mediated suppressor cell mechanism during cell-mediated immune response in experimental visceral leishmaniasis.

    PubMed Central

    Murray, H W; Carriero, S M; Donelly, D M

    1986-01-01

    In susceptible BALB/c mice, systemic intracellular infection with Leishmania donovani provokes generation of adherent spleen cells which can suppress both mitogen- and specific-antigen-stimulated T-cell responses. To characterize the responsible suppressor cell, we irradiated (2,000 R) adherent spleen cells from L. donovani-infected mice or treated them with anti-Thy-1.2 antibody plus complement. Neither anti-T-cell treatment diminished the capacity to inhibit lymphocyte proliferative activity. In addition, as judged by morphologic and functional criteria, 80 to 90% of the adherent cells appeared to be macrophages. Four observations suggested an immunopathogenic role for these suppressor macrophages. (i) Their appearance and disappearance paralleled the establishment and resolution of L. donovani visceral infection in vivo. (ii) Suppressive effects included inhibition of production of the macrophage-activating lymphokine gamma interferon (IFN-gamma). (iii) On transfer into immune mice, suppressor macrophages impaired naturally acquired resistance to L. donovani. (iv) Inhibition of macrophage prostaglandin metabolism by indomethacin reduced suppressor activity in vitro and resulted in a 50% decrease in parasite visceral replication in vivo. In addition, prophylactic cyclophosphamide treatment inhibited the development of suppressor macrophages, and under these conditions visceral infection was rapidly controlled. These results suggested that disseminated L. donovani infection provokes a macrophage-mediated suppressor mechanism which appears to contribute to establishment of visceral leishmaniasis in a susceptible host. PMID:2945788

  10. 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

  11. The Mucosal Adjuvant Cyclic di-AMP Exerts Immune Stimulatory Effects on Dendritic Cells and Macrophages

    PubMed Central

    Libanova, Rimma; Lienenklaus, Stefan; Weiss, Siegfried; Guzmán, Carlos A.

    2014-01-01

    The cyclic di-nucleotide bis-(3′,5′)-cyclic dimeric adenosine monophosphate (c-di-AMP) is a candidate mucosal adjuvant with proven efficacy in preclinical models. It was shown to promote specific humoral and cellular immune responses following mucosal administration. To date, there is only fragmentary knowledge on the cellular and molecular mode of action of c-di-AMP. Here, we report on the identification of dendritic cells and macrophages as target cells of c-di-AMP. We show that c-di-AMP induces the cell surface up-regulation of T cell co-stimulatory molecules as well as the production of interferon-β. Those responses were characterized by in vitro experiments with murine and human immune cells and in vivo studies in mice. Analyses of dendritic cell subsets revealed conventional dendritic cells as principal responders to stimulation by c-di-AMP. We discuss the impact of the reported antigen presenting cell activation on the previously observed adjuvant effects of c-di-AMP in mouse immunization studies. PMID:24755640

  12. Macrophages enhance the radiosensitizing activity of lipid A: A novel role for immune cells in tumor cell radioresponse

    SciTech Connect

    Ridder, Mark de . E-mail: Mark.De.Ridder@vub.ac.be; Verovski, Valeri N.; Darville, Martine I.; Berge, Dirk L. van den; Monsaert, Christinne; Eizirik, Decio L.; Storme, Guy A.

    2004-10-01

    Purpose: This study examines whether activated macrophages may radiosensitize tumor cells through the release of proinflammatory mediators. Methods and materials: RAW 264.7 macrophages were activated by lipid A, and the conditioned medium (CM) was analyzed for the secretion of cytokines and the production of nitric oxide (NO) through inducible nitric oxide synthase (iNOS). EMT-6 tumor cells were exposed to CM and analyzed for hypoxic cell radiosensitivity. The role of nuclear factor (NF)-{kappa}B in the transcriptional activation of iNOS was examined by luciferase reporter gene assay. Results: Clinical immunomodulator lipid A, at a plasma-relevant concentration of 3 {mu}g/mL, stimulated RAW 264.7 macrophages to release NO, tumor necrosis factor (TNF)-{alpha}, and other cytokines. This in turn activated iNOS-mediated NO production in EMT-6 tumor cells and drastically enhanced their radiosensitivity. Radiosensitization was abrogated by the iNOS inhibitor aminoguanidine but not by a neutralizing anti-TNF-{alpha} antibody. The mechanism of iNOS induction was linked to NF-{kappa}B but not to JAK/STAT signaling. Interferon-{gamma} further increased the NO production by macrophages to a level that caused radiosensitization of EMT-6 cells through the bystanding effect of diffused NO. Conclusions: We demonstrate for the first time that activated macrophages may radiosensitize tumor cells through the induction of NO synthesis, which occurs in both tumor and immune cells.

  13. Macrophages and cellular immunity in Drosophila melanogaster.

    PubMed

    Gold, Katrina S; Brückner, Katja

    2015-12-01

    The invertebrate Drosophila melanogaster has been a powerful model for understanding blood cell development and immunity. Drosophila is a holometabolous insect, which transitions through a series of life stages from embryo, larva and pupa to adulthood. In spite of this, remarkable parallels exist between Drosophila and vertebrate macrophages, both in terms of development and function. More than 90% of Drosophila blood cells (hemocytes) are macrophages (plasmatocytes), making this highly tractable genetic system attractive for studying a variety of questions in macrophage biology. In vertebrates, recent findings revealed that macrophages have two independent origins: self-renewing macrophages, which reside and proliferate in local microenvironments in a variety of tissues, and macrophages of the monocyte lineage, which derive from hematopoietic stem or progenitor cells. Like vertebrates, Drosophila possesses two macrophage lineages with a conserved dual ontogeny. These parallels allow us to take advantage of the Drosophila model when investigating macrophage lineage specification, maintenance and amplification, and the induction of macrophages and their progenitors by local microenvironments and systemic cues. Beyond macrophage development, Drosophila further serves as a paradigm for understanding the mechanisms underlying macrophage function and cellular immunity in infection, tissue homeostasis and cancer, throughout development and adult life. PMID:27117654

  14. Two macrophage migration inhibitory factors regulate starfish larval immune cell chemotaxis.

    PubMed

    Furukawa, Ryohei; Tamaki, Kana; Kaneko, Hiroyuki

    2016-04-01

    Immune cell recruitment is critical step in the inflammatory response and associated diseases. However, the underlying regulatory mechanisms are poorly understood in invertebrates. Mesenchyme cells of the starfish larvae, which allowed Metchnikoff to complete his landmark experiments, are important model for analysis of immune cell migration. The present study investigated the role of macrophage migration inhibitory factor (MIF)-an evolutionarily conserved cytokine that is functionally similar to chemokines-in the larvae of the starfish Patiria (Asterina) pectinifera, which were found to possess two orthologs, ApMIF1 and ApMIF2. ApMIF1 and ApMIF2 clustered with mammalian MIF and its homolog D-dopachrome tautomerase (DDT), respectively, in the phylogenetic analysis. In contrast to the functional similarity between mammalian MIF and DDT, ApMIF1 knockdown resulted in the excessive recruitment of mesenchyme cells in vivo, whereas ApMIF2 deficiency inhibited the recruitment of these cells to foreign bodies. Mesenchyme cells migrated along a gradient of recombinant ApMIF2 in vitro, whereas recombinant ApMIF1 completely blocked ApMIF2-induced directed migration. Moreover, the expression patterns of ApMIF1 and ApMIF2 messenger RNA in bacteria-challenged mesenchyme cells were consistent with in vivo observations of cell behaviors. These results indicate that ApMIF1 and ApMIF2 act as chemotactic inhibitory and stimulatory factors, respectively, and coordinately regulate mesenchyme cell recruitment during the immune response in starfish larvae. This is the first report describing opposing functions for MIF- and DDT-like molecules. Our findings provide novel insight into the mechanisms underlying immune regulation in invertebrates. PMID:26833025

  15. MANGANESE CHLORIDE ENHANCES NATURAL CELL-MEDIATED IMMUNE EFFECTOR CELL FUNCTION: EFFECTS ON MACROPHAGES

    EPA Science Inventory

    A single intramuscular injection of MnCl2 in mice caused an increase in macrophage functional activity. Spleen cell antibody-dependent cellmediated cytotoxicity (ADCC) against both chicken erythrocytes and P815 tumor cell targets was enhanced 24 hours following a single injection...

  16. The early interaction of Leishmania with macrophages and dendritic cells and its influence on the host immune response

    PubMed Central

    Liu, Dong; Uzonna, Jude E.

    2012-01-01

    The complicated interactions between Leishmania and the host antigen-presenting cells (APCs) have fundamental effects on the final outcome of the disease. Two major APCs, macrophages and dendritic cells (DCs), play critical roles in mediating resistance and susceptibility during Leishmania infection. Macrophages are the primary resident cell for Leishmania: they phagocytose and permit parasite proliferation. However, these cells are also the major effector cells to eliminate infection. The effective clearance of parasites by macrophages depends on activation of appropriate immune response, which is usually initiated by DCs. Here, we review the early interaction of APCs with Leishmania parasites and how these interactions profoundly impact on the ensuing adaptive immune response. We also discuss how the current knowledge will allow further refinement of our understanding of the interplay between Leishmania and its hosts that leads to resistance or susceptibility. PMID:22919674

  17. Analysis of colony-stimulating factors and macrophage progenitor cells in mice immunized against Listeria monocytogenes by adoptive transfer.

    PubMed Central

    Wing, E J; Magee, D M; Barczynski, L K

    1987-01-01

    Experiments were performed to elucidate the role of colony-stimulating factors in host defenses to the intracellular pathogen Listeria monocytogenes. Mice were protected against Listeria sp. by adoptive transfer of immune spleen cells and were then challenged with listeriae intravenously. Control mice were injected with spleen cells from uninfected mice. Adoptively immunized (immune) mice had significantly fewer listeriae in spleens and livers 2 and 4 days after Listeria challenge than did control mice. During acute infection, colony-stimulating activity in serum was increased earlier (10 h) in immune mice than in controls. Concentrations of colony-stimulating activity were equal at 24 h. By 48 h, values were decreased in immune mice, but were elevated in control mice. Similar changes were noted when a specific colony-stimulating factor, macrophage colony-stimulating factor, was measured in serum by using a radioimmunoassay. The changes in serum colony-stimulating activity in mice adoptively immunized with immune spleen cells were eliminated if spleen cells were first treated with anti-Thy-1.2 monoclonal antibodies. The number of macrophage progenitor cells in bone marrow and spleen were also determined as measures of the hemopoietic potential in these organs. The number of macrophage progenitor cells in bone marrow was higher in immune animals than control animals at 1, 2, and 4 days of infection. Similarly, the number of these cells in spleens was higher during the early stages of infection in immune mice. These results indicate that both the regulation of leukocyte production and the transfer of specific cellular immunity by spleen cells are associated, and they therefore suggest that hemopoietic regulatory factors play a role in immune host defenses. PMID:2886433

  18. Cell signalling in macrophages, the principal innate immune effector cells of rheumatoid arthritis

    PubMed Central

    Drexler, Stefan K; Kong, Philip L; Wales, Jeremy; Foxwell, Brian M

    2008-01-01

    Rheumatoid arthritis is a multisystemic auto-inflammatory disease affecting up to 1% of the population and leading to the destruction of the joints. Evidence exists for the involvement of the innate as well as the adaptive immune systems in the pathology of the disease. The success of anti-tumour necrosis factor-α indicates the importance of pro-inflammatory mediators produced by innate immune cells in rheumatoid arthritis progression. Therefore, considerable efforts have been made in elucidating the signalling pathways leading to the expression of those mediators. This review will concentrate on the role of signalling pathways in innate immune cells in the context of rheumatoid arthritis. PMID:18947379

  19. Macrophages and Dendritic Cells as Actors in the Immune Reaction of Classical Hodgkin Lymphoma

    PubMed Central

    Tudor, Christiane Silke; Bruns, Heiko; Daniel, Christoph; Distel, Luitpold Valentin; Hartmann, Arndt; Gerbitz, Armin; Buettner, Maike Julia

    2014-01-01

    Background The inflammatory infiltrate plays a pivotal role in classical Hodgkin lymphoma (cHL). Here, we focussed on the role of macrophages (MΦ) and dendritic cells (DC). Methods MΦ and DC infiltration was investigated in 106 cHL specimens using immunohistochemistry and cytokine expression was analyzed in a subset by real-time PCR. Human peripheral blood-derived monocytes, DC, MΦ stimulated with GM-CSF (MΦGM-CSF, pro-inflammatory MΦ-1-model) or M-CSF (MΦM-CSF, immunomodulatory MΦ-2-model) were incubated with cHL cell line (L1236, HDLM2) supernatants (SN). DC maturation or MΦ polarization were investigated by flow cytometry. Furthermore, the impact of DC or MΦ on cHL cell proliferation was analyzed by BrdU/CFSE assay. Results In cHL tissues mature myeloid (m)DC and MΦ predominated. High numbers of CD83+ mDC and low numbers of CD163+ MΦ were associated with improved disease specific survival. In numerous cHL specimens increased levels of both pro- and anti-inflammatory cytokines and of IL13 and GM-CSF were observed compared to reactive lymphadenopathies. Maturation of DC and induction and maintenance of an immunomodulatory MΦ phenotype were promoted by SN derived from cHL cell lines. TNFα neutralization in SN resulted in a significant inhibition of mDC maturation. DC and pro-inflammatory MΦ inhibited the proliferation of cHL cells. Conclusion Adopting an immunomodulatory phenotype is a potential mechanism for how MΦ promote immune evasion in cHL. Mature DC, in contrast, might participate in antitumoral immunity. PMID:25470820

  20. Macrophage- and Neutrophil-Derived TNF-α Instructs Skin Langerhans Cells to Prime Antiviral Immune Responses

    PubMed Central

    Epaulard, Olivier; Adam, Lucille; Poux, Candice; Zurawski, Gerard; Salabert, Nina; Rosenbaum, Pierre; Dereuddre-Bosquet, Nathalie; Zurawski, Sandra; Flamar, Anne-Laure; Oh, Sangkon; Romain, Gabrielle; Chapon, Catherine; Banchereau, Jacques; Lévy, Yves; Le Grand, Roger; Martinon, Frédéric

    2014-01-01

    Dendritic cells (DCs) are major antigen presenting cells that can efficiently prime immune responses. However, the roles of skin resident Langerhans cells (LCs) in eliciting immune responses have not been fully understood. We here demonstrate for the first time that LCs in cynomolgus macaque skin are capable of inducing antiviral-specific immune responses in vivo. Targeting HIV-Gag or influenza hemagglutinin antigens to skin LCs using recombinant fusion proteins of anti-Langerin antibody and antigens resulted in the induction of the viral antigen-specific responses. We further demonstrated that such antigen-specific immune responses elicited by skin LCs were greatly enhanced by TLR ligands (TLR-Ls), polyriboinosinic polyribocytidylic acid (poly(I:C)) and R848. These enhancements were not due to the direct actions of TLR-Ls on LCs, but mainly dependent on TNF-α secreted from macrophages and neutrophils recruited to local tissues. Skin LC activation and migration out of the epidermis are associated with macrophage and neutrophil infiltration into the tissues. More importantly, blocking TNF-α abrogated the activation and migration of skin LCs. This study highlights that the cross-talk between innate immune cells in local tissues is an important component for the establishment of adaptive immunity. Understanding the importance of local immune networks will help us to design new and effective vaccines against microbial pathogens. PMID:25057007

  1. Porcine macrophage Cdelta2+ and Cdelta2- cell lines support influenza virus infection and replication and Cdelta2+ cells mount innate immune responses to influenza virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Respiratory epithelial cells are the first cells which are infected with influenza virus and these cells play a major role in influenza pathogenesis. However, many studies have shown that alveolar macrophages also play a very important role in the pathogenesis and immunity to influenza infection. Un...

  2. Vaccination with Irradiated Autologous Melanoma Cells Engineered to Secrete Human Granulocyte--Macrophage Colony-Stimulating Factor Generates Potent Antitumor Immunity in Patients with Metastatic Melanoma

    NASA Astrophysics Data System (ADS)

    Soiffer, Robert; Lynch, Thomas; Mihm, Martin; Jung, Ken; Rhuda, Catherine; Schmollinger, Jan C.; Hodi, F. Stephen; Liebster, Laura; Lam, Prudence; Mentzer, Steven; Singer, Samuel; Tanabe, Kenneth K.; Benedict Cosimi, A.; Duda, Rosemary; Sober, Arthur; Bhan, Atul; Daley, John; Neuberg, Donna; Parry, Gordon; Rokovich, Joseph; Richards, Laurie; Drayer, Jan; Berns, Anton; Clift, Shirley; Cohen, Lawrence K.; Mulligan, Richard C.; Dranoff, Glenn

    1998-10-01

    We conducted a Phase I clinical trial investigating the biologic activity of vaccination with irradiated autologous melanoma cells engineered to secrete human granulocyte--macrophage colony-stimulating factor in patients with metastatic melanoma. Immunization sites were intensely infiltrated with T lymphocytes, dendritic cells, macrophages, and eosinophils in all 21 evaluable patients. Although metastatic lesions resected before vaccination were minimally infiltrated with cells of the immune system in all patients, metastatic lesions resected after vaccination were densely infiltrated with T lymphocytes and plasma cells and showed extensive tumor destruction (at least 80%), fibrosis, and edema in 11 of 16 patients examined. Antimelanoma cytotoxic T cell and antibody responses were associated with tumor destruction. These results demonstrate that vaccination with irradiated autologous melanoma cells engineered to secrete granulocyte--macrophage colony-stimulating factor stimulates potent antitumor immunity in humans with metastatic melanoma.

  3. Immune polarization by hookworms: taking cues from T helper type 2, type 2 innate lymphoid cells and alternatively activated macrophages.

    PubMed

    Nair, Meera G; Herbert, De'Broski R

    2016-06-01

    Cellular and molecular investigation of parasitic helminth infections has greatly accelerated the understanding of type 2 immune responses. However, there remains considerable debate regarding the specific leucocytes that kill parasites and whether these mechanisms are distinct from those responsible for tissue repair. Herein, we chronicle discoveries over the past decade highlighting current paradigms in type 2 immunity with a particular emphasis upon how CD4(+) T helper type 2 cells, type 2 innate lymphoid cells and alternatively activated macrophages coordinately control helminth-induced parasitism. Primarily, this review will draw from studies of the murine nematode parasite Nippostrongylus brasiliensis, which bears important similarities to the human hookworms Ancylostoma duodenale and Necator americanus. Given that one or more hookworm species currently infect millions of individuals across the globe, we propose that vaccine and/or pharmaceutical-based cure strategies targeting these affected human populations should incorporate the conceptual advances outlined herein. PMID:26928141

  4. Streptococcus uberis strains isolated from the bovine mammary gland evade immune recognition by mammary epithelial cells, but not of macrophages.

    PubMed

    Günther, Juliane; Czabanska, Anna; Bauer, Isabel; Leigh, James A; Holst, Otto; Seyfert, Hans-Martin

    2016-01-01

    Streptococcus uberis is frequently isolated from the mammary gland of dairy cattle. Infection with some strains can induce mild subclinical inflammation whilst others induce severe inflammation and clinical mastitis. We compared here the inflammatory response of primary cultures of bovine mammary epithelial cells (pbMEC) towards S. uberis strains collected from clinical or subclinical cases (seven strains each) of mastitis with the strong response elicited by Escherichia coli. Neither heat inactivated nor live S. uberis induced the expression of 10 key immune genes (including TNF, IL1B, IL6). The widely used virulent strain 0140J and the avirulent strain, EF20 elicited similar responses; as did mutants defective in capsule (hasA) or biofilm formation (sub0538 and sub0539). Streptococcus uberis failed to activate NF-κB in pbMEC or TLR2 in HEK293 cells, indicating that S. uberis particles did not induce any TLR-signaling in MEC. However, preparations of lipoteichoic acid (LTA) from two strains strongly induced immune gene expression and activated NF-κB in pbMEC, without the involvement of TLR2. The immune-stimulatory LTA must be arranged in the intact S. uberis such that it is unrecognizable by the relevant pathogen receptors of the MEC. The absence of immune recognition is specific for MEC, since the same S. uberis preparations strongly induced immune gene expression and NF-κB activity in the murine macrophage model cell RAW264.7. Hence, the sluggish immune response of MEC and not of professional immune cells to this pathogen may aid establishment of the often encountered belated and subclinical phenotype of S. uberis mastitis. PMID:26738804

  5. Lewis Lung Cancer Cells Promote SIGNR1(CD209b)-Mediated Macrophages Polarization Induced by IL-4 to Facilitate Immune Evasion.

    PubMed

    Yan, Xiaolong; Li, Wenhai; Pan, Lei; Fu, Enqing; Xie, Yonghong; Chen, Min; Mu, Deguang

    2016-05-01

    Tumor-associated macrophages are a prominent component of lung cancer and contribute to tumor progression by facilitating the immune evasion of cancer cells. DC-SIGN (CD209) assists in the immune evasion of a broad spectrum of pathogens and neoplasms by inhibiting the maturation of DCs and subsequent cytokines production. However, the expression of DC-SIGN in macrophages and its role in mediating immune evasion in lung cancer and the underlying mechanism remain unclear. Our study aimed to identify the immunosuppressive role of SIGNR1 in murine macrophage differentiation and lung cancer progression. We found that SIGNR1-positive RAW264.7 macrophages were enriched in mixed cultures with Lewis lung cancer cells (LLC) (ratio of RAW 264.7 to LLC being 1:1) after stimulation with IL-4. Moreover, LLC-educated macrophages exhibited significantly higher levels of IL-10 but lower IL-12 in response to IL-4 treatment as determined by RT-PCR and ELISA. However, inhibition of SIGNR1 markedly hampered the production of IL-10, indicating that SIGNR1 was indispensable for IL-4+LLC induced macrophage polarization towards the M2 subtype. Furthermore, polarized M2 cells immersed in a tumor microenvironment promoted the migration of LLCs, as measured by transwell assays, but migration was suppressed after blockade of SIGNR1 using CD209b antibody. In addition, IL-4+LLC-educated macrophages reduced the proliferation of the activated T cells and reduced IFN-γ-mediated Th1 response in T cells, while SIGNR1 inhibition rescued Th1 cell functions. In conclusion, murine SIGNR1 expressed in LLC-educated macrophages appears to mediate IL-4-induced RAW264.7 macrophage polarization and thus facilitate lung cancer evasion. J. Cell. Biochem. 117: 1158-1166, 2016. © 2015 Wiley Periodicals, Inc. PMID:26447454

  6. Macrophages Subvert Adaptive Immunity to Urinary Tract Infection

    PubMed Central

    Mora-Bau, Gabriela; Platt, Andrew M.; van Rooijen, Nico; Randolph, Gwendalyn J.; Albert, Matthew L.; Ingersoll, Molly A.

    2015-01-01

    Urinary tract infection (UTI) is one of the most common bacterial infections with frequent recurrence being a major medical challenge. Development of effective therapies has been impeded by the lack of knowledge of events leading to adaptive immunity. Here, we establish conclusive evidence that an adaptive immune response is generated during UTI, yet this response does not establish sterilizing immunity. To investigate the underlying deficiency, we delineated the naïve bladder immune cell compartment, identifying resident macrophages as the most populous immune cell. To evaluate their impact on the establishment of adaptive immune responses following infection, we measured bacterial clearance in mice depleted of either circulating monocytes, which give rise to macrophages, or bladder resident macrophages. Surprisingly, mice depleted of resident macrophages, prior to primary infection, exhibited a nearly 2-log reduction in bacterial burden following secondary challenge compared to untreated animals. This increased bacterial clearance, in the context of a challenge infection, was dependent on lymphocytes. Macrophages were the predominant antigen presenting cell to acquire bacteria post-infection and in their absence, bacterial uptake by dendritic cells was increased almost 2-fold. These data suggest that bacterial uptake by tissue macrophages impedes development of adaptive immune responses during UTI, revealing a novel target for enhancing host responses to bacterial infection of the bladder. PMID:26182347

  7. Forward Genetics Screens Using Macrophages to Identify Toxoplasma gondii Genes Important for Resistance to IFN-γ-Dependent Cell Autonomous Immunity

    PubMed Central

    Lynch, Brian; Kim, Nathaniel; Ueda, Yukari; Vohora, Neal; Choe, Josh; Mordue, Dana G.

    2016-01-01

    Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan pathogen. The parasite invades and replicates within virtually any warm blooded vertebrate cell type. During parasite invasion of a host cell, the parasite creates a parasitophorous vacuole (PV) that originates from the host cell membrane independent of phagocytosis within which the parasite replicates. While IFN-dependentinnate and cell mediated immunity is important for eventual control of infection, innate immune cells, including neutrophils, monocytes and dendritic cells, can also serve as vehicles for systemic dissemination of the parasite early in infection. An approach is described that utilizes the host innate immune response, in this case macrophages, in a forward genetic screen to identify parasite mutants with a fitness defect in infected macrophages following activation but normal invasion and replication in naïve macrophages. Thus, the screen isolates parasite mutants that have a specific defect in their ability to resist the effects of macrophage activation. The paper describes two broad phenotypes of mutant parasites following activation of infected macrophages: parasite stasis versus parasite degradation, often in amorphous vacuoles. The parasite mutants are then analyzed to identify the responsible parasite genes specifically important for resistance to induced mediators of cell autonomous immunity. The paper presents a general approach for the forward genetics screen that, in theory, can be modified to target parasite genes important for resistance to specific antimicrobial mediators. It also describes an approach to evaluate the specific macrophage antimicrobial mediators to which the parasite mutant is susceptible. Activation of infected macrophages can also promote parasite differentiation from the tachyzoite to bradyzoite stage that maintains chronic infection. Therefore, methodology is presented to evaluate the importance of the identified parasite gene to establishment of chronic infection. PMID:25867017

  8. Forward genetics screens using macrophages to identify Toxoplasma gondii genes important for resistance to IFN-γ-dependent cell autonomous immunity.

    PubMed

    Walwyn, Odaelys; Skariah, Sini; Lynch, Brian; Kim, Nathaniel; Ueda, Yukari; Vohora, Neal; Choe, Josh; Mordue, Dana G

    2015-01-01

    Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan pathogen. The parasite invades and replicates within virtually any warm blooded vertebrate cell type. During parasite invasion of a host cell, the parasite creates a parasitophorous vacuole (PV) that originates from the host cell membrane independent of phagocytosis within which the parasite replicates. While IFN-dependent-innate and cell mediated immunity is important for eventual control of infection, innate immune cells, including neutrophils, monocytes and dendritic cells, can also serve as vehicles for systemic dissemination of the parasite early in infection. An approach is described that utilizes the host innate immune response, in this case macrophages, in a forward genetic screen to identify parasite mutants with a fitness defect in infected macrophages following activation but normal invasion and replication in naïve macrophages. Thus, the screen isolates parasite mutants that have a specific defect in their ability to resist the effects of macrophage activation. The paper describes two broad phenotypes of mutant parasites following activation of infected macrophages: parasite stasis versus parasite degradation, often in amorphous vacuoles. The parasite mutants are then analyzed to identify the responsible parasite genes specifically important for resistance to induced mediators of cell autonomous immunity. The paper presents a general approach for the forward genetics screen that, in theory, can be modified to target parasite genes important for resistance to specific antimicrobial mediators. It also describes an approach to evaluate the specific macrophage antimicrobial mediators to which the parasite mutant is susceptible. Activation of infected macrophages can also promote parasite differentiation from the tachyzoite to bradyzoite stage that maintains chronic infection. Therefore, methodology is presented to evaluate the importance of the identified parasite gene to establishment of chronic infection. PMID:25867017

  9. Cooperativity Between CD8+ T Cells, Non-Neutralizing Antibodies, and Alveolar Macrophages Is Important for Heterosubtypic Influenza Virus Immunity

    PubMed Central

    Laidlaw, Brian J.; Decman, Vilma; Ali, Mohammed-Alkhatim A.; Abt, Michael C.; Wolf, Amaya I.; Monticelli, Laurel A.; Mozdzanowska, Krystyna; Angelosanto, Jill M.; Artis, David; Erikson, Jan; Wherry, E. John

    2013-01-01

    Seasonal epidemics of influenza virus result in ∼36,000 deaths annually in the United States. Current vaccines against influenza virus elicit an antibody response specific for the envelope glycoproteins. However, high mutation rates result in the emergence of new viral serotypes, which elude neutralization by preexisting antibodies. T lymphocytes have been reported to be capable of mediating heterosubtypic protection through recognition of internal, more conserved, influenza virus proteins. Here, we demonstrate using a recombinant influenza virus expressing the LCMV GP33-41 epitope that influenza virus-specific CD8+ T cells and virus-specific non-neutralizing antibodies each are relatively ineffective at conferring heterosubtypic protective immunity alone. However, when combined virus-specific CD8 T cells and non-neutralizing antibodies cooperatively elicit robust protective immunity. This synergistic improvement in protective immunity is dependent, at least in part, on alveolar macrophages and/or other lung phagocytes. Overall, our studies suggest that an influenza vaccine capable of eliciting both CD8+ T cells and antibodies specific for highly conserved influenza proteins may be able to provide heterosubtypic protection in humans, and act as the basis for a potential “universal” vaccine. PMID:23516357

  10. Cooperativity between CD8+ T cells, non-neutralizing antibodies, and alveolar macrophages is important for heterosubtypic influenza virus immunity.

    PubMed

    Laidlaw, Brian J; Decman, Vilma; Ali, Mohammed-Alkhatim A; Abt, Michael C; Wolf, Amaya I; Monticelli, Laurel A; Mozdzanowska, Krystyna; Angelosanto, Jill M; Artis, David; Erikson, Jan; Wherry, E John

    2013-03-01

    Seasonal epidemics of influenza virus result in ∼36,000 deaths annually in the United States. Current vaccines against influenza virus elicit an antibody response specific for the envelope glycoproteins. However, high mutation rates result in the emergence of new viral serotypes, which elude neutralization by preexisting antibodies. T lymphocytes have been reported to be capable of mediating heterosubtypic protection through recognition of internal, more conserved, influenza virus proteins. Here, we demonstrate using a recombinant influenza virus expressing the LCMV GP33-41 epitope that influenza virus-specific CD8+ T cells and virus-specific non-neutralizing antibodies each are relatively ineffective at conferring heterosubtypic protective immunity alone. However, when combined virus-specific CD8 T cells and non-neutralizing antibodies cooperatively elicit robust protective immunity. This synergistic improvement in protective immunity is dependent, at least in part, on alveolar macrophages and/or other lung phagocytes. Overall, our studies suggest that an influenza vaccine capable of eliciting both CD8+ T cells and antibodies specific for highly conserved influenza proteins may be able to provide heterosubtypic protection in humans, and act as the basis for a potential "universal" vaccine. PMID:23516357

  11. Phagosomal Acidification Prevents Macrophage Inflammatory Cytokine Production to Malaria, and Dendritic Cells Are the Major Source at the Early Stages of Infection: IMPLICATION FOR MALARIA PROTECTIVE IMMUNITY DEVELOPMENT.

    PubMed

    Wu, Xianzhu; Gowda, Nagaraj M; Gowda, D Channe

    2015-09-18

    Inflammatory cytokines produced at the early stages of malaria infection contribute to shaping protective immunity and pathophysiology. To gain mechanistic insight into these processes, it is important to understand the cellular origin of cytokines because both cytokine input and cytokine-producing cells play key roles. Here, we determined cytokine responses by monocytes, macrophages, and dendritic cells (DCs) to purified Plasmodium falciparum and Plasmodium berghei ANKA, and by spleen macrophages and DCs from Plasmodium yoelii 17NXL-infected and P. berghei ANKA-infected mice. The results demonstrate that monocytes and macrophages do not produce inflammatory cytokines to malaria parasites and that DCs are the primary source early in infection, and DC subsets differentially produce cytokines. Importantly, blocking of phagosomal acidification by inhibiting vacuolar-type H(+)-ATPase enabled macrophages to elicit cytokine responses. Because cytokine responses to malaria parasites are mediated primarily through endosomal Toll-like receptors, our data indicate that the inability of macrophages to produce cytokines is due to the phagosomal acidification that disrupts endosomal ligand-receptor engagement. Macrophages efficiently produced cytokines to LPS upon simultaneously internalizing parasites and to heat-killed Escherichia coli, demonstrating that phagosomal acidification affects endosomal receptor-mediated, but not cell surface receptor-mediated, recognition of Toll-like receptor agonists. Enabling monocytes/macrophages to elicit immune responses to parasites by blocking endosomal acidification can be a novel strategy for the effective development of protective immunity to malaria. The results have important implications for enhancing the efficacy of a whole parasite-based malaria vaccine and for designing strategies for the development of protective immunity to pathogens that induce immune responses primarily through endosomal receptors. PMID:26240140

  12. Anti-G-CSF treatment induces protective tumor immunity in mouse colon cancer by promoting NK cell, macrophage and T cell responses

    PubMed Central

    Morris, Katherine T.; Castillo, Eliseo F.; Ray, Anita L.; Weston, Lea L.; Nofchissey, Robert A.; Hanson, Joshua A.; Samedi, Von G.; Pinchuk, Irina V.; Hudson, Laurie G.; Beswick, Ellen J.

    2015-01-01

    Granulocyte colony-stimulating factor (G-CSF) is a cytokine that is highly expressed in human and mouse colorectal cancers (CRC). We previously reported that G-CSF stimulated human CRC cell growth and migration, therefore in this study we sought to examine the therapeutic potential of anti-G-CSF treatment for CRC. G-CSF is known to mobilize neutrophils, however its impact on other immune cells has not been well examined. Here, we investigated the effects of therapeutic anti-G-CSF treatment on CRC growth and anti-tumor immune responses. C57BL/6 mice treated with azoxymethane/dextran sodium sulfate (AOM/DSS) to induce neoplasms were administered anti-G-CSF or isotype control antibodies three times a week for three weeks. Animals treated with anti-G-CSF antibodies had a marked decrease in neoplasm number and size compared to the isotype control group. Colon neutrophil and macrophage frequency were unchanged, but the number of macrophages producing IL-10 were decreased while IL-12 producing macrophages were increased. NK cells were substantially increased in colons of anti-G-CSF treated mice, along with IFNγ producing CD4+ and CD8+ T cells. These studies are the first to indicate a crucial role for G-CSF inhibition in promoting protective anti-tumor immunity, and suggest that anti-G-CSF treatment is a potential therapeutic approach for CRC. PMID:26061815

  13. Immunomodulatory effect of mesenchymal stem cells on the immune response of macrophages stimulated by Aspergillus fumigatus conidia.

    PubMed

    Cho, Sung-Yeon; Kwon, Eun-Young; Choi, Su-Mi; Lee, Dong-Gun; Park, Chulmin; Park, Sun Hee; Yoo, Jin-Hong; Choi, Jung-Hyun

    2016-05-01

    Mesenchymal stem cells (MSCs) are known to exert potent immunosuppression and anti-inflammatory effects. There is growing interest in their use for immunotherapy for controlling inflammation as well as acute organ injury. However, there are few reports regarding MSC's immunomodulatory effects in the settings of fungal infection. In this study, we attempted to examine the immunomodulatory effects of MSCs in response toAspergillus fumigatus We measured the cytokine response of murine MSCs on the immune response of murine macrophages (J774A.1 cells) evoked byA. fumigatusconidia. In addition, we evaluated the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the MSC-related cytokine response and fungal growth. As a results, after conidia stimulation, tumor necrosis factor (TNF)-α was down-regulated and interleukin (IL)-10 was up-regulated in MSC-treated J774A.1 cells when compared to J774A.1 cells alone. In addition, fungal growth was reduced in MSC-treated J774A.1 cells when compared to J774A.1 cells, which recovered by GM-CSF. However, the effect of MSCs on the cytokine response was not reversed by GM-CSF. NF-κB translocation decreased in MSC-treated J774A.1 cells compared to J774A.1 cells alone. In conclusion, MSCs demonstrate immunomodulatory properties in both aspects of cytokines and fungal growth. The anti-inflammatory effect of MSCs with regard to cytokine response might be associated with decreased NF-κB translocation, and is not reversed by GM-CSF. PMID:26768375

  14. Variable Processing and Cross-presentation of HIV by Dendritic Cells and Macrophages Shapes CTL Immunodominance and Immune Escape

    PubMed Central

    Dinter, Jens; Duong, Ellen; Lai, Nicole Y.; Berberich, Matthew J.; Kourjian, Georgio; Bracho-Sanchez, Edith; Chu, Duong; Su, Hang; Zhang, Shao Chong; Le Gall, Sylvie

    2015-01-01

    Dendritic cells (DCs) and macrophages (Møs) internalize and process exogenous HIV-derived antigens for cross-presentation by MHC-I to cytotoxic CD8+ T cells (CTL). However, how degradation patterns of HIV antigens in the cross-presentation pathways affect immunodominance and immune escape is poorly defined. Here, we studied the processing and cross-presentation of dominant and subdominant HIV-1 Gag-derived epitopes and HLA-restricted mutants by monocyte-derived DCs and Møs. The cross-presentation of HIV proteins by both DCs and Møs led to higher CTL responses specific for immunodominant epitopes. The low CTL responses to subdominant epitopes were increased by pretreatment of target cells with peptidase inhibitors, suggestive of higher intracellular degradation of the corresponding peptides. Using DC and Mø cell extracts as a source of cytosolic, endosomal or lysosomal proteases to degrade long HIV peptides, we identified by mass spectrometry cell-specific and compartment-specific degradation patterns, which favored the production of peptides containing immunodominant epitopes in all compartments. The intracellular stability of optimal HIV-1 epitopes prior to loading onto MHC was highly variable and sequence-dependent in all compartments, and followed CTL hierarchy with immunodominant epitopes presenting higher stability rates. Common HLA-associated mutations in a dominant epitope appearing during acute HIV infection modified the degradation patterns of long HIV peptides, reduced intracellular stability and epitope production in cross-presentation-competent cell compartments, showing that impaired epitope production in the cross-presentation pathway contributes to immune escape. These findings highlight the contribution of degradation patterns in the cross-presentation pathway to HIV immunodominance and provide the first demonstration of immune escape affecting epitope cross-presentation. PMID:25781895

  15. Variable processing and cross-presentation of HIV by dendritic cells and macrophages shapes CTL immunodominance and immune escape.

    PubMed

    Dinter, Jens; Duong, Ellen; Lai, Nicole Y; Berberich, Matthew J; Kourjian, Georgio; Bracho-Sanchez, Edith; Chu, Duong; Su, Hang; Zhang, Shao Chong; Le Gall, Sylvie

    2015-03-01

    Dendritic cells (DCs) and macrophages (Møs) internalize and process exogenous HIV-derived antigens for cross-presentation by MHC-I to cytotoxic CD8⁺ T cells (CTL). However, how degradation patterns of HIV antigens in the cross-presentation pathways affect immunodominance and immune escape is poorly defined. Here, we studied the processing and cross-presentation of dominant and subdominant HIV-1 Gag-derived epitopes and HLA-restricted mutants by monocyte-derived DCs and Møs. The cross-presentation of HIV proteins by both DCs and Møs led to higher CTL responses specific for immunodominant epitopes. The low CTL responses to subdominant epitopes were increased by pretreatment of target cells with peptidase inhibitors, suggestive of higher intracellular degradation of the corresponding peptides. Using DC and Mø cell extracts as a source of cytosolic, endosomal or lysosomal proteases to degrade long HIV peptides, we identified by mass spectrometry cell-specific and compartment-specific degradation patterns, which favored the production of peptides containing immunodominant epitopes in all compartments. The intracellular stability of optimal HIV-1 epitopes prior to loading onto MHC was highly variable and sequence-dependent in all compartments, and followed CTL hierarchy with immunodominant epitopes presenting higher stability rates. Common HLA-associated mutations in a dominant epitope appearing during acute HIV infection modified the degradation patterns of long HIV peptides, reduced intracellular stability and epitope production in cross-presentation-competent cell compartments, showing that impaired epitope production in the cross-presentation pathway contributes to immune escape. These findings highlight the contribution of degradation patterns in the cross-presentation pathway to HIV immunodominance and provide the first demonstration of immune escape affecting epitope cross-presentation. PMID:25781895

  16. Macrophages are involved in hexachlorobenzene-induced adverse immune effects

    SciTech Connect

    Ezendam, Janine . E-mail: Janine.Ezendam@rivm.nl; Kosterman, Kevin; Spijkerboer, Henneke; Bleumink, Rob; Hassing, Ine; Rooijen, Nico van; Vos, Joseph G.; Pieters, Raymond

    2005-11-15

    Hexachlorobenzene (HCB) is a persistent environmental pollutant that causes adverse immune effects in man and rat. The Brown Norway (BN) rat is very susceptible to HCB-induced immunopathology and oral exposure causes inflammatory skin and lung lesions, splenomegaly, lymph node (LN) enlargement, and increased serum levels of IgE and anti-ssDNA IgM. T cells play an important role but do not account for all adverse effects induced by HCB. Macrophages are probably also important and the relationship between macrophages and T cells was further investigated. To eliminate macrophages clodronate-liposomes were used. Furthermore, a kinetic study was performed to obtain insight in the early phase of the HCB-induced immune response. Also, experiments were performed to detect specific memory T cells. Therefore, an adoptive transfer study was performed. Our results indicate that macrophages are indeed involved in HCB-induced skin lesions, lung eosinophilia, and elevation of IgM against ssDNA. Kinetics showed that both skin and lung lesions appeared early after exposure. Moreover, immune effects could not be adaptively transferred. Thus, both macrophages and T cells are involved in HCB-induced immune effects but HCB exposure does not lead to specific T cell sensitization. Presumably, HCB exposure induces macrophage activation, thereby generating adjuvant signals that polyclonally stimulate T cells. Together, these events may lead to the observed immunopathology in BN rats.

  17. Impaired macrophage autophagy increases the immune response in obese mice by promoting proinflammatory macrophage polarization

    PubMed Central

    Liu, Kun; Zhao, Enpeng; Ilyas, Ghulam; Lalazar, Gadi; Lin, Yu; Haseeb, Muhammad; Tanaka, Kathryn E; Czaja, Mark J

    2015-01-01

    Recent evidence that excessive lipid accumulation can decrease cellular levels of autophagy and that autophagy regulates immune responsiveness suggested that impaired macrophage autophagy may promote the increased innate immune activation that underlies obesity. Primary bone marrow-derived macrophages (BMDM) and peritoneal macrophages from high-fat diet (HFD)-fed mice had decreased levels of autophagic flux indicating a generalized impairment of macrophage autophagy in obese mice. To assess the effects of decreased macrophage autophagy on inflammation, mice with a Lyz2-Cre-mediated knockout of Atg5 in macrophages were fed a HFD and treated with low-dose lipopolysaccharide (LPS). Knockout mice developed systemic and hepatic inflammation with HFD feeding and LPS. This effect was liver specific as knockout mice did not have increased adipose tissue inflammation. The mechanism by which the loss of autophagy promoted inflammation was through the regulation of macrophage polarization. BMDM and Kupffer cells from knockout mice exhibited abnormalities in polarization with both increased proinflammatory M1 and decreased anti-inflammatory M2 polarization as determined by measures of genes and proteins. The heightened hepatic inflammatory response in HFD-fed, LPS-treated knockout mice led to liver injury without affecting steatosis. These findings demonstrate that autophagy has a critical regulatory function in macrophage polarization that downregulates inflammation. Defects in macrophage autophagy may underlie inflammatory disease states such as the decrease in macrophage autophagy with obesity that leads to hepatic inflammation and the progression to liver injury. PMID:25650776

  18. Impaired macrophage autophagy increases the immune response in obese mice by promoting proinflammatory macrophage polarization.

    PubMed

    Liu, Kun; Zhao, Enpeng; Ilyas, Ghulam; Lalazar, Gadi; Lin, Yu; Haseeb, Muhammad; Tanaka, Kathryn E; Czaja, Mark J

    2015-01-01

    Recent evidence that excessive lipid accumulation can decrease cellular levels of autophagy and that autophagy regulates immune responsiveness suggested that impaired macrophage autophagy may promote the increased innate immune activation that underlies obesity. Primary bone marrow-derived macrophages (BMDM) and peritoneal macrophages from high-fat diet (HFD)-fed mice had decreased levels of autophagic flux indicating a generalized impairment of macrophage autophagy in obese mice. To assess the effects of decreased macrophage autophagy on inflammation, mice with a Lyz2-Cre-mediated knockout of Atg5 in macrophages were fed a HFD and treated with low-dose lipopolysaccharide (LPS). Knockout mice developed systemic and hepatic inflammation with HFD feeding and LPS. This effect was liver specific as knockout mice did not have increased adipose tissue inflammation. The mechanism by which the loss of autophagy promoted inflammation was through the regulation of macrophage polarization. BMDM and Kupffer cells from knockout mice exhibited abnormalities in polarization with both increased proinflammatory M1 and decreased anti-inflammatory M2 polarization as determined by measures of genes and proteins. The heightened hepatic inflammatory response in HFD-fed, LPS-treated knockout mice led to liver injury without affecting steatosis. These findings demonstrate that autophagy has a critical regulatory function in macrophage polarization that downregulates inflammation. Defects in macrophage autophagy may underlie inflammatory disease states such as the decrease in macrophage autophagy with obesity that leads to hepatic inflammation and the progression to liver injury. PMID:25650776

  19. Bacillus cereus immune escape: a journey within macrophages.

    PubMed

    Tran, Seav-Ly; Ramarao, Nalini

    2013-10-01

    During bacterial infection, professional phagocytes are attracted to the site of infection, where they constitute a first line of host cell defense. Their function is to engulf and destroy the pathogens. Thus, bacteria must withstand the bactericidal activity of professional phagocytes, including macrophages to counteract the host immune system. Bacillus cereus infections are characterized by bacteremia despite the accumulation of inflammatory cells at the site of infection. This implies that the bacteria have developed means of resisting the host immune system. Bacillus cereus spores survive, germinate, and multiply in contact with macrophages, eventually producing toxins that kill these cells. However, the exact mechanism by which B. cereus evades immune attack remains unclear. This review addresses the interaction between B. cereus and macrophages, highlighting, in particular, the ways in which the bacteria escape the microbicidal activities of professional phagocytes. PMID:23827020

  20. GPC3 expression in mouse ovarian cancer induces GPC3-specific T cell-mediated immune response through M1 macrophages and suppresses tumor growth

    PubMed Central

    LUO, CHENHONG; SHIBATA, KIYOSUMI; SUZUKI, SHIRO; KAJIYAMA, HIROAKI; SENGA, TAKESHI; KOYA, YOSHIHIRO; DAIMON, MINA; YAMASHITA, MAMORU; KIKKAWA, FUMITAKA

    2014-01-01

    Glypican-3 (GPC3) is specifically expressed in ovarian clear cell carcinoma (OCCC), hepatocellular carcinoma (HCC), and melanoma and lung cancer. GPC3 is being explored as a potential candidate for OCCC and HCC immunotherapy. As a tumor-associated antigen, induction of immune response of GPC3 in ovarian cancer remains elusive. We established a GPC3 transgenic mouse ovarian cancer cell line, OV2944-HM-1 (HM-1), and used the intraperitoneal ovarian cancer mouse model to investigate immune response in GPC3-expressing tumor. We found that GPC3 expression in the tumor increased F4/80+CD86+ macrophage (M1) proportion and caused GPC3-specific CD8+ T cell immune responses, and prolonged mouse survival. Our results demonstrated that GPC3 expression induced T cell-mediated immune response in this mouse ovarian cancer model and also provided supportive evidence that GPC3 is an ideal target for ovarian cancer immunotherapy. PMID:24992906

  1. GPC3 expression in mouse ovarian cancer induces GPC3‑specific T cell-mediated immune response through M1 macrophages and suppresses tumor growth.

    PubMed

    Luo, Chenhong; Shibata, Kiyosumi; Suzuki, Shiro; Kajiyama, Hiroaki; Senga, Takeshi; Koya, Yoshihiro; Daimon, Mina; Yamashita, Mamoru; Kikkawa, Fumitaka

    2014-09-01

    Glypican-3 (GPC3) is specifically expressed in ovarian clear cell carcinoma (OCCC), hepatocellular carci-noma (HCC), and melanoma and lung cancer. GPC3 is being explored as a potential candidate for OCCC and HCC immunotherapy. As a tumor-associated antigen, induction of immune response of GPC3 in ovarian cancer remains elusive. We established a GPC3 transgenic mouse ovarian cancer cell line, OV2944-HM-1 (HM-1), and used the intraperitoneal ovarian cancer mouse model to investigate immune response in GPC3-expressing tumor. We found that GPC3 expression in the tumor increased F4/80+CD86+ macrophage (M1) proportion and caused GPC3-specific CD8+ T cell immune responses, and prolonged mouse survival. Our results demonstrated that GPC3 expression induced T cell-mediated immune response in this mouse ovarian cancer model and also provided supportive evidence that GPC3 is an ideal target for ovarian cancer immunotherapy. PMID:24992906

  2. Ageing and the immune system: focus on macrophages

    PubMed Central

    Linehan, E.

    2015-01-01

    A fully functioning immune system is essential in order to maintain good health. However, the immune system deteriorates with advancing age, and this contributes to increased susceptibility to infection, autoimmunity, and cancer in the older population. Progress has been made in identifying age-related defects in the adaptive immune system. In contrast, relatively little research has been carried out on the impact of ageing on the innate immune response. This area requires further research as the innate immune system plays a crucial role in protection against infection and represents a first line of defence. Macrophages are central effector cells of the innate immune system and have many diverse functions. As a result, age-related impairments in macrophage function are likely to have important consequences for the health of the older population. It has been reported that ageing in macrophages impacts on many processes including toll-like receptor signalling, polarisation, phagocytosis, and wound repair. A detailed understanding of the impact of ageing on macrophages is required in order to develop therapeutics that will boost immune responses in the older population. PMID:25883791

  3. Immune memory-boosting dose of rapamycin impairs macrophage vesicle acidification and curtails glycolysis in effector CD8 cells, impairing defense against acute infections

    PubMed Central

    Goldberg, Emily L.; Smithey, Megan J.; Lutes, Lydia K.; Uhrlaub, Jennifer L.; Nikolich-Zugich, Janko

    2014-01-01

    Direct mTORC1 inhibition by short-term low-dose rapamycin treatment has recently been shown to improve CD8 T cell immunological memory. While these studies focused on memory development, the impact of low-dose rapamycin on the primary immune response, particularly as it relates to functional effector immunity, is far less clear. We investigated the impact of acute rapamycin treatment on immune effector cell function during the primary immune response to several acute infections. We found that functional CD8 T cell and macrophage responses to both viral and intracellular bacterial pathogens were depressed in mice in vivo and in humans to phorbol ester and calcium ionophore stimulation in vitro in the face of low-dose rapamycin treatment. Mechanistically, the CD8 defect was linked to impaired glycolytic switch in stimulated nave cells and the reduced formation of short-lived effector cells (SLEC). Therefore, more than one cell type required for a protective effector immune response are impaired by rapamycin in both mice and humans, at the dose shown to improve immune memory and extend lifespan. This urges caution with regard to the relative therapeutic costs and benefits of rapamycin treatment as means to improve immune memory. PMID:24913978

  4. Immune memory-boosting dose of rapamycin impairs macrophage vesicle acidification and curtails glycolysis in effector CD8 cells, impairing defense against acute infections.

    PubMed

    Goldberg, Emily L; Smithey, Megan J; Lutes, Lydia K; Uhrlaub, Jennifer L; Nikolich-Žugich, Janko

    2014-07-15

    Direct mammalian target of rapamycin (Rapa) complex 1 inhibition by short-term low-dose Rapa treatment has recently been shown to improve CD8 T cell immunological memory. Whereas these studies focused on memory development, the impact of low-dose Rapa on the primary immune response, particularly as it relates to functional effector immunity, is far less clear. In this study, we investigated the impact of acute Rapa treatment on immune effector cell function during the primary immune response to several acute infections. We found that functional CD8 T cell and macrophage responses to both viral and intracellular bacterial pathogens were depressed in mice in vivo and in humans to phorbol ester and calcium ionophore stimulation in vitro in the face of low-dose Rapa treatment. Mechanistically, the CD8 defect was linked to impaired glycolytic switch in stimulated naive cells and the reduced formation of short-lived effector cells. Therefore, more than one cell type required for a protective effector immune response is impaired by Rapa in both mice and humans, at the dose shown to improve immune memory and extend lifespan. This urges caution with regard to the relative therapeutic costs and benefits of Rapa treatment as means to improve immune memory. PMID:24913978

  5. Crude extract of Polygonum cuspidatum promotes immune responses in leukemic mice through enhancing phagocytosis of macrophage and natural killer cell activities in vivo.

    PubMed

    Chueh, Fu-Shin; Lin, Jen-Jyh; Lin, Jing-Pin; Yu, Fu-Shun; Lin, Ju-Hwa; Ma, Yi-Shih; Huang, Yi-Ping; Lien, Jin-Cherng; Chung, Jing-Gung

    2015-01-01

    Polygonum cuspidatum is a traditional Chinese herbal medicine used in the treatment of various diseases. In the present study, we investigated whether the crude extract of Polygonum cuspidatum (CEPC) could affect immune responses of murine leukemia cells in vivo. Normal BALB/c mice were i.p. injected with WEHI-3 cells to generate leukemic mice and then were treated orally with CEPC at 0, 50, 100 and 200 mg/kg for three weeks. Animals were weighed and blood, liver, spleen samples were collected for further analyses. Results indicated that CEPC did not significantly affect the body and liver weight of animals, but reduced the weight of spleen when compared to control groups. Flow cytometric assay demonstrated that CEPC increased the percentage of CD3- (T-cell marker) and CD19- (B-cell marker) positive cells, but reduced that of CD11b-positive ones (monocytes). However, it did not significantly affect the proportion of Mac-3-positive cells (macrophages), compared to control groups. Results indicated that CEPC promoted phagocytosis by macrophages from blood samples at all examined doses but did not affect that of macrophages from the peritoneal cavity. CEPC also promoted natural killer cell activity of splenocytes at 200 mg/kg of CEPC. CEPC promoted B-cell proliferation at 200 mg/kg treatment when cells were stimulated with lipopolysaccharides but did not promote T-cell proliferation at three doses of CEPC treatment on concanavalin A stimulation. PMID:25792654

  6. Flexible cytokine production by macrophages and T cells in response to probiotic bacteria: a possible mechanism by which probiotics exert multifunctional immune regulatory activities.

    PubMed

    Shida, Kan; Nanno, Masanobu; Nagata, Satoru

    2011-01-01

    Probiotics have been reported to be efficacious against cancers, infections, allergies, inflammatory bowel diseases and autoimmune diseases, and it is important to explain how such multifunctional activities are realized. Lactobacillus casei Shirota (LcS) is one of these multifunctional probiotics, and its ability to augment the host immune system has been extensively examined. We have shown that the cell wall structure of this probiotic strain is responsible for potently inducing IL-12 production. In addition, we have recently found that LcS differentially controls the inflammatory cytokine responses of macrophages and T cells in either Peyer's patches or the spleen. Other studies revealed that LcS-induced IL-12 production by macrophages is modified when other bacteria or their cell components are simultaneously present. These findings can provide a theoretical basis for understanding the multifunctional activities of specific probiotics. PMID:21637028

  7. Macrophage Autophagy in Immunity to Cryptococcus neoformans and Candida albicans

    PubMed Central

    Nicola, André Moraes; Albuquerque, Patrícia; Martinez, Luis R.; Dal-Rosso, Rafael Antonio; Saylor, Carolyn; De Jesus, Magdia; Nosanchuk, Joshua D.

    2012-01-01

    Autophagy is used by eukaryotes in bulk cellular material recycling and in immunity to intracellular pathogens. We evaluated the role of macrophage autophagy in the response to Cryptococcus neoformans and Candida albicans, two important opportunistic fungal pathogens. The autophagosome marker LC3 (microtubule-associated protein 1 light chain 3 alpha) was present in most macrophage vacuoles containing C. albicans. In contrast, LC3 was found in only a few vacuoles containing C. neoformans previously opsonized with antibody but never after complement-mediated phagocytosis. Disruption of host autophagy in vitro by RNA interference against ATG5 (autophagy-related 5) decreased the phagocytosis of C. albicans and the fungistatic activity of J774.16 macrophage-like cells against both fungi, independent of the opsonin used. ATG5-knockout bone marrow-derived macrophages (BMMs) also had decreased fungistatic activity against C. neoformans when activated. In contrast, nonactivated ATG5-knockout BMMs actually restricted C. neoformans growth more efficiently, suggesting that macrophage autophagy plays different roles against C. neoformans, depending on the macrophage type and activation. Interference with autophagy in J774.16 cells also decreased nonlytic exocytosis of C. neoformans, increased interleukin-6 secretion, and decreased gamma interferon-induced protein 10 secretion. Mice with a conditionally knocked out ATG5 gene in myeloid cells showed increased susceptibility to intravenous C. albicans infection. In contrast, these mice manifested no increased susceptibility to C. neoformans, as measured by survival, but had fewer alternatively activated macrophages and less inflammation in the lungs after intratracheal infection than control mice. These results demonstrate the complex roles of macrophage autophagy in restricting intracellular parasitism by fungi and reveal connections with nonlytic exocytosis, humoral immunity, and cytokine signaling. PMID:22710871

  8. Impact of macrophage and dendritic cell subset elimination on antiviral immunity, viral clearance and production of type 1 interferon.

    PubMed

    Ciavarra, Richard P; Taylor, Lisa; Greene, Amy R; Yousefieh, Nazita; Horeth, Dale; van Rooijen, Nico; Steel, Christina; Gregory, Betsy; Birkenbach, Mark; Sekellick, Margaret

    2005-11-25

    We report herein that vesicular stomatitis virus (VSV) induced a concurrent primary Th1 (T helper 1) and Th2 cytokine response detectable ex vivo. Liposome-encapsulated clodronate-mediated elimination of CD8- marginal dendritic cells (DCs) and splenic macrophages (m Phi), but not CD8+ interdigitating DCs, prior to infection resulted in a markedly diminished chemokine and Th1 (IL-2, interferon-gamma) cytokine response, although the Th2 response (IL-4) remained relatively intact. Repopulation with marginal DCs and marginal metallophilic macrophages (MMM) restored Th1 cytokine profiles but did not restore chemokine responsiveness or reduce VSV-induced morbidity/mortality. Chemokine competency returned approximately 4 weeks post-depletion, which correlated temporally with repopulation of the spleen with marginal zone macrophages (MZM) and red pulp macrophages (RPM). Unexpectedly, virus-induced morbidity persisted for over 1 month post-depletion and was associated with virus dissemination and distinctive histological lesions in the liver. Depletion of interferon-producing plasmacytoid dendritic cells did not account for virus-induced morbidity because serum levels of type I interferon were not diminished in Cl2MBP-liposome-treated mice. Thus, distinct m Phi subsets are critical for chemokine production and viral clearance, and, in their absence, VSV disseminates even in the presence of high titers of interferon. PMID:16143360

  9. Comparative Analysis of the Effects of Two Probiotic Bacterial Strains on Metabolism and Innate Immunity in the RAW 264.7 Murine Macrophage Cell Line.

    PubMed

    Pradhan, Biswaranjan; Guha, Dipanjan; Ray, Pratikshya; Das, Debashmita; Aich, Palok

    2016-06-01

    Probiotic and potential probiotic bacterial strains are routinely prescribed and used as supplementary therapy for a variety infectious diseases, including enteric disorders among a wide range of individuals. While there are an increasing number of studies defining the possible mechanisms of probiotic activity, a great deal remains unknown regarding the diverse modes of action attributed to these therapeutic agents. More precise information is required to support the appropriate application of probiotics. To address this objective, we selected two probiotics strains, Lactobacillus acidophilus MTCC-10307 (LA) and Bacillus clausii MTCC-8326 (BC) that are frequently prescribed for the treatment of intestinal disorders and investigated their effects on the RAW 264.7 murine macrophage cell line. Our results reveal that LA and BC are potent activators of both metabolic activity and innate immune responses in these cells. We also observed that LA and BC possessed similar activity in preventing infection simulated in vitro in murine macrophages by Salmonella typhimurium serovar enterica. PMID:27038159

  10. Neuro-immune Interactions Drive Tissue Programming in Intestinal Macrophages.

    PubMed

    Gabanyi, Ilana; Muller, Paul A; Feighery, Linda; Oliveira, Thiago Y; Costa-Pinto, Frederico A; Mucida, Daniel

    2016-01-28

    Proper adaptation to environmental perturbations is essential for tissue homeostasis. In the intestine, diverse environmental cues can be sensed by immune cells, which must balance resistance to microorganisms with tolerance, avoiding excess tissue damage. By applying imaging and transcriptional profiling tools, we interrogated how distinct microenvironments in the gut regulate resident macrophages. We discovered that macrophages exhibit a high degree of gene-expression specialization dependent on their proximity to the gut lumen. Lamina propria macrophages (LpMs) preferentially expressed a pro-inflammatory phenotype when compared to muscularis macrophages (MMs), which displayed a tissue-protective phenotype. Upon luminal bacterial infection, MMs further enhanced tissue-protective programs, and this was attributed to swift activation of extrinsic sympathetic neurons innervating the gut muscularis and norepinephrine signaling to β2 adrenergic receptors on MMs. Our results reveal unique intra-tissue macrophage specialization and identify neuro-immune communication between enteric neurons and macrophages that induces rapid tissue-protective responses to distal perturbations. PMID:26777404

  11. Macrophages as IL-25/IL-33-responsive cells play an important role in the induction of type 2 immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Th2 immunity is essential for the host protection against nematode infection, while detrimental in allergic inflammation or asthma. Although many of the details regarding the cellular and molecular events in Th2 immunity have been described, the specific cell types and effector molecules involved i...

  12. Macrophages and Dendritic Cells: Partners in Atherogenesis.

    PubMed

    Cybulsky, Myron I; Cheong, Cheolho; Robbins, Clinton S

    2016-02-19

    Atherosclerosis is a complex chronic disease. The accumulation of myeloid cells in the arterial intima, including macrophages and dendritic cells (DCs), is a feature of early stages of disease. For decades, it has been known that monocyte recruitment to the intima contributes to the burden of lesion macrophages. Yet, this paradigm may require reevaluation in light of recent advances in understanding of tissue macrophage ontogeny, their capacity for self-renewal, as well as observations that macrophages proliferate throughout atherogenesis and that self-renewal is critical for maintenance of macrophages in advanced lesions. The rate of atherosclerotic lesion formation is profoundly influenced by innate and adaptive immunity, which can be regulated locally within atherosclerotic lesions, as well as in secondary lymphoid organs, the bone marrow and the blood. DCs are important modulators of immunity. Advances in the past decade have cemented our understanding of DC subsets, functions, hematopoietic origin, gene expression patterns, transcription factors critical for differentiation, and provided new tools for study of DC biology. The functions of macrophages and DCs overlap to some extent, thus it is important to reassess the contributions of each of these myeloid cells taking into account strict criteria of cell identification, ontogeny, and determine whether their key roles are within atherosclerotic lesions or secondary lymphoid organs. This review will highlight key aspect of macrophage and DC biology, summarize how these cells participate in different stages of atherogenesis and comment on complexities, controversies, and gaps in knowledge in the field. PMID:26892963

  13. Vaccination with Irradiated Tumor Cells Engineered to Secrete Murine Granulocyte-Macrophage Colony-Stimulating Factor Stimulates Potent, Specific, and Long-Lasting Anti-Tumor Immunity

    NASA Astrophysics Data System (ADS)

    Dranoff, Glenn; Jaffee, Elizabeth; Lazenby, Audrey; Golumbek, Paul; Levitsky, Hyam; Brose, Katja; Jackson, Valerie; Hamada, Hirofumi; Pardoll, Drew; Mulligan, Richard C.

    1993-04-01

    To compare the ability of different cytokines and other molecules to enhance the immunogenicity of tumor cells, we generated 10 retroviruses encoding potential immunomodulators and studied the vaccination properties of murine tumor cells transduced by the viruses. Using a B16 melanoma model, in which irradiated tumor cells alone do not stimulate significant anti-tumor immunity, we found that irradiated tumor cells expressing murine granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulated potent, long-lasting, and specific anti-tumor immunity, requiring both CD4^+ and CD8^+ cells. Irradiated cells expressing interleukins 4 and 6 also stimulated detectable, but weaker, activity. In contrast to the B16 system, we found that in a number of other tumor models, the levels of anti-tumor immunity reported previously in cytokine gene transfer studies involving live, transduced cells could be achieved through the use of irradiated cells alone. Nevertheless, manipulation of the vaccine or challenge doses made it possible to demonstrate the activity of murine GM-CSF in those systems as well. Overall, our results have important implications for the clinical use of genetically modified tumor cells as therapeutic cancer vaccines.

  14. Sulforaphane promotes immune responses in a WEHI‑3‑induced leukemia mouse model through enhanced phagocytosis of macrophages and natural killer cell activities in vivo.

    PubMed

    Shih, Yung-Luen; Wu, Lung-Yuan; Lee, Ching-Hsiao; Chen, Yung-Liang; Hsueh, Shu-Ching; Lu, Hsu-Feng; Liao, Nien-Chieh; Chung, Jing-Gung

    2016-05-01

    Sulforaphane (SFN) is an isothiocyanate, inducing cytotoxic effects in various human cancer cells, including leukemia cells through cell cycle arrest and apoptosis. However, the effect of SFN on the immune responses in a leukemia mouse model remains to be investigated. The present study investigated whether SFN has an effect on the immune responses in a WEHI‑3‑induced leukemia mouse model in vivo. Normal BALB/c mice were injected with WEHI‑3 cells to generate the leukemia mouse model, and were subsequently treated with placebo or SFN (0, 285, 570 and 1,140 mg/kg) for 3 weeks. Following treatment, all mice were weighted and blood samples were collected. In addition, liver and spleen samples were isolated to determine cell markers, phagocytosis and natural killer (NK) cell activities, and cell proliferation was examined using flow cytometry. The results indicated that SFN treatment had no significant effect on the spleen weight, however it decreased liver and body weight. Furthermore, SFN treatment increased the percentage levels of CD3 (T cells) and CD19 (B cell maker), however had no effect on the levels of CD11b (monocytes) or Mac‑3 (macrophages), compared with the WEHI‑3 control groups. The administration of SFN increased the phagocytosis of macrophages from peripheral blood mononuclear cells and peritoneal cavity, and increased the activity of NK cells from splenocytes. Administration of SFN promoted T and B cell proliferation following stimulation with concanavalin A and lipopolysaccharide, respectively. PMID:27035756

  15. M1 and M2 macrophages: the chicken and the egg of immunity.

    PubMed

    Mills, Charles D; Ley, Klaus

    2014-01-01

    The purpose of this perspective is to describe a critical advance in understanding how immune responses work. Macrophages are required for all animal life: 'Inhibit' type macrophages in all animals (called M1) can rapidly kill pathogens, and are thus the primary host defense, and 'Heal' type macrophages (M2) routinely repair and maintain tissue integrity. Macrophages perform these activities in all animals without T cells, and also in T cell-deficient vertebrates. Although adaptive immunity can amplify macrophage polarization, the long-held notion that macrophages need to be 'activated' or 'alternatively activated' by T cells is incorrect; indeed, immunology has had it backward. M1/M2-type macrophages necessarily direct T cells toward Th1- or Th2-like activities, respectively. That such macrophage-innate activities are the central directing element in immune responses is a dramatic change in understanding how immune systems operate. Most important, this revelation is opening up whole new approaches to immunotherapy. For example, many modern diseases, such as cancer and atherosclerosis, may not display 'foreign' antigens. However, there are clear imbalances in M1/M2-type responses. Correcting such innate imbalances can result in better health. Macrophages are the chicken and the egg of immunity. PMID:25138714

  16. M1 and M2 Macrophages: The Chicken and the Egg of Immunity

    PubMed Central

    Mills, Charles D.; Ley, Klaus

    2015-01-01

    The purpose of this perspective is to describe a critical advance in understanding how immune responses work. Macrophages are required for all animal life: ‘Inhibit’ type macrophages in all animals (called M1) can rapidly kill pathogens, and are thus the primary host defense, and ‘Heal’ type macrophages (M2) routinely repair and maintain tissue integrity. Macrophages perform these activities in all animals without T cells, and also in T cell-deficient vertebrates. Although adaptive immunity can amplify macrophage polarization, the long-held notion that macrophages need to be ‘activated’ or ‘alternatively activated’ by T cells is incorrect; indeed, immunology has had it backward. M1/M2-type macrophages necessarily direct T cells toward Th1- or Th2-like activities, respectively. That such macrophage-innate activities are the central directing element in immune responses is a dramatic change in understanding how immune systems operate. Most important, this revelation is opening up whole new approaches to immunotherapy. For example, many modern diseases, such as cancer and atherosclerosis, may not display ‘foreign’ antigens. However, there are clear imbalances in M1/M2-type responses. Correcting such innate imbalances can result in better health. Macrophages are the chicken and the egg of immunity. PMID:25138714

  17. Interaction with Epithelial Cells Modifies Airway Macrophage Response to Ozone

    EPA Science Inventory

    The initial innate immune response to ozone (03) in the lung is orchestrated by structural cells, such as epithelial cells, and resident immune cells, such as airway macrophages (Macs). We developed an epithelial cell-Mac coculture model to investigate how epithelial cell-derived...

  18. Regulation of mucosal and systemic antibody responses by T helper cell subsets, macrophages, and derived cytokines following oral immunization with live recombinant Salmonella.

    PubMed

    VanCott, J L; Staats, H F; Pascual, D W; Roberts, M; Chatfield, S N; Yamamoto, M; Coste, M; Carter, P B; Kiyono, H; McGhee, J R

    1996-02-15

    We have assessed regulatory Th cell and cytokine responses in mice after oral immunization with recombinant Salmonella (BRD 847) expressing fragment C of tetanus toxoid, since little information is available to explain how these vectors induce mucosal IgA responses. A single dose of BRD 847 elicited serum IgG2a and mucosal IgA anti-tetanus toxoid Ab responses. To assess Th1-and Th2-type responses, CD4+ T cells from Peyer's patches and spleen were restimulated in vitro, and cytokine-specific ELISPOT, ELISA, and reverse transcriptase-PCR assays were used to assess cytokine patterns. CD4+ T cells produced IFN-gamma and IL-2 as well as IL-10, but not IL-4 or IL-5. Although IL-6 was elevated, further purification of cells from in vitro cultures into CD4+ Mac-1- T cells and Mac-1+ CD4- cells revealed that only the latter cell population had consistently elevated IL-6 gene expression, whereas both sorted populations exhibited increased IFN-gamma and IL-10 gene expression. Thus, orally administered recombinant Salmonella expressing fragment C of tetanus toxoid elicited dominant Ag-specific Th1-type responses together with Th2-type cells producing IL-10 in both mucosal and systemic tissues. Macrophages producing IL-6 were also evident. Our results are consistent with the suggestion that Ag-specific Th1 cells and their derived cytokines, IFN-gamma and IL-2, and Th2-derived IL-10 together with IL-6 produced by macrophages provide important signals for the development of mucosal IgA and serum IgG subclass responses in the absence of preferential expression of Th2 cytokines IL-4 and IL-5. PMID:8568254

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

    PubMed

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

    2014-05-01

    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 20mg/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 10weeks of age, femurs were collected and bone marrow-derived macrophages were generated. Cytokine production was measured in bone marrow-derived macrophages incubated for 24h 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 changes in macrophage function that are sustained into adulthood. PMID:24566386

  20. Microarray expression analysis of genes involved in innate immune memory in peritoneal macrophages.

    PubMed

    Yoshida, Keisuke; Renard-Guillet, Claire; Inoue, Kentaro; Shirahige, Katsuhiko; Okada-Hatakeyama, Mariko; Ishii, Shunsuke

    2016-03-01

    Immunological memory has been believed to be a feature of the adaptive immune system for long period, but recent reports suggest that the innate immune system also exhibits memory-like reaction. Although evidence of innate immune memory is accumulating, no in vivo experimental data has clearly implicated a molecular mechanism, or even a cell-type, for this phenomenon. In this study of data deposited into Gene Expression Omnibus (GEO) under GSE71111, we analyzed the expression profile of peritoneal macrophages isolated from mice pre-administrated with toll-like receptor (TLR) ligands, mimicking pathogen infection. In these macrophages, increased expression of a group of innate immunity-related genes was sustained over a long period of time, and these genes overlapped with ATF7-regulated genes. We conclude that ATF7 plays an important role in innate immune memory in macrophages. PMID:26981372

  1. Microarray expression analysis of genes involved in innate immune memory in peritoneal macrophages

    PubMed Central

    Yoshida, Keisuke; Renard-Guillet, Claire; Inoue, Kentaro; Shirahige, Katsuhiko; Okada-Hatakeyama, Mariko; Ishii, Shunsuke

    2015-01-01

    Immunological memory has been believed to be a feature of the adaptive immune system for long period, but recent reports suggest that the innate immune system also exhibits memory-like reaction. Although evidence of innate immune memory is accumulating, no in vivo experimental data has clearly implicated a molecular mechanism, or even a cell-type, for this phenomenon. In this study of data deposited into Gene Expression Omnibus (GEO) under GSE71111, we analyzed the expression profile of peritoneal macrophages isolated from mice pre-administrated with toll-like receptor (TLR) ligands, mimicking pathogen infection. In these macrophages, increased expression of a group of innate immunity-related genes was sustained over a long period of time, and these genes overlapped with ATF7-regulated genes. We conclude that ATF7 plays an important role in innate immune memory in macrophages.

  2. Immune cell interplay in colorectal cancer prognosis

    PubMed Central

    Norton, Samuel E; Ward-Hartstonge, Kirsten A; Taylor, Edward S; Kemp, Roslyn A

    2015-01-01

    The immune response to colorectal cancer has proven to be a reliable measure of patient outcome in several studies. However, the complexity of the immune response in this disease is not well understood, particularly the interactions between tumour-associated cells and cells of the innate and adaptive immune system. This review will discuss the relationship between cancer associated fibroblasts and macrophages, as well as between macrophages and T cells, and demonstrate how each population may support or prevent tumour growth in a different immune environment. PMID:26483876

  3. Mice Lacking Endoglin in Macrophages Show an Impaired Immune Response.

    PubMed

    Ojeda-Fernández, Luisa; Recio-Poveda, Lucía; Aristorena, Mikel; Lastres, Pedro; Blanco, Francisco J; Sanz-Rodríguez, Francisco; Gallardo-Vara, Eunate; de Las Casas-Engel, Mateo; Corbí, Ángel; Arthur, Helen M; Bernabeu, Carmelo; Botella, Luisa M

    2016-03-01

    Endoglin is an auxiliary receptor for members of the TGF-β superfamily and plays an important role in the homeostasis of the vessel wall. Mutations in endoglin gene (ENG) or in the closely related TGF-β receptor type I ACVRL1/ALK1 are responsible for a rare dominant vascular dysplasia, the Hereditary Hemorrhagic Telangiectasia (HHT), or Rendu-Osler-Weber syndrome. Endoglin is also expressed in human macrophages, but its role in macrophage function remains unknown. In this work, we show that endoglin expression is triggered during the monocyte-macrophage differentiation process, both in vitro and during the in vivo differentiation of blood monocytes recruited to foci of inflammation in wild-type C57BL/6 mice. To analyze the role of endoglin in macrophages in vivo, an endoglin myeloid lineage specific knock-out mouse line (Engfl/flLysMCre) was generated. These mice show a predisposition to develop spontaneous infections by opportunistic bacteria. Engfl/flLysMCre mice also display increased survival following LPS-induced peritonitis, suggesting a delayed immune response. Phagocytic activity is impaired in peritoneal macrophages, altering one of the main functions of macrophages which contributes to the initiation of the immune response. We also observed altered expression of TGF-β1 target genes in endoglin deficient peritoneal macrophages. Overall, the altered immune activity of endoglin deficient macrophages could help to explain the higher rate of infectious diseases seen in HHT1 patients. PMID:27010826

  4. Mice Lacking Endoglin in Macrophages Show an Impaired Immune Response

    PubMed Central

    Ojeda-Fernández, Luisa; Recio-Poveda, Lucía; Aristorena, Mikel; Lastres, Pedro; Blanco, Francisco J.; Sanz-Rodríguez, Francisco; Gallardo-Vara, Eunate; de las Casas-Engel, Mateo; Corbí, Ángel; Arthur, Helen M.; Bernabeu, Carmelo; Botella, Luisa M.

    2016-01-01

    Endoglin is an auxiliary receptor for members of the TGF-β superfamily and plays an important role in the homeostasis of the vessel wall. Mutations in endoglin gene (ENG) or in the closely related TGF-β receptor type I ACVRL1/ALK1 are responsible for a rare dominant vascular dysplasia, the Hereditary Hemorrhagic Telangiectasia (HHT), or Rendu-Osler-Weber syndrome. Endoglin is also expressed in human macrophages, but its role in macrophage function remains unknown. In this work, we show that endoglin expression is triggered during the monocyte-macrophage differentiation process, both in vitro and during the in vivo differentiation of blood monocytes recruited to foci of inflammation in wild-type C57BL/6 mice. To analyze the role of endoglin in macrophages in vivo, an endoglin myeloid lineage specific knock-out mouse line (Engfl/flLysMCre) was generated. These mice show a predisposition to develop spontaneous infections by opportunistic bacteria. Engfl/flLysMCre mice also display increased survival following LPS-induced peritonitis, suggesting a delayed immune response. Phagocytic activity is impaired in peritoneal macrophages, altering one of the main functions of macrophages which contributes to the initiation of the immune response. We also observed altered expression of TGF-β1 target genes in endoglin deficient peritoneal macrophages. Overall, the altered immune activity of endoglin deficient macrophages could help to explain the higher rate of infectious diseases seen in HHT1 patients. PMID:27010826

  5. 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

    2016-01-01

    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

  6. A TNF-Regulated Recombinatorial Macrophage Immune Receptor Implicated in Granuloma Formation in Tuberculosis

    PubMed Central

    Streich, Roswita; Breysach, Caroline; Raddatz, Dirk; Oniga, Septimia; Peccerella, Teresa; Findeisen, Peter; Kzhyshkowska, Julia; Gratchev, Alexei; Schweyer, Stefan; Saunders, Bernadette; Wessels, Johannes T.; Möbius, Wiebke; Keane, Joseph; Becker, Heinz; Ganser, Arnold; Neumaier, Michael; Kaminski, Wolfgang E.

    2011-01-01

    Macrophages play a central role in host defense against mycobacterial infection and anti- TNF therapy is associated with granuloma disorganization and reactivation of tuberculosis in humans. Here, we provide evidence for the presence of a T cell receptor (TCR) αβ based recombinatorial immune receptor in subpopulations of human and mouse monocytes and macrophages. In vitro, we find that the macrophage-TCRαβ induces the release of CCL2 and modulates phagocytosis. TNF blockade suppresses macrophage-TCRαβ expression. Infection of macrophages from healthy individuals with mycobacteria triggers formation of clusters that express restricted TCR Vβ repertoires. In vivo, TCRαβ bearing macrophages abundantly accumulate at the inner host-pathogen contact zone of caseous granulomas from patients with lung tuberculosis. In chimeric mouse models, deletion of the variable macrophage-TCRαβ or TNF is associated with structurally compromised granulomas of pulmonary tuberculosis even in the presence of intact T cells. These results uncover a TNF-regulated recombinatorial immune receptor in monocytes/macrophages and demonstrate its implication in granuloma formation in tuberculosis. PMID:22114556

  7. Effects of microwave exposure on the hamster immune system. II. Peritoneal macrophage function

    SciTech Connect

    Rama Rao, G.; Cain, C.A.; Lockwood, J.; Tompkins, W.A.

    1983-01-01

    Acute exposure to hamsters to microwave energy (2.45 GHz; 25 mW/cm2 for 60 min) resulted in activation of peritoneal macrophages that were significantly more viricidal to vaccinia virus as compared to sham-exposed or normal (minimum-handling) controls. Macrophages from microwave-exposed hamsters became activated as early as 6 h after exposure and remained activated for up to 12 days. The activation of macrophages by microwave exposure paralleled the macrophage activation after vaccinia virus immunization. Activated macrophages from vaccinia-immunized hamsters did not differ in their viricidal activity when the hamsters were microwave- or sham-exposed. Exposure for 60 min at 15 mW/cm2 did not activate the macrophages while 40 mW/cm2 exposure was harmful to some hamsters. Average maximum core temperatures in the exposed (25 mW/cm2) and sham groups were 40.5 degrees C (+/- 0.35 SD) and 38.4 degrees C (+/- 0.5 SD), respectively. In vitro heating of macrophages to 40.5 degrees C was not as effective as in vivo microwave exposure in activating macrophages to the viricidal state. Macrophages from normal, sham-exposed, and microwave-exposed hamsters were not morphologically different, and they all phagocytosed India ink particles. Moreover, immune macrophage cytotoxicity for virus-infected or noninfected target cells was not suppressed in the microwave-irradiated group (25 mW/cm2, 1 h) as compared to sham-exposed controls, indicating that peritoneal macrophages were not functionally suppressed or injured by microwave hyperthermia.

  8. Applications of myeloid-specific promoters in transgenic mice support in vivo imaging and functional genomics but do not support the concept of distinct macrophage and dendritic cell lineages or roles in immunity.

    PubMed

    Hume, David A

    2011-04-01

    Myeloid lineage cells contribute to innate and acquired immunity, homeostasis, wound repair, and inflammation. There is considerable interest in manipulation of their function in transgenic mice using myeloid-specific promoters. This review considers the applications and specificity of some of the most widely studied transgenes, driven by promoter elements of the lysM, csf1r, CD11c, CD68, macrophage SRA, and CD11b genes, as well as several others. Transgenes have been used in mice to generate myeloid lineage-specific cell ablation, expression of genes of interest, including fluorescent reporters, or deletion via recombination. In general, the specificity of such transgenes has been overinterpreted, and none of them provide well-documented, reliable, differential expression in any specific myeloid cell subset, macrophages, granulocytes, or myeloid DCs. Nevertheless, they have proved valuable in cell isolation, functional genomics, and live imaging of myeloid cell behavior in many different pathologies. PMID:21169519

  9. Using RNA-interference to investigate the innate immune response in mouse macrophages.

    PubMed

    De Arras, Lesly; Guthrie, Brandon S; Alper, Scott

    2014-01-01

    Macrophages are key phagocytic innate immune cells. When macrophages encounter a pathogen, they produce antimicrobial proteins and compounds to kill the pathogen, produce various cytokines and chemokines to recruit and stimulate other immune cells, and present antigens to stimulate the adaptive immune response. Thus, being able to efficiently manipulate macrophages with techniques such as RNA-interference (RNAi) is critical to our ability to investigate this important innate immune cell. However, macrophages can be technically challenging to transfect and can exhibit inefficient RNAi-induced gene knockdown. In this protocol, we describe methods to efficiently transfect two mouse macrophage cell lines (RAW264.7 and J774A.1) with siRNA using the Amaxa Nucleofector 96-well Shuttle System and describe procedures to maximize the effect of siRNA on gene knockdown. Moreover, the described methods are adapted to work in 96-well format, allowing for medium and high-throughput studies. To demonstrate the utility of this approach, we describe experiments that utilize RNAi to inhibit genes that regulate lipopolysaccharide (LPS)-induced cytokine production. PMID:25407484

  10. Dendritic Cells and Macrophages: Sentinels in the Kidney

    PubMed Central

    Weisheit, Christina K.; Engel, Daniel R.

    2015-01-01

    The mononuclear phagocytes (dendritic cells and macrophages) are closely related immune cells with central roles in anti-infectious defense and maintenance of organ integrity. The canonical function of dendritic cells is the activation of T cells, whereas macrophages remove apoptotic cells and microbes by phagocytosis. In the kidney, these cell types form an intricate system of mononuclear phagocytes that surveys against injury and infection and contributes to organ homeostasis and tissue repair but may also promote progression of CKD. This review summarizes the general functions and classification of dendritic cells and macrophages in the immune system and recapitulates why overlapping definitions and historically separate research have created controversy about their tasks. Their roles in acute kidney disease, CKD, and renal transplantation are described, and therapeutic strategy to modify these cells for therapeutic purposes is discussed. PMID:25568218

  11. Myelin-phagocytosing macrophages modulate autoreactive T cell proliferation

    PubMed Central

    2011-01-01

    Introduction Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating disease of the central nervous system (CNS) in which macrophages play a central role. Initially, macrophages where thought to be merely detrimental in MS, however, recent evidence suggests that their functional phenotype is altered following myelin phagocytosis. Macrophages that have phagocytosed myelin may be less inflammatory and may exert beneficial effects. The presence of myelin-containing macrophages in CNS-draining lymph nodes and perivascular spaces of MS patients suggests that these cells are ideally positioned to exert an immune regulatory role. Therefore we evaluated in this study the effect of myelin-phagocytosing macrophages on lymphocyte reactivity. Methods Thioglycolate-elicited rat peritoneal macrophages were loaded with myelin and cocultured with myelin-basic protein (MBP) or ovalbumin (OVA) reactive lymphocytes. Lymphocyte proliferation was determined by CFSE-labeling. The role of nitric oxide in regulating lymphocyte proliferation was assessed by addition of an inhibitor of inducible nitric oxide synthase to the coculture. In vivo immune regulation was investigated by treating MBP- and OVA-immunized animals subcutaneously with myelin. Cognate antigen specific lymphocyte proliferation and nitric oxide production were determined 9d post-immunization. Results In this study we demonstrate that myelin-phagocytosing macrophages inhibit TCR-triggered lymphocyte proliferation in an antigen-independent manner. The observed immune suppression is mediated by an increase in NO production by myelin-phagocytosing macrophages upon contact with lymphocytes. Additionally, myelin delivery to primarily CD169+ macrophages in popliteal lymph nodes of OVA-immunized animals results in a reduced cognate antigen specific proliferation. In contrast to OVA-immunized animals, lymphocytes from MBP-immunized animals displayed an increased proliferation after stimulation with their cognate antigen, indicating that myelin-phagocytosing macrophages have dual effects depending on the specificity of surrounding lymphocytes. Conclusions Collectively our data show that myelin phagocytosis leads to an altered macrophage function that inhibits lymphocyte proliferation. Additionally, results from this study indicate that myelin-phagocytosing macrophages fulfill a dual role in vivo. On one hand they aggravate autoimmunity by activating myelin-reactive lymphocytes and on the other hand they suppress lymphocyte reactivity by producing NO. PMID:21781347

  12. Interplay of macrophages and T cells in the lung vasculature.

    PubMed

    Gerasimovskaya, Evgenia; Kratzer, Adelheid; Sidiakova, Asya; Salys, Jonas; Zamora, Martin; Taraseviciene-Stewart, Laimute

    2012-05-15

    In severe pulmonary arterial hypertension (PAH), vascular lesions are composed of phenotypically altered vascular and inflammatory cells that form clusters or tumorlets. Because macrophages are found in increased numbers in intravascular and perivascular space in human PAH, here we address the question whether macrophages play a role in pulmonary vascular remodeling and whether accumulation of macrophages in the lung vasculature could be compromised by the immune system. We used the mouse macrophage cell line RAW 264.7 because these cells are resistant to apoptosis, have high proliferative capacity, and resemble cells in the plexiform lesions that tend to pile up instead of maintaining a monolayer. Cells were characterized by immunocytochemistry with cell surface markers (Lycopersicon Esculentum Lectin, CD117, CD133, FVIII, CD31, VEGFR-2, and S100). Activated, but not quiescent, T cells were able to suppress RAW 264.7 cell proliferative and migration activity in vitro. The carboxyfluorescein diacetate-labeled RAW 264.7 cells were injected into the nave Sprague Dawley (SD) rat and athymic nude rat. Twelve days later, cells were found in the lung vasculature of athymic nude rats that lack functional T cells, contributing to vascular remodeling. No labeled RAW 264.7 cells were detected in the lungs of immune-competent SD rats. Our data demonstrate that T cells can inhibit in vitro migration and in vivo accumulation of macrophage-like cells. PMID:22387295

  13. Dendritic cells and macrophages in the genitourinary tract

    PubMed Central

    Iijima, N; Thompson, JM; Iwasaki, A

    2009-01-01

    Dendritic cells (DCs) and macrophages are antigen-presenting cells (APCs) that are important in innate immune defense as well as in the generation and regulation of adaptive immunity against a wide array of pathogens. The genitourinary (GU) tract, which serves an important reproductive function, is constantly exposed to numerous agents of sexually transmitted infections (STIs). To combat these STIs, several subsets of DCs and macrophages are strategically localized within the GU tract. In the female genital mucosa, recruitment and function of these APCs are uniquely governed by sex hormones. This review summarizes the latest advances in our understanding of DCs and macrophages in the GU tract with respect to their subsets, lineage, and function. In addition, we discuss the divergent roles of these cells in immune defense against STIs as well as in maternal tolerance to the fetus. PMID:19079212

  14. Unfolded protein response (UPR) signaling regulates arsenic trioxide-mediated macrophage innate immune function disruption

    SciTech Connect

    Srivastava, Ritesh K.; Li, Changzhao; Chaudhary, Sandeep C.; Ballestas, Mary E.; Elmets, Craig A.; Robbins, David J.; Matalon, Sadis; Deshane, Jessy S.; Afaq, Farrukh; Bickers, David R.; Athar, Mohammad

    2013-11-01

    Arsenic exposure is known to disrupt innate immune functions in humans and in experimental animals. In this study, we provide a mechanism by which arsenic trioxide (ATO) disrupts macrophage functions. ATO treatment of murine macrophage cells diminished internalization of FITC-labeled latex beads, impaired clearance of phagocytosed fluorescent bacteria and reduced secretion of pro-inflammatory cytokines. These impairments in macrophage functions are associated with ATO-induced unfolded protein response (UPR) signaling pathway characterized by the enhancement in proteins such as GRP78, p-PERK, p-eIF2α, ATF4 and CHOP. The expression of these proteins is altered both at transcriptional and translational levels. Pretreatment with chemical chaperon, 4-phenylbutyric acid (PBA) attenuated the ATO-induced activation in UPR signaling and afforded protection against ATO-induced disruption of macrophage functions. This treatment also reduced ATO-mediated reactive oxygen species (ROS) generation. Interestingly, treatment with antioxidant N-acetylcysteine (NAC) prior to ATO exposure, not only reduced ROS production and UPR signaling but also improved macrophage functions. These data demonstrate that UPR signaling and ROS generation are interdependent and are involved in the arsenic-induced pathobiology of macrophage. These data also provide a novel strategy to block the ATO-dependent impairment in innate immune responses. - Highlights: • Inorganic arsenic to humans and experimental animals disrupt innate immune responses. • The mechanism underlying arsenic impaired macrophage functions involves UPR signaling. • Chemical chaperon attenuates arsenic-mediated macrophage function impairment. • Antioxidant, NAC blocks impairment in arsenic-treated macrophage functions.

  15. Biofilm-derived Legionella pneumophila evades the innate immune response in macrophages

    PubMed Central

    Abu Khweek, Arwa; Fernández Dávila, Natalia S.; Caution, Kyle; Akhter, Anwari; Abdulrahman, Basant A.; Tazi, Mia; Hassan, Hoda; Novotny, Laura A.; Bakaletz, Lauren O.; Amer, Amal O.

    2013-01-01

    Legionella pneumophila, the causative agent of Legionnaire's disease, replicates in human alveolar macrophages to establish infection. There is no human-to-human transmission and the main source of infection is L. pneumophila biofilms established in air conditioners, water fountains, and hospital equipments. The biofilm structure provides protection to the organism from disinfectants and antibacterial agents. L. pneumophila infection in humans is characterized by a subtle initial immune response, giving time for the organism to establish infection before the patient succumbs to pneumonia. Planktonic L. pneumophila elicits a strong immune response in murine, but not in human macrophages enabling control of the infection. Interactions between planktonic L. pneumophila and murine or human macrophages have been studied for years, yet the interface between biofilm-derived L. pneumophila and macrophages has not been explored. Here, we demonstrate that biofilm-derived L. pneumophila replicates significantly more in murine macrophages than planktonic bacteria. In contrast to planktonic L. pneumophila, biofilm-derived L. pneumophila lacks flagellin expression, do not activate caspase-1 or -7 and trigger less cell death. In addition, while planktonic L. pneumophila is promptly delivered to lysosomes for degradation, most biofilm-derived bacteria were enclosed in a vacuole that did not fuse with lysosomes in murine macrophages. This study advances our understanding of the innate immune response to biofilm-derived L. pneumophila and closely reproduces the natural mode of infection in human. PMID:23750338

  16. Biofilm-derived Legionella pneumophila evades the innate immune response in macrophages.

    PubMed

    Abu Khweek, Arwa; Fernández Dávila, Natalia S; Caution, Kyle; Akhter, Anwari; Abdulrahman, Basant A; Tazi, Mia; Hassan, Hoda; Novotny, Laura A; Bakaletz, Lauren O; Amer, Amal O

    2013-01-01

    Legionella pneumophila, the causative agent of Legionnaire's disease, replicates in human alveolar macrophages to establish infection. There is no human-to-human transmission and the main source of infection is L. pneumophila biofilms established in air conditioners, water fountains, and hospital equipments. The biofilm structure provides protection to the organism from disinfectants and antibacterial agents. L. pneumophila infection in humans is characterized by a subtle initial immune response, giving time for the organism to establish infection before the patient succumbs to pneumonia. Planktonic L. pneumophila elicits a strong immune response in murine, but not in human macrophages enabling control of the infection. Interactions between planktonic L. pneumophila and murine or human macrophages have been studied for years, yet the interface between biofilm-derived L. pneumophila and macrophages has not been explored. Here, we demonstrate that biofilm-derived L. pneumophila replicates significantly more in murine macrophages than planktonic bacteria. In contrast to planktonic L. pneumophila, biofilm-derived L. pneumophila lacks flagellin expression, do not activate caspase-1 or -7 and trigger less cell death. In addition, while planktonic L. pneumophila is promptly delivered to lysosomes for degradation, most biofilm-derived bacteria were enclosed in a vacuole that did not fuse with lysosomes in murine macrophages. This study advances our understanding of the innate immune response to biofilm-derived L. pneumophila and closely reproduces the natural mode of infection in human. PMID:23750338

  17. IL-10-producing intestinal macrophages prevent excessive antibacterial innate immunity by limiting IL-23 synthesis.

    PubMed

    Krause, Petra; Morris, Venetia; Greenbaum, Jason A; Park, Yoon; Bjoerheden, Unni; Mikulski, Zbigniew; Muffley, Tracy; Shui, Jr-Wen; Kim, Gisen; Cheroutre, Hilde; Liu, Yun-Cai; Peters, Bjoern; Kronenberg, Mitchell; Murai, Masako

    2015-01-01

    Innate immune responses are regulated in the intestine to prevent excessive inflammation. Here we show that a subset of mouse colonic macrophages constitutively produce the anti-inflammatory cytokine IL-10. In mice infected with Citrobacter rodentium, a model for enteropathogenic Escherichia coli infection in humans, these macrophages are required to prevent intestinal pathology. IL-23 is significantly increased in infected mice with a myeloid cell-specific deletion of IL-10, and the addition of IL-10 reduces IL-23 production by intestinal macrophages. Furthermore, blockade of IL-23 leads to reduced mortality in the context of macrophage IL-10 deficiency. Transcriptome and other analyses indicate that IL-10-expressing macrophages receive an autocrine IL-10 signal. Interestingly, only transfer of the IL-10 positive macrophages could rescue IL-10-deficient infected mice. Therefore, these data indicate a pivotal role for intestinal macrophages that constitutively produce IL-10, in controlling excessive innate immune activation and preventing tissue damage after an acute bacterial infection. PMID:25959063

  18. PPE26 induces TLR2-dependent activation of macrophages and drives Th1-type T-cell immunity by triggering the cross-talk of multiple pathways involved in the host response

    PubMed Central

    Su, Haibo; Kong, Cong; Zhu, Lin; Huang, Qi; Luo, Liulin; Wang, Honghai; Xu, Ying

    2015-01-01

    The pathophysiological functions and the underlying molecular basis of PE /PPE proteins of M. tuberculosis remain largely unknown. In this study, we focused on the link between PPE26 and host response. We demonstrated that PPE26 can induce extensive inflammatory responses in macrophages through triggering the cross-talk of multiple pathways involved in the host response, as revealed by iTRAQ-based subcellular quantitative proteomics. We observed that PPE26 is able to specifically bind to TLR2 leading to the subsequent activation of MAPKs and NF-κB signaling. PPE26 functionally stimulates macrophage activation by augmenting pro-inflammatory cytokine production (TNF-α, IL-6 and IL-12 p40) and the expression of cell surface markers (CD80, CD86, MHC class I and II). We observed that PPE26-treated macrophages effectively polarizes naïve CD4+ T cells to up-regulate CXCR3 expression, and to secrete IFN-γ and IL-2, indicating PPE26 contributes to the Th1 polarization during the immune response. Importantly, rBCG::PPE26 induces stronger antigen-specific TNF-α and IFN-γ activity, and higher levels of the Th1 cytokines TNF-α and IFN-γ comparable to BCG. Moreover, PPE26 effectively induces the reciprocal expansion of effector/memory CD4+/CD8+ CD44highCD62Llow T cells in the spleens of mice immunized with this strain. These results suggest that PPE26 may be a TLR2 agonist that stimulates innate immunity and adaptive immunity, indicating that PPE26 is a potential antigen for the rational design of an efficient vaccine against M. tuberculosis. PMID:26439698

  19. Minocycline differentially modulates macrophage mediated peripheral immune response following Japanese encephalitis virus infection.

    PubMed

    Dutta, Kallol; Mishra, Manoj Kumar; Nazmi, Arshed; Kumawat, Kanhaiya Lal; Basu, Anirban

    2010-11-01

    Japanese encephalitis virus (JEV) is a neurotropic flavivirus that is the causative agent of a major mosquito-borne encephalitis in the world. Evasion of peripheral immune system facilitates the entry of the virus into the central nervous system (CNS) where it causes extensive neuronal inflammatory damage that leads to death or severe neuropschychiatric sequel in survivors. It has been proposed that after entry into the body, the virus is carried into the CNS by peripheral immune cells that act as Trojan horses. In this study we investigate whether macrophages can be considered as such a Trojan horse. We also investigate the role of minocycline, a synthetic tetracycline, in such processes. Minocycline has been found to be broadly protective in neurological disease models featuring inflammation and cell death but there has been no report of it having any modulatory role in peripheral macrophage-mediated immune response against viral infection. Persistence of internalized virus within macrophages was visualized by immunofluorescent staining. Cytotoxicity assay revealed that there was no significant cell death after 24 h and 72 h infection with JEV. Proinflammatory cytokine levels were elevated in cells that were infected with JEV but it was abrogated following minocycline treatment. Reactive oxygen species level was also increased after JEV infection. Nitric oxide level was found to increase after 72 h post infection but remained unchanged after 24h. The cellular levels of signaling molecules such as PI3 kinase, phophoAkt and phospho p38MAP kinase were found to be altered after JEV infection and minocycline treatment. JEV infection also affected the VEGF-MMP pathway. Increased activity of MMP-9 was detected from JEV-infected macrophage culture supernatants after 72 h; minocycline treatment resulted in reduced activity. Thus it seems that minocycline dampens peripheral immune reactions by decreasing proinflammatory cytokine release from infected macrophages and the virus survives within macrophages long enough to be carried into the CNS, even though minocycline inhibits cell survival. PMID:20153075

  20. Macrophages: sentinels and regulators of the immune system.

    PubMed

    Franken, Lars; Schiwon, Marzena; Kurts, Christian

    2016-04-01

    The important role of macrophages in host defense against a variety of pathogens has long been recognized and has been documented and reviewed in numerous publications. Recently, it has become clear that tissue macrophages are not entirely derived from monocytes, as has been assumed for a long time, but rather show an ontogenetic dichotomy in most tissues: while part of the tissue macrophages are derived from monocytes, a major subset is prenatally seeded from the yolk sac. The latter subset shows a remarkable longevity and is maintained by self-renewal in the adult animal. This paradigm shift poses interesting questions: are these two macrophage subsets functionally equivalent cells that are recruited into the tissue at different development stages, or are both macrophage subsets discrete cell types with distinct functions, which have to exist side by side? Is the functional specialization that can be observed in most macrophages due to their lineage or due to their anatomical niche? This review will give an overview about what we know of macrophage ontogeny and will discuss the influence of the macrophage lineage and location on their functional specialization. PMID:26880038

  1. The Yin-Yang of tumor-associated macrophages in neoplastic progression and immune surveillance.

    PubMed

    Allavena, Paola; Sica, Antonio; Garlanda, Cecilia; Mantovani, Alberto

    2008-04-01

    An intrinsic (oncogene-driven) pathway and an extrinsic (microenvironment-driven) pathway connect inflammatory reactions and cancer. M2-polarized tumor-associated macrophages and the related myeloid-derived suppressor cells are key prototypic components of smoldering inflammation driving neoplastic progression. However, mononuclear phagocytes can exert anti-tumor activity by killing tumor cells and eliciting tissue disruptive reactions (M1), a likely scenario in the early phases of carcinogenesis of immunogenic tumors and following therapeutic intervention. Shifting the macrophage balance represents a viable therapeutic target. Herein, the 'macrophage balance' is discussed in the context of the apparent paradox of tumor promotion by innate immunity-driven inflammation and the seemingly opposed tumor surveillance by adaptive immune responses. PMID:18364000

  2. Ubiquitination by SAG regulates macrophage survival/death and immune response during infection.

    PubMed

    Chang, S C; Ding, J L

    2014-09-01

    The checkpoint between the life and death of macrophages is crucial for the host's frontline immune defense during acute phase infection. However, the mechanism as to how the immune cell equilibrates between apoptosis and immune response is unclear. Using in vitro and ex vivo approaches, we showed that macrophage survival is synchronized by SAG (sensitive to apoptosis gene), which is a key member of the ubiquitin-proteasome system (UPS). When challenged by pathogen-associated molecular patterns (PAMPs), we observed a reciprocal expression profile of pro- and antiapoptotic factors in macrophages. However, SAG knockdown disrupted this balance. Further analysis revealed that ubiquitination of Bax and SARM (sterile α- and HEAT/armadillo-motif-containing protein) by SAG-UPS confers survival advantage to infected macrophages. SAG knockdown caused the accumulation of proapoptotic Bax and SARM, imbalance of Bcl-2/Bax in the mitochondria, induction of cytosolic cytochrome c and activation of caspase-9 and -3, all of which led to disequilibrium between life and death of macrophages. In contrast, SAG-overexpressing macrophages challenged with PAMPs exhibited upregulation of protumorigenic cytokines (IL-1β, IL-6 and TNF-α), and downregulation of antitumorigenic cytokine (IL-12p40) and anti-inflammatory cytokine (IL-10). This suggests that SAG-dependent UPS is a key switch between immune defense and apoptosis or immune overactivation and tumorigenesis. Altogether, our results indicate that SAG-UPS facilitates a timely and appropriate level of immune response, prompting future development of potential immunomodulators of SAG-UPS. PMID:24786833

  3. Immune Reaction and Survivability of Salmonella Typhimurium and Salmonella Infantis after Infection of Primary Avian Macrophages

    PubMed Central

    Braukmann, Maria; Methner, Ulrich; Berndt, Angela

    2015-01-01

    Salmonella serovars are differentially able to infect chickens. The underlying causes are not yet fully understood. Aim of the present study was to elucidate the importance of Salmonella Pathogenicity Island 1 and 2 (SPI-1 and -2) for the virulence of two non-host-specific, but in-vivo differently invasive, Salmonella serovars in conjunction with the immune reaction of the host. Primary avian splenic macrophages were inoculated with Salmonella enterica sub-species enterica serovar (S.) Typhimurium and S. Infantis. The number and viability of intracellular bacteria and transcription of SPI-1 and -2 genes by the pathogens, as well as transcription of immune-related proteins, surface antigen expression and nitric oxide production by the macrophages, were compared at different times post inoculation. After infection, both of the Salmonella serovars were found inside the primary macrophages. Invasion-associated SPI-1 genes were significantly higher transcribed in S. Infantis- than S. Typhimurium-infected macrophages. The macrophages counteracted the S. Infantis and S. Typhimurium infection with elevated mRNA expression of inducible nitric oxide synthase (iNOS), interleukin (IL)-12, IL-18 and lipopolysaccharide-induced tumor necrosis factor alpha factor (LITAF) as well as with an increased synthesis of nitric oxide. Despite these host cell attacks, S. Typhimurium was better able than S. Infantis to survive within the macrophages and transcribed higher rates of the SPI-2 genes spiC, ssaV, sifA, and sseA. The results showed similar immune reactions of primary macrophages after infection with both of the Salmonella strains. The more rapid and stronger transcription of SPI-2-related genes by intracellular S. Typhimurium compared to S. Infantis might be responsible for its better survival in avian primary macrophages. PMID:25811871

  4. Photodynamic therapy mediates innate immune responses via fibroblast-macrophage interactions.

    PubMed

    Zulaziz, N; Azhim, A; Himeno, N; Tanaka, M; Satoh, Y; Kinoshita, M; Miyazaki, H; Saitoh, D; Shinomiya, N; Morimoto, Y

    2015-10-01

    Antibacterial photodynamic therapy (PDT) has come to attract attention as an alternative therapy for drug-resistant bacteria. Recent reports revealed that antibacterial PDT induces innate immune response and stimulates abundant cytokine secretion as a part of inflammatory responses. However, the underlying mechanism how antibacterial PDT interacts with immune cells responsible for cytokine secretion has not been well outlined. In this study, we aimed to clarify the difference in gene expression and cytokine secretion between combined culture of fibroblasts and macrophages and their independent cultures. SCRC-1008, mouse fibroblast cell line and J774, mouse macrophage-like cell line were co-cultured and PDT treatments with different parameters were carried out. After various incubation periods (1-24 h), cells and culture medium were collected, and mRNA and protein levels for cytokines were measured using real-time PCR and ELISA, respectively. Our results showed that fibroblasts and macrophages interact with each other to mediate the immune response. We propose that fibroblasts initially respond to PDT by expressing Hspa1b, which regulates the NF-κB pathway via Tlr2 and Tlr4. Activation of the NF-κB pathway then results in an enhanced secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) and neutrophil chemoattractant MIP-2 and KC from macrophages. PMID:25997703

  5. Homolog of allograft inflammatory factor-1 induces macrophage migration during innate immune response in leech.

    PubMed

    Schorn, Tilo; Drago, Francesco; Tettamanti, Gianluca; Valvassori, Roberto; de Eguileor, Magda; Vizioli, Jacopo; Grimaldi, Annalisa

    2015-03-01

    Allograft inflammatory factor-1 (AIF-1) is a 17-kDa cytokine-inducible calcium-binding protein that, in vertebrates, plays an important role in the allograft immune response. Its expression is mostly limited to the monocyte/macrophage lineage. Until recently, AIF-1 was assumed to be a novel molecule involved in inflammatory responses. To clarify this aspect, we have investigated the expression of AIF-1 after bacterial challenge and its potential role in regulating the innate immune response in an invertebrate model, the medicinal leech (Hirudo medicinalis). Analysis of an expressed sequence tag library from the central nervous system of Hirudo revealed the presence of the gene Hmaif-1/alias Hmiba1, showing high homology with vertebrate aif-1. Immunohistochemistry with an anti-HmAIF-1 polyclonal antibody revealed the constitutive presence of this protein in spread CD68(+) macrophage-like cells. A few hours after pathogen (bacterial) injection into the body wall, the amount of these immunopositive cells co-expressing HmAIF-1 and the common leucocyte marker CD45 increased at the injected site. Moreover, the recombinant protein HmAIF-1 induced massive angiogenesis and was a potent chemoattractant for macrophages. Following rHmAIF-1 stimulation, macrophage-like cells co-expressed the macrophage marker CD68 and the surface glycoprotein CD45, which, in vertebrates, seems to have a role in the integrin-mediated adhesion of macrophages and in the regulation of the functional responsiveness of cells to chemoattractants. CD45 is therefore probably involved in leech macrophage-like cell activation and migration towards an inflammation site. We have also examined its potential effect on HmAIF-1-induced signalling. PMID:25435328

  6. Macrophages as APC and the dendritic cell myth.

    PubMed

    Hume, David A

    2008-11-01

    Dendritic cells have been considered an immune cell type that is specialized for the presentation of Ag to naive T cells. Considerable effort has been applied to separate their lineage, pathways of differentiation, and effectiveness in Ag presentation from those of macrophages. This review summarizes evidence that dendritic cells are a part of the mononuclear phagocyte system and are derived from a common precursor, responsive to the same growth factors (including CSF-1), express the same surface markers (including CD11c), and have no unique adaptation for Ag presentation that is not shared by other macrophages. PMID:18941170

  7. The journey from stem cell to macrophage.

    PubMed

    Pittet, Mikael J; Nahrendorf, Matthias; Swirski, Filip K

    2014-06-01

    Essential protectors against infection and injury, macrophages can also contribute to many common and fatal diseases. Here, we discuss the mechanisms that control different types of macrophage activities in mice. We follow the cells' maturational pathways over time and space and elaborate on events that influence the type of macrophage eventually settling a particular destination. The nature of the precursor cells, developmental niches, tissues, environmental cues, and other connecting processes appear to contribute to the identity of macrophage type. Together, the spatial and developmental relationships of macrophages compose a topo-ontogenic map that can guide our understanding of their biology. PMID:24673186

  8. Neisseria gonorrhoeae Induces a Tolerogenic Phenotype in Macrophages to Modulate Host Immunity

    PubMed Central

    Candia, Enzo; Reyes-Cerpa, Sebastian; Villegas-Valdes, Bélgica; Neira, Tanya; Lopez, Mercedes; Maisey, Kevin; Tempio, Fabián; Ríos, Miguel; Acuña-Castillo, Claudio; Imarai, Mónica

    2013-01-01

    Neisseria gonorrhoeae is the etiological agent of gonorrhoea, which is a sexually transmitted disease widespread throughout the world. N. gonorrhoeae does not improve immune response in patients with reinfection, suggesting that gonococcus displays several mechanisms to evade immune response and survive in the host. N. gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and dendritic cells. In this study, we determined whether N. gonorrhoeae directly conditions the phenotype of RAW 264.7 murine macrophage cell line and its response. We established that gonococcus was effectively phagocytosed by the RAW 264.7 cells and upregulates production of immunoregulatory cytokines (IL-10 and TGF-β1) but not the production of proinflammatory cytokine TNF-α, indicating that gonococcus induces a shift towards anti-inflammatory cytokine production. Moreover, N. gonorrhoeae did not induce significant upregulation of costimulatory CD86 and MHC class II molecules. We also showed that N. gonorrhoeae infected macrophage cell line fails to elicit proliferative CD4+ response. This implies that macrophage that can phagocytose gonococcus do not display proper antigen-presenting functions. These results indicate that N. gonorrhoeae induces a tolerogenic phenotype in antigen-presenting cells, which seems to be one of the mechanisms to induce evasion of immune response. PMID:24204097

  9. Non-traditional cytokines: How catecholamines and adipokines influence macrophages in immunity, metabolism and the central nervous system

    PubMed Central

    Barnes, Mark A.; Carson, Monica J.; Nair, Meera G.

    2015-01-01

    Catecholamines and adipokines function as hormones; catecholamines as neurotransmitters in the sympathetic nervous system, and adipokines as mediators of metabolic processes. It has become increasingly clear, however, that both also function as immunomodulators of innate and adaptive immune cells, including macrophages. Macrophages can respond to, as well as produce their own catecholamines. Dopamine, noradrenaline, and adrenaline are the most abundant catecholamines in the body, and can induce both pro-inflammatory and anti-inflammatory immune responses in macrophages, as well as non-immune processes such as thermogenesis. Though they are responsive to adipokines, particularly lipoproteins, leptin, and adiponectin, macrophages generally do synthesize their own adipokines, with the exception being resistin-like molecules. Adipokines contribute to adverse metabolic and immune response by stimulating lipid accumulation, foam cell formation and pro-inflammatory cytokine production in macrophages. Adipokines can also promote balance or resolution during metabolic and immune processes by promoting reverse lipid transport and expression of Th2 cytokines. This review will explore the mechanisms by which catecholamines and adipokines influence macrophage function in neural pathways, immunity and metabolism. PMID:25703786

  10. PDT-treated apoptotic cells induce macrophage synthesis NO

    NASA Astrophysics Data System (ADS)

    Song, S.; Xing, D.; Zhou, F. F.; Chen, W. R.

    2009-11-01

    Nitric oxide (NO) is a biologically active molecule which has multi-functional in different species. As a second messenger and neurotransmitter, NO is not only an important regulatory factor between cells' information transmission, but also an important messenger in cell-mediated immunity and cytotoxicity. On the other side, NO is involving in some diseases' pathological process. In pathological conditions, the macrophages are activated to produce a large quantity of nitric oxide synthase (iNOS), which can use L-arginine to produce an excessive amount of NO, thereby killing bacteria, viruses, parasites, fungi, tumor cells, as well as in other series of the immune process. In this paper, photofrin-based photodynamic therapy (PDT) was used to treat EMT6 mammary tumors in vitro to induce apoptotic cells, and then co-incubation both apoptotic cells and macrophages, which could activate macrophage to induce a series of cytotoxic factors, especially NO. This, in turn, utilizes macrophages to activate a cytotoxic response towards neighboring tumor cells. These results provided a new idea for us to further study the immunological mechanism involved in damaging effects of PDT, also revealed the important function of the immune effect of apoptotic cells in PDT.

  11. Neither classical nor alternative macrophage activation is required for Pneumocystis clearance during immune reconstitution inflammatory syndrome.

    PubMed

    Zhang, Zhuo-Qian; Wang, Jing; Hoy, Zachary; Keegan, Achsah; Bhagwat, Samir; Gigliotti, Francis; Wright, Terry W

    2015-12-01

    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 PcP-related IRIS. PMID:26371121

  12. The journey from stem cell to macrophage

    PubMed Central

    Pittet, Mikael J.; Nahrendorf, Matthias; Swirski, Filip K.

    2014-01-01

    Essential protectors against infection and injury, macrophages can also contribute to many common and fatal diseases. Here we discuss the mechanisms that control different types of macrophage activities in mice. We follow the cells’ maturational pathways over time and space, and elaborate on events that influence the type of macrophage eventually settling a particular destination. The nature of the precursor cells, developmental niches, tissues, environmental cues, and other connecting processes appear to contribute to the identity of macrophage type. Together, the spatial and developmental relationships of macrophages comprise a topo-ontogenic map that can guide our understanding of their biology. PMID:24673186

  13. Ribonucleic acid synthesis in normal and immune macrophages after antigenic stimulus.

    PubMed

    Soderberg, L S; Tewari, R P; Solotorovsky, M

    1976-06-01

    Macrophage ribonucleic acid (RNA) synthesis is an important metabolic process intimately related to the function of these cells. Mouse peritoneal macrophage RNA was extracted with phenol in the presence of bentonite and electrophoresed on composite agarose-polyacrylamide gels. The pulse-chase technique was used to follow the precursor relationships in macrophage ribosomal RNA (rRNA) maturation. The rRNA species at 18S and 28S appeared at 15 and 45 min, respectively, after RNA synthesis was halted. Their appearance corresponded closely to decreases in the rRNA precursors at 45S, 36S, and 34S. Studies of RNA methylation aided in confirming the identity of these ribosomal species. Unmethylated RNA species appeared as messenger RNA between 5S and 15S, and at about 55S probably represented heterodisperse nuclear RNA. When normal macrophages were incubated with heat-killed Salmonella enteritidis, an acceleration in the maturation of RNA was observed. The accelerated maturation was indicated by the earlier appearance of 28S rRNA and the more rapid development of an equilibrium state, where further labeling did not change the RNA profile. In macrophage RNA from mice immunized with S. enteritidis, rRNA species appeared rapidly but did not accumulate to the same extent as observed for normal macrophages. Precursor rRNA and other RNA species developed as usual, suggesting specific degradation of mature rRNA. Such rRNA wastage could indicate a mechanism controlling ribosome assembly in the non-proliferating activated macrophage. The pattern of RNA synthesis in immune macrophages was essentially unchanged by the presence of heat-killed S. enteritidis in vitro. PMID:971940

  14. Epigenetic programming during monocyte to macrophage differentiation and trained innate immunity

    PubMed Central

    Saeed, Sadia; Quintin, Jessica; Kerstens, Hindrik H.D.; Rao, Nagesha A; Aghajanirefah, Ali; Matarese, Filomena; Cheng, Shih-Chin; Ratter, Jacqueline; Berentsen, Kim; van der Ent, Martijn A.; Sharifi, Nilofar; Janssen-Megens, Eva M.; Huurne, Menno Ter; Mandoli, Amit; van Schaik, Tom; Ng, Aylwin; Burden, Frances; Downes, Kate; Frontini, Mattia; Kumar, Vinod; Giamarellos-Bourboulis, Evangelos J; Ouwehand, Willem H; van der Meer, Jos W.M.; Joosten, Leo A.B.; Wijmenga, Cisca; Martens, Joost H.A.; Xavier, Ramnik J.; Logie, Colin; Netea, Mihai G.; Stunnenberg, Hendrik G.

    2014-01-01

    Structured Abstract Introduction Monocytes circulate in the bloodstream for up to 3–5 days. Concomitantly, immunological imprinting of either tolerance (immunosuppression) or trained immunity (innate immune memory) determines the functional fate of monocytes and monocyte-derived macrophages, as observed after infection or vaccination. Methods Purified circulating monocytes from healthy volunteers were differentiated under the homeostatic M-CSF concentrations present in human serum. During the first 24 hours, trained immunity was induced by β-glucan (BG) priming, while post-sepsis immunoparalysis was mimicked by exposure to LPS, generating endotoxin-induced tolerance. Epigenomic profiling of the histone marks H3K4me1, H3K4me3 and H3K27ac, DNase I accessibility and RNA sequencing were performed at both the start of the experiment (ex vivo monocytes) and at the end of the six days of in vitro culture (macrophages). Results Compared to monocytes (Mo), naïve macrophages (Mf) display a remodeled metabolic enzyme repertoire and attenuated innate inflammatory pathways; most likely necessary to generate functional tissue macrophages. Epigenetic profiling uncovered ~8000 dynamic regions associated with ~11000 DNase I hypersensitive sites. Changes in histone acetylation identified most dynamic events. Furthermore, these regions of differential histone marks displayed some degree of DNase I accessibility that was already present in monocytes. H3K4me1 mark increased in parallel with de novo H3K27ac deposition at distal regulatory regions; H3K4me1 mark remained even after the loss of H3K27ac, marking decommissioned regulatory elements. β-glucan priming specifically induced ~3000 distal regulatory elements, whereas LPS-tolerization uniquely induced H3K27ac at ~500 distal regulatory regions. At the transcriptional level, we identified co-regulated gene modules during monocyte to macrophage differentiation, as well as discordant modules between trained and tolerized cells. These indicate that training likely involves an increased expression of modules expressed in naïve macrophages, including genes that code for metabolic enzymes. On the other hand, endotoxin tolerance involves gene modules that are more active in monocytes than in naïve macrophages. About 12% of known human transcription factors display variation in expression during macrophage differentiation, training and tolerance. We also observed transcription factor motifs in DNase I hypersensitive sites at condition-specific dynamic epigenomic regions, implying that specific transcription factors are required for trained and tolerized macrophage epigenetic and transcriptional programs. Finally, our analyses and functional validation indicate that the inhibition of cAMP generation blocked trained immunity in vitro and during an in vivo model of lethal C. albicans infection, abolishing the protective effects of trained immunity. Discussion We documented the importance of epigenetic regulation of the immunological pathways underlying monocyte-to-macrophage differentiation and trained immunity. These dynamic epigenetic elements may inform on potential pharmacological targets that modulate innate immunity. Altogether, we uncovered the epigenetic and transcriptional programs of monocyte differentiation to macrophages that distinguish tolerant and trained macrophage phenotypes, providing a resource to further understand and manipulate immune-mediated responses. PMID:25258085

  15. DNA-Protein Immunization Using Leishmania Peroxidoxin-1 Induces a Strong CD4+ T Cell Response and Partially Protects Mice from Cutaneous Leishmaniasis: Role of Fusion Murine Granulocyte-Macrophage Colony-Stimulating Factor DNA Adjuvant

    PubMed Central

    Bayih, Abebe Genetu; Daifalla, Nada S.; Gedamu, Lashitew

    2014-01-01

    Background To date, no universally effective and safe vaccine has been developed for general human use. Leishmania donovani Peroxidoxin-1 (LdPxn-1) is a member of the antioxidant family of proteins and is predominantly expressed in the amastigote stage of the parasite. The aim of this study was to evaluate the immunogenicity and protective efficacy of LdPxn-1 in BALB/c mice in heterologous DNA-Protein immunization regimen in the presence of fusion murine granulocyte-macrophage colony-stimulating factor (mGMCSF) DNA adjuvant. Methodology and Principal Findings A fusion DNA of LdPxn1 and mGMCSF was cloned into a modified pcDNA vector. To confirm the expression in mammalian system, Chinese hamster ovary cells were transfected with the plasmid vector containing LdPxn1 gene. BALB/c mice were immunized twice with pcDNA-mGMCSF-LdPxn-1 or pcDNA-LdPxn1 DNA and boosted once with recombinant LdPxn-1 protein. Three weeks after the last immunization, mice were infected with Leishmania major promastigotes. The result showed that immunization with pcDNA-mGMCSF-LdPxn1 elicited a mixed Th-1/Th-2 immune response with significantly higher production of IFN-γ than controls. Intracellular cytokine staining of antigen-stimulated spleen cells showed that immunization with this antigen elicited significantly higher proportion of CD4+ T cells that express IFN-γ, TNF-α, or IL-2. The antigen also induced significantly higher proportion of multipotent CD4+ cells that simultaneously express the three Th-1 cytokines. Moreover, a significant reduction in the footpad swelling was seen in mice immunized with pcDNA-mGMCSF-LdPxn1 antigen. Expression study in CHO cells demonstrated that pcDNA-mGMCSF-LdPxn-1 was expressed in mammalian system. Conclusion The result demonstrates that immunization of BALB/c mice with a plasmid expressing LdPxn1 in the presence of mGMCSF adjuvant elicits a strong specific immune response with high level induction of multipotent CD4+ cells that mediate protection of the mice from Leishmania major infection. To our knowledge, this is the first study showing the vaccine potential of Leishmania peroxidoxin -1. PMID:25500571

  16. Cross-talk among myeloid-derived suppressor cells, macrophages, and tumor cells impacts the inflammatory milieu of solid tumors

    PubMed Central

    Beury, Daniel W.; Parker, Katherine H.; Nyandjo, Maeva; Sinha, Pratima; Carter, Kayla A.; Ostrand-Rosenberg, Suzanne

    2014-01-01

    MDSC and macrophages are present in most solid tumors and are important drivers of immune suppression and inflammation. It is established that cross-talk between MDSC and macrophages impacts anti-tumor immunity; however, interactions between tumor cells and MDSC or macrophages are less well studied. To examine potential interactions between these cells, we studied the impact of MDSC, macrophages, and four murine tumor cell lines on each other, both in vitro and in vivo. We focused on IL-6, IL-10, IL-12, TNF-α, and NO, as these molecules are produced by macrophages, MDSC, and many tumor cells; are present in most solid tumors; and regulate inflammation. In vitro studies demonstrated that MDSC-produced IL-10 decreased macrophage IL-6 and TNF-α and increased NO. IL-6 indirectly regulated MDSC IL-10. Tumor cells increased MDSC IL-6 and vice versa. Tumor cells also increased macrophage IL-6 and NO and decreased macrophage TNF-α. Tumor cell-driven macrophage IL-6 was reduced by MDSC, and tumor cells and MDSC enhanced macrophage NO. In vivo analysis of solid tumors identified IL-6 and IL-10 as the dominant cytokines and demonstrated that these molecules were produced predominantly by stromal cells. These results suggest that inflammation within solid tumors is regulated by the ratio of tumor cells to MDSC and macrophages and that interactions of these cells have the potential to alter significantly the inflammatory milieu within the tumor microenvironment. PMID:25170116

  17. Generation and characterization of bovine bone marrow-derived macrophage cell line.

    PubMed

    Xiao, Jiajia; Xie, Rongxia; Li, Qiaoqiao; Chen, Wuju; Zhang, Yong

    2016-05-01

    Macrophages, as the forefront of innate immune defense, have an important role in the host responses to mycobacterial infection. Therefore, a stable macrophage cell line is needed for future bovine immune system research on the bacterial infection. In this study, we established a bovine macrophage cell line by introducing the human telomerase reverse transcriptase (hTERT) gene into bovine bone marrow-derived macrophages (bBMMs). The TERT-bBMMs cells expressed macrophage surface antigen (CD11b, CD282) and upregulated expression of the cytokines IL-1β, IL-6, IL-10, IL-12, TNF-α in response to bacterial invasion. These results demonstrate that this cell line provide reliable cell model system for future studies on interactions between the bovine macrophages and Mycobacterium tuberculosis. PMID:26936441

  18. Mycoplasma bovis isolates recovered from cattle and bison (Bison bison) show differential in vitro effects on PBMC proliferation, alveolar macrophage apoptosis and invasion of epithelial and immune cells.

    PubMed

    Suleman, Muhammad; Prysliak, Tracy; Clarke, Kyle; Burrage, Pat; Windeyer, Claire; Perez-Casal, Jose

    2016-04-15

    In the last few years, several outbreaks of pneumonia, systemically disseminated infection, and high mortality associated with Mycoplasma bovis (M. bovis) in North American bison (Bison bison) have been reported in Alberta, Manitoba, Saskatchewan, Nebraska, New Mexico, Montana, North Dakota, and Kansas. M. bovis causes Chronic Pneumonia and Polyarthritis Syndrome (CPPS) in young, stressed calves in intensively-managed feedlots. M. bovis is not classified as a primary pathogen in cattle, but in bison it appears to be a primary causative agent with rapid progression of disease with fatal outcomes and an average 20% mature herd mortality. Thus, there is a possibility that M. bovis isolates from cattle and bison differ in their pathogenicity. Hence, we decided to compare selected cattle isolates to several bison isolates obtained from clinical cases. We show differences in modulation of PBMC proliferation, invasion of trachea and lung epithelial cells, along with modulation of apoptosis and survival in alveolar macrophages. We concluded that some bison isolates showed less inhibition of cattle and bison PBMC proliferation, were not able to suppress alveolar macrophage apoptosis as efficiently as cattle isolates, and were more or less invasive than the cattle isolate in various cells. These findings provide evidence about the differential properties of M. bovis isolated from the two species and has helped in the selection of bison isolates for genomic sequencing. PMID:27016754

  19. Immune Cells in the Female Reproductive Tract

    PubMed Central

    Kim, Chul Jung; Kim, Dong-Jae; Kang, Jee-hyun

    2015-01-01

    The female reproductive tract has two main functions: protection against microbial challenge and maintenance of pregnancy to term. The upper reproductive tract comprises the fallopian tubes and the uterus, including the endocervix, and the lower tract consists of the ectocervix and the vagina. Immune cells residing in the reproductive tract play contradictory roles: they maintain immunity against vaginal pathogens in the lower tract and establish immune tolerance for sperm and an embryo/fetus in the upper tract. The immune system is significantly influenced by sex steroid hormones, although leukocytes in the reproductive tract lack receptors for estrogen and progesterone. The leukocytes in the reproductive tract are distributed in either an aggregated or a dispersed form in the epithelial layer, lamina propria, and stroma. Even though immune cells are differentially distributed in each organ of the reproductive tract, the predominant immune cells are T cells, macrophages/dendritic cells, natural killer (NK) cells, neutrophils, and mast cells. B cells are rare in the female reproductive tract. NK cells in the endometrium significantly expand in the late secretory phase and further increase their number during early pregnancy. It is evident that NK cells and regulatory T (Treg) cells are extremely important in decidual angiogenesis, trophoblast migration, and immune tolerance during pregnancy. Dysregulation of endometrial/decidual immune cells is strongly related to infertility, miscarriage, and other obstetric complications. Understanding the immune system of the female reproductive tract will significantly contribute to women's health and to success in pregnancy. PMID:25713505

  20. Macrophage polarization in nerve injury: do Schwann cells play a role?

    PubMed Central

    Stratton, Jo Anne; Shah, Prajay T.

    2016-01-01

    In response to peripheral nerve injury, the inflammatory response is almost entirely comprised of infiltrating macrophages. Macrophages are a highly plastic, heterogenic immune cell, playing an indispensable role in peripheral nerve injury, clearing debris and regulating the microenvironment to allow for efficient regeneration. There are several cells within the microenvironment that likely interact with macrophages to support their function – most notably the Schwann cell, the glial cell of the peripheral nervous system. Schwann cells express several ligands that are known to interact with receptors expressed by macrophages, yet the effects of Schwann cells in regulating macrophage phenotype remains largely unexplored. This review discusses macrophages in peripheral nerve injury and how Schwann cells may regulate their behavior. PMID:26981078

  1. The Debate about Dendritic Cells and Macrophages in the Kidney

    PubMed Central

    Gottschalk, Catherine; Kurts, Christian

    2015-01-01

    The mononuclear phagocyte system includes macrophages and dendritic cells (DCs), which are usually classified by morphology, phenotypical characteristics, and function. In the last decades, large research communities have gathered substantial knowledge on the roles of these cells in immune homeostasis and anti-infectious defense. However, these communities developed to a degree independent from each other, so that the nomenclature and functions of the numerous DC and macrophage subsets overlap, resulting in the present intense debate about the correct nomenclature. This controversy has also reached the field of experimental nephrology. At present, no mutually accepted way to distinguish renal DC and macrophages is available, so that many important roles in acute and chronic kidney disease have been ascribed to both DCs and macrophages. In this perspective article, we discuss the causes and consequences of the overlapping DC–macrophage classification systems, functional roles of DCs and macrophages, and the transferability of recent findings from other disciplines to the renal mononuclear phagocyte system from the nephrologist’s point of view. PMID:26388867

  2. T CellMacrophage Interactions and Granuloma Formation in Vasculitis

    PubMed Central

    Hilhorst, Marc; Shirai, Tsuyoshi; Berry, Gerald; Goronzy, Jrg J.; Weyand, Cornelia M.

    2014-01-01

    Granuloma formation, bringing into close proximity highly activated macrophages and T cells, is a typical event in inflammatory blood vessel diseases, and is noted in the name of several of the vasculitides. It is not known whether specific properties of the microenvironment in the blood vessel wall or the immediate surroundings of blood vessels contribute to granuloma formation and, in some cases, generation of multinucleated giant cells. Granulomas provide a specialized niche to optimize macrophageT cell interactions, strongly activating both cell types. This is mirrored by the intensity of the systemic inflammation encountered in patients with vasculitis, often presenting with malaise, weight loss, fever, and strongly upregulated acute phase responses. As a sophisticated and highly organized structure, granulomas can serve as an ideal site to induce differentiation and maturation of T cells. The granulomas possibly seed aberrant Th1 and Th17 cells into the circulation, which are known to be the main pathogenic cells in vasculitis. Through the induction of memory T cells, aberrant innate immune responses can imprint the host immune system for decades to come and promote chronicity of the disease process. Improved understanding of T cellmacrophage interactions will redefine pathogenic models in the vasculitides and provide new avenues for immunomodulatory therapy. PMID:25309534

  3. Diverse influences of androgen-disrupting chemicals on immune responses mounted by macrophages.

    PubMed

    Kim, Kyong Hoon; Yeon, Seung-min; Kim, Hyun Gyung; Choi, Hyun Suk; Kang, Hyojeung; Park, Hee-Deung; Park, Tae Won; Pack, Seung Pil; Lee, Eun Hee; Byun, Youngjoo; Choi, Sang-Eun; Lee, Kenneth Sung; Ha, Un-Hwan; Jung, Yong Woo

    2014-06-01

    Androgen-disrupting chemicals (ADCs) can alter male sexual development. Although the effects of ADCs on hormone disruption have been studied, their influence on the immune response is not fully understood. To investigate the effects of ADCs on innate immunity, we tested eight candidate ADCs for their influence on macrophages by measuring nitric oxide (NO) production and cell viability. Our results showed that treatment with a mixture of lipopolysaccharide and hexachlorobenzene increased NO production in RAW 264.7 cells, a murine macrophage cell line. In contrast, compared to exposure to a negative control, exposure to di-2-ethylhexyl adipate (DEHA), benzylbutyl phthalate (BBP), testosterone (TTT), or permethrin decreased NO production. DEHA, BBP, and TTT inhibited NO production in an inducible nitric oxide synthase-dependent manner. Treatment with bisphenol A (BPA), nonylphenol (NNP), or tributyltin chloride (TBTC) reduced NO production and induced cell death. While BPA induced RAW 264.7 cell death through apoptosis, NNP and TBTC caused cell death through necrosis. These results offer insights into the influences of ADCs on the innate immune system. PMID:24287822

  4. p-Cresyl sulfate suppresses lipopolysaccharide-induced anti-bacterial immune responses in murine macrophages in vitro.

    PubMed

    Shiba, Takahiro; Makino, Ikuyo; Kawakami, Koji; Kato, Ikuo; Kobayashi, Toshihide; Kaneko, Kimiyuki

    2016-03-14

    p-Cresyl sulfate (pCS) is a known uremic toxin that is metabolized from p-cresol produced by intestinal bacteria. Abnormal accumulation of pCS in the blood is a characteristic of chronic kidney disease (CKD). pCS is suggested to cause immune dysfunction and increase the risk of infectious diseases in CKD patients. In this study, we focused on the effects of pCS on macrophage functions related to host defense. We evaluated the effects of pCS on cytokine production, nitric oxide (NO) production, arginase activity, expression of cell-surface molecules, and phagocytosis in the macrophage-like cell line, RAW264.7. pCS significantly decreased interleukin (IL)-12 p40 production and increased IL-10 production. pCS also decreased NO production, but did not influence arginase activity. pCS suppressed lipopolysaccharide-induced CD40 expression on the cell surface, but did not influence phagocytosis. We further assessed whether the effects of pCS observed in the macrophage-like cell line were consistent in primary macrophages. Similar to RAW264.7 cells, pCS decreased IL-12 p40 and p70 production and increased IL-10 production in primary peritoneal macrophages. These data indicate that pCS suppresses certain macrophage functions that contribute to host defense, and may play a role in CKD-related immune dysfunction. PMID:26784855

  5. Innate immune recognition triggers secretion of lysosomal enzymes by macrophages.

    PubMed

    Lackman, Rebecca L; Jamieson, Amanda M; Griffith, Janice M; Geuze, Hans; Cresswell, Peter

    2007-09-01

    Gamma interferon-induced lysosomal thiolreductase (GILT) is expressed constitutively in antigen-presenting cells, where it reduces disulfide bonds to facilitate antigen presentation. GILT is synthesized as an enzymatically active precursor protein and is processed in early endosomes to yield the mature enzyme. The exposure of the promonocytic cell line THP-1 to Escherichia coli causes a differentiation-dependent induction of GILT expression in which the majority of precursor GILT is secreted as active enzyme. We confirm this result in cultured primary monocytes and macrophages, and demonstrate, as an in vivo correlate of the phenomenon, upregulation of precursor GILT levels in the serum of mice injected with lipopolysaccharide. We show that macrophage differentiation is accompanied by a transcriptional downregulation of mannose-6-phosphorylation, which likely prevents the recognition and proper sorting of soluble lysosomal enzymes by the mannose-6-phosphate receptors. We provide evidence for a mechanism of generalized soluble lysosomal enzyme secretion through the constitutive secretory pathway. PMID:17555533

  6. Mesenchymal Stromal Cells Affect Disease Outcomes via Macrophage Polarization

    PubMed Central

    Zheng, Guoping; Ge, Menghua; Qiu, Guanguan; Shu, Qiang; Xu, Jianguo

    2015-01-01

    Mesenchymal stromal cells (MSCs) are multipotent and self-renewable cells that reside in almost all postnatal tissues. In recent years, many studies have reported the effect of MSCs on the innate and adaptive immune systems. MSCs regulate the proliferation, activation, and effector function of T lymphocytes, professional antigen presenting cells (dendritic cells, macrophages, and B lymphocytes), and NK cells via direct cell-to-cell contact or production of soluble factors including indoleamine 2,3-dioxygenase, prostaglandin E2, tumor necrosis factor-α stimulated gene/protein 6, nitric oxide, and IL-10. MSCs are also able to reprogram macrophages from a proinflammatory M1 phenotype toward an anti-inflammatory M2 phenotype capable of regulating immune response. Because of their capacity for differentiation and immunomodulation, MSCs have been used in many preclinical and clinical studies as possible new therapeutic agents for the treatment of autoimmune, degenerative, and inflammatory diseases. In this review, we discuss the central role of MSCs in macrophage polarization and outcomes of diseases such as wound healing, brain/spinal cord injuries, and diseases of heart, lung, and kidney in animal models. PMID:26257791

  7. Host lung immunity is severely compromised during tropical pulmonary eosinophilia: role of lung eosinophils and macrophages.

    PubMed

    Sharma, Pankaj; Sharma, Aditi; Vishwakarma, Achchhe Lal; Agnihotri, Promod Kumar; Sharma, Sharad; Srivastava, Mrigank

    2016-04-01

    Eosinophils play a central role in the pathogenesis of tropical pulmonary eosinophilia, a rare, but fatal, manifestation of filariasis. However, no exhaustive study has been done to identify the genes and proteins of eosinophils involved in the pathogenesis of tropical pulmonary eosinophilia. In the present study, we established a mouse model of tropical pulmonary eosinophilia that mimicked filarial manifestations of human tropical pulmonary eosinophilia pathogenesis and used flow cytometry-assisted cell sorting and real-time RT-PCR to study the gene expression profile of flow-sorted, lung eosinophils and lung macrophages during tropical pulmonary eosinophilia pathogenesis. Our results show that tropical pulmonary eosinophilia mice exhibited increased levels of IL-4, IL-5, CCL5, and CCL11 in the bronchoalveolar lavage fluid and lung parenchyma along with elevated titers of IgE and IgG subtypes in the serum. Alveolar macrophages from tropical pulmonary eosinophilia mice displayed decreased phagocytosis, attenuated nitric oxide production, and reduced T-cell proliferation capacity, and FACS-sorted lung eosinophils from tropical pulmonary eosinophilia mice upregulated transcript levels of ficolin A and anti-apoptotic geneBcl2,but proapoptotic genesBimandBaxwere downregulated. Similarly, flow-sorted lung macrophages upregulated transcript levels of TLR-2, TLR-6, arginase-1, Ym-1, and FIZZ-1 but downregulated nitric oxide synthase-2 levels, signifying their alternative activation. Taken together, we show that the pathogenesis of tropical pulmonary eosinophilia is marked by functional impairment of alveolar macrophages, alternative activation of lung macrophages, and upregulation of anti-apoptotic genes by eosinophils. These events combine together to cause severe lung inflammation and compromised lung immunity. Therapeutic interventions that can boost host immune response in the lungs might thus provide relief to patients with tropical pulmonary eosinophilia. PMID:26489428

  8. Differentiation of THP1 Cells into Macrophages for Transwell Co-culture Assay with Melanoma Cells

    PubMed Central

    Smith, Michael P; Young, Helen; Hurlstone, Adam; Wellbrock, Claudia

    2016-01-01

    Understanding how immune cells such as macrophages interact with cancer cells is of increasing interest, as cancer treatments move towards combining both targeted- and immuno- therapies in new treatment regimes. This protocol is using THP-1 cells, a human leukemia monocytic cell line that can be differentiated into macrophages. This allows studying the effects of the macrophage secretome on cancer cells (on e.g. growth, drug response or gene expression) in co-cultures without direct cell contact interactions. This is an important aspect as it removes the presence of any phagocytic aspect to changes in the cancer cell number and behaviour. The in vitro THP-1 monocyte differentiation into polarized macrophages was used to study the effects of both M1 and M2 type populations of macrophages on melanoma cells (Smith et al., 2014; Tsuchiya et al., 1980). M1 type macrophages are classically thought to be tumour suppressing as opposed to M2 type macrophages, which are thought to possess tissue repairing and tumour growth promoting activities.

  9. IL-10 producing intestinal macrophages prevent excessive anti-bacterial innate immunity by limiting IL-23 synthesis

    PubMed Central

    Krause, Petra; Morris, Venetia; Greenbaum, Jason A.; Park, Yoon; Bjoerheden, Unni; Mikulski, Zbigniew; Muffley, Tracy; Shui, Jr-Wen; Kim, Gisen; Cheroutre, Hilde; Liu, Yun- Cai; Peters, Bjoern; Kronenberg, Mitchell; Murai, Masako

    2015-01-01

    Innate immune responses are regulated in the intestine to prevent excessive inflammation. Here we show that a subset of mouse colonic macrophages constitutively produce the anti-inflammatory cytokine IL-10. In mice infected with Citrobacter rodentium, a model for enteropathogenic Escherichia coli infection in humans, these macrophages are required to prevent intestinal pathology. IL-23 is significantly increased in infected mice with a myeloid cell-specific deletion of IL-10, and the addition of IL-10 reduces IL-23 production by intestinal macrophages. Furthermore, blockade of IL-23 leads to reduced mortality in the context of macrophage IL-10 deficiency. Transcriptome and other analyses indicate that IL-10-expressing macrophages receive an autocrine IL-10 signal. Interestingly, only transfer of the IL-10 positive macrophages could rescue IL-10 deficient infected mice. Therefore, these data indicate a pivotal role for intestinal macrophages that constitutively produce IL-10, in controlling excessive innate immune activation and preventing tissue damage after an acute bacterial infection. PMID:25959063

  10. Immune cells tracing using quantum dots

    NASA Astrophysics Data System (ADS)

    Hoshino, Akiyoshi; Fujioka, Kouki; Kawamura, Yuki I.; Toyama-Sorimachi, Noriko; Yasuhara, Masato; Dohi, Taeko; Yamamoto, Kenji

    2006-02-01

    Fluorescent nanoparticles, such as nanocrystal quantum dots (QDs), have potential to be applied to molecular biology and bioimaging, since some nanocrystals emit higher and longer lasting fluorescence than conventional organic probes do. Here we report an example of labeling immune cells by QDs. We collected splenic CD4 + T-lymphocyte and peritoneal macrophages from mice. Then cells were labeled with QDs. QDs are incorporated into the T-lymphocyte and macrophages immediately after addition and located in the cytoplasm via endocytosis pathway. The fluorescence of QDs held in the endosomes was easily detected for more than a week. In addition, T-lymphocytes labeled with QDs were stable and cell proliferation or cytokine production including IL-2 and IFN-γ was not affected. When QD-labeled T-lymphocytes were adoptively transferred intravenously to mice, they remained in the peripheral blood and spleen up to a week. Using QD-labeled peritoneal macrophages, we studied cell traffic during inflammation on viscera in peritoneum cavity. QD-labeled macrophages were transplanted into the peritoneum of the mouse, and colitis was induced by intracolonic injection of a hapten, trinitrobenzensulfonic acid. With the aid of stong signals of QDs, we found that macrophage accumuled on the inflammation site of the colon. These results suggested that fluorescent probes of QDs might be useful as bioimaging tools for tracing target cells in vivo.

  11. 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

  12. Protective Immunity against Pulmonary Cryptococcosis Is Associated with STAT1-Mediated Classical Macrophage Activation

    PubMed Central

    Hardison, Sarah E.; Herrera, Gina; Young, Mattie L.; Hole, Camaron R.; Wozniak, Karen L.

    2012-01-01

    Experimental pulmonary Cryptococcus neoformans infection in BALB/c mice is associated with polarized Th2-type cytokine production, alternative macrophage activation, and severe bronchopneumonia. In contrast, pulmonary infection with a C. neoformans strain that secretes IFN-γ, H99γ, elicits Th1-type cytokine production and classical macrophage activation. Additionally, mice infected with H99γ resolve the acute infection and are subsequently protected against challenge with wild-type C. neoformans. The present study characterizes macrophage activation during the protective response to wild-type C. neoformans in mice previously immunized with H99γ. We observed increased pulmonary Th1-type cytokine production in lung homogenates and classical macrophage activation as evidenced by enhanced expression of inducible NO synthase in the lungs of H99γ-immunized mice compared with mice given a nonprotective immunization with heat-killed C. neoformans (HKCn). Furthermore, macrophages isolated from H99γ-immunized mice on day 7 postchallenge and cultured in vitro were fungistatic against C. neoformans, whereas cryptococcal growth was uncontrolled within macrophages from HKCn-immunized mice. Th2-type cytokine production and induction of alternatively activated macrophages were also observed in lungs of HKCn-immunized mice during rechallenge. Gene expression arrays showed that classical macrophage activation during challenge infection in H99γ-immunized mice was associated with induction of the transcription factor STAT1 and its downstream targets IFN regulatory factor-1, suppressor of cytokine signaling-1, CXCL9, and CXCL10. These studies demonstrate that protective responses to C. neoformans challenge in immunized mice include classical macrophage activation and enhanced macrophage fungistasis of C. neoformans yeasts. Finally, the classical activation phenotype of protective anticryptococcal macrophages is likely mediated via STAT1 signal transduction pathways. PMID:22984078

  13. Protective immunity against pulmonary cryptococcosis is associated with STAT1-mediated classical macrophage activation.

    PubMed

    Hardison, Sarah E; Herrera, Gina; Young, Mattie L; Hole, Camaron R; Wozniak, Karen L; Wormley, Floyd L

    2012-10-15

    Experimental pulmonary Cryptococcus neoformans infection in BALB/c mice is associated with polarized Th2-type cytokine production, alternative macrophage activation, and severe bronchopneumonia. In contrast, pulmonary infection with a C. neoformans strain that secretes IFN-γ, H99γ, elicits Th1-type cytokine production and classical macrophage activation. Additionally, mice infected with H99γ resolve the acute infection and are subsequently protected against challenge with wild-type C. neoformans. The present study characterizes macrophage activation during the protective response to wild-type C. neoformans in mice previously immunized with H99γ. We observed increased pulmonary Th1-type cytokine production in lung homogenates and classical macrophage activation as evidenced by enhanced expression of inducible NO synthase in the lungs of H99γ-immunized mice compared with mice given a nonprotective immunization with heat-killed C. neoformans (HKCn). Furthermore, macrophages isolated from H99γ-immunized mice on day 7 postchallenge and cultured in vitro were fungistatic against C. neoformans, whereas cryptococcal growth was uncontrolled within macrophages from HKCn-immunized mice. Th2-type cytokine production and induction of alternatively activated macrophages were also observed in lungs of HKCn-immunized mice during rechallenge. Gene expression arrays showed that classical macrophage activation during challenge infection in H99γ-immunized mice was associated with induction of the transcription factor STAT1 and its downstream targets IFN regulatory factor-1, suppressor of cytokine signaling-1, CXCL9, and CXCL10. These studies demonstrate that protective responses to C. neoformans challenge in immunized mice include classical macrophage activation and enhanced macrophage fungistasis of C. neoformans yeasts. Finally, the classical activation phenotype of protective anticryptococcal macrophages is likely mediated via STAT1 signal transduction pathways. PMID:22984078

  14. Structurally well-defined macrophage activating factor derived from vitamin D3-binding protein has a potent adjuvant activity for immunization.

    PubMed

    Yamamoto, N; Naraparaju, V R

    1998-06-01

    Freund's adjuvant produced severe inflammation that augments development of antibodies. Thus, mixed administration of antigens with adjuvant was not required as long as inflammation was induced in the hosts. Since macrophage activation for phagocytosis and antigen processing is the first step of antibody development, inflammation-primed macrophage activation plays a major role in immune development. Therefore, macrophage activating factor should act as an adjuvant for immunization. The inflammation-primed macrophage activation process is the major macrophage activating cascade that requires participation of serum vitamin D3-binding protein (DBP; human DBP is known as Gc protein) and glycosidases of B and T lymphocytes. Stepwise incubation of Gc protein with immobilized beta-galactosidase and sialidase efficiently generated the most potent macrophage activating factor (designated GcMAF) we have ever encountered. Administration of GcMAF (20 or 100 pg/mouse) resulted in stimulation of the progenitor cells for extensive mitogenesis and activation of macrophages. Administration of GcMAF (100 pg/mouse) along with immunization of mice with sheep red blood cells (SRBC) produced a large number of anti-SRBC antibody secreting splenic cells in 2-4 days. Thus, GcMAF has a potent adjuvant activity for immunization. Although malignant tumours are poorly immunogenic, 4 days after GcMAF-primed immunization of mice with heat-killed Ehrlich ascites tumour cells, the ascites tumour was no longer transplantable in these mice. PMID:9682967

  15. Alveolar macrophages and type I IFN in airway homeostasis and immunity.

    PubMed

    Divangahi, Maziar; King, Irah L; Pernet, Erwan

    2015-05-01

    Globally, respiratory infections cause more than 4 million deaths per year, with influenza and tuberculosis (TB) in particular being major causes of mortality and morbidity. Although immune cell activation is critical for killing respiratory pathogens, this response must be tightly regulated to effectively control and eliminate invading microorganisms while minimizing immunopathology and maintaining pulmonary function. The distinct microenvironment of the lung is constantly patrolled by alveolar macrophages (Mφ), which are essential for tissue homeostasis, early pathogen recognition, initiation of the local immune response, and resolution of inflammation. Here, we focus on recent advances that have provided insight into the relation between pulmonary Mφ, type I interferon (IFN) signaling, and the delicate balance between protective and pathological immune responses in the lung. PMID:25843635

  16. Innate Immune Cells in Liver Inflammation

    PubMed Central

    Liaskou, Evaggelia; Wilson, Daisy V.; Oo, Ye H.

    2012-01-01

    Innate immune system is the first line of defence against invading pathogens that is critical for the overall survival of the host. Human liver is characterised by a dual blood supply, with 80% of blood entering through the portal vein carrying nutrients and bacterial endotoxin from the gastrointestinal tract. The liver is thus constantly exposed to antigenic loads. Therefore, pathogenic microorganism must be efficiently eliminated whilst harmless antigens derived from the gastrointestinal tract need to be tolerized in the liver. In order to achieve this, the liver innate immune system is equipped with multiple cellular components; monocytes, macrophages, granulocytes, natural killer cells, and dendritic cells which coordinate to exert tolerogenic environment at the same time detect, respond, and eliminate invading pathogens, infected or transformed self to mount immunity. This paper will discuss the innate immune cells that take part in human liver inflammation, and their roles in both resolution of inflammation and tissue repair. PMID:22933833

  17. Immune evasion, stress resistance, and efficient nutrient acquisition are crucial for intracellular survival of Candida glabrata within macrophages.

    PubMed

    Seider, Katja; Gerwien, Franziska; Kasper, Lydia; Allert, Stefanie; Brunke, Sascha; Jablonowski, Nadja; Schwarzmüller, Tobias; Barz, Dagmar; Rupp, Steffen; Kuchler, Karl; Hube, Bernhard

    2014-01-01

    Candida glabrata is both a human fungal commensal and an opportunistic pathogen which can withstand activities of the immune system. For example, C. glabrata can survive phagocytosis and replicates within macrophages. However, the mechanisms underlying intracellular survival remain unclear. In this work, we used a functional genomic approach to identify C. glabrata determinants necessary for survival within human monocyte-derived macrophages by screening a set of 433 deletion mutants. We identified 23 genes which are required to resist killing by macrophages. Based on homologies to Saccharomyces cerevisiae orthologs, these genes are putatively involved in cell wall biosynthesis, calcium homeostasis, nutritional and stress response, protein glycosylation, or iron homeostasis. Mutants were further characterized using a series of in vitro assays to elucidate the genes' functions in survival. We investigated different parameters of C. glabrata-phagocyte interactions: uptake by macrophages, replication within macrophages, phagosomal pH, and recognition of mutant cells by macrophages as indicated by production of reactive oxygen species and tumor necrosis factor alpha (TNF-α). We further studied the cell surface integrity of mutant cells, their ability to grow under nutrient-limited conditions, and their susceptibility to stress conditions mirroring the harsh environment inside a phagosome. Additionally, resistance to killing by neutrophils was analyzed. Our data support the view that immune evasion is a key aspect of C. glabrata virulence and that increased immune recognition causes increased antifungal activities by macrophages. Furthermore, stress resistance and efficient nutrient acquisition, in particular, iron uptake, are crucial for intraphagosomal survival of C. glabrata. PMID:24363366

  18. Immune Evasion, Stress Resistance, and Efficient Nutrient Acquisition Are Crucial for Intracellular Survival of Candida glabrata within Macrophages

    PubMed Central

    Seider, Katja; Gerwien, Franziska; Kasper, Lydia; Allert, Stefanie; Brunke, Sascha; Jablonowski, Nadja; Schwarzmüller, Tobias; Barz, Dagmar; Rupp, Steffen; Kuchler, Karl

    2014-01-01

    Candida glabrata is both a human fungal commensal and an opportunistic pathogen which can withstand activities of the immune system. For example, C. glabrata can survive phagocytosis and replicates within macrophages. However, the mechanisms underlying intracellular survival remain unclear. In this work, we used a functional genomic approach to identify C. glabrata determinants necessary for survival within human monocyte-derived macrophages by screening a set of 433 deletion mutants. We identified 23 genes which are required to resist killing by macrophages. Based on homologies to Saccharomyces cerevisiae orthologs, these genes are putatively involved in cell wall biosynthesis, calcium homeostasis, nutritional and stress response, protein glycosylation, or iron homeostasis. Mutants were further characterized using a series of in vitro assays to elucidate the genes' functions in survival. We investigated different parameters of C. glabrata-phagocyte interactions: uptake by macrophages, replication within macrophages, phagosomal pH, and recognition of mutant cells by macrophages as indicated by production of reactive oxygen species and tumor necrosis factor alpha (TNF-α). We further studied the cell surface integrity of mutant cells, their ability to grow under nutrient-limited conditions, and their susceptibility to stress conditions mirroring the harsh environment inside a phagosome. Additionally, resistance to killing by neutrophils was analyzed. Our data support the view that immune evasion is a key aspect of C. glabrata virulence and that increased immune recognition causes increased antifungal activities by macrophages. Furthermore, stress resistance and efficient nutrient acquisition, in particular, iron uptake, are crucial for intraphagosomal survival of C. glabrata. PMID:24363366

  19. Nanogel-based immunologically stealth vaccine targets macrophages in the medulla of lymph node and induces potent antitumor immunity.

    PubMed

    Muraoka, Daisuke; Harada, Naozumi; Hayashi, Tae; Tahara, Yoshiro; Momose, Fumiyasu; Sawada, Shin-ichi; Mukai, Sada-atsu; Akiyoshi, Kazunari; Shiku, Hiroshi

    2014-09-23

    Because existing therapeutic cancer vaccines provide only a limited clinical benefit, a different vaccination strategy is necessary to improve vaccine efficacy. We developed a nanoparticulate cancer vaccine by encapsulating a synthetic long peptide antigen within an immunologically inert nanoparticulate hydrogel (nanogel) of cholesteryl pullulan (CHP). After subcutaneous injection to mice, the nanogel-based vaccine was efficiently transported to the draining lymph node, and was preferentially engulfed by medullary macrophages but was not sensed by other macrophages and dendritic cells (so-called "immunologically stealth mode"). Although the function of medullary macrophages in T cell immunity has been unexplored so far, these macrophages effectively cross-primed the vaccine-specific CD8(+) T cells in the presence of a Toll-like receptor (TLR) agonist as an adjuvant. The nanogel-based vaccine significantly inhibited in vivo tumor growth in the prophylactic and therapeutic settings, compared to another vaccine formulation using a conventional delivery system, incomplete Freund's adjuvant. We also revealed that lymph node macrophages were highly responsive to TLR stimulation, which may underlie the potency of the macrophage-oriented, nanogel-based vaccine. These results indicate that targeting medullary macrophages using the immunologically stealth nanoparticulate delivery system is an effective vaccine strategy. PMID:25180962

  20. Innate immune cells in the pathogenesis of primary systemic vasculitis.

    PubMed

    Misra, Durga Prasanna; Agarwal, Vikas

    2016-02-01

    Innate immune system forms the first line of defense against foreign substances. Neutrophils, eosinophils, erythrocytes, platelets, monocytes, macrophages, dendritic cells, γδ T cells, natural killer and natural killer T cells comprise the innate immune system. Genetic polymorphisms influencing the activation of innate immune cells predispose to development of vasculitis and influence its severity. Abnormally activated innate immune cells cross-talk with other cells of the innate immune system, present antigens more efficiently and activate T and B lymphocytes and cause tissue destruction via cell-mediated cytotoxicity and release of pro-inflammatory cytokines. These secreted cytokines further recruit other cells to the sites of vascular injury. They are involved in both the initiation as well as the perpetuation of vasculitis. Evidences suggest reversal of aberrant activation of immune cells in response to therapy. Understanding the role of innate immune cells in vasculitis helps understand the potential of therapeutic modulation of their activation to treat vasculitis. PMID:26403285

  1. Control of growth and inflammatory response of macrophages and foam cells with nanotopography

    NASA Astrophysics Data System (ADS)

    Mohiuddin, Mohammed; Pan, Hsu-An; Hung, Yao-Ching; Huang, Guewha Steven

    2012-07-01

    Macrophages play an important role in modulating the immune function of the human body, while foam cells differentiated from macrophages with subsequent fatty streak formation play a key role in atherosclerosis. We hypothesized that nanotopography modulates the behavior and function of macrophages and foam cells without bioactive agent. In the present study, nanodot arrays ranging from 10- to 200-nm were used to evaluate the growth and function of macrophages and foam cells. In the quantitative analysis, the cell adhesion area in macrophages increased with 10- to 50-nm nanodot arrays compared to the flat surface, while it decreased with 100- and 200-nm nanodot arrays. A similar trend of adhesion was observed in foam cells. Immunostaining, specific to vinculin and actin filaments, indicated that a 50-nm surface promoted cell adhesion and cytoskeleton organization. On the contrary, 200-nm surfaces hindered cell adhesion and cytoskeleton organization. Further, based on quantitative real-time polymerase chain reaction data, expression of inflammatory genes was upregulated for the 100- and 200-nm surfaces in macrophages and foam cells. This suggests that nanodots of 100- and 200-nm triggered immune inflammatory stress response. In summary, nanotopography controls cell morphology, adhesions, and proliferation. By adjusting the nanodot diameter, we could modulate the growth and expression of function-related genes in the macrophages and foam cell system. The nanotopography-mediated control of cell growth and morphology provides potential insight for designing cardiovascular implants.

  2. 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

  3. Immune cells and angiogenesis

    PubMed Central

    Ribatti, Domenico; Crivellato, Enrico

    2009-01-01

    Both innate and adaptive immune cells are involved in the mechanisms of endothelial cell proliferation, migration and activation, through the production and release of a large spectrum of pro-angiogenic mediators. These may create the specific microenvironment that favours an increased rate of tissue vascularization. In this review, we will focus on the immune cell component of the angiogenic process in inflammation and tumour growth. As angiogenesis is the result of a net balance between the activities exerted by positive and negative regulators, we will also provide information on some antiangiogenic properties of immune cells that may be utilized for a potential pharmacological use as antiangiogenic agents in inflammation as well as in cancer. PMID:19538473

  4. Cell motility is decreased in macrophages activated by cancer cell-conditioned medium.

    PubMed

    Go, Ahreum; Ryu, Yun-Kyoung; Lee, Jae-Wook; Moon, Eun-Yi

    2013-11-01

    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

  5. Immunopathogenesis of Myocarditis: The Interplay Between Cardiac Fibroblast Cells, Dendritic Cells, Macrophages and CD4+ T Cells.

    PubMed

    Amoah, B Prince; Yang, H; Zhang, P; Su, Z; Xu, H

    2015-07-01

    The myocardium responds to aetiologically different pathological injuries through a common multistep process involving highly co-ordinated interactions between cardiac and immune cells. Cardiac fibroblast cells which constitute the prevalent cell type in the heart to have their functional effects that express contractile proteins and exhibit increased migratory, proliferative and secretory properties. During the pathogenesis of myocarditis, cardiac fibroblast, dendritic cells, macrophages, CD4(+) T cells and other immune cells are known to play variable roles. It is becoming increasingly clear that cardiac fibroblasts are not passive players in immune responses, and several evidences show this through the release of soluble signals and/or direct interactions with these immune cells. Typically, fibroblasts are involved in synthesizing factors such as cytokines, chemokines, prostanoids, matrix components and matrix-degrading enzymes to influence dendritic cells, CD4(+) T cells and macrophage functions and vice versa in the pathogenesis of myocarditis. Again, evidence proves a crosstalk between cardiac fibroblasts and immune cells recruited into the myocardium during myocarditis in the microenvironments. This piece reviews the properties and roles of cardiac fibroblast cells, dendritic cells, macrophages and CD4(+) T cells in the pathogenesis of myocarditis, and how these cells interplay on each other in the microenvironment. PMID:25845946

  6. Biodegradation of carbon nanohorns in macrophage cells

    NASA Astrophysics Data System (ADS)

    Zhang, Minfang; Yang, Mei; Bussy, Cyrill; Iijima, Sumio; Kostarelos, Kostas; Yudasaka, Masako

    2015-02-01

    With the rapid developments in the medical applications of carbon nanomaterials such as carbon nanohorns (CNHs), carbon nanotubes, and graphene based nanomaterials, understanding the long-term fate, health impact, excretion, and degradation of these materials has become crucial. Herein, the in vitro biodegradation of CNHs was determined using a non-cellular enzymatic oxidation method and two types of macrophage cell lines. Approximately 60% of the CNHs was degraded within 24 h in a phosphate buffer solution containing myeloperoxidase. Furthermore, approximately 30% of the CNHs was degraded by both RAW 264.7 and THP-1 macrophage cells within 9 days. Inflammation markers such as pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α were not induced by exposure to CNHs. However, reactive oxygen species were generated by the macrophage cells after uptake of CNHs, suggesting that these species were actively involved in the degradation of the nanomaterials rather than in an inflammatory pathway induction.With the rapid developments in the medical applications of carbon nanomaterials such as carbon nanohorns (CNHs), carbon nanotubes, and graphene based nanomaterials, understanding the long-term fate, health impact, excretion, and degradation of these materials has become crucial. Herein, the in vitro biodegradation of CNHs was determined using a non-cellular enzymatic oxidation method and two types of macrophage cell lines. Approximately 60% of the CNHs was degraded within 24 h in a phosphate buffer solution containing myeloperoxidase. Furthermore, approximately 30% of the CNHs was degraded by both RAW 264.7 and THP-1 macrophage cells within 9 days. Inflammation markers such as pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α were not induced by exposure to CNHs. However, reactive oxygen species were generated by the macrophage cells after uptake of CNHs, suggesting that these species were actively involved in the degradation of the nanomaterials rather than in an inflammatory pathway induction. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06175f

  7. Receptor-Interacting Protein Kinase-2 Inhibition by CYLD Impairs Antibacterial Immune Responses in Macrophages

    PubMed Central

    Wex, Katharina; Schmid, Ursula; Just, Sissy; Wang, Xu; Wurm, Rebecca; Naumann, Michael; Schlüter, Dirk; Nishanth, Gopala

    2016-01-01

    Upon infection with intracellular bacteria, nucleotide oligomerization domain protein 2 recognizes bacterial muramyl dipeptide and binds, subsequently, to receptor-interacting serine/threonine kinase 2 (RIPK2), which activates immune responses via the nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) and extracellular signal-regulated kinase (ERK) pathways. Activation of RIPK2 depends on its K63 ubiquitination by E3 ligases, whereas the deubiquitinating enzyme A20 counter regulates RIPK2 activity by cleaving K63-polyubiquitin chains from RIPK2. Here, we newly identify the deubiquitinating enzyme CYLD as a new inhibitor of RIPK2. We show that CYLD binds to and removes K63-polyubiquitin chains from RIPK2 in Listeria monocytogenes (Lm) infected murine bone marrow-derived macrophages. CYLD-mediated K63 deubiquitination of RIPK2 resulted in an impaired activation of both NF-κB and ERK1/2 pathways, reduced production of proinflammatory cytokines interleukin-6 (IL-6), IL-12, anti-listerial reactive oxygen species (ROS) and nitric oxide (NO), and, finally, impaired pathogen control. In turn, RIPK2 inhibition by siRNA prevented activation of NF-κB and ERK1/2 and completely abolished the protective effect of CYLD deficiency with respect to the production of IL-6, NO, ROS, and pathogen control. Noteworthy, CYLD also inhibited autophagy of Listeria in a RIPK2-ERK1/2-dependent manner. The protective function of CYLD deficiency was dependent on interferon gamma (IFN-γ) prestimulation of infected macrophages. Interestingly, the reduced NF-κB activation in CYLD-expressing macrophages limited the protective effect of IFN-γ by reducing NF-κB-dependent signal transducers and activators of transcription-1 (STAT1) activation. Taken together, our study identifies CYLD as an important inhibitor of RIPK2-dependent antibacterial immune responses in macrophages. PMID:26834734

  8. The Interplay Between Monocytes/Macrophages and CD4+ T Cell Subsets in Rheumatoid Arthritis

    PubMed Central

    Roberts, Ceri A.; Dickinson, Abigail K.; Taams, Leonie S.

    2015-01-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by inflammation of the synovial lining (synovitis). The inflammation in the RA joint is associated with and driven by immune cell infiltration, synovial hyperproliferation, and excessive production of proinflammatory mediators, such as tumor necrosis factor α (TNFα), interferon γ (IFNγ), interleukin (IL)-1β, IL-6, and IL-17, eventually resulting in damage to the cartilage and underlying bone. The RA joint harbors a wide range of immune cell types, including monocytes, macrophages, and CD4+ T cells (both proinflammatory and regulatory). The interplay between CD14+ myeloid cells and CD4+ T cells can significantly influence CD4+ T cell function, and conversely, effector vs. regulatory CD4+ T cell subsets can exert profound effects on monocyte/macrophage function. In this review, we will discuss how the interplay between CD4+ T cells and monocytes/macrophages may contribute to the immunopathology of RA. PMID:26635790

  9. Trophoblast debris modulates the expression of immune proteins in macrophages: a key to maternal tolerance of the fetal allograft?

    PubMed

    Abumaree, M H; Chamley, L W; Badri, M; El-Muzaini, M F

    2012-06-01

    Interactions between maternal immune cells and the placenta are of substantial interest since diseases of pregnancy, such as recurrent miscarriage, villitis of unknown etiology and preeclampsia may arise due to inadequate adaptation of the maternal immune system. During normal pregnancy trophoblast debris is shed from the placenta into the maternal blood in large quantities. This trophoblast debris is then rapidly cleared from the maternal circulation. In this study, we exposed trophoblast debris generated from an in vitro placental explant model to peripheral blood-derived macrophages and quantified a variety of molecules that are important in immune responses by ELISA or flow cytometry. Phagocytosis of trophoblast debris resulted in reduced cell-surface expression of MHC-II molecules, the costimulatory molecules (CD80, CD86, CD40 and B7H3), monocyte chemoattractant protein-1 (MCP-1), inter-cellular adhesion molecule 1 (ICAM-1) and IL-8 receptors in macrophages while the expression of programmed death-1 ligand 1 (PD-L1) was upregulated. In addition, phagocytosis of trophoblast debris induced the secretion of the anti-inflammatory cytokines IL-10, IL6 and IL1Ra and decreased the secretion of pro-inflammatory cytokines IL-1?, IL12p70 and IL-8 by macrophages. Phagocytosis of trophoblast debris also increased macrophage expression of the immunosuppressive enzyme indoleamine 2,3-dioxygenase (IDO). We have shown that phagocytosis of trophoblast debris from normal placentae alters the phenotype of macrophages such that they are likely to deviate maternal immune responses towards tolerance and away from inflammation. This may be one of the mechanisms that allow the human fetal allograft to survive in direct contact with the maternal immune system. PMID:22542910

  10. Anoctamin 6 mediates effects essential for innate immunity downstream of P2X7 receptors in macrophages

    NASA Astrophysics Data System (ADS)

    Ousingsawat, Jiraporn; Wanitchakool, Podchanart; Kmit, Arthur; Romao, Ana M.; Jantarajit, Walailak; Schreiber, Rainer; Kunzelmann, Karl

    2015-02-01

    Purinergic P2X7 receptors (P2X7R) are fundamental to innate immune response. In macrophages, transient stimulation of P2X7R activates several transport mechanisms and induces the scrambling of phospholipids with subsequent membrane blebbing and apoptosis. These processes support phagocytosis and subsequent killing of phagocytosed bacteria. Here we demonstrate that the stimulation of P2X7 receptors activates anoctamin 6 (ANO6, TMEM16F), a protein that functions as Ca2+ dependent phospholipid scramblase and Ca2+-activated Cl- channel. Inhibition or knockdown of ANO6 attenuates ATP-induced cell shrinkage, cell migration and phospholipid scrambling. In mouse macrophages, Ano6 produces large ion currents by stimulation of P2X7 receptors and contributes to ATP-induced membrane blebbing and apoptosis, which is largely reduced in macrophages from Ano6-/- mice. ANO6 supports bacterial phagocytosis and killing by mouse and human THP-1 macrophages. Our data demonstrate that anoctamin 6 is an essential component of the immune defense by macrophages.

  11. Tumor cell-activated CARD9 signaling contributes to metastasis-associated macrophage polarization

    PubMed Central

    Yang, M; Shao, J-H; Miao, Y-J; Cui, W; Qi, Y-F; Han, J-H; Lin, X; Du, J

    2014-01-01

    Macrophages are critical immune effector cells of the tumor microenvironment that promote seeding, extravasation and persistent growth of tumor cells in primary tumors and metastatic sites. Tumor progression and metastasis are affected by dynamic changes in the specific phenotypes of macrophage subpopulations; however, the mechanisms by which tumor cells modulate macrophage polarization remain incompletely understood. Caspase recruitment domain-containing protein 9 (CARD9) is a central adaptor protein of innate immune responses to extracellular pathogens. We report that increased CARD9 expression is primarily localized in infiltrated macrophages and significantly associated with advanced histopathologic stage and the presence of metastasis. Using CARD9-deficient (CARD9−/−) mice, we show that bone marrow-derived CARD9 promotes liver metastasis of colon carcinoma cells. Mechanistic studies reveal that CARD9 contributes to tumor metastasis by promoting metastasis-associated macrophage polarization through activation of the nuclear factor-kappa B signaling pathway. We further demonstrate that tumor cell-secreted vascular endothelial growth factor facilitates spleen tyrosine kinase activation in macrophages, which is necessary for formation of the CARD9–B-cell lymphoma/leukemia 10–mucosa-associated lymphoid tissue lymphoma translocation protein 1 complex. Taken together, our results indicating that CARD9 is a regulator of metastasis-associated macrophages will lead to new insights into evolution of the microenvironments supporting tumor metastasis, thereby providing targets for anticancer therapies. PMID:24722209

  12. T cells and macrophages in Trypanosoma brucei-related glomerulopathy.

    PubMed Central

    van Velthuysen, M L; Mayen, A E; van Rooijen, N; Fleuren, G J; de Heer, E; Bruijn, J A

    1994-01-01

    In a previous study, susceptibility for Trypanosoma brucei-related glomerulopathy in mice was shown to be dependent on non-major histocompatibility complex genes. Glomerular disease in this model could not be explained by the production of autoantibodies alone. In order to analyze which part of the defense system, in addition to the B-cell compartment, is involved in the development of this infection-related glomerular disease, groups of athymic (BALB/c rnu/rnu), splenectomized, or macrophage-depleted BALB/c mice were inoculated with T. brucei parasites. Polyclonal B-cell activation, invariably observed in infected BALB/c mice, was absent in BALB/c rnu/rnu mice. Glomerular disease in athymic mice, however, as defined by albuminuria and deposition of immune complexes, was not different from that seen in euthymic infected BALB/c mice. Splenectomy prior to inoculation of parasites led to a decreased incidence of albuminuria in 40% of the animals, whereas splenectomy 21 days after inoculation reduced albuminuria significantly, suggesting a role for spleen cells in the induction of glomerular disease. After macrophage depletion with liposome-encapsulated dichlorodimethylene-diphosphonate, infected BALB/c mice developed significantly higher albuminuria levels for a period up to 2 weeks after depletion. Therefore, it was concluded that the development of T. brucei-related glomerular disease is independent of thymus-matured T cells, while the involvement of macrophages in the development of proteinuria is inhibitory rather than disease inducing. Spleen cells other than thymus-dependent T cells, B cells, and macrophages should be investigated for their role in the pathogenesis of this glomerulopathy. Images PMID:7913696

  13. HIV-1 Mutation and Recombination Rates Are Different in Macrophages and T-cells

    PubMed Central

    Cromer, Deborah; Schlub, Timothy E.; Smyth, Redmond P.; Grimm, Andrew J.; Chopra, Abha; Mallal, Simon; Davenport, Miles P.; Mak, Johnson

    2016-01-01

    High rates of mutation and recombination help human immunodeficiency virus (HIV) to evade the immune system and develop resistance to antiretroviral therapy. Macrophages and T-cells are the natural target cells of HIV-1 infection. A consensus has not been reached as to whether HIV replication results in differential recombination between primary T-cells and macrophages. Here, we used HIV with silent mutation markers along with next generation sequencing to compare the mutation and the recombination rates of HIV directly in T lymphocytes and macrophages. We observed a more than four-fold higher recombination rate of HIV in macrophages compared to T-cells (p < 0.001) and demonstrated that this difference is not due to different reliance on C-X-C chemokine receptor type 4 (CXCR4) and C-C chemokine receptor type 5 (CCR5) co-receptors between T-cells and macrophages. We also found that the pattern of recombination across the HIV genome (hot and cold spots) remains constant between T-cells and macrophages despite a three-fold increase in the overall recombination rate. This indicates that the difference in rates is a general feature of HIV DNA synthesis during macrophage infection. In contrast to HIV recombination, we found that T-cells have a 30% higher mutation rate than macrophages (p < 0.001) and that the mutational profile is similar between these cell types. Unexpectedly, we found no association between mutation and recombination in macrophages, in contrast to T-cells. Our data highlights some of the fundamental difference of HIV recombination and mutation amongst these two major target cells of infection. Understanding these differences will provide invaluable insights toward HIV evolution and how the virus evades immune surveillance and anti-retroviral therapeutics. PMID:27110814

  14. HIV-1 Mutation and Recombination Rates Are Different in Macrophages and T-cells.

    PubMed

    Cromer, Deborah; Schlub, Timothy E; Smyth, Redmond P; Grimm, Andrew J; Chopra, Abha; Mallal, Simon; Davenport, Miles P; Mak, Johnson

    2016-01-01

    High rates of mutation and recombination help human immunodeficiency virus (HIV) to evade the immune system and develop resistance to antiretroviral therapy. Macrophages and T-cells are the natural target cells of HIV-1 infection. A consensus has not been reached as to whether HIV replication results in differential recombination between primary T-cells and macrophages. Here, we used HIV with silent mutation markers along with next generation sequencing to compare the mutation and the recombination rates of HIV directly in T lymphocytes and macrophages. We observed a more than four-fold higher recombination rate of HIV in macrophages compared to T-cells (p < 0.001) and demonstrated that this difference is not due to different reliance on C-X-C chemokine receptor type 4 (CXCR4) and C-C chemokine receptor type 5 (CCR5) co-receptors between T-cells and macrophages. We also found that the pattern of recombination across the HIV genome (hot and cold spots) remains constant between T-cells and macrophages despite a three-fold increase in the overall recombination rate. This indicates that the difference in rates is a general feature of HIV DNA synthesis during macrophage infection. In contrast to HIV recombination, we found that T-cells have a 30% higher mutation rate than macrophages (p < 0.001) and that the mutational profile is similar between these cell types. Unexpectedly, we found no association between mutation and recombination in macrophages, in contrast to T-cells. Our data highlights some of the fundamental difference of HIV recombination and mutation amongst these two major target cells of infection. Understanding these differences will provide invaluable insights toward HIV evolution and how the virus evades immune surveillance and anti-retroviral therapeutics. PMID:27110814

  15. Macrophage PTEN Regulates Expression and Secretion of Arginase I Modulating Innate and Adaptive Immune Responses

    PubMed Central

    Sahin, Emine; Haubenwallner, Stefan; Kuttke, Mario; Kollmann, Isabella; Halfmann, Angela; Dohnal, Alexander B.; Chen, Li; Cheng, Paul; Hoesel, Bastian; Einwallner, Elisa; Brunner, Julia; Kral, Julia B.; Schrottmaier, Waltraud C.; Thell, Kathrin; Saferding, Victoria; Blüml, Stephan

    2014-01-01

    The activation of innate immune cells triggers numerous intracellular signaling pathways, which require tight control to mount an adequate immune response. The PI3K signaling pathway is intricately involved in innate immunity, and its activation dampens the expression and release of proinflammatory cytokines in myeloid cells. These signaling processes are strictly regulated by the PI3K antagonist, the lipid phosphatase, PTEN, a known tumor suppressor. Importantly, PTEN is responsible for the elevated production of cytokines such as IL-6 in response to TLR agonists, and deletion of PTEN results in diminished inflammatory responses. However, the mechanisms by which PI3K negatively regulates TLR signaling are only partially resolved. We observed that Arginase I expression and secretion were markedly induced by PTEN deletion, suggesting PTEN−/− macrophages were alternatively activated. This was mediated by increased expression and activation of the transcription factors C/EBPβ and STAT3. Genetic and pharmacologic experimental approaches in vitro, as well as in vivo autoimmunity models, provide convincing evidence that PI3K/PTEN-regulated extracellular Arginase I acts as a paracrine regulator of inflammation and immunity. PMID:25015834

  16. PER1 prevents excessive innate immune response during endotoxin-induced liver injury through regulation of macrophage recruitment in mice

    PubMed Central

    Wang, T; Wang, Z; Yang, P; Xia, L; Zhou, M; Wang, S; Du, Jie; Zhang, J

    2016-01-01

    The severity of acute liver failure (ALF) induced by bacterial lipopolysaccharide (LPS) is associated with the hepatic innate immune response. The core circadian molecular clock modulates the innate immune response by controlling rhythmic pathogen recognition by the innate immune system and daily variations in cytokine gene expression. However, the molecular link between circadian genes and the innate immune system has remained unclear. Here, we showed that mice lacking the clock gene Per1 (Period1) are more susceptible to LPS/d-galactosamine (LPS/GalN)-induced macrophage-dependent ALF compared with wild-type (WT) mice. Per1 deletion caused a remarkable increase in the number of Kupffer cells (KCs) in the liver, resulting in an elevation of the levels of pro-inflammatory cytokines after LPS treatment. Loss of Per1 had no effect on the proliferation or apoptosis of macrophages; however, it enhanced the recruitment of macrophages, which was associated with an increase in CC chemokine receptor 2 (Ccr2) expression levels in monocytes/macrophages. Deletion of Ccr2 rescued d-GalN/LPS-induced liver injury in Per1−/− mice. We demonstrated that the upregulation of Ccr2 expression by Per1 deletion could be reversed by the synthetic peroxisome proliferator-activated receptor gamma (PPAR-γ) antagonist GW9662. Further analysis indicated that PER1 binds to PPAR-γ on the Ccr2 promoter and enhanced the inhibitory effect of PPAR-γ on Ccr2 expression. These results reveal that Per1 reduces hepatic macrophage recruitment through interaction with PPAR-γ and prevents an excessive innate immune response in endotoxin-induced liver injury. PMID:27054331

  17. Brugia malayi Microfilariae Induce a Regulatory Monocyte/Macrophage Phenotype That Suppresses Innate and Adaptive Immune Responses

    PubMed Central

    Venugopal, Gopinath; Rao, Gopala B.; Lucius, Richard; Srikantam, Aparna; Hartmann, Susanne

    2014-01-01

    Background Monocytes and macrophages contribute to the dysfunction of immune responses in human filariasis. During patent infection monocytes encounter microfilariae in the blood, an event that occurs in asymptomatically infected filariasis patients that are immunologically hyporeactive. Aim To determine whether blood microfilariae directly act on blood monocytes and in vitro generated macrophages to induce a regulatory phenotype that interferes with innate and adaptive responses. Methodology and principal findings Monocytes and in vitro generated macrophages from filaria non-endemic normal donors were stimulated in vitro with Brugia malayi microfilarial (Mf) lysate. We could show that monocytes stimulated with Mf lysate develop a defined regulatory phenotype, characterised by expression of the immunoregulatory markers IL-10 and PD-L1. Significantly, this regulatory phenotype was recapitulated in monocytes from Wuchereria bancrofti asymptomatically infected patients but not patients with pathology or endemic normals. Monocytes from non-endemic donors stimulated with Mf lysate directly inhibited CD4+ T cell proliferation and cytokine production (IFN-γ, IL-13 and IL-10). IFN-γ responses were restored by neutralising IL-10 or PD-1. Furthermore, macrophages stimulated with Mf lysate expressed high levels of IL-10 and had suppressed phagocytic abilities. Finally Mf lysate applied during the differentiation of macrophages in vitro interfered with macrophage abilities to respond to subsequent LPS stimulation in a selective manner. Conclusions and significance Conclusively, our study demonstrates that Mf lysate stimulation of monocytes from healthy donors in vitro induces a regulatory phenotype, characterized by expression of PD-L1 and IL-10. This phenotype is directly reflected in monocytes from filarial patients with asymptomatic infection but not patients with pathology or endemic normals. We suggest that suppression of T cell functions typically seen in lymphatic filariasis is caused by microfilaria-modulated monocytes in an IL-10-dependent manner. Together with suppression of macrophage innate responses, this may contribute to the overall down-regulation of immune responses observed in asymptomatically infected patients. PMID:25275395

  18. Micro- and Nanopatterned Topographical Cues for Regulating Macrophage Cell Shape and Phenotype.

    PubMed

    Luu, Thuy U; Gott, Shannon C; Woo, Bryan W K; Rao, Masaru P; Liu, Wendy F

    2015-12-30

    Controlling the interactions between macrophages and biomaterials is critical for modulating the response to implants. While it has long been thought that biomaterial surface chemistry regulates the immune response, recent studies have suggested that material geometry may in fact dominate. Our previous work demonstrated that elongation of macrophages regulates their polarization toward a pro-healing phenotype. In this work, we elucidate how surface topology might be leveraged to alter macrophage cell morphology and polarization state. Using a deep etch technique, we fabricated titanium surfaces containing micro- and nanopatterned grooves, which have been previously shown to promote cell elongation. Morphology, phenotypic markers, and cytokine secretion of murine bone marrow derived macrophages on different groove widths were analyzed. The results suggest that micro- and nanopatterned grooves influenced macrophage elongation, which peaked on substrates with 400-500 nm wide grooves. Surface grooves did not affect inflammatory activation but drove macrophages toward an anti-inflammatory, pro-healing phenotype. While secretion of TNF-alpha remained low in macrophages across all conditions, macrophages secreted significantly higher levels of anti-inflammatory cytokine, IL-10, on intermediate groove widths compared to cells on other Ti surfaces. Our findings highlight the potential of using surface topography to regulate macrophage function, and thus control the wound healing and tissue repair response to biomaterials. PMID:26605491

  19. Interactions between neutrophils and macrophages promote macrophage killing of rat muscle cells in vitro

    NASA Technical Reports Server (NTRS)

    Nguyen, Hal X.; Tidball, James G.

    2003-01-01

    Current evidence indicates that the physiological functions of inflammatory cells are highly sensitive to their microenvironment, which is partially determined by the inflammatory cells and their potential targets. In the present investigation, interactions between neutrophils, macrophages and muscle cells that may influence muscle cell death are examined. Findings show that in the absence of macrophages, neutrophils kill muscle cells in vitro by superoxide-dependent mechanisms, and that low concentrations of nitric oxide (NO) protect against neutrophil-mediated killing. In the absence of neutrophils, macrophages kill muscle cells through a NO-dependent mechanism, and the presence of target muscle cells causes a three-fold increase in NO production by macrophages, with no change in the concentration of inducible nitric oxide synthase. Muscle cells that are co-cultured with both neutrophils and macrophages in proportions that are observed in injured muscle show cytotoxicity through a NO-dependent, superoxide-independent mechanism. Furthermore, the concentration of myeloid cells that is necessary for muscle killing is greatly reduced in assays that use mixed myeloid cell populations, rather than uniform populations of neutrophils or macrophages. These findings collectively show that the magnitude and mechanism of muscle cell killing by myeloid cells are modified by interactions between muscle cells and neutrophils, between muscle cells and macrophages and between macrophages and neutrophils.

  20. Interactions between neutrophils and macrophages promote macrophage killing of rat muscle cells in vitro.

    PubMed

    Nguyen, Hal X; Tidball, James G

    2003-02-15

    Current evidence indicates that the physiological functions of inflammatory cells are highly sensitive to their microenvironment, which is partially determined by the inflammatory cells and their potential targets. In the present investigation, interactions between neutrophils, macrophages and muscle cells that may influence muscle cell death are examined. Findings show that in the absence of macrophages, neutrophils kill muscle cells in vitro by superoxide-dependent mechanisms, and that low concentrations of nitric oxide (NO) protect against neutrophil-mediated killing. In the absence of neutrophils, macrophages kill muscle cells through a NO-dependent mechanism, and the presence of target muscle cells causes a three-fold increase in NO production by macrophages, with no change in the concentration of inducible nitric oxide synthase. Muscle cells that are co-cultured with both neutrophils and macrophages in proportions that are observed in injured muscle show cytotoxicity through a NO-dependent, superoxide-independent mechanism. Furthermore, the concentration of myeloid cells that is necessary for muscle killing is greatly reduced in assays that use mixed myeloid cell populations, rather than uniform populations of neutrophils or macrophages. These findings collectively show that the magnitude and mechanism of muscle cell killing by myeloid cells are modified by interactions between muscle cells and neutrophils, between muscle cells and macrophages and between macrophages and neutrophils. PMID:12562965

  1. SCS macrophages suppress melanoma by restricting tumor-derived vesicle-B cell interactions.

    PubMed

    Pucci, Ferdinando; Garris, Christopher; Lai, Charles P; Newton, Andita; Pfirschke, Christina; Engblom, Camilla; Alvarez, David; Sprachman, Melissa; Evavold, Charles; Magnuson, Angela; von Andrian, Ulrich H; Glatz, Katharina; Breakefield, Xandra O; Mempel, Thorsten R; Weissleder, Ralph; Pittet, Mikael J

    2016-04-01

    Tumor-derived extracellular vesicles (tEVs) are important signals in tumor-host cell communication, yet it remains unclear how endogenously produced tEVs affect the host in different areas of the body. We combined imaging and genetic analysis to track melanoma-derived vesicles at organismal, cellular, and molecular scales to show that endogenous tEVs efficiently disseminate via lymphatics and preferentially bind subcapsular sinus (SCS) CD169(+) macrophages in tumor-draining lymph nodes (tdLNs) in mice and humans. The CD169(+) macrophage layer physically blocks tEV dissemination but is undermined during tumor progression and by therapeutic agents. A disrupted SCS macrophage barrier enables tEVs to enter the lymph node cortex, interact with B cells, and foster tumor-promoting humoral immunity. Thus, CD169(+) macrophages may act as tumor suppressors by containing tEV spread and ensuing cancer-enhancing immunity. PMID:26989197

  2. Helical Carbon Nanotubes Enhance the Early Immune Response and Inhibit Macrophage-Mediated Phagocytosis of Pseudomonas aeruginosa

    PubMed Central

    Walling, Brent E.; Kuang, Zhizhou; Hao, Yonghua; Estrada, David; Wood, Joshua D.; Lian, Feifei; Miller, Lou Ann; Shah, Amish B.; Jeffries, Jayme L.; Haasch, Richard T.; Lyding, Joseph W.; Pop, Eric; Lau, Gee W.

    2013-01-01

    Aerosolized or aspirated manufactured carbon nanotubes have been shown to be cytotoxic, cause pulmonary lesions, and demonstrate immunomodulatory properties. CD-1 mice were used to assess pulmonary toxicity of helical carbon nanotubes (HCNTs) and alterations of the immune response to subsequent infection by Pseudomonas aeruginosa in mice. HCNTs provoked a mild inflammatory response following either a single exposure or 2X/week for three weeks (multiple exposures) but were not significantly toxic. Administering HCNTs 2X/week for three weeks resulted in pulmonary lesions including granulomas and goblet cell hyperplasia. Mice exposed to HCNTs and subsequently infected by P. aeruginosa demonstrated an enhanced inflammatory response to P. aeruginosa and phagocytosis by alveolar macrophages was inhibited. However, clearance of P. aeruginosa was not affected. HCNT exposed mice depleted of neutrophils were more effective in clearing P. aeruginosa compared to neutrophil-depleted control mice, accompanied by an influx of macrophages. Depletion of systemic macrophages resulted in slightly inhibited bacterial clearance by HCNT treated mice. Our data indicate that pulmonary exposure to HCNTs results in lesions similar to those caused by other nanotubes and pre-exposure to HCNTs inhibit alveolar macrophage phagocytosis of P. aeruginosa. However, clearance was not affected as exposure to HCNTs primed the immune system for an enhanced inflammatory response to pulmonary infection consisting of an influx of neutrophils and macrophages. PMID:24324555

  3. Antimicrobial Mechanisms of Macrophages and the Immune Evasion Strategies of Staphylococcus aureus

    PubMed Central

    Flannagan, Ronald S.; Heit, Bryan; Heinrichs, David E.

    2015-01-01

    Habitually professional phagocytes, including macrophages, eradicate microbial invaders from the human body without overt signs of infection. Despite this, there exist select bacteria that are professional pathogens, causing significant morbidity and mortality across the globe and Staphylococcus aureus is no exception. S. aureus is a highly successful pathogen that can infect virtually every tissue that comprises the human body causing a broad spectrum of diseases. The profound pathogenic capacity of S. aureus can be attributed, in part, to its ability to elaborate a profusion of bacterial effectors that circumvent host immunity. Macrophages are important professional phagocytes that contribute to both the innate and adaptive immune response, however from in vitro and in vivo studies, it is evident that they fail to eradicate S. aureus. This review provides an overview of the antimicrobial mechanisms employed by macrophages to combat bacteria and describes the immune evasion strategies and some representative effectors that enable S. aureus to evade macrophage-mediated killing. PMID:26633519

  4. Modulation of Decidual Macrophage Polarization by Macrophage Colony-Stimulating Factor Derived from First-Trimester Decidual Cells: Implication in Preeclampsia.

    PubMed

    Li, Min; Piao, Longzhu; Chen, Chie-Pein; Wu, Xianqing; Yeh, Chang-Ching; Masch, Rachel; Chang, Chi-Chang; Huang, S Joseph

    2016-05-01

    During human pregnancy, immune tolerance of the fetal semiallograft occurs in the presence of abundant maternal leukocytes. At the implantation site, macrophages comprise approximately 20% of the leukocyte population and act as primary mediators of tissue remodeling. Decidual macrophages display a balance between anti-inflammatory and proinflammatory phenotypes. However, a shift to an M1 subtype is reported in preeclampsia. Granulocyte-macrophage colony-stimulating-factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) are major differentiating factors that mediate M1 and M2 polarization, respectively. Previously, we observed the following: i) the preeclamptic decidua contains an excess of both macrophages and GM-CSF, ii) the preeclampsia-associated proinflammatory cytokines, IL-1β and tumor necrosis factor-α, markedly enhance GM-CSF and M-CSF expression in cultured leukocyte-free first-trimester decidual cells (FTDCs), iii) FTDC-secreted GM-CSF polarizes macrophages toward an M1 subtype. The microenvironment is a key determinant of macrophage phenotype. Thus, we examined proinflammatory stimulation of FTDC-secreted M-CSF and its role in macrophage development. Immunofluorescence staining demonstrated elevated M-CSF-positive decidual cell numbers in preeclamptic decidua. In FTDCs, IL-1β and tumor necrosis factor-α signal through the NF-κB pathway to induce M-CSF production, which does the following: i) enhances differentiation of and elevates CD163 expression in macrophages, ii) increases macrophage phagocytic capacity, and iii) inhibits signal-regulatory protein α expression by macrophages. These findings suggest that FTDC-secreted M-CSF modulates the decidual immune balance by inducing M2 macrophage polarization and phagocytic capacity in response to proinflammatory stimuli. PMID:26970370

  5. 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-1?. 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. PMID:24465430

  6. The role of macrophages and dendritic cells in the initiation of inflammation in IBD

    PubMed Central

    Steinbach, Erin C.; Plevy, Scott E.

    2014-01-01

    In the healthy gastrointestinal tract, homeostasis is an active process that requires a careful balance of host responses to the enteric luminal contents. Intestinal macrophages and dendritic cells comprise a unique group of tissue immune cells that are ideally situated at the interface of the host and the enteric luminal environment to appropriately respond to microbes and ingested stimuli. However, intrinsic defects in macrophage and dendritic cell function contribute to the pathogenesis of inflammatory bowel diseases (IBD), as highlighted by recent genome-wide association studies. Gastrointestinal macrophages and dendritic cells participate in IBD development through inappropriate responses to enteric microbial stimuli, inefficient clearance of microbes from host tissues, and impaired transition from appropriate pro-inflammatory responses to anti-inflammatory responses that promote resolution. By understanding how intestinal macrophages and dendritic cells initiate chronic inflammation, new pathogenesis-based therapeutic strategies to treat human IBD will be elucidated. PMID:23974993

  7. Intestinal immune cells in Strongyloides stercoralis infection.

    PubMed Central

    Trajman, A; MacDonald, T T; Elia, C C

    1997-01-01

    BACKGROUND: Strongyloides stercoralis can cause a wide spectrum of disease in man, ranging from a chronic asymptomatic infection to a hyperinfective, often fatal syndrome. In rodents, spontaneous expulsion of Strongyloides spp occurs after experimental infection. Mast cells, goblet cells, and eosinophils have been identified as possible effectors of this expulsion. AIMS: To investigate intestinal histopathology and mucosal immunity in immunocompetent patients with chronic S stercoralis infection. METHODS: Jejunal biopsies were performed in 19 immunocompetent patients with a positive stool examination for S stercoralis and few or no symptoms, and in seven healthy controls. Specimens were processed for histopathological analysis and stained by the immunoperoxidase technique, using the following monoclonal antibodies: CD2, CD3, CD4, CD8, anti-T cell receptor (TcR) gamma/delta, RFD1 and RFD7 (two different macrophage markers), Ki67+ (proliferating) cells, antihuman leucocyte antigen (HLA)-DR, and anticollagen IV. In addition, CD25+ cells, mast cells, IgE expressing cells, calprotectin containing cells, and neutrophil elastase positive cells were stained by the alkaline phosphatase method. RESULTS: Jejunal morphology and the numbers of different T cell subsets, mast cells, IgE expressing cells, eosinophils, and goblet cells were unaffected by S stercoralis infection. Conversely, the numbers of mature macrophages and dividing enterocytes in the crypts were reduced significantly. Crypt enterocytes did not express HLA-DR in both groups. The expression of HLA-DR by villus enterocytes was also comparable in patients and controls. There were no activated (CD25+) cells in the mucosa of either patients or controls. CONCLUSIONS: Compared with seven healthy uninfected volunteers, a group of 19 Brazilians with clinically mild strongyloides infection showed no abnormality of mucosal structure and no increase in non-specific inflammatory cells. Likewise, there was no increase in mucosal T cells or macrophages. Images PMID:9516879

  8. A Group A Streptococcus ADP-Ribosyltransferase Toxin Stimulates a Protective Interleukin 1β-Dependent Macrophage Immune Response

    PubMed Central

    Lin, Ann E.; Beasley, Federico C.; Keller, Nadia; Hollands, Andrew; Urbano, Rodolfo; Troemel, Emily R.; Hoffman, Hal M.

    2015-01-01

    ABSTRACT The M1T1 clone of group A Streptococcus (GAS) is associated with severe invasive infections, including necrotizing fasciitis and septicemia. During invasive M1T1 GAS disease, mutations in the covRS regulatory system led to upregulation of an ADP-ribosyltransferase, SpyA. Surprisingly, a GAS ΔspyA mutant was resistant to killing by macrophages and caused higher mortality with impaired bacterial clearance in a mouse intravenous challenge model. GAS expression of SpyA triggered macrophage cell death in association with caspase-1-dependent interleukin 1β (IL-1β) production, and differences between wild-type (WT) and ΔspyA GAS macrophage survival levels were lost in cells lacking caspase-1, NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), or pro-IL-1β. Similar in vitro findings were identified in macrophage studies performed with pseudomonal exotoxin A, another ADP-ribosylating toxin. Thus, SpyA triggers caspase-1-dependent inflammatory cell death in macrophages, revealing a toxin-triggered IL-1β-dependent innate immune response pathway critical in defense against invasive bacterial infection. PMID:25759502

  9. Interaction with epithelial cells modifies airway macrophage response to ozone.

    PubMed

    Bauer, Rebecca N; Müller, Loretta; Brighton, Luisa E; Duncan, Kelly E; Jaspers, Ilona

    2015-03-01

    The initial innate immune response to ozone (O3) in the lung is orchestrated by structural cells, such as epithelial cells, and resident immune cells, such as airway macrophages (Macs). We developed an epithelial cell-Mac coculture model to investigate how epithelial cell-derived signals affect Mac response to O3. Macs from the bronchoalveolar lavage (BAL) of healthy volunteers were cocultured with the human bronchial epithelial (16HBE) or alveolar (A549) epithelial cell lines. Cocultures, Mac monocultures, and epithelial cell monocultures were exposed to O3 or air, and Mac immunophenotype, phagocytosis, and cytotoxicity were assessed. Quantities of hyaluronic acid (HA) and IL-8 were compared across cultures and in BAL fluid from healthy volunteers exposed to O3 or air for in vivo confirmation. We show that Macs in coculture had increased markers of alternative activation, enhanced cytotoxicity, and reduced phagocytosis compared with Macs in monoculture that differed based on coculture with A549 or 16HBE. Production of HA by epithelial cell monocultures was not affected by O3, but quantities of HA in the in vitro coculture and BAL fluid from volunteers exposed in vivo were increased with O3 exposure, indicating that O3 exposure impairs Mac regulation of HA. Together, we show epithelial cell-Mac coculture models that have many similarities to the in vivo responses to O3, and demonstrate that epithelial cell-derived signals are important determinants of Mac immunophenotype and response to O3. PMID:25054807

  10. Recent progress in understandıng the function of intestinal macrophages and dendritic cells

    PubMed Central

    Kelsall, Brian

    2016-01-01

    Mucosal immune responses must be tightly controlled, particularly in the intestine, As members of the mononuclear phagocyte family, dendritic cells and macrophages, are well represented in intestinal tissues, and have developed unique functional niches. This review will focus on recent findings on antigen uptake and processing in the intestine, and the role of DCs in the imprinting homing receptors on T and B cells, the induction of IgA B cell responses, and the differentiation of regulatory T cells (Tregs). It will also address the unique phenotype of intestinal macrophages and briefly what is known regarding the relationships between these cell types. PMID:19079213

  11. Novel insights into the immunomodulatory role of the dendritic cell and macrophage-expressed C-type lectin MGL.

    PubMed

    van Kooyk, Yvette; Ilarregui, Juan M; van Vliet, Sandra J

    2015-02-01

    Based on their ability to balance tolerance and inflammation, antigen presenting cells, such as dendritic cells and macrophages contribute to the maintenance of immune homeostasis as well as the instigation of immune activation. Acting as key sensors of tissue integrity and pathogen invasion, they are well equipped with a wide variety of pattern recognition receptors, to which the C-type lectin family also belongs. C-type lectins are glycan-binding receptors that mediate cell-cell communication and pathogen recognition, besides participating in the endocytosis of antigens for presentation to T cells and the fine-tuning of immune responses. Here we review the current state-of-the-art on the dendritic cell and macrophage-expressed C-type lectin macrophage galactose-type lectin (MGL), highlighting the binding specificities, signaling properties and modulation of innate and adaptive immunity by its human and murine orthologues. PMID:25454488

  12. T-cell- and macrophage-mediated axon damage in the absence of a CNS-specific immune response: involvement of metalloproteinases.

    PubMed

    Newman, T A; Woolley, S T; Hughes, P M; Sibson, N R; Anthony, D C; Perry, V H

    2001-11-01

    Recent evidence has highlighted the fact that axon injury is an important component of multiple sclerosis pathology. The issue of whether a CNS antigen-specific immune response is required to produce axon injury remains unresolved. We investigated the extent and time course of axon injury in a rodent model of a delayed-type hypersensitivity (DTH) reaction directed against the mycobacterium bacille Calmette-Guérin (BCG). Using MRI, we determined whether the ongoing axon injury is restricted to the period during which the blood-brain barrier is compromised. DTH lesions were initiated in adult rats by intracerebral injection of heat-killed BCG followed by a peripheral challenge with BCG. Our findings demonstrate that a DTH reaction to a non-CNS antigen within a CNS white matter tract leads to axon injury. Ongoing axon injury persisted throughout the 3-month period studied and was not restricted to the period of blood-brain barrier breakdown, as detected by MRI enhancing lesions. We have previously demonstrated that matrix metalloproteinases (MMPs) are upregulated in multiple sclerosis plaques and DTH lesions. In this study we demonstrated that microinjection of activated MMPs into the cortical white matter results in axon injury. Our results show that axon injury, possibly mediated by MMPs, is immunologically non-specific and may continue behind an intact blood-brain barrier. PMID:11673322

  13. T-cell-induced expression of human immunodeficiency virus in macrophages.

    PubMed Central

    Schrier, R D; McCutchan, J A; Venable, J C; Nelson, J A; Wiley, C A

    1990-01-01

    Macrophages are major reservoirs of human immunodeficiency virus (HIV) in the tissues of infected humans. As monocytes in the peripheral blood do not show high levels of infection, we have investigated the expression of HIV in T-cell-activated, differentiated macrophages. Peripheral blood mononuclear cells were isolated from HIV-seropositive individuals and stimulated with antigens or mitogens, and the nonadherent fraction was removed. Macrophages were cultured alone for 2 weeks, and HIV expression was assessed. Results from p24 antigen capture assays demonstrated that the presence of autologous T cells and concanavalin A or autologous T cells and allogeneic cells for the initial 24 h of culture induced HIV expression in 35 of 47 (74%) HIV-seropositive patients tested. The macrophage monolayers could be immunostained with anti-HIV antibodies to reveal discrete infectious centers, indicating that complete virus replication was occurring in the macrophages and that infection of adjacent cells was mediated by cell-cell contact. Time course studies of the interval of coculture of the adherent and nonadherent cells indicated that 24 h (but not 2 h) was sufficient for induction of HIV in the macrophages. Direct contact between the adherent cells and activated T cells was required as well. Since the presence of autologous T cells also appeared to be necessary, induction of HIV expression in macrophages may be genetically restricted. HIV-seronegative nonadherent cells were able to induce HIV expression in macrophages from HIV-seropositive donors, demonstrating that the virus originated in the monocytes and was reactivated in the context of a classic T-cell-mediated immune reaction. The high percentage of monocytes from HIV-seropositive donors which can be induced to replicate HIV by activated T cells suggests that infection of monocytes may be critical to the pathogenesis of this lentivirus infection. Images PMID:2112615

  14. Macrophages and dendritic cells in the post-testicular environment.

    PubMed

    Da Silva, Nicolas; Barton, Claire R

    2016-01-01

    Macrophages (MΦ) and dendritic cells (DCs) are heterogeneous families of functionally and developmentally related immune cells that play crucial roles in tissue homeostasis and the regulation of immune responses. During the past 5 years, immunologists have generated a considerable amount of data that challenge dogmas about the ontogeny and functions of these highly versatile cells. The male excurrent duct system plays a critical role in the establishment of fertility by allowing sperm maturation, transport and storage. In addition, it is challenged by pathogens and must establish a protective and tolerogenic environment for a continuous flow of autoantigenic spermatozoa. The post-testicular environment and, in particular, the epididymis contain an intricate network of DCs and MΦ; however, the immunophysiology of this intriguing and highly specialized mucosal system is poorly understood. This review summarizes the current trends in mouse MΦ and DC biology and speculates about their roles in the steady-state epididymis. Unraveling immune cell functions in the male reproductive tract is an essential prerequisite for the design of innovative strategies aimed at controlling male fertility and treating infertility. PMID:26337514

  15. T CellMediated Host Immune Defenses in the Lung

    PubMed Central

    Chen, Kong; Kolls, Jay K.

    2014-01-01

    Evidence has increasingly shown that the lungs are a major site of immune regulation. A robust and highly regulated immune response in the lung protects the host from pathogen infection, whereas an inefficient or deleterious response can lead to various pulmonary diseases. Many cell types, such as epithelial cells, dendritic cells, macrophages, neutrophils, eosinophils, and B and T lymphocytes, contribute to lung immunity. This review focuses on the recent advances in understanding how T lymphocytes mediate pulmonary host defenses against bacterial, viral, and fungal pathogens. PMID:23516986

  16. Telomere profiles and tumor-associated macrophages with different immune signatures affect prognosis in glioblastoma.

    PubMed

    Hung, Noelyn A; Eiholzer, Ramona A; Kirs, Stenar; Zhou, Jean; Ward-Hartstonge, Kirsten; Wiles, Anna K; Frampton, Chris M; Taha, Ahmad; Royds, Janice A; Slatter, Tania L

    2016-03-01

    Telomere maintenance is a hallmark of cancer and likely to be targeted in future treatments. In glioblastoma established methods of identifying telomerase and alternative lengthening of telomeres leave a significant proportion of tumors with no defined telomere maintenance mechanism. This study investigated the composition of these tumors using RNA-Seq. Glioblastomas with an indeterminate telomere maintenance mechanism had an increased immune signature compared with alternative lengthening of telomeres and telomerase-positive tumors. Immunohistochemistry for CD163 confirmed that the majority (80%) of tumors with an indeterminate telomere maintenance mechanism had a high presence of tumor-associated macrophages. The RNA-Seq and immunostaining data separated tumors with no defined telomere maintenance mechanism into three subgroups: alternative lengthening of telomeres like tumors with a high presence of tumor-associated macrophages and telomerase like tumors with a high presence of tumor-associated macrophages. The third subgroup had no increase in tumor-associated macrophages and may represent a distinct category. The presence of tumor-associated macrophages conferred a worse prognosis with reduced patient survival times (alternative lengthening of telomeres with and without macrophages P=0.0004, and telomerase with and without macrophages P=0.013). The immune signatures obtained from RNA-Seq were significantly different between telomere maintenance mechanisms. Alternative lengthening of telomeres like tumors with macrophages had increased expression of interferon-induced proteins with tetratricopeptide repeats (IFIT1-3). Telomerase-positive tumors with macrophages had increased expression of macrophage receptor with collagenous structure (MARCO), CXCL12 and sushi-repeat containing protein x-linked 2 (SRPX2). Telomerase-positive tumors with macrophages were also associated with a reduced frequency of total/near total resections (44% vs >76% for all other subtypes, P=0.014). In summary, different immune signatures are found among telomere maintenance mechanism-based subgroups in glioblastoma. The reduced extent of surgical resection of telomerase-positive tumors with macrophages suggests that some tumor-associated macrophages are more unfavorable. PMID:26769142

  17. Granulocyte-macrophage colony-stimulating factor as an immune-based therapy in HIV infection

    PubMed Central

    Brown, Pierre Antoine; Angel, Jonathan B

    2005-01-01

    The HIV/AIDS epidemic continues to spread despite more than 20 years of significant research and major advances in its treatment. The introduction of highly active antiretroviral therapy in recent years has significantly improved disease treatment with a dramatic impact in HIV/AIDS associated morbidity and mortality in countries which have access to this therapy. Despite these advances, such therapies are imperfect and other therapeutic modalities, including immune-based therapies, are being actively sought. Potential benefits of immune-based therapies include: 1) the improvement of HIV-specific immunity to enhance control of viral replication, 2) the improvement of other aspects of host immunity in order to prevent or delay the development of opportunistic infections and 3) the potential to purge virus from cellular reservoirs which are sustained despite the effects of potent antiretroviral therapy. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been studied as one of these immune-based therapies. Several randomized, controlled trials have demonstrated benefits of using GM-CSF as an adjunct to conventional anti-retroviral therapy, although such benefits have not been universally observed. Individual studies have shown that GM-CSF increases CD4+ T cells counts and may be associated with decreased plasma HIV RNA levels. There is limited evidence that GM-CSF may help prevent the emergence of antiretroviral drug resistant viruses and that it may decrease the risk of infection in advanced HIV disease. Despite its high costs and the need to be administered subcutaneously, encouraging results continue to emerge from further studies, suggesting that GM-CSF has the potential to become an effective agent in the treatment of HIV infection. PMID:15904525

  18. Prostaglandin E2 Regulation of Macrophage Innate Immunity.

    PubMed

    Kimmel, Danielle W; Rogers, Lisa M; Aronoff, David M; Cliffel, David E

    2016-01-19

    Globally, maternal and fetal health is greatly impacted by extraplacental inflammation. Group B Streptococcus (GBS), a leading cause of chorioamnionitis, is thought to take advantage of the uterine environment during pregnancy in order to cause inflammation and infection. In this study, we demonstrate the metabolic changes of murine macrophages caused by GBS exposure. GBS alone prompted a delayed increase in lactate production, highlighting its ability to redirect macrophage metabolism from aerobic to anaerobic respiration. This production of lactate is thought to aid in the development and propagation of GBS throughout the surrounding tissue. Additionally, this study shows that PGE2 priming was able to exacerbate lactate production, shown by the rapid and substantial lactate increases seen upon GBS exposure. These data provide a novel model to study the role of GBS exposure to macrophages with and without PGE2 priming. PMID:26656203

  19. Teleost T and NK cell immunity.

    PubMed

    Fischer, Uwe; Koppang, Erling Olaf; Nakanishi, Teruyuki

    2013-08-01

    The main function of the immune system is to maintain the organism's homeostasis when invaded by foreign material or organisms. Prior to successful elimination of the invader it is crucial to distinguish self from non-self. Most pathogens and altered cells can be recognized by immune cells through expressed pathogen- or danger-associated molecular patterns (PAMPS or DAMPS, respectively), through non-self (e.g. allogenic or xenogenic cells) or missing major histocompatibility (MHC) class I molecules (some virus-infected target cells), and by presenting foreign non-self peptides of intracellular (through MHC class I-e.g. virus-infected target cells) or extracellular (through MHC class II-e.g. from bacteria) origin. In order to eliminate invaders directly or by destroying their ability to replicate (e.g. virus-infected cells) specialized immune cells of the innate and adaptive responses appeared during evolution. The first line of defence is represented by the evolutionarily ancient macrophages and natural killer (NK) cells. These innate mechanisms are well developed in bony fish. Two types of NK cell homologues have been described in fish: non-specific cytotoxic cells and NK-like cells. Adaptive cell-mediated cytotoxicity (CMC) requires key molecules expressed on cytotoxic T lymphocytes (CTLs) and target cells. CTLs kill host cells harbouring intracellular pathogens by binding of their T cell receptor (TCR) and its co-receptor CD8 to a complex of MHC class I and bound peptide on the infected host cell. Alternatively, extracellular antigens are taken up by professional antigen presenting cells such as macrophages, dendritic cells and B cells to process those antigens and present the resulting peptides in association with MHC class II to CD4(+) T helper cells. During recent years, genes encoding MHC class I and II, TCR and its co-receptors CD8 and CD4 have been cloned in several fish species and antibodies have been developed to study protein expression in morphological and functional contexts. Functional assays for innate and adaptive lymphocyte responses have been developed in only a few fish species. This review summarizes and discusses recent results and developments in the field of T and NK cell responses with focus on economically important and experimental model fish species in the context of vaccination. PMID:23664867

  20. Biomarkers of CD4+ CTL cell Mediated Immunity to Tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The immune responses mediated by interactions between T-lymphocyte subsets and mycobacteria-infected macrophages are critical for control of tuberculosis. In these studies, the bovine model was used to characterize the cytolytic and mycobactericidal CD4+ T cell response induced by BCG vaccination. ...

  1. Mesenchymal stem/stromal cells precondition lung monocytes/macrophages to produce tolerance against allo- and autoimmunity in the eye.

    PubMed

    Ko, Jung Hwa; Lee, Hyun Ju; Jeong, Hyun Jeong; Kim, Mee Kum; Wee, Won Ryang; Yoon, Sun-Ok; Choi, Hosoon; Prockop, Darwin J; Oh, Joo Youn

    2016-01-01

    Intravenously administered mesenchymal stem/stromal cells (MSCs) engraft only transiently in recipients, but confer long-term therapeutic benefits in patients with immune disorders. This suggests that MSCs induce immune tolerance by long-lasting effects on the recipient immune regulatory system. Here, we demonstrate that i.v. infusion of MSCs preconditioned lung monocytes/macrophages toward an immune regulatory phenotype in a TNF-α-stimulated gene/protein (TSG)-6-dependent manner. As a result, mice were protected against subsequent immune challenge in two models of allo- and autoimmune ocular inflammation: corneal allotransplantation and experimental autoimmune uveitis (EAU). The monocytes/macrophages primed by MSCs expressed high levels of MHC class II, B220, CD11b, and IL-10, and exhibited T-cell-suppressive activities independently of FoxP3(+) regulatory T cells. Adoptive transfer of MSC-induced B220(+)CD11b(+) monocytes/macrophages prevented corneal allograft rejection and EAU. Deletion of monocytes/macrophages abrogated the MSC-induced tolerance. However, MSCs with TSG-6 knockdown did not induce MHC II(+)B220(+)CD11b(+) cells, and failed to attenuate EAU. Therefore, the results demonstrate a mechanism of the MSC-mediated immune modulation through induction of innate immune tolerance that involves monocytes/macrophages. PMID:26699483

  2. Frustrated Phagocytosis on Micro-Patterned Immune Complexes to Characterize Lysosome Movements in Live Macrophages

    PubMed Central

    Labrousse, Arnaud M.; Meunier, Etienne; Record, Julien; Labernadie, Anna; Beduer, Amélie; Vieu, Christophe; Ben Safta, Thouraya; Maridonneau-Parini, Isabelle

    2011-01-01

    Lysosome mobilization is a key cellular process in phagocytes for bactericidal activities and trans-matrix migration. The molecular mechanisms that regulate lysosome mobilization are still poorly known. Lysosomes are hard to track as they move toward phagosomes throughout the cell volume. In order to anticipate cell regions where lysosomes are recruited to, human and RAW264.7 macrophages were seeded on surfaces that were micro-patterned with immune complexes (ICs) as 4 μm-side squares. Distances between IC patterns were adapted to optimize cell spreading in order to constrain lysosome movements mostly in two dimensions. FcΓ receptors triggered local frustrated phagocytosis, frustrated phagosomes appeared as rings of F-actin dots around the IC patterns as early as 5 min after cells made contact with the substratum. Frustrated phagosomes recruited actin-associated proteins (vinculin, paxillin, and gelsolin). The fusion of lysosomes with frustrated phagosomes was shown by the release of beta-hexosaminidase and the recruitment of Lamp1 to frustrated phagosomes. Lysosomes of RAW264.7 macrophages were labeled with cathepsin-D-mCherry to visualize their movements toward frustrated phagosomes. Lysosomes saltatory movements were markedly slowed down compared to cells layered on non-opsonized patterns. In addition, the linearity of the trajectories and the frequency and duration of contacts of lysosomes with frustrated phagosomes were measured. Our experimental set-up is the first step toward deciphering molecular mechanisms which are involved in lysosome movements in the cytoplasm (speed, directionality, and interaction with phagosomes), and opens the door to approaches such as RNA interference, pharmacological inhibition, or mutant expression. PMID:22566841

  3. Interleukin-27 in T Cell Immunity

    PubMed Central

    Iwasaki, Yukiko; Fujio, Keishi; Okamura, Tomohisa; Yamamoto, Kazuhiko

    2015-01-01

    Interleukin (IL)-27, a member of IL-12/IL-23 heterodimeric family of cytokines, has pleiotropic properties that can enhance or limit immune responses. IL-27 acts on various cell types, including T cells, B cells, macrophages, dendritic cells, natural killer (NK) cells and non-hematopoietic cells. Intensive studies have been conducted especially on T cells, revealing that various subsets of T cells respond uniquely to IL-27. IL-27 induces expansion of Th1 cells by activating signal transducer and activator of transcription (STAT) 1-mediated T-bet signaling pathway. On the other hand, IL-27 suppresses immune responses through inhibition of the development of T helper (Th) 17 cells and induction of IL-10 production in a STAT1- and STAT3-dependent manner. IL-27 is a potentially promising cytokine for therapeutic approaches on various human diseases. Here, we provide an overview of the biology of IL-27 related to T cell subsets, its structure, and production mechanism. PMID:25633106

  4. Platelet Interaction with Innate Immune Cells

    PubMed Central

    Kral, Julia Barbara; Schrottmaier, Waltraud Cornelia; Salzmann, Manuel; Assinger, Alice

    2016-01-01

    Summary Beyond their traditional role in haemostasis and thrombosis, platelets are increasingly recognised as immune modulatory cells. Activated platelets and platelet-derived microparticles can bind to leukocytes, which stimulates mutual activation and results in rapid, local release of platelet-derived cytokines. Thereby platelets modulate leukocyte effector functions and contribute to inflammatory and immune responses to injury or infection. Platelets enhance leukocyte extravasation, differentiation and cytokine release. Platelet-neutrophil interactions boost oxidative burst, neutrophil extracellular trap formation and phagocytosis and play an important role in host defence. Platelet interactions with monocytes propagate their differentiation into macrophages, modulate cytokine release and attenuate macrophage functions. Depending on the underlying pathology, platelets can enhance or diminish leukocyte cytokine production, indicating that platelet-leukocyte interactions represent a fine balanced system to restrict excessive inflammation during infection. In atherosclerosis, platelet interaction with neutrophils, monocytes and dendritic cells accelerates key steps of atherogenesis by promoting leukocyte extravasation and foam cell formation. Platelet-leukocyte interactions at sites of atherosclerotic lesions destabilise atherosclerotic plaques and promote plaque rupture. Leukocytes in turn also modulate platelet function and production, which either results in enhanced platelet destruction or increased platelet production. This review aims to summarise the key effects of platelet-leukocyte interactions in inflammation, infection and atherosclerosis.

  5. Involvement of Immune Cell Network in Aortic Valve Stenosis: Communication between Valvular Interstitial Cells and Immune Cells

    PubMed Central

    Lee, Seung Hyun

    2016-01-01

    Aortic valve stenosis is a heart disease prevalent in the elderly characterized by valvular calcification, fibrosis, and inflammation, but its exact pathogenesis remains unclear. Previously, aortic valve stenosis was thought to be caused by chronic passive and degenerative changes associated with aging. However, recent studies have demonstrated that atherosclerotic processes and inflammation can induce valvular calcification and bone deposition, leading to valvular stenosis. In particular, the most abundant cell type in cardiac valves, valvular interstitial cells, can differentiate into myofibroblasts and osteoblast-like cells, leading to valvular calcification and stenosis. Differentiation of valvular interstitial cells can be trigged by inflammatory stimuli from several immune cell types, including macrophages, dendritic cells, T cells, B cells, and mast cells. This review indicates that crosstalk between immune cells and valvular interstitial cells plays an important role in the development of aortic valve stenosis. PMID:26937229

  6. Involvement of Immune Cell Network in Aortic Valve Stenosis: Communication between Valvular Interstitial Cells and Immune Cells.

    PubMed

    Lee, Seung Hyun; Choi, Jae-Hoon

    2016-02-01

    Aortic valve stenosis is a heart disease prevalent in the elderly characterized by valvular calcification, fibrosis, and inflammation, but its exact pathogenesis remains unclear. Previously, aortic valve stenosis was thought to be caused by chronic passive and degenerative changes associated with aging. However, recent studies have demonstrated that atherosclerotic processes and inflammation can induce valvular calcification and bone deposition, leading to valvular stenosis. In particular, the most abundant cell type in cardiac valves, valvular interstitial cells, can differentiate into myofibroblasts and osteoblast-like cells, leading to valvular calcification and stenosis. Differentiation of valvular interstitial cells can be trigged by inflammatory stimuli from several immune cell types, including macrophages, dendritic cells, T cells, B cells, and mast cells. This review indicates that crosstalk between immune cells and valvular interstitial cells plays an important role in the development of aortic valve stenosis. PMID:26937229

  7. Interaction with Epithelial Cells Modifies Airway Macrophage Response to Ozone

    PubMed Central

    Bauer, Rebecca N.; Müller, Loretta; Brighton, Luisa E.; Duncan, Kelly E.

    2015-01-01

    The initial innate immune response to ozone (O3) in the lung is orchestrated by structural cells, such as epithelial cells, and resident immune cells, such as airway macrophages (Macs). We developed an epithelial cell–Mac coculture model to investigate how epithelial cell–derived signals affect Mac response to O3. Macs from the bronchoalveolar lavage (BAL) of healthy volunteers were cocultured with the human bronchial epithelial (16HBE) or alveolar (A549) epithelial cell lines. Cocultures, Mac monocultures, and epithelial cell monocultures were exposed to O3 or air, and Mac immunophenotype, phagocytosis, and cytotoxicity were assessed. Quantities of hyaluronic acid (HA) and IL-8 were compared across cultures and in BAL fluid from healthy volunteers exposed to O3 or air for in vivo confirmation. We show that Macs in coculture had increased markers of alternative activation, enhanced cytotoxicity, and reduced phagocytosis compared with Macs in monoculture that differed based on coculture with A549 or 16HBE. Production of HA by epithelial cell monocultures was not affected by O3, but quantities of HA in the in vitro coculture and BAL fluid from volunteers exposed in vivo were increased with O3 exposure, indicating that O3 exposure impairs Mac regulation of HA. Together, we show epithelial cell–Mac coculture models that have many similarities to the in vivo responses to O3, and demonstrate that epithelial cell–derived signals are important determinants of Mac immunophenotype and response to O3. PMID:25054807

  8. Immune cell infiltration as an indicator of the immune microenvironment of pancreatic cancer

    PubMed Central

    Ino, Y; Yamazaki-Itoh, R; Shimada, K; Iwasaki, M; Kosuge, T; Kanai, Y; Hiraoka, N

    2013-01-01

    Background: The host immune reaction is represented by immune/inflammatory cell infiltrates. Here we systematically analysed tumour-infiltrating immune/inflammatory cells in pancreatic ductal carcinoma (PDC) and evaluated their clinicopathological impact. Methods: Using immunohistochemistry, we examined tumour-infiltrating CD68+ pan-macrophages, HLA-DR+CD68+ M1 macrophages (M1), CD163+ or CD204+ M2 macrophages (M2), CD66b+ neutrophils (Neu), CD4+ T cells (CD4+T), CD8+ T cells (CD8+T), and FOXP3+CD4+ regulatory T cells (Treg) in 212 cases of PDC, and conducted correlation and survival analyses using the Kaplan–Meier method and Cox proportional hazards model. Results: Higher levels of tumour-infiltrating pan-macrophages, M2, Neu, or the ratio of Tregs to CD4+T (%Treg) were significantly associated with shorter survival, whereas higher levels of tumour-infiltrating CD4+T, CD8+T, or the ratio of M1 to pan-macrophages (%M1) were significantly associated with longer survival. Survival analysis of pairs of these variables revealed that some of the resulting patient groups had exclusively longer survival. We then connected the apparently related factors, and two significant variables emerged: tumour-infiltrating CD4+Thigh/CD8+Thigh/%Treglow and tumour-infiltrating %M1high/M2low. Multivariate survival analysis revealed that these variables were significantly correlated with longer survival and had a higher hazard ratio. Conclusion: Tumour-infiltrating CD4+Thigh/CD8+Thigh/%Treglow and %M1high/M2low are independent prognosticators useful for evaluating the immune microenvironment of PDC. PMID:23385730

  9. Depletion of CLL-associated patrolling monocytes and macrophages controls disease development and repairs immune dysfunction in vivo.

    PubMed

    Hanna, B S; McClanahan, F; Yazdanparast, H; Zaborsky, N; Kalter, V; Rößner, P M; Benner, A; Dürr, C; Egle, A; Gribben, J G; Lichter, P; Seiffert, M

    2016-03-01

    Chronic lymphocytic leukemia (CLL) is characterized by apoptosis resistance and a dysfunctional immune system. Previous reports suggested a potential role of myeloid cells in mediating these defects. However, the composition and function of CLL-associated myeloid cells have not been thoroughly investigated in vivo. Using the Eμ-TCL1 mouse model, we observed severe skewing of myeloid cell populations with CLL development. Monocytes and M2-like macrophages infiltrated the peritoneal cavity of leukemic mice. Monocytes also accumulated in the spleen in a CCR2-dependent manner, and were severely skewed toward Ly6C(low) patrolling or nonclassical phenotype. In addition, the percentage of MHC-II(hi) dendritic cells and macrophages significantly dropped in the spleen. Gene expression profiling of CLL-associated monocytes revealed aberrantly high PD-L1 expression and secretion of multiple inflammatory and immunosuppressive cytokines like interleukin-10, tumor necrosis factor-α and CXCL9. In vivo myeloid cell depletion using liposomal Clodronate resulted in a significant control of CLL development accompanied by a pronounced repair of innate immune cell phenotypes and a partial resolution of systemic inflammation. In addition, CLL-associated skewing of T cells toward antigen-experienced phenotypes was repaired. The presented data suggest that targeting nonmalignant myeloid cells might serve as a novel immunotherapeutical strategy for CLL. PMID:26522085

  10. Improved Method for Culturing Guinea-Pig Macrophage Cells

    NASA Technical Reports Server (NTRS)

    Savage, J.

    1982-01-01

    Proper nutrients and periodic changes in culture medium maintain cell viability for a longer period. New method uses a thioglycolate solution, instead of mineral oil, to induce macrophage cells in guinea pigs and also uses an increased percent of fetal-calf bovine serum in cultivation medium. Macrophage cells play significant roles in the body's healing and defense systems.

  11. Training modifies innate immune responses in blood monocytes and in pulmonary alveolar macrophages.

    PubMed

    Frellstedt, Linda; Waldschmidt, Ingrid; Gosset, Philippe; Desmet, Christophe; Pirottin, Dimitri; Bureau, Fabrice; Farnir, Frédéric; Franck, Thierry; Dupuis-Tricaud, Marie-Capucine; Lekeux, Pierre; Art, Tatiana

    2014-07-01

    In humans, strenuous exercise causes increased susceptibility to respiratory infections associated with down-regulated expression of Toll-like receptors (TLRs) and costimulatory and antigen-presenting molecules. Lower airway diseases are also a common problem in sport and racing horses. Because innate immunity plays an essential role in lung defense mechanisms, we assessed the effect of acute exercise and training on innate immune responses in two different compartments. Blood monocytes and pulmonary alveolar macrophages (PAMs) were collected from horses in untrained, moderately trained, intensively trained, and deconditioned states before and after a strenuous exercise test. The cells were analyzed for TLR messenger ribonucleic acid (mRNA) expression by real-time PCR in vitro, and cytokine production after in vitro stimulation with TLR ligands was measured by ELISA. Our results showed that training, but not acute exercise, modified the innate immune responses in both compartments. The mRNA expression of TLR3 was down-regulated by training in both cell types, whereas the expression of TLR4 was up-regulated in monocytes. Monocytes treated with LPS and a synthetic diacylated lipoprotein showed increased cytokine secretion in trained and deconditioned subjects, indicating the activation of cells at the systemic level. The production of TNF-α and IFN-β in nonstimulated and stimulated PAMs was decreased in trained and deconditioned horses and might therefore explain the increased susceptibility to respiratory infections. Our study reports a dissociation between the systemic and the lung response to training that is probably implicated in the systemic inflammation and in the pulmonary susceptibility to infection. PMID:24502337

  12. [Adipose-derived stem cells promote the polarization from M1 macrophages to M2 macrophages].

    PubMed

    Yin, Xuehong; Pang, Chunyan; Bai, Li; Zhang, Ying; Geng, Lixia

    2016-03-01

    Objective To investigate the effects of adipose-derived stem cells (ADSCs) on M1/M2 macrophages and whether ADSCs are able to promote the polarization from M1 macrophages to M2 macrophages. Methods M1 macrophages were induced from J774.1 macrophages by 24-hour stimulation of lipopolysaccharide (LPS) and interferon γ (IFN-γ), and M2 macrophages were induced from J774.1 macrophages by interleukin 4 (IL-4) for another 24 hours. Then M1/M2 macrophages were separately cultured in the presence of ADSCs for 24 hours. The M1/M2 macrophages and their corresponding supernatants were collected for further analysis. The expressions of IL-6, tumor necrosis factor α (TNF-α), inducible nitric oxide synthase (iNOS), CC chemokine ligand 2 (CCL2), CD86, arginase 1 (Arg1), mannose receptors/CD206 (MR/CD206), IL-10, found in inflammatory zone 1 (FIZZ1), chitinase 3-like 3 (Ym-1) were detected by real-time PCR and ELISA. Results ADSCs significantly decreased the levels of IL-6, TNF-α, iNOS, CCL2 and CD86, and increased the levels of Arg1, CD206 and IL-10 in M1 macrophages. In the supernatant of M1 macrophages, the expressions of IL-6 and TNF-α were reduced, while those of CD206 were enhanced. In M2 macrophages, ADSCs resulted in down-regulation of IL-6, TNF-α, iNOS, CD86 and up-regulation of Arg1, CD206, FIZZ-1, Ym-1 and IL-10. In the supernatant of M2 macrophages, the expression levels of IL-6 and TNF-α were down-regulated and those of CD206 were up-regulated. Conclusion ADSCs can inhibit the gene expression of M1 macrophages and promote the gene expression of M2 macrophages, as well as mediate the polarization from M1 macrophages to M2 macrophages. PMID:26927552

  13. Regulation of Macrophage, Dendritic Cell, and Microglial Phenotype and Function by the SOCS Proteins

    PubMed Central

    McCormick, Sarah M.; Heller, Nicola M.

    2015-01-01

    Macrophages are innate immune cells of dynamic phenotype that rapidly respond to external stimuli in the microenvironment by altering their phenotype to respond to and to direct the immune response. The ability to dynamically change phenotype must be carefully regulated to prevent uncontrolled inflammatory responses and subsequently to promote resolution of inflammation. The suppressor of cytokine signaling (SOCS) proteins play a key role in regulating macrophage phenotype. In this review, we summarize research to date from mouse and human studies on the role of the SOCS proteins in determining the phenotype and function of macrophages. We will also touch on the influence of the SOCS on dendritic cell (DC) and microglial phenotype and function. The molecular mechanisms of SOCS function in macrophages and DCs are discussed, along with how dysregulation of SOCS expression or function can lead to alterations in macrophage/DC/microglial phenotype and function and to disease. Regulation of SOCS expression by microRNA is discussed. Novel therapies and unanswered questions with regard to SOCS regulation of monocyte–macrophage phenotype and function are highlighted. PMID:26579124

  14. Osteogenesis differentiation of human periodontal ligament cells by CO2 laser-treatment stimulating macrophages via BMP2 signalling pathway

    NASA Astrophysics Data System (ADS)

    Hsieh, Wen-Hui; Chen, Yi-Jyun; Hung, Chi-Jr; Huang, Tsui-Hsien; Kao, Chia-Tze; Shie, Ming-You

    2014-11-01

    Immune reactions play an important role in determining the biostimulation of bone formation, either in new bone formation or inflammatory fibrous tissue encapsulation. Macrophage cell, the important effector cells in the immune reaction, which are indispensable for osteogenesis and their heterogeneity and plasticity, render macrophages a primer target for immune system modulation. However, there are very few studies about the effects of macrophage cells on laser treatment-regulated osteogenesis. In this study, we used CO2 laser as a model biostimulation to investigate the role of macrophage cells on the CO2 laser stimulated osteogenesis. Bone morphogenetic protein 2 (BMP2) was also significantly up regulated by the CO2 laser stimulation, indicating that macrophage may participate in the CO2 laser stimulated osteogenesis. Interestingly, when laser treatment macrophage-conditioned medium were applied to human periodontal ligament cells (hPDLs), the osteogenesis differentiation of hPDLs was significantly enhanced, indicating the important role of macrophages in CO2 laser-induced osteogenesis. These findings provided valuable insights into the mechanism of CO2 laser-stimulated osteogenic differentiation, and a strategy to optimize the evaluation system for the in vitro osteogenesis capacity of laser treatment.

  15. Macrophage recognition of thiol-group oxidized cells: recognition of carbohydrate chains by macrophage surface nucleolin as apoptotic cells.

    PubMed

    Miki, Yuichi; Hirano, Kazuya; Beppu, Masatoshi

    2012-01-01

    The mechanism was investigated for macrophage recognition of cells oxidized by diamide, a thiol group-specific oxidizing reagent. Jurkat cells exposed to various concentrations of diamide were recognized by macrophages, the cells exposed to 25 µM diamide being best recognized. CD43, a major glycoprotein on the Jurkat cell surface, tended to form clusters upon diamide oxidization, and pretreating Jurkat cells with the anti-CD43 antibody inhibited macrophage binding. This indicates that macrophages appeared to recognize CD43. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and a Western blot analysis of CD43 of the diamide-oxidized cells showed no increase in the amount of cross-linked CD43 compared with control cells, indicating that cross-linking of CD43 by a disulphide bond was not involved in the clustering. Both CD43 clustering and binding of the oxidized cells to macrophages was prevented by the caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethyl ketone (Z-VAD-fmk), suggesting that the oxidized and macrophage-bound cells were undergoing apoptosis. A closer examination revealed that the caspase-3 activity, chromatin condensation, and DNA fragmentation in Jurkat cells were all increased by oxidation. The macrophage receptor involved in the binding appeared to be the cell-surface protein, nucleolin; an anti-nucleolin antibody treatment inhibited the binding. These results suggest that thiol group-oxidized cells underwent early apoptosis and were recognized by nucleolin on macrophages as early apoptotic cells. PMID:23132587

  16. Elimination of allogeneic multipotent stromal cells by host macrophages in different models of regeneration

    PubMed Central

    Arutyunyan, Irina; Elchaninov, Andrey; Fatkhudinov, Timur; Makarov, Andrey; Kananykhina, Evgeniya; Usman, Natalia; Bolshakova, Galina; Glinkina, Valeria; Goldshtein, Dmitry; Sukhikh, Gennady

    2015-01-01

    Allogeneic multipotent stromal cells were previously thought to be poorly recognized by host immune system; the prolonged survival in host environments was explained by their immune privileged status. As long as the concept is currently reconsidered, the routes of elimination of allogeneic multipotent stromal cells by host immunity must be taken into account. This is necessary for correct comprehension of their therapeutic action. The study was focused upon survival of umbilical cord-derived allogeneic multipotent stromal cells in different rat models of tissue regeneration induced by partial hepatectomy or by critical limb ischemia. The observations were carried out by means of vital labeling of the cells with PKH26 prior to injection, in combination with differential immunostaining of host macrophages with anti-CD68 antibody. According to the results, allogeneic multipotent stromal cells are specifically eliminated by host immune system; the efficacy can reach 100%. Massive clearance of transplanted cells by host macrophages is accompanied by appropriation of the label by the latter, and this is a pronounced case of misleading presentation of exogenous label by host cells. The study emphasizes the role of macrophages in host response and also the need of additional criteria for correct data interpretation. PMID:26191137

  17. The dynamic lives of macrophage and dendritic cell subsets in atherosclerosis

    PubMed Central

    Taghavie-Moghadam, Paresa L.; Butcher, Matthew J.; Galkina, Elena V.

    2014-01-01

    Atherosclerosis, the major pathological process through which arterial plaques are formed, is a dynamic chronic inflammatory disease of large and medium sized arteries in which the vasculature, lipid metabolism, and the immune system all play integral roles. Both the innate and adaptive immune systems are involved in the development and progression of atherosclerosis but myeloid cells represent the major component of the burgeoning atherosclerotic plaque. Various myeloid cells, including monocytes, macrophages, and dendritic cells can be found within the healthy and atherosclerotic arterial wall, where they can contribute to or regulate inflammation. However, the precise behaviors and functions of these cells in situ are still active areas of investigation that continue to yield exciting and surprising new data. Here, we review recent progress in understanding of the complex biology of macrophages and dendritic cells, focusing particularly on the dynamic regulation of these subsets in the arterial wall and novel, emerging functions of these cells during atherogenesis. PMID:24628328

  18. Murine macrophage inflammatory cytokine production and immune activation in response to Vibrio parahaemolyticus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vibrio parahaemolyticus is the most common cause of bacterial seafood-related illness in the United States. Currently, there is a dearth of literature regarding immunity to infection with this pathogen. Here we studied V. parahaemolyticus-infected RAW 264.7 murine macrophage detecting both pro- and...

  19. Differential regulation of the nature and functions of dendritic cells and macrophages by cathepsin E.

    PubMed

    Kakehashi, Hiroe; Nishioku, Tsuyoshi; Tsukuba, Takayuki; Kadowaki, Tomoko; Nakamura, Seiji; Yamamoto, Kenji

    2007-11-01

    The aspartic proteinase cathepsin E is localized mainly in the endosomal structures of APCs and has been implicated in a variety of immune responses, however, the precise roles of cathepsin E in these cells remain speculative. In this study, we report the effect of disrupting the gene encoding cathepsin E on the nature and functions of dendritic cells (DCs) and macrophages derived from mouse bone marrow precursors, as well as mouse peritoneal macrophages. Whereas cathepsin E deficiency induced the accumulation of the lysosome-associated membrane protein (LAMP)-1 and LAMP-2 and elevated the lysosomal pH in macrophages, it did not have these effects on DCs. Although cathepsin E deficiency also caused a marked decrease in degradation of phagocytosed OVA and chemotactic responses to MCP-1 and fMLP by macrophages, these abilities were little affected in DCs by the absence of cathepsin E. Interestingly, cathepsin E deficiency markedly decreased the ability of macrophages to present intact OVA, as well as an OVA-derived antigenic peptide (266-281), to cognate T cells, while that of DCs was inversely enhanced by the absence of this protein. This paradox was resolved, in part, by the enhanced phagocytic activity and the increased expression of the costimulatory molecules CD86, CD80, and CD40, which amplify the response of T cells, in cathepsin E-deficient DCs compared with the wild-type cells. These results indicate that cathepsin E differentially regulates the nature and function of DCs and macrophages. PMID:17947645

  20. Mycobacterium leprae-Infected Macrophages Preferentially Primed Regulatory T Cell Responses and Was Associated with Lepromatous Leprosy

    PubMed Central

    Miranda, Jake W.; Gilson, Danny J.; Song, Zhengyu; Chen, Jia; Shi, Chao; Zhu, Jianyu; Yang, Jun; Jing, Zhichun

    2016-01-01

    Background The persistence of Mycobacterium leprae (M. leprae) infection is largely dependent on the types of host immune responses being induced. Macrophage, a crucial modulator of innate and adaptive immune responses, could be directly infected by M. leprae. We therefore postulated that M. leprae-infected macrophages might have altered immune functions. Methodology/Principal Findings Here, we treated monocyte-derived macrophages with live or killed M. leprae, and examined their activation status and antigen presentation. We found that macrophages treated with live M. leprae showed committed M2-like function, with decreased interleukin 1 beta (IL-1beta), IL-6, tumor necrosis factor alpha (TNF-alpha) and MHC class II molecule expression and elevated IL-10 and CD163 expression. When incubating with naive T cells, macrophages treated with live M. leprae preferentially primed regulatory T (Treg) cell responses with elevated FoxP3 and IL-10 expression, while interferon gamma (IFN-gamma) expression and CD8+ T cell cytotoxicity were reduced. Chromium release assay also found that live M. leprae-treated macrophages were more resistant to CD8+ T cell-mediated cytotoxicity than sonicated M. leprae-treated monocytes. Ex vivo studies showed that the phenotype and function of monocytes and macrophages had clear differences between L-lep and T-lep patients, consistent with the in vitro findings. Conclusions/Significance Together, our data demonstrate that M. leprae could utilize infected macrophages by two mechanisms: firstly, M. leprae-infected macrophages preferentially primed Treg but not Th1 or cytotoxic T cell responses; secondly, M. leprae-infected macrophages were more effective at evading CD8+ T cell-mediated cytotoxicity. PMID:26751388

  1. Dual Roles for Perivascular Macrophages in Immune-to-Brain Signaling

    PubMed Central

    Serrats, Jordi; Schiltz, Jennifer C.; García-Bueno, Borja; van Rooijen, Nico; Reyes, Teresa M.; Sawchenko, Paul E.

    2009-01-01

    Cytokines produced during infection/inflammation activate adaptive CNS responses, including acute stress responses mediated by the hypothalamo-pituitary-adrenal (HPA) axis. The mechanisms by which cytokines engage HPA control circuitry remain unclear, though stimulated release of prostanoids from neighboring vascular cells has been implicated in this regard. How specific vascular cell types, endothelial cells (ECs) vs. perivascular cells (PVCs; a subset of brain-resident macrophages), participate in this response remains unsettled. We exploited the phagocytic activity of PVCs to deplete them in rats by central injection of a liposome-encapsulated pro-apoptotic drug. This manipulation abrogated CNS and hormonal indices of HPA activation under immune challenge conditions (interleukin-1; IL-1) that activated prostanoid synthesis only in PVCs, while enhancing these responses to stimuli (lipopolysaccaride; LPS) that engaged prostanoid production by ECs as well. Thus, PVCs provide both prostanoid-mediated drive to the HPA axis, and an anti-inflammatory action that constrains endothelial, and overall CNS, responses to inflammatory insults. PMID:20152116

  2. Nanoengineering of Immune Cell Function

    PubMed Central

    Shen, Keyue; Milone, Michael C.; Dustin, Michael L.; Kam, Lance C.

    2010-01-01

    T lymphocytes are a key regulatory component of the adaptive immune system. Understanding how the micro- and nano-scale details of the extracellular environment influence T cell activation may have wide impact on the use of T cells for therapeutic purposes. In this article, we examine how the micro- and nano-scale presentation of ligands to cell surface receptors, including microscale organization and nanoscale mobility, influences the activation of T cells. We extend these studies to include the role of cell-generated forces, and the rigidity of the microenvironment, on T cell activation. These approaches enable delivery of defined signals to T cells, a step toward understanding the cell-cell communication in the immune system, and developing micro/nano- and material- engineered systems for tailoring immune responses for adoptive T cell therapies. PMID:21562611

  3. Antagonism by Ganoderma lucidum polysaccharides against the suppression by culture supernatants of B16F10 melanoma cells on macrophage.

    PubMed

    Lu, Jie; Sun, Li-Xin; Lin, Zhi-Bin; Duan, Xin-Suo; Ge, Zhi-Hua; Xing, En-Hong; Lan, Tian-Fei; Yang, Ning; Li, Xue-Jun; Li, Min; Li, Wei-Dong

    2014-02-01

    It is well-documented that macrophages have the functions to regulate antitumor immune response. Antitumor response can be launched by a series of events, starting with inflammation mediated by monocyte/macrophages, which stimulates natural killer and dendritic cells and finally activates the cytotoxic lymphoid system. Monocytes/macrophages may be the first line of defense in tumors. However, specific and nonspecific immunotherapy for human cancer has shown no success or limited success in clinical trials. Part of the reasons attribute to tumor-derived soluble factors that suppress functions of immune cells or induce apoptosis of these cells, including macrophages. Therefore, antagonism of the suppression on the macrophages is an important goal for tumor immunotherapy. To achieve this purpose, Ganoderma lucidum polysaccharides (Gl-PS) with multiple bioactivities were used on mouse peritoneal macrophages incubating with culture supernatants of B16F10 melanoma cells (B16F10-CS). It was shown that the viability, phagocytic activity, NO production, TNF-α production and activity in peritoneal macrophages after activation by lipopolysaccharide were suppressed by B16F10-CS, while the suppressions were fully or partially antagonized by Gl-PS. In conclusion, B16F10-CS is suppressive to the viability, phagocytic activity, NO production, TNF-α production and activity in peritoneal macrophages while Gl-PS had the antagonistic effects against this suppression, suggesting this potential of Gl-PS to facilitate cancer immunotherapy. PMID:23519930

  4. Clearance of oxidatively damaged cells by macrophages: recognition of glycoprotein clusters by macrophage-surface nucleolin as early apoptotic cells.

    PubMed

    Miki, Yuichi; Itoh, Takashi; Hirano, Kazuya; Eda, Shigetoshi; Hayashi, Akiko; Yamanaka, Masahiro; Beppu, Masatoshi

    2009-04-01

    The mechanism of macrophage recognition of oxidatively damaged cells was investigated. Jurkat T cells exposed to various concentrations of H(2)O(2) were bound and phagocytosed by macrophages. The cells exposed to 0.1 mM H(2)O(2) were best bound. The cell-surface ligands recognized by macrophages were suggested to be sialylpolylactosaminyl sugar chains of a major sialoglycoprotein CD43 because 1) the cell binding was inhibited by oligosaccharides containing sialylpolylactosaminyl chains, and their inhibitory activity was destroyed by a polylactosamine-cleaving enzyme endo-beta-galactosidase, and by neuraminidase; 2) the oxidized Jurkat cells pretreated with either glycosidase or with anti-CD43 antibody were not bound. The macrophage receptor involved in the binding was suggested to be cell-surface nucleolin because 1) anti-nucleolin antibody inhibited the binding; 2) nucleolin-transfected HEK293 cells bound the oxidized cells; and 3) this binding was inhibited by anti-nucleolin antibody and by anti-CD43 antibody. CD43 on oxidized Jurkat cells tended to form clusters in good accordance with their susceptibility to the macrophage binding. CD43 clustering and the oxidized-cell binding to macrophages were prevented by a caspase inhibitor Z-VAD-fmk, suggesting that the oxidized and bound cells were undergoing apoptosis. Indeed, caspase-3 activity of Jurkat cells increased by the oxidation. These results suggest that moderately oxidized cells undergo apoptosis and are recognized by macrophages as early apoptotic cells. PMID:19336885

  5. Polarization of immune responses in fish: The 'macrophages first' point of view.

    PubMed

    Wiegertjes, Geert F; Wentzel, Annelieke S; Spaink, Herman P; Elks, Philip M; Fink, Inge R

    2016-01-01

    In this review, we support taking polarized immune responses in teleost fish from a 'macrophage first' point of view, a hypothesis that reverts the dichotomous T helper (TH)1 and TH2 driving forces by building on the idea of conservation of innate immune responses in lower vertebrates. It is plausible that the initial trigger for macrophage polarization into M1 (inflammation) or M2 (healing) could rely only on sensing microbial/parasite infection or other innate danger signals, without the influence of adaptive immunity. Given the long and ongoing debate on the presence/absence of a typical TH1 cytokine environment and, in particular, TH2 cytokine environment in fish immune responses, it stands out that the presence of macrophages with polarized phenotypes, alike M1 and M2, have been relatively easy to demonstrate for fish. We summarize in short present knowledge in teleost fish on those cytokines considered most critical to the dichotomous development of TH1/M1 and TH2/M2 polarization, in particular, but not exclusively, interferon-γ and interleukin (IL)-4/IL-13. We review, in more detail, polarization of fish immune responses taken from the macrophage point of view for which we adopted the simple nomenclature of M1 and M2. We discuss inducible nitric oxide synthase, or NOS-2, as a reliable M1 marker and arginase-2 as a reliable M2 marker for teleost fish and discuss the value of these macrophage markers for the generation of zebrafish reporter lines to study M1/M2 polarization in vivo. PMID:26471699

  6. Interaction of mouse splenocytes and macrophages with bacterial strains in vitro: the effect of age in the immune response.

    PubMed

    Van Beek, A A; Hoogerland, J A; Belzer, C; De Vos, P; De Vos, W M; Savelkoul, H F J; Leenen, P J M

    2016-03-11

    Probiotics influence the immune system, both at the local and systemic level. Recent findings suggest the relation between microbiota and the immune system alters with age. Our objective was to address direct effects of six bacterial strains on immune cells from young and aged mice: Lactobacillus plantarum WCFS1, Lactobacillus casei BL23, Lactococcus lactis MG1363, Bifidobacterium breve ATCC15700, Bifidobacterium infantis ATCC15697, and Akkermansia muciniphila ATCC BAA-835. We used splenocytes and naïve or interferon-γ-stimulated bone marrow-derived macrophages (BMDM) as responder populations. All tested bacterial strains induced phenotypic and cytokine responses in splenocytes and BMDM. Based on magnitude of the cellular inflammatory response and cytokine profiles, two subgroups of bacteria were identified, i.e. L. plantarum and L. casei versus B. breve, B. infantis, and A. muciniphila. The latter group of bacteria induced high levels of cytokines produced under inflammatory conditions, including tumour necrosis factor (TNF), interleukin (IL)-6 and IL-10. Responses to L. lactis showed features of both subgroups. In addition, we compared responses by splenocytes and BMDM derived from young mice to those of aged mice, and found that splenocytes and BMDM derived from aged mice had an increased IL-10 production and dysregulated IL-6 and TNF production compared to young immune cells. Overall, our study shows differential inflammatory responses to distinct bacterial strains, and profound age-dependent effects. These findings, moreover, support the view that immune environment importantly influences bacterial immune effects. PMID:26689225

  7. Macrophages and the Viral Dissemination Super Highway

    PubMed Central

    Klepper, Arielle; Branch, Andrea D

    2016-01-01

    Monocytes and macrophages are key components of the innate immune system yet they are often the victims of attack by infectious agents. This review examines the significance of viral infection of macrophages. The central hypothesis is that macrophage tropism enhances viral dissemination and persistence, but these changes may come at the cost of reduced replication in cells other than macrophages. PMID:26949751

  8. Regulation of ICAM-1 in Cells of the Monocyte/Macrophage System in Microgravity

    PubMed Central

    Paulsen, Katrin; Tauber, Svantje; Dumrese, Claudia; Bradacs, Gesine; Simmet, Dana M.; Gölz, Nadine; Hauschild, Swantje; Raig, Christiane; Engeli, Stephanie; Gutewort, Annett; Hürlimann, Eva; Biskup, Josefine; Rieder, Gabriela; Hofmänner, Daniel; Mutschler, Lisa; Krammer, Sonja; Philpot, Claudia; Huge, Andreas; Lier, Hartwin; Barz, Ines; Engelmann, Frank; Layer, Liliana E.; Thiel, Cora S.

    2015-01-01

    Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells. PMID:25654110

  9. Regulation of ICAM-1 in cells of the monocyte/macrophage system in microgravity.

    PubMed

    Paulsen, Katrin; Tauber, Svantje; Dumrese, Claudia; Bradacs, Gesine; Simmet, Dana M; Gölz, Nadine; Hauschild, Swantje; Raig, Christiane; Engeli, Stephanie; Gutewort, Annett; Hürlimann, Eva; Biskup, Josefine; Unverdorben, Felix; Rieder, Gabriela; Hofmänner, Daniel; Mutschler, Lisa; Krammer, Sonja; Buttron, Isabell; Philpot, Claudia; Huge, Andreas; Lier, Hartwin; Barz, Ines; Engelmann, Frank; Layer, Liliana E; Thiel, Cora S; Ullrich, Oliver

    2015-01-01

    Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells. PMID:25654110

  10. Dietary fats affect macrophage-mediated cytotoxicity towards tumour cells.

    PubMed

    Wallace, F A; Neely, S J; Miles, E A; Calder, P C

    2000-02-01

    In the present study, the effects of feeding mice diets of different fatty acid compositions on the production of TNF-alpha and nitric oxide by lipopolysaccharide-stimulated peritoneal macrophages and on macrophage-mediated cytotoxicity towards L929 and P815 cells were investigated. C57Bl6 mice were fed on a low-fat (LF) diet or on high-fat diets (21% fat by weight), which included coconut oil (CO), olive oil (OO), safflower oil (SO) or fish oil (FO) as the principal fat source. The fatty acid composition of the macrophages was markedly influenced by that of the diet fed. Lipopolysaccharide (LPS)-stimulated macrophages from FO-fed mice showed significantly lower production (up to 80%) of PGE2 than those from mice fed on each of the other diets. There was a significant positive linear correlation between the proportion of arachidonic acid in macrophage lipids and the ability of macrophages, to produce PGE2. Lipopolysaccharide-stimulated TNF-alpha production by macrophages decreased with increasing unsaturated fatty acid content of the diet (i.e. FO < SO < OO < CO < LF). Macrophages from FO-fed mice showed significantly lower production of TNF-alpha than those from mice fed on each of the other diets. Nitrite production was highest for LPS-stimulated macrophages from mice fed on the LF diet. Macrophages from FO-fed mice showed significantly higher production of nitrite than those from mice fed on the OO and SO diets. Compared with feeding the LF diet, feeding the CO, OO or SO diets significantly decreased macrophage- mediated killing of P815 cells (killed by nitric oxide). Fish oil feeding did not alter killing of P815 cells by macrophages, compared with feeding the LF diet; killing of P815 cells was greater after FO feeding than after feeding the other high fat diets. Compared with feeding the LF diet, feeding the OO or SO diets significantly decreased macrophage-mediated killing of L929 cells (killed by TNF). Coconut oil or FO feeding did not alter killing of L929 cells by macrophages, compared with feeding the LF diet. It is concluded that the type of fat in the diet affects macrophage composition and alters the ability of macrophages to produce cytotoxic and immunoregulatory mediators and to kill target tumour cells. PMID:10651928

  11. Sessile alveolar macrophages communicate with alveolar epithelium to modulate immunity

    NASA Astrophysics Data System (ADS)

    Westphalen, Kristin; Gusarova, Galina A.; Islam, Mohammad N.; Subramanian, Manikandan; Cohen, Taylor S.; Prince, Alice S.; Bhattacharya, Jahar

    2014-02-01

    The tissue-resident macrophages of barrier organs constitute the first line of defence against pathogens at the systemic interface with the ambient environment. In the lung, resident alveolar macrophages (AMs) provide a sentinel function against inhaled pathogens. Bacterial constituents ligate Toll-like receptors (TLRs) on AMs, causing AMs to secrete proinflammatory cytokines that activate alveolar epithelial receptors, leading to recruitment of neutrophils that engulf pathogens. Because the AM-induced response could itself cause tissue injury, it is unclear how AMs modulate the response to prevent injury. Here, using real-time alveolar imaging in situ, we show that a subset of AMs attached to the alveolar wall form connexin 43 (Cx43)-containing gap junction channels with the epithelium. During lipopolysaccharide-induced inflammation, the AMs remained sessile and attached to the alveoli, and they established intercommunication through synchronized Ca2+ waves, using the epithelium as the conducting pathway. The intercommunication was immunosuppressive, involving Ca2+-dependent activation of Akt, because AM-specific knockout of Cx43 enhanced alveolar neutrophil recruitment and secretion of proinflammatory cytokines in the bronchoalveolar lavage. A picture emerges of a novel immunomodulatory process in which a subset of alveolus-attached AMs intercommunicates immunosuppressive signals to reduce endotoxin-induced lung inflammation.

  12. Whole-cell MALDI-TOF MS: a new tool to assess the multifaceted activation of macrophages.

    PubMed

    Ouedraogo, Richard; Daumas, Aurélie; Ghigo, Eric; Capo, Christian; Mege, Jean-Louis; Textoris, Julien

    2012-10-22

    Whole-cell MALDI-TOF MS is routinely used to identify bacterial species in clinical samples. This technique has also proven to allow identification of intact mammalian cells, including macrophages. Here, we wondered whether this approach enabled the assessment human macrophages plasticity. The whole-cell MALDI-TOF spectra of macrophages stimulated with IFN-γ and IL-4, two inducers of M1 and M2 macrophage polarisation, consisted of peaks ranging from 2 to 12 kDa. The spectra of unstimulated and stimulated macrophages were clearly different. The fingerprints induced by the M1 agonists, IFN-γ, TNF, LPS and LPS+IFN-γ, and the M2 agonists, IL-4, TGF-β1 and IL-10, were specific and readily identifiable. Thus, whole-cell MALDI-TOF MS was able to characterise M1 and M2 macrophage subtypes. In addition, the fingerprints induced by extracellular (group B Streptococcus, Staphylococcus aureus) or intracellular (BCG, Orientia tsutsugamushi, Coxiella burnetii) bacteria were bacterium-specific. The whole-cell MALDI-TOF MS fingerprints therefore revealed the multifaceted activation of human macrophages. This approach opened a new avenue of studies to assess the immune response in the clinical setting, by monitoring the various activation patterns of immune cells in pathological conditions. PMID:22967923

  13. The innate and adaptive immune response induced by alveolar macrophages exposed to ambient particulate matter

    SciTech Connect

    Miyata, Ryohei; Eeden, Stephan F. van

    2011-12-15

    Emerging epidemiological evidence suggests that exposure to particulate matter (PM) air pollution increases the risk of cardiovascular events but the exact mechanism by which PM has adverse effects is still unclear. Alveolar macrophages (AM) play a major role in clearing and processing inhaled PM. This comprehensive review of research findings on immunological interactions between AM and PM provides potential pathophysiological pathways that interconnect PM exposure with adverse cardiovascular effects. Coarse particles (10 {mu}m or less, PM{sub 10}) induce innate immune responses via endotoxin-toll-like receptor (TLR) 4 pathway while fine (2.5 {mu}m or less, PM{sub 2.5}) and ultrafine particles (0.1 {mu}m or less, UFP) induce via reactive oxygen species generation by transition metals and/or polyaromatic hydrocarbons. The innate immune responses are characterized by activation of transcription factors [nuclear factor (NF)-{kappa}B and activator protein-1] and the downstream proinflammatory cytokine [interleukin (IL)-1{beta}, IL-6, and tumor necrosis factor-{alpha}] production. In addition to the conventional opsonin-dependent phagocytosis by AM, PM can also be endocytosed by an opsonin-independent pathway via scavenger receptors. Activation of scavenger receptors negatively regulates the TLR4-NF-{kappa}B pathway. Internalized particles are subsequently subjected to adaptive immunity involving major histocompatibility complex class II (MHC II) expression, recruitment of costimulatory molecules, and the modulation of the T helper (Th) responses. AM show atypical antigen presenting cell maturation in which phagocytic activity decreases while both MHC II and costimulatory molecules remain unaltered. PM drives AM towards a Th1 profile but secondary responses in a Th1- or Th-2 up-regulated milieu drive the response in favor of a Th2 profile.

  14. High expression levels of macrophage migration inhibitory factor sustain the innate immune responses of neonates.

    PubMed

    Roger, Thierry; Schneider, Anina; Weier, Manuela; Sweep, Fred C G J; Le Roy, Didier; Bernhagen, Jürgen; Calandra, Thierry; Giannoni, Eric

    2016-02-23

    The vulnerability to infection of newborns is associated with a limited ability to mount efficient immune responses. High concentrations of adenosine and prostaglandins in the fetal and neonatal circulation hamper the antimicrobial responses of newborn immune cells. However, the existence of mechanisms counterbalancing neonatal immunosuppression has not been investigated. Remarkably, circulating levels of macrophage migration inhibitory factor (MIF), a proinflammatory immunoregulatory cytokine expressed constitutively, were 10-fold higher in newborns than in children and adults. Newborn monocytes expressed high levels of MIF and released MIF upon stimulation with Escherichia coli and group B Streptococcus, the leading pathogens of early-onset neonatal sepsis. Inhibition of MIF activity or MIF expression reduced microbial product-induced phosphorylation of p38 and ERK1/2 mitogen-activated protein kinases and secretion of cytokines. Recombinant MIF used at newborn, but not adult, concentrations counterregulated adenosine and prostaglandin E2-mediated inhibition of ERK1/2 activation and TNF production in newborn monocytes exposed to E. coli. In agreement with the concept that once infection is established high levels of MIF are detrimental to the host, treatment with a small molecule inhibitor of MIF reduced systemic inflammatory response, bacterial proliferation, and mortality of septic newborn mice. Altogether, these data provide a mechanistic explanation for how newborns may cope with an immunosuppressive environment to maintain a certain threshold of innate defenses. However, the same defense mechanisms may be at the expense of the host in conditions of severe infection, suggesting that MIF could represent a potential attractive target for immune-modulating adjunctive therapies for neonatal sepsis. PMID:26858459

  15. Neisseria gonorrhoeae Modulates Immunity by Polarizing Human Macrophages to a M2 Profile

    PubMed Central

    Ortiz, María Carolina; Lefimil, Claudia; Rodas, Paula I.; Vernal, Rolando; Lopez, Mercedes; Acuña-Castillo, Claudio; Imarai, Mónica; Escobar, Alejandro

    2015-01-01

    Current data suggest that Neisseria gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and antigen-presenting cells. The present report is focused on gonococcus evasion mechanism on macrophages (MФ) and its impact in the subsequent immune response. In response to various signals MФ may undergo classical-M1 (M1-MФ) or alternative-M2 (M2-MФ) activation. Until now there are no reports of the gonococcus effects on human MФ polarization. We assessed the phagocytic ability of monocyte-derived MФ (MDM) upon gonococcal infection by immunofluorescence and gentamicin protection experiments. Then, we evaluated cytokine profile and M1/M2 specific-surface markers on MФ challenged with N. gonorrhoeae and their proliferative effect on T cells. Our findings lead us to suggest N. gonorrhoeae stimulates a M2-MФ phenotype in which some of the M2b and none of the M1-MФ-associated markers are induced. Interestingly, N. gonorrhoeae exposure leads to upregulation of a Programmed Death Ligand 1 (PD-L1), widely known as an immunosuppressive molecule. Moreover, functional results showed that N. gonorrhoeae-treated MФ are unable to induce proliferation of human T-cells, suggesting a more likely regulatory phenotype. Taken together, our data show that N. gonorroheae interferes with MФ polarization. This study has important implications for understanding the mechanisms of clearance versus long-term persistence of N. gonorroheae infection and might be applicable for the development of new therapeutic strategies. PMID:26125939

  16. T cells down-regulate macrophage TNF production by IRAK1-mediated IL-10 expression and control innate hyperinflammation

    PubMed Central

    Inoue, Makoto; Arikawa, Tomohiro; Chen, Yu-Hsun; Moriwaki, Yasuhiro; Price, Michael; Brown, Michael; Perfect, John R.; Shinohara, Mari L.

    2014-01-01

    Endotoxemia is caused by excessive inflammation, but the immune system has various mechanisms to avoid collateral organ damage in endotoxemia. A handful of reports have shown that innate immune responses are suppressed by the adaptive immune system. However, the molecular mechanism by which adaptive immune cells suppress innate inflammatory responses is not clear. Here, we report that T cells are shown to interact with macrophages at the early stage of enodotoxemia and to prolong survival of mice through controlling TNF and IL-10 levels by macrophage CD40 stimulation. The cross-talk between CD40 and toll-like receptor (TLR4) signaling first mediates IL-1 receptor-associated kinase 1 (IRAK1) nuclear translocation and its binding to the IL-10 gene promoter in macrophages, without interfering with the NFκB pathway. IL-10 is then detected by macrophages in an autocrine fashion to destabilize Tnfa mRNA. To induce IRAK1-mediated IL-10 expression, signals from both CD40 and TLR4 are essential. CD40 signaling induces IRAK1 sumoylation in the presence of TNF receptor-associated factor 2 (TRAF2) and intracellular isoform of osteopontin (iOPN) whereas TLR4 signaling provides IFN regulatory factor 5 (IRF5) as a chaperone for sumoylated IRAK1 nuclear translocation. Interaction of T cells with macrophages was observed in the spleen in vivo after endotoxemia induction with LPS injection. Our study demonstrates a mechanistic basis for the immunosuppressive role of macrophage CD40 in LPS endotoxemia. PMID:24706909

  17. Modulators affecting the immune dialogue between human immune and colon cancer cells

    PubMed Central

    Djaldetti, Meir; Bessler, Hanna

    2014-01-01

    The link between chronic inflammation and colorectal cancer has been well established. The events proceeding along tumorigenesis are complicated and involve cells activated at the cancer microenvironment, tumor infiltrating polymorphonuclears, immune cells including lymphocyte subtypes and peripheral blood mononuclear cells (PBMC), as well as tumor-associated macrophages. The immune cells generate inflammatory cytokines, several of them playing a crucial role in tumorigenesis. Additional factors, such as gene expression regulated by cytokines, assembling of tumor growth- and transforming factors, accelerated angiogenesis, delayed apoptosis, contribute all to initiation, development and migration of tumor cells. Oxygen radical species originating from the inflammatory area promote cell mutation and cancer proliferation. Tumor cells may over-express pro-inflammatory mediators that in turn activate immune cells for inflammatory cytokines production. Consequently, an immune dialogue emerges between immune and cancer cells orchestrated through a number of activated molecular pathways. Cytokines, encompassing migration inhibitory factor, transforming growth factor beta 1, tumor necrosis factor-α, Interleukin (IL)-6, IL-10, IL-12, IL-17, IL-23 have been reported to be involved in human cancer development. Some cytokines, namely IL-5, IL-6, IL-10, IL-22 and growth factors promote tumor development and metastasis, and inhibit apoptosis via activation of signal transducer activator transcription-3 transcription factor. Colon cancer environment comprises mesenchymal, endothelial and immune cells. Assessment of the interaction between components in the tumor environment and malignant cells requires a reconsideration of a few topics elucidating the role of chronic inflammation in carcinogenesis, the function of the immune cells expressed by inflammatory cytokine production, the immunomodulation of cancer cells and the existence of a cross-talk between immune and malignant cells leading to a balance in cytokine production. It is conceivable that the prevalence of anti-inflammatory cytokine production by PBMC in the affected colonic mucosa will contribute to the delay, or even to halt down malignant expansion. Targeting the interplay between immune and cancer cells by mediators capable to alter cytokine secretion toward increased anti-inflammatory cytokine release by PBMC and tumor associated macrophages, may serve as an additional strategy for treatment of malignant diseases. This review will focus on the inflammatory events preceding tumorigenesis in general, and on a number of modulators capable to affect colon cancer cell-induced production of inflammatory cytokines by PBMC through alteration of the immune cross-talk between PBMC and cancer cells. PMID:24834143

  18. Guardians of the Gut – Murine Intestinal Macrophages and Dendritic Cells

    PubMed Central

    Gross, Mor; Salame, Tomer-Meir; Jung, Steffen

    2015-01-01

    Intestinal mononuclear phagocytes find themselves in a unique environment, most prominently characterized by its constant exposure to commensal microbiota and food antigens. This anatomic setting has resulted in a number of specializations of the intestinal mononuclear phagocyte compartment that collectively contribute the unique steady state immune landscape of the healthy gut, including homeostatic innate lymphoid cells, B, and T cell compartments. As in other organs, macrophages and dendritic cells (DCs) orchestrate in addition the immune defense against pathogens, both in lymph nodes and mucosa-associated lymphoid tissue. Here, we will discuss origins and functions of intestinal DCs and macrophages and their respective subsets, focusing largely on the mouse and cells residing in the lamina propria. PMID:26082775

  19. Responses of macrophages to the danger signals released from necrotic cells.

    PubMed

    Kimura, Toshifumi; Kobayashi, Shuhei; Hanihara-Tatsuzawa, Fumito; Sayama, Aoi; MaruYama, Takashi; Muta, Tatsushi

    2014-12-01

    The immune system maintains homeostasis by recognizing and responding to cell death caused by various stresses. The immune response is considered to be elicited by 'danger signals' released from necrotic cells. However, the identity of the danger signals remains elusive. In this study, we focused on the expression of chemokines by macrophages stimulated with necrotic cells. In mouse bone-marrow-derived macrophages, the chemokine monocyte chemoattractant protein (MCP)-3 was induced at both the mRNA and protein levels in response to heat-killed murine cells. The induction of MCP-3 was also observed in MyD88-deficient macrophages, indicating that Toll-like receptors and the IL-1 receptor are not involved in this response. Consistent with this observation, the activation of NF-κB was not detected in RAW264.7 macrophages stimulated with necrotic cells. Treatments with proteinase K, DNaseI or RNaseA did not affect the ' STIMULATING ACTIVITY': of necrotic cells. In contrast, treatment with apyrase, which removes phosphates from nucleoside tri- and di-phosphates, abolished the inducing activity. Purified UDP at 30 µM concentration elicited similar induction of MCP-3 in RAW264.7 macrophages. Small interfering RNA-mediated knock-down of the UDP receptor P2Y6 in RAW264.7 cells significantly reduced the induction of MCP-3 in response to necrotic cells, but not its induction by lipopolysaccharide. Furthermore, ectopic expression of the P2Y6 receptor in HEK293 cells conferred responsiveness to necrotic cells. These results suggest that UDP released by necrotic cells plays a critical role as an endogenous danger signal and that P2Y6 is required for the induction of MCP-3 in response to necrotic cells. PMID:25096411

  20. Constant light suppresses production of Met-enkephalin-containing peptides in cultured splenic macrophages and impairs primary immune response in rats.

    PubMed

    Valdés-Tovar, Marcela; Escobar, Carolina; Solís-Chagoyán, Héctor; Asai, Miguel; Benítez-King, Gloria

    2015-03-01

    The light-dark cycle is an environmental factor that influences immune physiology, and so, variations of the photoperiod length result in altered immune responsivity. Macrophage physiology comprises a spectrum of functions that goes from host defense to immune down-regulation, in addition to their homeostatic activities. Macrophages also play a key role in the transition from innate to adaptive immune responses. Met-enkephalin (MEnk) has been recognized as a modulator of macrophage physiology acting in an autocrine or paracrine fashion to influence macrophage activation, phenotype polarization and production of cytokines that would enhance lymphocyte activation at early stages of an immune response. Previously it was shown that splenic MEnk tissue content is reduced in rats exposed to constant light. In this work, we explored whether production of Met-enkephalin-containing peptides (MECPs) in cultured splenic macrophages is affected by exposure of rats to a constant light regime. In addition, we explored whether primary immune response was impaired under this condition. We found that in rats, 15 days in constant light was sufficient to disrupt their general activity rhythm. Splenic MEnk content oscillations and levels were also blunted throughout a 24-h period in animals subjected to constant light. In agreement, de novo synthesis of MECPs evaluated through incorporation of (35)S-methionine was reduced in splenic macrophages from rats exposed to constant light. Moreover, MECPs immunocytochemistry showed a decrease in the intracellular content and lack of granule-like deposits in this condition. Furthermore, we found that primary T-dependent antibody response was compromised in rats exposed to constant light. In those animals, pharmacologic treatment with MEnk increased IFN-γ-secreting cells. Also, IL-2 secretion from antigen-stimulated splenocytes was reduced after incubation with naloxone, suggesting that immune-derived opioid peptides and stimulation of opioid receptors are involved in this process. Thus, the immune impairment observed from early stages of the response in constant light-subjected rats, could be associated with reduced production of macrophage-derived enkephalins, leading to a sub-optimal interaction between macrophages and lymphocytes in the spleen and the subsequent deficiency in antibody production. PMID:25245012

  1. Fc Gamma Receptor IIb on GM-CSF Macrophages Controls Immune Complex Mediated Inhibition of Inflammatory Signals

    PubMed Central

    Santegoets, Kim C. M.; Wenink, Mark H.; van den Berg, Wim B.; Radstake, Timothy R. D. J.

    2014-01-01

    Background In rheumatoid arthritis (RA) macrophages play a major role in amplifying synovial inflammation. Important activating signals are those induced by Toll-like receptor (TLR) ligands and by activated T cells. The balance between activating and inhibitory Fc gamma receptors (FcγRs) on macrophages might be crucial in modulating these inflammatory responses. The purpose of this study was to determine FcγR expression on pro- and anti-inflammatory macrophages (gmMφ and mMφ, respectively) and identify functional consequences on immune complex uptake and macrophage activation. Methods Human monocytes were isolated and differentiated into gmMφ and mMφ. A full FcγR characterization of both macrophage subtypes was performed and uptake of fluorescent immune complexes (ICs) was determined. FcγRIIb isoforms were determined by qPCR. Macrophages were stimulated via different TLRs or cytokine activated T cells in the presence or absence of ICs and cytokine production was determined. Blocking studies were performed to look into the pathways involved. Results mMφ expressed high levels of the activating FcγRIIa and FcγRIII and low levels of the inhibitory FcγRIIb, while the FcγR balance on gmMφ was shifted towards the inhibitory FcγRIIb. This was accompanied by a clear increase in FcγRIIb1 mRNA expression in gmMφ. This resulted in higher IC uptake by mMφ compared to gmMφ. Furthermore, FcγR-mediated stimulation of gmMφ inhibited TLR2, 3, 4 and 7/8 mediated cytokine production via FcγRIIb and PI3K signaling. In addition, gmMφ but not mMφ produced TNFα upon co-culture with cytokine activated T cells, which was reduced by IC binding to FcγRIIb. The latter was dependent on PI3K signaling and COX2. Conclusions FcγR expression patterns on gmMφ and mMφ are significantly different, which translates in clear functional differences further substantiating FcγRIIb as an interesting target for inflammation control in RA and other autoimmune/inflammatory diseases. PMID:25340460

  2. Macrophage migration inhibitory factor (MIF) expression in human malignant gliomas contributes to immune escape and tumour progression.

    PubMed

    Mittelbronn, Michel; Platten, Michael; Zeiner, Pia; Dombrowski, Yvonne; Frank, Brigitte; Zachskorn, Cornelia; Harter, Patrick N; Weller, Michael; Wischhusen, Jörg

    2011-09-01

    Macrophage migration inhibitory factor (MIF), which inhibits apoptosis and promotes angiogenesis, is expressed in cancers suppressing immune surveillance. Its biological role in human glioblastoma is, however, only poorly understood. We examined in-vivo expression of MIF in 166 gliomas and 23 normal control brains by immunohistochemistry. MIF immunoreactivity was enhanced in neoplastic astrocytes in WHO grade II glioma and increased significantly in higher tumour grades (III-IV). MIF expression was further assessed in 12 glioma cell lines in vitro. Quantitative RT-PCR showed that MIF mRNA expression was elevated up to 800-fold in malignant glioma cells compared with normal brain. This translated into high protein levels as assessed by immunoblotting of total cell lysates and by ELISA-based measurement of secreted MIF. Wild-type p53-retaining glioma cell lines expressed higher levels of MIF, which may be connected with the previously described role of MIF as a negative regulator of wild-type p53 signalling in tumour cells. Stable knockdown of MIF by shRNA in glioma cells significantly increased tumour cell susceptibility towards NK cell-mediated cytotoxicity. Furthermore, supernatant from mock-transfected cells, but not from MIF knockdown cells, induced downregulation of the activating immune receptor NKG2D on NK and CD8+ T cells. We thus propose that human glioma cell-derived MIF contributes to the immune escape of malignant gliomas by counteracting NK and cytotoxic T-cell-mediated tumour immune surveillance. Considering its further cell-intrinsic and extrinsic tumour-promoting effects and the availability of small molecule inhibitors, MIF seems to be a promising candidate for future glioma therapy. PMID:21773885

  3. Macrophages sustain HIV replication in vivo independently of T cells.

    PubMed

    Honeycutt, Jenna B; Wahl, Angela; Baker, Caroline; Spagnuolo, Rae Ann; Foster, John; Zakharova, Oksana; Wietgrefe, Stephen; Caro-Vegas, Carolina; Madden, Victoria; Sharpe, Garrett; Haase, Ashley T; Eron, Joseph J; Garcia, J Victor

    2016-04-01

    Macrophages have long been considered to contribute to HIV infection of the CNS; however, a recent study has contradicted this early work and suggests that myeloid cells are not an in vivo source of virus production. Here, we addressed the role of macrophages in HIV infection by first analyzing monocytes isolated from viremic patients and patients undergoing antiretroviral treatment. We were unable to find viral DNA or viral outgrowth in monocytes isolated from peripheral blood. To determine whether tissue macrophages are productively infected, we used 3 different but complementary humanized mouse models. Two of these models (bone marrow/liver/thymus [BLT] mice and T cell-only mice [ToM]) have been previously described, and the third model was generated by reconstituting immunodeficient mice with human CD34+ hematopoietic stem cells that were devoid of human T cells (myeloid-only mice [MoM]) to specifically evaluate HIV replication in this population. Using MoM, we demonstrated that macrophages can sustain HIV replication in the absence of T cells; HIV-infected macrophages are distributed in various tissues including the brain; replication-competent virus can be rescued ex vivo from infected macrophages; and infected macrophages can establish de novo infection. Together, these results demonstrate that macrophages represent a genuine target for HIV infection in vivo that can sustain and transmit infection. PMID:26950420

  4. Antigen targeting reveals splenic CD169+ macrophages as promoters of germinal center B‐cell responses

    PubMed Central

    Veninga, Henrike; Borg, Ellen G. F.; Vreeman, Kyle; Taylor, Philip R.; Kalay, Hakan; van Kooyk, Yvette; Kraal, Georg; Martinez‐Pomares, Luisa

    2015-01-01

    Ag delivery to specific APCs is an attractive approach in developing strategies for vaccination. CD169+ macrophages in the marginal zone of the spleen represent a suitable target for delivery of Ag because of their strategic location, which is optimal for the capture of blood‐borne Ag and their close proximity to B cells and T cells in the white pulp. Here we show that Ag targeting to CD169+ macrophages in mice resulted in strong, isotype‐switched, high‐affinity Ab production and the preferential induction and long‐term persistence of Ag‐specific GC B cells and follicular Th cells. In agreement with these observations, CD169+ macrophages retained intact Ag, induced cognate activation of B cells, and increased expression of costimulatory molecules upon activation. In addition, macrophages were required for the production of cytokines that promote B‐cell responses. Our results identify CD169+ macrophages as promoters of high‐affinity humoral immune responses and emphasize the value of CD169 as target for Ag delivery to improve vaccine responses. PMID:25487358

  5. Development of a cell system for siRNA screening of pathogen responses in human and mouse macrophages.

    PubMed

    Li, Ning; Sun, Jing; Benet, Zachary L; Wang, Ze; Al-Khodor, Souhaila; John, Sinu P; Lin, Bin; Sung, Myong-Hee; Fraser, Iain D C

    2015-01-01

    Macrophages play a critical role in the innate immune response to pathogen infection, but few tools exist for systematic dissection of these responses using modern genome-wide perturbation methods. To develop an assay platform for high-throughput analysis of macrophage activation by pathogenic stimuli, we generated reporter systems in human and mouse macrophages with dynamic readouts for NF-κB and/or TNF-α responses. These reporter cells show responsiveness to a broad range of TLR ligands and to gram-negative bacterial infection. There are significant challenges to the use of RNAi in innate immune cells, including efficient small RNA delivery and non-specific immune responses to dsRNA. To permit the interrogation of the macrophage pathogen response pathways with RNAi, we employed the stably expressed reporter genes to develop efficient siRNA delivery protocols for maximal target gene silencing with minimal activation of the innate macrophage response to nucleic acids. We demonstrate the utility of these macrophage cell systems for siRNA screening of pathogen responses by targeting components of the human and mouse TLR pathways, and observe species-specific perturbation of signaling and cytokine responses. Our approach to reporter cell development and siRNA delivery optimization provides an experimental paradigm with significant potential for developing genetic screening platforms in mammalian cells. PMID:25831078

  6. Modulation of Intracellular Restriction Factors Contributes to Methamphetamine-Mediated Enhancement of Acquired Immune Deficiency Syndrome Virus Infection of Macrophages

    PubMed Central

    Wang, Xu; Wang, Yizhong; Ye, Li; Li, Jieliang; Zhou, Yu; Sakarcan, Sinem; Ho, Wenzhe

    2014-01-01

    Epidemiological studies have demonstrated that the use of methamphetamine (METH), a sympathomimetic stimulant, is particularly common among patients infected with HIV. In vitro studies have determined that METH enhances HIV infection of CD4+ T cells, monocyte-derived dendritic cells, and macrophages. In addition, animal studies have also showed that METH treatment increases brain viral load of SIV-infected monkeys and promotes HIV replication and viremia in HIV/hu-CycT1 transgenic mice. However, the mechanisms (s) of METH actions on HIV remain to be determined. In this study, we investigated the impact of METH on intracellular restriction factors against HIV and SIV. We demonstrated that METH treatment of human blood mononuclear phagocytes significantly affected the expression of anti-HIV microRNAs and several key elements (RIG-I, IRF-3/5, SOCS-2, 3 and PIAS-1, 3, X, Y) in the type I IFN pathway. The suppression of these innate restriction factors was associated with a reduced production of type I IFNs and the enhancement of HIV or SIV infection of macrophages. These findings indicate that METH use impairs intracellular innate antiviral mechanism(s) in macrophages, contributing to cell susceptibility to the acquired immune deficiency syndrome (AIDS) virus infection. PMID:22591364

  7. Cell mechanics and immune system link up to fight infections

    NASA Astrophysics Data System (ADS)

    Ekpenyong, Andrew; Man, Si Ming; Tourlomousis, Panagiotis; Achouri, Sarra; Cammarota, Eugenia; Hughes, Katherine; Rizzo, Alessandro; Ng, Gilbert; Guck, Jochen; Bryant, Clare

    2015-03-01

    Infectious diseases, in which pathogens invade and colonize host cells, are responsible for one third of all mortality worldwide. Host cells use special proteins (immunoproteins) and other molecules to fight viral and bacterial invaders. The mechanisms by which immunoproteins enable cells to reduce bacterial loads and survive infections remain unclear. Moreover, during infections, some immunoproteins are known to alter the cytoskeleton, the structure that largely determines cellular mechanical properties. We therefore used an optical stretcher to measure the mechanical properties of primary immune cells (bone marrow derived macrophages) during bacterial infection. We found that macrophages become stiffer upon infection. Remarkably, macrophages lacking the immunoprotein, NLR-C4, lost the stiffening response to infection. This in vitro result correlates with our in vivo data whereby mice lacking NLR-C4 have more lesions and hence increased bacterial distribution and spread. Thus, the immune-protein-dependent increase in cell stiffness in response to bacterial infection (in vitro result) seems to have a functional role in the system level fight against pathogens (in vivo result). We will discuss how this functional link between cell mechanical properties and innate immunity, effected by actin polymerization, reduces the spread of infection.

  8. Deficiency of the B Cell-Activating Factor Receptor Results in Limited CD169+ Macrophage Function during Viral Infection

    PubMed Central

    Xu, Haifeng C.; Huang, Jun; Khairnar, Vishal; Duhan, Vikas; Pandyra, Aleksandra A.; Grusdat, Melanie; Shinde, Prashant; McIlwain, David R.; Maney, Sathish Kumar; Gommerman, Jennifer; Lhning, Max; Ohashi, Pamela S.; Mak, Tak W.; Pieper, Kathrin; Sic, Heiko; Speletas, Matthaios; Eibel, Hermann; Ware, Carl F.; Tumanov, Alexei V.; Kruglov, Andrey A.; Nedospasov, Sergei A.; Hussinger, Dieter; Recher, Mike; Lang, Karl S.

    2015-01-01

    ABSTRACT The B cell-activating factor (BAFF) is critical for B cell development and humoral immunity in mice and humans. While the role of BAFF in B cells has been widely described, its role in innate immunity remains unknown. Using BAFF receptor (BAFFR)-deficient mice, we characterized BAFFR-related innate and adaptive immune functions following infection with vesicular stomatitis virus (VSV) and lymphocytic choriomeningitis virus (LCMV). We identified a critical role for BAFFR signaling in the generation and maintenance of the CD169+ macrophage compartment. Consequently, Baffr?/? mice exhibited limited induction of innate type I interferon production after viral infection. Lack of BAFFR signaling reduced virus amplification and presentation following viral infection, resulting in highly reduced antiviral adaptive immune responses. As a consequence, BAFFR-deficient mice showed exacerbated and fatal disease after viral infection. Mechanistically, transient lack of B cells in Baffr?/? animals resulted in limited lymphotoxin expression, which is critical for maintenance of CD169+ cells. In conclusion, BAFFR signaling affects both innate and adaptive immune activation during viral infections. IMPORTANCE Viruses cause acute and chronic infections in humans resulting in millions of deaths every year. Innate immunity is critical for the outcome of a viral infection. Innate type I interferon production can limit viral replication, while adaptive immune priming by innate immune cells induces pathogen-specific immunity with long-term protection. Here, we show that BAFFR deficiency not only perturbed B cells, but also resulted in limited CD169+ macrophages. These macrophages are critical in amplifying viral particles to trigger type I interferon production and initiate adaptive immune priming. Consequently, BAFFR deficiency resulted in reduced enforced viral replication, limited type I interferon production, and reduced adaptive immunity compared to BAFFR-competent controls. As a result, BAFFR-deficient mice were predisposed to fatal viral infections. Thus, BAFFR expression is critical for innate immune activation and antiviral immunity. PMID:25673724

  9. M2 Polarized Macrophages and Giant Cells Contribute to Myofibrosis in Neuromuscular Sarcoidosis

    PubMed Central

    Prokop, Stefan; Heppner, Frank L.; Goebel, Hans H.; Stenzel, Werner

    2011-01-01

    The etiopathogenesis of sarcoidosis, a systemic granulomatous disease, still remains obscure. A multitude of organs have been described to be affected in systemic sarcoidosis. Skeletal muscles may also be affected, leading to myalgia and weakness. A workup of the specific immune response with emphasis on the macrophage response is provided herein. Affected muscle tissue from seven patients with systemic sarcoidosis was analyzed and compared with that from seven patients with other myopathies containing macrophagocytic infiltration. Monocytes/macrophages and giant cells in granulomas of muscle tissue from patients with sarcoidosis show a status of alternative activation (M2) based on their expression of CD206, CD301, arginase-1, and suppressor of cytokine signaling-1 as a consequence of a functionally type 2 helper T cell (Th2)-biased cytokine profile. Significant fibrosis and up-regulation of CCL18 were associated with the M2 phenotype of macrophages. Conversely, up-regulated Th1 cytokines did not result in significant classical activation of macrophages (M1), with poor inducible nitric oxide synthase and cyclooxygenase-2 production. Giant cell formation was further associated with up-regulated expression of DNAX-activating protein of 12 kDa (DAP12; gene symbol TYROBP). Functionally, alternative activation of macrophages on the basis of a Th2-biased immune response may induce clinical symptoms and chronic evolution of neuromuscular sarcoidosis. This is the first characterization of Th2-mediated immune mechanisms in neuromuscular sarcoidosis suggesting that a specific macrophage activation status leading to myofibrosis may be a key event in the pathogenesis of this disease. PMID:21356378

  10. Dendritic cells and tumor immunity.

    PubMed

    Gunzer, M; Jänich, S; Varga, G; Grabbe, S

    2001-10-01

    Researchers and clinicians have tried for decades to use the mechanisms of immunity for the fight against cancer. Early attempts aimed at the instrumentation of soluble immune mediators such as antibodies or cytotoxic proteins for the therapy of malignancies. Major improvements in understanding the induction and regulation of cellular immunity have now made it possible to generate effector cells in cancer patients which are specific for the neoplastic disease. At the beginning of every cellular immune reaction against cancers tumor antigens have to be presented to T cells in order to activate them and drive them into clonal expansion. This is done by antigen presenting cells, the most powerful of which is the dendritic cell (DC). While DC were hard to isolate initially, they can be generated in large numbers in vitro today and manipulated in multiple ways before given back to a patient to induce tumor immunity. Thus, a great amount of hope lies in the use of DC as inducers of tumor immunity. However, the first clinical studies, which have now been completed with only limited success make clear, that still a lot of open questions remain to be answered. This review tries to give an overview of this rapidly developing field, mentioning the major conceptual approaches and techniques, but also discussing important caveats. The next years will show whether we can improve our understanding of DC biology and the mechanisms of immune induction strongly enough to effectively employ DC for immunotherapy of cancer. PMID:11502164

  11. Salmonella Typhimurium Co-Opts the Host Type I IFN System To Restrict Macrophage Innate Immune Transcriptional Responses Selectively.

    PubMed

    Perkins, Darren J; Rajaiah, Rajesh; Tennant, Sharon M; Ramachandran, Girish; Higginson, Ellen E; Dyson, Tristan N; Vogel, Stefanie N

    2015-09-01

    Innate immune inflammatory responses are subject to complex layers of negative regulation at intestinal mucosal surfaces. Although the type I IFN system is critical for amplifying antiviral immunity, it has been shown to play a homeostatic role in some models of autoimmune inflammation. Type I IFN is triggered in the gut by select bacterial pathogens, but whether and how the type I IFN might regulate innate immunity in the intestinal environment have not been investigated in the context of Salmonella enterica serovar Typhimurium (ST). ST infection of human or murine macrophages reveals that IFN-? selectively restricts the transcriptional responses mediated by both the TLRs and the NOD-like receptors. Specifically, IFN-? potently represses ST-dependent innate induction of IL-1 family cytokines and neutrophil chemokines. This IFN-?-mediated transcriptional repression was independent of the effects of IFN-? on ST-induced macrophage cell death, but significantly dependent on IL-10 regulation. We further evaluated ST pathogenesis in vivo following oral inoculation of mice lacking IFN-?. We show that IFN-?(-/-) mice exhibit greater resistance to oral ST infection and a slower spread of ST to distal sterile sites. This work provides mechanistic insight into the relationship between ST and type I IFN, and demonstrates an additional mechanism by which IFN-? may promote spread of enteric pathogens. PMID:26202980

  12. CD40 and CD154 in cell-mediated immunity.

    PubMed

    Grewal, I S; Flavell, R A

    1998-01-01

    CD40-CD154-mediated contact-dependent signals between B and T cells are required for the generation of thymus dependent (TD) humoral immune responses. CD40-CD154 interactions are however also important in many other cell systems. CD40 is expressed by a large variety of cell types other than B cells, and these include dendritic cells, follicular dendritic cells, monocytes, macrophages, mast cells, fibroblasts, and endothelial cells. CD40- and CD154-knockout mice and antibodies to CD40 and CD154 have helped to elucidate the role of the CD40-CD154 system in immune responses. Recently published studies indicate that CD40-CD154 interactions can influence T cell priming and T cell-mediated effector functions; they can also upregulate costimulatory molecules and activate macrophages, NK cells, and endothelia as well as participate in organ-specific autoimmune disease, graft rejection, and even atherosclerosis. This review focuses on the role of the CD40-CD154 system in the regulation of many newly discovered functions important in inflammation and cell-mediated immunity. PMID:9597126

  13. Norcantharidin facilitates LPS-mediated immune responses by up-regulation of AKT/NF-?B signaling in macrophages.

    PubMed

    Zhao, Qufei; Qian, Yu; Li, Ruimei; Tan, Binghe; Han, Honghui; Liu, Mingyao; Qian, Min; Du, Bing

    2012-01-01

    Norcantharidin (NCTD), a demethylated analog of cantharidin, is a common used clinical drug to inhibit proliferation and metastasis of cancer cells. But the role of NCTD in modulating immune responses remains unknown. Here, we investigated the function and mechanism of NCTD in regulation of TLR4 associated immune response in macrophages. We evaluated the influence of NCTD on host defense against invaded pathogens by acute peritonitis mouse model, ELISA, Q-PCR, nitrite quantification, phagocytosis assay and gelatin zymography assay. Our data showed that the survival and the serum concentrations of IL-6 and TNF-? were all enhanced by NCTD significantly in peritonitis mouse model. Accordingly, LPS-induced cytokine, nitric oxide and MMP-9 production as well as the phagocytosis of bacteria were all up-regulated by NCTD in a dose dependent manner in both RAW264.7 cells and bone marrow-derived macrophages (BMMs). Then we further analyzed TLR4 associated signaling pathway by Western blot, Immunofluorescence and EMSA in the presence or absence of LPS. The phosphorylation of AKT and p65 at serine 536 but not serine 468 was enhanced obviously by NCTD in a dose dependent manner, whereas the degradation of I?B? was little effected. Consequently, the nuclear translocation and DNA binding ability of NF-?B was also increased by NCTD obviously in RAW264.7 cells. Our results demonstrated that NCTD could facilitate LPS-mediated immune response through promoting the phosphorylation of AKT/p65 and transcriptional activity of NF-?B, thus reprofiling the traditional anti-tumor drug NCTD as a novel immune regulator in promoting host defense against bacterial infection. PMID:22984593

  14. Endoplasmic reticulum chaperone gp96 in macrophages is essential for protective immunity during Gram-negative pneumonia.

    PubMed

    Anas, Adam A; de Vos, Alex F; Hoogendijk, Arie J; van Lieshout, Miriam Hp; van Heijst, Jeroen Wj; Florquin, Sandrine; Li, Zihai; van 't Veer, Cornelis; van der Poll, Tom

    2016-01-01

    Klebsiella pneumoniae is among the most common Gram-negative bacteria that cause pneumonia. Gp96 is an endoplasmic reticulum chaperone that is essential for the trafficking and function of Toll-like receptors (TLRs) and integrins. To determine the role of gp96 in myeloid cells in host defence during Klebsiella pneumonia, mice homozygous for the conditional Hsp90b1 allele encoding gp96 were crossed with mice expressing Cre-recombinase under control of the LysM promoter to generate LysMcre-Hsp90b1-flox mice. LysMcre-Hsp90b1-flox mice showed absence of gp96 protein in macrophages and partial depletion in monocytes and granulocytes. This was accompanied by almost complete absence of TLR2 and TLR4 on macrophages. Likewise, integrin subunits CD11b and CD18 were not detectable on macrophages, while being only slightly reduced on monocytes and granulocytes. Gp96-deficient macrophages did not release pro-inflammatory cytokines in response to Klebsiella and displayed reduced phagocytic capacity independent of CD18. LysMcre-Hsp90b1-flox mice were highly vulnerable to lower airway infection induced by K. pneumoniae, as reflected by enhanced bacterial growth and a higher mortality rate. The early inflammatory response in Hsp90b1-flox mice was characterized by strongly impaired recruitment of granulocytes into the lungs, accompanied by attenuated production of pro-inflammatory cytokines, while the inflammatory response during late-stage pneumonia was not dependent on the presence of gp96. Blocking CD18 did not reproduce the impaired host defence of LysMcre-Hsp90b1-flox mice during Klebsiella pneumonia. These data indicate that macrophage gp96 is essential for protective immunity during Gram-negative pneumonia by regulating TLR expression. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:26365983

  15. STAT1 signaling regulates tumor-associated macrophage-mediated T cell deletion.

    PubMed

    Kusmartsev, Sergei; Gabrilovich, Dmitry I

    2005-04-15

    It is well established that tumor progression is associated with the accumulation of myeloid suppressive cells, which in mice include Gr-1+ immature myeloid cells and F4/80+ macrophages. The paradox is that with the exception of terminal stages of the disease or chemotherapy treatment, tumor-bearing mice or cancer patients do not display a profound systemic immune suppression. We therefore raised the question as to whether myeloid cell-mediated T cell suppression is controlled at a local level at the site of the tumor. We have demonstrated that after adoptive transfer to tumor-bearing recipients, Gr-1+ (immature myeloid cells) freshly isolated from spleens of tumor-bearing mice become F4/80+ tumor-associated macrophages (TAM). These TAM, but not F4/80+ macrophages or Gr-1+ cells freshly isolated from spleens of tumor-bearing or naive mice were able to inhibit T cell-mediated immune response in vitro via induction of T cell apoptosis. Arginase and NO were both responsible for the apoptotic mechanism, and were seen only in TAM, but not in freshly isolated Gr1+ cells. Using the analysis of STAT activity in combination with STAT knockout mice, we have determined that STAT1, but not STAT3 or STAT6, was responsible for TAM-suppressive activity. PMID:15814715

  16. Integrative Model of the Immune Response to a Pulmonary Macrophage Infection: What Determines the Infection Duration?

    PubMed Central

    Go, Natacha; Bidot, Caroline; Belloc, Catherine; Touzeau, Suzanne

    2014-01-01

    The immune mechanisms which determine the infection duration induced by pathogens targeting pulmonary macrophages are poorly known. To explore the impact of such pathogens, it is indispensable to integrate the various immune mechanisms and to take into account the variability in pathogen virulence and host susceptibility. In this context, mathematical models complement experimentation and are powerful tools to represent and explore the complex mechanisms involved in the infection and immune dynamics. We developed an original mathematical model in which we detailed the interactions between the macrophages and the pathogen, the orientation of the adaptive response and the cytokine regulations. We applied our model to the Porcine Respiratory and Reproductive Syndrome virus (PRRSv), a major concern for the swine industry. We extracted value ranges for the model parameters from modelling and experimental studies on respiratory pathogens. We identified the most influential parameters through a sensitivity analysis. We defined a parameter set, the reference scenario, resulting in a realistic and representative immune response to PRRSv infection. We then defined scenarios corresponding to graduated levels of strain virulence and host susceptibility around the reference scenario. We observed that high levels of antiviral cytokines and a dominant cellular response were associated with either short, the usual assumption, or long infection durations, depending on the immune mechanisms involved. To identify these mechanisms, we need to combine the levels of antiviral cytokines, including , and . The latter is a good indicator of the infected macrophage level, both combined provide the adaptive response orientation. Available PRRSv vaccines lack efficiency. By integrating the main interactions between the complex immune mechanisms, this modelling framework could be used to help designing more efficient vaccination strategies. PMID:25233096

  17. Regulation of IL-10 and IL-12 production and function in macrophages and dendritic cells

    PubMed Central

    Ma, Xiaojing; Yan, Wenjun; Zheng, Hua; Du, Qinglin; Zhang, Lixing; Ban, Yi; Li, Na; Wei, Fang

    2015-01-01

    Interleukin-10 and Interleukin-12 are produced primarily by pathogen-activated antigen-presenting cells, particularly macrophages and dendritic cells. IL-10 and IL-12 play very important immunoregulatory roles in host defense and immune homeostasis. Being anti- and pro-inflammatory in nature, respectively, their functions are antagonistically opposing. A comprehensive and in-depth understanding of their immunological properties and signaling mechanisms will help develop better clinical intervention strategies in therapy for a wide range of human disorders. Here, we provide an update on some emerging concepts, controversies, unanswered questions, and opinions regarding the immune signaling of IL-10 and IL-12. PMID:26918147

  18. Regulation of IL-10 and IL-12 production and function in macrophages and dendritic cells.

    PubMed

    Ma, Xiaojing; Yan, Wenjun; Zheng, Hua; Du, Qinglin; Zhang, Lixing; Ban, Yi; Li, Na; Wei, Fang

    2015-01-01

    Interleukin-10 and Interleukin-12 are produced primarily by pathogen-activated antigen-presenting cells, particularly macrophages and dendritic cells. IL-10 and IL-12 play very important immunoregulatory roles in host defense and immune homeostasis. Being anti- and pro-inflammatory in nature, respectively, their functions are antagonistically opposing. A comprehensive and in-depth understanding of their immunological properties and signaling mechanisms will help develop better clinical intervention strategies in therapy for a wide range of human disorders. Here, we provide an update on some emerging concepts, controversies, unanswered questions, and opinions regarding the immune signaling of IL-10 and IL-12. PMID:26918147

  19. 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. PMID:24661941

  20. An essential regulatory role for macrophage migration inhibitory factor in T-cell activation.

    PubMed Central

    Bacher, M; Metz, C N; Calandra, T; Mayer, K; Chesney, J; Lohoff, M; Gemsa, D; Donnelly, T; Bucala, R

    1996-01-01

    The protein known as macrophage migration inhibitory factor (MIF) was one of the first cytokines to be discovered and was described 30 years ago to be a T-cell-derived factor that inhibited the random migration of macrophages in vitro. A much broader role for MIF has emerged recently as a result of studies that have demonstrated it to be released from the anterior pituitary gland in vivo. MIF also is the first protein that has been identified to be secreted from monocytes/macrophages upon glucocorticoid stimulation. Once released, MIF acts to "override" or counter-regulate the suppressive effects of glucocorticoids on macrophage cytokine production. We report herein that MIF plays an important regulatory role in the activation of T cells induced by mitogenic or antigenic stimuli. Activated T cells produce MIF and neutralizing anti-MIF antibodies inhibit T-cell proliferation and interleukin 2 production in vitro, and suppress antigen-driven T-cell activation and antibody production in vivo. T cells also release MIF in response to glucocorticoid stimulation and MIF acts to override glucocorticoid inhibition of T-cell proliferation and interleukin 2 and interferon gamma production. These studies indicate that MIF acts in concert with glucocorticoids to control T-cell activation and assign a previously unsuspected but critical role for MIF in antigen-specific immune responses. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8755565

  1. 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

  2. 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

  3. Neutrophil extracellular traps license macrophages and Th17 cells for cytokine production in atherosclerosis

    PubMed Central

    Warnatsch, Annika; Ioannou, Marianna; Wang, Qian; Papayannopoulos, Venizelos

    2016-01-01

    Secretion of the cytokine interleukin-1β (IL-1β) by macrophages, a major driver of pathogenesis in atherosclerosis, requires two steps. First, priming signals promote transcription of immature IL-1β and then, endogenous “danger” signals activate innate immune signaling complexes called inflammasomes, to process IL-1β processing for secretion. While cholesterol crystals act as danger signals in atherosclerosis, what primes IL-1β transcription remains elusive. Using a murine model of atherosclerosis, we show that cholesterol crystals acted both as priming and danger signals for IL-1β production. Cholesterol crystals triggered neutrophils to release neutrophil extracellular traps (NETs). NETs primed macrophages for cytokine release, activating Th-17 cells that amplify immune cell recruitment in atherosclerotic plaques. Therefore, danger signals may drive sterile inflammation, such as that seen in atherosclerosis, through their interactions with neutrophils. PMID:26185250

  4. Lactobacillus and Lactobacillus cell-free culture supernatants modulate chicken macrophage activities.

    PubMed

    Quinteiro-Filho, W M; Brisbin, J T; Hodgins, D C; Sharif, S

    2015-12-01

    Lactobacilli are commensal microbes that reside in the intestines of several species, including chickens. Structural constituents of lactobacilli are able to stimulate the host immune system. Macrophages are crucial players in both innate and adaptive immune systems. Here, we investigated the effects of Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus salivarius and their cell-free culture supernatants on the pro-inflammatory gene expression profile, nitric oxide (NO) production and phagocytosis by chicken macrophages. Substantial differences were found among Lactobacillus strains in their capacity to induce pro-inflammatory cytokines. L. acidophilus only up-regulated interferon (IFN)-γ, while L. reuteri and L. salivarius up-regulated interleukin (IL)-1β, IL-6, IL-8 and IL-12 expression. Supernatant of L. salivarius up-regulated IL-1β, IL-8 and IFN-γ expression, while the other cell-free supernatants did not induce significant changes. Moreover, L. reuteri and L. salivarius increased macrophage phagocytosis, but all cell-free supernatants increased macrophage NO production and did not change phagocytosis activity. PMID:26679813

  5. The cell and molecular biology of apolipoprotein E synthesis by macrophages.

    PubMed

    Werb, Z; Chin, J R; Takemura, R; Oropeza, R L; Bainton, D F; Stenberg, P; Taylor, J M; Reardon, C

    1986-01-01

    Mononuclear phagocytes secrete over 50 different proteins that are regulated during differentiation and that are under the influence of various materials and factors in their extracellular milieu as part of the inflammatory response. The complex nature of the regulation of the expression of these molecules is displayed by apolipoprotein E (ApoE). ApoE mRNA first appears as monocytes differentiate into macrophages, and this expression is paralleled by the secretion of ApoE by the cells. In mature macrophages ApoE synthesis and secretion are decreased by activation of macrophages with endotoxin and interferon-gamma. Although these macrophages contain abundant translatable ApoE mRNA, little ApoE is synthesized, suggesting that this decrease occurs largely at the translational level. ApoE is also controlled at the level of secretion. ApoE is concentrated in the Golgi complex of macrophages and is also found in endoplasmic reticulum, secretion vesicles and coated vesicles. When macrophages come in contact with immune complexes the intracellular ApoE compartment degranulates rapidly. Therefore, ApoE is regulated at the levels of secretion, translation and transcription. PMID:3525037

  6. Drag cells in immunity

    PubMed Central

    Bonaccorsi, Irene; Pezzino, Gaetana; Morandi, Barbara; Ferlazzo, Guido

    2014-01-01

    Cross-dressing, in immunology, is a term originally coined to indicate the transfer of peptide-MHC complexes belonging to neighboring cells on antigen presenting cells. We have recently shown that plasmacytoid dendritic cells (pDCs) are particularly suited to be cross-dressed by tumor cells and that this phenomenon provides a unique pathway for abundant presentation of tumor antigens by pDCs. PMID:25083317

  7. 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 manipulation of the Tim-3 and PD-1 molecules restored the functionality of T cells and macrophages to restrict bacterial growth. Our results provide a novel immune strategy that may be implemented in the near future in order to improve the immune responses in HIV+ patients. PMID:26486200

  8. Stimulatory Effects of Polysaccharide Fraction from Solanum nigrum on RAW 264.7 Murine Macrophage Cells

    PubMed Central

    Razali, Faizan Naeem; Ismail, Amirah; Abidin, Nurhayati Zainal; Shuib, Adawiyah Suriza

    2014-01-01

    The polysaccharide fraction from Solanum nigrum Linne has been shown to have antitumor activity by enhancing the CD4+/CD8+ ratio of the T-lymphocyte subpopulation. In this study, we analyzed a polysaccharide extract of S. nigrum to determine its modulating effects on RAW 264.7 murine macrophage cells since macrophages play a key role in inducing both innate and adaptive immune responses. Crude polysaccharide was extracted from the stem of S. nigrum and subjected to ion-exchange chromatography to partially purify the extract. Five polysaccharide fractions were then subjected to a cytotoxicity assay and a nitric oxide production assay. To further analyze the ability of the fractionated polysaccharide extract to activate macrophages, the phagocytosis activity and cytokine production were also measured. The polysaccharide fractions were not cytotoxic, but all of the fractions induced nitric oxide in RAW 264.7 cells. Of the five fractions tested, SN-ppF3 was the least toxic and also induced the greatest amount of nitric oxide, which was comparable to the inducible nitric oxide synthase expression detected in the cell lysate. This fraction also significantly induced phagocytosis activity and stimulated the production of tumor necrosis factor-α and interleukin-6. Our study showed that fraction SN-ppF3 could classically activate macrophages. Macrophage induction may be the manner in which polysaccharides from S. nigrum are able to prevent tumor growth. PMID:25299340

  9. The Uptake of Apoptotic Cells Drives Coxiella burnetii Replication and Macrophage Polarization: A Model for Q Fever Endocarditis

    PubMed Central

    Benoit, Marie; Ghigo, Eric; Capo, Christian; Raoult, Didier; Mege, Jean-Louis

    2008-01-01

    Patients with valvulopathy have the highest risk to develop infective endocarditis (IE), although the relationship between valvulopathy and IE is not clearly understood. Q fever endocarditis, an IE due to Coxiella burnetii, is accompanied by immune impairment. Patients with valvulopathy exhibited increased levels of circulating apoptotic leukocytes, as determined by the measurement of active caspases and nucleosome determination. The binding of apoptotic cells to monocytes and macrophages, the hosts of C. burnetii, may be responsible for the immune impairment observed in Q fever endocarditis. Apoptotic lymphocytes (AL) increased C. burnetii replication in monocytes and monocyte-derived macrophages in a cell-contact dependent manner, as determined by quantitative PCR and immunofluorescence. AL binding induced a M2 program in monocytes and macrophages stimulated with C. burnetii as determined by a cDNA chip containing 440 arrayed sequences and functional tests, but this program was in part different in monocytes and macrophages. While monocytes that had bound AL released high levels of IL-10 and IL-6, low levels of TNF and increased CD14 expression, macrophages that had bound AL released high levels of TGF-β1 and expressed mannose receptor. The neutralization of IL-10 and TGF-β1 prevented the replication of C. burnetii due to the binding of AL, suggesting that they were critically involved in bacterial replication. In contrast, the binding of necrotic cells to monocytes and macrophages led to C. burnetii killing and typical M1 polarization. Finally, interferon-γ corrected the immune deactivation induced by apoptotic cells: it prevented the replication of C. burnetii and re-directed monocytes and macrophages toward a M1 program, which was deleterious for C. burnetii. We suggest that leukocyte apoptosis associated with valvulopathy may be critical for the pathogenesis of Q fever endocarditis by deactivating immune cells and creating a favorable environment for bacterial persistence. PMID:18483547

  10. Keratinocyte growth factor supports pulmonary innate immune defense through maintenance of alveolar antimicrobial protein levels and macrophage function.

    PubMed

    Gardner, Jason C; Wu, Huixing; Noel, John G; Ramser, Benjamin J; Pitstick, Lori; Saito, Atsushi; Nikolaidis, Nikolaos M; McCormack, Francis X

    2016-05-01

    Keratinocyte growth factor (KGF) is an epithelial mitogen that has been reported to protect the lungs from a variety of toxic and infectious insults. In prior studies we found that recombinant human KGF accelerates clearance of bacteria from the murine lung by augmenting the function of alveolar macrophages (AM). In this study we tested the hypothesis that endogenous KGF plays a role in the maintenance of innate pulmonary defense against gram-negative bacterial infections. KGF-deficient mice exhibited delayed clearance of Escherichia coli from the lungs, attenuated phagocytosis by AM, and decreased antimicrobial activity in bronchoalveolar lavage (BAL) fluid, due in part to reductions in levels of surfactant protein A, surfactant protein D, and lysozyme. These immune deficits were accompanied by lower alveolar type II epithelial cell counts and reduced alveolar type II epithelial cell expression of collectin and lysozyme genes on a per cell basis. No significant between-group differences were detected in selected inflammatory cytokines or BAL inflammatory cell populations at baseline or after bacterial challenge in the wild-type and KGF-deficient mice. A single intranasal dose of recombinant human KGF reversed defects in bacterial clearance, AM function, and BAL fluid antimicrobial activity. We conclude that KGF supports alveolar innate immune defense through maintenance of alveolar antimicrobial protein levels and functions of AM. Together these data demonstrate a role for endogenous KGF in maintenance of normal pulmonary innate immune function. PMID:26919897

  11. Regulation of innate immune cell function by mTOR.

    PubMed

    Weichhart, Thomas; Hengstschläger, Markus; Linke, Monika

    2015-10-01

    The innate immune system is central for the maintenance of tissue homeostasis and quickly responds to local or systemic perturbations by pathogenic or sterile insults. This rapid response must be metabolically supported to allow cell migration and proliferation and to enable efficient production of cytokines and lipid mediators. This Review focuses on the role of mammalian target of rapamycin (mTOR) in controlling and shaping the effector responses of innate immune cells. mTOR reconfigures cellular metabolism and regulates translation, cytokine responses, antigen presentation, macrophage polarization and cell migration. The mTOR network emerges as an integrative rheostat that couples cellular activation to the environmental and intracellular nutritional status to dictate and optimize the inflammatory response. A detailed understanding of how mTOR metabolically coordinates effector responses by myeloid cells will provide important insights into immunity in health and disease. PMID:26403194

  12. Hemocyanins Stimulate Innate Immunity by Inducing Different Temporal Patterns of Proinflammatory Cytokine Expression in Macrophages.

    PubMed

    Zhong, Ta-Ying; Arancibia, Sergio; Born, Raimundo; Tampe, Ricardo; Villar, Javiera; Del Campo, Miguel; Manubens, Augusto; Becker, María Inés

    2016-06-01

    Hemocyanins induce a potent Th1-dominant immune response with beneficial clinical outcomes when used as a carrier/adjuvant in vaccines and nonspecific immunostimulant in cancer. However, the mechanisms by which hemocyanins trigger innate immune responses, leading to beneficial adaptive immune responses, are unknown. This response is triggered by a proinflammatory signal from various components, of which macrophages are an essential part. To understand how these proteins influence macrophage response, we investigated the effects of mollusks hemocyanins with varying structural and immunological properties, including hemocyanins from Concholepas concholepas, Fissurella latimarginata, and Megathura crenulata (keyhole limpet hemocyanin), on cultures of peritoneal macrophages. Hemocyanins were phagocytosed and slowly processed. Analysis of this process showed differential gene expression along with protein levels of proinflammatory markers, including IL-1β, IL-6, IL-12p40, and TNF-α. An extended expression analysis of 84 cytokines during a 24-h period showed a robust proinflammatory response for F. latimarginata hemocyanin in comparison with keyhole limpet hemocyanin and C. concholepas hemocyanin, which was characterized by an increase in the transcript levels of M1 cytokines involved in leukocyte recruitment. These cytokine genes included chemokines (Cxcl1, Cxcl3, Cxcl5, Ccl2, and Ccl3), ILs (Il1b and Ifng), growth factors (Csf2 and Csf3), and TNF family members (Cd40lg). The protein levels of certain cytokines were increased. However, every hemocyanin maintains downregulated key M2 cytokine genes, including Il4 and Il5 Collectively, our data demonstrate that hemocyanins are able to trigger the release of proinflammatory factors with different patterns of cytokine expression, suggesting differential signaling pathways and transcriptional network mechanisms that lead to the activation of M1-polarized macrophages. PMID:27183578

  13. Hemocyanins Stimulate Innate Immunity by Inducing Different Temporal Patterns of Proinflammatory Cytokine Expression in Macrophages

    PubMed Central

    Zhong, Ta-Ying; Arancibia, Sergio; Born, Raimundo; Tampe, Ricardo; Villar, Javiera; Del Campo, Miguel; Manubens, Augusto

    2016-01-01

    Hemocyanins induce a potent Th1-dominant immune response with beneficial clinical outcomes when used as a carrier/adjuvant in vaccines and nonspecific immunostimulant in cancer. However, the mechanisms by which hemocyanins trigger innate immune responses, leading to beneficial adaptive immune responses, are unknown. This response is triggered by a proinflammatory signal from various components, of which macrophages are an essential part. To understand how these proteins influence macrophage response, we investigated the effects of mollusks hemocyanins with varying structural and immunological properties, including hemocyanins from Concholepas concholepas, Fissurella latimarginata, and Megathura crenulata (keyhole limpet hemocyanin), on cultures of peritoneal macrophages. Hemocyanins were phagocytosed and slowly processed. Analysis of this process showed differential gene expression along with protein levels of proinflammatory markers, including IL-1β, IL-6, IL-12p40, and TNF-α. An extended expression analysis of 84 cytokines during a 24-h period showed a robust proinflammatory response for F. latimarginata hemocyanin in comparison with keyhole limpet hemocyanin and C. concholepas hemocyanin, which was characterized by an increase in the transcript levels of M1 cytokines involved in leukocyte recruitment. These cytokine genes included chemokines (Cxcl1, Cxcl3, Cxcl5, Ccl2, and Ccl3), ILs (Il1b and Ifng), growth factors (Csf2 and Csf3), and TNF family members (Cd40lg). The protein levels of certain cytokines were increased. However, every hemocyanin maintains downregulated key M2 cytokine genes, including Il4 and Il5. Collectively, our data demonstrate that hemocyanins are able to trigger the release of proinflammatory factors with different patterns of cytokine expression, suggesting differential signaling pathways and transcriptional network mechanisms that lead to the activation of M1-polarized macrophages. PMID:27183578

  14. Emodin suppresses pulmonary metastasis of breast cancer cells accompanied with decreased macrophage recruitment and M2 polarization in the lungs

    PubMed Central

    Jia, Xuemei; Yu, Fang; Wang, Junfeng; Iwanowycz, Stephen; Saaoud, Fatma; Wang, Yuzhen; Hu, Jun; Wang, Qian; Fan, Daping

    2014-01-01

    Purpose Breast cancer is the leading cause of death in female cancer patients due to the lack of effective treatment for metastasis. Macrophages are the most abundant immune cells in the primary and metastatic tumors, and contribute to tumor initiation, progression and metastasis. Emodin has been found to exert anti-tumor effects through promoting cell cycle arrest and apoptosis, and inhibiting angiogenesis, but its effects on tumor-associated macrophages during cancer metastasis have not been investigated. Methods Mice inoculated with 4T1 or EO771 breast cancer cells orthotopically were treated with Emodin after the primary tumors reached 200 mm3 in size. Primary tumor growth, lung metastasis, and macrophage infiltration in the lungs were analyzed. In vitro experiments were performed to examine the effects of Emodin on macrophage migration and M2 polarization, and the underlying mechanisms. Results Emodin significantly suppressed breast cancer lung metastasis in both orthotopic mouse models without apparent effects on primary tumors. Reduced infiltration of F4/80+ macrophages and Ym1+ M2 macrophages in lungs was observed in Emodin-treated mice. In vitro experiments demonstrated that Emodin decreased the migration of macrophages towards tumor cell conditioned medium (TCM) and inhibited macrophage M2 polarization induced by TCM. Mechanistically, Emodin suppressed STAT6 phosphorylation and C/EBPβ expression, two crucial signaling events in macrophage M2 polarization, in macrophages treated with IL-4 or TCM. Conclusion Taken together, our study, for the first time, demonstrated that Emodin suppressed pulmonary metastasis of breast cancer probably through inhibiting macrophage recruitment and M2 polarization in the lungs by reducing STAT6 phosphorylation and C/EBPβ expression. PMID:25311112

  15. Interactions Between Macrophages of Guinea Pigs and Salmonellae III. Bactericidal Action and Cytophilic Antibodies of Macrophages of Infected Guinea Pigs

    PubMed Central

    Hsu, H. S.; Mayo, Donald R.

    1973-01-01

    The fate of virulent Salmonella typhimurium within macrophages of guinea pigs was assessed by a suspended cell culture procedure. The present study confirmed that macrophages of normal guinea pigs were capable of inactivating the ingested salmonellae. Macrophages of previously infected guinea pigs were not endowed with any significant increase in their ability to eliminate the ingested pathogen. However, the immune macrophages were observed to clump together tightly when they were exposed to salmonellae. This phenomenon was attributed to the presence of specific cytophilic antibodies on the immune macrophages. When immune macrophages were inactivated with Merthiolate, they agglutinated with both the H and the O antigens of S. typhimurium, but not with the O antigens of other species of Salmonella nor with the O antigens of Escherichia coli. Cytophilic antibodies could be eluted from immune macrophages by incubation in the absence of immune serum. Conversely, cytophilic antibodies could be passively transferred onto normal macrophages by incubation in the presence of immune serum. Furthermore, using immune serum previously adsorbed with the O antigens of S. typhimurium, cytophilic antibodies against the H antigens alone could be transferred onto normal macrophages, or those against the O antigens alone could be eluted from immune macrophages. These data suggest that immune macrophages possess specific cytophilic antibodies against both the H and the O antigens of S. typhimurium. It is proposed that the presence of cytophilic antibodies on immune macrophages represents an expression of antibacterial cellular immunity by enhanced clumping and phagocytic activities of the macrophages. PMID:4579899

  16. Evolution of B Cell Immunity

    PubMed Central

    Sunyer, J. Oriol

    2013-01-01

    Two types of adaptive immune strategies are known to have evolved in vertebrates: the VLR-based system, which is present in jawless organisms and is mediated by VLRA and VLRB lymphocytes, and the BCR/TCR-based system, which is present in jawed species and is provided by B and T cell receptors expressed on B and T cells, respectively. Here we summarize features of B cells and their predecessors in the different animal phyla, focusing the review on B cells from jawed vertebrates. We point out the critical role of nonclassical species and comparative immunology studies in the understanding of B cell immunity. Because nonclassical models include species relevant to veterinary medicine, basic science research performed in these animals contributes to the knowledge required for the development of more efficacious vaccines against emerging pathogens. PMID:25340015

  17. Macrophage characteristics of stem cells revealed by transcriptome profiling

    SciTech Connect

    Charriere, Guillaume M.; Cousin, Beatrice; Arnaud, Emmanuelle; Saillan-Barreau, Corinne; Andre, Mireille; Massoudi, Ali; Dani, Christian; Penicaud, Luc; Casteilla, Louis . E-mail: casteil@toulouse.inserm.fr

    2006-10-15

    We previously showed that the phenotypes of adipocyte progenitors and macrophages were close. Using functional analyses and microarray technology, we first tested whether this intriguing relationship was specific to adipocyte progenitors or could be shared with other progenitors. Measurements of phagocytic activity and gene profiling analysis of different progenitor cells revealed that the latter hypothesis should be retained. These results encouraged us to pursue and to confirm our analysis with a gold-standard stem cell population, embryonic stem cells or ESC. The transcriptomic profiles of ESC and macrophages were clustered together, unlike differentiated ESC. In addition, undifferentiated ESC displayed higher phagocytic activity than other progenitors, and they could phagocytoze apoptotic bodies. These data suggest that progenitors and stem cells share some characteristics of macrophages. This opens new perspectives on understanding stem cell phenotype and functionalities such as a putative role of stem cells in tissue remodeling by discarding dead cells but also their immunomodulation or fusion properties.

  18. Selective inhibitory effects of 50-nm gold nanoparticles on mouse macrophage and spleen cells.

    PubMed

    Kingston, Micah; Pfau, Jean C; Gilmer, John; Brey, Richard

    2016-03-01

    Nanoparticles (NP) are significant to multiple industrial processes, consumer products and medical applications today. The health effects of many different types of NP, however, are largely unknown. The purpose of this study was to test the effects of 50-nm gold NP coated with poly-N-vinylpyrrolidone (PVP) on mouse macrophage and spleen cells with and without lipopolysaccharide (LPS), testing the hypothesis that the NP would modulate immune responses without being overtly toxic. Gold NP had no effect on macrophage viability and, in the absence of LPS, they had no effect on tumor necrosis factor (TNF)-α production as measured by ELISA. The presence of LPS significantly increased the release of TNFα from the macrophages above no-treatment controls, but increasing gold NP concentration led to decreasing release of TNFα. The reactive oxygen species (ROS) produced by exposed macrophages were also reduced compared to untreated controls, both with and without LPS, suggesting some kind of oxygen radical scavenging. In splenocyte cultures, gold NP had no effect alone, but significantly reduced the release of interleukin (IL)-17 and TNFα triggered by LPS. These results suggest that the gold NP used here are not cytotoxic to immune cells at these concentrations, but may affect cellular responses to infection or inflammation by altering the balance of cytokines. PMID:25875326

  19. Immune targeting of cancer stem cells in gastrointestinal oncology.

    PubMed

    Canter, Robert J; Grossenbacher, Steven K; Ames, Erik; Murphy, William J

    2016-04-01

    The cancer stem cell (CSC) hypothesis postulates that a sub-population of quiescent cells exist within tumors which are resistant to conventional cytotoxic/anti-proliferative therapies. It is these CSCs which then seed tumor relapse, even in cases of apparent complete response to systemic therapy. Therefore, therapies, such as immunotherapy, which add a specific anti-CSC strategy to standard cytoreductive treatments may provide a promising new direction for future cancer therapies. CSCs are an attractive target for immune therapies since, unlike chemotherapy or radiotherapy, immune effector cells do not specifically require target cells to be proliferating in order to effectively kill them. Although recent advances have been made in the development of novel systemic and targeted therapies for advanced gastro-intestinal (GI) malignancies, there remains an unmet need for durable new therapies for these refractory malignancies. Novel immunotherapeutic strategies targeting CSCs are in pre-clinical and clinical development across the spectrum of the immune system, including strategies utilizing adaptive immune cell-based effectors, innate immune effectors, as well as vaccine approaches. Lastly, since important CSC functions are affected by the tumor microenvironment, targeting of both cellular (myeloid derived suppressor cells and tumor-associated macrophages) and sub-cellular (cytokines, chemokines, and PD1/PDL1) components of the tumor microenvironment is under investigation in the immune targeting of CSCs. These efforts are adding to the significant optimism about the potential utility of immunotherapy to overcome cancer resistance mechanisms and cure greater numbers of patients with advanced malignancy. PMID:27034806

  20. Immune targeting of cancer stem cells in gastrointestinal oncology

    PubMed Central

    Grossenbacher, Steven K.; Ames, Erik; Murphy, William J.

    2016-01-01

    The cancer stem cell (CSC) hypothesis postulates that a sub-population of quiescent cells exist within tumors which are resistant to conventional cytotoxic/anti-proliferative therapies. It is these CSCs which then seed tumor relapse, even in cases of apparent complete response to systemic therapy. Therefore, therapies, such as immunotherapy, which add a specific anti-CSC strategy to standard cytoreductive treatments may provide a promising new direction for future cancer therapies. CSCs are an attractive target for immune therapies since, unlike chemotherapy or radiotherapy, immune effector cells do not specifically require target cells to be proliferating in order to effectively kill them. Although recent advances have been made in the development of novel systemic and targeted therapies for advanced gastro-intestinal (GI) malignancies, there remains an unmet need for durable new therapies for these refractory malignancies. Novel immunotherapeutic strategies targeting CSCs are in pre-clinical and clinical development across the spectrum of the immune system, including strategies utilizing adaptive immune cell-based effectors, innate immune effectors, as well as vaccine approaches. Lastly, since important CSC functions are affected by the tumor microenvironment, targeting of both cellular (myeloid derived suppressor cells and tumor-associated macrophages) and sub-cellular (cytokines, chemokines, and PD1/PDL1) components of the tumor microenvironment is under investigation in the immune targeting of CSCs. These efforts are adding to the significant optimism about the potential utility of immunotherapy to overcome cancer resistance mechanisms and cure greater numbers of patients with advanced malignancy. PMID:27034806

  1. Innate Immune Defenses in Human Tuberculosis: An Overview of the Interactions between Mycobacterium tuberculosis and Innate Immune Cells

    PubMed Central

    Sia, Jonathan Kevin; Georgieva, Maria; Rengarajan, Jyothi

    2015-01-01

    Tuberculosis (TB) remains a serious global public health problem that results in up to 2 million deaths each year. TB is caused by the human pathogen, Mycobacterium tuberculosis (Mtb), which infects primarily innate immune cells patrolling the lung. Innate immune cells serve as barometers of the immune response against Mtb infection by determining the inflammatory milieu in the lungs and promoting the generation of adaptive immune responses. However, innate immune cells are also potential niches for bacterial replication and are readily manipulated by Mtb. Our understanding of the early interactions between Mtb and innate immune cells is limited, especially in the context of human infection. This review will focus on Mtb interactions with human macrophages, dendritic cells, neutrophils, and NK cells and detail evidence that Mtb modulation of these cells negatively impacts Mtb-specific immune responses. Furthermore, this review will emphasize important innate immune pathways uncovered through human immunogenetic studies. Insights into the human innate immune response to Mtb infection are necessary for providing a rational basis for the augmentation of immune responses against Mtb infection, especially with respect to the generation of effective anti-TB immunotherapeutics and vaccines. PMID:26258152

  2. Innate Immune Defenses in Human Tuberculosis: An Overview of the Interactions between Mycobacterium tuberculosis and Innate Immune Cells.

    PubMed

    Sia, Jonathan Kevin; Georgieva, Maria; Rengarajan, Jyothi

    2015-01-01

    Tuberculosis (TB) remains a serious global public health problem that results in up to 2 million deaths each year. TB is caused by the human pathogen, Mycobacterium tuberculosis (Mtb), which infects primarily innate immune cells patrolling the lung. Innate immune cells serve as barometers of the immune response against Mtb infection by determining the inflammatory milieu in the lungs and promoting the generation of adaptive immune responses. However, innate immune cells are also potential niches for bacterial replication and are readily manipulated by Mtb. Our understanding of the early interactions between Mtb and innate immune cells is limited, especially in the context of human infection. This review will focus on Mtb interactions with human macrophages, dendritic cells, neutrophils, and NK cells and detail evidence that Mtb modulation of these cells negatively impacts Mtb-specific immune responses. Furthermore, this review will emphasize important innate immune pathways uncovered through human immunogenetic studies. Insights into the human innate immune response to Mtb infection are necessary for providing a rational basis for the augmentation of immune responses against Mtb infection, especially with respect to the generation of effective anti-TB immunotherapeutics and vaccines. PMID:26258152

  3. Evolutionary implication of B-1 lineage cells from innate to adaptive immunity.

    PubMed

    Zhu, Lv-yun; Shao, Tong; Nie, Li; Zhu, Ling-yun; Xiang, Li-xin; Shao, Jian-zhong

    2016-01-01

    The paradigm that B cells mainly play a central role in adaptive immunity may have to be reevaluated because B-1 lineage cells have been found to exhibit innate-like functions, such as phagocytic and bactericidal activities. Therefore, the evolutionary connection of B-1 lineage cells between innate and adaptive immunities have received much attention. In this review, we summarized various innate-like characteristics of B-1 lineage cells, such as natural antibody production, antigen-presenting function in primary adaptive immunity, and T cell-independent immune responses. These characteristics seem highly conserved between fish B cells and mammalian B-1 cells during vertebrate evolution. We proposed an evolutionary outline of B cells by comparing biological features, including morphology, phenotype, ontogeny, and functional activity between B-1 lineage cells and macrophages or B-2 cells. The B-1 lineage may be a transitional cell type between phagocytic cells (e.g., macrophages) and B-2 cells that functionally connects innate and adaptive immunities. Our discussion would contribute to the understanding on the origination of B cells specialized in adaptive immunity from innate immunity. The results might provide further insight into the evolution of the immune system as a whole. PMID:26573260

  4. Monarch-1 Activation in Murine Macrophage Cell Line (J774 A.1) Infected with Iranian Strain of Leishmania major

    PubMed Central

    Fata, A; Mahmoudian, MR; Varasteh, A; Sankian, M

    2013-01-01

    Background Leishmania major is an intracellular parasite transmitted through the bite of the female phlebotomine sand flies. Leishmania major is able to escape the host immune defense and survive within macrophages. Modulation of the NF-κB (Nuclear Factor-Kappa B) activation and suppression of the pro-inflammatory cytokines by L. major are the main evasion mechanisms that remain to be explored. This study aims to examine the expression level of the Monarch-1 in L. major-infected macrophages, as a negative regulator of the NF-κB activation. Methods Murine macrophage cell line (J774 A.1) was infected by metacyclic form of Leishmania promastigotes at macrophage/parasite ratio of 1:10. After harvesting infected cells at different times, total RNA was extracted and converted to cDNA. Semi-quantitative RT-PCR was performed for Monarch-1 by specific primers. Hypoxanthine Phospho-Ribosyl Transferase (HPRT) was used as an internal control to adjust the amount of mRNA in each sample. Results Semiquantitive analysis of Monarch-1 mRNA expression level showed a significant expression increase within 6 to 30 hours after L. major infection of macrophages when compared to the control macrophages. Conclusion Monarch-1 expression level reveals a significant increase in the early phase of macrophage infection with L. major, which in turn may suppress IL-12 production in Leishmania infected macrophages and deeply influence the relationship between host and parasite. PMID:23914232

  5. Macrophage-T cell interactions mediate neuropathic pain through the glucocorticoid-induced tumor necrosis factor ligand system.

    PubMed

    Kobayashi, Yuka; Kiguchi, Norikazu; Fukazawa, Yohji; Saika, Fumihiro; Maeda, Takehiko; Kishioka, Shiroh

    2015-05-15

    Peripheral neuroinflammation caused by activated immune cells can provoke neuropathic pain. Herein, we investigate the actions of macrophages and T cells through glucocorticoid-induced tumor neurosis factor receptor ligand (GITRL) and its receptor (GITR) in neuropathic pain. After partial sciatic nerve ligation (PSL) in enhanced green fluorescent protein (eGFP) chimeric mice generated by the transplantation of eGFP(+) bone marrow cells, eGFP(+) macrophages, and T cells markedly migrated to the injured site after PSL. Administration of agents to deplete macrophages (liposome-clodronate and Clophosome-A(TM)) or T cells (anti-CD4 antibody and FTY720) could suppress PSL-induced thermal hyperalgesia and tactile allodynia. The expression levels of co-stimulatory molecules GITRL and GITR were increased on infiltrating macrophages and T cells, respectively. The perineural injection of a GITRL neutralizing antibody that could inhibit the function of the GITRL-GITR pathway attenuated PSL-induced neuropathic pain. Additionally, the induction of inflammatory cytokines and the accumulation of GITR(+) T cells in the injured SCN were abrogated after macrophage depletion by Clophosome-A(TM). In conclusion, GITRL expressed on macrophages drives cytokine release and T cell activation, resulting in neuropathic pain via GITR-dependent actions. The GITRL-GITR pathway might represent a novel target for the treatment of neuropathic pain. PMID:25787078

  6. Immune and Inflammatory Cell Composition of Human Lung Cancer Stroma

    PubMed Central

    Banat, G-Andre; Tretyn, Aleksandra; Pullamsetti, Soni Savai; Wilhelm, Jochen; Weigert, Andreas; Olesch, Catherine; Ebel, Katharina; Stiewe, Thorsten; Grimminger, Friedrich; Seeger, Werner; Fink, Ludger; Savai, Rajkumar

    2015-01-01

    Recent studies indicate that the abnormal microenvironment of tumors may play a critical role in carcinogenesis, including lung cancer. We comprehensively assessed the number of stromal cells, especially immune/inflammatory cells, in lung cancer and evaluated their infiltration in cancers of different stages, types and metastatic characteristics potential. Immunohistochemical analysis of lung cancer tissue arrays containing normal and lung cancer sections was performed. This analysis was combined with cyto-/histomorphological assessment and quantification of cells to classify/subclassify tumors accurately and to perform a high throughput analysis of stromal cell composition in different types of lung cancer. In human lung cancer sections we observed a significant elevation/infiltration of total-T lymphocytes (CD3+), cytotoxic-T cells (CD8+), T-helper cells (CD4+), B cells (CD20+), macrophages (CD68+), mast cells (CD117+), mononuclear cells (CD11c+), plasma cells, activated-T cells (MUM1+), B cells, myeloid cells (PD1+) and neutrophilic granulocytes (myeloperoxidase+) compared with healthy donor specimens. We observed all of these immune cell markers in different types of lung cancers including squamous cell carcinoma, adenocarcinoma, adenosquamous cell carcinoma, small cell carcinoma, papillary adenocarcinoma, metastatic adenocarcinoma, and bronchioloalveolar carcinoma. The numbers of all tumor-associated immune cells (except MUM1+ cells) in stage III cancer specimens was significantly greater than those in stage I samples. We observed substantial stage-dependent immune cell infiltration in human lung tumors suggesting that the tumor microenvironment plays a critical role during lung carcinogenesis. Strategies for therapeutic interference with lung cancer microenvironment should consider the complexity of its immune cell composition. PMID:26413839

  7. Estradiol reduces susceptibility of CD4+ T cells and macrophages to HIV-infection.

    PubMed

    Rodriguez-Garcia, Marta; Biswas, Nabanita; Patel, Mickey V; Barr, Fiona D; Crist, Sarah G; Ochsenbauer, Christina; Fahey, John V; Wira, Charles R

    2013-01-01

    The magnitude of the HIV epidemic in women requires urgent efforts to find effective preventive methods. Even though sex hormones have been described to influence HIV infection in epidemiological studies and regulate different immune responses that may affect HIV infection, the direct role that female sex hormones play in altering the susceptibility of target cells to HIV-infection is largely unknown. Here we evaluated the direct effect of 17-β-estradiol (E2) and ethinyl estradiol (EE) in HIV-infection of CD4(+) T-cells and macrophages. Purified CD4(+) T-cells and monocyte-derived macrophages were generated in vitro from peripheral blood and infected with R5 and X4 viruses. Treatment of CD4(+) T-cells and macrophages with E2 prior to viral challenge reduced their susceptibility to HIV infection in a dose-dependent manner. Addition of E2 2 h after viral challenge however did not result in reduced infection. In contrast, EE reduced infection in macrophages to a lesser extent than E2 and had no effect on CD4(+) T-cell infection. Reduction of HIV-infection induced by E2 in CD4(+) T-cells was not due to CCR5 down-regulation, but was an entry-mediated mechanism since infection with VSV-G pseudotyped HIV was not modified by E2. In macrophages, despite the lack of an effect of E2 on CCR5 expression, E2-treatment reduced viral entry 2 h after challenge and increased MIP-1β secretion. These results demonstrate the direct effect of E2 on susceptibility of HIV-target cells to infection and indicate that inhibition of target cell infection involves cell-entry related mechanisms. PMID:23614015

  8. Establishment of a leukocyte cell line derived from peritoneal macrophages of fish, Labeo rohita (Hamilton, 1822).

    PubMed

    Awasthi, Abhishek; Rathore, Gaurav; Sood, Neeraj; Khan, M Y; Lakra, W S

    2015-01-01

    A continuous leukocyte cell line with phagocytic activity was established from peritoneal macrophages of rohu, Labeo rohita (LRPM). LRPM was initiated from adherent mononuclear leukocytes isolated from peritoneal cavity of rohu, without use of any growth factors or feeder cells. These cells exhibited maximum growth at 30 °C in L-15 medium containing 20 % foetal bovine serum, and has been subcultured for more than 60 passages till date. The cells showed 85 % viability after 6 months of storage in liquid nitrogen. The species of origin of the LRPM was confirmed by the amplification and sequencing of 655 bp fragment of cytochrome oxidase subunit I of mitochondrial DNA. Functionally, LRPM showed phagocytic activity of yeast cells and fluorescent latex beads as evaluated by phase contrast and scanning electron microscopy, respectively. Immuno-modulators such as bacterial lipopolysaccharide and phorbol myristate acetate resulted in functional activation of LRPM; and enhanced their microbicidal activity through release of reactive oxygen species and nitric oxide. Culture supernatant from activated cells also revealed lysozyme activity. Cells of LRPM were positive for alpha-naphthyl acetate esterase enzyme indicating macrophage lineage. Our results indicate that this cell line can be a useful in vitro tool to study the role of macrophages in teleost immune system and to evaluate the effects of new aquaculture drugs. The LRPM cell line represents the first reported leukocyte cell line of peritoneal origin from any freshwater species of fish. PMID:24248274

  9. Characterization of PAMP/PRR interactions in European eel (Anguilla anguilla) macrophage-like primary cell cultures.

    PubMed

    Callol, A; Roher, N; Amaro, C; MacKenzie, S

    2013-10-01

    The eel (Anguilla anguilla) has been identified as a vulnerable species with stocks dramatically declining over the past decade. In an effort to support the species from overfishing of wild stocks increased interest in eel aquaculture has been notable. In order to expand the scarce knowledge concerning the biology of this species significant research efforts are required in several fields of biology. The development of cell culture systems to study the immune response is a key step towards an increased understanding of the immune response and to develop resources to support further study in this threatened species. Macrophages are one of the most important effector cells of the innate immune system. The capacity to engulf pathogens and orchestrate the immune response relies on the existence of different surface receptors, such as scavenger receptors and toll-like receptors. We have developed and described an eel macrophage-like in vitro model and studied its functional and transcriptomic responses. Macrophage-like cells from both head kidney and purified peripheral blood leukocytes were obtained and phagocytic activity measured for different whole bacteria and yeast. Moreover, based on PAMP-PRR association the innate immune response of both head kidney and PBL derived macrophage-like cells was evaluated against different pathogen-associated molecular patterns (PAMPs). Results highlight that peptidoglycan stimulation strongly induces inflammatory mRNA expression reflected in the up-regulation of pro-inflammatory genes IL1β and IL18 in PBL derived cells whereas IL8 is upregulated in head kidney derived cells. Furthermore TLR2 mRNA abundance is regulated by all stimuli supporting a multifunctional role for this pathogen recognition receptor (PRR) in eel macrophage-like cells. PMID:23911651

  10. Nuclear DAMP complex-mediated RAGE-dependent macrophage cell death

    SciTech Connect

    Chen, Ruochan; Fu, Sha; Fan, Xue-Gong; Lotze, Michael T.; Zeh, Herbert J.; Tang, Daolin; Kang, Rui

    2015-03-13

    High mobility group box 1 (HMGB1), histone, and DNA are essential nuclear components involved in the regulation of chromosome structure and function. In addition to their nuclear function, these molecules act as damage-associated molecular patterns (DAMPs) alone or together when released extracellularly. The synergistic effect of these nuclear DNA-HMGB1-histone complexes as DAMP complexes (nDCs) on immune cells remains largely unexplored. Here, we demonstrate that nDCs limit survival of macrophages (e.g., RAW264.7 and peritoneal macrophages) but not cancer cells (e.g., HCT116, HepG2 and Hepa1-6). nDCs promote production of inflammatory tumor necrosis factor α (TNFα) release, triggering reactive oxygen species-dependent apoptosis and necrosis. Moreover, the receptor for advanced glycation end products (RAGE), but not toll-like receptor (TLR)-4 and TLR-2, was required for Akt-dependent TNFα release and subsequent cell death following treatment with nDCs. Genetic depletion of RAGE by RNAi, antioxidant N-Acetyl-L-cysteine, and TNFα neutralizing antibody significantly attenuated nDC-induced cell death. These findings provide evidence supporting novel signaling mechanisms linking nDCs and inflammation in macrophage cell death. - Highlights: • Nuclear DAMP complexes (nDCs) selectively induce cell death in macrophages, but not cancer cells. • TNFα-mediated oxidative stress is required for nDC-induced death. • RAGE-mediated Akt activation is required for nDC-induced TNFα release. • Blocking RAGE and TNFα inhibits nDC-induced macrophage cell death.

  11. The role of immune system exhaustion on cancer cell escape and anti-tumor immune induction after irradiation.

    PubMed

    Mendes, Fernando; Domingues, Cátia; Rodrigues-Santos, Paulo; Abrantes, Ana Margarida; Gonçalves, Ana Cristina; Estrela, Jéssica; Encarnação, João; Pires, Ana Salomé; Laranjo, Mafalda; Alves, Vera; Teixo, Ricardo; Sarmento, Ana Bela; Botelho, Maria Filomena; Rosa, Manuel Santos

    2016-04-01

    Immune surveillance seems to represent an effective tumor suppressor mechanism. However, some cancer cells survive and become variants, being poorly immunogenic and able to enter a steady-state phase. These cells become functionally dormant or remain hidden clinically throughout. Neoplastic cells seem to be able to instruct immune cells to undergo changes promoting malignancy. Radiotherapy may act as a trigger of the immune response. After radiotherapy a sequence of reactions occurs, starting in the damage of oncogenic cells by multiple mechanisms, leading to the immune system positive feedback against the tumor. The link between radiotherapy and the immune system is evident. T cells, macrophages, Natural Killer cells and other immune cells seem to have a key role in controlling the tumor. T cells may be dysfunctional and remain in a state of T cell exhaustion, nonetheless, they often retain a high potential for successful defense against cancer, being able to be mobilized to become highly functional. The lack of clinical trials on a large scale makes data a little robust, in spite of promising information, there are still many variables in the studies relating to radiation and immune system. The clarification of the mechanisms underlying immune response to radiation exposure may contribute to treatment improvement, gain of life quality and span of patients. PMID:26868867

  12. Immune Cells in Blood Recognize Tumors

    Cancer.gov

    NCI scientists have developed a novel strategy for identifying immune cells circulating in the blood that recognize specific proteins on tumor cells, a finding they believe may have potential implications for immune-based therapies.

  13. Upregulation of Retinal Dehydrogenase 2 in Alternatively Activated Macrophages during Retinoid-dependent Type-2 Immunity to Helminth Infection in Mice

    PubMed Central

    Broadhurst, Mara J.; Leung, Jacqueline M.; Lim, K. C.; Girgis, Natasha M.; Gundra, Uma Mahesh; Fallon, Padraic G.; Premenko-Lanier, Mary; McKerrow, James H.; McCune, Joseph M.; Loke, P'ng

    2012-01-01

    Although the vitamin A metabolite retinoic acid (RA) plays a critical role in immune function, RA synthesis during infection is poorly understood. Here, we show that retinal dehydrogenases (Raldh), required for the synthesis of RA, are induced during a retinoid-dependent type-2 immune response elicited by Schistosoma mansoni infection, but not during a retinoid-independent anti-viral immune response. Vitamin A deficient mice have a selective defect in TH2 responses to S. mansoni, but retained normal LCMV specific TH1 responses. A combination of in situ imaging, intra-vital imaging, and sort purification revealed that alternatively activated macrophages (AAMφ) express high levels of Raldh2 during S. mansoni infection. IL-4 induces Raldh2 expression in bone marrow-derived macrophages in vitro and peritoneal macrophages in vivo. Finally, in vivo derived AAMφ have an enhanced capacity to induce Foxp3 expression in CD4+ cells through an RA dependent mechanism, especially in combination with TGF-β. The regulation of Raldh enzymes during infection is pathogen specific and reflects differential requirements for RA during effector responses. Specifically, AAMφ are an inducible source of RA synthesis during helminth infections and TH2 responses that may be important in regulating immune responses. PMID:22927819

  14. Production of a macrophage growth factor(s) by a goldfish macrophage cell line and macrophages derived from goldfish kidney leukocytes.

    PubMed

    Neumann, N F; Barreda, D; Belosevic, M

    1998-01-01

    We recently established a spontaneously proliferating macrophage cell line from the goldfish (GMCL), and in this report demonstrate the production of a macrophage-specific growth factor(s) (MGFs) by these cells. The supernatants from GMCL cultures induced proliferation and differentiation of macrophage-like cells from kidney hematopoietic tissues of goldfish. Kidney leukocytes cultured at 6.25 x 10(4)cells/ml in the presence of GMCL-derived MGFs proliferated during two weeks of cultivation, whereas those cultured without the MGFs did not. Leukocytes cultured at higher densities (2.5 x 10(5) cells/ml) proliferated in the absence of exogenous growth factor, but not to the same extent as those stimulated with GMCL-derived MGFs, suggesting that kidney leukocytes may produce endogenous MGFs. At higher cell density (1 x 10(6) cells/ml), kidney leukocytes multiplied extensively over a two-week cultivation period in the absence of exogenous GMCL-derived MGFs. The supernatants from these cultures restored the proliferative ability of leukocytes cultured at low densities, providing direct evidence of MGFs production by kidney leukocytes. The predominant cell-type in cultures grown in the presence of GMCL or kidney leukocyte-MGFs was the macrophage based on the following criteria: (1) non-specific esterase staining; (2) morphologic similarity to GMCL; (3) phagocytosis of the bacterium, A. salmonicida; (4) production of reactive oxygen and nitrogen intermediates in response to stimulation with macrophage activating factors and/or bacterial lipopolysaccharide; and (5) flow cytometric analyses. Both in vitro-derived kidney macrophage (IVDKM) and GMCL cultures contained three distinct populations of cells, (determined by flow cytometry), suggesting that these macrophage cultures are comprised of cells arrested at distinct differentiation junctures in macrophage development. Production of MGFs by macrophages and kidney leukocytes may play an important role in regulating macrophage hematopoiesis in fish. PMID:9699487

  15. Oxygen plasma surface modification augments poly(L-lactide-co-glycolide) cytocompatibility toward osteoblasts and minimizes immune activation of macrophages.

    PubMed

    Scislowska-Czarnecka, Anna; Szmigiel, Dariusz; Genet, Michel; Dupont-Gillain, Christine; Pamula, Elzbieta; Kolaczkowska, Elzbieta

    2015-12-01

    Here, we report on modification of one of the model biomedical polymers, poly L-lactide-co-glycolide (PLGA; 85:15), by reactive ion etching (RIE) oxygen plasma treatment. PLGA's major disadvantage is high hydrophobicity which restrains binding of cell-adhesive proteins and host cells. In the current approach, we aimed to answer two questions: (1) will only short (10 s) and moderate (20-200 mTorr, 45-90 W) RIE oxygen plasma treatment, leading to decrease of water contact angle by only up to 10°, sufficiently improve PLGA adherence to cells, and (2) how will this affect osteoblasts and activation of the immune system? All obtained modified PLGAs had improved hydrophilicity but unaltered roughness (as revealed by water contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy) resulting in significantly improved adhesion of osteoblasts (MG-63) and their low activation. Importantly, macrophages (RAW 264.7), one of the key cells initiating inflammation and bone resorption, responded significantly less vigorously to the modified polymers, expressing/releasing lower amounts of nitric oxide, matrix metalloproteinases (MMP-9), and pro-inflammatory cytokines (TNF-α, IL-6, IL-12p70, IFN-γ, IL-10). We conclude that already slight RIE oxygen plasma modification of PLGA is sufficient to improve its surface properties, and enhance cytocompatibility. Most importantly, this type of modification prevents excessive immune response. PMID:26014580

  16. Human Granulocyte Macrophage Colony-Stimulating Factor Enhances Antibiotic Susceptibility of Pseudomonas aeruginosa Persister Cells

    PubMed Central

    Choudhary, Geetika S.; Yao, Xiangyu; Wang, Jing; Peng, Bo; Bader, Rebecca A.; Ren, Dacheng

    2015-01-01

    Bacterial persister cells are highly tolerant to antibiotics and cause chronic infections. However, little is known about the interaction between host immune systems with this subpopulation of metabolically inactive cells, and direct effects of host immune factors (in the absence of immune cells) on persister cells have not been studied. Here we report that human granulocyte macrophage-colony stimulating factor (GM-CSF) can sensitize the persister cells of Pseudomonas aeruginosa PAO1 and PDO300 to multiple antibiotics including ciprofloxacin, tobramycin, tetracycline, and gentamicin. GM-CSF also sensitized the biofilm cells of P. aeruginosa PAO1 and PDO300 to tobramycin in the presence of biofilm matrix degrading enzymes. The DNA microarray and qPCR results indicated that GM-CSF induced the genes for flagellar motility and pyocin production in the persister cells, but not the normal cells of P. aeruginosa PAO1. Consistently, the supernatants from GM-CSF treated P. aeruginosa PAO1 persister cell suspensions were found cidal to the pyocin sensitive strain P. aeruginosa PAK. Collectively, these findings suggest that host immune factors and bacterial persisters may directly interact, leading to enhanced susceptibility of persister cells to antibiotics. PMID:26616387

  17. Phenotypic and Functional Heterogeneity of Macrophages and Dendritic Cell Subsets in the Healthy and Atherosclerosis-Prone Aorta

    PubMed Central

    Butcher, Matthew J.; Galkina, Elena V.

    2012-01-01

    Atherosclerosis continues to be the leading cause of cardiovascular disease. Development of atherosclerosis depends on chronic inflammation in the aorta and multiple immune cells are involved in this process. Importantly, resident macrophages and dendritic cells (DCs) are present within the healthy aorta, but the functions of these cells remain poorly characterized. Local inflammation within the aortic wall promotes the recruitment of monocytes and DC precursors to the aorta and micro-environmental factors direct the differentiation of these emigrated cells into multiple subsets of macrophages and DCs. Recent data suggest that several populations of macrophages and DCs can co-exist within the aorta. Although the functions of M1, M2, Mox, and M4 macrophages are well characterized in vitro, there is a limited set of data on the role of these populations in atherogenesis in vivo. Recent studies on the origin and the potential role of aortic DCs provide novel insights into the biology of aortic DC subsets and prospective mechanisms of the immune response in atherosclerosis. This review integrates the results of experiments analyzing heterogeneity of DCs and macrophage subsets in healthy and diseased vessels and briefly discusses the known and potential functions of these cells in atherogenesis. PMID:22457649

  18. Strain- and host species-specific inflammasome activation, IL-1β release, and cell death in macrophages infected with uropathogenic Escherichia coli.

    PubMed

    Schaale, K; Peters, K M; Murthy, A M; Fritzsche, A K; Phan, M-D; Totsika, M; Robertson, A A B; Nichols, K B; Cooper, M A; Stacey, K J; Ulett, G C; Schroder, K; Schembri, M A; Sweet, M J

    2016-01-01

    Uropathogenic Escherichia coli (UPEC) is the main etiological agent of urinary tract infections (UTIs). Little is known about interactions between UPEC and the inflammasome, a key innate immune pathway. Here we show that UPEC strains CFT073 and UTI89 trigger inflammasome activation and lytic cell death in human macrophages. Several other UPEC strains, including two multidrug-resistant ST131 isolates, did not kill macrophages. In mouse macrophages, UTI89 triggered cell death only at a high multiplicity of infection, and CFT073-mediated inflammasome responses were completely NLRP3-dependent. Surprisingly, CFT073- and UTI89-mediated responses only partially depended on NLRP3 in human macrophages. In these cells, NLRP3 was required for interleukin-1β (IL-1β) maturation, but contributed only marginally to cell death. Similarly, caspase-1 inhibition did not block cell death in human macrophages. In keeping with such differences, the pore-forming toxin α-hemolysin mediated a substantial proportion of CFT073-triggered IL-1β secretion in mouse but not human macrophages. There was also a more substantial α-hemolysin-independent cell death response in human vs. mouse macrophages. Thus, in mouse macrophages, CFT073-triggered inflammasome responses are completely NLRP3-dependent, and largely α-hemolysin-dependent. In contrast, UPEC activates an NLRP3-independent cell death pathway and an α-hemolysin-independent IL-1β secretion pathway in human macrophages. This has important implications for understanding UTI in humans. PMID:25993444

  19. CD4+ T-Cell-Independent Secondary Immune Responses to Pneumocystis Pneumonia

    PubMed Central

    de la Rua, Nicholas M.; Samuelson, Derrick R.; Charles, Tysheena P.; Welsh, David A.; Shellito, Judd E.

    2016-01-01

    Pneumocystis pneumonia is a major cause of morbidity and mortality among immunocompromised patients, especially in the context of HIV/AIDS. In the murine model of Pneumocystis pneumonia, CD4+ T-cells are required for clearance of a primary infection of Pneumocystis, but not the memory recall response. We hypothesized that the memory recall response in the absence of CD4+ T-cells is mediated by a robust memory humoral response, CD8+ T-cells, and IgG-mediated phagocytosis by alveolar macrophages. To investigate the role of CD8+ T-cells and alveolar macrophages in the immune memory response to Pneumocystis, mice previously challenged with Pneumocystis were depleted of CD8+ T-cells or alveolar macrophages prior to re-infection. Mice depleted of CD4+ T-cells prior to secondary challenge cleared Pneumocystis infection within 48 h identical to immunocompetent mice during a secondary memory recall response. However, loss of CD8+ T-cells or macrophages prior to the memory recall response significantly impaired Pneumocystis clearance. Specifically, mice depleted of CD8+ T-cells or alveolar macrophages had significantly higher fungal burden in the lungs. Furthermore, loss of alveolar macrophages significantly skewed the lung CD8+ T-cell response toward a terminally differentiated effector memory population and increased the percentage of IFN-γ+ CD8+ T-cells. Finally, Pneumocystis-infected animals produced significantly more bone marrow plasma cells and Pneumocystis-specific IgG significantly increased macrophage-mediated killing of Pneumocystis in vitro. These data suggest that secondary immune memory responses to Pneumocystis are mediated, in part, by CD8+ T-cells, alveolar macrophages, and the production of Pneumocystis-specific IgG.

  20. Genetically Modified Live Attenuated Leishmania donovani Parasites Induce Innate Immunity through Classical Activation of Macrophages That Direct the Th1 Response in Mice

    PubMed Central

    Bhattacharya, Parna; Dey, Ranadhir; Dagur, Pradeep K.; Kruhlak, Michael; Ismail, Nevien; Debrabant, Alain; Joshi, Amritanshu B.; Akue, Adovi; Kukuruga, Mark; Takeda, Kazuyo; Selvapandiyan, Angamuthu; McCoy, John Philip

    2015-01-01

    Visceral leishmaniasis (VL) causes significant mortality and there is no effective vaccine. Previously, we have shown that genetically modified Leishmania donovani parasites, here described as live attenuated parasites, induce a host protective adaptive immune response in various animal models. In this study, we demonstrate an innate immune response upon infection with live attenuated parasites in macrophages from BALB/c mice both in vitro and in vivo. In vitro infection of macrophages with live attenuated parasites (compared to that with wild-type [WT] L. donovani parasites) induced significantly higher production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-12 [IL-12], gamma interferon [IFN-γ], and IL-6), chemokines (monocyte chemoattractant protein 1/CCL-2, macrophage inflammatory protein 1α/CCL-3, and IP-10), reactive oxygen species (ROS), and nitric oxide, while concomitantly reducing anti-inflammatory cytokine IL-10 and arginase-1 activities, suggesting a dominant classically activated/M1 macrophage response. The classically activated response in turn helps in presenting antigen to T cells, as observed with robust CD4+ T cell activation in vitro. Similarly, parasitized splenic macrophages from live attenuated parasite-infected mice also demonstrated induction of an M1 macrophage phenotype, indicated by upregulation of IL-1β, TNF-α, IL-12, and inducible nitric oxide synthase 2 and downregulation of genes associated with the M2 phenotype, i.e., the IL-10, YM1, Arg-1, and MRC-1 genes, compared to WT L. donovani-infected mice. Furthermore, an ex vivo antigen presentation assay showed macrophages from live attenuated parasite-infected mice induced higher IFN-γ and IL-2 but significantly less IL-10 production by ovalbumin-specific CD4+ T cells, resulting in proliferation of Th1 cells. These data suggest that infection with live attenuated parasites promotes a state of classical activation (M1 dominant) in macrophages that leads to the generation of protective Th1 responses in BALB/c mice. PMID:26169275

  1. Genetically Modified Live Attenuated Leishmania donovani Parasites Induce Innate Immunity through Classical Activation of Macrophages That Direct the Th1 Response in Mice.

    PubMed

    Bhattacharya, Parna; Dey, Ranadhir; Dagur, Pradeep K; Kruhlak, Michael; Ismail, Nevien; Debrabant, Alain; Joshi, Amritanshu B; Akue, Adovi; Kukuruga, Mark; Takeda, Kazuyo; Selvapandiyan, Angamuthu; McCoy, John Philip; Nakhasi, Hira L

    2015-10-01

    Visceral leishmaniasis (VL) causes significant mortality and there is no effective vaccine. Previously, we have shown that genetically modified Leishmania donovani parasites, here described as live attenuated parasites, induce a host protective adaptive immune response in various animal models. In this study, we demonstrate an innate immune response upon infection with live attenuated parasites in macrophages from BALB/c mice both in vitro and in vivo. In vitro infection of macrophages with live attenuated parasites (compared to that with wild-type [WT] L. donovani parasites) induced significantly higher production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-12 [IL-12], gamma interferon [IFN-γ], and IL-6), chemokines (monocyte chemoattractant protein 1/CCL-2, macrophage inflammatory protein 1α/CCL-3, and IP-10), reactive oxygen species (ROS), and nitric oxide, while concomitantly reducing anti-inflammatory cytokine IL-10 and arginase-1 activities, suggesting a dominant classically activated/M1 macrophage response. The classically activated response in turn helps in presenting antigen to T cells, as observed with robust CD4(+) T cell activation in vitro. Similarly, parasitized splenic macrophages from live attenuated parasite-infected mice also demonstrated induction of an M1 macrophage phenotype, indicated by upregulation of IL-1β, TNF-α, IL-12, and inducible nitric oxide synthase 2 and downregulation of genes associated with the M2 phenotype, i.e., the IL-10, YM1, Arg-1, and MRC-1 genes, compared to WT L. donovani-infected mice. Furthermore, an ex vivo antigen presentation assay showed macrophages from live attenuated parasite-infected mice induced higher IFN-γ and IL-2 but significantly less IL-10 production by ovalbumin-specific CD4(+) T cells, resulting in proliferation of Th1 cells. These data suggest that infection with live attenuated parasites promotes a state of classical activation (M1 dominant) in macrophages that leads to the generation of protective Th1 responses in BALB/c mice. PMID:26169275

  2. Development and characterization of a continuous macrophage cell line, LRTM, derived from thymus of Labeo rohita (Hamilton 1822).

    PubMed

    Rebello, Sanjay C; Rathore, Gaurav; Punia, Peyush; Sood, Neeraj; Elangovan, V

    2014-01-01

    A long-term thymic macrophage cell line from the thymus explants of Labeo rohita designated as LRTM (L. rohita thymic macrophages) was established, which has been maintained in culture for more than 1 yr. This cell line designated LRTM cells have been subcultured for 70 passages. The cells shape was initially long and elongated; with subsequent passages, the cells became short and epithelial like. The cells exhibited optimum growth in L-15 containing 10% fetal bovine serum and also in Dulbecco's modified Eagle's medium at 37°C with 5% CO2 and showed 85+-% viability after 12 mo storage in liquid nitrogen. In addition, cells showed nonspecific esterase and surface expression of Fc receptors for immunoglobulin G and classes I and II major histocompatibility complex antigens. These observations confirmed that this cell line had the morphologic and functional features as a macrophage. The cells exhibited phagocytic activity by engulfing yeast cells as well as fluorescent latex beads, which was demonstrated by scanning electron microscopy and Giemsa staining. The long-term cultured cells show rapid production of reactive oxygen and nitrogen intermediates following stimulation with lipopolysaccharides and phorbol miristate acetate (PMA). Mostly, all the cells were alpha napthyl esterase acetate positive. After stimulation with PMA and lipopolysaccharide, cultured fish macrophages produced reactive oxygen and nitrogen intermediates. The karyotype analysis showed that these cells have a tetraploid karyotype with 100 chromosomes in each cell, indicating that they are normal L. rohita cells. Amplification, sequencing, and alignment of fragments of two mitochondrial genes 12S rRNA from rohu confirmed that the cell line originated from L. rohita. This cell line should be useful for studying the role of thymic macrophages in differentiation and maturation of thymocytes and can be source of macrophage-specific enzymes and cytokines. The macrophage cell line will be invaluable in studies of pathogen/macrophage interactions, the mechanisms of macrophage antimicrobial effector functions and the contribution of macrophages to the specific immune responses of teleosts. PMID:23955429

  3. Sesquiterpene lactones induce distinct forms of cell death that modulate human monocyte-derived macrophage responses.

    PubMed

    López-Antón, Nancy; Hermann, Corinna; Murillo, Renato; Merfort, Irmgard; Wanner, Gerhard; Vollmar, Angelika M; Dirsch, Verena M

    2007-01-01

    Sesquiterpene lactones (SQTLs) are shown to possess anti-inflammatory as well as cytotoxic activity. No study, however, links both activities. We, therefore, hypothesized that SQTL-treated, dying cells might induce an anti-inflammatory response in cocultured THP-1 macrophages. Here we show that SQTLs bearing either an alpha,beta-unsaturated cyclopentenone or an alpha-methylene-gamma-lactone induce different forms of cell death. Whereas the cyclopentenone SQTL induced typical apoptosis, the alpha-methylene-gamma-lactone SQTLs-induced cell death lacked partly classical signs of apoptosis, such as DNA fragmentation. All SQTLs, however, activated caspases and the nuclear morphology of cell death was dependent on caspase activation. Most interestingly, alpha-methylene-gamma-lactone SQTLs induced a more pronounced phosphatidylserine (PS) exposure than the cyclopentenone SQTL. Especially, 7-hydroxycostunolide (HC), with an alpha-methylene-gamma-lactone substituted with a hydroxyl group, showed a striking fast and pronounced PS translocation. This result was in agreement with a strong activation of phagocytosis in cocultured THP-1 macrophages. Interestingly, HC-treated Jurkat cells led to an early (3.5 h) but transient increase in TNF-alpha levels in macrophage coculture. Release of TGF-beta remained unaffected after 18 h. We propose that this type of SQTL may influence local inflammation by transiently activating the immune system and help to clear cells by inducing a form of cell death that promotes phagocytosis. PMID:17080325

  4. Cellular senescence impact on immune cell fate and function.

    PubMed

    Vicente, Rita; Mausset-Bonnefont, Anne-Laure; Jorgensen, Christian; Louis-Plence, Pascale; Brondello, Jean-Marc

    2016-06-01

    Cellular senescence occurs not only in cultured fibroblasts, but also in undifferentiated and specialized cells from various tissues of all ages, in vitro and in vivo. Here, we review recent findings on the role of cellular senescence in immune cell fate decisions in macrophage polarization, natural killer cell phenotype, and following T-lymphocyte activation. We also introduce the involvement of the onset of cellular senescence in some immune responses including T-helper lymphocyte-dependent tissue homeostatic functions and T-regulatory cell-dependent suppressive mechanisms. Altogether, these data propose that cellular senescence plays a wide-reaching role as a homeostatic orchestrator. PMID:26910559

  5. The Secretome of Hydrogel-Coembedded Endothelial Progenitor Cells and Mesenchymal Stem Cells Instructs Macrophage Polarization in Endotoxemia

    PubMed Central

    Zullo, Joseph A.; Nadel, Ellen P.; Rabadi, May M.; Baskind, Matthew J.; Rajdev, Maharshi A.; Demaree, Cameron M.; Vasko, Radovan; Chugh, Savneek S.; Lamba, Rajat; Goligorsky, Michael S.

    2015-01-01

    We previously reported the delivery of endothelial progenitor cells (EPCs) embedded in hyaluronic acid-based (HA)-hydrogels protects renal function during acute kidney injury (AKI) and promotes angiogenesis. We attempted to further ameliorate renal dysfunction by coembedding EPCs with renal mesenchymal stem cells (MSCs), while examining their paracrine influence on cytokine/chemokine release and proinflammatory macrophages. A live/dead assay determined whether EPC-MSC coculturing improved viability during lipopolysaccharide (LPS) treatment, and HA-hydrogel-embedded delivery of cells to LPS-induced AKI mice was assessed for effects on mean arterial pressure (MAP), renal blood flow (RBF), circulating cytokines/chemokines, serum creatinine, proteinuria, and angiogenesis (femoral ligation). Cytokine/chemokine release from embedded stem cells was examined, including effects on macrophage polarization and release of proinflammatory molecules. EPC-MSC coculturing improved stem cell viability during LPS exposure, an effect augmented by MSC hypoxic preconditioning. The delivery of coembedded EPCs with hypoxic preconditioned MSCs to AKI mice demonstrated additive improvement (compared with EPC delivery alone) in medullary RBF and proteinuria, with comparable effects on serum creatinine, MAP, and angiogenesis. Exposure of proinflammatory M1 macrophages to EPC-MSC conditioned medium changed their polarization to anti-inflammatory M2. Incubation of coembedded EPCs-MSCs with macrophages altered their release of cytokines/chemokines, including enhanced release of anti-inflammatory interleukin (IL)-4 and IL-10. EPC-MSC delivery to endotoxemic mice elevated the levels of circulating M2 macrophages and reduced the circulating cytokines/chemokines. In conclusion, coembedding EPCs-MSCs improved their resistance to stress, impelled macrophage polarization from M1 to M2 while altering their cytokine/chemokines release, reduced circulating cytokines/chemokines, and improved renal and vascular function when MSCs were hypoxically preconditioned. Significance This report provides insight into a new therapeutic approach for treatment of sepsis and provides a new and improved strategy using hydrogels for the delivery of stem cells to treat sepsis and, potentially, other injuries and/or diseases. The delivery of two different stem cell lines (endothelial progenitor cells and mesenchymal stem cells; delivered alone and together) embedded in a protective bioengineered scaffolding (hydrogel) offers many therapeutic benefits for the treatment of sepsis. This study shows how hydrogel-delivered stem cells elicit their effects and how hydrogel embedding enhances the therapeutic efficacy of delivered stem cells. Hydrogel-delivered stem cells influence the components of the overactive immune system during sepsis and work to counterbalance the release of many proinflammatory and prodamage substances from immune cells, thereby improving the associated vascular and kidney damage. PMID:25947337

  6. Innate immune cells in ischaemic heart disease: does myocardial infarction beget myocardial infarction?

    PubMed

    Nahrendorf, Matthias; Swirski, Filip K

    2016-03-14

    Knowledge of macrophages in steady-state and diseased tissue is rapidly expanding, propelled by improved diagnostic capacity to detect and monitor cells in their native environments. In this review, we discuss implications for ischaemic heart disease and examine innate immune cell pathways that increase systemic leucocyte supply after myocardial infarction (MI). Acute MI alters the macrophage phenotype and supply chain from tissue resident to blood monocytes sourced from haematopoietic organs. That blood leucocytosis closely associates with cardiovascular mortality provides a strong motivation to understand why and how organ ischaemia alters cellular immunity. PMID:26351395

  7. Regenerative function of immune system: Modulation of muscle stem cells.

    PubMed

    Saini, Jasdeep; McPhee, Jamie S; Al-Dabbagh, Sarah; Stewart, Claire E; Al-Shanti, Nasser

    2016-05-01

    Ageing is characterised by progressive deterioration of physiological systems and the loss of skeletal muscle mass is one of the most recognisable, leading to muscle weakness and mobility impairments. This review highlights interactions between the immune system and skeletal muscle stem cells (widely termed satellite cells or myoblasts) to influence satellite cell behaviour during muscle regeneration after injury, and outlines deficits associated with ageing. Resident neutrophils and macrophages in skeletal muscle become activated when muscle fibres are damaged via stimuli (e.g. contusions, strains, avulsions, hyperextensions, ruptures) and release high concentrations of cytokines, chemokines and growth factors into the microenvironment. These localised responses serve to attract additional immune cells which can reach in excess of 1×10(5) immune cell/mm(3) of skeletal muscle in order to orchestrate the repair process. T-cells have a delayed response, reaching peak activation roughly 4 days after the initial damage. The cytokines and growth factors released by activated T-cells play a key role in muscle satellite cell proliferation and migration, although the precise mechanisms of these interactions remain unclear. T-cells in older people display limited ability to activate satellite cell proliferation and migration which is likely to contribute to insufficient muscle repair and, consequently, muscle wasting and weakness. If the factors released by T-cells to activate satellite cells can be identified, it may be possible to develop therapeutic agents to enhance muscle regeneration and reduce the impact of muscle wasting during ageing and disease. PMID:27039885

  8. Communication of bone cells with hematopoiesis, immunity and energy metabolism.

    PubMed

    Asada, Noboru; Sato, Mari; Katayama, Yoshio

    2015-01-01

    The bone contains the bone marrow. The functional communication between bone cells and hematopoiesis has been extensively studied in the past decade or so. Osteolineage cells and their modulators, such as the sympathetic nervous system, macrophages and osteoclasts, form a complex unit to maintain the homeostasis of hematopoiesis, called the 'microenvironment'. Recently, bone-embedded osteocytes, the sensors of gravity and mechanical stress, have joined the microenvironment, and they are demonstrated to contribute to whole body homeostasis through the control of immunity and energy metabolism. The inter-organ communication orchestrated by the bone is summarized in this article. PMID:26512322

  9. Exosome-like vesicles derived by Schistosoma japonicum adult worms mediates M1 type immune- activity of macrophage.

    PubMed

    Wang, Lifu; Li, Zhitao; Shen, Jia; Liu, Zhen; Liang, Jinyi; Wu, Xiaoying; Sun, Xi; Wu, Zhongdao

    2015-05-01

    Exosomes are 30-100-nm membrane vesicles of endocytic origin that are released into the extracellular space upon fusion of the multi-vesicular bodies (MVB) with the plasma membrane, while initial studies described that the role of exosomes was a reticulocyte cargo-disposal mechanism allowing remodeling of the plasma membrane during the maturation of reticulocytes to erythrocytes. Recent studies indicate that exosomes are secreted by most cells and pathogens and play an important role in intercellular signaling and exert regulatory function by carrying bioactive molecules. As numerous pathogens, adult worm of Schistosoma japonicum (S. japonicum) reside in mesenteric veins of definitive host including man and mammal animals. It was reported that the worms or the eggs also have specialized secretion systems to export effector proteins or other molecules into host target cells. However, the mechanisms involved remained unclear. This study investigated the isolation of the exosome-like vesicles secreted by S. japonicum adult worms and its immune activity on microphage in vitro. In this report, we identified exosome-based secretion as a new mechanism for protein secretion by S. japonicum. Electron microscopy tomography revealed the previously unidentified ultrastructural detail of exosome-like vesicles with high resolution; they were found to be typical spherical shape and to have a diverse population that varies in size of 30-100 nm. Exosome-like vesicles isolated from S. japonicum contained a significantly different protein compared with debris pelleted and the apoptosis body. We also demonstrate that macrophages were preferentially differentiated into the M1 subtype while being treated with S. japonicum exosome-like vesicles. This study reveals there are exosome-like vesicles derived by S. japonicum adult worms, and the exosome-like vesicles can mediate M1-type immune- activity of macrophage. PMID:25855345

  10. [Adipose tissue, a new playground for immune cells].

    PubMed

    Dalmas, Elise; Tordjman, Joan; Guerre-Millo, Michèle; Clément, Karine

    2011-11-01

    Adipose tissue has been under focus in the last decade and pivotal concepts have emerged from the studies of its complex biology. Low-grade inflammation both at the systemic level and in adipose tissue itself characterizes obesity. Among the different cell types contributing to inflammation, this review focuses on the mechanisms and consequences of macrophage accumulation in obese adipose tissue. Mechanisms for monocyte recruitment to adipose tissue, and how macrophages' phenotypes are modified in this environment in response to increasing fat mass, are considered. We review recent studies addressing the complex and versatile phenotype of adipose tissue macrophages that contribute to inflammatory and metabolic alterations, but could also help to maintain adipose tissue homeostasis in the setting of obesity both in mouse and human situations. A newly discovered consequence of adipose tissue inflammation is fibrosis. Whether macrophages and/or other immune cells exert a pro-fibrotic effect in adipose tissue is still unclear. This wealth of new information will hopefully help to design new ways to control adipose tissue inflammation and its deleterious sequels. PMID:22130027

  11. Gliotoxin Suppresses Macrophage Immune Function by Subverting Phosphatidylinositol 3,4,5-Trisphosphate Homeostasis

    PubMed Central

    Schlam, Daniel; Canton, Johnathan; Carreño, Marvin; Kopinski, Hannah; Freeman, Spencer A.; Grinstein, Sergio

    2016-01-01

    ABSTRACT Aspergillus fumigatus, an opportunistic fungal pathogen, spreads in the environment by releasing numerous conidia that are capable of reaching the small alveolar airways of mammalian hosts. In otherwise healthy individuals, macrophages are responsible for rapidly phagocytosing and eliminating these conidia, effectively curbing their germination and consequent invasion of pulmonary tissue. However, under some circumstances, the fungus evades phagocyte-mediated immunity and persists in the respiratory tree. Here, we report that A. fumigatus escapes macrophage recognition by strategically targeting phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3] metabolism through gliotoxin, a potent immunosuppressive mycotoxin. Time-lapse microscopy revealed that, in response to the toxin, macrophages cease to ruffle, undergo abrupt membrane retraction, and fail to phagocytose large targets effectively. Gliotoxin was found to prevent integrin activation and interfere with actin dynamics, both of which are instrumental for phagocytosis; similar effects were noted in immortalized and primary phagocytes. Detailed studies of the underlying molecular mechanisms of toxicity revealed that inhibition of phagocytosis is attributable to impaired accumulation of PtdIns(3,4,5)P3 and the associated dysregulation of downstream effectors, including Rac and/or Cdc42. Strikingly, in response to the diacylglycerol mimetic phorbol 12-myristate 13-acetate, gliotoxin-treated macrophages reactivate beta integrins, reestablish actin dynamics, and regain phagocytic capacity, despite the overt absence of plasmalemmal PtdIns(3,4,5)P3. Together, our findings identify phosphoinositide metabolism as a critical upstream target of gliotoxin and also indicate that increased diacylglycerol levels can bypass the requirement for PtdIns(3,4,5)P3 signaling during membrane ruffling and phagocytosis. PMID:27048806

  12. Immune complex–FcγR interaction modulates monocyte/macrophage molecules involved in inflammation and immune response

    PubMed Central

    BARRIONUEVO, P; BEIGIER-BOMPADRE, M; FERNANDEZ, G C; GOMEZ, S; ALVES-ROSA, M F; PALERMO, M S; ISTURIZ, M A

    2003-01-01

    The interaction between receptors for the Fc portion of IgG (FcγRs) from monocytes/macrophages and immune complexes (IC) triggers regulatory and effector functions. Recently, we have demonstrated that IC exert a drastic inhibition of basal and IFN-γ-induced expression of MHC class II on human monocytes. Taking into account that the regulation of MHC class II molecules is a crucial event in the immune response, in this report we extend our previous studies analysing the effect of STAT-1 phosphorylation in the down-regulatory process, the fate of the intracellular pool of MHC class II molecules and the effect of complement on MHC class II down-regulation induced by IC. We also studied the effect of IC on the expression of MHC class II (I-Ad) in macrophages using a mouse model of chronic inflammation. We demonstrate that IC induce a depletion not only on surface expressed but also on intracellular MHC class II content and that IC-induced down-regulation of MHC class II is not mediated by the inhibition of STAT-1 phosphorylation. On the other hand, the effect of IC is not specific for the down-regulation of MHC class II, for it could be restricted to other molecules involved in inflammatory processes. Our experiments also show that the activation of the complement system could be a crucial step on the regulation of the effect of IC on MHC class II expression. In agreement with our in vitro experiments using human monocytes, IC treatment reduces the expression of MHC class II in a mouse model of chronic inflammation. PMID:12869025

  13. Transcriptional profiling of macrophage and tumor cell interactions in vitro.

    PubMed

    Roudnicky, Filip; Hollmén, Maija

    2016-06-01

    Macrophages are important mediators of tumor progression and their function is broadly influenced by different microenvironmental stimuli. To understand the molecular basis of the tumor-supporting role of macrophages in aggressive breast cancer we co-cultured human peripheral monocytes with two breast cancer cell lines representing distinct aggressive cellular phenotype and transcriptionally profiled the changes occurring in both cells during in vitro activated crosstalk. Here we provide a detailed description of the experimental design, sample identity and analysis of the Illumina RNA-Seq data, which have been deposited into Gene Expression Omnibus (GEO): GSE75130. PMID:27081631

  14. Transcriptional profiling of macrophage and tumor cell interactions in vitro

    PubMed Central

    Roudnicky, Filip; Hollmén, Maija

    2016-01-01

    Macrophages are important mediators of tumor progression and their function is broadly influenced by different microenvironmental stimuli. To understand the molecular basis of the tumor-supporting role of macrophages in aggressive breast cancer we co-cultured human peripheral monocytes with two breast cancer cell lines representing distinct aggressive cellular phenotype and transcriptionally profiled the changes occurring in both cells during in vitro activated crosstalk. Here we provide a detailed description of the experimental design, sample identity and analysis of the Illumina RNA-Seq data, which have been deposited into Gene Expression Omnibus (GEO): GSE75130. PMID:27081631

  15. Gliadin stimulation of murine macrophage inflammatory gene expression and intestinal permeability are MyD88-dependent: role of the innate immune response in Celiac disease.

    PubMed

    Thomas, Karen E; Sapone, Anna; Fasano, Alessio; Vogel, Stefanie N

    2006-02-15

    Recent studies have demonstrated the importance of TLR signaling in intestinal homeostasis. Celiac disease (CD) is an autoimmune enteropathy triggered in susceptible individuals by the ingestion of gliadin-containing grains. In this study, we sought to test the hypothesis that gliadin initiates this response by stimulating the innate immune response to increase intestinal permeability and by up-regulating macrophage proinflammatory gene expression and cytokine production. To this end, intestinal permeability and the release of zonulin (an endogenous mediator of gut permeability) in vitro, as well as proinflammatory gene expression and cytokine release by primary murine macrophage cultures, were measured. Gliadin and its peptide derivatives, 33-mer and p31-43, were found to be potent inducers of both a zonulin-dependent increase in intestinal permeability and macrophage proinflammatory gene expression and cytokine secretion. Gliadin-induced zonulin release, increased intestinal permeability, and cytokine production were dependent on myeloid differentiation factor 88 (MyD88), a key adapter molecule in the TLR/IL-1R signaling pathways, but were neither TLR2- nor TLR4-dependent. Our data support the following model for the innate immune response to gliadin in the initiation of CD. Gliadin interaction with the intestinal epithelium increases intestinal permeability through the MyD88-dependent release of zonulin that, in turn, enables paracellular translocation of gliadin and its subsequent interaction with macrophages within the intestinal submucosa. There, the interaction of gliadin with macrophages elicits a MyD88-dependent proinflammatory cytokine milieu that facilitates the interaction of T cells with APCs, leading ultimately to the Ag-specific adaptive immune response seen in patients with CD. PMID:16456012

  16. Impact of carbon nanotubes and graphene on immune cells

    PubMed Central

    2014-01-01

    It has been recently proposed that nanomaterials, alone or in concert with their specific biomolecular conjugates, can be used to directly modulate the immune system, therefore offering a new tool for the enhancement of immune-based therapies against infectious disease and cancer. Here, we revised the publications on the impact of functionalized carbon nanotubes (f-CNTs), graphene and carbon nanohorns on immune cells. Whereas f-CNTs are the nanomaterial most widely investigated, we noticed a progressive increase of studies focusing on graphene in the last couple of years. The majority of the works (56%) have been carried out on macrophages, following by lymphocytes (30% of the studies). In the case of lymphocytes, T cells were the most investigated (22%) followed by monocytes and dendritic cells (7%), mixed cell populations (peripheral blood mononuclear cells, 6%), and B and natural killer (NK) cells (1%). Most of the studies focused on toxicity and biocompatibility, while mechanistic insights on the effect of carbon nanotubes on immune cells are generally lacking. Only very recently high-throughput gene-expression analyses have shed new lights on unrecognized effects of carbon nanomaterials on the immune system. These investigations have demonstrated that some f-CNTs can directly elicitate specific inflammatory pathways. The interaction of graphene with the immune system is still at a very early stage of investigation. This comprehensive state of the art on biocompatible f-CNTs and graphene on immune cells provides a useful compass to guide future researches on immunological applications of carbon nanomaterials in medicine. PMID:24885781

  17. Effects of PVA coated nanoparticles on human immune cells

    PubMed Central

    Strehl, Cindy; Gaber, Timo; Maurizi, Lionel; Hahne, Martin; Rauch, Roman; Hoff, Paula; Häupl, Thomas; Hofmann-Amtenbrink, Margarethe; Poole, A Robin; Hofmann, Heinrich; Buttgereit, Frank

    2015-01-01

    Nanotechnology provides new opportunities in human medicine, mainly for diagnostic and therapeutic purposes. The autoimmune disease rheumatoid arthritis (RA) is often diagnosed after irreversible joint structural damage has occurred. There is an urgent need for a very early diagnosis of RA, which can be achieved by more sensitive imaging methods. Superparamagnetic iron oxide nanoparticles (SPION) are already used in medicine and therefore represent a promising tool for early diagnosis of RA. The focus of our work was to investigate any potentially negative effects resulting from the interactions of newly developed amino-functionalized amino-polyvinyl alcohol coated (a-PVA) SPION (a-PVA-SPION), that are used for imaging, with human immune cells. We analyzed the influence of a-PVA-SPION with regard to cell survival and cell activation in human whole blood in general, and in human monocytes and macrophages representative of professional phagocytes, using flow cytometry, multiplex suspension array, and transmission electron microscopy. We found no effect of a-PVA-SPION on the viability of human immune cells, but cytokine secretion was affected. We further demonstrated that the percentage of viable macrophages increased on exposure to a-PVA-SPION. This effect was even stronger when a-PVA-SPION were added very early in the differentiation process. Additionally, transmission electron microscopy analysis revealed that both monocytes and macrophages are able to endocytose a-PVA-SPION. Our findings demonstrate an interaction between human immune cells and a-PVA-SPION which needs to be taken into account when considering the use of a-PVA-SPION in human medicine. PMID:26056442

  18. Effects of PVA coated nanoparticles on human immune cells.

    PubMed

    Strehl, Cindy; Gaber, Timo; Maurizi, Lionel; Hahne, Martin; Rauch, Roman; Hoff, Paula; Häupl, Thomas; Hofmann-Amtenbrink, Margarethe; Poole, A Robin; Hofmann, Heinrich; Buttgereit, Frank

    2015-01-01

    Nanotechnology provides new opportunities in human medicine, mainly for diagnostic and therapeutic purposes. The autoimmune disease rheumatoid arthritis (RA) is often diagnosed after irreversible joint structural damage has occurred. There is an urgent need for a very early diagnosis of RA, which can be achieved by more sensitive imaging methods. Superparamagnetic iron oxide nanoparticles (SPION) are already used in medicine and therefore represent a promising tool for early diagnosis of RA. The focus of our work was to investigate any potentially negative effects resulting from the interactions of newly developed amino-functionalized amino-polyvinyl alcohol coated (a-PVA) SPION (a-PVA-SPION), that are used for imaging, with human immune cells. We analyzed the influence of a-PVA-SPION with regard to cell survival and cell activation in human whole blood in general, and in human monocytes and macrophages representative of professional phagocytes, using flow cytometry, multiplex suspension array, and transmission electron microscopy. We found no effect of a-PVA-SPION on the viability of human immune cells, but cytokine secretion was affected. We further demonstrated that the percentage of viable macrophages increased on exposure to a-PVA-SPION. This effect was even stronger when a-PVA-SPION were added very early in the differentiation process. Additionally, transmission electron microscopy analysis revealed that both monocytes and macrophages are able to endocytose a-PVA-SPION. Our findings demonstrate an interaction between human immune cells and a-PVA-SPION which needs to be taken into account when considering the use of a-PVA-SPION in human medicine. PMID:26056442

  19. Secreted Factors from Colorectal and Prostate Cancer Cells Skew the Immune Response in Opposite Directions

    PubMed Central

    Lundholm, Marie; Hägglöf, Christina; Wikberg, Maria L.; Stattin, Pär; Egevad, Lars; Bergh, Anders; Wikström, Pernilla; Palmqvist, Richard; Edin, Sofia

    2015-01-01

    Macrophage infiltration has been associated with an improved prognosis in patients with colorectal cancer (CRC), but a poor prognosis in prostate cancer (PC) patients. In this study, the distribution and prognostic value of proinflammatory M1 macrophages (NOS2+) and immunosuppressive M2 macrophages (CD163+) was evaluated in a cohort of 234 PC patients. We found that macrophages infiltrating PC were mainly of an M2 type and correlated with a more aggressive tumor and poor patient prognosis. Furthermore, the M1/M2 ratio was significantly decreased in PC compared to CRC. Using in vitro cell culture experiments, we could show that factors secreted from CRC and PC cells induced macrophages of a proinflammatory or immunosuppressive phenotype, respectively. These macrophages differentially affected autologous T lymphocyte proliferation and activation. Consistent with this, CRC specimens were found to have higher degrees of infiltrating T-helper 1 cells and active cytotoxic T lymphocytes, while PC specimens displayed functionally inactive T cells. In conclusion, our results imply that tumour-secreted factors from cancers of different origin can drive macrophage differentiation in opposite directions and thereby regulate the organization of the anti-tumour immune response. Our findings suggest that reprogramming of macrophages could be an important tool in the development of new immunotherapeutic strategies. PMID:26503803

  20. Low cost delivery of proteins bioencapsulated in plant cells to human non-immune or immune modulatory cells.

    PubMed

    Xiao, Yuhong; Kwon, Kwang-Chul; Hoffman, Brad E; Kamesh, Aditya; Jones, Noah T; Herzog, Roland W; Daniell, Henry

    2016-02-01

    Targeted oral delivery of GFP fused with a GM1 receptor binding protein (CTB) or human cell penetrating peptide (PTD) or dendritic cell peptide (DCpep) was investigated. Presence of GFP(+) intact plant cells between villi of ileum confirm their protection in the digestive system from acids/enzymes. Efficient delivery of GFP to gut-epithelial cells by PTD or CTB and to M cells by all these fusion tags confirm uptake of GFP in the small intestine. PTD fusion delivered GFP more efficiently to most tissues or organs than the other two tags. GFP was efficiently delivered to the liver by all fusion tags, likely through the gut-liver axis. In confocal imaging studies of human cell lines using purified GFP fused with different tags, GFP signal of DCpep-GFP was only detected within dendritic cells. PTD-GFP was only detected within kidney or pancreatic cells but not in immune modulatory cells (macrophages, dendritic, T, B, or mast cells). In contrast, CTB-GFP was detected in all tested cell types, confirming ubiquitous presence of GM1 receptors. Such low-cost oral delivery of protein drugs to sera, immune system or non-immune cells should dramatically lower their cost by elimination of prohibitively expensive fermentation, protein purification cold storage/transportation and increase patient compliance. PMID:26706477

  1. Adoptively transferred immune T cells eradicate established tumors in spite of cancer-induced immune suppression

    PubMed Central

    Arina, Ainhoa; Schreiber, Karin; Binder, David C.; Karrison, Theodore; Liu, Rebecca B.; Schreiber, Hans

    2014-01-01

    Myeloid-derived CD11b+Gr1+ suppressor cells (MDSC) and tumor-associated macrophages (TAM) are considered a major obstacle for effective adoptive T cell therapy. Myeloid cells suppress naive T cell proliferation ex vivo and can prevent the generation of T cell responses in vivo. We find, however, that immune T cells adoptively transferred eradicate well-established tumors in the presence of MDSC and TAM which are strongly immunosuppressive ex vivo. These MDSC and TAM were comparable in levels and immunosuppression among different tumor models. Longitudinal microscopy of tumors in vivo revealed that after T cell transfer tumor vasculature and cancer cells disappeared simultaneously. During T-cell mediated tumor destruction, the tumor stroma contained abundant myeloid cells (mainly TAM) that retained their suppressive properties. Preimmunized but not naive mice resisted immune suppression caused by an unrelated tumor-burden supporting the idea that in vivo, myeloid immunosuppressive cells can suppress naive but not memory T cell responses. PMID:24367029

  2. Primary Role for Toll-Like Receptor-Driven Tumor Necrosis Factor Rather than Cytosolic Immune Detection in Restricting Coxiella burnetii Phase II Replication within Mouse Macrophages.

    PubMed

    Bradley, William P; Boyer, Mark A; Nguyen, Hieu T; Birdwell, L Dillon; Yu, Janet; Ribeiro, Juliana M; Weiss, Susan R; Zamboni, Dario S; Roy, Craig R; Shin, Sunny

    2016-04-01

    Coxiella burnetiireplicates within permissive host cells by employing a Dot/Icm type IV secretion system (T4SS) to translocate effector proteins that direct the formation of a parasitophorous vacuole. C57BL/6 mouse macrophages restrict the intracellular replication of theC. burnetiiNine Mile phase II (NMII) strain. However, eliminating Toll-like receptor 2 (TLR2) permits bacterial replication, indicating that the restriction of bacterial replication is immune mediated. Here, we examined whether additional innate immune pathways are employed by C57BL/6 macrophages to sense and restrict NMII replication. In addition to the known role of TLR2 in detecting and restricting NMII infection, we found that TLR4 also contributes to cytokine responses but is not required to restrict bacterial replication. Furthermore, the TLR signaling adaptors MyD88 and Trif are required for cytokine responses and restricting bacterial replication. TheC. burnetiiNMII T4SS translocates bacterial products into C57BL/6 macrophages. However, there was little evidence of cytosolic immune sensing of NMII, as there was a lack of inflammasome activation, T4SS-dependent cytokine responses, and robust type I interferon (IFN) production, and these pathways were not required to restrict bacterial replication. Instead, endogenous tumor necrosis factor (TNF) produced upon TLR sensing ofC. burnetiiNMII was required to control bacterial replication. Therefore, our findings indicate a primary role for TNF produced upon immune detection ofC. burnetiiNMII by TLRs, rather than cytosolic PRRs, in enabling C57BL/6 macrophages to restrict bacterial replication. PMID:26787725

  3. 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

  4. Orchestration of pulmonary T cell immunity during Mycobacterium tuberculosis infection: immunity interruptus

    PubMed Central

    Behar, Samuel M.; Carpenter, Stephen M.; Booty, Matthew G.; Barber, Daniel L.; Jayaraman, Pushpa

    2014-01-01

    Despite the introduction almost a century ago of Mycobacterium bovis BCG (BCG), an attenuated form of M. bovis that is used as a vaccine against Mycobacterium tuberculosis, tuberculosis remains a global health threat and kills more than 1.5 million people each year. This is mostly because BCG fails to prevent pulmonary disease – the contagious form of tuberculosis. Although there have been significant advances in understanding how the immune system responds to infection, the qualities that define protective immunity against M. tuberculosis remain poorly characterized. The ability to predict who will maintain control over the infection and who will succumb to clinical disease would revolutionize our approach to surveillance, control, and treatment. Here we review the current understanding of pulmonary T cell responses following M. tuberculosis infection. While infection elicits a strong immune response that contains infection, M. tuberculosis evades eradication. Traditionally, its intracellular lifestyle and alteration of macrophage function are viewed as the dominant mechanisms of evasion. Now we appreciate that chronic inflammation leads to T cell dysfunction. While this may arise as the host balances the goals of bacterial sterilization and avoidance of tissue damage, it is becoming clear that T cell dysfunction impairs host resistance. Defining the mechanisms that lead to T cell dysfunction is crucial as memory T cell responses are likely to be subject to the same subject to the same pressures. Thus, success of T cell based vaccines is predicated on memory T cells avoiding exhaustion while at the same time not promoting overt tissue damage. PMID:25311810

  5. Viewing Malignant Melanoma Cells as Macrophage-Tumor Hybrids

    PubMed Central

    2007-01-01

    Cutaneous malignant melanoma (CMM) begins in the epidermis as the clonal emergence of melanocytes having a deregulated mitotic cycle. In a manner not yet understood, some descendents of these cells loosen their adhesions in situ and migrate into the dermis, thus initiating the processes of invasion and metastasis. These cells look and act much like macrophage-melanoma hybrids created in the lab or arising in mice. But genetic proof for hybrids in human melanoma is still lacking. Nonetheless, should tumor cell hybridization account for the invasive phenotype, this would surely evoke new therapeutic approaches regarding mechanisms of cell fusion and hybrid-specific molecular signatures. Here are described some of the remarkable phenotypic similarities between experimental macrophage-melanoma hybrids and CMM. The results suggest that invasive and metastatic CMM might well arise through fusion and genomic hybridization between melanoma cells and migratory bone marrow-derived cells. PMID:19262091

  6. Cell death, clearance and immunity in the skeletal muscle.

    PubMed

    Sciorati, C; Rigamonti, E; Manfredi, A A; Rovere-Querini, P

    2016-06-01

    The skeletal muscle is an immunologically unique tissue. Leukocytes, virtually absent in physiological conditions, are quickly recruited into the tissue upon injury and persist during regeneration. Apoptosis, necrosis and autophagy coexist in the injured/regenerating muscles, including those of patients with neuromuscular disorders, such as inflammatory myopathies, dystrophies, metabolic and mitochondrial myopathies and drug-induced myopathies. Macrophages are able to alter their function in response to microenvironment conditions and as a consequence coordinate changes within the tissue from the early injury throughout regeneration and eventual healing, and regulate the activation and the function of stem cells. Early after injury, classically activated macrophages ('M1') dominate the picture. Alternatively activated M2 macrophages predominate during resolution phases and regulate the termination of the inflammatory responses. The dynamic M1/M2 transition is increasingly felt to be the key to the homeostasis of the muscle. Recognition and clearance of debris originating from damaged myofibers and from dying stem/progenitor cells, stromal cells and leukocytes are fundamental actions of macrophages. Clearance of apoptotic cells and M1/M2 transition are causally connected and represent limiting steps for muscle healing. The accumulation of apoptotic cells, which reflects their defective clearance, has been demonstrated in various tissues to prompt autoimmunity against intracellular autoantigens. In the muscle, in the presence of type I interferon, apoptotic myoblasts indeed cause the production of autoantibodies, lymphocyte infiltration and continuous cycles of muscle injury and regeneration, mimicking human inflammatory myopathies. The clearance of apoptotic cells thus modulates the homeostatic response of the skeletal muscle to injury. Conversely, defects in the process may have deleterious local effects, guiding maladaptive tissue remodeling with collagen and fat accumulation and promoting autoimmunity itself. There is strong promise for novel treatments based on new knowledge of cell death, clearance and immunity in the muscle. PMID:26868912

  7. Intracellular replication of Staphylococcus aureus in mature phagolysosomes in macrophages precedes host cell death, and bacterial escape and dissemination.

    PubMed

    Flannagan, Ronald S; Heit, Bryan; Heinrichs, David E

    2016-04-01

    The success of Staphylococcus aureus as a pathogen is partly attributable to its ability to thwart host innate immune responses, which includes resisting the antimicrobial functions of phagocytes. Here, we have studied the interaction of methicillin-resistant S. aureus (MRSA) strain USA300 with murine RAW 264.7 and primary human macrophages using molecular imaging and single cell analysis to obtain an unprecedented understanding of the interaction between the macrophage and MRSA. Herein we demonstrate that macrophages fail to control intracellular infection by MRSA USA300 despite trafficking the bacteria into mature phagolysosomes. Using fluorescence-based proliferation assays we also show that intracellular staphylococci proliferate and that replication commences while the bacteria are residing in mature phagolysosomes hours after initial phagocytosis. Finally, live-cell fluorescence video microscopy allowed for unprecedented visual insight into the escape of MRSA from macrophages, demonstrating that the macrophages die through a pathway characterized by membrane blebbing and activation of caspase-3 followed by acquisition of the vital dye propidium iodide. Moreover, cell death precedes the emergence of MRSA from infected macrophages, and these events can be ablated by prolonged exposure of infected phagocytes to gentamicin. PMID:26408990

  8. Macrophage-Associated Osteoactivin/GPNMB Mediates Mesenchymal Stem Cell Survival, Proliferation, and Migration Via a CD44-Dependent Mechanism.

    PubMed

    Yu, Bing; Sondag, Gregory R; Malcuit, Christopher; Kim, Min-Ho; Safadi, Fayez F

    2016-07-01

    Although MSCs have been widely recognized to have therapeutic potential in the repair of injured or diseased tissues, it remains unclear how functional activities of mesenchymal stem cells (MSCs) are influenced by the surrounding inflammatory milieu at the site of tissue injury. Macrophages constitute an essential component of innate immunity and have been shown to exhibit a phenotypic plasticity in response to various stimuli, which play a central role in both acute inflammation and wound repair. Osteoactivin (OA)/Glycoprotein non-metastatic melanoma protein B (GPNMB), a transmembrane glycoprotein that plays a role in cell differentiation, survival, and angiogenesis. The objective of this study was to investigate the potential role of OA/GPNMB in macrophage-induced MSC function. We found that reparative M2 macrophages express significantly greater levels of OA/GPNMB than pro-inflammatory M1 macrophages. Furthermore, using loss of function and rescue studies, we demonstrated that M2 macrophages-secreted OA/GPNMB positively regulates the viability, proliferation, and migration of MSCs. More importantly, we demonstrated that OA/GPNMB acts through ERK and AKT signaling pathways in MSCs via CD44, to induce these effects. Taken together, our results provide pivotal insight into the mechanism by which OA/GPNMB contributes to the tissue reparative phenotype of M2 macrophages and positively regulates functional activities of MSCs. J. Cell. Biochem. 117: 1511-1521, 2016. © 2015 Wiley Periodicals, Inc. PMID:26442636

  9. Progesterone-induced activation of membrane-bound progesterone receptors in murine macrophage cells.

    PubMed

    Lu, Jing; Reese, Joshua; Zhou, Ying; Hirsch, Emmet

    2015-02-01

    Parturition is an inflammatory process mediated to a significant extent by macrophages. Progesterone (P4) maintains uterine quiescence in pregnancy, and a proposed functional withdrawal of P4 classically regulated by nuclear progesterone receptors (nPRs) leads to labor. P4 can affect the functions of macrophages despite the reported lack of expression of nPRs in these immune cells. Therefore, in this study we investigated the effects of the activation of the putative membrane-associated PR on the function of macrophages (a key cell for parturition) and discuss the implications of these findings for pregnancy and parturition. In murine macrophage cells (RAW 264.7), activation of mPRs by P4 modified to be active only extracellularly by conjugation to BSA (P4BSA, 1.0×10(-7) mol/l) caused a pro-inflammatory shift in the mRNA expression profile, with significant upregulation of the expression of cyclooxygenase 2 (COX2 (Ptgs2)), Il1B, and Tnf and downregulation of membrane progesterone receptor alpha (Paqr7) and oxytocin receptor (Oxtr). Pretreatment with PD98059, a MEK1/2 inhibitor, significantly reduced P4BSA-induced expression of mRNA of Il1B, Tnf, and Ptgs2. Inhibition of protein kinase A (PKA) by H89 blocked P4BSA-induced expression of Il1B and Tnf mRNA. P4BSA induced rapid phosphorylation of MEK1/2 and CREB (a downstream target of PKA). This phosphorylation was inhibited by pretreatment with PD98059 and H89, respectively, revealing that MEK1/2 and PKA are two of the components involved in mPR signaling. Taken together, these results indicate that changes in membrane progesterone receptor alpha expression and signaling in macrophages are associated with the inflammatory responses; and that these changes might contribute to the functional withdrawal of P4 related to labor. PMID:25472814

  10. Progesterone-induced activation of membrane-bound progesterone receptors in murine macrophage cells

    PubMed Central

    Lu, Jing; Reese, Joshua; Zhou, Ying; Hirsch, Emmet

    2014-01-01

    Parturition is an inflammatory process mediated to a significant extent by macrophages. Progesterone maintains uterine quiescence in pregnancy, and a proposed functional withdrawal of progesterone classically regulated by nuclear progesterone receptors (nPRs) leads to labor. Progesterone can impact the functions of macrophages despite the reported lack of expression of nPRs in these immune cells. Therefore, in this study we investigated the effects of the activation of the putative membrane-associated progesterone receptor on the function of macrophages (a key cell for parturition) and discuss the implications of these findings for pregnancy and parturition. In murine macrophage cells (RAW264.7), activation of mPRs by progesterone modified to be active only extracellularly by conjugation to BSA (P4BSA, 1.010?7 mol/l) caused a pro-inflammatory shift in mRNA expression profile, with significant up-regulation of the expression of cyclooxygenase 2 (Ptgs2), Il1B, and Tnf and down-regulation of membrane progesterone receptor alpha (Paqr7) and oxytocin receptor (Oxtr). Pretreatment with PD98059, a MEK 1/2 inhibitor, significantly reduced P4BSA-induced Il1B, Tnf and Ptgs2 mRNA. Inhibition of protein kinase A (PKA) by H89 blocked P4BSA-induced Il1B and Tnf mRNA levels. P4BSA induced rapid phosphorylation of MEK1/2 and cAMP responsive element binding protein (CREB, a downstream target of PKA). This phosphorylation was inhibited by pretreatment with PD98059 and H89, respectively, revealing that MEK1/2 and PKA are two of the components involved in mPR signaling. Taken together, these data demonstrate that changes in membrane progesterone receptor alpha expression and signaling in macrophages are associated with the inflammatory responses; and that these changes might contribute to the functional withdrawal of progesterone related to labor. PMID:25472814

  11. Memory T Cell-Derived interferon-γ Instructs Potent Innate Cell Activation For Protective Immunity

    PubMed Central

    Soudja, Saidi M’Homa; Chandrabos, Ceena; Yakob, Ernest; Veenstra, Mike; Palliser, Deborah; Lauvau, Grégoire

    2014-01-01

    SUMMARY Cells of the innate immune system are essential for host defenses against primary microbial pathogen infections, yet their involvement in effective memory responses of vaccinated individuals has been poorly investigated. Here we show that memory T cells instruct innate cells to become potent effector cells in a systemic and a mucosal model of infection. Memory T cells controlled phagocyte, dendritic cell and NK or NK T cell mobilization and induction of a strong program of differentiation, which included their expression of effector cytokines and microbicidal pathways, all of which were delayed in non-vaccinated hosts. Disruption of IFN-γ-signaling in Ly6C+ monocytes, dendritic cells and macrophages impaired these processes and the control of pathogen growth. These results reveal how memory T cells, through rapid secretion of IFN-γ, orchestrate extensive modifications of host innate immune responses that are essential for effective protection of vaccinated hosts. PMID:24931122

  12. Cigarette smoke-induced iBALT mediates macrophage activation in a B cell-dependent manner in COPD.

    PubMed

    John-Schuster, Gerrit; Hager, Katrin; Conlon, Thomas M; Irmler, Martin; Beckers, Johannes; Eickelberg, Oliver; Yildirim, Ali Önder

    2014-11-01

    Chronic obstructive pulmonary disease (COPD) is characterized by a progressive decline in lung function, caused by exposure to exogenous particles, mainly cigarette smoke (CS). COPD is initiated and perpetuated by an abnormal CS-induced inflammatory response of the lungs, involving both innate and adaptive immunity. Specifically, B cells organized in iBALT structures and macrophages accumulate in the lungs and contribute to CS-induced emphysema, but the mechanisms thereof remain unclear. Here, we demonstrate that B cell-deficient mice are significantly protected against CS-induced emphysema. Chronic CS exposure led to an increased size and number of iBALT structures, and increased lung compliance and mean linear chord length in wild-type (WT) but not in B cell-deficient mice. The increased accumulation of lung resident macrophages around iBALT and in emphysematous alveolar areas in CS-exposed WT mice coincided with upregulated MMP12 expression. In vitro coculture experiments using B cells and macrophages demonstrated that B cell-derived IL-10 drives macrophage activation and MMP12 upregulation, which could be inhibited by an anti-IL-10 antibody. In summary, B cell function in iBALT formation seems necessary for macrophage activation and tissue destruction in CS-induced emphysema and possibly provides a new target for therapeutic intervention in COPD. PMID:25128521

  13. A Brucella Virulence Factor Targets Macrophages to Trigger B-cell Proliferation*

    PubMed Central

    Spera, Juan M.; Herrmann, Claudia K.; Roset, Mara S.; Comerci, Diego J.; Ugalde, Juan E.

    2013-01-01

    Brucella spp. and Trypanosoma cruzi are two intracellular pathogens that have no evolutionary common origins but share a similar lifestyle as they establish chronic infections for which they have to circumvent the host immune response. Both pathogens have a virulence factor (prpA in Brucella and tcPrac in T. cruzi) that induces B-cell proliferation and promotes the establishment of the chronic phase of the infectious process. We show here that, even though PrpA promotes B-cell proliferation, it targets macrophages in vitro and is translocated to the cytoplasm during the intracellular replication phase. We observed that PrpA-treated macrophages induce the secretion of a soluble factor responsible for B-cell proliferation and identified nonmuscular myosin IIA (NMM-IIA) as a receptor required for binding and function of this virulence factor. Finally, we show that the Trypanosoma cruzi homologue of PrpA also targets macrophages to induce B-cell proliferation through the same receptor, indicating that this virulence strategy is conserved between a bacterial and a protozoan pathogen. PMID:23720774

  14. Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries

    PubMed Central

    McArdle, Sara; Chodaczek, Grzegorz; Ray, Nilanjan; Ley, Klaus

    2015-01-01

    Abstract. Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe−/−Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP+ macrophages “dancing on the spot” and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells. PMID:25710308

  15. Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries

    NASA Astrophysics Data System (ADS)

    McArdle, Sara; Chodaczek, Grzegorz; Ray, Nilanjan; Ley, Klaus

    2015-02-01

    Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe-/-Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP+ macrophages "dancing on the spot" and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells.

  16. Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries.

    PubMed

    McArdle, Sara; Chodaczek, Grzegorz; Ray, Nilanjan; Ley, Klaus

    2015-02-01

    Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe−/−Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP + macrophages “dancing on the spot” and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells. PMID:25710308

  17. The Macrophage Switch in Obesity Development

    PubMed Central

    Castoldi, Angela; Naffah de Souza, Cristiane; Câmara, Niels Olsen Saraiva; Moraes-Vieira, Pedro M.

    2016-01-01

    Immune cell infiltration in (white) adipose tissue (AT) during obesity is associated with the development of insulin resistance. In AT, the main population of leukocytes are macrophages. Macrophages can be classified into two major populations: M1, classically activated macrophages, and M2, alternatively activated macrophages, although recent studies have identified a broad range of macrophage subsets. During obesity, AT M1 macrophage numbers increase and correlate with AT inflammation and insulin resistance. Upon activation, pro-inflammatory M1 macrophages induce aerobic glycolysis. By contrast, in lean humans and mice, the number of M2 macrophages predominates. M2 macrophages secrete anti-inflammatory cytokines and utilize oxidative metabolism to maintain AT homeostasis. Here, we review the immunologic and metabolic functions of AT macrophages and their different facets in obesity and the metabolic syndrome. PMID:26779183

  18. A novel lipopolysaccharide-binding protein (LBP) gene from sweetfish Plecoglossus altivelis: molecular characterization and its role in the immune response of monocytes/macrophages.

    PubMed

    Lu, Xin-Jiang; Chu, Chang-Qing; Chen, Qiang; Chen, Jiong

    2014-05-01

    Lipopolysaccharide-binding protein (LBP) belongs to the lipid transfer/LBP (LT-LBP) family, and plays a crucial role in the recognition of bacterial components that modulate cellular signals in phagocytic cells. Although several LBPs have been identified in teleosts, the effects of LBP homologs on teleost phagocytic cells are still obscure. Here, we report the cloning a novel full-length cDNA sequence of LBP-like protein (paLBP) gene from sweetfish, Plecoglossus altivelis. The paLBP cDNA encoded a 464 aa polypeptide, which was closest to that of rainbow smelt (Osmerus mordax). paLBP mRNA was detected mainly in the spleen, liver, and head kidney and levels dramatically increased in various tissues after Listonella anguillarum infection. In contrast to mammalian studies, paLBP mRNA could also be detected in sweetfish monocytes/macrophages. Recombinant paLBP showed LPS-binding activity and Western blot results revealed a significant increase of paLBP in the supernatant of sweetfish monocytes/macrophages challenged with L. anguillarum. Moreover, paLBP neutralization led to up-regulation of IL-1β and TNF-α mRNA as well as respiratory burst activity in sweetfish monocytes/macrophages in response to L. anguillarum or LPS challenge. Therefore, these results suggest that paLBP is an inducible acute-phase protein mediating the immune response of sweetfish monocytes/macrophages upon bacterial challenge. PMID:24594008

  19. The Metastasis-Promoting Roles of Tumor-Associated Immune Cells

    PubMed Central

    Smith, Heath A.; Kang, Yibin

    2013-01-01

    Tumor metastasis is driven not only by the accumulation of intrinsic alterations in malignant cells, but also by the interactions of cancer cells with various stromal cell components of the tumor microenvironment. In particular, inflammation and infiltration of the tumor tissue by host immune cells, such as tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells have been shown to support tumor growth in addition to invasion and metastasis. Each step of tumor development, from initiation through metastatic spread, is promoted by communication between tumor and immune cells via the secretion of cytokines, growth factors and proteases that remodel the tumor microenvironment. Invasion and metastasis requires neovascularization, breakdown of the basement membrane, and remodeling of the extracellular matrix for tumor cell invasion and extravasation into the blood and lymphatic vessels. The subsequent dissemination of tumor cells to distant organ sites necessitates a treacherous journey through the vasculature, which is fostered by close association with platelets and macrophages. Additionally, the establishment of the pre-metastatic niche and specific metastasis organ tropism is fostered by neutrophils and bone marrow-derived hematopoietic immune progenitor cells and other inflammatory cytokines derived from tumor and immune cells, which alter the local environment of the tissue to promote adhesion of circulating tumor cells. This review focuses on the interactions between tumor cells and immune cells recruited to the tumor microenvironment, and examines the factors allowing these cells to promote each stage of metastasis. PMID:23515621

  20. Estrogen promotes Leydig cell engulfment by macrophages in male infertility

    PubMed Central

    Yu, Wanpeng; Zheng, Han; Lin, Wei; Tajima, Astushi; Zhang, Yong; Zhang, Xiaoyan; Zhang, Hongwen; Wu, Jihua; Han, Daishu; Rahman, Nafis A.; Korach, Kenneth S.; Gao, George Fu; Inoue, Ituro; Li, Xiangdong

    2014-01-01

    Male infertility accounts for almost half of infertility cases worldwide. A subset of infertile men exhibit reduced testosterone and enhanced levels of estradiol (E2), though it is unclear how increased E2 promotes deterioration of male fertility. Here, we utilized a transgenic mouse strain that overexpresses human CYP19, which encodes aromatase (AROM+ mice), and mice with knockout of Esr1, encoding estrogen receptor α (ERαKO mice), to analyze interactions between viable Leydig cells (LCs) and testicular macrophages that may lead to male infertility. In AROM+ males, enhanced E2 promoted LC hyperplasia and macrophage activation via ERα signaling. E2 stimulated LCs to produce growth arrest–specific 6 (GAS6), which mediates phagocytosis of apoptotic cells by bridging cells with surface exposed phosphatidylserine (PS) to macrophage receptors, including the tyrosine kinases TYRO3, AXL, and MER. Overproduction of E2 increased apoptosis-independent extrusion of PS on LCs, which in turn promoted engulfment by E2/ERα-activated macrophages that was mediated by AXL-GAS6-PS interaction. We further confirmed E2-dependant engulfment of LCs by real-time 3D imaging. Furthermore, evaluation of molecular markers in the testes of patients with nonobstructive azoospermia (NOA) revealed enhanced expression of CYP19, GAS6, and AXL, which suggests that the AROM+ mouse model reflects human infertility. Together, these results suggest that GAS6 has a potential as a clinical biomarker and therapeutic target for male infertility. PMID:24762434

  1. Estrogen promotes Leydig cell engulfment by macrophages in male infertility.

    PubMed

    Yu, Wanpeng; Zheng, Han; Lin, Wei; Tajima, Astushi; Zhang, Yong; Zhang, Xiaoyan; Zhang, Hongwen; Wu, Jihua; Han, Daishu; Rahman, Nafis A; Korach, Kenneth S; Gao, George Fu; Inoue, Ituro; Li, Xiangdong

    2014-06-01

    Male infertility accounts for almost half of infertility cases worldwide. A subset of infertile men exhibit reduced testosterone and enhanced levels of estradiol (E2), though it is unclear how increased E2 promotes deterioration of male fertility. Here, we utilized a transgenic mouse strain that overexpresses human CYP19, which encodes aromatase (AROM+ mice), and mice with knockout of Esr1, encoding estrogen receptor α (ERαKO mice), to analyze interactions between viable Leydig cells (LCs) and testicular macrophages that may lead to male infertility. In AROM+ males, enhanced E2 promoted LC hyperplasia and macrophage activation via ERα signaling. E2 stimulated LCs to produce growth arrest-specific 6 (GAS6), which mediates phagocytosis of apoptotic cells by bridging cells with surface exposed phosphatidylserine (PS) to macrophage receptors, including the tyrosine kinases TYRO3, AXL, and MER. Overproduction of E2 increased apoptosis-independent extrusion of PS on LCs, which in turn promoted engulfment by E2/ERα-activated macrophages that was mediated by AXL-GAS6-PS interaction. We further confirmed E2-dependant engulfment of LCs by real-time 3D imaging. Furthermore, evaluation of molecular markers in the testes of patients with nonobstructive azoospermia (NOA) revealed enhanced expression of CYP19, GAS6, and AXL, which suggests that the AROM+ mouse model reflects human infertility. Together, these results suggest that GAS6 has a potential as a clinical biomarker and therapeutic target for male infertility. PMID:24762434

  2. Recognition of tumor cells by Dectin-1 orchestrates innate immune cells for anti-tumor responses

    PubMed Central

    Chiba, Shiho; Ikushima, Hiroaki; Ueki, Hiroshi; Yanai, Hideyuki; Kimura, Yoshitaka; Hangai, Sho; Nishio, Junko; Negishi, Hideo; Tamura, Tomohiko; Saijo, Shinobu; Iwakura, Yoichiro; Taniguchi, Tadatsugu

    2014-01-01

    The eradication of tumor cells requires communication to and signaling by cells of the immune system. Natural killer (NK) cells are essential tumor-killing effector cells of the innate immune system; however, little is known about whether or how other immune cells recognize tumor cells to assist NK cells. Here, we show that the innate immune receptor Dectin-1 expressed on dendritic cells and macrophages is critical to NK-mediated killing of tumor cells that express N-glycan structures at high levels. Receptor recognition of these tumor cells causes the activation of the IRF5 transcription factor and downstream gene induction for the full-blown tumoricidal activity of NK cells. Consistent with this, we show exacerbated in vivo tumor growth in mice genetically deficient in either Dectin-1 or IRF5. The critical contribution of Dectin-1 in the recognition of and signaling by tumor cells may offer new insight into the anti-tumor immune system with therapeutic implications. DOI: http://dx.doi.org/10.7554/eLife.04177.001 PMID:25149452

  3. High-Content Quantification of Single-Cell Immune Dynamics

    PubMed Central

    Junkin, Michael; Kaestli, Alicia J.; Cheng, Zhang; Jordi, Christian; Albayrak, Cem; Hoffmann, Alexander; Tay, Savaş

    2016-01-01

    Summary Cells receive time-varying signals from the environment and generate functional responses by secreting their own signaling molecules. Characterizing dynamic input-output relationships in single cells is crucial for understanding and modeling cellular systems. We developed an automated microfluidic system that delivers precisely defined dynamical inputs to individual living cells and simultaneously measures key immune parameters dynamically. Our system combines nanoliter immunoassays, microfluidic input generation, and time-lapse microscopy, enabling study of previously untestable aspects of immunity by measuring time-dependent cytokine secretion and transcription factor activity from single cells stimulated with dynamic inflammatory inputs. Employing this system to analyze macrophage signal processing under pathogen inputs, we found that the dynamics of TNF secretion are highly heterogeneous and surprisingly uncorrelated with the dynamics of NF-κB, the transcription factor controlling TNF production. Computational modeling of the LPS/TLR4 pathway shows that post-transcriptional regulation by TRIF is a key determinant of noisy and uncorrelated TNF secretion dynamics in single macrophages. PMID:27050527

  4. Dendritic Cells and Humoral Immunity in Humans

    PubMed Central

    Ueno, Hideki; Schmitt, Nathalie; Palucka, A. Karolina; Banchereau, Jacques

    2010-01-01

    Summary Dendritic cells (DCs) orchestrate the innate and adaptive immune systems to induce tolerance and immunity. DC plasticity and subsets are prominent determinants in the regulation of immune responses. Our recent studies suggest that humoral and cellular immunity is regulated by different myeloid DC subsets with distinct intrinsic properties in humans. While antibody response is preferentially mediated by CD14+ dermal DCs, cytotoxic T cell response is preferentially mediated by Langerhans cells (LCs). Thus, mechanisms whereby DCs induce humoral and cellular immunity appear to be fundamentally distinct. In this review, we will focus on the role of DCs in the development of humoral immunity. We will also discuss the mechanisms whereby DCs induce CD4+ T cells associated with the help of B cell response, including T follicular helper (Tfh) cells, and why human LCs lack this ability. PMID:20309010

  5. Role of Copper Efflux in Pneumococcal Pathogenesis and Resistance to Macrophage-Mediated Immune Clearance

    PubMed Central

    Johnson, Michael D. L.; Kehl-Fie, Thomas E.; Klein, Roger; Kelly, Jacqueline; Burnham, Corinna; Mann, Beth

    2015-01-01

    In bacteria, the intracellular levels of metals are mediated by tightly controlled acquisition and efflux systems. This is particularly true of copper, a trace element that is universally toxic in excess. During infection, the toxic properties of copper are exploited by the mammalian host to facilitate bacterial clearance. To better understand the role of copper during infection, we characterized the contribution of the cop operon to copper homeostasis and virulence in Streptococcus pneumoniae. Deletion of either the exporter, encoded by copA, or the chaperone, encoded by cupA, led to hypersensitivity to copper stress. We further demonstrated that loss of the copper exporter encoded by copA led to decreased virulence in pulmonary, intraperitoneal, and intravenous models of infection. Deletion of copA resulted in enhanced macrophage-mediated bacterial clearance in vitro. The attenuation phenotype of the copA mutant in the lung was found to be dependent on pulmonary macrophages, underscoring the importance of copper efflux in evading immune defenses. Overall, these data provide insight into the role of the cop operon in pneumococcal pathogenesis. PMID:25667262

  6. Sessile alveolar macrophages modulate immunity through connexin 43-based epithelial communication

    PubMed Central

    Westphalen, Kristin; Gusarova, Galina A.; Islam, Mohammad N.; Subramanian, Manikandan; Cohen, Taylor S.; Prince, Alice S.; Bhattacharya, Jahar

    2014-01-01

    Tissue-resident macrophages of barrier organs constitute the first line of defense against pathogens at the systemic interface with the ambient environment. In lung, resident alveolar macrophages (AMs) provide sentinel function against inhaled pathogens1. Bacterial constituents ligate toll-like receptors (TLRs) on AMs2, causing AMs to secrete proinflammatory cytokines3 that activate alveolar epithelial receptors4, leading to recruitment of neutrophils that engulf pathogens5,6. However, since the AM-induced immune response could itself cause tissue injury, it is unclear how AMs modulate the response to prevent injury. Here, through real-time alveolar imaging in situ, we show that a subset of AMs attached to the alveolar wall, formed connexin 43 (Cx43)-containing gap junctional channels (GJCs) with the epithelium. During lipopolysaccharide (LPS)-induced inflammation, the AMs remained alveolus-attached and sessile, and they established intercommunication through synchronized Ca2+ waves, using the epithelium as the conducting pathway. The intercommunication was immunosuppressive, involving Ca2+ dependent activation of Akt, since AM-specific knockout of Cx43 enhanced alveolar neutrophil recruitment and secretion of proinflammatory cytokines in the bronchoalveolar lavage (BAL). The picture emerges of a novel immunomodulatory process in which a subset of alveolus-attached AMs intercommunicates immunosuppressive signals to reduce endotoxin-induced lung inflammation. PMID:24463523

  7. Nanosized silver (II) pyridoxine complex to cause greater inflammatory response and less cytotoxicity to RAW264.7 macrophage cells

    NASA Astrophysics Data System (ADS)

    Paul, Avijit; Ju, Hee; Rangasamy, Sabarinathan; Shim, Yumi; Song, Joon Myong

    2015-03-01

    With advancements in nanotechnology, silver has been engineered into a nanometre size and has attracted great research interest for use in the treatment of wounds. Silver nanoparticles (AgNPs) have emerged as a potential alternative to conventional antibiotics because of their potential antimicrobial property. However, AgNPs also induce cytotoxicity, generate reactive oxygen species (ROS), and cause mitochondrial damage to human cells. Pyridoxine possesses antioxidant and cell proliferation activity. Therefore, in the present investigation, a nanosilver-pyridoxine complex (AgPyNP) was synthesized, and its cytotoxicity and immune response was compared with AgNPs in macrophage RAW264.7 cells. Results revealed that AgPyNPs showed less cytotoxicity compared with AgNPs by producing a smaller amount of ROS in RAW264.7 cells. Surprisingly, however, AgPyNPs caused macrophage RAW264.7 cells to secrete a larger amount of interleukin-8 (IL-8) and generate a more active inflammatory response compared to AgNPs. It activated TNF-α, NF-κB p65, and NF-κB p50 to generate a more vigorous immune protection that produces a greater amount of IL-8 compared to AgNPs. Overall findings indicate that AgPyNPs exhibited less cytotoxicity and evoked a greater immune response in macrophage RAW264.7 cells. Thus, it can be used as a better wound-healing agent than AgNPs.

  8. γδ T Cell and Other Immune Cells Crosstalk in Cellular Immunity

    PubMed Central

    He, Ying; Wu, Kangni; Hu, Yongxian; Sheng, Lixia; Tie, Ruxiu; Wang, Binsheng; Huang, He

    2014-01-01

    γδ T cells have been recognized as effectors with immunomodulatory functions in cellular immunity. These abilities enable them to interact with other immune cells, thus having the potential for treatment of various immune-mediated diseases with adoptive cell therapy. So far, the interactions between γδ T cell and other immune cells have not been well defined. Here we will discuss the interactivities among them and the perspective on γδ T cells for their use in immunotherapy could be imagined. The understanding of the crosstalk among the immune cells in immunopathology might be beneficial for the clinical application of γδ T cell. PMID:24741636

  9. Glycosylation in immune cell trafficking

    PubMed Central

    Sperandio, Markus; Gleissner, Christian A.; Ley, Klaus

    2009-01-01

    Summary Leukocyte recruitment encompasses cell adhesion and activation steps that enable circulating leukocytes to roll, arrest, and firmly adhere on the endothelial surface before they extravasate into distinct tissue locations. This complex sequence of events relies on adhesive interactions between surface structures on leukocytes and endothelial cells and also on signals generated during the cell-cell contacts. Cell surface glycans play a crucial role in leukocyte recruitment. Several glycosyltransferases such as α1,3 fucosyltransferases, α2,3 sialyltransferases, core 2 N-acetylglucosaminlytransferases, β1,4 galactosyltransferases and polypeptide N-acetylgalactosaminyltransferases have been implicated in the generation of functional selectin ligands that mediate leukocyte rolling via binding to selectins. Recent evidence also suggests a role of α2,3 sialylated carbohydrate determinants in triggering chemokine-mediated leukocyte arrest and influencing β1 integrin function. Additional mechanisms by galectin- and siglec-dependent processes contribute to the growing number of reports emphasizing the significant role of glycans for the successful recruitment of leukocytes into tissues. Advancing the knowledge on glycan function into appropriate pathology models is likely to suggest interesting new therapeutic strategies in the treatment of immune- and inflammation-mediated diseases. PMID:19594631

  10. CD163(+) M2-type tumor-associated macrophage support the suppression of tumor-infiltrating T cells in osteosarcoma.

    PubMed

    Han, Qinglin; Shi, Hongguang; Liu, Fan

    2016-05-01

    Osteosarcoma is one of the most common childhood cancers with high numbers of cancer-related deaths. Progress in conventional therapies is showing limited improvement. An adaptive T cell-based immunotherapy represents a promising new therapeutic option, but to improve its efficacy, regulatory mechanisms in osteosarcoma need further elucidation. Here, to evaluate the regulatory effect of tumor microenvironment of T cells in osteosarcoma, we examined the peripheral blood (PB) and tumor infiltrating (TI) T cells, and their correlations with PB and tumor immune characteristics. We found that TI T cells contained significantly higher levels of TIM-3(+)PD-1(-) and TIM-3(+)PD-1(+) cells than their PB counterparts. Similar to that in chronic HIV and HCV infections, these TIM-3(+)PD-1(-) and TIM-3(+)PD-1(+) T cells presented reduced proliferation and proinflammatory cytokine secretion in response to stimulation. Presence of M2-type (CD163(+)) macrophages exacerbated T cell immunosuppression, since frequencies of CD163(+) tumor-associated macrophages were directly correlated with the frequencies of suppressed TIM-3(+)PD-1(+) T cells. Moreover, depletion of CD163(+) macrophages significantly improved T cell proliferation and proinflammatory cytokine production. Overall, our data presented an intratumoral T cell-specific immunosuppression that was amplified by M2-type tumor-associated macrophages. PMID:26938675

  11. Human dermal CD14⁺ cells are a transient population of monocyte-derived macrophages.

    PubMed

    McGovern, Naomi; Schlitzer, Andreas; Gunawan, Merry; Jardine, Laura; Shin, Amanda; Poyner, Elizabeth; Green, Kile; Dickinson, Rachel; Wang, Xiao-Nong; Low, Donovan; Best, Katie; Covins, Samuel; Milne, Paul; Pagan, Sarah; Aljefri, Khadija; Windebank, Martin; Miranda-Saavedra, Diego; Saavedra, Diego Miranda; Larbi, Anis; Wasan, Pavandip Singh; Duan, Kaibo; Poidinger, Michael; Bigley, Venetia; Ginhoux, Florent; Collin, Matthew; Haniffa, Muzlifah

    2014-09-18

    Dendritic cells (DCs), monocytes, and macrophages are leukocytes with critical roles in immunity and tolerance. The DC network is evolutionarily conserved; the homologs of human tissue CD141(hi)XCR1⁺ CLEC9A⁺ DCs and CD1c⁺ DCs are murine CD103⁺ DCs and CD64⁻ CD11b⁺ DCs. In addition, human tissues also contain CD14⁺ cells, currently designated as DCs, with an as-yet unknown murine counterpart. Here we have demonstrated that human dermal CD14⁺ cells are a tissue-resident population of monocyte-derived macrophages with a short half-life of <6 days. The decline and reconstitution kinetics of human blood CD14⁺ monocytes and dermal CD14⁺ cells in vivo supported their precursor-progeny relationship. The murine homologs of human dermal CD14⁺ cells are CD11b⁺ CD64⁺ monocyte-derived macrophages. Human and mouse monocytes and macrophages were defined by highly conserved gene transcripts, which were distinct from DCs. The demonstration of monocyte-derived macrophages in the steady state in human tissue supports a conserved organization of human and mouse mononuclear phagocyte system. PMID:25200712

  12. Differentiation of human monocytes and derived subsets of macrophages and dendritic cells by the HLDA10 monoclonal antibody panel

    PubMed Central

    Ohradanova-Repic, Anna; Machacek, Christian; Fischer, Michael B; Stockinger, Hannes

    2016-01-01

    The mononuclear phagocyte system, consisting of monocytes, macrophages and dendritic cells (DCs), has an important role in tissue homeostasis as well as in eliciting immune responses against invading pathogens. Blood monocytes have been viewed for decades as precursors of tissue macrophages. Although the newest data show that in the steady state resident macrophages of many organs are monocyte independent, blood monocytes critically contribute to tissue macrophage and DC pools upon inflammation. To better understand the relationship between these populations and their phenotype, we isolated and differentiated human blood CD14+ monocytes in vitro into immature and mature monocyte-derived dendritic cells (MoDCs) as well as into seven different monocyte-derived macrophage subsets. We used the panel of 70 monoclonal antibodies (mAbs) submitted to the 10th Human Leukocyte Differentiation Antigen Workshop to determine the expression profiles of these 10 populations by flow cytometry. We now can compile subpanels of mAbs to differentiate the 10 monocyte/macrophage/MoDC subsets, providing the basis for novel diagnostic and therapeutic tools. PMID:26900469

  13. Human intestinal epithelial cells express IL-10 through Toll-like receptor 4 (TLR4)-mediated epithelial-macrophage crosstalk

    PubMed Central

    Hyun, Jinhee; Romero, Laura; Riveron, Reldy; Flores, Claudia; Kanagavelu, Saravana; Chung, Kristina D.; Alonso, Ana; Sotolongo, John; Ruiz, Jose; Manukyan, Armine; Chun, Sally; Singh, Gaurav; Pedro, Salas; Targan, Stephan R.; Fukata, Masayuki

    2015-01-01

    In the intestine, interaction between epithelial cells and macrophages creates a unique immunoregulatory microenvironment necessary to maintain local immune and tissue homeostasis. Human intestinal epithelial cells (IECs) have been shown to express IL-10, which keeps epithelial integrity. We have demonstrated that bacterial signaling through TLR4 induces 15-Deoxy-Delta-12,14-prostaglandin J2 (15d-PGJ2) synthesis in intestinal macrophages by Cox-2 expression. Here we show that TLR4 signaling generates crosstalk between IECs and macrophages that enhances IL-10 expression in IECs. Direct stimulation of TLR4 leads to the expression of IL-10 in IECs, while the presence of macrophages in a transwell system induces another peak of IL-10 in IECs at a later time point. The second peak of the IL-10 expression is two times greater than the first peak. This late induction of IL-10 depends on a nuclear receptor peroxisome proliferator-activated receptor (PPAR)γ that is accumulated in IECs by TLR4-mediated inhibition of the ubiquitin-proteasomal pathway. TLR4 signaling in macrophages in turn synthesizes 15d-PGJ2 through p38 and ERK activation and Cox-2 induction, which activates PPARγ in IECs. These results suggest that TLR4 signaling maintains IL-10 production in IECs by generating epithelial-macrophage crosstalk, which is an important mechanism in maintenance of intestinal homeostasis mediated through host-bacterial interactions. PMID:25171731

  14. Tissue-resident macrophages

    PubMed Central

    Davies, Luke C.; Jenkins, Stephen J.; Allen, Judith E.; Taylor, Philip R.

    2014-01-01

    Tissue-resident macrophages are a heterogeneous population of immune cells that fulfill tissue-specific and niche-specific functions. These range from dedicated homeostatic functions, such as clearance of cellular debris and iron processing, to central roles in tissue immune-surveillance, response to infection and the resolution of inflammation. Recent studies highlight marked heterogeneity in the origins of tissue macrophages that arise from hematopoietic versus self-renewing embryo-derived populations. We discuss the tissue–niche-specific factors that dictate cell phenotype, the definition of which will allow novel strategies to promote the restoration of tissue homeostasis. Understanding the mechanisms that dictate tissue macrophage heterogeneity should explain why simplified paradigms of macrophage activation do not explain the extent of heterogeneity seen in vivo. PMID:24048120

  15. Cervical Cancer Cell Supernatants Induce a Phenotypic Switch from U937-Derived Macrophage-Activated M1 State into M2-Like Suppressor Phenotype with Change in Toll-Like Receptor Profile

    PubMed Central

    Sánchez-Reyes, Karina; Bravo-Cuellar, Alejandro; Hernández-Flores, Georgina; Lerma-Díaz, José Manuel; Jave-Suárez, Luis Felipe; Gómez-Lomelí, Paulina; de Celis, Ruth; Aguilar-Lemarroy, Adriana; Domínguez-Rodríguez, Jorge Ramiro; Ortiz-Lazareno, Pablo Cesar

    2014-01-01

    Cervical cancer (CC) is the second most common cancer among women worldwide. Infection with human papillomavirus (HPV) is the main risk factor for developing CC. Macrophages are important immune effector cells; they can be differentiated into two phenotypes, identified as M1 (classically activated) and M2 (alternatively activated). Macrophage polarization exerts profound effects on the Toll-like receptor (TLR) profile. In this study, we evaluated whether the supernatant of human CC cells HeLa, SiHa, and C-33A induces a shift of M1 macrophage toward M2 macrophage in U937-derived macrophages. Results. The results showed that soluble factors secreted by CC cells induce a change in the immunophenotype of macrophages from macrophage M1 into macrophage M2. U937-derived macrophages M1 released proinflammatory cytokines and nitric oxide; however, when these cells were treated with the supernatant of CC cell lines, we observed a turnover of M1 toward M2. These cells increased CD163 and IL-10 expression. The expression of TLR-3, -7, and -9 is increased when the macrophages were treated with the supernatant of CC cells. Conclusions. Our result strongly suggests that CC cells may, through the secretion of soluble factors, induce a change of immunophenotype M1 into M2 macrophages. PMID:25309919

  16. 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-Gurin (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 nave 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. PMID:26586698

  17. Immune chaperone gp96 drives the contributions of macrophages to inflammatory colon tumorigenesis.

    PubMed

    Morales, Crystal; Rachidi, Saleh; Hong, Feng; Sun, Shaoli; Ouyang, Xinshou; Wallace, Caroline; Zhang, Yongliang; Garret-Mayer, Elizabeth; Wu, Jennifer; Liu, Bei; Li, Zihai

    2014-01-15

    Macrophages are important drivers in the development of inflammation-associated colon cancers, but the mechanistic underpinnings for their contributions are not fully understood. Furthermore, Toll-like receptors have been implicated in colon cancer, but their relevant cellular sites of action are obscure. In this study, we show that the endoplasmic reticulum chaperone gp96 is essential in tumor-associated macrophages (TAM) to license their contributions to inflammatory colon tumorigenesis. Mice where gp96 was genetically deleted in a macrophage-specific manner exhibited reduced colitis and inflammation-associated colon tumorigenesis. Attenuation of colon cancer in these mice correlated strikingly with reduced mutation rates of β-catenin, increased efficiency of the DNA repair machinery, and reduced expression of proinflammatory cytokines, including interleukin (IL)-17 and IL-23 in the tumor microenvironment. The genotoxic nature of TAM-associated inflammation was evident by increased expression of genes in the DNA repair pathway. Our work deepens understanding of how TAM promote oncogenesis by altering the molecular oncogenic program within epithelial cells, and it identifies gp96 as a lynchpin chaperone needed in TAM to license their function and impact on expression of critical inflammatory cytokines in colon tumorigenesis. PMID:24322981

  18. The Fungal Quorum-Sensing Molecule Farnesol Activates Innate Immune Cells but Suppresses Cellular Adaptive Immunity

    PubMed Central

    Leonhardt, Ines; Spielberg, Steffi; Weber, Michael; Albrecht-Eckardt, Daniela; Bläss, Markus; Claus, Ralf; Barz, Dagmar; Scherlach, Kirstin; Hertweck, Christian; Löffler, Jürgen; Hünniger, Kerstin

    2015-01-01

    ABSTRACT Farnesol, produced by the polymorphic fungus Candida albicans, is the first quorum-sensing molecule discovered in eukaryotes. Its main function is control of C. albicans filamentation, a process closely linked to pathogenesis. In this study, we analyzed the effects of farnesol on innate immune cells known to be important for fungal clearance and protective immunity. Farnesol enhanced the expression of activation markers on monocytes (CD86 and HLA-DR) and neutrophils (CD66b and CD11b) and promoted oxidative burst and the release of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α] and macrophage inflammatory protein 1 alpha [MIP-1α]). However, this activation did not result in enhanced fungal uptake or killing. Furthermore, the differentiation of monocytes to immature dendritic cells (iDC) was significantly affected by farnesol. Several markers important for maturation and antigen presentation like CD1a, CD83, CD86, and CD80 were significantly reduced in the presence of farnesol. Furthermore, farnesol modulated migrational behavior and cytokine release and impaired the ability of DC to induce T cell proliferation. Of major importance was the absence of interleukin 12 (IL-12) induction in iDC generated in the presence of farnesol. Transcriptome analyses revealed a farnesol-induced shift in effector molecule expression and a down-regulation of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor during monocytes to iDC differentiation. Taken together, our data unveil the ability of farnesol to act as a virulence factor of C. albicans by influencing innate immune cells to promote inflammation and mitigating the Th1 response, which is essential for fungal clearance. PMID:25784697

  19. Mast cells: new therapeutic target in helminth immune modulation.

    PubMed

    Vukman, K V; Lalor, R; Aldridge, A; O'Neill, S M

    2016-01-01

    Helminth infection and their secreted antigens have a protective role in many immune-mediated inflammatory disorders such as inflammatory bowel disease, rheumatoid arthritis and multiple sclerosis. However, studies have focused primarily on identifying immune protective mechanisms of helminth infection and their secreted molecules on dendritic cells and macrophages. Given that mast cells have been shown to be implicated in the pathogenesis and progression of many inflammatory disorders, their role should also be examined and considered as cellular target for helminth-based therapies. As there is a dearth of studies examining the interaction of helminth-derived antigens and mast cells, this review will focus on the role of mast cells during helminth infection and examine our current understanding of the involvement of mast cells in TH 1/TH 17-mediated immune disorders. In this context, potential mechanisms by which helminths could target the TH 1/TH 17 promoting properties of mast cells can be identified to unveil novel therapeutic mast cell driven targets in combating these inflammatory disorders. PMID:26577605

  20. Regulatory iNKT cells lack PLZF expression and control Treg cell and macrophage homeostasis in adipose tissue

    PubMed Central

    Lynch, Lydia; Michelet, Xavier; Zhang, Sai; Brennan, Patrick J.; Moseman, Ashley; Lester, Chantel; Besra, Gurdyal; Vomhof-Dekrey, Emilie E.; Tighe, Mike; Koay, Hui-Fern; Godfrey, Dale I.; Leadbetter, Elizabeth A.; Sant’Angelo, Derek B.; von Andrian, Ulrich; Brenner, Michael B.

    2015-01-01

    iNKT cells are CD1d-restricted lipid-sensing innate T cells that express the transcription factor PLZF. iNKT cells accumulate in adipose tissue, where they are anti-inflammatory, but the factors that contribute to their anti-inflammatory nature, and their targets in adipose tissue are unknown. Here we report that adipose tissue iNKT cells have a unique transcriptional program and produce interleukin 2 (IL-2) and IL-10. Unlike other iNKT cells, they lack PLZF, but express the transcription factor E4BP4, which controls their IL-10 production. Adipose iNKT cells are a tissue resident population that induces an anti-inflammatory phenotype in macrophages and, through production of IL-2, controls the number, proliferation and suppressor function of adipose regulatory T (Treg) cells. Thus, adipose tissue iNKT cells are unique regulators of immune homeostasis in this tissue. PMID:25436972

  1. Surface engineering of macrophages with nucleic acid aptamers for the capture of circulating tumor cells.

    PubMed

    Sugimoto, Shunsuke; Moriyama, Rui; Mori, Takeshi; Iwasaki, Yasuhiko

    2015-12-21

    In order to enhance the interactions between macrophages and cancer cells, thiol-terminated nucleic acid aptamers were immobilized on methacryloyl-functionalised carbohydrates of macrophages. The adhesion of cancer cells on the surface modified macrophages was significantly accelerated. PMID:26468496

  2. Transcription of innate immunity genes and cytokine secretion by canine macrophages resistant or susceptible to intracellular survival of Leishmania infantum.

    PubMed

    Turchetti, Andréia Pereira; da Costa, Luciana Fachini; Romão, Everton de Lima; Fujiwara, Ricardo Toshio; da Paixão, Tatiane Alves; Santos, Renato Lima

    2015-01-15

    In this study we assessed the basal transcription of genes associated with innate immunity (i.e. Nramp1, NOD1, NOD2, TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, and TLR9) in canine monocyte-derived macrophages from Leishmania-free dogs. Additionally, secretion of cytokines (IL-10, IL-12, TNF-α and IFN-γ) and nitric oxide in culture supernatants of macrophages with higher or lower resistance to intracellular survival of Leishmania infantum was also measured. Constitutive transcription of TLR9 and NOD2 were negligible; NOD1, TLR1, and TLR7 had low levels of transcription, whereas Nramp1 and TLR2, 3, 4, 5, and 6 had higher levels of constitutive transcription in canine monocyte-derived macrophages. There were no significant differences in transcription between macrophages with higher or lower resistance to intracellular survival of L. infantum. Secretion of TNF-α was higher in more resistant macrophages (designated as resistant) at 24h after infection when compared to less resistant macrophages (designated as susceptible), as well as the secretion of IFN-γ at 72 h post infection. Secretion of IL-10 was lower in resistant macrophages at 24h after infection. No detectable production of nitric oxide was observed. Interestingly, there was a negative correlation between NOD2 transcript levels and intracellular survival of L. infantum in resistant macrophages. This study demonstrated that decreased intracellular survival of L. infantum in canine macrophages was associated with increased production of TNF-α and IFN-γ and decreased production of IL-10; and that constitutive transcription of Nramp1, TLR and NLR does not interfere in intracellular survival of L. infantum. PMID:25466388

  3. Complement protein C1q directs macrophage polarization and limits inflammasome activity during the uptake of apoptotic cells

    PubMed Central

    Benoit, Marie E.; Clarke, Elizabeth V.; Morgado, Pedro; Fraser, Deborah A.; Tenner, Andrea J.

    2012-01-01

    Deficiency in C1q, the recognition component of the classical complement cascade and a pattern recognition receptor involved in apoptotic cell clearance, leads to lupus-like auto-immune diseases characterized by auto-antibodies to self proteins and aberrant innate immune cell activation likely due to impaired clearance of apoptotic cells. Here, we developed an autologous system using primary human lymphocytes and monocyte-derived macrophages (HMDMs) to characterize the effect of C1q on macrophage gene expression profiles during the uptake of apoptotic cells. C1q bound to autologous apoptotic lymphocytes modulated expression of genes associated with JAK/STAT signaling, chemotaxis, immunoregulation and NLRP3 inflammasome activation in LPS-stimulated HMDMs. Specifically, C1q sequentially induced type I interferons (IFNs), IL-27 and IL-10 in LPS-stimulated HMDMs and IL-27 in HMDMs when incubated with AL conditioned media. Co-incubation with C1q tails prevented the induction of type I IFNs and IL-27 in a dose dependent manner and neutralization of type I IFNs partially prevented IL-27 induction by C1q. Finally, C1q decreased procaspase-1 cleavage and caspase-1 dependent cleavage of IL-1β suggesting potent inhibitory effect of C1q on inflammasome activation. These results identify specific molecular pathways induced by C1q to suppress macrophage inflammation providing potential therapeutic targets to control macrophage polarization, and thus inflammation and autoimmunity. PMID:22523386

  4. Silencing Triggering Receptors Expressed on Myeloid Cells-1 Impaired the Inflammatory Response to Oxidized Low-Density Lipoprotein in Macrophages.

    PubMed

    Li, Houxuan; Hong, Feifei; Pan, Shengbo; Lei, Lang; Yan, Fuhua

    2016-02-01

    Atherosclerosis is a chronic progressive inflammatory disease characterized by the accumulation of lipid contents in arterial walls. Previous studies suggest participation of Toll-like receptors (TLRs) in lipid deposition and inflammatory response in vascular wall. The triggering receptor expressed on myeloid cells 1 (TREM-1) is a cell surface receptor of the immunoglobulin superfamily, which amplifies signal transduction of TLR pathway and enhances immune response to microbial infections. The aim of the present study was to investigate the effect of the oxidized low-density lipoprotein (oxLDL) on the expression of the TREM-1, as well as its engagement in proinflammatory cytokine production and foam cell formation in RAW264.7 mice macrophages. oxLDL enhanced TREM-1 and TLR-4, but not TLR-2 gene expression in macrophages; furthermore, silencing TREM-1 expression by short hairpin interfering RNA inhibited lipid phagocytosis and proinflammatory tumor necrosis factor-? (TNF-?) as well as interleukin-6 (IL-6) production in macrophages; moreover, application of synthetic antagonist, LP-17 polypeptide, reduced IL-6 production upon oxLDL stimulation in vitro and in vivo. In conclusion, in macrophages, oxLDL enhanced expression of TREM-1, which amplifies the innate immune response of TLR pathway; activation of TREM-1 contributes to atherogenesis process by enhancing proinflammatory cytokine production and foam cell formation. PMID:26277357

  5. Polyclonal immunoglobulin synthesis induced by a macrophage factor acting via T cells.

    PubMed Central

    Waldrep, J C; Reese, A C

    1981-01-01

    New Zealand White rabbits were killed 7 days after immunization with 1 mg of alum precipitated, keyhole limpet hemocyanin (KLH) into each hind footpad and 3 days after intraperitoneal injection of thioglycollate. When supernatants from cultures of purified, elicited macrophages were added to Mishell-Dutton cultures of primed popliteal lymphocytes, they induced synthesis of both general immunoglobulins and antibody specific for KLH. The active factor(s), polyclonal lymphocyte activator (PLA), appears to be a glycoprotein with a molecular weight between 150,000 and 200,000 daltons. Absorption with high concentrations of thymocytes but not bone marrow cells removed polyclonal stimulatory activity from peritoneal macrophage supernatants which contained PLA. Purified lymph-node B cells were stimulated by PLA only in the presence of T cells. In addition, supernatants from PLA activated, washed T cells were effective at inducing polyclonal B-cell activation. Thus, PLA appears to act indirectly on B cells by stimulating T cells to produce a soluble factor which induces polyclonal B-cell activation. Images Figure 2 PMID:6972349

  6. Inhibition of mast cell-dependent conversion of cultured macrophages into foam cells with antiallergic drugs.

    PubMed

    Ma, H; Kovanen, P T

    2000-12-01

    Degranulation of isolated, rat peritoneal mast cells in the presence of low density lipoprotein (LDL) induces cholesteryl ester accumulation in cocultured macrophages with ensuing foam cell formation. This event occurs when the macrophages phagocytose LDL particles that have been bound to the heparin proteoglycans of exocytosed granules. In an attempt to inhibit such foam cell formation pharmacologically, rat peritoneal mast cells that had been passively sensitized with anti-ovalbumin-IgE were treated with 2 mast cell-stabilizing antianaphylactic drugs, MY-1250 or disodium cromoglycate (DSCG). Both drugs were found to inhibit antigen (ovalbumin)-triggered release of histamine from the mast cells, revealing mast cell stabilization. In cocultures of rat peritoneal macrophages and passively sensitized mast cells, addition of MY-1250 before addition of the antigen resulted in parallel reductions in histamine release from mast cells, uptake of [(14)C]sucrose-LDL, and accumulation of LDL-derived cholesteryl esters in the cocultured macrophages. Similarly, when passively sensitized mast cells were stimulated with antigen in the presence of DSCG and the preconditioned media containing all substances released from the drug-treated mast cells were collected and added to macrophages cultured in LDL-containing medium, uptake and esterification of LDL cholesterol by the macrophages were inhibited. The inhibitory effects of both drugs were mast cell-specific because neither drug inhibited the ability of macrophages to take up and esterify LDL cholesterol. Analysis of heparin proteoglycan contents of the incubation media revealed that both drugs had inhibited mast cells from expelling their granule remnants. Thus, both MY-1250 and DSCG prevent mast cells from releasing the heparin proteoglycan-containing vehicles that bind LDL and carry it into macrophages. This study suggests that antiallergic pharmacological agents could be used in animal models to prevent mast cell-dependent formation of foam cells in vivo. PMID:11116078

  7. Sex hormone modulation of cell growth and apoptosis of the human monocytic/macrophage cell line

    PubMed Central

    Cutolo, Maurizio; Capellino, Silvia; Montagna, Paola; Ghiorzo, Paola; Sulli, Alberto; Villaggio, Barbara

    2005-01-01

    Sex hormones seem to modulate the immune/inflammatory responses by different mechanisms in female and male rheumatoid arthritis patients. The effects of 17β-oestradiol and of testosterone were tested on the cultured human monocytic/macrophage cell line (THP-1) activated with IFN-γ in order to investigate their role in cell proliferation and apoptosis. Activated human THP-1 cells were cultured in the presence of 17β-oestradiol and testosterone (final concentration, 10 nM). The evaluation of markers of cell proliferation included the NF-κB DNA-binding assay, the NF-κB inhibition complex, the proliferating cell nuclear antigen expression and the methyl-tetrazolium salt test. Apoptosis was detected by the annexin V-propidium assay and by the cleaved poly-ADP ribose polymerase expression. Specific methods included flow analysis cytometry scatter analysis, immunocytochemistry and western blot analysis. Cell growth inhibition and increased apoptosis were observed in testosterone-treated THP-1 cells. Increased poly-ADP ribose polymerase-cleaved expression and decreased proliferating cell nuclear antigen expression, as well as an increase of IκB-α and a decrease of the IκB-α phosphorylated form (ser 32), were found in testosterone-treated THP-1 cells. However, the NF-κB DNA binding was found increased in 17β-oestradiol-treated THP-1 cells. The treatment with staurosporine (enhancer of apoptosis) induced decreased NF-κB DNA binding in all conditions, but particularly in testosterone-treated THP-1 cells. Treatment of THP-1 by sex hormones was found to influence cell proliferation and apoptosis. Androgens were found to increase the apoptosis, and oestrogens showed a protective trend on cell death – both acting as modulators of the NF-κB complex. PMID:16207329

  8. Impact of Host Membrane Pore Formation by the Yersinia pseudotuberculosis Type III Secretion System on the Macrophage Innate Immune Response

    PubMed Central

    Kwuan, Laura; Adams, Walter

    2013-01-01

    Type III secretion systems (T3SSs) are used by Gram-negative pathogens to form pores in host membranes and deliver virulence-associated effector proteins inside host cells. In pathogenic Yersinia, the T3SS pore-forming proteins are YopB and YopD. Mammalian cells recognize the Yersinia T3SS, leading to a host response that includes secretion of the inflammatory cytokine interleukin-1β (IL-1β), Toll-like receptor (TLR)-independent expression of the stress-associated transcription factor Egr1 and the inflammatory cytokine tumor necrosis factor alpha (TNF-α), and host cell death. The known Yersinia T3SS effector proteins are dispensable for eliciting these responses, but YopB is essential. Three models describe how the Yersinia T3SS might trigger inflammation: (i) mammalian cells sense YopBD-mediated pore formation, (ii) innate immune stimuli gain access to the host cytoplasm through the YopBD pore, and/or (iii) the YopB-YopD translocon itself or its membrane insertion is proinflammatory. To test these models, we constructed a Yersinia pseudotuberculosis mutant expressing YopD devoid of its predicted transmembrane domain (YopDΔTM) and lacking the T3SS cargo proteins YopHEMOJTN. This mutant formed pores in macrophages, but it could not mediate translocation of effector proteins inside host cells. Importantly, this mutant did not elicit rapid host cell death, IL-1β secretion, or TLR-independent Egr1 and TNF-α expression. These data suggest that YopBD-mediated translocation of unknown T3SS cargo leads to activation of host pathways influencing inflammation, cell death, and response to stress. As the YopDΔTM Y. pseudotuberculosis mutant formed somewhat smaller pores with delayed kinetics, an alternative model is that the wild-type YopB-YopD translocon is specifically sensed by host cells. PMID:23297383

  9. Macrophage Contact Dependent and Independent TLR4 Mechanisms Induce ?-Cell Dysfunction and Apoptosis in a Mouse Model of Type 2 Diabetes

    PubMed Central

    Cucak, Helena; Mayer, Christopher; Tonnesen, Morten; Thomsen, Lise Hj; Grunnet, Lars Groth; Rosendahl, Alexander

    2014-01-01

    Type 2 diabetes (T2D) is evolving into a global disease and patients have a systemic low-grade inflammation, yet the role of this inflammation is still not established. One plausible mechanism is enhanced expression and activity of the innate immune system. Therefore, we evaluated the expression and the function of the toll-like receptor 4 (TLR4) on pancreatic ?-cells in primary mouse islets and on the murine ?-cell line MIN6 in the presence or absence of macrophages. Diabetic islets have 40% fewer TLR4 positive ?-cells, but twice the number of TLR4 positive macrophages as compared to healthy islets. Healthy and diabetic islets respond to a TLR4 challenge with enhanced production of cytokines (510-fold), while the TLR4 negative ?-cell line MIN6 fails to produce cytokines. TLR4 stimulation induces ?-cell dysfunction in mouse islets, measured as reduced glucose stimulated insulin secretion. Diabetic macrophages from 4-months old mice have acquired a transient enhanced capacity to produce cytokines when stimulated with LPS. Interestingly, this is lost in 6-months old diabetic mice. TLR4 activation alone does not induce apoptosis in islets or MIN-6 cells. In contrast, macrophages mediate TLR4-dependent cell-contact dependent (3-fold) as well as cell-contact independent (2-fold) apoptosis of both islets and MIN-6 cells. Importantly, diabetic macrophages have a significantly enhanced capacity to induce ?-cell apoptosis compared to healthy macrophages. Taken together, the TLR4 responsiveness is elevated in the diabetic islets and mainly mediated by newly recruited macrophages. The TLR4 positive macrophages, in both a cell-contact dependent and independent manner, induce apoptosis of ?-cells in a TLR4 dependent fashion and TLR4 activation directly induces ?-cell dysfunction. Thus, targeting either the TLR4 pathway or the macrophages provides a novel attractive treatment regime for T2D. PMID:24594974

  10. Lactic acid bacterial colonization and human rotavirus infection influence distribution and frequencies of monocytes/macrophages and dendritic cells in neonatal gnotobiotic pigs

    PubMed Central

    Zhang, Wei; Wen, Ke; Azevedo, Marli S.P.; Gonzalez, Ana; Saif, Linda J.; Li, Guohua; Yousef, Ahmed E.; Yuan, Lijuan

    2007-01-01

    Despite accumulating knowledge of porcine macrophages and dendritic cells (DCs) from in vitro studies, information regarding monocytes/macrophages and DCs in lymphoid tissues of enteric pathogen-infected neonatal animals in vivo is limited. In this study we evaluated the influence of commensal bacterial [two strains of lactic acid bacteria (LAB), Lactobacillus acidophilus and L. reuteri] colonization and rotavirus infection on distribution and frequencies of monocytes/macrophages and conventional DCs (cDCs) in ileum, spleen and blood. Gnotobiotic pigs were inoculated with LAB and virulent Wa strain human rotavirus (HRV) (LAB+HRV+), HRV only (LAB−HRV+), LAB only (LAB+HRV−) or mock (LAB−HRV−). The cDCs were characterized as SWC3+CD11R1+, whereas monocytes/macrophages were identified as SWC3+CD11R1− by flow cytometry in the gnotobiotic pigs at 10 days of age. Infection with HRV alone activated/recruited significantly more monocytes/macrophages to the intestine than LAB colonization and 56% versus 28% of these cells expressed CD14. Colonization with LAB alone also significantly increased the frequencies of monocytes/macrophages and cDCs and the CD14 expression on monocytes/macrophages in ileum and spleen compared to the controls. LAB colonization plus HRV infection significantly reduced macrophage and cDC frequencies in spleen compared to LAB colonization or HRV infection alone, suggesting that LAB colonization down-regulated HRV− infection-induced monocyte/macrophage activation/recruitment at the systemic lymphoid tissue. These results illustrated the distribution of porcine monocytes/macrophages and cDCs and the frequencies of CD14 expression on these cells in intestinal and systemic lymphoid tissues in the early stage of immune responses to intestinal colonization by LAB versus infection by an enteric pathogen HRV and will facilitate further in vivo studies on functional characterization of these immune cells in neonates. PMID:18006076

  11. Immune Cells of the Human Peripheral Taste System: Dominant Dendritic Cells and CD4 T-Cells

    PubMed Central

    Feng, Pu; Yee, Karen K.; Rawson, Nancy E.; Feldman, Lauren M.; Feldman, Roy S.; Breslin, Paul A. S.

    2009-01-01

    Taste loss or alterations can seriously impact health and quality of life due to the resulting negative influence on eating habits and nutrition. Infection and inflammation are thought to be some of the most common causes of taste perception disorders. Supporting this view, neuro-immune interactions in the peripheral gustatory system have been identified, underlying the importance of this tissue in mucosal immunity, but we have little understanding of how these interactions influence taste perception directly or indirectly. This limited understanding is evident by the lack of even a basic knowledge of the resident immune cell populations in or near taste tissues. The present study characterized the distribution and population of the major immune cells and their subsets in healthy human anterior, lingual, fungiform papillae (FP) using immunohistochemistry. Dendritic cells (DCs) were the predominant innate immune cells in this tissue, including four subtypes: CD11c+ DCs, DC-SIGN+ immature DCs, CD83+ mature DCs, and CD1a+ DCs (Langerhans cells). While most DCs were localized beneath the lamina propria and only moderately in the epithelium, CD1a + Langerhans cells were exclusively present within the epithelium and not in sub-strata. A small number of macrophages were observed. T lymphocytes were present throughout the FP with CD4+ T cells more prevalent than CD8+ T cells. Very few CD19+ B lymphocytes were detected. The results show that DCs, macrophages, and T lymphocytes are the constitutive guardians of human FP taste tissue, with DCs and CD4 T cells being dominant, while B lymphocytes are rare under normal, healthy conditions These observations provide a basic anatomical foundation for the immune response in the healthy human tongue as a basis for subsequent disease-related studies, but none of the present data indicate that the immune cell populations identified are, in fact, altered in individuals with abnormal taste perception. PMID:19268521

  12. Integrin CD11b positively regulates TLR4-induced signalling pathways in dendritic cells but not in macrophages

    NASA Astrophysics Data System (ADS)

    Ling, Guang Sheng; Bennett, Jason; Woollard, Kevin J.; Szajna, Marta; Fossati-Jimack, Liliane; Taylor, Philip R.; Scott, Diane; Franzoso, Guido; Cook, H. Terence; Botto, Marina

    2014-01-01

    Tuned and distinct responses of macrophages and dendritic cells to Toll-like receptor 4 (TLR4) activation induced by lipopolysaccharide (LPS) underpin the balance between innate and adaptive immunity. However, the molecule(s) that confer these cell-type-specific LPS-induced effects remain poorly understood. Here we report that the integrin αM (CD11b) positively regulates LPS-induced signalling pathways selectively in myeloid dendritic cells but not in macrophages. In dendritic cells, which express lower levels of CD14 and TLR4 than macrophages, CD11b promotes MyD88-dependent and MyD88-independent signalling pathways. In particular, in dendritic cells CD11b facilitates LPS-induced TLR4 endocytosis and is required for the subsequent signalling in the endosomes. Consistent with this, CD11b deficiency dampens dendritic cell-mediated TLR4-triggered responses in vivo leading to impaired T-cell activation. Thus, by modulating the trafficking and signalling functions of TLR4 in a cell-type-specific manner CD11b fine tunes the balance between adaptive and innate immune responses initiated by LPS.

  13. In vivo inhibition of c-MYC in myeloid cells impairs tumor-associated macrophage maturation and pro-tumoral activities.

    PubMed

    Pello, Oscar M; Chvre, Raphael; Laoui, Damya; De Juan, Alba; Lolo, Fidel; Andrs-Manzano, Mara Jess; Serrano, Manuel; Van Ginderachter, Jo A; Andrs, Vicente

    2012-01-01

    Although tumor-associated macrophages (TAMs) are involved in tumor growth and metastasis, the mechanisms controlling their pro-tumoral activities remain largely unknown. The transcription factor c-MYC has been recently shown to regulate in vitro human macrophage polarization and be expressed in macrophages infiltrating human tumors. In this study, we exploited the predominant expression of LysM in myeloid cells to generate c-Myc(fl/fl) LysM(cre/+) mice, which lack c-Myc in macrophages, to investigate the role of macrophage c-MYC expression in cancer. Under steady-state conditions, immune system parameters in c-Myc(fl/fl) LysM(cre/+) mice appeared normal, including the abundance of different subsets of bone marrow hematopoietic stem cells, precursors and circulating cells, macrophage density, and immune organ structure. In a model of melanoma, however, TAMs lacking c-Myc displayed a delay in maturation and showed an attenuation of pro-tumoral functions (e.g., reduced expression of VEGF, MMP9, and HIF1?) that was associated with impaired tissue remodeling and angiogenesis and limited tumor growth in c-Myc(fl/fl) LysM(cre/+) mice. Macrophage c-Myc deletion also diminished fibrosarcoma growth. These data identify c-Myc as a positive regulator of the pro-tumoral program of TAMs and suggest c-Myc inactivation as an attractive target for anti-cancer therapy. PMID:23028984

  14. In Vivo Inhibition of c-MYC in Myeloid Cells Impairs Tumor-Associated Macrophage Maturation and Pro-Tumoral Activities

    PubMed Central

    Pello, Oscar M.; De Juan, Alba; Lolo, Fidel; Andrés-Manzano, María Jesús; Serrano, Manuel; Van Ginderachter, Jo A.; Andrés, Vicente

    2012-01-01

    Although tumor-associated macrophages (TAMs) are involved in tumor growth and metastasis, the mechanisms controlling their pro-tumoral activities remain largely unknown. The transcription factor c-MYC has been recently shown to regulate in vitro human macrophage polarization and be expressed in macrophages infiltrating human tumors. In this study, we exploited the predominant expression of LysM in myeloid cells to generate c-Mycfl/fl LysMcre/+ mice, which lack c-Myc in macrophages, to investigate the role of macrophage c-MYC expression in cancer. Under steady-state conditions, immune system parameters in c-Mycfl/fl LysMcre/+ mice appeared normal, including the abundance of different subsets of bone marrow hematopoietic stem cells, precursors and circulating cells, macrophage density, and immune organ structure. In a model of melanoma, however, TAMs lacking c-Myc displayed a delay in maturation and showed an attenuation of pro-tumoral functions (e.g., reduced expression of VEGF, MMP9, and HIF1α) that was associated with impaired tissue remodeling and angiogenesis and limited tumor growth in c-Mycfl/fl LysMcre/+ mice. Macrophage c-Myc deletion also diminished fibrosarcoma growth. These data identify c-Myc as a positive regulator of the pro-tumoral program of TAMs and suggest c-Myc inactivation as an attractive target for anti-cancer therapy. PMID:23028984

  15. Riboflavin deprivation inhibits macrophage viability and activity - a study on the RAW 264.7 cell line.

    PubMed

    Mazur-Bialy, Agnieszka Irena; Buchala, Beata; Plytycz, Barbara

    2013-08-28

    Riboflavin, or vitamin B2, as a precursor of the coenzymes FAD and FMN, has an indirect influence on many metabolic processes and determines the proper functioning of several systems, including the immune system. In the human population, plasma riboflavin concentration varies from 31 nM (in a moderate deficiency, e.g. in pregnant women) to 104 nM (in healthy adults) and 300 nM (in cases of riboflavin supplementation). The purpose of the present study was to investigate the effects of riboflavin concentration on the activity and viability of macrophages, i.e. on one of the immunocompetent cell populations. The study was performed on the murine monocyte/macrophage RAW 264.7 cell line cultured in medium with various riboflavin concentrations (31, 104, 300 and 531 nM). The results show that riboflavin deprivation has negative effects on both the activity and viability of macrophages and reduces their ability to generate an immune response. Signs of riboflavin deficiency developed in RAW 264.7 cells within 4 d of culture in the medium with a low riboflavin concentration (31 nM). In particular, the low riboflavin content reduced the proliferation rate and enhanced apoptotic cell death connected with the release of lactate dehydrogenase. The riboflavin deprivation impaired cell adhesion, completely inhibited the respiratory burst and slightly impaired phagocytosis of the zymosan particles. In conclusion, macrophages are sensitive to riboflavin deficiency; thus, a low riboflavin intake in the diet may affect the immune system and may consequently decrease proper host immune defence. PMID:23415257

  16. Mycobacterium abscessus activates the macrophage innate immune response via a physical and functional interaction between TLR2 and dectin-1.

    PubMed

    Shin, Dong-Min; Yang, Chul-Su; Yuk, Jae-Min; Lee, Ji-Yeon; Kim, Ki Hye; Shin, Sung Jae; Takahara, Kazuhiko; Lee, Sung Joong; Jo, Eun-Kyeong

    2008-08-01

    Mycobacterium abscessus (Mab) is an emerging and rapidly growing non-tuberculous mycobacterium (NTM). Compared with M. tuberculosis, which is responsible for tuberculosis, much less is known about NTM-induced innate immune mechanisms. Here we investigated the involvement of pattern-recognition receptors and associated signalling in Mab-mediated innate immune responses. Mab activated the extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinases (MAPKs), and induced the secretion of tumour necrosis factor-alpha, interleukin (IL)-6 and IL-12p40 in murine macrophages via Toll-like receptor (TLR) 2. Notably, the activation of ERK1/2, but not p38, was crucial for Mab-induced pro-inflammatory cytokine production. The ITAM-like motif of dectin-1 critically contributed to Mab internalization and cytokine secretion by macrophages. In addition, dectin-1, in cooperation with TLR2, was required for the efficient phagocytosis of Mab, ERK1/2 activation and pro-inflammatory cytokine secretion. Co-immunoprecipitation and confocal analysis showed the physical interaction and colocalization of dectin-1 with TLR2 following Mab stimulation. Moreover, dectin-1-induced Syk activation was essential for the production of inflammatory cytokines and the release of reactive oxygen species by Mab-infected macrophages. Collectively, these data demonstrate that Mab actively internalizes into and robustly activates innate immune responses in macrophages through a physical and functional interaction between TLR2 and dectin-1. PMID:18373632

  17. TPL-2 negatively regulates interferon-β production in macrophages and myeloid dendritic cells

    PubMed Central

    Kaiser, Frank; Cook, Dorthe; Papoutsopoulou, Stamatia; Rajsbaum, Ricardo; Wu, Xuemei; Yang, Huei-Ting; Grant, Susan; Ricciardi-Castagnoli, Paola; Tsichlis, Philip N.; O'Garra, Anne

    2009-01-01

    Stimulation of Toll-like receptors (TLRs) on macrophages and dendritic cells (DCs) by pathogen-derived products induces the production of cytokines, which play an important role in immune responses. Here, we investigated the role of the TPL-2 signaling pathway in TLR induction of interferon-β (IFN-β) and interleukin-10 (IL-10) in these cell types. It has previously been suggested that IFN-β and IL-10 are coordinately regulated after TLR stimulation. However, in the absence of TPL-2 signaling, lipopolysaccharide (TLR4) and CpG (TLR9) stimulation resulted in increased production of IFN-β while decreasing IL-10 production by both macrophages and myeloid DCs. In contrast, CpG induction of both IFN-α and IFN-β by plasmacytoid DCs was decreased in the absence of TPL-2, although extracellular signal-regulated kinase (ERK) activation was blocked. Extracellular signal-related kinase–dependent negative regulation of IFN-β in macrophages was IL-10–independent, required protein synthesis, and was recapitulated in TPL-2–deficient myeloid DCs by retroviral transduction of the ERK-dependent transcription factor c-fos. PMID:19667062

  18. Mycobacterial infection primes T cells and macrophages for enhanced recruitment of neutrophils.

    PubMed

    Appelberg, R

    1992-05-01

    C57BL/6 mice intraperitoneally infected with Mycobacterium bovis BCG (substrain Pasteur) recruited significantly higher numbers of neutrophils after an intraperitoneal inoculation of either BCG protein antigen or of endotoxin than uninfected control mice. Antigen-induced neutrophil recruitment was mediated by T cells of both CD4+ and CD8+ phenotype and was also observed in the C5-deficient DBA/2 mouse strain. The adoptive transfer of immune serum did not prime mice for enhanced antigen-mediated recruitment of neutrophils. The endotoxin-mediated recruitment of neutrophils was also enhanced in infected as compared to uninfected DBA/2 mice. Finally, endotoxin-pulsed purified macrophages from infected C57BL/6 mice recruited higher numbers of neutrophils than endotoxin-pulsed macrophages from normal mice in an adoptive transfer to peritoneal cavities of naive recipient mice. These data show that during mycobacterial infection, T cells and macrophages are primed for recruitment of neutrophils after being triggered in specific or nonspecific ways. This may represent a means to cope with secondary infections by allowing for extensive neutrophil infiltration readily upon microbial challenge. PMID:1376352

  19. Integrated regulation of the cellular metabolism and function of immune cells in adipose tissue.

    PubMed

    Oishi, Yumiko; Manabe, Ichiro

    2016-03-01

    Obesity is known to associate with low-grade, sustained, systemic inflammation, which is considered to be a key pathological basis for obesity-associated diseases such as diabetes and atherosclerosis. Immune cells, including both lymphocytes and macrophages, play physiological and pathological roles in adipose tissue. They increasingly infiltrate obese adipose tissue as body weight is gained, after which the infiltrated cells promote adipose tissue inflammation and strongly impact systemic metabolism. Recent studies have shown that the immune and metabolic systems are highly integrated with one another. This recognition has provided new insight into the mechanisms of metabolic diseases. In addition to the link at the tissue level, studies have shown that immune cell function is coordinately regulated with cellular metabolism. This review summarizes the current understanding of the specific metabolic signatures adopted by lymphocytes and macrophages to mediate proper effecter function. These findings will be related to the regulation of adipose tissue homeostasis and inflammation. PMID:26728525

  20. Macrophages eat cancer cells using their own calreticulin as a guide: Roles of TLR and Btk

    PubMed Central

    Feng, Mingye; Chen, James Y.; Weissman-Tsukamoto, Rachel; Volkmer, Jens-Peter; Ho, Po Yi; McKenna, Kelly M.; Cheshier, Samuel; Zhang, Michael; Guo, Nan; Gip, Phung; Mitra, Siddhartha S.; Weissman, Irving L.

    2015-01-01

    Macrophage-mediated programmed cell removal (PrCR) is an important mechanism of eliminating diseased and damaged cells before programmed cell death. The induction of PrCR by eat-me signals on tumor cells is countered by don’t-eat-me signals such as CD47, which binds macrophage signal-regulatory protein α to inhibit phagocytosis. Blockade of CD47 on tumor cells leads to phagocytosis by macrophages. Here we demonstrate that the activation of Toll-like receptor (TLR) signaling pathways in macrophages synergizes with blocking CD47 on tumor cells to enhance PrCR. Bruton’s tyrosine kinase (Btk) mediates TLR signaling in macrophages. Calreticulin, previously shown to be an eat-me signal on cancer cells, is activated in macrophages for secretion and cell-surface exposure by TLR and Btk to target cancer cells for phagocytosis, even if the cancer cells themselves do not express calreticulin. PMID:25646432

  1. Macrophages eat cancer cells using their own calreticulin as a guide: roles of TLR and Btk.

    PubMed

    Feng, Mingye; Chen, James Y; Weissman-Tsukamoto, Rachel; Volkmer, Jens-Peter; Ho, Po Yi; McKenna, Kelly M; Cheshier, Samuel; Zhang, Michael; Guo, Nan; Gip, Phung; Mitra, Siddhartha S; Weissman, Irving L

    2015-02-17

    Macrophage-mediated programmed cell removal (PrCR) is an important mechanism of eliminating diseased and damaged cells before programmed cell death. The induction of PrCR by eat-me signals on tumor cells is countered by don't-eat-me signals such as CD47, which binds macrophage signal-regulatory protein α to inhibit phagocytosis. Blockade of CD47 on tumor cells leads to phagocytosis by macrophages. Here we demonstrate that the activation of Toll-like receptor (TLR) signaling pathways in macrophages synergizes with blocking CD47 on tumor cells to enhance PrCR. Bruton's tyrosine kinase (Btk) mediates TLR signaling in macrophages. Calreticulin, previously shown to be an eat-me signal on cancer cells, is activated in macrophages for secretion and cell-surface exposure by TLR and Btk to target cancer cells for phagocytosis, even if the cancer cells themselves do not express calreticulin. PMID:25646432

  2. Mesenchymal stem cells reciprocally regulate the M1/M2 balance in mouse bone marrow-derived macrophages.

    PubMed

    Cho, Dong-Im; Kim, Mi Ra; Jeong, Hye-yun; Jeong, Hae Chang; Jeong, Myung Ho; Yoon, Sung Ho; Kim, Yong Sook; Ahn, Youngkeun

    2014-01-01

    Mesenchymal stem cells (MSCs) have been widely studied for their applications in stem cell-based regeneration. During myocardial infarction (MI), infiltrated macrophages have pivotal roles in inflammation, angiogenesis and cardiac remodeling. We hypothesized that MSCs may modulate the immunologic environment to accelerate regeneration. This study was designed to assess the functional relationship between the macrophage phenotype and MSCs. MSCs isolated from bone marrow and bone marrow-derived macrophages (BMDMs) underwent differentiation induced by macrophage colony-stimulating factor. To determine the macrophage phenotype, classical M1 markers and alternative M2 markers were analyzed with or without co-culturing with MSCs in a transwell system. For animal studies, MI was induced by the ligation of the rat coronary artery. MSCs were injected within the infarct myocardium, and we analyzed the phenotype of the infiltrated macrophages by immunostaining. In the MSC-injected myocardium, the macrophages adjacent to the MSCs showed strong expression of arginase-1 (Arg1), an M2 marker. In BMDMs co-cultured with MSCs, the M1 markers such as interleukin-6 (IL-6), IL-1β, monocyte chemoattractant protein-1 and inducible nitric oxide synthase (iNOS) were significantly reduced. In contrast, the M2 markers such as IL-10, IL-4, CD206 and Arg1 were markedly increased by co-culturing with MSCs. Specifically, the ratio of iNOS to Arg1 in BMDMs was notably downregulated by co-culturing with MSCs. These results suggest that the preferential shift of the macrophage phenotype from M1 to M2 may be related to the immune-modulating characteristics of MSCs that contribute to cardiac repair. PMID:24406319

  3. Bisphosphonates target B cells to enhance humoral immune responses

    PubMed Central

    Tonti, Elena; Jiménez de Oya, Nereida; Galliverti, Gabriele; Moseman, E. Ashley; Di Lucia, Pietro; Amabile, Angelo; Sammicheli, Stefano; De Giovanni, Marco; Sironi, Laura; Chevrier, Nicolas; Sitia, Giovanni; Gennari, Luigi; Guidotti, Luca G.; von Andrian, Ulrich H.; Iannacone, Matteo

    2013-01-01

    Summary Bisphosphonates are a class of drugs that are widely used to inhibit loss of bone mass in patients. We show here that the administration of clinically relevant doses of bisphosphonates in mice increases antibody responses to live and inactive viruses, proteins, haptens and existing commercial vaccine formulations. Bisphosphonates exert this adjuvant-like activity in the absence of CD4+ and γδ T cells, neutrophils or dendritic cells and their effect does not rely on local macrophage depletion nor does it depend upon Toll-like receptor signaling or the inflammasome. Rather, bisphosphonates target directly B cells and enhance B cell expansion and antibody production upon antigen encounter. These data establish bisphosphonates as a novel class of adjuvants that boost humoral immune responses. PMID:24120862

  4. Bisphosphonates target B cells to enhance humoral immune responses.

    PubMed

    Tonti, Elena; Jiménez de Oya, Nereida; Galliverti, Gabriele; Moseman, E Ashley; Di Lucia, Pietro; Amabile, Angelo; Sammicheli, Stefano; De Giovanni, Marco; Sironi, Laura; Chevrier, Nicolas; Sitia, Giovanni; Gennari, Luigi; Guidotti, Luca G; von Andrian, Ulrich H; Iannacone, Matteo

    2013-10-31

    Bisphosphonates are a class of drugs that are widely used to inhibit loss of bone mass in patients. We show here that the administration of clinically relevant doses of bisphosphonates in mice increases antibody responses to live and inactive viruses, proteins, haptens, and existing commercial vaccine formulations. Bisphosphonates exert this adjuvant-like activity in the absence of CD4(+) and γδ T cells, neutrophils, or dendritic cells, and their effect does not rely on local macrophage depletion, Toll-like receptor signaling, or the inflammasome. Rather, bisphosphonates target directly B cells and enhance B cell expansion and antibody production upon antigen encounter. These data establish bisphosphonates as an additional class of adjuvants that boost humoral immune responses. PMID:24120862

  5. Mesenchymal stem cells: immune evasive, not immune privileged

    PubMed Central

    Ankrum, James A.; Ong, Joon Faii; Karp, Jeffrey M.

    2014-01-01

    The diverse immunomodulatory properties of mesenchymal stem/stromal cells (MSCs) may be exploited for treatment of a multitude of inflammatory conditions. MSCs have long been reported to be hypoimmunogenic or ‘immune privileged’; this property is thought to enable MSC transplantation across major histocompatibility barriers and the creation of off-the-shelf therapies consisting of MSCs grown in culture. However, recent studies describing generation of antibodies against and immune rejection of allogeneic donor MSCs suggest that MSCs may not actually be immune privileged. Nevertheless, whether rejection of donor MSCs influences the efficacy of allogeneic MSC therapies is not known, and no definitive clinical advantage of autologous MSCs over allogeneic MSCs has been demonstrated to date. Although MSCs may exert therapeutic function through a brief ‘hit and run’ mechanism, protecting MSCs from immune detection and prolonging their persistence in vivo may improve clinical outcomes and prevent patient sensitization toward donor antigens. PMID:24561556

  6. TGF-β1-Induced Epithelial–Mesenchymal Transition Promotes Monocyte/Macrophage Properties in Breast Cancer Cells

    PubMed Central

    Johansson, Joel; Tabor, Vedrana; Wikell, Anna; Jalkanen, Sirpa; Fuxe, Jonas

    2015-01-01

    Breast cancer progression toward metastatic disease is linked to re-activation of epithelial–mesenchymal transition (EMT), a latent developmental process. Breast cancer cells undergoing EMT lose epithelial characteristics and gain the capacity to invade the surrounding tissue and migrate away from the primary tumor. However, less is known about the possible role of EMT in providing cancer cells with properties that allow them to traffic to distant sites. Given the fact that pro-metastatic cancer cells share a unique capacity with immune cells to traffic in-and-out of blood and lymphatic vessels we hypothesized that tumor cells undergoing EMT may acquire properties of immune cells. To study this, we performed gene-profiling analysis of mouse mammary EpRas tumor cells that had been allowed to adopt an EMT program after long-term treatment with TGF-β1 for 2 weeks. As expected, EMT cells acquired traits of mesenchymal cell differentiation and migration. However, in addition, we found another cluster of induced genes, which was specifically enriched in monocyte-derived macrophages, mast cells, and myeloid dendritic cells, but less in other types of immune cells. Further studies revealed that this monocyte/macrophage gene cluster was enriched in human breast cancer cell lines displaying an EMT or a Basal B profile, and in human breast tumors with EMT and undifferentiated (ER−/PR−) characteristics. The results identify an EMT-induced monocyte/macrophage gene cluster, which may play a role in breast cancer cell dissemination and metastasis. PMID:25674539

  7. Cell-mediated immune phenomena induced by lymphokines from splenic lymphocytes of mice with chronic staphylococcal infection.

    PubMed Central

    Baughin, R E; Bonventre, P F

    1975-01-01

    Splenic lymphocytes from normal mice and from mice displaying delayed hypersensitivity to Staphylococcus aureus were cultured in the presence or absence of specific staphylococcal antigens. The cell-free supernatant fluids from these lymphocyte cultures were assessed for their ability to alter the functional capacities of normal macrophages. It was found that supernatants from staphylococcus-immune cells cultured in vitro with antigen possessed migration inhibitory factor activity and also were capable of stimulating the incorporation of [14C]glucosamine into macrophage membrane glycoproteins. In addition, the lymphokine-containing supernatants were capable of inducing activation of normal macrophages so that they inhibited the multiplication of intracellular Listeria monocytogenes. Although it was not possible to snow any significant enhancement of intracellular killing of S. aureus by the activated macrophages, evidence is presented that suggests that cell-mediated immune responses to S. aureus may significantly enhance pahgocytosis of staphylococci and, thereby, may provide for their rapid clearance from extracellular fluids. PMID:803469

  8. Presence of T cells and macrophages in inflammatory vitiligo skin parallels melanocyte disappearance.

    PubMed Central

    Le Poole, I. C.; van den Wijngaard, R. M.; Westerhof, W.; Das, P. K.

    1996-01-01

    Evidence for the involvement of cellular immunity in the etiopathogenesis of the hypopigmentary disorder vitiligo is provided by rare cases of inflammatory vitiligo. Nonlesional, perilesional, and lesional skin biopsies from three inflammatory vitiligo patients were immunohistochemically analyzed. The composition of inflammatory infiltrates present in perilesional skin was analyzed by antibodies to T cells (CD2, CD3, CD4, and CD8), Langerhans cells (CD1a), and macrophages (CD36 and CD68). The presence of activation markers on inflammatory cells was evaluated by analysis of HLA-DR, interleukin-2 receptor, and HECA452 expression. The presence or absence of melanocytes was determined by the antibody NKI-beteb. Moreover, the abundance of matrix molecule tenascin was semi-quantified using T2H5. Results indicate that within perilesional skin, epidermis-infiltrating T cells exhibit an increased CD8/CD4 ratio and increased cutaneous lymphocyte antigen and interleukin-2 receptor expression. These cells are frequently juxtapositionally apposed to remaining melanocytes. In perilesional dermis, CD68+OKM5- macrophages were more numerous than in lesional or nonlesional skin. Keratinocytes as well as melanocytes consistently express major histocompatibility complex class II antigens along stretches of basal and suprabasal layers in perilesional epidermis. Moreover, inflammation is accompanied by increased tenascin content. Although these observations do not permit differentiation between the immune infiltrates being a result as opposed to the cause of the disease process, results presented in this study are very suggestive of involvement of local immune reactivity in melanocyte destruction. Images Figure 1 Figure 4 Figure 8 Figure 9 PMID:8644862

  9. Inflammatory features of pancreatic cancer highlighted by monocytes/macrophages and CD4+ T cells with clinical impact

    PubMed Central

    Komura, Takuya; Sakai, Yoshio; Harada, Kenichi; Kawaguchi, Kazunori; Takabatake, Hisashi; Kitagawa, Hirohisa; Wada, Takashi; Honda, Masao; Ohta, Tetsuo; Nakanuma, Yasuni; Kaneko, Shuichi

    2015-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is among the most fatal of malignancies with an extremely poor prognosis. The objectives of this study were to provide a detailed understanding of PDAC pathophysiology in view of the host immune response. We examined the PDAC tissues, sera, and peripheral blood cells of PDAC patients using immunohistochemical staining, the measurement of cytokine/chemokine concentrations, gene expression analysis, and flow cytometry. The PDAC tissues were infiltrated by macrophages, especially CD33+CD163+ M2 macrophages and CD4+ T cells that concomitantly express programmed cell death-1 (PD-1). Concentrations of interleukin (IL)-6, IL-7, IL-15, monocyte chemotactic protein-1, and interferon-γ-inducible protein-1 in the sera of PDAC patients were significantly elevated. The gene expression profile of CD14+ monocytes and CD4+ T cells was discernible between PDAC patients and healthy volunteers, and the differentially expressed genes were related to activated inflammation. Intriguingly, PD-1 was significantly upregulated in the peripheral blood CD4+ T cells of PDAC patients. Correspondingly, the frequency of CD4+PD-1+ T cells was increased in the peripheral blood cells of PDAC patients, and this increase correlated to chemotherapy resistance. In conclusion, inflammatory conditions in both PDAC tissue and peripheral blood cells in PDAC patients were prominent, highlighting monocytes/macrophages as well as CD4+ T cells with influence of the clinical prognosis. We examined the inflammatory features of PDAC patients using the PDAC tissues, sera, and peripheral blood by immunohistochemical staining, measurement of cytokines/chemokines, gene expression analysis, and flow cytometry. We foundg that monocyte/macrophage cells and CD4+ T cells were highlighted immune-mediating cells in local cancer tissue as well as in peripheral blood of PDAC patients, among which the important subfraction with clinical impact influencing PDAC prognosis by chemotherapy was involved. PMID:25827621

  10. Biosynthesis of anandamide and related acylethanolamides in mouse J774 macrophages and N18 neuroblastoma cells.

    PubMed Central

    Di Marzo, V; De Petrocellis, L; Sepe, N; Buono, A

    1996-01-01

    Anandamide (arachidonoylethanolamide, AnNH) has been recently proposed as the endogenous ligand at the brain cannabinoid receptor CB1. Two alternative pathways have been suggested for the biosynthesis of this putative mediator in the central nervous system. Here we present data (1) substantiating further the mechanism by which AnNH is produced by phospholipase D (PLD)-catalysed hydrolysis of N-arachidonoylphosphatidylethanolamine in mouse neuroblastoma N18TG2 cells, and (2) suggesting for the first time that AnNH is biosynthesized via the same mechanism in a non-neuronal cell line, mouse J774 macrophages, together with other acylethanolamides and is possibly involved in the control of the immune/inflammatory response. Lipids from both neuroblastoma cells and J774 macrophages were shown to contain a family of N-acylphosphatidylethanolamines (N-aPEs), including the possible precursor of AnNH, N-arachidonoyl-PE. Treatment with exogenous PLD, but not with exogenous phospholipase A2 and ethanolamine, resulted in the production of a series of acylethanolamides (AEs), including AnNH, from both cell types. The formation of AEs was accompanied by a decrease in the levels of the corresponding N-aPEs. Enzymically active homogenates from either neuroblastoma cells or J774 macrophages were shown to convert synthetic N-[3H]arachidonoyl-PE into [3H]AnNH, thus suggesting that in both cells an enzyme is present which is capable of catalysing the hydrolysis of N-aPE(s) to the corresponding AE(s). Finally, as previously shown in central neurons, on stimulation with ionomycin, J774 macrophages also produced a mixture of AEs including AnNH and palmitoylethanolamide, which has been proposed as the preferential endogenous ligand at the peripheral cannabinoid receptor CB2 and, consequently, as a possible down-modulator of mast cells. On the basis of this as well as previous findings it is now possible to hypothesize for AnNH and palmitoylethanolamide, co-synthesized by macrophages, a role as peripheral mediators with multiple actions on blood cell function. PMID:8670178

  11. Effect of acute nutritional deprivation on macrophage colony-stimulating factor and macrophage progenitor cells in mice.

    PubMed Central

    Wing, E J; Barczynski, L K; Sherbondy, J M

    1986-01-01

    The effect of short-term nutritional deprivation on host defenses and on the parameters of macrophage production was determined in outbred mice. Confirming previous data from this laboratory, initial experiments demonstrated that starved mice were relatively resistant to infection by Listeria monocytogenes as determined by spleen and liver bacterial counts. The number of macrophage progenitor cells in bone marrow rose slightly during a 72-h starvation period and returned to normal during refeeding. By contrast, the number of progenitor cells in spleens fell to 12% of the base line during starvation. The concentration of the macrophage colony-stimulating factor in serum decreased during starvation and returned to normal during refeeding. Additional experiments were performed to determine whether starved mice had increased parameters of macrophage production during listerial infection. The number of progenitor cells in the bone marrow and spleens of starved mice had increased compared with that of fed mice early in infection. Macrophage colony-stimulating factor levels in starved mice rose early and remained elevated during infection but were not as high as in fed mice. These data document the changes in the parameters of monocyte production during starvation and suggest that the number of macrophage progenitor cells may be related to increased resistance to L. monocytogenes. PMID:3489677

  12. An in vitro one-dimensional assay to study growth factor-regulated tumor cell-macrophage interaction.

    PubMed

    Sharma, Ved P; Beaty, Brian T; Cox, Dianne; Condeelis, John S; Eddy, Robert J

    2014-01-01

    Growth factor-dependent pairing and motility between tumor cells and tumor-associated macrophages on extracellular matrix (ECM) fibers of the tumor microenvironment have been shown to enhance intravasation and metastatic spread of breast carcinomas. We describe an in vitro motility assay that combines time-lapse wide-field microscopy and micro-patterned linear adhesive substrates to reconstitute the in vivo behavior between macrophages, tumor cells, and ECM fibers in orthotopic rodent tumor models observed by intravital imaging. Commercially available linear stripes of 650 nm dye-labeled fibronectin microlithographed onto glass cover slips are sequentially plated with fluorescently labeled MTLn3 tumor cells and bone marrow-derived macrophages and time-lapse imaged for up to 8 h. Incubation with pharmacological inhibitors during the assay can identify important paracrine or autocrine signaling pathways involved in the macrophage-tumor cell interaction. This high-resolution motility assay will lead to a more detailed description of immune cell-tumor cell behavior as well as interrogating additional cell types within the tumor microenvironment which use cytokine/growth factor paracrine signaling interactions to facilitate intravasation and metastasis. PMID:24908299

  13. Macrophage and Innate Lymphoid Cell Interplay in the Genesis of Fibrosis

    PubMed Central

    Hams, Emily; Bermingham, Rachel; Fallon, Padraic G.

    2015-01-01

    Fibrosis is a characteristic pathological feature of an array of chronic diseases, where development of fibrosis in tissue can lead to marked alterations in the architecture of the affected organs. As a result of this process of sustained attrition to organs, many diseases that involve fibrosis are often progressive conditions and have a poor long-term prognosis. Inflammation is often a prelude to fibrosis, with innate and adaptive immunity involved in both the initiation and regulation of the fibrotic process. In this review, we will focus on the emerging roles of the newly described innate lymphoid cells (ILCs) in the generation of fibrotic disease with an examination of the potential interplay between ILC and macrophages and the adaptive immune system. PMID:26635811

  14. Expression of CD200 by macrophage-like cells in ischemic core of rat brain after transient middle cerebral artery occlusion.

    PubMed

    Matsumoto, Hiroaki; Kumon, Yoshiaki; Watanabe, Hideaki; Ohnishi, Takanori; Takahashi, Hisaaki; Imai, Yoshinori; Tanaka, Junya

    2007-05-11

    Brain ischemia causes the death of neurons and glial cells. Such brain cells are believed to inevitably undergo degeneration in the core of ischemic lesions, whereas neurons and glial cells may survive in the region surrounding the core that is often referred to as the ischemic penumbra. However, many cells, particularly immune cells infiltrate and survive in the core. In this study, we characterized macrophage-like cells that accumulated in the ischemic core of a rat brain whose right middle cerebral artery was transiently occluded for 90 min. At 7 days post-reperfusion, we observed macrophage-like cells expressing CD200, a cell surface glycoprotein belonging to an immunoglobulin superfamily and that elicits suppressive effects on myeloid cells including microglia by interacting with the CD200 receptor (CD200R). RT-PCR and immunoblot analyses revealed the presence of CD200-mRNA and protein in the ischemic core as well as in the contralateral region. As revealed by immunohistochemistry, CD200 is located on the cell membrane of spherical Iba1(+) cells with many cytoplasmic granules. CD200(-)/Iba1(+) macrophage-like cells were also present, which have a more irregular shape than CD200(+)/Iba1(+) cells. CD200 was detected in isolated spherical Iba1(+) macrophage-like cells. Thus, CD200 is expressed in some populations of macrophage-like cells that may be responsible for the suppression of CD200R(+) myeloid cell functions in the ischemic core. PMID:17403569

  15. Cytotoxic macrophage-released tumour necrosis factor-alpha (TNF-α) as a killing mechanism for cancer cell death after cold plasma activation

    NASA Astrophysics Data System (ADS)

    Kaushik, Nagendra Kumar; Kaushik, Neha; Min, Booki; Choi, Ki Hong; Hong, Young June; Miller, Vandana; Fridman, Alexander; Choi, Eun Ha

    2016-03-01

    The present study aims at studying the anticancer role of cold plasma-activated immune cells. The direct anti-cancer activity of plasma-activated immune cells against human solid cancers has not been described so far. Hence, we assessed the effect of plasma-treated RAW264.7 macrophages on cancer cell growth after co-culture. In particular, flow cytometer analysis revealed that plasma did not induce any cell death in RAW264.7 macrophages. Interestingly, immunofluorescence and western blot analysis confirmed that TNF-α released from plasma-activated macrophages acts as a tumour cell death inducer. In support of these findings, activated macrophages down-regulated the cell growth in solid cancer cell lines and induced cell death in vitro. Together our findings suggest plasma-induced reactive species recruit cytotoxic macrophages to release TNF-α, which blocks cancer cell growth and can have the potential to contribute to reducing tumour growth in vivo in the near future.

  16. Immune Homeostatic Macrophages Programmed by the Bacterial Surface Protein NhhA Potentiate Nasopharyngeal Carriage of Neisseria meningitidis

    PubMed Central

    Wang, Xiao; Sjölinder, Mikael; Gao, Yumin; Wan, Yi

    2016-01-01

    ABSTRACT Neisseria meningitidis colonizes the nasopharyngeal mucosa of healthy populations asymptomatically, although the bacterial surface is rich in motifs that activate the host innate immunity. What determines the tolerant host response to this bacterium in asymptomatic carriers is poorly understood. We demonstrated that the conserved meningococcal surface protein NhhA orchestrates monocyte (Mo) differentiation specifically into macrophage-like cells with a CD200Rhi phenotype (NhhA-Mφ). In response to meningococcal stimulation, NhhA-Mφ failed to produce proinflammatory mediators. Instead, they upregulated interleukin-10 (IL-10) and Th2/regulatory T cell (Treg)-attracting chemokines, such as CCL17, CCL18, and CCL22. Moreover, NhhA-Mφ were highly efficient in eliminating bacteria. The in vivo validity of these findings was corroborated using a murine model challenged with N. meningitidis systematically or intranasally. The NhhA-modulated immune response protected mice from septic shock; Mo/Mφ depletion abolished this protective effect. Intranasal administration of NhhA induced an anti-inflammatory response, which was associated with N. meningitidis persistence at the nasopharynx. In vitro studies demonstrated that NhhA-triggered Mo differentiation occurred upon engaged Toll-like receptor 1 (TLR1)/TLR2 signaling and extracellular signal-regulated kinase (ERK) and Jun N-terminal protein kinase (JNK) activation and required endogenously produced IL-10 and tumor necrosis factor alpha (TNF-α). Our findings reveal a strategy that might be adopted by N. meningitidis to maintain asymptomatic nasopharyngeal colonization. PMID:26884432

  17. 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

  18. Steroid Hormone Signaling Is Essential to Regulate Innate Immune Cells and Fight Bacterial Infection in Drosophila

    PubMed Central

    Regan, Jennifer C.; Brando, Ana S.; Leito, Alexandre B.; Mantas Dias, ngela Raquel; Sucena, lio; Jacinto, Antnio; Zaidman-Rmy, Anna

    2013-01-01

    Coupling immunity and development is essential to ensure survival despite changing internal conditions in the organism. Drosophila metamorphosis represents a striking example of drastic and systemic physiological changes that need to be integrated with the innate immune system. However, nothing is known about the mechanisms that coordinate development and immune cell activity in the transition from larva to adult. Here, we reveal that regulation of macrophage-like cells (hemocytes) by the steroid hormone ecdysone is essential for an effective innate immune response over metamorphosis. Although it is generally accepted that steroid hormones impact immunity in mammals, their action on monocytes (e.g. macrophages and neutrophils) is still not well understood. Here in a simpler model system, we used an approach that allows in vivo, cell autonomous analysis of hormonal regulation of innate immune cells, by combining genetic manipulation with flow cytometry, high-resolution time-lapse imaging and tissue-specific transcriptomic analysis. We show that in response to ecdysone, hemocytes rapidly upregulate actin dynamics, motility and phagocytosis of apoptotic corpses, and acquire the ability to chemotax to damaged epithelia. Most importantly, individuals lacking ecdysone-activated hemocytes are defective in bacterial phagocytosis and are fatally susceptible to infection by bacteria ingested at larval stages, despite the normal systemic and local production of antimicrobial peptides. This decrease in survival is comparable to the one observed in pupae lacking immune cells altogether, indicating that ecdysone-regulation is essential for hemocyte immune functions and survival after infection. Microarray analysis of hemocytes revealed a large set of genes regulated at metamorphosis by EcR signaling, among which many are known to function in cell motility, cell shape or phagocytosis. This study demonstrates an important role for steroid hormone regulation of immunity in vivo in Drosophila, and paves the way for genetic dissection of the mechanisms at work behind steroid regulation of innate immune cells. PMID:24204269

  19. Immune Modulation of Stem Cells and Regeneration

    PubMed Central

    Aurora, Arin B.; Olson, Eric N.

    2014-01-01

    The immune system, best known as the first line of defense against invading pathogens, is integral to tissue development, homeostasis and wound repair. In recent years, there has been a growing appreciation that cellular and humoral components of the immune system also contribute to regeneration of damaged tissues, including limbs, skeletal muscle, heart and the nervous system. Here, we discuss key findings that implicate inflammatory cells and their secreted factors in tissue replacement following injury via stem cells and other reparative mechanisms. We highlight clinical conditions that are amenable to immune-mediated regeneration and suggest immune targeting strategies for tissue regeneration. PMID:24996166

  20. T cell metabolic fitness in antitumor immunity.

    PubMed

    Siska, Peter J; Rathmell, Jeffrey C

    2015-04-01

    T cell metabolism has a central role in supporting and shaping immune responses and may have a key role in antitumor immunity. T cell metabolism is normally held under tight regulation in an immune response of glycolysis to promote effector T cell expansion and function. However, tumors may deplete nutrients, generate toxic products, or stimulate conserved negative feedback mechanisms, such as through Programmed Cell Death 1 (PD-1), to impair effector T cell nutrient uptake and metabolic fitness. In addition, regulatory T cells are favored in low glucose conditions and may inhibit antitumor immune responses. Here, we review how the tumor microenvironment modifies metabolic and functional pathways in T cells and how these changes may uncover new targets and challenges for cancer immunotherapy and treatment. PMID:25773310

  1. Immune surveillance of mammary tissue by phagocytic cells.

    PubMed

    Paape, M J; Shafer-Weaver, K; Capuco, A V; Van Oostveldt, K; Burvenich, C

    2000-01-01

    The leukocytes in milk consist of lymphocytes, neutrophil polymorphonuclear leukocytes (PMN) and macrophages. Lymphocytes together with antigen-presenting cells function in the generation of an effective immune response. Lymphocytes can be divided into two distinct subsets, T- and B-lymphocytes, that differ in function and protein products. The professional phagocytic cells of the bovine mammary gland are PMN and macrophages. In the normal mammary gland macrophages are the predominate cells which act as sentinels to invading mastitis causing pathogens. Once the invaders are detected, macrophages release chemical messengers called chemoattractants that cause the directed migration of PMN into the infection. Migration of neutrophils into mammary tissue provides the first immunological line of defense against bacteria that penetrate the physical barrier of the teat canal. However, their presence is like a double-edged sword. While the PMN are phagocytosing and destroying the invading pathogens, they inadvertently release chemicals which induces swelling of secretory epithelium cytoplasm, sloughing of secretory cells, and decreased secretory activity. Permanent scarring will result in a loss of milk production. Resident and newly migrated macrophages help reduce the damage to the epithelium by phagocytosing PMN that undergo programmed cell death through a process called apoptosis. Specific ligands on the neutrophil surface are required for directed migration and phagocytosis. In response to infection, freshly migrated leukocytes express greater numbers of cell surface receptors for immunoglobulins and complement and are more phagocytic than their counterparts in blood. However, phagocytic activity rapidly decreases with continued exposure to inhibitory factors such as milk fat globules and casein in mammary secretions. Compensatory hypertrophy in non-mastitic quarters partially compensates for lost milk production in diseased quarters. Advances in molecular biology are making available the tools, techniques, and products to study and modulate host-parasite interactions. For example the cloning and expression of proteins that bind endotoxin may provide ways of reducing damaging effects of endotoxin during acute coliform mastitis. The successful formation of bifunctional monoclonal antibodies for the targeted lysis of mastitis causing bacteria represents a new line of therapeutics for the control of mastitis in dairy cows. PMID:10959434

  2. Monocytes and macrophages, implications for breast cancer migration and stem cell-like activity and treatment.

    PubMed

    Ward, Rebecca; Sims, Andrew H; Lee, Alexander; Lo, Christina; Wynne, Luke; Yusuf, Humza; Gregson, Hannah; Lisanti, Michael P; Sotgia, Federica; Landberg, Gran; Lamb, Rebecca

    2015-06-10

    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

  3. 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

  4. Macrophage Autophagy in Atherosclerosis

    PubMed Central

    Maiuri, Maria Chiara; Grassia, Gianluca; Platt, Andrew M.; Carnuccio, Rosa; Ialenti, Armando; Maffia, Pasquale

    2013-01-01

    Macrophages play crucial roles in atherosclerotic immune responses. Recent investigation into macrophage autophagy (AP) in atherosclerosis has demonstrated a novel pathway through which these cells contribute to vascular inflammation. AP is a cellular catabolic process involving the delivery of cytoplasmic contents to the lysosomal machinery for ultimate degradation and recycling. Basal levels of macrophage AP play an essential role in atheroprotection during early atherosclerosis. However, AP becomes dysfunctional in the more advanced stages of the pathology and its deficiency promotes vascular inflammation, oxidative stress, and plaque necrosis. In this paper, we will discuss the role of macrophages and AP in atherosclerosis and the emerging evidence demonstrating the contribution of macrophage AP to vascular pathology. Finally, we will discuss how AP could be targeted for therapeutic utility. PMID:23401644

  5. Macrophages increase the resistance of pancreatic adenocarcinoma cells to gemcitabine by upregulating cytidine deaminase

    PubMed Central

    Amit, Moran; Gil, Ziv

    2013-01-01

    Tumor-associated macrophages play a central role in tumor progression and metastasis. Macrophages can also promote the resistance of malignant cells to chemotherapy by stimulating the upregulation of cytidine deaminase, an intracellular enzyme that catabolizes the active form of gemcitabine. Targeting macrophage-dependent chemoresistance may reduce tumor-associated morbidity and mortality. PMID:24498570

  6. Cerebral regulatory T cells restrain microglia/macrophage-mediated inflammatory responses via IL-10

    PubMed Central

    Xie, Luokun; Choudhury, Gourav Roy; Winters, Ali; Yang, Shao-Hua; Jin, Kunlin

    2014-01-01

    Forkhead box P3 (Foxp3)+ regulatory T (Treg) cells maintain the immune tolerance and prevent inflammatory responses in the periphery. However, the presence of Treg cells in the central nervous system under steady state has not been studied. Here, for the first time, we show a substantial TCRαβ+CD4+Foxp3+ T-cell population (cerebral Treg cells) in the normal rat cerebrum, constituting more than 15% of the cerebral CD4+ T-cell compartment. Cerebral Treg cells showed an activated/memory phenotype and expressed many Treg-cell signature genes at higher levels than peripheral Treg cells. Consistent with their activated/memory phenotype, cerebral Treg cells robustly restrained the LPS-induced inflammatory responses of brain microglia/macrophages, suggesting a role in maintaining the cerebral homeostasis by inhibiting the neuroinflammation. In addition, brain astrocytes were the helper cells that sustained Foxp3 expression in Treg cells through IL-2/STAT5 signaling, showing that the interaction between astrocytes and Treg cells contributes to the maintenance of Treg-cell identity in the brain. Taken together, our work represents the first study to characterize the phenotypic and functional features of Treg cells in the normal rat cerebrum. Our data have provided a novel insight for the contribution of Treg cells to the immunosurveillance and immunomodulation in the cerebrum under steady state. PMID:25329858

  7. uPAR Induces Expression of Transforming Growth Factor β and Interleukin-4 in Cancer Cells to Promote Tumor-Permissive Conditioning of Macrophages

    PubMed Central

    Hu, Jingjing; Jo, Minji; Eastman, Boryana M.; Gilder, Andrew S.; Bui, Jack D.; Gonias, Steven L.

    2015-01-01

    Cancer cells condition macrophages and other inflammatory cells in the tumor microenvironment so that these cells are more permissive for cancer growth and metastasis. Conditioning of inflammatory cells reflects, at least in part, soluble mediators (such as transforming growth factor β and IL-4) that are released by cancer cells and alter the phenotype of cells of the innate immune system. Signaling pathways in cancer cells that potentiate this activity are incompletely understood. The urokinase receptor (uPAR) is a cell-signaling receptor known to promote cancer cell survival, proliferation, metastasis, and cancer stem cell–like properties. The present findings show that uPAR expression in diverse cancer cells, including breast cancer, pancreatic cancer, and glioblastoma cells, promotes the ability of these cells to condition co-cultured bone marrow–derived macrophages so that the macrophages express significantly increased levels of arginase 1, a biomarker of the alternatively activated M2 macrophage phenotype. Expression of transforming growth factor β was substantially increased in uPAR-expressing cancer cells via a mechanism that requires uPA-initiated cell signaling. uPAR also controlled expression of IL-4 in cancer cells via a mechanism that involves activation of ERK1/2. The ability of uPAR to induce expression of factors that condition macrophages in the tumor microenvironment may constitute an important mechanism by which uPAR promotes cancer progression. PMID:25310970

  8. Macrophages and mast cells in chronic cholecystitis and "normal" gall bladders.

    PubMed Central

    Hudson, I; Hopwood, D

    1986-01-01

    An attempt was made to quantify mast cells using toluidine blue and macrophages, with alpha-1-antitrypsin as a marker, from adjacent sections in the mucosa of two groups of gall bladders showing either minimal inflammatory change or established chronic cholecystitis. The results were expressed as cells/mm2 of mucosa. Alpha-1-antitrypsin showed both macrophages and mast cells, and therefore an estimate of macrophage numbers was obtained by subtraction. Mast cells comprised more than 60% of the alpha-1-antitrypsin positive cells. There were significantly (p greater than 0.001) more mast cells and macrophages in minimal inflammatory gall bladder mucosa than in established chronic cholecystitis. Images PMID:2431004

  9. ENHANCED CD8 T CELL CROSS-PRESENTATION BY MACROPHAGES WITH TARGETED DISRUPTION OF STAT3

    PubMed Central

    Brayer, Jason; Cheng, Fengdong; Wang, Hongwei; Horna, Pedro; Vicente-Suarez, Ildefonso; Pinilla-Ibarz, Javier; Sotomayor, Eduardo M.

    2010-01-01

    SUMMARY CD8 T cell tolerance, once thought to be largely a result of clonal deletion, is now appreciated to be much more complex, additionally involving multiple permutations of partial loss of effector function in residual clonal populations. This is especially important in the context of tumor immunity, in which persistent tolerized cytotoxic CD8 T cells (CTL), if reactivated, could potentially mount a protective response. Previously we have shown that antigen-presenting cells (APCs) with a targeted disruption of STAT3 break tolerance in CD4 T cells. Here we evaluate the STAT3-defective APC in terms of its ability to induce a productive CTL response. Our data demonstrate that macrophages derived from conditional STAT3 knockout mice are superior to wild-type macrophages in terms of their ability to prime cognate CTL responses, and to cross-present tumor-derived antigen to CTLs in vitro. CTLs cultured with STAT3-deficient APCs demonstrated a stronger proliferative response and produced increased amounts of IFN-γ and TNF-α, all of which have been shown to be diminished in tumor-tolerized CD8 T cells. Targeting STAT3 signaling represents therefore an enticing strategy to augment CTL responses in the tumor-bearing host. PMID:20346983

  10. Macrophage and T cell dynamics during the development and disintegration of mycobacterial granulomas.

    PubMed

    Egen, Jackson G; Rothfuchs, Antonio Gigliotti; Feng, Carl G; Winter, Nathalie; Sher, Alan; Germain, Ronald N

    2008-02-01

    Granulomas play a key role in host protection against mycobacterial pathogens, with their breakdown contributing to exacerbated disease. To better understand the initiation and maintenance of these structures, we employed both high-resolution multiplex static imaging and intravital multiphoton microscopy of Mycobacterium bovis BCG-induced liver granulomas. We found that Kupffer cells directly capture blood-borne bacteria and subsequently nucleate formation of a nascent granuloma by recruiting both uninfected liver-resident macrophages and blood-derived monocytes. Within the mature granuloma, these myeloid cell populations formed a relatively immobile cellular matrix that interacted with a highly dynamic effector T cell population. The efficient recruitment of these T cells was highly dependent on TNF-alpha-derived signals, which also maintained the granuloma structure through preferential effects on uninfected macrophage populations. By characterizing the migration of both innate and adaptive immune cells throughout the process of granuloma development, these studies provide a new perspective on the cellular events involved in mycobacterial containment and escape. PMID:18261937

  11. Effect of lactoferrin protein on red blood cells and macrophages: mechanism of parasite–host interaction

    PubMed Central

    Anand, Namrata; Kanwar, Rupinder K; Dubey, Mohan Lal; Vahishta, R K; Sehgal, Rakesh; Verma, Anita K; Kanwar, Jagat R

    2015-01-01

    Background Lactoferrin is a natural multifunctional protein known to have antitumor, antimicrobial, and anti-inflammatory activity. Apart from its antimicrobial effects, lactoferrin is known to boost the immune response by enhancing antioxidants. Lactoferrin exists in various forms depending on its iron saturation. The present study was done to observe the effect of lactoferrin, isolated from bovine and buffalo colostrum, on red blood cells (RBCs) and macrophages (human monocytic cell line-derived macrophages THP1 cells). Methods Lactoferrin obtained from both species and in different iron saturation forms were used in the present study, and treatment of host cells were given with different forms of lactoferrin at different concentrations. These treated host cells were used for various studies, including morphometric analysis, viability by MTT assay, survivin gene expression, production of reactive oxygen species, phagocytic properties, invasion assay, and Toll-like receptor-4, Toll-like receptor-9, and MDR1 expression, to investigate the interaction between lactoferrin and host cells and the possible mechanism of action with regard to parasitic infections. Results The mechanism of interaction between host cells and lactoferrin have shown various aspects of gene expression and cellular activity depending on the degree of iron saturation of lactoferrin. A significant increase (P<0.05) in production of reactive oxygen species, phagocytic activity, and Toll-like receptor expression was observed in host cells incubated with iron-saturated lactoferrin when compared with an untreated control group. However, there was no significant (P>0.05) change in percentage viability in the different groups of host cells treated, and no downregulation of survivin gene expression was found at 48 hours post-incubation. Upregulation of the Toll-like receptor and downregulation of the P-gp gene confirmed the immunomodulatory potential of lactoferrin protein. Conclusion The present study details the interaction between lactoferrin and parasite host cells, ie, RBCs and macrophages, using various cellular processes and expression studies. The study reveals the possible mechanism of action against various intracellular pathogens such as Toxoplasma, Plasmodium, Leishmania, Trypanosoma, and Mycobacterium. The presence of iron in lactoferrin plays an important role in enhancing the various activities taking place inside these cells. This work provides a lot of information about targeting lactoferrin against many parasitic infections which can rule out the exact pathways for inhibition of diseases caused by intracellular microbes mainly targeting RBCs and macrophages for their survival. Therefore, this initial study can serve as a baseline for further evaluation of the mechanism of action of lactoferrin against parasitic diseases, which is not fully understood to date. PMID:26251568

  12. Tissue macrophage identity and self-renewal.

    PubMed

    Gentek, Rebecca; Molawi, Kaaweh; Sieweke, Michael H

    2014-11-01

    Macrophages are cellular components of the innate immune system that reside in virtually all tissues and contribute to immunity, repair, and homeostasis. The traditional view that all tissue-resident macrophages derive from the bone marrow through circulating monocyte intermediates has dramatically shifted recently with the observation that macrophages from embryonic progenitors can persist into adulthood and self-maintain by local proliferation. In several tissues, however, monocytes also contribute to the resident macrophage population, on which the local environment can impose tissue-specific macrophage functions. These observations have raised important questions: What determines resident macrophage identity and function, ontogeny or environment? How is macrophage proliferation regulated? In this review, we summarize the current knowledge about the identity, proliferation, and turnover of tissue-resident macrophages and how they differ from freshly recruited short-lived monocyte-derived cells. We examine whether macrophage proliferation can be qualified as self-renewal of mature differentiated cells and whether the concepts and molecular pathways are comparable to self-renewal mechanisms in stem cells. Finally, we discuss how improved understanding of macrophage identity and self-renewal could be exploited for therapeutic intervention of macrophage-mediated pathologies by selectively targeting freshly recruited or resident macrophages. PMID:25319327

  13. Cell-to-cell spread and massive vacuole formation after Cryptococcus neoformans infection of murine macrophages

    PubMed Central

    Alvarez, Mauricio; Casadevall, Arturo

    2007-01-01

    Background The interaction between macrophages and Cryptococcus neoformans (Cn) is critical for containing dissemination of this pathogenic yeast. However, Cn can either lyse macrophages or escape from within them through a process known as phagosomal extrusion. Both events result in live extracellular yeasts capable of reproducing and disseminating in the extracellular milieu. Another method of exiting the intracellular confines of cells is through host cell-to-cell transfer of the pathogen, and this commonly occurs with the human immuno-deficiency virus (HIV) and CD4+ T cells and macrophages. In this report we have used time-lapse imaging to determine if this occurs with Cn. Results Live imaging of Cryptococcus neoformans interactions with murine macrophages revealed cell-to-cell spread of yeast cells from infected donor cells to uninfected cells. Although this phenomenon was relatively rare its occurrence documents a new capacity for this pathogen to infect adjacent cells without exiting the intracellular space. Cell-to-cell spread appeared to be an actin-dependent process. In addition, we noted that cryptococcal phagosomal extrusion was followed by the formation of massive vacuoles suggesting that intracellular residence is accompanied by long lasting damage to host cells. Conclusion C. neoformans can escape the intracellular confines of macrophages in an actin dependent manner by cell-to-cell transfer of the yeast leading to infection of adjacent cells. In addition, complete extrusion of internalized Cn cells can lead to the formation of a massive vacuole which may be a sign of damage to the host macrophage. These observations document new outcomes for the interaction of C. neoformans with host cells that provide precedents for cell biological effects that may contribute to the pathogenesis of cryptococcal infections. PMID:17705844

  14. A Protocol for the Comprehensive Flow Cytometric Analysis of Immune Cells in Normal and Inflamed Murine Non-Lymphoid Tissues

    PubMed Central

    Yu, Yen-Rei A.; O’Koren, Emily G.; Hotten, Danielle F.; Kan, Matthew J.; Kopin, David; Nelson, Erik R.; Que, Loretta; Gunn, Michael D.

    2016-01-01

    Flow cytometry is used extensively to examine immune cells in non-lymphoid tissues. However, a method of flow cytometric analysis that is both comprehensive and widely applicable has not been described. We developed a protocol for the flow cytometric analysis of non-lymphoid tissues, including methods of tissue preparation, a 10-fluorochrome panel for cell staining, and a standardized gating strategy, that allows the simultaneous identification and quantification of all major immune cell types in a variety of normal and inflamed non-lymphoid tissues. We demonstrate that our basic protocol minimizes cell loss, reliably distinguishes macrophages from dendritic cells (DC), and identifies all major granulocytic and mononuclear phagocytic cell types. This protocol is able to accurately quantify 11 distinct immune cell types, including T cells, B cells, NK cells, neutrophils, eosinophils, inflammatory monocytes, resident monocytes, alveolar macrophages, resident/interstitial macrophages, CD11b- DC, and CD11b+ DC, in normal lung, heart, liver, kidney, intestine, skin, eyes, and mammary gland. We also characterized the expression patterns of several commonly used myeloid and macrophage markers. This basic protocol can be expanded to identify additional cell types such as mast cells, basophils, and plasmacytoid DC, or perform detailed phenotyping of specific cell types. In examining models of primary and metastatic mammary tumors, this protocol allowed the identification of several distinct tumor associated macrophage phenotypes, the appearance of which was highly specific to individual tumor cell lines. This protocol provides a valuable tool to examine immune cell repertoires and follow immune responses in a wide variety of tissues and experimental conditions. PMID:26938654

  15. A New Triggering Receptor Expressed on Myeloid Cells (TREM) Family Member, TLT-6, is Involved in Activation and Proliferation of Macrophages

    PubMed Central

    Won, Kyung-Jong; Park, Sung-Won; Lee, Seunghoon; Kong, Il-Keun; Chae, Jung-Il; Kim, Bokyung; Lee, Eun-Jong

    2015-01-01

    The triggering receptor expressed on myeloid cells (TREM) family, which is abundantly expressed in myeloid lineage cells, plays a pivotal role in innate and adaptive immune response. In this study, we aimed to identify a novel receptor expressed on hematopoietic stem cells (HSCs) by using in silico bioinformatics and to characterize the identified receptor. We thus found the TREM-like transcript (TLT)-6, a new member of TREM family. TLT-6 has a single immunoglobulin domain in the extracellular region and a long cytoplasmic region containing 2 immunoreceptor tyrosine-based inhibitory motif-like domains. TLT-6 transcript was expressed in HSCs, monocytes and macrophages. TLT-6 protein was up-regulated on the surface of bone marrow-derived and peritoneal macrophages by lipopolysaccharide stimulation. TLT-6 exerted anti-proliferative effects in macrophages. Our results demonstrate that TLT-6 may regulate the activation and proliferation of macrophages. PMID:26557807

  16. 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.

  17. Macrophage migration inhibitory factor (MIF) is a critical mediator of the innate immune response to Mycobacterium tuberculosis

    PubMed Central

    Das, Rituparna; Koo, Mi-Sun; Kim, Bae Hoon; Jacob, Shevin T.; Subbian, Selvakumar; Yao, Jie; Leng, Lin; Levy, Rebecca; Murchison, Charles; Burman, William J.; Moore, Christopher C.; Scheld, W. Michael; David, John R.; Kaplan, Gilla; MacMicking, John D.; Bucala, Richard

    2013-01-01

    Macrophage migration inhibitory factor (MIF), an innate cytokine encoded in a functionally polymorphic genetic locus, contributes to detrimental inflammation but may be crucial for controlling infection. We explored the role of variant MIF alleles in tuberculosis. In a Ugandan cohort, genetic low expressers of MIF were 2.4-times more frequently identified among patients with Mycobacterium tuberculosis (TB) bacteremia than those without. We also found mycobacteria-stimulated transcription of MIF and serum MIF levels to be correlated with MIF genotype in human macrophages and in a separate cohort of US TB patients, respectively. To determine mechanisms for MIF’s protective role, we studied both aerosolized and i.v. models of mycobacterial infection and observed MIF-deficient mice to succumb more quickly with higher organism burden, increased lung pathology, and decreased innate cytokine production (TNF-α, IL-12, IL-10). MIF-deficient animals showed increased pulmonary neutrophil accumulation but preserved adaptive immune response. MIF-deficient macrophages demonstrated decreased cytokine and reactive oxygen production and impaired mycobacterial killing. Transcriptional investigation of MIF-deficient macrophages revealed reduced expression of the pattern recognition receptor dectin-1; restoration of dectin-1 expression recovered innate cytokine production and mycobacterial killing. Our data place MIF in a crucial upstream position in the innate immune response to mycobacteria and suggest that commonly occurring low expression MIF alleles confer an increased risk of TB disease in some populations. PMID:23882081

  18. Ongoing cell death and immune influences on regeneration in the vestibular sensory organs

    NASA Technical Reports Server (NTRS)

    Warchol, M. E.; Matsui, J. I.; Simkus, E. L.; Ogilive, J. M.

    2001-01-01

    Hair cells in the vestibular organs of birds have a relatively short life span. Mature hair cells appear to die spontaneously and are then quickly replaced by new hair cells that arise from the division of epithelial supporting cells. A similar regenerative mechanism also results in hair cell replacement after ototoxic damage. The cellular basis of hair cell turnover in the avian ear is not understood. We are investigating the signaling pathways that lead to hair cell death and the relationship between ongoing cell death and cell production. In addition, work from our lab and others has demonstrated that the avian inner ear contains a resident population of macrophages and that enhanced numbers of macrophages are recruited to sites of hair cells lesions. Those observations suggest that macrophages and their secretory products (cytokines) may be involved in hair cell regeneration. Consistent with that suggestion, we have found that treatment with the anti-inflammatory drug dexamethasone reduces regenerative cell proliferation in the avian ear, and that certain macrophage-secreted cytokines can influence the proliferation of vestibular supporting cells and the survival of statoacoustic neurons. Those results suggest a role for the immune system in the process of sensory regeneration in the inner ear.

  19. Cutting edge: microbial products elicit formation of dendritic cell aggresome-like induced structures in macrophages.

    PubMed

    Canadien, Veronica; Tan, Tracy; Zilber, Rachelle; Szeto, Jason; Perrin, Andrew J; Brumell, John H

    2005-03-01

    In response to a maturation stimulus, dendritic cells undergo the formation of ubiquitinated protein aggregates known as dendritic cell aggresome-like induced structures (DALIS). DALIS are thought to act as Ag storage structures, allowing for the prioritized degradation of proteins during infection. In this study, we demonstrate that murine macrophages can also form ubiquitinated protein aggregates that are indistinguishable from DALIS. These were formed in a dose- and time-dependent manner, and in response to a variety of microbial products. Surprisingly, the proteasome did not accumulate on these ubiquitinated protein structures, further underlining the difference between DALIS and aggresomes. Our studies suggest that DALIS formation is important for the function of Ag-presenting immune cells during infection. PMID:15728449

  20. Parasite limiting macrophages promote IL-17 secretion in naive bovine CD4⁺ T-cells during Neospora caninum infection.

    PubMed

    Flynn, Robin J; Marshall, Edward S

    2011-12-15

    Neospora caninum infects bovine hosts giving rise to pro-inflammatory immune responses that can result in foetal death or spontaneous abortion, this appears to be mediated by the actions of IFN-γ on cell activation and migration/trafficking. Yet successful vaccination or natural immunity is also strongly correlated with IFN-γ production. We utilised in vitro infection of bovine macrophages to prime naive T-cell responses. Naive T-cells in contact with infected macrophages produce both IFN-γ and IL-17 in a pattern that is dependent on whether the priming macrophage was protected or non-protected. Our results may explain the apparent dual role of IFN-γ during infection if a second major pro-inflammatory cytokine, IL-17, is produced simultaneously. PMID:22005586

  1. Macrophage immunoregulatory pathways in tuberculosis

    PubMed Central

    Rajaram, Murugesan V.S.; Ni, Bin; Dodd, Claire E.; Schlesinger, Larry S.

    2014-01-01

    Macrophages, the major host cells harboring Mycobacterium tuberculosis (M.tb), are a heterogeneous cell type depending on their tissue of origin and host they are derived from. Significant discord in macrophage responses to M.tb exists due to differences in M.tb strains and the various types of macrophages used to study tuberculosis (TB). This review will summarize current concepts regarding macrophage responses to M.tb infection, while pointing out relevant differences in experimental outcomes due to the use of divergent model systems. A brief description of the lung environment is included since there is increasing evidence that the alveolar macrophage (AM) has immunoregulatory properties that can delay optimal protective host immune responses. In this context, this review focuses on selected macrophage immunoregulatory pattern recognition receptors (PRRs), cytokines, negative regulators of inflammation, lipid mediators and microRNAs (miRNAs). PMID:25453226

  2. Lavandula angustifolia Mill. Essential Oil Exerts Antibacterial and Anti-Inflammatory Effect in Macrophage Mediated Immune Response to Staphylococcus aureus.

    PubMed

    Giovannini, D; Gismondi, A; Basso, A; Canuti, L; Braglia, R; Canini, A; Mariani, F; Cappelli, G

    2016-01-01

    Different studies described the antibacterial properties of Lavandula angustifolia (Mill.) essential oil and its anti-inflammatory effects. Besides, no data exist on its ability to activate human macrophages during the innate response against Staphylococcus aureus. The discovery of promising regulators of macrophage-mediated inflammatory response, without side effects, could be useful for the prevention of, or as therapeutic remedy for, various inflammation-mediated diseases. This study investigated, by transcriptional analysis, how a L. angustifolia essential oil treatment influences the macrophage response to Staphylococcus aureus infection. The results showed that the treatment increases the phagocytic rate and stimulates the containment of intracellular bacterial replication by macrophages. Our data showed that this stimulation is coupled with expression of genes involved in reactive oxygen species production (i.e., CYBB and NCF4). Moreover, the essential oil treatment balanced the inflammatory signaling induced by S. aureus by repressing the principal pro-inflammatory cytokines and their receptors and inducing the heme oxygenase-1 gene transcription. These data showed that the L. angustifolia essential oil can stimulate the human innate macrophage response to a bacterium which is responsible for one of the most important nosocomial infection and might suggest the potential development of this plant extract as an anti-inflammatory and immune regulatory coadjutant drug. PMID:26730790

  3. The Majority of In Vitro Macrophage Activation Exhibited by Extracts of Some Immune Enhancing Botanicals is Due to Bacterial Lipoproteins and Lipopolysaccharides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have identified potent monocyte/macrophage activating bacterial lipoproteins within commonly used immune enhancing botanicals such as Echinacea, American ginseng and alfalfa sprouts. These bacterial lipoproteins, along with lipopolysaccharides, were substantially more potent than other bacteriall...

  4. Vorinostat Modulates the Imbalance of T Cell Subsets, Suppresses Macrophage Activity, and Ameliorates Experimental Autoimmune Uveoretinitis.

    PubMed

    Fang, Sijie; Meng, Xiangda; Zhang, Zhuhong; Wang, Yang; Liu, Yuanyuan; You, Caiyun; Yan, Hua

    2016-03-01

    The purpose of the study was to investigate the anti-inflammatory efficiency of vorinostat, a histone deacetylase inhibitor, in experimental autoimmune uveitis (EAU). EAU was induced in female C57BL/6J mice immunized with interphotoreceptor retinoid-binding protein peptide. Vorinostat or the control treatment, phosphate-buffered saline, was administrated orally from 3 days before immunization until euthanasia at day 21 after immunization. The clinical and histopathological scores of mice were graded, and the integrity of the blood-retinal barrier was examined by Evans blue staining. T helper cell subsets were measured by flow cytometry, and the macrophage functions were evaluated with immunohistochemistry staining and immunofluorescence assays. The mRNA levels of tight junction proteins were measured by qRT-PCR. The expression levels of intraocular cytokines and transcription factors were examined by western blotting. Vorinostat relieved both clinical and histopathological manifestations of EAU in our mouse model, and the BRB integrity was maintained in vorinostat-treated mice, which had less vasculature leakage and higher mRNA and protein expressions of tight junction proteins than controls. Moreover, vorinostat repressed Th1 and Th17 cells and increased Th0 and Treg cells. Additionally, the INF-γ and IL-17A expression levels were significantly decreased, while the IL-10 level was increased by vorinostat treatment. Furthermore, due to the reduced TNF-α level, the macrophage activity was considerably inhibited in EAU mice. Finally, transcription factors, including STAT1, STAT3, and p65, were greatly suppressed by vorinostat treatment. Our data suggest that vorinostat might be a potential anti-inflammatory agent in the management of uveitis and other autoimmune inflammatory diseases. PMID:26798022

  5. Activation of T cell death-associated gene 8 regulates the cytokine production of T cells and macrophages in vitro.

    PubMed

    Onozawa, Yoshiko; Fujita, Yoshifumi; Kuwabara, Harumi; Nagasaki, Miyuki; Komai, Tomoaki; Oda, Tomiichiro

    2012-05-15

    An orphan G-protein-coupled receptor, T cell death-associated gene 8 (TDAG8) which has been reported to be a proton sensor, inhibits the production of pro-inflammatory cytokines induced by extracellular acidification. Recently, we have found that TDAG8 knockout mice showed significant exacerbation in various immune-mediated inflammation disease models. To elucidate the role of TDAG8, we screened an in-house library to find compounds which have a profile as a TDAG8 agonist using a cyclic adenosine 5'-monophosphate assay. Among the screening hits, we focused on (3-[(2,4-dichlorobenzyl)thio]-1,6-dimethyl-5,6-dihydro-1H-pyridazino[4,5-e][1,3,4]thiadiazin-5-one) (named BTB09089). BTB09089 did not act on other proton sensing G-protein-coupled receptors such as G-protein-coupled receptor 4 (GPR4) nor ovarian cancer G-protein-coupled receptor 1 (OGR1). Moreover, BTB09089 increased cAMP level in the splenocytes from wild-type littermates but not from TDAG8-deficient mice. Thus, BTB09089 was found to be a TDAG8 specific agonist. We then investigated the effects of BTB09089 on T cells and macrophages in vitro. In splenocytes, BTB09089 suppressed the production of IL-2 stimulated with anti-CD3 and anti-CD28 antibodies. In peritoneal exuded macrophages induced by thioglycollate, BTB09089 suppressed the production of TNF-? and IL-6 while it increased that of IL-10 when stimulated with lipopolysaccharide. These effects were observed in cells from wild type mice, but not those from TDAG8 knockout mice. These results indicate that activation of TDAG8 attenuates immune-mediated inflammation by regulating the cytokine production of T cells and macrophages. PMID:22445881

  6. From mouth to macrophage: mechanisms of innate immune subversion by Mycobacterium avium subsp. paratuberculosis

    PubMed Central

    2014-01-01

    Johne’s disease (JD) is a chronic enteric infection of cattle caused by Mycobacterium avium subsp. paratuberculosis (MAP). The high economic cost and potential zoonotic threat of JD have driven efforts to develop tools and approaches to effectively manage this disease within livestock herds. Efforts to control JD through traditional animal management practices are complicated by MAP’s ability to cause long-term environmental contamination as well as difficulties associated with diagnosis of JD in the pre-clinical stages. As such, there is particular emphasis on the development of an effective vaccine. This is a daunting challenge, in large part due to MAP’s ability to subvert protective host immune responses. Accordingly, there is a priority to understand MAP’s interaction with the bovine host: this may inform rational targets and approaches for therapeutic intervention. Here we review the early host defenses encountered by MAP and the strategies employed by the pathogen to avert or subvert these responses, during the critical period between ingestion and the establishment of persistent infection in macrophages. PMID:24885748

  7. Neutrophil Elastase-Generated Fragment of Vascular Endothelial Growth Factor-A Stimulates Macrophage and Endothelial Progenitor Cell Migration.

    PubMed

    Kurtagic, Elma; Rich, Celeste B; Buczek-Thomas, Jo Ann; Nugent, Matthew A

    2015-01-01

    Elastase released from neutrophils as part of the innate immune system has been implicated in chronic diseases such as emphysema and cardiovascular disease. We have previously shown that neutrophil elastase targets vascular endothelial growth factor-A (VEGF) for partial degradation to generate a fragment of VEGF (VEGFf) that has distinct activities. Namely, VEGFf binds to VEGF receptor 1 but not to VEGF receptor 2 and shows altered signaling compared to intact VEGF. In the present study we investigated the chemotactic function of VEGF and VEGFf released from cells by neutrophil elastase. We found that endothelial cells migrated in response to intact VEGF but not VEGFf whereas RAW 264.7 macrophages/monocytes and embryonic endothelial progenitor cells were stimulated to migrate by either VEGF or VEGFf. To investigate the role of elastase-mediated release of VEGF from cells/extracellular matrices, a co-culture system was established. High or low VEGF producing cells were co-cultured with macrophages, endothelial or endothelial progenitor cells and treated with neutrophil elastase. Elastase treatment stimulated macrophage and endothelial progenitor cell migration with the response being greater with the high VEGF expressing cells. However, elastase treatment led to decreased endothelial cell migration due to VEGF cleavage to VEGF fragment. These findings suggest that the tissue response to NE-mediated injury might involve the generation of diffusible VEGF fragments that stimulate inflammatory cell recruitment. PMID:26672607

  8. Neutrophil Elastase-Generated Fragment of Vascular Endothelial Growth Factor-A Stimulates Macrophage and Endothelial Progenitor Cell Migration

    PubMed Central

    Kurtagic, Elma; Rich, Celeste B.; Buczek-Thomas, Jo Ann; Nugent, Matthew A.

    2015-01-01

    Elastase released from neutrophils as part of the innate immune system has been implicated in chronic diseases such as emphysema and cardiovascular disease. We have previously shown that neutrophil elastase targets vascular endothelial growth factor-A (VEGF) for partial degradation to generate a fragment of VEGF (VEGFf) that has distinct activities. Namely, VEGFf binds to VEGF receptor 1 but not to VEGF receptor 2 and shows altered signaling compared to intact VEGF. In the present study we investigated the chemotactic function of VEGF and VEGFf released from cells by neutrophil elastase. We found that endothelial cells migrated in response to intact VEGF but not VEGFf whereas RAW 264.7 macrophages/monocytes and embryonic endothelial progenitor cells were stimulated to migrate by either VEGF or VEGFf. To investigate the role of elastase-mediated release of VEGF from cells/extracellular matrices, a co-culture system was established. High or low VEGF producing cells were co-cultured with macrophages, endothelial or endothelial progenitor cells and treated with neutrophil elastase. Elastase treatment stimulated macrophage and endothelial progenitor cell migration with the response being greater with the high VEGF expressing cells. However, elastase treatment led to decreased endothelial cell migration due to VEGF cleavage to VEGF fragment. These findings suggest that the tissue response to NE-mediated injury might involve the generation of diffusible VEGF fragments that stimulate inflammatory cell recruitment. PMID:26672607

  9. The role of CD40-CD154 interactions in the regulation of cell mediated immunity.

    PubMed

    Miga, A; Masters, S; Gonzalez, M; Noelle, R J

    2000-05-01

    CD40 is expressed on a diverse array of cell types from the hematopoietic and non-hematopoietic compartments. Within the hematopoietic compartment, CD40 is found constitutively expressed on B cells, dendritic cells (DC) and macrophages. The function of CD40 in B cells has been documented as being essential in the control of humoral immunity. In DCs and macrophages, CD40 has been shown to be important in the induction of antigen-presenting cell (APC) maturation and effector function. CD40 is also expressed on non-hematopoietic cells like keratinocytes, epithelial cells, and vascular endothelial cells and has been shown to be functionally important on these cell types. PMID:10854177

  10. Candida albicans cell surface superoxide dismutases degrade host-derived reactive oxygen species to escape innate immune surveillance

    PubMed Central

    Frohner, Ingrid E; Bourgeois, Christelle; Yatsyk, Kristina; Majer, Olivia; Kuchler, Karl

    2009-01-01

    Mammalian innate immune cells produce reactive oxygen species (ROS) in the oxidative burst reaction to destroy invading microbial pathogens. Using quantitative real-time ROS assays, we show here that both yeast and filamentous forms of the opportunistic human fungal pathogen Candida albicans trigger ROS production in primary innate immune cells such as macrophages and dendritic cells. Through a reverse genetic approach, we demonstrate that coculture of macrophages or myeloid dendritic cells with C. albicans cells lacking the superoxide dismutase (SOD) Sod5 leads to massive extracellular ROS accumulation in vitro. ROS accumulation was further increased in coculture with fungal cells devoid of both Sod4 and Sod5. Survival experiments show that C. albicans mutants lacking Sod5 and Sod4 exhibit a severe loss of viability in the presence of macrophages in vitro. The reduced viability of sod5Δ/Δ and sod4Δ/Δsod5Δ/Δ mutants relative to wild type is not evident with macrophages from gp91phox−/− mice defective in the oxidative burst activity, demonstrating a ROS-dependent killing activity of macrophages targeting fungal pathogens. These data show a physiological role for cell surface SODs in detoxifying ROS, and suggest a mechanism whereby C. albicans, and perhaps many other microbial pathogens, can evade host immune surveillance in vivo. PMID:19019164

  11. The Isolation and Characterization of Murine Macrophages

    PubMed Central

    Zhang, Xia; Goncalves, Ricardo; Mosser, David M.

    2010-01-01

    Macrophages are mononuclear phagocytes that are widely distributed throughout the body. These cells can contribute to development and homeostasis and participate in innate and adaptive immune responses. The physiology of macrophages can vary tremendously depending on the environment in which they reside and the local stimuli to which they are exposed. Macrophages are prodigious secretory cells, and in that role can promote and regulate immune responses and contribute to autoimmune pathologies. Macrophages are highly phagocytic, and in this capacity have long been considered to be essential immune effector cells. The important roles of macrophages in maintaining homeostasis and in contributing to tissue remodeling and wound healing is sometimes overlooked because of their vital role in host defense. PMID:19016445

  12. Tetherin Can Restrict Cell-Free and Cell-Cell Transmission of HIV from Primary Macrophages to T Cells

    PubMed Central

    Giese, Sebastian; Marsh, Mark

    2014-01-01

    Bst-2/Tetherin inhibits the release of HIV by tethering newly formed virus particles to the plasma membrane of infected cells. Although the mechanisms of Tetherin-mediated restriction are increasingly well understood, the biological relevance of this restriction in the natural target cells of HIV is unclear. Moreover, whether Tetherin exerts any restriction on the direct cell-cell spread of HIV across intercellular contacts remains controversial. Here we analyse the restriction endogenous Tetherin imposes on HIV transmission from primary human macrophages, one of the main targets of HIV in vivo. We find that the mRNA and protein levels of Tetherin in macrophages are comparable to those in T cells from the same donors, and are highly upregulated by type I interferons. Improved immunocytochemistry protocols enable us to demonstrate that Tetherin localises to the cell surface, the trans-Golgi network, and the macrophage HIV assembly compartments. Tetherin retains budded virions in the assembly compartments, thereby impeding the release and cell-free spread of HIV, but it is not required for the maintenance of these compartments per se. Notably, using a novel assay to quantify cell-cell spread, we show that Tetherin promotes the transfer of virus clusters from macrophages to T cells and thereby restricts the direct transmission of a dual-tropic HIV-1. Kinetic analyses provide support for the notion that this direct macrophage-T cell spread is mediated, at least in part, by so-called virological synapses. Finally, we demonstrate that the viral Vpu protein efficiently downregulates the cell surface and overall levels of Tetherin, and thereby abrogates this HIV restriction in macrophages. Together, our study shows that Tetherin, one of the most potent HIV restriction factors identified to date, can inhibit virus spread from primary macrophages, regardless of the mode of transmission. PMID:24991932

  13. Protection Of Alveolar Macrophages And MARC 145 Cells From Porcine Reproductive And Respiratory Syndrome Virus Challenge By Swine Interferon-Beta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interferon beta, a type I IFN, is crucial in initiating the innate immune response and in the generation of the adaptive response. This study demonstrated the capacity of swine interferon beta (swIFN beta) to protect porcine alveolar macrophages (PAM) and MARC145 cells from infection with porcine re...

  14. Manipulating the immune system: humoral versus cell-mediated immunity.

    PubMed

    McNeela, E A; Mills, K H

    2001-09-23

    Many of the vaccines in use today were designed on an empirical basis with little understanding of the mechanism of protective immunity or knowledge of the protective antigens. Certain of these vaccines, based on killed or attenuated bacteria or viruses, are associated with unacceptable side-effects. New generation vaccines based on recombinant proteins or naked DNA have considerably improved safety profiles, but are often poorly immunogenic, especially when administered by mucosal routes. This is a particular problem with oral delivery; where high doses of antigen are required to generate even modest immune responses. In contrast, nasal delivery of antigens with a range of adjuvants or delivery systems has been shown to generate relatively potent immune responses and to protect against infection in animal models. Advances in immunology have demonstrated that a variety of cellular and humoral immune effector mechanisms, that are regulated by distinct Th1 and Th2 subtypes of T cells, mediate protection against different infectious diseases. The identification of adjuvants and immunomodulators, that can promote the selective induction of these distinct populations of T cells, has now made it possible to rationally design safe and effective mucosal vaccines against a range of infectious diseases of man. PMID:11516778

  15. IL-10 Production in Macrophages Is Regulated by a TLR-Driven CREB-Mediated Mechanism That Is Linked to Genes Involved in Cell Metabolism

    PubMed Central

    Sanin, David E.; Prendergast, Catriona T.

    2015-01-01

    IL-10 is produced by macrophages in diverse immune settings and is critical in limiting immune-mediated pathology. In helminth infections, macrophages are an important source of IL-10; however, the molecular mechanism underpinning production of IL-10 by these cells is poorly characterized. In this study, bone marrow–derived macrophages exposed to excretory/secretory products released by Schistosoma mansoni cercariae rapidly produce IL-10 as a result of MyD88-mediated activation of MEK/ERK/RSK and p38. The phosphorylation of these kinases was triggered by TLR2 and TLR4 and converged on activation of the transcription factor CREB. Following phosphorylation, CREB is recruited to a novel regulatory element in the Il10 promoter and is also responsible for regulating a network of genes involved in metabolic processes, such as glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation. Moreover, skin-resident tissue macrophages, which encounter S. mansoni excretory/secretory products during infection, are the first monocytes to produce IL-10 in vivo early postinfection with S. mansoni cercariae. The early and rapid release of IL-10 by these cells has the potential to condition the dermal microenvironment encountered by immune cells recruited to this infection site, and we propose a mechanism by which CREB regulates the production of IL-10 by macrophages in the skin, but also has a major effect on their metabolic state. PMID:26116503

  16. Middle East respiratory syndrome coronavirus shows poor replication but significant induction of antiviral responses in human monocyte-derived macrophages and dendritic cells.

    PubMed

    Tynell, Janne; Westenius, Veera; Rönkkö, Esa; Munster, Vincent J; Melén, Krister; Österlund, Pamela; Julkunen, Ilkka

    2016-02-01

    In this study we assessed the ability of Middle East respiratory syndrome coronavirus (MERS-CoV) to replicate and induce innate immunity in human monocyte-derived macrophages and dendritic cells (MDDCs), and compared it with severe acute respiratory syndrome coronavirus (SARS-CoV). Assessments of viral protein and RNA levels in infected cells showed that both viruses were impaired in their ability to replicate in these cells. Some induction of IFN-λ1, CXCL10 and MxA mRNAs in both macrophages and MDDCs was seen in response to MERS-CoV infection, but almost no such induction was observed in response to SARS-CoV infection. ELISA and Western blot assays showed clear production of CXCL10 and MxA in MERS-CoV-infected macrophages and MDDCs. Our data suggest that SARS-CoV and MERS-CoV replicate poorly in human macrophages and MDDCs, but MERS-CoV is nonetheless capable of inducing a readily detectable host innate immune response. Our results highlight a clear difference between the viruses in activating host innate immune responses in macrophages and MDDCs, which may contribute to the pathogenesis of infection. PMID:26602089

  17. Type I Interferon Induced Epigenetic Regulation of Macrophages Suppresses Innate and Adaptive Immunity in Acute Respiratory Viral Infection.

    PubMed

    Kroetz, Danielle N; Allen, Ronald M; Schaller, Matthew A; Cavallaro, Cleyton; Ito, Toshihiro; Kunkel, Steven L

    2015-12-01

    Influenza A virus (IAV) is an airborne pathogen that causes significant morbidity and mortality each year. Macrophages (Mϕ) are the first immune population to encounter IAV virions in the lungs and are required to control infection. In the present study, we explored the mechanism by which cytokine signaling regulates the phenotype and function of Mϕ via epigenetic modification of chromatin. We have found that type I interferon (IFN-I) potently upregulates the lysine methyltransferase Setdb2 in murine and human Mϕ, and in turn Setdb2 regulates Mϕ-mediated immunity in response to IAV. The induction of Setdb2 by IFN-I was significantly impaired upon inhibition of the JAK-STAT signaling cascade, and chromatin immunoprecipitation revealed that both STAT1 and interferon regulatory factor 7 bind upstream of the transcription start site to induce expression. The generation of Setdb2LacZ reporter mice revealed that IAV infection results in systemic upregulation of Setdb2 in myeloid cells. In the lungs, alveolar Mϕ expressed the highest level of Setdb2, with greater than 70% lacZ positive on day 4 post-infection. Silencing Setdb2 activity in Mϕ in vivo enhanced survival in lethal IAV infection. Enhanced host protection correlated with an amplified antiviral response and less obstruction to the airways. By tri-methylating H3K9, Setdb2 silenced the transcription of Mx1 and Isg15, antiviral effectors that inhibit IAV replication. Accordingly, a reduced viral load in knockout mice on day 8 post-infection was linked to elevated Isg15 and Mx1 transcript in the lungs. In addition, Setdb2 suppressed the expression of a large number of other genes with proinflammatory or immunomodulatory function. This included Ccl2, a chemokine that signals through CCR2 to regulate monocyte recruitment to infectious sites. Consistently, knockout mice produced more CCL2 upon IAV infection and this correlated with a 2-fold increase in the number of inflammatory monocytes and alveolar Mϕ in the lungs. Finally, Setdb2 expression by Mϕ suppressed IL-2, IL-10, and IFN-γ production by CD4+ T cells in vitro, as well as proliferation in IAV-infected lungs. Collectively, these findings identify Setdb2 as a novel regulator of the immune system in acute respiratory viral infection. PMID:26709698

  18. Type I Interferon Induced Epigenetic Regulation of Macrophages Suppresses Innate and Adaptive Immunity in Acute Respiratory Viral Infection

    PubMed Central

    Kroetz, Danielle N.; Allen, Ronald M.; Schaller, Matthew A.; Cavallaro, Cleyton; Ito, Toshihiro; Kunkel, Steven L.

    2015-01-01

    Influenza A virus (IAV) is an airborne pathogen that causes significant morbidity and mortality each year. Macrophages (Mϕ) are the first immune population to encounter IAV virions in the lungs and are required to control infection. In the present study, we explored the mechanism by which cytokine signaling regulates the phenotype and function of Mϕ via epigenetic modification of chromatin. We have found that type I interferon (IFN-I) potently upregulates the lysine methyltransferase Setdb2 in murine and human Mϕ, and in turn Setdb2 regulates Mϕ-mediated immunity in response to IAV. The induction of Setdb2 by IFN-I was significantly impaired upon inhibition of the JAK-STAT signaling cascade, and chromatin immunoprecipitation revealed that both STAT1 and interferon regulatory factor 7 bind upstream of the transcription start site to induce expression. The generation of Setdb2LacZ reporter mice revealed that IAV infection results in systemic upregulation of Setdb2 in myeloid cells. In the lungs, alveolar Mϕ expressed the highest level of Setdb2, with greater than 70% lacZ positive on day 4 post-infection. Silencing Setdb2 activity in Mϕ in vivo enhanced survival in lethal IAV infection. Enhanced host protection correlated with an amplified antiviral response and less obstruction to the airways. By tri-methylating H3K9, Setdb2 silenced the transcription of Mx1 and Isg15, antiviral effectors that inhibit IAV replication. Accordingly, a reduced viral load in knockout mice on day 8 post-infection was linked to elevated Isg15 and Mx1 transcript in the lungs. In addition, Setdb2 suppressed the expression of a large number of other genes with proinflammatory or immunomodulatory function. This included Ccl2, a chemokine that signals through CCR2 to regulate monocyte recruitment to infectious sites. Consistently, knockout mice produced more CCL2 upon IAV infection and this correlated with a 2-fold increase in the number of inflammatory monocytes and alveolar Mϕ in the lungs. Finally, Setdb2 expression by Mϕ suppressed IL-2, IL-10, and IFN-γ production by CD4+ T cells in vitro, as well as proliferation in IAV-infected lungs. Collectively, these findings identify Setdb2 as a novel regulator of the immune system in acute respiratory viral infection. PMID:26709698

  19. T cell immunity using transgenic B lymphocytes

    NASA Astrophysics Data System (ADS)

    Gerloni, Mara; Rizzi, Marta; Castiglioni, Paola; Zanetti, Maurizio

    2004-03-01

    Adaptive immunity exists in all vertebrates and plays a defense role against microbial pathogens and tumors. T cell responses begin when precursor T cells recognize antigen on specialized antigen-presenting cells and differentiate into effector cells. Currently, dendritic cells are considered the only cells capable of stimulating T lymphocytes. Here, we show that mature naïve B lymphocytes can be genetically programmed by using nonviral DNA and turned into powerful antigen-presenting cells with a dual capacity of synthesis and presentation of antigen to T cells in vivo. A single i.v. injection of transgenic lymphocytes activates T cell responses reproducibly and specifically even at very low cell doses (102). We also demonstrate that T cell priming can occur in the absence of dendritic cells and results in immunological memory with protective effector functions. These findings disclose aspects in the regulation of adaptive immunity and indicate possibilities for vaccination against viruses and cancer in humans.

  20. Cellular interactions in bovine tuberculosis: release of active mycobacteria from infected macrophages by antigen‐stimulated T cells

    PubMed Central

    Liébana, E; Aranaz, A; Aldwell, F E; McNair, J; Neill, S D; Smyth, A J; Pollock, J M

    2000-01-01

    The outcome of Mycobacterium bovis infections depends on the interactions of infected macrophages with T lymphocytes. Several studies in humans and in mouse models have suggested an important role for cytotoxicity in the protective immune response to mycobacterial infections, and both CD4+ and CD8+ T cells have been shown to elicit appropriate cytolytic activity. The present study investigated in vitro interactions of T cells with M. bovis‐infected macrophages in bovine tuberculosis. The results showed that following interaction with antigen‐stimulated peripheral blood mononuclear cells (PBMC) from infected cattle, there was an increased presence of M. bovis in the extracellular compartment of infected macrophage cultures, as measured by incorporation of [3H]uracil into mycobacterial RNA. Furthermore, out of a panel of T‐cell clones from infected cattle, it was found that a higher proportion of CD8+ clones produced an increase in the number of metabolically active extracellular M. bovis organisms compared with CD4+ clones. Finally, a positive correlation between percentage of antigen‐dependent release of mycobacteria and total uracil uptake by M. bovis within culture systems was detected. This could be regarded as an indication of preferential intracellular control of mycobacteria by activated macrophages. PMID:10651937

  1. Inhibitory receptor expression on neonatal immune cells

    PubMed Central

    Walk, J; Westerlaken, G H A; van Uden, N O; Belderbos, M E; Meyaard, L; Bont, L J

    2012-01-01

    Neonates are born with quantitative and qualitative defects in both adaptive and innate immune responses. The immune system is regulated by several mechanisms, including the signalling of inhibitory receptors. Increased expression of inhibitory receptors may result in a higher threshold for activation and suppressed function of neonatal cells. The aim of this study was to determine whether the expression of seven inhibitory receptors is increased on neonatal immune cells compared to adult immune cells. In a healthy birth cohort, we examined the expression of seven inhibitory immune receptors on neonatal neutrophils, monocytes, natural killer (NK) cells, CD4+ and CD8+ T cells. The expression of leucocyte-associated immunoglobulin (Ig)-like receptor-1 (LAIR-1), signal inhibitory receptor on leucocytes-1 (SIRL-1), CD31, signal-regulatory protein alpha (SIRPα), Siglec-9, CD200R, immune receptor expressed on myeloid cells-1 (IREM-1) and the membrane-bound ligand CD200 was studied by flow cytometry on leucocytes in cord blood (n = 14), neonatal venous blood (n = 24) and adult venous blood (n = 22). Expression of LAIR-1, CD31 and CD200 was increased consistently across all neonatal T cell subsets. Neonatal monocytes exhibited decreased expression of LAIR-1 and IREM-1 compared to adults. Furthermore, cord blood and neonatal venous blood samples contained a distinct LAIR-1-positive neutrophil population, which was not detected in adult blood. We demonstrated distinct expression of inhibitory receptors on neonatal peripheral blood immune cells in a healthy birth cohort. This is the first evidence that inhibitory receptors play a role in regulation of the neonatal immune system. Consistently increased inhibitory receptor expression on T cells may be an important mechanism in preventing the development of allergy and autoimmunity. PMID:22774991

  2. Inhibitory receptor expression on neonatal immune cells.

    PubMed

    Walk, J; Westerlaken, G H A; van Uden, N O; Belderbos, M E; Meyaard, L; Bont, L J

    2012-08-01

    Neonates are born with quantitative and qualitative defects in both adaptive and innate immune responses. The immune system is regulated by several mechanisms, including the signalling of inhibitory receptors. Increased expression of inhibitory receptors may result in a higher threshold for activation and suppressed function of neonatal cells. The aim of this study was to determine whether the expression of seven inhibitory receptors is increased on neonatal immune cells compared to adult immune cells. In a healthy birth cohort, we examined the expression of seven inhibitory immune receptors on neonatal neutrophils, monocytes, natural killer (NK) cells, CD4(+) and CD8(+)T cells. The expression of leucocyte-associated immunoglobulin (Ig)-like receptor-1 (LAIR-1), signal inhibitory receptor on leucocytes-1 (SIRL-1), CD31, signal-regulatory protein alpha (SIRPα), Siglec-9, CD200R, immune receptor expressed on myeloid cells-1 (IREM-1) and the membrane-bound ligand CD200 was studied by flow cytometry on leucocytes in cord blood (n = 14), neonatal venous blood (n = 24) and adult venous blood (n = 22). Expression of LAIR-1, CD31 and CD200 was increased consistently across all neonatal T cell subsets. Neonatal monocytes exhibited decreased expression of LAIR-1 and IREM-1 compared to adults. Furthermore, cord blood and neonatal venous blood samples contained a distinct LAIR-1-positive neutrophil population, which was not detected in adult blood. We demonstrated distinct expression of inhibitory receptors on neonatal peripheral blood immune cells in a healthy birth cohort. This is the first evidence that inhibitory receptors play a role in regulation of the neonatal immune system. Consistently increased inhibitory receptor expression on T cells may be an important mechanism in preventing the development of allergy and autoimmunity. PMID:22774991

  3. The role of cystatins in cells of the immune system.

    PubMed

    Kopitar-Jerala, Natasa

    2006-11-27

    The cystatins constitute a large group of evolutionary related proteins with diverse biological activities. Initially, they were characterized as inhibitors of lysosomal cysteine proteases - cathepsins. Cathepsins are involved in processing and presentation of antigens, as well as several pathological conditions such as inflammation and cancer. Recently, alternative functions of cystatins have been proposed: they also induce tumour necrosis factor and interleukin 10 synthesis and stimulate nitric oxide production. The aim of the present review was the analysis of data on cystatins from NCBI GEO database and the literature, and obtained in microarray and serial analysis of gene expression (SAGE) experiments. The expression of cystatins A, B, C, and F in macrophages, dendritic cells and natural killer cells of the immune system, during differentiation and activation is discussed. PMID:17098233

  4. Alterations in marginal zone macrophages and marginal zone B cells in old mice.

    PubMed

    Birjandi, Shirin Z; Ippolito, Jill A; Ramadorai, Anand K; Witte, Pamela L

    2011-03-15

    Marginal zones (MZs) are architecturally organized for clearance of and rapid response against blood-borne Ags entering the spleen. MZ macrophages (MZMs) and MZ B cells are particularly important in host defense against T-independent pathogens and may be crucial for the prevention of diseases, such as streptococcal pneumonia, that are devastating in older patients. Our objective was to determine whether there are changes in the cellular components of the MZ between old and young mice. Using immunocytochemistry and a blinded scoring system, we observed gross architectural changes in the MZs of old mice, including reduction in the abundance of MZMs surrounding the MZ sinus as well as disruptions in positioning of mucosal addressin cell adhesion molecule 1 (MAdCAM-1)(+) sinus lining cells and metallophilic macrophages. Loss of frequency of MZMs was corroborated by flow cytometry. A majority of old mice also showed reduced frequency of MZ B cells, which correlated with decreased abundance of MZM in individual old mice. The spleens of old mice showed less deposition of intravenously injected dextran particles within the MZ, likely because of the decreased frequency in MZMs, because SIGN-R1 expression was not reduced on MZM from old mice. The phagocytic ability of individual MZMs was examined using Staphylococcus aureus bioparticles, and no differences in phagocytosis were found between macrophages from young or old spleens. In summary, an anatomical breakdown of the MZ occurs in advanced age, and a reduction in frequency of MZM may affect the ability of the MZM compartment to clear blood-borne Ags and mount proper T-independent immune responses. PMID:21307289

  5. Orchestration of Angiogenesis by Immune Cells

    PubMed Central

    Bruno, Antonino; Pagani, Arianna; Pulze, Laura; Albini, Adriana; Dallaglio, Katiuscia; Noonan, Douglas M.; Mortara, Lorenzo

    2014-01-01

    It is widely accepted that the tumor microenvironment (TUMIC) plays a major role in cancer and is indispensable for tumor progression. The TUMIC involves many “players” going well beyond the malignant-transformed cells, including stromal, immune, and endothelial cells (ECs). The non-malignant cells can acquire tumor-promoting functions during carcinogenesis. In particular, these cells can “orchestrate” the “symphony” of the angiogenic switch, permitting the creation of new blood vessels that allows rapid expansion and progression toward malignancy. Considerable attention within the context of tumor angiogenesis should focus not only on the ECs, representing a fundamental unit, but also on immune cells and on the inflammatory tumor infiltrate. Immune cells infiltrating tumors typically show a tumor-induced polarization associated with attenuation of anti-tumor functions and generation of pro-tumor activities, among these angiogenesis. Here, we propose a scenario suggesting that the angiogenic switch is an immune switch arising from the pro-angiogenic polarization of immune cells. This view links immunity, inflammation, and angiogenesis to tumor progression. Here, we review the data in the literature and seek to identify the “conductors” of this “orchestra.” We also suggest that interrupting the immune → inflammation → angiogenesis → tumor progression process can delay or prevent tumor insurgence and malignant disease. PMID:25072019

  6. Reciprocal interactions between endothelial cells and macrophages in angiogenic vascular niches

    SciTech Connect

    Baer, Caroline; Squadrito, Mario Leonardo; Iruela-Arispe, M. Luisa; De Palma, Michele

    2013-07-01

    The ability of macrophages to promote vascular growth has been associated with the secretion and local delivery of classic proangiogenic factors (e.g., VEGF-A and proteases). More recently, a series of studies have also revealed that physical contact of macrophages with growing blood vessels coordinates vascular fusion of emerging sprouts. Interestingly, the interactions between macrophages and vascular endothelial cells (ECs) appear to be bidirectional, such that activated ECs also support the expansion and differentiation of proangiogenic macrophages from myeloid progenitors. Here, we discuss recent findings suggesting that dynamic angiogenic vascular niches might also exist in vivo, e.g. in tumors, where sprouting blood vessels and immature myeloid cells like monocytes engage in heterotypic interactions that are required for angiogenesis. Finally, we provide an account of emerging mechanisms of cell-to-cell communication that rely on secreted microvesicles, such as exosomes, which can offer a vehicle for the rapid exchange of molecules and genetic information between macrophages and ECs engaged in angiogenesis. -- Highlights: • Macrophages promote angiogenesis by secreting proangiogenic factors. • Macrophages modulate angiogenesis via cell-to-cell contacts with endothelial cells. • Endothelial cells promote the differentiation of proangiogenic macrophages. • Macrophages and endothelial cells may cooperate to form angiogenic vascular niches.

  7. Macrophage recognition of cells with elevated calcium is mediated by carbohydrate chains of CD43.

    PubMed

    Miki, Yuichi; Oguri, Emiri; Hirano, Kazuya; Beppu, Masatoshi

    2013-01-01

    Macrophages remove deteriorating cells (those undergoing apoptosis and oxidation) via poly-N-acetyllactosaminyl chains on CD43 caps, a major cell-surface glycoprotein. Unusually high intracellular calcium levels are also deteriorating for cells and tissue. Here we artificially elevated calcium levels in cells and examined the mechanism by which this elevation was resolved by macrophages. Results showed that treatment with the calcium ionophore A23187 and ionomycin induces capping of CD43 on Jurkat cells, which are subsequently recognized and phagocytosed by macrophages, indicating that macrophages regard cells with elevated calcium as targets for removal. Further tests showed that A23187- and ionomycin-treated Jurkat cells did not induce apoptotic changes such as DNA fragmentation or phosphatidylserine expression, indicating that these cells were removed despite still being viable. Jurkat cells pretreated with anti-CD43 antibody or those with poly-N-acetyllactosaminyl chains containing oligosaccharides inhibited macrophage binding, indicating that macrophages recognize the poly-N-acetyllactosaminyl chains on CD43. Binding was also inhibited by treating macrophages with anti-nucleolin antibody, indicating that recognition occurs through nucleolin, a cell-surface receptor. Further, nucleolin-transfected HEK293 cells bound A23187-treated cells, and this binding was inhibited by in the presence of oligosaccharides. Taken together, these results show that elevated calcium levels induce CD43 capping, and macrophages remove the cells if their nucleolin receptors can bind to the poly-N-acetyllactosaminyl chains of capped CD43. PMID:23400223

  8. Dickkopf-3 Contributes to the Regulation of Anti-Tumor Immune Responses by Mesenchymal Stem Cells

    PubMed Central

    Lu, Kun-Hui; Tounsi, Amel; Shridhar, Naveen; Küblbeck, Günter; Klevenz, Alexandra; Prokosch, Sandra; Bald, Tobias; Tüting, Thomas; Arnold, Bernd

    2015-01-01

    Mesenchymal stem cells (MSCs) are known to limit immune responses in vivo by multiple soluble factors. Dickkopf-3 (DKK3), a secreted glycoprotein, has recently been identified as a novel immune modulator. Since DKK3 has been reported to be produced by MSCs, we investigated whether DKK3 contributes to the immune suppression of anti-tumor responses by MSCs. Whereas wild-type MSCs inhibited immune responses against two different transplantation tumors, DKK3-deficient MSCs did not affect the rejection process. Increased CD8+ T cell and reduced M2-type macrophages infiltration was observed in tumors inoculated together with DKK3-deficient MSCs. Thus, DKK3 could alter the composition of the tumor stroma, thereby supporting the MSCs-mediated suppression of immune responses against these tumor transplants. PMID:26734010

  9. Subversion of Cell-Autonomous Immunity and Cell Migration by Legionella pneumophila Effectors

    PubMed Central

    Simon, Sylvia; Hilbi, Hubert

    2015-01-01

    Bacteria trigger host defense and inflammatory processes, such as cytokine production, pyroptosis, and the chemotactic migration of immune cells toward the source of infection. However, a number of pathogens interfere with these immune functions by producing specific so-called “effector” proteins, which are delivered to host cells via dedicated secretion systems. Air-borne Legionella pneumophila bacteria trigger an acute and potential fatal inflammation in the lung termed Legionnaires’ disease. The opportunistic pathogen L. pneumophila is a natural parasite of free-living amoebae, but also replicates in alveolar macrophages and accidentally infects humans. The bacteria employ the intracellular multiplication/defective for organelle trafficking (Icm/Dot) type IV secretion system and as many as 300 different effector proteins to govern host–cell interactions and establish in phagocytes an intracellular replication niche, the Legionella-containing vacuole. Some Icm/Dot-translocated effector proteins target cell-autonomous immunity or cell migration, i.e., they interfere with (i) endocytic, secretory, or retrograde vesicle trafficking pathways, (ii) organelle or cell motility, (iii) the inflammasome and programed cell death, or (iv) the transcription factor NF-κB. Here, we review recent mechanistic insights into the subversion of cellular immune functions by L. pneumophila. PMID:26441958

  10. Subversion of Cell-Autonomous Immunity and Cell Migration by Legionella pneumophila Effectors.

    PubMed

    Simon, Sylvia; Hilbi, Hubert

    2015-01-01

    Bacteria trigger host defense and inflammatory processes, such as cytokine production, pyroptosis, and the chemotactic migration of immune cells toward the source of infection. However, a number of pathogens interfere with these immune functions by producing specific so-called "effector" proteins, which are delivered to host cells via dedicated secretion systems. Air-borne Legionella pneumophila bacteria trigger an acute and potential fatal inflammation in the lung termed Legionnaires' disease. The opportunistic pathogen L. pneumophila is a natural parasite of free-living amoebae, but also replicates in alveolar macrophages and accidentally infects humans. The bacteria employ the intracellular multiplication/defective for organelle trafficking (Icm/Dot) type IV secretion system and as many as 300 different effector proteins to govern host-cell interactions and establish in phagocytes an intracellular replication niche, the Legionella-containing vacuole. Some Icm/Dot-translocated effector proteins target cell-autonomous immunity or cell migration, i.e., they interfere with (i) endocytic, secretory, or retrograde vesicle trafficking pathways, (ii) organelle or cell motility, (iii) the inflammasome and programed cell death, or (iv) the transcription factor NF-κB. Here, we review recent mechanistic insights into the subversion of cellular immune functions by L. pneumophila. PMID:26441958

  11. The Process of Macrophage Migration Promotes Matrix Metalloproteinase-Independent Invasion by Tumor Cells

    PubMed Central

    Guiet, Romain; Van Goethem, Emeline; Cougoule, Céline; Balor, Stéphanie; Valette, Annie; Saati, Talal Al; Lowell, Clifford A.; Le Cabec, Véronique; Maridonneau-Parini, Isabelle

    2014-01-01

    Tumor-associated macrophages are known to amplify the malignant potential of tumors by secreting a variety of cytokines and proteases involved in tumor cell invasion and metastasis, but how these macrophages infiltrate tumors and whether the macrophage migration process facilitates tumor cell invasion remain poorly documented. To address these questions, we used cell spheroids of breast carcinoma SUM159PT cells as an in vitro model of solid tumors. We found that macrophages used both the mesenchymal mode requiring matrix metalloproteinases (MMPs) and the amoeboid migration mode to infiltrate tumor cell spheroids. Whereas individual SUM159PT cells invaded Matrigel using an MMP-dependent mesenchymal mode, when they were grown as spheroids, tumor cells were unable to invade the Matrigel surrounding spheroids. When spheroids were infiltrated or in contact with macrophages, tumor cell invasiveness was restored. It was dependent on the capacity of macrophages to remodel the matrix and migrate in an MMP-independent mesenchymal mode. This effect of macrophages was much reduced when spheroids were infiltrated by Matrigel migration-defective Hck−/− macrophages. In the presence of macrophages, SUM159PT migrated into Matrigel in the proximity of macrophages and switched from an MMP-dependent mesenchymal migration to an amoeboid mode resistant to protease inhibitors. Thus, in addition to the well-described paracrine loop between macrophages and tumor cells, macrophages can also contribute to the invasiveness of tumor cells by remodeling the extracellular matrix and by opening the way to exit the tumor and colonize the surrounding tissues in an MMP-dispensable manner. PMID:21880978

  12. The role of chemokines in recruitment of immune cells to the artery wall and adipose tissue.

    PubMed

    Surmi, Bonnie K; Hasty, Alyssa H

    2010-01-01

    The role of the immune system is to recognize pathogens, tumor cells or dead cells and to react with a very specific and localized response. By taking advantage of a highly sophisticated system of chemokines and chemokine receptors, leukocytes such as neutrophils, macrophages, and T-lymphocytes are targeted to the precise location of inflammation. While this is a beneficial process for acute infection and inflammation, recruitment of immune cells to sites of chronic inflammation can be detrimental. It is becoming clear that these inflammatory cells play a significant role in the initiation and progression of metabolic disorders such as atherosclerosis and insulin resistance by infiltrating the artery wall and adipose tissue (AT), respectively. Data from human studies indicate that elevated plasma levels of chemokines are correlated with these metabolic diseases. Recruitment of macrophages to the artery wall is well known to be one of the first steps in early atherosclerotic lesion formation. Likewise, recruitment of macrophages to AT is thought to contribute to insulin resistance associated with obesity. Based on this knowledge, much recent work in these areas has focused on the role of chemokines in attracting immune cells (monocytes/macrophages in particular) to these 2 sites. Thus, understanding the potential for chemokines to contribute to metabolic disease can help direct studies of chemokines as therapeutic targets. In this article, we will review current literature regarding the role of chemokines in atherosclerosis and obesity-related insulin resistance. We will focus on novel work showing that chemokine secretion from endothelial cells, platelets, and adipocytes can contribute to immune cell recruitment, with a diagram showing the time course of chemokine expression and leukocyte recruitment to AT. We will also highlight a few of the less-commonly known chemokine-chemokine receptor pairs. Finally, we will discuss the potential for chemokines as therapeutic targets for treatment of atherosclerosis and insulin resistance. PMID:20026286

  13. Immune interferon production by lymphoid cells: role in the inhibition of herpesviruses.

    PubMed Central

    Babiuk, L A; Rouse, B T

    1976-01-01

    Bovine peripheral blood lymphocytes (PBL) obtained from infectious bovine rhinotracheitis (IBR) virus- and tuberculin-immunized animals produced large quantities of interferon within 24 h of in vitro stimulation by IBR and purified protein derivative antigens. Separation of PBL into populations enriched in T lymphocytes or B lymphocyte provided the antigen-specific step for immune interferon production. A 2- to 10-fold increase in interferon occurred when lymphocytes were combined with autologous macrophages. Although macrophages, even if treated with antilymphocyte serum to remove any contaminating lymphocytes, could produce some interferon, the augmented interferon produced by macrophage-lypmhocyte cultures was not dmpocytes. Direct physical contact between macrophages and lymphocytes was required for the production of enhanced levels of interferon. Antigen-antibody complexes of irradiated virus-infected cells in the presence of antibody were as efficient or better at stimulating interferon than was free antigen. Because IBR virus was inhibited by interferon levels stimulated in cultures by IBR antigen, it was suggested that the local production of interferon by immune cells might play a similar role in curtailing virus dissemination in vivo, thus leading to recovery from disease. PMID:1085748

  14. Innate immune activation in the pathogenesis of a murine model of globoid cell leukodystrophy.

    PubMed

    Snook, Eric R; Fisher-Perkins, Jeanne M; Sansing, Hope A; Lee, Kim M; Alvarez, Xavier; MacLean, Andrew G; Peterson, Karin E; Lackner, Andrew A; Bunnell, Bruce A

    2014-02-01

    Globoid cell leukodystrophy is a lysosomal storage disease characterized by the loss of galactocerebrosidase. Galactocerebrosidase loss leads to the accumulation of psychosine and subsequent oligodendrocyte cell death, demyelination, macrophage recruitment, and astroglial activation and proliferation. To date, no studies have elucidated the mechanism of glial cell activation and cytokine and chemokine up-regulation and release. We explored a novel explanation for the development of the pathological changes in the early stages of globoid cell leukodystrophy associated with toll-like receptor (TLR) 2 up-regulation in the hindbrain and cerebellum as a response to dying oligodendrocytes. TLR2 up-regulation on microglia/macrophages coincided with morphological changes consistent with activation at 2 and 3 weeks of age. TLR2 up-regulation on activated microglia/macrophages resulted in astrocyte activation and marked up-regulation of cytokines/chemokines. Because oligodendrocyte cell death is an important feature of globoid cell leukodystrophy, we tested the ability of TLR2 reporter cells to respond to oligodendrocyte cell death. These reporter cells responded in vitro to medium conditioned by psychosine-treated oligodendrocytes, indicating the likelihood that oligodendrocytes release a TLR2 ligand during apoptosis. TLRs are a member of the innate immune system and initiate immune and inflammatory events; therefore, the identification of TLR2 as a potential driver in the activation of central nervous system glial activity in globoid cell leukodystrophy may provide important insight into its pathogenesis. PMID:24316110

  15. Lipids from Mycobacterium leprae cell wall are endowed with an anti-inflammatory property and inhibit macrophage function in vivo.

    PubMed

    Moura, A C; Mariano, M

    1996-12-01

    In general, the majority of bacteria are pre-inflammatory when injected in experimental animals. However, Mycobacterium leprae has no inflammatory effect when injected into mouse footpad, but using the delipidated mycobacteria we observed a mild significant increase in footpad oedema. Other mycobacteria, Mycobacterium bovis-BCG or M. tuberculosis induce a strong paw oedema. Furthermore, M. leprae reduced locally the BCG-induced inflammatory reaction in mouse footpad, whereas delipidated M. leprae did not influence this reaction. Both M. leprae and M. leprae cell wall lipids blocked immune phagocytosis in vivo by inflammatory macrophages (from an induced focus). In contrast delipidated M. leprae stimulated the phagocytosis reaction. Neither intact M. leprae. delipidated M. leprae, nor its lipids had any toxic effect on macrophages or on cell migration. Although M. leprae did not interfere on cell influx and cell type in an induced-inflammatory site, this mycobacterium led to the appearance of a distinct cell population in vivo. The hypothesis is that M. leprae would transform macrophages in epithelioid cells, suggested by morphology analysis of cells by fluorescence-activated cell sorter and observed under optic microscopy. PMID:9014830

  16. TLR2, TLR4 and Dectin-1 signalling in hematopoietic stem and progenitor cells determines the antifungal phenotype of the macrophages they produce.

    PubMed

    Megías, Javier; Martínez, Alba; Yáñez, Alberto; Goodridge, Helen S; Gozalbo, Daniel; Gil, M Luisa

    2016-05-01

    TLRs represent an attractive target for the stimulation of myeloid cell production by HSPCs. We have previously demonstrated that HSPCs use TLR2 to sense Candida albicans in vivo and induce the production of macrophages. In this work, we used an in vitro model of HSPCs differentiation to investigate the functional consequences for macrophages of exposure of HSPCs to various PAMPs and C. albicans cells. Mouse HSPCs (Lin(-) cells) were cultured with M-CSF to induce macrophage differentiation, in the presence or absence of the following PRR agonists: Pam3CSK4 (TLR2 ligand), LPS (TLR4 ligand), depleted zymosan (which only activates Dectin-1), or C. albicans yeasts (which activate several PRRs, but principally TLR2 and Dectin-1). Our data show that these PAMPs differentially impact the anti-microbial function of the macrophages produced by the exposed HSPCs. Pure TLR2 and TLR4 ligands generate macrophages with a diminished ability to produce inflammatory cytokines. In contrast, HSPCs activation in response to C. albicans leads to the generation of macrophages that are better prepared to deal with the infection, as they produce higher amounts of inflammatory cytokines and have higher fungicidal capacity than control macrophages. Therefore, the tailored manipulation of the differentiation process may help to boost the innate immune response to infection. PMID:26828664

  17. Keratinocyte growth factor augments pulmonary innate immunity through epithelium-driven, GM-CSF-dependent paracrine activation of alveolar macrophages.

    PubMed

    Wu, Huixing; Suzuki, Takuji; Carey, Brenna; Trapnell, Bruce C; McCormack, Francis X

    2011-04-29

    Keratinocyte growth factor (KGF) is an epithelial mitogen that has been reported to protect the lungs from a variety of insults. In this study, we tested the hypothesis that KGF augments pulmonary host defense. We found that a single dose of intrapulmonary KGF enhanced the clearance of Escherichia coli or Pseudomonas aeruginosa instilled into the lungs 24 h later. KGF augmented the recruitment, phagocytic activity, and oxidant responses of alveolar macrophages, including lipopolysaccharide-stimulated nitric oxide release and zymosan-induced superoxi