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Sample records for evades macrophage defenses

  1. Marine biofilm bacteria evade eukaryotic predation by targeted chemical defense.

    PubMed

    Matz, Carsten; Webb, Jeremy S; Schupp, Peter J; Phang, Shui Yen; Penesyan, Anahit; Egan, Suhelen; Steinberg, Peter; Kjelleberg, Staffan

    2008-07-23

    Many plants and animals are defended from predation or herbivory by inhibitory secondary metabolites, which in the marine environment are very common among sessile organisms. Among bacteria, where there is the greatest metabolic potential, little is known about chemical defenses against bacterivorous consumers. An emerging hypothesis is that sessile bacterial communities organized as biofilms serve as bacterial refuge from predation. By testing growth and survival of two common bacterivorous nanoflagellates, we find evidence that chemically mediated resistance against protozoan predators is common among biofilm populations in a diverse set of marine bacteria. Using bioassay-guided chemical and genetic analysis, we identified one of the most effective antiprotozoal compounds as violacein, an alkaloid that we demonstrate is produced predominately within biofilm cells. Nanomolar concentrations of violacein inhibit protozoan feeding by inducing a conserved eukaryotic cell death program. Such biofilm-specific chemical defenses could contribute to the successful persistence of biofilm bacteria in various environments and provide the ecological and evolutionary context for a number of eukaryote-targeting bacterial metabolites.

  2. Amphibian macrophage development and antiviral defenses.

    PubMed

    Grayfer, Leon; Robert, Jacques

    2016-05-01

    Macrophage lineage cells represent the cornerstone of vertebrate physiology and immune defenses. In turn, comparative studies using non-mammalian animal models have revealed that evolutionarily distinct species have adopted diverse molecular and physiological strategies for controlling macrophage development and functions. Notably, amphibian species present a rich array of physiological and environmental adaptations, not to mention the peculiarity of metamorphosis from larval to adult stages of development, involving drastic transformation and differentiation of multiple new tissues. Thus it is not surprising that different amphibian species and their respective tadpole and adult stages have adopted unique hematopoietic strategies. Accordingly and in order to establish a more comprehensive view of these processes, here we review the hematopoietic and monopoietic strategies observed across amphibians, describe the present understanding of the molecular mechanisms driving amphibian, an in particular Xenopus laevis macrophage development and functional polarization, and discuss the roles of macrophage-lineage cells during ranavirus infections.

  3. Macrophage defense mechanisms against intracellular bacteria

    PubMed Central

    Weiss, Günter; Schaible, Ulrich E

    2015-01-01

    Macrophages and neutrophils play a decisive role in host responses to intracellular bacteria including the agent of tuberculosis (TB), Mycobacterium tuberculosis as they represent the forefront of innate immune defense against bacterial invaders. At the same time, these phagocytes are also primary targets of intracellular bacteria to be abused as host cells. Their efficacy to contain and eliminate intracellular M. tuberculosis decides whether a patient initially becomes infected or not. However, when the infection becomes chronic or even latent (as in the case of TB) despite development of specific immune activation, phagocytes have also important effector functions. Macrophages have evolved a myriad of defense strategies to combat infection with intracellular bacteria such as M. tuberculosis. These include induction of toxic anti-microbial effectors such as nitric oxide and reactive oxygen intermediates, the stimulation of microbe intoxication mechanisms via acidification or metal accumulation in the phagolysosome, the restriction of the microbe's access to essential nutrients such as iron, fatty acids, or amino acids, the production of anti-microbial peptides and cytokines, along with induction of autophagy and efferocytosis to eliminate the pathogen. On the other hand, M. tuberculosis, as a prime example of a well-adapted facultative intracellular bacterium, has learned during evolution to counter-balance the host's immune defense strategies to secure survival or multiplication within this otherwise hostile environment. This review provides an overview of innate immune defense of macrophages directed against intracellular bacteria with a focus on M. tuberculosis. Gaining more insights and knowledge into this complex network of host-pathogen interaction will identify novel target sites of intervention to successfully clear infection at a time of rapidly emerging multi-resistance of M. tuberculosis against conventional antibiotics. PMID:25703560

  4. Macrophage defense mechanisms against intracellular bacteria.

    PubMed

    Weiss, Günter; Schaible, Ulrich E

    2015-03-01

    Macrophages and neutrophils play a decisive role in host responses to intracellular bacteria including the agent of tuberculosis (TB), Mycobacterium tuberculosis as they represent the forefront of innate immune defense against bacterial invaders. At the same time, these phagocytes are also primary targets of intracellular bacteria to be abused as host cells. Their efficacy to contain and eliminate intracellular M. tuberculosis decides whether a patient initially becomes infected or not. However, when the infection becomes chronic or even latent (as in the case of TB) despite development of specific immune activation, phagocytes have also important effector functions. Macrophages have evolved a myriad of defense strategies to combat infection with intracellular bacteria such as M. tuberculosis. These include induction of toxic anti-microbial effectors such as nitric oxide and reactive oxygen intermediates, the stimulation of microbe intoxication mechanisms via acidification or metal accumulation in the phagolysosome, the restriction of the microbe's access to essential nutrients such as iron, fatty acids, or amino acids, the production of anti-microbial peptides and cytokines, along with induction of autophagy and efferocytosis to eliminate the pathogen. On the other hand, M. tuberculosis, as a prime example of a well-adapted facultative intracellular bacterium, has learned during evolution to counter-balance the host's immune defense strategies to secure survival or multiplication within this otherwise hostile environment. This review provides an overview of innate immune defense of macrophages directed against intracellular bacteria with a focus on M. tuberculosis. Gaining more insights and knowledge into this complex network of host-pathogen interaction will identify novel target sites of intervention to successfully clear infection at a time of rapidly emerging multi-resistance of M. tuberculosis against conventional antibiotics. PMID:25703560

  5. Polyglycerol-coated nanodiamond as a macrophage-evading platform for selective drug delivery in cancer cells.

    PubMed

    Zhao, Li; Xu, Yong-Hong; Akasaka, Tsukasa; Abe, Shigeaki; Komatsu, Naoki; Watari, Fumio; Chen, Xiao

    2014-07-01

    A successful targeted drug delivery device for cancer chemotherapy should ideally be able to avoid non-specific uptake by nonmalignant cells, particularly the scavenging monocyte-macrophage system as well as targeting efficacy to bring the drug preferentially into tumor cells. To this purpose, we developed a platform based on detonation nanodiamond (dND) with hyperbranched polyglycerol (PG) coating (dND-PG). dND-PG was first demonstrated to evade non-specific cell uptake, particularly by macrophages (U937). RGD targeting peptide was then conjugated to dND-PG through multistep organic transformations to yield dND-PG-RGD that still evaded macrophage uptake but was preferentially taken up by targeted A549 cancer cells (expressing RGD peptide receptors). dND-PG and dND-PG-RGD showed good aqueous solubility and cytocompatibitlity. Subsequently, the anticancer agent doxorubicin (DOX) was loaded through acid-labile hydrazone linkage to yield dND-PG-DOX and dND-PG-RGD-DOX. Their cellular uptake and cytotoxicity were compared against DOX in A549 cells and U937 macrophages. It was found that dND-PG-DOX uptake was substantially reduced, displaying little toxicity in either type of cells by virtue of PG coating, whereas dND-PG-RGD-DOX exerted selective toxicity to A549 cells over U937 macrophages that are otherwise highly sensitive to DOX. Finally, dND-PG was demonstrated to have little influence on U937 macrophage cell functions, except for a slight increase of TNF-α production in resting U937 macrophages. dND-PG is a promising drug carrier for realization of highly selective drug delivery in tumor cells through specific uptake mechanisms, with minimum uptake in and influence on macrophages. PMID:24720879

  6. Selective pathogen targeting and macrophage evading carbon nanotubes through dextran sulfate coating and PEGylation for photothermal theranostics.

    PubMed

    Kotagiri, Nalinikanth; Lee, Ju Seok; Kim, Jin-Woo

    2013-06-01

    Single-walled carbon nanotubes (SWNTs) have shown promise as in vivo contrast nanoagents for medical theranostics, in particular photoacoustic and photothermal imaging and therapy, as well as targeted drug delivery systems. However, SWNTs have not proved able to evade biological obstacles, such as opsonization and phagocytosis by macrophage and nonspecific attachments to cells and other biological components in the bloodstream, before reaching target tissues and cells in vivo. Here, we demonstrate the stealth character of dextran sulfate (DS) coated SWNTs (DS-SWNTs) towards human macrophages and other biological barriers using Staphylococcus aureus, a bacterial pathogen, as a model. DS-SWNTs were compared to PEGylated SWNTs, a commonly accepted standard for rendering nanoparticles immune to opsonization. Also a new site-specific conjugation strategy was developed to functionalize antibody (Ab) on DS-SWNT in an upright way, enhancing their targeting efficiency. DS coating was proved to be resistant to opsonins and bacterial cells, demonstrating its potential to provide considerable stealth.character to SWNTs with excellent immunity versus macrophages and other biological barriers, and achieve prolonged blood circulation times. Moreover, the hybrid nanoagents could not only selectively bind to target pathogenic cells upon the controlled Ab attachment but also effectively eradicate pathogens after near-infrared laser irradiation. PMID:23858965

  7. 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

  8. Antioxidant Defenses of Francisella tularensis Modulate Macrophage Function and Production of Proinflammatory Cytokines.

    PubMed

    Rabadi, Seham M; Sanchez, Belkys C; Varanat, Mrudula; Ma, Zhuo; Catlett, Sally V; Melendez, Juan Andres; Malik, Meenakshi; Bakshi, Chandra Shekhar

    2016-03-01

    Francisella tularensis, the causative agent of a fatal human disease known as tularemia, has been used in the bioweapon programs of several countries in the past, and now it is considered a potential bioterror agent. Extreme infectivity and virulence of F. tularensis is due to its ability to evade immune detection and to suppress the host's innate immune responses. However, Francisella-encoded factors and mechanisms responsible for causing immune suppression are not completely understood. Macrophages and neutrophils generate reactive oxygen species (ROS)/reactive nitrogen species as a defense mechanism for the clearance of phagocytosed microorganisms. ROS serve a dual role; at high concentrations they act as microbicidal effector molecules that destroy intracellular pathogens, and at low concentrations they serve as secondary signaling messengers that regulate the expression of various inflammatory mediators. We hypothesized that the antioxidant defenses of F. tularensis maintain redox homeostasis in infected macrophages to prevent activation of redox-sensitive signaling components that ultimately result in suppression of pro-inflammatory cytokine production and macrophage microbicidal activity. We demonstrate that antioxidant enzymes of F. tularensis prevent the activation of redox-sensitive MAPK signaling components, NF-κB signaling, and the production of pro-inflammatory cytokines by inhibiting the accumulation of ROS in infected macrophages. We also report that F. tularensis inhibits ROS-dependent autophagy to promote its intramacrophage survival. Collectively, this study reveals novel pathogenic mechanisms adopted by F. tularensis to modulate macrophage innate immune functions to create an environment permissive for its intracellular survival and growth. PMID:26644475

  9. A Stenotrophomonas maltophilia Strain Evades a Major Caenorhabditis elegans Defense Pathway

    PubMed Central

    White, Corin V.; Darby, Brian J.; Breeden, Robert J.

    2015-01-01

    Stenotrophomonas maltophilia is a ubiquitous bacterium and an emerging nosocomial pathogen. This bacterium is resistant to many antibiotics, associated with a number of infections, and a significant health risk, especially for immunocompromised patients. Given that Caenorhabditis elegans shares many conserved genetic pathways and pathway components with higher organisms, the study of its interaction with bacterial pathogens has biomedical implications. S. maltophilia has been isolated in association with nematodes from grassland soils, and it is likely that C. elegans encounters this bacterium in nature. We found that a local S. maltophilia isolate, JCMS, is more virulent than the other S. maltophilia isolates (R551-3 and K279a) tested. JCMS virulence correlates with intestinal distension and bacterial accumulation and requires the bacteria to be alive. Many of the conserved innate immune pathways that serve to protect C. elegans from various pathogenic bacteria also play a role in combating S. maltophilia JCMS. However, S. maltophilia JCMS is virulent to normally pathogen-resistant DAF-2/16 insulin-like signaling pathway mutants. Furthermore, several insulin-like signaling effector genes were not significantly differentially expressed between S. maltophilia JCMS and avirulent bacteria (Escherichia coli OP50). Taken together, these findings suggest that S. maltophilia JCMS evades the pathogen resistance conferred by the loss of DAF-2/16 pathway components. In summary, we have discovered a novel host-pathogen interaction between C. elegans and S. maltophilia and established a new animal model with which to study the mode of action of this emerging nosocomial pathogen. PMID:26644380

  10. A Stenotrophomonas maltophilia Strain Evades a Major Caenorhabditis elegans Defense Pathway.

    PubMed

    White, Corin V; Darby, Brian J; Breeden, Robert J; Herman, Michael A

    2015-12-07

    Stenotrophomonas maltophilia is a ubiquitous bacterium and an emerging nosocomial pathogen. This bacterium is resistant to many antibiotics, associated with a number of infections, and a significant health risk, especially for immunocompromised patients. Given that Caenorhabditis elegans shares many conserved genetic pathways and pathway components with higher organisms, the study of its interaction with bacterial pathogens has biomedical implications. S. maltophilia has been isolated in association with nematodes from grassland soils, and it is likely that C. elegans encounters this bacterium in nature. We found that a local S. maltophilia isolate, JCMS, is more virulent than the other S. maltophilia isolates (R551-3 and K279a) tested. JCMS virulence correlates with intestinal distension and bacterial accumulation and requires the bacteria to be alive. Many of the conserved innate immune pathways that serve to protect C. elegans from various pathogenic bacteria also play a role in combating S. maltophilia JCMS. However, S. maltophilia JCMS is virulent to normally pathogen-resistant DAF-2/16 insulin-like signaling pathway mutants. Furthermore, several insulin-like signaling effector genes were not significantly differentially expressed between S. maltophilia JCMS and avirulent bacteria (Escherichia coli OP50). Taken together, these findings suggest that S. maltophilia JCMS evades the pathogen resistance conferred by the loss of DAF-2/16 pathway components. In summary, we have discovered a novel host-pathogen interaction between C. elegans and S. maltophilia and established a new animal model with which to study the mode of action of this emerging nosocomial pathogen.

  11. A Stenotrophomonas maltophilia Strain Evades a Major Caenorhabditis elegans Defense Pathway.

    PubMed

    White, Corin V; Darby, Brian J; Breeden, Robert J; Herman, Michael A

    2016-02-01

    Stenotrophomonas maltophilia is a ubiquitous bacterium and an emerging nosocomial pathogen. This bacterium is resistant to many antibiotics, associated with a number of infections, and a significant health risk, especially for immunocompromised patients. Given that Caenorhabditis elegans shares many conserved genetic pathways and pathway components with higher organisms, the study of its interaction with bacterial pathogens has biomedical implications. S. maltophilia has been isolated in association with nematodes from grassland soils, and it is likely that C. elegans encounters this bacterium in nature. We found that a local S. maltophilia isolate, JCMS, is more virulent than the other S. maltophilia isolates (R551-3 and K279a) tested. JCMS virulence correlates with intestinal distension and bacterial accumulation and requires the bacteria to be alive. Many of the conserved innate immune pathways that serve to protect C. elegans from various pathogenic bacteria also play a role in combating S. maltophilia JCMS. However, S. maltophilia JCMS is virulent to normally pathogen-resistant DAF-2/16 insulin-like signaling pathway mutants. Furthermore, several insulin-like signaling effector genes were not significantly differentially expressed between S. maltophilia JCMS and avirulent bacteria (Escherichia coli OP50). Taken together, these findings suggest that S. maltophilia JCMS evades the pathogen resistance conferred by the loss of DAF-2/16 pathway components. In summary, we have discovered a novel host-pathogen interaction between C. elegans and S. maltophilia and established a new animal model with which to study the mode of action of this emerging nosocomial pathogen. PMID:26644380

  12. Bordetella pertussis modulates human macrophage defense gene expression.

    PubMed

    Valdez, Hugo Alberto; Oviedo, Juan Marcos; Gorgojo, Juan Pablo; Lamberti, Yanina; Rodriguez, Maria Eugenia

    2016-08-01

    Bordetella pertussis, the etiological agent of whooping cough, still causes outbreaks. We recently found evidence that B. pertussis can survive and even replicate inside human macrophages, indicating that this host cell might serve as a niche for persistence. In this work, we examined the interaction of B. pertussis with a human monocyte cell line (THP-1) that differentiates into macrophages in culture in order to investigate the host cell response to the infection and the mechanisms that promote that intracellular survival. To that end, we investigated the expression profile of a selected number of genes involved in cellular bactericidal activity and the inflammatory response during the early and late phases of infection. The bactericidal and inflammatory response of infected macrophages was progressively downregulated, while the number of THP-1 cells heavily loaded with live bacteria increased over time postinfection. Two of the main toxins of B. pertussis, pertussis toxin (Ptx) and adenylate cyclase (CyaA), were found to be involved in manipulating the host cell response. Therefore, failure to express either toxin proved detrimental to the development of intracellular infections by those bacteria. Taken together, these results support the relevance of host defense gene manipulation to the outcome of the interaction between B. pertussis and macrophages.

  13. Bordetella pertussis modulates human macrophage defense gene expression.

    PubMed

    Valdez, Hugo Alberto; Oviedo, Juan Marcos; Gorgojo, Juan Pablo; Lamberti, Yanina; Rodriguez, Maria Eugenia

    2016-08-01

    Bordetella pertussis, the etiological agent of whooping cough, still causes outbreaks. We recently found evidence that B. pertussis can survive and even replicate inside human macrophages, indicating that this host cell might serve as a niche for persistence. In this work, we examined the interaction of B. pertussis with a human monocyte cell line (THP-1) that differentiates into macrophages in culture in order to investigate the host cell response to the infection and the mechanisms that promote that intracellular survival. To that end, we investigated the expression profile of a selected number of genes involved in cellular bactericidal activity and the inflammatory response during the early and late phases of infection. The bactericidal and inflammatory response of infected macrophages was progressively downregulated, while the number of THP-1 cells heavily loaded with live bacteria increased over time postinfection. Two of the main toxins of B. pertussis, pertussis toxin (Ptx) and adenylate cyclase (CyaA), were found to be involved in manipulating the host cell response. Therefore, failure to express either toxin proved detrimental to the development of intracellular infections by those bacteria. Taken together, these results support the relevance of host defense gene manipulation to the outcome of the interaction between B. pertussis and macrophages. PMID:27465637

  14. In vivo bronchoalveolar macrophage defense against Rhizopus oryzae and Aspergillus fumigatus.

    PubMed

    Waldorf, A R; Levitz, S M; Diamond, R D

    1984-11-01

    The ability of bronchoalveolar macrophages from normal, diabetic, and cortisone-treated mice to inhibit spore germination and kill fungal spores in vivo was investigated. The data indicated that the normal host controls different fungal infections in the lungs by different mechanisms. Prevention of mucormycosis required inhibition of fungal spore germination by alveolar macrophages. In contrast, pulmonary defense against aspergillosis depended on early killing of conidia by alveolar macrophages and not on inhibition of germination by bronchoalveolar macrophages. Bronchoalveolar macrophages in diabetic and cortisone-treated animals allowed fungal spore germination, thereby permitting infection by Rhizopus oryzae. In the cortisone-treated mouse, bronchoalveolar macrophages did not kill fungal conidia and progressive infection by Aspergillus fumigatus occurred. Fungicidal activity of bronchoalveolar macrophages was measured with a new in vivo killing assay.

  15. Mechanisms of Defense against Intracellular Pathogens Mediated by Human Macrophages.

    PubMed

    Bloom, Barry R; Modlin, Robert L

    2016-06-01

    The key question our work has sought to address has been, "What are the necessary and sufficient conditions that engender protection from intracellular pathogens in the human host?" The origins of this work derive from a long-standing interest in the mechanisms of protection against two such paradigmatic intracellular pathogens, Mycobacterium tuberculosis and Mycobacterium leprae, that have brilliantly adapted to the human host. It was obvious that these pathogens, which cause chronic diseases and persist in macrophages, must have acquired subtle strategies to resist host microbicidal mechanisms, yet since the vast majority of individuals infected with M. tuberculosis do not develop disease, there must be some potent human antimicrobial mechanisms. What follows is not a comprehensive review of the vast literature on the role of human macrophages in protection against infectious disease, but a summary of the research in our two laboratories with collaborators that we hope has contributed to some understanding of mechanisms of resistance and pathogenesis. While mouse models revealed some necessary conditions for protection, e.g., innate immunity, Th1 cells and their cytokines, and major histocompatibility complex class I-restricted T cells, here we emphasize multiple antimicrobial mechanisms that exist in human macrophages that differ from those of most experimental animals. Prominent here is the vitamin D-dependent antimicrobial pathway common to human macrophages activated by innate and acquired immune responses, mediated by antimicrobial peptides, e.g., cathelicidin, through an interleukin-15- and interleukin-32-dependent common pathway that is necessary for macrophage killing of M. tuberculosis in vitro. PMID:27337485

  16. PFKFB3-Driven Macrophage Glycolytic Metabolism Is a Crucial Component of Innate Antiviral Defense.

    PubMed

    Jiang, Hui; Shi, Hengfei; Sun, Man; Wang, Yafeng; Meng, Qingzhou; Guo, Panpan; Cao, Yanlan; Chen, Jiong; Gao, Xiang; Li, Erguang; Liu, Jianghuai

    2016-10-01

    Signaling by viral nucleic acids and subsequently by type I IFN is central to antiviral innate immunity. These signaling events are also likely to engage metabolic changes in immune and nonimmune cells to support antiviral defense. In this study, we show that cytosolic viral recognition, by way of secondary IFN signaling, leads to upregulation of glycolysis preferentially in macrophages. This metabolic switch involves induction of glycolytic activator 6-phosphofructose-2-kinase and fructose-2,6-bisphosphatase (PFKFB3). Using a genetic inactivation approach together with pharmacological perturbations in mouse cells, we show that PFKFB3-driven glycolysis selectively promotes the extrinsic antiviral capacity of macrophages, via metabolically supporting the engulfment and removal of virus-infected cells. Furthermore, the antiviral function of PFKFB3, as well as some contribution of its action from the hematopoietic compartment, was confirmed in a mouse model of respiratory syncytial virus infection. Therefore, different from the long-standing perception of glycolysis as a proviral pathway, our findings establish an antiviral, immunometabolic aspect of glycolysis that may have therapeutic implications. PMID:27566823

  17. Human Macrophage SCN5A Activates an Innate Immune Signaling Pathway for Antiviral Host Defense*

    PubMed Central

    Jones, Alexis; Kainz, Danielle; Khan, Faatima; Lee, Cara; Carrithers, Michael D.

    2014-01-01

    Pattern recognition receptors contain a binding domain for pathogen-associated molecular patterns coupled to a signaling domain that regulates transcription of host immune response genes. Here, a novel mechanism that links pathogen recognition to channel activation and downstream signaling is proposed. We demonstrate that an intracellular sodium channel variant, human macrophage SCN5A, initiates signaling and transcription through a calcium-dependent isoform of adenylate cyclase, ADCY8, and the transcription factor, ATF2. Pharmacological stimulation with a channel agonist or treatment with cytoplasmic poly(I:C), a mimic of viral dsRNA, activates this pathway to regulate expression of SP100-related genes and interferon β. Electrophysiological analysis reveals that the SCN5A variant mediates nonselective outward currents and a small, but detectable, inward current. Intracellular poly(I:C) markedly augments an inward voltage-sensitive sodium current and inhibits the outward nonselective current. These results suggest human macrophage SCN5A initiates signaling in an innate immune pathway relevant to antiviral host defense. It is postulated that SCN5A is a novel pathogen sensor and that this pathway represents a channel activation-dependent mechanism of transcriptional regulation. PMID:25368329

  18. Phosphoethanolamine Modification of Neisseria gonorrhoeae Lipid A Reduces Autophagy Flux in Macrophages.

    PubMed

    Zughaier, Susu M; Kandler, Justin L; Balthazar, Jacqueline T; Shafer, William M

    2015-01-01

    Autophagy, an ancient homeostasis mechanism for macromolecule degradation, performs an important role in host defense by facilitating pathogen elimination. To counteract this host defense strategy, bacterial pathogens have evolved a variety of mechanisms to avoid or otherwise dysregulate autophagy by phagocytic cells so as to enhance their survival during infection. Neisseria gonorrhoeae is a strictly human pathogen that causes the sexually transmitted infection, gonorrhea. Phosphoethanolamine (PEA) addition to the 4' position of the lipid A (PEA-lipid A) moiety of the lipooligosaccharide (LOS) produced by gonococci performs a critical role in this pathogen's ability to evade innate defenses by conferring decreased susceptibility to cationic antimicrobial (or host-defense) peptides, complement-mediated killing by human serum and intraleukocytic killing by human neutrophils compared to strains lacking this PEA decoration. Heretofore, however, it was not known if gonococci can evade autophagy and if so, whether PEA-lipid A contributes to this ability. Accordingly, by using murine macrophages and human macrophage-like phagocytic cell lines we investigated if PEA decoration of gonococcal lipid A modulates autophagy formation. We report that infection with PEA-lipid A-producing gonococci significantly reduced autophagy flux in murine and human macrophages and enhanced gonococcal survival during their association with macrophages compared to a PEA-deficient lipid A mutant. Our results provide further evidence that PEA-lipid A produced by gonococci is a critical component in the ability of this human pathogen to evade host defenses. PMID:26641098

  19. Cutaneous Na+ storage strengthens the antimicrobial barrier function of the skin and boosts macrophage-driven host defense.

    PubMed

    Jantsch, Jonathan; Schatz, Valentin; Friedrich, Diana; Schröder, Agnes; Kopp, Christoph; Siegert, Isabel; Maronna, Andreas; Wendelborn, David; Linz, Peter; Binger, Katrina J; Gebhardt, Matthias; Heinig, Matthias; Neubert, Patrick; Fischer, Fabian; Teufel, Stefan; David, Jean-Pierre; Neufert, Clemens; Cavallaro, Alexander; Rakova, Natalia; Küper, Christoph; Beck, Franz-Xaver; Neuhofer, Wolfgang; Muller, Dominik N; Schuler, Gerold; Uder, Michael; Bogdan, Christian; Luft, Friedrich C; Titze, Jens

    2015-03-01

    Immune cells regulate a hypertonic microenvironment in the skin; however, the biological advantage of increased skin Na(+) concentrations is unknown. We found that Na(+) accumulated at the site of bacterial skin infections in humans and in mice. We used the protozoan parasite Leishmania major as a model of skin-prone macrophage infection to test the hypothesis that skin-Na(+) storage facilitates antimicrobial host defense. Activation of macrophages in the presence of high NaCl concentrations modified epigenetic markers and enhanced p38 mitogen-activated protein kinase (p38/MAPK)-dependent nuclear factor of activated T cells 5 (NFAT5) activation. This high-salt response resulted in elevated type-2 nitric oxide synthase (Nos2)-dependent NO production and improved Leishmania major control. Finally, we found that increasing Na(+) content in the skin by a high-salt diet boosted activation of macrophages in a Nfat5-dependent manner and promoted cutaneous antimicrobial defense. We suggest that the hypertonic microenvironment could serve as a barrier to infection. PMID:25738463

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

    PubMed

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

    2006-03-01

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

  1. Lipocalin-2 ensures host defense against Salmonella Typhimurium by controlling macrophage iron homeostasis and immune response

    PubMed Central

    Nairz, Manfred; Schroll, Andrea; Haschka, David; Dichtl, Stefanie; Sonnweber, Thomas; Theurl, Igor; Theurl, Milan; Lindner, Ewald; Demetz, Egon; Aβhoff, Malte; Bellmann-Weiler, Rosa; Müller, Raphael; Gerner, Romana R.; Moschen, Alexander R.; Baumgartner, Nadja; Moser, Patrizia L.; Talasz, Heribert; Tilg, Herbert; Fang, Ferric C.; Weiss, Günter

    2015-01-01

    Lipocalin-2 (Lcn2) is an innate immune peptide with pleiotropic effects. Lcn2 binds iron-laden bacterial siderophores, chemo-attracts neutrophils and has immunomodulatory and apoptosis-regulating effects. In this study we show that upon infection with Salmonella enterica serovar Typhimurium, Lcn2 promotes iron export from Salmonella-infected macrophages, which reduces cellular iron content and enhances the generation of pro-inflammatory cytokines. Lcn2 represses IL-10 production while augmenting Nos2, TNF-α and IL-6 expression. Lcn2-/- macrophages have elevated IL-10 levels as a consequence of increased iron content. The crucial role of Lcn-2/IL-10 interactions was further demonstrated by the greater ability of Lcn2-/- IL-10-/- macrophages and mice to control intracellular Salmonella proliferation in comparison to Lcn2-/- counterparts. Over-expression of the iron exporter ferroportin-1 in Lcn2-/- macrophages represses IL-10 and restores TNF-α and IL-6 production to the levels found in wild-type macrophages, so that killing and clearance of intracellular Salmonella is promoted. Our observations suggest that Lcn2 promotes host resistance to Salmonella Typhimurium infection by binding bacterial siderophores and suppressing IL-10 production, and that both functions are linked to its ability to shuttle iron from macrophages. PMID:26332507

  2. Mitochondrial respiratory-chain adaptations in macrophages contribute to antibacterial host defense.

    PubMed

    Garaude, Johan; Acín-Pérez, Rebeca; Martínez-Cano, Sarai; Enamorado, Michel; Ugolini, Matteo; Nistal-Villán, Estanislao; Hervás-Stubbs, Sandra; Pelegrín, Pablo; Sander, Leif E; Enríquez, José A; Sancho, David

    2016-09-01

    Macrophages tightly scale their core metabolism after being activated, but the precise regulation of the mitochondrial electron-transport chain (ETC) and its functional implications are currently unknown. Here we found that recognition of live bacteria by macrophages transiently decreased assembly of the ETC complex I (CI) and CI-containing super-complexes and switched the relative contributions of CI and CII to mitochondrial respiration. This was mediated by phagosomal NADPH oxidase and the reactive oxygen species (ROS)-dependent tyrosine kinase Fgr. It required Toll-like receptor signaling and the NLRP3 inflammasome, which were both connected to bacterial viability-specific immune responses. Inhibition of CII during infection with Escherichia coli normalized serum concentrations of interleukin 1β (IL-1β) and IL-10 to those in mice treated with dead bacteria and impaired control of bacteria. We have thus identified ETC adaptations as an early immunological-metabolic checkpoint that adjusts innate immune responses to bacterial infection.

  3. Contributions of dendritic cells and macrophages to intestinal homeostasis and immune defense.

    PubMed

    Farache, Julia; Zigmond, Ehud; Shakhar, Guy; Jung, Steffen

    2013-03-01

    Intestinal mononuclear phagocytes have collectively emerged as key players in the maintenance of gut homeostasis, the development of gut inflammation and its resolution. Moreover, recent intense research efforts of many laboratories have revealed evidence for critical labor division between lamina propria-resident CD103(+) dendritic cells and CX3CR1(+) macrophages. In depth understanding of the respective activities of these cells in the mucosal landscape might pave the way for novel treatments of inflammatory bowel disorders (IBD).

  4. Interdiction of a Markovian evader

    SciTech Connect

    Hagberg, Aric; Izraelevitz, David; Pan, Feng; Gutfraind, Alexander

    2008-01-01

    Network interdiction is a combinatorial optimization problem on an activity network arising in a number of important security-related applications. It is classically formulated as a bilevel maximin problem representing an 'interdictor' and an 'evader'. The evader tries to move from a source node to the target node along the shortest or safest path while the interdictor attempts to frustrate this motion by cutting edges or nodes. The interdiction objective is to find the optimal set of edges to cut given that there is a finite interdiction budget and the interdictor must move first. We reformulate the interdiction problem for stochastic evaders by introducing a model in which the evader follows a Markovian random walk guided by the least-cost path to the target. This model can represent incomplete knowledge about the evader and the graph as well as partial interdiction. We formulate the optimization problem for this model and show how, by exploiting topological ordering of the nodes, one can achieve an order-of-magnitude speedup in computing the objective function. We also introduce an evader-motion-based heuristic that can significantly improve solution quality by providing a global view of the network to approximation methods.

  5. The late endosomal adaptor p14 is a macrophage host-defense factor against Salmonella infection.

    PubMed

    Taub, Nicole; Nairz, Manfred; Hilber, Diana; Hess, Michael W; Weiss, Günter; Huber, Lukas A

    2012-06-01

    The outcome of an infection depends on the balance between host resistance and bacterial virulence. Here, we show that the late endosomal adaptor p14 (also known as LAMTOR2) is one of the components for cellular host defense against the intracellular pathogen Salmonella enterica serovar Typhimurium. During Salmonella infection, the complex of p14 and MP1 is required for the accurately timed transport of Salmonella through the endolysosomal system. Loss of p14 opens a time window that allows Salmonella to populate a replication niche, in which early and late antimicrobial effector systems, comprising NADPH phagocytic oxidase and inducible nitric oxide synthase, respectively, are inappropriately activated. Thus, p14 supports the accurate transport of Salmonella through the endolysosomal system, thereby limiting bacterial replication in both, professional phagocytes and in non-phagocytic cells in vitro, and helps mice to successfully battle Salmonella infection in vivo.

  6. Evader Interdiction and Collateral Damage

    SciTech Connect

    Gutfraind, Alexander

    2011-01-01

    In network interdiction problems, evaders (hostile agents or data packets) are moving through a network towards their targets and we wish to choose sensor placement locations in order to intercept them before they reach their destinations. Sensor locations should be chosen economically, balancing security gains with cost, including the inconvenience sensors inflict upon innocent travelers. We give optimal sensor allocation algorithms for several classes of special graphs and hardness and optimal approximation results for general graphs, including for deterministic or Markov chain-based and oblivious or reactive evaders. In a similar-sounding but much different problem setting posed by [10] where the innocent travelers can also be reactive, we again give optimal algorithms for special cases and hardness and (essentially) optimal approximation results on general graphs.

  7. Leishmania amazonensis amastigotes highly express a tryparedoxin peroxidase isoform that increases parasite resistance to macrophage antimicrobial defenses and fosters parasite virulence.

    PubMed

    Henard, Calvin A; Carlsen, Eric D; Hay, Christie; Kima, Peter E; Soong, Lynn

    2014-07-01

    Professional phagocytes generate a myriad of antimicrobial molecules to kill invading microorganisms, of which nitrogen oxides are integral in controlling the obligate intracellular pathogen Leishmania. Although reactive nitrogen species produced by the inducible nitric oxide synthase (iNOS) can promote the clearance of intracellular parasites, some Leishmania species/stages are relatively resistant to iNOS-mediated antimicrobial activity. The underlying mechanism for this resistance remains largely uncharacterized. Here, we show that the amastigote form of L. amazonensis is hyper-resistant to the antimicrobial actions of cytokine-activated murine and human macrophages as compared to its promastigote counterpart. Amastigotes exhibit a marked ability to directly counter the cytotoxicity of peroxynitrite (ONOO-), a leishmanicidal oxidant that is generated during infection through the combined enzymatic activities of NADPH oxidase and iNOS. The enhanced antinitrosative defense of amastigotes correlates with the increased expression of a tryparedoxin peroxidase (TXNPx) isoform that is also upregulated in response to iNOS enzymatic activity within infected macrophages. Accordingly, ectopic over-expression of the TXNPx isoform by L. amazonensis promastigotes significantly enhances parasite resistance against ONOO- cytotoxicity. Moreover, TXNPx-overexpressing parasites exhibit greater intra-macrophage survival, and increased parasite growth and lesion development in a murine model of leishmaniasis. Our investigations indicate that TXNPx isoforms contribute to Leishmania's ability to adapt to and antagonize the hostile microenvironment of cytokine-activated macrophages, and provide a mechanistic explanation for persistent infection in experimental and human leishmaniasis.

  8. Leishmania amazonensis Amastigotes Highly Express a Tryparedoxin Peroxidase Isoform That Increases Parasite Resistance to Macrophage Antimicrobial Defenses and Fosters Parasite Virulence

    PubMed Central

    Henard, Calvin A.; Carlsen, Eric D.; Hay, Christie; Kima, Peter E.; Soong, Lynn

    2014-01-01

    Professional phagocytes generate a myriad of antimicrobial molecules to kill invading microorganisms, of which nitrogen oxides are integral in controlling the obligate intracellular pathogen Leishmania. Although reactive nitrogen species produced by the inducible nitric oxide synthase (iNOS) can promote the clearance of intracellular parasites, some Leishmania species/stages are relatively resistant to iNOS-mediated antimicrobial activity. The underlying mechanism for this resistance remains largely uncharacterized. Here, we show that the amastigote form of L. amazonensis is hyper-resistant to the antimicrobial actions of cytokine-activated murine and human macrophages as compared to its promastigote counterpart. Amastigotes exhibit a marked ability to directly counter the cytotoxicity of peroxynitrite (ONOO−), a leishmanicidal oxidant that is generated during infection through the combined enzymatic activities of NADPH oxidase and iNOS. The enhanced antinitrosative defense of amastigotes correlates with the increased expression of a tryparedoxin peroxidase (TXNPx) isoform that is also upregulated in response to iNOS enzymatic activity within infected macrophages. Accordingly, ectopic over-expression of the TXNPx isoform by L. amazonensis promastigotes significantly enhances parasite resistance against ONOO− cytotoxicity. Moreover, TXNPx-overexpressing parasites exhibit greater intra-macrophage survival, and increased parasite growth and lesion development in a murine model of leishmaniasis. Our investigations indicate that TXNPx isoforms contribute to Leishmania's ability to adapt to and antagonize the hostile microenvironment of cytokine-activated macrophages, and provide a mechanistic explanation for persistent infection in experimental and human leishmaniasis. PMID:25033301

  9. Arginase II Restricts Host Defense to Helicobacter pylori by Attenuating Inducible Nitric Oxide Synthase Translation in Macrophages

    PubMed Central

    Lewis, Nuruddeen D.; Asim, Mohammad; Barry, Daniel P.; Singh, Kshipra; de Sablet, Thibaut; Boucher, Jean-Luc; Gobert, Alain P.; Chaturvedi, Rupesh; Wilson, Keith T.

    2010-01-01

    Helicobacter pylori infection of the stomach causes peptic ulcer disease and gastric cancer. Despite eliciting a vigorous immune response, the bacterium persists for the life of the host. An important antimicrobial mechanism is the production of NO derived from inducible NO synthase (iNOS). We have reported that macrophages can kill H. pylori in vitro by an NO-dependent mechanism, but supraphysiologic levels of the iNOS substrate L-arginine are required. Because H. pylori induces arginase activity in macrophages, we determined if this restricts NO generation by reducing L-arginine availability. Inhibition of arginase with S-(2-boronoethyl)-L-cysteine (BEC) significantly enhanced NO generation in H. pylori-stimulated RAW 264.7 macrophages by enhancing iNOS protein translation but not iNOS mRNA levels. This effect resulted in increased killing of H. pylori that was attenuated with an NO scavenger. In contrast, inhibition of arginase in macrophages activated by the colitis-inducing bacterium Citrobacter rodentium increased NO without affecting iNOS levels. H. pylori upregulated levels of arginase II (Arg2) mRNA and protein, which localized to mitochondria, whereas arginase I was not induced. Increased iNOS protein and NO levels were also demonstrated by small interfering RNA knockdown of Arg2 and in peritoneal macrophages from C57BL/6 Arg2−/− mice. In H. pylori-infected mice, treatment with BEC or deletion of Arg2 increased iNOS protein levels and NO generation in gastric macrophages, but treatment of Arg2−/− mice with BEC had no additional effect. These studies implicate Arg2 in the immune evasion of H. pylori by causing intracellular depletion of L-arginine and thus reduction of NO-dependent bactericidal activity. PMID:20097867

  10. Optimal interdiction of unreactive Markovian evaders

    SciTech Connect

    Hagberg, Aric; Pan, Feng; Gutfraind, Alex

    2009-01-01

    The interdiction problem arises in a variety of areas including military logistics, infectious disease control, and counter-terrorism. In the typical formulation of network interdiction. the task of the interdictor is to find a set of edges in a weighted network such that the removal of those edges would increase the cost to an evader of traveling on a path through the network. Our work is motivated by cases in which the evader has incomplete information about the network or lacks planning time or computational power, e.g. when authorities set up roadblocks to catch bank robbers, the criminals do not know all the roadblock locations or the best path to use for their escape. We introduce a model of network interdiction in which the motion of one or more evaders is described by Markov processes on a network and the evaders are assumed not to react to interdiction decisions. The interdiction objective is to find a node or set. of size at most B, that maximizes the probability of capturing the evaders. We prove that similar to the classical formulation this interdiction problem is NP-hard. But unlike the classical problem our interdiction problem is submodular and the optimal solution can be approximated within 1-lie using a greedy algorithm. Additionally. we exploit submodularity to introduce a priority evaluation strategy that speeds up the greedy algorithm by orders of magnitude. Taken together the results bring closer the goal of finding realistic solutions to the interdiction problem on global-scale networks.

  11. A Leishmania Ortholog of Macrophage Migration Inhibitory Factor Modulates Host Macrophage Responses

    SciTech Connect

    Kamir,D.; Zierow, S.; Leng, L.; Cho, Y.; Diaz, Y.; Griffith, J.; McDonald, C.; Merk, M.; Mitchell, R.; et al

    2008-01-01

    Parasitic organisms have evolved specialized strategies to evade immune defense mechanisms. We describe herein an ortholog of the cytokine, macrophage migration inhibitory factor (MIF), which is produced by the obligate intracellular parasite, Leishmania major. The Leishmania MIF protein, Lm1740MIF, shows significant structural homology with human MIF as revealed by a high-resolution x-ray crystal structure (1.03 A). Differences between the two proteins in the N-terminal tautomerization site are evident, and we provide evidence for the selective, species-specific inhibition of MIF by small-molecule antagonists that target this site. Lm1740MIF shows significant binding interaction with the MIF receptor, CD74 (K(d) = 2.9 x 10(-8) M). Like its mammalian counterpart, Lm1740MIF induces ERK1/2 MAP kinase activation in a CD74-dependent manner and inhibits the activation-induced apoptosis of macrophages. The ability of Lm1740MIF to inhibit apoptosis may facilitate the persistence of Leishmania within the macrophage and contribute to its evasion from immune destruction.

  12. A Leishmania Ortholog of Macrophage Migration Inhibitory Factor Modulates Host Macrophage Responses1

    PubMed Central

    Kamir, Daniela; Zierow, Swen; Leng, Lin; Cho, Yoonsang; Diaz, Yira; Griffith, Jason; McDonald, Courtney; Merk, Melanie; Mitchell, Robert A.; Trent, John; Chen, Yibang; Kwong, Yuen-Kwan Amy; Xiong, Huabao; Vermeire, Jon; Cappello, Michael; McMahon-Pratt, Diane; Walker, John; Bernhagen, Jurgen; Lolis, Elias; Bucala, Richard

    2009-01-01

    Parasitic organisms have evolved specialized strategies to evade immune defense mechanisms. We describe herein an ortholog of the cytokine, macrophage migration inhibitory factor (MIF), which is produced by the obligate intracellular parasite, Leishmania major. The Leishmania MIF protein, Lm1740MIF, shows significant structural homology with human MIF as revealed by a high-resolution x-ray crystal structure (1.03 Å). Differences between the two proteins in the N-terminal tautomerization site are evident, and we provide evidence for the selective, species-specific inhibition of MIF by small-molecule antagonists that target this site. Lm1740MIF shows significant binding interaction with the MIF receptor, CD74 (Kd = 2.9 × 10−8 M). Like its mammalian counterpart, Lm1740MIF induces ERK1/2 MAP kinase activation in a CD74-dependent manner and inhibits the activation-induced apoptosis of macrophages. The ability of Lm1740MIF to inhibit apoptosis may facilitate the persistence of Leishmania within the macrophage and contribute to its evasion from immune destruction. PMID:18523291

  13. M2 Polarization of Human Macrophages Favors Survival of the Intracellular Pathogen Chlamydia pneumoniae.

    PubMed

    Buchacher, Tanja; Ohradanova-Repic, Anna; Stockinger, Hannes; Fischer, Michael B; Weber, Viktoria

    2015-01-01

    for the ability of C. pneumoniae to evade cellular defense and to persist in human macrophages.

  14. Macrophage polarization in inflammatory diseases.

    PubMed

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

    2014-01-01

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

  15. An Intracellular Arrangement of Histoplasma capsulatum Yeast-Aggregates Generates Nuclear Damage to the Cultured Murine Alveolar Macrophages

    PubMed Central

    Pitangui, Nayla de Souza; Sardi, Janaina de Cássia Orlandi; Voltan, Aline R.; dos Santos, Claudia T.; da Silva, Julhiany de Fátima; da Silva, Rosangela A. M.; Souza, Felipe O.; Soares, Christiane P.; Rodríguez-Arellanes, Gabriela; Taylor, Maria Lucia; Mendes-Giannini, Maria J. S.; Fusco-Almeida, Ana M.

    2016-01-01

    Histoplasma capsulatum is responsible for a human systemic mycosis that primarily affects lung tissue. Macrophages are the major effector cells in humans that respond to the fungus, and the development of respiratory disease depends on the ability of Histoplasma yeast cells to survive and replicate within alveolar macrophages. Therefore, the interaction between macrophages and H. capsulatum is a decisive step in the yeast dissemination into host tissues. Although the role played by components of cell-mediated immunity in the host's defense system and the mechanisms used by the pathogen to evade the host immune response are well understood, knowledge regarding the effects induced by H. capsulatum in host cells at the nuclear level is limited. According to the present findings, H. capsulatum yeast cells display a unique architectural arrangement during the intracellular infection of cultured murine alveolar macrophages, characterized as a formation of aggregates that seem to surround the host cell nucleus, resembling a “crown.” This extranuclear organization of yeast-aggregates generates damage on the nucleus of the host cell, producing DNA fragmentation and inducing apoptosis, even though the yeast cells are not located inside the nucleus and do not trigger changes in nuclear proteins. The current study highlights a singular intracellular arrangement of H. capsulatum yeast near to the nucleus of infected murine alveolar macrophages that may contribute to the yeast's persistence under intracellular conditions, since this fungal pathogen may display different strategies to prevent elimination by the host's phagocytic mechanisms. PMID:26793172

  16. Optimal interdiction of unreactive Markovian evaders

    SciTech Connect

    Gutfraind, Alexander; Hagberg, Aric; Pan, Feng

    2008-01-01

    The network interdiction problem arises in a wide variety of areas including military logistics, infectious disease control and counter-terrorism. In the classical formulation one is given a weighted network G(N, E) and the task is to find b nodes (or edges) whose removal would maximally increase the least-cost path from a source node s to a target node r. In practical applications. G represenLs a transportation or activity network; node/edge removal is done by an agent, the 'interdictor' against another agent the 'evader' who wants to traverse G from s to t along the least-cost route. Our work is motivated by cases in which both agents have bounded rationality: e.g. when the authorities set up road blocks to catch bank robbers, neither party can plot its actions with full information about the other. We introduce a novel model of network interdiction in which the motion of (possibly) several evaders i. described by a Markov pr cess on G.We further suppose that the evaden; do not respond to interdiction decisions because of time, knowledge or computational constraint . We prove that this interdiction problem is NP-hard, like the classical formulation, but unlike the classical problem the objective function is submodular. This implies that the solution could be approximated within 1-lie using a greedy algorithm. Exploiting submodularity again. we demonstrate that a 'priority' (or 'lazy') evaluation algorithm can improve performance by orders of magnitude. Taken together, the results bring closer realistic solutions to the interdiction problem on global-scale networks.

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2012-01-01

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

  19. Effects of ozone on the defense to a respiratory Listeria monocytogenes infection in the rat. Suppression of macrophage function and cellular immunity and aggravation of histopathology in lung and liver during infection

    SciTech Connect

    Van Loveren, H.; Rombout, P.J.; Wagenaar, S.S.; Walvoort, H.C.; Vos, J.G.

    1988-07-01

    We have investigated the effect of exposure to ozone on defense mechanisms to a respiratory infection with Listeria monocytogenes in the rat. For this purpose rats were continuously exposed to O/sub 3/ concentrations ranging from 0.25 to 2.0 mg/m3 for a period of 1 week. In this model defense to a respiratory infection with Listeria depends on acquired specific cellular immune responses, as well as on natural nonspecific defense mechanisms. The results confirm earlier findings that show that ozone exposure can suppress the capacity of macrophages to ingest and kill Listeria. Moreover, the results show that ozone can also have a suppressive effect on the development of cellular immune responses to a respiratory Listeria infection, i.e., on T/B ratios in lung draining lymph nodes, delayed-type hypersensitivity responses to Listeria antigen, and lymphoproliferative responses in spleen and lung draining lymph nodes to Listeria antigen. The effects on the specific immune responses are especially overt if exposure to the oxidant gas occurs during an ongoing primary infection. The pathological lesions induced by a pulmonary Listeria monocytogenes infection were characterized by multifocal infiltrates of histiocytic and lymphoid cells. The foci sometimes had a granulomatous appearance. Moreover, the cellularity of the interstitial tissues was increased. In the lung many diffuse alveolar macrophages could be seen in the alveoli. Ozone exposure greatly increased the severity of the lung lesions and also of liver lesions resulting from the pulmonary infection. A prominent finding was the formation of granulomas in ozone-exposed and Listeria-infected rats.

  20. Biology of Bony Fish Macrophages

    PubMed Central

    Hodgkinson, Jordan W.; Grayfer, Leon; Belosevic, Miodrag

    2015-01-01

    Macrophages are found across all vertebrate species, reside in virtually all animal tissues, and play critical roles in host protection and homeostasis. Various mechanisms determine and regulate the highly plastic functional phenotypes of macrophages, including antimicrobial host defenses (pro-inflammatory, M1-type), and resolution and repair functions (anti-inflammatory/regulatory, M2-type). The study of inflammatory macrophages in immune defense of teleosts has garnered much attention, and antimicrobial mechanisms of these cells have been extensively studied in various fish models. Intriguingly, both similarities and differences have been documented for the regulation of lower vertebrate macrophage antimicrobial defenses, as compared to what has been described in mammals. Advances in our understanding of the teleost macrophage M2 phenotypes likewise suggest functional conservation through similar and distinct regulatory strategies, compared to their mammalian counterparts. In this review, we discuss the current understanding of the molecular mechanisms governing teleost macrophage functional heterogeneity, including monopoetic development, classical macrophage inflammatory and antimicrobial responses as well as alternative macrophage polarization towards tissues repair and resolution of inflammation. PMID:26633534

  1. Staphylococcus aureus Strain USA300 Perturbs Acquisition of Lysosomal Enzymes and Requires Phagosomal Acidification for Survival inside Macrophages

    PubMed Central

    Tranchemontagne, Zachary R.; Camire, Ryan B.; O'Donnell, Vanessa J.; Baugh, Jessfor

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) causes invasive, drug-resistant skin and soft tissue infections. Reports that S. aureus bacteria survive inside macrophages suggest that the intramacrophage environment may be a niche for persistent infection; however, mechanisms by which the bacteria might evade macrophage phagosomal defenses are unclear. We examined the fate of the S. aureus-containing phagosome in THP-1 macrophages by evaluating bacterial intracellular survival and phagosomal acidification and maturation and by testing the impact of phagosomal conditions on bacterial viability. Multiple strains of S. aureus survived inside macrophages, and in studies using the MRSA USA300 clone, the USA300-containing phagosome acidified rapidly and acquired the late endosome and lysosome protein LAMP1. However, fewer phagosomes containing live USA300 bacteria than those containing dead bacteria associated with the lysosomal hydrolases cathepsin D and β-glucuronidase. Inhibiting lysosomal hydrolase activity had no impact on intracellular survival of USA300 or other S. aureus strains, suggesting that S. aureus perturbs acquisition of lysosomal enzymes. We examined the impact of acidification on S. aureus intramacrophage viability and found that inhibitors of phagosomal acidification significantly impaired USA300 intracellular survival. Inhibition of macrophage phagosomal acidification resulted in a 30-fold reduction in USA300 expression of the staphylococcal virulence regulator agr but had little effect on expression of sarA, saeR, or sigB. Bacterial exposure to acidic pH in vitro increased agr expression. Together, these results suggest that S. aureus survives inside macrophages by perturbing normal phagolysosome formation and that USA300 may sense phagosomal conditions and upregulate expression of a key virulence regulator that enables its intracellular survival. PMID:26502911

  2. Salmonella Mitigates Oxidative Stress and Thrives in the Inflamed Gut by Evading Calprotectin-Mediated Manganese Sequestration.

    PubMed

    Diaz-Ochoa, Vladimir E; Lam, Diana; Lee, Carlin S; Klaus, Suzi; Behnsen, Judith; Liu, Janet Z; Chim, Nicholas; Nuccio, Sean-Paul; Rathi, Subodh G; Mastroianni, Jennifer R; Edwards, Robert A; Jacobo, Christina M; Cerasi, Mauro; Battistoni, Andrea; Ouellette, André J; Goulding, Celia W; Chazin, Walter J; Skaar, Eric P; Raffatellu, Manuela

    2016-06-01

    Neutrophils hinder bacterial growth by a variety of antimicrobial mechanisms, including the production of reactive oxygen species and the secretion of proteins that sequester nutrients essential to microbes. A major player in this process is calprotectin, a host protein that exerts antimicrobial activity by chelating zinc and manganese. Here we show that the intestinal pathogen Salmonella enterica serovar Typhimurium uses specialized metal transporters to evade calprotectin sequestration of manganese, allowing the bacteria to outcompete commensals and thrive in the inflamed gut. The pathogen's ability to acquire manganese in turn promotes function of SodA and KatN, enzymes that use the metal as a cofactor to detoxify reactive oxygen species. This manganese-dependent SodA activity allows the bacteria to evade neutrophil killing mediated by calprotectin and reactive oxygen species. Thus, manganese acquisition enables S. Typhimurium to overcome host antimicrobial defenses and support its competitive growth in the intestine. PMID:27281571

  3. Quantum Backaction Evading Measurement of Collective Mechanical Modes

    NASA Astrophysics Data System (ADS)

    Ockeloen-Korppi, C. F.; Damskägg, E.; Pirkkalainen, J.-M.; Clerk, A. A.; Woolley, M. J.; Sillanpää, M. A.

    2016-09-01

    The standard quantum limit constrains the precision of an oscillator position measurement. It arises from a balance between the imprecision and the quantum backaction of the measurement. However, a measurement of only a single quadrature of the oscillator can evade the backaction and be made with arbitrary precision. Here we demonstrate quantum backaction evading measurements of a collective quadrature of two mechanical oscillators, both coupled to a common microwave cavity. The work allows for quantum state tomography of two mechanical oscillators, and provides a foundation for macroscopic mechanical entanglement and force sensing beyond conventional quantum limits.

  4. Inhalation of particulate lead oxide disrupts pulmonary macrophage-mediated functions important for host defense and tumor surveillance in the lung

    SciTech Connect

    Zelikoff, J.T.; Parsons, E.; Schlesinger, R.B. )

    1993-08-01

    Lead, an immunomodulator and potential human carcinogen, is a major airborne pollutant in industrial environments which poses a serious threat to human health. Despite the wide-spread occurrence of respirable lead particles in the air, and the potential human health risks, effects associated with inhalation of particulate lead on the the lung have been poorly studied. This study was performed to determine whether inhalation of particulate lead oxide (PbO), at a concentration below the currently acceptable air lead standard for occupational exposure, disrupts macrophage (M phi) functions important for maintaining pulmonary immunocompetence. These functions include phagocytosis, production of reactive oxygen intermediates, and the biological activity of tumor necrosis factor-alpha (TNF-alpha). Rabbits exposed to PbO at 30 micrograms/m3 for 4 days (3 hr/day) were sacrificed and their lungs lavaged immediately, 24 hr, and 72 hr after the final exposure. Lactate dehydrogenase (a marker of lung cell damage) and lysozyme activity (a marker of lysosome permeability), measured in the lavage fluid, were significantly increased 24 and 72 hr after exposure. PbO produced neutrophil infiltration nor effects on M phi viability or total numbers. Effects on M phi functions were as follows. Phagocytic uptake of latex particles was reduced with increasing post-exposure time reaching a maximum inhibition at 72 hr. Inhalation of PbO enhanced hydrogen peroxide (H2O2) and superoxide anion radical (O2-) production in a time-dependent manner; effects on H2O2 began at 24 hr and were persistent up to 72 hr. Effects on TNF-alpha release/activity appeared earliest and were persistent up to 72 hr. Immediately and 24 hr after exposure, lipopolysaccharide-stimulated activity of TNF-alpha was depressed by 62 and 50%, respectively; after 72 hr, TNF-alpha release was significantly enhanced compared to control levels.

  5. Leishmania major Promastigotes Evade LC3-Associated Phagocytosis through the Action of GP63.

    PubMed

    Matte, Christine; Casgrain, Pierre-André; Séguin, Olivier; Moradin, Neda; Hong, Wan Jin; Descoteaux, Albert

    2016-06-01

    The protozoan Leishmania parasitizes macrophages and evades the microbicidal consequences of phagocytosis through the inhibition of phagolysosome biogenesis. In this study, we investigated the impact of this parasite on LC3-associated phagocytosis, a non-canonical autophagic process that enhances phagosome maturation and functions. We show that whereas internalization of L. major promastigotes by macrophages promoted LC3 lipidation, recruitment of LC3 to phagosomes was inhibited through the action of the parasite surface metalloprotease GP63. Reactive oxygen species generated by the NOX2 NADPH oxidase are necessary for LC3-associated phagocytosis. We found that L. major promastigotes prevented, in a GP63-dependent manner, the recruitment of NOX2 to phagosomes through a mechanism that does not involve NOX2 cleavage. Moreover, we found that the SNARE protein VAMP8, which regulates phagosomal assembly of the NADPH oxidase NOX2, was down-modulated by GP63. In the absence of VAMP8, recruitment of LC3 to phagosomes containing GP63-deficient parasites was inhibited, indicating that VAMP8 is involved in the phagosomal recruitment of LC3. These findings reveal a role for VAMP8 in LC3-associated phagocytosis and highlight a novel mechanism exploited by L. major promastigotes to interfere with the host antimicrobial machinery.

  6. Leishmania major Promastigotes Evade LC3-Associated Phagocytosis through the Action of GP63

    PubMed Central

    Matte, Christine; Casgrain, Pierre-André; Séguin, Olivier; Moradin, Neda; Hong, Wan Jin; Descoteaux, Albert

    2016-01-01

    The protozoan Leishmania parasitizes macrophages and evades the microbicidal consequences of phagocytosis through the inhibition of phagolysosome biogenesis. In this study, we investigated the impact of this parasite on LC3-associated phagocytosis, a non-canonical autophagic process that enhances phagosome maturation and functions. We show that whereas internalization of L. major promastigotes by macrophages promoted LC3 lipidation, recruitment of LC3 to phagosomes was inhibited through the action of the parasite surface metalloprotease GP63. Reactive oxygen species generated by the NOX2 NADPH oxidase are necessary for LC3-associated phagocytosis. We found that L. major promastigotes prevented, in a GP63-dependent manner, the recruitment of NOX2 to phagosomes through a mechanism that does not involve NOX2 cleavage. Moreover, we found that the SNARE protein VAMP8, which regulates phagosomal assembly of the NADPH oxidase NOX2, was down-modulated by GP63. In the absence of VAMP8, recruitment of LC3 to phagosomes containing GP63-deficient parasites was inhibited, indicating that VAMP8 is involved in the phagosomal recruitment of LC3. These findings reveal a role for VAMP8 in LC3-associated phagocytosis and highlight a novel mechanism exploited by L. major promastigotes to interfere with the host antimicrobial machinery. PMID:27280768

  7. Respiratory Syncytial Virus Persistence in Murine Macrophages Impairs IFN-β Response but Not Synthesis

    PubMed Central

    Rivera-Toledo, Evelyn; Torres-González, Laura; Gómez, Beatriz

    2015-01-01

    Type-I interferon (IFN-I) production is an early response to viral infection and pathogenic viruses have evolved multiple strategies to evade this cellular defense. Some viruses can establish and maintain persistent infections by altering the IFN-I signaling pathway. Here, we studied IFN-I synthesis and response in an in vitro model of persistent infection by respiratory syncytial virus (RSV) in a murine macrophage-like cell line. In this model, interferon regulatory factor 3 was constitutively active and located at nuclei of persistently infected cells, inducing expression of IFN-beta mRNA and protein. However, persistently infected macrophages did not respond in an autocrine manner to the secreted-IFN-beta or to recombinant-IFN-beta, since phosphorylated-STAT1 was not detected by western blot and transcription of the interferon-stimulated genes (ISGs) Mx1 and ISG56 was not induced. Treatment of non-infected macrophages with supernatants from persistently infected cells induced STAT1 phosphorylation and ISGs expression, mediated by the IFN-I present in the supernatants, because blocking the IFN-I receptor inhibited STAT1 phosphorylation. Results suggest that the lack of autocrine response to IFN-I by the host cell may be one mechanism for maintenance of RSV persistence. Furthermore, STAT1 phosphorylation and ISGs expression induced in non-infected cells by supernatants from persistently infected macrophages suggest that RSV persistence may trigger a proinflammatory phenotype in non-infected cells as part of the pathogenesis of RSV infection. PMID:26501312

  8. The Inflammasome in Host Defense

    PubMed Central

    Chen, Gang; Pedra, Joao H.F.

    2010-01-01

    Nod-like receptors have emerged as an important family of sensors in host defense. These receptors are expressed in macrophages, dendritic cells and monocytes and play an important role in microbial immunity. Some Nod-like receptors form the inflammasome, a protein complex that activates caspase-1 in response to several stimuli. Caspase-1 activation leads to processing and secretion of pro-inflammatory cytokines such as interleukin (IL)-1β and IL-18. Here, we discuss recent advances in the inflammasome field with an emphasis on host defense. We also compare differential requirements for inflammasome activation in dendritic cells, macrophages and monocytes. PMID:22315529

  9. Non-toxic antimicrobials that evade drug resistance

    PubMed Central

    Davis, Stephen A.; Vincent, Benjamin M.; Endo, Matthew M.; Whitesell, Luke; Marchillo, Karen; Andes, David R.; Lindquist, Susan; Burke, Martin D.

    2015-01-01

    Drugs that act more promiscuously provide fewer routes for the emergence of resistant mutants. But this benefit often comes at the cost of serious off-target and dose-limiting toxicities. The classic example is the antifungal amphotericin B (AmB), which has evaded resistance for more than half a century. We report dramatically less toxic amphotericins that nevertheless evade resistance. They are scalably accessed in just three steps from the natural product, and bind their target (the fungal sterol, ergosterol) with far greater selectivity than AmB. Hence, they are less toxic and far more effective in a mouse model of systemic candidiasis. Surprisingly, exhaustive efforts to select for mutants resistant to these more selective compounds revealed that they are just as impervious to resistance as AmB. Thus, highly selective cytocidal action and the evasion of resistance are not mutually exclusive, suggesting practical routes to the discovery of less toxic, resistance-evasive therapies. PMID:26030729

  10. Efficient natural defense mechanisms against Listeria monocytogenes in T and B cell-deficient allogeneic bone marrow radiation chimeras. Preactivated macrophages are the main effector cells in an early phase after bone marrow transfer

    SciTech Connect

    Roesler, J.; Groettrup, E.B.; Baccarini, M.; Lohmann-Mattes, M.L. )

    1989-09-01

    Radiation chimeras in the early phase after bone marrow transplantation are a good model to study the efficiency of the body's nonspecific defense system represented by macrophages (M phi), polymorphonuclear cells (PMN), and NK cells. These cell types are present in large numbers in spleen and liver at that time, whereas the specific immune system represented by T and B cells is functionally deficient. We previously reported enhanced activities in vitro of M phi (and PMN) from recipient animals in an early phase after allogeneic bone marrow transfer. We here demonstrate that these activities result in enhanced spontaneous resistance against Listeria monocytogenes in vivo: CFU of L. monocytogenes in spleen and liver 48 h after infection were about 1 or 2 to 4 log steps less than in untreated control mice of donor or host haplotype. This enhanced resistance decreased over the 4-mo period after marrow transfer. Preactivated M phi were identified as the most important effector cells. Isolated from spleen and peritoneal cavity, they performed enhanced killing of phagocytosed Listeria. Such preactivated M phi occurred in recipient animals after transfer of allogeneic but not of syngeneic bone marrow. The precise mechanism of M phi activation in the allogeneic radiation chimera in the complete absence of any detectable T cell function is not clear at present. However, these preactivated M phi display an important protective effect against L. monocytogenes: chimeras could eliminate Listeria without acquisition of positive delayed-type sensitivity when infected with 10(3) bacteria. An inoculum of 5 . 10(3) L. monocytogenes resulted either in prolonged survival compared with normal mice of the recipient haplotype or in definitive survival accompanied by a positive delayed-type sensitivity.

  11. [Pharmacological properties of law-evading chemical substances].

    PubMed

    Funada, Masahiko

    2015-09-01

    In recent years, frequent cases of people suffering disturbed consciousness, dyspnea, etc. due to abuse of synthetic cannabis and being transported by ambulance or causing traffic accidents are occurring and are becoming a serious social problem in Japan. Most law-evading herbal products have colorful illustrations and logos and are sold as incense or herbs. Law-evading herbal products consist of finely chopped dry vegetative matter mixed with chemical substances (drugs), and the drugs are injurious to health. Analysis of chemical substances in herbal products clarified that they contain synthetic cannabinoid, a chemical component that exhibits action similar to that of hemp. There are many affinity compounds of cannabinoid, so presently, even if a particular drug is regulated, similar compounds that partially differ in structure will propagate. There is thus a cat-and-mouse game between regulations on chemical substances and their propagation. This paper summarizes the pharmacological actions and danger of chemical substances contained in law-evading herbal products by focusing on synthetic cannabinoid or synthetic cathinone, a chemical substance it contains. PMID:26394508

  12. Surface modification of nanoparticles enables selective evasion of phagocytic clearance by distinct macrophage phenotypes

    NASA Astrophysics Data System (ADS)

    Qie, Yaqing; Yuan, Hengfeng; von Roemeling, Christina A.; Chen, Yuanxin; Liu, Xiujie; Shih, Kevin D.; Knight, Joshua A.; Tun, Han W.; Wharen, Robert E.; Jiang, Wen; Kim, Betty Y. S.

    2016-05-01

    Nanomedicine is a burgeoning industry but an understanding of the interaction of nanomaterials with the immune system is critical for clinical translation. Macrophages play a fundamental role in the immune system by engulfing foreign particulates such as nanoparticles. When activated, macrophages form distinct phenotypic populations with unique immune functions, however the mechanism by which these polarized macrophages react to nanoparticles is unclear. Furthermore, strategies to selectively evade activated macrophage subpopulations are lacking. Here we demonstrate that stimulated macrophages possess higher phagocytic activities and that classically activated (M1) macrophages exhibit greater phagocytic capacity than alternatively activated (M2) macrophages. We show that modification of nanoparticles with polyethylene-glycol results in decreased clearance by all macrophage phenotypes, but importantly, coating nanoparticles with CD47 preferentially lowers phagocytic activity by the M1 phenotype. These results suggest that bio-inspired nanoparticle surface design may enable evasion of specific components of the immune system and provide a rational approach for developing immune tolerant nanomedicines.

  13. Group A Streptococcal M1 Protein Sequesters Cathelicidin to Evade Innate Immune Killing

    PubMed Central

    LaRock, Christopher N.; Döhrmann, Simon; Todd, Jordan; Corriden, Ross; Olson, Joshua; Johannssen, Timo; Lepenies, Bernd; Gallo, Richard L.; Ghosh, Partho; Nizet, Victor

    2015-01-01

    SUMMARY The antimicrobial peptide LL-37 is generated upon proteolytic cleavage of cathelicidin and limits invading pathogens by directly targeting microbial membranes as well as stimulating innate immune cell function. However, some microbes evade LL-37-mediated defense. Notably, Group A Streptococcus (GAS) strains belonging to the hypervirulent M1T1 serogroup are more resistant to human LL-37 than other GAS serogroups. We show that the GAS surface-associated M1 protein sequesters and neutralizes LL-37 antimicrobial activity through its N-terminal domain. M1 protein also binds the cathelicidin precursor hCAP-18, preventing its proteolytic maturation into antimicrobial forms. Exogenous M1 protein rescues M1-deficient GAS from killing by neutrophils and within neutrophil extracellular traps and neutralizes LL-37 chemotactic properties. M1 also binds murine cathelicidin, and its virulence contribution in a murine model of necrotizing skin infection is largely driven by its ability to neutralize this host defense peptide. Thus, cathelicidin resistance is essential for the pathogenesis of hyperinvasive M1T1 GAS. PMID:26468750

  14. Gaining insight into soybean defense responses using functional genomics approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean pathogens significantly impact yield, resulting in over 4 billion dollars in lost revenue annually in the United States alone as a result of disease. Despite the deployment of improved soybean cultivars, pathogens continue to evolve to evade plant defense responses. Thus, there is an urgent ...

  15. Cronobacter sakazakii clinical isolates overcome host barriers and evade the immune response.

    PubMed

    Almajed, Faisal S; Forsythe, Stephen J

    2016-01-01

    Cronobacter sakazakii is the most frequently clinically isolated species of the Cronobacter genus. However the virulence factors of C. sakazakii including their ability to overcome host barriers remains poorly studied. In this study, ten clinical isolates of C. sakazakii were assessed for their ability to invade and translocate through human colonic carcinoma epithelial cells (Caco-2) and human brain microvascular endothelial cells (HBMEC). Their ability to avoid phagocytosis in human macrophages U937 and human brain microglial cells was investigated. Additionally, they were tested for serum sensitivity and the presence of the Cronobacter plasminogen activation gene (cpa) gene, which is reported to confer serum resistance. Our data showed that the clinical C. sakazakii strains invaded and translocated through Caco-2 and HBMEC cell lines and some strains showed significantly higher levels of invasion and translocation. Moreover, C. sakazakii was able to persist and even multiply in phagocytic macrophage and microglial cells. All strains, except one, were able to withstand human serum exposure, the single serum sensitive strain was also the only one which did not encode for the cpa gene. These results demonstrate that C. sakazakii clinical isolates are able to overcome host barriers and evade the host immune response indicating their capacity to cause diseases such as necrotizing enterocolitis (NEC) and meningitis. Our data showed for the first time the ability of C. sakazakii clinical isolates to survive and multiply within human microglial cells. Additionally, it was shown that C. sakazakii clinical strains have the capacity to translocate through the Caco-2 and HBMEC cell lines paracellularly.

  16. Metabolic Reprograming in Macrophage Polarization

    PubMed Central

    Galván-Peña, Silvia; O’Neill, Luke A. J.

    2014-01-01

    Studying the metabolism of immune cells in recent years has emphasized the tight link existing between the metabolic state and the phenotype of these cells. Macrophages in particular are a good example of this phenomenon. Whether the macrophage obtains its energy through glycolysis or through oxidative metabolism can give rise to different phenotypes. Classically activated or M1 macrophages are key players of the first line of defense against bacterial infections and are known to obtain energy through glycolysis. Alternatively activated or M2 macrophages on the other hand are involved in tissue repair and wound healing and use oxidative metabolism to fuel their longer-term functions. Metabolic intermediates, however, are not just a source of energy but can be directly implicated in a particular macrophage phenotype. In M1 macrophages, the Krebs cycle intermediate succinate regulates HIF1α, which is responsible for driving the sustained production of the pro-inflammatory cytokine IL1β. In M2 macrophages, the sedoheptulose kinase carbohydrate kinase-like protein is critical for regulating the pentose phosphate pathway. The potential to target these events and impact on disease is an exciting prospect. PMID:25228902

  17. Stealth nanotubes: strategies of shielding carbon nanotubes to evade opsonization and improve biodistribution.

    PubMed

    Kotagiri, Nalinikanth; Kim, Jin-Woo

    2014-01-01

    Carbon nanotubes (CNTs) have recently been in the limelight for their potential role in disease diagnostics and therapeutics, as well as in tissue engineering. Before these medical applications can be realized, there is a need to address issues like opsonization, phagocytosis by macrophages, and sequestration to the liver and spleen for eventual elimination from the body; along with equally important issues such as aqueous solubility, dispersion, biocompatibility, and biofunctionalization. CNTs have not been shown to be able to evade such biological obstacles, which include their nonspecific attachments to cells and other biological components in the bloodstream, before reaching target tissues and cells in vivo. This will eventually determine their longevity in circulation and clearance rate from the body. This review article discusses the current status, challenges, practical strategies, and implementations of coating CNTs with biocompatible and opsonin-resistant moieties, rendering CNTs transparent to opsonins and deceiving the innate immune response to make believe that the CNTs are not foreign. A holistic approach to the development of such "stealth" CNTs is presented, which encompasses not only several biophysicochemical factors that are not limited to surface treatment of CNTs, but also extraneous biological factors such as the protein corona formation that inevitably controls the in vivo fate of the particles. This review also discusses the present and potential applications, along with the future directions, of CNTs and their hybrid-based nanotheranostic agents for multiplex, multimodal molecular imaging and therapy, as well as in other applications, such as drug delivery and tissue engineering.

  18. Stealth nanotubes: strategies of shielding carbon nanotubes to evade opsonization and improve biodistribution

    PubMed Central

    Kotagiri, Nalinikanth; Kim, Jin-Woo

    2014-01-01

    Carbon nanotubes (CNTs) have recently been in the limelight for their potential role in disease diagnostics and therapeutics, as well as in tissue engineering. Before these medical applications can be realized, there is a need to address issues like opsonization, phagocytosis by macrophages, and sequestration to the liver and spleen for eventual elimination from the body; along with equally important issues such as aqueous solubility, dispersion, biocompatibility, and biofunctionalization. CNTs have not been shown to be able to evade such biological obstacles, which include their nonspecific attachments to cells and other biological components in the bloodstream, before reaching target tissues and cells in vivo. This will eventually determine their longevity in circulation and clearance rate from the body. This review article discusses the current status, challenges, practical strategies, and implementations of coating CNTs with biocompatible and opsonin-resistant moieties, rendering CNTs transparent to opsonins and deceiving the innate immune response to make believe that the CNTs are not foreign. A holistic approach to the development of such “stealth” CNTs is presented, which encompasses not only several biophysicochemical factors that are not limited to surface treatment of CNTs, but also extraneous biological factors such as the protein corona formation that inevitably controls the in vivo fate of the particles. This review also discusses the present and potential applications, along with the future directions, of CNTs and their hybrid-based nanotheranostic agents for multiplex, multimodal molecular imaging and therapy, as well as in other applications, such as drug delivery and tissue engineering. PMID:24872705

  19. Stealth nanotubes: strategies of shielding carbon nanotubes to evade opsonization and improve biodistribution.

    PubMed

    Kotagiri, Nalinikanth; Kim, Jin-Woo

    2014-01-01

    Carbon nanotubes (CNTs) have recently been in the limelight for their potential role in disease diagnostics and therapeutics, as well as in tissue engineering. Before these medical applications can be realized, there is a need to address issues like opsonization, phagocytosis by macrophages, and sequestration to the liver and spleen for eventual elimination from the body; along with equally important issues such as aqueous solubility, dispersion, biocompatibility, and biofunctionalization. CNTs have not been shown to be able to evade such biological obstacles, which include their nonspecific attachments to cells and other biological components in the bloodstream, before reaching target tissues and cells in vivo. This will eventually determine their longevity in circulation and clearance rate from the body. This review article discusses the current status, challenges, practical strategies, and implementations of coating CNTs with biocompatible and opsonin-resistant moieties, rendering CNTs transparent to opsonins and deceiving the innate immune response to make believe that the CNTs are not foreign. A holistic approach to the development of such "stealth" CNTs is presented, which encompasses not only several biophysicochemical factors that are not limited to surface treatment of CNTs, but also extraneous biological factors such as the protein corona formation that inevitably controls the in vivo fate of the particles. This review also discusses the present and potential applications, along with the future directions, of CNTs and their hybrid-based nanotheranostic agents for multiplex, multimodal molecular imaging and therapy, as well as in other applications, such as drug delivery and tissue engineering. PMID:24872705

  20. Pyoverdine, the Major Siderophore in Pseudomonas aeruginosa, Evades NGAL Recognition

    PubMed Central

    Peek, Mary E.; Bhatnagar, Abhinav; McCarty, Nael A.; Zughaier, Susu M.

    2012-01-01

    Pseudomonas aeruginosa is the most common pathogen that persists in the cystic fibrosis lungs. Bacteria such as P. aeruginosa secrete siderophores (iron-chelating molecules) and the host limits bacterial growth by producing neutrophil-gelatinase-associated lipocalin (NGAL) that specifically scavenges bacterial siderophores, therefore preventing bacteria from establishing infection. P. aeruginosa produces a major siderophore known as pyoverdine, found to be important for bacterial virulence and biofilm development. We report that pyoverdine did not bind to NGAL, as measured by tryptophan fluorescence quenching, while enterobactin bound to NGAL effectively causing a strong response. The experimental data indicate that pyoverdine evades NGAL recognition. We then employed a molecular modeling approach to simulate the binding of pyoverdine to human NGAL using NGAL's published crystal structures. The docking of pyoverdine to NGAL predicted nine different docking positions; however, neither apo- nor ferric forms of pyoverdine docked into the ligand-binding site in the calyx of NGAL where siderophores are known to bind. The molecular modeling results offer structural support that pyoverdine does not bind to NGAL, confirming the results obtained in the tryptophan quenching assay. The data suggest that pyoverdine is a stealth siderophore that evades NGAL recognition allowing P. aeruginosa to establish chronic infections in CF lungs. PMID:22973307

  1. *Ambient Particluate Matter Supresses Alveolar Macrophage Cytokine Response to Lipopolysaccharide

    EPA Science Inventory

    Reports link ambient particulate matter (PM) exposure with cardiopulmonary mortality and morbidity, including the exacerbation of inflammatory disease and increased hospitalization for lung infections. Alveolar macrophages (AM) play an important defense role against infections v...

  2. Homegrown Macrophages.

    PubMed

    Kim, Ki-Wook; Zhang, Nan; Choi, Kyunghee; Randolph, Gwendalyn J

    2016-09-20

    Macrophages residing in different organs have diverse gene-expression programs. Mass et al. (2016) propose that this diversity develops "at home"-within those organs-after the recruitment of a common precursor that had not made prior commitments to diversity. PMID:27653599

  3. 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.

  4. A simple motion differential game with different constraints on controls and under phase constraint on the state of the evader

    NASA Astrophysics Data System (ADS)

    Rakhmanov, Askar; Ibragimov, Gafurjan

    2016-06-01

    We consider a simple motion pursuit differential game of one pursuer and one evader. Control of the pursuer is subjected to integral constraint, and that of the evader is subjected to geometric constraint. More precisely, value of control parameter of the evader belongs to a given convex subset of ℝn. Pursuit is completed if the evader becomes in l vicinity of the pursuer. Sufficient conditions of completion of pursuit are obtained.

  5. Parasitic Cape honeybee workers, Apis mellifera capensis, evade policing.

    PubMed

    Martin, Stephen J; Beekman, Madeleine; Wossler, Theresa C; Ratnieks, Francis L W

    2002-01-10

    Relocation of the Cape honeybee, Apis mellifera capensis, by bee-keepers from southern to northern South Africa in 1990 has caused widespread death of managed African honeybee, A. m. scutellata, colonies. Apis mellifera capensis worker bees are able to lay diploid, female eggs without mating by means of automictic thelytoky (meiosis followed by fusion of two meiotic products to restore egg diploidy), whereas workers of other honeybee subspecies are able to lay only haploid, male eggs. The A. m. capensis workers, which are parasitizing and killing A. m. scutellata colonies in northern South Africa, are the asexual offspring of a single, original worker in which the small amount of genetic variation observed is due to crossing over during meiosis (P. Kryger, personal communication). Here we elucidate two principal mechanisms underlying this parasitism. Parasitic A. m. capensis workers activate their ovaries in host colonies that have a queen present (queenright colonies), and they lay eggs that evade being killed by other workers (worker policing)-the normal fate of worker-laid eggs in colonies with a queen. This unique parasitism by workers is an instance in which a society is unable to control the selfish actions of its members. PMID:11805832

  6. Fungal biosynthesis of the bibenzoquinone oosporein to evade insect immunity

    PubMed Central

    Feng, Peng; Shang, Yanfang; Cen, Kai; Wang, Chengshu

    2015-01-01

    Quinones are widely distributed in nature and exhibit diverse biological or pharmacological activities; however, their biosynthetic machineries are largely unknown. The bibenzoquinone oosporein was first identified from the ascomycete insect pathogen Beauveria bassiana >50 y ago. The toxin can also be produced by different plant pathogenic and endophytic fungi with an array of biological activities. Here, we report the oosporein biosynthetic machinery in fungi, a polyketide synthase (PKS) pathway including seven genes for quinone biosynthesis. The PKS oosporein synthase 1 (OpS1) produces orsellinic acid that is hydroxylated to benzenetriol by the hydroxylase OpS4. The intermediate is oxidized either nonenzymatically to 5,5′-dideoxy-oosporein or enzymatically to benzenetetrol by the putative dioxygenase OpS7. The latter is further dimerized to oosporein by the catalase OpS5. The transcription factor OpS3 regulates intrapathway gene expression. Insect bioassays revealed that oosporein is required for fungal virulence and acts by evading host immunity to facilitate fungal multiplication in insects. These results contribute to the known mechanisms of quinone biosynthesis and the understanding of small molecules deployed by fungi that interact with their hosts. PMID:26305932

  7. Parasitic Cape honeybee workers, Apis mellifera capensis, evade policing

    NASA Astrophysics Data System (ADS)

    Martin, Stephen J.; Beekman, Madeleine; Wossler, Theresa C.; Ratnieks, Francis L. W.

    2002-01-01

    Relocation of the Cape honeybee, Apis mellifera capensis, by bee-keepers from southern to northern South Africa in 1990 has caused widespread death of managed African honeybee, A. m. scutellata, colonies. Apis mellifera capensis worker bees are able to lay diploid, female eggs without mating by means of automictic thelytoky (meiosis followed by fusion of two meiotic products to restore egg diploidy), whereas workers of other honeybee subspecies are able to lay only haploid, male eggs. The A. m. capensis workers, which are parasitizing and killing A. m. scutellata colonies in northern South Africa, are the asexual offspring of a single, original worker in which the small amount of genetic variation observed is due to crossing over during meiosis (P. Kryger, personal communication). Here we elucidate two principal mechanisms underlying this parasitism. Parasitic A. m. capensis workers activate their ovaries in host colonies that have a queen present (queenright colonies), and they lay eggs that evade being killed by other workers (worker policing)-the normal fate of worker-laid eggs in colonies with a queen. This unique parasitism by workers is an instance in which a society is unable to control the selfish actions of its members.

  8. 'Stealth' nanoparticles evade neural immune cells but also evade major brain cell populations: Implications for PEG-based neurotherapeutics.

    PubMed

    Jenkins, Stuart I; Weinberg, Daniel; Al-Shakli, Arwa F; Fernandes, Alinda R; Yiu, Humphrey H P; Telling, Neil D; Roach, Paul; Chari, Divya M

    2016-02-28

    Surface engineering to control cell behavior is of high interest across the chemical engineering, drug delivery and biomaterial communities. Defined chemical strategies are necessary to tailor nanoscale protein interactions/adsorption, enabling control of cell behaviors for development of novel therapeutic strategies. Nanoparticle-based therapies benefit from such strategies but particle targeting to sites of neurological injury remains challenging due to circulatory immune clearance. As a strategy to overcome this barrier, the use of stealth coatings can reduce immune clearance and prolong circulatory times, thereby enhancing therapeutic capacity. Polyethylene glycol (PEG) is the most widely-used stealth coating and facilitates particle accumulation in the brain. However, once within the brain, the mode of handling of PEGylated particles by the resident immune cells of the brain itself (the 'microglia') is unknown. This is a critical question as it is well established that microglia avidly sequester nanoparticles, limiting their bioavailability and posing a major translational barrier. If PEGylation can be proved to promote evasion of microglia, then this information will be of high value in developing tailored nanoparticle-based therapies for neurological applications. Here, we have conducted the first comparative study of uptake of PEGylated particles by all the major (immune and non-immune) brain cell types. We prove for the first time that PEGylated nanoparticles evade major brain cell populations - a phenomenon which will enhance extracellular bioavailability. We demonstrate changes in protein coronas around these particles within biological media, and discuss how surface chemistry presentation may affect this process and subsequent cellular interactions.

  9. HIV-1 evades innate immune recognition through specific cofactor recruitment

    NASA Astrophysics Data System (ADS)

    Rasaiyaah, Jane; Tan, Choon Ping; Fletcher, Adam J.; Price, Amanda J.; Blondeau, Caroline; Hilditch, Laura; Jacques, David A.; Selwood, David L.; James, Leo C.; Noursadeghi, Mahdad; Towers, Greg J.

    2013-11-01

    Human immunodeficiency virus (HIV)-1 is able to replicate in primary human macrophages without stimulating innate immunity despite reverse transcription of genomic RNA into double-stranded DNA, an activity that might be expected to trigger innate pattern recognition receptors. We reasoned that if correctly orchestrated HIV-1 uncoating and nuclear entry is important for evasion of innate sensors then manipulation of specific interactions between HIV-1 capsid and host factors that putatively regulate these processes should trigger pattern recognition receptors and stimulate type 1 interferon (IFN) secretion. Here we show that HIV-1 capsid mutants N74D and P90A, which are impaired for interaction with cofactors cleavage and polyadenylation specificity factor subunit 6 (CPSF6) and cyclophilins (Nup358 and CypA), respectively, cannot replicate in primary human monocyte-derived macrophages because they trigger innate sensors leading to nuclear translocation of NF-κB and IRF3, the production of soluble type 1 IFN and induction of an antiviral state. Depletion of CPSF6 with short hairpin RNA expression allows wild-type virus to trigger innate sensors and IFN production. In each case, suppressed replication is rescued by IFN-receptor blockade, demonstrating a role for IFN in restriction. IFN production is dependent on viral reverse transcription but not integration, indicating that a viral reverse transcription product comprises the HIV-1 pathogen-associated molecular pattern. Finally, we show that we can pharmacologically induce wild-type HIV-1 infection to stimulate IFN secretion and an antiviral state using a non-immunosuppressive cyclosporine analogue. We conclude that HIV-1 has evolved to use CPSF6 and cyclophilins to cloak its replication, allowing evasion of innate immune sensors and induction of a cell-autonomous innate immune response in primary human macrophages.

  10. The Tuberculosis Necrotizing Toxin kills macrophages by hydrolyzing NAD

    PubMed Central

    Sun, Jim; Siroy, Axel; Lokareddy, Ravi K.; Speer, Alexander; Doornbos, Kathryn S.; Cingolani, Gino; Niederweis, Michael

    2015-01-01

    Mycobacterium tuberculosis (Mtb) induces necrosis of infected cells to evade immune responses. Recently, we found that Mtb utilizes the protein CpnT to kill human macrophages by secreting its C-terminal domain, named tuberculosis necrotizing toxin (TNT) that induces necrosis by an unknown mechanism. Here we show that TNT gains access to the cytosol of Mtb-infected macrophages, where it hydrolyzes the essential co-enzyme nicotinamide adenine dinucleotide (NAD+). Expression or injection of a non-catalytic TNT mutant showed no cytotoxicity in macrophages or zebrafish zygotes, respectively, demonstrating that the NAD+-glycohydrolase activity is required for TNT-induced cell death. To prevent self-poisoning, Mtb produces an immunity factor for TNT (IFT) that binds TNT and inhibits its activity. The crystal structure of the TNT-IFT complex revealed a novel NAD+-glycohydrolase fold of TNT, which constitutes the founding member of a toxin family wide-spread in pathogenic microorganisms. PMID:26237511

  11. Herbivore exploits orally secreted bacteria to suppress plant defenses.

    PubMed

    Chung, Seung Ho; Rosa, Cristina; Scully, Erin D; Peiffer, Michelle; Tooker, John F; Hoover, Kelli; Luthe, Dawn S; Felton, Gary W

    2013-09-24

    Induced plant defenses in response to herbivore attack are modulated by cross-talk between jasmonic acid (JA)- and salicylic acid (SA)-signaling pathways. Oral secretions from some insect herbivores contain effectors that overcome these antiherbivore defenses. Herbivores possess diverse microbes in their digestive systems and these microbial symbionts can modify plant-insect interactions; however, the specific role of herbivore-associated microbes in manipulating plant defenses remains unclear. Here, we demonstrate that Colorado potato beetle (Leptinotarsa decemlineata) larvae exploit bacteria in their oral secretions to suppress antiherbivore defenses in tomato (Solanum lycopersicum). We found that antibiotic-untreated larvae decreased production of JA and JA-responsive antiherbivore defenses, but increased SA accumulation and SA-responsive gene expression. Beetles benefit from down-regulating plant defenses by exhibiting enhanced larval growth. In SA-deficient plants, suppression was not observed, indicating that suppression of JA-regulated defenses depends on the SA-signaling pathway. Applying bacteria isolated from larval oral secretions to wounded plants confirmed that three microbial symbionts belonging to the genera Stenotrophomonas, Pseudomonas, and Enterobacter are responsible for defense suppression. Additionally, reinoculation of these bacteria to antibiotic-treated larvae restored their ability to suppress defenses. Flagellin isolated from Pseudomonas sp. was associated with defense suppression. Our findings show that the herbivore exploits symbiotic bacteria as a decoy to deceive plants into incorrectly perceiving the threat as microbial. By interfering with the normal perception of herbivory, beetles can evade antiherbivore defenses of its host. PMID:24019469

  12. Herbivore exploits orally secreted bacteria to suppress plant defenses

    PubMed Central

    Chung, Seung Ho; Rosa, Cristina; Scully, Erin D.; Peiffer, Michelle; Tooker, John F.; Hoover, Kelli; Luthe, Dawn S.; Felton, Gary W.

    2013-01-01

    Induced plant defenses in response to herbivore attack are modulated by cross-talk between jasmonic acid (JA)- and salicylic acid (SA)-signaling pathways. Oral secretions from some insect herbivores contain effectors that overcome these antiherbivore defenses. Herbivores possess diverse microbes in their digestive systems and these microbial symbionts can modify plant–insect interactions; however, the specific role of herbivore-associated microbes in manipulating plant defenses remains unclear. Here, we demonstrate that Colorado potato beetle (Leptinotarsa decemlineata) larvae exploit bacteria in their oral secretions to suppress antiherbivore defenses in tomato (Solanum lycopersicum). We found that antibiotic-untreated larvae decreased production of JA and JA-responsive antiherbivore defenses, but increased SA accumulation and SA-responsive gene expression. Beetles benefit from down-regulating plant defenses by exhibiting enhanced larval growth. In SA-deficient plants, suppression was not observed, indicating that suppression of JA-regulated defenses depends on the SA-signaling pathway. Applying bacteria isolated from larval oral secretions to wounded plants confirmed that three microbial symbionts belonging to the genera Stenotrophomonas, Pseudomonas, and Enterobacter are responsible for defense suppression. Additionally, reinoculation of these bacteria to antibiotic-treated larvae restored their ability to suppress defenses. Flagellin isolated from Pseudomonas sp. was associated with defense suppression. Our findings show that the herbivore exploits symbiotic bacteria as a decoy to deceive plants into incorrectly perceiving the threat as microbial. By interfering with the normal perception of herbivory, beetles can evade antiherbivore defenses of its host. PMID:24019469

  13. Herbivore exploits orally secreted bacteria to suppress plant defenses.

    PubMed

    Chung, Seung Ho; Rosa, Cristina; Scully, Erin D; Peiffer, Michelle; Tooker, John F; Hoover, Kelli; Luthe, Dawn S; Felton, Gary W

    2013-09-24

    Induced plant defenses in response to herbivore attack are modulated by cross-talk between jasmonic acid (JA)- and salicylic acid (SA)-signaling pathways. Oral secretions from some insect herbivores contain effectors that overcome these antiherbivore defenses. Herbivores possess diverse microbes in their digestive systems and these microbial symbionts can modify plant-insect interactions; however, the specific role of herbivore-associated microbes in manipulating plant defenses remains unclear. Here, we demonstrate that Colorado potato beetle (Leptinotarsa decemlineata) larvae exploit bacteria in their oral secretions to suppress antiherbivore defenses in tomato (Solanum lycopersicum). We found that antibiotic-untreated larvae decreased production of JA and JA-responsive antiherbivore defenses, but increased SA accumulation and SA-responsive gene expression. Beetles benefit from down-regulating plant defenses by exhibiting enhanced larval growth. In SA-deficient plants, suppression was not observed, indicating that suppression of JA-regulated defenses depends on the SA-signaling pathway. Applying bacteria isolated from larval oral secretions to wounded plants confirmed that three microbial symbionts belonging to the genera Stenotrophomonas, Pseudomonas, and Enterobacter are responsible for defense suppression. Additionally, reinoculation of these bacteria to antibiotic-treated larvae restored their ability to suppress defenses. Flagellin isolated from Pseudomonas sp. was associated with defense suppression. Our findings show that the herbivore exploits symbiotic bacteria as a decoy to deceive plants into incorrectly perceiving the threat as microbial. By interfering with the normal perception of herbivory, beetles can evade antiherbivore defenses of its host.

  14. Nanoparticles Evading The Reticuloendothelial System: Role of The Supported Bilayer

    PubMed Central

    Li, Shyh-Dar; Huang, Leaf

    2009-01-01

    Summary We have previously shown that the PEGylated LPD (liposome-polycation-DNA) nanoparticles were highly efficient in delivering siRNA to the tumor with low liver uptake. Its mechanism of evading the reticuloendothelial system (RES) is reported here. In LPD, nucleic acids were condensed with protamine into a compact core, which was then coated by two cationic lipid bilayers with the inner bilayer stabilized by charge-charge interaction (also called the supported bilayer). Finally, a detergent-like molecule, polyethylene glycol (PEG)-phospholipid is post-inserted into the lipid bilayer to modify the surface of LPD. The dynamic light scattering (DLS) data showed that LPD had improved stability compared to cationic liposomes after incubation with a high concentration of DSPE-PEG2000, which is known to disrupt the bilayer. LPD prepared with a multivalent cationic lipid, DSGLA, had enhanced stability compared to those containing DOTAP, a monovalent cationic lipid, suggesting that stronger charge-charge interaction in the supported bilayer contributed to a higher stability. Distinct nanoparticle structure was found in the PEGylated LPD by transmission electron microscopy, while the cationic liposomes were transformed into tubular micelles. Size exclusion chromatography data showed that approximately 60% of the total cationic lipids, which were located in the outer bilayer of LPD, were stripped off during the PEGylation; and about 20% of the input DSPE-PEG2000 was incorporated into the inner bilayer with about 10.6 mol% of DSPE-PEG2000 presented on the particle surface. This led to complete charge shielding, low liver sinusoidal uptake, and 32.5% injected dose delivered to the NCI-H460 tumor in a xenograft model. PMID:19595666

  15. [Option and evasion of a bachelor's degree programme in nursing evaded students' perception].

    PubMed

    Barlem, Jamila Geri Tomaschewski; Lunardi, Valéria Lerch; Bordignon, Simoní Saraiva; Barlem, Edison Luiz Devos; Lunardi Filho, Wilson Danilo; da Silveira, Rosemary Silva; Zacarias, Caroline Ceolin

    2012-06-01

    Qualitative study, developed in a Federal University in southern Brazil aiming to know the motives for choosing and evading a Bachelor's degree programme in Nursing, in the evaded students 'perception. The data were collected through a questionnaire sent by e-mail to 19 evaded students. The 9 questionnaires that returned were submitted to Qualitative Textual Analysis, and two categories emerged motives to opt for the nursing programme and motives to evade from the nursing programme. The results showed that the option for the programme is associated to personal vocation, perception of Nursing as a profession of care, and its closeness to the health area. Evasion seems to be related to passing the first option of undergraduate programme, ignorance about the profession, financial difficulties, and professional depreciation. We demonstrated that greater emphasis should be put on promoting knowledge about the nursing work, areas of activity and attributions. PMID:23155591

  16. 'Stealth' nanoparticles evade neural immune cells but also evade major brain cell populations: Implications for PEG-based neurotherapeutics.

    PubMed

    Jenkins, Stuart I; Weinberg, Daniel; Al-Shakli, Arwa F; Fernandes, Alinda R; Yiu, Humphrey H P; Telling, Neil D; Roach, Paul; Chari, Divya M

    2016-02-28

    Surface engineering to control cell behavior is of high interest across the chemical engineering, drug delivery and biomaterial communities. Defined chemical strategies are necessary to tailor nanoscale protein interactions/adsorption, enabling control of cell behaviors for development of novel therapeutic strategies. Nanoparticle-based therapies benefit from such strategies but particle targeting to sites of neurological injury remains challenging due to circulatory immune clearance. As a strategy to overcome this barrier, the use of stealth coatings can reduce immune clearance and prolong circulatory times, thereby enhancing therapeutic capacity. Polyethylene glycol (PEG) is the most widely-used stealth coating and facilitates particle accumulation in the brain. However, once within the brain, the mode of handling of PEGylated particles by the resident immune cells of the brain itself (the 'microglia') is unknown. This is a critical question as it is well established that microglia avidly sequester nanoparticles, limiting their bioavailability and posing a major translational barrier. If PEGylation can be proved to promote evasion of microglia, then this information will be of high value in developing tailored nanoparticle-based therapies for neurological applications. Here, we have conducted the first comparative study of uptake of PEGylated particles by all the major (immune and non-immune) brain cell types. We prove for the first time that PEGylated nanoparticles evade major brain cell populations - a phenomenon which will enhance extracellular bioavailability. We demonstrate changes in protein coronas around these particles within biological media, and discuss how surface chemistry presentation may affect this process and subsequent cellular interactions. PMID:26780172

  17. [Case of law-evading herbs poisoning that induced shock and myocardial damage].

    PubMed

    Nakamura, Yoshihiko; Nakano, Minoru; Nakamura, Mitsunobu; Miyazaki, Dai; Okamori, Satoshi; Akuzawa, Hisashi; Yuasa, Masahiro

    2014-12-01

    Law-evading herbs may induce poisoning symptoms, especially when they contain synthetic cannabinoids. However, their detailed pharmacological effects have not yet been clarified. Some reports have previously described symptoms of poisoning, but only a few reports have so far described shock and myocardial damage (MD). We experienced a case of shock and MD in a patient who had smoked law-evading herbs. A 61-year-old male presented at an emergency department 8 hours after smoking law-evading herbs (Rush Trip, High Men Monster) with chest pain. A vasopressor agent was administered to treat shock and antiarrhythmic drugs were administered due to ventricular arrhythmia. The contents of the law-evading herbs were unknown, so an in-hospital follow-up was conducted to treat the patient's symptoms. The follow-up blood test showed an increased level of cardiac enzymes, which thereafter demonstrated a spontaneous remission. The systemic conditions tended to improve and the patient was discharged from the hospital on the 5th hospital day. The contents of the law-evading herbs in question were thereafter,analyzed, and synthetic cannabinoids (JWH-210, JWH-081 and JWH-122) as well as caffeine were detected. The cause for the poisoning symptoms were suspected to be the presence of synthetic cannabinoids and caffeine. Such law-evading herbs may contain synthetic cannabinoids and caffeine which both may induce shock and MD.

  18. Macrophage diversity in renal injury and repair

    PubMed Central

    Ricardo, Sharon D.; van Goor, Harry; Eddy, Allison A.

    2008-01-01

    Monocyte-derived macrophages can determine the outcome of the immune response and whether this response contributes to tissue repair or mediates tissue destruction. In addition to their important role in immune-mediated renal disease and host defense, macrophages play a fundamental role in tissue remodeling during embryonic development, acquired kidney disease, and renal allograft responses. This review summarizes macrophage phenotype and function in the orchestration of kidney repair and replacement of specialized renal cells following injury. Recent advances in our understanding of macrophage heterogeneity in response to their microenvironment raise new and exciting therapeutic possibilities to attenuate or conceivably reverse progressive renal disease in the context of fibrosis. Furthermore, parallels with pathological processes in many other organs also exist. PMID:18982158

  19. Suppressive effects of ketamine on macrophage functions

    SciTech Connect

    Chang Yi; Chen, T.-L.; Sheu, J.-R.; Chen, R.-M. . E-mail: rmchen@tmu.edu.tw

    2005-04-01

    Ketamine is an intravenous anesthetic agent. Clinically, induction of anesthesia with ketamine can cause immunosuppression. Macrophages play important roles in host defense. In this study, we attempted to evaluate the effects of ketamine on macrophage functions and its possible mechanism using mouse macrophage-like Raw 264.7 cells as the experimental model. Exposure of macrophages to 10 and 100 {mu}M ketamine, which correspond to 0.1 and 1 times the clinically relevant concentration, for 1, 6, and 24 h had no effect on cell viability or lactate dehydrogenase release. When the administered concentration reached 1000 {mu}M, ketamine caused a release of lactate dehydrogenase and cell death. Ketamine, at 10 and 100 {mu}M, did not affect the chemotactic activity of macrophages. Administration of 1000 {mu}M ketamine in macrophages resulted in a decrease in cell migration. Treatment of macrophages with ketamine reduced phagocytic activities. The oxidative ability of macrophages was suppressed by ketamine. Treatment with lipopolysaccharide induced TNF-{alpha}, IL-1{beta}, and IL-6 mRNA in macrophages. Administration of ketamine alone did not influence TNF-{alpha}, IL-1{beta}, or IL-6 mRNA production. Meanwhile, cotreatment with ketamine and lipopolysaccharide significantly inhibited lipopolysaccharide-induced TNF-{alpha}, IL-1{beta}, and IL-6 mRNA levels. Exposure to ketamine led to a decrease in the mitochondrial membrane potential. However, the activity of mitochondrial complex I NADH dehydrogenase was not affected by ketamine. This study shows that a clinically relevant concentration of ketamine (100 {mu}M) can suppress macrophage function of phagocytosis, its oxidative ability, and inflammatory cytokine production possibly via reduction of the mitochondrial membrane potential instead of direct cellular toxicity.

  20. Macrophages in diabetic gastroparesis– the missing link?

    PubMed Central

    Neshatian, Leila; Gibbons, Simon J.; Farrugia, Gianrico

    2015-01-01

    Background Diabetic gastroparesis results in significant morbidity for patients and major economic burden for society. Treatment options for diabetic gastroparesis are currently directed at symptom control rather than the underlying disease and are limited. The pathophysiology of diabetic gastroparesis includes damage to intrinsic and extrinsic neurons, smooth muscle and interstitial cells of Cajal (ICC). Oxidative damage in diabetes appears to be one of the primary insults involved in the pathogenesis of several complications of diabetes, including gastroparesis. Recent studies have highlighted the potential role of macrophages as key cellular elements in the pathogenesis of diabetic gastroparesis. Macrophages are important for both homeostasis and defense against a variety of pathogens. Heme oxygenase 1 (HO1), an enzyme expressed in a subset of macrophages has emerged as a major protective mechanism against oxidative stress. Activation of macrophages with high levels of HO1 expression protects against development of delayed gastric emptying in animal models of diabetes, while activation of macrophages that do not express HO1 are linked to neuromuscular cell injury. Targeting macrophages and HO1 may therefore be a therapeutic option in diabetic gastroparesis. Purpose This report briefly reviews the pathophysiology of diabetic gastroparesis with a focus on oxidative damage and how activation and polarization of different subtypes of macrophages in the muscularis propria determines development of delay in gastric emptying or protects against its development. PMID:25168158

  1. The Role of Decidual Macrophages During Normal and Pathological Pregnancy.

    PubMed

    Ning, Fen; Liu, Huishu; Lash, Gendie E

    2016-03-01

    Macrophages perform many specific functions including host defense, homeostasis, angiogenesis, and tissue development. Macrophages are the second most abundant leukocyte population in the non-pregnant endometrium and pregnant decidua and likely play a central role in the establishment and maintenance of normal pregnancy. Importantly, aberrantly activated uterine macrophages can affect trophoblast function and placental development, which may result in various adverse pregnancy outcomes ranging from pre-eclampsia to fetal growth restriction or demise. Only by fully understanding the roles of macrophage in pregnancy will we be able to develop interventions for the treatment of these various pregnancy complications. This review discusses the general origin and classification of monocytes and macrophages and focuses on the phenotype and functional roles of decidual macrophage at the maternal-fetal interface in normal pregnancy, as well as discussing the potential contribution of the abnormal state of these cells to various aspects of pregnancy pathologies. PMID:26750089

  2. Alveolar macrophage kinetics and function after interruption of canine marrow function

    SciTech Connect

    Springmeyer, S.C.; Altman, L.C.; Kopecky, K.J.; Deeg, H.J.; Storb, R.

    1982-03-01

    To study the kinetics and function of alveolar macrophages after interruption of marrow function, we performed serial bronchoalveolar lavages in dogs. The studies were performed before and after 9.0 to 9.5 Grey total body irradiation and marrow infusion. Monocytes had disappeared from the bloodstream by Day 7 after the irradiation. Alveolar macrophages were significantly decreased at Day 21. At Days 14 and 21 myeloperoxidase-positive alveolar macrophages were also significantly decreased. Beyond Day 30 the number of circulating monocytes, myeloperoxidase-positive and total alveolar macrophages had returned. Sex chromatin stains of alveolar macrophages obtained from a male dog that received female marrow indicated that the repopulating macrophages were of marrow origin. In vitro studies of alveolar macrophage migration and phagocytosis demonstrated increased activities beyond Day 30. These studies suggest that in this model the alveolar macrophage is dependent on the bone marrow for support and that the alveolar macrophage depletion may impair lung defense mechanisms.

  3. 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

    2016-04-01

    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.

  4. Yersinia pestis Requires Host Rab1b for Survival in Macrophages

    PubMed Central

    Connor, Michael G.; Pulsifer, Amanda R.; Price, Christopher T.; Abu Kwaik, Yousef; Lawrenz, Matthew B.

    2015-01-01

    Yersinia pestis is a facultative intracellular pathogen that causes the disease known as plague. During infection of macrophages Y. pestis actively evades the normal phagosomal maturation pathway to establish a replicative niche within the cell. However, the mechanisms used by Y. pestis to subvert killing by the macrophage are unknown. Host Rab GTPases are central mediators of vesicular trafficking and are commonly targeted by bacterial pathogens to alter phagosome maturation and killing by macrophages. Here we demonstrate for the first time that host Rab1b is required for Y. pestis to effectively evade killing by macrophages. We also show that Rab1b is specifically recruited to the Yersinia containing vacuole (YCV) and that Y. pestis is unable to subvert YCV acidification when Rab1b expression is knocked down in macrophages. Furthermore, Rab1b knockdown also altered the frequency of association between the YCV with the lysosomal marker Lamp1, suggesting that Rab1b recruitment to the YCV directly inhibits phagosome maturation. Finally, we show that Rab1b knockdown also impacts the pH of the Legionella pneumophila containing vacuole, another pathogen that recruits Rab1b to its vacuole. Together these data identify a novel role for Rab1b in the subversion of phagosome maturation by intracellular pathogens and suggest that recruitment of Rab1b to the pathogen containing vacuole may be a conserved mechanism to control vacuole pH. PMID:26495854

  5. 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

  6. HIV-1 evades virus-specific IgG2 and IgA class switching by targeting systemic and intestinal B cells via long-range intercellular conduits

    PubMed Central

    Xu, Weifeng; Santini, Paul A.; Sullivan, John S.; He, Bing; Shan, Meimei; Ball, Susan C.; Dyer, Wayne B.; Ketas, Thomas J.; Chadburn, Amy; Cohen-Gould, Leona; Knowles, Daniel M.; Chiu, April; Sanders, Rogier W.; Chen, Kang; Cerutti, Andrea

    2009-01-01

    Contact-dependent communication between immune cells generates protection, but also facilitates viral spread. We found that macrophages formed long-range actin-propelled conduits in response to negative factor (Nef), a human immunodeficiency virus type-1 (HIV-1) protein with immunosuppressive functions. Conduits attenuated immunoglobulin G2 (IgG2) and IgA class switching in systemic and intestinal lymphoid follicles by shuttling Nef from infected macrophages to B cells through a guanine exchange factor-dependent pathway involving the amino-terminal anchor, central core and carboxy-terminal flexible loop of Nef. By showing stronger virus-specific IgG2 and IgA responses in patients harboring Nef-deficient virions, our data suggest that HIV-1 exploits intercellular highways as a “Trojan horse” to deliver Nef to B cells and evade humoral immunity systemically and at mucosal sites of entry. PMID:19648924

  7. Brucella melitensis and Mycobacterium tuberculosis depict overlapping gene expression patterns induced in infected THP-1 macrophages.

    PubMed

    Masoudian, M; Derakhshandeh, A; Ghahramani Seno, M M

    2015-01-01

    Pathogens infecting mammalian cells have developed various strategies to suppress and evade their hosts' defensive mechanisms. In this line, the intracellular bacteria that are able to survive and propagate within their host cells must have developed strategies to avert their host's killing attitude. Studying the interface of host-pathogen confrontation can provide valuable information for defining therapeutic approaches. Brucellosis, caused by the Brucella strains, is a zoonotic bacterial disease that affects thousands of humans and animals around the world inflicting discomfort and huge economic losses. Similar to many other intracellular dwelling bacteria, infections caused by Brucella are difficult to treat, and hence any attempt at identifying new and common therapeutic targets would prove beneficial for the purpose of curing infections caused by the intracellular bacteria. In THP-1 macrophage infected with Brucella melitensis we studied the expression levels of four host's genes, i.e. EMP2, ST8SIA4, HCP5 and FRMD5 known to be involved in pathogenesis of Mycobacterium tuberculosis. Our data showed that at this molecular level, except for FRMD5 that was downregulated, the other three genes were upregulated by B. melitensis. Brucella melitensis and M. tuberculosis go through similar intracellular processes and interestingly two of the investigated genes, i.e. EMP2 and ST4SIA8 were upregulated in THP-1 cell infected with B. melitensis similar to that reported for THP-1 cells infected with M. tuberculosis. At the host-pathogen interaction interface, this study depicts overlapping changes for different bacteria with common survival strategies; a fact that implies designing therapeutic approaches based on common targets may be possible. PMID:27175205

  8. The Many Alternative Faces of Macrophage Activation

    PubMed Central

    Hume, David A.

    2015-01-01

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

  9. Surface modification of nanoparticles enables selective evasion of phagocytic clearance by distinct macrophage phenotypes

    PubMed Central

    Qie, Yaqing; Yuan, Hengfeng; von Roemeling, Christina A.; Chen, Yuanxin; Liu, Xiujie; Shih, Kevin D.; Knight, Joshua A.; Tun, Han W.; Wharen, Robert E.; Jiang, Wen; Kim, Betty Y.S.

    2016-01-01

    Nanomedicine is a burgeoning industry but an understanding of the interaction of nanomaterials with the immune system is critical for clinical translation. Macrophages play a fundamental role in the immune system by engulfing foreign particulates such as nanoparticles. When activated, macrophages form distinct phenotypic populations with unique immune functions, however the mechanism by which these polarized macrophages react to nanoparticles is unclear. Furthermore, strategies to selectively evade activated macrophage subpopulations are lacking. Here we demonstrate that stimulated macrophages possess higher phagocytic activities and that classically activated (M1) macrophages exhibit greater phagocytic capacity than alternatively activated (M2) macrophages. We show that modification of nanoparticles with polyethylene-glycol results in decreased clearance by all macrophage phenotypes, but importantly, coating nanoparticles with CD47 preferentially lowers phagocytic activity by the M1 phenotype. These results suggest that bio-inspired nanoparticle surface design may enable evasion of specific components of the immune system and provide a rational approach for developing immune tolerant nanomedicines. PMID:27197045

  10. Cytosolic Replication of Group A Streptococcus in Human Macrophages

    PubMed Central

    O’Neill, Alan M.; Thurston, Teresa L. M.

    2016-01-01

    ABSTRACT As key components of innate immune defense, macrophages are essential in controlling bacterial pathogens, including group A Streptococcus (GAS). Despite this, only a limited number of studies have analyzed the recovery of GAS from within human neutrophils and macrophages. Here, we determined the intracellular fate of GAS in human macrophages by using several quantitative approaches. In both U937 and primary human macrophages, the appearance over time of long GAS chains revealed that despite GAS-mediated cytotoxicity, replication occurred in viable, propidium iodide-negative macrophages. Whereas the major virulence factor M1 did not contribute to bacterial growth, a GAS mutant strain deficient in streptolysin O (SLO) was impaired for intracellular replication. SLO promoted bacterial escape from the GAS-containing vacuole (GCV) into the macrophage cytosol. Up to half of the cytosolic GAS colocalized with ubiquitin and p62, suggesting that the bacteria were targeted by the autophagy machinery. Despite this, live imaging of U937 macrophages revealed proficient replication of GAS after GCV rupture, indicating that escape from the GCV is important for growth of GAS in macrophages. Our results reveal that GAS can replicate within viable human macrophages, with SLO promoting GCV escape and cytosolic growth, despite the recruitment of autophagy receptors to bacteria. PMID:27073088

  11. Escape Analysis on the Confinement-Escape Problem of a Defender Against an Evader Escaping From a Circular Region.

    PubMed

    Li, Wei

    2016-09-01

    In this paper, we investigate some mathematical properties of the confinement-escape problem of a defender and an evader with respect to a circular region, which was proposed in the author's previous work. Initially, the evader is located inside the circle, the defender patrols on the circle and tries to seal it to prevent the evader' escape; while the evader attempts to escape with avoidance of the defender. Here, we adopt the same control laws of the agents and consider particularly the successful-escape conditions which ensure a monotone-increasing distance (MID) between the defender and the evader as the system evolves, for abbreviation, we call it the escape with the MID to the defender, or simply the MID escape. Then, we: 1) provide some sufficient conditions for the MID escape under different situations; 2) provide the corresponding upper-limit estimations of the escape time; and 3) discuss the characteristics of the analytical results. PMID:27390195

  12. Augmentation of Human Macrophage Candidacidal Capacity by Recombinant Human Myeloperoxidase and GranulocyteMacrophage Colony-Stimulating Factor

    PubMed Central

    Maródi, László; Tournay, Christophe; Káposzta, Rita; Johnston, Richard B.; Moguilevsky, Nicole

    1998-01-01

    Phagocyte myeloperoxidase (MPO) is believed to be particularly important in defense against candida infection. We reported earlier that monocytes, rich in MPO, killed Candida albicans at a significantly higher rate and extent than did monocyte-derived macrophages, known to lack MPO, and that C. albicans is less resistant to MPO-dependent oxidants than less pathogenic Candida species. We hypothesized, therefore, that the capacity of macrophages to kill C. albicans might be improved in the presence of MPO. In this study, we evaluated the ability of recombinant human MPO (rhMPO) to augment the killing of C. albicans by resident macrophages and macrophages activated by recombinant human granulocyte-macrophage colony-stimulating factor. Addition of rhMPO (concentration range, 0.8 to 6.4 U/ml) to suspensions of resident and activated macrophages and opsonized C. albicans resulted in concentration-dependent and significant increases in candida killing. This enhancement was particularly pronounced with activated macrophages, whether C. albicans was opsonized or unopsonized and ingested through the macrophage mannose receptor. rhMPO did not affect the killing of C. albicans by monocytes, nor did it affect phagocytosis of opsonized or unopsonized C. albicans. These results indicate that exogenous rhMPO can augment the candidacidal capacity of both resident and activated macrophages, with a more profound effect on activated cells. We suggest that rhMPO may be effective in the treatment of invasive candidiasis. PMID:9596743

  13. Regulatory Effects of Macrophage Inflammatory Protein 1α/CCL3 on the Development of Immunity to Cryptococcus neoformans Depend on Expression of Early Inflammatory Cytokines

    PubMed Central

    Olszewski, Michal A.; Huffnagle, Gary B.; Traynor, Timothy R.; McDonald, Roderick A.; Cook, Donald N.; Toews, Galen B.

    2001-01-01

    Macrophage inflammatory protein 1α (MIP-1α)/CCL3 prevents the development of eosinophilic pneumonia (EP) driven by a nonprotective T2-type immunity during infection with a highly virulent strain of Cryptococcus neoformans. The present study evaluated the interaction of MIP-1α with other innate immune system cytokines by comparing the immune responses that followed pulmonary infections with high- (C. neoformans 145A) and low (C. neoformans 52D)-virulence strains. In contrast to what was found for C. neoformans 145A infection, lack of MIP-1α in C. neoformans 52D infection did not cause the development of EP. C. neoformans 52D induced tumor necrosis factor alpha (TNF-α), gamma interferon (IFN-γ), and MCP-1 in the lungs of infected wild-type (WT) and MIP-1α knockout (KO) mice by day 7 postinfection. Both WT and MIP-1α KO mice subsequently cleared this infection. Thus, the robust expression of early inflammatory cytokines in C. neoformans 52D-infected mice promoted the development of protective immunity even in the absence of MIP-1α. Alternatively, C. neoformans 145A-infected WT and MIP-1α KO mice had diminished TNF-α, IFN-γ, and macrophage chemoattractant protein 1 (MCP-1) responses, indicating that virulent C. neoformans 145A evaded early innate host defenses. However C. neoformans 145A-infected WT mice had an early induction of MIP-1α and subsequently did not develop EP. In contrast, C. neoformans 145A-infected MIP-1α KO mice developed EP and had increased C. neoformans dissemination into the brain by day 35. We conclude that, in the absence of other innate immune response effector molecules, MIP-1α is crucial to prevent the development of EP and to control C. neoformans dissemination to the brain. PMID:11553568

  14. Assessing Anti-fungal Activity of Isolated Alveolar Macrophages by Confocal Microscopy

    PubMed Central

    Grimm, Melissa J.; D'Auria, Anthony C.; Segal, Brahm H.

    2014-01-01

    The lung is an interface where host cells are routinely exposed to microbes and microbial products. Alveolar macrophages are the first-line phagocytic cells that encounter inhaled fungi and other microbes. Macrophages and other immune cells recognize Aspergillus motifs by pathogen recognition receptors and initiate downstream inflammatory responses. The phagocyte NADPH oxidase generates reactive oxygen intermediates (ROIs) and is critical for host defense. Although NADPH oxidase is critical for neutrophil-mediated host defense1-3, the importance of NADPH oxidase in macrophages is not well defined. The goal of this study was to delineate the specific role of NADPH oxidase in macrophages in mediating host defense against A. fumigatus. We found that NADPH oxidase in alveolar macrophages controls the growth of phagocytosed A. fumigatus spores4. Here, we describe a method for assessing the ability of mouse alveolar macrophages (AMs) to control the growth of phagocytosed Aspergillus spores (conidia). Alveolar macrophages are stained in vivo and ten days later isolated from mice by bronchoalveolar lavage (BAL). Macrophages are plated onto glass coverslips, then seeded with green fluorescent protein (GFP)-expressing A. fumigatus spores. At specified times, cells are fixed and the number of intact macrophages with phagocytosed spores is assessed by confocal microscopy. PMID:25045941

  15. Defense use and defense understanding in children.

    PubMed

    Cramer, P; Brilliant, M A

    2001-04-01

    This study investigated the relation between children's use of defense mechanisms and their understanding of those defenses. We hypothesized that, once a child understands how a particular defense functions, the use of that defense will no longer be successful and will be replaced by another defense mechanism that is not yet understood. Defense use was assessed from the Thematic Appreception Test (TAT) stories told by 122 children; defense understanding was determined from the children's understanding of stories portraying defenses. The results indicated that younger children (mean age = 7-8) used the defense of denial more than the older children (mean age = 9-11). Older children understood the functioning of denial and projection better than the younger children. A comparison of children who did and did not understand a defense showed that younger children who understood the functioning of denial were less likely to themselves use denial. Likewise, older children who understood the functioning of projection were less likely to use this defense.

  16. Pulmonary defense mechanisms against opportunistic fungal pathogens.

    PubMed

    Waldorf, A R

    1989-01-01

    Though of critical importance, nonimmune host defense mechanisms against aspergillosis and mucormycosis are not completely understood. Prevention of these infections presumably requires control of either spore germination and/or hyphal growth by the host. The data suggest that the host provides an important barrier to infection by control of spore or conidia germination, the critical step involving conversion of the fungus to its tissue-invasive form. The mechanisms of host defense against A. fumigatus are not strictly dependent on inhibition of conidia germination. Rather, pulmonary defense against Aspergillus appears to depend to a greater degree on early killing of fungal conidia by alveolar macrophages. In contrast, prevention of mucormycosis appears to require inhibition of fungal spore germination by the bronchoalveolar macrophage, thereby preventing conversion of the fungus to its hyphal form, although resident bronchoalveolar macrophages are unable to kill R. oryzae spores. Thus, host pulmonary defenses to Rhizopus and Aspergillus vary, even in normal animals. The tissue-invasive hyphal forms of the fungi which cause aspergillosis and mucormycosis are too large to be ingested by phagocytic cells. Although macrophages and monocytes can damage hyphae, the bulk of this role appears to fall upon the neutrophil. However, antihyphal mechanisms of neutrophils may not necessarily be identical for all types of hyphae. Moreover, interactions of several potential oxidative and nonoxidative antihyphal mechanisms may define the host's ability to limit fungal infections. In individuals where concentrations of oxidative or nonoxidative substances are limiting or suboptimal, interactions of mechanisms may be required for antihyphal activity, and studies of these interactions are important to gain better knowledge of the defense mechanisms against opportunistic mycoses in the intact host. In summary, at least two distinct lines of defense against Aspergillus and Rhizopus

  17. Insights into battles between Mycobacterium tuberculosis and macrophages.

    PubMed

    Xu, Guanghua; Wang, Jing; Gao, George Fu; Liu, Cui Hua

    2014-10-01

    As the first line of immune defense for Mycobacterium tuberculosis (Mtb), macrophages also provide a major habitat for Mtb to reside in the host for years. The battles between Mtb and macrophages have been constant since ancient times. Triggered upon Mtb infection, multiple cellular pathways in macrophages are activated to initiate a tailored immune response toward the invading pathogen and regulate the cellular fates of the host as well. Toll-like receptors (TLRs) expressed on macrophages can recognize pathogen-associated-molecular patterns (PAMPs) on Mtb and mediate the production of immune-regulatory cytokines such as tumor necrosis factor (TNF) and type I Interferons (IFNs). In addition, Vitamin D receptor (VDR) and Vitamin D-1-hydroxylase are up-regulated in Mtb-infected macrophages, by which Vitamin D participates in innate immune responses. The signaling pathways that involve TNF, type I IFNs and Vitamin D are inter-connected, which play critical roles in the regulation of necroptosis, apoptosis, and autophagy of the infected macrophages. This review article summarizes current knowledge about the interactions between Mtb and macrophages, focusing on cellular fates of the Mtb-infected macrophages and the regulatory molecules and cellular pathways involved in those processes.

  18. 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.

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

    PubMed

    Matta, Sumit Kumar; Kumar, Dhiraj

    2015-09-01

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

  20. Evading surface and detector frequency noise in harmonic oscillator measurements of force gradients

    NASA Astrophysics Data System (ADS)

    Moore, Eric W.; Lee, SangGap; Hickman, Steven A.; Harrell, Lee E.; Marohn, John A.

    2010-07-01

    We introduce and demonstrate a method of measuring small force gradients acting on a harmonic oscillator in which the force-gradient signal of interest is used to parametrically up-convert a forced oscillation below resonance into an amplitude signal at the oscillator's resonance frequency. The approach, which we demonstrate in a mechanically detected electron spin resonance experiment, allows the force-gradient signal to evade detector frequency noise by converting a slowly modulated frequency signal into an amplitude signal.

  1. How the Okubo-Zweig-Iizuka rule evades large loop corrections

    SciTech Connect

    Paul Geiger; Nathan Isgur

    1991-08-26

    Arguments based on unitarity indicate that hadronic loop diagrams should produce large violations of the Okubo-Zweig-Iizuka rule. The mechanism by which these corrections are evaded has long been a mystery. We have found that there is an exact cancellation of all such loops in a particular limit and that, at least for the rho - omega - phi system which we have studied in detail, the cancellation is maintained in a realistic calculation which takes into account departures from this limit.

  2. [Drug Dependence and Cytotoxicity of Law-evading Drugs: Their Identities Explored from Basic Research].

    PubMed

    Funada, Masahiko

    2016-01-01

      Cases of people experiencing disturbed consciousness or dyspnea, causing traffic accidents, or requiring ambulance transport to hospital due to abuse of law-evading chemical substances have become a serious social problem in Japan. Most law-evading herbal products are marketed as incense or herbs and consist of finely chopped, dry vegetative matter mixed with chemical substances (drugs). Analysis of the chemical substances in these herbal products has demonstrated that they contain synthetic cannabinoids. Because there are many cannabinoid compounds, even if a particular drug is regulated, similar compounds that differ only slightly in structure may be added in their place. Therefore a cat-and-mouse game exists between regulations on chemical substances and their propagation. This paper summarizes the pharmacological actions and dangers of chemical substances contained in law-evading herbal products by focusing on synthetic cannabinoids, as a group of chemical substances contained in these products. Furthermore, comprehensive designations of synthetic cannabinoids have been introduced as a new method of regulation that emphasizes the similarity of chemical structures; this paper also outlines the comprehensive designations. We established a psychic-dependence liability and cytotoxicity screening system for synthetic cannabinoids using animals (behavioral analysis in vivo) and cell cultures (cytotoxicity analysis in vitro). With our drug-screening system, we were able rapidly to evaluate and quantify psychic-dependence liabilities and cytotoxicity of synthetic cannabinoids contained in law-evading herbal products. These scientific data using our screening system contributed to the establishment of legislation for comprehensive designations of synthetic cannabinoids. PMID:26725670

  3. The elicitin-like glycoprotein, ELI025, is secreted by the pathogenic oomycete Pythium insidiosum and evades host antibody responses.

    PubMed

    Lerksuthirat, Tassanee; Lohnoo, Tassanee; Inkomlue, Ruchuros; Rujirawat, Thidarat; Yingyong, Wanta; Khositnithikul, Rommanee; Phaonakrop, Narumon; Roytrakul, Sittiruk; Sullivan, Thomas D; Krajaejun, Theerapong

    2015-01-01

    Pythium insidiosum is a unique oomycete that can infect humans and animals. Patients with a P. insidiosum infection (pythiosis) have high rates of morbidity and mortality. The pathogen resists conventional antifungal drugs. Information on the biology and pathogenesis of P. insidiosum is limited. Many pathogens secrete proteins, known as effectors, which can affect the host response and promote the infection process. Elicitins are secretory proteins and are found only in the oomycetes, primarily in Phytophthora and Pythium species. In plant-pathogenic oomycetes, elicitins function as pathogen-associated molecular pattern molecules, sterol carriers, and plant defense stimulators. Recently, we reported a number of elicitin-encoding genes from the P. insidiosum transcriptome. The function of elicitins during human infections is unknown. One of the P. insidiosum elicitin-encoding genes, ELI025, is highly expressed and up-regulated at body temperature. This study aims to characterize the biochemical, immunological, and genetic properties of the elicitin protein, ELI025. A 12.4-kDa recombinant ELI025 protein (rELI025) was expressed in Escherichia coli. Rabbit anti-rELI025 antibodies reacted strongly with the native ELI025 in P. insidiosum's culture medium. The detected ELI025 had two isoforms: glycosylated and non-glycosylated. ELI025 was not immunoreactive with sera from pythiosis patients. The region near the transcriptional start site of ELI025 contained conserved oomycete core promoter elements. In conclusion, ELI025 is a small, abundant, secreted glycoprotein that evades host antibody responses. ELI025 is a promising candidate for development of diagnostic and therapeutic targets for pythiosis. PMID:25793767

  4. Incoming Influenza A Virus Evades Early Host Recognition, while Influenza B Virus Induces Interferon Expression Directly upon Entry

    PubMed Central

    Strengell, Mari; Sarin, L. Peter; Poranen, Minna M.; Fagerlund, Riku; Melén, Krister; Julkunen, Ilkka

    2012-01-01

    The activation of the interferon (IFN) system, which is triggered largely by the recognition of viral nucleic acids, is one of the most important host defense reactions against viral infections. Although influenza A and B viruses, which both have segmented negative-strand RNA genomes, share major structural similarities, they have evolutionarily diverged, with total genetic incompatibility. Here we compare antiviral-inducing mechanisms during infections with type A and B influenza viruses in human dendritic cells. We observed that IFN responses are induced significantly faster in cells infected with influenza B virus than in cells infected with type A influenza virus and that the early induction of antiviral gene expression is mediated by the activation of the transcription factor IFN regulatory factor 3 (IRF3). We further demonstrate that influenza A virus infection activates IFN responses only after viral RNA (vRNA) synthesis, whereas influenza B virus induces IFN responses even if its infectivity is destroyed by UV treatment. Thus, initial viral transcription, replication, and viral protein synthesis are dispensable for influenza B virus-induced antiviral responses. Moreover, vRNA molecules from both type A and B viruses are equally potent activators of IFN induction, but incoming influenza B virus structures are recognized directly in the cytosol, while influenza A virus is able to evade early recognition. Collectively, our data provide new evidence of a novel antiviral evasion strategy for influenza A virus without a contribution of the viral NS1 protein, and this opens up new insights into different influenza virus pathogenicities. PMID:22855501

  5. The Elicitin-Like Glycoprotein, ELI025, Is Secreted by the Pathogenic Oomycete Pythium insidiosum and Evades Host Antibody Responses

    PubMed Central

    Lerksuthirat, Tassanee; Lohnoo, Tassanee; Inkomlue, Ruchuros; Rujirawat, Thidarat; Yingyong, Wanta; Khositnithikul, Rommanee; Phaonakrop, Narumon; Roytrakul, Sittiruk; Sullivan, Thomas D.; Krajaejun, Theerapong

    2015-01-01

    Pythium insidiosum is a unique oomycete that can infect humans and animals. Patients with a P. insidiosum infection (pythiosis) have high rates of morbidity and mortality. The pathogen resists conventional antifungal drugs. Information on the biology and pathogenesis of P. insidiosum is limited. Many pathogens secrete proteins, known as effectors, which can affect the host response and promote the infection process. Elicitins are secretory proteins and are found only in the oomycetes, primarily in Phytophthora and Pythium species. In plant-pathogenic oomycetes, elicitins function as pathogen-associated molecular pattern molecules, sterol carriers, and plant defense stimulators. Recently, we reported a number of elicitin-encoding genes from the P. insidiosum transcriptome. The function of elicitins during human infections is unknown. One of the P. insidiosum elicitin-encoding genes, ELI025, is highly expressed and up-regulated at body temperature. This study aims to characterize the biochemical, immunological, and genetic properties of the elicitin protein, ELI025. A 12.4-kDa recombinant ELI025 protein (rELI025) was expressed in Escherichia coli. Rabbit anti-rELI025 antibodies reacted strongly with the native ELI025 in P. insidiosum’s culture medium. The detected ELI025 had two isoforms: glycosylated and non-glycosylated. ELI025 was not immunoreactive with sera from pythiosis patients. The region near the transcriptional start site of ELI025 contained conserved oomycete core promoter elements. In conclusion, ELI025 is a small, abundant, secreted glycoprotein that evades host antibody responses. ELI025 is a promising candidate for development of diagnostic and therapeutic targets for pythiosis. PMID:25793767

  6. Incoming influenza A virus evades early host recognition, while influenza B virus induces interferon expression directly upon entry.

    PubMed

    Österlund, Pamela; Strengell, Mari; Sarin, L Peter; Poranen, Minna M; Fagerlund, Riku; Melén, Krister; Julkunen, Ilkka

    2012-10-01

    The activation of the interferon (IFN) system, which is triggered largely by the recognition of viral nucleic acids, is one of the most important host defense reactions against viral infections. Although influenza A and B viruses, which both have segmented negative-strand RNA genomes, share major structural similarities, they have evolutionarily diverged, with total genetic incompatibility. Here we compare antiviral-inducing mechanisms during infections with type A and B influenza viruses in human dendritic cells. We observed that IFN responses are induced significantly faster in cells infected with influenza B virus than in cells infected with type A influenza virus and that the early induction of antiviral gene expression is mediated by the activation of the transcription factor IFN regulatory factor 3 (IRF3). We further demonstrate that influenza A virus infection activates IFN responses only after viral RNA (vRNA) synthesis, whereas influenza B virus induces IFN responses even if its infectivity is destroyed by UV treatment. Thus, initial viral transcription, replication, and viral protein synthesis are dispensable for influenza B virus-induced antiviral responses. Moreover, vRNA molecules from both type A and B viruses are equally potent activators of IFN induction, but incoming influenza B virus structures are recognized directly in the cytosol, while influenza A virus is able to evade early recognition. Collectively, our data provide new evidence of a novel antiviral evasion strategy for influenza A virus without a contribution of the viral NS1 protein, and this opens up new insights into different influenza virus pathogenicities.

  7. Macrophage Pro-Resolving Mediators—the When and Where

    PubMed Central

    DALLI, JESMOND; SERHAN, CHARLES

    2016-01-01

    Macrophages and neutrophils orchestrate acute inflammation and host defense as well as the resolution phase and return to homeostasis. In this article, we review the contribution of macrophages to local lipid mediator (LM) levels and the regulation of macrophage LM profiles by neutrophils and neutrophil-derived microparticles. We carried out LM metabololipidomics profiling distinct phagocytes: neutrophils (PMN), apoptotic PMN, and macrophages. Efferocytosis increased specialized proresolving mediator (SPM) biosynthesis, including Resolvin D1 (RvD1), RvD2, and RvE2, which were further elevated by PMN microparticles. Using deuterium-labeled precursors (d8-arachidonic acid, d5-eicosapentaenoic acid, and d5-docosahexaenoic acid), apoptotic PMN and microparticles contributed to SPM biosynthesis during efferocytosis. Assessment of macrophage LM profiles in M2 macrophages demonstrated higher SPM levels in this macrophage subset, including maresin 1 (MaR1), and lower amounts of leukotriene B4 and prostaglandins than M1. Apoptotic PMN uptake by both macrophage subtypes led to modulation of their LM profiles. Leukotriene B4 was down-regulated in M2 whereas SPM including lipoxin A4 were increased. Conversely, uptake of apoptotic PMN by M2 macrophages reduced (~ 25%) overall LM. MaR1 displays potent tissue regenerative and anti-nociceptive actions in addition to its pro-resolving and anti-inflammatory actions. In addition the MaR1 biosynthetic intermediate 13S,14S-epoxy-Maresin is also bioactive, inhibiting LTB4 biosynthesis and switching macrophage phenotypes from M1 to M2. Together, these results establish LM signature profiles of human phagocytes and related subpopulations. They demonstrate microparticle regulation of specific macrophage endogenous LM during defined stages of acute inflammation and their dynamic changes in human primary phagocytes. PMID:27337457

  8. Pulmonary and thoracic macrophage subpopulations and clearance of particles from the lung.

    PubMed Central

    Lehnert, B E

    1992-01-01

    Pulmonary macrophages consist of several subpopulations that can be defined by their anatomical locations as well as by other criteria. In addition to the well-known alveolar macrophages that reside on the alveolar surface, pulmonary macrophages also occur in the conducting airways, in various pulmonary interstitial regions, and, in some mammalian species, in the lung's intravascular compartment. Other thoracic macrophages of relevance to pulmonary defense and some lung disease processes are the pleural macrophages resident in the pleural space and macrophages present in regional lymph nodes that receive lymphatic drainage from the lung. Of the above subpopulations of pulmonary and thoracic macrophages, the alveolar macrophages have received the most experimental attention in the context of the pulmonary clearance and retention of deposited particles. Accordingly, less information is currently available regarding the roles other pulmonary and thoracic populations of macrophages may play in the removal of particles from the lower respiratory tract and associated tissue compartments. This report provides an overview of the various subpopulations of pulmonary and thoracic macrophages, as defined by their anatomical locations. The known and postulated roles of macrophages in the pulmonary clearance and retention of particles are reviewed, with particular emphasis on macrophage-associated processes involved in the pulmonary clearance of relatively insoluble particles. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 5. FIGURE 8. FIGURE 12. FIGURE 14. FIGURE 15. FIGURE 16. FIGURE 17. FIGURE 18. FIGURE 19. A FIGURE 19. B FIGURE 21. FIGURE 22. PMID:1396454

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

    PubMed Central

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

    1986-01-01

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

  10. Nontransformed, GM-CSF-dependent macrophage lines are a unique model to study tissue macrophage functions.

    PubMed

    Fejer, György; Wegner, Mareike Dorothee; Györy, Ildiko; Cohen, Idan; Engelhard, Peggy; Voronov, Elena; Manke, Thomas; Ruzsics, Zsolt; Dölken, Lars; Prazeres da Costa, Olivia; Branzk, Nora; Huber, Michael; Prasse, Antje; Schneider, Robert; Apte, Ron N; Galanos, Chris; Freudenberg, Marina A

    2013-06-11

    Macrophages are diverse cell types in the first line of antimicrobial defense. Only a limited number of primary mouse models exist to study their function. Bone marrow-derived, macrophage-CSF-induced cells with a limited life span are the most common source. We report here a simple method yielding self-renewing, nontransformed, GM-CSF/signal transducer and activator of transcription 5-dependent macrophages (Max Planck Institute cells) from mouse fetal liver, which reflect the innate immune characteristics of alveolar macrophages. Max Planck Institute cells are exquisitely sensitive to selected microbial agents, including bacterial LPS, lipopeptide, Mycobacterium tuberculosis, cord factor, and adenovirus and mount highly proinflammatory but no anti-inflammatory IL-10 responses. They show a unique pattern of innate responses not yet observed in other mononuclear phagocytes. This includes differential LPS sensing and an unprecedented regulation of IL-1α production upon LPS exposure, which likely plays a key role in lung inflammation in vivo. In conclusion, Max Planck Institute cells offer an useful tool to study macrophage biology and for biomedical science.

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

    PubMed

    Braian, Clara; Hogea, Valentin; Stendahl, Olle

    2013-01-01

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

  12. [The Characteristics of Law-evading Drug Users and Effective Approaches].

    PubMed

    Kondo, Ayumi

    2016-01-01

      The increasing number of law-evading drug users in Japan is becoming a serious social problem. Previous studies have shown that law-evading drug users are younger, more educated, and less antisocial than methamphetamine users. They also tend to have some type of psychiatric disorder before starting drug use; therefore one of the reasons that they start using drugs may be to alleviate certain psychiatric symptoms. Furthermore, if drug users are successful in avoiding arrest, they often lack the motivation to stop, which makes treatment difficult. Therapists are required to be non-confrontational, to keep pace with their patients, and to take their patients' other existing disorders into account. Recently, the Matrix Model has shown promise as a new treatment strategy for drug abusers in Japan. The Matrix Model, which was originally developed in response to the 1980s cocaine epidemic in the USA, is an intensive outpatient treatment approach for drug abuse and dependence. The Matrix Model integrates cognitive-behavioral therapy, contingency management, motivational interviewing, 12-step facilitation, family involvement, and so on, with a directive, non-confrontational approach, and this style of therapy seems to fit with law-evading drug users. A Matrix Model-based treatment program was first established in Japan in 2006. The aim of this report is to introduce and assess the benefits of the TAMA Mental Health and Welfare Center Relapse Prevention Program, a Matrix Model-based treatment program established at the Tama Mental Health and Welfare Center in 2007. PMID:26725673

  13. Glutamine Modulates Macrophage Lipotoxicity

    PubMed Central

    He, Li; Weber, Kassandra J.; Schilling, Joel D.

    2016-01-01

    Obesity and diabetes are associated with excessive inflammation and impaired wound healing. Increasing evidence suggests that macrophage dysfunction is responsible for these inflammatory defects. In the setting of excess nutrients, particularly dietary saturated fatty acids (SFAs), activated macrophages develop lysosome dysfunction, which triggers activation of the NLRP3 inflammasome and cell death. The molecular pathways that connect lipid stress to lysosome pathology are not well understood, but may represent a viable target for therapy. Glutamine uptake is increased in activated macrophages leading us to hypothesize that in the context of excess lipids glutamine metabolism could overwhelm the mitochondria and promote the accumulation of toxic metabolites. To investigate this question we assessed macrophage lipotoxicity in the absence of glutamine using LPS-activated peritoneal macrophages exposed to the SFA palmitate. We found that glutamine deficiency reduced lipid induced lysosome dysfunction, inflammasome activation, and cell death. Under glutamine deficient conditions mTOR activation was decreased and autophagy was enhanced; however, autophagy was dispensable for the rescue phenotype. Rather, glutamine deficiency prevented the suppressive effect of the SFA palmitate on mitochondrial respiration and this phenotype was associated with protection from macrophage cell death. Together, these findings reveal that crosstalk between activation-induced metabolic reprogramming and the nutrient microenvironment can dramatically alter macrophage responses to inflammatory stimuli. PMID:27077881

  14. Alternative activation of macrophages and pulmonary fibrosis are modulated by scavenger receptor, macrophage receptor with collagenous structure.

    PubMed

    Murthy, Shubha; Larson-Casey, Jennifer L; Ryan, Alan J; He, Chao; Kobzik, Lester; Carter, A Brent

    2015-08-01

    Alternative activation of alveolar macrophages is linked to fibrosis following exposure to asbestos. The scavenger receptor, macrophage receptor with collagenous structure (MARCO), provides innate immune defense against inhaled particles and pathogens; however, a receptor for asbestos has not been identified. We hypothesized that MARCO acts as an initial signaling receptor for asbestos, polarizes macrophages to a profibrotic M2 phenotype, and is required for the development of asbestos-induced fibrosis. Compared with normal subjects, alveolar macrophages isolated from patients with asbestosis express higher amounts of MARCO and have greater profibrotic polarization. Arginase 1 (40-fold) and IL-10 (265-fold) were higher in patients. In vivo, the genetic deletion of MARCO attenuated the profibrotic environment and pulmonary fibrosis in mice exposed to chrysotile. Moreover, alveolar macrophages from MARCO(-/-) mice polarize to an M1 phenotype, whereas wild-type mice have higher Ym1 (>3.0-fold) and nearly 7-fold more active TGF-β1 in bronchoalveolar lavage (BAL) fluid (BALF). Arg(432) and Arg(434) in domain V of MARCO are required for the polarization of macrophages to a profibrotic phenotype as mutation of these residues reduced FIZZ1 expression (17-fold) compared with cells expressing MARCO. These observations demonstrate that a macrophage membrane protein regulates the fibrotic response to lung injury and suggest a novel target for therapeutic intervention.

  15. M2 polarization enhances silica nanoparticle uptake by macrophages

    PubMed Central

    Hoppstädter, Jessica; Seif, Michelle; Dembek, Anna; Cavelius, Christian; Huwer, Hanno; Kraegeloh, Annette; Kiemer, Alexandra K.

    2015-01-01

    While silica nanoparticles have enabled numerous industrial and medical applications, their toxicological safety requires further evaluation. Macrophages are the major cell population responsible for nanoparticle clearance in vivo. The prevailing macrophage phenotype largely depends on the local immune status of the host. Whereas M1-polarized macrophages are considered as pro-inflammatory macrophages involved in host defense, M2 macrophages exhibit anti-inflammatory and wound-healing properties, but also promote tumor growth. We employed different models of M1 and M2 polarization: granulocyte-macrophage colony-stimulating factor/lipopolysaccharide (LPS)/interferon (IFN)-γ was used to generate primary human M1 cells and macrophage colony-stimulating factor (M-CSF)/interleukin (IL)-10 to differentiate M2 monocyte-derived macrophages (MDM). PMA-differentiated THP-1 cells were polarized towards an M1 type by LPS/IFN-γ and towards M2 by IL-10. Uptake of fluorescent silica nanoparticles (Ø26 and 41 nm) and microparticles (Ø1.75 μm) was quantified. At the concentration used (50 μg/ml), silica nanoparticles did not influence cell viability as assessed by MTT assay. Nanoparticle uptake was enhanced in M2-polarized primary human MDM compared with M1 cells, as shown by flow cytometric and microscopic approaches. In contrast, the uptake of microparticles did not differ between M1 and M2 phenotypes. M2 polarization was also associated with increased nanoparticle uptake in the macrophage-like THP-1 cell line. In accordance, in vivo polarized M2-like primary human tumor-associated macrophages obtained from lung tumors took up more nanoparticles than M1-like alveolar macrophages isolated from the surrounding lung tissue. In summary, our data indicate that the M2 polarization of macrophages promotes nanoparticle internalization. Therefore, the phenotypical differences between macrophage subsets should be taken into consideration in future investigations on nanosafety, but

  16. Radiological Defense. Textbook.

    ERIC Educational Resources Information Center

    Defense Civil Preparedness Agency (DOD), Washington, DC.

    This textbook has been prepared under the direction of the Defense Civil Preparedness Agency (DCPA) Staff College for use as a student reference manual in radiological defense (RADEF) courses. It provides much of the basic technical information necessary for a proper understanding of radiological defense and summarizes RADEF planning and expected…

  17. Growth regulation by macrophages

    SciTech Connect

    Wharton, W.; Walker, E.; Stewart, C.C.

    1982-01-01

    The evidence reviewed here indicates that macrophages, either acting alone or in concert with other cells, influence the proliferation of multiple types of cells. Most of the data indicate that these effects are mediated by soluble macrophage-elaborated products (probably proteins) although the role of direct cell-to-cell contacts cannot be ruled out in all cases. A degree of success has been achieved on the biochemical characterization of these factors, due mainly to their low specific activity in conditioned medium and the lack of rapid, specific assays. Understanding the growth-regulating potential of macrophages is an important and needed area of research.

  18. 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

  19. The Elusive Antifibrotic Macrophage

    PubMed Central

    Adhyatmika, Adhyatmika; Putri, Kurnia S. S.; Beljaars, Leonie; Melgert, Barbro N.

    2015-01-01

    Fibrotic diseases, especially of the liver, the cardiovascular system, the kidneys, and the lungs, account for approximately 45% of deaths in Western societies. Fibrosis is a serious complication associated with aging and/or chronic inflammation or injury and cannot be treated effectively yet. It is characterized by excessive deposition of extracellular matrix (ECM) proteins by myofibroblasts and impaired degradation by macrophages. This ultimately destroys the normal structure of an organ, which leads to loss of function. Most efforts to develop drugs have focused on inhibiting ECM production by myofibroblasts and have not yielded many effective drugs yet. Another option is to stimulate the cells that are responsible for degradation and uptake of excess ECM, i.e., antifibrotic macrophages. However, macrophages are plastic cells that have many faces in fibrosis, including profibrotic behavior-stimulating ECM production. This can be dependent on their origin, as the different organs have tissue-resident macrophages with different origins and a various influx of incoming monocytes in steady-state conditions and during fibrosis. To be able to pharmacologically stimulate the right kind of behavior in fibrosis, a thorough characterization of antifibrotic macrophages is necessary, as well as an understanding of the signals they need to degrade ECM. In this review, we will summarize the current state of the art regarding the antifibrotic macrophage phenotype and the signals that stimulate its behavior. PMID:26618160

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

    PubMed Central

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

    2014-01-01

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

  1. Two systems and defenses.

    PubMed

    Novick, Jack; Novick, Kerry Kelly

    2013-02-01

    The authors suggest that Freud's concept of defense differentiated psychoanalysis from other medical and psychological theories of personality development and functioning then and now. Reclaiming the concept's centrality and linking it with interdisciplinary research findings, they illustrate their extension of defense into a two-system model of self-protection and self-regulation with a clinical example. The authors suggest that the two-system model allows for the reintegration of defense into a multidimensional psychoanalytic theory and multimodal therapeutic technique.

  2. Dynamic defense workshop :

    SciTech Connect

    Crosby, Sean Michael; Doak, Justin E.; Haas, Jason Juedes.; Helinski, Ryan; Lamb, Christopher C.

    2013-02-01

    On September 5th and 6th, 2012, the Dynamic Defense Workshop: From Research to Practice brought together researchers from academia, industry, and Sandia with the goals of increasing collaboration between Sandia National Laboratories and external organizations, de ning and un- derstanding dynamic, or moving target, defense concepts and directions, and gaining a greater understanding of the state of the art for dynamic defense. Through the workshop, we broadened and re ned our de nition and understanding, identi ed new approaches to inherent challenges, and de ned principles of dynamic defense. Half of the workshop was devoted to presentations of current state-of-the-art work. Presentation topics included areas such as the failure of current defenses, threats, techniques, goals of dynamic defense, theory, foundations of dynamic defense, future directions and open research questions related to dynamic defense. The remainder of the workshop was discussion, which was broken down into sessions on de ning challenges, applications to host or mobile environments, applications to enterprise network environments, exploring research and operational taxonomies, and determining how to apply scienti c rigor to and investigating the eld of dynamic defense.

  3. The military insanity defense.

    PubMed

    Lande, R G

    1991-01-01

    This article describes the military insanity defense. The success of the litigated insanity defense is explored through the number of insanity acquittals over a 28-month period. A questionnaire distributed to all United States Army psychiatrists provided information on the number of forensic evaluations performed, the number of not criminally responsible (NCR) opinions made, and the disposition of noncontested NCR opinions. The questionnaire also tested the Army psychiatrists' knowledge about recent changes in the military insanity defense. This pilot study raises interesting questions about the military insanity defense that further research can address.

  4. Technologies for distributed defense

    NASA Astrophysics Data System (ADS)

    Seiders, Barbara; Rybka, Anthony

    2002-07-01

    For Americans, the nature of warfare changed on September 11, 2001. Our national security henceforth will require distributed defense. One extreme of distributed defense is represented by fully deployed military troops responding to a threat from a hostile nation state. At the other extreme is a country of 'citizen soldiers', with families and communities securing their common defense through heightened awareness, engagement as good neighbors, and local support of and cooperation with local law enforcement, emergency and health care providers. Technologies - for information exploitation, biological agent detection, health care surveillance, and security - will be critical to ensuring success in distributed defense.

  5. Technologies for Distributed Defense

    SciTech Connect

    Seiders, Barbara AB; Rybka, Anthony J.

    2002-07-01

    For Americans, the nature of warfare changed on September 11, 2001. Our national security henceforth will require distributed defense. One extreme of distributed defense is represented by fully deployed military troops responding to a threat from a hostile nation state. At the other extreme is a country of "citizen soldiers," with families and communities securing their common defense through heightened awareness, engagement as good neighbors, and local support of and cooperation with local law enforcement, emergency and health care providers. Technologies - for information exploitation, biological agent detection, health care surveillance, and security - will be critical to ensuring success in distributed defense.

  6. Die hard: a blend of freezing and fleeing as a dynamic defense--implications for the control of defensive behavior.

    PubMed

    Eilam, David

    2005-01-01

    Freezing, fleeing or fighting back are general defensive responses in many taxa. These defenses are mutually exclusive, since a prey cannot simultaneously flee and fight, or freeze and flee. Each of these defenses by itself is rudimentary and probably cannot provide a completely effective means to elude predation. Freezing is efficient only if employed before the prey is spotted by the predator, otherwise the prey becomes a stationary, easy to catch target. In fleeing, the prey can move directly away and maximize its distance from the predator, move toward the predator to confine it to a single clashing point, or dodge sideways to evade the attack. Prey can also run in a straight path that is efficient against slow or distant predators, or in a zigzag path that is efficient when a raptor is close or fast. In all, freezing and fleeing constitute together a complex and flexible defensive response, and are probably controlled by different motor systems that are inter-connected to allow fast switching between these behaviors, as required for an effective and versatile response.

  7. Evading the pulsar constraints on the cosmic string tension in supergravity inflation

    SciTech Connect

    Kamada, Kohei; Miyamoto, Yuhei; Yokoyama, Jun'ichi E-mail: miyamoto@resceu.s.u-tokyo.ac.jp

    2012-10-01

    The cosmic string is a useful probe of the early Universe and may give us a clue to physics at high energy scales which particle accelerators cannot reach. Although the most promising tool to observe it is the cosmic microwave background (CMB), the constraint from gravitational waves is becoming so stringent that detecting its signatures in CMB may be impossible. In this paper, we construct a scenario that contains cosmic strings observable in the cosmic microwave background while evading the constraint imposed by the recent pulsar timing data. We argue that cosmic strings with relatively large tension are allowed by diluting loops contributing to the relevant frequency range of the gravitational wave background. We also present a particle physics model to realize such dilution in the context of chaotic inflation in supergravity, where the phase transition occurs during inflation due to the time-dependence of the Hubble induced mass.

  8. Macrophages and Iron Metabolism.

    PubMed

    Soares, Miguel P; Hamza, Iqbal

    2016-03-15

    Iron is a transition metal that due to its inherent ability to exchange electrons with a variety of molecules is essential to support life. In mammals, iron exists mostly in the form of heme, enclosed within an organic protoporphyrin ring and functioning primarily as a prosthetic group in proteins. Paradoxically, free iron also has the potential to become cytotoxic when electron exchange with oxygen is unrestricted and catalyzes the production of reactive oxygen species. These biological properties demand that iron metabolism is tightly regulated such that iron is available for core biological functions while preventing its cytotoxic effects. Macrophages play a central role in establishing this delicate balance. Here, we review the impact of macrophages on heme-iron metabolism and, reciprocally, how heme-iron modulates macrophage function.

  9. [Macrophages in asthma].

    PubMed

    Medina Avalos, M A; Orea Solano, M

    1997-01-01

    Every time they exist more demonstrations of the paper than performs the line monocytes-macrophage in the patogenesis of the bronchial asthma. The mononuclear phagocytes cells, as the alveolar macrophages, also they can be activated during allergic methods. The monocytes macrophages are possible efficient inductors of the inflammation; this due to the fact that they can secrete inflammatory mediators, between those which are counted the pre-forming granules of peptides, metabolites of oxidation activation, activator of platelets activator and metabolites of the arachidonic acid. The identification of IL-1 in the liquidate of the bronchial ablution of sick asthmatic, as well as the identification of IL-1 in the I bronchioalveolar washing of places of allergens cutaneous prick, supports the activation concept mononuclear of phagocytic cells in allergic sufferings. PMID:9432275

  10. 22 CFR 130.4 - Defense articles and defense services.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense articles and...

  11. 22 CFR 130.4 - Defense articles and defense services.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense articles and...

  12. 22 CFR 130.4 - Defense articles and defense services.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense articles and...

  13. 22 CFR 130.4 - Defense articles and defense services.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense articles and...

  14. 22 CFR 130.4 - Defense articles and defense services.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense articles and...

  15. Defense Mechanisms: A Bibliography.

    ERIC Educational Resources Information Center

    Pedrini, D. T.; Pedrini, Bonnie C.

    This bibliography includes studies of defense mechanisms, in general, and studies of multiple mechanisms. Defense mechanisms, briefly and simply defined, are the unconscious ego defendants against unpleasure, threat, or anxiety. Sigmund Freud deserves the clinical credit for studying many mechanisms and introducing them in professional literature.…

  16. Schools and Civil Defense.

    ERIC Educational Resources Information Center

    Office of Civil Defense (DOD), Washington, DC.

    Civil defense is a planned, coordinated action to protect the population during any emergency whether arising from thermonuclear attack or natural disaster. The Federal Government has assumed four responsibilities--(1) to keep track of the nature of the threat which the civil defense program must meet, (2) to prepare and disseminate information…

  17. Forgiveness and Defense Style

    ERIC Educational Resources Information Center

    Maltby, John; Day, Liz

    2004-01-01

    Within the literature on the psychology of forgiveness, researchers have hypothesized that the 1st stage in the process of being able to forgive is the role of psychological defense. To examine such a hypothesis, the authors explored the relationship between forgiveness and defense style. The 304 respondents (151 men, 153 women) completed measures…

  18. Defense Workforce Training Programs.

    ERIC Educational Resources Information Center

    Fletcher, J. D.; And Others

    This report discusses the amount and kinds of Department of Defense (DoD) interactive courseware (ICW) programs that are candidates for transfer to the private sector. Candidates for transfer were identified through an analysis of the Defense Instructional Technology Information System (DITIS). Out of 4,644 ICW programs that have been reported to…

  19. Current concepts on pulmonary host defense mechanisms in children.

    PubMed

    Wilmott, R W; Khurana-Hershey, G; Stark, J M

    2000-06-01

    The respiratory tract is exposed continuously to noxious agents, microbial organisms, particles, and allergens. It has therefore evolved both innate and specific defense mechanisms. The innate host defense mechanisms include components such as collectins, beta-defensins, lactoferrin, and complement, all of which have an important role in modulating the immune response. Immune protection of the lungs by specific antibody is reviewed. The airways are protected by alveolar macrophages, neutrophils, and lymphocytes, and their origins, regulation, functions, and antimicrobial activity are summarized. Antimicrobial peptides and immune-modulating peptides are likely to have a significant therapeutic role for infection and inflammation in the respiratory tract.

  20. Formulation of a Cooperative-Confinement-Escape problem of multiple cooperative defenders against an evader escaping from a circular region

    NASA Astrophysics Data System (ADS)

    Li, Wei

    2016-10-01

    In this paper, we propose and formulate the Cooperative-Confinement-Escape (CCE) problem of multiple cooperative defenders against an evader escaping from a circular region, in which the defenders are moving on the circle with attempt to prevent possible escape of a single evader who is initially located inside the circle. The main contributions are summarized as follows: (1) we first provide an effective formulation of the CCE problem, which is an emphasis of this paper, with design of two nonlinear control strategies for the cooperative defenders and the adversarial evader, respectively. Particularly, we consider to include a proper interaction between each pair of the nearest-neighbor defenders, and an adaptive trajectory prediction mechanism in the strategies of the defenders to increase the chance of successful confinement. (2) For the first attempt on analyzing the CCE dynamics which is unavoidably strongly nonlinear, we analyze the minimum energy of the evader for possible escape. (3) For understanding of the behaviors of the system under different parameters, (i) we illustrate the effectiveness of the confinement strategy using the adaptive trajectory prediction mechanism, and (ii) the physical roles of the system parameters with respect to the system dynamics, some of which may be unexpected or not straightforward. A separate paper will be presented for systematic analysis of the agents' behaviors with respect to the large intervals of the parameter settings.

  1. 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

  2. Response gene to complement 32 protein promotes macrophage phagocytosis via activation of protein kinase C pathway.

    PubMed

    Tang, Rui; Zhang, Gui; Chen, Shi-You

    2014-08-15

    Macrophage phagocytosis plays an important role in host defense. The molecular mechanism, especially factors regulating the phagocytosis, however, is not completely understood. In the present study, we found that response gene to complement 32 (RGC-32) is an important regulator of phagocytosis. Although RGC-32 is induced and abundantly expressed in macrophage during monocyte-macrophage differentiation, RGC-32 appears not to be important for this process because RGC-32-deficient bone marrow progenitor can normally differentiate to macrophage. However, both peritoneal macrophages and bone marrow-derived macrophages with RGC-32 deficiency exhibit significant defects in phagocytosis, whereas RGC-32-overexpressed macrophages show increased phagocytosis. Mechanistically, RGC-32 is recruited to macrophage membrane where it promotes F-actin assembly and the formation of phagocytic cups. RGC-32 knock-out impairs F-actin assembly. RGC-32 appears to interact with PKC to regulate PKC-induced phosphorylation of F-actin cross-linking protein myristoylated alanine-rich protein kinase C substrate. Taken together, our results demonstrate for the first time that RGC-32 is a novel membrane regulator for macrophage phagocytosis.

  3. Analysis of Nitric Oxide-Dependent Antimicrobial Actions in Macrophages and Mice

    PubMed Central

    Vazquez-Torres, Andrés; Stevanin, Tania; Jones-Carson, Jessica; Castor, Margaret; Read, Robert C.; Fang, Ferric C.

    2009-01-01

    Nitric oxide (NO•) is a critical component of mammalian host defense that is produced in macrophages and other cells comprising the innate immune system. Isolated mammalian macrophages have been utilized to measure the kinetics of NO production and to demonstrate NO-related antimicrobial actions. Some microorganisms possess enzymes to detoxify nitrogen oxides, and mutant strains lacking these enzymes can be used to demonstrate the importance of these mechanisms for intracellular bacterialsurvival. This chapter describes techniques with which to analyze the antimicrobial actions of nitric oxide in murine and human macrophages and in laboratory mice. PMID:18433645

  4. IL-33 Priming Enhances Peritoneal Macrophage Activity in Response to Candida albicans.

    PubMed

    Tran, Vuvi G; Cho, Hong R; Kwon, Byungsuk

    2014-08-01

    IL-33 is a member of the IL-1 cytokine family and plays a role in the host defense against bacteria, viruses, and fungi. In this study, we investigated the function of IL-33 and its receptor in in vitro macrophage responses to Candida albicans. Our results demonstrate that pre-sensitization of isolated peritoneal macrophages with IL-33 enhanced their pro-inflammatory cytokine production and phagocytic activity in response to C. albicans. These macrophage activities were entirely dependent on the ST2-MyD88 signaling pathway. In addition, pre-sensitization with IL-33 also increased ROS production and the subsequent killing ability of macrophages following C. albicans challenge. These results indicate that IL-33 may increase anti-fungal activity against Candida through macrophage-mediated resistance mechanisms. PMID:25177252

  5. Wormhole Travel for Macrophages.

    PubMed

    Okabe, Yasutaka; Medzhitov, Ruslan

    2016-04-21

    Leukocyte recruitment is generally achieved by rapid migration of inflammatory cells out of circulation, through modified blood vessels, and into affected tissues. Now, Wang and Kubes show that macrophages can be rapidly recruited from body cavities to the liver, via a non-vascular route, where they help to coordinate tissue repair.

  6. TRPV4 Mechanosensitive Ion Channel Regulates Lipopolysaccharide-Stimulated Macrophage Phagocytosis.

    PubMed

    Scheraga, Rachel G; Abraham, Susamma; Niese, Kathryn A; Southern, Brian D; Grove, Lisa M; Hite, R Duncan; McDonald, Christine; Hamilton, Thomas A; Olman, Mitchell A

    2016-01-01

    Macrophage phagocytosis of particles and pathogens is an essential aspect of innate host defense. Phagocytic function requires cytoskeletal rearrangements that depend on the interaction between macrophage surface receptors, particulates/pathogens, and the extracellular matrix. In the present study we determine the role of a mechanosensitive ion channel, transient receptor potential vanilloid 4 (TRPV4), in integrating the LPS and matrix stiffness signals to control macrophage phenotypic change for host defense and resolution from lung injury. We demonstrate that active TRPV4 mediates LPS-stimulated murine macrophage phagocytosis of nonopsonized particles (Escherichia coli) in vitro and opsonized particles (IgG-coated latex beads) in vitro and in vivo in intact mice. Intriguingly, matrix stiffness in the range seen in inflamed or fibrotic lung is required to sensitize the TRPV4 channel to mediate the LPS-induced increment in macrophage phagocytosis. Furthermore, TRPV4 is required for the LPS induction of anti-inflammatory/proresolution cytokines. These findings suggest that signaling through TRPV4, triggered by changes in extracellular matrix stiffness, cooperates with LPS-induced signals to mediate macrophage phagocytic function and lung injury resolution. These mechanisms are likely to be important in regulating macrophage function in the context of pulmonary infection and fibrosis.

  7. IFN-γ Prevents Adenosine Receptor (A2bR) Upregulation To Sustain the Macrophage Activation Response.

    PubMed

    Cohen, Heather B; Ward, Amanda; Hamidzadeh, Kajal; Ravid, Katya; Mosser, David M

    2015-10-15

    The priming of macrophages with IFN-γ prior to TLR stimulation results in enhanced and prolonged inflammatory cytokine production. In this study, we demonstrate that, following TLR stimulation, macrophages upregulate the adenosine 2b receptor (A2bR) to enhance their sensitivity to immunosuppressive extracellular adenosine. This upregulation of A2bR leads to the induction of macrophages with an immunoregulatory phenotype and the downregulation of inflammation. IFN-γ priming of macrophages selectively prevents the induction of the A2bR in macrophages to mitigate sensitivity to adenosine and to prevent this regulatory transition. IFN-γ-mediated A2bR blockade leads to a prolonged production of TNF-α and IL-12 in response to TLR ligation. The pharmacologic inhibition or the genetic deletion of the A2bR results in a hyperinflammatory response to TLR ligation, similar to IFN-γ treatment of macrophages. Conversely, the overexpression of A2bR on macrophages blunts the IFN-γ effects and promotes the development of immunoregulatory macrophages. Thus, we propose a novel mechanism whereby IFN-γ contributes to host defense by desensitizing macrophages to the immunoregulatory effects of adenosine. This mechanism overcomes the transient nature of TLR activation, and prolongs the antimicrobial state of the classically activated macrophage. This study may offer promising new targets to improve the clinical outcome of inflammatory diseases in which macrophage activation is dysregulated. PMID:26355158

  8. Alterations in macrophage functions by environmental chemicals.

    PubMed Central

    Gardner, D E

    1984-01-01

    The establishment of infectious diseases is rarely entirely attributed to a single entity, but instead is the result of a primary stress and one or more secondary factors that interfere with homeostasis and the ability of the host to cope with the primary etiologic assault. Any environmental chemical that can suppress the normal functioning of the host's body defenses would be expected to increase the risk of the host to such diseases. Within the lung, the alveolar macrophages are the crucial elements responsible for defending the body against such airborne viable agents. The effects of inhaled gases and particulates on these defense cells are a major concern of the environmental health scientist since such chemicals have the capability of adversely affecting the integrity and functioning of these pulmonary defense cells. The objective of this report is to provide an overview that will improve our understanding of how a variety of environmental chemicals can alter the biochemical, physiological and immunological functioning of these cells. PMID:6376106

  9. Two systems and defenses.

    PubMed

    Novick, Jack; Novick, Kerry Kelly

    2013-02-01

    The authors suggest that Freud's concept of defense differentiated psychoanalysis from other medical and psychological theories of personality development and functioning then and now. Reclaiming the concept's centrality and linking it with interdisciplinary research findings, they illustrate their extension of defense into a two-system model of self-protection and self-regulation with a clinical example. The authors suggest that the two-system model allows for the reintegration of defense into a multidimensional psychoanalytic theory and multimodal therapeutic technique. PMID:23421665

  10. Transcriptional Regulation and Macrophage Differentiation.

    PubMed

    Hume, David A; Summers, Kim M; Rehli, Michael

    2016-06-01

    Monocytes and macrophages are professional phagocytes that occupy specific niches in every tissue of the body. Their survival, proliferation, and differentiation are controlled by signals from the macrophage colony-stimulating factor receptor (CSF-1R) and its two ligands, CSF-1 and interleukin-34. In this review, we address the developmental and transcriptional relationships between hematopoietic progenitor cells, blood monocytes, and tissue macrophages as well as the distinctions from dendritic cells. A huge repertoire of receptors allows monocytes, tissue-resident macrophages, or pathology-associated macrophages to adapt to specific microenvironments. These processes create a broad spectrum of macrophages with different functions and individual effector capacities. The production of large transcriptomic data sets in mouse, human, and other species provides new insights into the mechanisms that underlie macrophage functional plasticity. PMID:27337479

  11. Serum amyloid A inhibits osteoclast differentiation to maintain macrophage function.

    PubMed

    Kim, Jiseon; Yang, Jihyun; Park, Ok-Jin; Kang, Seok-Seong; Yun, Cheol-Heui; Han, Seung Hyun

    2016-04-01

    Serum amyloid A is an acute phase protein that is elevated under inflammatory conditions. Additionally, the serum levels of serum amyloid A are associated with the progression of inflammatory arthritis; thus, serum amyloid A might be involved in the regulation of osteoclast differentiation. In the present study, we examined the effects of serum amyloid A on osteoclast differentiation and function. When bone marrow-derived macrophages, as osteoclast precursors, were stimulated with serum amyloid A in the presence of M-CSF and receptor activator of nuclear factor-κB ligand, osteoclast differentiation and its bone-resorption activity were substantially inhibited. TLR2 was important in the inhibitory effect of serum amyloid A on osteoclast differentiation, because serum amyloid A stimulated TLR2. The inhibitory effect was absent in bone marrow-derived macrophages obtained from TLR2-deficient mice. Furthermore, serum amyloid A inhibited the expression of c-Fos and nuclear factor of activated T cells c1, which are crucial transcription factors for osteoclast differentiation, but prevented downregulation of IFN regulatory factor-8, a negative regulator of osteoclast differentiation. In contrast, serum amyloid A sustained the endocytic capacity of bone marrow-derived macrophages and their ability to induce the proinflammatory cytokines, IL-6, IL-1β, and TNF-α. Taken together, these results suggest that serum amyloid A, when increased by inflammatory conditions, inhibits differentiation of macrophages to osteoclasts, likely to maintain macrophage function for host defense.

  12. A novel real time imaging platform to quantify macrophage phagocytosis.

    PubMed

    Kapellos, Theodore S; Taylor, Lewis; Lee, Heyne; Cowley, Sally A; James, William S; Iqbal, Asif J; Greaves, David R

    2016-09-15

    Phagocytosis of pathogens, apoptotic cells and debris is a key feature of macrophage function in host defense and tissue homeostasis. Quantification of macrophage phagocytosis in vitro has traditionally been technically challenging. Here we report the optimization and validation of the IncuCyte ZOOM® real time imaging platform for macrophage phagocytosis based on pHrodo® pathogen bioparticles, which only fluoresce when localized in the acidic environment of the phagolysosome. Image analysis and fluorescence quantification were performed with the automated IncuCyte™ Basic Software. Titration of the bioparticle number showed that the system is more sensitive than a spectrofluorometer, as it can detect phagocytosis when using 20× less E. coli bioparticles. We exemplified the power of this real time imaging platform by studying phagocytosis of murine alveolar, bone marrow and peritoneal macrophages. We further demonstrate the ability of this platform to study modulation of the phagocytic process, as pharmacological inhibitors of phagocytosis suppressed bioparticle uptake in a concentration-dependent manner, whereas opsonins augmented phagocytosis. We also investigated the effects of macrophage polarization on E. coli phagocytosis. Bone marrow-derived macrophage (BMDM) priming with M2 stimuli, such as IL-4 and IL-10 resulted in higher engulfment of bioparticles in comparison with M1 polarization. Moreover, we demonstrated that tolerization of BMDMs with lipopolysaccharide (LPS) results in impaired E. coli bioparticle phagocytosis. This novel real time assay will enable researchers to quantify macrophage phagocytosis with a higher degree of accuracy and sensitivity and will allow investigation of limited populations of primary phagocytes in vitro.

  13. A novel real time imaging platform to quantify macrophage phagocytosis.

    PubMed

    Kapellos, Theodore S; Taylor, Lewis; Lee, Heyne; Cowley, Sally A; James, William S; Iqbal, Asif J; Greaves, David R

    2016-09-15

    Phagocytosis of pathogens, apoptotic cells and debris is a key feature of macrophage function in host defense and tissue homeostasis. Quantification of macrophage phagocytosis in vitro has traditionally been technically challenging. Here we report the optimization and validation of the IncuCyte ZOOM® real time imaging platform for macrophage phagocytosis based on pHrodo® pathogen bioparticles, which only fluoresce when localized in the acidic environment of the phagolysosome. Image analysis and fluorescence quantification were performed with the automated IncuCyte™ Basic Software. Titration of the bioparticle number showed that the system is more sensitive than a spectrofluorometer, as it can detect phagocytosis when using 20× less E. coli bioparticles. We exemplified the power of this real time imaging platform by studying phagocytosis of murine alveolar, bone marrow and peritoneal macrophages. We further demonstrate the ability of this platform to study modulation of the phagocytic process, as pharmacological inhibitors of phagocytosis suppressed bioparticle uptake in a concentration-dependent manner, whereas opsonins augmented phagocytosis. We also investigated the effects of macrophage polarization on E. coli phagocytosis. Bone marrow-derived macrophage (BMDM) priming with M2 stimuli, such as IL-4 and IL-10 resulted in higher engulfment of bioparticles in comparison with M1 polarization. Moreover, we demonstrated that tolerization of BMDMs with lipopolysaccharide (LPS) results in impaired E. coli bioparticle phagocytosis. This novel real time assay will enable researchers to quantify macrophage phagocytosis with a higher degree of accuracy and sensitivity and will allow investigation of limited populations of primary phagocytes in vitro. PMID:27475716

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

    PubMed

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

    1996-12-01

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

  15. [The current situation of aggravated intoxication with "kiken" drugs (law-evading drugs)].

    PubMed

    Akashi, Akiko; Kashiura, Masahiro; Mikami, Manabu; Hamabe, Yuichi

    2016-03-01

    The intoxication caused by "kiken" drugs (law-evading drugs), such as synthetic cannabinoids, cathinones, and methoxetamine, has recently increased in Japan. We retrospectively examined the characteristics of patients poisoned with the "kiken" drugs. We included patients who presented at the emergency department at the Tokyo Metropolitan Bokutoh Hospital from January 2011 to December 2014. Eighteen patients admitted between January 2011 and December 2013 were included in the early period group and 10 patients admitted between January and December 2014 were categorized into the late period group. The number of the patients transported to our emergency department between 2011 and 2014 increased annually. Patients were mainly admitted between May and October 2014; no patients were admitted after November 2014. The patients' age, history of previous mental disease, habitual use, Triage DOA results, serum creatinine values on admission, and respiratory management differed significantly between the groups. However, the median serum creatinine values of both groups on admission were within the normal level. Patients poisoned with the "kiken" drugs showed more severe symptoms, higher rate of habitual use, and higher average age. The annual increase in the number of the patients observed thus far is expected to decrease in the future. Maintenance of the law and expansion of medical institutions that treat patients addicted to the "kiken" drugs are warranted. PMID:27255020

  16. Leukemic Stem Cells Evade Chemotherapy by Metabolic Adaptation to an Adipose Tissue Niche.

    PubMed

    Ye, Haobin; Adane, Biniam; Khan, Nabilah; Sullivan, Timothy; Minhajuddin, Mohammad; Gasparetto, Maura; Stevens, Brett; Pei, Shanshan; Balys, Marlene; Ashton, John M; Klemm, Dwight J; Woolthuis, Carolien M; Stranahan, Alec W; Park, Christopher Y; Jordan, Craig T

    2016-07-01

    Adipose tissue (AT) has previously been identified as an extra-medullary reservoir for normal hematopoietic stem cells (HSCs) and may promote tumor development. Here, we show that a subpopulation of leukemic stem cells (LSCs) can utilize gonadal adipose tissue (GAT) as a niche to support their metabolism and evade chemotherapy. In a mouse model of blast crisis chronic myeloid leukemia (CML), adipose-resident LSCs exhibit a pro-inflammatory phenotype and induce lipolysis in GAT. GAT lipolysis fuels fatty acid oxidation in LSCs, especially within a subpopulation expressing the fatty acid transporter CD36. CD36(+) LSCs have unique metabolic properties, are strikingly enriched in AT, and are protected from chemotherapy by the GAT microenvironment. CD36 also marks a fraction of human blast crisis CML and acute myeloid leukemia (AML) cells with similar biological properties. These findings suggest striking interplay between leukemic cells and AT to create a unique microenvironment that supports the metabolic demands and survival of a distinct LSC subpopulation. PMID:27374788

  17. How to evade a coevolving brood parasite: egg discrimination versus egg variability as host defences.

    PubMed

    Spottiswoode, Claire N; Stevens, Martin

    2011-12-01

    Arms races between avian brood parasites and their hosts often result in parasitic mimicry of host eggs, to evade rejection. Once egg mimicry has evolved, host defences could escalate in two ways: (i) hosts could improve their level of egg discrimination; and (ii) negative frequency-dependent selection could generate increased variation in egg appearance (polymorphism) among individuals. Proficiency in one defence might reduce selection on the other, while a combination of the two should enable successful rejection of parasitic eggs. We compared three highly variable host species of the Afrotropical cuckoo finch Anomalospiza imberbis, using egg rejection experiments and modelling of avian colour and pattern vision. We show that each differed in their level of polymorphism, in the visual cues they used to reject foreign eggs, and in their degree of discrimination. The most polymorphic host had the crudest discrimination, whereas the least polymorphic was most discriminating. The third species, not currently parasitized, was intermediate for both defences. A model simulating parasitic laying and host rejection behaviour based on the field experiments showed that the two host strategies result in approximately the same fitness advantage to hosts. Thus, neither strategy is superior, but rather they reflect alternative potential evolutionary trajectories.

  18. Macrophage polarization following chitosan implantation.

    PubMed

    Vasconcelos, Daniela P; Fonseca, Ana C; Costa, Madalena; Amaral, Isabel F; Barbosa, Mário A; Águas, Artur P; Barbosa, Judite N

    2013-12-01

    Macrophages are a key cell in the host response to implants and can be polarized into different phenotypes capable of inducing both detrimental and beneficial outcomes in tissue repair and remodeling, being important in tissue engineering and regenerative medicine. The objective of this study was to evaluate the macrophage response to 3D porous chitosan (Ch) scaffolds with different degrees of acetylation (DA, 5% and 15%). The M1/M2 phenotypic polarization profile of macrophages was investigated in vivo using a rodent air-pouch model. Our results show that the DA affects the macrophage response. Ch scaffolds with DA 5% induced the adhesion of lower numbers of inflammatory cells, being the M2 the predominant phenotypic profile among the adherent macrophages. In the inflammatory exudates F4/80(+)/CD206(+) cells (M2 macrophages) appeared in higher numbers then F4/80(+)/CCR7(+) cells (M1 macrophages), in addition, lower levels of pro-inflammatory cytokines together with higher levels of anti-inflammatory cytokines were found. Ch scaffolds with DA 15% showed opposite results, since M1 were the predominant macrophages both adherent to the scaffold and in the exudates, together with high levels of pro-inflammatory cytokines. In conclusion, Ch scaffolds with DA 5% induced a benign M2 anti-inflammatory macrophage response, whereas Ch scaffolds with DA 15% caused a macrophage M1 pro-inflammatory response.

  19. Imaging macrophages with nanoparticles

    NASA Astrophysics Data System (ADS)

    Weissleder, Ralph; Nahrendorf, Matthias; Pittet, Mikael J.

    2014-02-01

    Nanomaterials have much to offer, not only in deciphering innate immune cell biology and tracking cells, but also in advancing personalized clinical care by providing diagnostic and prognostic information, quantifying treatment efficacy and designing better therapeutics. This Review presents different types of nanomaterial, their biological properties and their applications for imaging macrophages in human diseases, including cancer, atherosclerosis, myocardial infarction, aortic aneurysm, diabetes and other conditions. We anticipate that future needs will include the development of nanomaterials that are specific for immune cell subsets and can be used as imaging surrogates for nanotherapeutics. New in vivo imaging clinical tools for noninvasive macrophage quantification are thus ultimately expected to become relevant to predicting patients' clinical outcome, defining treatment options and monitoring responses to therapy.

  20. Early hematopoiesis and macrophage development.

    PubMed

    McGrath, Kathleen E; Frame, Jenna M; Palis, James

    2015-12-01

    The paradigm that all blood cells are derived from hematopoietic stem cells (HSCs) has been challenged by two findings. First, there are tissue-resident hematopoietic cells, including subsets of macrophages that are not replenished by adult HSCs, but instead are maintained by self-renewal of fetal-derived cells. Second, during embryogenesis, there is a conserved program of HSC-independent hematopoiesis that precedes HSC function and is required for embryonic survival. The presence of waves of HSC-independent hematopoiesis as well as fetal HSCs raises questions about the origin of fetal-derived adult tissue-resident macrophages. In the murine embryo, historical examination of embryonic macrophage and monocyte populations combined with recent reports utilizing genetic lineage-tracing approaches has led to a model of macrophage ontogeny that can be integrated with existing models of hematopoietic ontogeny. The first wave of hematopoiesis contains primitive erythroid, megakaryocyte and macrophage progenitors that arise in the yolk sac, and these macrophage progenitors are the source of early macrophages throughout the embryo, including the liver. A second wave of multipotential erythro-myeloid progenitors (EMPs) also arises in the yolk sac. EMPs colonize the fetal liver, initiating myelopoiesis and forming macrophages. Lineage tracing indicates that this second wave of macrophages are distributed in most fetal tissues, although not appreciably in the brain. Thus, fetal-derived adult tissue-resident macrophages, other than microglia, appear to predominately derive from EMPs. While HSCs emerge at midgestation and colonize the fetal liver, the relative contribution of fetal HSCs to tissue macrophages at later stages of development is unclear. The inclusion of macrophage potential in multiple waves of hematopoiesis is consistent with reports of their functional roles throughout development in innate immunity, phagocytosis, and tissue morphogenesis and remodeling

  1. Emodin Bidirectionally Modulates Macrophage Polarization and Epigenetically Regulates Macrophage Memory.

    PubMed

    Iwanowycz, Stephen; Wang, Junfeng; Altomare, Diego; Hui, Yvonne; Fan, Daping

    2016-05-27

    Macrophages are pleiotropic cells capable of performing a broad spectrum of functions. Macrophage phenotypes are classified along a continuum between the extremes of proinflammatory M1 macrophages and anti-inflammatory M2 macrophages. The seemingly opposing functions of M1 and M2 macrophages must be tightly regulated for an effective and proper response to foreign molecules or damaged tissue. Excessive activation of either M1 or M2 macrophages contributes to the pathology of many diseases. Emodin is a Chinese herb-derived compound and has shown potential to inhibit inflammation in various settings. In this study, we tested the ability of emodin to modulate the macrophage response to both M1 and M2 stimuli. Primary mouse macrophages were stimulated with LPS/IFNγ or IL4 with or without emodin, and the effects of emodin on gene transcription, cell signaling pathways, and histone modifications were examined by a variety of approaches, including microarray, quantitative real-time PCR, Western blotting, chromatin immunoprecipitation, and functional assays. We found that emodin bidirectionally tunes the induction of LPS/IFNγ- and IL4-responsive genes through inhibiting NFκB/IRF5/STAT1 signaling and IRF4/STAT6 signaling, respectively. Thereby, emodin modulates macrophage phagocytosis, migration, and NO production. Furthermore, emodin inhibited the removal of H3K27 trimethylation (H3K27m3) marks and the addition of H3K27 acetylation (H3K27ac) marks on genes required for M1 or M2 polarization of macrophages. In conclusion, our data suggest that emodin is uniquely able to suppress the excessive response of macrophages to both M1 and M2 stimuli and therefore has the potential to restore macrophage homeostasis in various pathologies.

  2. Epigenomics of macrophages.

    PubMed

    Gosselin, David; Glass, Christopher K

    2014-11-01

    Macrophages play essential roles in tissue homeostasis, pathogen elimination, and tissue repair. A defining characteristic of these cells is their ability to efficiently adapt to a variety of abruptly changing and complex environments. This ability is intrinsically linked to a capacity to quickly alter their transcriptome, and this is tightly associated with the epigenomic organization of these cells and, in particular, their enhancer repertoire. Indeed, enhancers are genomic sites that serve as platforms for the integration of signaling pathways with the mechanisms that regulate mRNA transcription. Notably, transcription is pervasive at active enhancers and enhancer RNAs (eRNAs) are tightly coupled to regulated transcription of protein-coding genes. Furthermore, given that each cell type possesses a defining enhancer repertoire, studies on enhancers provide a powerful method to study how specialization of functions among the diverse macrophage subtypes may arise. Here, we review recent studies providing insights into the distinct mechanisms that contribute to the establishment of enhancers and their role in the regulation of transcription in macrophages.

  3. Epigenomics of macrophages

    PubMed Central

    Gosselin, David; Glass, Christopher K

    2014-01-01

    Summary Macrophages play essential roles in tissue homeostasis, pathogen elimination, and tissue repair. A defining characteristic of these cells is their ability to efficiently adapt to a variety of abruptly changing and complex environments. This ability is intrinsically linked to a capacity to quickly alter their transcriptome, and this is tightly associated with the epigenomic organization of these cells and, in particular, their enhancer repertoire. Indeed, enhancers are genomic sites that serve as platforms for the integration of signaling pathways with the mechanisms that regulate mRNA transcription. Notably, transcription is pervasive at active enhancers and enhancer RNAs (eRNAs) are tightly coupled to regulated transcription of protein-coding genes. Furthermore, given that each cell type possesses a defining enhancer repertoire, studies on enhancers provide a powerful method to study how specialization of functions among the diverse macrophage subtypes may arise. Here, we review recent studies providing insights into the distinct mechanisms that contribute to the establishment of enhancers and their role in the regulation of transcription in macrophages. PMID:25319330

  4. Embryonic stem cell-derived M2-like macrophages delay cutaneous wound healing.

    PubMed

    Dreymueller, Daniela; Denecke, Bernd; Ludwig, Andreas; Jahnen-Dechent, Willi

    2013-01-01

    In adults, repair of deeply injured skin wounds results in the formation of scar tissue, whereas in embryos wounds heal almost scar-free. Macrophages are important mediators of wound healing and secrete cytokines and tissue remodeling enzymes. In contrast to host defense mediated by inflammatory M1 macrophages, wound healing and tissue repair involve regulatory M2/M2-like macrophages. Embryonic/fetal macrophages are M2-like, and this may promote scar-free wound healing. In the present study, we asked whether atopical application of ex vivo generated, embryonic stem cell-derived macrophages (ESDM) improve wound healing in mice. ESDM were tested side by side with bone marrow-derived macrophages (BMDM). Compared to BMDM, ESDM resembled a less inflammatory and more M2-like macrophage subtype as indicated by their reduced responsiveness to lipopolysaccharide, reduced expression of Toll-like receptors, and reduced bacterial phagocytosis. Despite this anti-inflammatory phenotype in cell culture, ESDM prolonged the healing of deep skin wounds even more than BMDM. Healed wounds had more scar formation compared to wounds receiving BMDM or cell-free treatment. Our data indicate that atopical application of ex vivo generated macrophages is not a suitable cell therapy of dermal wounds.

  5. The macrophages in rheumatic diseases

    PubMed Central

    Laria, Antonella; Lurati, Alfredomaria; Marrazza, Mariagrazia; Mazzocchi, Daniela; Re, Katia Angela; Scarpellini, Magda

    2016-01-01

    Macrophages belong to the innate immune system giving us protection against pathogens. However it is known that they are also involved in rheumatic diseases. Activated macrophages have two different phenotypes related to different stimuli: M1 (classically activated) and M2 (alternatively activated). M1 macrophages release high levels of pro-inflammatory cytokines, reactive nitrogen and oxygen intermediates killing microorganisms and tumor cells; while M2 macrophages are involved in resolution of inflammation through phagocytosis of apoptotic neutrophils, reduced production of pro-inflammatory cytokines, and increased synthesis of mediators important in tissue remodeling, angiogenesis, and wound repair. The role of macrophages in the different rheumatic diseases is different according to their M1/M2 macrophages phenotype. PMID:26929657

  6. Moscow's defense intellectuals

    SciTech Connect

    Lambeth, B.S.

    1990-01-01

    This essay was originally written two decades ago as a seminar paper. A substantial portion of it addresses what were then only the first steps toward the establishment of a community of professional civilian defense analysts in the Soviet Union. Throughout most of the intervening period, that community found itself mired in immobilism as jurisdiction over such key Soviet national security inputs as military doctrine, force requirements, resource needs, and to a considerable degree, arms negotiating positions remained an exclusive prerogative of the Defense Ministry and the General Staff. Today, this former military monopoly has come to be challenged with increasing success by a host of newcomers to the Soviet defense scene, including the Foreign Ministry, the Supreme Soviet, and an ambitious cadre of civilian analysts attached to the social science research institutes of the Academy of Sciences. These individuals are making a determined bid for greater influence over Soviet defense policy, with the express encouragement of President Gorbachev and his supporters. The result has been an unprecedented infusion of pluralism into Soviet defense politics and a significant change in the content and goals of Soviet military policy.

  7. Macrophage Roles Following Myocardial Infarction

    PubMed Central

    Lambert, Jessica M.; Lopez, Elizabeth F.; Lindsey, Merry L.

    2010-01-01

    Following myocardial infarction (MI), circulating blood monocytes respond to chemotactic factors, migrate into the infarcted myocardium, and differentiate into macrophages. At the injury site, macrophages remove necrotic cardiac myocytes and apoptotic neutrophils; secrete cytokines, chemokines, and growth factors; and modulate phases of the angiogenic response. As such, the macrophage is a primary responder cell type that is involved in the regulation of post-MI wound healing at multiple levels. This review summarizes what is currently known about macrophage functions post-MI and borrows literature from other injury and inflammatory models to speculate on additional roles. Basic science and clinical avenues that remain to be explored are also discussed. PMID:18656272

  8. Bioelectric modulation of macrophage polarization

    NASA Astrophysics Data System (ADS)

    Li, Chunmei; Levin, Michael; Kaplan, David L.

    2016-02-01

    Macrophages play a critical role in regulating wound healing and tissue regeneration by changing their polarization state in response to local microenvironmental stimuli. The native roles of polarized macrophages encompass biomaterials and tissue remodeling needs, yet harnessing or directing the polarization response has been largely absent as a potential strategy to exploit in regenerative medicine to date. Recent data have revealed that specific alteration of cells’ resting potential (Vmem) is a powerful tool to direct proliferation and differentiation in a number of complex tissues, such as limb regeneration, craniofacial patterning and tumorigenesis. In this study, we explored the bioelectric modulation of macrophage polarization by targeting ATP sensitive potassium channels (KATP). Glibenclamide (KATP blocker) and pinacidil (KATP opener) treatment not only affect macrophage polarization, but also influence the phenotype of prepolarized macrophages. Furthermore, modulation of cell membrane electrical properties can fine-tune macrophage plasticity. Glibenclamide decreased the secretion and gene expression of selected M1 markers, while pinacidil augmented M1 markers. More interestingly, glibencalmide promoted macrophage alternative activation by enhancing certain M2 markers during M2 polarization. These findings suggest that control of bioelectric properties of macrophages could offer a promising approach to regulate macrophage phenotype as a useful tool in regenerative medicine.

  9. Macrophages in homeostatic immune function.

    PubMed

    Jantsch, Jonathan; Binger, Katrina J; Müller, Dominik N; Titze, Jens

    2014-01-01

    Macrophages are not only involved in inflammatory and anti-infective processes, but also play an important role in maintaining tissue homeostasis. In this review, we summarize recent evidence investigating the role of macrophages in controlling angiogenesis, metabolism as well as salt and water balance. Particularly, we summarize the importance of macrophage tonicity enhancer binding protein (TonEBP, also termed nuclear factor of activated T-cells 5 [NFAT5]) expression in the regulation of salt and water homeostasis. Further understanding of homeostatic macrophage function may lead to new therapeutic approaches to treat ischemia, hypertension and metabolic disorders. PMID:24847274

  10. Macrophages in homeostatic immune function

    PubMed Central

    Jantsch, Jonathan; Binger, Katrina J.; Müller, Dominik N.; Titze, Jens

    2014-01-01

    Macrophages are not only involved in inflammatory and anti-infective processes, but also play an important role in maintaining tissue homeostasis. In this review, we summarize recent evidence investigating the role of macrophages in controlling angiogenesis, metabolism as well as salt and water balance. Particularly, we summarize the importance of macrophage tonicity enhancer binding protein (TonEBP, also termed nuclear factor of activated T-cells 5 [NFAT5]) expression in the regulation of salt and water homeostasis. Further understanding of homeostatic macrophage function may lead to new therapeutic approaches to treat ischemia, hypertension and metabolic disorders. PMID:24847274

  11. Has the tobacco industry evaded the FDA's ban on ‘Light’ cigarette descriptors?

    PubMed Central

    Connolly, Gregory N; Alpert, Hillel R

    2014-01-01

    Background Under the Family Smoking Prevention and Tobacco Control Act (FSPTCA), the Food and Drug Administration (FDA) banned the use of “Lights” descriptors or similar terms on tobacco products that convey messages of reduced risk. Manufacturers eliminated terms explicitly stated and substituted colour name descriptors corresponding to the banned terms. This paper examines whether the tobacco industry complied with or circumvented the law and potential FDA regulatory actions. Methods Philip Morris retailer manuals, manufacturers' annual reports filed with the Massachusetts Department of Public Health, a national public opinion survey, and market-wide cigarette sales data were examined. Results Manufacturers substituted “Gold” for “Light” and “Silver” for “Ultra-light” in the names of Marlboro sub-brands, and “Blue”, “Gold”, and “Silver” for banned descriptors in sub-brand names. Percent filter ventilation levels, used to generate the smoke yield ranges associated with “Lights” categories, appear to have been reassigned to the new colour brand name descriptors. Following the ban, 92% of smokers reported they could easily identify their usual brands, and 68% correctly named the package colour associated with their usual brand, while sales for “Lights” cigarettes remained unchanged. Conclusions Tobacco manufacturers appear to have evaded a critical element of the FSPTCA, the ban on misleading descriptors that convey reduced health risk messages. The FPSTCA provides regulatory mechanisms, including banning these products as adulterated (Section 902). Manufacturers could then apply for pre-market approval as new products and produce evidence for FDA evaluation and determination whether or not sales of these products are in the public health interest. PMID:23485704

  12. Plasmodium falciparum evades mosquito immunity by disrupting JNK-mediated apoptosis of invaded midgut cells

    PubMed Central

    Ramphul, Urvashi N.; Garver, Lindsey S.; Molina-Cruz, Alvaro; Canepa, Gaspar E.; Barillas-Mury, Carolina

    2015-01-01

    The malaria parasite, Plasmodium, must survive and develop in the mosquito vector to be successfully transmitted to a new host. The Plasmodium falciparum Pfs47 gene is critical for malaria transmission. Parasites that express Pfs47 (NF54 WT) evade mosquito immunity and survive, whereas Pfs47 knockouts (KO) are efficiently eliminated by the complement-like system. Two alternative approaches were used to investigate the mechanism of action of Pfs47 on immune evasion. First, we examined whether Pfs47 affected signal transduction pathways mediating mosquito immune responses, and show that the Jun-N-terminal kinase (JNK) pathway is a key mediator of Anopheles gambiae antiplasmodial responses to P. falciparum infection and that Pfs47 disrupts JNK signaling. Second, we used microarrays to compare the global transcriptional responses of A. gambiae midguts to infection with WT and KO parasites. The presence of Pfs47 results in broad and profound changes in gene expression in response to infection that are already evident 12 h postfeeding, but become most prominent at 26 h postfeeding, the time when ookinetes invade the mosquito midgut. Silencing of 15 differentially expressed candidate genes identified caspase-S2 as a key effector of Plasmodium elimination in parasites lacking Pfs47. We provide experimental evidence that JNK pathway regulates activation of caspases in Plasmodium-invaded midgut cells, and that caspase activation is required to trigger midgut epithelial nitration. Pfs47 alters the cell death pathway of invaded midgut cells by disrupting JNK signaling and prevents the activation of several caspases, resulting in an ineffective nitration response that makes the parasite undetectable by the mosquito complement-like system. PMID:25552553

  13. Virulent Salmonella enterica serovar typhimurium evades adaptive immunity by preventing dendritic cells from activating T cells.

    PubMed

    Tobar, Jaime A; Carreño, Leandro J; Bueno, Susan M; González, Pablo A; Mora, Jorge E; Quezada, Sergio A; Kalergis, Alexis M

    2006-11-01

    Dendritic cells (DCs) constitute the link between innate and adaptive immunity by directly recognizing pathogen-associated molecular patterns (PAMPs) in bacteria and by presenting bacterial antigens to T cells. Recognition of PAMPs renders DCs as professional antigen-presenting cells able to prime naïve T cells and initiate adaptive immunity against bacteria. Therefore, interfering with DC function would promote bacterial survival and dissemination. Understanding the molecular mechanisms that have evolved in virulent bacteria to evade activation of adaptive immunity requires the characterization of virulence factors that interfere with DC function. Salmonella enterica serovar Typhimurium, the causative agent of typhoid-like disease in the mouse, can prevent antigen presentation to T cells by avoiding lysosomal degradation in DCs. Here, we show that this feature of virulent Salmonella applies in vivo to prevent activation of adaptive immunity. In addition, this attribute of virulent Salmonella requires functional expression of a type three secretion system (TTSS) and effector proteins encoded within the Salmonella pathogenicity island 2 (SPI-2). In contrast to wild-type virulent Salmonella, mutant strains carrying specific deletions of SPI-2 genes encoding TTSS components or effectors proteins are targeted to lysosomes and are no longer able to prevent DCs from activating T cells in vitro or in vivo. SPI-2 mutant strains are attenuated in vivo, showing reduced tissue colonization and enhanced T-cell activation, which confers protection against a challenge with wild-type virulent Salmonella. Our data suggest that impairment of DC function by the activity of SPI-2 gene products is crucial for Salmonella pathogenesis.

  14. Value of space defenses

    SciTech Connect

    Canavan, G.H.

    1992-10-29

    This report discusses the economic value of defenses against Near-Earth Object (NEO) impacts is bounded by calculating expected losses in their absence, which illustrates the contributions from NEOs of different sizes and the sensitivity of total expected losses to impact frequencies. For typical size distributions and damage of only a few decades duration, losses are most sensitive to small NEOs, and lead to defenses worth a few $M/yr. When the persistence of damage with NEO size is taken into account, that shifts the loss to the largest NEOs and greatly increases expected loss and values.

  15. 76 FR 28960 - Defense Intelligence Agency National Defense Intelligence College Board of Visitors Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-19

    ... of the Secretary Defense Intelligence Agency National Defense Intelligence College Board of Visitors Closed Meeting AGENCY: National Defense Intelligence College, Defense Intelligence Agency, Department of... a closed meeting of the Defense Intelligence Agency National Defense Intelligence College Board...

  16. 75 FR 76423 - Defense Intelligence Agency National Defense Intelligence College Board of Visitors Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... of the Secretary Defense Intelligence Agency National Defense Intelligence College Board of Visitors Closed Meeting AGENCY: National Defense Intelligence College, Defense Intelligence Agency, Department of... a closed meeting of the Defense Intelligence Agency National Defense Intelligence College Board...

  17. 76 FR 28757 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION: Notice of Availability (NOA) of Revised Defense Logistics Agency Regulation. SUMMARY: The Defense...

  18. Targeting the non-neuronal cholinergic system in macrophages for the management of infectious diseases and cancer: challenge and promise

    PubMed Central

    Reichrath, Sandra; Reichrath, Jörg; Moussa, Amira-Talaat; Meier, Carola; Tschernig, Thomas

    2016-01-01

    Macrophages represent key players of the immune system exerting highly effective defense mechanisms against microbial infections and cancer that include phagocytosis and programmed cell removal. Recent findings highlight the relevance of the non-neuronal cholinergic system for the regulation of macrophage function that opens promising new concepts for the treatment of infectious diseases and cancer. This mini review summarizes our present knowledge on this topic and gives an outlook on future developments. PMID:27785369

  19. In Defense of Rubrics

    ERIC Educational Resources Information Center

    Spandel, Vicki

    2006-01-01

    In this article, the author expresses her views in defense of writing rubrics. She explains that when rubrics are thoughtfully crafted and used with discretion and understanding, they can be among the most useful instructional tools that teachers have. A rubric captures the essence of performance at various levels. Because rubric demands…

  20. Radiological Defense Manual.

    ERIC Educational Resources Information Center

    Defense Civil Preparedness Agency (DOD), Washington, DC.

    Originally prepared for use as a student textbook in Radiological Defense (RADEF) courses, this manual provides the basic technical information necessary for an understanding of RADEF. It also briefly discusses the need for RADEF planning and expected postattack emergency operations. There are 14 chapters covering these major topics: introduction…

  1. S100A12 Is Part of the Antimicrobial Network against Mycobacterium leprae in Human Macrophages.

    PubMed

    Realegeno, Susan; Kelly-Scumpia, Kindra M; Dang, Angeline Tilly; Lu, Jing; Teles, Rosane; Liu, Philip T; Schenk, Mirjam; Lee, Ernest Y; Schmidt, Nathan W; Wong, Gerard C L; Sarno, Euzenir N; Rea, Thomas H; Ochoa, Maria T; Pellegrini, Matteo; Modlin, Robert L

    2016-06-01

    Triggering antimicrobial mechanisms in macrophages infected with intracellular pathogens, such as mycobacteria, is critical to host defense against the infection. To uncover the unique and shared antimicrobial networks induced by the innate and adaptive immune systems, gene expression profiles generated by RNA sequencing (RNAseq) from human monocyte-derived macrophages (MDMs) activated with TLR2/1 ligand (TLR2/1L) or IFN-γ were analyzed. Weighed gene correlation network analysis identified modules of genes strongly correlated with TLR2/1L or IFN-γ that were linked by the "defense response" gene ontology term. The common TLR2/1L and IFN-γ inducible human macrophage host defense network contained 16 antimicrobial response genes, including S100A12, which was one of the most highly induced genes by TLR2/1L. There is limited information on the role of S100A12 in infectious disease, leading us to test the hypothesis that S100A12 contributes to host defense against mycobacterial infection in humans. We show that S100A12 is sufficient to directly kill Mycobacterium tuberculosis and Mycobacterium leprae. We also demonstrate that S100A12 is required for TLR2/1L and IFN-γ induced antimicrobial activity against M. leprae in infected macrophages. At the site of disease in leprosy, we found that S100A12 was more strongly expressed in skin lesions from tuberculoid leprosy (T-lep), the self-limiting form of the disease, compared to lepromatous leprosy (L-lep), the progressive form of the disease. These data suggest that S100A12 is part of an innate and adaptive inducible antimicrobial network that contributes to host defense against mycobacteria in infected macrophages. PMID:27355424

  2. S100A12 Is Part of the Antimicrobial Network against Mycobacterium leprae in Human Macrophages

    PubMed Central

    Realegeno, Susan; Kelly-Scumpia, Kindra M.; Dang, Angeline Tilly; Lu, Jing; Teles, Rosane; Liu, Philip T.; Schenk, Mirjam; Schmidt, Nathan W.; Wong, Gerard C. L.; Sarno, Euzenir N.; Ochoa, Maria T.; Pellegrini, Matteo; Modlin, Robert L.

    2016-01-01

    Triggering antimicrobial mechanisms in macrophages infected with intracellular pathogens, such as mycobacteria, is critical to host defense against the infection. To uncover the unique and shared antimicrobial networks induced by the innate and adaptive immune systems, gene expression profiles generated by RNA sequencing (RNAseq) from human monocyte-derived macrophages (MDMs) activated with TLR2/1 ligand (TLR2/1L) or IFN-γ were analyzed. Weighed gene correlation network analysis identified modules of genes strongly correlated with TLR2/1L or IFN-γ that were linked by the “defense response” gene ontology term. The common TLR2/1L and IFN-γ inducible human macrophage host defense network contained 16 antimicrobial response genes, including S100A12, which was one of the most highly induced genes by TLR2/1L. There is limited information on the role of S100A12 in infectious disease, leading us to test the hypothesis that S100A12 contributes to host defense against mycobacterial infection in humans. We show that S100A12 is sufficient to directly kill Mycobacterium tuberculosis and Mycobacterium leprae. We also demonstrate that S100A12 is required for TLR2/1L and IFN-γ induced antimicrobial activity against M. leprae in infected macrophages. At the site of disease in leprosy, we found that S100A12 was more strongly expressed in skin lesions from tuberculoid leprosy (T-lep), the self-limiting form of the disease, compared to lepromatous leprosy (L-lep), the progressive form of the disease. These data suggest that S100A12 is part of an innate and adaptive inducible antimicrobial network that contributes to host defense against mycobacteria in infected macrophages. PMID:27355424

  3. Adipose tissue macrophages: amicus adipem?

    PubMed Central

    Odegaard, Justin I.; Ganeshan, Kirthana; Chawla, Ajay

    2014-01-01

    Chronic overnutrition drives complex adaptations within both professional metabolic and bystander tissues that, despite intense investigation, are still poorly understood. Xu et al. (2013) now describe the unexpected ability of adipose tissue macrophages to buffer lipids released from obese adipocytes in a manner independent of inflammatory macrophage activation. PMID:24315364

  4. Consequences of the crosstalk between monocytes/macrophages and natural killer cells

    PubMed Central

    Michel, Tatiana; Hentges, François; Zimmer, Jacques

    2013-01-01

    The interaction between natural killer (NK) cells and different other immune cells like T cells and dendritic cells is well-described, but the crosstalk with monocytes or macrophages and the nature of ligands/receptors implicated are just emerging. The macrophage-NK interaction is a major first-line defense against pathogens (bacteria, viruses, fungi, and parasites). The recruitment and the activation of NK cells to perform cytotoxicity or produce cytokines at the sites of inflammation are important to fight infections. The two main mechanisms by which macrophages can prime NK cells are (1) activation through soluble mediators such as IL-12, IL-18, and (2) stimulation through direct cell-to-cell contact. We will discuss the progress in matters of modulation of NK cell functions by monocytes and macrophages, in the steady state and during diseases. PMID:23316194

  5. Diverse macrophage populations mediate acute lung inflammation and resolution

    PubMed Central

    King, Landon S.; D'Alessio, Franco R.

    2014-01-01

    Acute respiratory distress syndrome (ARDS) is a devastating disease with distinct pathological stages. Fundamental to ARDS is the acute onset of lung inflammation as a part of the body's immune response to a variety of local and systemic stimuli. In patients surviving the inflammatory and subsequent fibroproliferative stages, transition from injury to resolution and recovery is an active process dependent on a series of highly coordinated events regulated by the immune system. Experimental animal models of acute lung injury (ALI) reproduce key components of the injury and resolution phases of human ARDS and provide a methodology to explore mechanisms and potential new therapies. Macrophages are essential to innate immunity and host defense, playing a featured role in the lung and alveolar space. Key aspects of their biological response, including differentiation, phenotype, function, and cellular interactions, are determined in large part by the presence, severity, and chronicity of local inflammation. Studies support the importance of macrophages to initiate and maintain the inflammatory response, as well as a determinant of resolution of lung inflammation and repair. We will discuss distinct roles for lung macrophages during early inflammatory and late resolution phases of ARDS using experimental animal models. In addition, each section will highlight human studies that relate to the diverse role of macrophages in initiation and resolution of ALI and ARDS. PMID:24508730

  6. Characterization of the murine macrophage receptor for group B streptococci.

    PubMed

    Sloan, A R; Pistole, T G

    1993-06-01

    The macrophage has been shown to bind potentially pathogenic bacteria in the absence of serum components or opsonins but the mechanism is poorly understood. The rich array of sugars on the surface of group B streptococci plus the presence of membrane-associated lectin receptors on the macrophage suggests that this is a likely means for bacterial recognition by these host defense cells. Inhibition studies with free sugars and neoglycoconjugates of bovine serum albumin, however, failed to confirm this hypothesis. Furthermore, neuraminidase-treatment to expose galactose residues and the use of isogenic bacterial strains having no capsule or no capsular sialic acid yielded no confirmation of lectin-mediated recognition. The trypsin-sensitive receptor exhibited temperature dependence and a requirement for divalent cations distinct from that reported for the lectin-like galactose receptor. The activity of this streptococcal binding receptor was inhibited by 2-deoxy-D-glucose but not by neutrophil elastase. Pre-exposure of macrophages to bound fibronectin and treatment with phorbol ester each enhanced bacterial binding. These data fail to support a role for the galactose lectin and provide preliminary evidence for involvement of the leukocyte integrins in macrophage recognition of group B streptococci.

  7. Defense styles of pedophilic offenders.

    PubMed

    Drapeau, Martin; Beretta, Véronique; de Roten, Yves; Koerner, Annett; Despland, Jean-Nicolas

    2008-04-01

    This pilot study investigated the defense styles of pedophile sexual offenders. Interviews with 20 pedophiles and 20 controls were scored using the Defense Mechanisms Rating Scales. Results showed that pedophiles had a significantly lower overall defensive functioning score than the controls. Pedophiles used significantly fewer obsessional-level defenses but more major image-distorting and action-level defenses. Results also suggested differences in the prevalence of individual defenses where pedophiles used more dissociation, displacement, denial, autistic fantasy, splitting of object, projective identification, acting out, and passive aggressive behavior but less intellectualization and rationalization.

  8. A fungal anticodon nuclease ribotoxin exploits a secondary cleavage site to evade tRNA repair.

    PubMed

    Meineke, Birthe; Kast, Alene; Schwer, Beate; Meinhardt, Friedhelm; Shuman, Stewart; Klassen, Roland

    2012-09-01

    PaOrf2 and γ-toxin subunits of Pichia acaciae toxin (PaT) and Kluyveromyces lactis zymocin are tRNA anticodon nucleases. These secreted ribotoxins are assimilated by Saccharomyces cerevisiae, wherein they arrest growth by depleting specific tRNAs. Toxicity can be recapitulated by induced intracellular expression of PaOrf2 or γ-toxin in S. cerevisiae. Mutational analysis of γ-toxin has identified amino acids required for ribotoxicity in vivo and RNA transesterification in vitro. Here, we report that PaOrf2 residues Glu9 and His287 (putative counterparts of γ-toxin Glu9 and His209) are essential for toxicity. Our results suggest a similar basis for RNA transesterification by PaOrf2 and γ-toxin, despite their dissimilar primary structures and distinctive tRNA target specificities. PaOrf2 makes two sequential incisions in tRNA, the first of which occurs 3' from the mcm(5)s(2)U wobble nucleoside and depends on mcm(5). A second incision two nucleotides upstream results in the net excision of a di-nucleotide. Expression of phage and plant tRNA repair systems can relieve PaOrf2 toxicity when tRNA cleavage is restricted to the secondary site in elp3 cells that lack the mcm(5) wobble U modification. Whereas the endogenous yeast tRNA ligase Trl1 can heal tRNA halves produced by PaOrf2 cleavage in elp3 cells, its RNA sealing activity is inadequate to complete the repair. Compatible sealing activity can be provided in trans by plant tRNA ligase. The damage-rescuing ability of tRNA repair systems is lost when PaOrf2 can break tRNA at both sites. These results highlight the logic of a two-incision mechanism of tRNA anticodon damage that evades productive repair by tRNA ligases. PMID:22836353

  9. Granulocyte Macrophage-Colony Stimulating Factor-induced Zn Sequestration Enhances Macrophage Superoxide and Limits Intracellular Pathogen Survival

    PubMed Central

    Vignesh, Kavitha Subramanian; Landero Figueroa, Julio A.; Porollo, Aleksey; Caruso, Joseph A.; Deepe, George S.

    2013-01-01

    SUMMARY Macrophages possess numerous mechanisms to combat microbial invasion, including sequestration of essential nutrients, like Zn. The pleiotropic cytokine granulocyte macrophage-colony stimulating factor (GM-CSF) enhances antimicrobial defenses against intracellular pathogens such as Histoplasma capsulatum, but its mode of action remains elusive. We have found that GM-CSF activated infected macrophages sequestered labile Zn by inducing binding to metallothioneins (MTs) in a STAT3 and STAT5 transcription factor-dependent manner. GM-CSF upregulated expression of Zn exporters, Slc30a4 and Slc30a7 and the metal was shuttled away from phagosomes and into the Golgi apparatus. This distinctive Zn sequestration strategy elevated phagosomal H+ channel function and triggered reactive oxygen species (ROS) generation by NADPH oxidase. Consequently, H. capsulatum was selectively deprived of Zn, thereby halting replication and fostering fungal clearance. GM-CSF mediated Zn sequestration via MTs in vitro and in vivo in mice and in human macrophages. These findings illuminate a GM-CSF-induced Zn-sequestration network that drives phagocyte antimicrobial effector function. PMID:24138881

  10. β-Glucans inhibit intracellular growth of Mycobacterium bovis BCG but not virulent Mycobacterium tuberculosis in human macrophages

    PubMed Central

    Morris, Jessica D.; Rajaram, Murugesan V.S.; Schlesinger, Larry S.

    2014-01-01

    The yeast polysaccharide, β-glucan, has been shown to promote both anti-microbial and anti-tumor activities through its interaction with macrophages. Here we analyzed the effects of an insoluble whole glucan particle (WGP), a 1,3/1,6-β-glucan from Saccharomyces cerevisiae, and a soluble poly-1-6-β-d-glucopyranosyl-1-3-β-d-glucopyranose (PGG), a hydrolytic product of WGP, on the anti-microbial response of human macrophages against mycobacterial infection. Treatment of macrophages with WGP and PGG significantly decreased cell association and intracellular growth of Mycobacterium bovis BCG, but not Mycobacterium tuberculosis (M.tb) when compared to untreated controls. We characterized the influence of β-glucans on the generation of macrophage oxidative products and pro-inflammatory cytokines, two important anti-microbial defense mechanisms. WGP but not PGG treatment enhanced the oxidative response of macrophages as determined by the 2′,7′-dichlorofluorescin (DCF) assay. WGP treatment also induced macrophages to produce pro-inflammatory cytokines. The β-glucan receptor, Dectin-1, was found to be involved in the WGP-induced macrophage oxidative burst and intracellular growth inhibition of M. bovis BCG. This report indicates that although some forms of β-glucan are able to stimulate the respiratory burst and cytokine production in human macrophages, and exhibit antimicrobial properties against M. bovis BCG, the β-glucans tested here did not inhibit growth of M.tb within human macrophages. PMID:21762773

  11. PE_PGRS30 of Mycobacterium tuberculosis mediates suppression of proinflammatory immune response in macrophages through its PGRS and PE domains.

    PubMed

    Chatrath, Shweta; Gupta, Vineet Kumar; Dixit, Aparna; Garg, Lalit C

    2016-09-01

    The success of Mycobacterium tuberculosis as a pathogen relies on its ability to survive inside macrophages and evade host immune mechanisms. M. tuberculosis employs multiple strategies to confer resistance against immune system including inhibition of phago-lysosomal fusion, modulation of cytokine responses and granuloma formation. PE_PGRS proteins, uniquely present in pathogenic mycobacteria, are cell surface molecules that are suggested to interact with host cells. PE_PGRS proteins have also been implicated in its pathogenesis. In the present study, immuno-regulatory property of Rv1651c-encoded PE_PGRS30 protein was explored. Infection of PMA-differentiated human THP-1 macrophages with Mycobacterium smegmatis harbouring pVV(1651c) resulted in reduced production of IL-12, TNF-α and IL-6, as compared to infection with M. smegmatis harbouring the control plasmid pVV16. No differential effect was observed on bacterial persistence inside macrophages or on macrophage mortality upon infection with the two recombinant strains. Infection of THP-1 macrophages with recombinant M. smegmatis expressing deletion variants of PE_PGRS30 indicated that anti-inflammatory function of the protein is possessed by its PGRS and PE domains while the C-terminal domain, when expressed alone, displayed antagonistic effect in terms of TNF-α secretion. These results suggest that PE_PGRS30 interferes with macrophage immune functions important for activation of adaptive T-cell responses. PMID:27129781

  12. PE_PGRS30 of Mycobacterium tuberculosis mediates suppression of proinflammatory immune response in macrophages through its PGRS and PE domains.

    PubMed

    Chatrath, Shweta; Gupta, Vineet Kumar; Dixit, Aparna; Garg, Lalit C

    2016-09-01

    The success of Mycobacterium tuberculosis as a pathogen relies on its ability to survive inside macrophages and evade host immune mechanisms. M. tuberculosis employs multiple strategies to confer resistance against immune system including inhibition of phago-lysosomal fusion, modulation of cytokine responses and granuloma formation. PE_PGRS proteins, uniquely present in pathogenic mycobacteria, are cell surface molecules that are suggested to interact with host cells. PE_PGRS proteins have also been implicated in its pathogenesis. In the present study, immuno-regulatory property of Rv1651c-encoded PE_PGRS30 protein was explored. Infection of PMA-differentiated human THP-1 macrophages with Mycobacterium smegmatis harbouring pVV(1651c) resulted in reduced production of IL-12, TNF-α and IL-6, as compared to infection with M. smegmatis harbouring the control plasmid pVV16. No differential effect was observed on bacterial persistence inside macrophages or on macrophage mortality upon infection with the two recombinant strains. Infection of THP-1 macrophages with recombinant M. smegmatis expressing deletion variants of PE_PGRS30 indicated that anti-inflammatory function of the protein is possessed by its PGRS and PE domains while the C-terminal domain, when expressed alone, displayed antagonistic effect in terms of TNF-α secretion. These results suggest that PE_PGRS30 interferes with macrophage immune functions important for activation of adaptive T-cell responses.

  13. TLR Stimulation Dynamically Regulates Heme and Iron Export Gene Expression in Macrophages

    PubMed Central

    Philip, Mary; Chiu, Edison Y.; Hajjar, Adeline M.; Abkowitz, Janis L.

    2016-01-01

    Pathogenic bacteria have evolved multiple mechanisms to capture iron or iron-containing heme from host tissues or blood. In response, organisms have developed defense mechanisms to keep iron from pathogens. Very little of the body's iron store is available as free heme; rather nearly all body iron is complexed with heme or other proteins. The feline leukemia virus, subgroup C (FeLV-C) receptor, FLVCR, exports heme from cells. It was unknown whether FLVCR regulates heme-iron availability after infection, but given that other heme regulatory proteins are upregulated in macrophages in response to bacterial infection, we hypothesized that macrophages dynamically regulate FLVCR. We stimulated murine primary macrophages or macrophage cell lines with LPS and found that Flvcr is rapidly downregulated in a TLR4/MD2-dependent manner; TLR1/2 and TLR3 stimulation also decreased Flvcr expression. We identified several candidate TLR-activated transcription factors that can bind to the Flvcr promoter. Macrophages must balance the need to sequester iron from systemic circulating or intracellular pathogens with the macrophage requirement for heme and iron to produce reactive oxygen species. Our findings underscore the complexity of this regulation and point to a new role for FLVCR and heme export in macrophages responses to infection and inflammation. PMID:27006955

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  16. Macrophage activation: role of toll-like receptors, nitric oxide, and nuclear factor kappa B.

    PubMed

    Billack, Blase

    2006-10-15

    Macrophages play an important role in host-defense and inflammation. In response to an immune challenge, macrophages become activated and produce proinflammatory mediators that contribute to nonspecific immunity. The mediators released by activated macrophages include: superoxide anion; reactive nitrogen intermediates, such as nitric oxide and peroxynitrite; bioactive lipids; and cytokines. Although essential to the immune response, overproduction of certain macrophage-derived mediators during an immune challenge or inflammatory response can result in tissue injury and cellular death. The present report is focused on understanding some of the molecular mechanisms used by macrophages to produce reactive nitrogen intermediates in response to immunostimulatory agents such as heat shock protein 60 and bacterial lipopolysaccharide. The role of Toll-like receptors and transcription factors such as nuclear factor kappa B (NFkappaB) in the innate immune response is also described. A basic understanding of the underlying molecular mechanisms responsible for macrophage activation should serve as a foundation for novel drug development aimed at modulating macrophage activity.

  17. Deficiencies in Jasmonate-Mediated Plant Defense Reveal Quantitative Variation in Botrytis cinerea Pathogenesis

    PubMed Central

    Rowe, Heather C.; Walley, Justin W.; Corwin, Jason; Chan, Eva K.-F.; Dehesh, Katayoon; Kliebenstein, Daniel J.

    2010-01-01

    Despite the described central role of jasmonate signaling in plant defense against necrotrophic pathogens, the existence of intraspecific variation in pathogen capacity to activate or evade plant jasmonate-mediated defenses is rarely considered. Experimental infection of jasmonate-deficient and jasmonate-insensitive Arabidopsis thaliana with diverse isolates of the necrotrophic fungal pathogen Botrytis cinerea revealed pathogen variation for virulence inhibition by jasmonate-mediated plant defenses and induction of plant defense metabolites. Comparison of the transcriptional effects of infection by two distinct B. cinerea isolates showed only minor differences in transcriptional responses of wild-type plants, but notable isolate-specific transcript differences in jasmonate-insensitive plants. These transcriptional differences suggest B. cinerea activation of plant defenses that require plant jasmonate signaling for activity in response to only one of the two B. cinerea isolates tested. Thus, similar infection phenotypes observed in wild-type plants result from different signaling interactions with the plant that are likely integrated by jasmonate signaling. PMID:20419157

  18. Neisseria gonorrhoeae induces a tolerogenic phenotype in macrophages to modulate host immunity.

    PubMed

    Escobar, Alejandro; 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- β 1) 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.

  19. 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

  20. Mycobacterium tuberculosis Hip1 modulates macrophage responses through proteolysis of GroEL2.

    PubMed

    Naffin-Olivos, Jacqueline L; Georgieva, Maria; Goldfarb, Nathan; Madan-Lala, Ranjna; Dong, Lauren; Bizzell, Erica; Valinetz, Ethan; Brandt, Gabriel S; Yu, Sarah; Shabashvili, Daniil E; Ringe, Dagmar; Dunn, Ben M; Petsko, Gregory A; Rengarajan, Jyothi

    2014-05-01

    Mycobacterium tuberculosis (Mtb) employs multiple strategies to evade host immune responses and persist within macrophages. We have previously shown that the cell envelope-associated Mtb serine hydrolase, Hip1, prevents robust macrophage activation and dampens host pro-inflammatory responses, allowing Mtb to delay immune detection and accelerate disease progression. We now provide key mechanistic insights into the molecular and biochemical basis of Hip1 function. We establish that Hip1 is a serine protease with activity against protein and peptide substrates. Further, we show that the Mtb GroEL2 protein is a direct substrate of Hip1 protease activity. Cleavage of GroEL2 is specifically inhibited by serine protease inhibitors. We mapped the cleavage site within the N-terminus of GroEL2 and confirmed that this site is required for proteolysis of GroEL2 during Mtb growth. Interestingly, we discovered that Hip1-mediated cleavage of GroEL2 converts the protein from a multimeric to a monomeric form. Moreover, ectopic expression of cleaved GroEL2 monomers into the hip1 mutant complemented the hyperinflammatory phenotype of the hip1 mutant and restored wild type levels of cytokine responses in infected macrophages. Our studies point to Hip1-dependent proteolysis as a novel regulatory mechanism that helps Mtb respond rapidly to changing host immune environments during infection. These findings position Hip1 as an attractive target for inhibition for developing immunomodulatory therapeutics against Mtb.

  1. RNA sequencing provides exquisite insight into the manipulation of the alveolar macrophage by tubercle bacilli.

    PubMed

    Nalpas, Nicolas C; Magee, David A; Conlon, Kevin M; Browne, John A; Healy, Claire; McLoughlin, Kirsten E; Rue-Albrecht, Kévin; McGettigan, Paul A; Killick, Kate E; Gormley, Eamonn; Gordon, Stephen V; MacHugh, David E

    2015-09-08

    Mycobacterium bovis, the agent of bovine tuberculosis, causes an estimated $3 billion annual losses to global agriculture due, in part, to the limitations of current diagnostics. Development of next-generation diagnostics requires a greater understanding of the interaction between the pathogen and the bovine host. Therefore, to explore the early response of the alveolar macrophage to infection, we report the first application of RNA-sequencing to define, in exquisite detail, the transcriptomes of M. bovis-infected and non-infected alveolar macrophages from ten calves at 2, 6, 24 and 48 hours post-infection. Differentially expressed sense genes were detected at these time points that revealed enrichment of innate immune signalling functions, and transcriptional suppression of host defence mechanisms (e.g., lysosome maturation). We also detected differentially expressed natural antisense transcripts, which may play a role in subverting innate immune mechanisms following infection. Furthermore, we report differential expression of novel bovine genes, some of which have immune-related functions based on orthology with human proteins. This is the first in-depth transcriptomics investigation of the alveolar macrophage response to the early stages of M. bovis infection and reveals complex patterns of gene expression and regulation that underlie the immunomodulatory mechanisms used by M. bovis to evade host defence mechanisms.

  2. Interaction of Aspergillus fumigatus conidia with Acanthamoeba castellanii parallels macrophage-fungus interactions.

    PubMed

    Van Waeyenberghe, Lieven; Baré, Julie; Pasmans, Frank; Claeys, Myriam; Bert, Wim; Haesebrouck, Freddy; Houf, Kurt; Martel, An

    2013-12-01

    Aspergillus fumigatus and free-living amoebae are common inhabitants of soil. Mechanisms of A. fumigatus to circumvent the amoeba's digestion may facilitate overcoming the vertebrate macrophage defence mechanisms. We performed co-culture experiments using A. fumigatus conidia and the amoeba Acanthamoeba castellanii. Approximately 25% of the amoebae ingested A. fumigatus conidia after 1 h of contact. During intra-amoebal passage, part of the ingested conidia was able to escape the food vacuole and to germinate inside the cytoplasm of A. castellanii. Fungal release into the extra-protozoan environment by exocytosis of conidia or by germination was observed with light and transmission electron microscopy. These processes resulted in structural changes in A. castellanii, leading to amoebal permeabilization without cell lysis. In conclusion, A. castellanii internalizes A. fumigatus conidia, resulting in fungal intracellular germination and subsequent amoebal death. As such, this interaction highly resembles that of A. fumigatus with mammalian and avian macrophages. This suggests that A. fumigatus virulence mechanisms to evade macrophage killing may be acquired by co-evolutionary interactions among A. fumigatus and environmental amoebae. PMID:24249290

  3. RNA sequencing provides exquisite insight into the manipulation of the alveolar macrophage by tubercle bacilli

    PubMed Central

    Nalpas, Nicolas C.; Magee, David A.; Conlon, Kevin M.; Browne, John A.; Healy, Claire; McLoughlin, Kirsten E.; Rue-Albrecht, Kévin; McGettigan, Paul A.; Killick, Kate E.; Gormley, Eamonn; Gordon, Stephen V.; MacHugh, David E.

    2015-01-01

    Mycobacterium bovis, the agent of bovine tuberculosis, causes an estimated $3 billion annual losses to global agriculture due, in part, to the limitations of current diagnostics. Development of next-generation diagnostics requires a greater understanding of the interaction between the pathogen and the bovine host. Therefore, to explore the early response of the alveolar macrophage to infection, we report the first application of RNA-sequencing to define, in exquisite detail, the transcriptomes of M. bovis-infected and non-infected alveolar macrophages from ten calves at 2, 6, 24 and 48 hours post-infection. Differentially expressed sense genes were detected at these time points that revealed enrichment of innate immune signalling functions, and transcriptional suppression of host defence mechanisms (e.g., lysosome maturation). We also detected differentially expressed natural antisense transcripts, which may play a role in subverting innate immune mechanisms following infection. Furthermore, we report differential expression of novel bovine genes, some of which have immune-related functions based on orthology with human proteins. This is the first in-depth transcriptomics investigation of the alveolar macrophage response to the early stages of M. bovis infection and reveals complex patterns of gene expression and regulation that underlie the immunomodulatory mechanisms used by M. bovis to evade host defence mechanisms. PMID:26346536

  4. Joint stabilizing projects in defense

    SciTech Connect

    Canavan, G.H.; Browne, J.C.; Joseph, R.J.

    1992-06-01

    Joint defensive projects could increase stability and decrease the alert rates of strategic forces. Areas include the defense of the US, Commonwealth of Independent States (CIS), and their allies against third world threats; protection against each other's accidental or unauthorized launches; and defense against intentional attacks. The most promising area appears to be defining interfaces for the handover of satellite warning and trajectory information, which applies to most phases of theater defense and mutual protection. 19 refs.

  5. Joint stabilizing projects in defense

    SciTech Connect

    Canavan, G.H.; Browne, J.C.; Joseph, R.J.

    1992-06-01

    Joint defensive projects could increase stability and decrease the alert rates of strategic forces. Areas include the defense of the US, Commonwealth of Independent States (CIS), and their allies against third world threats; protection against each other`s accidental or unauthorized launches; and defense against intentional attacks. The most promising area appears to be defining interfaces for the handover of satellite warning and trajectory information, which applies to most phases of theater defense and mutual protection. 19 refs.

  6. 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

  7. Defense on the Move: Ant-Based Cyber Defense

    SciTech Connect

    Fink, Glenn A.; Haack, Jereme N.; McKinnon, Archibald D.; Fulp, Errin W.

    2014-04-15

    Many common cyber defenses (like firewalls and IDS) are as static as trench warfare allowing the attacker freedom to probe them at will. The concept of Moving Target Defense (MTD) adds dynamism to the defender side, but puts the systems to be defended themselves in motion, potentially at great cost to the defender. An alternative approach is a mobile resilient defense that removes attackers’ ability to rely on prior experience without requiring motion in the protected infrastructure itself. The defensive technology absorbs most of the cost of motion, is resilient to attack, and is unpredictable to attackers. The Ant-Based Cyber Defense (ABCD) is a mobile resilient defense providing a set of roaming, bio-inspired, digital-ant agents working with stationary agents in a hierarchy headed by a human supervisor. The ABCD approach provides a resilient, extensible, and flexible defense that can scale to large, multi-enterprise infrastructures like the smart electric grid.

  8. [Effect of tocopherol acetate, indomethacin and dexamethasone on some indices of local lung defense in rheumatoid arthritis].

    PubMed

    Musaev, M U; Mavlianov, I R

    2001-01-01

    Marked disorders in the system of local lung defence are noted in experimental rheumatoid arthritis. In such a setting non-unidirectional shifts occur in the quantitative and qualitative indicators of cellular factors for the local pulmonary defensive system, characterized by discordant changes in the indicators of alveolar macrophages and segmented neutrophiles. There occur apparent disturbances in the functional activity of alveolar macrophages manifested by changes both in their phagocytary and metabolic activity and by depression of humoral mechanisms in the local pulmonary defensive system. The use of indomethacin, dexamethasone and vitamin E in an experimental rheumatoid arthritis setting favors positive shifts in indices for humoral and cellular links of the local pulmonary defensive system. Effects of vitamin E on indices for cellular and humoral links of the local pulmonary defensive system are more manifest as compared to those of indomethacin and dexamethasone.

  9. Cellular metabolism and macrophage functional polarization.

    PubMed

    Zhu, Linnan; Zhao, Qingjie; Yang, Tao; Ding, Wenjun; Zhao, Yong

    2015-01-01

    Macrophages are a functionally heterogeneous cell population that is mainly shaped by a variety of microenvironmental stimuli. Interferon γ (IFN-γ), interleukin-1β (IL-1β), and lipopolysaccharide (LPS) induce a classical activation of macrophages (M1), whereas IL-4 and IL-13 induce an alternative activation program in macrophages (M2). Reprogramming of intracellular metabolisms is required for the proper polarization and functions of activated macrophages. Similar to the Warburg effect observed in tumor cells, M1 macrophages increase glucose consumption and lactate release and decreased oxygen consumption rate. In comparison, M2 macrophages mainly employ oxidative glucose metabolism pathways. In addition, fatty acids, vitamins, and iron metabolisms are also related to macrophage polarization. However, detailed metabolic pathways involved in macrophages have remained elusive. Understanding the bidirectional interactions between cellular metabolism and macrophage functions in physiological and pathological situations and the regulatory pathways involved may offer novel therapies for macrophage-associated diseases.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  12. Plant Defense against Insect Herbivores

    PubMed Central

    Fürstenberg-Hägg, Joel; Zagrobelny, Mika; Bak, Søren

    2013-01-01

    Plants have been interacting with insects for several hundred million years, leading to complex defense approaches against various insect feeding strategies. Some defenses are constitutive while others are induced, although the insecticidal defense compound or protein classes are often similar. Insect herbivory induce several internal signals from the wounded tissues, including calcium ion fluxes, phosphorylation cascades and systemic- and jasmonate signaling. These are perceived in undamaged tissues, which thereafter reinforce their defense by producing different, mostly low molecular weight, defense compounds. These bioactive specialized plant defense compounds may repel or intoxicate insects, while defense proteins often interfere with their digestion. Volatiles are released upon herbivory to repel herbivores, attract predators or for communication between leaves or plants, and to induce defense responses. Plants also apply morphological features like waxes, trichomes and latices to make the feeding more difficult for the insects. Extrafloral nectar, food bodies and nesting or refuge sites are produced to accommodate and feed the predators of the herbivores. Meanwhile, herbivorous insects have adapted to resist plant defenses, and in some cases even sequester the compounds and reuse them in their own defense. Both plant defense and insect adaptation involve metabolic costs, so most plant-insect interactions reach a stand-off, where both host and herbivore survive although their development is suboptimal. PMID:23681010

  13. NLRP12 Modulates Host Defense through IL-17A-CXCL1 Axis

    PubMed Central

    Cai, Shanshan; Batra, Sanjay; Piero, Fabio Del; Jeyaseelan, Samithamby

    2015-01-01

    We used an extracellular pathogen Klebsiella pneumoniae to determine the role of NLRP12 since this bacterium is associated with devastating pulmonary infections. We found human myeloid cells (neutrophils and macrophages) and non-myeloid cells (epithelial cells) show upregulation of NLRP12 in human pneumonic lungs. NLRP12 silenced human macrophages and murine Nlrp12−/− macrophages displayed reduced activation of NF-κB and MAPK and expression of HDACs following K. pneumoniae infection. NLRP12 is important for the production of IL-1β in human and murine macrophages following K. pneumoniae infection. Furthermore, host survival, bacterial clearance and neutrophil recruitment are dependent on NLRP12 following K. pneumoniae infection. Using bone marrow chimeras, we showed that hematopoietic cell driven NLRP12 signaling predominantly contributes to host defense against K. pneumoniae. Intratracheal administration of either IL-17A+ CD4 T cells or CXCL1+ macrophages rescues host survival, bacterial clearance, and neutrophil recruitment in Nlrp12−/− mice following K. pneumoniae infection. These novel findings reveal the critical role of NLRP12-IL-17A-CXCL1 axis in host defense via modulating neutrophil recruitment against this extracellular pathogen. PMID:26349659

  14. Synthetic plant defense elicitors

    PubMed Central

    Bektas, Yasemin; Eulgem, Thomas

    2015-01-01

    To defend themselves against invading pathogens plants utilize a complex regulatory network that coordinates extensive transcriptional and metabolic reprogramming. Although many of the key players of this immunity-associated network are known, the details of its topology and dynamics are still poorly understood. As an alternative to forward and reverse genetic studies, chemical genetics-related approaches based on bioactive small molecules have gained substantial popularity in the analysis of biological pathways and networks. Use of such molecular probes can allow researchers to access biological space that was previously inaccessible to genetic analyses due to gene redundancy or lethality of mutations. Synthetic elicitors are small drug-like molecules that induce plant defense responses, but are distinct from known natural elicitors of plant immunity. While the discovery of some synthetic elicitors had already been reported in the 1970s, recent breakthroughs in combinatorial chemical synthesis now allow for inexpensive high-throughput screens for bioactive plant defense-inducing compounds. Along with powerful reverse genetics tools and resources available for model plants and crop systems, comprehensive collections of new synthetic elicitors will likely allow plant scientists to study the intricacies of plant defense signaling pathways and networks in an unparalleled fashion. As synthetic elicitors can protect crops from diseases, without the need to be directly toxic for pathogenic organisms, they may also serve as promising alternatives to conventional biocidal pesticides, which often are harmful for the environment, farmers and consumers. Here we are discussing various types of synthetic elicitors that have been used for studies on the plant immune system, their modes-of-action as well as their application in crop protection. PMID:25674095

  15. Viral pseudo-enzymes activate RIG-I via deamidation to evade cytokine production.

    PubMed

    He, Shanping; Zhao, Jun; Song, Shanshan; He, Xiaojing; Minassian, Arlet; Zhou, Yu; Zhang, Junjie; Brulois, Kevin; Wang, Yuqi; Cabo, Jackson; Zandi, Ebrahim; Liang, Chengyu; Jung, Jae U; Zhang, Xuewu; Feng, Pinghui

    2015-04-01

    RIG-I is a pattern recognition receptor that senses viral RNA and is crucial for host innate immune defense. Here, we describe a mechanism of RIG-I activation through amidotransferase-mediated deamidation. We show that viral homologs of phosphoribosylformylglycinamidine synthetase (PFAS), although lacking intrinsic enzyme activity, recruit cellular PFAS to deamidate and activate RIG-I. Accordingly, depletion and biochemical inhibition of PFAS impair RIG-I deamidation and concomitant activation. Purified PFAS and viral homolog thereof deamidate RIG-I in vitro. Ultimately, herpesvirus hijacks activated RIG-I to avoid antiviral cytokine production; loss of RIG-I or inhibition of RIG-I deamidation results in elevated cytokine production. Together, these findings demonstrate a surprising mechanism of RIG-I activation that is mediated by an enzyme. PMID:25752576

  16. Viral Pseudo Enzymes Activate RIG-I via Deamidation to Evade Cytokine Production

    PubMed Central

    He, Shanping; Zhao, Jun; Song, Shanshan; He, Xiaojing; Minassian, Arlet; Zhou, Yu; Zhang, Junjie; Brulois, Kevin; Wang, Yuqi; Cabo, Jackson; Zandi, Ebrahim; Liang, Chengyu; Jung, Jae U; Zhang, Xuewu; Feng, Pinghui

    2015-01-01

    SUMMARY RIG-I is a pattern recognition receptor that senses viral RNA and is crucial for host innate immune defense. Here we describe a mechanism of RIG-I activation through amidotransferase-mediated deamidation. We show that viral homologues of phosphoribosylformyglycinamide synthase (PFAS), although lacking intrinsic enzyme activity, recruit cellular PFAS to deamidate and activate RIG-I. Accordingly, depletion and biochemical inhibition of PFAS impair RIG-I deamidation and concomitant activation. Purified PFAS and viral homologue thereof deamidate RIG-I in vitro. Ultimately, herpesvirus hijacks activated RIG-I to avoid antiviral cytokine production; loss of RIG-I or inhibition of RIG-I deamidation results in elevated cytokine production. Together, these findings demonstrate a surprising mechanism of RIG-I activation that is mediated by an enzyme. PMID:25752576

  17. Genome-wide protective response used by group A Streptococcus to evade destruction by human polymorphonuclear leukocytes.

    PubMed

    Voyich, Jovanka M; Sturdevant, Daniel E; Braughton, Kevin R; Kobayashi, Scott D; Lei, Benfang; Virtaneva, Kimmo; Dorward, David W; Musser, James M; DeLeo, Frank R

    2003-02-18

    Group A Streptococcus (GAS) evades polymorphonuclear leukocyte (PMN) phagocytosis and killing to cause human disease, including pharyngitis and necrotizing fasciitis (flesh-eating syndrome). We show that GAS genes differentially regulated during phagocytic interaction with human PMNs comprise a global pathogen-protective response to innate immunity. GAS prophage genes and genes involved in virulence, oxidative stress, cell wall biosynthesis, and gene regulation were up-regulated during PMN phagocytosis. Genes encoding novel secreted proteins were up-regulated, and the proteins were produced during human GAS infections. We discovered an essential role for the Ihk-Irr two-component regulatory system in evading PMN-mediated killing and promoting host-cell lysis, processes that would facilitate GAS pathogenesis. Importantly, the irr gene was highly expressed during human GAS pharyngitis. We conclude that a complex pathogen genetic program circumvents human innate immunity to promote disease. The gene regulatory program revealed by our studies identifies previously undescribed potential vaccine antigens and targets for therapeutic interventions designed to control GAS infections.

  18. Allergic Host Defenses

    PubMed Central

    Palm, Noah W.; Rosenstein, Rachel K.

    2012-01-01

    Allergies are generally thought to be a detrimental outcome of a mistargeted immune response that evolved to provide immunity to macro-parasites. Here we present arguments to suggest that allergic immunity plays an important role in host defense against noxious environmental substances, including venoms, hematophagous fluids, environmental xenobiotics and irritants. We argue that appropriately targeted allergic reactions are beneficial, although they can become detrimental when excessive. Furthermore, we suggest that allergic hypersensitivity evolved to elicit anticipatory responses and to promote avoidance of suboptimal environments. PMID:22538607

  19. Nanomaterials for Defense Applications

    NASA Astrophysics Data System (ADS)

    Turaga, Uday; Singh, Vinitkumar; Lalagiri, Muralidhar; Kiekens, Paul; Ramkumar, Seshadri S.

    Nanotechnology has found a number of applications in electronics and healthcare. Within the textile field, applications of nanotechnology have been limited to filters, protective liners for chemical and biological clothing and nanocoatings. This chapter presents an overview of the applications of nanomaterials such as nanofibers and nanoparticles that are of use to military and industrial sectors. An effort has been made to categorize nanofibers based on the method of production. This chapter particularly focuses on a few latest developments that have taken place with regard to the application of nanomaterials such as metal oxides in the defense arena.

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

    PubMed Central

    de Dios Rosado, Juan; Rodriguez-Sosa, Miriam

    2011-01-01

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

  1. Proteomic Analysis of Salmonella enterica Serovar Typhimurium Isolated from RAW 264.7 Macrophages: identification of a novel protein that contributes to the replication of serovar Typhimurium inside macrophages

    SciTech Connect

    Shi, Liang; Adkins, Joshua N.; Coleman, James R.; Schepmoes, Athena A.; Dohnalkova, Alice; Mottaz, Heather M.; Norbeck, Angela D.; Purvine, Samuel O.; Manes, Nathan P.; Smallwood, Heather S.; Wang, Haixing H.; Forbes, John; Gros, Philippe; Uzzau, Sergio; Rodland, Karin D.; Heffron, Fred; Smith, Richard D.; Squier, Thomas C.

    2006-09-01

    ABSTRACT: To evade host resistance mechanisms, Salmonella enterica serovar Typhimurium (STM), a facultative intracellular pathogen, must alter its proteome following macrophage infection. To identify new colonization and virulence factors that mediate STM pathogenesis, we have isolated STM cells from RAW 264.7 macrophages at various time-points following infection and used a liquid chromatography-mass spectrometry (LC-MS)-based proteomic approach to detect the changes in STM protein abundances. Because host resistance to STM infection is strongly modulated by the expression of a functional host resistant regulator, i.e., natural resistance associated macrophage protein 1 (Nramp1, also called Slc11a1), we have also examined the effects of Nramp1 activity on the changes of STM protein abundances. A total of 315 STM proteins have been identified from isolated STM cells, which are largely house-keeping proteins whose abundances remain relatively constant during the time-course of infection. However, 39 STM proteins are strongly induced after infection, suggesting their involvement in modulating colonization and infection. Of the 39 induced proteins, 6 proteins are specifically modulated by Nramp1 activity, including STM3117, as well as STM3118-3119 whose time-dependent abundance changes were confirmed using Western blot analysis. Deletion of the gene encoding STM3117 resulted in a dramatic reduction in the ability of STM to colonize wild-type RAW 264.7 macrophages, demonstrating a critical involvement of STM3117 in promoting the replication of STM inside macrophages. The predicted function common for STM3117-3119 is biosynthesis and modification of the peptidoglycan layer of STM cell wall, emphasizing their important roles in the colonization of macrophages by Salmonella.

  2. Boron Induces Lymphocyte Proliferation and Modulates the Priming Effects of Lipopolysaccharide on Macrophages.

    PubMed

    Routray, Indusmita; Ali, Shakir

    2016-01-01

    Chemical mediators of inflammation (CMI) are important in host defense against infection. The reduced capacity of host to induce the secretion of these mediators following infection is one of the factors in host susceptibility to infection. Boron, which has been suggested for its role in infection, is reported in this study to increase lymphocyte proliferation and the secretion of CMI by the lipopolysaccharide (LPS)-stimulated peritoneal macrophages in BALB/c mice. Boron was administered to mice orally as borax at different doses for 10 consecutive days, followed by the stimulation of animals with ovalbumin and isolation of splenocytes for proliferation assay. The lymphocyte subsets were determined by flow cytometry in spleen cell suspension. The mediators of inflammation, TNF-α, IL-6, IL-1β and nitric oxide (NO), were measured in culture supernatant of LPS-primed macrophages isolated from borax treated mice. TNF and ILs were measured by ELISA. NO was determined by Griess test. The expression of inducible nitric oxide synthase (iNOS) in macrophages was studied by confocal microscopy. Results showed a significant increase in T and B cell populations, as indicated by an increase in CD4 and CD19, but not CD8, cells. Boron further stimulated the secretion of TNF-α, IL-6, IL-1β, NO and the expression of iNOS by the LPS-primed macrophages. The effect was dose dependent and most significant at a dose level of 4.6 mg/kg b. wt. Taken together, the study concludes that boron at physiological concentration induces lymphocyte proliferation and increases the synthesis and secretion of pro-inflammatory mediators by the LPS-primed macrophages, more specifically the M1 macrophages, possibly acting through Toll-like receptor. The study implicates boron as a regulator of the immune and inflammatory reactions and macrophage polarization, thus playing an important role in augmenting host defense against infection, with possible role in cancer and other diseases. PMID:26934748

  3. Boron Induces Lymphocyte Proliferation and Modulates the Priming Effects of Lipopolysaccharide on Macrophages

    PubMed Central

    Routray, Indusmita; Ali, Shakir

    2016-01-01

    Chemical mediators of inflammation (CMI) are important in host defense against infection. The reduced capacity of host to induce the secretion of these mediators following infection is one of the factors in host susceptibility to infection. Boron, which has been suggested for its role in infection, is reported in this study to increase lymphocyte proliferation and the secretion of CMI by the lipopolysaccharide (LPS)-stimulated peritoneal macrophages in BALB/c mice. Boron was administered to mice orally as borax at different doses for 10 consecutive days, followed by the stimulation of animals with ovalbumin and isolation of splenocytes for proliferation assay. The lymphocyte subsets were determined by flow cytometry in spleen cell suspension. The mediators of inflammation, TNF-α, IL-6, IL-1β and nitric oxide (NO), were measured in culture supernatant of LPS-primed macrophages isolated from borax treated mice. TNF and ILs were measured by ELISA. NO was determined by Griess test. The expression of inducible nitric oxide synthase (iNOS) in macrophages was studied by confocal microscopy. Results showed a significant increase in T and B cell populations, as indicated by an increase in CD4 and CD19, but not CD8, cells. Boron further stimulated the secretion of TNF-α, IL-6, IL-1β, NO and the expression of iNOS by the LPS-primed macrophages. The effect was dose dependent and most significant at a dose level of 4.6 mg/kg b. wt. Taken together, the study concludes that boron at physiological concentration induces lymphocyte proliferation and increases the synthesis and secretion of pro-inflammatory mediators by the LPS-primed macrophages, more specifically the M1 macrophages, possibly acting through Toll-like receptor. The study implicates boron as a regulator of the immune and inflammatory reactions and macrophage polarization, thus playing an important role in augmenting host defense against infection, with possible role in cancer and other diseases. PMID:26934748

  4. Boron Induces Lymphocyte Proliferation and Modulates the Priming Effects of Lipopolysaccharide on Macrophages.

    PubMed

    Routray, Indusmita; Ali, Shakir

    2016-01-01

    Chemical mediators of inflammation (CMI) are important in host defense against infection. The reduced capacity of host to induce the secretion of these mediators following infection is one of the factors in host susceptibility to infection. Boron, which has been suggested for its role in infection, is reported in this study to increase lymphocyte proliferation and the secretion of CMI by the lipopolysaccharide (LPS)-stimulated peritoneal macrophages in BALB/c mice. Boron was administered to mice orally as borax at different doses for 10 consecutive days, followed by the stimulation of animals with ovalbumin and isolation of splenocytes for proliferation assay. The lymphocyte subsets were determined by flow cytometry in spleen cell suspension. The mediators of inflammation, TNF-α, IL-6, IL-1β and nitric oxide (NO), were measured in culture supernatant of LPS-primed macrophages isolated from borax treated mice. TNF and ILs were measured by ELISA. NO was determined by Griess test. The expression of inducible nitric oxide synthase (iNOS) in macrophages was studied by confocal microscopy. Results showed a significant increase in T and B cell populations, as indicated by an increase in CD4 and CD19, but not CD8, cells. Boron further stimulated the secretion of TNF-α, IL-6, IL-1β, NO and the expression of iNOS by the LPS-primed macrophages. The effect was dose dependent and most significant at a dose level of 4.6 mg/kg b. wt. Taken together, the study concludes that boron at physiological concentration induces lymphocyte proliferation and increases the synthesis and secretion of pro-inflammatory mediators by the LPS-primed macrophages, more specifically the M1 macrophages, possibly acting through Toll-like receptor. The study implicates boron as a regulator of the immune and inflammatory reactions and macrophage polarization, thus playing an important role in augmenting host defense against infection, with possible role in cancer and other diseases.

  5. Thermoregulatory defense mechanisms.

    PubMed

    Sessler, Daniel I

    2009-07-01

    Core body temperature is normally tightly regulated by an effective thermoregulatory system. Thermoregulatory control is sometimes impaired by serious illness, but more typically remains intact. The primary autonomic defenses against heat are sweating and active precapillary vasodilation; the primary autonomic defenses against cold are arteriovenous shunt vasoconstriction and shivering. The core temperature triggering each response defines its activation threshold. Temperatures between the sweating and vasoconstriction thresholds define the inter-threshold range. The shivering threshold is usually a full 1 degrees C below the vasoconstriction threshold and is therefore a "last resort" response. Both vasoconstriction and shivering are associated with autonomic and hemodynamic activation; and each response is effective, thus impeding induction of therapeutic hypothermia. It is thus helpful to accompany core cooling with drugs that pharmacologically induce a degree of thermal tolerance. No perfect drug or drug combination has been identified. Anesthetics, for example, induce considerable tolerance, but are rarely suitable. Meperidine-especially in combination with buspirone-is especially effective while provoking only modest toxicity. The combination of buspirone and dexmedetomidine is comparably effective while avoiding the respiratory depression association with opioid administration.

  6. Hybrid nanoparticles improve targeting to inflammatory macrophages through phagocytic signals.

    PubMed

    Bagalkot, Vaishali; Badgeley, Marcus A; Kampfrath, Thomas; Deiuliis, Jeffrey A; Rajagopalan, Sanjay; Maiseyeu, Andrei

    2015-11-10

    Macrophages are innate immune cells with great phenotypic plasticity, which allows them to regulate an array of physiological processes such as host defense, tissue repair, and lipid/lipoprotein metabolism. In this proof-of-principle study, we report that macrophages of the M1 inflammatory phenotype can be selectively targeted by model hybrid lipid-latex (LiLa) nanoparticles bearing phagocytic signals. We demonstrate a simple and robust route to fabricate nanoparticles and then show their efficacy through imaging and drug delivery in inflammatory disease models of atherosclerosis and obesity. Self-assembled LiLa nanoparticles can be modified with a variety of hydrophobic entities such as drug cargos, signaling lipids, and imaging reporters resulting in sub-100nm nanoparticles with low polydispersities. The optimized theranostic LiLa formulation with gadolinium, fluorescein and "eat-me" phagocytic signals (Gd-FITC-LiLa) a) demonstrates high relaxivity that improves magnetic resonance imaging (MRI) sensitivity, b) encapsulates hydrophobic drugs at up to 60% by weight, and c) selectively targets inflammatory M1 macrophages concomitant with controlled release of the payload of anti-inflammatory drug. The mechanism and kinetics of the payload discharge appeared to be phospholipase A2 activity-dependent, as determined by means of intracellular Förster resonance energy transfer (FRET). In vivo, LiLa targets M1 macrophages in a mouse model of atherosclerosis, allowing noninvasive imaging of atherosclerotic plaque by MRI. In the context of obesity, LiLa particles were selectively deposited to M1 macrophages within inflamed adipose tissue, as demonstrated by single-photon intravital imaging in mice. Collectively, our results suggest that phagocytic signals can preferentially target inflammatory macrophages in experimental models of atherosclerosis and obesity, thus opening the possibility of future clinical applications that diagnose/treat these conditions. Tunable Li

  7. Hybrid nanoparticles improve targeting to inflammatory macrophages through phagocytic signals

    PubMed Central

    Bagalkot, Vaishali; Badgeley, Marcus A.; Kampfrath, Thomas; Deiuliis, Jeffrey A.; Rajagopalan, Sanjay; Maiseyeu, Andrei

    2016-01-01

    Macrophages are innate immune cells with great phenotypic plasticity, which allows them to regulate an array of physiological processes such as host defense, tissue repair, and lipid/lipoprotein metabolism. In this proof-of-principle study, we report that macrophages of the M1 inflammatory phenotype can be selectively targeted by model hybrid lipid–latex (LiLa) nanoparticles bearing phagocytic signals. We demonstrate a simple and robust route to fabricate nanoparticles and then show their efficacy through imaging and drug delivery in inflammatory disease models of atherosclerosis and obesity. Self-assembled LiLa nanoparticles can be modified with a variety of hydrophobic entities such as drug cargos, signaling lipids, and imaging reporters resulting in sub-100 nm nano-particles with low polydispersities. The optimized theranostic LiLa formulation with gadolinium, fluorescein and “eat-me” phagocytic signals (Gd-FITC-LiLa) a) demonstrates high relaxivity that improves magnetic resonance imaging (MRI) sensitivity, b) encapsulates hydrophobic drugs at up to 60% by weight, and c) selectively targets inflammatory M1 macrophages concomitant with controlled release of the payload of anti-inflammatory drug. The mechanism and kinetics of the payload discharge appeared to be phospholipase A2 activity-dependent, as determined by means of intracellular Förster resonance energy transfer (FRET). In vivo, LiLa targets M1 macrophages in a mouse model of atherosclerosis, allowing noninvasive imaging of atherosclerotic plaque by MRI. In the context of obesity, LiLa particles were selectively deposited to M1 macrophages within inflamed adipose tissue, as demonstrated by single-photon intravital imaging in mice. Collectively, our results suggest that phagocytic signals can preferentially target inflammatory macrophages in experimental models of atherosclerosis and obesity, thus opening the possibility of future clinical applications that diagnose/treat these conditions. Tunable

  8. Assessment of carbon nanoparticle exposure on murine macrophage function

    NASA Astrophysics Data System (ADS)

    Suro-Maldonado, Raquel M.

    There is growing concern about the potential cytotoxicity of nanoparticles. Exposure to respirable ultrafine particles (2.5uM) can adversely affect human health and have been implicated with episodes of increased respiratory diseases such as asthma and allergies. Nanoparticles are of particular interest because of their ability to penetrate into the lung and potentially elicit health effects triggering immune responses. Nanoparticles are structures and devises with length scales in the 1 to 100-nanometer range. Black carbon (BC) nanoparticles have been observed to be products of combustion, especially flame combustion and multi-walled carbon nanotubes (MWCNT) have been shown to be found in both indoor and outdoor air. Furthermore, asbestos, which have been known to cause mesothelioma as well as lung cancer, have been shown to be structurally identical to MWCNTs. The aims of these studies were to examine the effects of carbon nanoparticles on murine macrophage function and clearance mechanisms. Macrophages are immune cells that function as the first line of defense against invading pathogens and are likely to be amongst the first cells affected by nanoparticles. Our research focused on two manufactured nanoparticles, MWCNT and BC. The two were tested against murine-derived macrophages in a chronic contact model. We hypothesized that long-term chronic exposure to carbon nanoparticles would decrease macrophages ability to effectively respond to immunological challenge. Production of nitric oxide (NO), tumor necrosis factor alpha (TNF-alpha), cell surface macrophage; activation markers, reactive oxygen species formation (ROS), and antigen processing and presentation were examined in response to lipopolysaccharide (LPS) following a 144hr exposure to the particulates. Data demonstrated an increase in TNF-alpha, and NO production; a decrease in phagocytosis and antigen processing and presentation; and a decrease in the expression levels of cell surface macrophage

  9. Hybrid nanoparticles improve targeting to inflammatory macrophages through phagocytic signals.

    PubMed

    Bagalkot, Vaishali; Badgeley, Marcus A; Kampfrath, Thomas; Deiuliis, Jeffrey A; Rajagopalan, Sanjay; Maiseyeu, Andrei

    2015-11-10

    Macrophages are innate immune cells with great phenotypic plasticity, which allows them to regulate an array of physiological processes such as host defense, tissue repair, and lipid/lipoprotein metabolism. In this proof-of-principle study, we report that macrophages of the M1 inflammatory phenotype can be selectively targeted by model hybrid lipid-latex (LiLa) nanoparticles bearing phagocytic signals. We demonstrate a simple and robust route to fabricate nanoparticles and then show their efficacy through imaging and drug delivery in inflammatory disease models of atherosclerosis and obesity. Self-assembled LiLa nanoparticles can be modified with a variety of hydrophobic entities such as drug cargos, signaling lipids, and imaging reporters resulting in sub-100nm nanoparticles with low polydispersities. The optimized theranostic LiLa formulation with gadolinium, fluorescein and "eat-me" phagocytic signals (Gd-FITC-LiLa) a) demonstrates high relaxivity that improves magnetic resonance imaging (MRI) sensitivity, b) encapsulates hydrophobic drugs at up to 60% by weight, and c) selectively targets inflammatory M1 macrophages concomitant with controlled release of the payload of anti-inflammatory drug. The mechanism and kinetics of the payload discharge appeared to be phospholipase A2 activity-dependent, as determined by means of intracellular Förster resonance energy transfer (FRET). In vivo, LiLa targets M1 macrophages in a mouse model of atherosclerosis, allowing noninvasive imaging of atherosclerotic plaque by MRI. In the context of obesity, LiLa particles were selectively deposited to M1 macrophages within inflamed adipose tissue, as demonstrated by single-photon intravital imaging in mice. Collectively, our results suggest that phagocytic signals can preferentially target inflammatory macrophages in experimental models of atherosclerosis and obesity, thus opening the possibility of future clinical applications that diagnose/treat these conditions. Tunable Li

  10. Intracellular Shigella remodels its LPS to dampen the innate immune recognition and evade inflammasome activation.

    PubMed

    Paciello, Ida; Silipo, Alba; Lembo-Fazio, Luigi; Curcurù, Laura; Zumsteg, Anna; Noël, Gaëlle; Ciancarella, Valeria; Sturiale, Luisa; Molinaro, Antonio; Bernardini, Maria Lina

    2013-11-12

    LPS is a potent bacterial effector triggering the activation of the innate immune system following binding with the complex CD14, myeloid differentiation protein 2, and Toll-like receptor 4. The LPS of the enteropathogen Shigella flexneri is a hexa-acylated isoform possessing an optimal inflammatory activity. Symptoms of shigellosis are produced by severe inflammation caused by the invasion process of Shigella in colonic and rectal mucosa. Here we addressed the question of the role played by the Shigella LPS in eliciting a dysregulated inflammatory response of the host. We unveil that (i) Shigella is able to modify the LPS composition, e.g., the lipid A and core domains, during proliferation within epithelial cells; (ii) the LPS of intracellular bacteria (iLPS) and that of bacteria grown in laboratory medium differ in the number of acyl chains in lipid A, with iLPS being the hypoacylated; (iii) the immunopotential of iLPS is dramatically lower than that of bacteria grown in laboratory medium; (iv) both LPS forms mainly signal through the Toll-like receptor 4/myeloid differentiation primary response gene 88 pathway; (v) iLPS down-regulates the inflammasome-mediated release of IL-1β in Shigella-infected macrophages; and (vi) iLPS exhibits a reduced capacity to prime polymorfonuclear cells for an oxidative burst. We propose a working model whereby the two forms of LPS might govern different steps of the invasive process of Shigella. In the first phases, the bacteria, decorated with hypoacylated LPS, are able to lower the immune system surveillance, whereas, in the late phases, shigellae harboring immunopotent LPS are fully recognized by the immune system, which can then successfully resolve the infection.

  11. Intracellular Shigella remodels its LPS to dampen the innate immune recognition and evade inflammasome activation

    PubMed Central

    Paciello, Ida; Silipo, Alba; Lembo-Fazio, Luigi; Curcurù, Laura; Zumsteg, Anna; Noël, Gaëlle; Ciancarella, Valeria; Sturiale, Luisa; Molinaro, Antonio; Bernardini, Maria Lina

    2013-01-01

    LPS is a potent bacterial effector triggering the activation of the innate immune system following binding with the complex CD14, myeloid differentiation protein 2, and Toll-like receptor 4. The LPS of the enteropathogen Shigella flexneri is a hexa-acylated isoform possessing an optimal inflammatory activity. Symptoms of shigellosis are produced by severe inflammation caused by the invasion process of Shigella in colonic and rectal mucosa. Here we addressed the question of the role played by the Shigella LPS in eliciting a dysregulated inflammatory response of the host. We unveil that (i) Shigella is able to modify the LPS composition, e.g., the lipid A and core domains, during proliferation within epithelial cells; (ii) the LPS of intracellular bacteria (iLPS) and that of bacteria grown in laboratory medium differ in the number of acyl chains in lipid A, with iLPS being the hypoacylated; (iii) the immunopotential of iLPS is dramatically lower than that of bacteria grown in laboratory medium; (iv) both LPS forms mainly signal through the Toll-like receptor 4/myeloid differentiation primary response gene 88 pathway; (v) iLPS down-regulates the inflammasome-mediated release of IL-1β in Shigella-infected macrophages; and (vi) iLPS exhibits a reduced capacity to prime polymorfonuclear cells for an oxidative burst. We propose a working model whereby the two forms of LPS might govern different steps of the invasive process of Shigella. In the first phases, the bacteria, decorated with hypoacylated LPS, are able to lower the immune system surveillance, whereas, in the late phases, shigellae harboring immunopotent LPS are fully recognized by the immune system, which can then successfully resolve the infection. PMID:24167293

  12. microRNA-20a Inhibits Autophagic Process by Targeting ATG7 and ATG16L1 and Favors Mycobacterial Survival in Macrophage Cells

    PubMed Central

    Guo, Le; Zhao, Jin; Qu, Yuliang; Yin, Runting; Gao, Qian; Ding, Shuqin; Zhang, Ying; Wei, Jun; Xu, Guangxian

    2016-01-01

    Autophagy plays important roles in the host immune response against mycobacterial infection. Mycobacterium tuberculosis (M. tuberculosis) can live in macrophages owing to its ability to evade attacks by regulating autophagic response. MicroRNAs (miRNAs) are small noncoding, endogenously encoded RNA which plays critical roles in precise regulation of macrophage functions. Whether miRNAs specifically influence the activation of macrophage autophagy during M. tuberculosis infection are largely unknown. In this study, we demonstrate that BCG infection of macrophages resulted in enhanced expression of miRNA-20a, which inhibits autophagic process by targeting ATG7 and ATG16L1 and promotes BCG survival in macrophages. Forced overexpression of miR-20a decreased the expression levels of LC3-II and the number of LC3 puncta in macrophages, and promoted BCG survival in macrophages, while transfection with miR-20a inhibitor had the opposite effect. Moreover, the inhibitory effect of miR-20a on autophagy was further confirmed by transmission electron microscopy (TEM) analysis. Quantification of autophagosomes per cellular cross-section revealed a significant reduction upon transfection with miR-20a mimic, but transfection with miR-20a inhibitor increased the number of autophagosomes per cellular cross-section. Moreover, silencing of ATG7 significantly inhibited autophagic response, and transfection with ATG7 siRNA plus miR-20a mimic could further decrease autophagic response. Collectively, our data reveal that miR-20a inhibits autophagic response and promotes BCG survival in macrophages by targeting ATG7 and ATG16L1, which may have implications for a better understanding of pathogenesis of M. tuberculosis infection. PMID:27803889

  13. 1,25-Dihydroxyvitamin D Modulates Antibacterial and Inflammatory Response in Human Cigarette Smoke-Exposed Macrophages

    PubMed Central

    Heulens, Nele; Korf, Hannelie; Mathyssen, Carolien; Everaerts, Stephanie; De Smidt, Elien; Dooms, Christophe; Yserbyt, Jonas; Gysemans, Conny; Gayan-Ramirez, Ghislaine; Mathieu, Chantal; Janssens, Wim

    2016-01-01

    Cigarette smoking is associated with increased inflammation and defective antibacterial responses in the airways. Interestingly, vitamin D has been shown to suppress inflammation and to improve antibacterial defense. However, it is currently unknown whether vitamin D may modulate inflammation and antibacterial defects in human cigarette smoke (CS)-exposed airways. To explore these unresolved issues, alveolar macrophages obtained from non-smoking and smoking subjects as well as human cigarette smoke extract (CSE)-treated THP-1 macrophages were stimulated with 1,25-dihydroxyvitamin D (1,25(OH)2D) to address inflammatory and antibacterial responses. Although basal levels of inflammatory cytokines and chemokines did not differ between non-smoking and smoking subjects, 1,25(OH)2D did reduce levels of IL-6, TNF-α and MCP-1 in alveolar macrophages in response to LPS/IFN-γ, although not statistically significant for TNF-α and IL-6 in smokers. CSE did not significantly alter vitamin D metabolism (expression levels of CYP24A1 or CYP27B1) in THP-1 macrophages. Furthermore, stimulation with 1,25(OH)2D reduced mRNA expression levels and/or protein levels of IL-8, TNF-α and MCP-1 in CSE-treated THP-1 macrophages. 1,25(OH)2D did not improve defects in phagocytosis of E. coli bacteria or the oxidative burst response in CSE-treated THP-1 macrophages or alveolar macrophages from smokers. However, 1,25(OH)2D significantly enhanced mRNA expression and/or protein levels of the antimicrobial peptide cathelicidin in alveolar macrophages and THP-1 macrophages, independently of CS exposure. In conclusion, our results provide the first evidence that vitamin D could be a new strategy for attenuating airway inflammation and improving antibacterial defense in CS-exposed airways. PMID:27513734

  14. 1,25-Dihydroxyvitamin D Modulates Antibacterial and Inflammatory Response in Human Cigarette Smoke-Exposed Macrophages.

    PubMed

    Heulens, Nele; Korf, Hannelie; Mathyssen, Carolien; Everaerts, Stephanie; De Smidt, Elien; Dooms, Christophe; Yserbyt, Jonas; Gysemans, Conny; Gayan-Ramirez, Ghislaine; Mathieu, Chantal; Janssens, Wim

    2016-01-01

    Cigarette smoking is associated with increased inflammation and defective antibacterial responses in the airways. Interestingly, vitamin D has been shown to suppress inflammation and to improve antibacterial defense. However, it is currently unknown whether vitamin D may modulate inflammation and antibacterial defects in human cigarette smoke (CS)-exposed airways. To explore these unresolved issues, alveolar macrophages obtained from non-smoking and smoking subjects as well as human cigarette smoke extract (CSE)-treated THP-1 macrophages were stimulated with 1,25-dihydroxyvitamin D (1,25(OH)2D) to address inflammatory and antibacterial responses. Although basal levels of inflammatory cytokines and chemokines did not differ between non-smoking and smoking subjects, 1,25(OH)2D did reduce levels of IL-6, TNF-α and MCP-1 in alveolar macrophages in response to LPS/IFN-γ, although not statistically significant for TNF-α and IL-6 in smokers. CSE did not significantly alter vitamin D metabolism (expression levels of CYP24A1 or CYP27B1) in THP-1 macrophages. Furthermore, stimulation with 1,25(OH)2D reduced mRNA expression levels and/or protein levels of IL-8, TNF-α and MCP-1 in CSE-treated THP-1 macrophages. 1,25(OH)2D did not improve defects in phagocytosis of E. coli bacteria or the oxidative burst response in CSE-treated THP-1 macrophages or alveolar macrophages from smokers. However, 1,25(OH)2D significantly enhanced mRNA expression and/or protein levels of the antimicrobial peptide cathelicidin in alveolar macrophages and THP-1 macrophages, independently of CS exposure. In conclusion, our results provide the first evidence that vitamin D could be a new strategy for attenuating airway inflammation and improving antibacterial defense in CS-exposed airways. PMID:27513734

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

    PubMed Central

    Rajaram, Krithika

    2015-01-01

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2013-01-01

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

  18. [The ecological-morphological aspects of adaptation and the role of the macrophages in body dehydration].

    PubMed

    Proshina, L G

    1995-01-01

    The morphological aspects of rearrangement of macrophages in white rats' subcutaneous areolar tissue during dehydration and their impact on the recovery of osmotic homeostasis were studied. A response of macrophages to dehydration with preliminary injection of antioxidant dibunol was revealed. Macrophages respond to dehydration by a rise in number, elevated cytoplasmic activity of lipolytic enzymes (beta-oxibutyrate dehydrogenase), and a peculiar ultrastructural rearrangement, i.e. a decrease of vacuoles, their sizes, an increase of the lipid volumetric fraction. However, the higher activity of macrophages in terms of production of metabolic water is concurrent to increased malonic dialdehyde production and inhibited activity of the cell antioxidant defense (superoxide dismutase). To correct the observed changes, dehydration was performed on the background of antioxidant dibunol injection. The antioxidant and subsequent dehydration did not annul the response of macrophages to increased intrabody osmolality although slightly masked the effect of dehydration. Survivability in this group of animals was by 22% higher than in the water-deprived group. Hence, the areolar macrophages can be considered the controllers of adaptive reactions of the body during dehydration, whereas antioxidants are the correction factor for these reactions.

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

    PubMed Central

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

    2013-01-01

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

  20. Binding and Phagocytosis by Opsonized and Nonopsonized Channel Catfish Macrophages of Viable DsRed-fluorescent-labeled Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phagocyte-mediated killing of bacterial pathogens is one of the major defensive mechanisms in fish. The binding, uptake and destruction of recombinant fluorescent protein DsRed transformed Edwardsiella ictaluri by opsonized and nonopsonized channel catfish (Ictalurus punctatus) macrophages was chara...

  1. Mycobacterium massiliense Induces Macrophage Extracellular Traps with Facilitating Bacterial Growth

    PubMed Central

    Yoon, Yina; Na, Yirang; Kim, Bum-Joon; Seok, Seung Hyeok

    2016-01-01

    Human neutrophils have been known to release neutrophil extracellular traps (NETs), antimicrobial DNA structures capable of capturing and killing microbes. Recently, a similar phenomenon has been reported in macrophages infected with various pathogens. However, a role for macrophages extracellular traps (METs) in host defense responses against Mycobacterium massiliense (M. mass) has yet to be described. In this study, we show that M. mass, a rapid growing mycobacterium (RGM), also induces the release of METs from PMA-differentiated THP-1 cells. Intriguingly, this process is not dependent on NADPH oxidase activity, which regulates NET formation. Instead, M. mass-induced MET formation partially depends on calcium influx and requires phagocytosis of high bacterial load. The METs consist of a DNA backbone embedded with microbicidal proteins such as histone, MPO and elastase. Released METs entrap M. mass and prevent their dissemination, but do not have bactericidal activity. Instead, they result in enhanced bacterial growth. In this regard, METs were considered to provide interaction of M. mass with cells and an environment for bacterial aggregation, which may facilitate mycobacterial survival and growth. In conclusion, our results demonstrate METs as an innate defense response against M. mass infection, and suggest that extracellular traps play a multifaceted role in the interplay between host and bacteria. PMID:27191593

  2. Polyamine transporter in Streptococcus pneumoniae is essential for evading early innate immune responses in pneumococcal pneumonia

    PubMed Central

    Rai, Aswathy N.; Thornton, Justin A.; Stokes, John; Sunesara, Imran; Swiatlo, Edwin; Nanduri, Bindu

    2016-01-01

    Streptococcus pneumoniae is the most common bacterial etiology of pneumococcal pneumonia in adults worldwide. Genomic plasticity, antibiotic resistance and extreme capsular antigenic variation complicates the design of effective therapeutic strategies. Polyamines are ubiquitous small cationic molecules necessary for full expression of pneumococcal virulence. Polyamine transport system is an attractive therapeutic target as it is highly conserved across pneumococcal serotypes. In this study, we compared an isogenic deletion strain of S. pneumoniae TIGR4 in polyamine transport operon (ΔpotABCD) with the wild type in a mouse model of pneumococcal pneumonia. Our results show that the wild type persists in mouse lung 24 h post infection while the mutant strain is cleared by host defense mechanisms. We show that intact potABCD is required for survival in the host by providing resistance to neutrophil killing. Comparative proteomics analysis of murine lungs infected with wild type and ΔpotABCD pneumococci identified expression of proteins that could confer protection to wild type strain and help establish infection. We identified ERM complex, PGLYRP1, PTPRC/CD45 and POSTN as new players in the pathogenesis of pneumococcal pneumonia. Additionally, we found that deficiency of polyamine transport leads to up regulation of the polyamine synthesis genes speE and cad in vitro. PMID:27247105

  3. Polyamine transporter in Streptococcus pneumoniae is essential for evading early innate immune responses in pneumococcal pneumonia.

    PubMed

    Rai, Aswathy N; Thornton, Justin A; Stokes, John; Sunesara, Imran; Swiatlo, Edwin; Nanduri, Bindu

    2016-01-01

    Streptococcus pneumoniae is the most common bacterial etiology of pneumococcal pneumonia in adults worldwide. Genomic plasticity, antibiotic resistance and extreme capsular antigenic variation complicates the design of effective therapeutic strategies. Polyamines are ubiquitous small cationic molecules necessary for full expression of pneumococcal virulence. Polyamine transport system is an attractive therapeutic target as it is highly conserved across pneumococcal serotypes. In this study, we compared an isogenic deletion strain of S. pneumoniae TIGR4 in polyamine transport operon (ΔpotABCD) with the wild type in a mouse model of pneumococcal pneumonia. Our results show that the wild type persists in mouse lung 24 h post infection while the mutant strain is cleared by host defense mechanisms. We show that intact potABCD is required for survival in the host by providing resistance to neutrophil killing. Comparative proteomics analysis of murine lungs infected with wild type and ΔpotABCD pneumococci identified expression of proteins that could confer protection to wild type strain and help establish infection. We identified ERM complex, PGLYRP1, PTPRC/CD45 and POSTN as new players in the pathogenesis of pneumococcal pneumonia. Additionally, we found that deficiency of polyamine transport leads to up regulation of the polyamine synthesis genes speE and cad in vitro. PMID:27247105

  4. Perforin-2 restricts growth of Chlamydia trachomatis in macrophages.

    PubMed

    Fields, K A; McCormack, R; de Armas, L R; Podack, E R

    2013-08-01

    Chlamydia trachomatis is a Gram-negative obligate intracellular bacterium that preferentially infects epithelial cells. Professional phagocytes provide C. trachomatis only a limited ability to survive and are proficient killers of chlamydiae. We present evidence herein that identifies a novel host defense protein, perforin-2, that plays a significant role in the eradication of C. trachomatis during the infection of macrophages. Knockdown of perforin-2 in macrophages did not alter the invasion of host cells but did result in chlamydial growth that closely mirrored that detected in HeLa cells. C trachomatis L2, serovar B, and serovar D and C. muridarum were all equally susceptible to perforin-2-mediated killing. Interestingly, induction of perforin-2 expression in epithelial cells is blocked during productive chlamydial growth, thereby protecting chlamydiae from bactericidal attack. Ectopic expression of perforin-2 in HeLa cells, however, does result in killing. Overall, our data implicate a new innate resistance protein in the control of chlamydial infection and may help explain why the macrophage environment is hostile to chlamydial growth. PMID:23753625

  5. Defense acquisition programs

    SciTech Connect

    Not Available

    1990-06-01

    The continuing instability in the overall defense budget and the recent changes in Eastern Europe are forcing DOD and the military services to reexamine the need, priority, and annual funding levels for many weapon system acquisition programs. GAO reviewed six weapon system acquisition programs that DOD was scheduled to make an acquisition milestone decision on during fiscal year 1991. Under milestone authorization, up to five years funding can be approved to cover the entire acquisition phase for either full-scale development or full-rate production. This report examines the Non-Line-of-Sight Missile, the Light Helicopter, the MK-50 Torpedo, the Sensor Fuzed Weapon, the Advanced Tactical Fighter, and the Joint Tactical Information Distribution System Class 2 Terminals.

  6. Macrophage functions in Biozzi mice.

    PubMed Central

    Dockrell, H M; Taverne, J; Lelchuk, R; Depledge, P; Brown, I N; Playfair, J H

    1985-01-01

    The faster degradation of antigen by macrophages in Biozzi low (L) responder mice, compared to Biozzi high (H) responder mice, is thought to be responsible for their lower antibody response. We have measured four functions associated with macrophages to see whether macrophages from L mice were generally more active than those from H mice. Peritoneal macrophages obtained from normal mice were compared with those from groups of mice given Mycobacterium bovis BCG or Propionibacterium acnes. Cells from normal H mice gave a stronger oxidative burst when triggered with phorbol myristate acetate, and were more cytotoxic for tumour cells than cells from L mice. Cells from all mice injected with BCG or P. acnes gave a stronger oxidative burst, and were more cytotoxic for tumour cells; again, both responses were higher in H mice than in L mice. By contrast, when groups of mice that had received P. acnes were given endotoxin and bled, higher titres of tumour necrosis factor were found in the sera of L mice. Spleen cells from both lines of mice released similar levels of interleukin-1, both spontaneously and in response to lipopolysaccharide. Our results suggest that these various macrophage responses are expressed independently in H and L mice. PMID:3894222

  7. Efficient internalization of mesoporous silica particles of different sizes by primary human macrophages without impairment of macrophage clearance of apoptotic or antibody-opsonized target cells

    SciTech Connect

    Witasp, Erika; Kupferschmidt, Natalia; Bengtsson, Linnea; Hultenby, Kjell; Smedman, Christian; Paulie, Staffan; Garcia-Bennett, Alfonso E.; Fadeel, Bengt

    2009-09-15

    Macrophage recognition and ingestion of apoptotic cell corpses, a process referred to as programmed cell clearance, is of considerable importance for the maintenance of tissue homeostasis and in the resolution of inflammation. Moreover, macrophages are the first line of defense against microorganisms and other foreign materials including particles. However, there is sparse information on the mode of uptake of engineered nanomaterials by primary macrophages. In this study, mesoporous silica particles with cubic pore geometries and covalently fluorescein-grafted particles were synthesized through a novel route, and their interactions with primary human monocyte-derived macrophages were assessed. Efficient and active internalization of mesoporous silica particles of different sizes was observed by transmission electron microscopic and flow cytometric analysis and studies using pharmacological inhibitors suggested that uptake occurred through a process of endocytosis. Moreover, uptake of silica particles was independent of serum factors. The silica particles with very high surface areas due to their porous structure did not impair cell viability or function of macrophages, including the ingestion of different classes of apoptotic or opsonized target cells. The current findings are relevant to the development of mesoporous materials for drug delivery and other biomedical applications.

  8. Jagged1 Instructs Macrophage Differentiation in Leprosy.

    PubMed

    Kibbie, Jon; Teles, Rosane M B; Wang, Zhiming; Hong, Patrick; Montoya, Dennis; Krutzik, Stephan; Lee, Seung; Kwon, Ohyun; Modlin, Robert L; Cruz, Daniel

    2016-08-01

    As circulating monocytes enter the site of disease, the local microenvironment instructs their differentiation into tissue macrophages (MΦ). To identify mechanisms that regulate MΦ differentiation, we studied human leprosy as a model, since M1-type antimicrobial MΦ predominate in lesions in the self-limited form, whereas M2-type phagocytic MΦ are characteristic of the lesions in the progressive form. Using a heterotypic co-culture model, we found that unstimulated endothelial cells (EC) trigger monocytes to become M2 MΦ. However, biochemical screens identified that IFN-γ and two families of small molecules activated EC to induce monocytes to differentiate into M1 MΦ. The gene expression profiles induced in these activated EC, when overlapped with the transcriptomes of human leprosy lesions, identified Jagged1 (JAG1) as a potential regulator of MΦ differentiation. JAG1 protein was preferentially expressed in the lesions from the self-limited form of leprosy, and localized to the vascular endothelium. The ability of activated EC to induce M1 MΦ was JAG1-dependent and the addition of JAG1 to quiescent EC facilitated monocyte differentiation into M1 MΦ with antimicrobial activity against M. leprae. Our findings indicate a potential role for the IFN-γ-JAG1 axis in instructing MΦ differentiation as part of the host defense response at the site of disease in human leprosy. PMID:27532668

  9. Jagged1 Instructs Macrophage Differentiation in Leprosy

    PubMed Central

    Teles, Rosane M. B.; Wang, Zhiming; Hong, Patrick; Montoya, Dennis; Krutzik, Stephan; Lee, Seung; Kwon, Ohyun; Modlin, Robert L.; Cruz, Daniel

    2016-01-01

    As circulating monocytes enter the site of disease, the local microenvironment instructs their differentiation into tissue macrophages (MΦ). To identify mechanisms that regulate MΦ differentiation, we studied human leprosy as a model, since M1-type antimicrobial MΦ predominate in lesions in the self-limited form, whereas M2-type phagocytic MΦ are characteristic of the lesions in the progressive form. Using a heterotypic co-culture model, we found that unstimulated endothelial cells (EC) trigger monocytes to become M2 MΦ. However, biochemical screens identified that IFN-γ and two families of small molecules activated EC to induce monocytes to differentiate into M1 MΦ. The gene expression profiles induced in these activated EC, when overlapped with the transcriptomes of human leprosy lesions, identified Jagged1 (JAG1) as a potential regulator of MΦ differentiation. JAG1 protein was preferentially expressed in the lesions from the self-limited form of leprosy, and localized to the vascular endothelium. The ability of activated EC to induce M1 MΦ was JAG1-dependent and the addition of JAG1 to quiescent EC facilitated monocyte differentiation into M1 MΦ with antimicrobial activity against M. leprae. Our findings indicate a potential role for the IFN-γ-JAG1 axis in instructing MΦ differentiation as part of the host defense response at the site of disease in human leprosy. PMID:27532668

  10. Antipredator defenses predict diversification rates

    PubMed Central

    Arbuckle, Kevin; Speed, Michael P.

    2015-01-01

    The “escape-and-radiate” hypothesis predicts that antipredator defenses facilitate adaptive radiations by enabling escape from constraints of predation, diversified habitat use, and subsequently speciation. Animals have evolved diverse strategies to reduce the direct costs of predation, including cryptic coloration and behavior, chemical defenses, mimicry, and advertisement of unprofitability (conspicuous warning coloration). Whereas the survival consequences of these alternative defenses for individuals are well-studied, little attention has been given to the macroevolutionary consequences of alternative forms of defense. Here we show, using amphibians as the first, to our knowledge, large-scale empirical test in animals, that there are important macroevolutionary consequences of alternative defenses. However, the escape-and-radiate hypothesis does not adequately describe them, due to its exclusive focus on speciation. We examined how rates of speciation and extinction vary across defensive traits throughout amphibians. Lineages that use chemical defenses show higher rates of speciation as predicted by escape-and-radiate but also show higher rates of extinction compared with those without chemical defense. The effect of chemical defense is a net reduction in diversification compared with lineages without chemical defense. In contrast, acquisition of conspicuous coloration (often used as warning signals or in mimicry) is associated with heightened speciation rates but unchanged extinction rates. We conclude that predictions based on the escape-and-radiate hypothesis must incorporate the effect of traits on both speciation and extinction, which is rarely considered in such studies. Our results also suggest that knowledge of defensive traits could have a bearing on the predictability of extinction, perhaps especially important in globally threatened taxa such as amphibians. PMID:26483488

  11. Optomechanical effects of two-level systems in a back-action evading measurement of micro-mechanical motion

    NASA Astrophysics Data System (ADS)

    Suh, J.; Weinstein, A. J.; Schwab, K. C.

    2013-07-01

    We show that the two-level systems (TLS) in lithographic superconducting circuits act as a power-dependent dielectric leading to non-linear responses in a parametrically coupled electromechanical system. Driven TLS shift the microwave resonance frequency and modulate the mechanical resonance through the optical spring effect. By pumping with two tones in a back-action evading measurement, these effects produce a mechanical parametric instability which limits single quadrature imprecision to 1.4 xzp. The microwave resonator noise is also consistent to a TLS-noise model. These observations suggest design strategies for minimizing TLS effects to improve ground-state cooling and quantum non-demolition measurements of motion.

  12. Effect of sulfur dioxide on pulmonary macrophage endocytosis at rest and during exercise

    SciTech Connect

    Skornik, W.A.; Brain, J.D. )

    1990-09-01

    Inhaled SO2 may cause damage by injuring upper airways. To what extent can SO2 also alter pulmonary macrophage function in the parenchyma and what is the impact of exercise We studied the effect of SO2 on pulmonary macrophage endocytosis in resting and in exercising animals by measuring the rates of macrophage endocytosis in situ for 1 h of a test particle of insoluble radioactive colloidal gold (198Au), 1, 24, or 48 h after inhalation exposure to SO2. Resting hamsters exposed for 4 h to 50 ppm SO2 had no significant reduction in macrophage endocytosis compared with air-breathing control hamsters. However, if hamsters were exposed to the same concentration of SO2 while continuously running (40 min at 0.9 km/h), macrophage endocytosis was significantly reduced 1 h after exposure even though the exposure time was only one-sixth as long. Twenty-four hours later, the percentage of gold ingested by pulmonary macrophages remained significantly depressed. By 48 h, the rate had returned to control values. Exercise alone did not affect endocytosis. Hamsters exposed to 50 ppm SO2, with or without exercise, also showed significant reductions in the number of lavaged macrophages. This decrease was greatest and most persistent in the SO2 plus exercise group. These data indicate that even when animals are exposed to water-soluble gases, which are normally removed by the upper airways, exercise can potentiate damage to more peripheral components of the pulmonary defense system such as the macrophage.

  13. MET-Independent Lung Cancer Cells Evading EGFR Kinase Inhibitors are Therapeutically Susceptible to BH3 Mimetic Agents

    PubMed Central

    Fan, Weiwen; Tang, Zhe; Yin, Lihong; Morrison, Bei; Hafez-Khayyata, Said; Fu, Pingfu; Huang, Honglian; Bagai, Rakesh; Jiang, Shan; Kresak, Adam; Howell, Scott; Vasanji, Amit; Flask, Chris A.; Halmos, Balazs; Koon, Henry; Ma, Patrick C.

    2011-01-01

    Targeted therapies for cancer are inherently limited by the inevitable recurrence of resistant disease after initial responses. To define early molecular changes within residual tumor cells that persist after treatment, we analyzed drug sensitive lung adenocarcinoma cell lines exposed to reversible or irreversible EGFR inhibitors, alone or in combination with MET kinase inhibitors, to characterize the adaptive response that engenders drug resistance. Tumor cells displaying early resistance exhibited dependence on MET-independent activation of BCL-2/BCL-XL survival signaling. Further, such cells displayed a quiescence-like state associated with greatly retarded cell proliferation and cytoskeletal functions that were readily reversed after withdrawal of targeted inhibitors. Findings were validated in a xenograft model, demonstrating BCL-2 induction and p-STAT3[Y705] activation within the residual tumor cells surviving the initial anti-tumor response to targeted therapies. Disrupting the mitochondrial BCL-2/BCL-XL antiapoptotic machinery in early survivor cells using BH3 mimetic agents such as ABT-737, or by dual RNAi-mediated knockdown of BCL-2/BCL-XL, was sufficient to eradicate the early resistant lung tumor cells evading targeted inhibitors. Similarly, in a xenograft model the preemptive co-treatment of lung tumor cells with an EGFR inhibitor and a BH3 mimetic eradicated early TKI-resistant evaders and ultimately achieved a more durable response with prolonged remission. Our findings prompt prospective clinical investigations using BH3-mimetics combined with targeted receptor kinase inhibitors to optimize and improve clinical outcomes in lung cancer treatment. PMID:21555370

  14. Leonurus sibiricus induces nitric oxide and tumor necrosis factor-alpha in mouse peritoneal macrophages.

    PubMed

    An, Hyo-Jin; Rim, Hong-Kun; Lee, Jong-Hyun; Suh, Se-Eun; Lee, Ji-Hyun; Kim, Na-Hyung; Choi, In-Young; Jeong, Hyun-Ja; Kim, Il Kwang; Lee, Ju-Young; An, Nyeon-Hyoung; Kim, Hyung-Ryong; Um, Jae-Young; Kim, Hyung-Min; Hong, Seung-Heon

    2008-10-01

    Using mouse peritoneal macrophages, we have examined the mechanism by which Leonurus sibiricus (LS) regulates nitric oxide (NO) production. When LS was used in combination with recombinant interferon-gamma (rIFN-gamma), there was a marked cooperative induction of NO production; however, LS by itself had no effect on NO production. The increased production of NO from rIFN-gamma plus LS-stimulated cells was almost completely inhibited by pretreatment with pyrrolidine dithiocarbamate (PDTC), an inhibitor of nuclear factor kappaB. Furthermore, treatment of peritoneal macrophages with rIFN-gamma plus LS caused a significant increase in tumor necrosis factor-alpha (TNF-alpha) production. PDTC also decreased the effect of LS on TNF-alpha production significantly. Because NO and TNF-alpha play an important role in immune function and host defense, LS treatment could modulate several aspects of host defense mechanisms as a result of stimulation of the inducible nitric oxide synthase.

  15. Cisplatin stimulates protein tyrosine phosphorylation in macrophages.

    PubMed

    Kumar, R; Shrivastava, A; Sodhi, A

    1995-03-01

    Cisplatin [cis-dichlorodiamine platinum (II)], a potent anti-tumor compound, stimulates immune responses by activating monocyte-macrophages and other cells of the immune system. The mechanism by which cisplatin activates these cells is poorly characterized. Since protein tyrosine phosphorylation appears to be a major intracellular signalling event that mediates cellular responses, we examined whether cisplatin alters tyrosine phosphorylation in macrophages. We found that cisplatin increased tyrosine phosphorylation of several proteins in peritoneal macrophages and in P388D1 and IC-21 macrophage cell lines. Treatment of macrophages with tyrosine kinase inhibitors, genestein and lavendustin A, inhibited cisplatin-stimulated protein tyrosine phosphorylation in macrophages. Macrophages treated with cisplatin also exhibit increased fluorescence with anti-phosphotyrosine-FITC antibody. These data indicate that protein tyrosine phosphorylation plays a role in cisplatin-induced activation of macrophages. PMID:7539662

  16. Phenotypic Transitions of Macrophages Orchestrate Tissue Repair

    PubMed Central

    Novak, Margaret L.; Koh, Timothy J.

    2014-01-01

    Macrophages are essential for the efficient healing of numerous tissues, and they contribute to impaired healing and fibrosis. Tissue repair proceeds through overlapping phases of inflammation, proliferation, and remodeling, and macrophages are present throughout this progression. Macrophages exhibit transitions in phenotype and function as tissue repair progresses, although the precise factors regulating these transitions remain poorly defined. In efficiently healing injuries, macrophages present during a given stage of repair appear to orchestrate transition into the next phase and, in turn, can promote debridement of the injury site, cell proliferation and angiogenesis, collagen deposition, and matrix remodeling. However, dysregulated macrophage function can contribute to failure to heal or fibrosis in several pathological situations. This review will address current knowledge of the origins and functions of macrophages during the progression of tissue repair, with emphasis on skin and skeletal muscle. Dysregulation of macrophages in disease states and therapies targeting macrophage activation to promote tissue repair are also discussed. PMID:24091222

  17. Macrophage-induced thymic lymphocyte maturation.

    PubMed Central

    Van den Tweel, J G; Walker, W S

    1977-01-01

    Guinea-pig peritoneal macrophages were found to influence the functional maturation of thymic lymphocytes. Autologous thymic lymphocytes obtained from macrophage co-cultures responded to three different mitogens and were reduced in their ability to reassociate spontaneously with macrophages. Neither of these properties were found in thymic lymphocytes that had not been cultured with macrophages. These functional changes appeared to be specific for macrophages since thymic lymphocytes incubated with skin fibroblasts failed to respond to the test mitogens. Furthermore, they were not the result of either the inactivation, by macrophages, of a putative suppressor thymocyte or a soluble macrophage product. In addition to influencing the functional maturation of thymic lymphocytes, macrophages also appeared to play a direct role in inducing the mitogen response of functionally mature cells. PMID:304037

  18. Isolation and culture of murine macrophages.

    PubMed

    Davies, John Q; Gordon, Siamon

    2005-01-01

    The two most convenient sources of primary murine macrophages are the bone marrow and the peritoneal cavity. Resident peritoneal macrophages can readily be harvested from mice and purified by adherence to tissue culture plastic. The injection of Bio-Gel polyacrylamide beads or thioglycollate broth into the peritoneal cavity produces an inflammatory response allowing the purification of large numbers of elicited macrophages. The production of an activated macrophage population can be achieved by using Bacillus-Calmette-Guerin as the inflammatory stimulus. Resident bone marrow macrophages can be isolated following enzymatic separation of cells from bone marrow plugs and enrichment on 30% fetal calf serum containing medium or Ficoll-Hypaque gradients. Bone marrow-derived macrophages can be produced by differentiating nonadherent macrophage precursors with medium containing macrophage colony-stimulating factor.

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

    PubMed Central

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

    2013-01-01

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

  20. Adolescent Suicide and Defensive Style.

    ERIC Educational Resources Information Center

    Recklitis, Christopher J.; And Others

    1992-01-01

    Examined relationship between ego defense mechanisms, diagnoses, and suicidality among 200 adolescent psychiatric patients classified as suicide attempters, suicidal ideators, and nonsuicidal patients. Using Defense Mechanisms Inventory, found the suicidal adolescents score higher on turning-against-self and lower on reversal, as compared to…

  1. Macrophages and HIV-1: An Unhealthy Constellation.

    PubMed

    Sattentau, Quentin J; Stevenson, Mario

    2016-03-01

    Lentiviruses have a long-documented association with macrophages. Abundant evidence exists for in vitro and, in a tissue-specific manner, in vivo infection of macrophages by the primate lentiviruses HIV-1 and SIV. However, macrophage contribution to aspects of HIV-1 and SIV pathogenesis, and their role in viral persistence in individuals on suppressive antiretroviral therapy, remains unclear. Here we discuss recent evidence implicating macrophages in HIV-1-mediated disease and highlight directions for further investigation.

  2. 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

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

    PubMed

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

    1994-08-01

    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. PMID:7913696

  4. Macrophage Heterogeneity and Plasticity: Impact of Macrophage Biomarkers on Atherosclerosis

    PubMed Central

    Rojas, Joselyn; Salazar, Juan; Martínez, María Sofía; Palmar, Jim; Bautista, Jordan; Chávez-Castillo, Mervin; Gómez, Alexis; Bermúdez, Valmore

    2015-01-01

    Cardiovascular disease (CVD) is a global epidemic, currently representing the worldwide leading cause of morbidity and mortality. Atherosclerosis is the fundamental pathophysiologic component of CVD, where the immune system plays an essential role. Monocytes and macrophages are key mediators in this aspect: due to their heterogeneity and plasticity, these cells may act as either pro- or anti-inflammatory mediators. Indeed, monocytes may develop heterogeneous functional phenotypes depending on the predominating pro- or anti-inflammatory microenvironment within the lesion, resulting in classic, intermediate, and non-classic monocytes, each with strikingly differing features. Similarly, macrophages may also adopt heterogeneous profiles being mainly M1 and M2, the former showing a proinflammatory profile while the latter demonstrates anti-inflammatory traits; they are further subdivided in several subtypes with more specialized functions. Furthermore, macrophages may display plasticity by dynamically shifting between phenotypes in response to specific signals. Each of these distinct cell profiles is associated with diverse biomarkers which may be exploited for therapeutic intervention, including IL-10, IL-13, PPAR-γ, LXR, NLRP3 inflammasomes, and microRNAs. Direct modulation of the molecular pathways concerning these potential macrophage-related targets represents a promising field for new therapeutic alternatives in atherosclerosis and CVD. PMID:26491604

  5. Investigation of macrophage polarization using bone marrow derived macrophages.

    PubMed

    Ying, Wei; Cheruku, Patali S; Bazer, Fuller W; Safe, Stephen H; Zhou, Beiyan

    2013-06-23

    The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic stem/progenitor cells from the bone marrow are directed into monocytic differentiation, followed by M1 or M2 stimulation. The activation status can be tracked by changes in cell surface antigens, gene expression and cell signaling pathways.

  6. Mouse macrophages are permissive to motile Legionella species that fail to trigger pyroptosis.

    PubMed

    Whitfield, Natalie N; Byrne, Brenda G; Swanson, Michele S

    2010-01-01

    Legionella pneumophila, a motile opportunistic pathogen of humans, is restricted from replicating in the lungs of C57BL/6 mice. Resistance of mouse macrophages to L. pneumophila depends on recognition of cytosolic flagellin. Once detected by the NOD-like receptors Naip5 and Ipaf (Nlrc4), flagellin triggers pyroptosis, a proinflammatory cell death. In contrast, motile strains of L. parisiensis and L. tucsonensis replicate profusely within C57BL/6 macrophages, similar to flagellin-deficient L. pneumophila. To gain insight into how motile species escape innate defense mechanisms of mice, we compared their impacts on macrophages. L. parisiensis and L. tucsonensis do not induce proinflammatory cell death, as measured by lactate dehydrogenase (LDH) release and interleukin-1beta (IL-1beta) secretion. However, flagellin isolated from L. parisiensis and L. tucsonensis triggers cell death and IL-1beta secretion when transfected into the cytosol of macrophages. Neither strain displays three characteristics of the canonical L. pneumophila Dot/Icm type IV secretion system: sodium sensitivity, LAMP-1 evasion, and pore formation. Therefore, we postulate that when L. parisiensis and L. tucsonensis invade a mouse macrophage, flagellin is confined to the phagosome, protecting the bacteria from recognition by the cytosolic surveillance system and allowing Legionella to replicate. Despite their superior capacity to multiply in mouse macrophages, L. parisiensis and L. tucsonensis have been associated with only two cases of disease, both in renal transplant patients. These results point to the complexity of disease, a product of the pathogenic potential of the microbe, as defined in the laboratory, and the capacity of the host to mount a measured defense.

  7. 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.

  8. Bacteria evade immune recognition via TLR13 and binding of their 23S rRNA by MLS antibiotics by the same mechanisms

    PubMed Central

    Hochrein, Hubertus; Kirschning, Carsten J.

    2013-01-01

    The immune system recognizes pathogens and other danger by means of pattern recognition receptors. Recently, we have demonstrated that the orphan Toll-like receptor 13 (TLR13) senses a defined sequence of the bacterial rRNA and that bacteria use specific mechanisms to evade macrolide lincosamide streptogramin (MLS) antibiotics detection via TLR13. PMID:23802068

  9. Survival of Mycobacterium avium and Mycobacterium tuberculosis in Acidified Vacuoles of Murine Macrophages

    PubMed Central

    Gomes, Maria Salomé; Paul, Simon; Moreira, Andre L.; Appelberg, Rui; Rabinovitch, Michel; Kaplan, Gilla

    1999-01-01

    Despite the antimicrobial mechanisms of vertebrate phagocytes, mycobacteria can survive within the phagosomes of these cells. These organisms use various strategies to evade destruction, including inhibition of acidification of the phagosome and inhibition of phagosome-lysosome fusion. In contrast to mycobacteria, Coxiella burnetii, the etiologic agent of Q fever, inhabits a spacious acidified intracellular vacuole which is prone to fusion with other vacuoles of the host cell, including phagosomes containing mycobacteria. The Coxiella-infected cell thus provides a unique model for investigating the survival of mycobacteria in an acidified phagosome-like compartment. In the present study, murine bone marrow-derived macrophages were infected with either Mycobacterium avium or Mycobacterium tuberculosis and then coinfected with C. burnetii. We observed that the majority of phagocytosed mycobacteria colocalized to the C. burnetii-containing vacuole, which maintained its acidic properties. In coinfected macrophages, the growth of M. avium was not impaired following fusion with the acidified vacuole. In contrast, the growth rate of M. tuberculosis was reduced in acidified vacuoles. These results suggest that although both species of mycobacteria inhibit phagosome-lysosome fusion, they may be differentially susceptible to the toxic effects of the acidic environment in the mature phagolysosome. PMID:10377091

  10. Direct measurement of oxidative and nitrosative stress dynamics in Salmonella inside macrophages

    PubMed Central

    van der Heijden, Joris; Bosman, Else S.; Reynolds, Lisa A.; Finlay, B. Brett

    2015-01-01

    Many significant bacterial pathogens have evolved virulence mechanisms to evade degradation and exposure to reactive oxygen (ROS) and reactive nitrogen species (RNS), allowing them to survive and replicate inside their hosts. Due to the highly reactive and short-lived nature of ROS and RNS, combined with limitations of conventional detection agents, the mechanisms underlying these evasion strategies remain poorly understood. In this study, we describe a system that uses redox-sensitive GFP to nondisruptively measure real-time fluctuations in the intrabacterial redox environment. Using this system coupled with high-throughput microscopy, we report the intrabacterial redox dynamics of Salmonella enterica Typhimurium (S. Typhimurium) residing inside macrophages. We found that the bacterial SPI-2 type III secretion system is required for ROS evasion strategies and this evasion relies on an intact Salmonella-containing vacuole (SCV) within which the bacteria reside during infection. Additionally, we found that cytosolic bacteria that escape the SCV experience increased redox stress in human and murine macrophages. These results highlight the existence of specialized evasion strategies used by intracellular pathogens that either reside inside a vacuole or “escape” into the cytosol. Taken together, the use of redox-sensitive GFP inside Salmonella significantly advances our understanding of ROS and RNS evasion strategies during infection. This technology can also be applied to measuring bacterial oxidative and nitrosative stress dynamics under different conditions in a wide variety of bacteria. PMID:25548165

  11. Macrophage biology and their activation by protozoan-derived glycosylphosphatidylinositol anchors and hemozoin.

    PubMed

    Aldridge, Jerry R; Vogel, Ian A

    2014-12-01

    Despite recent advances in medical technology and a global effort to improve public health and hygiene, parasitic infections remain a major health and economic burden worldwide. The World Health Organization estimates that about 1/3 of the world's population is currently infected with a soil-transmitted helminth, and millions more suffer from diseases caused by protozoan parasites including Plasmodium, Trypanosoma, and Leishmania species. Due to the selective pressure applied by parasitic and other infections, animals have evolved an intricate immune system; however, the current worldwide prevalence of parasitic infections clearly indicates that these pathogens have adapted equally well. Thus, developing a better understanding of the host-parasite relationship, particularly by focusing on the host immune response and the mechanisms by which parasites evade this response, is a critical first step in mitigating the detrimental effects of parasitic diseases. Macrophages are critical contributors during the host response to protozoan parasites, and the success or failure of these cells often tips the balance in favor of the host or parasite. Herein, we briefly discuss macrophage biology and provide an update on our current understanding of how these cells recognize glycosylphosphatidylinositol anchors from protozoan parasites as well as malarial hemozoin.

  12. Direct measurement of oxidative and nitrosative stress dynamics in Salmonella inside macrophages.

    PubMed

    van der Heijden, Joris; Bosman, Else S; Reynolds, Lisa A; Finlay, B Brett

    2015-01-13

    Many significant bacterial pathogens have evolved virulence mechanisms to evade degradation and exposure to reactive oxygen (ROS) and reactive nitrogen species (RNS), allowing them to survive and replicate inside their hosts. Due to the highly reactive and short-lived nature of ROS and RNS, combined with limitations of conventional detection agents, the mechanisms underlying these evasion strategies remain poorly understood. In this study, we describe a system that uses redox-sensitive GFP to nondisruptively measure real-time fluctuations in the intrabacterial redox environment. Using this system coupled with high-throughput microscopy, we report the intrabacterial redox dynamics of Salmonella enterica Typhimurium (S. Typhimurium) residing inside macrophages. We found that the bacterial SPI-2 type III secretion system is required for ROS evasion strategies and this evasion relies on an intact Salmonella-containing vacuole (SCV) within which the bacteria reside during infection. Additionally, we found that cytosolic bacteria that escape the SCV experience increased redox stress in human and murine macrophages. These results highlight the existence of specialized evasion strategies used by intracellular pathogens that either reside inside a vacuole or "escape" into the cytosol. Taken together, the use of redox-sensitive GFP inside Salmonella significantly advances our understanding of ROS and RNS evasion strategies during infection. This technology can also be applied to measuring bacterial oxidative and nitrosative stress dynamics under different conditions in a wide variety of bacteria.

  13. Changes in the proteomic profile during the differential polarization status of the human monocyte-derived macrophage THP-1 cell line.

    PubMed

    Zhang, Fan; Liu, Hao; Jiang, Guanmin; Wang, Hongsheng; Wang, Xianfeng; Wang, Hao; Fang, Rui; Cai, Shaohui; Du, Jun

    2015-02-01

    Macrophages are heterogeneous and plastic populations that are an essential component of inflammation and host defense. To understand how macrophages respond to cytokine signals, we used 2DE to identify protein profiles in macrophages stimulated with interleukin 4 (M2) and those stimulated with lipopolysaccharide and interferon γ (M1). In total, 32 differentially expressed proteins in THP-1 cells were identified by MALDI-TOF MS/MS analysis. The different proteins were mainly involved in cellular structure, protein metabolism, stress response, oxidative response, and nitric oxide production during macrophage polarization. In particular, proteins playing important roles in production of nitric oxide (NO) were downregulated in M2 macrophages. Many antioxidant and heat shock proteins, which are related to oxidative response, were upregulated in M2 macrophages. More importantly, a remarkable decrease in intracellular ROS and NO production were detected in M2 macrophages. Our results provide a proteomic profile of differentially polarized macrophages and validate the function of the identified proteins, which may indicate possible mechanism of macrophage polarization process.

  14. Modulating macrophage response to biomaterials

    NASA Astrophysics Data System (ADS)

    Zaveri, Toral

    Macrophages recruited to the site of biomaterial implantation are the primary mediators of the chronic foreign body response to implanted materials. Since foreign body response limits performance and functional life of numerous implanted biomaterials/medical devices, various approaches have been investigated to modulate macrophage interactions with biomaterial surfaces to mitigate this response. In this work we have explored two independent approaches to modulate the macrophage inflammatory response to biomaterials. The first approach targets surface integrins, cell surface receptors that mediate cell adhesion to biomaterials through adhesive proteins spontaneously adsorbed on biomaterial surfaces. The second approach involves surface modification of biomaterials using nanotopographic features since nanotopography has been reported to modulate cell adhesion and viability in a cell type-dependent manner. More specifically, Zinc Oxide (ZnO) nanorod surface was investigated for its role in modulating macrophage adhesion and survival in vitro and foreign body response in vivo. For the first approach, we have investigated the role of integrin Mac-1 and RGD-binding integrins in the in-vivo osteolysis response and macrophage inflammatory processes of phagocytosis as well as inflammatory cytokine secretion in response to particulate biomaterials. We have also investigated the in vivo foreign body response (FBR) to subcutaneously implanted biomaterials by evaluating the thickness of fibrous capsule formed around the implants after 2 weeks of implantation. The role of Mac-1 integrin was isolated using a Mac-1 KO mouse and comparing it to a WT control. The role of RGD binding integrins in FBR was investigated by coating the implanted biomaterial with ELVAX(TM) polymer loaded with Echistatin which contains the RGD sequence. For the in-vivo osteolysis study and to study the in-vitro macrophage response to particulate biomaterials, we used the RGD peptide encapsulated in ELVAX

  15. [Progresses on macrophages of male reproductive tract].

    PubMed

    Li, Jing-Jing; Wang, Tao; Wang, Geng-Xin

    2002-12-01

    The review summarized the recent progress on macrophages of male reproductive tract and the action of macrophages on male reproductive physiology and pathology. The close correlation and effect between testicular macrophages and Leydig cells, Sertoli cells, germ cells, hypothalamic-pituitary-gonadal axis were introduced, respectively. At the same time, it pointed out the changes of macrophages' morphology and function in immune orchitis, and their regulation on the development of orchitis. So the complex immune regulation network in testes and testicular macrophages playing an important role on spermatogenesis and the stableness of spermatogenetic microenvironment in testes were further illuminated, which can provide theoretical basis for clinic therapy.

  16. Contribution of Macrophage Polarization to Metabolic Diseases.

    PubMed

    Komohara, Yoshihiro; Fujiwara, Yukio; Ohnishi, Koji; Shiraishi, Daisuke; Takeya, Motohiro

    2016-01-01

    Macrophage activation is one of the major immunological events in the pathogenesis of various diseases. Recent studies have disclosed that complicated mechanisms are involved in macrophage activation and polarization, and many published research articles have been based on the M1/M2 polarization concept. It is considered that M1- and M2-like macrophages are associated with T helper (Th)1-type and Th2-type immune responses, respectively, via several immune mediators. In this article, we summarize the correlations between macrophage polarization and metabolic disorders in both humans and mice and discuss the contribution of macrophage polarization to the pathogenic process of metabolic diseases.

  17. Directed energy planetary defense

    NASA Astrophysics Data System (ADS)

    Lubin, Philip; Hughes, Gary B.; Bible, Johanna; Bublitz, Jesse; Arriola, Josh; Motta, Caio; Suen, Jon; Johansson, Isabella; Riley, Jordan; Sarvian, Nilou; Clayton-Warwick, Deborah; Wu, Jane; Milich, Andrew; Oleson, Mitch; Pryor, Mark; Krogen, Peter; Kangas, Miikka

    2013-09-01

    Asteroids and comets that cross Earth's orbit pose a credible risk of impact, with potentially severe disturbances to Earth and society. Numerous risk mitigation strategies have been described, most involving dedicated missions to a threatening object. We propose an orbital planetary defense system capable of heating the surface of potentially hazardous objects to the vaporization point as a feasible approach to impact risk mitigation. We call the system DE-STAR for Directed Energy System for Targeting of Asteroids and exploRation. DE-STAR is a modular phased array of kilowatt class lasers powered by photovoltaic's. Modular design allows for incremental development, test, and initial deployment, lowering cost, minimizing risk, and allowing for technological co-development, leading eventually to an orbiting structure that would be developed in stages with both technological and target milestones. The main objective of DE-STAR is to use the focused directed energy to raise the surface spot temperature to ~3,000K, allowing direct vaporization of all known substances. In the process of heating the surface ejecting evaporated material a large reaction force would alter the asteroid's orbit. The baseline system is a DE-STAR 3 or 4 (1-10km array) depending on the degree of protection desired. A DE-STAR 4 allows for asteroid engagement starting beyond 1AU with a spot temperature sufficient to completely evaporate up to 500-m diameter asteroids in one year. Small asteroids and comets can be diverted/evaporated with a DESTAR 2 (100m) while space debris is vaporized with a DE-STAR 1 (10m).

  18. Insanity defenses: contested or conceded?

    PubMed

    Rogers, J L; Bloom, J D; Manson, S M

    1984-07-01

    The authors examined 316 Oregon criminal cases in which the accused successfully pleaded the insanity defense. Prosecutors agreed to the insanity verdict in more than four out of five cases. In most cases all examining experts diagnosed the defendant as psychotic. The smaller number of defendants who were diagnosed by the state hospital staff as displaying only personality disorders accounted for a disproportionately large percentage of the contested trials. Observing that Oregon's insanity defense system is run by consensus, the authors suggest a reorientation of the insanity defense debate.

  19. Macrophage Polarization during Murine Lyme Borreliosis.

    PubMed

    Lasky, Carrie E; Olson, Rachel M; Brown, Charles R

    2015-07-01

    Infection of C3H mice with Borrelia burgdorferi, the causative agent of Lyme disease, reliably produces an infectious arthritis and carditis that peak around 3 weeks postinfection and then spontaneously resolve. Macrophage polarization has been suggested to drive inflammation, the clearance of bacteria, and tissue repair and resolution in a variety of infectious disease models. During Lyme disease it is clear that macrophages are capable of clearing Borrelia spirochetes and exhausted neutrophils; however, the role of macrophage phenotype in disease development or resolution has not been studied. Using classical (NOS2) and alternative (CD206) macrophage subset-specific markers, we determined the phenotype of F4/80(+) macrophages within the joints and heart throughout the infection time course. Within the joint, CD206(+) macrophages dominated throughout the course of infection, and NOS2(+) macrophage numbers became elevated only during the peak of inflammation. We also found dual NOS2(+) CD206(+) macrophages which increased during resolution. In contrast to findings for the ankle joints, numbers of NOS2(+) and CD206(+) macrophages in the heart were similar at the peak of inflammation. 5-Lipoxygenase-deficient (5-LOX(-/-)) mice, which display a failure of Lyme arthritis resolution, recruited fewer F4/80(+) cells to the infected joints and heart, but macrophage subset populations were unchanged. These results highlight differences in the inflammatory infiltrates during Lyme arthritis and carditis and demonstrate the coexistence of multiple macrophage subsets within a single inflammatory site.

  20. Identification of polarized macrophage subsets in zebrafish

    PubMed Central

    Nguyen-Chi, Mai; Laplace-Builhe, Béryl; Travnickova, Jana; Luz-Crawford, Patricia; Tejedor, Gautier; Phan, Quang Tien; Duroux-Richard, Isabelle; Levraud, Jean-Pierre; Kissa, Karima; Lutfalla, Georges

    2015-01-01

    While the mammalian macrophage phenotypes have been intensively studied in vitro, the dynamic of their phenotypic polarization has never been investigated in live vertebrates. We used the zebrafish as a live model to identify and trail macrophage subtypes. We generated a transgenic line whose macrophages expressing tumour necrosis factor alpha (tnfa), a key feature of classically activated (M1) macrophages, express fluorescent proteins Tg(mpeg1:mCherryF/tnfa:eGFP-F). Using 4D-confocal microscopy, we showed that both aseptic wounding and Escherichia coli inoculation triggered macrophage recruitment, some of which started to express tnfa. RT-qPCR on Fluorescence Activated Cell Sorting (FACS)-sorted tnfa+ and tnfa− macrophages showed that they, respectively, expressed M1 and alternatively activated (M2) mammalian markers. Fate tracing of tnfa+ macrophages during the time-course of inflammation demonstrated that pro-inflammatory macrophages converted into M2-like phenotype during the resolution step. Our results reveal the diversity and plasticity of zebrafish macrophage subsets and underline the similarities with mammalian macrophages proposing a new system to study macrophage functional dynamic. DOI: http://dx.doi.org/10.7554/eLife.07288.001 PMID:26154973

  1. 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

  2. Tissue-Resident Macrophage Ontogeny and Homeostasis.

    PubMed

    Ginhoux, Florent; Guilliams, Martin

    2016-03-15

    Defining the origins and developmental pathways of tissue-resident macrophages should help refine our understanding of the role of these cells in various disease settings and enable the design of novel macrophage-targeted therapies. In recent years the long-held belief that macrophage populations in the adult are continuously replenished by monocytes from the bone marrow (BM) has been overturned with the advent of new techniques to dissect cellular ontogeny. The new paradigm suggests that several tissue-resident macrophage populations are seeded during waves of embryonic hematopoiesis and self-maintain independently of BM contribution during adulthood. However, the exact nature of the embryonic progenitors that give rise to adult tissue-resident macrophages is still debated, and the mechanisms enabling macrophage population maintenance in the adult are undefined. Here, we review the emergence of these concepts and discuss current controversies and future directions in macrophage biology. PMID:26982352

  3. Macrophages in Tissue Repair, Regeneration, and Fibrosis.

    PubMed

    Wynn, Thomas A; Vannella, Kevin M

    2016-03-15

    Inflammatory monocytes and tissue-resident macrophages are key regulators of tissue repair, regeneration, and fibrosis. After tissue injury, monocytes and macrophages undergo marked phenotypic and functional changes to play critical roles during the initiation, maintenance, and resolution phases of tissue repair. Disturbances in macrophage function can lead to aberrant repair, such that uncontrolled production of inflammatory mediators and growth factors, deficient generation of anti-inflammatory macrophages, or failed communication between macrophages and epithelial cells, endothelial cells, fibroblasts, and stem or tissue progenitor cells all contribute to a state of persistent injury, and this could lead to the development of pathological fibrosis. In this review, we discuss the mechanisms that instruct macrophages to adopt pro-inflammatory, pro-wound-healing, pro-fibrotic, anti-inflammatory, anti-fibrotic, pro-resolving, and tissue-regenerating phenotypes after injury, and we highlight how some of these mechanisms and macrophage activation states could be exploited therapeutically.

  4. Host defenses trigger salmonella's arsenal.

    PubMed

    Keestra, A Marijke; Bäumler, Andreas J

    2011-03-17

    Salmonella survives in macrophages by using a molecular syringe to deliver proteins into the host-cell cytosol where they manipulate phagocyte physiology. Arpaia and colleagues (Arpaia et al., 2011) show that deployment of this virulence factor is triggered by the very responses that are intended to confer host resistance. PMID:21402352

  5. TLR-mediated secretion of endoplasmic reticulum aminopeptidase 1 from macrophages.

    PubMed

    Goto, Yoshikuni; Ogawa, Kenji; Nakamura, Takahiro J; Hattori, Akira; Tsujimoto, Masafumi

    2014-05-01

    Macrophages play an important role in host defense under several immunological, inflammatory, and/or infectious conditions. In our previous work, we demonstrated that endoplasmic reticulum aminopeptidase 1 (ERAP1) was secreted from macrophages in response to LPS and IFN-γ, and it enhanced their phagocytic activity. In this study, we analyzed the mechanism of LPS/IFN-γ-induced ERAP1 secretion. LPS/IFN-γ-induced secretion of the enzyme from the murine macrophage cell line RAW264.7 was suppressed by polymyxin B. Several agonists of TLRs, such as Pam3CSK4, FSL-1, and ODN1826, induced its secretion. In contrast, neutralizing Abs to IFN-β and TNF-α receptor type 1 suppressed its secretion. Using murine peritoneal macrophages derived from TNF-α and type 1 IFNR knockout mice, we confirmed the involvement of these two cytokines in ERAP1 secretion. In addition, secretion of ERAP1 from both RAW264.7 cells and murine peritoneal macrophages was induced by A23187 and thapsigargin and inhibited by BAPTA-AM and the calmodulin inhibitor W7. These results suggest that LPS/IFN-γ-induced secretion of ERAP1 is mediated by TLRs via induction of intermediate cytokines such as IFN-β and TNF-α, which in turn lead to enhanced cytosolic Ca(2+) levels and calmodulin activation.

  6. Strategic Defense Initiative - an overview

    SciTech Connect

    Abrahamson, J.A.

    1985-01-01

    A general framework for developing the concept and implementing options for strategic ballistic missile defense systems is emerging. The objective of the Strategic Defense Initiative (SDI) program is to conduct research on those technologies for defensive system which could intercept ballistic missiles after they have been launched and prevent them from hitting their targets. Its goal is to acquire the technical knowledge as a basis for a later decision on deployment, not a program for deployment or star wars. Abrahamson reviews the basic technological questions facing researchers, outlines the multi-layered defense possibilities and summarizes the status of technology to date. He argues for a continuity of resources to conduct the program. 4 figures.

  7. Defenseive Structuring and Environmental Stress

    ERIC Educational Resources Information Center

    Siegel, Bernard J.

    1970-01-01

    This essay explores a kind of adaptation, referred to as defenseive structuring, that recurs with great regularity among groups that perceive themselves as exposed to environmental stress of long duration with which they cannot cope directly and aggressively." (Author)

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

    PubMed

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

    2015-08-01

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

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

    PubMed Central

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

    2015-01-01

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

  10. Heme Oxygenase-1 Dysregulates Macrophage Polarization and the Immune Response to Helicobacter pylori

    PubMed Central

    Gobert, Alain P.; Verriere, Thomas; Asim, Mohammad; Barry, Daniel P.; Piazuelo, M. Blanca; de Sablet, Thibaut; Delgado, Alberto G.; Bravo, Luis E.; Correa, Pelayo; Peek, Richard M.; Chaturvedi, Rupesh; Wilson, Keith T.

    2014-01-01

    Helicobacter pylori incites a futile inflammatory response, which is the key feature of its immunopathogenesis. This leads to the ability of this bacterial pathogen to survive in the stomach and cause peptic ulcers and gastric cancer. Myeloid cells recruited to the gastric mucosa during Helicobacter pylori infection have been directly implicated in the modulation of host defense against the bacterium and gastric inflammation. Heme oxygenase-1 (HO-1) is an inducible enzyme that exhibits anti-inflammatory functions. Our aim was to analyze the induction and role of HO-1 in macrophages during H. pylori infection. We now show that phosphorylation of the H. pylori virulence factor cytotoxin associated gene A (CagA) in macrophages results in expression of hmox-1, the gene encoding HO-1, through p38/nuclear factor (erythroid-derived 2)-like 2 signaling. Blocking phagocytosis prevented CagA phosphorylation and HO-1 induction. The expression of HO-1 was also increased in gastric mononuclear cells of human patients and macrophages of mice infected with cagA+ H. pylori strains. Genetic ablation of hmox-1 in H. pylori-infected mice increased histologic gastritis, which was associated with enhanced M1/Th1/Th17 responses, decreased Mreg response, and reduced H. pylori colonization. Gastric macrophages of H. pylori-infected mice and macrophages infected in vitro with this bacterium showed an M1/Mreg mixed polarization type; deletion of hmox-1 or inhibition of HO-1 in macrophages caused an increased M1 and a decreased of Mreg phenotype. These data highlight a mechanism by which H. pylori impairs the immune response and favors its own survival via activation of macrophage HO-1. PMID:25108023

  11. Interferon-γ promotes phagocytosis of Cryptococcus neoformans but not Cryptococcus gattii by murine macrophages.

    PubMed

    Ikeda-Dantsuji, Yurika; Ohno, Hideaki; Tanabe, Koichi; Umeyama, Takashi; Ueno, Keigo; Nagi, Minoru; Yamagoe, Satoshi; Kinjo, Yuki; Miyazaki, Yoshitsugu

    2015-12-01

    Among invasive fungal infections, cryptococcosis caused by inhalation of Cryptococcus neoformans or Cryptococcus gattii is particularly dangerous because it can disseminate to the central nervous system and cause life-threatening meningitis or meningoencephalitis. Previous reports described significant differences in the histopathological features of C. neoformans and C. gattii infection, such as greater pathogen proliferation and a limited macrophage response in mouse lung infected by C. gattii. To elucidate the difference in pathogenicity of these two Cryptococcus species, we investigated the interaction of C. neoformans and C. gattii with murine macrophages, the first line of host defense, by confocal laser microscopy. Only thin-capsulated, and not thick-capsulated C. neoformans and C. gattii were phagocytosed by macrophages. Preactivation with interferon-γ increased the phagocytic rate of thin-capsulated C. neoformans up to two-fold, but did not promote phagocytosis of thin-capsulated C. gattii. Lipopolysaccharide preactivation or Aspergillus fumigatus conidia co-incubation had no effect on internalization of thin-capsulated C. neoformans or C. gattii by macrophages. Phagocytosis of live thin-capsulated C. neoformans, but not that of live thin-capsulated C. gattii, induced interleukin-12 release from macrophages. However, phagocytosis of heat-killed or paraformaldehyde-fixed thin-capsulated C. neoformans did not increase IL-12 release, showing that the internalization of live yeast is important for initiating the immune response during C. neoformans-macrophage interactions. Our data suggest that macrophage response to C. gattii is limited compared with that to C. neoformans and that these results may partially explain the limited immune response and the greater pathogenicity of C. gattii.

  12. Adverse effects of wood smoke PM2.5 exposure on macrophage functions

    PubMed Central

    Migliaccio, Christopher T.; Kobos, Emily; King, Quinton O.; Porter, Virginia; Jessop, Forrest; Ward, Tony

    2016-01-01

    Epidemiological studies have shown a correlation between chronic biomass smoke exposure and increased respiratory infection. Pulmonary macrophages are instrumental in both the innate and the adaptive immune responses to respiratory infection. In the present study, in vitro systems were utilized where alveolar macrophages (AM) and bone marrow-derived macrophages (BMdM) were exposed to concentrated wood smoke-derived particulate matter (WS-PM) and mice were exposed in vivo to either concentrated WS-PM or inhaled WS. In vivo studies demonstrated that WS-exposed mice inoculated with Streptococcus pneumoniae had a higher bacterial load 24 h post-exposure, and corresponding AM were found to have decreased lymphocyte activation activity. Additionally, while classic markers of inflammation (cellular infiltration, total protein, neutrophils) were not affected, there were changes in pulmonary macrophages populations, including significant decreases in macrophages expressing markers of activation in WS-exposed mice. The lymphocyte activation activity of WS-PM-exposed AM was significantly suppressed, but the phagocytic activity appeared unchanged. In an effort to determine a pathway for WS-induced suppression, RelB activation, assessed by nuclear translocation, was observed in AM exposed to either inhaled WS or instilled WS-PM. Finally, an analysis of WS-PM fractions determined the presence of 4–5 polycyclic aromatic hydrocarbons (PAHs), and preliminary work suggests a potential role for these PAHs to alter macrophage functions. These studies show a decreased ability of WS-exposed pulmonary macrophages to effectively mount a defense against infection, the effect lasts at least a week post-exposure, and appears to be mediated via RelB activation. PMID:23363038

  13. The insanity defense on trial.

    PubMed

    Stone, A A

    1982-08-01

    What was once a great romance between law and psychiatry has ended in disenchantment on both sides. Legal rulings during the 1950s intended to increase the psychiatric presence in the courtroom have been repudiated, and there is now a mood to abolish the traditional insanity defense. Abolitionists charge that the insanity defense has been successfully employed by large numbers of dangerous criminals to avoid punishment, that psychiatrists are dishonest because they serve as expert witnesses for both sides, and that the existence of the defense is evidence of a permissive society that coddles violent criminals. Each of these charges is rebutted by the author, who contends that until recently the insanity defense was a profound hypocrisy: the courts found the defendants not guilty by reason of insanity and then relied on psychiatry to confine them for the rest of their lives. But legal reforms and changes in psychiatric practice during the past 20 years have made it more difficult to confine such persons, and thus the insanity defense has real meaning for the first time. The author believes that despite the loss of protection to society, there are important legal and moral barriers to abolishing the insanity defense.

  14. Strategic defense initiative: critical issues

    SciTech Connect

    Nuckolls, J.H.

    1985-06-01

    The objectives of the Strategic Defense Initiative (SDI) as outlined by President Reagan are discussed. The principal objective for SDI is as a defense against ballistic missiles. Soviet objections and a summary of US-USSR dialogue on the subject are reviewed. Most US studies have been critical of SDI. Four critical issues are addressed in depth: are defense weapons technologically feasible which have high economic leverage relative to offensive ballistic missiles; would the defense feasibility and leverage be degraded or enhanced in the technological race between weapons innovation and countermeasures; could stability be achieved during and after the transition to the defense dominated world envisioned by SDI proponents; would the deployment of high leverage defensive weapons increase or decrease the security of NATO Europe, and the probability of major conventional or nuclear wars. The issue of SDI may lead to a paradox that contains the seeds of catastrophe. The author concludes by warning that nuclear disarmament may eliminate the highly successful deterrent mechanism for avoiding another major world war. In a world made safe for major conventional wars by the apparent ''elimination'' of nuclear weapons, the leaders in a conventional World War III - involving unimaginable suffering, hatred, terror, and death - would be strongly motivated to introduce nuclear weapons in the crucial decisive battles. Even if diplomacy could ''eliminate'' nuclear weapons, man's knowledge of nuclear weapons can never be eliminated. The paradox is the attempt to eliminate nuclear weapons may maximize the probability of their use. (DMC)

  15. Fusion between Intestinal epithelial cells and macrophages in a cancer context results in nuclear reprogramming.

    PubMed

    Powell, Anne E; Anderson, Eric C; Davies, Paige S; Silk, Alain D; Pelz, Carl; Impey, Soren; Wong, Melissa H

    2011-02-15

    The most deadly phase in cancer progression is attributed to the inappropriate acquisition of molecular machinery leading to metastatic transformation and spread of disease to distant organs. Although it is appreciated that metastasis involves epithelial-mesenchymal interplay, the underlying mechanism defining this process is poorly understood. Specifically, how cancer cells evade immune surveillance and gain the ability to navigate the circulatory system remains a focus. One possible mechanism underlying metastatic conversion is fusion between blood-derived immune cells and cancer cells. While this notion is a century old, in vivo evidence that cell fusion occurs within tumors and imparts genetic or physiologic changes remains controversial. We have previously demonstrated in vivo cell fusion between blood cells and intestinal epithelial cells in an injury setting. Here, we hypothesize that immune cells, such as macrophages, fuse with tumor cells imparting metastatic capabilities by transferring their cellular identity. We used parabiosis to introduce fluorescent-labeled bone marrow-derived cells to mice with intestinal tumors, finding that fusion between circulating blood-derived cells and tumor epithelium occurs during the natural course of tumorigenesis. Moreover, we identify the macrophage as a key cellular partner for this process. Interestingly, cell fusion hybrids retain a transcriptome identity characteristic of both parental derivatives, while also expressing a unique subset of transcripts. Our data supports the novel possibility that tumorigenic cell fusion may impart physical behavior attributed to migratory macrophages, including navigation of circulation and immune evasion. As such, cell fusion may represent a promising novel mechanism underlying the metastatic conversion of cancer cells.

  16. Mnn10 Maintains Pathogenicity in Candida albicans by Extending α-1,6-Mannose Backbone to Evade Host Dectin-1 Mediated Antifungal Immunity.

    PubMed

    Zhang, Shi Qun; Zou, Zui; Shen, Hui; Shen, Shuai Shuai; Miao, Qi; Huang, Xin; Liu, Wei; Li, Li Ping; Chen, Si Min; Yan, Lan; Zhang, Jun Dong; Zhao, Jing Jun; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

    2016-05-01

    The cell wall is a dynamic structure that is important for the pathogenicity of Candida albicans. Mannan, which is located in the outermost layer of the cell wall, has been shown to contribute to the pathogenesis of C. albicans, however, the molecular mechanism by which this occurs remains unclear. Here we identified a novel α-1,6-mannosyltransferase encoded by MNN10 in C. albicans. We found that Mnn10 is required for cell wall α-1,6-mannose backbone biosynthesis and polysaccharides organization. Deletion of MNN10 resulted in significant attenuation of the pathogenesis of C. albicans in a murine systemic candidiasis model. Inhibition of α-1,6-mannose backbone extension did not, however, impact the invasive ability of C. albicans in vitro. Notably, mnn10 mutant restored the invasive capacity in athymic nude mice, which further supports the notion of an enhanced host antifungal defense related to this backbone change. Mnn10 mutant induced enhanced Th1 and Th17 cell mediated antifungal immunity, and resulted in enhanced recruitment of neutrophils and monocytes for pathogen clearance in vivo. We also demonstrated that MNN10 could unmask the surface β-(1,3)-glucan, a crucial pathogen-associated molecular pattern (PAMP) of C. albicans recognized by host Dectin-1. Our results demonstrate that mnn10 mutant could stimulate an enhanced Dectin-1 dependent immune response of macrophages in vitro, including the activation of nuclear factor-κB, mitogen-activated protein kinase pathways, and secretion of specific cytokines such as TNF-α, IL-6, IL-1β and IL-12p40. In summary, our study indicated that α-1,6-mannose backbone is critical for the pathogenesis of C. albicans via shielding β-glucan from recognition by host Dectin-1 mediated immune recognition. Moreover, our work suggests that inhibition of α-1,6-mannose extension by Mnn10 may represent a novel modality to reduce the pathogenicity of C. albicans. PMID:27144456

  17. Mnn10 Maintains Pathogenicity in Candida albicans by Extending α-1,6-Mannose Backbone to Evade Host Dectin-1 Mediated Antifungal Immunity

    PubMed Central

    Zhang, Shi Qun; Zou, Zui; Shen, Hui; Shen, Shuai Shuai; Miao, Qi; Huang, Xin; Liu, Wei; Li, Li Ping; Chen, Si Min; Yan, Lan; Zhang, Jun Dong; Zhao, Jing Jun; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

    2016-01-01

    The cell wall is a dynamic structure that is important for the pathogenicity of Candida albicans. Mannan, which is located in the outermost layer of the cell wall, has been shown to contribute to the pathogenesis of C. albicans, however, the molecular mechanism by which this occurs remains unclear. Here we identified a novel α-1,6-mannosyltransferase encoded by MNN10 in C. albicans. We found that Mnn10 is required for cell wall α-1,6-mannose backbone biosynthesis and polysaccharides organization. Deletion of MNN10 resulted in significant attenuation of the pathogenesis of C. albicans in a murine systemic candidiasis model. Inhibition of α-1,6-mannose backbone extension did not, however, impact the invasive ability of C. albicans in vitro. Notably, mnn10 mutant restored the invasive capacity in athymic nude mice, which further supports the notion of an enhanced host antifungal defense related to this backbone change. Mnn10 mutant induced enhanced Th1 and Th17 cell mediated antifungal immunity, and resulted in enhanced recruitment of neutrophils and monocytes for pathogen clearance in vivo. We also demonstrated that MNN10 could unmask the surface β-(1,3)-glucan, a crucial pathogen-associated molecular pattern (PAMP) of C. albicans recognized by host Dectin-1. Our results demonstrate that mnn10 mutant could stimulate an enhanced Dectin-1 dependent immune response of macrophages in vitro, including the activation of nuclear factor-κB, mitogen-activated protein kinase pathways, and secretion of specific cytokines such as TNF-α, IL-6, IL-1β and IL-12p40. In summary, our study indicated that α-1,6-mannose backbone is critical for the pathogenesis of C. albicans via shielding β-glucan from recognition by host Dectin-1 mediated immune recognition. Moreover, our work suggests that inhibition of α-1,6-mannose extension by Mnn10 may represent a novel modality to reduce the pathogenicity of C. albicans. PMID:27144456

  18. β-Glucans inhibit intracellular growth of Mycobacterium bovis BCG but not virulent Mycobacterium tuberculosis in human macrophages.

    PubMed

    Betz, Bret E; Azad, Abul K; Morris, Jessica D; Rajaram, Murugesan V S; Schlesinger, Larry S

    2011-10-01

    The yeast polysaccharide, β-glucan, has been shown to promote both anti-microbial and anti-tumor activities through its interaction with macrophages. Here we analyzed the effects of an insoluble whole glucan particle (WGP), a 1,3/1,6-β-glucan from Saccharomyces cerevisiae, and a soluble poly-1-6-β-d-glucopyranosyl-1-3-β-d-glucopyranose (PGG), a hydrolytic product of WGP, on the anti-microbial response of human macrophages against mycobacterial infection. Treatment of macrophages with WGP and PGG significantly decreased cell association and intracellular growth of Mycobacterium bovis BCG, but not Mycobacterium tuberculosis (M.tb) when compared to untreated controls. We characterized the influence of β-glucans on the generation of macrophage oxidative products and pro-inflammatory cytokines, two important anti-microbial defense mechanisms. WGP but not PGG treatment enhanced the oxidative response of macrophages as determined by the 2',7'-dichlorofluorescin (DCF) assay. WGP treatment also induced macrophages to produce pro-inflammatory cytokines. The β-glucan receptor, Dectin-1, was found to be involved in the WGP-induced macrophage oxidative burst and intracellular growth inhibition of M. bovis BCG. This report indicates that although some forms of β-glucan are able to stimulate the respiratory burst and cytokine production in human macrophages, and exhibit anti-microbial properties against M. bovis BCG, the β-glucans tested here did not inhibit growth of M.tb within human macrophages.

  19. Hepatitis C virus strategies to evade the specific-T cell response: a possible mission favoring its persistence.

    PubMed

    Quarleri, Jorge Fabián; Oubiña, José Raúl

    2016-01-01

    Hepatitis C virus (HCV) is a small, enveloped RNA virus. The number of HCV-infected individuals worldwide is estimated to be approximately 200 million. The vast majority of HCV infections persist, with up to 80% of all cases leading to chronic hepatitis associated with liver fibrosis, cirrhosis, and hepatocellular carcinoma. The interaction between HCV and the host have a pivotal role in viral fitness, persistence, pathogenicity, and disease progression. The control of HCV infection requires both effective innate and adaptive immune responses. The HCV clearance during acute infection is associated with an early induction of the innate and a delayed initiation of the adaptive immune responses. However, in the vast majority of acute HCV infections, these responses are overcome and the virus persistence almost inexorably occurs. Recently, several host- and virus-related mechanisms responsible for the failure of both the innate and the adaptive immune responses have been recognized. Among the latter, the wide range of escape mutations to evade the specific-T-and B-cell responses as well as the T cell anergy and the CD8+ T cell exhaustion together with the interference with its function after prolonged virus exposure hold a pivotal role. Other HCV strategies include the modification or manipulation of molecules playing key roles in the induction of the interferon response and its induced effector proteins. In this review, we attempt to gain insights on the main T cell immune evasion strategies used by the virus in order to favor its persistence. PMID:26626636

  20. The West Nile virus assembly process evades the conserved antiviral mechanism of the interferon-induced MxA protein.

    PubMed

    Hoenen, Antje; Gillespie, Leah; Morgan, Garry; van der Heide, Peter; Khromykh, Alexander; Mackenzie, Jason

    2014-01-01

    Flaviviruses have evolved means to evade host innate immune responses. Recent evidence suggests this is due to prevention of interferon production and signaling in flavivirus-infected cells. Here we show that the interferon-induced MxA protein can sequester the West Nile virus strain Kunjin virus (WNVKUN) capsid protein in cytoplasmic tubular structures in an expression-replication system. This sequestering resulted in reduced titers of secreted WNVKUN particles. We show by electron microscopy, tomography and 3D modeling that these cytoplasmic tubular structures form organized bundles. Additionally we show that recombinant ER-targeted MxA can restrict production of infectious WNVKUN under conditions of virus infection. Our results indicate a co-ordinated and compartmentalized WNVKUN assembly process may prevent recognition of viral components by MxA, particularly the capsid protein. This recognition can be exploited if MxA is targeted to intracellular sites of WNVKUN assembly. This results in further understanding of the mechanisms of flavivirus evasion from the immune system.

  1. How much of the world’s land has been urbanized, really? A hierarchical framework for evading confusion

    SciTech Connect

    Liu, zhifeng; He, Chunyang; Zhou, Yuyu; Wu, jianguo

    2014-05-01

    Urbanization has transformed the world’s landscapes, resulting in a series of ecological and environmental problems. To assess urbanization impacts and improve sustainability, one of the first questions that we must address is: how much of the world’s land has been urbanized? Unfortunately, the estimates of the global urban land reported in the literature vary widely from less than 1% to 3% primarily because different definitions of urban land were used. To evade confusion, here we propose a hierarchical framework for representing and communicating the spatial extent of the world’s urbanized land at the global, regional, and more local levels. The hierarchical framework consists of three spatially nested definitions: “urban area” that is delineated by administrative boundaries, “built-up area” that is dominated by artificial surfaces, and “impervious surface area” that is devoid of life. These are really three different measures of urbanization. In 2010, the global urban land was close to 3%, the global built-up area was 0.65%, and the global impervious surface area was 0.45%, of the word’s total land area (excluding Antarctica and Greenland). We argue that this hierarchy of urban land measures, in particular the ratios between them, can also facilitate better understanding the biophysical and socioeconomic processes and impacts of urbanization.

  2. Escape and evade control policies for ensuring the physical security of nonholonomic, ground-based, unattended mobile sensor nodes

    NASA Astrophysics Data System (ADS)

    Mascarenas, David; Stull, Christopher; Farrar, Charles

    2011-06-01

    In order to realize the wide-scale deployment of high-endurance, unattended mobile sensing technologies, it is vital to ensure the self-preservation of the sensing assets. Deployed mobile sensor nodes face a variety of physical security threats including theft, vandalism and physical damage. Unattended mobile sensor nodes must be able to respond to these threats with control policies that facilitate escape and evasion to a low-risk state. In this work the Precision Immobilization Technique (PIT) problem has been considered. The PIT maneuver is a technique that a pursuing, car-like vehicle can use to force a fleeing vehicle to abruptly turn ninety degrees to the direction of travel. The abrupt change in direction generally causes the fleeing driver to lose control and stop. The PIT maneuver was originally developed by law enforcement to end vehicular pursuits in a manner that minimizes damage to the persons and property involved. It is easy to imagine that unattended autonomous convoys could be targets of this type of action by adversarial agents. This effort focused on developing control policies unattended mobile sensor nodes could employ to escape, evade and recover from PIT-maneuver-like attacks. The development of these control policies involved both simulation as well as small-scale experimental testing. The goal of this work is to be a step toward ensuring the physical security of unattended sensor node assets.

  3. The West Nile virus assembly process evades the conserved antiviral mechanism of the interferon-induced MxA protein

    SciTech Connect

    Hoenen, Antje; Gillespie, Leah; Morgan, Garry; Heide, Peter van der; Khromykh, Alexander; Mackenzie, Jason

    2014-01-05

    Flaviviruses have evolved means to evade host innate immune responses. Recent evidence suggests this is due to prevention of interferon production and signaling in flavivirus-infected cells. Here we show that the interferon-induced MxA protein can sequester the West Nile virus strain Kunjin virus (WNV{sub KUN}) capsid protein in cytoplasmic tubular structures in an expression-replication system. This sequestering resulted in reduced titers of secreted WNV{sub KUN} particles. We show by electron microscopy, tomography and 3D modeling that these cytoplasmic tubular structures form organized bundles. Additionally we show that recombinant ER-targeted MxA can restrict production of infectious WNV{sub KUN} under conditions of virus infection. Our results indicate a co-ordinated and compartmentalized WNV{sub KUN} assembly process may prevent recognition of viral components by MxA, particularly the capsid protein. This recognition can be exploited if MxA is targeted to intracellular sites of WNV{sub KUN} assembly. This results in further understanding of the mechanisms of flavivirus evasion from the immune system. - Highlights: • We show that the ISG MxA can recognize the West Nile virus capsid protein. • Interaction between WNV C protein and MxA induces cytoplasmic fibrils. • MxA can be retargeted to the ER to restrict WNV particle release. • WNV assembly process is a strategy to avoid MxA recognition.

  4. The globally disseminated M1T1 clone of Group A Streptococcus evades autophagy for intracellular replication

    PubMed Central

    Barnett, Timothy C.; Liebl, David; Seymour, Lisa M.; Gillen, Christine M.; Lim, Jin Yan; LaRock, Christopher N.; Davies, Mark R.; Schulz, Benjamin L.; Nizet, Victor; Teasdale, Rohan D.; Walker, Mark J.

    2014-01-01

    SUMMARY Autophagy is reported to be an important innate immune defence against the intracellular bacterial pathogen Group A Streptococcus (GAS). However, the GAS strains examined to-date belong to serotypes infrequently associated with human disease. We find that the globally disseminated serotype M1T1 clone of GAS can evade autophagy and replicate efficiently in the cytosol of infected cells. Cytosolic M1T1 GAS (strain 5448), but not M6 GAS (strain JRS4), avoids ubiquitylation and recognition by the host autophagy marker LC3 and ubiquitin-LC3 adaptor proteins NDP52, p62 and NBR1. Expression of SpeB, a streptococcal cysteine protease, is critical for this process, as an isogenic M1T1 ΔspeB mutant is targeted to autophagy and attenuated for intracellular replication. SpeB degrades p62, NDP52 and NBR1 in vitro and within the host cell cytosol. These results uncover a proteolytic mechanism utilized by GAS to escape the host autophagy pathway which may underpin the success of the M1T1 clone. PMID:24331465

  5. Pasteurella pneumotropica Evades the Human Complement System by Acquisition of the Complement Regulators Factor H and C4BP

    PubMed Central

    Sahagún-Ruiz, Alfredo; Granados Martinez, Adriana Patricia; Breda, Leandro Carvalho Dantas; Fraga, Tatiana Rodrigues; Castiblanco Valencia, Mónica Marcela; Barbosa, Angela Silva; Isaac, Lourdes

    2014-01-01

    Pasteurella pneumotropica is an opportunist Gram negative bacterium responsible for rodent pasteurellosis that affects upper respiratory, reproductive and digestive tracts of mammals. In animal care facilities the presence of P. pneumotropica causes severe to lethal infection in immunodeficient mice, being also a potential source for human contamination. Indeed, occupational exposure is one of the main causes of human infection by P. pneumotropica. The clinical presentation of the disease includes subcutaneous abscesses, respiratory tract colonization and systemic infections. Given the ability of P. pneumotropica to fully disseminate in the organism, it is quite relevant to study the role of the complement system to control the infection as well as the possible evasion mechanisms involved in bacterial survival. Here, we show for the first time that P. pneumotropica is able to survive the bactericidal activity of the human complement system. We observed that host regulatory complement C4BP and Factor H bind to the surface of P. pneumotropica, controlling the activation pathways regulating the formation and maintenance of C3-convertases. These results show that P. pneumotropica has evolved mechanisms to evade the human complement system that may increase the efficiency by which this pathogen is able to gain access to and colonize inner tissues where it may cause severe infections. PMID:25347183

  6. Upregulated Op18/stathmin activity causes chromosomal instability through a mechanism that evades the spindle assembly checkpoint

    SciTech Connect

    Holmfeldt, Per; Sellin, Mikael E.; Gullberg, Martin

    2010-07-15

    Op18/stathmin (Op18) is a microtubule-destabilizing protein that is phosphorylation-inactivated during mitosis and its normal function is to govern tubulin subunit partitioning during interphase. Human tumors frequently overexpress Op18 and a tumor-associated Q18{yields}E mutation has been identified that confers hyperactivity, destabilizes spindle microtubules, and causes mitotic aberrancies, polyploidization, and chromosome loss in K562 leukemia cells. Here we determined whether wild-type and mutant Op18 have the potential to cause chromosomal instability by some means other than interference with spindle assembly, and thereby bypassing the spindle assembly checkpoint. Our approach was based on Op18 derivatives with distinct temporal order of activity during mitosis, conferred either by differential phosphorylation inactivation or by anaphase-specific degradation through fusion with the destruction box of cyclin B1. We present evidence that excessive Op18 activity generates chromosomal instability through interference occurring subsequent to the metaphase-to-anaphase transition, which reduces the fidelity of chromosome segregation to spindle poles during anaphase. Similar to uncorrected merotelic attachment, this mechanism evades detection by the spindle assembly checkpoint and thus provides an additional route to chromosomal instability.

  7. Attenuated rabies virus activates, while pathogenic rabies virus evades, the host innate immune responses in the central nervous system.

    PubMed

    Wang, Zhi W; Sarmento, Luciana; Wang, Yuhuan; Li, Xia-qing; Dhingra, Vikas; Tseggai, Tesfai; Jiang, Baoming; Fu, Zhen F

    2005-10-01

    Rabies virus (RV) induces encephalomyelitis in humans and animals. However, the pathogenic mechanism of rabies is not fully understood. To investigate the host responses to RV infection, we examined and compared the pathology, particularly the inflammatory responses, and the gene expression profiles in the brains of mice infected with wild-type (wt) virus silver-haired bat RV (SHBRV) or laboratory-adapted virus B2C, using a mouse genomic array (Affymetrix). Extensive inflammatory responses were observed in animals infected with the attenuated RV, but little or no inflammatory responses were found in mice infected with wt RV. Furthermore, attenuated RV induced the expression of the genes involved in the innate immune and antiviral responses, especially those related to the alpha/beta interferon (IFN-alpha/beta) signaling pathways and inflammatory chemokines. For the IFN-alpha/beta signaling pathways, many of the interferon regulatory genes, such as the signal transduction activation transducers and interferon regulatory factors, as well as the effector genes, for example, 2'-5'-oligoadenylate synthetase and myxovirus proteins, are highly induced in mice infected with attenuated RV. However, many of these genes were not up-regulated in mice infected with wt SHBRV. The data obtained by microarray analysis were confirmed by real-time PCR. Together, these data suggest that attenuated RV activates, while pathogenic RV evades, the host innate immune and antiviral responses.

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

    PubMed Central

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

    2001-01-01

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

  9. THE PARTICULATE HYDROLASES OF MACROPHAGES

    PubMed Central

    Cohn, Zanvil A.; Wiener, Edith

    1963-01-01

    The influence of phagocytosis on the morphological and biochemical properties of macrophage hydrolase-containing granules has been studied in vitro. Following the uptake of large numbers of heat-killed bacteria, an intracellular rearrangement of hydrolytic enzymes occurred. This was associated with the solubilization of 50 to 60 per cent of the total cell content of acid phosphatase, cathepsin, lysozyme, beta glucuronidase, acid ribonuclease, and acid desoxyribonuclease and with a corresponding decrease in granule-bound enzyme. With more prolonged incubation the majority of the soluble intracellular pool of acid ribonuclease and lysozyme was lost to the extracellular medium. No change in the total content of any of the hydrolases was noted during 180 minutes of incubation in vitro. The morphological fate of the granules was studied by a histochemical method for acid phosphatase. After the phagocytosis of yeast cell walls there was a disappearance of acid phosphatase-positive granules and an accumulation of reaction product about the ingested particle. Experiments employing macrophages which were supravitally stained with neutral red also demonstrated the loss of neutral red-positive granules and the accumulation of the dye about the yeast cell walls. These results strongly suggest that lysis of macrophage granules occurs following phagocytosis and that a portion of the granule contents are then resegregated within the newly formed phagocytic vacuole. PMID:14112262

  10. Macrophages in resistance to candidiasis.

    PubMed Central

    Vázquez-Torres, A; Balish, E

    1997-01-01

    Candida albicans, an increasingly common opportunistic pathogenic fungus, frequently causes disease in immunodeficient but not immunocompetent hosts. Clarifying the role of the phagocytic cells that participate in resistance to candidiasis not only is basic to understanding how the host copes with this dimorphic pathogen but also will expedite the development of innovative prophylactic and therapeutic approaches for treating the multiple clinical presentations that candidiasis encompasses. In this review, we present evidence that a diverse population of mononuclear phagocytes, in different states of activation and differentiation and from a variety of host species, can phagocytize C. albicans blastoconidia via an array of opsonic and nonopsonic mechanisms and can kill C. albicans blastoconidia and hyphae by means of oxygen-dependent and -independent mechanisms. Reactive nitrogen intermediates should now be added to the well-established candidacidal reactive oxygen intermediates of macrophages. Furthermore, what were thought to be two independent pathways, i.e., nitric oxide and superoxide anion, have now been shown to combine to form a potent macrophage candidacidal molecule, peroxynitrite. In contrast to monocytes and neutrophils, which are important in resistance to early stages of C. albicans infections, more differentiated macrophages activated by cytokines such as gamma interferon participate in the acquired resistance of hosts with C. albicans-specific, cell-mediated immunity. Evidence presented in this review demonstrates that mononuclear phagocytes, in some instances in the absence of other professional phagocytes such as neutrophils, play an import role in resistance to systemic and mucosal candidiasis. PMID:9184009

  11. The neuroecology of chemical defenses.

    PubMed

    Derby, Charles D; Aggio, Juan F

    2011-11-01

    Chemicals are a frequent means whereby organisms defend themselves against predators, competitors, parasites, microbes, and other potentially harmful organisms. Much progress has been made in understanding how a phylogenetic diversity of organisms living in a variety of environments uses chemical defenses. Chief among these advances is determining the molecular identity of defensive chemicals and the roles they play in shaping interactions between individuals. Some progress has been made in deciphering the molecular, cellular, and systems level mechanisms underlying these interactions, as well as how these interactions can lead to structuring of communities and even ecosystems. The neuroecological approach unifies practices and principles from these diverse disciplines and at all scales as it attempts to explain in a single conceptual framework the abundances of organisms and the distributions of species within natural habitats. This article explores the neuroecology of chemical defenses with a focus on aquatic organisms and environments. We review the concept of molecules of keystone significance, including examples of how saxitoxin and tetrodotoxin can shape the organization and dynamics of marine and riparian communities, respectively. We also describe the current status and future directions of a topic of interest to our research group-the use of ink by marine molluscs, especially sea hares, in their defense. We describe a diversity of molecules and mechanisms mediating the protective effects of sea hares' ink, including use as chemical defenses against predators and as alarm cues toward conspecifics, and postulate that some defensive molecules may function as molecules of keystone significance. Finally, we propose future directions for studying the neuroecology of the chemical defenses of sea hares and their molluscan relatives, the cephalopods.

  12. Elevated CO2 selectively inhibits interleukin-6 and tumor necrosis factor expression and decreases phagocytosis in the macrophage

    PubMed Central

    Wang, Naizhen; Gates, Khalilah L.; Trejo, Humberto; Favoreto, Silvio; Schleimer, Robert P.; Sznajder, Jacob I.; Beitel, Greg J.; Sporn, Peter H. S.

    2010-01-01

    Elevated blood and tissue CO2, or hypercapnia, is common in severe lung disease. Patients with hypercapnia often develop lung infections and have an increased risk of death following pneumonia. To explore whether hypercapnia interferes with host defense, we studied the effects of elevated PCO2 on macrophage innate immune responses. In differentiated human THP-1 macrophages and human and mouse alveolar macrophages stimulated with lipopolysaccharide (LPS) and other Toll-like receptor ligands, hypercapnia inhibited expression of tumor necrosis factor and interleukin (IL)-6, nuclear factor (NF)-κB-dependent cytokines critical for antimicrobial host defense. Inhibition of IL-6 expression by hypercapnia was concentration dependent, rapid, reversible, and independent of extracellular and intracellular acidosis. In contrast, hypercapnia did not down-regulate IL-10 or interferon-β, which do not require NF-κB. Notably, hypercapnia did not affect LPS-induced degradation of IκBα, nuclear translocation of RelA/p65, or activation of mitogen-activated protein kinases, but it did block IL-6 promoter-driven luciferase activity in mouse RAW 264.7 macrophages. Elevated PCO2 also decreased phagocytosis of opsonized polystyrene beads and heat-killed bacteria in THP-1 and human alveolar macrophages. By interfering with essential innate immune functions in the macrophage, hypercapnia may cause a previously unrecognized defect in resistance to pulmonary infection in patients with advanced lung disease.—Wang, N., Gates, K. L., Trejo, H., Favoreto, Jr., S., Schleimer, R. P., Sznajder, J. I., Beitel, G. J., Sporn, P. H. S. Elevated CO2 selectively inhibits interleukin-6 and tumor necrosis factor expression and decreases phagocytosis in the macrophage. PMID:20181940

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2008-09-15

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

  15. 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

  16. Activation of Hepatic STAT3 Maintains Pulmonary Defense during Endotoxemia

    PubMed Central

    Hilliard, Kristie L.; Allen, Eri; Traber, Katrina E.; Kim, Yuri; Wasserman, Gregory A.; Jones, Matthew R.; Mizgerd, Joseph P.

    2015-01-01

    Pneumonia and infection-induced sepsis are worldwide public health concerns. Both pathologies elicit systemic inflammation and induce a robust acute-phase response (APR). Although APR activation is well regarded as a hallmark of infection, the direct contributions of liver activation to pulmonary defense during sepsis remain unclear. By targeting STAT3-dependent acute-phase changes in the liver, we evaluated the role of liver STAT3 activity in promoting host defense in the context of sepsis and pneumonia. We employed a two-hit endotoxemia/pneumonia model, whereby administration of 18 h of intraperitoneal lipopolysaccharide (LPS; 5 mg/kg of body weight) was followed by intratracheal Escherichia coli (106 CFU) in wild-type mice or those lacking hepatocyte STAT3 (hepSTAT3−/−). Pneumonia alone (without endotoxemia) was effectively controlled in the absence of liver STAT3. Following endotoxemia and pneumonia, however, hepSTAT3−/− mice, with significantly reduced levels of circulating and airspace acute-phase proteins, exhibited significantly elevated lung and blood bacterial burdens and mortality. These data suggested that STAT3-dependent liver responses are necessary to promote host defense. While neither recruited airspace neutrophils nor lung injury was altered in endotoxemic hepSTAT3−/− mice, alveolar macrophage reactive oxygen species generation was significantly decreased. Additionally, bronchoalveolar lavage fluid from this group of hepSTAT3−/− mice allowed greater bacterial growth ex vivo. These results suggest that hepatic STAT3 activation promotes both cellular and humoral lung defenses. Taken together, induction of liver STAT3-dependent gene expression programs is essential to countering the deleterious consequences of sepsis on pneumonia susceptibility. PMID:26216424

  17. Is the insanity defense "unconscionable"?

    PubMed

    Perr, I N

    1975-01-01

    The debate over the meaningfulness and utility of the insanity defense has continued unabated ober the years. President Nixon has referred to the "unconscionably abuse" of the defense. This paper, presented as part of a panel on the subject, has propounded the view that the defense is unconscionable, using that aspect of the definition dealing with unreasonableness. The historical antecedents and the religious and social philosophy of the concept of responsibility and nonresponsibility have been reviewed. In addition to the inapplicability of the concept to current social problems, and the difficulties of applying current psychiatric knowledge to effect a rational delineation between the two legal entities encompassed under the rubric of responsibility and nonresponsibility, the potential problems and the potential opportunities which may result from the abolition of the plea are presented. With these factors in mind, as well as the obvious failure of the legal-social-penal system in handling the problems of the behaviorally deviant, I believe that the use of the current system has hampered the development of possibly more reasonable alternative systems and that, therefore, the maintenance of the insanity defense is unreasonable and harmful to our society. The insanity defense, as currently constituted and institutionalized, has evolved into a rigid and archaic vestige of the legal system of an earlier era and therefore its use has, in the sense defined, indeed become "unconscionable" and lacking in social meaningfulness.

  18. Autochthonous primary and metastatic melanomas in Hgf-Cdk4 R24C mice evade T-cell-mediated immune surveillance.

    PubMed

    Landsberg, Jennifer; Gaffal, Evelyn; Cron, Mira; Kohlmeyer, Judith; Renn, Marcel; Tüting, Thomas

    2010-10-01

    Genetically engineered mouse models offer new opportunities to investigate the role of cell-mediated immunity in the natural progression of melanoma in an immunocompetent host. Here we report that Hgf-Cdk4(R24C) mice spontaneously develop a spectrum of primary melanomas with high penetrance during their first year of life. Malignant transformation proceeds in a stepwise manner from multiple melanocytic nevi to single nodular melanomas and disseminated metastases in most mice. Migrating melanoma cells invade the draining lymph nodes without activating the immune system. Autochthonous primary tumors are destroyed following experimental introduction of immune surveillance using an adoptive lymphocyte transfer approach. However, some tumor cells are able to survive, evade immune cell control, and recur both locally and systemically. Immune tolerance in recurring tumors may be supported by immunosuppressive Gr1(+) myeloid cells. Taken together, our results demonstrate that primary and metastatic melanomas developing spontaneously in Hgf-Cdk4(R24C) mice effectively evade cellular immune surveillance.

  19. Dietary antioxidants: immunity and host defense.

    PubMed

    Puertollano, María A; Puertollano, Elena; de Cienfuegos, Gerardo Álvarez; de Pablo, Manuel A

    2011-01-01

    Natural antioxidants may be defined as molecules that prevent cell damage against free radicals and are critical for maintaining optimum health in both animals and humans. In all living systems, cells require adequate levels of antioxidant defenses in order to avoid the harmful effect of an excessive production of reactive oxygen species (ROS) and to prevent damage to the immune cells. During the inflammatory processes, the activation of phagocytes and/or the action of bacterial products with specific receptors are capable of promoting the assembly of the multicomponent flavoprotein NADPH oxidase, which catalyzes the production of high amounts of the superoxide anion radical (O(2)(-)). Under these particular circumstances, neutrophils and macrophages are recognized to produce superoxide free radicals and H(2)O(2), which are essential for defence against phagocytized or invading microbes. In this state, antioxidants are absolutely necessary to regulate the reactions that release free radicals. Antioxidant nutrients commonly included in the diet such as vitamin E, vitamin C, β-carotene, selenium, copper, iron and zinc improve different immune function exhibiting an important protective role in infections caused by bacteria, viruses or parasites. As a result, dietary antioxidants have been related to modulate the host susceptibility or resistance to infectious pathogens. Overall, numerous studies have suggested that the development of tolerance, and control of inflammation are strongly correlated with specific immune mechanisms that may be altered by an inadequate supply of either macronutrients or micronutrients. Therefore, the present paper will review the effects of dietary antioxidants on immune cell function and the impact on protection against infectious microorganisms. PMID:21506934

  20. Changes in macrophage function modulated by the lipid environment.

    PubMed

    Williams, Michael R; Cauvi, David M; Rivera, Isabel; Hawisher, Dennis; De Maio, Antonio

    2016-04-01

    Macrophages (Mφs) play a critical role in the defense against pathogens, orchestrating the inflammatory response during injury and maintaining tissue homeostasis. During these processes, macrophages encounter a variety of environmental conditions that are likely to change their gene expression pattern, which modulates their function. In this study, we found that murine Mφs displayed two different subpopulations characterized by differences in morphologies, expression of surface markers and phagocytic capacity under non-stimulated conditions. These two subpopulations could be recapitulated by changes in the culture conditions. Thus, Mφs grown in suspension in the presence of serum were highly phagocytic, whereas subtraction of serum resulted in rapid attachment and reduced phagocytic activity. The difference in phagocytosis between these subpopulations was correlated with the expression levels of FcγR. These two cell subpopulations also differed in their responses to LPS and the expression of surface markers, including CD14, CD86, scavenger receptor A1, TLR4 and low-density lipoprotein receptor. Moreover, we found that the lipid/cholesterol content in the culture medium mediated the differences between these two cell subpopulations. Thus, we described a mechanism that modulates Mφ function depending on the exposure to lipids within their surrounding microenvironment.

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

    PubMed

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

    2015-12-01

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

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

    PubMed Central

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

    2015-01-01

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

  3. Mycobacterium tuberculosis Rv2882c Protein Induces Activation of Macrophages through TLR4 and Exhibits Vaccine Potential

    PubMed Central

    Back, Yong Woo; Park, Hye-Soo; Bae, Hyun Shik; Choi, Chul Hee; Kim, Hwa-Jung

    2016-01-01

    Macrophages constitute the first line of defense against Mycobacterium tuberculosis and are critical in linking innate and adaptive immunity. Therefore, the identification and characterization of mycobacterial proteins that modulate macrophage function are essential for understanding tuberculosis pathogenesis. In this study, we identified the novel macrophage-activating protein, Rv2882c, from M. tuberculosis culture filtrate proteins. Recombinant Rv2882c protein activated macrophages to secrete pro-inflammatory cytokines and express co-stimulatory and major histocompatibility complex molecules via Toll-like receptor 4, myeloid differentiation primary response protein 88, and Toll/IL-1 receptor-domain-containing adaptor inducing IFN-beta. Mitogen-activated protein kinases and NF-κB signaling pathways were involved in Rv2882c-induced macrophage activation. Further, Rv2882c-treated macrophages induced expansion of the effector/memory T cell population and Th1 immune responses. In addition, boosting Bacillus Calmette-Guerin vaccination with Rv2882c improved protective efficacy against M. tuberculosis in our model system. These results suggest that Rv2882c is an antigen that could be used for tuberculosis vaccine development. PMID:27711141

  4. Tissue-resident macrophages: then and now.

    PubMed

    Davies, Luke C; Taylor, Philip R

    2015-04-01

    Macrophages have been at the heart of immune research for over a century and are an integral component of innate immunity. Macrophages are often viewed as terminally differentiated monocytic phagocytes. They infiltrate tissues during inflammation, and form polarized populations that perform pro-inflammatory or anti-inflammatory functions. Tissue-resident macrophages were regarded as differentiated monocytes, which seed the tissues to perform immune sentinel and homeostatic functions. However, tissue-resident macrophages are not a homogeneous population, but are in fact a grouping of cells with similar functions and phenotypes. In the last decade, it has been revealed that many of these cells are not terminally differentiated and, in most cases, are not derived from haematopoiesis in the adult. Recent research has highlighted that tissue-resident macrophages cannot be grouped into simple polarized categories, especially in vivo, when they are exposed to complex signalling events. It has now been demonstrated that the tissue environment itself is a major controller of macrophage phenotype, and can influence the expression of many genes regardless of origin. This is consistent with the concept that cells within different tissues have diverse responses in inflammation. There is still a mountain to climb in the field, as it evolves to encompass not only tissue-resident macrophage diversity, but also categorization of specific tissue environments and the plasticity of macrophages themselves. This knowledge provides a new perspective on therapeutic strategies, as macrophage subsets can potentially be manipulated to control the inflammatory environment in a tissue-specific manner. PMID:25684236

  5. Development and maintainance of resident macrophages

    PubMed Central

    Perdiguero, Elisa Gomez; Geissmann, Frederic

    2016-01-01

    The molecular and cellular mechanisms that underlie the many roles of macrophages in health and disease states in vivo remain poorly understood. The purpose of this Review is to present and discuss current knowledge on the developmental biology of macrophages, as it underlies the concept of a layered myeloid system composed of ‘resident’ macrophages that mostly originate from yolk sac progenitors and of ‘passenger’ or ‘transitory’ myeloid cells that originate and renew from bone marrow hematopoietic stem cells, and to provide a framework to investigate the functions of macrophages in vivo. PMID:26681456

  6. Collagenase Production by Endotoxin-Activated Macrophages

    PubMed Central

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

    1974-01-01

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

  7. Bulgy tadpoles: inducible defense morph.

    PubMed

    Kishida, Osamu; Nishimura, Kinya

    2004-08-01

    Predator induced morphological defenses are marked morphological shifts induced directly by cues associated with a predator. Generally, remote cues, i.e., chemical substances emitted from predators or injured conspecifics, are considered to be ideal signals to induce morphological change in aquatic environments rather than close cues, i.e., close chemical or tactile cues, since chemical substances that can propagate over relatively long distances and persist for a long period may allow organisms to keep safe and to deliberately change their morph. In fact, most organisms adopting an inducible morphological defense utilize remote chemical cues to detect predation risk and to produce morphological defenses. In this paper, we report a unique and functionally well designed inducible morphological defense strategy where the induction process requires close cues from a predator. The tadpoles of Rana pirica exhibited a bulgy bodied morphology when threatened with predation by larval salamanders, Hynobius retardatus, in close proximity. Predation trials and a function experiment showed that the induced bulgy morph is an adaptive defense phenotype against the gape-limited predator larval H. retardatus. Furthermore, R. pirica tadpoles use two adaptive strategies in terms of cost saving, i.e., adjustment of the extent of bulginess according to predation risk and reversibility by actual shrink of bulgy body after removing the predation threat. In general, R. pirica hatch earlier than H. retardatus. In natural ponds, during the early developmental stage R. pirica tadpoles live in close proximity to young H. retardatus larvae. As they grow, the salamanders gradually become serious predators and the predator-prey interaction becomes intimate. After a while, predation, cannibalism and metamorphosis decrease the number of salamanders in the ponds, and the predator-prey interaction weakens. Such a phenology in the predator-prey interaction allows the evolution of a close

  8. Bulgy tadpoles: inducible defense morph.

    PubMed

    Kishida, Osamu; Nishimura, Kinya

    2004-08-01

    Predator induced morphological defenses are marked morphological shifts induced directly by cues associated with a predator. Generally, remote cues, i.e., chemical substances emitted from predators or injured conspecifics, are considered to be ideal signals to induce morphological change in aquatic environments rather than close cues, i.e., close chemical or tactile cues, since chemical substances that can propagate over relatively long distances and persist for a long period may allow organisms to keep safe and to deliberately change their morph. In fact, most organisms adopting an inducible morphological defense utilize remote chemical cues to detect predation risk and to produce morphological defenses. In this paper, we report a unique and functionally well designed inducible morphological defense strategy where the induction process requires close cues from a predator. The tadpoles of Rana pirica exhibited a bulgy bodied morphology when threatened with predation by larval salamanders, Hynobius retardatus, in close proximity. Predation trials and a function experiment showed that the induced bulgy morph is an adaptive defense phenotype against the gape-limited predator larval H. retardatus. Furthermore, R. pirica tadpoles use two adaptive strategies in terms of cost saving, i.e., adjustment of the extent of bulginess according to predation risk and reversibility by actual shrink of bulgy body after removing the predation threat. In general, R. pirica hatch earlier than H. retardatus. In natural ponds, during the early developmental stage R. pirica tadpoles live in close proximity to young H. retardatus larvae. As they grow, the salamanders gradually become serious predators and the predator-prey interaction becomes intimate. After a while, predation, cannibalism and metamorphosis decrease the number of salamanders in the ponds, and the predator-prey interaction weakens. Such a phenology in the predator-prey interaction allows the evolution of a close

  9. 75 FR 52732 - Renewal of Department of Defense Federal Advisory Committee; Missile Defense Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-27

    ... of the Secretary Renewal of Department of Defense Federal Advisory Committee; Missile Defense... notice that it is renewing the charter for the Missile Defense Advisory Committee (hereafter referred to... Secretary of Defense for Acquisition, Technology & Logistics and the Director, Missile Defense...

  10. 76 FR 61279 - Defense Federal Acquisition Regulation Supplement; Defense Cargo Riding Gang Member (DFARS Case...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... Defense Acquisition Regulations System 48 CFR Parts 212, 247, and 252 RIN 0750-AG25 Defense Federal Acquisition Regulation Supplement; Defense Cargo Riding Gang Member (DFARS Case 2007-D002) AGENCY: Defense Acquisition Regulations System, Department of Defense (DoD). ACTION: Final rule. SUMMARY: DoD is adopting...

  11. 75 FR 65437 - Defense Federal Acquisition Regulation Supplement; Defense Cargo Riding Gang Members (DFARS Case...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... Defense Acquisition Regulations System 48 CFR Parts 212, 247, and 252 RIN 0750-AG81 Defense Federal Acquisition Regulation Supplement; Defense Cargo Riding Gang Members (DFARS Case 2007-D002) AGENCY: Defense Acquisition Regulations System, Department of Defense (DoD). ACTION: Interim rule with request for...

  12. 76 FR 53119 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-25

    ... of Availability (NOA) in the Federal Register (76 FR 28757) announcing the revised Defense Logistics... Office of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense....

  13. Violence and the epilepsy defense.

    PubMed

    Treiman, D M

    1999-05-01

    The essence of the epilepsy defense is the argument that a crime was committed as a result of the perpetrator having epilepsy, and thus that he or she should not be held responsible for a violent crime. Neurologists are frequently asked to pass judgment regarding whether an alleged act may have been the result of an epileptic condition; therefore, neurologists should be informed as to what criteria should be used to decide if a given act was, or could have been, the result of an epileptic seizure. This article discusses three cases where epilepsy is used as the defense argument. In addition, this article reviews types of epileptic seizures, syncopal events, and pseudoseizures.

  14. RNase 7 in Cutaneous Defense

    PubMed Central

    Rademacher, Franziska; Simanski, Maren; Harder, Jürgen

    2016-01-01

    RNase 7 belongs to the RNase A superfamily and exhibits a broad spectrum of antimicrobial activity against various microorganisms. RNase 7 is expressed in human skin, and expression in keratinocytes can be induced by cytokines and microbes. These properties suggest that RNase 7 participates in innate cutaneous defense. In this review, we provide an overview about the role of RNase 7 in cutaneous defense with focus on the molecular mechanism of the antimicrobial activity of RNase 7, the regulation of RNase 7 expression, and the role of RNase 7 in skin diseases. PMID:27089327

  15. Physical detection of influenza A epitopes identifies a stealth subset on human lung epithelium evading natural CD8 immunity.

    PubMed

    Keskin, Derin B; Reinhold, Bruce B; Zhang, Guang Lan; Ivanov, Alexander R; Karger, Barry L; Reinherz, Ellis L

    2015-02-17

    Vaccines eliciting immunity against influenza A viruses (IAVs) are currently antibody-based with hemagglutinin-directed antibody titer the only universally accepted immune correlate of protection. To investigate the disconnection between observed CD8 T-cell responses and immunity to IAV, we used a Poisson liquid chromatography data-independent acquisition MS method to physically detect PR8/34 (H1N1), X31 (H3N2), and Victoria/75 (H3N2) epitopes bound to HLA-A*02:01 on human epithelial cells following in vitro infection. Among 32 PR8 peptides (8-10mers) with predicted IC50 < 60 nM, 9 were present, whereas 23 were absent. At 18 h postinfection, epitope copies per cell varied from a low of 0.5 for M13-11 to a high of >500 for M1(58-66) with PA, HA, PB1, PB2, and NA epitopes also detected. However, aside from M1(58-66), natural CD8 memory responses against conserved presented epitopes were either absent or only weakly observed by blood Elispot. Moreover, the functional avidities of the immunodominant M1(58-66)/HLA-A*02:01-specific T cells were so poor as to be unable to effectively recognize infected human epithelium. Analysis of T-cell responses to primary PR8 infection in HLA-A*02:01 transgenic B6 mice underscores the poor avidity of T cells recognizing M1(58-66). By maintaining high levels of surface expression of this epitope on epithelial and dendritic cells, the virus exploits the combination of immunodominance and functional inadequacy to evade HLA-A*02:01-restricted T-cell immunity. A rational approach to CD8 vaccines must characterize processing and presentation of pathogen-derived epitopes as well as resultant immune responses. Correspondingly, vaccines may be directed against "stealth" epitopes, overriding viral chicanery.

  16. Dihydro-CDDO-trifluoroethyl amide suppresses inflammatory responses in macrophages via activation of Nrf2

    SciTech Connect

    Li, Bin; Abdalrahman, Akram; Lai, Yimu; Janicki, Joseph S.; Ward, Keith W.; Meyer, Colin J.; Wang, Xing Li; Tang, Dongqi; Cui, Taixing

    2014-02-21

    Highlights: • Dh404 suppresses the expression of a selected set of pro-inflammatory cytokines in inflamed macrophages via activating Nrf2. • Dh404 activates Nrf2 while keeping Keap1 function intact in macrophages. • Dh404 minimally regulates NF-κB pathway in macrophages. - Abstract: Nuclear factor erythroid 2-related factor (Nrf2) is the major regulator of cellular defenses against various pathological stresses in a variety of organ systems, thus Nrf2 has evolved to be an attractive drug target for the treatment and/or prevention of human disease. Several synthetic oleanolic triterpenoids including dihydro-CDDO-trifluoroethyl amide (dh404) appear to be potent activators of Nrf2 and exhibit chemopreventive promises in multiple disease models. While the pharmacological efficacy of Nrf2 activators may be dependent on the nature of Nrf2 activation in specific cell types of target organs, the precise role of Nrf2 in mediating biological effects of Nrf2 activating compounds in various cell types remains to be further explored. Herein we report a unique and Nrf2-dependent anti-inflammatory profile of dh404 in inflamed macrophages. In lipopolysaccharide (LPS)-inflamed RAW264.7 macrophages, dh404 dramatically suppressed the expression of pro-inflammatory cytokines including inducible nitric oxide synthase (iNOS), monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-1 beta (MIP-1β), while minimally regulating the expression of interleulin-6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNFα). Dh404 potently activated Nrf2 signaling; however, it did not affect LPS-induced NF-κB activity. Dh404 did not interrupt the interaction of Nrf2 with its endogenous inhibitor Kelch-like ECH associating protein 1 (Keap1) in macrophages. Moreover, knockout of Nrf2 blocked the dh404-induced anti-inflammatory responses in LPS-inflamed macrophages. These results demonstrated that dh404 suppresses pro-inflammatory responses in macrophages via an activation

  17. [Effect of cigarette smoke extract on phagocytosis of Staphylococcus aureus by macrophages].

    PubMed

    Ak, Sibel; Gürses, Serdar Abidin; Eser, Bekir Engin

    2016-04-01

    Staphylococcus aureus is one of the most important pathogen that causes community acquired and nosocomial infections worldwide. Phagocytosis by macrophages plays an important role in the first line defense against infections caused by S.aureus. On the other hand, the conducted studies have indicated that cigarette smoke has negative effects on both innate and acquired immune responses. The aim of this study was to investigate the effects of cigarette smoke on macrophage viability and their capacity of S.aureus phagocytosis. For this purpose THP-1 cell lines (human leukemic monocyte cell culture) were used and after the differentiation of the cells with PMA (phorbol myristate acetate) treatment, the macrophages were exposed to cigarette smoke extract (CSE) for 2- and 4-hours at concentrations of 1%, 5%, 10%, 25%, and 50%. Afterwards, the cells were stained with propidium iodide and the viability of the cells was analyzed by a flow cytometer. Two different methods were used to investigate the effect of CSE on the phagocytosis of S.aureus. The first one was the classical bacteriological method, in which macrophages were exposed to CSE for 2 hours in five different concentrations and were infected with 100 MOI (multiplicity of infection) S.aureus. After 1 hour of incubation, macrophages were lysed with PBS-0.1% Triton X-100 and plated on Luria-Bertani (LB) agar following serial dilutions. Newly formed colonies were counted and the number of bacteria phagocytosed were evaluated as colony forming units (CFU). The second method for the detection of phagocytosis was flow cytometric analysis in which SYBR(®) Green-labeled bacteria were used. To confirm that the macrophages were infected, bacteria were stained with SYBR(®) Green and macrophages were analyzed following infection via flow cytometry. Macrophages were exposed to 10% and 50% CSE and infected with bacteria stained with SYBR(®) Green. The level of phagocytosis was analyzed by flow cytometry in terms of median

  18. [Effect of cigarette smoke extract on phagocytosis of Staphylococcus aureus by macrophages].

    PubMed

    Ak, Sibel; Gürses, Serdar Abidin; Eser, Bekir Engin

    2016-04-01

    Staphylococcus aureus is one of the most important pathogen that causes community acquired and nosocomial infections worldwide. Phagocytosis by macrophages plays an important role in the first line defense against infections caused by S.aureus. On the other hand, the conducted studies have indicated that cigarette smoke has negative effects on both innate and acquired immune responses. The aim of this study was to investigate the effects of cigarette smoke on macrophage viability and their capacity of S.aureus phagocytosis. For this purpose THP-1 cell lines (human leukemic monocyte cell culture) were used and after the differentiation of the cells with PMA (phorbol myristate acetate) treatment, the macrophages were exposed to cigarette smoke extract (CSE) for 2- and 4-hours at concentrations of 1%, 5%, 10%, 25%, and 50%. Afterwards, the cells were stained with propidium iodide and the viability of the cells was analyzed by a flow cytometer. Two different methods were used to investigate the effect of CSE on the phagocytosis of S.aureus. The first one was the classical bacteriological method, in which macrophages were exposed to CSE for 2 hours in five different concentrations and were infected with 100 MOI (multiplicity of infection) S.aureus. After 1 hour of incubation, macrophages were lysed with PBS-0.1% Triton X-100 and plated on Luria-Bertani (LB) agar following serial dilutions. Newly formed colonies were counted and the number of bacteria phagocytosed were evaluated as colony forming units (CFU). The second method for the detection of phagocytosis was flow cytometric analysis in which SYBR(®) Green-labeled bacteria were used. To confirm that the macrophages were infected, bacteria were stained with SYBR(®) Green and macrophages were analyzed following infection via flow cytometry. Macrophages were exposed to 10% and 50% CSE and infected with bacteria stained with SYBR(®) Green. The level of phagocytosis was analyzed by flow cytometry in terms of median

  19. Collaborative Attack vs. Collaborative Defense

    NASA Astrophysics Data System (ADS)

    Xu, Shouhuai

    We have witnessed many attacks in the cyberspace. However, most attacks are launched by individual attackers even though an attack may involve many compromised computers. In this paper, we envision what we believe to be the next generation cyber attacks — collaborative attacks. Collaborative attacks can be launched by multiple attackers (i.e., human attackers or criminal organizations), each of which may have some specialized expertise. This is possible because cyber attacks can become very sophisticated and specialization of attack expertise naturally becomes relevant. To counter collaborative attacks, we might need collaborative defense because each “chain” in a collaborative attack may be only adequately dealt with by a different defender. In order to understand collaborative attack and collaborative defense, we present a high-level abstracted framework for evaluating the effectiveness of collaborative defense against collaborative attacks. As a first step towards realizing and instantiating the framework, we explore a characterization of collaborative attacks and collaborative defense from the relevant perspectives.

  20. Directions for Defense Digital Libraries.

    ERIC Educational Resources Information Center

    Larsen, Ronald L.

    1998-01-01

    Describes directions, challenges, and objectives of the information management program of the United States Defense Advanced Research Projects Agency (DARPA). The program envisions the rigor and organization normally associated with a research library to be virtually rendered and extended in the networked world of distributed information. (AEF)

  1. Radiological Defense Officer. Student Workbook.

    ERIC Educational Resources Information Center

    Defense Civil Preparedness Agency (DOD), Washington, DC.

    This student workbook includes the necessary administrative materials, briefs, exercises and answer sheets for the quizzes and final course examination as needed by the students during the conduct of the Radiological Defense Officer course. Among the briefs included are the following: (1) Reporting Forms; (2) Forecasting Dose Rates; (3) Dose…

  2. In Defense of Darwin's Theory.

    ERIC Educational Resources Information Center

    Naylor, Bruce G.; Handford, Paul

    1985-01-01

    Examines issues regarding the defensibility and utility of natural selection as a scientific theory, focusing on the process of population change over time. Topics considered include criticisms of Darwinian theory, tautology and the meaning of fitness, the ability of theories to predict and explain, and the sufficiency of natural selection. (DH)

  3. In Defense of the Vendors

    ERIC Educational Resources Information Center

    Irwin, G. Brockett

    1975-01-01

    The problems that are encountered when cooperation breaks down between the industrial source operator and the pollution control equipment vendor are examined. The focal point of this examination is the study of defenses available to the equipment vendor when industrial source operators refuse to cooperate. (Author/BT)

  4. Evading the CKM Hierarchy

    SciTech Connect

    Brodsky, Stanley J.

    2001-08-15

    We show that the presence of intrinsic charm in the hadrons' light-cone wave functions, even at a few percent level, provides new, competitive decay mechanisms for B decays which are nominally CKM-suppressed. For example, the weak decays of the B-meson to two-body exclusive states consisting of strange plus light hadrons, such as B {yields} {pi} K, are expected to be dominated by penguin contributions since the tree-level b {yields} s u{bar u} decay is CKM suppressed However, higher Fock states in the B wave function containing charm quark pairs can mediate the decay via a CKM-favored b {yields} s c{bar c} tree-level transition. Such intrinsic charm contributions can be phenomenologically significant. Since they mimic the amplitude structure of ''charming'' penguin contributions, charming penguins need not be penguins at all.

  5. EST: Evading Scientific Text.

    ERIC Educational Resources Information Center

    Ward, Jeremy

    2001-01-01

    Examines chemical engineering students' attitudes to text and other parts of English language textbooks. A questionnaire was administered to a group of undergraduates. Results reveal one way students get around the problem of textbook reading. (Author/VWL)

  6. Chemical defense lowers plant competitiveness.

    PubMed

    Ballhorn, Daniel J; Godschalx, Adrienne L; Smart, Savannah M; Kautz, Stefanie; Schädler, Martin

    2014-11-01

    Both plant competition and plant defense affect biodiversity and food web dynamics and are central themes in ecology research. The evolutionary pressures determining plant allocation toward defense or competition are not well understood. According to the growth-differentiation balance hypothesis (GDB), the relative importance of herbivory and competition have led to the evolution of plant allocation patterns, with herbivore pressure leading to increased differentiated tissues (defensive traits), and competition pressure leading to resource investment towards cellular division and elongation (growth-related traits). Here, we tested the GDB hypothesis by assessing the competitive response of lima bean (Phaseolus lunatus) plants with quantitatively different levels of cyanogenesis-a constitutive direct, nitrogen-based defense against herbivores. We used high (HC) and low cyanogenic (LC) genotypes in different competition treatments (intra-genotypic, inter-genotypic, interspecific), and in the presence or absence of insect herbivores (Mexican bean beetle, Epilachna varivestis) to quantify vegetative and generative plant parameters (above and belowground biomass as well as seed production). Highly defended HC-plants had significantly lower aboveground biomass and seed production than LC-plants when grown in the absence of herbivores implying significant intrinsic costs of plant cyanogenesis. However, the reduced performance of HC- compared to LC-plants was mitigated in the presence of herbivores. The two plant genotypes exhibited fundamentally different responses to various stresses (competition, herbivory). Our study supports the GDB hypothesis by demonstrating that competition and herbivory affect different plant genotypes differentially and contributes to understanding the causes of variation in defense within a single plant species.

  7. Purinergic signaling during macrophage differentiation results in M2 alternative activated macrophages.

    PubMed

    Barberà-Cremades, Maria; Baroja-Mazo, Alberto; Pelegrín, Pablo

    2016-02-01

    Macrophages represent a highly heterogenic cell population of the innate immune system, with important roles in the initiation and resolution of the inflammatory response. Purinergic signaling regulates both M1 and M2 macrophage function at different levels by controlling the secretion of cytokines, phagocytosis, and the production of reactive oxygen species. We found that extracellular nucleotides arrest macrophage differentiation from bone marrow precursors via adenosine and P2 receptors. This results in a mature macrophage with increased expression of M2, but not M1, genes. Similar to adenosine and ATP, macrophage growth arrested with LPS treatment resulted in an increase of the M2-related marker Ym1. Recombinant Ym1 was able to affect macrophage proliferation and could, potentially, be involved in the arrest of macrophage growth during hematopoiesis.

  8. Effect of alveolar macrophages on Toxoplasma gondii.

    PubMed Central

    Ryning, F W; Remington, J S

    1977-01-01

    As pulmonary involvement can occur in disseminated toxoplasmosis in immunosuppressed patients, studies were initiated to define local mechanisms of resistance of the lung to Toxoplasma gondii. Alveolar macrophages were obtained from normal mice and mice chronically infected with T. gondii by bronchopulmonary lavage and cultured in vitro. Although normal alveolar macrophages were difficult to infect with Toxoplasma, they supported intracellular multiplication of this organism. When exposed to Toxoplasma that had been pretreated with heat-inactivated serum containing specific antibody, the number of intracellular organisms increased remarkably, and the macrophages destroyed the coated parasites. After development of chronic infections with Toxoplasma, there was a transient period during which a striking increase in numbers of alveolar macrophages was observed in lavage specimens. These macrophages differed from those of normal alveolar macrophages. There was a greater percentage of large cells, a greater tendency to spread on glass, and an increased number of intracellular Toxoplasma, and the cells were activated to kill or inhibit multiplication of the parasite. During the period when activated macrophages were demonstrable in bronchopulmonary washings, histological changes in the lungs revealed a marked mononuclear cell infiltrate. These studies support a role for the activated alveolar macrophage as an effector in resistance of the lung to infection with Toxoplasma. PMID:591065

  9. A broken krebs cycle in macrophages.

    PubMed

    O'Neill, Luke A J

    2015-03-17

    Macrophages undergo metabolic rewiring during polarization but details of this process are unclear. In this issue of Immunity, Jha et al. (2015) report a systems approach for unbiased analysis of cellular metabolism that reveals key metabolites and metabolic pathways required for distinct macrophage polarization states.

  10. Interaction of Chlamydiae with human macrophages.

    PubMed

    Herweg, Jo-Ana; Rudel, Thomas

    2016-02-01

    The phylum Chlamydiae contains several members that are well-known human pathogens, like Chlamydia trachomatis and C. pneumoniae. Establishing a chronic bacterial infection requires the active evasion of the host immune response. A major arm of the innate immune defence is constituted by macrophages, which fight infections by removing bacteria and triggering an adaptive immune response. However, some pathogenic Chlamydia infect and survive in macrophages at least for a certain period of time. Therefore, macrophages can serve as vehicles for the dissemination of bacterial infections from the primary infection site via the urogenital or respiratory tract to distant sites in the body. The capacity to infect macrophages seems to depend on the chlamydial strain and the source of macrophages. In vitro infections of macrophages with C. trachomatis, C. psittaci and C. pneumoniae reveal low efficiency of infection and progeny formation, as well as failure to develop mature inclusions. In contrast, the emerging pathogen, Simkania negevensis, actively replicates in macrophages. Here we summarize the current knowledge of the intracellular and molecular key mechanisms of C. trachomatis, C. pneumoniae and S. negevensis infections in human macrophages. PMID:26613554

  11. Macrophage polarization in virus-host interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macrophage involvement in viral infections and antiviral states is common. However, this involvement has not been well-studied in the paradigm of macrophage polarization, which typically has been categorized by the dichotomy of classical (M1) and alternative (M2) statuses. Recent studies have reveal...

  12. Rewiring macrophages for anti-tumour immunity.

    PubMed

    Lee, Yunqin; Biswas, Subhra K

    2016-06-28

    Tumour-associated macrophages facilitate cancer progression, but whether they can be reprogrammed to elicit an anti-tumour response remains unclear. Deletion of the microRNA-processing enzyme Dicer is now shown to rewire macrophages to an anti-tumour mode, leading to an enhanced response to immunotherapy and inhibition of tumour progression. PMID:27350442

  13. Mannose-binding lectin enhances phagocytosis and killing of Neisseria meningitidis by human macrophages.

    PubMed

    Jack, Dominic L; Lee, Margaret E; Turner, Malcolm W; Klein, Nigel J; Read, Robert C

    2005-03-01

    Deficiency of mannose-binding lectin (MBL) is probably the most common human immunodeficiency and is associated with an increased risk of mucosally acquired infections including meningococcal disease. Tissue macrophages are an important component of mucosal defense, and so we determined the effect of MBL on uptake of meningococci by human monocyte-derived macrophages. Opsonization with MBL significantly increased the capture and doubled the amount of internalization of Neisseria meningitidis. Inhibition of f-actin polymerization indicated that MBL exerted this effect by a dose-dependent acceleration of uptake into phagosomes, which was maximal within the normal physiological concentration of MBL (1.5 microg/ml) and was independent of scavenger receptors. MBL accelerated the acquisition and subsequent loss of the early endosome marker, early endosomal antigen-1, and enhanced the acquisition of the late endosomal marker, lysosome-associated membrane protein-1. MBL reduced the survival of meningococci within macrophages by more than half, despite the increased uptake of organisms, and significantly reduced the number of viable extracellular bacteria by 80%. We conclude that MBL is a dependent opsonin able to accelerate microbial uptake and killing. These results suggest that MBL could modify disease susceptibility by modulating macrophage interactions with mucosal organisms at the site of initial acquisition.

  14. Acute exposure to methamphetamine alters TLR9-mediated cytokine expression in human macrophage.

    PubMed

    Burns, Ariel; Ciborowski, Pawel

    2016-02-01

    Recent studies show that methamphetamine (Meth) use leads to higher susceptibility to and progression of infections, which suggests impairment of the immune system. The first line of defense against infections is the innate immune system and the macrophage is a key player in preventing and fighting infections. So we profiled cytokines over time in Meth treated THP-1 cells, as a human macrophage model, at a relevant concentration using high throughput screening to find a signaling target. We showed that after a single exposure, the effect of Meth on macrophage cytokine production was rapid and time dependent and shifted the balance of expression of cytokines to pro-inflammatory. Our results were analogous to previous reports in that Meth up-regulates TNF-α and IL-8 after two hours of exposure. However, global screening led to the novel identification of CXCL16, CXCL1 and many other up-regulated cytokines. We also showed CCL7 as the most down-regulated chemokine due to Meth exposure, which led us to hypothesize that Meth dysregulates the MyD88-dependent Toll-like receptor 9 (TLR9) signaling pathway. In conclusion, altered cytokine expression in macrophages suggests it could lead to a suppressed innate immunity in people who use Meth.

  15. Elaboration of Sterically Stabilized Liposomes for S-Nitrosoglutathione Targeting to Macrophages.

    PubMed

    Diab, R; Virriat, A S; Ronzani, C; Fontanay, S; Grandemange, S; Elaissari, A; Foliguet, B; Maincent, P; Leroy, P; Duvaj, R E; Rihn, B H; Joubert, O

    2016-01-01

    S-nitrosoglutathione (GSNO) is a potential therapeutic for infectious disease treatment because of its pivotal role in macrophage-mediated inflammatory responses and host defense in addition to direct antibacterial activities. In this study, sterically stabilized cationic liposomes (SSCL) and sterically stabilized anionic liposomes (SSAL) were developed as nanocarriers for macrophage targeting. Elaborated liposomes were characterized in terms of size, zeta potential, morphology, encapsulation efficiency, in vitro drug release behavior and cytotoxicity. Their versatility in targeting monocytes/macrophages was determined by confocal laser scanning microscopy and transmission electron microscopy. Flow cytometry revealed that cellular uptake of both SSCL and SSAL was governed by several endocytic clathrin- and caveolae-dependent mechanisms. Quantitative assessments of intracellular nitric oxide demonstrated highly efficient uptake of GSNO-loaded SSCL that was twenty-fold higher than that of GSNO-free molecules. GSNO-loaded SSCL displayed strong bacteriostatic effects on Staphylococcus aureus and Pseudomonas aeruginosa, which can be involved in pulmonary infectious diseases. These results reveal the potential of liposomal GSNO as an anti-infective therapeutic due to its macrophage targeting capacity and direct antibacterial effects. PMID:27301185

  16. Contribution of Lung Macrophages to the Inflammatory Responses Induced by Exposure to Air Pollutants

    PubMed Central

    van Eeden, Stephan F.

    2013-01-01

    Large population cohort studies have indicated an association between exposure to particulate matter and cardiopulmonary morbidity and mortality. The inhalation of toxic environmental particles and gases impacts the innate and adaptive defense systems of the lung. Lung macrophages play a critically important role in the recognition and processing of any inhaled foreign material such as pathogens or particulate matter. Alveolar macrophages and lung epithelial cells are the predominant cells that process and remove inhaled particulate matter from the lung. Cooperatively, they produce proinflammatory mediators when exposed to atmospheric particles. These mediators produce integrated local (lung, controlled predominantly by epithelial cells) and systemic (bone marrow and vascular system, controlled predominantly by macrophages) inflammatory responses. The systemic response results in an increase in the release of leukocytes from the bone marrow and an increased production of acute phase proteins from the liver, with both factors impacting blood vessels and leading to destabilization of existing atherosclerotic plaques. This review focuses on lung macrophages and their role in orchestrating the inflammatory responses induced by exposure to air pollutants. PMID:24058272

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

    PubMed Central

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

    2016-01-01

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

  18. Macrophagic myofasciitis: characterization and pathophysiology

    PubMed Central

    Gherardi, Romain K.; Authier, François-Jérôme

    2012-01-01

    Summary Aluminium oxyhydroxide (alum), a nano-crystaline compound forming agglomerates, has been introduced in vaccine for its immunologic adjuvant effect in 1927. Alum is the most commonly used adjuvant in human and veterinary vaccines but mechanisms by which it stimulates immune responses remains incompletely understood. Although generally well tolerated, alum may occasionally cause disabling health problems in presumably susceptible individuals. A small proportion of vaccinated people present with delayed onset of diffuse myalgia, chronic fatigue and cognitive dysfunction, and exhibit very long-term persistence of alum-loaded macrophages at site of previous intra-muscular (i.m.) immunization, forming a granulomatous lesion called macrophagic myofasciitis (MMF). Clinical symptoms associated with MMF are paradigmatic of the recently delineated “autoimmune/inflammatory syndrome induced by adjuvants” (ASIA). The stereotyped cognitive dysfunction is reminiscent of cognitive deficits described in foundry workers exposed to inhaled Al particles. Alum safety concerns will largely depend on whether the compound remains localized at site of injection or may diffuse and accumulate in distant organs. Animal experiments indicate that biopersistent nanomaterials taken-up by monocytes-lineage cells in tissues, e.g. fluorescent alum surrogates, can first translocate to draining lymph nodes, and thereafter circulate in blood within phagocytes and reach the spleen, and, eventually, slowly accumulate in brain. PMID:22235051

  19. Mycobacteria, metals, and the macrophage.

    PubMed

    Neyrolles, Olivier; Wolschendorf, Frank; Mitra, Avishek; Niederweis, Michael

    2015-03-01

    Mycobacterium tuberculosis is a facultative intracellular pathogen that thrives inside host macrophages. A key trait of M. tuberculosis is to exploit and manipulate metal cation trafficking inside infected macrophages to ensure survival and replication inside the phagosome. Here, we describe the recent fascinating discoveries that the mammalian immune system responds to infections with M. tuberculosis by overloading the phagosome with copper and zinc, two metals which are essential nutrients in small quantities but are toxic in excess. M. tuberculosis has developed multi-faceted resistance mechanisms to protect itself from metal toxicity including control of uptake, sequestration inside the cell, oxidation, and efflux. The host response to infections combines this metal poisoning strategy with nutritional immunity mechanisms that deprive M. tuberculosis from metals such as iron and manganese to prevent bacterial replication. Both immune mechanisms rely on the translocation of metal transporter proteins to the phagosomal membrane during the maturation process of the phagosome. This review summarizes these recent findings and discusses how metal-targeted approaches might complement existing TB chemotherapeutic regimens with novel anti-infective therapies.

  20. Mycobacteria, Metals, and the Macrophage

    PubMed Central

    Niederweis, Michael; Wolschendorf, Frank; Mitra, Avishek; Neyrolles, Olivier

    2015-01-01

    Summary Mycobacterium tuberculosis is a facultative intracellular pathogen that thrives inside host macrophages. A key trait of M. tuberculosis is to exploit and manipulate metal cation trafficking inside infected macrophages to ensure survival and replication inside the phagosome. Here we describe the recent fascinating discoveries that the mammalian immune system responds to infections with M. tuberculosis by overloading the phagosome with copper and zinc, two metals which are essential nutrients in small quantities but are toxic in excess. M. tuberculosis has developed multi-faceted resistance mechanisms to protect itself from metal toxicity including control of uptake, sequestration inside the cell, oxidation, and efflux. The host response to infections combines this metal poisoning strategy with nutritional immunity mechanisms that deprive M. tuberculosis from metals such as iron and manganese to prevent bacterial replication. Both immune mechanisms rely on the translocation of metal transporter proteins to the phagosomal membrane during the maturation process of the phagosome. This review summarizes these recent findings and discusses how metal-targeted approaches might complement existing TB chemotherapeutic regimens with novel anti-infective therapies. PMID:25703564

  1. Mycobacteria, metals, and the macrophage.

    PubMed

    Neyrolles, Olivier; Wolschendorf, Frank; Mitra, Avishek; Niederweis, Michael

    2015-03-01

    Mycobacterium tuberculosis is a facultative intracellular pathogen that thrives inside host macrophages. A key trait of M. tuberculosis is to exploit and manipulate metal cation trafficking inside infected macrophages to ensure survival and replication inside the phagosome. Here, we describe the recent fascinating discoveries that the mammalian immune system responds to infections with M. tuberculosis by overloading the phagosome with copper and zinc, two metals which are essential nutrients in small quantities but are toxic in excess. M. tuberculosis has developed multi-faceted resistance mechanisms to protect itself from metal toxicity including control of uptake, sequestration inside the cell, oxidation, and efflux. The host response to infections combines this metal poisoning strategy with nutritional immunity mechanisms that deprive M. tuberculosis from metals such as iron and manganese to prevent bacterial replication. Both immune mechanisms rely on the translocation of metal transporter proteins to the phagosomal membrane during the maturation process of the phagosome. This review summarizes these recent findings and discusses how metal-targeted approaches might complement existing TB chemotherapeutic regimens with novel anti-infective therapies. PMID:25703564

  2. CD44 Occupancy Prevents Macrophage Multinucleation

    PubMed Central

    Sterling, Hyacinth; Saginario, Charles; Vignery, Agnès

    1998-01-01

    Cells of the mononuclear phagocyte lineage have the capability to adhere to and fuse with each other and to differentiate into osteoclasts and giant cells. To investigate the macrophage adhesion/fusion mechanism, we focused our attention on CD44, a surface glycoprotein known to play a role in hematopoietic cell–cell adhesion. We report that CD44 expression by macrophages is highly and transiently induced by fusogenic conditions both in vitro and in vivo. We show that CD44 ligands, hyaluronic acid, chondroitin sulfates, and osteopontin prevent macrophage multinucleation. In addition, we report that the recombinant extracellular domain of CD44 binds fusing macrophages and prevents multinucleation in vitro. These data suggest that CD44 may control the mononucleated status of macrophages in tissues by virtue of mediating cell–cell interaction. PMID:9813101

  3. ROCK inhibition impedes macrophage polarity and functions.

    PubMed

    Liu, Yianzhu; Tejpal, Neelam; You, Junping; Li, Xian C; Ghobrial, Rafik M; Kloc, Malgorzata

    2016-02-01

    Macrophages play an important role in immune responses including allograft rejection and they are one of the potential targets of anti-rejection therapies in organ transplantation. Macrophage alloreactivity relies on their phenotype/polarity, motility, phagocytosis and matrix degradation, which in turn depend on proper functioning of actin cytoskeleton and its regulators, the small GTPase RhoA and its downstream effector the Rho-associated protein kinase (ROCK). Several laboratories showed that administration of ROCK inhibitor Y-27632 to the graft recipient inhibits chronic rejection or rodent cardiac allografts. Here we studied the effect of Y-27632 on mouse peritoneal macrophage structure, polarity and functions in in vitro assays. We show that Y-27632 inhibitor affects macrophage phenotype/polarity, phagocytosis, migration, and matrix degradation. These novel findings suggest that the impediment of macrophage structure and function via interference with the RhoA/ROCK pathway has a potential to be therapeutically effective in organ transplantation.

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

    PubMed

    Onoprienko, L V

    2011-01-01

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

  5. Cuckoos combat socially transmitted defenses of reed warbler hosts with a plumage polymorphism.

    PubMed

    Thorogood, Rose; Davies, Nicholas B

    2012-08-01

    In predator-prey and host-parasite interactions, an individual's ability to combat an opponent often improves with experience--for example, by learning to identify enemy signals. Although learning occurs through individual experience, individuals can also assess threats from social information. Such recognition could promote the evolution of polymorphisms if socially transmitted defenses depend on enemy morph frequency. This would allow rare variants to evade detection. Female brood parasitic common cuckoos, Cuculus canorus, are either gray or rufous. The gray morph is a Batesian mimic whose hawk-like appearance deters host attack. Hosts reject this disguise through social learning, increasing their own defenses when they witness neighbors mobbing a cuckoo. Our experiments reveal that social learning is specific to the cuckoo morph that neighbors mob. Therefore, while neighbors alert hosts to local cuckoo activity, frequency-dependent social information selects for a cuckoo plumage polymorphism to thwart host detection. Our results suggest that selection for mimicry and polymorphisms comes not only from personal experience but also from social learning. PMID:22859487

  6. Defense of the lungs in oxygen-injured baboons

    SciTech Connect

    Fowler, S.R.; Rawlinson, W.K.; Roach, F.M.; Seidenfeld, J.J.

    1986-03-05

    Pneumonia and subsequent sepsis have been linked with multiple organ failure and death in patients with adult respiratory distress syndrome. This suggests that lung defense may be impaired. In a model of ARDS, 13 baboons were intubated and ventilated with 80% O/sub 2/ for 6 days, following which 7 were inoculated intratracheally with Pseudomonas aeruginosa (PA) strain DGI-RI30. After 5 days on 50% O/sub 2/ the animals were sacrificed. Bronchoalveolar lavage (BAL) was performed before O/sub 2/ exposure, after 6 days of 80% O/sub 2/, and at sacrifice. Total WBC and differential counts were determined for BAL cells. Mononuclear BAL cells were isolated for in vitro phagocytosis assays. BAL fluid (BALF) was tested for in vitro PMN chemotactic activity. An index of bacterial infection (sum of log CFU/g lung homogenate) was greater for infected animals (p < 0.01). Percentage of PMN in BALF was significantly increased at sacrifice in PA-inoculated animals. BALF from PA-inoculated animals at sacrifice elicited increased in vitro PMN chemotaxis, which was destroyed at 100/sup 0/C but not 56/sup 0/C, extracted by ether, and not degraded by proteases. Mononuclear BAL cells from inoculated animals at sacrifice were phagocytially more active than baseline cells. These data suggest that oxygen injury does not inhibit recruitment of PMN or phagocytosis of bacteria by alveolar macrophages in baboons; however, the addition of bacterial inoculation results in clinical deterioration despite unimpaired local defense.

  7. Preadipocyte conversion to macrophage. Evidence of plasticity.

    PubMed

    Charrière, Guillaume; Cousin, Béatrice; Arnaud, Emmanuelle; André, Mireille; Bacou, Francis; Penicaud, Luc; Casteilla, Louis

    2003-03-14

    Preadipocytes are present throughout adult life in adipose tissues and can proliferate and differentiate into mature adipocytes according to the energy balance. An increasing number of reports demonstrate that cells from adipose lineages (preadipocytes and adipocytes) and macrophages share numerous functional or antigenic properties. No large scale comparison reflecting the phenotype complexity has been performed between these different cell types until now. We used profiling analysis to define the common features shared by preadipocyte, adipocyte, and macrophage populations. Our analysis showed that the preadipocyte profile is surprisingly closer to the macrophage than to the adipocyte profile. From these data, we hypothesized that in a macrophage environment preadipocytes could effectively be converted into macrophages. We injected labeled stroma-vascular cells isolated from mouse white adipose tissue or 3T3-L1 preadipocyte cell line into the peritoneal cavity of nude mice and investigated changes in their phenotype. Preadipocytes rapidly and massively acquired high phagocytic activity and index. 60-70% of preadipocytes also expressed five macrophage-specific antigens: F4/80, Mac-1, CD80, CD86, and CD45. These values were similar to those observed for peritoneal macrophages. In vitro experiments showed that cell-to-cell contact between preadipocytes and peritoneal macrophages partially induced this preadipocyte phenotype conversion. Overall, these results suggest that preadipocyte and macrophage phenotypes are very similar and that preadipocytes have the potential to be very efficiently and rapidly converted into macrophages. This work emphasizes the great cellular plasticity of adipose precursors and reinforces the link between adipose tissue and innate immunity processes. PMID:12519759

  8. Civil Defense, U. S. A.: A Programmed Orientation to Civil Defense. Unit 1. Civil Defense - Protection Against What?

    ERIC Educational Resources Information Center

    Defense Civil Preparedness Agency (DOD), Battle Creek, MI.

    An explanation of the need for civil defense in nuclear and natural disasters is presented. A brief historical background of civil defense is given. Major topics include: (1) Types of disasters, (2) Probable objectives of a nuclear attack on the United States, (3) The major defensive measures against a nuclear attack, (4) Some reasons for low…

  9. Civil Defense, U. S. A.: A Programmed Orientation to Civil Defense. Unit 5. Governmental Responsibilities for Civil Defense.

    ERIC Educational Resources Information Center

    Defense Civil Preparedness Agency (DOD), Battle Creek, MI.

    A description of the laws and orders that provide necessary legal authorization for civil defense activities is provided. In addition, an outline of the responsibilities of all governments and the role of the private sector in civil defense is presented. Topics discussed include: (1) Legal authority for civil defense, (2) Civil defense…

  10. An Arginine Deprivation Response Pathway Is Induced in Leishmania during Macrophage Invasion.

    PubMed

    Goldman-Pinkovich, Adele; Balno, Caitlin; Strasser, Rona; Zeituni-Molad, Michal; Bendelak, Keren; Rentsch, Doris; Ephros, Moshe; Wiese, Martin; Jardim, Armando; Myler, Peter J; Zilberstein, Dan

    2016-04-01

    Amino acid sensing is an intracellular function that supports nutrient homeostasis, largely through controlled release of amino acids from lysosomal pools. The intracellular pathogen Leishmania resides and proliferates within human macrophage phagolysosomes. Here we describe a new pathway in Leishmania that specifically senses the extracellular levels of arginine, an amino acid that is essential for the parasite. During infection, the macrophage arginine pool is depleted due to its use to produce metabolites (NO and polyamines) that constitute part of the host defense response and its suppression, respectively. We found that parasites respond to this shortage of arginine by up-regulating expression and activity of the Leishmania arginine transporter (LdAAP3), as well as several other transporters. Our analysis indicates the parasite monitors arginine levels in the environment rather than the intracellular pools. Phosphoproteomics and genetic analysis indicates that the arginine-deprivation response is mediated through a mitogen-activated protein kinase-2-dependent signaling cascade. PMID:27043018

  11. An Arginine Deprivation Response Pathway Is Induced in Leishmania during Macrophage Invasion

    PubMed Central

    Strasser, Rona; Zeituni-Molad, Michal; Bendelak, Keren; Rentsch, Doris; Ephros, Moshe; Wiese, Martin; Jardim, Armando; Myler, Peter J.; Zilberstein, Dan

    2016-01-01

    Amino acid sensing is an intracellular function that supports nutrient homeostasis, largely through controlled release of amino acids from lysosomal pools. The intracellular pathogen Leishmania resides and proliferates within human macrophage phagolysosomes. Here we describe a new pathway in Leishmania that specifically senses the extracellular levels of arginine, an amino acid that is essential for the parasite. During infection, the macrophage arginine pool is depleted due to its use to produce metabolites (NO and polyamines) that constitute part of the host defense response and its suppression, respectively. We found that parasites respond to this shortage of arginine by up-regulating expression and activity of the Leishmania arginine transporter (LdAAP3), as well as several other transporters. Our analysis indicates the parasite monitors arginine levels in the environment rather than the intracellular pools. Phosphoproteomics and genetic analysis indicates that the arginine-deprivation response is mediated through a mitogen-activated protein kinase-2-dependent signaling cascade. PMID:27043018

  12. Dectin-1-dependent LC3 recruitment to phagosomes enhances fungicidal activity in macrophages.

    PubMed

    Tam, Jenny M; Mansour, Michael K; Khan, Nida S; Seward, Michael; Puranam, Sravanthi; Tanne, Antoine; Sokolovska, Anna; Becker, Christine E; Acharya, Mridu; Baird, Michelle A; Choi, Augustine M K; Davidson, Michael W; Segal, Brahm H; Lacy-Hulbert, Adam; Stuart, Lynda M; Xavier, Ramnik J; Vyas, Jatin M

    2014-12-01

    Autophagy has been postulated to play role in mammalian host defense against fungal pathogens, although the molecular details remain unclear. Here, we show that primary macrophages deficient in the autophagic factor LC3 demonstrate diminished fungicidal activity but increased cytokine production in response to Candida albicans stimulation. LC3 recruitment to fungal phagosomes requires activation of the fungal pattern receptor dectin-1. LC3 recruitment to the phagosome also requires Syk signaling but is independent of all activity by Toll-like receptors and does not require the presence of the adaptor protein Card9. We further demonstrate that reactive oxygen species generation by NADPH oxidase is required for LC3 recruitment to the fungal phagosome. These observations directly link LC3 to the inflammatory pathway against C. albicans in macrophages. PMID:24842831

  13. Elucidation of monocyte/macrophage dynamics and function by intravital imaging

    PubMed Central

    Rua, Rejane; McGavern, Dorian B.

    2015-01-01

    Monocytes and macrophages are a diverse population of innate immune cells that play a critical role in homeostasis and inflammation. These cells are surveillant by nature and closely monitor the vasculature and surrounding tissue during states of health and disease. Given their abundance and strategic positioning throughout the body, myeloid cells are among the first responders to any inflammatory challenge and are active participants in most immune-mediated diseases. Recent studies have shed new light on myeloid cell dynamics and function by use of an imaging technique referred to as intravital microscopy (IVM). This powerful approach allows researchers to gain real-time insights into monocytes and macrophages performing homeostatic and inflammatory tasks in living tissues. In this review, we will present a contemporary synopsis of how intravital microscopy has revolutionized our understanding of myeloid cell contributions to vascular maintenance, microbial defense, autoimmunity, tumorigenesis, and acute/chronic inflammatory diseases. PMID:26162402

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

    PubMed Central

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

    2011-01-01

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

  15. The Paramyxoviruses Simian Virus 5 and Mumps Virus Recruit Host Cell CD46 To Evade Complement-Mediated Neutralization ▿

    PubMed Central

    Johnson, John B.; Grant, Ken; Parks, Griffith D.

    2009-01-01

    The complement system is a critical component of the innate immune response that all animal viruses must face during natural infections. Our previous results have shown that treatment of the paramyxovirus simian virus 5 (SV5) with human serum results in deposition of complement C3-derived polypeptides on virion particles. Here, we show that the virion-associated C3 component includes the inactive form iC3b, suggesting that SV5 may have mechanisms to evade the host complement system. Electron microscopy, gradient centrifugation, and Western blot analysis indicated that purified SV5 virions derived from human A549 cells contained CD46, a plasma membrane-expressed regulator of complement that acts as a cofactor for cleavage and inactivation of C3b into iC3b. In vitro cleavage assays with purified complement components showed that SV5 virions had C3b cofactor activity, resulting in specific factor I-mediated cleavage of C3b into inactive iC3b. SV5 particles generated in CHO cells, which do not express CD46, did not have cofactor activity. Conversely, virions derived from a CHO cell line that was engineered to overexpress human CD46 contained elevated levels of virion-associated CD46 and displayed enhanced C3b cofactor activity. In comparison with C3b, purified SV5 virions had very low cofactor activity against C4b, consistent with the known preference of CD46 for C3b versus C4b. Similar results were obtained for the closely related mumps virus (MuV), except that MuV particles derived from CHO-CD46 cells had higher C4b cofactor activity than SV5 virions. In neutralization assays with human serum, SV5 and MuV containing CD46 showed slower kinetics and more resistance to neutralization than SV5 and MuV that lacked CD46. Our results support a model in which the rubulaviruses SV5 and MuV incorporate cell surface complement inhibitors into progeny virions as a mechanism to limit complement-mediated neutralization. PMID:19457998

  16. An Evolutionarily Conserved PLC-PKD-TFEB Pathway for Host Defense.

    PubMed

    Najibi, Mehran; Labed, Sid Ahmed; Visvikis, Orane; Irazoqui, Javier Elbio

    2016-05-24

    The mechanisms that tightly control the transcription of host defense genes have not been fully elucidated. We previously identified TFEB as a transcription factor important for host defense, but the mechanisms that regulate TFEB during infection remained unknown. Here, we used C. elegans to discover a pathway that activates TFEB during infection. Gene dkf-1, which encodes a homolog of protein kinase D (PKD), was required for TFEB activation in nematodes infected with Staphylococcus aureus. Conversely, pharmacological activation of PKD was sufficient to activate TFEB. Furthermore, phospholipase C (PLC) gene plc-1 was also required for TFEB activation, downstream of Gαq homolog egl-30 and upstream of dkf-1. Using reverse and chemical genetics, we discovered a similar PLC-PKD-TFEB axis in Salmonella-infected mouse macrophages. In addition, PKCα was required in macrophages. These observations reveal a previously unknown host defense signaling pathway, which has been conserved across one billion years of evolution.

  17. An Evolutionarily Conserved PLC-PKD-TFEB Pathway for Host Defense.

    PubMed

    Najibi, Mehran; Labed, Sid Ahmed; Visvikis, Orane; Irazoqui, Javier Elbio

    2016-05-24

    The mechanisms that tightly control the transcription of host defense genes have not been fully elucidated. We previously identified TFEB as a transcription factor important for host defense, but the mechanisms that regulate TFEB during infection remained unknown. Here, we used C. elegans to discover a pathway that activates TFEB during infection. Gene dkf-1, which encodes a homolog of protein kinase D (PKD), was required for TFEB activation in nematodes infected with Staphylococcus aureus. Conversely, pharmacological activation of PKD was sufficient to activate TFEB. Furthermore, phospholipase C (PLC) gene plc-1 was also required for TFEB activation, downstream of Gαq homolog egl-30 and upstream of dkf-1. Using reverse and chemical genetics, we discovered a similar PLC-PKD-TFEB axis in Salmonella-infected mouse macrophages. In addition, PKCα was required in macrophages. These observations reveal a previously unknown host defense signaling pathway, which has been conserved across one billion years of evolution. PMID:27184844

  18. [Multiplication of Brucella abortus and production of nitric oxide in two macrophage cell lines of different origin].

    PubMed

    Serafino, J; Conde, S; Zabal, O; Samartino, L

    2007-01-01

    Brucella abortus is a bacterium which causes abortions and infertility in cattle and undulant fever in humans. It multiplies intracellularly, evading the mechanisms of cellular death. Nitric oxide (NO) is important in the regulation of the immune response. In the present work, we studied the ability of three B. abortus strains to survive intracellularly in two macrophage cell lines. The bacterial multiplication in both cell lines was determined at two different times in UFC/ ml units. Moreover the inoculated cells were also observed under light-field and fluorescence microscopy stained with Giemsa and acridine orange, respectively. The stain of both cellular lines showed similar results with respect to the UFC/ml determination. The presence of B. abortus was confirmed by electronic microscopy. In both macrophage cell lines inoculated with the rough strain RB51, the multiplication diminished and the level of NO was higher, compared with cells inoculated with smooth strains (S19 and 2308). These results suggest that the absence of O-chain of LPS probably affects the intracellular growth of B. abortus.

  19. Binding Sites for Acylated Trehalose Analogs of Glycolipid Ligands on an Extended Carbohydrate Recognition Domain of the Macrophage Receptor Mincle*

    PubMed Central

    Feinberg, Hadar; Rambaruth, Neela D. S.; Jégouzo, Sabine A. F.; Jacobsen, Kristian M.; Djurhuus, Rasmus; Poulsen, Thomas B.; Weis, William I.; Taylor, Maureen E.; Drickamer, Kurt

    2016-01-01

    The macrophage receptor mincle binds to trehalose dimycolate on the surface of Mycobacterium tuberculosis. Signaling initiated by this interaction leads to cytokine production, which underlies the ability of mycobacteria to evade the immune system and also to function as adjuvants. In previous work the mechanism for binding of the sugar headgroup of trehalose dimycolate to mincle has been elucidated, but the basis for enhanced binding to glycolipid ligands, in which hydrophobic substituents are attached to the 6-hydroxyl groups, has been the subject of speculation. In the work reported here, the interaction of trehalose derivatives with bovine mincle has been probed with a series of synthetic mimics of trehalose dimycolate in binding assays, in structural studies by x-ray crystallography, and by site-directed mutagenesis. Binding studies reveal that, rather than reflecting specific structural preference, the apparent affinity of mincle for ligands with hydrophobic substituents correlates with their overall size. Structural and mutagenesis analysis provides evidence for interaction of the hydrophobic substituents with multiple different portions of the surface of mincle and confirms the presence of three Ca2+-binding sites. The structure of an extended portion of the extracellular domain of mincle, beyond the minimal C-type carbohydrate recognition domain, also constrains the way the binding domains may interact on the surface of macrophages. PMID:27542410

  20. Novel role of the nitrite transporter NirC in Salmonella pathogenesis: SPI2-dependent suppression of inducible nitric oxide synthase in activated macrophages.

    PubMed

    Das, Priyanka; Lahiri, Amit; Lahiri, Ayan; Chakravortty, Dipshikha

    2009-08-01

    Activation of macrophages by interferon gamma (IFN-gamma) and the subsequent production of nitric oxide (NO) are critical for the host defence against Salmonella enterica serovar Typhimurium infection. We report here the inhibition of IFN-gamma-induced NO production in RAW264.7 macrophages infected with wild-type Salmonella. This phenomenon was shown to be dependent on the nirC gene, which encodes a potential nitrite transporter. We observed a higher NO output from IFN-gamma-treated macrophages infected with a nirC mutant of Salmonella. The nirC mutant also showed significantly decreased intracellular proliferation in a NO-dependent manner in activated RAW264.7 macrophages and in liver, spleen and secondary lymph nodes of mice, which was restored by complementing the gene in trans. Under acidified nitrite stress, a twofold more pronounced NO-mediated repression of SPI2 was observed in the nirC knockout strain compared to the wild-type. This enhanced SPI2 repression in the nirC knockout led to a higher level of STAT-1 phosphorylation and inducible nitric oxide synthase (iNOS) expression than seen with the wild-type strain. In iNOS knockout mice, the organ load of the nirC knockout strain was similar to that of the wild-type strain, indicating that the mutant is exclusively sensitive to the host nitrosative stress. Taken together, these results reveal that intracellular Salmonella evade killing in activated macrophages by downregulating IFN-gamma-induced NO production, and they highlight the critical role of nirC as a virulence gene.

  1. Effect of aqueous extract of Tinospora cordifolia on functions of peritoneal macrophages isolated from CCl4 intoxicated male albino mice

    PubMed Central

    2011-01-01

    cordifolia at a dose of 150 mg/kg body weight. Conclusion From our findings it can be suggested that, polar fractions of Tinospora cordifolia stem parts contain major bioactive compounds, which directly act on peritoneal macrophages and have been found to boost the non-specific host defenses of the immune system. However, the molecular mechanism of this activity of Tinospora cordifolia on immune functions needs to be elucidated. PMID:22035196

  2. 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

  3. 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.

  4. Changing pattern of the subcellular distribution of erythroblast macrophage protein (Emp) during macrophage differentiation.

    PubMed

    Soni, Shivani; Bala, Shashi; Kumar, Ajay; Hanspal, Manjit

    2007-01-01

    Erythroblast macrophage protein (Emp) mediates the attachment of erythroid cells to macrophages and is required for normal differentiation of both cell lineages. In erythroid cells, Emp is believed to be involved in nuclear extrusion, however, its role in macrophage differentiation is unknown. Information on the changes in the expression level and subcellular distribution of Emp in differentiating macrophages is essential for understanding the function of Emp. Macrophages of varying maturity were examined by immunofluorescence microscopy and biochemical methods. Our data show that Emp is expressed in all stages of maturation, but its localization pattern changes dramatically during maturation: in immature macrophages, a substantial fraction of Emp is associated with the nuclear matrix, whereas in more mature cells, Emp is expressed largely at cell surface. Pulse-chase experiments show that nascent Emp migrates intracellularly from the cytoplasm to the plasma membrane more efficiently in mature macrophages than in immature cells. Incubation of erythroid cells with macrophages in culture shows that erythroid cells attach to mature macrophages but not to immature macrophage precursors. Together, our data show that the temporal and spatial expression of Emp correlates with its role in erythroblastic island formation and suggest that Emp may be involved in multiple cellular functions.

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

    PubMed

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

    2010-10-01

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

  6. Glutathione Reductase Is Essential for Host Defense against Bacterial Infection

    PubMed Central

    Yan, Jing; Ralston, Melissa M.; Meng, Xiaomei; Bongiovanni, Kathleen D.; Jones, Amanda L.; Benndorf, Rainer; Nelin, Leif D.; Frazier, W. Joshua; Rogers, Lynette K.; Smith, Charles V.; Liu, Yusen

    2013-01-01

    Glutathione reductase (Gsr)1 catalyzes the reduction of glutathione disulfide to glutathione, a major cellular antioxidant. We have recently shown that Gsr is essential for host defense against the Gram-negative bacteria Escherichia coli in a mouse model of sepsis. While we have demonstrated that Gsr is required for sustaining the oxidative burst and the development of neutrophil extracellular traps, the role of Gsr in other phagocytic functions remains unclear. It is also unclear whether Gsr-deficient mice exhibit host defense defects against Gram-positive bacteria. In the present study, we characterized the effects of Gsr deficiency on the innate immune responses to a Gram-positive bacterium, group B Streptococcus, and to the Gram-negative bacterial cell wall component lipopolysaccharide (LPS). We found that like, E. coli, group B Streptococcus resulted in a substantially more robust cytokine response and a markedly higher morbidity and mortality in Gsr-deficient mice than in wildtype mice. The increased morbidity and mortality were associated with greater bacterial burden in the Gsr-deficient mice. Interestingly, Gsr-deficient mice did not exhibit a greater sensitivity to LPS than did wildtype mice. Analysis of the neutrophils of Gsr-deficient mice revealed impaired phagocytosis. In response to thioglycollate stimulation, Gsr-deficient mice mobilized far fewer phagocytes, including neutrophils, macrophages, and eosinophils, into their peritoneal cavities than did wildtype mice. The defective phagocyte mobilization is associated with profound oxidation and aggregation of ascitic proteins, particularly albumin. Our results indicate that the oxidative defense mechanism mediated by Gsr is required for an effective innate immune response against bacteria, likely by preventing phagocyte dysfunction due to oxidative damage. PMID:23623936

  7. Issues in national missile defense

    SciTech Connect

    Canavan, G.H.

    1998-12-01

    Strategic missiles and weapons are proliferating rapidly; thus, the US and its Allies are likely to face both capable bilateral threats and multilateral configurations with complex coalitions for which defenses could be essential for stability. Current hit-to-kill interceptor and radar and infrared detection, track, and discrimination technology should suffice for limited threats, but it is necessary to meet those threats in time while maintaining growth potential for the more sophisticated threats likely to follow. National Missile Defense faces a confusing array of threats, programs, and alternatives, but the technologies in development are clearly an appropriate first step towards any of them. They are likely to succeed in the near term; the challenge is to retain flexibility to provide needed options in the mid and long terms.

  8. Defense bill: Earmarking as usual

    NASA Astrophysics Data System (ADS)

    Earmarked funds in the $268 billion defense appropriations bill for fiscal year 1991 stirred congressional debate in late October. Senator Sam Nunn (D-Ga.), chairman of the Senate Armed Services Committee, charged that the defense bill contains questionable projects totaling tens of millions of dollars. AGU opposes legislative earmarking of money for particular institutions, maintaining that the practice prevents the best use of federal funding by circumventing competitive review. Nunn noted on the Senate floor that the appropriations bill provided specific funds for cited institutions—contravening a federal law promoting competition. “ If these programs have merit, they will succeed in a fair and competent review in competition,” Nunn said. “If no other institution in the country is able to compete, there should be no fear whatever of competition… But no one else in the world is allowed to compete to work on these projects.”

  9. The insanity defense to suicide.

    PubMed

    Massello, W

    1986-07-01

    The certification of suicide as the manner of death can result in either the complete loss or a significant reduction in life insurance benefits to the victim's survivors. It is, thus, not uncommon for these beneficiaries to contest suicide as the manner of death. Insanity is a recognized defense in law against suicide. It is recognized in law that, in some cases, an insane man cannot intentionally destroy himself. However, it is also recognized that life insurers can exclude suicide by an insane man from coverage. This article discusses the common law doctrines upon which the insanity defense to suicide is based, with references to judicial opinions from cases which involve contested suicides and the issue of insanity.

  10. Homeland Security and Defense Applications

    SciTech Connect

    2014-11-06

    Homeland Security and Defense Applications personnel are the best in the world at detecting and locating dirty bombs, loose nukes, and other radiological sources. The site trains the Nation's emergency responders, who would be among the first to confront a radiological or nuclear emergency. Homeland Security and Defense Applications highly training personnel, characterize the threat environment, produce specialized radiological nuclear detection equipment, train personnel on the equipment and its uses, test and evaluate the equipment, and develop different kinds of high-tech equipment to defeat terrorists. In New York City for example, NNSS scientists assisted in characterizing the radiological nuclear environment after 9/11, and produced specialized radiological nuclear equipment to assist local officials in their Homeland Security efforts.

  11. Second line of defense program

    SciTech Connect

    Cantut, L; Thomas, L L

    1999-07-15

    Since the collapse of the Soviet Union, the prospect of nuclear materials entering the world market has become an ever-increasing threat. The Second Line of Defense (SLD) program was developed by the U.S. Department of Energy's (DOE) Nuclear Transfer and Supplier Policy Division (NN-43) to assist the Russian Federation State Customs Committee (RFSCC) in strengthening its capability to prevent illicit trafficking of nuclear materials across Russia's borders. The SLD program is a natural complement to the Material Protection Control and Accounting (MPC and A) program, which represents a first line of defense against the theft and diversion of nuclear materials. The SLD program is the first U.S.-Russian cooperative program to combat the illicit trafficking of nuclear and nuclear-related materials to would-be proliferators across Russia's borders.

  12. Homeland Security and Defense Applications

    ScienceCinema

    None

    2016-07-12

    Homeland Security and Defense Applications personnel are the best in the world at detecting and locating dirty bombs, loose nukes, and other radiological sources. The site trains the Nation's emergency responders, who would be among the first to confront a radiological or nuclear emergency. Homeland Security and Defense Applications highly training personnel, characterize the threat environment, produce specialized radiological nuclear detection equipment, train personnel on the equipment and its uses, test and evaluate the equipment, and develop different kinds of high-tech equipment to defeat terrorists. In New York City for example, NNSS scientists assisted in characterizing the radiological nuclear environment after 9/11, and produced specialized radiological nuclear equipment to assist local officials in their Homeland Security efforts.

  13. Technical issues in theater missile defense

    SciTech Connect

    Canavan, G.H.

    1992-05-01

    This note discusses technical issues in theater missile defenses in the terminal, midcourse, and boost phases. The first two are familiar and developed, but face fundamental countermeasures. Boost phase intercepts engage missiles when they are most vulnerable, but have been studied less for theater defense because the engagement times are short. Overall, theater missile defenses resemble strategic defenses, complicated by the tenfold shorter boost phase. 12 refs.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2015-10-01

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

  16. Specific Neuropilins Expression in Alveolar Macrophages among Tissue-Specific Macrophages

    PubMed Central

    Aung, Naing Ye; Ohe, Rintaro; Meng, Hongxue; Kabasawa, Takanobu; Yang, Suran; Kato, Tomoya; Yamakawa, Mitsunori

    2016-01-01

    In the immune system, neuropilins (NRPs), including NRP-1 and NRP-2, are expressed in thymocytes, dendritic cells, regulatory T cells and macrophages. Their functions on immune cells around the neoplastic cells vary into pro-angiogenesis, tumor progression and anti-angiogenesis according to their ligands. Even though NRPs expression on malignant tumors and immune system has studied, a PubMed-based literature query did not yield any articles describing NRPs expression on tissue-specific macrophages. The aims of this study were (i) to detect NRPs expression on tissue-specific macrophages in the brain, liver, spleen, lymph node and lung; (ii) to observe NRPs expression in classes of macrophages, including alveolar macrophages (AMs), bronchial macrophages (BMs), interstitial macrophages (IMs), intravascular macrophages (IVMs) and macrophage subsets (M1, M2 and Mox) in lung; and (iii) to detect the co-expression of NRPs and dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN) in AMs. Both NRPs were specifically detected in AMs among tissue-specific macrophages by immunohistochemistry (IHC). NRPs mRNA expression levels were characterized in normal lung by reverse transcriptase polymerase chain reaction (RT-PCR) and in situ-polymerase chain reaction (in situ-PCR). The expression of both NRPs was detected in AMs, BMs and IVMs by IHC. The frequency of NRPs+ AMs in lung tissue adjacent to the cancer margin was significantly higher than the frequencies in inflamed and normal lung tissue. Double and triple IHC demonstrated that NRPs are expressed on all macrophage subsets in lung. Double IHC showed co-expression of DC-SIGN and NRPs in AMs. This study demonstrated for the first time the specific expression of both NRPs in AMs among tissue-specific macrophages and their expression on M1, M2 and Mox macrophages. Furthermore, the possible origin of AMs from blood monocytes could be suggested from a co-expression of NRPs and DC-SIGN. PMID:26900851

  17. Defense of a space elevator

    SciTech Connect

    Laubscher, B. E.

    2004-01-01

    The Space Elevator (SE) represents a major paradigm shift in space access. If the SE's promise of low-cost access is to be realized, everything becomes economically more feasible to accomplish in space. In this paper we describe a defensive system of the SE. The primary scenario adopted for this analysis is the SE based on a floating platform in the ocean along the equator. A second possible scenario is the SE stationed on land (island or continent) on or near the equator. The SE will capture the imaginations of people around the world. It will become a symbol of power, capability, wealth and prestige for the country that builds it. As such, it will become a prime terrorist target. Moreover, the tremendous economic leverage afforded by the SE might motivate rogue nations to plot its destruction. Therefore, it is necessary to consider the requirements for defense of the SE. For the purposes of this paper it is assumed that the SE is to be deployed by the United States or one of its companies, and the resources of the US are available for its defense.

  18. Problems of National Missile Defense

    NASA Astrophysics Data System (ADS)

    Cornwall, John

    2000-04-01

    The currently-proposed national missile defense (NMD) is supposed to counter accidental Russian or Chinese launches of intercontinental nuclear-armed missiles, or rogue nation launches of similar nuclear missiles or of missiles armed with biological weapons, by using mid-course hit-to-kill vehicles guided by IR and radar. But it seems very likely that any nation capable of building (or buying) such a missile offense can build (or buy) effective countermeasures to NMD. These include anti-simulation decoys made of multi-layer insulation (MLI), with warheads covered in MLI sheaths so their signatures resemble those of the decoys. MLI can be effective against both passive IR and radar detection/discrimination. Biological warheads can counter any mid-course defense by releasing a great number of submunitions early in flight. Both nuclear and biological weapons can be deployed by other means, including covert ships in port; trucks; and cruise missiles. The best defense against Russian/Chinese accidental launches is assistance to these countries in improving their launch control systems.

  19. 22 CFR 120.6 - Defense article.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Defense article. 120.6 Section 120.6 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.6 Defense article. Defense article means any item or technical data designated in § 121.1 of this...

  20. 22 CFR 120.6 - Defense article.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Defense article. 120.6 Section 120.6 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.6 Defense article. Defense article means any item or technical data designated in § 121.1 of this...

  1. 22 CFR 120.6 - Defense article.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Defense article. 120.6 Section 120.6 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.6 Defense article. Defense article means any item or technical data designated in § 121.1 of this...

  2. 22 CFR 120.6 - Defense article.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Defense article. 120.6 Section 120.6 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.6 Defense article. Defense article means any item or technical data designated in § 121.1 of this...

  3. 22 CFR 120.6 - Defense article.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Defense article. 120.6 Section 120.6 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.6 Defense article. Defense article means any item or technical data designated in § 121.1 of this...

  4. 22 CFR 120.9 - Defense service.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Defense service. (a) Defense service means: (1) The furnishing of assistance (including training) to foreign persons, whether in the United States or abroad in the design, development, engineering... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Defense service. 120.9 Section 120.9...

  5. Radiological Defense. Planning and Operations Guide. Revised.

    ERIC Educational Resources Information Center

    Office of Civil Defense (DOD), Washington, DC.

    This guide is a reprint of published and draft materials from the Federal Civil Defense Guide. This guide is intended to assist the student in planning, developing, implementing and operating a local, county, or state radiological defense (RADEF) system. The state and local radiological defense program objectives are to create an effective and…

  6. Ontogeny of Tissue-Resident Macrophages

    PubMed Central

    Hoeffel, Guillaume; Ginhoux, Florent

    2015-01-01

    The origin of tissue-resident macrophages, crucial for homeostasis and immunity, has remained controversial until recently. Originally described as part of the mononuclear phagocyte system, macrophages were long thought to derive solely from adult blood circulating monocytes. However, accumulating evidence now shows that certain macrophage populations are in fact independent from monocyte and even from adult bone marrow hematopoiesis. These tissue-resident macrophages derive from sequential seeding of tissues by two precursors during embryonic development. Primitive macrophages generated in the yolk sac (YS) from early erythro-myeloid progenitors (EMPs), independently of the transcription factor c-Myb and bypassing monocytic intermediates, first give rise to microglia. Later, fetal monocytes, generated from c-Myb+ EMPs that initially seed the fetal liver (FL), then give rise to the majority of other adult macrophages. Thus, hematopoietic stem cell-independent embryonic precursors transiently present in the YS and the FL give rise to long-lasting self-renewing macrophage populations. PMID:26441990

  7. Developmental origin of lung macrophage diversity

    PubMed Central

    Tan, Serena Y. S.; Krasnow, Mark A.

    2016-01-01

    Macrophages are specialized phagocytic cells, present in all tissues, which engulf and digest pathogens, infected and dying cells, and debris, and can recruit and regulate other immune cells and the inflammatory response and aid in tissue repair. Macrophage subpopulations play distinct roles in these processes and in disease, and are typically recognized by differences in marker expression, immune function, or tissue of residency. Although macrophage subpopulations in the brain have been found to have distinct developmental origins, the extent to which development contributes to macrophage diversity between tissues and within tissues is not well understood. Here, we investigate the development and maintenance of mouse lung macrophages by marker expression patterns, genetic lineage tracing and parabiosis. We show that macrophages populate the lung in three developmental waves, each giving rise to a distinct lineage. These lineages express different markers, reside in different locations, renew in different ways, and show little or no interconversion. Thus, development contributes significantly to lung macrophage diversity and targets each lineage to a different anatomical domain. PMID:26952982

  8. Role of alveolar macrophages in innate immunity in neonates: evidence for selective lipopolysaccharide binding protein production by rat neonatal alveolar macrophages.

    PubMed

    Lee, P T; Holt, P G; McWilliam, A S

    2000-11-01

    As the first line of defense against inhaled substances, alveolar macrophages (AM) play a crucial role in maintaining lung homeostasis. This is achieved via phagocytosis of foreign material and the secretion of a wide range of mediator molecules, including those involved in neutrophil recruitment. Neonates are known to manifest increased susceptibility to lung infections, and we hypothesize that this may be due in part to a deficiency in the function of AM. We report here that although recruitment of neutrophils into the respiratory tract of newborn animals in response to Moraxalla catarrhalis exposure is greatly delayed and diminished, AM from newborn animals have greater phagocytic capacity when compared with those from adult animals. Additionally, newborn AM respond normally to lipopolysaccharide (LPS) via production of a variety of chemokines, including macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, monocyte chemotactic protein-1, gro/ cytokine-induced neutrophil chemoattractant, MIP-2, and tumor necrosis factor-alpha. We have also demonstrated an LPS inducible expression of messenger RNA for LPS binding protein (LBP) in neonatal AM that was not observed in AM from adult animals or in peritoneal macrophages. We speculate that local production of LBP by AM may be a significant factor in the neonatal immunologic response to infections, providing a compensatory mechanism for the deficiency in specific neonatal immunity during this period of development when the newborn is being exposed to a range of potentially pathogenic materials for the first time.

  9. 78 FR 78163 - Eligibility of the Gulf Cooperation Council To Receive Defense Articles and Defense Services...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ..., Washington, December 16, 2013. [FR Doc. 2013-30984 Filed 12-23-13; 11:15 am] Billing code 4710-10 ... Cooperation Council To Receive Defense Articles and Defense Services Under the Foreign Assistance Act of 1961... that the furnishing of defense articles and defense services to the Gulf Cooperation Council...

  10. 76 FR 71467 - Defense Federal Acquisition Regulation Supplement; Extension of Department of Defense Mentor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE... Federal Acquisition Regulation Supplement; Extension of Department of Defense Mentor-Prot g Pilot Program (DFARS Case 2011-D050) AGENCY: Defense Acquisition Regulations System, Department of Defense...

  11. 77 FR 11367 - Defense Federal Acquisition Regulation Supplement; Extension of the Department of Defense Mentor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF DEFENSE... Federal Acquisition Regulation Supplement; Extension of the Department of Defense Mentor-Prot g Pilot Program (DFARS Case 2012-D024) AGENCY: Defense Acquisition Regulations System, Department of Defense...

  12. 75 FR 65462 - Renewal of Department of Defense Federal Advisory Committee; Department of Defense Military...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Office of the Secretary Renewal of Department of Defense Federal Advisory Committee; Department of Defense Military Family Readiness Council AGENCY: Department of Defense (DoD). ACTION: Renewal of Federal...

  13. 76 FR 72391 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... (DLA) published a Notice of Availability (NOA) in the Federal Register (76 FR 28757) announcing the... of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION:...

  14. The killing of macrophages by Corynebacterium ulcerans.

    PubMed

    Hacker, Elena; Ott, Lisa; Schulze-Luehrmann, Jan; Lührmann, Anja; Wiesmann, Veit; Wittenberg, Thomas; Burkovski, Andreas

    2016-01-01

    Corynebacterium ulcerans is an emerging pathogen transmitted by a zoonotic pathway with a very broad host spectrum to humans. Despite rising numbers of infections and potentially fatal outcomes, data on the molecular basis of pathogenicity are scarce. In this study, the interaction of 2 C. ulcerans isolates - one from an asymptomatic dog, one from a fatal case of human infection - with human macrophages was investigated. C. ulcerans strains were able to survive in macrophages for at least 20 hours. Uptake led to delay of phagolysosome maturation and detrimental effects on the macrophages as deduced from cytotoxicity measurements and FACS analyses. The data presented here indicate a high infectious potential of this emerging pathogen.

  15. ERK Signaling Is Essential for Macrophage Development

    PubMed Central

    Richardson, Edward T.; Shukla, Supriya; Nagy, Nancy; Boom, W. Henry; Beck, Rose C.; Zhou, Lan; Landreth, Gary E.; Harding, Clifford V.

    2015-01-01

    Macrophages depend on colony stimulating factor 1 (also known as M-CSF) for their growth and differentiation, but the requirements for intracellular signals that lead to macrophage differentiation and function remain unclear. M-CSF is known to activate ERK1 and ERK2, but the importance of this signaling pathway in macrophage development is unknown. In these studies, we characterized a novel model of Erk1-/- Erk2flox/flox Lyz2Cre/Cre mice in which the ERK2 isoform is deleted from macrophages in the background of global ERK1 deficiency. Cultures of M-CSF-stimulated bone marrow precursors from these mice yielded reduced numbers of macrophages. Whereas macrophages developing from M-CSF-stimulated bone marrow of Erk2flox/flox Lyz2Cre/Cre mice showed essentially complete loss of ERK2 expression, the reduced number of macrophages that develop from Erk1-/- Erk2flox/flox Lyz2Cre/Cre bone marrow show retention of ERK2 expression, indicating selective outgrowth of a small proportion of precursors in which Cre-mediated deletion failed to occur. The bone marrow of Erk1-/- Erk2flox/flox Lyz2Cre/Cre mice was enriched for CD11b+ myeloid cells, CD11bhi Gr-1hi neutrophils, Lin- c-Kit+ Sca–1+ hematopoietic stem cells, and Lin- c-Kit+ CD34+ CD16/32+ granulocyte-macrophage progenitors. Culture of bone marrow Lin- cells under myeloid-stimulating conditions yielded reduced numbers of monocytes. Collectively, these data indicate that the defect in production of macrophages is not due to a reduced number of progenitors, but rather due to reduced ability of progenitors to proliferate and produce macrophages in response to M-CSF-triggered ERK signaling. Macrophages from Erk1-/- Erk2flox/flox Lyz2Cre/Cre bone marrow showed reduced induction of M-CSF-regulated genes that depend on the ERK pathway for their expression. These data demonstrate that ERK1/ERK2 play a critical role in driving M-CSF-dependent proliferation of bone marrow progenitors for production of macrophages. PMID:26445168

  16. 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

  17. Macrophages and Uveitis in Experimental Animal Models

    PubMed Central

    Mérida, Salvador; Palacios, Elena; Bosch-Morell, Francisco

    2015-01-01

    Resident and infiltrated macrophages play relevant roles in uveitis as effectors of innate immunity and inductors of acquired immunity. They are major effectors of tissue damage in uveitis and are also considered to be potent antigen-presenting cells. In the last few years, experimental animal models of uveitis have enabled us to enhance our understanding of the leading role of macrophages in eye inflammation processes, including macrophage polarization in experimental autoimmune uveoretinitis and the major role of Toll-like receptor 4 in endotoxin-induced uveitis. This improved knowledge should guide advantageous iterative research to establish mechanisms and possible therapeutic targets for human uveitis resolution. PMID:26078494

  18. ERK Signaling Is Essential for Macrophage Development.

    PubMed

    Richardson, Edward T; Shukla, Supriya; Nagy, Nancy; Boom, W Henry; Beck, Rose C; Zhou, Lan; Landreth, Gary E; Harding, Clifford V

    2015-01-01

    Macrophages depend on colony stimulating factor 1 (also known as M-CSF) for their growth and differentiation, but the requirements for intracellular signals that lead to macrophage differentiation and function remain unclear. M-CSF is known to activate ERK1 and ERK2, but the importance of this signaling pathway in macrophage development is unknown. In these studies, we characterized a novel model of Erk1(-/-) Erk2(flox/flox) Lyz2(Cre/Cre) mice in which the ERK2 isoform is deleted from macrophages in the background of global ERK1 deficiency. Cultures of M-CSF-stimulated bone marrow precursors from these mice yielded reduced numbers of macrophages. Whereas macrophages developing from M-CSF-stimulated bone marrow of Erk2(flox/flox) Lyz2(Cre/Cre) mice showed essentially complete loss of ERK2 expression, the reduced number of macrophages that develop from Erk1(-/-) Erk2(flox/flox) Lyz2(Cre/Cre) bone marrow show retention of ERK2 expression, indicating selective outgrowth of a small proportion of precursors in which Cre-mediated deletion failed to occur. The bone marrow of Erk1(-/-) Erk2(flox/flox) Lyz2(Cre/Cre) mice was enriched for CD11b+ myeloid cells, CD11b(hi) Gr-1(hi) neutrophils, Lin- c-Kit+ Sca-1+ hematopoietic stem cells, and Lin- c-Kit+ CD34+ CD16/32+ granulocyte-macrophage progenitors. Culture of bone marrow Lin- cells under myeloid-stimulating conditions yielded reduced numbers of monocytes. Collectively, these data indicate that the defect in production of macrophages is not due to a reduced number of progenitors, but rather due to reduced ability of progenitors to proliferate and produce macrophages in response to M-CSF-triggered ERK signaling. Macrophages from Erk1(-/-) Erk2(flox/flox) Lyz2(Cre/Cre) bone marrow showed reduced induction of M-CSF-regulated genes that depend on the ERK pathway for their expression. These data demonstrate that ERK1/ERK2 play a critical role in driving M-CSF-dependent proliferation of bone marrow progenitors for production of

  19. Identification and expression of macrophage migration inhibitory factor in Sarcoptes scabiei.

    PubMed

    Cote, N M; Jaworski, D C; Wasala, N B; Morgan, M S; Arlian, L G

    2013-09-01

    Macrophage migration inhibitory factor (MIF) is a pleiotropic proinflammatory cytokine produced by many mammalian tissues including skin. It is also found in many invertebrate parasites of mammals including ticks and may function to aid the parasite to evade the innate and adaptive immune responses in the host. In this study, the cDNA for a MIF gene was sequenced from Sarcoptes scabiei, the scabies mite, using RT-PCR and RACE molecular techniques. The resulting nucleotide sequence had a length of 405 base pairs and the putative amino acid sequences for the mite and tick (Dermacentor variabilis) proteins were identical. The initial steps for the project resulted in the production of expressed scabies mite cDNAs. A real time (qPCR) assay was performed with MIF from scabies mites and various tick species. Results show that mRNA encoding MIF homologues was three times more abundant in the mite samples when compared to RNA prepared from D. variabilis salivary glands and 1.3 times more abundant when compared with RNA prepared from D. variabilis midgut.

  20. IL-15 protects NKT cells from inhibition by tumor-associated macrophages and enhances antimetastatic activity.

    PubMed

    Liu, Daofeng; Song, Liping; Wei, Jie; Courtney, Amy N; Gao, Xiuhua; Marinova, Ekaterina; Guo, Linjie; Heczey, Andras; Asgharzadeh, Shahab; Kim, Eugene; Dotti, Gianpietro; Metelitsa, Leonid S

    2012-06-01

    Vα24-invariant NKT cells inhibit tumor growth by targeting tumor-associated macrophages (TAMs). Tumor progression therefore requires that TAMs evade NKT cell activity through yet-unknown mechanisms. Here we report that a subset of cells in neuroblastoma (NB) cell lines and primary tumors expresses membrane-bound TNF-α (mbTNF-α). These proinflammatory tumor cells induced production of the chemokine CCL20 from TAMs via activation of the NF-κB signaling pathway, an effect that was amplified in hypoxia. Flow cytometry analyses of human primary NB tumors revealed selective accumulation of CCL20 in TAMs. Neutralization of the chemokine inhibited in vitro migration of NKT cells toward tumor-conditioned hypoxic monocytes and localization of NKT cells to NB grafts in mice. We also found that hypoxia impaired NKT cell viability and function. Thus, CCL20-producing TAMs served as a hypoxic trap for tumor-infiltrating NKT cells. IL-15 protected antigen-activated NKT cells from hypoxia, and transgenic expression of IL-15 in adoptively transferred NKT cells dramatically enhanced their antimetastatic activity in mice. Thus, tumor-induced chemokine production in hypoxic TAMs and consequent chemoattraction and inhibition of NKT cells represents a mechanism of immune escape that can be reversed by adoptive immunotherapy with IL-15-transduced NKT cells.

  1. [The effect of silica on the development of experimental Acanthamoeba meningoencephalitis with reference to the macrophage role in mice].

    PubMed

    Lee, H S; Shin, H J; La, M S; Im, K

    1994-12-01

    The role of macrophages was observed in intranasally infected C3H/HeJ mice with trophozoites (3 x 10(5)) of Acanthamoeba culbertsoni which was a kind of free-living amoebae inducing meningoencephalitis in human and experimental animals. The mortality was 60% in the group of intraperitoneally injected mice with silica (0.5 mg/0.5 ml). It was much higher than that of 10% in the group of amoeba infected mice without silica administration. The phagocytic index of peritoneal macrophages co-cultured with Toxoplasma gondii was estimated daily. In contrast to the control and amoeba infected group which didn't show significant fluctuation of the phagocytic indices, the silica administrated group revealed under 3% until day 3, and gradual increase up to 24.7% in day 5 which was same level of amoeba infected group without silica administration. The level of interleukin-1b (IL-1b) measured by ELISA was the highest in the amoeba infected group without silica injection and the lowest in the amoeba infected group with silica administration. In the test of the amoebicidal activity of mice peritoneal macrophages in vitro, silica administration revealed reducing effect on amoebicidal activity of macrophages. In conclusion, macrophages were proven to play a significant role in defense mechanism against the development of experimentally induced Acanthamoeba meningoencephalitis. PMID:7834243

  2. 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.

  3. Vibrio cholerae porin OmpU mediates M1-polarization of macrophages/monocytes via TLR1/TLR2 activation.

    PubMed

    Khan, Junaid; Sharma, Praveen K; Mukhopadhaya, Arunika

    2015-11-01

    Polarization of the monocytes and macrophages toward the M1 and M2 states is important for hosts' defense against the pathogens. Moreover, it plays a crucial role to resolve the overwhelming inflammatory responses that can be harmful to the host. Polarization of macrophages/monocytes can be induced by pathogen-associated molecular patterns (PAMPs). PAMP-mediated monocyte/macrophage polarization is important during the infection, as pathogen can suppress host immune system by altering the polarization status of the macrophages/monocytes. OmpU, an outer membrane porin protein of Vibrio cholerae, possesses the ability to induce pro-inflammatory responses in monocytes/macrophages. It is also able to down-regulate the LPS-mediated activation of the monocytes/macrophages. Such observation leads us to believe that OmpU may induce a state that can be called as M1/M2-intermediate state. In the present study, we evaluated a set of M1 and M2 markers in RAW 264.7 murine macrophage cell line, and THP-1 human monocytic cell line, in response to the purified OmpU protein. We observed that OmpU, as a PAMP, induced M1-polarization by activating the Toll-like receptor (TLR) signaling pathway. OmpU induced formation of TLR1/TLR2-heterodimers. OmpU-mediated TLR-activation led to the MyD88 recruitment to the TLR1/TLR2 complex. MyD88, in turn, recruited IRAK1. Ultimately, OmpU-mediated signaling led to the activation and subsequent nuclear translocation of the NFκB p65 subunit. We also observed that blocking of the TLR1, TLR2, IRAK1, and NFκB affected OmpU-mediated production of M1-associated pro-inflammatory cytokines such as TNFα and IL-6.

  4. Contrasting regulation of macrophage iron homeostasis in response to infection with Listeria monocytogenes depending on localization of bacteria.

    PubMed

    Haschka, David; Nairz, Manfred; Demetz, Egon; Wienerroither, Sebastian; Decker, Thomas; Weiss, Günter

    2015-06-01

    Due to its multiple roles for the proliferation and pathogenicity of many microbes on the one hand and via modulation of immune effector functions on the other hand the control over iron homeostasis is thought to play a decisive role in the course of infections. Diversion of cellular iron traffic is considered as an important defense mechanism of macrophages to reduce metal availability for intracellular bacteria residing in the phagosome. However, evidence is lacking whether such alterations of iron homeostasis also become evident upon infection with bacteria gaining access to the cytosol like Listeria monocytogenes. Here we show that infection of macrophages with L. monocytogenes triggers the expression of the major cellular iron exporter ferroportin1 and induces cellular iron egress. As the growth of Listeria within macrophages is promoted by iron, stimulation of ferroportin1 functionality limits the availability of the metal for Listeria residing in the cytoplasm, whereas ferroportin1 degradation upon hepcidin treatment increases intracellular bacterial growth. In parallel to an increase of ferroportin1 expression, infected macrophages induce anti-microbial immune effector mechanisms such as TNFα formation or NO expression which are aggravated upon iron deficiency. These adaptive changes of iron homeostasis and immune response pathways are only found in macrophages infected with Listeria which express listeriolysin O and are therefore able to escape from the phagosome to the cytoplasm. Listeriolysin O deficient Listeria which are restricted to the phagosome are even killed by excess iron which may be based on "iron intoxification" via macrophage radical formation, because iron supplementation in that setting is paralleled by increased ROS formation. Our results indicate that ferroportin1 mediated iron export is a nutritional immune effector pathway to control infection with Listeria residing in the cytoplasm, whereas a different strategy is observed in mutant

  5. Priming of antiherbivore defensive responses in plants.

    PubMed

    Kim, Jinwon; Felton, Gary W

    2013-06-01

    Defense priming is defined as increased readiness of defense induction. A growing body of literature indicates that plants (or intact parts of a plant) are primed in anticipation of impending environmental stresses, both biotic and abiotic, and upon the following stimulus, induce defenses more quickly and strongly. For instance, some plants previously exposed to herbivore-inducible plant volatiles (HIPVs) from neighboring plants under herbivore attack show faster or stronger defense activation and enhanced insect resistance when challenged with secondary insect feeding. Research on priming of antiherbivore defense has been limited to the HIPV-mediated mechanism until recently, but significant advances were made in the past three years, including non-HIPV-mediated defense priming, epigenetic modifications as the molecular mechanism of priming, and others. It is timely to consider the advances in research on defense priming in the plant-insect interactions.

  6. The response of macrophages to titanium particles is determined by macrophage polarization.

    PubMed

    Pajarinen, Jukka; Kouri, Vesa-Petteri; Jämsen, Eemeli; Li, Tian-Fang; Mandelin, Jami; Konttinen, Yrjö T

    2013-11-01

    Aseptic loosening of total joint replacements is driven by the reaction of macrophages to foreign body particles released from the implant. It was hypothesized that the macrophages' response to these particles is dependent, in addition to particle characteristics and contaminating biomolecules, on the state of macrophage polarization as determined by the local cytokine microenvironment. To test this hypothesis we differentiated M1 and M2 macrophages from human peripheral blood monocytes and compared their responses to titanium particles using genome-wide microarray analysis and a multiplex cytokine assay. In comparison to non-activated M0 macrophages, the overall chemotactic and inflammatory responses to titanium particles were greatly enhanced in M1 macrophages and effectively suppressed in M2 macrophages. In addition, the genome-wide approach revealed several novel, potentially osteolytic, particle-induced mediators, and signaling pathway analysis suggested the involvement of toll-like and nod-like receptor signaling in particle recognition. It is concluded that the magnitude of foreign body reaction caused by titanium particles is dependent on the state of macrophage polarization. Thus, by limiting the action of M1 polarizing factors, e.g. bacterial biofilm formation, in peri-implant tissues and promoting M2 macrophage polarization by biomaterial solutions or pharmacologically, it might be possible to restrict wear-particle-induced inflammation and osteolysis.

  7. Fetuin-A-Containing Calciprotein Particles Reduce Mineral Stress in the Macrophage

    PubMed Central

    Smith, Edward R.; Hanssen, Eric; McMahon, Lawrence P.; Holt, Stephen G.

    2013-01-01

    The formation of fetuin-A-containing calciprotein particles (CPP) may facilitate the clearance of calcium phosphate nanocrystals from the extracellular fluid. These crystals may otherwise seed extra-osseous mineralization. Fetuin-A is a partially phosphorylated glycoprotein that plays a critical role in stabilizing these particles, inhibiting crystal growth and aggregation. CPP removal is thought to be predominantly mediated by cells of the reticuloendothelial system via type I and type II class A scavenger receptor (SR-AI/II). Naked calcium phosphate crystals are known to stimulate macrophages and other cell types in vitro, but little is known of the effect of CPP on these cells. We report here, for the first time, that CPP induce expression and secretion of tumour necrosis factor (TNF)-α, interleukin (IL)-1β in murine RAW 264.7 macrophages. Importantly, however, CPP induced significantly lower cytokine secretion than hydroxyapatite (HAP) crystals of equivalent size and calcium content. Furthermore, CPP only had a modest effect on macrophage viability and apoptosis, even at very high levels, compared to HAP crystals, which were strongly pro-apoptotic at much lower levels. Fetuin-A phosphorylation was found to modulate the effect of CPP on cytokine secretion and apoptosis, but not uptake via SR-AI/II. Prolonged exposure of macrophages to CPP was found to result in up-regulated expression of SR-AI/II. CPP formation may help protect against some of the pro-inflammatory and harmful effects of calcium phosphate nanocrystals, perhaps representing a natural defense system for calcium mineral stress. However, in pathological states where production exceeds clearance capacity, these particles may still stimulate pro-inflammatory and pro-apoptotic cascades in macrophages, which may be important in the pathogenesis of vascular calcification. PMID:23577176

  8. The Mycobacterium tuberculosis PE Proteins Rv0285 and Rv1386 Modulate Innate Immunity and Mediate Bacillary Survival in Macrophages

    PubMed Central

    Tiwari, Bhavana Mishra; Kannan, Nisha; Vemu, Lakshmi; Raghunand, Tirumalai R.

    2012-01-01

    The unique PE/PPE multigene family of proteins occupies almost 10% of the coding sequence of Mycobacterium tuberculosis (M.tb), the causative agent of human tuberculosis. Although some members of this family have been shown to be involved in pathways essential to M.tb pathogenesis, their precise physiological functions remain largely undefined. Here, we investigate the roles of the conserved members of the ‘PE only’ subfamily Rv0285 (PE5) and Rv1386 (PE15) in mediating host-pathogen interactions. Recombinant Mycobacterium smegmatis strains expressing PE5 and PE15 showed enhanced survival vs controls in J774.1 and THP-1 macrophages - this increase in viable counts was correlated with a reduction in transcript levels of inducible nitric oxide synthase. An up-regulation of anti- and down-regulation of pro-inflammatory cytokine levels was also observed in infected macrophages implying an immuno-modulatory function for these proteins. Induction of IL-10 production upon infection of THP-1 macrophages was associated with increased phosphorylation of the MAP Kinases p38 and ERK1/2, which was abolished in the presence of the pharmacological inhibitors SB203580 and PD98059. The PE5-PPE4 and PE15-PPE20 gene pairs were observed to be co-operonic in M.tb, hinting at an additional level of complexity in the functioning of these proteins. We conclude that M.tb exploits the PE proteins to evade the host immune response by altering the Th1 and Th2 type balance thereby favouring in vivo bacillary survival. PMID:23284742

  9. Macrophages in Vascular Inflammation: Origins and Functions.

    PubMed

    Decano, Julius L; Mattson, Peter C; Aikawa, Masanori

    2016-06-01

    Macrophages influence various processes of cardiovascular inflammation. Whether they are of embryonic or post-natal hematopoietic origin, their balance in differential activation may direct the course of inflammation. Accelerated macrophage activation and accumulation through a pro-inflammatory signaling pathway may result in extensive tissue damage, adverse repair, and worsened clinical outcomes. Attenuation of such a mechanism and/or promotion of the anti-inflammatory macrophage activation may lead to early resolution of inflammation. Elucidating multiple novel mechanisms of monocyte and macrophage activation leads to a better understanding of their roles in vascular inflammation. In turn, this begets better therapeutic target identification and biomarker discovery. Combined with increasingly sensitive and specific imaging techniques, we continue to push back early detection and monitoring to provide us with a greater window for disease modification. The potential success of cytokine-targeted therapy will be solid proof of the inflammatory hypothesis of atherothrombosis. PMID:27125207

  10. Generation and Characterization of Mouse Regulatory Macrophages.

    PubMed

    Carretero-Iglesia, Laura; Hill, Marcelo; Cuturi, Maria Cristina

    2016-01-01

    In the last years, cell therapy has become a promising approach to therapeutically manipulate immune responses in autoimmunity, cancer, and transplantation. Several types of lymphoid and myeloid cells origin have been generated in vitro and tested in animal models. Their efficacy to decrease pharmacological treatment has successfully been established. Macrophages play an important role in physiological and pathological processes. They represent an interesting cell population due to their high plasticity in vivo and in vitro. Here, we describe a protocol to differentiate murine regulatory macrophages in vitro from bone marrow precursors. We also describe several methods to assess macrophage classical functions, as their bacterial killing capacity and antigen endocytosis and degradation. Importantly, regulatory macrophages also display suppressive characteristics, which are addressed by the study of their hypostimulatory T lymphocyte capacity and polyclonal T lymphocyte activation suppression.

  11. Trophic macrophages in development and disease

    PubMed Central

    Pollard, Jeffrey W.

    2013-01-01

    Specialized phagocytes are found in the most primitive multicellular organisms. Their roles in homeostasis and in distinguishing self from non-self have evolved with the complexity of organisms and their immune systems. Equally important, but often overlooked, are the roles of macrophages in tissue development. As discussed in this Review, these include functions in branching morphogenesis, neuronal patterning, angiogenesis, bone morphogenesis and the generation of adipose tissue. In each case, macrophage depletion impairs the formation of the tissue and compromises its function. I argue that in several diseases, the unrestrained acquisition of these developmental macrophage functions exacerbates pathology. For example, macrophages enhance tumour progression and metastasis by affecting tumour-cell migration and invasion, as well as angiogenesis. PMID:19282852

  12. 47 CFR 0.181 - The Defense Commissioner.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... in public safety, homeland security, national security, emergency preparedness, disaster management..., Defense and Emergency Preparedness Functions § 0.181 The Defense Commissioner. The Defense Commissioner is... emergency preparedness, and defense activities of the Commission and has the following duties...

  13. 47 CFR 0.181 - The Defense Commissioner.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... in public safety, homeland security, national security, emergency preparedness, disaster management..., Defense and Emergency Preparedness Functions § 0.181 The Defense Commissioner. The Defense Commissioner is... emergency preparedness, and defense activities of the Commission and has the following duties...

  14. 47 CFR 0.181 - The Defense Commissioner.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... in public safety, homeland security, national security, emergency preparedness, disaster management..., Defense and Emergency Preparedness Functions § 0.181 The Defense Commissioner. The Defense Commissioner is... emergency preparedness, and defense activities of the Commission and has the following duties...

  15. 47 CFR 0.181 - The Defense Commissioner.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... in public safety, homeland security, national security, emergency preparedness, disaster management..., Defense and Emergency Preparedness Functions § 0.181 The Defense Commissioner. The Defense Commissioner is... emergency preparedness, and defense activities of the Commission and has the following duties...

  16. 47 CFR 0.181 - The Defense Commissioner.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... in public safety, homeland security, national security, emergency preparedness, disaster management..., Defense and Emergency Preparedness Functions § 0.181 The Defense Commissioner. The Defense Commissioner is... emergency preparedness, and defense activities of the Commission and has the following duties...

  17. Senescence and quiescence induced compromised function in cultured macrophages.

    PubMed

    Holt, Dolly J; Grainger, David W

    2012-10-01

    Implants are predisposed to infection even years after implantation, despite ostensibly being surrounded by innumerable macrophages as part of the host foreign body response. The local implant environment could adversely influence the implant-associated macrophage phenotype, proliferative capacity, activation states, and ability to neutralize pathogens. This study monitored cultured macrophage proliferative states and phagocytotic competence on tissue culture plastic to address the hypothesis that extended contact with foreign materials alters macrophage phenotype. That such macrophage alterations might also occur around implants has significance to the foreign body response, infection, cancer, autoimmune and other diseases. Specifically, multiple indicators of macrophage proliferation in various culture conditions, including cell confluence, long-term culture (21 days), lipopolysaccharide (LPS) stimulation, passaging, and mitogenic stimulation are reported. Importantly, primary murine macrophages became quiescent at high confluence and senescent during long-term culture. Senescent macrophages significantly reduced their ability to phagocytose particles, while quiescent macrophages did not. Cell senescence and quiescence were not observed with repeated passaging. Primary macrophage stimulation with LPS delayed senescence but did not eliminate it. These results prompt the conclusion that both cell quiescence and senescence are observed under common macrophage culture conditions and could alter macrophage behavior and phenotypes in extended in vitro culture, such as the ability to phagocytose. Such macrophage transitions around foreign bodies in vivo are not documented: quiescence and senescence reported here in macrophage culture could be relevant to macrophage behavior both in vitro in bioassays and in vivo in the foreign body response and implant-centered infection.

  18. Imaging macrophages in trehalose with SIMS

    NASA Astrophysics Data System (ADS)

    Parry, S. A.; Kurczy, M. E.; Fan, X.; Halleck, M. S.; Schlegel, R. A.; Winograd, N.

    2008-12-01

    Phagocytosis is a major component of the animal immune system where apoptotic cellular material, metabolites, and waste are safely processed. Further, efficient phagocytosis by macrophages is key to maintaining healthy vascular systems and preventing atherosclerosis. Single-cell images of macrophage phagocytosis of red blood cells, RBCs, and polystyrene microspheres have been chemically mapped with TOF-SIMS. We demonstrate here cholesterol and phosphocholine localizations as relative to time and activity.

  19. Background issues for defensive interceptors

    SciTech Connect

    Canavan, G.H.

    1991-03-01

    Mean nuclear backgrounds are large, but are arguably amenable to frame-to-frame subtraction. Striated backgrounds on the sensors for defensive interceptors could, however, cause clutter leak-through, which could make detection and track difficult. Nominal motions and backgrounds give signal to clutter ratios too low to be useful. Clutter leakage due to line-of-sight drift can be reduced by stabilizing the line of sight around the background clutter itself. Current interceptors have detector arrays large enough for operation independent of nuclear backgrounds in their fields of view. 6 refs., 2 figs.

  20. Prostaglandin D2-loaded microspheres effectively activate macrophage effector functions.

    PubMed

    Pereira, Priscilla Aparecida Tartari; Bitencourt, Claudia da Silva; dos Santos, Daiane Fernanda; Nicolete, Roberto; Gelfuso, Guilherme Martins; Faccioli, Lúcia Helena

    2015-10-12

    Biodegradable lactic-co-glycolic acid (PLGA) microspheres (MS) improve the stability of biomolecules stability and allow enable their sustained release. Lipid mediators represent a strategy for improving host defense; however, most of these mediators, such as prostaglandin D2 (PGD2), have low water solubility and are unstable. The present study aimed to develop and characterize MS loaded with PGD2 (PGD2-MS) to obtain an innovative tool to activate macrophages. PGD2-MS were prepared using an oil-in-water emulsion solvent extraction-evaporation process, and the size, zeta potential, surface morphology and encapsulation efficiency were determined. It was also evaluated in vitro the phagocytic index, NF-κB activation, as well as nitric oxide and cytokine production by alveolar macrophages (AMs) in response to PGD2-MS. PGD2-MS were spherical with a diameter of 5.0±3.3 μm and regular surface, zeta potential of -13.4±5.6 mV, and 36% of encapsulation efficiency, with 16-26% release of entrapped PGD2 at 4 and 48 h, respectively. PGD2-MS were more efficiently internalized by AMs than unloaded-MS, and activated NF-κB more than free PGD2. Moreover, PGD2-MS stimulated the production of nitric oxide, TNF-α, IL-1β, and TGF-β, more than free PGD2, indicating that microencapsulation increased the activating effect of PGD2 on cells. In LPS-pre-treated AMs, PGD2-MS decreased the release of IL-6 but increased the production of nitric oxide and IL-1β. These results show that the morphological characteristics of PGD2-MS facilitated interaction with, and activation of phagocytic cells; moreover, PGD2-MS retained the biological activities of PGD2 to trigger effector mechanisms in AMs. It is suggested that PGD2-MS represent a strategy for therapeutic intervention in the lungs of immunocompromised subjects.

  1. Molecular Consequences of Proprotein Convertase 1/3 (PC1/3) Inhibition in Macrophages for Application to Cancer Immunotherapy: A Proteomic Study.

    PubMed

    Duhamel, Marie; Rodet, Franck; Delhem, Nadira; Vanden Abeele, Fabien; Kobeissy, Firas; Nataf, Serge; Pays, Laurent; Desjardins, Roxanne; Gagnon, Hugo; Wisztorski, Maxence; Fournier, Isabelle; Day, Robert; Salzet, Michel

    2015-11-01

    Macrophages provide the first line of host immune defense. Their activation triggers the secretion of pro-inflammatory cytokines and chemokines recruiting other immune cells. In cancer, macrophages present an M2 anti-inflammatory phenotype promoting tumor growth. In this way, strategies need to be develop to reactivate macrophages. Previously thought to be expressed only in cells with a neural/neuroendocrine phenotype, the proprotein convertase 1/3 has been shown to also be expressed in macrophages and regulated as a function of the Toll-like receptor immune response. Here, we investigated the intracellular impact of the down-regulation of the proprotein convertase 1/3 in NR8383 macrophages and confirmed the results on macrophages from PC1/3 deficient mice. A complete proteomic study of secretomes and intracellular proteins was undertaken and revealed that inhibition of proprotein convertase 1/3 orient macrophages toward an M1 activated phenotype. This phenotype is characterized by filopodial extensions, Toll-like receptor 4 MyD88-dependent signaling, calcium entry augmentation and the secretion of pro-inflammatory factors. In response to endotoxin/lipopolysaccharide, these intracellular modifications increased, and the secreted factors attracted naïve T helper lymphocytes to promote the cytotoxic response. Importantly, the application of these factors onto breast and ovarian cancer cells resulted in a decrease viability or resistance. Under inhibitory conditions using interleukin 10, PC1/3-knockdown macrophages continued to secrete inflammatory factors. These data indicate that targeted inhibition of proprotein convertase 1/3 could represent a novel type of immune therapy to reactivate intra-tumoral macrophages. PMID:26330543

  2. Autochthonous primary and metastatic melanomas in Hgf-Cdk4 R24C mice evade T-cell-mediated immune surveillance.

    PubMed

    Landsberg, Jennifer; Gaffal, Evelyn; Cron, Mira; Kohlmeyer, Judith; Renn, Marcel; Tüting, Thomas

    2010-10-01

    Genetically engineered mouse models offer new opportunities to investigate the role of cell-mediated immunity in the natural progression of melanoma in an immunocompetent host. Here we report that Hgf-Cdk4(R24C) mice spontaneously develop a spectrum of primary melanomas with high penetrance during their first year of life. Malignant transformation proceeds in a stepwise manner from multiple melanocytic nevi to single nodular melanomas and disseminated metastases in most mice. Migrating melanoma cells invade the draining lymph nodes without activating the immune system. Autochthonous primary tumors are destroyed following experimental introduction of immune surveillance using an adoptive lymphocyte transfer approach. However, some tumor cells are able to survive, evade immune cell control, and recur both locally and systemically. Immune tolerance in recurring tumors may be supported by immunosuppressive Gr1(+) myeloid cells. Taken together, our results demonstrate that primary and metastatic melanomas developing spontaneously in Hgf-Cdk4(R24C) mice effectively evade cellular immune surveillance. PMID:20649939

  3. Macrophages modulate adult zebrafish tail fin regeneration.

    PubMed

    Petrie, Timothy A; Strand, Nicholas S; Yang, Chao-Tsung; Tsung-Yang, Chao; Rabinowitz, Jeremy S; Moon, Randall T

    2014-07-01

    Neutrophils and macrophages, as key mediators of inflammation, have defined functionally important roles in mammalian tissue repair. Although recent evidence suggests that similar cells exist in zebrafish and also migrate to sites of injury in larvae, whether these cells are functionally important for wound healing or regeneration in adult zebrafish is unknown. To begin to address these questions, we first tracked neutrophils (lyzC(+), mpo(+)) and macrophages (mpeg1(+)) in adult zebrafish following amputation of the tail fin, and detailed a migratory timecourse that revealed conserved elements of the inflammatory cell response with mammals. Next, we used transgenic zebrafish in which we could selectively ablate macrophages, which allowed us to investigate whether macrophages were required for tail fin regeneration. We identified stage-dependent functional roles of macrophages in mediating fin tissue outgrowth and bony ray patterning, in part through modulating levels of blastema proliferation. Moreover, we also sought to detail molecular regulators of inflammation in adult zebrafish and identified Wnt/β-catenin as a signaling pathway that regulates the injury microenvironment, inflammatory cell migration and macrophage phenotype. These results provide a cellular and molecular link between components of the inflammation response and regeneration in adult zebrafish. PMID:24961798

  4. Immunological characterization of pulmonary intravascular macrophages

    NASA Technical Reports Server (NTRS)

    Chitko-McKown, C. G.; Reddy, D. N.; Chapes, S. K.; McKown, R. D.; Blecha, F.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    Pulmonary intravascular macrophages (PIMs) are lung macrophages found apposed to the endothelium of pulmonary capillaries. In many species, they are responsible for the clearance of blood-borne particulates and pathogens; however, little else is known about their roles as immunologic effector cells. We compared PIMs with pulmonary alveolar macrophages (PAMs) to determine the relative immunological activities of these two cell populations. Our results suggested that both populations possess similar phagocytic and bactericidal activities. In assays measuring cytotoxicity, PIMs were more cytotoxic than PAMs against virally infected target cells; however, differences between these macrophage populations were not as marked when noninfected targets were used. LPS-stimulated PIMs produced more T-cell proliferative cytokines than PAMs, and both populations of nonstimulated macrophages produced similar amounts of the cytokines. In contrast, PAMs produced more TNF alpha and NO2- than PIMs when both populations were stimulated with LPS; however, nonstimulated PAMs and PIMs produced similar amounts of TNF alpha and NO2. These data suggest that bovine PIMs are immunologically active. Differences between the degrees of activity of PIMs and PAMs indicate that these macrophage populations may have different roles in lung surveillance.

  5. Cyclosporine inhibits macrophage-mediated antigen presentation

    SciTech Connect

    Ziegler, H.K.; Palay, D.; Wentworth, P.; Cluff, C.

    1986-03-01

    The influence of cyclosporine on antigen-specific, macrophage-dependent T cell activation was analyzed in vitro. Murine T cell activation by antigens derived from Listeria monocytogenes was monitored by the production of interleukin-2. Pretreatment (2 hrs., 37/sup 0/C) of macrophages with cyclosporine resulted in a population of macrophages with a markedly diminished capacity to support the activation of T lymphocytes. When cyclosporine-pretreated macrophages were added to cultures of antigen and untreated T cells, the dose of cyclosporine which produced 50% inhibition was 1.5 ..mu..g/ml. Appropriate control experiments indicated that cyclosporine was indeed inhibiting at the macrophage level. The addition of interleukin-1 or indomethacin to the cultures did not alter the inhibitory effect of cyclosporine. Under conditions which produced >90% inhibition of antigen presentation, macrophage surface Ia expression was not altered, and the uptake and catabolism of radiolabelled antigen was normal. Thus, cyclosporine inhibits antigen presentation by a mechanism which appears unrelated to changes in Il-1 elaboration, prostaglandin production, Ia expression, or antigen uptake and catabolism.

  6. Macrophages - silent enemies in juvenile idiopathic arthritis.

    PubMed

    Świdrowska-Jaros, Joanna; Orczyk, Krzysztof; Smolewska, Elżbieta

    2016-07-06

    The inflammatory response by secretion of cytokines and other mediators is postulated as one of the most significant factors in the pathophysiology of juvenile idiopathic arthritis (JIA). The effect of macrophage action depends on the type of their activation. Classically activated macrophages (M1) are responsible for release of molecules crucial for joint inflammation. Alternatively activated macrophages (M2) may recognize self antigens by scavenger receptors and induce the immunological reaction leading to autoimmune diseases such as JIA. Molecules essential for JIA pathophysiology include: TNF-α, the production of which precedes synovial inflammation in rheumatoid arthritis; IL-1 as a key mediator of synovial damage; chemotactic factors for macrophages IL-8 and MCP-1; IL6, the level of which correlates with the radiological joint damage; MIF, promoting the secretion of TNF-α and IL-6; CCL20 and HIF, significant for the hypoxic synovial environment in JIA; GM-CSF, stimulating the production of macrophages; and IL-18, crucial for NK cell functions. Recognition of the role of macrophages creates the potential for a new therapeutic approach.

  7. Macrophage-mediated cholesterol handling in atherosclerosis.

    PubMed

    Chistiakov, Dimitry A; Bobryshev, Yuri V; Orekhov, Alexander N

    2016-01-01

    Formation of foam cells is a hallmark at the initial stages of atherosclerosis. Monocytes attracted by pro-inflammatory stimuli attach to the inflamed vascular endothelium and penetrate to the arterial intima where they differentiate to macrophages. Intimal macrophages phagocytize oxidized low-density lipoproteins (oxLDL). Several scavenger receptors (SR), including CD36, SR-A1 and lectin-like oxLDL receptor-1 (LOX-1), mediate oxLDL uptake. In late endosomes/lysosomes of macrophages, oxLDL are catabolysed. Lysosomal acid lipase (LAL) hydrolyses cholesterol esters that are enriched in LDL to free cholesterol and free fatty acids. In the endoplasmic reticulum (ER), acyl coenzyme A: cholesterol acyltransferase-1 (ACAT1) in turn catalyses esterification of cholesterol to store cholesterol esters as lipid droplets in the ER of macrophages. Neutral cholesteryl ester hydrolases nCEH and NCEH1 are involved in a secondary hydrolysis of cholesterol esters to liberate free cholesterol that could be then out-flowed from macrophages by cholesterol ATP-binding cassette (ABC) transporters ABCA1 and ABCG1 and SR-BI. In atherosclerosis, disruption of lipid homoeostasis in macrophages leads to cholesterol accumulation and formation of foam cells. PMID:26493158

  8. Salmonella acquires ferrous iron from haemophagocytic macrophages.

    PubMed

    Nagy, Toni A; Moreland, Sarah M; Detweiler, Corrella S

    2014-09-01

    Bacteria harbour both ferrous and ferric iron transporters. We now report that infection of macrophages and mice with a Salmonella enterica Typhimurium strain containing an inactivated feoB-encoded ferrous iron transporter results in increased bacterial replication, compared to infection with wild type. Inactivation of other cation transporters, SitABCD or MntH, did not increase bacterial replication. The feoB mutant strain does not have an intrinsically faster growth rate. Instead, increased replication correlated with increased expression in macrophages of the fepB-encoded bacterial ferric iron transporter and also required siderophores, which capture ferric iron. Co-infection of mice with wild type and a feoB mutant strain yielded a different outcome: FeoB is clearly required for tissue colonization. In co-infected primary mouse macrophages, FeoB is required for S. Typhimurium replication if the macrophages were IFNγ treated and contain phagocytosed erythrocytes, a model for haemophagocytosis. Haemophagocytes are macrophages that have engulfed erythrocytes and/or leucocytes and can harbour Salmonella in mice. These observations suggest that Salmonella acquires ferrous iron from haemophagocytic macrophages.

  9. Endometriosis, a disease of the macrophage.

    PubMed

    Capobianco, Annalisa; Rovere-Querini, Patrizia

    2013-01-01

    Endometriosis, a common cause of pelvic pain and female infertility, depends on the growth of vascularized endometrial tissue at ectopic sites. Endometrial fragments reach the peritoneal cavity during the fertile years: local cues decide whether they yield endometriotic lesions. Macrophages are recruited at sites of hypoxia and tissue stress, where they clear cell debris and heme-iron and generate pro-life and pro-angiogenesis signals. Macrophages are abundant in endometriotic lesions, where are recruited and undergo alternative activation. In rodents macrophages are required for lesions to establish and to grow; bone marrow-derived Tie-2 expressing macrophages specifically contribute to lesions neovasculature, possibly because they concur to the recruitment of circulating endothelial progenitors, and sustain their survival and the integrity of the vessel wall. Macrophages sense cues (hypoxia, cell death, iron overload) in the lesions and react delivering signals to restore the local homeostasis: their action represents a necessary, non-redundant step in the natural history of the disease. Endometriosis may be due to a misperception of macrophages about ectopic endometrial tissue. They perceive it as a wound, they activate programs leading to ectopic cell survival and tissue vascularization. Clearing this misperception is a critical area for the development of novel medical treatments of endometriosis, an urgent and unmet medical need.

  10. Endometriosis, a disease of the macrophage

    PubMed Central

    Capobianco, Annalisa; Rovere-Querini, Patrizia

    2013-01-01

    Endometriosis, a common cause of pelvic pain and female infertility, depends on the growth of vascularized endometrial tissue at ectopic sites. Endometrial fragments reach the peritoneal cavity during the fertile years: local cues decide whether they yield endometriotic lesions. Macrophages are recruited at sites of hypoxia and tissue stress, where they clear cell debris and heme-iron and generate pro-life and pro-angiogenesis signals. Macrophages are abundant in endometriotic lesions, where are recruited and undergo alternative activation. In rodents macrophages are required for lesions to establish and to grow; bone marrow-derived Tie-2 expressing macrophages specifically contribute to lesions neovasculature, possibly because they concur to the recruitment of circulating endothelial progenitors, and sustain their survival and the integrity of the vessel wall. Macrophages sense cues (hypoxia, cell death, iron overload) in the lesions and react delivering signals to restore the local homeostasis: their action represents a necessary, non-redundant step in the natural history of the disease. Endometriosis may be due to a misperception of macrophages about ectopic endometrial tissue. They perceive it as a wound, they activate programs leading to ectopic cell survival and tissue vascularization. Clearing this misperception is a critical area for the development of novel medical treatments of endometriosis, an urgent and unmet medical need. PMID:23372570

  11. Defensive weapons and defense signals in plants: some metabolites serve both roles.

    PubMed

    Maag, Daniel; Erb, Matthias; Köllner, Tobias G; Gershenzon, Jonathan

    2015-02-01

    The defense of plants against herbivores and pathogens involves the participation of an enormous range of different metabolites, some of which act directly as defensive weapons against enemies (toxins or deterrents) and some of which act as components of the complex internal signaling network that insures that defense is timed to enemy attack. Recent work reveals a surprising trend: The same compounds may act as both weapons and signals of defense. For example, two groups of well-studied defensive weapons, glucosinolates and benzoxazinoids, trigger the accumulation of the protective polysaccharide callose as a barrier against aphids and pathogens. In the other direction, several hormones acting in defense signaling (and their precursors and products) exhibit activity as weapons against pathogens. Knowing which compounds are defensive weapons, which are defensive signals and which are both is vital for understanding the functioning of plant defense systems.

  12. Nrf2 and cardiovascular defense.

    PubMed

    Howden, Reuben

    2013-01-01

    The cardiovascular system is susceptible to a group of diseases that are responsible for a larger proportion of morbidity and mortality than any other disease. Many cardiovascular diseases are associated with a failure of defenses against oxidative stress-induced cellular damage and/or death, leading to organ dysfunction. The pleiotropic transcription factor, nuclear factor-erythroid (NF-E) 2-related factor 2 (Nrf2), regulates the expression of antioxidant enzymes and proteins through the antioxidant response element. Nrf2 is an important component in antioxidant defenses in cardiovascular diseases such as atherosclerosis, hypertension, and heart failure. Nrf2 is also involved in protection against oxidant stress during the processes of ischemia-reperfusion injury and aging. However, evidence suggests that Nrf2 activity does not always lead to a positive outcome and may accelerate the pathogenesis of some cardiovascular diseases (e.g., atherosclerosis). The precise conditions under which Nrf2 acts to attenuate or stimulate cardiovascular disease processes are unclear. Further studies on the cellular environments related to cardiovascular diseases that influence Nrf2 pathways are required before Nrf2 can be considered a therapeutic target for the treatment of cardiovascular diseases.

  13. Defense mutualisms enhance plant diversification.

    PubMed

    Weber, Marjorie G; Agrawal, Anurag A

    2014-11-18

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity.

  14. Biogeography of a defensive symbiosis

    PubMed Central

    Kaltenpoth, Martin; Roeser-Mueller, Kerstin; Stubblefield, J. William; Seger, Jon; Strohm, Erhard

    2014-01-01

    Mutualistic microorganisms play important roles in nutrition, reproduction and defense of many insects, yet the factors contributing to their maintenance and dispersal remain unknown in most cases. Theory suggests that collaboration can be maintained by repeated interaction of the same partners (partner fidelity) or by selective discrimination against non-cooperative partners (partner choice). In the defensive mutualism between solitary beewolf wasps and their antibiotic-producing Streptomyces bacteria, partner choice by host control of vertical symbiont transmission reinforces partner fidelity and has helped to maintain this highly specific association since it originated in the late Cretaceous. However, co-phylogenetic and biogeographic analyses suggest that there has also been considerable horizontal transmission of the symbionts. While the beewolves clearly have a paleotropic or palearctic origin, with later colonization of the nearctic and neotropics via Beringia and the Aves ridge, respectively, the bacteria show only weak geographical clustering, implying global dispersal or vicariance within the confines of an otherwise apparently exclusive symbiotic relationship. We discuss several hypotheses that may explain these patterns. Future studies investigating the occurrence of beewolf symbionts in the environment could yield broadly applicable insights into the relative impact of animal-vectored and free-living dispersal on the distribution of microorganisms in nature. PMID:26479018

  15. Defense mutualisms enhance plant diversification

    PubMed Central

    Weber, Marjorie G.; Agrawal, Anurag A.

    2014-01-01

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity. PMID:25349406

  16. Defensive anality and anal narcissism.

    PubMed

    Shengold, L

    1985-01-01

    This paper aims at demonstrating a currently beleaguered assumption: the central importance, the continuing vitality, and the appropriate complexity of Freud's theory of the drives and of his idea of the primacy of the body ego. It is not enough to consider man a thinking machine or a social being; his animal nature must be given a central place in psychology. The paper postulates that 'anal or sphincter defensiveness' is one of the precursors of the repression barrier. Anality has been comparatively neglected in recent psychoanalytic literature, and so has its explorer, Karl Abraham. The paper's thesis is that there is a special defensive importance to anal erogeneity and libido, and to those aspects of ego and superego that are functionally operative (as the 'sadistic-anal organization' (Freud, 1917)) during the so-called 'sadistic-anal' developmental phase. Any of the psychic danger situations can evoke regression to manifestations of 'anal narcissim'--an attempt to master overwhelming feeling by a kind of emotional sphincter action, narrowing down the world to the controllable and the predictable. The basic assumption here is Fliess's idea that the attainment of anal sphincter control functions--with, as-it-were, 'psychic resonance'--as a means to master primal (murderous, cannibalistic) affect. For optimal psychic development, a proper balance must be attained between anal control of, and anal expression of, instinctual derivatives--especially of affect laden with aggression.

  17. The role of antimicrobial peptides in animal defenses

    NASA Astrophysics Data System (ADS)

    Hancock, Robert E. W.; Scott, Monisha G.

    2000-08-01

    It is becoming clear that the cationic antimicrobial peptides are an important component of the innate defenses of all species of life. Such peptides can be constitutively expressed or induced by bacteria or their products. The best peptides have good activities vs. a broad range of bacterial strains, including antibiotic-resistant isolates. They kill very rapidly, do not easily select resistant mutants, are synergistic with conventional antibiotics, other peptides, and lysozyme, and are able to kill bacteria in animal models. It is known that bacterial infections, especially when treated with antibiotics, can lead to the release of bacterial products such as lipopolysaccharide (LPS) and lipoteichoic acid, resulting in potentially lethal sepsis. In contrast to antibiotics, the peptides actually prevent cytokine induction by bacterial products in tissue culture and human blood, and they block the onset of sepsis in mouse models of endotoxemia. Consistent with this, transcriptional gene array experiments using a macrophage cell line demonstrated that a model peptide, CEMA, blocks the expression of many genes whose transcription was induced by LPS. The peptides do this in part by blocking LPS interaction with the serum protein LBP. In addition, CEMA itself has a direct effect on macrophage gene expression. Because cationic antimicrobial peptides are induced by LPS and are able to dampen the septic response of animal cells to LPS, we propose that, in addition to their role in direct and lysozyme-assisted killing of microbes, they have a role in feedback regulation of cytokine responses. We are currently developing variant peptides as therapeutics against antibiotic-resistant infections.

  18. Cellular defense processes regulated by pathogen-elicited receptor signaling

    NASA Astrophysics Data System (ADS)

    Wu, Rongcong; Goldsipe, Arthur; Schauer, David B.; Lauffenburger, Douglas A.

    2011-06-01

    Vertebrates are constantly threatened by the invasion of microorganisms and have evolved systems of immunity to eliminate infectious pathogens in the body. Initial sensing of microbial agents is mediated by the recognition of pathogens by means of molecular structures expressed uniquely by microbes of a given type. So-called 'Toll-like receptors' are expressed on host epithelial barrier cells play an essential role in the host defense against microbial pathogens by inducing cell responses (e.g., proliferation, death, cytokine secretion) via activation of intracellular signaling networks. As these networks, comprising multiple interconnecting dynamic pathways, represent highly complex multi-variate "information processing" systems, the signaling activities particularly critical for governing the host cell responses are poorly understood and not easily ascertained by a priori theoretical notions. We have developed over the past half-decade a "data-driven" computational modeling approach, on a 'cue-signal-response' combined experiment/computation paradigm, to elucidate key multi-variate signaling relationships governing the cell responses. In an example presented here, we study how a canonical set of six kinase pathways combine to effect microbial agent-induced apoptotic death of a macrophage cell line. One modeling technique, partial least-squares regression, yielded the following key insights: {a} signal combinations most strongly correlated to apoptotic death are orthogonal to those most strongly correlated with release of inflammatory cytokines; {b} the ratio of two key pathway activities is the most powerful predictor of microbe-induced macrophage apoptotic death; {c} the most influential time-window of this signaling activity ratio is surprisingly fast: less than one hour after microbe stimulation.

  19. Secreted aspartic protease 2 of Candida albicans inactivates factor H and the macrophage factor H-receptors CR3 (CD11b/CD18) and CR4 (CD11c/CD18).

    PubMed

    Svoboda, Eliška; Schneider, Andrea E; Sándor, Noémi; Lermann, Ulrich; Staib, Peter; Kremlitzka, Mariann; Bajtay, Zsuzsa; Barz, Dagmar; Erdei, Anna; Józsi, Mihály

    2015-11-01

    The opportunistic pathogenic yeast Candida albicans employs several mechanisms to interfere with the human complement system. This includes the acquisition of host complement regulators, the release of molecules that scavenge complement proteins or block cellular receptors, and the secretion of proteases that inactivate complement components. Secreted aspartic protease 2 (Sap2) was previously shown to cleave C3b, C4b and C5. C. albicans also recruits the complement inhibitor factor H (FH), but yeast-bound FH can enhance the antifungal activity of human neutrophils via binding to complement receptor type 3 (CR3). In this study, we characterized FH binding to human monocyte-derived macrophages. Inhibition studies with antibodies and siRNA targeting CR3 (CD11b/CD18) and CR4 (CD11c/CD18), as well as analysis of colocalization of FH with these integrins indicated that both function as FH receptors on macrophages. Preincubation of C. albicans yeast cells with FH induced increased production of IL-1β and IL-6 in macrophages. Furthermore, FH enhanced zymosan-induced production of these cytokines. C. albicans Sap2 cleaved FH, diminishing its complement regulatory activity, and Sap2-treatment resulted in less detectable CR3 and CR4 on macrophages. These data show that FH enhances the activation of human macrophages when bound on C. albicans. However, the fungus can inactivate both FH and its receptors on macrophages by secreting Sap2, which may represent an additional means for C. albicans to evade the host innate immune system.

  20. Depletion of Alveolar Macrophages Does Not Prevent Hantavirus Disease Pathogenesis in Golden Syrian Hamsters

    PubMed Central

    Hammerbeck, Christopher D.; Brocato, Rebecca L.; Bell, Todd M.; Schellhase, Christopher W.; Mraz, Steven R.; Queen, Laurie A.

    2016-01-01

    ABSTRACT Andes virus (ANDV) is associated with a lethal vascular leak syndrome in humans termed hantavirus pulmonary syndrome (HPS). The mechanism for the massive vascular leakage associated with HPS is poorly understood; however, dysregulation of components of the immune response is often suggested as a possible cause. Alveolar macrophages are found in the alveoli of the lung and represent the first line of defense to many airborne pathogens. To determine whether alveolar macrophages play a role in HPS pathogenesis, alveolar macrophages were depleted in an adult rodent model of HPS that closely resembles human HPS. Syrian hamsters were treated, intratracheally, with clodronate-encapsulated liposomes or control liposomes and were then challenged with ANDV. Treatment with clodronate-encapsulated liposomes resulted in significant reduction in alveolar macrophages, but depletion did not prevent pathogenesis or prolong disease. Depletion also did not significantly reduce the amount of virus in the lung of ANDV-infected hamsters but altered neutrophil recruitment, MIP-1α and MIP-2 chemokine expression, and vascular endothelial growth factor (VEGF) levels in hamster bronchoalveolar lavage (BAL) fluid early after intranasal challenge. These data demonstrate that alveolar macrophages may play a limited protective role early after exposure to aerosolized ANDV but do not directly contribute to hantavirus disease pathogenesis in the hamster model of HPS. IMPORTANCE Hantaviruses continue to cause disease worldwide for which there are no FDA-licensed vaccines, effective postexposure prophylactics, or therapeutics. Much of this can be attributed to a poor understanding of the mechanism of hantavirus disease pathogenesis. Hantavirus disease has long been considered an immune-mediated disease; however, by directly manipulating the Syrian hamster model, we continue to eliminate individual immune cell types. As the most numerous immune cells present in the respiratory tract

  1. Colonic macrophage polarization in homeostasis, inflammation, and cancer.

    PubMed

    Isidro, Raymond A; Appleyard, Caroline B

    2016-07-01

    Our review focuses on the colonic macrophage, a monocyte-derived, tissue-resident macrophage, and the role it plays in health and disease, specifically in inflammatory conditions such as inflammatory bowel disease and cancer of the colon and rectum. We give special emphasis to macrophage polarization, or phenotype, in these different states. We focus on macrophages because they are one of the most numerous leukocytes in the colon, and because they normally contribute to homeostasis through an anti-inflammatory phenotype. However, in conditions such as inflammatory bowel disease, proinflammatory macrophages are increased in the colon and have been linked to disease severity and progression. In colorectal cancer, tumor cells may employ anti-inflammatory macrophages to promote tumor growth and dissemination, whereas proinflammatory macrophages may antagonize tumor growth. Given the key roles that this cell type plays in homeostasis, inflammation, and cancer, the colonic macrophage is an intriguing therapeutic target. As such, potential macrophage-targeting strategies are discussed.

  2. Macrophage iron homeostasis and polarization in the context of cancer.

    PubMed

    Jung, Michaela; Mertens, Christina; Brüne, Bernhard

    2015-02-01

    Macrophages are central in regulating iron homeostasis, which is tightly linked to their versatile role during innate immunity. They sequester iron by phagocytosis of senescent erythrocytes and represent a major source of available iron in the body. Macrophage iron homeostasis is coupled to the functional heterogeneity and plasticity of these cells, with their extreme roles during inflammation, immune modulation, and resolution of inflammation. It is now appreciated that the macrophage polarization process dictates expression profiles of genes involved in iron metabolism. Therefore, macrophages have evolved a multitude of mechanisms to sequester, transport, store, and release iron. A new, enigmatic protein entering the iron scene and affecting the macrophage phenotype is lipocalin-2. Iron sequestration in macrophages depletes the microenvironment, thereby limiting extracellular pathogen or tumor growth, while fostering inflammation. In contrast, iron release from macrophages contributes to bystander cell proliferation, which is important for tissue regeneration and repair. This dichotomy is also reflected by the dual role of lipocalin-2 in macrophages. Unfortunately, the iron release macrophage phenotype is also a characteristic of tumor-associated macrophages and stimulates tumor cell survival and growth. Iron sequestration versus its release is now appreciated to be associated with the macrophage polarization program and can be used to explain a number of biological functions attributed to distinct macrophage phenotypes. Here we discuss macrophage iron homeostasis with a special focus on lipocalin-2 related to the formation and function of tumor-associated macrophages.

  3. Mannheimia haemolytica and Its Leukotoxin Cause Macrophage Extracellular Trap Formation by Bovine Macrophages

    PubMed Central

    Aulik, Nicole A.; Hellenbrand, Katrina M.

    2012-01-01

    Human and bovine neutrophils release neutrophil extracellular traps (NETs), which are protein-studded DNA matrices capable of extracellular trapping and killing of pathogens. Recently, we reported that bovine neutrophils release NETs in response to the important respiratory pathogen Mannheimia haemolytica and its leukotoxin (LKT). Here, we demonstrate macrophage extracellular trap (MET) formation by bovine monocyte-derived macrophages exposed to M. haemolytica or its LKT. Both native fully active LKT and noncytolytic pro-LKT (produced by an lktC mutant of M. haemolytica) stimulated MET formation. Confocal and scanning electron microscopy revealed a network of DNA fibrils with colocalized histones in extracellular traps released from bovine macrophages. Formation of METs required NADPH oxidase activity, as previously demonstrated for NET formation. METs formed in response to LKT trapped and killed a portion of the M. haemolytica cells. Bovine alveolar macrophages, but not peripheral blood monocytes, also formed METs in response to M. haemolytica cells. MET formation was not restricted to bovine macrophages. We also observed MET formation by the mouse macrophage cell line RAW 264.7 and by human THP-1 cell-derived macrophages, in response to Escherichia coli hemolysin. The latter is a member of the repeats-in-toxin (RTX) toxin family related to the M. haemolytica leukotoxin. This study demonstrates that macrophages, like neutrophils, can form extracellular traps in response to bacterial pathogens and their exotoxins. PMID:22354029

  4. 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.

  5. Probiotic Bacillus amyloliquefaciens mediate M1 macrophage polarization in mouse bone marrow-derived macrophages.

    PubMed

    Ji, Jian; Hu, Sheng-Lan; Cui, Zhi-Wen; Li, Wei-Fen

    2013-05-01

    Depending on the microenvironment, macrophages can acquire distinct functional phenotypes, referred to as classically activated M1 and M2. M1 macrophages are considered potent effector cells that kill intracellular pathogens, and M2 macrophages promote the resolution of wound healing. In this study, we are interested to know whether probiotic Bacillus amyloliquefaciens (Ba) can induce macrophages polarization. Real-time fluorescence PCR analysis demonstrated that the expression of IL-1β, iNOS, TNF-α and IL-6 genes for M1 macrophages was significantly increased at 1.5 h after probiotic Ba treatment compared to the probiotic Ba-free treatment (P < 0.01), whereas the expression of M2 macrophage marker genes (Arg1, Fizz1, MR, Ym1) was decreased (P < 0.05). Furthermore, the phagocytic activity was dramatically increased in the Ba-treated BMDMs using a FITC-dextran endocytosis assay. Together, these findings indicated that probiotic Ba facilitated polarization of M1 macrophages and enhanced its phagocytic capacity. The results expanded our knowledge about probiotic function-involved macrophage polarization.

  6. Mannheimia haemolytica and its leukotoxin cause macrophage extracellular trap formation by bovine macrophages.

    PubMed

    Aulik, Nicole A; Hellenbrand, Katrina M; Czuprynski, Charles J

    2012-05-01

    Human and bovine neutrophils release neutrophil extracellular traps (NETs), which are protein-studded DNA matrices capable of extracellular trapping and killing of pathogens. Recently, we reported that bovine neutrophils release NETs in response to the important respiratory pathogen Mannheimia haemolytica and its leukotoxin (LKT). Here, we demonstrate macrophage extracellular trap (MET) formation by bovine monocyte-derived macrophages exposed to M. haemolytica or its LKT. Both native fully active LKT and noncytolytic pro-LKT (produced by an lktC mutant of M. haemolytica) stimulated MET formation. Confocal and scanning electron microscopy revealed a network of DNA fibrils with colocalized histones in extracellular traps released from bovine macrophages. Formation of METs required NADPH oxidase activity, as previously demonstrated for NET formation. METs formed in response to LKT trapped and killed a portion of the M. haemolytica cells. Bovine alveolar macrophages, but not peripheral blood monocytes, also formed METs in response to M. haemolytica cells. MET formation was not restricted to bovine macrophages. We also observed MET formation by the mouse macrophage cell line RAW 264.7 and by human THP-1 cell-derived macrophages, in response to Escherichia coli hemolysin. The latter is a member of the repeats-in-toxin (RTX) toxin family related to the M. haemolytica leukotoxin. This study demonstrates that macrophages, like neutrophils, can form extracellular traps in response to bacterial pathogens and their exotoxins. PMID:22354029

  7. Secured network sensor-based defense system

    NASA Astrophysics Data System (ADS)

    Wei, Sixiao; Shen, Dan; Ge, Linqiang; Yu, Wei; Blasch, Erik P.; Pham, Khanh D.; Chen, Genshe

    2015-05-01

    Network sensor-based defense (NSD) systems have been widely used to defend against cyber threats. Nonetheless, if the adversary finds ways to identify the location of monitor sensors, the effectiveness of NSD systems can be reduced. In this paper, we propose both temporal and spatial perturbation based defense mechanisms to secure NSD systems and make the monitor sensor invisible to the adversary. The temporal-perturbation based defense manipulates the timing information of published data so that the probability of successfully recognizing monitor sensors can be reduced. The spatial-perturbation based defense dynamically redeploys monitor sensors in the network so that the adversary cannot obtain the complete information to recognize all of the monitor sensors. We carried out experiments using real-world traffic traces to evaluate the effectiveness of our proposed defense mechanisms. Our data shows that our proposed defense mechanisms can reduce the attack accuracy of recognizing detection sensors.

  8. The methodological defense of realism scrutinized.

    PubMed

    Wray, K Brad

    2015-12-01

    I revisit an older defense of scientific realism, the methodological defense, a defense developed by both Popper and Feyerabend. The methodological defense of realism concerns the attitude of scientists, not philosophers of science. The methodological defense is as follows: a commitment to realism leads scientists to pursue the truth, which in turn is apt to put them in a better position to get at the truth. In contrast, anti-realists lack the tenacity required to develop a theory to its fullest. As a consequence, they are less likely to get at the truth. My aim is to show that the methodological defense is flawed. I argue that a commitment to realism does not always benefit science, and that there is reason to believe that a research community with both realists and anti-realists in it may be better suited to advancing science. A case study of the Copernican Revolution in astronomy supports this claim.

  9. The methodological defense of realism scrutinized.

    PubMed

    Wray, K Brad

    2015-12-01

    I revisit an older defense of scientific realism, the methodological defense, a defense developed by both Popper and Feyerabend. The methodological defense of realism concerns the attitude of scientists, not philosophers of science. The methodological defense is as follows: a commitment to realism leads scientists to pursue the truth, which in turn is apt to put them in a better position to get at the truth. In contrast, anti-realists lack the tenacity required to develop a theory to its fullest. As a consequence, they are less likely to get at the truth. My aim is to show that the methodological defense is flawed. I argue that a commitment to realism does not always benefit science, and that there is reason to believe that a research community with both realists and anti-realists in it may be better suited to advancing science. A case study of the Copernican Revolution in astronomy supports this claim. PMID:26568089

  10. The functional dissection of the plasma corona of SiO₂-NPs spots histidine rich glycoprotein as a major player able to hamper nanoparticle capture by macrophages.

    PubMed

    Fedeli, Chiara; Segat, Daniela; Tavano, Regina; Bubacco, Luigi; De Franceschi, Giorgia; de Laureto, Patrizia Polverino; Lubian, Elisa; Selvestrel, Francesco; Mancin, Fabrizio; Papini, Emanuele

    2015-11-14

    uniquely confers to these particles the ability to evade macrophage capture. PMID:26451907

  11. The functional dissection of the plasma corona of SiO₂-NPs spots histidine rich glycoprotein as a major player able to hamper nanoparticle capture by macrophages.

    PubMed

    Fedeli, Chiara; Segat, Daniela; Tavano, Regina; Bubacco, Luigi; De Franceschi, Giorgia; de Laureto, Patrizia Polverino; Lubian, Elisa; Selvestrel, Francesco; Mancin, Fabrizio; Papini, Emanuele

    2015-11-14

    uniquely confers to these particles the ability to evade macrophage capture.

  12. Macrophage Polarisation: an Immunohistochemical Approach for Identifying M1 and M2 Macrophages

    PubMed Central

    Barros, Mário Henrique M.; Hauck, Franziska; Dreyer, Johannes H.; Kempkes, Bettina; Niedobitek, Gerald

    2013-01-01

    Macrophage polarization is increasingly recognised as an important pathogenetic factor in inflammatory and neoplastic diseases. Proinflammatory M1 macrophages promote T helper (Th) 1 responses and show tumoricidal activity. M2 macrophages contribute to tissue repair and promote Th2 responses. CD68 and CD163 are used to identify macrophages in tissue sections. However, characterisation of polarised macrophages in situ has remained difficult. Macrophage polarisation is regulated by transcription factors, pSTAT1 and RBP-J for M1, and CMAF for M2. We reasoned that double-labelling immunohistochemistry for the detection of macrophage markers together with transcription factors may be suitable to characterise macrophage polarisation in situ. To test this hypothesis, we have studied conditions associated with Th1- and Th2-predominant immune responses: infectious mononucleosis and Crohn’s disease for Th1 and allergic nasal polyps, oxyuriasis, wound healing and foreign body granulomas for predominant Th2 response. In all situations, CD163+ cells usually outnumbered CD68+ cells. Moreover, CD163+ cells, usually considered as M2 macrophages, co-expressing pSTAT1 and RBP-J were found in all conditions examined. The numbers of putative M1 macrophages were higher in Th1- than in Th2-associated diseases, while more M2 macrophages were seen in Th2- than in Th1 related disorders. In most Th1-related diseases, the balance of M1 over M2 cells was shifted towards M1 cells, while the reverse was observed for Th2-related conditions. Hierarchical cluster analysis revealed two distinct clusters: cluster I included Th1 diseases together with cases with high numbers of CD163+pSTAT1+, CD68+pSTAT1+, CD163+RBP-J+ and CD68+RBP-J+ macrophages; cluster II comprised Th2 conditions together with cases displaying high numbers of CD163+CMAF+ and CD68+CMAF+ macrophages. These results suggest that the detection of pSTAT1, RBP-J, and CMAF in the context of CD68 or CD163 expression is a suitable tool

  13. p53 integrates host defense and cell fate during bacterial pneumonia

    PubMed Central

    Madenspacher, Jennifer H.; Azzam, Kathleen M.; Gowdy, Kymberly M.; Malcolm, Kenneth C.; Nick, Jerry A.; Dixon, Darlene; Aloor, Jim J.; Draper, David W.; Guardiola, John J.; Shatz, Maria; Menendez, Daniel; Lowe, Julie; Lu, Jun; Bushel, Pierre; Li, Leping; Merrick, B. Alex; Resnick, Michael A.

    2013-01-01

    Cancer and infection are predominant causes of human mortality and derive, respectively, from inadequate genomic and host defenses against environmental agents. The transcription factor p53 plays a central role in human tumor suppression. Despite its expression in immune cells and broad responsiveness to stressors, it is virtually unknown whether p53 regulates host defense against infection. We report that the lungs of naive p53−/− mice display genome-wide induction of NF-κB response element–enriched proinflammatory genes, suggestive of type 1 immune priming. p53-null and p53 inhibitor–treated mice clear Gram-negative and -positive bacteria more effectively than controls after intrapulmonary infection. This is caused, at least in part, by cytokines produced by an expanded population of apoptosis-resistant, TLR-hyperresponsive alveolar macrophages that enhance airway neutrophilia. p53−/− neutrophils, in turn, display heightened phagocytosis, Nox-dependent oxidant generation, degranulation, and bacterial killing. p53 inhibition boosts bacterial killing by mouse neutrophils and oxidant generation by human neutrophils. Despite enhanced bacterial clearance, infected p53−/− mice suffer increased mortality associated with aggravated lung injury. p53 thus modulates host defense through regulating microbicidal function and fate of phagocytes, revealing a fundamental link between defense of genome and host during environmental insult. PMID:23630228

  14. Role of nitric oxide in host defense against an extracellular, metazoan parasite, Brugia malayi.

    PubMed Central

    Rajan, T V; Porte, P; Yates, J A; Keefer, L; Shultz, L D

    1996-01-01

    The mechanisms by which mammalian hosts eliminate microparasites such as bacteria and viruses are well established. In viral infections, these mechanisms include the interferons, neutralizing and opsonizing antibodies, and cytotoxic T lymphocytes. In bacterial infections, polymorphonuclear leukocytes and macrophages, often facilitated by opsonizing antibodies, ingest the infectious agent and mediate host defense. In addition, complement, in the presence of specific antibodies directed against surface antigens, can lyse certain bacterial pathogens. In contrast, our understanding of the host defenses against metazoan, extracellular parasites is less well grounded. We obtained data by two different approaches to document the role of nitric oxide (NO) as a mediator of host defense against a human nematode parasite. First, treatment of immunocompetent, nonpermissive mice with an inhibitor of NO synthase abrogated resistance to Brugia malayi, one of the causative agents of human lymphatic filariasis. Second, treatment of permissive, immunodeficient mice with a compound that releases NO conferred resistance to infection. These data reinforce studies by James and her coworkers (I. P. Oswald, T. A. Wynn, A. Sher, and S. L. James, Comp. Biochem. Physiol. Pharmacol. Toxicol. Endocrinol. 108:11-18, 1994) on the role of NO in defense against trematode parasites and of Kanazawa et al. (T. Kanazawa, H. Asahi, H. Hata; K. Machida, N. Kagei, and M. J. Stadecker, Parasite Immunol. 15: 619-623, 1993) on cestode parasites. PMID:8757874

  15. BMP pathway regulation of and by macrophages.

    PubMed

    Talati, Megha; West, James; Zaynagetdinov, Rinat; Hong, Charles C; Han, Wei; Blackwell, Tom; Robinson, Linda; Blackwell, Timothy S; Lane, Kirk

    2014-01-01

    Pulmonary arterial hypertension (PAH) is a disease of progressively increasing pulmonary vascular resistance, associated with mutations of the type 2 receptor for the BMP pathway, BMPR2. The canonical signaling pathway for BMPR2 is through the SMAD family of transcription factors. BMPR2 is expressed in every cell type, but the impact of BMPR2 mutations affecting SMAD signaling, such as Bmpr2delx4+, had only previously been investigated in smooth muscle and endothelium. In the present study, we created a mouse with universal doxycycline-inducible expression of Bmpr2delx4+ in order to determine if broader expression had an impact relevant to the development of PAH. We found that the most obvious phenotype was a dramatic, but patchy, increase in pulmonary inflammation. We crossed these double transgenic mice onto an NF-κB reporter strain, and by luciferase assays on live mice, individual organs and isolated macrophages, we narrowed down the origin of the inflammatory phenotype to constitutive activation of tissue macrophages. Study of bone marrow-derived macrophages from mutant and wild-type mice suggested a baseline difference in differentiation state in Bmpr2 mutants. When activated with LPS, both mutant and wild-type macrophages secrete BMP pathway inhibitors sufficient to suppress BMP pathway activity in smooth muscle cells (SMC) treated with conditioned media. Functionally, co-culture with macrophages results in a BMP signaling-dependent increase in scratch closure in cultured SMC. We conclude that SMAD signaling through BMP is responsible, in part, for preventing macrophage activation in both live animals and in cells in culture, and that activated macrophages secrete BMP inhibitors in sufficient quantity to cause paracrine effect on vascular smooth muscle. PMID:24713633

  16. IL-4 Induces Metallothionein 3- and SLC30A4-Dependent Increase in Intracellular Zn(2+) that Promotes Pathogen Persistence in Macrophages.

    PubMed

    Subramanian Vignesh, Kavitha; Landero Figueroa, Julio A; Porollo, Aleksey; Divanovic, Senad; Caruso, Joseph A; Deepe, George S

    2016-09-20

    Alternative activation of macrophages promotes wound healing but weakens antimicrobial defenses against intracellular pathogens. The mechanisms that suppress macrophage function to create a favorable environment for pathogen growth remain elusive. We show that interleukin (IL)-4 triggers a metallothionein 3 (MT3)- and Zn exporter SLC30A4-dependent increase in the labile Zn(2+) stores in macrophages and that intracellular pathogens can exploit this increase in Zn to survive. IL-4 regulates this pathway by shuttling extracellular Zn into macrophages and by activating cathepsins that act on MT3 to release bound Zn. We show that IL-4 can modulate Zn homeostasis in both human monocytes and mice. In vivo, MT3 can repress macrophage function in an M2-polarizing environment to promote pathogen persistence. Thus, MT3 and SLC30A4 dictate the size of the labile Zn(2+) pool and promote the survival of a prototypical intracellular pathogen in M2 macrophages. PMID:27653687

  17. Flexible defense strategies: competition modifies investment in behavioral vs. morphological defenses.

    PubMed

    Teplitsky, Céline; Laurila, Anssi

    2007-07-01

    Competition is predicted to affect the expression of inducible defenses, but because costs of behavioral and morphological antipredator defenses differ along resource gradients, its effects on defenses may depend on the traits considered. We tested the predictions from different defense models in tadpoles of the common frog Rana temporaria, which exhibit both types of defenses. In an outdoor experiment, we exposed the tadpoles to nonlethal predators (Aeshna dragonfly larvae) and to a gradient of intraspecific competition. Morphological responses did not follow any of the expected patterns, since investment in defense was not affected by resource level. Instead, tail depth decreased in the absence of predators. Behavioral defenses followed a state-dependent model. Overall, the defense strategy of the tadpoles revealed a shift from morphological and behavioral defenses at low tadpole density to morphological defense only at high density. This difference probably reflects the different efficiency of the defenses. Hiding is an effective means of defense, but it is unsustainable when resources are scarce. Morphological responses become more important with increasing density to compensate for the increase in behavioral risk-taking. Our results indicate that competition can strongly affect reaction norms of inducible defenses and highlight the importance of integrating ecological parameters that affect the cost-benefit balance of phenotypic plasticity.

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

    PubMed

    Taniyama, T; Holden, H T

    1980-07-15

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

  19. Theater missile defense programs: Status and prospects

    SciTech Connect

    Pike, J.

    1994-09-01

    The Clinton administration now calls the Strategic Defense Initiative (SDI) the ballistic missile defense program. But the names have simply been changed to protect the guilty - the new program exhibits substantial continuity with the old in technology and goals. While acronyms have been changed, many of the programs continued by the Clinton administration date from the Reagan or Bush eras. And most strikingly, the Clinton administrations` ambitions for a virtually perfect defense against theater ballistic missiles harken to the unattainable goals for strategic defense initially set by President Reagan over a decade ago.

  20. Defense styles in Intermittent Explosive Disorder.

    PubMed

    Puhalla, Alexander A; McCloskey, Michael S; Brickman, Lauren J; Fauber, Robert; Coccaro, Emil F

    2016-04-30

    The overreliance on immature and/or neurotic defense mechanisms, as opposed to more mature defensive functioning has been linked to several psychiatric disorders. However, to date, the role of defense styles among individuals with Intermittent Explosive Disorder (IED) has not been examined. Given that individuals with IED display difficulties controlling their anger and aggression, one might expect these individuals to exhibit more immature and less mature defense styles. The current study compared participants with IED to a personality disorder (PD) comparison group, as well as to healthy volunteers (HV) on the Defense Style Questionnaire, a self-report measure that assesses the extent to which individuals endorse using mature, immature, and neurotic defense styles. Subjects with IED had significantly higher scores than both comparison groups on immature defense styles and exhibited lower scores on mature defense mechanisms. Hierarchical regression of significant defense style subscales showed that higher levels of acting out and lower levels of sublimation uniquely discriminated participants with IED from the PD and HV comparison groups. PMID:27086223

  1. Defense styles in Intermittent Explosive Disorder.

    PubMed

    Puhalla, Alexander A; McCloskey, Michael S; Brickman, Lauren J; Fauber, Robert; Coccaro, Emil F

    2016-04-30

    The overreliance on immature and/or neurotic defense mechanisms, as opposed to more mature defensive functioning has been linked to several psychiatric disorders. However, to date, the role of defense styles among individuals with Intermittent Explosive Disorder (IED) has not been examined. Given that individuals with IED display difficulties controlling their anger and aggression, one might expect these individuals to exhibit more immature and less mature defense styles. The current study compared participants with IED to a personality disorder (PD) comparison group, as well as to healthy volunteers (HV) on the Defense Style Questionnaire, a self-report measure that assesses the extent to which individuals endorse using mature, immature, and neurotic defense styles. Subjects with IED had significantly higher scores than both comparison groups on immature defense styles and exhibited lower scores on mature defense mechanisms. Hierarchical regression of significant defense style subscales showed that higher levels of acting out and lower levels of sublimation uniquely discriminated participants with IED from the PD and HV comparison groups.

  2. CD163 Identifies Perivascular Macrophages in Normal and Viral Encephalitic Brains and Potential Precursors to Perivascular Macrophages in Blood

    PubMed Central

    Kim, Woong-Ki; Alvarez, Xavier; Fisher, Jeanne; Bronfin, Benjamin; Westmoreland, Susan; McLaurin, JoAnne; Williams, Kenneth

    2006-01-01

    Perivascular macrophages are uniquely situated at the intersection between the nervous and immune systems. Although combined myeloid marker detection differentiates perivascular from resident brain macrophages (parenchymal microglia), no single marker distinguishes perivascular macrophages in humans and mice. Here, we present the macrophage scavenger receptor CD163 as a marker for perivascular macrophages in humans, monkeys, and mice. CD163 was primarily confined to perivascular macrophages and populations of meningeal and choroid plexus macrophages in normal brains and in brains of humans and monkeys with human immunodeficiency virus or simian immunodeficiency virus (SIV) encephalitis. Scattered microglia in SIV encephalitis lesions and multinucleated giant cells were also CD163 positive. Consistent with prior findings that perivascular macrophages are primary targets of human immunodeficiency virus and SIV, all SIV-infected cells in the brain were CD163 positive. Using fluorescent dyes that definitively and selectively label perivascular macrophages in vivo, we confirmed that dye-labeled simian perivascular macrophages were CD163 positive and able to repopulate the central nervous system within 24 hours. Flow cytometric studies demonstrated a subset of monocytes (CD163+CD14+CD16+) that were immunophenotypically similar to brain perivascular macrophages. These findings recognize CD163+ blood monocytes/macrophages as a source of brain perivascular macrophages and underscore the utility of this molecule in studying the biology of perivascular macrophages and their precursors in humans, monkeys, and mice. PMID:16507898

  3. Much More than M1 and M2 Macrophages, There are also CD169+ and TCR+ Macrophages

    PubMed Central

    Chávez-Galán, Leslie; Olleros, Maria L.; Vesin, Dominique; Garcia, Irene

    2015-01-01

    Monocytes are considered to be precursor cells of the mononuclear phagocytic system, and macrophages are one of the leading members of this cellular system. Macrophages play highly diverse roles in maintaining an organism’s integrity by either directly participating in pathogen elimination or repairing tissue under sterile inflammatory conditions. There are different subpopulations of macrophages and each one has its own characteristics and functions. In this review, we summarize present knowledge on the polarization of macrophages that allows the generation of subpopulations called classically activated macrophages or M1 and alternative activated macrophages or M2. Furthermore, there are macrophages that their origin and characterization still remain unclear but have been involved as main players in some human pathologies. Thus, we also review three other categories of macrophages: tumor-associated macrophages, CD169+ macrophages, and the recently named TCR+ macrophages. Based on the literature, we provide information on the molecular characterization of these macrophage subpopulations and their specific involvement in several human pathologies such as cancer, infectious diseases, obesity, and asthma. The refined characterization of the macrophage subpopulations can be useful in designing new strategies, supplementing those already established for the treatment of diseases using macrophages as a therapeutic target. PMID:26074923

  4. Antibiotics, microbiota, and immune defense.

    PubMed

    Ubeda, Carles; Pamer, Eric G

    2012-09-01

    The gastrointestinal tract microbiota contributes to the development and differentiation of the mammalian immune system. The composition of the microbiota affects immune responses and affects susceptibility to infection by intestinal pathogens and development of allergic and inflammatory bowel diseases. Antibiotic administration, while facilitating clearance of targeted infections, also perturbs commensal microbial communities and decreases host resistance to antibiotic-resistant microbes. Here, we review recent advances that begin to define the interactions between complex intestinal microbial populations and the mammalian immune system and how this relation is perturbed by antibiotic administration. We further discuss how antibiotic-induced disruption of the microbiota and immune homeostasis can lead to disease and we review strategies to restore immune defenses during antibiotic administration.

  5. Female resistance to pneumonia identifies lung macrophage nitric oxide synthase-3 as a therapeutic target

    PubMed Central

    Yang, Zhiping; Huang, Yuh-Chin T; Koziel, Henry; de Crom, Rini; Ruetten, Hartmut; Wohlfart, Paulus; Thomsen, Reimar W; Kahlert, Johnny A; Sørensen, Henrik Toft; Jozefowski, Szczepan; Colby, Amy; Kobzik, Lester

    2014-01-01

    To identify new approaches to enhance innate immunity to bacterial pneumonia, we investigated the natural experiment of gender differences in resistance to infections. Female and estrogen-treated male mice show greater resistance to pneumococcal pneumonia, seen as greater bacterial clearance, diminished lung inflammation, and better survival. In vitro, lung macrophages from female mice and humans show better killing of ingested bacteria. Inhibitors and genetically altered mice identify a critical role for estrogen-mediated activation of lung macrophage nitric oxide synthase-3 (NOS3). Epidemiologic data show decreased hospitalization for pneumonia in women receiving estrogen or statins (known to activate NOS3). Pharmacologic targeting of NOS3 with statins or another small-molecule compound (AVE3085) enhanced macrophage bacterial killing, improved bacterial clearance, and increased host survival in both primary and secondary (post-influenza) pneumonia. The data identify a novel mechanism for host defense via NOS3 and suggest a potential therapeutic strategy to reduce secondary bacterial pneumonia after influenza. DOI: http://dx.doi.org/10.7554/eLife.03711.001 PMID:25317947

  6. Distinct signal transduction pathways for activation of rabbit alveolar macrophages in vitro by cotton bract tannin.

    PubMed

    Prévost, M C; Soulat, J M; Comminges, C; Maury, E; Aslane, R; Cohen-Jonathan, E; Cariven, C; Lauque, D; Chap, H

    1996-05-01

    These experiments were designed to study signal transduction pathways in alveolar macrophages stimulated by condensed tannin or zymosan. Condensed tannins, present in cotton mill dust, alter the host-defense function of alveolar macrophages and may contribute to the pathogenesis of byssinosis. We tried to determine the early steps in signal transduction mechanisms of cell activation by tannin. With the quantification of 51Cr release, we determined that tannin was cytotoxic for the cells after 30 min activation with 130 micrograms for 2 x 10(6) cells. 51Cr release was similar for control cells and zymosan- or 30 micrograms tannin-activated cells. Using the luciferine luciferase reaction, we showed that tannin markedly depleted ATP cell content. In inositol-labeled cells, tannin increased inositolphosphate release in a dose-dependent manner. In lysoPAF-labeled cells, tannin induced synthesis of phosphatidic acid and diglycerides. In the presence of ethanol, the level of tannin-induced phosphatidic acid was slightly reduced, and phosphatidylethanol was synthesized. No phosphatidylethanol was found in alveolar macrophages stimulated by zymosan in the presence of ethanol. GF 109203X, a specific inhibitor of protein kinase C decreased only tannin-induced phosphatidylethanol synthesis. In conclusion, tannin (at 30 or 130 micrograms/ml) activated an inositol phospholipase C in alveolar membranes. Phosphatidylcholine phospholipases C and D were found only at the higher concentration of tannin.

  7. Peroxynitrite, a potent macrophage-derived oxidizing cytotoxin to combat invading pathogens

    PubMed Central

    Prolo, Carolina; Álvarez, María Noel; Radi, Rafael

    2013-01-01

    Macrophages are among the first cellular actors facing the invasion of microorganisms. These cells are able to internalize pathogens and destroy them by means of toxic mediators, many of which are produced enzymatically and have strong oxidizing capacity. Indeed, macrophages count on the NADPH oxidase complex activity, which is triggered during pathogen invasion and leads to the production of superoxide radical inside the phagosome. At the same time, the induction of nitric oxide synthase results in the production of nitric oxide in the cytosol which is able to readily diffuse to the phagocytic vacuole. Superoxide radical and nitric oxide react at diffusion controlled rates with each other inside the phagosome to yield peroxynitrite, a powerful oxidant capable to kill microorganisms. Peroxynitrite toxicity resides on oxidations and nitrations of biomolecules in the target cell. The central role of peroxynitrite as a key effector molecule in the control of infections has been proven in a wide number of models. However, some microorganisms and virulent strains adapt to survive inside the potentially hostile oxidizing microenvironment of the phagosome by either impeding peroxynitrite formation or rapidly detoxifying it once formed. In this context, the outcome of the infection process is a result of the interplay between the macrophage-derived oxidizing cytotoxins such as peroxynitrite and the antioxidant defense machinery of the invading pathogens. PMID:24281946

  8. An Empirical Investigation of Defense Interpretation Depth, Defensive Functioning, and Alliance Strength in Psychodynamic Psychotherapy.

    PubMed

    Petraglia, Jonathan; Bhatia, Maneet; De Roten, Yves; Despland, Jean-Nicolas; Drapeau, Martin

    2015-01-01

    The present study examined the relationship between depth of defense interpretations by therapists, and patient defensive functioning, on the therapeutic alliance in a sample of 36 patients undergoing short-term dynamic psychotherapy. Defense interpretation depth was defined as the degree to which therapist interpretations contained information regarding the motivation for patient defenses and historical origins of the defensive processes (Greensen, 1967). Mean depth of interpretation was compared between sessions that were identified beforehand as either high-alliance or low-alliance sessions using the Helping Alliance Questionnaire (HAq-II: Luborsky et al., 1996). Results indicated that defensive functioning was correlated to defense interpretation depth in low-alliance sessions. Moreover, mean depth of interpretation was also higher in low-alliance sessions, pointing to the possible "destabilizing" effects that these interpretations may have on both defensive functioning and the therapeutic alliance. These results are discussed within the context of previous studies of therapeutic technique in dynamic psychotherapy.

  9. On the role of macrophages in anthrax.

    PubMed Central

    Hanna, P C; Acosta, D; Collier, R J

    1993-01-01

    Bacillus anthracis, the causative agent of anthrax, produces systemic shock and death in susceptible animals, primarily through the action of its lethal toxin. This toxin, at high concentrations, induces lysis of macrophages in vitro but shows little or no effect on other cells. We found that when mice were specifically depleted of macrophages by silica injections, they became resistant to the toxin. Sensitivity could be restored by coinjection of toxin-sensitive cultured macrophages (RAW 264.7 cells) but not by coinjection of other cell lines tested. These results implied that macrophages mediate the action of lethal toxin in vivo and led us to investigate their role in death of the mammalian host. Sublytic concentrations of lethal toxin, orders of magnitude lower than those required to induce lysis of RAW 264.7 cells, were found to induce these cells to express interleukin 1 (IL-1) and tumor necrosis factor in vitro. Passive immunization against IL-1 or injection of an IL-1 receptor antagonist protected mice from toxin challenge, whereas anti-tumor necrosis factor provided little, if any, protection. These results imply that systemic shock and death from anthrax result primarily from the effects of high levels of cytokines, principally IL-1, produced by macrophages that have been stimulated by the anthrax lethal toxin. PMID:8234277

  10. Macrophages: important accessory cells for reproductive function.

    PubMed

    Cohen, P E; Nishimura, K; Zhu, L; Pollard, J W

    1999-11-01

    Macrophages are found throughout reproductive tissues. To determine their role(s), we have studied mice homozygous for a null mutation (Csfm(op)) in the gene encoding the major macrophage growth factor, colony-stimulating factor-1 (CSF-1). Both male and female Csfm(op)/Csfm(op) mice have fertility defects. Males have low sperm number and libido as a consequence of dramatically reduced circulating testosterone. Females have extended estrous cycles and poor ovulation rates. CSF-1 is the principal growth factor regulating macrophage populations in the testis, male accessory glands, ovary, and uterus. However, analyses of CSF-1 nullizygous mice suggest that the primary reproductive defect is in the development of feedback regulation of the hypothalamic-pituitary axis. Although not correlating with deficiencies of microglia populations, electrophysiological investigations indicate an impairment of neuronal responses. This suggests that microglia, under the influence of CSF-1, act to organize neuronal connectivity during development and that the absence of this function results in a perturbation of the hypothalamic-pituitary-gonadal axis. Macrophages also appear to have functions in the differentiated tissues of the reproductive system, including having a positive influence on steroidogenic cells. These data suggest that macrophages, through their trophic functions, can be considered as essential accessory cells for normal reproductive functioning.

  11. Tumor Associated Macrophages in Kidney Cancer

    PubMed Central

    Kovaleva, Olga V.; Samoilova, Daria V.; Shitova, Maria S.

    2016-01-01

    Tumor associated macrophages (TAMs) are an important element of tumor stroma. They originate from blood monocytes attracted by chemokines and cytokines produced by tumor cells and, being instructed by tumor microenvironment, develop into potent tumor-supporting cell population. TAMs were demonstrated to directly stimulate tumor cell proliferation and to promote angiogenesis. Further TAMs provide for efficient immune escape by producing immunosuppressive cytokines and facilitate tumor dissemination by producing extracellular matrix remodeling enzymes. In renal cell carcinoma (RCC), numerous studies were performed for elucidation of the role of TAM in tumor progression. Using pan-macrophages marker CD68 and type 2 macrophage (M2) markers CD163 and CD206, it was demonstrated that increased density of TAMs is associated with poor survival of patients. Although most of the studies are focused on M2 population in RCC, several markers rather typical for type 1 macrophages (M1) were also characterized. Macrophages isolated from RCC tumors were shown to produce proinflammatory cytokines TNFα, IL-1β, IL-6, and CCL2. It can be concluded that RCC is an excellent example of a tumor with hybrid phenotype of TAMs that share both M1 and M2 properties. Moreover, TAMs seem to be an attractive therapeutic target as well. Further investigations are needed for identification of RCC-specific TAM markers with high predictive capacity and/or suitable for therapeutic targeting. PMID:27807511

  12. Modeling the transcriptome of genital tract epithelial cells and macrophages in healthy mucosa versus mucosa inflamed by Chlamydia muridarum infection.

    PubMed

    Johnson, Raymond M; Kerr, Micah S

    2015-12-01

    Chlamydia trachomatis urogenital serovars are intracellular bacteria that parasitize human reproductive tract epithelium. As the principal cell type supporting bacterial replication, epithelial cells are central to Chlamydia immunobiology initially as sentries and innate defenders, and subsequently as collaborators in adaptive immunity-mediated bacterial clearance. In asymptomatic individuals who do not seek medical care a decisive struggle between C. trachomatis and host defenses occurs at the epithelial interface. For this study, we modeled the immunobiology of epithelial cells and macrophages lining healthy genital mucosa and inflamed/infected mucosa during the transition from innate to adaptive immunity. Upper reproductive tract epithelial cell line responses were compared to bone marrow-derived macrophages utilizing gene expression microarray technology. Those comparisons showed minor differences in the intrinsic innate defenses of macrophages and epithelial cells. Major lineage-specific differences in immunobiology relate to epithelial collaboration with adaptive immunity including an epithelial requirement for inflammatory cytokines to express MHC class II molecules, and a paucity and imbalance between costimulatory and coinhibitory ligands on epithelial cells that potentially limits sterilizing immunity (replication termination) to Chlamydia-specific T cells activated with limited or unconventional second signals.

  13. Monosodium urate activates Src/Pyk2/PI3 kinase and cathepsin dependent unconventional protein secretion from human primary macrophages.

    PubMed

    Välimäki, Elina; Miettinen, Juho J; Lietzén, Niina; Matikainen, Sampsa; Nyman, Tuula A

    2013-03-01

    Monosodium urate (MSU) is an endogenous danger signal that is crystallized from uric acid released from injured cells. MSU is known to activate inflammatory response in macrophages but the molecular mechanisms involved have remained uncharacterized. Activated macrophages start to secrete proteins to activate immune response and to recruit other immune cells to the site of infection and/or tissue damage. Secretome characterization after activation of innate immune system is essential to unravel the details of early phases of defense responses. Here, we have analyzed the secretome of human primary macrophages stimulated with MSU using quantitative two-dimensional gel electrophoresis based proteomics as well as high-throughput qualitative GeLC-MS/MS approach combining protein separation by SDS-PAGE and protein identification by liquid chromatography-MS/MS. Both methods showed that MSU stimulation induced robust protein secretion from lipopolysaccharide-primed human macrophages. Bioinformatic analysis of the secretome data showed that MSU stimulation strongly activates unconventional, vesicle mediated protein secretion. The unconventionally secreted proteins included pro-inflammatory cytokines like IL-1β and IL-18, interferon-induced proteins, and danger signal proteins. Also active forms of lysosomal proteases cathepsins were secreted on MSU stimulation, and cathepsin activity was essential for MSU-induced unconventional protein secretion. Additionally, proteins associated to phosphorylation events including Src family tyrosine kinases were increased in the secretome of MSU-stimulated cells. Our functional studies demonstrated that Src, Pyk2, and PI3 kinases act upstream of cathepsins to activate the overall protein secretion from macrophages. In conclusion, we provide the first comprehensive characterization of protein secretion pathways activated by MSU in human macrophages, and reveal a novel role for cathepsins and Src, Pyk2, PI3 kinases in the activation of

  14. Plant Defense Mechanisms Are Activated during Biotrophic and Necrotrophic Development of Colletotricum graminicola in Maize1[W][OA

    PubMed Central

    Vargas, Walter A.; Martín, José M. Sanz; Rech, Gabriel E.; Rivera, Lina P.; Benito, Ernesto P.; Díaz-Mínguez, José M.; Thon, Michael R.; Sukno, Serenella A.

    2012-01-01

    Hemibiotrophic plant pathogens first establish a biotrophic interaction with the host plant and later switch to a destructive necrotrophic lifestyle. Studies of biotrophic pathogens have shown that they actively suppress plant defenses after an initial microbe-associated molecular pattern-triggered activation. In contrast, studies of the hemibiotrophs suggest that they do not suppress plant defenses during the biotrophic phase, indicating that while there are similarities between the biotrophic phase of hemibiotrophs and biotrophic pathogens, the two lifestyles are not analogous. We performed transcriptomic, histological, and biochemical studies of the early events during the infection of maize (Zea mays) with Colletotrichum graminicola, a model pathosystem for the study of hemibiotrophy. Time-course experiments revealed that mRNAs of several defense-related genes, reactive oxygen species, and antimicrobial compounds all begin to accumulate early in the infection process and continue to accumulate during the biotrophic stage. We also discovered the production of maize-derived vesicular bodies containing hydrogen peroxide targeting the fungal hyphae. We describe the fungal respiratory burst during host infection, paralleled by superoxide ion production in specific fungal cells during the transition from biotrophy to a necrotrophic lifestyle. We also identified several novel putative fungal effectors and studied their expression during anthracnose development in maize. Our results demonstrate a strong induction of defense mechanisms occurring in maize cells during C. graminicola infection, even during the biotrophic development of the pathogen. We hypothesize that the switch to necrotrophic growth enables the fungus to evade the effects of the plant immune system and allows for full fungal pathogenicity. PMID:22247271

  15. Strategic Defense Initiative: Splendid Defense or Pipe Dream? Headline Series No. 275.

    ERIC Educational Resources Information Center

    Armstrong, Scott; Grier, Peter

    This pamphlet presents a discussion of the various components of President Reagan's Strategic Defense Initiative (SDI) including the problem of pulling together various new technologies into an effective defensive system and the politics of the so-called "star wars" system. An important part of the defense initiative is the "layered" defense…

  16. 75 FR 13093 - Renewal of Department of Defense Federal Advisory Committee; Defense Acquisition University Board...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... University Board of Visitors AGENCY: Department of Defense (DoD). ACTION: Renewal of Federal advisory... amended), and 41 CFR 102-3.50(c), the Department of Defense gives notice that it is renewing the charter for the Defense Acquisition University Board of Visitors (hereafter referred to as the Board)....

  17. 75 FR 15695 - Renewal of Department of Defense Federal Advisory Committee; Board of Visitors National Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... Defense gives notice that it is renewing the charter for the Board of Visitors National Defense University (hereafter referred to as the Board). FOR FURTHER INFORMATION CONTACT: Jim Freeman, Deputy Committee... of the Secretary Renewal of Department of Defense Federal Advisory Committee; Board of...

  18. Defense Economic Impact Modeling System (DEIMS). A New Concept in Economic Forecasting for Defense Expenditures.

    ERIC Educational Resources Information Center

    Blond, David L.

    The Defense Economic Impact Modeling System (DEIMS) analyzes the economic effect of defense expenditures on the United States economy by using a consistent, reliable framework of economic models and government policy assumptions. Planning information on defense requirements is also provided to private sector firms. The DEIMS allows the Department…

  19. Adipocyte Fetuin-A Contributes to Macrophage Migration into Adipose Tissue and Polarization of Macrophages*

    PubMed Central

    Chatterjee, Priyajit; Seal, Soma; Mukherjee, Sandip; Kundu, Rakesh; Mukherjee, Sutapa; Ray, Sukanta; Mukhopadhyay, Satinath; Majumdar, Subeer S.; Bhattacharya, Samir

    2013-01-01

    Macrophage infiltration into adipose tissue during obesity and their phenotypic conversion from anti-inflammatory M2 to proinflammatory M1 subtype significantly contributes to develop a link between inflammation and insulin resistance; signaling molecule(s) for these events, however, remains poorly understood. We demonstrate here that excess lipid in the adipose tissue environment may trigger one such signal. Adipose tissue from obese diabetic db/db mice, high fat diet-fed mice, and obese diabetic patients showed significantly elevated fetuin-A (FetA) levels in respect to their controls; partially hepatectomized high fat diet mice did not show noticeable alteration, indicating adipose tissue to be the source of this alteration. In adipocytes, fatty acid induces FetA gene and protein expressions, resulting in its copious release. We found that FetA could act as a chemoattractant for macrophages. To simulate lipid-induced inflammatory conditions when proinflammatory adipose tissue and macrophages create a niche of an altered microenvironment, we set up a transculture system of macrophages and adipocytes; the addition of fatty acid to adipocytes released FetA into the medium, which polarized M2 macrophages to M1. This was further confirmed by direct FetA addition to macrophages. Taken together, lipid-induced FetA from adipocytes is an efficient chemokine for macrophage migration and polarization. These findings open a new dimension for understanding obesity-induced inflammation. PMID:23943623

  20. Adipocyte fetuin-A contributes to macrophage migration into adipose tissue and polarization of macrophages.

    PubMed

    Chatterjee, Priyajit; Seal, Soma; Mukherjee, Sandip; Kundu, Rakesh; Mukherjee, Sutapa; Ray, Sukanta; Mukhopadhyay, Satinath; Majumdar, Subeer S; Bhattacharya, Samir

    2013-09-27

    Macrophage infiltration into adipose tissue during obesity and their phenotypic conversion from anti-inflammatory M2 to proinflammatory M1 subtype significantly contributes to develop a link between inflammation and insulin resistance; signaling molecule(s) for these events, however, remains poorly understood. We demonstrate here that excess lipid in the adipose tissue environment may trigger one such signal. Adipose tissue from obese diabetic db/db mice, high fat diet-fed mice, and obese diabetic patients showed significantly elevated fetuin-A (FetA) levels in respect to their controls; partially hepatectomized high fat diet mice did not show noticeable alteration, indicating adipose tissue to be the source of this alteration. In adipocytes, fatty acid induces FetA gene and protein expressions, resulting in its copious release. We found that FetA could act as a chemoattractant for macrophages. To simulate lipid-induced inflammatory conditions when proinflammatory adipose tissue and macrophages create a niche of an altered microenvironment, we set up a transculture system of macrophages and adipocytes; the addition of fatty acid to adipocytes released FetA into the medium, which polarized M2 macrophages to M1. This was further confirmed by direct FetA addition to macrophages. Taken together, lipid-induced FetA from adipocytes is an efficient chemokine for macrophage migration and polarization. These findings open a new dimension for understanding obesity-induced inflammation.