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Sample records for macrophages rapid killing

  1. Killing of Pseudomonas pseudomallei by polymorphonuclear leukocytes and peritoneal macrophages from chicken, sheep, swine and rabbits.

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    Markova, N; Kussovski, V; Radoucheva, T

    1998-07-01

    Differences in the kinetics of Pseudomonas pseudomallei killing by peritoneal macrophages (PM) and polymorphonuclear leucocytes (PMNL) from chickens, sheep, swine and rabbits were found. P. pseudomallei was rapidly killed by porcine PM and PMNL. However the bacterial killing by ovine and lapine PM and PMNL proceeded at a slower rate. In contrast, chicken PM and PMNL ingested and killed the lowest number of P. pseudomallei bacteria. The differences in the bactericidal activity of PM and PMNL from different animal species correlated with the level of their acid phosphatase and glycolytic activity.

  2. The killing of macrophages by Corynebacterium ulcerans.

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    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.

  3. Measurement of bacterial ingestion and killing by macrophages.

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    Campbell, P A; Canono, B P; Drevets, D A

    2001-05-01

    This unit presents fairly simple assays for measuring the binding of bacteria to macrophages, internalization of bacteria (also called ingestion or phagocytosis), and bacterial killing by macrophages. The first basic protocol describes how to measure the ability of macrophages to ingest bacteria. Because it is critical to remove residual extracellular organisms, the protocol presents two alternative steps to accomplish this: a washing procedure and a more stringent method in which cells are sedimented through sucrose. In addition, it is important to distinguish those bacteria truly ingested by a macrophage from those that are bound to, but not internalized by, the cell. A simple but effective way to do this is described in an alternate protocol. The unit also presents two ways to measure the ability of a macrophage to kill bacteria it has internalized. The first is a straightforward assay in which bacterial colonies are enumerated before and after a killing period; a subsequent colony count will indicate whether the bacteria grew within or were killed by the macrophage. The second protocol describes a way to measure bacterial viability based on bacterial metabolism, in which the ability of bacterial dehydrogenases to mediate the reduction of a tetrazolium salt to purple formazan is monitored by measuring absorbance spectrophotometrically.

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

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    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. IFNγ: Issuing macrophages a license to kill

    OpenAIRE

    2007-01-01

    T cells tell macrophages when to start making the toxic soup of lysosomal enzymes, reactive oxygen species, and nitric oxide that destroys intracellular pathogens. In 1983, Carl Nathan proved that this start signal comes in the form of the secreted cytokine IFNγ.

  6. Increased Lytic Efficiency of Bovine Macrophages Trained with Killed Mycobacteria

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    Juste, Ramon A.; Alonso-Hearn, Marta; Garrido, Joseba M.; Abendaño, Naiara; Sevilla, Iker A.; Gortazar, Christian; de la Fuente, José; Dominguez, Lucas

    2016-01-01

    Innate immunity is evolutionarily conserved in multicellular organisms and was considered to lack memory until very recently. One of its more characteristic mechanisms is phagocytosis, the ability of cells to engulf, process and eventually destroy any injuring agent. We report the results of an ex vivo experiment in bovine macrophages in which improved clearance of Mycobacterium bovis (M. bovis) was induced by pre-exposure to a heat killed M. bovis preparation. The effects were independent of humoral and cellular adaptive immune responses and lasted up to six months. Specifically, our results demonstrate the existence of a training effect in the lytic phase of phagocytosis that can be activated by killed mycobacteria, thus suggesting a new mechanism of vaccine protection. These findings are compatible with the recently proposed concept of trained immunity, which was developed to explain the observation that innate immune responses provide unspecific protection against pathogens including other than those that originally triggered the immune response. PMID:27820836

  7. Killing of Klebsiella pneumoniae by human alveolar macrophages.

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    Hickman-Davis, Judy M; O'Reilly, Philip; Davis, Ian C; Peti-Peterdi, Janos; Davis, Glenda; Young, K Randall; Devlin, Robert B; Matalon, Sadis

    2002-05-01

    We investigated putative mechanisms by which human surfactant protein A (SP-A) effects killing of Klebsiella pneumoniae by human alveolar macrophages (AMs) isolated from bronchoalveolar lavagates of patients with transplanted lungs. Coincubation of AMs with human SP-A (25 microg/ml) and Klebsiella resulted in a 68% decrease in total colony forming units by 120 min compared with AMs infected with Klebsiella in the absence of SP-A, and this SP-A-mediated effect was abolished by preincubation with N(G)-monomethyl-L-arginine. Incubation of transplant AMs with SP-A increased intracellular Ca(2+) concentration ([Ca(2+)](i)) by 70% and nitrite and nitrate (NO(x)) production by 45% (from 0.24 +/- 0.02 to 1.3 +/- 0.21 nmol small middle dot 10(6) AMs(-1).h(-1)). Preincubation with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester inhibited the increase in [Ca(2+)](i) and abrogated the SP-A-mediated Klebsiella phagocytosis and killing. In contrast, incubation of AMs from normal volunteers with SP-A decreased both [Ca(2+)](i) and NO(x) production and did not result in killing of Klebsiella. Significant killing of Klebsiella was also seen in a cell-free system by sustained production of peroxynitrite (>1 microM/min) at pH 5 but not at pH 7.4. These findings indicate that SP-A mediates pathogen killing by AMs from transplant lungs by stimulating phagocytosis and production of reactive oxygen-nitrogen intermediates.

  8. Effect of Shark Liver Oil on Peritoneal Murine Macrophages in Responses to Killed-Candida albicans

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    Monire Hajimoradi

    2009-09-01

    Full Text Available Objective(sShark Liver Oil (SLO is an immunomodulator. Macrophages play a key role in host defense against pathogens like fungi. Candida albicans have mechanisms to escape immune system. We determined the effect of killed-Candida on the in vitro viability of macrophages and the effect of SLO on augmentation of this potency.Materials and MethodsPeritoneal macrophages were separated and cultured (3×105/well. At first, the effect of killed-Candida (200 cells/well on macrophage viability was evaluated, using MTT test. Then, MTT was performed on macrophages stimulated with killed-Candida in the presence of SLO. ResultsKilled-Candida suppressed the ability of MTT reduction and hence macrophages viability (P=0.026, but addition of SLO (100 mg/ml significantly enhanced cell viability (P=0.00. So, SLO could neutralize the inhibitory effect of Candida.ConclusionSimultaneous with cytotoxic effect of killed-Candida cells on macrophages viability, SLO augment macrophages viability. So, it can be applied in candidiasis as a complement.

  9. Reactive-oxygen-species-mediated P. aeruginosa killing is functional in human cystic fibrosis macrophages.

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    Noemi Cifani

    Full Text Available Pseudomonas aeruginosa is the most common pathogen for chronic lung infection in cystic fibrosis (CF patients. About 80% of adult CF patients have chronic P. aeruginosa infection, which accounts for much of the morbidity and most of the mortality. Both bacterial genetic adaptations and defective innate immune responses contribute to the bacteria persistence. It is well accepted that CF transmembrane conductance regulator (CFTR dysfunction impairs the airways-epithelium-mediated lung defence; however, other innate immune cells also appear to be affected, such as neutrophils and macrophages, which thus contribute to this infectious pathology in the CF lung. In macrophages, the absence of CFTR has been linked to defective P. aeruginosa killing, increased pro-inflammatory cytokine secretion, and reduced reactive oxygen species (ROS production. To learn more about macrophage dysfunction in CF patients, we investigated the generation of the oxidative burst and its impact on bacterial killing in CF macrophages isolated from peripheral blood or lung parenchyma of CF patients, after P. aeruginosa infection. Our data demonstrate that CF macrophages show an oxidative response of similar intensity to that of non-CF macrophages. Intracellular ROS are recognized as one of the earliest microbicidal mechanisms against engulfed pathogens that are activated by macrophages. Accordingly, NADPH inhibition resulted in a significant increase in the intracellular bacteria survival in CF and non-CF macrophages, both as monocyte-derived macrophages and as lung macrophages. These data strongly suggest that the contribution of ROS to P. aeruginosa killing is not affected by CFTR mutations.

  10. Neutrophils exert protection in the early tuberculous granuloma by oxidative killing of mycobacteria phagocytosed from infected macrophages.

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    Yang, Chao-Tsung; Cambier, C J; Davis, J Muse; Hall, Christopher J; Crosier, Philip S; Ramakrishnan, Lalita

    2012-09-13

    Neutrophils are typically the first responders in host defense against invading pathogens, which they destroy by both oxidative and nonoxidative mechanisms. However, despite a longstanding recognition of neutrophil presence at disease sites in tuberculosis, their role in defense against mycobacteria is unclear. Here we exploit the genetic tractability and optical transparency of zebrafish to monitor neutrophil behavior and its consequences during infection with Mycobacterium marinum, a natural fish pathogen. In contrast to macrophages, neutrophils do not interact with mycobacteria at initial infection sites. Neutrophils are subsequently recruited to the nascent granuloma in response to signals from dying infected macrophages within the granuloma, which they phagocytose. Some neutrophils then rapidly kill the internalized mycobacteria through NADPH oxidase-dependent mechanisms. Our results provide a mechanistic link to the observed patterns of neutrophils in human tuberculous granulomas and the susceptibility of humans with chronic granulomatous disease to mycobacterial infection.

  11. Phenylbutyrate induces LL-37-dependent autophagy and intracellular killing of Mycobacterium tuberculosis in human macrophages.

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    Rekha, Rokeya Sultana; Rao Muvva, S S V Jagadeeswara; Wan, Min; Raqib, Rubhana; Bergman, Peter; Brighenti, Susanna; Gudmundsson, Gudmundur H; Agerberth, Birgitta

    2015-01-01

    LL-37 is a human antimicrobial peptide (AMP) of the cathelicidin family with multiple activities including a mediator of vitamin D-induced autophagy in human macrophages, resulting in intracellular killing of Mycobacterium tuberculosis (Mtb). In a previous trial in healthy volunteers, we have shown that LL-37 expression and subsequent Mtb-killing can be further enhanced by 4-phenylbutyrate (PBA), also an inducer of LL-37 expression. Here, we explore a potential mechanism(s) behind PBA and LL-37-induced autophagy and intracellular killing of Mtb. Mtb infection of macrophages downregulated the expression of both the CAMP transcript and LL-37 peptide as well as certain autophagy-related genes (BECN1 and ATG5) at both the mRNA and protein levels. In addition, activation of LC3-II in primary macrophages and THP-1 cells was not detected. PBA and the active form of vitamin D3 (1,25[OH]2D3), separately or particularly in combination, were able to overcome Mtb-induced suppression of LL-37 expression. Notably, reactivation of autophagy occurred by stimulation of macrophages with PBA and promoted colocalization of LL-37 and LC3-II in autophagosomes. Importantly, PBA treatment failed to induce autophagy in Mtb-infected THP-1 cells, when the expression of LL-37 was silenced. However, PBA-induced autophagy was restored when the LL-37 knockdown cells were supplemented with synthetic LL-37. Interestingly, we have found that LL-37-induced autophagy was mediated via P2RX7 receptor followed by enhanced cytosolic free Ca(2+), and activation of AMPK and PtdIns3K pathways. Altogether, these results suggest a novel activity for PBA as an inducer of autophagy, which is LL-37-dependent and promotes intracellular killing of Mtb in human macrophages.

  12. Killing of Escherichia coli by Crohn's Disease Monocyte-derived Macrophages and Its Enhancement by Hydroxychloroquine and Vitamin D

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    Flanagan, Paul K.; Chiewchengchol, Direkrit; Helen L Wright; Edwards, Steven W.; Alswied, Abdullah; Satsangi, Jack; Subramanian, Sreedhar; Rhodes, Jonathan M.; Campbell, Barry J.

    2015-01-01

    BACKGROUND: Crohn's disease (CD) is associated with defective innate immunity, including impaired neutrophil chemotaxis, and mucosal invasion by bacteria, particularly adherent and invasive Escherichia coli that replicate inside macrophage phagolysosomes. We compared CD and healthy control (HC) macrophages for their abilities to kill E. coli and generate neutrophil chemoattractants and also assessed the effects of hydroxychloroquine (HCQ) and vitamin D on killing of phagocytosed E. coli.METHO...

  13. Bacterial killing in macrophages and amoeba: do they all use a brass dagger?

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    German, Nadezhda; Doyscher, Dominik; Rensing, Christopher

    2013-10-01

    Macrophages are immune cells that are known to engulf pathogens and destroy them by employing several mechanisms, including oxidative burst, induction of Fe(II) and Mn(II) efflux, and through elevation of Cu(I) and Zn(II) concentrations in the phagosome ('brass dagger'). The importance of the latter mechanism is supported by the presence of multiple counteracting efflux systems in bacteria, responsible for the efflux of toxic metals. We hypothesize that similar bacteria-killing mechanisms are found in predatory protozoa/amoeba species. Here, we present a brief summary of soft metal-related mechanisms used by macrophages, and perhaps amoeba, to inactivate and destroy bacteria. Based on this, we think it is likely that copper resistance is also selected for by protozoan grazing in the environment.

  14. Degranulating Neutrophils Promote Leukotriene B4 Production by Infected Macrophages To Kill Leishmania amazonensis Parasites.

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    Tavares, Natália; Afonso, Lilian; Suarez, Martha; Ampuero, Mariana; Prates, Deboraci Brito; Araújo-Santos, Théo; Barral-Netto, Manoel; DosReis, George A; Borges, Valéria Matos; Brodskyn, Cláudia

    2016-02-15

    Neutrophils mediate early responses against pathogens, and they become activated during endothelial transmigration toward the inflammatory site. In the current study, human neutrophils were activated in vitro with immobilized extracellular matrix proteins, such as fibronectin (FN), collagen, and laminin. Neutrophil activation by FN, but not other extracellular matrix proteins, induces the release of the granules' contents, measured as matrix metalloproteinase 9 and neutrophil elastase activity in culture supernatant, as well as reactive oxygen species production. Upon contact with Leishmania amazonensis-infected macrophages, these FN-activated neutrophils reduce the parasite burden through a mechanism independent of cell contact. The release of granule proteases, such as myeloperoxidase, neutrophil elastase, and matrix metalloproteinase 9, activates macrophages through TLRs, leading to the production of inflammatory mediators, TNF-α and leukotriene B4 (LTB4), which are involved in parasite killing by infected macrophages. The pharmacological inhibition of degranulation reverted this effect, abolishing LTB4 and TNF production. Together, these results suggest that FN-driven degranulation of neutrophils induces the production of LTB4 and TNF by infected macrophages, leading to the control of Leishmania infection.

  15. Antibodies Against Sporothrix schenckii Enhance TNF-α Production and Killing by Macrophages.

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    Franco, D de Lima; Nascimento, R C; Ferreira, K S; Almeida, S R

    2012-02-01

    Sporotrichosis is a chronic granulomatous mycosis caused by the dimorphic fungus Sporothrix schenckii. The immunological mechanisms involved in the prevention and control of sporotrichosis suggest that cell-mediated immunity plays an important role in protecting the host against S. schenckii. Nonetheless, recent data strongly support the existence of protective Abs against this pathogenic fungus. In a previous study, we showed that passive Ab therapy led to a significant reduction in the number of colony forming unit in the organs of mice when the MAb was injected before and during S. schenckii infection. The ability of opsonization to enhance macrophage damage to S. schenckii and subsequent cytokine production was investigated in this work. Here we show that the fungicidal characteristics of macrophages are increased when the fungus is phagocytosed in the presence of inactivated serum from mice infected with S. schenckii or mAb anti-gp70. Additionally, we show an increase in the levels of pro-inflammatory cytokines such as TNF-α and IL-1β. This study provides additional support for the importance of antibodies in protecting against S. schenckii and concludes that opsonization is an important process to increase TNF-α production and fungus killing by macrophages in experimental sporotrichosis.

  16. Delineating the importance of serum opsonins and the bacterial capsule in affecting the uptake and killing of Burkholderia pseudomallei by murine neutrophils and macrophages.

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    Minal Mulye

    2014-08-01

    Full Text Available Infection of susceptible hosts by the encapsulated Gram-negative bacterium Burkholderia pseudomallei (Bp causes melioidosis, with septic patients attaining mortality rates ≥ 40%. Due to its high infectivity through inhalation and limited effective therapies, Bp is considered a potential bioweapon. Thus, there is great interest in identifying immune effectors that effectively kill Bp. Our goal is to compare the relative abilities of murine macrophages and neutrophils to clear Bp, as well as determine the importance of serum opsonins and bacterial capsule. Our findings indicate that murine macrophages and neutrophils are inherently unable to clear either unopsonized Bp or the relatively-avirulent acapsular bacterium B. thailandensis (Bt. Opsonization of Bp and Bt with complement or pathogen-specific antibodies increases macrophage-uptake, but does not promote clearance, although antibody-binding enhances complement deposition. In contrast, complement opsonization of Bp and Bt causes enhanced uptake and killing by neutrophils, which is linked with rapid ROS induction against bacteria exhibiting a threshold level of complement deposition. Addition of bacteria-specific antibodies enhances complement deposition, but antibody-binding alone cannot elicit neutrophil clearance. Bp capsule provides some resistance to complement deposition, but is not anti-phagocytic or protective against reactive oxygen species (ROS-killing. Macrophages were observed to efficiently clear Bp only after pre-activation with IFNγ, which is independent of serum- and/or antibody-opsonization. These studies indicate that antibody-enhanced complement activation is sufficient for neutrophil-clearance of Bp, whereas macrophages are ineffective at clearing serum-opsonized Bp unless pre-activated with IFNγ. This suggests that effective immune therapies would need to elicit both antibodies and Th1-adaptive responses for successful prevention/eradication of melioidosis.

  17. Delineating the importance of serum opsonins and the bacterial capsule in affecting the uptake and killing of Burkholderia pseudomallei by murine neutrophils and macrophages.

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    Mulye, Minal; Bechill, Michael P; Grose, William; Ferreira, Viviana P; Lafontaine, Eric R; Wooten, R Mark

    2014-08-01

    Infection of susceptible hosts by the encapsulated Gram-negative bacterium Burkholderia pseudomallei (Bp) causes melioidosis, with septic patients attaining mortality rates ≥ 40%. Due to its high infectivity through inhalation and limited effective therapies, Bp is considered a potential bioweapon. Thus, there is great interest in identifying immune effectors that effectively kill Bp. Our goal is to compare the relative abilities of murine macrophages and neutrophils to clear Bp, as well as determine the importance of serum opsonins and bacterial capsule. Our findings indicate that murine macrophages and neutrophils are inherently unable to clear either unopsonized Bp or the relatively-avirulent acapsular bacterium B. thailandensis (Bt). Opsonization of Bp and Bt with complement or pathogen-specific antibodies increases macrophage-uptake, but does not promote clearance, although antibody-binding enhances complement deposition. In contrast, complement opsonization of Bp and Bt causes enhanced uptake and killing by neutrophils, which is linked with rapid ROS induction against bacteria exhibiting a threshold level of complement deposition. Addition of bacteria-specific antibodies enhances complement deposition, but antibody-binding alone cannot elicit neutrophil clearance. Bp capsule provides some resistance to complement deposition, but is not anti-phagocytic or protective against reactive oxygen species (ROS)-killing. Macrophages were observed to efficiently clear Bp only after pre-activation with IFNγ, which is independent of serum- and/or antibody-opsonization. These studies indicate that antibody-enhanced complement activation is sufficient for neutrophil-clearance of Bp, whereas macrophages are ineffective at clearing serum-opsonized Bp unless pre-activated with IFNγ. This suggests that effective immune therapies would need to elicit both antibodies and Th1-adaptive responses for successful prevention/eradication of melioidosis.

  18. Extracellular traps are associated with human and mouse neutrophil and macrophage mediated killing of larval Strongyloides stercoralis.

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    Bonne-Année, Sandra; Kerepesi, Laura A; Hess, Jessica A; Wesolowski, Jordan; Paumet, Fabienne; Lok, James B; Nolan, Thomas J; Abraham, David

    2014-06-01

    Neutrophils are multifaceted cells that are often the immune system's first line of defense. Human and murine cells release extracellular DNA traps (ETs) in response to several pathogens and diseases. Neutrophil extracellular trap (NET) formation is crucial to trapping and killing extracellular pathogens. Aside from neutrophils, macrophages and eosinophils also release ETs. We hypothesized that ETs serve as a mechanism of ensnaring the large and highly motile helminth parasite Strongyloides stercoralis thereby providing a static target for the immune response. We demonstrated that S. stercoralis larvae trigger the release of ETs by human neutrophils and macrophages. Analysis of NETs revealed that NETs trapped but did not kill larvae. Induction of NETs was essential for larval killing by human but not murine neutrophils and macrophages in vitro. In mice, extracellular traps were induced following infection with S. stercoralis larvae and were present in the microenvironment of worms being killed in vivo. These findings demonstrate that NETs ensnare the parasite facilitating larval killing by cells of the immune system.

  19. Killing of Staphylococcus aureus in murine macrophages by chloroquine used alone and in combination with ciprofloxacin or azithromycin

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    Dey S

    2015-01-01

    Full Text Available Somrita Dey, Biswadev BishayiDepartment of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, Calcutta, IndiaAbstract: This study aimed to determine any alteration in the killing of Staphylococcus aureus in murine peritoneal macrophages when chloroquine (CQ is used alone compared with when it is used in combination with ciprofloxacin (CIP or azithromycin (AZM. The study also aimed to find out the implication of reactive oxygen species (ROS production and cytokine release in the intracellular killing of S. aureus in macrophages. We present here data obtained with a model of S. aureus-infected mouse peritoneal macrophages in which the intracellular growth of the bacteria and the influence of antibiotics was monitored for 30, 60, and 90 minutes in the presence or absence of CQ along with the production of ROS and alteration in levels of antioxidant enzymes and cytokines. It was observed that S. aureus-triggered cytokine response was regulated when macrophages were co-cultured with CQ and AZM as compared with CQ stimulation only. It can be suggested that action of AZM in mediating bacterial killing is enhanced by the presence of CQ, indicating enhanced uptake of AZM during early infection that may be essential for bacteria killing by AZM. Reduction of oxidative stress burden on the S. aureus-infected macrophages may pave the way for better killing of internalized S. aureus by CQ plus ciprofloxacin (CIP or CQ plus AZM. Based on these observations, one may speculate that in an inflammatory milieu, CQ loaded with AZM elicits a stronger proinflammatory response by increasing the intracellular uptake of AZM or CIP, thus enabling the immune system to mount a more robust and prolonged response against intracellular pathogens.Keywords: azithromycin, ciprofloxacin, intracellular survival

  20. Candida albicans SUR7 contributes to secretion, biofilm formation, and macrophage killing

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    Bernardo Stella M

    2010-04-01

    Full Text Available Abstract Background Candida albicans SUR7 has been shown to be required for plasma membrane organization and cell wall synthesis, but its role in virulence is not known. Using a bioinformatics strategy, we previously identified several novel putative secretion pathway proteins potentially involved in virulence, including the C. albicans homolog of the Saccharomyces cerevisiae endocytosis-related protein Sur7p. We therefore generated a C. albicans sur7Δ null mutant and examined its contribution to key virulence attributes. Results Structurally, the C. albicans sur7Δ mutant was impaired in response to filamentation-inducing conditions, and formed aberrant hyphae with extensive accumulation of plasma membrane-derived structures within the cell. Absence of SUR7 resulted in a temperature-sensitive growth defect at high temperatures (42°C, which was partially rescued by addition of NaCl. We next examined the role of the SUR7 paralog C. albicans FMP45 in this temperature-sensitive phenotype. Analysis of C. albicans Fmp45p-GFP demonstrated co-localization of Fmp45p with Sur7p and increased fluorescence in the plasma membrane in the presence of high salt. We next focused on key virulence-related phenotypes. The C. albicans sur7Δ null mutant exhibited secretory defects: reduced lipase secretion, and increased levels of secreted Sap2p. The null mutant was hyper-susceptible to sub-inhibitory concentrations of caspofungin, but not amphotericin B and 5-fluorocytosine. Functionally, the sur7Δ mutant demonstrated increased adhesion to polystyrene and of note, was markedly defective in biofilm formation. In an in vitro macrophage model of virulence, the sur7Δ mutant was impaired in macrophage killing. Conclusions Plasma membrane and cell wall organization are important for cell morphology, and alterations of these structures contributed to impairment of several key virulence-associated phenotypes in the C. albicans sur7Δ mutant.

  1. Ion Channel Blockers as Antimicrobial Agents, Efflux Inhibitors, and Enhancers of Macrophage Killing Activity against Drug Resistant Mycobacterium tuberculosis.

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    Diana Machado

    Full Text Available Given the ability of M. tuberculosis to survive as an intracellular pathogen and its propensity to develop resistance to the existing antituberculosis drugs, its treatment requires new approaches. Here the antimycobacterial properties of verapamil, thioridazine, chlorpromazine, flupenthixol and haloperidol were investigated against a panel of drug resistant M. tuberculosis strains, both in vitro and on human-infected macrophages. These compounds are efflux inhibitors that share among them the characteristic of being ion channel blockers. In vitro, all compounds exhibited synergistic inhibitory activities when combined with isoniazid and rifampicin, and were able to inhibit active efflux, demonstrating their role as efflux inhibitors. Gene expression analysis showed that M. tuberculosis efflux genes were overexpressed in response to antibiotic exposure, in vitro and within macrophages, irrespective of their resistance pattern. These compounds displayed a rapid and high killing activity against M. tuberculosis, associated with a decrease in intracellular ATP levels demonstrating that the bactericidal action of the ion channel blockers against M. tuberculosis clinical strains is associated with their interference with energy metabolism. The compounds led to a decrease in the intracellular mycobacterial load by increasing phagosome acidification and activating lysosomal hydrolases. The results presented in this study enable us to propose the following mechanism of action for these compounds: a in the bacteria, the compounds generate a cascade of events involving the inhibition of the respiratory chain complexes and energy production for efflux activity. Indirectly, this reduce the resistance level to antituberculosis drugs potentiating their activity; b on the host cell, the treatment with the ion channel blockers increases phagosome acidification and induces the expression of phagosomal hydrolases, leading to bacterial growth restriction

  2. Rapid kill-novel endodontic sealer and Enterococcus faecalis.

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    Beyth, Nurit; Kesler Shvero, Dana; Zaltsman, Nathan; Houri-Haddad, Yael; Abramovitz, Itzhak; Davidi, Michael Perez; Weiss, Ervin I

    2013-01-01

    With growing concern over bacterial resistance, the identification of new antimicrobial means is paramount. In the oral cavity microorganisms are essential to the development of periradicular diseases and are the major causative factors associated with endodontic treatment failure. As quaternary ammonium compounds have the ability to kill a wide array of bacteria through electrostatic interactions with multiple anionic targets on the bacterial surface, it is likely that they can overcome bacterial resistance. Melding these ideas, we investigated the potency of a novel endodontic sealer in limiting Enterococcus faecalis growth. We used a polyethyleneimine scaffold to synthesize nano-sized particles, optimized for incorporation into an epoxy-based endodontic sealer. The novel endodontic sealer was tested for its antimicrobial efficacy and evaluated for biocompatibility and physical eligibility. Our results show that the novel sealer foundation affixes the nanoparticles, achieving surface bactericidal properties, but at the same time impeding nanoparticle penetration into eukaryotic cells and thereby mitigating a possible toxic effect. Moreover, adequate physical properties are maintained. The nanosized quaternary amine particles interact within minutes with bacteria, triggering cell death across wide pH values. Throughout this study we demonstrate a new antibacterial perspective for endodontic sealers; a novel antibacterial, effective and safe antimicrobial means.

  3. Azurophil granule proteins constitute the major mycobactericidal proteins in human neutrophils and enhance the killing of mycobacteria in macrophages.

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    Prajna Jena

    Full Text Available Pathogenic mycobacteria reside in, and are in turn controlled by, macrophages. However, emerging data suggest that neutrophils also play a critical role in innate immunity to tuberculosis, presumably by their different antibacterial granule proteins. In this study, we purified neutrophil azurophil and specific granules and systematically analyzed the antimycobacterial activity of some purified azurophil and specific granule proteins against M. smegmatis, M. bovis-BCG and M. tuberculosis H37Rv. Using gel overlay and colony forming unit assays we showed that the defensin-depleted azurophil granule proteins (AZP were more active against mycobacteria compared to other granule proteins and cytosolic proteins. The proteins showing antimycobacterial activity were identified by MALDI-TOF mass spectrometry. Electron microscopic studies demonstrate that the AZP disintegrate bacterial cell membrane resulting in killing of mycobacteria. Exogenous addition of AZP to murine macrophage RAW 264.7, THP-1 and peripheral blood monocyte-derived macrophages significantly reduced the intracellular survival of mycobacteria without exhibiting cytotoxic activity on macrophages. Immunofluorescence studies showed that macrophages actively endocytose neutrophil granular proteins. Treatment with AZP resulted in increase in co-localization of BCG containing phagosomes with lysosomes but not in increase of autophagy. These data demonstrate that neutrophil azurophil proteins may play an important role in controlling intracellular survival of mycobacteria in macrophages.

  4. Azurophil granule proteins constitute the major mycobactericidal proteins in human neutrophils and enhance the killing of mycobacteria in macrophages.

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    Jena, Prajna; Mohanty, Soumitra; Mohanty, Tirthankar; Kallert, Stephanie; Morgelin, Matthias; Lindstrøm, Thomas; Borregaard, Niels; Stenger, Steffen; Sonawane, Avinash; Sørensen, Ole E

    2012-01-01

    Pathogenic mycobacteria reside in, and are in turn controlled by, macrophages. However, emerging data suggest that neutrophils also play a critical role in innate immunity to tuberculosis, presumably by their different antibacterial granule proteins. In this study, we purified neutrophil azurophil and specific granules and systematically analyzed the antimycobacterial activity of some purified azurophil and specific granule proteins against M. smegmatis, M. bovis-BCG and M. tuberculosis H37Rv. Using gel overlay and colony forming unit assays we showed that the defensin-depleted azurophil granule proteins (AZP) were more active against mycobacteria compared to other granule proteins and cytosolic proteins. The proteins showing antimycobacterial activity were identified by MALDI-TOF mass spectrometry. Electron microscopic studies demonstrate that the AZP disintegrate bacterial cell membrane resulting in killing of mycobacteria. Exogenous addition of AZP to murine macrophage RAW 264.7, THP-1 and peripheral blood monocyte-derived macrophages significantly reduced the intracellular survival of mycobacteria without exhibiting cytotoxic activity on macrophages. Immunofluorescence studies showed that macrophages actively endocytose neutrophil granular proteins. Treatment with AZP resulted in increase in co-localization of BCG containing phagosomes with lysosomes but not in increase of autophagy. These data demonstrate that neutrophil azurophil proteins may play an important role in controlling intracellular survival of mycobacteria in macrophages.

  5. Antibodies against invasive phenotype-specific antigens increase Mycobacterium avium subspecies paratuberculosis translocation across a polarized epithelial cell model and enhance killing by bovine macrophages

    Science.gov (United States)

    Everman, Jamie L.; Bermudez, Luiz E.

    2015-01-01

    Johne's disease, caused by Mycobacterium avium subspecies paratuberculosis (MAP), is a severe chronic enteritis which affects large populations of ruminants globally. Prevention strategies to combat the spread of Johne's disease among cattle herds involve adhering to strict calving practices to ensure young susceptible animals do not come in contact with MAP-contaminated colostrum, milk, or fecal material. Unfortunately, the current vaccination options available are associated with high cost and suboptimal efficacy. To more successfully combat the spread of Johne's disease to young calves, an efficient method of protection is needed. In this study, we examined passive immunization as a mode of introducing protective antibodies against MAP to prevent the passage of the bacterium to young animals via colostrum and milk. Utilizing the infectious MAP phenotype developed after bacterial exposure to milk, we demonstrate that in vitro opsonization with serum from Johne's-positive cattle results in enhanced translocation across a bovine MDBK polarized epithelial cell monolayer. Furthermore, immune serum opsonization of MAP results in a rapid host cell-mediated killing by bovine macrophages in an oxidative-, nitrosative-, and extracellular DNA trap-independent manner. This study illustrates that antibody opsonization of MAP expressing an infectious phenotype leads to the killing of the bacterium during the initial stage of macrophage infection. PMID:26301206

  6. Radiometric macrophage culture assay for rapid evaluation of antileprosy activity of rifampin

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, A.; Seshadri, P.S.; Prasad, H.K.; Sathish, M.; Nath, I.

    1983-10-01

    The antileprosy effect of rifampin was evaluated by a newly developed rapid in vitro assay wherein 31 human-derived strains and 1 armadillo-derived strain of Mycobacterium leprae were maintained for 2 and 3 weeks, respectively, in murine and human macrophages in the presence of (3H)thymidine. Of these strains, 27 showed significant incorporation of the radiolabel in cultures of live bacilli as compared with control cultures of heat-killed bacilli of the same strain. Consistent and significant inhibition of (3H)thymidine uptake was observed in M. leprae resident cultures with 3 to 200 ng of rifampin per ml as compared with similar cultures without the drug. In general, an increase in percent inhibition was seen from 3 to 20 ng/ml, with marginal increases at 40, 50, and 100 ng/ml. M. leprae strains appear to be remarkably susceptible to this drug in the in vitro assay.

  7. Live and Heat-Killed Lactobacillus rhamnosus ATCC 7469 May Induce Modulatory Cytokines Profiles on Macrophages RAW 264.7.

    Science.gov (United States)

    Jorjão, Adeline Lacerda; de Oliveira, Felipe Eduardo; Leão, Mariella Vieira Pereira; Carvalho, Cláudio Antonio Talge; Jorge, Antonio Olavo Cardoso; de Oliveira, Luciane Dias

    2015-01-01

    This study aimed to evaluate the capacity of Lactobacillus rhamnosus and/or its products to induce the synthesis of cytokines (TNF-α, IL-1β, IL-4, IL-6, IL-10, and IL-12) by mouse macrophages (RAW 264.7). Three microorganism preparations were used: live L. rhamnosus (LLR) suspension, heat-killed L. rhamnosus (HKLR) suspension, and the supernatant of a heat-killed L. rhamnosus (SHKLR) suspension, which were cultured with macrophages (37°C, 5% CO2) for 2 h and 30 min. After that, cells were cultured for 16 h. The supernatants were used for the quantitation of cytokines, by ELISA. The results were compared with the synthesis induced by lipopolysaccharide (LPS) and analysed, using ANOVA and Tukey test, 5%. LLR and HKLR groups were able to significantly increase the production of TNF-α, IL-6, and IL-10 (P 0.05). All the L. rhamnosus suspensions were not able to produce detectable levels of IL-1β or significant levels of IL-4 and IL-12 (P > 0.05). In conclusion, live and heat-killed L. rhamnosus suspensions were able to induce the synthesis of different cytokines with proinflammatory (TNF-α and IL-6) or regulatory (IL-10) functions, suggesting the role of strain L. rhamnosus ATCC 7469 in the modulation or in the stimulation of immune responses.

  8. Live and Heat-Killed Lactobacillus rhamnosus ATCC 7469 May Induce Modulatory Cytokines Profiles on Macrophages RAW 264.7

    Directory of Open Access Journals (Sweden)

    Adeline Lacerda Jorjão

    2015-01-01

    Full Text Available This study aimed to evaluate the capacity of Lactobacillus rhamnosus and/or its products to induce the synthesis of cytokines (TNF-α, IL-1β, IL-4, IL-6, IL-10, and IL-12 by mouse macrophages (RAW 264.7. Three microorganism preparations were used: live L. rhamnosus (LLR suspension, heat-killed L. rhamnosus (HKLR suspension, and the supernatant of a heat-killed L. rhamnosus (SHKLR suspension, which were cultured with macrophages (37°C, 5% CO2 for 2 h and 30 min. After that, cells were cultured for 16 h. The supernatants were used for the quantitation of cytokines, by ELISA. The results were compared with the synthesis induced by lipopolysaccharide (LPS and analysed, using ANOVA and Tukey test, 5%. LLR and HKLR groups were able to significantly increase the production of TNF-α, IL-6, and IL-10 (P0.05. All the L. rhamnosus suspensions were not able to produce detectable levels of IL-1β or significant levels of IL-4 and IL-12 (P>0.05. In conclusion, live and heat-killed L. rhamnosus suspensions were able to induce the synthesis of different cytokines with proinflammatory (TNF-α and IL-6 or regulatory (IL-10 functions, suggesting the role of strain L. rhamnosus ATCC 7469 in the modulation or in the stimulation of immune responses.

  9. Intracellular growth of Mycobacterium tuberculosis after macrophage cell death leads to serial killing of host cells.

    Science.gov (United States)

    Mahamed, Deeqa; Boulle, Mikael; Ganga, Yashica; Mc Arthur, Chanelle; Skroch, Steven; Oom, Lance; Catinas, Oana; Pillay, Kelly; Naicker, Myshnee; Rampersad, Sanisha; Mathonsi, Colisile; Hunter, Jessica; Wong, Emily B; Suleman, Moosa; Sreejit, Gopalkrishna; Pym, Alexander S; Lustig, Gila; Sigal, Alex

    2017-01-28

    A hallmark of pulmonary tuberculosis is the formation of macrophage-rich granulomas. These may restrict Mycobacterium tuberculosis (Mtb) growth, or progress to central necrosis and cavitation, facilitating pathogen growth. To determine factors leading to Mtb proliferation and host cell death, we used live cell imaging to track Mtb infection outcomes in individual primary human macrophages. Internalization of Mtb aggregates caused macrophage death, and phagocytosis of large aggregates was more cytotoxic than multiple small aggregates containing similar numbers of bacilli. Macrophage death did not result in clearance of Mtb. Rather, it led to accelerated intracellular Mtb growth regardless of prior activation or macrophage type. In contrast, bacillary replication was controlled in live phagocytes. Mtb grew as a clump in dead cells, and macrophages which internalized dead infected cells were very likely to die themselves, leading to a cell death cascade. This demonstrates how pathogen virulence can be achieved through numbers and aggregation states.

  10. Apoptotic killing of HIV-1-infected macrophages is subverted by the viral envelope glycoprotein.

    Directory of Open Access Journals (Sweden)

    Simon Swingler

    2007-09-01

    Full Text Available Viruses have evolved strategies to protect infected cells from apoptotic clearance. We present evidence that HIV-1 possesses a mechanism to protect infected macrophages from the apoptotic effects of the death ligand TRAIL (tumor necrosis factor-related apoptosis-inducing ligand. In HIV-1-infected macrophages, the viral envelope protein induced macrophage colony-stimulating factor (M-CSF. This pro-survival cytokine downregulated the TRAIL receptor TRAIL-R1/DR4 and upregulated the anti-apoptotic genes Bfl-1 and Mcl-1. Inhibition of M-CSF activity or silencing of Bfl-1 and Mcl-1 rendered infected macrophages highly susceptible to TRAIL. The anti-cancer agent Imatinib inhibited M-CSF receptor activation and restored the apoptotic sensitivity of HIV-1-infected macrophages, suggesting a novel strategy to curtail viral persistence in the macrophage reservoir.

  11. Bactericidal activity of juvenile chinook salmon macrophages against Aeromonas salmonicida after exposure to live or heat-killed Renibacterium salmoninarum or to soluble proteins produced by R. salmoninarum

    Science.gov (United States)

    Siegel, D.C.; Congleton, J.L.

    1997-01-01

    Macrophages isolated from the anterior kidney of juvenile chinook salmon Oncorhynchus tshawytscha in 96-well microtiter plates were exposed for 72 h to 0, 105, or 106 live or heat-killed Renibacterium salmoninarum cells per well or to 0, 0.1, 1.0, or 10 ??g/mL of R. salmoninarum soluble proteins. After treatment, the bactericidal activity of the macrophages against Aerornonas salmonicida was determined by a colorimetric assay based on the reduction of the tetrazolium dye MTT to formazan by viable bacteria. The MTT assay was modified to allow estimation of the percentage of bacteria killed by reference to a standard curve relating the number of bacteria added to microtiter wells to absorbance by formazan at 600 nm. The live and heat-killed R. salmoninarum treatments significantly (P < 0.001) increased killing of A. salmonicida by chinook salmon macrophages. In each of the five trials, significantly (P < 0.05) greater increases in killing occurred after exposure to 105 R. salmoninarum cells than to 106 R. salmoninarum cells per well. In contrast, treatment of macrophages with 10 ??g/mL R. salmoninarum soluble proteins significantly (P < 0.001) decreased killing of A. salmonicida, but treatment with lower doses did not. These results show that the bactericidal activity of chinook salmon macrophages is stimulated by exposure to R. salmoninarum cells at lower dose levels but inhibited by exposure to R. salmoninarum cells or soluble proteins at higher dose levels.

  12. Novel water-based antiseptic lotion demonstrates rapid, broad-spectrum kill compared with alcohol antiseptic.

    Science.gov (United States)

    Czerwinski, Steven E; Cozean, Jesse; Cozean, Colette

    2014-01-01

    A novel alcohol-based antiseptic and a novel water-based antiseptic lotion, both with a synergistic combination of antimicrobial ingredients containing 0.2% benzethonium chloride, were evaluated using the standard time-kill method against 25 FDA-specified challenge microorganisms. The purpose of the testing was to determine whether a non-alcohol product could have equivalent rapid and broad-spectrum kill to a traditional alcohol sanitizer. Both the alcohol- and water-based products showed rapid and broad-spectrum antimicrobial activity. The average 15-s kill was 99.999% of the challenge organism for the alcohol-based antiseptic and 99.971% for the water-based antiseptic. The alcohol-based product demonstrated 100% of peak efficacy (60s) within the first 15s, whereas the water-based product showed 99.97%. The novel alcohol-based antiseptic reduced concentrations of 100% of organisms by 99.999%, whereas the water-based antiseptic lotion showed the same reduction for 96% of organisms. A novel water-based antiseptic product demonstrated equivalent rapid, broad-spectrum antimicrobial activity to an alcohol-based sanitizer and provided additional benefits of reduced irritation, persistent effect, and greater efficacy against common viruses. The combination of rapid, broad-spectrum immediate kill and persistent efficacy against pathogens may have significant clinical benefit in limiting the spread of disease.

  13. Oxidative Stress Induced by Polymyxin E Is Involved in Rapid Killing of Paenibacillus polymyxa

    Science.gov (United States)

    Zhu, Yuyi; Qin, Wangrong

    2017-01-01

    Historically, the colistin has been thought to kill bacteria through membrane lysis. Here, we present an alternative mechanism that colistin induces rapid Paenibacillus polymyxa death through reactive oxygen species production. This significantly augments our understanding of the mechanism of colistin action, which is critical knowledge toward the yield development of colistin in the future.

  14. Role of intracellular free calcium in killing Penicillium marneffei within human macrophages.

    Science.gov (United States)

    Chen, Renqiong; Ji, Guangquan; Ma, Tuan; Huang, Xiaowen; Ren, Hong; Xi, Liyan

    2015-01-01

    Increases in cytosolic Ca(2+) concentration ([Ca(2+)]c) promote phagocyte antimicrobial responses. Here, we investigated macrophages stimulated by Penicillium marneffei (P. marneffei). [Ca(2+)]c was determined in macrophages loaded with the fluorescent calcium probe Fura 2/AM as they were stimulated by P. marneffei. We found that P. marneffei induced an increase in [Ca(2+)]c in human macrophages. Further, increased [Ca(2+)]c with the ionophore A23187 promoted phagosomal acidification and maturation and reduced intracellular replication of P. marneffei in P. marneffei-infected human macrophages, whereas decreased [Ca(2+)]c with the chelation MAPTAM decreased TNF-α production, inhibited phagosomal acidification and maturation and increased intracellular replication of P. marneffei. These data indicate that Ca(2+) signaling may play an important role in controlling the replication of P. marneffei within macrophages.

  15. Vancomycin-modified mesoporous silica nanoparticles for selective recognition and killing of pathogenic gram-positive bacteria over macrophage-like cells.

    Science.gov (United States)

    Qi, Guobin; Li, Lili; Yu, Faquan; Wang, Hao

    2013-11-13

    Rapid, reliable recognition and detection of bacteria from an authentic specimen have been gained increasing interests in the past decades. Various materials have been designed and prepared for implementation of bacterial recognition and treatment in the artificial systems. However, in the complicated physiological condition, the macrophages always compromise the outcomes of bacterial detection and/or treatment. In this work, we demonstrated the vancomycin-modified mesoporous silica nanoparticles (MSNs is a subset of Van) for efficiently targeting and killing gram-positive bacteria over macrophage-like cells. Owing to the specific hydrogen bonding interactions of vancomycin toward the terminal d-alanyl-d-alanine moieties of gram-positive bacteria, the MSNs is a subset of Van exhibited enhanced recognition for gram-positive bacteria due to the multivalent hydrogen binding effect. Furthermore, the fluorescent molecules (FITC) were covalently decorated inside of mesopores of MSNs for tracking and visualizing the MSNs is a subset of Van during the detection/treatment processes. Upon incubation of FITC decorated MSNs with bacteria (i.e., S. aureus and E. coli as gram-positive and gram-negative bacteria, respectively) or macrophage-like cells (Raw 264.7), the fluorescence signals in S. aureus were 2-4 times higher than that in E. coli and no detectable fluorescence signals were observed in Raw 264.7 cells under the same condition. Finally, the MSNs is a subset of Van showed unambiguous antibacterial efficacy without decrease in cell viability of macrophage-like cells. This new strategy opens a new door for specific detection and treatment of pathogenic bacteria with minimized side effects.

  16. Intracellular growth of Mycobacterium tuberculosis after macrophage cell death leads to serial killing of host cells

    Science.gov (United States)

    Mahamed, Deeqa; Boulle, Mikael; Ganga, Yashica; Mc Arthur, Chanelle; Skroch, Steven; Oom, Lance; Catinas, Oana; Pillay, Kelly; Naicker, Myshnee; Rampersad, Sanisha; Mathonsi, Colisile; Hunter, Jessica; Sreejit, Gopalkrishna; Pym, Alexander S; Lustig, Gila; Sigal, Alex

    2017-01-01

    A hallmark of pulmonary tuberculosis is the formation of macrophage-rich granulomas. These may restrict Mycobacterium tuberculosis (Mtb) growth, or progress to central necrosis and cavitation, facilitating pathogen growth. To determine factors leading to Mtb proliferation and host cell death, we used live cell imaging to track Mtb infection outcomes in individual primary human macrophages. Internalization of Mtb aggregates caused macrophage death, and phagocytosis of large aggregates was more cytotoxic than multiple small aggregates containing similar numbers of bacilli. Macrophage death did not result in clearance of Mtb. Rather, it led to accelerated intracellular Mtb growth regardless of prior activation or macrophage type. In contrast, bacillary replication was controlled in live phagocytes. Mtb grew as a clump in dead cells, and macrophages which internalized dead infected cells were very likely to die themselves, leading to a cell death cascade. This demonstrates how pathogen virulence can be achieved through numbers and aggregation states. DOI: http://dx.doi.org/10.7554/eLife.22028.001 PMID:28130921

  17. Intracellular killing of bacteria: is Dictyostelium a model macrophage or an alien?

    Science.gov (United States)

    Cosson, Pierre; Lima, Wanessa C

    2014-01-01

    Predation of bacteria by phagocytic cells was first developed during evolution by environmental amoebae. Many of the core mechanisms used by amoebae to sense, ingest and kill bacteria have also been conserved in specialized phagocytic cells in mammalian organisms. Here we focus on recent results revealing how Dictyostelium discoideum senses and kills non-pathogenic bacteria. In this model, genetic analysis of intracellular killing of bacteria has revealed a surprisingly complex array of specialized mechanisms. These results raise new questions on these processes, and challenge current models based largely on studies in mammalian phagocytes. In addition, recent studies suggest one additional level on complexity by revealing how Dictyostelium recognizes specifically various bacterial species and strains, and adapts its metabolism to process them. It remains to be seen to what extent mechanisms uncovered in Dictyostelium are also used in mammalian phagocytic cells. PMID:24628900

  18. Activated Macrophages Destroy Intracellular Leishmania Major Amastigotes by an l-Arginine-Dependent Killing Mechanism

    Science.gov (United States)

    1990-01-01

    conversion of site from one that is supportive of replication, to one that the sandfly -adapted promastigote to the amastigote form is hostile to...Inaddiion th cometiivein-room temperature for 5 min. Absorbance at 543 om was measured.activated macrophages. In addition, t e p titi e tn- No2- was qu

  19. Innate Immune Memory: Activation of Macrophage Killing Ability by Developmental Duties.

    Science.gov (United States)

    Schneider, David; Tate, Ann Thomas

    2016-06-20

    Innate immune systems in many taxa exhibit hallmarks of memory in response to previous microbial exposure. A new study demonstrates that innate immune memory in Drosophila embryonic macrophages can also be induced by the successful engulfment of apoptotic cells, highlighting the importance of early exposure events for developing responsive immune systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Leishmania resistant to sodium stibogluconate: drug-associated macrophage-dependent killing

    DEFF Research Database (Denmark)

    Ibrahim, M E; Hag-Ali, M; el-Hassan, A M;

    1994-01-01

    A total of 17 Leishmania isolates, 6 of them isolated from antimony-resistant patients, were collected in the Sudan and tested for their sensitivity to sodium stibogluconate (Pentostam) as promastigotes. Six of those isolates were tested as amastigotes infecting a murine macrophage cell line...

  1. Immunity to Schistosoma mansoni in guinea-pigs vaccinated with radiation-attenuated cercariae. T-cell activation of macrophages for larval killing

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, J.R.; McLaren, D.J.

    1988-02-01

    This study addresses macrophage activation in guinea-pigs vaccinated with radiation-attenuated cercariae of Schistosom mansoni. Peritoneal exudate macrophages elicited in vaccinated animals by mineral oil injection were activated to kill larval schistosomes in vitro. Killing efficiency is dependent upon the cell:target ratio employed and is enhanced by, but is not strictly dependent on, the presence of specific antibodies. Macrophages co-cultured with parasites release superoxide radicals and hydrogen peroxide, but the use of inhibitors has shown that neither of these reactive oxygen intermediates are the causal agents of cellular cytotoxicity in this system. Oil-elicited macrophages from naive guinea-pigs do not show comparable activation; they can, however, be activated in vitro by incubation with culture supernatant fluids from schistosome antigen-stimulated spleen, or lymph node cells harvested from vaccinated guinea-pigs. Naive macrophages activated in this way kill schistosomula in vitro and release the activation markers IL-l and superoxide anion. The macrophage-activating factor (MAF) present in spleen cell culture supernatant fluids has a MW of 35,000-55,000, but does not have the chemical characteristics of gamma-interferon.

  2. Macrophages help NK cells to attack tumor cells by stimulatory NKG2D ligand but protect themselves from NK killing by inhibitory ligand Qa-1.

    Science.gov (United States)

    Zhou, Zhixia; Zhang, Cai; Zhang, Jian; Tian, Zhigang

    2012-01-01

    Natural killer (NK) cells and their crosstalk with other immune cells are important for innate immunity against tumor. To explore the role of the interaction between NK cells and macrophages in the regulation of anti-tumor activities of NK cells, we here demonstrate that poly I:C-treated macrophages increased NK cell-mediated cytotoxicity against target tumor cells in NKG2D-dependent manner. In addition, IL-15, IL-18, and IFN-β secreted by poly I:C-treated macrophages are also involved in NKG2D expression and NK cell activation. Interestingly, the increase in expression of NKG2D ligands on macrophages induced a highly NK cell-mediated cytotoxicity against tumor cells, but not against macrophages themselves. Notably, a high expression level of Qa-1, a NKG2A ligand, on macrophages may contribute to such protection of macrophages from NK cell-mediated killing. Furthermore, Qa-1 or NKG2A knockdown and Qa-1 antibody blockade caused the macrophages to be sensitive to NK cytolysis. These results suggested that macrophages may activate NK cells to attack tumor by NKG2D recognition whereas macrophages protect themselves from NK lysis via preferential expression of Qa-1.

  3. Macrophages help NK cells to attack tumor cells by stimulatory NKG2D ligand but protect themselves from NK killing by inhibitory ligand Qa-1.

    Directory of Open Access Journals (Sweden)

    Zhixia Zhou

    Full Text Available Natural killer (NK cells and their crosstalk with other immune cells are important for innate immunity against tumor. To explore the role of the interaction between NK cells and macrophages in the regulation of anti-tumor activities of NK cells, we here demonstrate that poly I:C-treated macrophages increased NK cell-mediated cytotoxicity against target tumor cells in NKG2D-dependent manner. In addition, IL-15, IL-18, and IFN-β secreted by poly I:C-treated macrophages are also involved in NKG2D expression and NK cell activation. Interestingly, the increase in expression of NKG2D ligands on macrophages induced a highly NK cell-mediated cytotoxicity against tumor cells, but not against macrophages themselves. Notably, a high expression level of Qa-1, a NKG2A ligand, on macrophages may contribute to such protection of macrophages from NK cell-mediated killing. Furthermore, Qa-1 or NKG2A knockdown and Qa-1 antibody blockade caused the macrophages to be sensitive to NK cytolysis. These results suggested that macrophages may activate NK cells to attack tumor by NKG2D recognition whereas macrophages protect themselves from NK lysis via preferential expression of Qa-1.

  4. Actinobacillus pleuropneumoniae culture supernatants interfere with killing of Pasteurella multocida by swine pulmonary alveolar macrophages.

    OpenAIRE

    Chung, W. B.; Bäckström, L; McDonald, J.; Collins, M T

    1993-01-01

    The effect of Actinobacillus pleuropneumoniae culture supernatant on swine pulmonary alveolar macrophage (PAM) functions was studied. The A. pleuropneumoniae culture supernatant was toxic to PAMs when tested by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and lactate dehydrogenase (LDH) release assays. Biological activity of the supernatant was ascribed to cytotoxins. Both the LDH and MTT assays were used for measurement of crude A. pleuropneumoniae cytotoxin concentrati...

  5. Attachment, ingestion and intracellular killing of Helicobacter pylori by human peripheral blood mononuclear leukocytes and mouse peritoneal inflammatory macrophages.

    Science.gov (United States)

    Chmiela, M; Paziak-Domanska, B; Wadström, T

    1995-02-01

    The different steps of phagocytosis, attachment, ingestion and intracellular killing of cells of Helicobacter pylori strain 17874 (expressing sialic acid-specific haemagglutinin) and cells of H. pylori strain 17875 (expressing non-sialic acid-specific haemagglutinin) have been studied. More cells of sialopositive H. pylori strain 17874 have been found attached to human peripheral blood mononuclear leukocytes (PBM) and mouse peritoneal inflammatory macrophages (PIM) than cells of sialonegative H. pylori strain 17875. Binding of cells of H. pylori strain 17874 has been significantly inhibited by treatment of phagocytes with neuraminidase. Inhibition of adhesion of these bacteria preincubated with foetuin to normal phagocytic cells has also been found. Well adhering cells of H. pylori strain 17874 were more resistant to killing mechanisms of human PBM and mouse PIM than cells of strain 17875. Good, probably sialic acid-specific haemagglutinin dependent, adhesion of H. pylori bacteria to phagocytes can be considered as an important virulence factor which facilitates the pathogen to avoid the defence mechanisms.

  6. A cardinal role for cathepsin d in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci.

    Directory of Open Access Journals (Sweden)

    Martin A Bewley

    2011-01-01

    Full Text Available The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D(-/- hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function.

  7. Enhancement of macrophage candidacidal activity by interferon-gamma. Increased phagocytosis, killing, and calcium signal mediated by a decreased number of mannose receptors.

    Science.gov (United States)

    Maródi, L; Schreiber, S; Anderson, D C; MacDermott, R P; Korchak, H M; Johnston, R B

    1993-01-01

    In contrast to its macrophage-activating capacity, IFN-gamma downregulates expression of the macrophage mannose receptor (MMR), which mediates uptake of Candida and other microorganisms. We found that IFN-gamma induced a concentration-dependent increase in the capacity of human monocyte-derived macrophages to ingest and kill both opsonized and unopsonized Candida albicans and to release superoxide anion upon stimulation with Candida. Mannan or mannosylated albumin inhibited this activated uptake of unopsonized Candida, but glucan did not. Addition of mAb to complement receptor (CR) 3 did not inhibit ingestion; macrophages that lacked CR3 (leukocyte adhesion defect) showed normal upregulation of ingestion by IFN-gamma. The increased candidacidal activity of IFN-gamma-activated macrophages was associated with reduced expression of MMR by a mean of 79% and decreased pinocytic uptake of 125I-mannosylated BSA by 73%; K(uptake) of pinocytosis was not changed. Exposure of resident macrophages to unopsonized Candida did not elicit a transient increase in intracellular free Ca2+ ([Ca2+]i); macrophages activated by IFN-gamma expressed a brisk increase in [Ca2+]i on exposure to Candida. These data suggest that macrophage activation by IFN-gamma can enhance resistance to C. albicans infection in spite of downregulation of the MMR, perhaps through enhanced coupling of the MMR to microbicidal functions. PMID:8390485

  8. The Bacillus anthracis cholesterol-dependent cytolysin, Anthrolysin O, kills human neutrophils, monocytes and macrophages

    Directory of Open Access Journals (Sweden)

    Rest Richard F

    2006-06-01

    Full Text Available Abstract Background Bacillus anthracis is an animal and human pathogen whose virulence is characterized by lethal and edema toxin, as well as a poly-glutamic acid capsule. In addition to these well characterized toxins, B. anthracis secretes several proteases and phospholipases, and a newly described toxin of the cholesterol-dependent cytolysin (CDC family, Anthrolysin O (ALO. Results In the present studies we show that recombinant ALO (rALO or native ALO, secreted by viable B. anthracis, is lethal to human primary polymorphonuclear leukocytes (PMNs, monocytes, monocyte-derived macrophages (MDMs, lymphocytes, THP-1 monocytic human cell line and ME-180, Detroit 562, and A549 epithelial cells by trypan blue exclusion or lactate dehydrogenase (LDH release viability assays. ALO cytotoxicity is dose and time dependent and susceptibility to ALO-mediated lysis differs between cell types. In addition, the viability of monocytes and hMDMs was assayed in the presence of vegetative Sterne strains 7702 (ALO+, UT231 (ALO-, and a complemented strain expressing ALO, UT231 (pUTE544, and was dependent upon the expression of ALO. Cytotoxicity of rALO is seen as low as 0.070 nM in the absence of serum. All direct cytotoxic activity is inhibited by the addition of cholesterol or serum concentration as low as 10%. Conclusion The lethality of rALO and native ALO on human monocytes, neutrophils, macrophages and lymphocytes supports the idea that ALO may represent a previously unidentified virulence factor of B. anthracis. The study of other factors produced by B. anthracis, along with the major anthrax toxins, will lead to a better understanding of this bacterium's pathogenesis, as well as provide information for the development of antitoxin vaccines for treating and preventing anthrax.

  9. 17-AAG Kills Intracellular Leishmania amazonensis while Reducing Inflammatory Responses in Infected Macrophages

    Science.gov (United States)

    Petersen, Antonio Luis de Oliveira Almeida; Guedes, Carlos Eduardo Sampaio; Versoza, Carolina Leite; Lima, José Geraldo Bomfim; de Freitas, Luiz Antônio Rodrigues; Borges, Valéria Matos; Veras, Patrícia Sampaio Tavares

    2012-01-01

    Background Leishmaniasis is a neglected endemic disease with a broad spectrum of clinical manifestations. Pentavalent antimonials have been the treatment of choice for the past 70 years and, due to the emergence of resistant cases, the efficacy of these drugs has come under scrutiny. Second-line drugs are less efficacious, cause a range of side effects and can be costly. The formulation of new generations of drugs, especially in developing countries, has become mandatory. Methodology/Principal Findings We investigated the anti-leishmanial effect of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG), an HSP90 inhibitor, in vitro. This inhibitor is currently in clinical trials for cancer treatment; however, its effects against intracellular Leishmania remain untested. Macrophages infected with L. amazonensis were treated with 17-AAG (25–500 nM) and parasite load was quantified using optical microscopy. Parasite load declined in 17-AAG-treated macrophages in a dose- and time-dependent manner. Intracellular parasite death became irreversible after 4 h of treatment with 17-AAG, and occurred independent of nitric oxide (NO) and superoxide (O2−) production. Additionally, intracellular parasite viability was severely reduced after 48 h of treatment. Interestingly, treatment with 17-AAG reduced pro-inflammatory mediator production, including TNF-α, IL-6 and MCP-1, yet IL-12 remained unaffected. Electron microscopy revealed morphological alterations, such as double-membrane vacuoles and myelin figures at 24 and 48 h after 17-AAG treatment. Conclusions/Significance The HSP90 inhibitor, 17-AAG, possesses high potency under low dosage and reduces both pro-inflammatory and oxidative molecule production. Therefore, further studies are warranted to investigate this inhibitor’s potential in the development of new generations of anti-leishmanials. PMID:23152914

  10. In vitro killing assays of antisera antibody sheep post-infected with Fasciola gigantica with the presence of macrophages cells against homologous and heterologous liver flukes

    Directory of Open Access Journals (Sweden)

    S.E Estuningsih

    1999-10-01

    Full Text Available The previous artificial infection known that the Indonesian Thin Tail (ITT sheep was resistance against the liver fluke of Fasciola gigantica, the resistances occurred in the early infection. In order to observe the immune resistance, some in vitro studies were undertaken in the laboratory, to assay the ability of the antisera antibody of ITT sheep post-infected with F. gigantica, with the presence of macrophages cells in killing the homologous and heterologous liver flukes. The viability of liver flukes were observed within 24-72 hours of incubation period by observing their motility (motile flukes were designated live and non-motile once were death. The results showed that after 72 hours incubation, the motilities of the Newly Excysted Juvenile (NEJ of F. gigantica incubated with the presence of post-infected sera and macrophages cells solution were significantly lower (P0.05. It seems that the occurrence of homologous antibody to the antigens is very important in the development of killing mechanism. The absence of homologous antibody did not reduce the number of flukes or the ability of macrophages cells in killing F. hepatica was not apparent.

  11. Intraphagosomal peroxynitrite as a macrophage-derived cytotoxin against internalized Trypanosoma cruzi: consequences for oxidative killing and role of microbial peroxiredoxins in infectivity.

    Science.gov (United States)

    Alvarez, María Noel; Peluffo, Gonzalo; Piacenza, Lucía; Radi, Rafael

    2011-02-25

    Macrophage-derived radicals generated by the NADPH oxidase complex and inducible nitric-oxide synthase (iNOS) participate in cytotoxic mechanisms against microorganisms. Nitric oxide ((•)NO) plays a central role in the control of acute infection by Trypanosoma cruzi, the causative agent of Chagas disease, and we have proposed that much of its action relies on macrophage-derived peroxynitrite (ONOO(-) + ONOOH) formation, a strong oxidant arising from the reaction of (•)NO with superoxide radical (O(2)(-)). Herein, we have shown that internalization of T. cruzi trypomastigotes by macrophages triggers the assembly of the NADPH oxidase complex to yield O(2)(-) during a 60-90-min period. This does not interfere with IFN-γ-dependent iNOS induction and a sustained (•)NO production (∼24 h). The major mechanism for infection control via reactive species formation occurred when (•)NO and O(2)() were produced simultaneously, generating intraphagosomal peroxynitrite levels compatible with microbial killing. Moreover, biochemical and ultrastructural analysis confirmed cellular oxidative damage and morphological disruption in internalized parasites. Overexpression of cytosolic tryparedoxin peroxidase in T. cruzi neutralized macrophage-derived peroxynitrite-dependent cytotoxicity to parasites and favored the infection in an animal model. Collectively, the data provide, for the first time, direct support for the action of peroxynitrite as an intraphagosomal cytotoxin against pathogens and the premise that microbial peroxiredoxins facilitate infectivity via decomposition of macrophage-derived peroxynitrite.

  12. Neutrophils activate macrophages for intracellular killing of Leishmania major through recruitment of TLR4 by neutrophil elastase.

    Science.gov (United States)

    Ribeiro-Gomes, Flavia L; Moniz-de-Souza, Maria Carolina A; Alexandre-Moreira, Magna S; Dias, Wagner B; Lopes, Marcela F; Nunes, Marise P; Lungarella, Giuseppe; DosReis, George A

    2007-09-15

    We investigated the role of neutrophil elastase (NE) in interactions between murine inflammatory neutrophils and macrophages infected with the parasite Leishmania major. A blocker peptide specific for NE prevented the neutrophils from inducing microbicidal activity in macrophages. Inflammatory neutrophils from mutant pallid mice were defective in the spontaneous release of NE, failed to induce microbicidal activity in wild-type macrophages, and failed to reduce parasite loads upon transfer in vivo. Conversely, purified NE activated macrophages and induced microbicidal activity dependent on secretion of TNF-alpha. Induction of macrophage microbicidal activity by either neutrophils or purified NE required TLR4 expression by macrophages. Injection of purified NE shortly after infection in vivo reduced the burden of L. major in draining lymph nodes of TLR4-sufficient, but not TLR4-deficient mice. These results indicate that NE plays a previously unrecognized protective role in host responses to L. major infection.

  13. Involvement of β-defensin 130 (DEFB130) in the macrophage microbicidal mechanisms for killing Plasmodium falciparum

    Science.gov (United States)

    Terkawi, Mohamad Alaa; Takano, Ryo; Furukawa, Atsushi; Murakoshi, Fumi; Kato, Kentaro

    2017-01-01

    Understanding the molecular defense mechanism of macrophages and identifying their effector molecules against malarial parasites may provide important clues for the discovery of new therapies. To analyze the immunological responses of malarial parasite-induced macrophages, we used DNA microarray technology to examine the gene profile of differentiated macrophages phagocytizing Plasmodium falciparum-parasitized erythrocytes (iRBC). The transcriptional gene profile of macrophages in response to iRBCs represented 168 down-regulated genes, which were mainly involved in the cellular immune response, and 216 upregulated genes, which were involved in cellular proteolysis, growth, and adhesion. Importantly, the specific upregulation of β-defensin 130 (DEFB130) in these macrophages suggested a possible role for DEFB130 in malarial parasite elimination. Differentiated macrophages phagocytizing iRBCs exhibited an increase in intracellular DEFB130 levels and DEFB130 appeared to accumulate at the site of iRBC engulfment. Transfection of esiRNA-mediated knockdown of DEFB130 into macrophages resulted in a remarkable reduction in their antiplasmodial activity in vitro. Furthermore, DEFB130 synthetic peptide exhibited a modest toxic effect on P. falciparum in vitro and P. yoelii in vivo, unlike scrambled DEFB130 peptide, which showed no antiplasmodial activity. Together, these results suggest that DEFB130 might be one of the macrophage effector molecules for eliminating malarial parasites. Our data broaden our knowledge of the immunological response of macrophages to iRBCs and shed light on a new target for therapeutic intervention. PMID:28181499

  14. Corticosterone rapidly promotes respiratory burst of mouse peritoneal macrophages via non-genomic mechanism

    Institute of Scientific and Technical Information of China (English)

    SHI Wen-lei; MA Qian; ZHANG Lu-ding; HUANG Jun-long; ZHOU Jian; LIU Lei; SHEN Xing-hua; JIANG Chun-lei

    2011-01-01

    Background The immunomodulatory effects of glucocorticoids (GCs) have been described as bimodal. High concentration of GCs exerts immunosuppressive effects and low levels of GCs are immunopermissive. While the immunosuppressive mechanisms of GCs have been investigated intensely, the immunopermissive effects of GCs remain unclear. A lot of studies showed GCs could exert rapid non-genomic actions. We herein studied the rapid immunopromoting effects of GCs.Methods We observed the rapid (within 30 minutes) effects of corticosterone on respiratory burst of mouse peritoneal macrophages and studied their mechanisms. The superoxide anions were measured by cytochrome C reduction assay.Protein kinase C phosphorylation was measured by Western blotting and membrane fluidity was evaluated by fluorescence polarization measurement.Results The 10-8 mol/L and 10-7 mol/L corticosterone rapidly increased the superoxide anions production by macrophages, which were insensitive to GC-receptor antagonist, mifepristone, and protein-synthesis inhibitor,cycloheximide. Corticosterone coupled to bovine serum albumin was able to mimic the effects of corticosterone. The effects were independent of protein kinase C pathway and the change in membrane fluidity.Conclusions The results indicate that corticosterone rapidly promote the superoxide anions production by mouse peritoneal macrophages may through non-genomic mechanisms. This study may contribute to understanding the effects of GCs under stress condition and the physiological significance of nongenomic effects of GCs.

  15. Toll-like receptor 5 (TLR5), IL-1β secretion, and asparagine endopeptidase are critical factors for alveolar macrophage phagocytosis and bacterial killing.

    Science.gov (United States)

    Descamps, Delphyne; Le Gars, Mathieu; Balloy, Viviane; Barbier, Diane; Maschalidi, Sophia; Tohme, Mira; Chignard, Michel; Ramphal, Reuben; Manoury, Bénédicte; Sallenave, Jean-Michel

    2012-01-31

    A deficit in early clearance of Pseudomonas aeruginosa (P. aeruginosa) is crucial in nosocomial pneumonia and in chronic lung infections. Few studies have addressed the role of Toll-like receptors (TLRs), which are early pathogen associated molecular pattern receptors, in pathogen uptake and clearance by alveolar macrophages (AMs). Here, we report that TLR5 engagement is crucial for bacterial clearance by AMs in vitro and in vivo because unflagellated P. aeruginosa or different mutants defective in TLR5 activation were resistant to AM phagocytosis and killing. In addition, the clearance of PAK (a wild-type P. aeruginosa strain) by primary AMs was causally associated with increased IL-1β release, which was dramatically reduced with PAK mutants or in WT PAK-infected primary TLR5(-/-) AMs, demonstrating the dependence of IL-1β production on TLR5. We showed that this IL-1β production was important in endosomal pH acidification and in inducing the killing of bacteria by AMs through asparagine endopeptidase (AEP), a key endosomal cysteine protease. In agreement, AMs from IL-1R1(-/-) and AEP(-/-) mice were unable to kill P. aeruginosa. Altogether, these findings demonstrate that TLR5 engagement plays a major role in P. aeruginosa internalization and in triggering IL-1β formation.

  16. Evaluation of methods of rapid mass killing of segregated early weaned piglets

    OpenAIRE

    Whiting, Terry L.; Steele, Gregory G.; Wamnes, Steinar; Green, Chris

    2011-01-01

    The operational logistics of mass killing of healthy, surplus piglets by manual blunt force trauma, controlled blunt force trauma, intraperitoneal injection of barbiturate, and free bullet were recorded. Objective performance variables evaluated were, speed of application, human resource and input cost, animal restraint required, and failure rate. Subjective evaluation of esthetics and difficulty of application indicated manual blunt force trauma is an unacceptable technique. Under field cond...

  17. Rapid killing of bed bugs (Cimex lectularius L.) on surfaces using heat: application to luggage.

    Science.gov (United States)

    Loudon, Catherine

    2017-01-01

    The resistance of bed bugs (Cimex lectularius L.) to chemical insecticides has motivated the development of non-chemical control methods such as heat treatment. However, because bed bugs tend to hide in cracks or crevices, their behavior incidentally generates a thermally insulated microenvironment for themselves. Bed bugs located on the outer surface of luggage are less insulated and potentially more vulnerable to brief heat treatment. Soft-sided suitcases with adult male bed bugs on the outside were exposed to an air temperature of 70-75 °C. It took 6 min to kill all of the bed bugs, even those that had concealed themselves under zipper flaps or decorative piping. During heating, only one bed bug (out of 250 in total) moved into the luggage (through a closed zipper). Over long periods of time (24 h) at room temperature, adult male bed bugs on the exterior of luggage only infrequently moved inside; only 3% (5/170) had moved inside during 24 h. Brief exterior heat treatment of luggage is a promising way to reduce the spread of bed bugs being transported on the outer surface of luggage. This treatment will not kill bed bugs inside the luggage, but could be a component of integrated management for this pest. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Short communication: rapid preparation of preventive and therapeutic whole-killed retroviral vaccines using the microbicide taurine chloramine.

    Science.gov (United States)

    Dudani, A K; Martyres, A; Fliss, H

    2008-04-01

    A current urgent priority is to develop microbicides and vaccines to combat retroviruses like human immunodeficiency virus (HIV). We show that the cysteine-selective natural compound, taurine chloramine (T-NCl), can be effective in this task. A number of proteins in all retroviruses contain highly conserved cysteine-rich regions that are essential for infection and replication. Our data show that by targeting these essential cysteine residues, T-NCl (2 or 5 mM) acts as a highly effective and safe microbicide that fully blocks the infectivity of high HIV-1 titers (10(6) TCID(50) units/ml) but is not injurious to eukaryotic cells. We also demonstrate that T-NCl can be used to prepare a highly effective whole-killed vaccine against murine AIDS (MAIDS) that shows both preventive and therapeutic efficacy. The vaccine consists of a T-NCl-inactivated retrovirus suspension in host cell lysate. The novelty of our approach lies in the ease and speed of vaccine preparation and its avoidance of harsh inactivation or purification steps that can alter native viral conformation. Our approach is therefore likely to overcome a number of intractable obstacles to the preparation of an effective whole-killed HIV vaccine, such as surviving infective viral particles, rapid viral mutation rates, numerous viral strains, and harsh purification steps. Our approach may also permit the rapid preparation of autologous, or custom-made, vaccines for individual patients.

  19. Innate invariant NKT cells recognize Mycobacterium tuberculosis-infected macrophages, produce interferon-gamma, and kill intracellular bacteria.

    Directory of Open Access Journals (Sweden)

    Isabel Sada-Ovalle

    2008-12-01

    Full Text Available Cellular immunity to Mycobacterium tuberculosis (Mtb requires a coordinated response between the innate and adaptive arms of the immune system, resulting in a type 1 cytokine response, which is associated with control of infection. The contribution of innate lymphocytes to immunity against Mtb remains controversial. We established an in vitro system to study this question. Interferon-gamma is produced when splenocytes from uninfected mice are cultured with Mtb-infected macrophages, and, under these conditions, bacterial replication is suppressed. This innate control of bacterial replication is dependent on CD1d-restricted invariant NKT (iNKT cells, and their activation requires CD1d expression by infected macrophages as well as IL-12 and IL-18. We show that iNKT cells, even in limiting quantities, are sufficient to restrict Mtb replication. To determine whether iNKT cells contribute to host defense against tuberculosis in vivo, we adoptively transferred iNKT cells into mice. Primary splenic iNKT cells obtained from uninfected mice significantly reduce the bacterial burden in the lungs of mice infected with virulent Mtb by the aerosol route. Thus, iNKT cells have a direct bactericidal effect, even in the absence of synthetic ligands such as alpha-galactosylceramide. Our finding that iNKT cells protect mice against aerosol Mtb infection is the first evidence that CD1d-restricted NKT cells mediate protection against Mtb in vivo.

  20. Critical Role for Monocytes/Macrophages in Rapid Progression to AIDS in Pediatric Simian Immunodeficiency Virus-Infected Rhesus Macaques.

    Science.gov (United States)

    Sugimoto, Chie; Merino, Kristen M; Hasegawa, Atsuhiko; Wang, Xiaolei; Alvarez, Xavier A; Wakao, Hiroshi; Mori, Kazuyasu; Kim, Woong-Ki; Veazey, Ronald S; Didier, Elizabeth S; Kuroda, Marcelo J

    2017-09-01

    Infant humans and rhesus macaques infected with the human or simian immunodeficiency virus (HIV or SIV), respectively, express higher viral loads and progress more rapidly to AIDS than infected adults. Activated memory CD4(+) T cells in intestinal tissues are major primary target cells for SIV/HIV infection, and massive depletion of these cells is considered a major cause of immunodeficiency. Monocytes and macrophages are important cells of innate immunity and also are targets of HIV/SIV infection. We reported previously that a high peripheral blood monocyte turnover rate was predictive for the onset of disease progression to AIDS in SIV-infected adult macaques. The purpose of this study was to determine if earlier or higher infection of monocytes/macrophages contributes to the more rapid progression to AIDS in infants. We observed that uninfected infant rhesus macaques exhibited higher physiologic baseline monocyte turnover than adults. Early after SIV infection, the monocyte turnover further increased, and it remained high during progression to AIDS. A high percentage of terminal deoxynucleotidyltransferase dUTP nick end label (TUNEL)-positive macrophages in the lymph nodes (LNs) and intestine corresponded with an increasing number of macrophages derived from circulating monocytes (bromodeoxyuridine positive [BrdU(+)] CD163(+)), suggesting that the increased blood monocyte turnover was required to rapidly replenish destroyed tissue macrophages. Immunofluorescence analysis further demonstrated that macrophages were a significant portion of the virus-producing cells found in LNs, intestinal tissues, and lungs. The higher baseline monocyte turnover in infant macaques and subsequent macrophage damage by SIV infection may help explain the basis of more rapid disease progression to AIDS in infants.IMPORTANCE HIV infection progresses much more rapidly in pediatric cases than in adults; however, the mechanism for this difference is unclear. Using the rhesus macaque model

  1. Rapid and efficient cancer cell killing mediated by high-affinity death receptor homotrimerizing TRAIL variants.

    Science.gov (United States)

    Reis, C R; van der Sloot, A M; Natoni, A; Szegezdi, E; Setroikromo, R; Meijer, M; Sjollema, K; Stricher, F; Cool, R H; Samali, A; Serrano, L; Quax, W J

    2010-10-21

    The tumour necrosis factor family member TNF-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in a variety of cancer cells through the activation of death receptors 4 (DR4) and 5 (DR5) and is considered a promising anticancer therapeutic agent. As apoptosis seems to occur primarily via only one of the two death receptors in many cancer cells, the introduction of DR selectivity is thought to create more potent TRAIL agonists with superior therapeutic properties. By use of a computer-aided structure-based design followed by rational combination of mutations, we obtained variants that signal exclusively via DR4. Besides an enhanced selectivity, these TRAIL-DR4 agonists show superior affinity to DR4, and a high apoptosis-inducing activity against several TRAIL-sensitive and -resistant cancer cell lines in vitro. Intriguingly, combined treatment of the DR4-selective variant and a DR5-selective TRAIL variant in cancer cell lines signalling by both death receptors leads to a significant increase in activity when compared with wild-type rhTRAIL or each single rhTRAIL variant. Our results suggest that TRAIL induced apoptosis via high-affinity and rapid-selective homotrimerization of each DR represent an important step towards an efficient cancer treatment.

  2. A novel transferrin receptor-targeted hybrid peptide disintegrates cancer cell membrane to induce rapid killing of cancer cells

    Directory of Open Access Journals (Sweden)

    Kawamoto Megumi

    2011-08-01

    Full Text Available Abstract Background Transferrin receptor (TfR is a cell membrane-associated glycoprotein involved in the cellular uptake of iron and the regulation of cell growth. Recent studies have shown the elevated expression levels of TfR on cancer cells compared with normal cells. The elevated expression levels of this receptor in malignancies, which is the accessible extracellular protein, can be a fascinating target for the treatment of cancer. We have recently designed novel type of immunotoxin, termed "hybrid peptide", which is chemically synthesized and is composed of target-binding peptide and lytic peptide containing cationic-rich amino acids components that disintegrates the cell membrane for the cancer cell killing. The lytic peptide is newly designed to induce rapid killing of cancer cells due to conformational change. In this study, we designed TfR binding peptide connected with this novel lytic peptide and assessed the cytotoxic activity in vitro and in vivo. Methods In vitro: We assessed the cytotoxicity of TfR-lytic hybrid peptide for 12 cancer and 2 normal cell lines. The specificity for TfR is demonstrated by competitive assay using TfR antibody and siRNA. In addition, we performed analysis of confocal fluorescence microscopy and apoptosis assay by Annexin-V binding, caspase activity, and JC-1 staining to assess the change in mitochondria membrane potential. In vivo: TfR-lytic was administered intravenously in an athymic mice model with MDA-MB-231 cells. After three weeks tumor sections were histologically analyzed. Results The TfR-lytic hybrid peptide showed cytotoxic activity in 12 cancer cell lines, with IC50 values as low as 4.0-9.3 μM. Normal cells were less sensitive to this molecule, with IC50 values > 50 μM. Competition assay using TfR antibody and knockdown of this receptor by siRNA confirmed the specificity of the TfR-lytic hybrid peptide. In addition, it was revealed that this molecule can disintegrate the cell membrane of T47

  3. Control of Rhagoletis indifferents using Thiamethoxam and Spinosad baits under external fly pressure and its relation to rapidity of kill and residual bait activity

    Science.gov (United States)

    Control of western cherry fruit fly (Rhagoletis indifferens Curran) using thiamethoxam in sucrose bait and spinosad bait in cherry orchards under external fly pressure and its relation to rapidity of kill and residual bait activity were studied in Washington and Utah in 2010 and 2011. Thiamethoxam ...

  4. Rapid recruitment and activation of macrophages by anti-Gal/α-Gal liposome interaction accelerates wound healing.

    Science.gov (United States)

    Wigglesworth, Kim M; Racki, Waldemar J; Mishra, Rabinarayan; Szomolanyi-Tsuda, Eva; Greiner, Dale L; Galili, Uri

    2011-04-01

    Macrophages are pivotal in promoting wound healing. We hypothesized that topical application of liposomes with glycolipids that carry Galα1-3Galβ1-4GlcNAc-R epitopes (α-gal liposomes) on wounds may accelerate the healing process by rapid recruitment and activation of macrophages in wounds. Immune complexes of the natural anti-Gal Ab (constituting ∼1% of Ig in humans) bound to its ligand, the α-gal epitope on α-gal liposomes would induce local activation of complement and generation of complement chemotactic factors that rapidly recruit macrophages. Subsequent binding of the Fc portion of anti-Gal coating α-gal liposomes to FcγRs on recruited macrophages may activate macrophage genes encoding cytokines that mediate wound healing. We documented the efficacy of this treatment in α1,3galactosyltrasferase knockout mice. In contrast to wild-type mice, these knockout mice lack α-gal epitopes and can produce the anti-Gal Ab. The healing time of excisional skin wounds treated with α-gal liposomes in these mice is twice as fast as that of control wounds. Moreover, scar formation in α-gal liposome-treated wounds is much lower than in physiologic healing. Additional sonication of α-gal liposomes resulted in their conversion into submicroscopic α-gal nanoparticles. These α-gal nanoparticles diffused more efficiently in wounds and further increased the efficacy of the treatment, resulting in 95-100% regeneration of the epidermis in wounds within 6 d. The study suggests that α-gal liposome and α-gal nanoparticle treatment may enhance wound healing in the clinic because of the presence of high complement activity and high anti-Gal Ab titers in humans.

  5. Rapid differentiation of Listeria monocytogenes epidemic clones III and IV and their intact compared with heat-killed populations using Fourier transform infrared spectroscopy and chemometrics.

    Science.gov (United States)

    Nyarko, Esmond B; Puzey, Kenneth A; Donnelly, Catherine W

    2014-06-01

    The objectives of this study were to determine if Fourier transform infrared (FT-IR) spectroscopy and multivariate statistical analysis (chemometrics) could be used to rapidly differentiate epidemic clones (ECs) of Listeria monocytogenes, as well as their intact compared with heat-killed populations. FT-IR spectra were collected from dried thin smears on infrared slides prepared from aliquots of 10 μL of each L. monocytogenes ECs (ECIII: J1-101 and R2-499; ECIV: J1-129 and J1-220), and also from intact and heat-killed cell populations of each EC strain using 250 scans at a resolution of 4 cm(-1) in the mid-infrared region in a reflectance mode. Chemometric analysis of spectra involved the application of the multivariate discriminant method for canonical variate analysis (CVA) and linear discriminant analysis (LDA). CVA of the spectra in the wavelength region 4000 to 600 cm(-1) separated the EC strains while LDA resulted in a 100% accurate classification of all spectra in the data set. Further, CVA separated intact and heat-killed cells of each EC strain and there was 100% accuracy in the classification of all spectra when LDA was applied. FT-IR spectral wavenumbers 1650 to 1390 cm(-1) were used to separate heat-killed and intact populations of L. monocytogenes. The FT-IR spectroscopy method allowed discrimination between strains that belong to the same EC. FT-IR is a highly discriminatory and reproducible method that can be used for the rapid subtyping of L. monocytogenes, as well as for the detection of live compared with dead populations of the organism. Fourier transform infrared (FT-IR) spectroscopy and multivariate statistical analysis can be used for L. monocytogenes source tracking and for clinical case isolate comparison during epidemiological investigations since the method is capable of differentiating epidemic clones and it uses a library of well-characterized strains. The FT-IR method is potentially less expensive and more rapid compared to genetic

  6. Treatment of Mycobacterium tuberculosis-Infected Macrophages with Poly(Lactic-Co-Glycolic Acid) Microparticles Drives NFκB and Autophagy Dependent Bacillary Killing.

    LENUS (Irish Health Repository)

    Lawlor, Ciaran

    2016-01-01

    The emergence of multiple-drug-resistant tuberculosis (MDR-TB) has pushed our available repertoire of anti-TB therapies to the limit of effectiveness. This has increased the urgency to develop novel treatment modalities, and inhalable microparticle (MP) formulations are a promising option to target the site of infection. We have engineered poly(lactic-co-glycolic acid) (PLGA) MPs which can carry a payload of anti-TB agents, and are successfully taken up by human alveolar macrophages. Even without a drug cargo, MPs can be potent immunogens; yet little is known about how they influence macrophage function in the setting of Mycobacterium tuberculosis (Mtb) infection. To address this issue we infected THP-1 macrophages with Mtb H37Ra or H37Rv and treated with MPs. In controlled experiments we saw a reproducible reduction in bacillary viability when THP-1 macrophages were treated with drug-free MPs. NFκB activity was increased in MP-treated macrophages, although cytokine secretion was unaltered. Confocal microscopy of immortalized murine bone marrow-derived macrophages expressing GFP-tagged LC3 demonstrated induction of autophagy. Inhibition of caspases did not influence the MP-induced restriction of bacillary growth, however, blockade of NFκB or autophagy with pharmacological inhibitors reversed this MP effect on macrophage function. These data support harnessing inhaled PLGA MP-drug delivery systems as an immunotherapeutic in addition to serving as a vehicle for targeted drug delivery. Such "added value" could be exploited in the generation of inhaled vaccines as well as inhaled MDR-TB therapeutics when used as an adjunct to existing treatments.

  7. Cytotoxic macrophage-released tumour necrosis factor-alpha (TNF-α) as a killing mechanism for cancer cell death after cold plasma activation

    Science.gov (United States)

    Kaushik, Nagendra Kumar; Kaushik, Neha; Min, Booki; Choi, Ki Hong; Hong, Young June; Miller, Vandana; Fridman, Alexander; Choi, Eun Ha

    2016-03-01

    The present study aims at studying the anticancer role of cold plasma-activated immune cells. The direct anti-cancer activity of plasma-activated immune cells against human solid cancers has not been described so far. Hence, we assessed the effect of plasma-treated RAW264.7 macrophages on cancer cell growth after co-culture. In particular, flow cytometer analysis revealed that plasma did not induce any cell death in RAW264.7 macrophages. Interestingly, immunofluorescence and western blot analysis confirmed that TNF-α released from plasma-activated macrophages acts as a tumour cell death inducer. In support of these findings, activated macrophages down-regulated the cell growth in solid cancer cell lines and induced cell death in vitro. Together our findings suggest plasma-induced reactive species recruit cytotoxic macrophages to release TNF-α, which blocks cancer cell growth and can have the potential to contribute to reducing tumour growth in vivo in the near future.

  8. Paediatric Crohn disease patients with stricturing behaviour exhibit ileal granulocyte–macrophage colony-stimulating factor (GM-CSF) autoantibody production and reduced neutrophil bacterial killing and GM-CSF bioactivity

    Science.gov (United States)

    Jurickova, I; Collins, M H; Chalk, C; Seese, A; Bezold, R; Lake, K; Allmen, D; Frischer, J S; Falcone, R A; Trapnell, B C; Denson, L A

    2013-01-01

    Granulocyte–macrophage colony-stimulating factor (GM-CSF) autoantibodies are associated with stricturing behaviour in Crohn disease (CD). We hypothesized that CD ileal lamina propria mononuclear cells (LPMC) would produce GM-CSF autoantibodies and peripheral blood (PB) samples would contain GM-CSF neutralizing capacity (NC). Paediatric CD and control PBMC and ileal biopsies or LPMC were isolated and cultured and GM-CSF, immunoglobulin (Ig)G and GM-CSF autoantibodies production were measured by enzyme-linked immunosorbent assay (ELISA). Basal and GM-CSF-primed neutrophil bacterial killing and signal transducer and activator of transcription 5 (STAT5) tyrosine phosphorylation (pSTAT5) were measured by flow cytometry. GM-CSF autoantibodies were enriched within total IgG for LPMC isolated from CD ileal strictures and proximal margins compared to control ileum. Neutrophil bacterial killing was reduced in CD patients compared to controls. Within CD, neutrophil GM-CSF-dependent STAT5 activation and bacterial killing were reduced as GM-CSF autoantibodies increased. GM-CSF stimulation of pSTAT5 did not vary between controls and CD patients in washed PB granulocytes in which serum was removed. However, GM-CSF stimulation of pSTAT5 was reduced in whole PB samples from CD patients. These data were used to calculate the GM-CSF NC. CD patients with GM-CSF NC greater than 25% exhibited a fourfold higher rate of stricturing behaviour and surgery. The likelihood ratio (95% confidence interval) for stricturing behaviour for patients with elevation in both GM-CSF autoantibodies and GM-CSF NC was equal to 5 (2, 11). GM-CSF autoantibodies are produced by LPMC isolated from CD ileal resection specimens and are associated with reduced neutrophil bacterial killing. CD peripheral blood contains GM-CSF NC, which is associated with increased rates of stricturing behaviour. PMID:23600834

  9. A highly conserved Toxo1 haplotype directs resistance to toxoplasmosis and its associated caspase-1 dependent killing of parasite and host macrophage.

    Science.gov (United States)

    Cavailles, Pierre; Flori, Pierre; Papapietro, Olivier; Bisanz, Cordelia; Lagrange, Dominique; Pilloux, Ludovic; Massera, Céline; Cristinelli, Sara; Jublot, Delphine; Bastien, Olivier; Loeuillet, Corinne; Aldebert, Delphine; Touquet, Bastien; Fournié, Gilbert J; Cesbron-Delauw, Marie France

    2014-04-01

    Natural immunity or resistance to pathogens most often relies on the genetic make-up of the host. In a LEW rat model of refractoriness to toxoplasmosis, we previously identified on chromosome 10 the Toxo1 locus that directs toxoplasmosis outcome and controls parasite spreading by a macrophage-dependent mechanism. Now, we narrowed down Toxo1 to a 891 kb interval containing 29 genes syntenic to human 17p13 region. Strikingly, Toxo1 is included in a haplotype block strictly conserved among all refractory rat strains. The sequencing of Toxo1 in nine rat strains (5 refractory and 4 susceptible) revealed resistant-restricted conserved polymorphisms displaying a distribution gradient that peaks at the bottom border of Toxo1, and highlighting the NOD-like receptor, Nlrp1a, as a major candidate. The Nlrp1 inflammasome is known to trigger, upon pathogen intracellular sensing, pyroptosis programmed-cell death involving caspase-1 activation and cleavage of IL-1β. Functional studies demonstrated that the Toxo1-dependent refractoriness in vivo correlated with both the ability of macrophages to restrict T. gondii growth and a T. gondii-induced death of intracellular parasites and its host macrophages. The parasite-induced cell death of infected macrophages bearing the LEW-Toxo1 alleles was found to exhibit pyroptosis-like features with ROS production, the activation of caspase-1 and IL1-β secretion. The pharmacological inactivation of caspase-1 using YVAD and Z-VAD inhibitors prevented the death of both intravacuolar parasites and host non-permissive macrophages but failed to restore parasite proliferation. These findings demonstrated that the Toxo1-dependent response of rat macrophages to T. gondii infection may trigger two pathways leading to the control of parasite proliferation and the death of parasites and host macrophages. The NOD-like receptor NLRP1a/Caspase-1 pathway is the best candidate to mediate the parasite-induced cell death. These data represent new insights

  10. The Killing

    DEFF Research Database (Denmark)

    Agger, Gunhild

    2013-01-01

    This article tracks the uncanny locations of The Killing (2007–2012), relating them to place, space and atmosphere, putting bits and pieces from the topographic puzzle together with cues from the symbolic space in order to see how they fit into the overall pattern of Nordic Noir. In The Killing, ...

  11. The Killing

    DEFF Research Database (Denmark)

    Agger, Gunhild

    2013-01-01

    This article tracks the uncanny locations of The Killing (2007–2012), relating them to place, space and atmosphere, putting bits and pieces from the topographic puzzle together with cues from the symbolic space in order to see how they fit into the overall pattern of Nordic Noir. In The Killing......, the abstract level of space and atmosphere meets the concrete level of place, both influencing the notion of location. This meeting, I suggest, has contributed towards the simultaneous domestic and international appeal of The Killing....

  12. Rapid necrotic killing of polymorphonuclear leukocytes is caused by quorum-sensing-controlled production of rhamnolipid by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Peter Ø; Bjarnsholt, Thomas; Phipps, Richard Kerry

    2007-01-01

    Quorum sensing (QS) denotes a density-dependent mode of inter-bacterial communication based on signal transmitter molecules. Active QS is present during chronic infections with the opportunistic pathogen Pseudomonas aeruginosa in immunocompromised patients. The authors have previously demonstrated...... a QS-regulated tolerance of biofilm bacteria to the antimicrobial properties of polymorphonuclear leukocytes (PMNs). The precise QS-regulated effect on the PMNs is, however, unknown. Incubation of human PMNs with supernatants from dense P. aeruginosa cultures showed that the QS-competent P. aeruginosa...... induced rapid necrosis of the PMNs. This mechanism was also observed in mouse lungs infected with P. aeruginosa, and in sputum obtained from P.-aeruginosa-infected patients with cystic fibrosis. Evidence is presented that the necrotic effect was caused by rhamnolipids, production of which is QS controlled...

  13. Hyphal growth of phagocytosed Fusarium oxysporum causes cell lysis and death of murine macrophages.

    Science.gov (United States)

    Schäfer, Katja; Bain, Judith M; Di Pietro, Antonio; Gow, Neil A R; Erwig, Lars P

    2014-01-01

    Fusarium oxysporum is an important plant pathogen and an opportunistic pathogen of humans. Here we investigated phagocytosis of F. oxysporum by J774.1 murine cell line macrophages using live cell video microscopy. Macrophages avidly migrated towards F. oxysporum germlings and were rapidly engulfed after cell-cell contact was established. F. oxysporum germlings continued hyphal growth after engulfment by macrophages, leading to associated macrophage lysis and escape. Macrophage killing depended on the multiplicity of infection. After engulfment, F. oxysporum inhibited macrophages from completing mitosis, resulting in large daughter cells fused together by means of a F. oxysporum hypha. These results shed new light on the initial stages of Fusarium infection and the innate immune response of the mammalian host.

  14. Depletion of spleen macrophages delays AA amyloid development: a study performed in the rapid mouse model of AA amyloidosis.

    Directory of Open Access Journals (Sweden)

    Katarzyna Lundmark

    Full Text Available AA amyloidosis is a systemic disease that develops secondary to chronic inflammatory diseases Macrophages are often found in the vicinity of amyloid deposits and considered to play a role in both formation and degradation of amyloid fibrils. In spleen reside at least three types of macrophages, red pulp macrophages (RPM, marginal zone macrophages (MZM, metallophilic marginal zone macrophages (MMZM. MMZM and MZM are located in the marginal zone and express a unique collection of scavenger receptors that are involved in the uptake of blood-born particles. The murine AA amyloid model that resembles the human form of the disease has been used to study amyloid effects on different macrophage populations. Amyloid was induced by intravenous injection of amyloid enhancing factor and subcutaneous injections of silver nitrate and macrophages were identified with specific antibodies. We show that MZMs are highly sensitive to amyloid and decrease in number progressively with increasing amyloid load. Total area of MMZMs is unaffected by amyloid but cells are activated and migrate into the white pulp. In a group of mice spleen macrophages were depleted by an intravenous injection of clodronate filled liposomes. Subsequent injections of AEF and silver nitrate showed a sustained amyloid development. RPMs that constitute the majority of macrophages in spleen, appear insensitive to amyloid and do not participate in amyloid formation.

  15. AN EXAMINATION OF THE CYTOTOXIC EFFECTS OF SILICA ON MACROPHAGES

    Science.gov (United States)

    Allison, A. C.; Harington, J. S.; Birbeck, M.

    1966-01-01

    Effects of silica, diamond dust, and carrageenan on mouse macrophages were studied by phase-contrast cine-micrography, electron microscopy, histochemical techniques for lysosomal enzymes and measurements of the release of lysosomal enzymes into the culture medium. All added materials were rapidly taken up into phagosomes, to which lysosomes became attached. In all cases lysosomal enzymes were discharged into the phagosomes to form secondary lysosomes. Within 24 hr most of the silica particles and enzyme had escaped from the secondary lysosomes and lysosomal enzymes were found in the culture media. Most macrophages were killed by this time. With nontoxic particles (diamond dust, aluminium-coated silica, or silica in the presence of the protective agent polyvinyl-pyridine-N-oxide, PVPNO) ingested particles and lysosomal enzymes were retained within the secondary lysosomes for a much longer time, and cytotoxic effects were considerably delayed or absent altogether. It is concluded that silica particles are toxic because they are efficiently taken up by macrophages and can then react relatively rapidly with the membranes surrounding the secondary lysosomes. The particles and lytic enzymes can then escape into the cytoplasm, producing general damage, and thence into the culture medium. It is suggested that hydrogen bonding of silicic acid with lipid and protein constituents of the membrane accounts for the induced permeability. Protective agents such as PVPNO are retamed in lysosomes and preferentially form hydrogen bonds with silicic acid. Carrageenan is demonstrable within macrophages by its metachromatic reaction. It brings about release of enzymes from secondary lysosomes, but much more slowly than does silica. Silica released from killed macrophages is as cytotoxic as the original preparation. It is suggested that repeated cycles of macrophage killing in vivo leads to the mobilization of fibroblasts and fibrogenesis characterizing the disease silicosis. PMID

  16. Why is particulate matter produced by wildfires toxic to lung macrophages?

    Energy Technology Data Exchange (ETDEWEB)

    Franzi, Lisa M.; Bratt, Jennifer M.; Williams, Keisha M.; Last, Jerold A., E-mail: jalast@ucdavis.edu

    2011-12-15

    The mechanistic basis of the high toxicity to lung macrophages of coarse PM from the California wildfires of 2008 was examined in cell culture experiments with mouse macrophages. Wildfire PM directly killed macrophages very rapidly in cell culture at relatively low doses. The wildfire coarse PM is about four times more toxic to macrophages on an equal weight basis than the same sized PM collected from normal ambient air (no wildfires) from the same region and season. There was a good correlation between the extent of cytotoxicity and the amount of oxidative stress observed at a given dose of wildfire PM in vitro. Our data implicate NF-{kappa}B signaling in the response of macrophages to wildfire PM, and suggest that most, if not all, of the cytotoxicity of wildfire PM to lung macrophages is the result of oxidative stress. The relative ratio of toxicity and of expression of biomarkers of oxidant stress between wildfire PM and 'normal' PM collected from ambient air is consistent with our previous results in mice in vivo, also suggesting that most, if not all, of the cytotoxicity of wildfire PM to lung macrophages is the result of oxidative stress. Our findings from this and earlier studies suggest that the active components of coarse PM from the wildfire are heat-labile organic compounds. While we cannot rule out a minor role for endotoxin in coarse PM preparations from the collected wildfire PM in our observed results both in vitro and in vivo, based on experiments using the inhibitor Polymyxin B most of the oxidant stress and pro-inflammatory activity observed was not due to endotoxin. -- Highlights: Black-Right-Pointing-Pointer Wildfire coarse PM kills macrophages at lower doses than coarse. Black-Right-Pointing-Pointer Wildfire coarse PM activates the NF-kB pathway at lower doses than ambient. Black-Right-Pointing-Pointer Wildfire coarse PM in vitro and in vivo kill macrophages by oxidative stress.

  17. Killing Effect on Liver Cancers by Mouse Macrophages Stimulated by Newcastle Disease Virus 7793 Strain in vitro and Its Mechanism%NDV7793体外激活的小鼠单核巨噬细胞(MΦ)对小鼠肝癌细胞的杀伤作用及其机制

    Institute of Scientific and Technical Information of China (English)

    刘金颖; 赖振屏; 宫金伶; 樊晓晖; 宋德志; 王立芳; 潘文宝胜; 殷君; 梁莹; 肖庆

    2012-01-01

    Objective To study the killing effect on liver cancers by mouse macrophages stimulated by Newcastle disease virus 7793 strain in vitro and the association of TRAIL. Methods The BALB/C mouse macrophages were harvested by using peritoneal lavage. And then the mouse macrophages were stimulate in -vitro by NDV7793. The concentration of TNF-α and TRAIL was determined by ELISA after NDV stimulation. Then the macrophages of mice were coincubated and activated with Novikoff cells. The cytotoxic effect of macrophages on Novikoff cells was performed by Lactate Dehydrogenase(LDH) assay after NDV stimulation. Three experiment control groups were simultaneously set up as following:TFN-β positive control group.ultraviolet ray inactivated NDV(UV-NDV) control group as well as blank control group. Results Compared with three control groups in vitro,the macrophages stimulated with NDV 7793 had been activated,and the level of TNF-a and TRAIL in culture supernatant increased. The killing ability of macrophage to Novikoff cells after NDV stimulation had increased. Conclusion The NDV 7793 can activate the mouse macrophages in vitro. The killing effect on liver cancer cells of the mouse macrophages is enhanced by NDV stimulation. And it is possible that TRAIL and TNF-a involve in this may enhance the killing effect.%目的 初步研究NDV7793激活的小鼠单核巨噬细胞(M(Φ))对小鼠肝癌Novikoff细胞的杀伤作用,并探讨其杀伤机制与TNF-α和TRAIL的关系.方法 从腹腔分离6周龄BALB/C小鼠M(Φ),用NDV7793于体外刺激小鼠M(Φ),以ELISA分别测定NDV7793刺激小鼠M(Φ)后产生的TNF-α及TRAIL水平;NDV7793体外刺激M(Φ)后,与小鼠肝癌Novikoff细胞混合培养,以LDH微量释放法测定小鼠M(Φ)对小鼠肝癌Novikoff细胞的杀伤效应.同时设立3组实验对照组:IFN-β阳性对照组、紫外线灭活NDV(UV-NDV)对照组以及空白对照组.结果 与3个对照组相比,NDV7793在体外能提高MO分泌TNF-α、TRAIL的水平;NDV

  18. The macrophages in rheumatic diseases

    Directory of Open Access Journals (Sweden)

    Laria A

    2016-02-01

    Full Text Available Antonella Laria, Alfredomaria Lurati , Mariagrazia Marrazza , Daniela Mazzocchi, Katia Angela Re, Magda Scarpellini Rheumatology Unit, Fornaroli Hospital, Magenta, Italy Abstract: 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. Keywords: macrophage, rheumatic diseases

  19. Macrophage-mediated tumor cytotoxicity: role of macrophage surface sialic acid.

    Science.gov (United States)

    Cameron, D J

    1983-02-01

    Cell surface sialic acid levels were compared for monocytes and macrophages obtained from normal volunteers and breast cancer patients. Equal quantities of sialic acid were found on the monocytes obtained from normal volunteers and breast cancer patients. Approximately 60% more cell surface sialic acid was found on the macrophages from breast cancer patients than was found on the macrophages from normal volunteers. In order to determine whether cell surface sialic acid had any effect on macrophage-mediated cytotoxicity, macrophages were pretreated with neuraminidase (NANAse) prior to co-cultivation with tumor cells. The normal macrophages, after neuraminidase treatment, no longer retained their ability to kill tumor cells. However, when macrophages from breast cancer patients were treated with NANAse, no difference was observed in the ability of untreated and NANAse treated macrophages to kill tumor cells.

  20. The interaction of Acanthamoeba castellanii cysts with macrophages and neutrophils.

    Science.gov (United States)

    Hurt, Michael; Proy, Vincent; Niederkorn, Jerry Y; Alizadeh, Hassan

    2003-06-01

    Acanthamoeba castellanii, a free-living amoeba, causes a sight-threatening form of keratitis. Even after extensive therapies, corneal damage can be severe, often requiring corneal transplantation to restore vision. However, A. castellanii cysts are not eliminated from the conjunctiva and stroma of humans and can excyst, resulting in infection of the corneal transplant. The aim of this study was to determine whether elements of the innate immune apparatus, neutrophils and macrophages, were capable of detecting and eliminating A. castellanii cysts and to examine the mechanism by which they kill the cysts. Results show that neither innate immune cell is attracted chemotactically to intact cysts, yet both were attracted to lysed cysts. Both macrophages and neutrophils were capable of killing significant numbers of cysts, yet neutrophils were 3-fold more efficient than macrophages. Activation of macrophages with lipopolysaccharide and interferon-gamma did not increase their cytolytic ability. Conditioned medium isolated from macrophages did not lyse the cysts; however, prevention of phagocytosis by cytochalasin D inhibited 100% of macrophage-mediated killing of the cysts. Conditioned medium from neutrophils did kill significant numbers of the cysts, and this killing was blocked by quercetin, a potent inhibitor of myeloperoxidase (MPO). These results indicate that neither macrophages nor neutrophils are chemoattracted to intact cysts, yet both are capable of killing the cysts. Macrophages killed the cysts by phagocytosis, whereas neutrophils killed cysts through the secretion of MPO.

  1. Anthrax lethal toxin-mediated killing of human and murine dendritic cells impairs the adaptive immune response.

    Directory of Open Access Journals (Sweden)

    Abdelkrim Alileche

    2005-10-01

    Full Text Available Many pathogens have acquired strategies to combat the immune response. Bacillus anthracis interferes with host defenses by releasing anthrax lethal toxin (LT, which inactivates mitogen-activated protein kinase pathways, rendering dendritic cells (DCs and T lymphocytes nonresponsive to immune stimulation. However, these cell types are considered resistant to killing by LT. Here we show that LT kills primary human DCs in vitro, and murine DCs in vitro and in vivo. Kinetics of LT-mediated killing of murine DCs, as well as cell death pathways induced, were dependent upon genetic background: LT triggered rapid necrosis in BALB/c-derived DCs, and slow apoptosis in C57BL/6-derived DCs. This is consistent with rapid and slow killing of LT-injected BALB/c and C57BL/6 mice, respectively. We present evidence that anthrax LT impairs adaptive immunity by specifically targeting DCs. This may represent an immune-evasion strategy of the bacterium, and contribute to anthrax disease progression. We also established that genetic background determines whether apoptosis or necrosis is induced by LT. Finally, killing of C57BL/6-derived DCs by LT mirrors that of human DCs, suggesting that C57BL/6 DCs represent a better model system for human anthrax than the prototypical BALB/c macrophages.

  2. Alveolar Macrophage Polarisation in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Saleh A. Almatroodi

    2014-01-01

    Full Text Available The role of alveolar macrophages in lung cancer is multifaceted and conflicting. Alveolar macrophage secretion of proinflammatory cytokines has been found to enhance antitumour functions, cytostasis (inhibition of tumour growth, and cytotoxicity (macrophage-mediated killing. In contrast, protumour functions of alveolar macrophages in lung cancer have also been indicated. Inhibition of antitumour function via secretion of the anti-inflammatory cytokine IL-10 as well as reduced secretion of proinflammatory cytokines and reduction of mannose receptor expression on alveolar macrophages may contribute to lung cancer progression and metastasis. Alveolar macrophages have also been found to contribute to angiogenesis and tumour growth via the secretion of IL-8 and VEGF. This paper reviews the evidence for a dual role of alveolar macrophages in lung cancer progression.

  3. Macrophage triggering by aggregated immunoglobulins. II. Comparison of IgE and IgG aggregates or immune complexes.

    Science.gov (United States)

    Pestel, J; Dessaint, J P; Joseph, M; Bazin, H; Capron, A

    1984-01-01

    Macrophages incubated with complexed or aggregated IgE released beta-glucuronidase (beta-G) within 30 min. In contrast in the presence of aggregated or complexed IgG, macrophages liberated equivalent amount of beta-G only after 6 h incubation. In addition the rapid macrophage stimulation induced by aggregated IgE was also followed by a faster 3H-glucosamine incorporation when compared to the delayed activation caused by aggregated IgG. However, macrophages stimulated either by IgG or by IgE oligomers produced the same percentage of plasminogen activator at 24 h. In contrast, while the interaction between macrophages and aggregated IgE was only followed by a peak of cyclic GMP and a beta-G release during the first 30 min of incubation, the interaction between macrophages and IgG oligomers was accompanied by a simultaneous increase of cyclic GMP and AMP nucleotides and by an absence of beta-G exocytosis. Moreover, the beta-G release induced by aggregated IgE was increased when macrophages were preincubated with aggregated IgG. This additive effect was not observed in the reverse situation. Finally macrophages activated by IgG oligomers were demonstrated to exert a cytotoxic effect on tumour cells and to kill schistosomula in the presence of a low level of complement. Taken together these results underline the peculiar ability of aggregated or complexed IgE to trigger rapidly the macrophage activation compared to aggregated IgG and can explain the important role of complexed IgE in some macrophage dependent cytotoxicity mechanisms (i.e. in parasitic diseases). PMID:6088135

  4. Plasma gelsolin improves lung host defense against pneumonia by enhancing macrophage NOS3 function.

    Science.gov (United States)

    Yang, Zhiping; Chiou, Terry Ting-Yu; Stossel, Thomas P; Kobzik, Lester

    2015-07-01

    Plasma gelsolin (pGSN) functions as part of the "extracellular actin-scavenging system," but its potential to improve host defense against infection has not been studied. In a mouse model of primary pneumococcal pneumonia, recombinant human pGSN (rhu-pGSN) caused enhanced bacterial clearance, reduced acute inflammation, and improved survival. In vitro, rhu-pGSN rapidly improved lung macrophage uptake and killing of bacteria (Streptococcus pneumoniae, Escherichia coli, and Francisella tularensis). pGSN triggers activating phosphorylation (Ser(1177)) of macrophage nitric oxide synthase type III (NOS3), an enzyme with important bactericidal functions in lung macrophages. rhu-pGSN failed to enhance bacterial killing by NOS3(-/-) macrophages in vitro or bacterial clearance in NOS3(-/-) mice in vivo. Prophylaxis with immunomodulators may be especially relevant for patients at risk for secondary bacterial pneumonia, e.g., after influenza. Treatment of mice with pGSN challenged with pneumococci on postinfluenza day 7 (the peak of enhanced susceptibility to secondary infection) caused a ∼15-fold improvement in bacterial clearance, reduced acute neutrophilic inflammation, and markedly improved survival, even without antibiotic therapy. pGSN is a potential immunomodulator for improving lung host defense against primary and secondary bacterial pneumonia. Copyright © 2015 the American Physiological Society.

  5. Irreducible Killing Tensors from Third Rank Killing-Yano Tensors

    OpenAIRE

    Popa, Florian Catalin; Tintareanu-Mircea, Ovidiu

    2006-01-01

    We investigate higher rank Killing-Yano tensors showing that third rank Killing-Yano tensors are not always trivial objects being possible to construct irreducible Killing tensors from them. We give as an example the Kimura IIC metric were from two rank Killing-Yano tensors we obtain a reducible Killing tensor and from third rank Killing-Yano tensors we obtain three Killing tensors, one reducible and two irreducible.

  6. Killing tensors on tori

    Science.gov (United States)

    Heil, Konstantin; Moroianu, Andrei; Semmelmann, Uwe

    2017-07-01

    We show that Killing tensors on conformally flat n-dimensional tori whose conformal factor only depends on one variable, are polynomials in the metric and in the Killing vector fields. In other words, every first integral of the geodesic flow polynomial in the momenta on the sphere bundle of such a torus is linear in the momenta.

  7. Effector mechanisms of the anti-cancer immune responses of macrophages in SR/CR mice.

    Science.gov (United States)

    Hicks, Amy M; Willingham, Mark C; Du, Wei; Pang, Changlee S; Old, Lloyd J; Cui, Zheng

    2006-10-31

    SR/CR (spontaneous regression/complete resistance) mice resist multiple types of cancer cells injected at numbers that are lethal to wild type (WT) mice. When the anti-tumor response was examined, leukocytes of the innate immune system, including neutrophils (PMN), macrophages and NK cells, infiltrated the tumor site for a multipronged killing response. Each cell type had independent killing activity against the cancer cells. A second aspect of this multipronged response was that cancer cells could be killed either via necrosis in vivo or via apoptosis by purified macrophages. Lymphoid cells displayed perforin (pfp) and granzymes (gzm) as effector molecules, but macrophages produced reactive oxygen species (ROS) and secreted serine proteases to kill the cancer cells. However, SR/CR macrophages did not use the well-studied tumoricidal mechanism of reactive nitrogen species (RNS) production. We previously demonstrated that macrophages tightly bound cancer cells in rosettes, and we show here that macrophages required contact with the target cells in order to unleash their cytotoxic mechanisms. Once SR/CR mice survived challenge with cancer cells, they produced antibodies that recognized the cancer cells. However, the antibodies were not required for killing by SR/CR macrophages through antibody-dependent cell-mediated cytotoxicity (ADCC) and did not enable wild type macrophages to kill target cells. In summary, purified SR/CR macrophages killed cancer cells in a non-ADCC manner via apoptosis induced by ROS and serine proteases.

  8. Expression of functions by normal sheep alveolar macrophages and their alteration by interaction with Mycoplasma ovipneumoniae.

    Science.gov (United States)

    Niang, M; Rosenbusch, R F; Lopez-Virella, J; Kaeberle, M L

    1997-10-31

    Normal sheep alveolar macrophages collected by bronchial lavage were exposed to live or heat-killed Mycoplasma ovipneumoniae organisms, and their capability to ingest Staphylococcus aureus and to elicit antibody-dependent cellular cytotoxicity against sensitized chicken red blood cells was tested. Controls consisted of non-infected macrophages in M199 medium. In addition, the effect of M. ovipneumoniae on expression of surface molecules on these sheep alveolar macrophages was determined. The percentage of S. aureus ingested by nontreated sheep alveolar macrophages was significantly higher than that of infected macrophages. Live mycoplasmas were more effective in suppressing the ingestion of S. aureus by these macrophages than killed mycoplasmas. Both live and killed mycoplasmas suppressed the cytolytic effect of the sheep alveolar macrophages to a similar degree. About 78% and 45% of the normal sheep alveolar macrophages had IgG and complement receptors, respectively. Infection of these macrophages with M. ovipneumoniae decreased significantly the expression of IgG receptors but had no effects on complement receptors. There were substantial increases in the expression of both MHC class I and class II by the mycoplasma-induced macrophages as compared with unstimulated macrophages. Live mycoplasmas were more effective in inducing expression of both classes than killed mycoplasmas. The results, taken together, suggest that M. ovipneumoniae induced alterations in macrophage activities and this may be a contributing factor in the pathogenesis of respiratory disease induced by the organism.

  9. Spermine oxidase is a regulator of macrophage host response to Helicobacter pylori: enhancement of antimicrobial nitric oxide generation by depletion of spermine.

    Science.gov (United States)

    Chaturvedi, Rupesh; Asim, Mohammad; Barry, Daniel P; Frye, Jeanetta W; Casero, Robert A; Wilson, Keith T

    2014-03-01

    The gastric pathogen Helicobacter pylori causes peptic ulcer disease and gastric cancer. We have reported that in H. pylori-activated macrophages, nitric oxide (NO) derived from inducible NO synthase (iNOS) can kill the bacterium, iNOS protein expression is dependent on uptake of its substrate L-arginine (L-Arg), the polyamine spermine can inhibit iNOS translation by inhibiting L-Arg uptake, and inhibition of polyamine synthesis enhances NO-mediated bacterial killing. Because spermine oxidase (SMO), which back-converts spermine to spermidine, is induced in macrophages by H. pylori, we determined its role in iNOS-dependent host defense. SMO shRNA knockdown in RAW 264.7 murine macrophages resulted in a marked decrease in H. pylori-stimulated iNOS protein, but not mRNA expression, and a 90% reduction in NO levels; NO production was also inhibited in primary murine peritoneal macrophages with SMO knockdown. There was an increase in spermine levels after H. pylori stimulation that rapidly decreased, while SMO knockdown caused a greater increase in spermine that was sustained. With SMO knockdown, L-Arg uptake and killing of H. pylori by macrophages was prevented. The overexpression of SMO by transfection of an expression plasmid prevented the H. pylori-stimulated increase in spermine levels, and led to increased L-Arg uptake, iNOS protein expression and NO production, and H. pylori killing. In two human monocytic cell lines, U937 and THP-1, overexpression of SMO caused a significant enhancement of NO production with H. pylori stimulation. By depleting spermine, SMO can abrogate the inhibitory effect of polyamines on innate immune responses to H. pylori by enhancing antimicrobial NO production.

  10. Role of macrophages in early host resistance to respiratory Acinetobacter baumannii infection.

    Directory of Open Access Journals (Sweden)

    Hongyu Qiu

    Full Text Available Acinetobacter baumannii is an emerging bacterial pathogen that causes nosocomial pneumonia and other infections. Although it is recognized as an increasing threat to immunocompromised patients, the mechanism of host defense against A. baumannii infection remains poorly understood. In this study, we examined the potential role of macrophages in host defense against A. baumannii infection using in vitro macrophage culture and the mouse model of intranasal (i.n. infection. Large numbers of A. baumannii were taken up by alveolar macrophages in vivo as early as 4 h after i.n. inoculation. By 24 h, the infection induced significant recruitment and activation (enhanced expression of CD80, CD86 and MHC-II of macrophages into bronchoalveolar spaces. In vitro cell culture studies showed that A. baumannii were phagocytosed by J774A.1 (J774 macrophage-like cells within 10 minutes of co-incubation, and this uptake was microfilament- and microtubule-dependent. Moreover, the viability of phagocytosed bacteria dropped significantly between 24 and 48 h after co-incubation. Infection of J774 cells by A. baumannii resulted in the production of large amounts of proinflammatory cytokines and chemokines, and moderate amounts of nitric oxide (NO. Prior treatment of J774 cells with NO inhibitors significantly suppressed their bactericidal efficacy (P<0.05. Most importantly, in vivo depletion of alveolar macrophages significantly enhanced the susceptibility of mice to i.n. A. baumannii challenge (P<0.01. These results indicate that macrophages may play an important role in early host defense against A. baumannii infection through the efficient phagocytosis and killing of A. baumannii to limit initial pathogen replication and the secretion of proinflammatory cytokines and chemokines for the rapid recruitment of other innate immune cells such as neutrophils.

  11. Theriocide: Naming Animal Killing

    Directory of Open Access Journals (Sweden)

    Piers Beirne

    2014-08-01

    Full Text Available In this essay I recommend ‘theriocide’ as the name for those diverse human actions that cause the deaths of animals. Like the killing of one human by another, theriocide may be socially acceptable or unacceptable, legal or illegal. It may be intentional or unintentional and may involve active maltreatment or passive neglect. Theriocide may occur one-on-one, in small groups or in large-scale social institutions. The numerous and sometimes intersecting sites of theriocide include intensive rearing regimes; hunting and fishing; trafficking; vivisection; militarism; pollution; and human-induced climate change. If the killing of animals by humans is as harmful to them as homicide is to humans, then the proper naming of such deaths offers a remedy, however small, to the extensive privileging of human lives over those of other animals. Inevitably, the essay leads to a shocking question: Is theriocide murder?

  12. Minimal killing unit of the mitochondrial targeting domain of Noxa.

    Science.gov (United States)

    Kim, Ji-Young; Han, Ji Hye; Moon, Ae-Ran; Park, Jung Hee; Chang, Jeong Hwan; Bae, Jeehyeon; Kim, Tae-Hyoung

    2013-08-01

    Noxa is a key player in p53-induced cell death via mitochondrial dysfunction, and the mitochondrial-targeting domain (MTD) of Noxa is responsible for the translocation of Noxa to mitochondria and for the induction of necrotic cell death. The purpose of this study was to define the minimal killing unit of MTD in vitro and in vivo. It was found that the peptides R8:MTD(10), R8:MTD(9), and R8:MTD(8) can kill various human tumor cells (HCT116, HeLa, MCF-7, BJAB), but that R8:MTD(7) abolishes the killing activity of MTD mainly because of the loss of mitochondrial targeting activity. We find it interesting that R8:MTD(8) was found to kill tumor cells but showed a limited killing activity on normal peritoneal macrophages. Furthermore, R8:MTD(10), R8:MTD(9), and R8:MTD(8) limitedly suppressed tumor growth when injected i.v. into BalB/C mice bearing CT26 cell-derived tumors. These results indicate that MTD(8) is the minimal killing unit of MTD.

  13. Downregulation of vimentin in macrophages infected with live Mycobacterium tuberculosis is mediated by Reactive Oxygen Species.

    Science.gov (United States)

    Mahesh, P P; Retnakumar, R J; Mundayoor, Sathish

    2016-02-15

    Mycobacterium tuberculosis persists primarily in macrophages after infection and manipulates the host defence pathways in its favour. 2D gel electrophoresis results showed that vimentin, an intermediate filament protein, is downregulated in macrophages infected with live Mycobacterium tuberculosis H37Rv when compared to macrophages infected with heat- killed H37Rv. The downregulation was confirmed by Western blot and quantitative RT-PCR. Besides, the expression of vimentin in avirulent strain, Mycobacterium tuberculosis H37Ra- infected macrophages was similar to the expression in heat-killed H37Rv- infected macrophages. Increased expression of vimentin in H2O2- treated live H37Rv-infected macrophages and decreased expression of vimentin both in NAC and DPI- treated heat-killed H37Rv-infected macrophages showed that vimentin expression is positively regulated by ROS. Ectopic expression of ESAT-6 in macrophages decreased both the level of ROS and the expression of vimentin which implies that Mycobacterium tuberculosis-mediated downregulation of vimentin is at least in part due to the downregulation of ROS by the pathogen. Interestingly, the incubation of macrophages with anti-vimentin antibody increased the ROS production and decreased the survival of H37Rv. In addition, we also showed that the pattern of phosphorylation of vimentin in macrophages by PKA/PKC is different from monocytes, emphasizing a role for vimentin phosphorylation in macrophage differentiation.

  14. Aging Enhances Production of Reactive Oxygen Species and Bactericidal Activity in Peritoneal Macrophages by Up-Regulating Classical Activation Pathways

    Science.gov (United States)

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

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-07

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

  16. Posttranscriptional control of NLRP3 inflammasome activation in colonic macrophages.

    Science.gov (United States)

    Filardy, A A; He, J; Bennink, J; Yewdell, J; Kelsall, B L

    2016-07-01

    Colonic macrophages (cMPs) are important for intestinal homeostasis as they kill microbes and yet produce regulatory cytokines. Activity of the NLRP3 (nucleotide-binding leucine-rich repeat-containing pyrin receptor 3) inflammasome, a major sensor of stress and microorganisms that results in pro-inflammatory cytokine production and cell death, must be tightly controlled in the intestine. We demonstrate that resident cMPs are hyporesponsive to NLRP3 inflammasome activation owing to a remarkable level of posttranscriptional control of NLRP3 and pro-interleukin-1β (proIL-1β) protein expression, which was also seen for tumor necrosis factor-α and IL-6, but lost during experimental colitis. Resident cMPs rapidly degraded NLRP3 and proIL-1β proteins by the ubiquitin/proteasome system. Finally, blocking IL-10R-signaling in vivo enhanced NLRP3 and proIL-1β protein but not mRNA levels in resident cMPs, implicating a role for IL-10 in environmental conditioning of cMPs. These data are the first to show dramatic posttranscriptional control of inflammatory cytokine production by a relevant tissue-derived macrophage population and proteasomal degradation of proIL-1β and NLRP3 as a mechanism to control inflammasome activation, findings which have broad implications for our understanding of intestinal and systemic inflammatory diseases.

  17. Analysing the Wrongness of Killing

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2014-01-01

    This article provides an in-depth analysis of the wrongness of killing by comparing different versions of three influential views: the traditional view that killing is always wrong; the liberal view that killing is wrong if and only if the victim does not want to be killed; and Don Marquis‟ future...... of value account of the wrongness of killing. In particular, I illustrate the advantages that a basic version of the liberal view and a basic version of the future of value account have over competing alternatives. Still, ultimately none of the views analysed here are satisfactory; but the different...... reasons why those competing views fail provide important insights into the ethics of killing....

  18. Killing Spinors -- Beyond Supergravity

    CERN Document Server

    Palomo-Lozano, Alberto

    2012-01-01

    This is a doctoral thesis on the application of techniques originally developed in the programme of characterisation of supersymmetric solutions to Supergravity theories, to finding alternative backgrounds. We start by discussing the concept of a Killing spinor, and how these are paramount to the process of classifying of these aforementioned supersymmetric solutions. Moreover, these geometric objects also have applications when considered in different scenarios (the 'beyond' in the title). In particular, techniques based on a parallelising rule for a spinorial field can be used for obtaining solutions to Einstein-Maxwell-De Sitter theories, as well as a (partial) classification of Lorentzian Einstein-Weyl manifolds, a problem of geometrical interest. The annexe contain an introduction and summary in Spanish language. The appendices discuss the tensorial and spinorial conventions employed, some relevant geometrical information on the scalar manifolds for the matter contents of interest, as well as for the nul...

  19. How to kill creativity.

    Science.gov (United States)

    Amabile, T M

    1998-01-01

    In today's knowledge economy, creativity is more important than ever. But many companies unwittingly employ managerial practices that kill it. How? By crushing their employees' intrinsic motivation--the strong internal desire to do something based on interests and passions. Managers don't kill creativity on purpose. Yet in the pursuit of productivity, efficiency, and control--all worthy business imperatives--they undermine creativity. It doesn't have to be that way, says Teresa Amabile. Business imperatives can comfortably coexist with creativity. But managers will have to change their thinking first. Specifically, managers will need to understand that creativity has three parts: expertise, the ability to think flexibly and imaginatively, and motivation. Managers can influence the first two, but doing so is costly and slow. It would be far more effective to increase employees' intrinsic motivation. To that end, managers have five levers to pull: the amount of challenge they give employees, the degree of freedom they grant around process, the way they design work groups, the level of encouragement they give, and the nature of organizational support. Take challenge as an example. Intrinsic motivation is high when employees feel challenged but not overwhelmed by their work. The task for managers, therefore, becomes matching people to the right assignments. Consider also freedom. Intrinsic motivation--and thus creativity--soars when managers let people decide how to achieve goals, not what goals to achieve. Managers can make a difference when it comes to employee creativity. The result can be truly innovative companies in which creativity doesn't just survive but actually thrives.

  20. Killing Symmetry on Finsler Manifold

    CERN Document Server

    Ootsuka, Takayoshi; Ishida, Muneyuki

    2016-01-01

    Killing vector fields $K$ are defined on Finsler manifold. The Killing symmetry is reformulated simply as $\\delta K^\\flat =0$ by using the Killing non-linear 1-form $K^\\flat$ and the spray operator $\\delta$ with the Finsler non-linear connection. $K^\\flat$ is related to the generalization of Killing tensors on Finsler manifold, and the condition $\\delta K^\\flat =0$ gives an analytical method of finding higher derivative conserved quantities, which may be called hidden conserved quantities. We show two examples: the Carter constant on Kerr spacetime and the Runge-Lentz vectors in Newtonian gravity.

  1. Pseudomonas aeruginosa PAO1 Kills Caenorhabditis elegans by Cyanide Poisoning

    OpenAIRE

    Gallagher, Larry A.; Manoil, Colin

    2001-01-01

    In this report we describe experiments to investigate a simple virulence model in which Pseudomonas aeruginosa PAO1 rapidly paralyzes and kills the nematode Caenorhabditis elegans. Our results imply that hydrogen cyanide is the sole or primary toxic factor produced by P. aeruginosa that is responsible for killing of the nematode. Four lines of evidence support this conclusion. First, a transposon insertion mutation in a gene encoding a subunit of hydrogen cyanide synthase (hcnC) eliminated ne...

  2. Soluble factor from murine bladder tumor-2 cell elevates nitric oxide production in macrophages and enhances the taxol-mediated macrophage cytotoxicity on tumor cells.

    Science.gov (United States)

    Choi, Suck-Chei; Oh, Hyun-Mee; Park, Jae-Sung; Han, Weon-Cheol; Yoon, Kwon-Ha; Kim, Tae-Hyeon; Yun, Ki-Jung; Kim, Eun-Cheol; Nah, Yong-Ho; Cha, Young-Nam; Chung, Hun-Taeg; Jun, Chang-Duk

    2003-01-01

    The therapeutic mechanism of taxol is believed to reside primarily in its ability to stabilize microtubules and prevent cell progression through mitosis. Taxol also can activate macrophage-mediated antitumor mechanism through a nitric oxide (NO)-dependent pathway. To address whether any mechanisms account for superficial urinary bladder tumor cell killing, we evaluated the effects of taxol on the growth and viability of murine bladder tumor-2 (MBT-2) cells in vitro, both in the absence and presence of murine macrophages. In addition, we evaluated whether a soluble factor generated from MBT-2 cells could modulate the antitumor activity of the taxol-activated macrophages. Although taxol inhibited the growth of MBT-2 cells, it did not kill the tumor cells. However, preincubation of macrophages with taxol significantly decreased the viability of MBT-2 cells. Secretion of NO correlated with MBT-2 cell killing, and the activated macrophages failed to kill tumor cell targets in the presence of NG-monomethyl-L-arginine, a competitive inhibitor of NO synthase. By the co-culture of macrophages and MBT-2 cells, untreated macrophages also released modest amount of NO and this was synergistically augmented by the treatment with taxol, indicating that MBT-2 tumor cells released some unknown factor that activated the macrophages and enhanced NO production. We named this factor the tumor-derived macrophage activating factor (TMAF). The TMAF-mediated activation of macrophages to enhance the NO production was not blocked by treatment of macrophages with oxidized low-density lipoprotein (Ox-LDL), implying that the scavenger receptor of macrophages is not involved. Sodium nitroprusside (SNP), an NO donor given to the MBT-2 cells, increased the activities of c-Jun N-terminal kinase and caspase-3 in MBT-2 cells and associated with nucleosomal fragmentation or apoptosis, whereas taxol had no direct effect on these parameters. Collectively, our results strongly suggest that taxol kills

  3. INTRACELLULAR Leishmania amazonensis KILLING INDUCED BY THE GUANINE NUCLEOSIDE 8-BROMOGUANOSINE

    Directory of Open Access Journals (Sweden)

    GIORGIO Selma

    1998-01-01

    Full Text Available In this study we investigated the effect of 8-Bromoguanosine, an immunostimulatory compound, on the cytotoxicity of macrophages against Leishmania amazonensis in an in vitro system. The results showed that macrophages treated with 8-Bromoguanosine before or after infection are capable to reduce parasite load, as monitored by the number of amastigotes per macrophage and the percentage of infected cells (i.e. phagocytic index. Since 8-Bromoguanosine was not directly toxic to the promastigotes, it was concluded that the ribonucleoside induced macrophage activation. Presumably, 8-Bromoguanosine primed macrophages by inducing interferon alpha and beta which ultimately led to L. amazonensis amastigote killing. The results suggest that guanine ribonucleosides may be useful to treat infections with intracellular pathogens.

  4. How mouse macrophages sense what is going on

    Directory of Open Access Journals (Sweden)

    Klaus eLey

    2016-06-01

    Full Text Available Macrophages are central to both innate and adaptive immunity. With few exceptions, macrophages are the first cells that sense trouble and respond to disturbances in almost all tissues and organs. They sense their environment, inhibit or kill pathogens, take up apoptotic and necrotic cells, heal tissue damage, and present antigens to T cells. Although the origins [yolk sac versus monocyte-derived] and phenotypes [functions, gene expression profiles, surface markers] of macrophages vary between tissues, they have many receptors in common that are specific to one or a few molecular species. Here, we review the expression and function of almost 200 key macrophage receptors that help the macrophages sense what is going on, including pathogen-derived molecules, the state of the surrounding tissue cells, apoptotic and necrotic cell death, antibodies and immune complexes, altered self molecules, extracellular matrix components, and cytokines including chemokines.

  5. A broken krebs cycle in macrophages

    National Research Council Canada - National Science Library

    O'Neill, Luke A J

    2015-01-01

    ... and an intact Krebs cycle as hallmark metabolic features. It is still not fully understood why these differences occur, or indeed how the metabolic rewiring is regulated. Rapidity of response might be an important reason for the metabolic differences (Ganeshan and Chawla, 2014 ). In M1 macrophages, glycolysis would allow for rapid ATP ...

  6. Persistence of avian oncoviruses in chicken macrophages.

    Science.gov (United States)

    Gazzolo, L; Moscovici, C; Moscovici, M G

    1979-01-01

    Inoculation of avian oncoviruses into 1- to 2-month old chickens led to a rapid production of antiviral humoral antibodies. Under these conditions it was found that avian leukosis viruses are sequestered in macrophages of peripheral blood, in which they can persist for a long period of time (up to about 3 years). In contrast, avian sarcoma viruses were never found in macrophages from chickens during the progression of sarcomas or after regression of the tumors. PMID:217827

  7. Phantom metrics with Killing spinors

    Directory of Open Access Journals (Sweden)

    W.A. Sabra

    2015-11-01

    Full Text Available We study metric solutions of Einstein–anti-Maxwell theory admitting Killing spinors. The analogue of the IWP metric which admits a space-like Killing vector is found and is expressed in terms of a complex function satisfying the wave equation in flat (2+1-dimensional space–time. As examples, electric and magnetic Kasner spaces are constructed by allowing the solution to depend only on the time coordinate. Euclidean solutions are also presented.

  8. Platelets Mediate Host Defense against Staphylococcus aureus through Direct Bactericidal Activity and by Enhancing Macrophage Activities.

    Science.gov (United States)

    Ali, Ramadan A; Wuescher, Leah M; Dona, Keith R; Worth, Randall G

    2017-01-01

    Platelets are the chief effector cells in hemostasis. However, recent evidence suggests they have multiple roles in host defense against infection. Reports by us and others showed that platelets functionally contribute to protection against Staphylococcus aureus infection. In the current study, the capacity of mouse platelets to participate in host defense against S. aureus infection was determined by assessing two possibilities. First, we determined the ability of platelets to kill S. aureus directly; and, second, we tested the possibility that platelets enhance macrophage phagocytosis and intracellular killing of S. aureus In this study we report evidence in support of both mechanisms. Platelets effectively killed two different strains of S. aureus. A clinical isolate of methicillin-resistant S. aureus was killed by platelets (>40% killing in 2 h) in a thrombin-dependent manner whereas a methicillin-sensitive strain was killed to equal extent but did not require thrombin. Interestingly, thrombin-stimulated platelets also significantly enhanced peritoneal macrophage phagocytosis of both methicillin-resistant S. aureus and methicillin-sensitive S. aureus by >70%, and restricted intracellular growth by >40%. Enhancement of macrophage anti-S. aureus activities is independent of contact with platelets but is mediated through releasable products, namely IL-1β. These data confirm our hypothesis that platelets participate in host defense against S. aureus both through direct killing of S. aureus and enhancing the antimicrobial function of macrophages in protection against S. aureus infection. Copyright © 2016 by The American Association of Immunologists, Inc.

  9. Vitamin D and the human antimicrobial peptide LL-37 enhance group a streptococcus resistance to killing by human cells.

    Science.gov (United States)

    Love, John F; Tran-Winkler, Hien J; Wessels, Michael R

    2012-10-23

    The CsrRS two-component regulatory system of group A Streptococcus (GAS; Streptococcus pyogenes) responds to subinhibitory concentrations of the human antimicrobial peptide LL-37. LL-37 signaling through CsrRS results in upregulation of genes that direct synthesis of virulence factors, including the hyaluronic acid capsule and streptolysin O (SLO). Here, we demonstrate that a consequence of this response is augmented GAS resistance to killing by human oropharyngeal keratinocytes, neutrophils, and macrophages. LL-37-induced upregulation of SLO and hyaluronic acid capsule significantly reduced internalization of GAS by keratinocytes and phagocytic killing by neutrophils and macrophages. Because vitamin D induces LL-37 production by macrophages, we tested its effect on macrophage killing of GAS. In contrast to the reported enhancement of macrophage function in relation to other pathogens, treatment of macrophages with 1α,25-dihydroxy-vitamin D3 paradoxically reduced the ability of macrophages to control GAS infection. These observations demonstrate that LL-37 signals through CsrRS to induce a virulence phenotype in GAS characterized by heightened resistance to ingestion and killing by both epithelial cells and phagocytes. By inducing LL-37 production in macrophages, vitamin D may contribute to this paradoxical exacerbation of GAS infection. IMPORTANCE It remains poorly understood why group A Streptococcus (GAS) causes asymptomatic colonization or localized throat inflammation in most individuals but rarely progresses to invasive infection. The human antimicrobial peptide LL-37, which is produced as part of the innate immune response to GAS infection, signals through the GAS CsrRS two-component regulatory system to upregulate expression of multiple virulence factors. This study reports that two CsrRS-regulated GAS virulence factors-streptolysin O and the hyaluronic acid capsule-are critical in LL-37-induced resistance of GAS to killing by human throat epithelial cells

  10. HIV-1 assembly in macrophages

    Directory of Open Access Journals (Sweden)

    Benaroch Philippe

    2010-04-01

    Full Text Available Abstract The molecular mechanisms involved in the assembly of newly synthesized Human Immunodeficiency Virus (HIV particles are poorly understood. Most of the work on HIV-1 assembly has been performed in T cells in which viral particle budding and assembly take place at the plasma membrane. In contrast, few studies have been performed on macrophages, the other major target of HIV-1. Infected macrophages represent a viral reservoir and probably play a key role in HIV-1 physiopathology. Indeed macrophages retain infectious particles for long periods of time, keeping them protected from anti-viral immune response or drug treatments. Here, we present an overview of what is known about HIV-1 assembly in macrophages as compared to T lymphocytes or cell lines. Early electron microscopy studies suggested that viral assembly takes place at the limiting membrane of an intracellular compartment in macrophages and not at the plasma membrane as in T cells. This was first considered as a late endosomal compartment in which viral budding seems to be similar to the process of vesicle release into multi-vesicular bodies. This view was notably supported by a large body of evidence involving the ESCRT (Endosomal Sorting Complex Required for Transport machinery in HIV-1 budding, the observation of viral budding profiles in such compartments by immuno-electron microscopy, and the presence of late endosomal markers associated with macrophage-derived virions. However, this model needs to be revisited as recent data indicate that the viral compartment has a neutral pH and can be connected to the plasma membrane via very thin micro-channels. To date, the exact nature and biogenesis of the HIV assembly compartment in macrophages remains elusive. Many cellular proteins potentially involved in the late phases of HIV-1 cycle have been identified; and, recently, the list has grown rapidly with the publication of four independent genome-wide screens. However, their respective

  11. Mycobacterium tuberculosis exploits the PPM1A signaling pathway to block host macrophage apoptosis

    Science.gov (United States)

    Schaaf, Kaitlyn; Smith, Samuel R.; Duverger, Alexandra; Wagner, Frederic; Wolschendorf, Frank; Westfall, Andrew O.; Kutsch, Olaf; Sun, Jim

    2017-01-01

    The ability to suppress host macrophage apoptosis is essential for M. tuberculosis (Mtb) to replicate intracellularly while protecting it from antibiotic treatment. We recently described that Mtb infection upregulated expression of the host phosphatase PPM1A, which impairs the antibacterial response of macrophages. Here we establish PPM1A as a checkpoint target used by Mtb to suppress macrophage apoptosis. Overproduction of PPM1A suppressed apoptosis of Mtb-infected macrophages by a mechanism that involves inactivation of the c-Jun N-terminal kinase (JNK). Targeted depletion of PPM1A by shRNA or inhibition of PPM1A activity by sanguinarine restored JNK activation, resulting in increased apoptosis of Mtb-infected macrophages. We also demonstrate that activation of JNK by subtoxic concentrations of anisomycin induced selective apoptotic killing of Mtb-infected human macrophages, which was completely blocked in the presence of a specific JNK inhibitor. Finally, selective killing of Mtb-infected macrophages and subsequent bacterial release enabled rifampicin to effectively kill Mtb at concentrations that were insufficient to act against intracellular Mtb, providing proof of principle for the efficacy of a “release and kill” strategy. Taken together, these findings suggest that drug-induced selective apoptosis of Mtb-infected macrophages is achievable. PMID:28176854

  12. Dynamics of Salmonella infection of macrophages at the single cell level.

    Science.gov (United States)

    Gog, Julia R; Murcia, Alicia; Osterman, Natan; Restif, Olivier; McKinley, Trevelyan J; Sheppard, Mark; Achouri, Sarra; Wei, Bin; Mastroeni, Pietro; Wood, James L N; Maskell, Duncan J; Cicuta, Pietro; Bryant, Clare E

    2012-10-07

    Salmonella enterica causes a range of diseases. Salmonellae are intracellular parasites of macrophages, and the control of bacteria within these cells is critical to surviving an infection. The dynamics of the bacteria invading, surviving, proliferating in and killing macrophages are central to disease pathogenesis. Fundamentally important parameters, however, such as the cellular infection rate, have not previously been calculated. We used two independent approaches to calculate the macrophage infection rate: mathematical modelling of Salmonella infection experiments, and analysis of real-time video microscopy of infection events. Cells repeatedly encounter salmonellae, with the bacteria often remain associated with the macrophage for more than ten seconds. Once Salmonella encounters a macrophage, the probability of that bacterium infecting the cell is remarkably low: less than 5%. The macrophage population is heterogeneous in terms of its susceptibility to the first infection event. Once infected, a macrophage can undergo further infection events, but these reinfection events occur at a lower rate than that of the primary infection.

  13. Killing, letting die and euthanasia.

    Science.gov (United States)

    Husak, D N

    1979-12-01

    Medical ethicists debate whether or not the moral assessment of cases of euthanasia should depend on whether the patient is 'killed' or 'allowed to die'. The usual presupposition is that a clear distinction between killing and letting die can be drawn so that this substantive question is not begged. I contend that the categorisation of cases of instances of killing rather than as instances of letting die depends in part on a prior moral assessment of the case. Hence is it trivially rather than substantively true that the distinction has moral significance. But even if a morally neutral (ie non-question begging) distinction could be drawn, its application to the euthanasia controversy is problematic. I illustrate the difficulties of employing this distinction to reach moral conclusions by critically discussing Philippa Foot's recent treatment of euthanasia. I conclude that even if an act of euthanasia is an instance of killing, and there exists a prima facie moral duty not to kill, and no more stringent duty overrides this duty, one still cannot determine such an act to be morally impermissible.

  14. Hemophagocytic macrophages harbor Salmonella enterica during persistent infection.

    Directory of Open Access Journals (Sweden)

    Rebecca N Nix

    2007-12-01

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

  15. Legionella pneumophila Strain 130b Evades Macrophage Cell Death Independent of the Effector SidF in the Absence of Flagellin

    Science.gov (United States)

    Speir, Mary; Vogrin, Adam; Seidi, Azadeh; Abraham, Gilu; Hunot, Stéphane; Han, Qingqing; Dorn, Gerald W.; Masters, Seth L.; Flavell, Richard A.; Vince, James E.; Naderer, Thomas

    2017-01-01

    The human pathogen Legionella pneumophila must evade host cell death signaling to enable replication in lung macrophages and to cause disease. After bacterial growth, however, L. pneumophila is thought to induce apoptosis during egress from macrophages. The bacterial effector protein, SidF, has been shown to control host cell survival and death by inhibiting pro-apoptotic BNIP3 and BCL-RAMBO signaling. Using live-cell imaging to follow the L. pneumophila-macrophage interaction, we now demonstrate that L. pneumophila evades host cell apoptosis independent of SidF. In the absence of SidF, L. pneumophila was able to replicate, cause loss of mitochondria membrane potential, kill macrophages, and establish infections in lungs of mice. Consistent with this, deletion of BNIP3 and BCL-RAMBO did not affect intracellular L. pneumophila replication, macrophage death rates, and in vivo bacterial virulence. Abrogating mitochondrial cell death by genetic deletion of the effectors of intrinsic apoptosis, BAX, and BAK, or the regulator of mitochondrial permeability transition pore formation, cyclophilin-D, did not affect bacterial growth or the initial killing of macrophages. Loss of BAX and BAK only marginally limited the ability of L. pneumophila to efficiently kill all macrophages over extended periods. L. pneumophila induced killing of macrophages was delayed in the absence of capsase-11 mediated pyroptosis. Together, our data demonstrate that L. pneumophila evades host cell death responses independently of SidF during replication and can induce pyroptosis to kill macrophages in a timely manner. PMID:28261564

  16. Self-renewal of pulmonary alveolar macrophages: evidence from radiation chimera studies

    Energy Technology Data Exchange (ETDEWEB)

    Tarling, J.D.; Lin, H.S.; Hsu, S.

    1987-11-01

    Radiation-induced chimeric mice were used to study the origin of pulmonary alveolar macrophages. Unlike in other studies, these radiation chimeras were prepared by using a special fractionated irradiation regimen to minimize the killing of alveolar macrophage colony-forming cells, putative local stem cells. For this study CBA mice with or without T6 chromosome marker were used. Under this experimental condition, the majority of alveolar macrophages in mitosis are of host origin even after 45 weeks. These data suggest that alveolar macrophages are a self-renewing population under normal steady-state conditions.

  17. Tumoricidal activation of murine resident peritoneal macrophages on pancreatic carcinoma by interleukin-2 and monoclonal antibodies

    Institute of Scientific and Technical Information of China (English)

    Qi Kui Chen; Shi Zhen Yuan; Zhi Yong Zeng; Zhi Qing Huang

    2000-01-01

    @@INTRODUCTION Macrophages play an important role in tumor lysis and growth inhibition. They can be activated to a tumoricidal state by a variety of agents such as IFNr, TNFa or IL2. The killing machanisms of activated macrophages have been extensively investigated[1,2]. Recently, it has been proved that antibody dependent cellular cytotoxicity (ADCC) is one of the potent arms to lyse tumor cells resistant to cytotoxic macrophages,and that the antitumorous effect of a macrophage activator is significantly augmented by the combined use of mAbs capable of inducing ADCC to tumor cells[3].

  18. Cellular internalization and cytotoxicity of the antimicrobial proline-rich peptide Bac7(1-35) in monocytes/macrophages, and its activity against phagocytosed Salmonella typhimurium.

    Science.gov (United States)

    Pelillo, Chiara; Benincasa, Monica; Scocchi, Marco; Gennaro, Renato; Tossi, Alessandro; Pacor, Sabrina

    2014-04-01

    Bac7(1-35) is an active fragment of the bovine cathelicidin antimicrobial peptide Bac7, which selectively inactivates Gram-negative bacteria both in vitro and in mice infected with Salmonella typhimurium. It has a non-lytic mechanism of action, is rapidly internalized by susceptible bacteria and mammalian cells and likely acts by binding to internal targets. In this study we show that Bac7(1-35) accumulates selectively within primed macrophages with respect to resting monocytes. Confocal microscopy analysis showed that the peptide mainly distributes in the cytoplasm and perinuclear region of macrophages within 3 hours of incubation, without affecting cell viability. Cytotoxicity studies showed that the peptide does not induce necrotic or apoptotic damage up to concentrations 50-100-fold higher than minimal inhibitory concentrations (MIC). Moreover, Bac7(1-35) did not affect the ability of macrophages to engulf S. typhimurium, a species that may proliferate within this cell type. Conversely, when added to macrophages after phagocytosis, Bac7(1-35) caused a significant reduction in the number of recovered bacteria, indicating that it can kill the engulfed microorganisms directly and/or indirectly, via activation of the defense response of the cells.

  19. The Many Alternative Faces of Macrophage Activation.

    Directory of Open Access Journals (Sweden)

    David A. Hume

    2015-07-01

    Full Text Available 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. In large gene expression datasets from multiple cells and tissues, it is possible to identify sets of genes that are co-regulated with the transcription factors that regulate them. In macrophages, they include lineage-specific genes, interferon-responsive genes, early inflammatory genes, and those associated with endocytosis. 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 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 (LPS. This response is reviewed herein. The network architecture is conserved across species, but many of the target genes 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 data and publication deluge related to macrophage activation requires the development of new analytical tools, and ways of presenting information in an

  20. To Kill For An Image

    DEFF Research Database (Denmark)

    Fausing, Bent

    Images can provide both an overview and insight, but also the opposite. This ambivalence has become an even bigger part of the nature of the image, of what is an Image? Today we kill for an image, seen from afar on a screen and captured by a drone. The time also asks: Should it be big data...

  1. "The Killing Fields" of Innovation

    DEFF Research Database (Denmark)

    Ingerslev, Karen

    2014-01-01

    This paper points to seemingly contradicted processes of framing innovation, idea generation and killing ideas. It reports from a yearlong innovation project, where health care professionals explored problems and tested ideas for solutions, regarding a future downsizing of the case hospital...

  2. Human Neutrophils Kill Bacillus anthracis.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available Bacillus anthracis spores cause natural infections and are used as biological weapons. Inhalation infection with B. anthracis, the etiological agent of anthrax, is almost always lethal, yet cutaneous infections usually remain localized and resolve spontaneously. Neutrophils are typically recruited to cutaneous but seldom to other forms of anthrax infections, raising the possibility that neutrophils kill B. anthracis. In this study we infected human neutrophils with either spores or vegetative bacteria of a wild-type strain, or strains, expressing only one of the two major virulence factors. The human neutrophils engulfed B. anthracis spores, which germinated intracellularly and were then efficiently killed. Interestingly, neutrophil killing was independent of reactive oxygen species production. We fractionated a human neutrophil granule extract by high-performance liquid chromatography and identified alpha-defensins as the component responsible for B. anthracis killing. These data suggest that the timely recruitment of neutrophils can control cutaneous infections and possibly other forms of B. anthracis infections, and that alpha-defensins play an important role in the potent anti-B. anthracis activity of neutrophils.

  3. Human neutrophils kill Bacillus anthracis.

    Directory of Open Access Journals (Sweden)

    Anne Mayer-Scholl

    2005-11-01

    Full Text Available Bacillus anthracis spores cause natural infections and are used as biological weapons. Inhalation infection with B. anthracis, the etiological agent of anthrax, is almost always lethal, yet cutaneous infections usually remain localized and resolve spontaneously. Neutrophils are typically recruited to cutaneous but seldom to other forms of anthrax infections, raising the possibility that neutrophils kill B. anthracis. In this study we infected human neutrophils with either spores or vegetative bacteria of a wild-type strain, or strains, expressing only one of the two major virulence factors. The human neutrophils engulfed B. anthracis spores, which germinated intracellularly and were then efficiently killed. Interestingly, neutrophil killing was independent of reactive oxygen species production. We fractionated a human neutrophil granule extract by high-performance liquid chromatography and identified alpha-defensins as the component responsible for B. anthracis killing. These data suggest that the timely recruitment of neutrophils can control cutaneous infections and possibly other forms of B. anthracis infections, and that alpha-defensins play an important role in the potent anti-B. anthracis activity of neutrophils.

  4. Human neutrophils kill Bacillus anthracis.

    Science.gov (United States)

    Mayer-Scholl, Anne; Hurwitz, Robert; Brinkmann, Volker; Schmid, Monika; Jungblut, Peter; Weinrauch, Yvette; Zychlinsky, Arturo

    2005-11-01

    Bacillus anthracis spores cause natural infections and are used as biological weapons. Inhalation infection with B. anthracis, the etiological agent of anthrax, is almost always lethal, yet cutaneous infections usually remain localized and resolve spontaneously. Neutrophils are typically recruited to cutaneous but seldom to other forms of anthrax infections, raising the possibility that neutrophils kill B. anthracis. In this study we infected human neutrophils with either spores or vegetative bacteria of a wild-type strain, or strains, expressing only one of the two major virulence factors. The human neutrophils engulfed B. anthracis spores, which germinated intracellularly and were then efficiently killed. Interestingly, neutrophil killing was independent of reactive oxygen species production. We fractionated a human neutrophil granule extract by high-performance liquid chromatography and identified alpha-defensins as the component responsible for B. anthracis killing. These data suggest that the timely recruitment of neutrophils can control cutaneous infections and possibly other forms of B. anthracis infections, and that alpha-defensins play an important role in the potent anti-B. anthracis activity of neutrophils.

  5. O-glycosylation in cell wall proteins in Scedosporium prolificans is critical for phagocytosis and inflammatory cytokines production by macrophages.

    Directory of Open Access Journals (Sweden)

    Mariana I D S Xisto

    Full Text Available In this study, we analyze the importance of O-linked oligosaccharides present in peptidorhamnomannan (PRM from the cell wall of the fungus Scedosporium prolificans for recognition and phagocytosis of conidia by macrophages. Adding PRM led to a dose-dependent inhibition of conidia phagocytosis, whereas de-O-glycosylated PRM did not show any effect. PRM induced the release of macrophage-derived antimicrobial compounds. However, O-linked oligosaccharides do not appear to be required for such induction. The effect of PRM on conidia-induced macrophage killing was examined using latex beads coated with PRM or de-O-glycosylated PRM. A decrease in macrophage viability similar to that caused by conidia was detected. However, macrophage killing was unaffected when beads coated with de-O-glycosylated PRM were used, indicating the toxic effect of O-linked oligosaccharides on macrophages. In addition, PRM triggered TNF-α release by macrophages. Chemical removal of O-linked oligosaccharides from PRM abolished cytokine induction, suggesting that the O-linked oligosaccharidic chains are important moieties involved in inflammatory responses through the induction of TNF-α secretion. In summary, we show that O-glycosylation plays a role in the recognition and uptake of S. prolificans by macrophages, killing of macrophages and production of pro- inflammatory cytokines.

  6. O-Glycosylation in Cell Wall Proteins in Scedosporium prolificans Is Critical for Phagocytosis and Inflammatory Cytokines Production by Macrophages

    Science.gov (United States)

    Xisto, Mariana I. D. S.; Bittencourt, Vera C. B.; Liporagi-Lopes, Livia Cristina; Haido, Rosa M. T.; Mendonça, Morena S. A.; Sassaki, Guilherme; Figueiredo, Rodrigo T.; Romanos, Maria Teresa V.; Barreto-Bergter, Eliana

    2015-01-01

    In this study, we analyze the importance of O-linked oligosaccharides present in peptidorhamnomannan (PRM) from the cell wall of the fungus Scedosporium prolificans for recognition and phagocytosis of conidia by macrophages. Adding PRM led to a dose-dependent inhibition of conidia phagocytosis, whereas de-O-glycosylated PRM did not show any effect. PRM induced the release of macrophage-derived antimicrobial compounds. However, O-linked oligosaccharides do not appear to be required for such induction. The effect of PRM on conidia-induced macrophage killing was examined using latex beads coated with PRM or de-O-glycosylated PRM. A decrease in macrophage viability similar to that caused by conidia was detected. However, macrophage killing was unaffected when beads coated with de-O-glycosylated PRM were used, indicating the toxic effect of O-linked oligosaccharides on macrophages. In addition, PRM triggered TNF-α release by macrophages. Chemical removal of O-linked oligosaccharides from PRM abolished cytokine induction, suggesting that the O-linked oligosaccharidic chains are important moieties involved in inflammatory responses through the induction of TNF-α secretion. In summary, we show that O-glycosylation plays a role in the recognition and uptake of S. prolificans by macrophages, killing of macrophages and production of pro- inflammatory cytokines. PMID:25875427

  7. Mycobacteria clumping increase their capacity to damage macrophages

    Directory of Open Access Journals (Sweden)

    Cecilia Brambilla

    2016-10-01

    Full Text Available The rough morphotypes of non-tuberculous mycobacteria have been associated with the most severe illnesses in humans. This idea is consistent with the fact that Mycobacterium tuberculosis presents a stable rough morphotype. Unlike smooth morphotypes, the bacilli of rough morphotypes grow close together, leaving no spaces among them and forming large aggregates (clumps. Currently, the initial interaction of macrophages with clumps remains unclear. Thus, we infected J774 macrophages with bacterial suspensions of rough morphotypes of Mycobacterium abscessus containing clumps and suspensions of smooth morphotypes, primarily containing isolated bacilli. Using confocal laser scanning microscopy and electron microscopy, we observed clumps of at least 5 rough-morphotype bacilli inside the phagocytic vesicles of macrophages at 3 hours post-infection. These clumps grew within the phagocytic vesicles, killing 100% of the macrophages at 72 hours post-infection, whereas the proliferation of macrophages infected with smooth morphotypes remained unaltered at 96 hours post-infection. Thus, macrophages phagocytose large clumps, exceeding the bactericidal capacities of these cells. Furthermore, proinflammatory cytokines and granuloma-like structures were only produced by macrophages infected with rough morphotypes. Thus, the present study provides a foundation for further studies that consider mycobacterial clumps as virulence factors.

  8. Mycobacteria Clumping Increase Their Capacity to Damage Macrophages

    Science.gov (United States)

    Brambilla, Cecilia; Llorens-Fons, Marta; Julián, Esther; Noguera-Ortega, Estela; Tomàs-Martínez, Cristina; Pérez-Trujillo, Miriam; Byrd, Thomas F.; Alcaide, Fernando; Luquin, Marina

    2016-01-01

    The rough morphotypes of non-tuberculous mycobacteria have been associated with the most severe illnesses in humans. This idea is consistent with the fact that Mycobacterium tuberculosis presents a stable rough morphotype. Unlike smooth morphotypes, the bacilli of rough morphotypes grow close together, leaving no spaces among them and forming large aggregates (clumps). Currently, the initial interaction of macrophages with clumps remains unclear. Thus, we infected J774 macrophages with bacterial suspensions of rough morphotypes of M. abscessus containing clumps and suspensions of smooth morphotypes, primarily containing isolated bacilli. Using confocal laser scanning microscopy and electron microscopy, we observed clumps of at least five rough-morphotype bacilli inside the phagocytic vesicles of macrophages at 3 h post-infection. These clumps grew within the phagocytic vesicles, killing 100% of the macrophages at 72 h post-infection, whereas the proliferation of macrophages infected with smooth morphotypes remained unaltered at 96 h post-infection. Thus, macrophages phagocytose large clumps, exceeding the bactericidal capacities of these cells. Furthermore, proinflammatory cytokines and granuloma-like structures were only produced by macrophages infected with rough morphotypes. Thus, the present study provides a foundation for further studies that consider mycobacterial clumps as virulence factors. PMID:27757105

  9. Post-transcriptional control of NLRP3 inflammasome activation in colonic macrophages

    Science.gov (United States)

    Filardy, Alessandra A.; He, Jianping; Bennink, Jack; Yewdell, Jonathan; Kelsall, Brian L.

    2016-01-01

    Colonic macrophages (cMPs) are important for intestinal homeostasis as they kill microbes yet produce regulatory cytokines. Activity of the NLRP3 inflammasome, a major sensor of stress and microorganisms that results in pro-inflammatory cytokine production and cell death must be tightly controlled in the intestine. We demonstrate that resident cMPs are hyporesponsive to NLRP3 inflammasome activation due to a remarkable level of post-transcriptional control of NLRP3 and proIL-1β protein expression, which was also seen for TNF-α and IL-6, but lost during experimental colitis. Resident cMPs rapidly degraded NLRP3 and proIL-1β proteins by the ubiquitin/proteasome system. Finally, blocking IL-10R-signaling in vivo enhanced NLRP3 and proIL-1β protein, but not mRNA levels in resident cMPs implicating a role for IL-10 in environmental conditioning of cMPs. These data are the first to show dramatic post-transcriptional control of inflammatory cytokine production by a relevant tissue-derived macrophage population and proteasomal degradation of proIL-1β and NLRP3 as a mechanism to control inflammasome activation; findings which have broad implications for our understanding of intestinal and systemic inflammatory diseases. PMID:26627461

  10. WOMEN'S RIGHTS VIOLATION: HONOUR KILLINGS

    Directory of Open Access Journals (Sweden)

    CRISTINA OTOVESCU FRASIE

    2011-04-01

    Full Text Available In this study I have presented the domestic violence concept and the situation regarding the observing of woman’s rights in Syria. We have also evidenced the juridical aspects regarding the honor killing directed against women after the modification of the article 548 from the Penal Code changed by the President al-Asad on July the 1st 2009. The data offered by NGOs have been of great help for the elaboration of the study as also the statistic data presented in Thara E-Magazine regarding the cities where had been done the honor killings and their number, the instrument of the murder, the age of the victim, and the motives for the murders. It must be noticed that, lately, the Government fought for the observing of the woman’s rights and promoted he gender equality by appointing women in leading positions, including the vice-president one.

  11. Anion Exchanger 2 Regulates Dectin-1-Dependent Phagocytosis and Killing of Candida albicans.

    Directory of Open Access Journals (Sweden)

    Katia Urso

    Full Text Available Anion exchanger 2 (Ae2; gene symbol, Slc4a2 is a plasma membrane Cl-/HCO3- exchanger expressed in the gastrointestinal tract, kidney and bone. We have previously shown that Ae2 is required for the function of osteoclasts, bone resorbing cells of the macrophage lineage, to maintain homeostatic cytoplasmic pH and electroneutrality during acid secretion. Macrophages require endosomal acidification for pathogen killing during the process known as phagocytosis. Chloride is thought to be the principal ion responsible for maintaining electroneutrality during organelle acidification, but whether Cl-/HCO3- exchangers such as Ae2 contribute to macrophage function is not known. In this study we investigated the role of Ae2 in primary macrophages during phagocytosis. We find that Ae2 is expressed in macrophages where it regulates intracellular pH and the binding of Zymosan, a fungal cell wall derivative. Surprisingly, the transcription and surface expression of Dectin-1, the major phagocytic receptor for Candida albicans (C. albicans and Zymosan, is reduced in the absence of Ae2. As a consequence, Zymosan-induced Tnfα expression is also impaired in Ae2-deficient macrophages. Similar to Ae2 deficiency, pharmacological alkalinization of lysosomal pH with bafilomycin A decreases both Dectin-1 mRNA and cell surface expression. Finally, Ae2-deficient macrophages demonstrate defective phagocytosis and killing of the human pathogenic fungus C. albicans. Our results strongly suggest that Ae2 is a critical factor in the innate response to C. albicans. This study represents an important contribution to a better understanding of how Dectin-1 expression and fungal clearance is regulated.

  12. The Many Alternative Faces of Macrophage Activation

    Science.gov (United States)

    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

  13. In vitro Leishmania major promastigote-induced macrophage migration is modulated by sensory and autonomic neuropeptides

    DEFF Research Database (Denmark)

    Ahmed, A A; Wahbi, A; Nordlind, K

    1998-01-01

    the chemotactic activities of live, killed and sonicated Leishmania major promastigotes and of the promastigote culture supernatant as well as the L. major surface protease gp63 towards a murine macrophage cell line, Raw 264.7, were investigated, using the Boyden technique. The sensory neuropeptides SOM, CGRP...... and SP, and the autonomic neuropeptides VIP and NPY, were also investigated for possible modulatory effects on this chemotaxis, using the living promastigotes. Living promastigotes were the most efficient attractants for macrophages compared with other forms of the parasites. Prior incubation...... of the macrophages with the parasites completely abolished the chemotactic activity. This might indicate that the living promastigote chemotaxis is a receptor-mediated process. On the other hand, paraformaldehyde-killed promastigotes not only failed to induce macrophage chemotaxis but also inhibited it in comparison...

  14. Women who kill their children.

    Science.gov (United States)

    Rougé-Maillart, Clotilde; Jousset, Nathalie; Gaudin, Arnaud; Bouju, Brigitte; Penneau, Michel

    2005-12-01

    The killing of a newborn on the day of its birth is known as neonaticide. A child aged 1 through 16 has a different role in the family, and their murder is perceived differently. We would expect mothers charged with filicide to be drawn from a slightly different population than other child-killing mothers. Our study was carried out at the Institute of Forensic Medicine in Angers over a 10-year period. All the victims were autopsied at the Institute of Forensic Medicine in Angers. Information concerning the mothers was collected from forensic medical files, police reports, and legal files. Interviews and forensic psychiatric examinations were available for consultation. Our study concerns 17 observations of child-killing mothers and 19 child autopsies. In 2 cases, the issue was in fact a double murder, with the mother killing all the siblings. The mean age was 3.5 years for victims and 29.5 years for the women. The majority of the mothers were married or lived with their partners. They often had an occupation. Generally the economic status was average. Head trauma, strangulation, suffocation, and drowning were the most frequent means of filicide. However, some mothers used more active methods such as striking and shooting. Disturbed or disturbing behavior was documented in 15 perpetrators. Seven women tried to commit suicide. It was often possible to identify apparent motivation for the offense. In our study, we can distinguish 2 types of killer mothers. We distinguished a first group made up of 5 mothers. These 5 women killed their children in a general context of abused children and present similarities with the neonaticide mothers (young, immature). The other group of filicide mothers is different. They are generally older, married, and employed. The crime is usually premeditated, committed with the direct use of hands and sometimes very violent. To understand the motives or the source of the impulse to kill, we can use a classification such as Resnick

  15. Listeria monocytogenes infection of HD11, chicken macrophage-like cells.

    Science.gov (United States)

    Jarvis, N A; Donaldson, J R; O'Bryan, C A; Ricke, S C; Crandall, P G

    2017-04-01

    Listeria monocytogenes can be carried by and infect poultry, although the clinical disease in birds is rare. Escape from macrophage phagocytosis is a key step in pathogenesis for L. monocytogenes. Therefore, we investigated the infection of the chicken macrophage-like cell line HD11 with 2 strains of L. monocytogenes EGD-e and Scott A. After infection, L. monocytogenes was quantified by spread plating and HD11 was quantified with trypan blue exclusion stain before enumeration. The standard macrophage killing protocols require washing the cell monolayers 3 times with PBS, which was found to negatively influence HD11 monolayers. Maximum bacterial densities within macrophages were not different between the 2 Listeria strains. HD11 required more than 11 h to effectively reduce intracellular L. monocytogenes Scott A, and Scott A was more susceptible to HD11 killing than EGD-e. It appears that Listeria infection initially causes attenuation of HD11 growth, and infected HD11 cells do not begin to lyse until at least 11 h post infection. These results suggest that there are subtle strain to strain differences in response to HD11 macrophage phagocytosis. The long lead-time required for HD11 to kill L. monocytogenes cells means that there is sufficient time available for chicken macrophages to circulate in the blood and transfer the intracellular Listeria to multiple tissues. © 2016 Poultry Science Association Inc.

  16. Killing(-Yano) Tensors in String Theory

    CERN Document Server

    Chervonyi, Yuri

    2015-01-01

    We construct the Killing(-Yano) tensors for a large class of charged black holes in higher dimensions and study general properties of such tensors, in particular, their behavior under string dualities. Killing(-Yano) tensors encode the symmetries beyond isometries, which lead to insights into dynamics of particles and fields on a given geometry by providing a set of conserved quantities. By analyzing the eigenvalues of the Killing tensor, we provide a prescription for constructing several conserved quantities starting from a single object, and we demonstrate that Killing tensors in higher dimensions are always associated with ellipsoidal coordinates. We also determine the transformations of the Killing(-Yano) tensors under string dualities, and find the unique modification of the Killing-Yano equation consistent with these symmetries. These results are used to construct the explicit form of the Killing(-Yano) tensors for the Myers-Perry black hole in arbitrary number of dimensions and for its charged version.

  17. How To Kill a Penguin

    CERN Document Server

    Haisch, Ulrich

    2007-01-01

    Within constrained minimal-flavor-violation the large destructive flavor-changing Z-penguin managed to survive eradication so far. We give a incisive description of how to kill it using the precision measurements of the Z -> b anti-b pseudo observables. The derived stringent range for the non-standard contribution to the universal Inami-Lim function C leads to tight two-sided limits for the branching ratios of all Z-penguin dominated flavor-changing K- and B-decays.

  18. How Ixtoc 1 was killed

    Energy Technology Data Exchange (ETDEWEB)

    1980-04-01

    More than nine months after it erupted 6/3/79, Petroleos Mexicanos' Ixtoc 1 blowout in Campeche Bay was killed with three cement plugs having a total length of 2885 ft. After drilling of relief wells, 200 sacks of cement were used to form the 685 ft. long bottom plug. After inserting an interval of mud, an additional 200 sacks of cement were pumped down to form a 550 ft. plug. The final up-hole plug was formed by 500 sacks of quick-setting cement, which formed a 1650 ft. long plug.

  19. LPS-inducible factor(s) from activated macrophages mediates cytolysis of Naegleria fowleri amoebae

    Energy Technology Data Exchange (ETDEWEB)

    Cleary, S.F.; Marciano-Cabral, F.

    1986-03-01

    Soluble cytolytic factors of macrophage origin have previously been described with respect to their tumoricidal activity. The purpose of this study was to investigate the mechanism and possible factor(s) responsible for cytolysis of the amoeba Naegleria fowleri by activated peritoneal macrophages from B6C3F1 mice. Macrophages or conditioned medium (CM) from macrophage cultures were incubated with /sup 3/H-Uridine labeled amoebae. Percent specific release of label served as an index of cytolysis. Bacille Calmette-Guerin (BCG) and Corynebacterium parvum macrophages demonstrated significant cytolysis of amoebae at 24 h with an effector to target ratio of 10:1. Treatment of macrophages with inhibitors of RNA or protein synthesis blocked amoebicidal activity. Interposition of a 1 ..mu..m pore membrane between macrophages and amoebae inhibited killing. Inhibition in the presence of the membrane was overcome by stimulating the macrophages with LPS. CM from SPS-stimulated, but not unstimulated, cultures of activated macrophages was cytotoxic for amoebae. The activity was heat sensitive and was recovered from ammonium sulfate precipitation of the CM. Results indicate that amoebicidal activity is mediated by a protein(s) of macrophage origin induced by target cell contact or stimulation with LPS.

  20. Tramadol differentially regulates M1 and M2 macrophages from human umbilical cord blood.

    Science.gov (United States)

    Zhang, Jun; Chen, Liang; Sun, Yunyun; Li, Yuanhai

    2017-03-17

    Tramadol is an analgesic drug and relieves pain through activating μ-opioid receptors and inhibiting serotonin and noradrenaline reuptake. Emerging evidence shows that it also stimulates immune cells, including NK cells, splenocytes, and lymphocytes, and elevates IL-2 production. However, it remains unknown whether and how tramadol directly affects macrophages. To answer these questions, we collected human umbilical cord blood, isolated macrophages, and examined their responses to tramadol. Although tramadol did not alter resting macrophages and the antigen-presenting function in lipopolysaccharide-activated macrophages, it regulated M1 and M2 macrophages, which are, respectively, transformed by IFN-γ and IL-4. Interestingly, tramadol inhibits production and secretion of cytokines in M1 macrophages, but facilitates the production of inflammation-responding molecules, synthesized in M2 macrophages. We also found that STAT6 cascade pathway in M2 macrophages was significantly enhanced by tramadol. Therefore, this study reveals that tramadol regulates inflammation by inhibiting M1 macrophages (killing process), but promoting the function of M2 macrophages (healing process).

  1. Phenotypic diversity and emerging new tools to study macrophage activation in bacterial infectious diseases

    Directory of Open Access Journals (Sweden)

    Jean-Louis eMege

    2014-10-01

    Full Text Available Macrophage polarization is a concept that has been useful to describe the different features of macrophage activation related to specific functions. Macrophage polarization is responsible for a dichotomic approach (killing versus repair of the host response to bacteria: M1-type conditions are protective, whereas M2-type conditions are associated with bacterial persistence. The use of the polarization concept to classify the features of macrophage activation in infected patients using transcriptional and/or molecular data and to provide biomarkers for diagnosis and prognosis has most often been unsuccessful. The confrontation of polarization with different clinical situations in which monocytes/macrophages encounter bacteria obliged us to reappraise this concept. With the exception of M2-type infectious diseases such as leprosy and Whipple’s disease, most acute (sepsis or chronic (Q fever, tuberculosis infectious diseases do not exhibit polarized monocytes/macrophages. This is also the case for commensals that shape the immune response and for probiotics that alter the immune response independent of macrophage polarization. We propose that the type of myeloid cells (monocytes vs. macrophages and the kinetics of the immune response (early vs. late responses are critical variables for understanding macrophage activation in human infectious diseases. Explorating the role of these new markers will provide important tools to better understand complex macrophage physiology.

  2. Clinical Concentrations of Thioridazine Kill Intracellular Multidrug-Resistant Mycobacterium tuberculosis

    Science.gov (United States)

    Ordway, Diane; Viveiros, Miguel; Leandro, Clara; Bettencourt, Rosário; Almeida, Josefina; Martins, Marta; Kristiansen, Jette E.; Molnar, Joseph; Amaral, Leonard

    2003-01-01

    The phenothiazines chlorpromazine (CPZ) and thioridazine (TZ) have equal in vitro activities against antibiotic-sensitive and -resistant Mycobacterium tuberculosis. These compounds have not been used as anti-M. tuberculosis agents because their in vitro activities take place at concentrations which are beyond those that are clinically achievable. In addition, chronic administration of CPZ produces frequent severe side effects. Because CPZ has been shown to enhance the killing of intracellular M. tuberculosis at concentrations in the medium that are clinically relevant, we have investigated whether TZ, a phenothiazine whose negative side effects are less frequent and serious than those associated with CPZ, kills M. tuberculosis organisms that have been phagocytosed by human macrophages, which have nominal killing activities against these bacteria. Both CPZ and TZ killed intracellular antibiotic-sensitive and -resistant M. tuberculosis organisms when they were used at concentrations in the medium well below those present in the plasma of patients treated with these agents. These concentrations in vitro were not toxic to the macrophage, nor did they affect in vitro cellular immune processes. TZ thus appears to be a serious candidate for the management of a freshly diagnosed infection of pulmonary tuberculosis or as an adjunct to conventional antituberculosis therapy if the patient originates from an area known to have a high prevalence of multidrug-resistant M. tuberculosis isolates. Nevertheless, we must await the outcomes of clinical trials to determine whether TZ itself may be safely and effectively used as an antituberculosis agent. PMID:12604522

  3. Glutamine Modulates Macrophage Lipotoxicity

    Directory of Open Access Journals (Sweden)

    Li He

    2016-04-01

    Full Text Available 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.

  4. Letting die and mercy killing.

    Science.gov (United States)

    Narbekovas, Andrius; Meilius, Kazimieras

    2003-01-01

    We are all called to make moral decisions, not only about preserving life and health, but also about accepting our death and dying. There are situations, when it is morally right, and indeed obligatory, to allow a dying person to die in peace and dignity. But there is a world of difference between allowing a peaceful death, and deliberately setting out to bring death of the person either by acts of commission (s.c. 'active euthanasia'), or by acts of omission (s.c. 'passive euthanasia'). The word "killing" seems proper for euthanasia, because "to kill" does mean " to intentionally cause the death of someone." It can be morally acceptable to withhold or withdraw a treatment precisely because it is reasonably judged as inefficacious (futile), or excessively burdensome for the patient. One's reason for withholding such treatment must not be a judgement about the desirability of putting an end to the patient's life, but a judgement about the desirability of putting an end to the treatment, which is futile or burdensome.

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

    Science.gov (United States)

    Tran, Seav-Ly; Ramarao, Nalini

    2013-10-01

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

  6. Macrophages in gene therapy: cellular delivery vehicles and in vivo targets.

    Science.gov (United States)

    Burke, B; Sumner, S; Maitland, N; Lewis, C E

    2002-09-01

    The appearance and activation of macrophages are thought to be rapid events in the development of many pathological lesions, including malignant tumors, atherosclerotic plaques, and arthritic joints. This has prompted recent attempts to use macrophages as novel cellular vehicles for gene therapy, in which macrophages are genetically modified ex vivo and then reintroduced into the body with the hope that a proportion will then home to the diseased site. Here, we critically review the efficacy of various gene transfer methods (viral, bacterial, protozoan, and various chemical and physical methods) in transfecting macrophages in vitro, and the results obtained when transfected macrophages are used as gene delivery vehicles. Finally, we discuss the use of various viral and nonviral methods to transfer genes to macrophages in vivo. As will be seen, definitive evidence for the use of macrophages as gene transfer vehicles has yet to be provided and awaits detailed trafficking studies in vivo. Moreover, although methods for transfecting macrophages have improved considerably in efficiency in recent years, targeting of gene transfer specifically to macrophages in vivo remains a problem. However, possible solutions to this include placing transgenes under the control of macrophage-specific promoters to limit expression to macrophages or stably transfecting CD34(+) precursors of monocytes/macrophages and then differentiating these cells into monocytes/macrophages ex vivo. The latter approach could conceivably lead to the bone marrow precursor cells of patients with inherited genetic disorders being permanently fortified or even replaced with genetically modified cells.

  7. Killing tensors in pp-wave spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Keane, Aidan J [87 Carlton Place, Glasgow G5 9TD, Scotland (United Kingdom); Tupper, Brian O J, E-mail: aidan@countingthoughts.co, E-mail: bt32@rogers.co [Department of Mathematics and Statistics, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3 (Canada)

    2010-12-21

    The formal solution of the second-order Killing tensor equations for the general pp-wave spacetime is given. The Killing tensor equations are integrated fully for some specific pp-wave spacetimes. In particular, the complete solution is given for the conformally flat plane wave spacetimes and we find that irreducible Killing tensors arise for specific classes. The maximum number of independent irreducible Killing tensors admitted by a conformally flat plane wave spacetime is shown to be six. It is shown that every pp-wave spacetime that admits an homothety will admit a Killing tensor of Koutras type and, with the exception of the singular scale-invariant plane wave spacetimes, this Killing tensor is irreducible.

  8. Mycobacterium bovis Bacillus Calmette-Guérin-Induced Macrophage Cytotoxicity against Bladder Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yi Luo

    2010-01-01

    Full Text Available Many details of the molecular and cellular mechanisms involved in Mycobacterium bovis bacillus Calmette-Guérin (BCG immunotherapy of bladder cancer have been discovered in the past decades. However, information on a potential role for macrophage cytotoxicity as an effector mechanism is limited. Macrophages play pivotal roles in the host innate immunity and serve as a first line of defense in mycobacterial infection. In addition to their function as professional antigen-presenting cells, the tumoricidal activity of macrophages has also been studied with considerable interest. Studies have shown that activated macrophages are potent in killing malignant cells of various tissue origins. This review summarizes the current understanding of the BCG-induced macrophage cytotoxicity toward bladder cancer cells with an intention to inspire investigation on this important but underdeveloped research field.

  9. Cryptococcus Neoformans Modulates Extracellular Killing by Neutrophils

    OpenAIRE

    Qureshi, Asfia; Grey, Angus; Rose, Kristie L; Schey, Kevin L.; Del Poeta, Maurizio

    2011-01-01

    We recently established a key role for host sphingomyelin synthase (SMS) in regulating the killing activity of neutrophils against Cryptococcus neoformans. In this paper, we studied the effect of C. neoformans on the killing activity of neutrophils and whether SMS would still be a player against C. neoformans in immunocompromised mice lacking T and natural killer (NK) cells (Tgε26 mice). To this end, we analyzed whether C. neoformans would have any effect on neutrophil survival and killing in...

  10. Supplementation of host response by targeting nitric oxide to the macrophage cytosol is efficacious in the hamster model of visceral leishmaniasis and adds to efficacy of amphotericin B

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    Sanketkumar Pandya

    2016-08-01

    Full Text Available We investigated efficacy of nitric oxide (NO against Leishmania donovani. NO is a mediator of host response to infection, with direct parasiticidal activity in addition to its role in signalling to evoke innate macrophage responses. However, it is short-lived and volatile, and is therefore difficult to introduce into infected cells and maintain inracellular concentrations for meaningful periods of time. We incorporated diethylenetriamine NO adduct (DETA/NO, a prodrug, into poly(lactide-co-glycolide particles of ∼200 nm, with or without amphotericin B (AMB. These particles sustained NO levels in mouse macrophage culture supernatants, generating an area under curve (AUC0.08-24h of 591.2 ± 95.1 mM × h. Free DETA/NO resulted in NO peaking at 3 h and declining rapidly to yield an AUC of 462.5 ± 193.4. Particles containing AMB and DETA/NO were able to kill ∼98% of promastigotes and ∼76% of amastigotes in 12 h when tested in vitro. Promastigotes and amastigotes were killed less efficiently by particles containing a single drug– either DETA/NO (∼42%, 35% or AMB (∼90%, 50% alone, or by equivalent concentrations of drugs in solution. In a pre-clinical efficacy study of power >0.95 in the hamster model, DETA/NO particles were non-inferior to Fungizone® but not Ambisome®, resulting in significant (∼73% reduction in spleen parasites in 7 days. Particles containing both DETA/NO and AMB were superior (∼93% reduction to Ambisome®. We conclude that NO delivered to the cytosol of macrophages infected with Leishmania possesses intrinsic activity and adds significantly to the efficacy of AMB.

  11. Francisella tularensis LVS evades killing by human neutrophils via inhibition of the respiratory burst and phagosome escape.

    Science.gov (United States)

    McCaffrey, Ramona L; Allen, Lee-Ann H

    2006-12-01

    Francisella tularensis is a Gram-negative bacterium and the causative agent of tularemia. Recent data indicate that F. tularensis replicates inside macrophages, but its fate in other cell types, including human neutrophils, is unclear. We now show that F. tularensis live vaccine strain (LVS), opsonized with normal human serum, was rapidly ingested by neutrophils but was not eliminated. Moreover, evasion of intracellular killing can be explained, in part, by disruption of the respiratory burst. As judged by luminol-enhanced chemiluminescence and nitroblue tetrazolium staining, neutrophils infected with live F. tularensis did not generate reactive oxygen species. Confocal microscopy demonstrated that NADPH oxidase assembly was disrupted, and LVS phagosomes did not acquire gp91/p22(phox) or p47/p67(phox). At the same time, F. tularensis also impaired neutrophil activation by heterologous stimuli such as phorbol esters and opsonized zymosan particles. Later in infection, LVS escaped the phagosome, and live organisms persisted in the neutrophil cytosol for at least 12 h. To our knowledge, our data are the first demonstration of a facultative intracellular pathogen, which disrupts the oxidative burst and escapes the phagosome to evade elimination inside neutrophils, and as such, our data define a novel mechanism of virulence.

  12. Yersinia pestis Requires Host Rab1b for Survival in Macrophages.

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    Michael G Connor

    2015-10-01

    Full Text Available 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.

  13. Enhancement of the immune response against Salmonella infection of mice by heat-killed multispecies combinations of lactic acid bacteria.

    Science.gov (United States)

    Chen, Chih-Yuan; Tsen, Hau-Yang; Lin, Chun-Li; Lin, Chien-Ku; Chuang, Li-Tsen; Chen, Chin-Shuh; Chiang, Yu-Cheng

    2013-11-01

    Heat-killed lactic acid bacteria (LAB) has advantages over live LAB in that it has a long shelf-life and is therefore easy to store and transport. From four LAB strains selected by immunomodulatory activity and adherent properties, we prepared the heat-killed multispecies combination of LAB (MLAB) and the cell walls from MLAB under two conditions (100 °C for 30 min and 121 °C for 15 min). Different effects on the adherent properties of these four LAB strains were observed, depending on the heating conditions. With mouse macrophage cells, the two heat-killed MLABs (HMLABs) showed significantly higher induction activities on the production of interleukin 12 (IL-12) than their individual strains did. Heat-killed MLABs and cell-wall preparations were able to reduce the Salmonella invasion of Caco-2 and mouse macrophage cells. Feeding mice with HMLAB could inhibit the Salmonella invasion of mice significantly. For these mice, the expression level of pro-inflammatory cytokines, such as TNF-α and IL-6, in mouse serum was reduced while that of the anti-inflammatory cytokine, i.e. IL-10, was enhanced. The HMLABs developed in this study showed higher protective effect against Salmonella invasion either of Caco-2 cells or of mice, relative to the heat-killed lactobacilli, which consisted of Lactobacillus acidophilus strains selected at random. In conclusion, the HMLABs were potentially useful for the protection of mice against Salmonella infection and the induced inflammation.

  14. Macrophage Apoptosis Triggered by IpaD from Shigella flexneri.

    Science.gov (United States)

    Arizmendi, Olivia; Picking, William D; Picking, Wendy L

    2016-06-01

    Shigellosis, a potentially severe bacillary dysentery, is an infectious gastrointestinal disease caused by Shigella spp. Shigella invades the human colonic epithelium and avoids clearance by promoting apoptosis of resident immune cells in the gut. This process is dependent on the Shigella type III secretion system (T3SS), which injects effector proteins into target cells to alter their normal cellular functions. Invasion plasmid antigen D (IpaD) is a structural component that forms a complex at the tip of the T3SS apparatus needle. Recently, IpaD has also been shown to indirectly induce apoptosis in B lymphocytes. In this study, we explored the cytotoxicity profile during macrophage infection by Shigella and discovered that the pathogen induces macrophage cell death independent of caspase-1. Our results demonstrate that IpaD triggers apoptosis in macrophages through activation of host caspases accompanied by mitochondrial disruption. Additionally, we found that the IpaD N-terminal domain is necessary for macrophage killing and SipD, a structural homologue from Salmonella, was found to promote similar cytotoxicity. Together, these findings indicate that IpaD is a contributing factor to macrophage cell death during Shigella infection.

  15. Killing and letting die: a defensible distinction.

    Science.gov (United States)

    Cartwright, W

    1996-04-01

    The distinction between killing and letting die is investigated and clarified. It is then argued that in most cases, though not in all, it is worse to kill than to let die. In euthanasia the significance of the distinction is diminished, but still important.

  16. Puzzling cases about killing and letting die.

    Science.gov (United States)

    Favor, C D

    1996-01-01

    Discussions of euthanasia often appeal to the distinction between killing people and letting them die. Favor asks whether this distinction is morally important--in particular, whether killing is worse than merely letting someone die, even when the motivations and consequences are the same. She explores our moral intuitions via a discussion of various subtly different hypothetical examples.

  17. The Killing Forms of Lie Triple Systems

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi Xue; GAO Rui

    2009-01-01

    For Lie triple systems in the characteristic zero setting, we obtain by means of the Killing forms two criterions for semisimplicity and for solvability respectively, and then investigate the relationship among the Killing forms of a real Lie triple system To, the complexification T of To, and the realification of T.

  18. Inactivation of [Fe-S] metalloproteins mediates nitric oxide-dependent killing of Burkholderia mallei.

    Directory of Open Access Journals (Sweden)

    Jessica Jones-Carson

    Full Text Available BACKGROUND: Much remains to be known about the mechanisms by which O(2-dependent host defenses mediate broad antimicrobial activity. METHODOLOGY/PRINCIPAL FINDINGS: We show herein that reactive nitrogen species (RNS generated by inducible nitric oxide (NO synthase (iNOS account for the anti-Burkholderia mallei activity of IFNgamma-primed macrophages. Inducible NOS-mediated intracellular killing may represent direct bactericidal activity, because B. mallei showed an exquisite sensitivity to NO generated chemically. Exposure of B. mallei to sublethal concentrations of NO upregulated transcription of [Fe-S] cluster repair genes, while damaging the enzymatic activity of the [Fe-S] protein aconitase. To test whether [Fe-S] clusters are critical targets for RNS-dependent killing of B. mallei, a mutation was constructed in the NO-induced, [Fe-S] cluster repair regulator iscR. Not only was the iscR mutant hypersusceptible to iNOS-mediated killing, but its aconitase pool was readily oxidized by NO donors as compared to wild-type controls. Although killed by authentic H(2O(2, which also oxidizes [Fe-S] clusters, B. mallei appear to be resilient to NADPH oxidase-mediated cytotoxicity. The poor respiratory burst elicited by this bacterium likely explains why the NADPH oxidase is nonessential to the killing of B. mallei while it is still confined within phagosomes. CONCLUSIONS/SIGNIFICANCE: Collectively, these findings have revealed a disparate role for NADPH oxidase and iNOS in the innate macrophage response against the strict aerobe B. mallei. To the best of our knowledge, this is the first instance in which disruption of [Fe-S] clusters is demonstrated as cause of the bactericidal activity of NO congeners.

  19. Killing, letting die, and simple conflicts.

    Science.gov (United States)

    Malm, H M

    1989-01-01

    Proponents of the moral equivalence of killing and letting die argue that in cases of simple conflict, where one agent must either perform a positive act and kill one person, or not perform that act and allow another person to die, the agent's alternatives are clearly morally equivalent. Malm rejects this view in a three part essay. He argues that in cases of simple conflict, the acts of killing and letting die are morally different, and that killing is not in itself worse than letting die. Malm considers and rejects the suggestion that the agent should decide randomly between the two alternatives. He concludes that while simple conflict cases require us to recognize a morally significant difference between killing and letting die, they do not require us to recognize a morally significant difference between acting and refraining.

  20. Killing cells by targeting mitosis.

    Science.gov (United States)

    Manchado, E; Guillamot, M; Malumbres, M

    2012-03-01

    Cell cycle deregulation is a common feature of human cancer. Tumor cells accumulate mutations that result in unscheduled proliferation, genomic instability and chromosomal instability. Several therapeutic strategies have been proposed for targeting the cell division cycle in cancer. Whereas inhibiting the initial phases of the cell cycle is likely to generate viable quiescent cells, targeting mitosis offers several possibilities for killing cancer cells. Microtubule poisons have proved efficacy in the clinic against a broad range of malignancies, and novel targeted strategies are now evaluating the inhibition of critical activities, such as cyclin-dependent kinase 1, Aurora or Polo kinases or spindle kinesins. Abrogation of the mitotic checkpoint or targeting the energetic or proteotoxic stress of aneuploid or chromosomally instable cells may also provide further benefits by inducing lethal levels of instability. Although cancer cells may display different responses to these treatments, recent data suggest that targeting mitotic exit by inhibiting the anaphase-promoting complex generates metaphase cells that invariably die in mitosis. As the efficacy of cell-cycle targeting approaches has been limited so far, further understanding of the molecular pathways modulating mitotic cell death will be required to move forward these new proposals to the clinic.

  1. Antibacterial surface design - Contact kill

    Science.gov (United States)

    Kaur, Rajbir; Liu, Song

    2016-08-01

    Designing antibacterial surfaces has become extremely important to minimize Healthcare Associated Infections which are a major cause of mortality worldwide. A previous biocide-releasing approach is based on leaching of encapsulated biocides such as silver and triclosan which exerts negative impacts on the environment and potentially contributes to the development of bacterial resistance. This drawback of leachable compounds led to the shift of interest towards a more sustainable and environmentally friendly approach: contact-killing surfaces. Biocides that can be bound onto surfaces to give the substrates contact-active antibacterial activity include quaternary ammonium compounds (QACs), quaternary phosphoniums (QPs), carbon nanotubes, antibacterial peptides, and N-chloramines. Among the above, QACs and N-chloramines are the most researched contact-active biocides. We review the engineering of contact-active surfaces using QACs or N-chloramines, the modes of actions as well as the test methods. The charge-density threshold of cationic surfaces for desired antibacterial efficacy and attempts to combine various biocides for the generation of new contact-active surfaces are discussed in detail. Surface positive charge density is identified as a key parameter to define antibacterial efficacy. We expect that this research field will continue to attract more research interest in view of the potential impact of self-disinfective surfaces on healthcare-associated infections, food safety and corrosion/fouling resistance required on industrial surfaces such as oil pipes and ship hulls.

  2. [Macrophages in asthma].

    Science.gov (United States)

    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.

  3. Macrophages and Iron Metabolism.

    Science.gov (United States)

    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.

  4. Yersinia pestis intracellular parasitism of macrophages from hosts exhibiting high and low severity of plague.

    Directory of Open Access Journals (Sweden)

    Duraisamy Ponnusamy

    Full Text Available BACKGROUND: Yersinia pestis causes severe disease in natural rodent hosts, but mild to inapparent disease in certain rodent predators such as dogs. Y. pestis initiates infection in susceptible hosts by parasitizing and multiplying intracellularly in local macrophages prior to systemic dissemination. Thus, we hypothesize that Y. pestis disease severity may depend on the degree to which intracellular Y. pestis overcomes the initial host macrophage imposed stress. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis, the progression of in vitro infection by Y. pestis KIM62053.1+ of mouse splenic and RAW264.7 tissue culture macrophages and dog peripheral blood-derived and DH82 tissue culture macrophages was studied using microscopy and various parameters of infection. The study showed that during the early stage of infection, intracellular Y. pestis assumed filamentous cellular morphology with multiple copies of the genome per bacterium in both mouse and dog macrophages. Later, in mouse macrophages, the infection elicited spacious vacuolar extension of Yersinia containing vacuoles (YCV, and the filamentous Y. pestis reverted to coccobacillary morphology with genomic equivalents approximately equaling colony forming units. In contrast, Y. pestis infected dog macrophages did not show noticeable extension of YCV, and intracellular Y. pestis retained the filamentous cellular morphology for the entire experiment in DH82 cells or were killed by blood-derived macrophages. In addition, during the later stage of infection, Y. pestis infected mouse macrophages exhibited cell lysis whereas dog macrophages did not. CONCLUSION/SIGNIFICANCE: Overall, these results support our hypothesis that Y. pestis in mouse macrophages can overcome the initial intracellular stress necessary for subsequent systemic infection. However, in dogs, failure of Y. pestis to overcome macrophage imposed stress may result in mild or in apparent disease in dogs.

  5. Cell elasticity determines macrophage function.

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    Naimish R Patel

    Full Text Available Macrophages serve to maintain organ homeostasis in response to challenges from injury, inflammation, malignancy, particulate exposure, or infection. Until now, receptor ligation has been understood as being the central mechanism that regulates macrophage function. Using macrophages of different origins and species, we report that macrophage elasticity is a major determinant of innate macrophage function. Macrophage elasticity is modulated not only by classical biologic activators such as LPS and IFN-γ, but to an equal extent by substrate rigidity and substrate stretch. Macrophage elasticity is dependent upon actin polymerization and small rhoGTPase activation, but functional effects of elasticity are not predicted by examination of gene expression profiles alone. Taken together, these data demonstrate an unanticipated role for cell elasticity as a common pathway by which mechanical and biologic factors determine macrophage function.

  6. Berberine augments ATP-induced inflammasome activation in macrophages by enhancing AMPK signaling

    Science.gov (United States)

    Xu, Li-Hui; Liang, Yi-Dan; Wei, Hong-Xia; Hu, Bo; Pan, Hao; Zha, Qing-Bing; Ouyang, Dong-Yun; He, Xian-Hui

    2017-01-01

    The isoquinoline alkaloid berberine possesses many pharmacological activities including antibacterial infection. Although the direct bactericidal effect of berberine has been documented, its influence on the antibacterial functions of macrophages is largely unknown. As inflammasome activation in macrophages is important for the defense against bacterial infection, we aimed to investigate the influence of berberine on inflammasome activation in murine macrophages. Our results showed that berberine significantly increased ATP-induced inflammasome activation as reflected by enhanced pyroptosis as well as increased release of caspase-1p10 and mature interleukin-1β (IL-1β) in macrophages. Such effects of berberine could be suppressed by AMP-activated protein kinase (AMPK) inhibitor compound C or by knockdown of AMPKα expression, indicating the involvement of AMPK signaling in this process. In line with increased IL-1β release, the ability of macrophages to kill engulfed bacteria was also intensified by berberine. This was corroborated by the in vivo finding that the peritoneal live bacterial load was decreased by berberine treatment. Moreover, berberine administration significantly improved survival of bacterial infected mice, concomitant with increased IL-1β levels and elevated neutrophil recruitment in the peritoneal cavity. Collectively, these data suggested that berberine could enhance bacterial killing by augmenting inflammasome activation in macrophages through AMPK signaling. PMID:27980220

  7. Klebsiella pneumoniae survives within macrophages by avoiding delivery to lysosomes.

    Science.gov (United States)

    Cano, Victoria; March, Catalina; Insua, Jose Luis; Aguiló, Nacho; Llobet, Enrique; Moranta, David; Regueiro, Verónica; Brennan, Gerard P; Millán-Lou, Maria Isabel; Martín, Carlos; Garmendia, Junkal; Bengoechea, José A

    2015-11-01

    Klebsiella pneumoniae is an important cause of community-acquired and nosocomial pneumonia. Evidence indicates that Klebsiella might be able to persist intracellularly within a vacuolar compartment. This study was designed to investigate the interaction between Klebsiella and macrophages. Engulfment of K. pneumoniae was dependent on host cytoskeleton, cell plasma membrane lipid rafts and the activation of phosphoinositide 3-kinase (PI3K). Microscopy studies revealed that K. pneumoniae resides within a vacuolar compartment, the Klebsiella-containing vacuole (KCV), which traffics within vacuoles associated with the endocytic pathway. In contrast to UV-killed bacteria, the majority of live bacteria did not co-localize with markers of the lysosomal compartment. Our data suggest that K. pneumoniae triggers a programmed cell death in macrophages displaying features of apoptosis. Our efforts to identify the mechanism(s) whereby K. pneumoniae prevents the fusion of the lysosomes to the KCV uncovered the central role of the PI3K-Akt-Rab14 axis to control the phagosome maturation. Our data revealed that the capsule is dispensable for Klebsiella intracellular survival if bacteria were not opsonized. Furthermore, the environment found by Klebsiella within the KCV triggered the down-regulation of the expression of cps. Altogether, this study proves evidence that K. pneumoniae survives killing by macrophages by manipulating phagosome maturation that may contribute to Klebsiella pathogenesis.

  8. Cytotoxic T-lymphocyte-mediated killing of human pancreatic islet cells in vitro.

    Science.gov (United States)

    Campbell, Peter D; Estella, Eugene; Dudek, Nadine L; Jhala, Gaurang; Thomas, Helen E; Kay, Thomas W H; Mannering, Stuart I

    2008-09-01

    Cytotoxic T lymphocytes (CTL) are believed to play an essential role in beta-cell destruction leading to development of type 1 diabetes and allogeneic islet graft failure. We aimed to identify the mechanisms used by CTL to kill human beta cells. CTL clones that recognize epitopes from influenza virus and Epstein-Barr virus restricted by human leukocyte antigen (HLA)-A0201 and -B0801, respectively, were used to investigate the susceptibility of human beta cells to CTL. In a short-term (5-hour) assay, CTL killed human islet cells of the appropriate major histocompatibility complex (MHC) class I type that had been pulsed with viral peptides. Killing was increased by pretreating islets with interferon gamma that increases MHC class I on target cells. Killing was abolished by incubation of CTL with the perforin inhibitor concanamycin A. The Fas pathway did not contribute to killing because blocking with neutralizing anti-Fas ligand antibody did not significantly reduce beta-cell killing. In conclusion, we report a novel way of investigating the interaction between CTL and human islets. Human islets were rapidly killed in vitro by MHC class I-restricted CTL predominantly by the granule exocytosis pathway.

  9. Household air pollution causes dose-dependent inflammation and altered phagocytosis in human macrophages.

    Science.gov (United States)

    Rylance, Jamie; Fullerton, Duncan G; Scriven, James; Aljurayyan, Abdullah N; Mzinza, David; Barrett, Steve; Wright, Adam K A; Wootton, Daniel G; Glennie, Sarah J; Baple, Katy; Knott, Amy; Mortimer, Kevin; Russell, David G; Heyderman, Robert S; Gordon, Stephen B

    2015-05-01

    Three billion people are exposed to household air pollution from biomass fuel use. Exposure is associated with higher incidence of pneumonia, and possibly tuberculosis. Understanding mechanisms underlying these defects would improve preventive strategies. We used human alveolar macrophages obtained from healthy Malawian adults exposed naturally to household air pollution and compared them with human monocyte-derived macrophages exposed in vitro to respirable-sized particulates. Cellular inflammatory response was assessed by IL-6 and IL-8 production in response to particulate challenge; phagosomal function was tested by uptake and oxidation of fluorescence-labeled beads; ingestion and killing of Streptococcus pneumoniae and Mycobacterium tuberculosis were measured by microscopy and quantitative culture. Particulate ingestion was quantified by digital image analysis. We were able to reproduce the carbon loading of naturally exposed alveolar macrophages by in vitro exposure of monocyte-derived macrophages. Fine carbon black induced IL-8 release from monocyte-derived and alveolar macrophages (P < 0.05) with similar magnitude responses (log10 increases of 0.93 [SEM = 0.2] versus 0.74 [SEM = 0.19], respectively). Phagocytosis of pneumococci and mycobacteria was impaired with higher particulate loading. High particulate loading corresponded with a lower oxidative burst capacity (P = 0.0015). There was no overall effect on killing of M. tuberculosis. Alveolar macrophage function is altered by particulate loading. Our macrophage model is comparable morphologically to the in vivo uptake of particulates. Wood smoke-exposed cells demonstrate reduced phagocytosis, but unaffected mycobacterial killing, suggesting defects related to chronic wood smoke inhalation limited to specific innate immune functions.

  10. Primary macrophages and J774 cells respond differently to infection with Mycobacterium tuberculosis

    Science.gov (United States)

    Andreu, Nuria; Phelan, Jody; de Sessions, Paola F.; Cliff, Jacqueline M.; Clark, Taane G.; Hibberd, Martin L.

    2017-01-01

    Macrophages play an essential role in the early immune response to Mycobacterium tuberculosis and are the cell type preferentially infected in vivo. Primary macrophages and macrophage-like cell lines are commonly used as infection models, although the physiological relevance of cell lines, particularly for host-pathogen interaction studies, is debatable. Here we use high-throughput RNA-sequencing to analyse transcriptome dynamics of two macrophage models in response to M. tuberculosis infection. Specifically, we study the early response of bone marrow-derived mouse macrophages and cell line J774 to infection with live and γ-irradiated (killed) M. tuberculosis. We show that infection with live bacilli specifically alters the expression of host genes such as Rsad2, Ifit1/2/3 and Rig-I, whose potential roles in resistance to M. tuberculosis infection have not yet been investigated. In addition, the response of primary macrophages is faster and more intense than that of J774 cells in terms of number of differentially expressed genes and magnitude of induction/repression. Our results point to potentially novel processes leading to immune containment early during M. tuberculosis infection, and support the idea that important differences exist between primary macrophages and cell lines, which should be taken into account when choosing a macrophage model to study host-pathogen interactions. PMID:28176867

  11. Neisseria gonorrhoeae survives within and modulates apoptosis and inflammatory cytokine production of human macrophages.

    Science.gov (United States)

    Château, Alice; Seifert, H Steven

    2016-04-01

    The human-adapted organism Neisseria gonorrhoeae is the causative agent of gonorrhoea, a sexually transmitted infection. It readily colonizes the genital, rectal and nasalpharyngeal mucosa during infection. While it is well established that N. gonorrhoeae recruits and modulates the functions of polymorphonuclear leukocytes during infection, how N. gonorrhoeae interacts with macrophages present in infected tissue is not fully defined. We studied the interactions of N. gonorrhoeae with two human monocytic cell lines, THP-1 and U937, and primary monocytes, all differentiated into macrophages. Most engulfed bacteria were killed in the phagolysosome, but a subset of bacteria was able to survive and replicate inside the macrophages suggesting that those cells may be an unexplored cellular reservoir for N. gonorrhoeae during infection. N. gonorrhoeae was able to modulate macrophage apoptosis: N. gonorrhoeae induced apoptosis in THP-1 cells whereas it inhibited induced apoptosis in U937 cells and primary human macrophages. Furthermore, N. gonorrhoeae induced expression of inflammatory cytokines in macrophages, suggesting a role for macrophages in recruiting polymorphonuclear leukocytes to the site of infection. These results indicate macrophages may serve as a significant replicative niche for N. gonorrhoeae and play an important role in gonorrheal pathogenesis.

  12. The role of TREM-2 in internalization and intracellular survival of Brucella abortus in murine macrophages.

    Science.gov (United States)

    Wei, Pan; Lu, Qiang; Cui, Guimei; Guan, Zhenhong; Yang, Li; Sun, Changjiang; Sun, Wanchun; Peng, Qisheng

    2015-02-15

    Triggering receptor expressed on myeloid cells-2 (TREM-2) is a cell surface receptor primarily expressed on macrophages and dendritic cells. TREM-2 functions as a phagocytic receptor for bacteria as well as an inhibitor of Toll like receptors (TLR) induced inflammatory cytokines. However, the role of TREM-2 in Brucella intracellular growth remains unknown. To investigate whether TREM-2 is involved in Brucella intracellular survival, we chose bone marrow derived macrophages (BMDMs), in which TREM-2 is stably expressed, as cell model. Colony formation Units (CFUs) assay suggests that TREM-2 is involved in the internalization of Brucella abortus (B. abortus) by macrophages, while silencing of TREM-2 decreases intracellular survival of B. abortus. To further study the underlying mechanisms of TREM-2-mediated bacterial intracellular survival, we examined the activation of B. abortus-infected macrophages through determining the kinetics of activation of the three MAPKs, including ERK, JNK and p38, and measuring TNFα production in response to lipopolysaccharide (LPS) of Brucella (BrLPS) or B. abortus stimulation. Our data show that TREM-2 deficiency promotes activation of Brucella-infected macrophages. Moreover, our data also demonstrate that macrophage activation promotes killing of Brucella by enhancing nitric oxygen (NO), but not reactive oxygen species (ROS) production, macrophage apoptosis or cellular death. Taken together, these findings provide a novel interpretation of Brucella intracellular growth through inhibition of NO production produced by TREM-2-mediated activated macrophages.

  13. Fungal and bacterial killing by neutrophils.

    Science.gov (United States)

    Ermert, David; Zychlinsky, Arturo; Urban, Constantin

    2009-01-01

    Neutrophils are professional phagocytes of the innate immune system that are essential to control bacterial and fungal infections. These cells engulf and kill invading microbes. Additionally, activated neutrophils are able to release neutrophil extracellular traps (NETs). These fibers consist of chromatin decorated with antimicrobial proteins to trap and kill microbes. Appropriate quantitative methods are required to understand the nature of interactions of neutrophils with pathogens. Here we present assays to measure killing mediated by phagocytosis, by NETs, by a combination of both, and by granular extract. As examples, we use Candida albicans for fungal and Shigella flexneri for bacterial pathogens.

  14. Macrophage recognition of ICAM-3 on apoptotic leukocytes.

    Science.gov (United States)

    Moffatt, O D; Devitt, A; Bell, E D; Simmons, D L; Gregory, C D

    1999-06-01

    Cells undergoing apoptosis are cleared rapidly by phagocytes, thus preventing tissue damage caused by loss of plasma membrane integrity. In this study, we show that the surface of leukocytes is altered during apoptosis such that the first Ig-like domain of ICAM-3 (CD50) can participate in the recognition and phagocytosis of the apoptotic cells by macrophages. Macrophage recognition of apoptotic cell-associated ICAM-3 was demonstrated both on leukocytes and, following transfection of exogenous ICAM-3, on nonleukocytes. The change in ICAM-3 was a consistent consequence of apoptosis triggered by various stimuli, suggesting that it occurs as part of a final common pathway of apoptosis. Alteration of ICAM-3 on apoptotic cells permitting recognition by macrophages resulted in a switch in ICAM-3-binding preference from the prototypic ICAM-3 counterreceptor, LFA-1, to an alternative macrophage receptor. Using mAbs to block macrophage/apoptotic cell interactions, we were unable to obtain evidence that either the alternative ICAM-3 counterreceptor alpha d beta 2 or the apoptotic cell receptor alpha v beta 3 was involved in the recognition of ICAM-3. By contrast, mAb blockade of macrophage CD14 inhibited ICAM-3-dependent recognition of apoptotic cells. These results show that ICAM-3 can function as a phagocytic marker of apoptotic leukocytes on which it acquires altered macrophage receptor-binding activity.

  15. Contagion in Mass Killings and School Shootings

    National Research Council Canada - National Science Library

    Towers, Sherry; Gomez-Lievano, Andres; Khan, Maryam; Mubayi, Anuj; Castillo-Chavez, Carlos

    2015-01-01

    ... the seeds of ideation in at-risk individuals to commit similar acts. Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings...

  16. Homefucking is Killing Prostitution / Taavi Eelmaa

    Index Scriptorium Estoniae

    Eelmaa, Taavi, 1971-

    2008-01-01

    Mis jääb vaatajale teatrietendusest meelde? Ilmus Kris Moori raamat "Homefucking is Killing Prostitution". Raamat sisaldab tekste ja Erki Lauri fotosid Von Krahli Teatri samanimelisest etendusest, mida kordagi ei mängitud

  17. Killing superalgebras for Lorentzian four-manifolds

    CERN Document Server

    de Medeiros, Paul; Santi, Andrea

    2016-01-01

    We determine the Killing superalgebras underpinning field theories with rigid unextended supersymmetry on Lorentzian four-manifolds by re-interpreting them as filtered deformations of $\\mathbb{Z}$-graded subalgebras with maximum odd dimension of the $N{=}1$ Poincar\\'e superalgebra in four dimensions. Part of this calculation involves computing a Spencer cohomology group which, by analogy with a similar result in eleven dimensions, prescribes a notion of Killing spinor, which we identify with the defining condition for bosonic supersymmetric backgrounds of minimal off-shell supergravity in four dimensions. We prove that such Killing spinors always generate a Lie superalgebra, and that this Lie superalgebra is a filtered deformation of a subalgebra of the $N{=}1$ Poincar\\'e superalgebra in four dimensions. Demanding the flatness of the connection defining the Killing spinors, we obtain equations satisfied by the maximally supersymmetric backgrounds. We solve these equations, arriving at the classification of ma...

  18. Acts and omissions, killing and letting die.

    Science.gov (United States)

    Gillon, R

    1986-01-11

    Gillon asks what, if any, moral importance resides in the distinction between killing and letting die in the context of medical care. He considers and rejects the acts and omissions doctrine, which claims that actions (killing) resulting in some undesirable end are in general morally worse than failures to act (allowing to die) that have the same result. He also refutes the argument that the moral distinction between killing and letting die is one of harming versus benefitting, and that a physician has a responsibility not to harm (kill) a patient but no duty to help (keep alive). Gillon concludes by discussing the moral claims upon which the Roman Catholic rejection of the acts and omissions doctrine is based, which are the subjects of his next British Medical Journal article on medical ethics.

  19. Homefucking is Killing Prostitution / Taavi Eelmaa

    Index Scriptorium Estoniae

    Eelmaa, Taavi, 1971-

    2008-01-01

    Mis jääb vaatajale teatrietendusest meelde? Ilmus Kris Moori raamat "Homefucking is Killing Prostitution". Raamat sisaldab tekste ja Erki Lauri fotosid Von Krahli Teatri samanimelisest etendusest, mida kordagi ei mängitud

  20. The Geometry of D=11 Killing Spinors

    CERN Document Server

    Gauntlett, J P; Gauntlett, Jerome P.; Pakis, Stathis

    2003-01-01

    We propose a way to classify all supersymmetric configurations of D=11 supergravity using the G-structures defined by the Killing spinors. We show that the most general bosonic geometries admitting a Killing spinor have at least an SU(5) or an (Spin(7)\\ltimes R^8)x R structure, depending on whether the Killing vector constructed from the Killing spinor is timelike or null, respectively. In the former case we determine what kind of SU(5) structure is present and show that almost all of the form of the geometry is determined by the structure. We also deduce what further conditions must be imposed in order that the equations of motion are satisfied. We illustrate the formalism with some known solutions and also present some new solutions including a rotating generalisation of the resolved membrane solutions and generalisations of the recently constructed D=11 Godel solution.

  1. Transcriptional Regulation and Macrophage Differentiation.

    Science.gov (United States)

    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.

  2. Killing vector fields and harmonic superfield theories

    Energy Technology Data Exchange (ETDEWEB)

    Groeger, Josua, E-mail: groegerj@mathematik.hu-berlin.de [Humboldt-Universität zu Berlin, Institut für Mathematik, Rudower Chaussee 25, 12489 Berlin (Germany)

    2014-09-15

    The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, also referred to as harmonic, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of this harmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.

  3. Killing Vector Fields and Superharmonic Field Theories

    CERN Document Server

    Groeger, Josua

    2013-01-01

    The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, referred to as superharmonic action, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of the superharmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.

  4. Is killing no worse than letting die?

    Science.gov (United States)

    Nesbitt, W

    1995-01-01

    Those who wish to refute the view that it is worse to kill than to let die sometimes produce examples of cases in which an agent lets someone die but would be generally agreed to be no less reprehensible than if he had killed. It is argued that the examples produced typically possess a feature which makes their use in this context illegitimate, and that when modified to remove this feature, they provide support for the view which they were designed to undermine.

  5. Killing and letting die: hidden value assumptions.

    Science.gov (United States)

    Atkinson, G

    1983-01-01

    In this paper I argue for several related theses: first, that the distinction between killing and letting die, as it is drawn by ordinary persons in ordinary contexts, is more complex than is generally understood; second, that the key feature of this complexity lies in the presence of a hidden normative component in what appears to be a straightforwardly descriptive distinction; and, third, that this complexity renders the killing/letting die distinction an inadequate and hazardous guide for moral reasoning.

  6. Cell killing by avian leukosis viruses.

    OpenAIRE

    Weller, S K; Temin, H M

    1981-01-01

    Infection of chicken cells with a cytopathic avian leukosis virus resulted in the detachment of killed cells from the culture dish. The detached, dead cells contained more unintegrated viral DNA than the attached cells. These results confirm the hypothesis that cell killing after infection with a cytopathic avian leukosis virus is associated with accumulation of large amounts of unintegrated viral DNA. No accumulation of large amounts of integrated viral DNA was found in cells infected with c...

  7. Cryptococcus neoformans modulates extracellular killing by neutrophils.

    Science.gov (United States)

    Qureshi, Asfia; Grey, Angus; Rose, Kristie L; Schey, Kevin L; Del Poeta, Maurizio

    2011-01-01

    We recently established a key role for host sphingomyelin synthase (SMS) in regulating the killing activity of neutrophils against Cryptococcus neoformans. In this paper, we studied the effect of C. neoformans on the killing activity of neutrophils and whether SMS would still be a player against C. neoformans in immunocompromised mice lacking T and natural killer (NK) cells (Tgε26 mice). To this end, we analyzed whether C. neoformans would have any effect on neutrophil survival and killing in vitro and in vivo. We show that unlike Candida albicans, neither the presence nor the capsule size of C. neoformans cells have any effect on neutrophil viability. Interestingly, melanized C. neoformans cells totally abrogated the killing activity of neutrophils. We monitored how exposure of neutrophils to C. neoformans cells would interfere with any further killing activity of the conditioned medium and found that pre-incubation with live but not "heat-killed" fungal cells significantly inhibits further killing activity of the medium. We then studied whether activation of SMS at the site of C. neoformans infection is dependent on T and NK cells. Using matrix-assisted laser desorption-ionization tissue imaging in infected lung we found that similar to previous observations in the isogenic wild-type CBA/J mice, SM 16:0 levels are significantly elevated at the site of infection in mice lacking T and NK cells, but only at early time points. This study highlights that C. neoformans may negatively regulate the killing activity of neutrophils and that SMS activation in neutrophils appears to be partially independent of T and/or NK cells.

  8. Cryptococcus neoformans modulates extracellular killing by neutrophils

    Directory of Open Access Journals (Sweden)

    Asfia eQureshi

    2011-09-01

    Full Text Available We recently established a key role for host sphingomyelin synthase (SMS in the regulation of the killing activity of neutrophils against Cryptococcus neoformans. In this work, we studied the effect of C. neoformans on the killing activity of neutrophils and whether SMS would still be a player against C. neoformans in immunocompromised mice lacking T and NK cells (Tgε26 mice. To this end, we analyzed whether C. neoformans would have any effect on neutrophil survival and killing in vitro and in vivo. We show that unlike C. albicans, neither the presence nor the capsule size of C. neoformans cells have any effect on neutrophil viability. Interestingly, melanized C. neoformans cells totally abrogated the killing activity of neutrophils. Next, we monitored how exposure of neutrophils to C. neoformans cells would interfere with any further killing activity of the medium and found that pre-incubation with live but not heat-killed fungal cells significantly inhibits further killing activity of the medium. We next studied whether activation of SMS at the site of C. neoformans infection is dependent on T and NK cells. Using matrix-assisted laser desorption-ionization (MALDI tissue imaging in infected lung we found that similarly to previous observations in the isogenic wild type CBA/J mice, SM 16:0 levels are significantly elevated at the site of infection in mice lacking T and NK cells but only at early time points. This study highlights that C. neoformans may negatively regulate the killing activity of neutrophils and that SMS activation in neutrophils appears to be partially independent of T and/or NK cells.

  9. Killing Forms of Isotropic Lie Algebras

    CERN Document Server

    Malagon, Audrey

    2010-01-01

    This paper presents a method for computing the Killing form of an isotropic Lie algebra defined over an arbitrary field based on the Killing form of a subalgebra containing its anisotropic kernel. This approach allows for streamlined formulas for many Lie algebras of types E6 and E7 and yields a unified formula for all Lie algebras of inner type E6, including the anisotropic ones.

  10. T-peptide Enhances the Killing Effects of Cisplatinum on Lung Cancer

    Directory of Open Access Journals (Sweden)

    Hongyi ZHANG

    2017-02-01

    Full Text Available Background and objective T peptide is extensively used in anti-tumor treatment. The aims of this study were to investigate whether T peptide enhances cisplatinum efficiency while reducing its side effects and to identify its effective mechanisms. Methods (1 Human macrophage U937 cells were treated with T peptide and/or cisplatinum. The levels of tumor necrosis factor-α (TNF-α and interferon-γ (IFN-γ of each group were detected by enzyme-linked immunosorbent assay (ELISA; (2 Xenograft mouse models of human lung cancer were treated with T peptide and/or cisplatinum once every five days for three times. Tumor volumes were measured during treatment; (3 The percentages of macrophages in the peripheral blood of the xenograft mouse models were measured by FACS. Results (1 Compared with other groups, the level of TNF-α was significantly higher in the human macrophage U937 cells that were treated with T peptide combined with cisplatinum. The levels of IFN-γ were significantly higher in human macrophage U937 cells that were treated with T peptide alone or T peptide combined with cisplatinum; (2 In the xenograft mouse models, T peptide combined with cisplatinum treatment significantly inhibited tumor growth without weight loss compared with the other groups; (3 The percentages of macrophages in the peripheral blood were significantly higher in the xenograft mouse models that were treated with T peptide combined with cisplatinum compared with in the other groups. Conclusion T peptide promotes macrophage proliferation and increases tumor cell killing factors (TNF-α, IFN-γ in vitro. Moreover, T peptide enhances the efficacy of cisplatin and reduces its toxicity in vivo.

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

    Science.gov (United States)

    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

  12. Glucocorticoid-induced impairment of macrophage antimicrobial activity: mechanisms and dependence on the state of activation.

    Science.gov (United States)

    Schaffner, A; Schaffner, T

    1987-01-01

    Experimental observations indicate that tissue macrophages deployed in great numbers at critical anatomic sites such as the liver, spleen, and lung are major targets for glucocorticoids compromising natural resistance of the host. Therapeutic concentrations of glucocorticoids appear to prevent destruction of microorganisms ingested by macrophages without interfering with phagocytosis, phagolysosomal fusion, and/or secretion of reactive oxygen intermediates. These findings indicate that at the cellular level the glucocorticoid target should be sought for in the nonoxidative armature of the phagocyte and that nonoxidative killing systems of resident tissue macrophages play an important role in natural resistance to opportunistic pathogens. Glucocorticoids do not prevent lymphokine-induced activation of oxidative killing systems. Thus, lymphokines such as interferon-gamma can restore the microbicidal activity of macrophages functionally impaired by glucocorticoids. Counterbalance of the suppressive effect of glucocorticoids by lymphokines might only be possible, however, for pathogens susceptible to oxidative killing and not for microorganisms that are more resistant to reactive oxygen intermediates such as Aspergillus spores and Nocardia, opportunists that appear to be particularly associated with hypercortisolism.

  13. p47phox Directs Murine Macrophage Cell Fate Decisions

    Science.gov (United States)

    Yi, Liang; Liu, Qi; Orandle, Marlene S.; Sadiq-Ali, Sara; Koontz, Sherry M.; Choi, Uimook; Torres-Velez, Fernando J.; Jackson, Sharon H.

    2012-01-01

    Macrophage differentiation and function are pivotal for cell survival from infection and involve the processing of microenvironmental signals that determine macrophage cell fate decisions to establish appropriate inflammatory balance. NADPH oxidase 2 (Nox2)–deficient chronic granulomatous disease (CGD) mice that lack the gp91phox (gp91phox−/−) catalytic subunit show high mortality rates compared with wild-type mice when challenged by infection with Listeria monocytogenes (Lm), whereas p47phox-deficient (p47phox−/−) CGD mice show survival rates that are similar to those of wild-type mice. We demonstrate that such survival results from a skewed macrophage differentiation program in p47phox−/− mice that favors the production of higher levels of alternatively activated macrophages (AAMacs) compared with levels of either wild-type or gp91phox−/− mice. Furthermore, the adoptive transfer of AAMacs from p47phox−/− mice can rescue gp91phox−/− mice during primary Lm infection. Key features of the protective function provided by p47phox−/− AAMacs against Lm infection are enhanced production of IL-1α and killing of Lm. Molecular analysis of this process indicates that p47phox−/− macrophages are hyperresponsive to IL-4 and show higher Stat6 phosphorylation levels and signaling coupled to downstream activation of AAMac transcripts in response to IL-4 stimulation. Notably, restoring p47phox protein expression levels reverts the p47phox-dependent AAMac phenotype. Our results indicate that p47phox is a previously unrecognized regulator for IL-4 signaling pathways that are important for macrophage cell fate choice. PMID:22222227

  14. VDRL antibodies enhance phagocytosis of Treponema pallidum by macrophages.

    Science.gov (United States)

    Baker-Zander, S A; Shaffer, J M; Lukehart, S A

    1993-05-01

    Although reactivity in nontreponemal tests develops in patients with untreated syphilis, no immunologic function has been ascribed to these antibodies. This study demonstrates that rabbit antibodies induced by immunization with VDRL antigen and VDRL antibodies affinity-purified from syphilitic rabbit serum enhance phagocytosis of Treponema pallidum. The proportion of macrophages ingesting treponemes in the presence of these antisera was 45% +/- 5% and 27% +/- 4%, respectively, versus 14% +/- 3% for normal serum (P VDRL antibodies from syphilitic serum diminished but did not eliminate opsonization, suggesting at least two classes of target molecules. Despite opsonic capacity, VDRL antibodies fail to facilitate macrophage-mediated killing of T. pallidum. Nevertheless, VDRL-immunized rabbits are partially protected against T. pallidum infection, developing fewer lesions (delayed and smaller) than do unimmunized controls. These results suggest a heretofore unrecognized functional role for VDRL antibodies in syphilis infection.

  15. Replication of Yersinia pestis in interferon gamma-activated macrophages requires ripA, a gene encoded in the pigmentation locus.

    Science.gov (United States)

    Pujol, Céline; Grabenstein, Jens P; Perry, Robert D; Bliska, James B

    2005-09-06

    Yersinia pestis is a facultative intracellular bacterial pathogen that can replicate in macrophages. Little is known about the mechanism by which Y. pestis replicates in macrophages, and macrophage defense mechanisms important for limiting intracellular survival of Y. pestis have not been characterized. In this work, we investigated the ability of Y. pestis to replicate in primary murine macrophages that were activated with IFN-gamma. Y. pestis was able to replicate in macrophages that were activated with IFN-gamma after infection (postactivated). A region of chromosomal DNA known as the pigmentation (pgm) locus was required for replication in postactivated macrophages, and this replication was associated with reduced nitric oxide (NO) levels but not with reduced inducible NO synthase (iNOS) expression. Y. pestis delta pgm replicated in iNOS-/- macrophages that were postactivated with IFN-gamma, suggesting that killing of delta pgm Y. pestis is NO-dependent. A specific genetic locus within pgm, which shares similarity to a pathogenicity island in Salmonella, was shown to be required for replication of Y. pestis and restriction of NO levels in postactivated macrophages. These data demonstrate that intracellular Y. pestis can evade killing by macrophages that are exposed to IFN-gamma and identify a potential virulence gene encoded in the pgm locus that is required for this activity.

  16. Immunohistological studies on macrophages in lymph nodes of onchocerciasis patients after treatment with ivermectin.

    Science.gov (United States)

    Knab, J; Darge, K; Büttner, D W

    1997-12-01

    The role of macrophages in the killing and elimination of microfilariae (mf) was studied immunohistologically in 14 lymph nodes from 10 patients with generalized onchocerciasis 20-68 h after treatment with a single oral dose of 150 microg/kg ivermectin. Mf with signs of damage at light microscopical level were surrounded by a cellular infiltrate comprising macrophages, eosinophils and neutrophils, whereas light microscopically intact mf mostly showed no cellular reaction. Resident mature macrophages expressing the CD 68 epitope usually neither migrated nor attached to damaged mf, especially on the first and second day after ivermectin treatment. However, many young invading macrophages labelled for the L1 protein (antibodies 27 E 10, MAC 387, S 36.48 and 8.5C2) were found within the cellular infiltrate around damaged mf and in adherence to the mf in all lymph nodes after ivermectin treatment. Free L1 protein was observed on the cuticle of the mf. The attacking macrophages contained increased amounts of the enzymes lysozyme, alpha-1-antichymotrypsin and alpha-1-antitrypsin compared to resident macrophages. Free enzymes were found on the cuticle of the mf and around them, indicating a role of these enzymes in the inflammatory reaction to the parasites. The attacking macrophages were strongly labelled for human HLA-DR and they showed further an increased expression of the complement receptors CR1 (CD 35) for C3b and CR3 (CD 11b) for C3 bi in comparison to resident macrophages and thus were considered as activated macrophages. Rarely fragments of mf were seen within multinuclear macrophages. We conclude that young activated macrophages play a major role in the elimination of mf transported to the regional lymph nodes after ivermectin treatment. The immunohistological findings are in accordance with the assumption that these activated macrophages together with granulocytes contribute to the killing of the damaged mf. They also help to limit the damage of the host tissue

  17. Functional activity of monocytes and macrophages in HTLV-1 infected subjects.

    Directory of Open Access Journals (Sweden)

    Camila F Amorim

    2014-12-01

    Full Text Available The Human T lymphotropic virus type-1 (HTLV-1 infects predominantly T cells, inducing proliferation and lymphocyte activation. Additionally, HTLV-1 infected subjects are more susceptible to other infections caused by other intracellular agents. Monocytes/macrophages are important cells in the defense against intracellular pathogens. Our aims were to determine the frequency of monocytes subsets, expression of co-stimulatory molecules in these cells and to evaluate microbicidal ability and cytokine and chemokine production by macrophages from HTLV-1 infected subjects. Participants were 23 HTLV-1 carriers (HC, 22 HAM/TSP patients and 22 healthy subjects (HS not infected with HTLV-1. The frequencies of monocyte subsets and expression of co-stimulatory molecules were determined by flow cytometry. Macrophages were infected with L. braziliensis or stimulated with LPS. Microbicidal activity of macrophages was determined by optic microscopy. Cytokines/chemokines from macrophage supernatants were measured by ELISA. HAM/TSP patients showed an increase frequency of intermediate monocytes, but expression of co-stimulatory molecules was similar between the groups. Macrophages from HTLV-1 infected individuals were infected with L. braziliensis at the same ratio than macrophages from HS, and all the groups had the same ability to kill Leishmania parasites. However, macrophages from HTLV-1 infected subjects produced more CXCL9 and CCL5, and less IL-10 than cells from HS. While there was no correlation between IFN-γ and cytokine/chemokine production by macrophages, there was a correlation between proviral load and TNF and CXCL10. These data showed a dissociation between the inflammatory response and microbicidal ability of macrophages from HTLV-1 infected subjects. While macrophages ability to kill an intracellular pathogen did not differ among HTLV-1 infected subjects, these cells secreted high amount of chemokines even in unstimulated cultures. Moreover the

  18. Candida albicans Chitin Increases Arginase-1 Activity in Human Macrophages, with an Impact on Macrophage Antimicrobial Functions

    Science.gov (United States)

    MacCallum, Donna M.; Brown, Gordon D.

    2017-01-01

    ABSTRACT   The opportunistic human fungal pathogen Candida albicans can cause a variety of diseases, ranging from superficial mucosal infections to life-threatening systemic infections. Phagocytic cells of the innate immune response, such as neutrophils and macrophages, are important first-line responders to an infection and generate reactive oxygen and nitrogen species as part of their protective antimicrobial response. During an infection, host cells generate nitric oxide through the enzyme inducible nitric oxide synthase (iNOS) to kill the invading pathogen. Inside the phagocyte, iNOS competes with the enzyme arginase-1 for a common substrate, the amino acid l-arginine. Several pathogenic species, including bacteria and parasitic protozoans, actively modulate the production of nitric oxide by inducing their own arginases or the host’s arginase activity to prevent the conversion of l-arginine to nitric oxide. We report here that C. albicans blocks nitric oxide production in human-monocyte-derived macrophages by induction of host arginase activity. We further determined that purified chitin (a fungal cell wall polysaccharide) and increased chitin exposure at the fungal cell wall surface induces this host arginase activity. Blocking the C. albicans-induced arginase activity with the arginase-specific substrate inhibitor Nω-hydroxy-nor-arginine (nor-NOHA) or the chitinase inhibitor bisdionin F restored nitric oxide production and increased the efficiency of fungal killing. Moreover, we determined that C. albicans influences macrophage polarization from a classically activated phenotype toward an alternatively activated phenotype, thereby reducing antimicrobial functions and mediating fungal survival. Therefore, C. albicans modulates l-arginine metabolism in macrophages during an infection, potentiating its own survival. PMID:28119468

  19. Imaging and measuring the biophysical properties of Fc gamma receptors on single macrophages using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mi [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Lianqing, E-mail: lqliu@sia.cn [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xi, Ning [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong (China); Wang, Yuechao [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xiao, Xiubin [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China); Zhang, Weijing, E-mail: zhangwj3072@163.com [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)

    2013-09-06

    Highlights: •Nanoscale cellular ultra-structures of macrophages were observed. •The binding affinities of FcγRs were measured directly on macrophages. •The nanoscale distributions of FcγRs were mapped on macrophages. -- Abstract: Fc gamma receptors (FcγR), widely expressed on effector cells (e.g., NK cells, macrophages), play an important role in clinical cancer immunotherapy. The binding of FcγRs to the Fc portions of antibodies that are attached to the target cells can activate the antibody-dependent cell-mediated cytotoxicity (ADCC) killing mechanism which leads to the lysis of target cells. In this work, we used atomic force microscopy (AFM) to observe the cellular ultra-structures and measure the biophysical properties (affinity and distribution) of FcγRs on single macrophages in aqueous environments. AFM imaging was used to obtain the topographies of macrophages, revealing the nanoscale cellular fine structures. For molecular interaction recognition, antibody molecules were attached onto AFM tips via a heterobifunctional polyethylene glycol (PEG) crosslinker. With AFM single-molecule force spectroscopy, the binding affinities of FcγRs were quantitatively measured on single macrophages. Adhesion force mapping method was used to localize the FcγRs, revealing the nanoscale distribution of FcγRs on local areas of macrophages. The experimental results can improve our understanding of FcγRs on macrophages; the established approach will facilitate further research on physiological activities involved in antibody-based immunotherapy.

  20. System x(c)(-) regulates microglia and macrophage glutamate excitotoxicity in vivo.

    Science.gov (United States)

    Kigerl, Kristina A; Ankeny, Daniel P; Garg, Sanjay K; Wei, Ping; Guan, Zhen; Lai, Wenmin; McTigue, Dana M; Banerjee, Ruma; Popovich, Phillip G

    2012-01-01

    It is widely believed that microglia and monocyte-derived macrophages (collectively referred to as central nervous system (CNS) macrophages) cause excitotoxicity in the diseased or injured CNS. This view has evolved mostly from in vitro studies showing that neurotoxic concentrations of glutamate are released from CNS macrophages stimulated with lipopolysaccharide (LPS), a potent inflammogen. We hypothesized that excitotoxic killing by CNS macrophages is more rigorously controlled in vivo, requiring both the activation of the glutamate/cystine antiporter (system x(c)(-)) and an increase in extracellular cystine, the substrate that drives glutamate release. Here, we show that non-traumatic microinjection of low-dose LPS into spinal cord gray matter activates CNS macrophages but without causing overt neuropathology. In contrast, neurotoxic inflammation occurs when LPS and cystine are co-injected. Simultaneous injection of NBQX, an antagonist of AMPA glutamate receptors, reduces the neurotoxic effects of LPS+cystine, implicating glutamate as a mediator of neuronal cell death in this model. Surprisingly, neither LPS nor LPS+cystine adversely affects survival of oligodendrocytes or oligodendrocyte progenitor cells. Ex vivo analyses show that redox balance in microglia and macrophages is controlled by induction of system x(c)(-) and that high GSH:GSSG ratios predict the neurotoxic potential of these cells. Together, these data indicate that modulation of redox balance in CNS macrophages, perhaps through regulating system x(c)(-), could be a novel approach for attenuating injurious neuroinflammatory cascades.

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

    Science.gov (United States)

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

    2016-01-01

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

  2. Regulation of the formyl peptide receptor 1 (FPR1 gene in primary human macrophages.

    Directory of Open Access Journals (Sweden)

    Claudio Gemperle

    Full Text Available The formyl peptide receptor 1 (FPR1 is mainly expressed by mammalian phagocytic leukocytes and plays a role in chemotaxis, killing of microorganisms through phagocytosis, and the generation of reactive oxygen species. A large number of ligands have been identified triggering FPR1 including formylated and non-formylated peptides of microbial and endogenous origin. While the expression of FPR1 in neutrophils has been investigated intensively, knowledge on the regulation of FPR1 expression in polarized macrophages is lacking. In this study we show that primary human neutrophils, monocytes and resting macrophages do express the receptor on their cell surface. Polarization of macrophages with IFNγ, LPS and with the TLR8 ligand 3M-002 further increases FPR1 mRNA levels but does not consistently increase protein expression or chemotaxis towards the FPR1 ligand fMLF. In contrast, polarization of primary human macrophages with IL-4 and IL-13 leading to the alternative activated macrophages, reduces FPR1 cell surface expression and abolishes chemotaxis towards fMLF. These results show that M2 macrophages will not react to triggering of FPR1, limiting the role for FPR1 to chemotaxis and superoxide production of resting and pro-inflammatory M1 macrophages.

  3. Killing superalgebras for Lorentzian four-manifolds

    Science.gov (United States)

    de Medeiros, Paul; Figueroa-O'Farrill, José; Santi, Andrea

    2016-06-01

    We determine the Killing superalgebras underpinning field theories with rigid unextended supersymmetry on Lorentzian four-manifolds by re-interpreting them as filtered deformations of mathbb{Z} -graded subalgebras with maximum odd dimension of the N = 1 Poincaré superalgebra in four dimensions. Part of this calculation involves computing a Spencer cohomology group which, by analogy with a similar result in eleven dimensions, prescribes a notion of Killing spinor, which we identify with the defining condition for bosonic supersymmetric backgrounds of minimal off-shell supergravity in four dimensions. We prove that such Killing spinors always generate a Lie superalgebra, and that this Lie superalgebra is a filtered deformation of a subalgebra of the N = 1 Poincaré superalgebra in four dimensions. Demanding the flatness of the connection defining the Killing spinors, we obtain equations satisfied by the maximally supersymmetric backgrounds. We solve these equations, arriving at the classification of maximally supersymmetric backgrounds whose associated Killing superalgebras are precisely the filtered deformations we classify in this paper.

  4. Monocyte chemoattractant protein-1 (MCP-1 regulates macrophage cytotoxicity in abdominal aortic aneurysm.

    Directory of Open Access Journals (Sweden)

    Qiwei Wang

    Full Text Available AIMS: In abdominal aortic aneurysm (AAA, macrophages are detected in the proximity of aortic smooth muscle cells (SMCs. We have previously demonstrated in a murine model of AAA that apoptotic SMCs attract monocytes and other leukocytes by producing MCP-1. Here we tested whether infiltrating macrophages also directly contribute to SMC apoptosis. METHODS AND RESULTS: Using a SMC/RAW264.7 macrophage co-culture system, we demonstrated that MCP-1-primed RAWs caused a significantly higher level of apoptosis in SMCs as compared to control macrophages. Next, we detected an enhanced Fas ligand (FasL mRNA level and membrane FasL protein expression in MCP-1-primed RAWs. Neutralizing FasL blocked SMC apoptosis in the co-culture. In situ proximity ligation assay showed that SMCs exposed to primed macrophages contained higher levels of receptor interacting protein-1 (RIP1/Caspase 8 containing cell death complexes. Silencing RIP1 conferred apoptosis resistance to SMCs. In the mouse elastase injury model of aneurysm, aneurysm induction increased the level of RIP1/Caspase 8 containing complexes in medial SMCs. Moreover, TUNEL-positive SMCs in aneurysmal tissues were frequently surrounded by CD68(+/FasL(+ macrophages. Conversely, elastase-treated arteries from MCP-1 knockout mice display a reduction of both macrophage infiltration and FasL expression, which was accompanied by diminished apoptosis of SMCs. CONCLUSION: Our data suggest that MCP-1-primed macrophages are more cytotoxic. MCP-1 appears to modulate macrophage cytotoxicity by increasing the level of membrane bound FasL. Thus, we showed that MCP-1-primed macrophages kill SMCs through a FasL/Fas-Caspase8-RIP1 mediated mechanism.

  5. Interleukin-15 increases Paracoccidioides brasiliensis killing by human neutrophils.

    Science.gov (United States)

    Tavian, Elisandra Garcia; Dias-Melicio, Luciane Alarcão; Acorci, Michele Janegitz; Graciani, Ana Paula Bordon; Peraçoli, Maria Terezinha Serrão; Soares, Angela Maria Victoriano de Campos

    2008-01-01

    Interleukin-15 is a cytokine produced by a wide range of different cell types, including macrophages, in response to lipopolysaccharide or microbial infection. This cytokine may play a crucial role in the activation of phagocytic cells against pathogens, especially during innate immune response. The effects of IL-15 on human polymorphonuclear leukocyte fungicidal activity against a highly virulent Paracoccidioides brasiliensis strain were investigated. Pretreatment of human neutrophils from healthy individuals with IL-15 for 18 hours increased cell fungicidal activity in a dose-dependent manner. In addition, the exposure to IL-15 induced an increase in neutrophil oxidative burst as evaluated by superoxide anion and H(2)O(2) release. Catalase inhibited fungicidal activity supporting a role for H(2)O(2) in fungus killing. In contrast, IL-8 and TNF-alpha levels were not affected by IL-15 suggesting that its effects were not mediated by these cytokines. Together, these results show that IL-15 is a potent stimulant of antifungal activities in human neutrophils, at least in part by a mechanism dependent on oxidative metabolism.

  6. 33 CFR 117.801 - Newtown Creek, Dutch Kills, English Kills and their tributaries.

    Science.gov (United States)

    2010-07-01

    ... the Grand Street/Avenue Bridge, mile 3.1, across Newtown Creek (East Branch) between Brooklyn and..., DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117... apply to all bridges across Newtown Creek, Dutch Kills, English Kills, and their tributaries: (1) The...

  7. 75 FR 62469 - Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their...

    Science.gov (United States)

    2010-10-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their Tributaries, NY, Maintenance AGENCY: Coast Guard, DHS. ACTION: Notice of...

  8. 75 FR 30299 - Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their...

    Science.gov (United States)

    2010-06-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their Tributaries, NY, Maintenance AGENCY: Coast Guard, DHS. ACTION: Notice of...

  9. 9 CFR 113.206 - Wart Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Wart Vaccine, Killed Virus. 113.206... AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart Vaccine, Killed Virus. Wart Vaccine, Killed Virus, shall be...

  10. Membrane lipid peroxidation in copper alloy-mediated contact killing of Escherichia coli.

    Science.gov (United States)

    Hong, Robert; Kang, Tae Y; Michels, Corinne A; Gadura, Nidhi

    2012-03-01

    Copper alloy surfaces are passive antimicrobial sanitizing agents that kill bacteria, fungi, and some viruses. Studies of the mechanism of contact killing in Escherichia coli implicate the membrane as the target, yet the specific component and underlying biochemistry remain unknown. This study explores the hypothesis that nonenzymatic peroxidation of membrane phospholipids is responsible for copper alloy-mediated surface killing. Lipid peroxidation was monitored with the thiobarbituric acid-reactive substances (TBARS) assay. Survival, TBARS levels, and DNA degradation were followed in cells exposed to copper alloy surfaces containing 60 to 99.90% copper or in medium containing CuSO(4). In all cases, TBARS levels increased with copper exposure levels. Cells exposed to the highest copper content alloys, C11000 and C24000, exhibited novel characteristics. TBARS increased immediately at a very rapid rate but peaked at about 30 min. This peak was associated with the period of most rapid killing, loss in membrane integrity, and DNA degradation. DNA degradation is not the primary cause of copper-mediated surface killing. Cells exposed to the 60% copper alloy for 60 min had fully intact genomic DNA but no viable cells. In a fabR mutant strain with increased levels of unsaturated fatty acids, sensitivity to copper alloy surface-mediated killing increased, TBARS levels peaked earlier, and genomic DNA degradation occurred sooner than in the isogenic parental strain. Taken together, these results suggest that copper alloy surface-mediated killing of E. coli is triggered by nonenzymatic oxidative damage of membrane phospholipids that ultimately results in the loss of membrane integrity and cell death.

  11. IMMUNOBIOLOGICAL ACTIVITY OF REGULATORY PEPTIDE FRACTIONS SYNTHESIZED BY NEUTROPHILS, AS TESTED IN A MACROPHAGE MODEL

    Directory of Open Access Journals (Sweden)

    G. I. Vasilieva

    2010-01-01

    Full Text Available The article presents experimental data on regulatory effect of neutrophilokine helper fractions on the macrophage (Mph functional activity in the course of antiplague immunity formation. It has revealed that these fractions content biologically active, low-molecular weight peptides. They stimulate Mph killing activity by increasing phagosome-lysosome fusion, thus boosting transformation of monocytes to Mph, and causing redistribution of macrophage subpopulations in the total cellular pool. The helper effect of neutrophilokine fractions upon functional activity of MPh is more pronounced during secondary immune response.

  12. Bioelectric modulation of macrophage polarization

    Science.gov (United States)

    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.

  13. Synthetic cationic peptide IDR-1018 modulates human macrophage differentiation.

    Directory of Open Access Journals (Sweden)

    Olga M Pena

    Full Text Available Macrophages play a critical role in the innate immune response. To respond in a rapid and efficient manner to challenges in the micro-environment, macrophages are able to differentiate towards classically (M1 or alternatively (M2 activated phenotypes. Synthetic, innate defense regulators (IDR peptides, designed based on natural host defence peptides, have enhanced immunomodulatory activities and reduced toxicity leading to protection in infection and inflammation models that is dependent on innate immune cells like monocytes/macrophages. Here we tested the effect of IDR-1018 on macrophage differentiation, a process essential to macrophage function and the immune response. Using transcriptional, protein and systems biology analysis, we observed that differentiation in the presence of IDR-1018 induced a unique signature of immune responses including the production of specific pro and anti-inflammatory mediators, expression of wound healing associated genes, and increased phagocytosis of apoptotic cells. Transcription factor IRF4 appeared to play an important role in promoting this IDR-1018-induced phenotype. The data suggests that IDR-1018 drives macrophage differentiation towards an intermediate M1-M2 state, enhancing anti-inflammatory functions while maintaining certain pro-inflammatory activities important to the resolution of infection. Synthetic peptides like IDR-1018, which act by modulating the immune system, could represent a powerful new class of therapeutics capable of treating the rising number of multidrug resistant infections as well as disorders associated with dysregulated immune responses.

  14. Axial symmetry and conformal Killing vectors

    CERN Document Server

    Mars, M; Mars, Marc; Senovilla, Jose M.M.

    1993-01-01

    Axisymmetric spacetimes with a conformal symmetry are studied and it is shown that, if there is no further conformal symmetry, the axial Killing vector and the conformal Killing vector must commute. As a direct consequence, in conformally stationary and axisymmetric spacetimes, no restriction is made by assuming that the axial symmetry and the conformal timelike symmetry commute. Furthermore, we prove that in axisymmetric spacetimes with another symmetry (such as stationary and axisymmetric or cylindrically symmetric spacetimes) and a conformal symmetry, the commutator of the axial Killing vector with the two others mush vanish or else the symmetry is larger than that originally considered. The results are completely general and do not depend on Einstein's equations or any particular matter content.

  15. 'Total disability' and the wrongness of killing.

    Science.gov (United States)

    Omelianchuk, Adam

    2015-08-01

    Walter Sinnott-Armstrong and Franklin G Miller recently argued that the wrongness of killing is best explained by the harm that comes to the victim, and that 'total disability' best explains the nature of this harm. Hence, killing patients who are already totally disabled is not wrong. I maintain that their notion of total disability is ambiguous and that they beg the question with respect to whether there are abilities left over that remain relevant for the goods of personhood and human worth. If these goods remain, then something more is lost in death than in 'total disability,' and their explanation of what makes killing wrong comes up short. But if total disability is equivalent with death, then their argument is an interesting one.

  16. Trafficking of Estrella lausannensis in human macrophages.

    Science.gov (United States)

    Rusconi, Brigida; Kebbi-Beghdadi, Carole; Greub, Gilbert

    2015-07-01

    Estrella lausannensis is a new member of the Chlamydiales order. Like other Chlamydia-related bacteria, it is able to replicate in amoebae and in fish cell lines. A preliminary study investigating the pathogenic potential of Chlamydia-related bacteria found a correlation between antibody response to E. lausannensis and pneumonia in children. To further investigate the pathogenic potential of E. lausannensis, we determined its ability to grow in human macrophages and its intracellular trafficking. The replication in macrophages resulted in viable E. lausannensis; however, it caused a significant cytopathic effect. The intracellular trafficking of E. lausannensis was analyzed by determining the interaction of the Estrella-containing inclusions with various endocytic markers as well as host organelles. The E. lausannensis inclusion escaped the endocytic pathway rapidly avoiding maturation into phagolysosomes by preventing both EEA-1 and LAMP-1 accumulation. Compared to Waddlia chondrophila, another Chlamydia-related bacteria, the recruitment of mitochondria and endoplasmic reticulum was minimal for E. lausannensis inclusions. Estrella lausannensis appears to use a distinct source of nutrients and energy compared to other members of the Chlamydiales order. In conclusion, we hypothesize that E. lausannensis has a restricted growth in human macrophages, due to its reduced capacity to control programmed cell death.

  17. Ambiguities in 'killing' and 'letting die'.

    Science.gov (United States)

    Atkinson, G M

    1983-05-01

    In a recent article Carla Kary (1980) attempts to show that there can be a significant moral difference between instances of killing and letting die. I shall maintain in Section I that Kary's argument is somewhat weakened by her failure to note an important ambiguity in the notion of killing a person. I shall also argue in Section II that a similar ambiguity affects the notion of letting someone die, and that failure to note this latter ambiguity also weakens the position developed by Robert Coburn (1980) with regard to defective newborns.

  18. On the algebraic structure of Killing superalgebras

    CERN Document Server

    Figueroa-O'Farrill, José

    2016-01-01

    We study the algebraic structure of the Killing superalgebra of a supersymmetric $11$-dimensional supergravity background and show that it is isomorphic to a filtered deformation of a $\\mathbb Z$-graded subalgebra of the Poincar\\'e superalgebra. We then re-interpret the classification problem for backgrounds which preserve more than half of the supersymmetry as the classification problem of certain admissible filtered subdeformations of the Poincar\\'e superalgebra. In particular we relate the bosonic field equations of $11$-dimensional supergravity to the Jacobi identity of the Killing superalgebra and show in this way that preserving more than half the supersymmetry implies the bosonic field equations.

  19. "Drone Killings in Principle and in Practice"

    DEFF Research Database (Denmark)

    Dige, Morten

    2017-01-01

    to argue that what we see in the real world cases of drone killings is not merely an accidental or contingent use of drone technology. The real life use reflects to a large extent features that are inherent of the dominant drone systems that has been developed to date. What is being imagined "in principle......" is thus to a large extent drone killings in dreamland. I use an historic example as a point of reference and departure: the debate over the lawfulness of nuclear weapons....

  20. Killed oral cholera vaccines: history, development and implementation challenges.

    Science.gov (United States)

    Lopez, Anna Lena; Gonzales, Maria Liza Antoinette; Aldaba, Josephine G; Nair, G Balakrish

    2014-09-01

    Cholera is still a major global health problem, affecting mainly people living in unsanitary conditions and who are at risk for outbreaks of cholera. During the past decade, outbreaks are increasingly reported from more countries. From the early killed oral cholera vaccine, rapid improvements in vaccine development occurred as a result of a better understanding of the epidemiology of the disease, pathogenesis of cholera infection and immunity. The newer-generation oral killed cholera vaccines have been shown to be safe and effective in field trials conducted in cholera endemic areas. Likewise, they have been shown to be protective when used during outbreak settings. Aside from providing direct protection to vaccinated individuals, recent studies have demonstrated that these killed oral vaccines also confer indirect protection through herd immunity. Although new-generation oral cholera vaccines should not be considered in isolation from other preventive approaches in countries where they are most needed, especially improved water quality and sanitation, these vaccines serve as immediately available public health tools for preventing further morbidity and mortality from cholera. However, despite its availability for more than two decades, use of these vaccines has not been optimized. Although there are limitations of the currently available oral cholera vaccines, recent data show that the vaccines are safe, feasible to use even in difficult circumstances and able to provide protection in various settings. Clear identification of the areas and target population groups who will benefit from the use of the cholera vaccines will be required and strategies to facilitate accessibility and usage of these vaccines in these areas and population groups will need to be developed.

  1. Role of cytokines and nitric oxide in the induction of tuberculostatic macrophage functions

    Directory of Open Access Journals (Sweden)

    Vera L. Petricevich

    2000-01-01

    Full Text Available The aim of this study was to determine phenotypic differences when BCG invades macrophages. Bacilli prepared from the same BCG primary seed, but produced in different culture media, were analysed with respect to the ability to stimulate macrophages and the susceptibility to treatment with cytokines and nitric oxide (NO. Tumour necrosis factor (TNF activity was assayed by measuring its cytotoxic activity on L-929 cells, interleukin-6 (IL-6 and interferon γ (IFN-γ were assayed by enzyme-linked immunosorbent assay (ELISA, whereas NO levels were detected by Griess colorimetric reactions in the culture supernatant of macrophages incubated with IFN-γ , TNF or NO and subsequently exposed to either BCG-I or BCG-S. We found that BCG-I and BCGS bacilli showed different ability to simulate peritoneal macrophages. Similar levels of IL-6 were detected in stimulated macrophages with lysate from two BCG samples. The highest levels of TNF and IFN-γ were observed in macrophages treated with BCG-S and BCG-I, respectively. The highest levels of NO were observed in cultures stimulated for 48h with BCG-S. We also found a different susceptibility of the bacilli to ex ogenous treatm ent w ith IFN-γ and TNF which were capable of killing 60 and 70% of both bacilli, whereas NO was capable of killing about 98 and 47% of BCG-I and BCG-S, respectively. The amount of bacilli proportionally decreased with IFN-γ and TNF, suggesting a cytokine-related cytotox ic effect. Moreover, NO also decreased the viable number of bacilli. Interestingly, NO levels of peritoneal macrophages were significantly increased after cytokine treatment. This indicates that the treatment of macrophages with cytokines markedly reduced bacilli number and presented effects on NO production. The results obtained here emphasize the importance of adequate stimulation for guaranteeing efficient killing of bacilli. In this particular case, the IFN-γ and TNF were involved in the activation of macrophage

  2. SIV Infection of Lung Macrophages.

    Directory of Open Access Journals (Sweden)

    Yue Li

    Full Text Available HIV-1 depletes CD4+ T cells in the blood, lymphatic tissues, gut and lungs. Here we investigated the relationship between depletion and infection of CD4+ T cells in the lung parenchyma. The lungs of 38 Indian rhesus macaques in early to later stages of SIVmac251 infection were examined, and the numbers of CD4+ T cells and macrophages plus the frequency of SIV RNA+ cells were quantified. We showed that SIV infected macrophages in the lung parenchyma, but only in small numbers except in the setting of interstitial inflammation where large numbers of SIV RNA+ macrophages were detected. However, even in this setting, the number of macrophages was not decreased. By contrast, there were few infected CD4+ T cells in lung parenchyma, but CD4+ T cells were nonetheless depleted by unknown mechanisms. The CD4+ T cells in lung parenchyma were depleted even though they were not productively infected, whereas SIV can infect large numbers of macrophages in the setting of interstitial inflammation without depleting them. These observations point to the need for future investigations into mechanisms of CD4+ T cell depletion at this mucosal site, and into mechanisms by which macrophage populations are maintained despite high levels of infection. The large numbers of SIV RNA+ macrophages in lungs in the setting of interstitial inflammation indicates that lung macrophages can be an important source for SIV persistent infection.

  3. SLAM is a microbial sensor that regulates bacterial phagosome functions in macrophages.

    Science.gov (United States)

    Berger, Scott B; Romero, Xavier; Ma, Chunyan; Wang, Guoxing; Faubion, William A; Liao, Gongxian; Compeer, Ewoud; Keszei, Marton; Rameh, Lucia; Wang, Ninghai; Boes, Marianne; Regueiro, Jose R; Reinecker, Hans-Christian; Terhorst, Cox

    2010-10-01

    Phagocytosis is a pivotal process by which macrophages eliminate microorganisms after recognition by pathogen sensors. Here we unexpectedly found that the self ligand and cell surface receptor SLAM functioned not only as a costimulatory molecule but also as a microbial sensor that controlled the killing of gram-negative bacteria by macrophages. SLAM regulated activity of the NADPH oxidase NOX2 complex and phagolysosomal maturation after entering the phagosome, following interaction with the bacterial outer membrane proteins OmpC and OmpF. SLAM recruited a complex containing the intracellular class III phosphatidylinositol kinase Vps34, its regulatory protein kinase Vps15 and the autophagy-associated molecule beclin-1 to the phagosome, which was responsible for inducing the accumulation of phosphatidylinositol-3-phosphate, a regulator of both NOX2 function and phagosomal or endosomal fusion. Thus, SLAM connects the gram-negative bacterial phagosome to ubiquitous cellular machinery responsible for the control of bacterial killing.

  4. Differential timing of antibody-mediated phagocytosis and cell-free killing of invasive African Salmonella allows immune evasion.

    Science.gov (United States)

    Siggins, Matthew K; O'Shaughnessy, Colette M; Pravin, John; Cunningham, Adam F; Henderson, Ian R; Drayson, Mark T; MacLennan, Calman A

    2014-04-01

    Nontyphoidal Salmonellae commonly cause fatal bacteraemia in African children lacking anti-Salmonella antibodies. These are facultative intracellular bacteria capable of cell-free and intracellular survival within macrophages. To better understand the relationship between extracellular and intracellular infection in blood and general mechanisms of Ab-related protection against Salmonella, we used human blood and sera to measure kinetics of Ab and complement deposition, serum-mediated bactericidal killing and phagocytosis of invasive African Salmonella enterica serovar Typhimurium D23580. Binding of antibodies peaked by 30 s, but C3 deposition lagged behind, peaking after 2-4 min. C5b-9 deposition was undetectable until between 2 and 6 min and peaked after 10 min, after which time an increase in serum-mediated killing occurred. In contrast, intracellular, opsonized Salmonellae were readily detectable within 5 min. By 10 min, around half of monocytes and most neutrophils contained bacteria. The same kinetics of serum-mediated killing and phagocytosis were observed with S. enterica Typhimurium laboratory strain SL1344, and the S. enterica Enteritidis African invasive isolate D24954 and laboratory strain PT4. The differential kinetics between cell-free killing and phagocytosis of invasive nontyphoidal Salmonella allows these bacteria to escape the blood and establish intracellular infection before they are killed by the membrane attack complex.

  5. Killing Hitler: A Writer's Journey and Angst.

    Science.gov (United States)

    Thaler, Paul

    2002-01-01

    Describes the author's experiences in preparing a talk that "evokes the specter" of Adolf Hitler and in writing an historical account of a British plot to kill Hitler. Address the question of why the British allowed him to live that final year of the war. Muses on why scholars write, and the impact of violence and terrorism. (SG)

  6. A moral dilemma: killing and letting die.

    Science.gov (United States)

    Johnson, K

    Most health care professionals believe that there is a clear difference between killing and letting die, i.e. between active and passive euthanasia. Philosophers, however, have repeatedly attacked the moral validity of their argument. This article explores various related issues and theoretical approaches to the distinction between acts and omissions.

  7. Killing Hitler: A Writer's Journey and Angst.

    Science.gov (United States)

    Thaler, Paul

    2002-01-01

    Describes the author's experiences in preparing a talk that "evokes the specter" of Adolf Hitler and in writing an historical account of a British plot to kill Hitler. Address the question of why the British allowed him to live that final year of the war. Muses on why scholars write, and the impact of violence and terrorism. (SG)

  8. Gas Well Blowout Kills 243 People

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ At least 243 people have been killed and scores of others poisoned in a devastating blowout at a natural gas field in Southwest China's Chongqing municipality on December 24. The accident happened at the Chuandongbei gas field in Kaixian county of Chongqing municipality.

  9. School Shootings; Standards Kill Students and Society

    Science.gov (United States)

    Angert, Betsy L.

    2008-01-01

    School shootings have been in the news of late. People ponder what occurs in classrooms today. Why would a young person wish to take a life? Within educational institutions, the killings are a concern. In our dire attempt to teach the children and ensure student success, it seems many of our offspring are lost. Some students feel separate from…

  10. Functional TRAIL receptors in monocytes and tumor-associated macrophages: A possible targeting pathway in the tumor microenvironment

    Science.gov (United States)

    Liguori, Manuela; Buracchi, Chiara; Pasqualini, Fabio; Bergomas, Francesca; Pesce, Samantha; Sironi, Marina; Grizzi, Fabio; Mantovani, Alberto

    2016-01-01

    Despite the accepted dogma that TRAIL kills only tumor cells and spares normal ones, we show in this study that mononuclear phagocytes are susceptible to recombinant TRAIL via caspase-dependent apoptosis. Human resting monocytes and in vitro-differentiated macrophages expressed substantial levels of the functional TRAIL receptors (TRAIL-R1 and TRAIL-R2), while neutrophils and lymphocytes mostly expressed the non-signaling decoy receptor (TRAIL-R3). Accordingly, exclusively monocytes and macrophages activated caspase-8 and underwent apoptosis upon recombinant TRAIL treatment. TRAIL-Rs were up-regulated by anti-inflammatory agents (IL-10, glucocorticoids) and by natural compounds (Apigenin, Quercetin, Palmitate) and their treatment resulted in increased TRAIL-induced apoptosis. In mice, the only signaling TRAIL-R (DR5) was preferentially expressed by blood monocytes rather than neutrophils or lymphocytes. In both mice and humans, Tumor-Associated Macrophages (TAM) expressed functional TRAIL-R, while resident macrophages in normal tissues did not. As a proof of principle, we treated mice bearing a murine TRAIL-resistant fibrosarcoma with recombinant TRAIL. We observed significant decrease of circulating monocytes and infiltrating TAM, as well as reduced tumor growth and lower metastasis formation. Overall, these findings demonstrate that human and murine monocytes/macrophages are, among leukocytes, uniquely susceptible to TRAIL-mediated killing. This differential susceptibility to TRAIL could be exploited to selectively target macrophages in tumors. PMID:27191500

  11. Contagion in Mass Killings and School Shootings.

    Science.gov (United States)

    Towers, Sherry; Gomez-Lievano, Andres; Khan, Maryam; Mubayi, Anuj; Castillo-Chavez, Carlos

    2015-01-01

    Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts. Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed). We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event. We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015). We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001). All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

  12. Contagion in Mass Killings and School Shootings.

    Directory of Open Access Journals (Sweden)

    Sherry Towers

    Full Text Available Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts.Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed. We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event.We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015. We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001. All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

  13. Contagion in Mass Killings and School Shootings

    Science.gov (United States)

    Towers, Sherry; Gomez-Lievano, Andres; Khan, Maryam; Mubayi, Anuj; Castillo-Chavez, Carlos

    2015-01-01

    Background Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts. Methods Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed). We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event. Conclusions We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015). We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001). All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings. PMID:26135941

  14. Biomonitoring of industrial dusts on animals. II. Bioindication on alveolar macrophages.

    Science.gov (United States)

    Kaváciková, Z

    1986-01-01

    Rats and rabbits were exposed through the respiratory system to industrial dusts (magnesite emissions, solid wastes from nickel refinery dump, cement emissions) at biomonitory stations or in experimental chamber. Following exposure the animals were killed, the alveolar macrophages isolated and acid phosphatase and beta-glucuronidase estimated in the isolated cells. The activity of both enzymes was enhanced in the exposed animals in all cases. The enhancement was dependent on the length of exposure and amount of inhaled particles.

  15. Effect of iNOS inhibitor LNMMA along with antibiotics Chloramphenicol or Ofloxacin in murine peritoneal macrophages regulates S.aureus infection as well as inflammation: An in vitro study.

    Science.gov (United States)

    Dey, Somrita; Bishayi, Biswadev

    2017-04-01

    Death due to sepsis by S. aureus is rapidly increasing because of their potent weaponries against macrophage mediated killing. Macrophages serve as intracellular reservoirs of S. aureus. Although significant resources have been invested during the last decade in new treatments for sepsis, only antibiotic therapy has failed to improve outcomes. Moreover the host pathogen interaction resulted in host cell death triggering inflammation. So, successful therapy requires amalgamation of therapies to delineate pathogen along with providing protection to host cell. With this idea, LNMMA, the iNOS inhibitor is used along with antibiotics Ofloxacin or Chloramphenicol on S. aureus infected mouse peritoneal macrophage. ROS like H2O2, O2(-) production has been measured. NO inhibition by iNOS inhibitor and antioxidant levels has been analysed. COX2, TLR2 and iNOS expression along with proinflammatory cytokine level was studied. It was found that the use of iNOS inhibitor LNMMA along with antibiotics not only enhances bacterial clearance but also decreases proinflammatory responses in Staphylococcus aureus infected macrophages. Inhibition of TLR2 as well as COX2 has also been found in combined treatment groups. The use of iNOS inhibitor LNMMA plus Ofloxacin or Chloramphenicol pretreatment enhanced bacterial clearance by increasing ROS. Decreases in NO protect the cell from harmful peroxynitril as well as inflammatory damage by changes in iNOS, COX2 activity along with reduced proinflammatory cytokines like TNFα, IFNγ, IL1-β etc. Changes in antioxidant level has been found. This in-vitro realm of augmented bacterial clearance and regulated inflammation may be considered as a novel and important therapeutic intervention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. 'David and Goliath' of the soil food web - Flagellates that kill nematodes

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Rønn, Regin

    2008-01-01

    Nematodes and flagellates are important bacterial predators in soil and sediments. Generally, these organisms are considered to be competitors for bacterial food. We studied the interaction among flagellates and nematodes using axenic liquid cultures amended with heat-killed bacteria as food...... and showed for the first time that a small and common soil flagellate (Cercomonas sp.) is able to attack and kill the much larger nematode Caenorhabditis elegans. The killing process is not caused by soluble metabolites but requires direct contact between the flagellate cells and the nematode surface...... and occurs rapidly (within a few hours) at high flagellate density. At lower flagellate density, adult nematodes sometimes avoid attachment of flagellates, feed on them and become the dominant bacterial predator. Considering that bacterial feeders affect bacterial communities differently, and that one...

  17. Sabretoothed carnivores and the killing of large prey.

    Directory of Open Access Journals (Sweden)

    Ki Andersson

    Full Text Available Sabre-like canines clearly have the potential to inflict grievous wounds leading to massive blood loss and rapid death. Hypotheses concerning sabretooth killing modes include attack to soft parts such as the belly or throat, where biting deep is essential to generate strikes reaching major blood vessels. Sabretoothed carnivorans are widely interpreted as hunters of larger and more powerful prey than that of their present-day nonsabretoothed relatives. However, the precise functional advantage of the sabretooth bite, particularly in relation to prey size, is unknown. Here, we present a new point-to-point bite model and show that, for sabretooths, depth of the killing bite decreases dramatically with increasing prey size. The extended gape of sabretooths only results in considerable increase in bite depth when biting into prey with a radius of less than ∼10 cm. For sabretooths, this size-reversed functional advantage suggests predation on species within a similar size range to those attacked by present-day carnivorans, rather than "megaherbivores" as previously believed. The development of the sabretooth condition appears to represent a shift in function and killing behaviour, rather than one in predator-prey relations. Furthermore, our results demonstrate how sabretoothed carnivorans are likely to have evolved along a functionally continuous trajectory: beginning as an extension of a jaw-powered killing bite, as adopted by present-day pantherine cats, followed by neck-powered biting and thereafter shifting to neck-powered shear-biting. We anticipate this new insight to be a starting point for detailed study of the evolution of pathways that encompass extreme specialisation, for example, understanding how neck-powered biting shifts into shear-biting and its significance for predator-prey interactions. We also expect that our model for point-to-point biting and bite depth estimations will yield new insights into the behaviours of a broad range of

  18. The Endoplasmic Reticulum Stress Sensor Inositol-Requiring Enzyme 1α Augments Bacterial Killing through Sustained Oxidant Production.

    Science.gov (United States)

    Abuaita, Basel H; Burkholder, Kristin M; Boles, Blaise R; O'Riordan, Mary X

    2015-07-14

    Bacterial infection can trigger cellular stress programs, such as the unfolded protein response (UPR), which occurs when misfolded proteins accumulate within the endoplasmic reticulum (ER). Here, we used the human pathogen methicillin-resistant Staphylococcus aureus (MRSA) as an infection model to probe how ER stress promotes antimicrobial function. MRSA infection activated the most highly conserved unfolded protein response sensor, inositol-requiring enzyme 1α (IRE1α), which was necessary for robust bacterial killing in vitro and in vivo. The macrophage IRE1-dependent bactericidal activity required reactive oxygen species (ROS). Viable MRSA cells excluded ROS from the nascent phagosome and strongly triggered IRE1 activation, leading to sustained generation of ROS that were largely Nox2 independent. In contrast, dead MRSA showed early colocalization with ROS but was a poor activator of IRE1 and did not trigger sustained ROS generation. The global ROS stimulated by IRE1 signaling was necessary, but not sufficient, for MRSA killing, which also required the ER resident SNARE Sec22B for accumulation of ROS in the phagosomal compartment. Taken together, these results suggest that IRE1-mediated persistent ROS generation might act as a fail-safe mechanism to kill bacterial pathogens that evade the initial macrophage oxidative burst. Cellular stress programs have been implicated as important components of the innate immune response to infection. The role of the IRE1 pathway of the ER stress response in immune secretory functions, such as antibody production, is well established, but its contribution to innate immunity is less well defined. Here, we show that infection of macrophages with viable MRSA induces IRE1 activation, leading to bacterial killing. IRE1-dependent bactericidal activity required generation of reactive oxygen species in a sustained manner over hours of infection. The SNARE protein Sec22B, which was previously demonstrated to control ER

  19. Reciprocal interactions between endothelial cells and macrophages in angiogenic vascular niches

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Caroline; Squadrito, Mario Leonardo [The Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland); Iruela-Arispe, M. Luisa, E-mail: arispe@mcdb.ucla.edu [The Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland); Department of Molecular, Cell and Developmental Biology and Molecular Biology Institute, University of California, Los Angeles 90095, CA (United States); De Palma, Michele, E-mail: michele.depalma@epfl.ch [The Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland)

    2013-07-01

    The ability of macrophages to promote vascular growth has been associated with the secretion and local delivery of classic proangiogenic factors (e.g., VEGF-A and proteases). More recently, a series of studies have also revealed that physical contact of macrophages with growing blood vessels coordinates vascular fusion of emerging sprouts. Interestingly, the interactions between macrophages and vascular endothelial cells (ECs) appear to be bidirectional, such that activated ECs also support the expansion and differentiation of proangiogenic macrophages from myeloid progenitors. Here, we discuss recent findings suggesting that dynamic angiogenic vascular niches might also exist in vivo, e.g. in tumors, where sprouting blood vessels and immature myeloid cells like monocytes engage in heterotypic interactions that are required for angiogenesis. Finally, we provide an account of emerging mechanisms of cell-to-cell communication that rely on secreted microvesicles, such as exosomes, which can offer a vehicle for the rapid exchange of molecules and genetic information between macrophages and ECs engaged in angiogenesis. -- Highlights: • Macrophages promote angiogenesis by secreting proangiogenic factors. • Macrophages modulate angiogenesis via cell-to-cell contacts with endothelial cells. • Endothelial cells promote the differentiation of proangiogenic macrophages. • Macrophages and endothelial cells may cooperate to form angiogenic vascular niches.

  20. Minimally oxidized LDL offsets the apoptotic effects of extensively oxidized LDL and free cholesterol in macrophages.

    Science.gov (United States)

    Boullier, Agnès; Li, Yankun; Quehenberger, Oswald; Palinski, Wulf; Tabas, Ira; Witztum, Joseph L; Miller, Yury I

    2006-05-01

    Lipid-loaded macrophage-derived foam cells populate atherosclerotic lesions and produce many pro-inflammatory and plaque-destabilizing factors. An excessive accumulation of extensively oxidized low-density lipoprotein (OxLDL) or free cholesterol (FC), both of which are believed to be major lipid components of macrophages in advanced lesions, rapidly induces apoptosis in macrophages. Indeed, there is evidence of macrophage death in lesions, but how the surviving macrophages avoid death induced by OxLDL, FC, and other factors is not known. Minimally oxidized LDL (mmLDL), which is an early product of progressive LDL oxidation in atherosclerotic lesions, countered OxLDL-induced or FC-induced apoptosis and stimulated macrophage survival both in cell culture and in vivo. DNA fragmentation and caspase-3 activity in OxLDL-treated peritoneal macrophages were significantly reduced by coincubation with mmLDL. In a separate set of experiments, mmLDL significantly reduced annexin V binding to macrophages in which apoptosis was induced by FC loading. In both cellular models, mmLDL activated a pro-survival PI3K/Akt signaling pathway, and PI3K inhibitors, wortmannin and LY294002, eliminated the pro-survival effect of mmLDL. Immunohistochemical examination demonstrated phospho-Akt in murine atherosclerotic lesions. Minimally oxidized LDL, an early form of oxidized LDL in atherosclerotic lesions, may contribute to prolonged survival of macrophage foam cells in lesions via a PI3K/Akt-dependent mechanism.

  1. Neutrophils and intracellular pathogens: beyond phagocytosis and killing.

    Science.gov (United States)

    Appelberg, Rui

    2007-02-01

    Neutrophils are not simply scavenging phagocytes that clear extracellular spaces of rapidly proliferating microbes; they are also active in the control of infections by intracellular pathogens. Several mechanisms for nonphagocytic roles of neutrophils in protective immunity have been put forth over the years but further evidence has recently been accumulating at an increasing pace. In this review, I present the evidence that suggests neutrophils are involved in pathogen shuttling into the lymphoid tissues, in antigen presentation, and in early T cell recruitment and initiation of granuloma organization. Also, a clearer view on the antimicrobial molecules that can be acquired by macrophages to enhance their antimicrobial activity is now emerging. Finally, neutrophils can adversely affect immunity against certain parasites by causing immune deviation.

  2. DMPD: Macrophage-stimulating protein and RON receptor tyrosine kinase: potentialregulators of macrophage inflammatory activities. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12472665 Macrophage-stimulating protein and RON receptor tyrosine kinase: potential...:545-53. (.png) (.svg) (.html) (.csml) Show Macrophage-stimulating protein and RON receptor tyrosine kinase:... potentialregulators of macrophage inflammatory activities. PubmedID 12472665 Title Macrophage-stimulatin

  3. Dirac operators and Killing spinors with torsion; Dirac-Operatoren und Killing-Spinoren mit Torsion

    Energy Technology Data Exchange (ETDEWEB)

    Becker-Bender, Julia

    2012-12-17

    On a Riemannian spin manifold with parallel skew torsion, we use the twistor operator to obtain an eigenvalue estimate for the Dirac operator with torsion. We consider the equality case in dimensions four and six. In odd dimensions we describe Sasaki manifolds on which equality in the estimate is realized by Killing spinors with torsion. In dimension five we characterize all Killing spinors with torsion and obtain certain naturally reductive spaces as exceptional cases.

  4. Phagocytic receptors on macrophages distinguish between different Sporothrix schenckii morphotypes.

    Science.gov (United States)

    Guzman-Beltran, Silvia; Perez-Torres, Armando; Coronel-Cruz, Cristina; Torres-Guerrero, Haydee

    2012-10-01

    Sporothrix schenckii is a human pathogen that causes sporotrichosis, a cutaneous subacute or chronic mycosis. Little is known about the innate immune response and the receptors involved in host recognition and phagocytosis of S. schenckii. Here, we demonstrate that optimal phagocytosis of conidia and yeast is dependent on preimmune human serum opsonisation. THP-1 macrophages efficiently ingested opsonised conidia. Competition with D-mannose, methyl α-D-mannopyranoside, D-fucose, and N-acetyl glucosamine blocked this process, suggesting the involvement of the mannose receptor in binding and phagocytosis of opsonised conidia. Release of TNF-α was not stimulated by opsonised or non-opsonised conidia, although reactive oxygen species (ROS) were produced, resulting in the killing of conidia by THP-1 macrophages. Heat inactivation of the serum did not affect conidia internalization, which was markedly decreased for yeast cells, suggesting the role of complement components in yeast uptake. Conversely, release of TNF-α and production of ROS were induced by opsonised and non-opsonised yeast. These data demonstrate that THP-1 macrophages respond to opsonised conidia and yeast through different phagocytic receptors, inducing a differential cellular response. Conidia induces a poor pro-inflammatory response and lower rate of ROS-induced cell death, thereby enhancing the pathogen's survival.

  5. Killing and replacing queen-laid eggs: low cost of worker policing in the honeybee.

    Science.gov (United States)

    Kärcher, Martin H; Ratnieks, Francis L W

    2014-07-01

    Worker honeybees, Apis mellifera, police each other's reproduction by killing worker-laid eggs. Previous experiments demonstrated that worker policing is effective, killing most (∼98%) worker-laid eggs. However, many queen-laid eggs were also killed (∼50%) suggesting that effective policing may have high costs. In these previous experiments, eggs were transferred using forceps into test cells, mostly into unrelated discriminator colonies. We measured both the survival of unmanipulated queen-laid eggs and the proportion of removal errors that were rectified by the queen laying a new egg. Across 2 days of the 3-day egg stage, only 9.6% of the queen-laid eggs in drone cells and 4.1% in worker cells were removed in error. When queen-laid eggs were removed from cells, 85% from drone cells and 61% from worker cells were replaced within 3 days. Worker policing in the honeybee has a high benefit to policing workers because workers are more related to the queen's sons (brothers, r = 0.25) than sister workers' sons (0.15). This study shows that worker policing also has a low cost in terms of the killing of queen-laid eggs, as only a small proportion of queen-laid eggs are killed, most of which are rapidly replaced.

  6. Mechanism involved in phagocytosis and killing of Listeria monocytogenes by Acanthamoeba polyphaga.

    Science.gov (United States)

    Akya, Alisha; Pointon, Andrew; Thomas, Connor

    2009-10-01

    Intra-cellular pathogen, Listeria monocytogenes, is capable of invasion and survival within mammalian cells. However, Acanthamoeba polyphaga trophozoites phagocytose and rapidly degrade Listeria cells. In order to provide more information on amoeba phagocytosis and killing mechanisms, this study used several inhibitor agents known to affect the phagocytosis and killing of bacteria by eukaryotes. Amoebae were pre-treated with mannose, cytochalasin D, wortmannin, suramin, ammonium chloride, bafilomycin A and monensin followed by co-culture with bacteria. Phagocytosis and killing of bacterial cells by amoeba trophozoites was assessed using plate counting methods and microscopy. The data presented indicates that actin polymerisation and cytoskeletal rearrangement are involved in phagocytosis of L. monocytogenes cells by A. polyphaga trophozoites. Further, both phagosomal acidification and phagosome-lysosome fusion are involved in killing and degradation of L. monocytogenes cells by A. polyphaga. However, the mannose-binding protein receptor does not play an important role in uptake of bacteria by amoeba trophozoites. In conclusion, this data reveals the similar principles of molecular mechanisms used by different types of eukaryotes in uptake and killing of bacteria.

  7. Time-kill studies of tea tree oils on clinical isolates.

    Science.gov (United States)

    May, J; Chan, C H; King, A; Williams, L; French, G L

    2000-05-01

    Tea tree oil has recently emerged as an effective topical antimicrobial agent active against a wide range of organisms. Tea tree oil may have a clinical application in both the hospital and community, especially for clearance of methicillin-resistant Staphylococcus aureus (MRSA) carriage or as a hand disinfectant to prevent cross-infection with Gram-positive and Gramnegative epidemic organisms. Our study, based on the time-kill approach, determined the kill rate of tea tree oil against several multidrug-resistant organisms, including MRSA, glycopeptide-resistant enterococci, aminoglycoside-resistant klebsiellae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, and also against sensitive microorganisms. The study was performed with two chemically different tea tree oils. One was a standard oil and the other was Clone 88 extracted from a specially bred tree, which has been selected and bred for increased activity and decreased skin irritation. Our results confirm that the cloned oil had increased antimicrobial activity when compared with the standard oil. Most results indicated that the susceptibility pattern and Gram reaction of the organism did not influence the kill rate. A rapid killing time (less than 60 min) was achieved with both tea tree oils with most isolates, but MRSA was killed more slowly than other organisms.

  8. Macrophage Infiltration and Alternative Activation during Wound Healing Promote MEK1-Induced Skin Carcinogenesis.

    Science.gov (United States)

    Weber, Christine; Telerman, Stephanie B; Reimer, Andreas S; Sequeira, Ines; Liakath-Ali, Kifayathullah; Arwert, Esther N; Watt, Fiona M

    2016-02-15

    Macrophages are essential for the progression and maintenance of many cancers, but their role during the earliest stages of tumor formation is unclear. To test this, we used a previously described transgenic mouse model of wound-induced skin tumorigenesis, in which expression of constitutively active MEK1 in differentiating epidermal cells results in chronic inflammation (InvEE mice). Upon wounding, the number of epidermal and dermal monocytes and macrophages increased in wild-type and InvEE skin, but the increase was greater, more rapid, and more sustained in InvEE skin. Macrophage ablation reduced tumor incidence. Furthermore, bioluminescent imaging in live mice to monitor macrophage flux at wound sites revealed that macrophage accumulation was predictive of tumor formation; wounds with the greatest number of macrophages at day 5 went on to develop tumors. Gene expression profiling of flow-sorted monocytes, macrophages, and T cells from InvEE and wild-type skin showed that as wound healing progressed, InvEE macrophages altered their phenotype. Throughout wound healing and after wound closure, InvEE macrophages demonstrated sustained upregulation of several markers implicated in alternative macrophage activation including arginase-1 (ARG1) and mannose receptor (CD206). Notably, inhibition of ARG1 activity significantly reduced tumor formation and epidermal proliferation in vivo, whereas addition of L-arginase to cultured keratinocytes stimulated proliferation. We conclude that macrophages play a key role in early, inflammation-mediated skin tumorigenesis, with mechanistic evidence suggesting that ARG1 secretion drives tumor development by stimulating epidermal cell proliferation. These findings highlight the importance of cancer immunotherapies aiming to polarize tumor-associated macrophages toward an antitumor phenotype.

  9. Generation, culture and flow-cytometric characterization of primary mouse macrophages.

    Science.gov (United States)

    Schleicher, Ulrike; Bogdan, Christian

    2009-01-01

    Macrophages are not only host cells for many pathogens, but also fulfill several key functions in the innate and adaptive immune response, including the release of pro- and anti-inflammatory cytokines, the generation of organic and inorganic autacoids, the phagocytosis and killing of intracellular microorganisms or tumor cells, and the degradation and presentation of antigens. Several of these functions are shared by other immune cells, including dendritic cells, granulocytes, NK cells, and/or T lymphocytes. Thus, the analysis of macrophage functions in vitro using primary mouse cell populations requires standardized methods for the generation and culture of macrophages that guarantee high cell purity as well as the absence of stimulatory microbial contaminants. This chapter presents methodology to achieve these aims.

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

    Directory of Open Access Journals (Sweden)

    Susu M Zughaier

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  12. Cytotoxicity of polyaniline nanomaterial on rat celiac macrophages in vitro.

    Science.gov (United States)

    Li, Yu-Sang; Chen, Bei-Fan; Li, Xiao-Jun; Zhang, Wei Kevin; Tang, He-Bin

    2014-01-01

    Polyaniline nanomaterial (nPANI) is getting popular in many industrial fields due to its conductivity and stability. The fate and effect of nPANI in the environment is of paramount importance towards its technological applications. In this work, the cytotoxicity of nPANI, which was prepared by rapid surface polymerization, was studied on rat celiac macrophages. Cell viability of macrophages treated with various concentrations of nPANI and different periods ranging from 24 to 72 hours was tested by a MTT assay. Damages of nPANI to structures of macrophages were evaluated according to the exposure level of cellular reactive oxygen species (ROS) and change of mitochondrial membrane potential (MMP). We observed no significant effects of nPANI on the survival, ROS level and MMP loss of macrophages at concentrations up to 1 µg/ml. However, higher dose of nPANI (10 µg/ml or above) induced cell death, changes of ROS level and MMP. In addition, an increase in the expression level of caspase-3 protein and its activated form was detected in a Western blot assay under the high dose exposure of nPANI. All together, our experimental results suggest that the hazardous potential of nPANI on macrophages is time- and dose-dependent and high dose of nPANI can induce cell apoptosis through caspase-3 mediated pathway.

  13. Engineering attenuated virulence of a Theileria annulata-infected macrophage.

    Directory of Open Access Journals (Sweden)

    Nadia Echebli

    Full Text Available Live attenuated vaccines are used to combat tropical theileriosis in North Africa, the Middle East, India, and China. The attenuation process is empirical and occurs only after many months, sometimes years, of in vitro culture of virulent clinical isolates. During this extensive culturing, attenuated lines lose their vaccine potential. To circumvent this we engineered the rapid ablation of the host cell transcription factor c-Jun, and within only 3 weeks the line engineered for loss of c-Jun activation displayed in vitro correlates of attenuation such as loss of adhesion, reduced MMP9 gelatinase activity, and diminished capacity to traverse Matrigel. Specific ablation of a single infected host cell virulence trait (c-Jun induced a complete failure of Theileria annulata-transformed macrophages to disseminate, whereas virulent macrophages disseminated to the kidneys, spleen, and lungs of Rag2/γC mice. Thus, in this heterologous mouse model loss of c-Jun expression led to ablation of dissemination of T. annulata-infected and transformed macrophages. The generation of Theileria-infected macrophages genetically engineered for ablation of a specific host cell virulence trait now makes possible experimental vaccination of calves to address how loss of macrophage dissemination impacts the disease pathology of tropical theileriosis.

  14. Macrophage-mediated response to hypoxia in disease

    Directory of Open Access Journals (Sweden)

    Tazzyman S

    2014-11-01

    Full Text Available Simon Tazzyman,1 Craig Murdoch,2 James Yeomans,1 Jack Harrison,1 Munitta Muthana3 1Department of Oncology, 2School of Clinical Dentistry, 3Department of Infection and Immunity, University of Sheffield, Sheffield, UK Abstract: Hypoxia plays a critical role in the pathobiology of various inflamed, diseased tissues, including malignant tumors, atherosclerotic plaques, myocardial infarcts, the synovia of rheumatoid arthritic joints, healing wounds, and sites of bacterial infection. These areas of hypoxia form when the blood supply is occluded and/or the oxygen supply is unable to keep pace with cell growth and/or infiltration of inflammatory cells. Macrophages are ubiquitous in all tissues of the body and exhibit great plasticity, allowing them to perform divergent functions, including, among others, patrolling tissue, combating invading pathogens and tumor cells, orchestrating wound healing, and restoring homeostasis after an inflammatory response. The number of tissue macrophages increases markedly with the onset and progression of many pathological states, with many macrophages accumulating in avascular and necrotic areas, where they are exposed to hypoxia. Recent studies show that these highly versatile cells then respond rapidly to the hypoxia present by altering their expression of a wide array of genes. Here we review the evidence for hypoxia-driven macrophage inflammatory responses in various disease states, and how this influences disease progression and treatment. Keywords: macrophage, hypoxia, inflammation, cytokine

  15. Alternatively activated macrophages produce catecholamines to sustain adaptive thermogenesis

    Science.gov (United States)

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

    2011-01-01

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

  16. Cytotoxicity of polyaniline nanomaterial on rat celiac macrophages in vitro.

    Directory of Open Access Journals (Sweden)

    Yu-Sang Li

    Full Text Available Polyaniline nanomaterial (nPANI is getting popular in many industrial fields due to its conductivity and stability. The fate and effect of nPANI in the environment is of paramount importance towards its technological applications. In this work, the cytotoxicity of nPANI, which was prepared by rapid surface polymerization, was studied on rat celiac macrophages. Cell viability of macrophages treated with various concentrations of nPANI and different periods ranging from 24 to 72 hours was tested by a MTT assay. Damages of nPANI to structures of macrophages were evaluated according to the exposure level of cellular reactive oxygen species (ROS and change of mitochondrial membrane potential (MMP. We observed no significant effects of nPANI on the survival, ROS level and MMP loss of macrophages at concentrations up to 1 µg/ml. However, higher dose of nPANI (10 µg/ml or above induced cell death, changes of ROS level and MMP. In addition, an increase in the expression level of caspase-3 protein and its activated form was detected in a Western blot assay under the high dose exposure of nPANI. All together, our experimental results suggest that the hazardous potential of nPANI on macrophages is time- and dose-dependent and high dose of nPANI can induce cell apoptosis through caspase-3 mediated pathway.

  17. Killing, letting die, and withdrawing aid.

    Science.gov (United States)

    McMahan, Jeff

    1993-01-01

    One of the aims of this article is to contribute to the identification of the empirical criteria governing the use of the concepts of killing and letting die. I will not attempt a comprehensive analysis of the concepts but will limit the inquiry to certain problematic cases -- namely, cases involving the removal or withdrawal of life-supporting aid or protection. The analysis of these cases will, however, shed light on the criteria for distinguishing killing and letting die in other cases as well. My overall aims in the article are partly constructive and partly skeptical. I hope to advance our understanding of the nature of the distinction between killing and letting die. This, I believe, will enable us to defend the moral relevance of the distinction against certain objections -- in particular, objections that claim that the distinction fails to coincide with commonsense moral intuitions. Yet I will suggest that, as we get clearer about the nature of the distinction and the sources of its intuitive appeal, it may seem that the intuitions it supports are not so well grounded as one could wish.

  18. 9 CFR 113.214 - Parvovirus Vaccine, Killed Virus (Canine).

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Parvovirus Vaccine, Killed Virus... REQUIREMENTS Killed Virus Vaccines § 113.214 Parvovirus Vaccine, Killed Virus (Canine). Parvovirus Vaccine... established as follows: (1) Twenty-five parvovirus susceptible dogs (20 vaccinates and 5 controls) shall be...

  19. 9 CFR 113.203 - Feline Panleukopenia Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Feline Panleukopenia Vaccine, Killed... REQUIREMENTS Killed Virus Vaccines § 113.203 Feline Panleukopenia Vaccine, Killed Virus. Feline Panleukopenia... shall be individually tested for neutralizing antibody against feline panleukopenia virus to...

  20. 9 CFR 113.201 - Canine Distemper Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Canine Distemper Vaccine, Killed Virus... REQUIREMENTS Killed Virus Vaccines § 113.201 Canine Distemper Vaccine, Killed Virus. Canine Distemper Vaccine... canine distemper susceptible dogs (20 vaccinates and 5 controls) shall be used as test animals....

  1. 9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Mink Enteritis Vaccine, Killed Virus... REQUIREMENTS Killed Virus Vaccines § 113.204 Mink Enteritis Vaccine, Killed Virus. Mink Enteritis Vaccine... have developed mink enteritis following inoculation with virulent mink enteritis virus. Each...

  2. 9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Newcastle Disease Vaccine, Killed... REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle Disease Vaccine, Killed Virus. Newcastle Disease Vaccine... Newcastle disease virus supplied by or approved by Veterinary Services and the vaccinates observed each...

  3. It's not just conflict that motivates killing of orangutans.

    Directory of Open Access Journals (Sweden)

    Jacqueline T Davis

    Full Text Available We investigated why orangutans are being killed in Kalimantan, Indonesia, and the role of conflict in these killings. Based on an analysis of interview data from over 5,000 respondents in over 450 villages, we also assessed the socio-ecological factors associated with conflict and non-conflict killings. Most respondents never kill orangutans. Those who reported having personally killed an orangutan primarily did so for non-conflict reasons; for example, 56% of these respondents said that the reason they had killed an orangutan was to eat it. Of the conflict-related reasons for killing, the most common reasons orangutans were killed was fear of orangutans or in self-defence. A similar pattern was evident among reports of orangutan killing by other people in the villages. Regression analyses indicated that religion and the percentage of intact forest around villages were the strongest socio-ecological predictors of whether orangutans were killed for conflict or non-conflict related reasons. Our data indicate that between 44,170 and 66,570 orangutans were killed in Kalimantan within the respondents' active hunting lifetimes: between 12,690 and 29,024 for conflict reasons (95%CI and between 26,361 and 41,688 for non-conflict reasons (95% CI. These findings confirm that habitat protection alone will not ensure the survival of orangutans in Indonesian Borneo, and that effective reduction of orangutan killings is urgently needed.

  4. 9 CFR 113.212 - Bursal Disease Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Bursal Disease Vaccine, Killed Virus..., DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.212 Bursal Disease Vaccine, Killed Virus. Bursal Disease...

  5. 9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ..., Killed Virus. 113.208 Section 113.208 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian Encephalomyelitis Vaccine, Killed Virus....

  6. 9 CFR 113.213 - Pseudorabies Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Pseudorabies Vaccine, Killed Virus..., DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.213 Pseudorabies Vaccine, Killed Virus. Pseudorabies Vaccine,...

  7. Robust growth of avirulent phase II Coxiella burnetii in bone marrow-derived murine macrophages

    Science.gov (United States)

    Cockrell, Diane C.; Long, Carrie M.; Robertson, Shelly J.; Shannon, Jeffrey G.; Miller, Heather E.; Myers, Lara; Larson, Charles L.; Starr, Tregei; Beare, Paul A.

    2017-01-01

    transporter does not negatively impact NMII growth. Results with NMII were recapitulated in primary macrophages where C57BL/6J Nramp1+ BMDM efficiently killed Salmonella enterica serovar Typhimurium. M-CSF differentiated murine macrophages from bone marrow and conditional ER-Hoxb8 myeloid progenitors will be useful ex vivo models for studying Coxiella-macrophage interactions. PMID:28278296

  8. Further characterization of a highly attenuated Yersinia pestis CO92 mutant deleted for the genes encoding Braun lipoprotein and plasminogen activator protease in murine alveolar and primary human macrophages.

    Science.gov (United States)

    van Lier, Christina J; Tiner, Bethany L; Chauhan, Sadhana; Motin, Vladimir L; Fitts, Eric C; Huante, Matthew B; Endsley, Janice J; Ponnusamy, Duraisamy; Sha, Jian; Chopra, Ashok K

    2015-03-01

    We recently characterized the Δlpp Δpla double in-frame deletion mutant of Yersinia pestis CO92 molecularly, biologically, and immunologically. While Braun lipoprotein (Lpp) activates toll-like receptor-2 to initiate an inflammatory cascade, plasminogen activator (Pla) protease facilitates bacterial dissemination in the host. The Δlpp Δpla double mutant was highly attenuated in evoking bubonic and pneumonic plague, was rapidly cleared from mouse organs, and generated humoral and cell-mediated immune responses to provide subsequent protection to mice against a lethal challenge dose of wild-type (WT) CO92. Here, we further characterized the Δlpp Δpla double mutant in two murine macrophage cell lines as well as in primary human monocyte-derived macrophages to gauge its potential as a live-attenuated vaccine candidate. We first demonstrated that the Δpla single and the Δlpp Δpla double mutant were unable to survive efficiently in murine and human macrophages, unlike WT CO92. We observed that the levels of Pla and its associated protease activity were not affected in the Δlpp single mutant, and, likewise, deletion of the pla gene from WT CO92 did not alter Lpp levels. Further, our study revealed that both Lpp and Pla contributed to the intracellular survival of WT CO92 via different mechanisms. Importantly, the ability of the Δlpp Δpla double mutant to be phagocytized by macrophages, to stimulate production of tumor necrosis factor-α and interleukin-6, and to activate the nitric oxide killing pathways of the host cells remained unaltered when compared to the WT CO92-infected macrophages. Finally, macrophages infected with either the WT CO92 or the Δlpp Δpla double mutant were equally efficient in their uptake of zymosan particles as determined by flow cytometric analysis. Overall, our data indicated that although the Δlpp Δpla double mutant of Y. pestis CO92 was highly attenuated, it retained the ability to elicit innate and subsequent acquired immune

  9. DMPD: Monocyte/macrophage traffic in HIV and SIV encephalitis. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12960230 Monocyte/macrophage traffic in HIV and SIV encephalitis. Kim WK, Corey S, ...Show Monocyte/macrophage traffic in HIV and SIV encephalitis. PubmedID 12960230 Title Monocyte/macrophage traffic

  10. A whole-genome RNAi screen uncovers a novel role for human potassium channels in cell killing by the parasite Entamoeba histolytica.

    Science.gov (United States)

    Marie, Chelsea; Verkerke, Hans P; Theodorescu, Dan; Petri, William A

    2015-09-08

    The parasite Entamoeba histolytica kills human cells resulting in ulceration, inflammation and invasion of the colonic epithelium. We used the cytotoxic properties of ameba to select a genome-wide RNAi library to reveal novel host factors that control susceptibility to amebic killing. We identified 281 candidate susceptibility genes and bioinformatics analyses revealed that ion transporters were significantly enriched among susceptibility genes. Potassium (K(+)) channels were the most common transporter identified. Their importance was further supported by colon biopsy of humans with amebiasis that demonstrated suppressed K(+) channel expression. Inhibition of human K(+) channels by genetic silencing, pharmacologic inhibitors and with excess K(+) protected diverse cell types from E. histolytica-induced death. Contact with E. histolytica parasites triggered K(+) channel activation and K(+) efflux by intestinal epithelial cells, which preceded cell killing. Specific inhibition of Ca(2+)-dependent K(+) channels was highly effective in preventing amebic cytotoxicity in intestinal epithelial cells and macrophages. Blockade of K(+) efflux also inhibited caspase-1 activation, IL-1β secretion and pyroptotic death in THP-1 macrophages. We concluded that K(+) channels are host mediators of amebic cytotoxicity in multiple cells types and of inflammasome activation in macrophages.

  11. Zinc and zinc transporters in macrophages and their roles in efferocytosis in COPD.

    Directory of Open Access Journals (Sweden)

    Rhys Hamon

    Full Text Available Our previous studies have shown that nutritional zinc restriction exacerbates airway inflammation accompanied by an increase in caspase-3 activation and an accumulation of apoptotic epithelial cells in the bronchioles of the mice. Normally, apoptotic cells are rapidly cleared by macrophage efferocytosis, limiting any secondary necrosis and inflammation. We therefore hypothesized that zinc deficiency is not only pro-apoptotic but also impairs macrophage efferocytosis. Impaired efferocytic clearance of apoptotic epithelial cells by alveolar macrophages occurs in chronic obstructive pulmonary disease (COPD, cigarette-smoking and other lung inflammatory diseases. We now show that zinc is a factor in impaired macrophage efferocytosis in COPD. Concentrations of zinc were significantly reduced in the supernatant of bronchoalveolar lavage fluid of patients with COPD who were current smokers, compared to healthy controls, smokers or COPD patients not actively smoking. Lavage zinc was positively correlated with AM efferocytosis and there was decreased efferocytosis in macrophages depleted of Zn in vitro by treatment with the membrane-permeable zinc chelator TPEN. Organ and cell Zn homeostasis are mediated by two families of membrane ZIP and ZnT proteins. Macrophages of mice null for ZIP1 had significantly lower intracellular zinc and efferocytosis capability, suggesting ZIP1 may play an important role. We investigated further using the human THP-1 derived macrophage cell line, with and without zinc chelation by TPEN to mimic zinc deficiency. There was no change in ZIP1 mRNA levels by TPEN but a significant 3-fold increase in expression of another influx transporter ZIP2, consistent with a role for ZIP2 in maintaining macrophage Zn levels. Both ZIP1 and ZIP2 proteins were localized to the plasma membrane and cytoplasm in normal human lung alveolar macrophages. We propose that zinc homeostasis in macrophages involves the coordinated action of ZIP1 and ZIP2

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

    Science.gov (United States)

    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.

  13. Haemophilus ducreyi-induced interleukin-10 promotes a mixed M1 and M2 activation program in human macrophages.

    Science.gov (United States)

    Li, Wei; Katz, Barry P; Spinola, Stanley M

    2012-12-01

    During microbial infection, macrophages are polarized to classically activated (M1) or alternatively activated (M2) cells in response to microbial components and host immune mediators. Proper polarization of macrophages is critical for bacterial clearance. To study the role of macrophage polarization during Haemophilus ducreyi infection, we analyzed a panel of macrophage surface markers in skin biopsy specimens of pustules obtained from experimentally infected volunteers. Lesional macrophages expressed markers characteristic of both M1 and M2 polarization. Monocyte-derived macrophages (MDM) also expressed a mixed M1 and M2 profile of surface markers and cytokines/chemokines upon infection with H. ducreyi in vitro. Endogenous interleukin 10 (IL-10) produced by infected MDM downregulated and enhanced expression of several M1 and M2 markers, respectively. Bacterial uptake, mediated mainly by class A scavenger receptors, and activation of mitogen-activated protein kinase and phosphoinositide 3-kinase signaling pathways were required for H. ducreyi-induced IL-10 production in MDM. Compared to M1 cells, IL-10-polarized M2 cells displayed enhanced phagocytic activity against H. ducreyi and similar bacterial killing. Thus, IL-10-modulated macrophage polarization may contribute to H. ducreyi clearance during human infection.

  14. Apoptotic neutrophils containing Staphylococcus epidermidis stimulate macrophages to release the proinflammatory cytokines tumor necrosis factor-alpha and interleukin-6.

    Science.gov (United States)

    Wilsson, Asa; Lind, Sara; Ohman, Lena; Nilsdotter-Augustinsson, Asa; Lundqvist-Setterud, Helen

    2008-06-01

    Staphylococcus epidermidis infections are usually nosocomial and involve colonization of biomaterials. The immune defense system cannot efficiently control the bacteria during these infections, which often results in protracted chronic inflammation, in which a key event is disturbed removal of neutrophils by tissue macrophages. While ingesting uninfected apoptotic neutrophils, macrophages release anti-inflammatory cytokines that lead to resolution of inflammation. In clinical studies, we have previously found elevated levels of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 in synovial fluid from prostheses infected with coagulase negative staphylococci. We show that macrophages phagocytosing apoptotic neutrophils containing S. epidermidis released TNF-alpha and interleukin-6, whereas macrophages phagocytosing spontaneously apoptotic neutrophils did not. This difference was not due to dissimilar phagocytic capacities, because macrophages ingested both types of neutrophils to the same extent. The activation was induced mainly by the apoptotic neutrophils themselves, not by the few remaining extracellular bacteria. Macrophages were not activated by apoptotic neutrophils that contained paraformaldehyde-killed S. epidermidis. Proinflammatory reactions induced by clearance of apoptotic neutrophils containing S. epidermidis might represent an important mechanism to combat the infective agent. This activation of macrophages may contribute to the development of chronic inflammation instead of inflammation resolution.

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

    Directory of Open Access Journals (Sweden)

    Degang Yang

    2016-01-01

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

  16. Mutations of Francisella novicida that alter the mechanism of its phagocytosis by murine macrophages.

    Directory of Open Access Journals (Sweden)

    Xin-He Lai

    Full Text Available Infection with the bacterial pathogen Francisella tularensis tularensis (F. tularensis causes tularemia, a serious and debilitating disease. Francisella tularensis novicida strain U112 (abbreviated F. novicida, which is closely related to F. tularensis, is pathogenic for mice but not for man, making it an ideal model system for tularemia. Intracellular pathogens like Francisella inhibit the innate immune response, thereby avoiding immune recognition and death of the infected cell. Because activation of inflammatory pathways may lead to cell death, we reasoned that we could identify bacterial genes involved in inhibiting inflammation by isolating mutants that killed infected cells faster than the wild-type parent. We screened a comprehensive transposon library of F. novicida for mutant strains that increased the rate of cell death following infection in J774 macrophage-like cells, as compared to wild-type F. novicida. Mutations in 28 genes were identified as being hypercytotoxic to both J774 and primary macrophages of which 12 were less virulent in a mouse infection model. Surprisingly, we found that F. novicida with mutations in four genes (lpcC, manB, manC and kdtA were taken up by and killed macrophages at a much higher rate than the parent strain, even upon treatment with cytochalasin D (cytD, a classic inhibitor of macrophage phagocytosis. At least 10-fold more mutant bacteria were internalized by macrophages as compared to the parent strain if the bacteria were first fixed with formaldehyde, suggesting a surface structure is required for the high phagocytosis rate. However, bacteria were required to be viable for macrophage toxicity. The four mutant strains do not make a complete LPS but instead have an exposed lipid A. Interestingly, other mutations that result in an exposed LPS core were not taken up at increased frequency nor did they kill host cells more than the parent. These results suggest an alternative, more efficient macrophage

  17. Killing-Yano forms and Killing tensors on a warped space

    CERN Document Server

    Krtous, Pavel; Kolar, Ivan

    2015-01-01

    We formulate several criteria under which the symmetries associated with the Killing and Killing-Yano tensors on the base space can be lifted to the symmetries of the full warped geometry. The procedure is explicitly illustrated on several examples, providing new prototypes of spacetimes admitting such tensors. In particular, we study a warped product of two Kerr-NUT-(A)dS spacetimes and show that it gives rise to a new class of highly symmetric vacuum (with cosmological constant) black hole solutions that inherit many of the properties of the Kerr-NUT-(A)dS geometry.

  18. Micro-sociology of mass rampage killings.

    Science.gov (United States)

    Collins, Randall

    2014-01-01

    Spectacular but very rare violent events such as mass killings by habitual non-criminals cannot be explained by factors which are very widespread, such as possession of firearms, being a victim of bullying, an introvert, or a career failure. A stronger clue is clandestine preparation of attack by one or two individuals, against randomly chosen representatives of a hated collective identity. Mass killers develop a deep back-stage, obsessed with planning their attack, overcoming social inferiority and isolation by an emotion of clandestine excitement.

  19. CD8+ Granzyme B+–Mediated Tissue Injury vs. CD4+IFNγ+–Mediated Parasite Killing in Human Cutaneous Leishmaniasis

    Science.gov (United States)

    Santos, Claire da Silva; Boaventura, Viviane; Ribeiro Cardoso, Cristina; Tavares, Natalia; Lordelo, Morgana J; Noronha, Almério; Costa, Jackson; Borges, Valéria M.; de Oliveira, Camila I; Van Weyenbergh, Johan; Barral, Aldina; Barral-Netto, Manoel; Brodskyn, Cláudia Ida

    2013-01-01

    A protective or deleterious role of CD8+T cells in human cutaneous leishmaniasis (CL) has been debated. The present report explores the participation of CD8+T cells in disease pathogenesis as well as in parasite killing. CD8+T cells accumulated in CL lesions as suggested by a higher frequency of CD8+CD45RO+T cells and CD8+CLA+T cells compared with peripheral blood mononuclear cells. Upon Leishmania braziliensis restimulation, most of the CD8+T cells from the lesion expressed cytolytic markers, CD107a and granzyme B. Granzyme B expression in CL lesions positively correlated with lesion size and percentage of TUNEL-positive cells. We also observed a significantly higher percentage of TUNEL-positive cells and granzyme B expression in the biopsies of patients showing a more intense necrotic process. Furthermore, coculture of infected macrophages and CD8+T lymphocytes resulted in the release of granzyme B, and the use of granzyme B inhibitor, as well as z-VAD, Fas:Fc, or anti-IFN-γ, had no effect upon parasite killing. However, coculture of infected macrophages with CD4+T cells strongly increased parasite killing, which was completely reversed by anti-IFN-γ. Our results reveal a dichotomy in human CL: CD8+ granzyme B+T cells mediate tissue injury, whereas CD4+IFN-γ+T cells mediate parasite killing. PMID:23321919

  20. Imaging of macrophage-related lung diseases

    Energy Technology Data Exchange (ETDEWEB)

    Marten, Katharina; Hansell, David M. [Royal Brompton Hospital, Department of Radiology, London (United Kingdom)

    2005-04-01

    Macrophage-related pulmonary diseases are a heterogeneous group of disorders characterized by macrophage accumulation, activation or dysfunction. These conditions include smoking-related interstitial lung diseases, metabolic disorders such as Niemann-Pick or Gaucher disease, and rare primary lung tumors. High-resolution computed tomography abnormalities include pulmonary ground-glass opacification secondary to infiltration by macrophages, centrilobular nodules or interlobular septal thickening reflecting peribronchiolar or septal macrophage accumulation, respectively, emphysema caused by macrophage dysfunction, and honeycombing following macrophage-related lung matrix remodeling. (orig.)

  1. CD64-directed microtubule associated protein tau kills leukemic blasts ex vivo.

    Science.gov (United States)

    Mladenov, Radoslav; Hristodorov, Dmitrij; Cremer, Christian; Gresch, Gerrit; Grieger, Elena; Schenke, Lea; Klose, Diana; Amoury, Manal; Woitok, Mira; Jost, Edgar; Brümmendorf, Tim H; Fendel, Rolf; Fischer, Rainer; Stein, Christoph; Thepen, Theo; Barth, Stefan

    2016-10-11

    Fc gamma receptor I (FcγRI, CD64) is a well-known target antigen for passive immunotherapy against acute myeloid leukemia and chronic myelomonocytic leukemia. We recently reported the preclinical immunotherapeutic potential of microtubule associated protein tau (MAP) against a variety of cancer types including breast carcinoma and Hodgkin's lymphoma. Here we demonstrate that the CD64-directed human cytolytic fusion protein H22(scFv)-MAP kills ex vivo 15-50% of CD64+ leukemic blasts derived from seven myeloid leukemia patients. Furthermore, in contrast to the nonspecific cytostatic agent paclitaxel, H22(scFv)-MAP showed no cytotoxicity towards healthy CD64+ PBMC-derived cells and macrophages. The targeted delivery of this microtubule stabilizing agent therefore offers a promising new strategy for specific treatment of CD64+ leukemia.

  2. Interactions between macrophage/Kupffer cells and hepatocytes in surgical sepsis

    Energy Technology Data Exchange (ETDEWEB)

    West, M.A.

    1988-01-01

    Experiments were performed to investigate the role of Kupffer cell/macrophage interactions with hepatocytes in modulating liver function during infections using direct in vitro cocultivation of rat macrophages or Kupffer cells with rat hepatocytes. Protein synthesis was assayed as a sensitive indicator of integrated hepatocellular function by measuring {sup 3}H-leucine incorporation into hepatocyte protein. Septic stimuli such as lipoploysaccharide and killed bacteria were added to cocultures of hepatocytes and macrophages or Kupffer cells and the responses compared to hepatocytes alone. Information about the types of proteins synthesized by hepatocytes under various culture conditions was determined using polyacrylamide gel electrophoresis and autoradiography. These experiments showed that septic stimuli alter the amount and type of protein synthesized by hepatocytes and had no direct effect on hepatocytes in the absence of macrophages or Kupffer cells. The mediator(s) appears to be a heat labile, soluble monokine(s) which is distinct from interleukin-1 or tumor necrosis factor. The important role of Kupffer cells/macrophages in mediating alterations in hepatocellular function in sepsis may ultimately improve patient care.

  3. Where and How Wolves (Canis lupus) Kill Beavers (Castor canadensis).

    Science.gov (United States)

    Gable, Thomas D; Windels, Steve K; Bruggink, John G; Homkes, Austin T

    2016-01-01

    Beavers (Castor canadensis) can be a significant prey item for wolves (Canis lupus) in boreal ecosystems due to their abundance and vulnerability on land. How wolves hunt beavers in these systems is largely unknown, however, because observing predation is challenging. We inferred how wolves hunt beavers by identifying kill sites using clusters of locations from GPS-collared wolves in Voyageurs National Park, Minnesota. We identified 22 sites where wolves from 4 different packs killed beavers. We classified these kill sites into 8 categories based on the beaver-habitat type near which each kill occurred. Seasonal variation existed in types of kill sites as 7 of 12 (58%) kills in the spring occurred at sites below dams and on shorelines, and 8 of 10 (80%) kills in the fall occurred near feeding trails and canals. From these kill sites we deduced that the typical hunting strategy has 3 components: 1) waiting near areas of high beaver use (e.g., feeding trails) until a beaver comes near shore or ashore, 2) using vegetation, the dam, or other habitat features for concealment, and 3) immediately attacking the beaver, or ambushing the beaver by cutting off access to water. By identifying kill sites and inferring hunting behavior we have provided the most complete description available of how and where wolves hunt and kill beavers.

  4. Steel-Jawed Leghold Traps and Killing Neck Snares: Similar Injuries Command Change to Agreement on International Humane Trapping Standards.

    Science.gov (United States)

    Proulx, Gilbert; Rodtka, Dwight

    2017-01-01

    According to the Agreement on International Humane Trapping Standards (AIHTS), which was signed by the European Community, Canada, and Russia in 1997, killing devices used for the capture of canids and other fur-bearing nonhuman animals should render an animal irreversibly unconscious within 300 s. However, killing neck snares are not included in the agreement. In this commentary, a parallel is drawn between injuries caused by steel-jawed leghold traps, which have been banned by the AIHTS signatory countries, and killing neck snares to demonstrate that these snares should also be included in international humane trapping standards (i.e., AIHTS). Previous scientific investigations have shown that neither manual nor power-killing neck snares can consistently render canids unconscious rapidly. Animals caught in killing neck snares suffer injuries that are similar to or worse than those reported for leg-captured canids. The authors strongly recommend that AIHTS be modified to include killing neck snares and that such devices be subject to the criteria applied to other trapping devices. Alternative restraining trapping devices, which are effective and more humane, are available for capturing wild canids.

  5. Protection of Candida parapsilosis from neutrophil killing through internalization by human endothelial cells.

    Science.gov (United States)

    Glass, Kyle A; Longley, Sarah J; Bliss, Joseph M; Shaw, Sunil K

    2015-01-01

    Candida parapsilosis is a fungal pathogen that is associated with hematogenously disseminated disease in premature neonates, acutely ill or immunocompromised patients. In cell culture, C. parapsilosis cells are actively and avidly endocytosed by endothelial cells via actin polymerization mediated by N-WASP. Here we present evidence that C. parapsilosis that were internalized by endothelial cells remained alive, and avoided being acidified or otherwise damaged via the host cell. Internalized fungal cells reproduced intracellularly and eventually burst out of the host endothelial cell. When neutrophils were added to endothelium and C. parapsilosis, they patrolled the endothelial surface and efficiently killed most adherent fungal cells prior to endocytosis. But after endocytosis by endothelial cells, internalized fungal cells evaded neutrophil killing. Silencing endothelial N-WASP blocked endocytosis of C. parapsilosis and left fungal cells stranded on the cell surface, where they were susceptible to neutrophil killing. These observations suggest that for C. parapsilosis to escape from the bloodstream, fungi may adhere to and be internalized by endothelial cells before being confronted and phagocytosed by a patrolling leukocyte. Once internalized by endothelial cells, C. parapsilosis may safely replicate to cause further rounds of infection. Immunosurveillance of the intravascular lumen by leukocytes crawling on the endothelial surface and rapid killing of adherent yeast may play a major role in controlling C. parapsilosis dissemination and infected endothelial cells may be a significant reservoir for fungal persistence.

  6. Effect of aqueous extract of Tinospora cordifolia on functions of peritoneal macrophages isolated from CCl4 intoxicated male albino mice

    Directory of Open Access Journals (Sweden)

    Sharma Gauri D

    2011-10-01

    Full Text Available Abstract Background The current practice of ingesting phytochemicals for supporting the immune system or fighting infections is based on centuries-old tradition. Macrophages are involved at all the stages of an immune response. The present study focuses on the immunostimulant properties of Tinospora cordifolia extract that are exerted on circulating macrophages isolated from CCl4 (0.5 ml/kg body weight intoxicated male albino mice. Methods Apart from damaging the liver system, carbon tetrachloride also inhibits macrophage functions thus, creating an immunocompromised state, as is evident from the present study. Such cell functions include cell morphology, adhesion property, phagocytosis, enzyme release (myeloperoxidase or MPO, nitric oxide (NO release, intracellular survival of ingested bacteria and DNA fragmentation in peritoneal macrophages isolated from these immunocompromised mice. T. cordifolia extract was tested for acute toxicity at the given dose (150 mg/kg body weight by lactate dehydrogenase (LDH assay. Results The number of morphologically altered macrophages was increased in mice exposed to CCl4. Administration of CCl4 (i.p. also reduced the phagocytosis, cell adhesion, MPO release, NO release properties of circulating macrophages of mice. The DNA fragmentation of peritoneal macrophages was observed to be higher in CCl4 intoxicated mice. The bacterial killing capacity of peritoneal macrophages was also adversely affected by CCl4. However oral administration of aqueous fraction of Tinospora cordifolia stem parts at a dose of 40 mg/kg body weight (in vivo in CCl4 exposed mice ameliorated the effect of CCl4, as the percentage of morphologically altered macrophages, phagocytosis activity, cell adhesion, MPO release, NO release, DNA fragmentation and intracellular killing capacity of CCl4 intoxicated peritoneal macrophages came closer to those of the control group. No acute toxicity was identified in oral administration of the aqueous

  7. Cumene hydroperoxide debilitates macrophage physiology by inducing oxidative stress: possible protection by alpha-tocopherol.

    Science.gov (United States)

    Kaur, Gurpreet; Alam, M Sarwar; Athar, Mohammad

    2009-05-15

    Macrophages, the major phagocytes of body, are largely dependent on membrane for their apposite functioning. Cum-OOH, a catalyst used in chemical and pharmaceutical industry, is a peroxidative agent, which may induce oxidative stress in macrophages hampering the integrity of their membrane. Alpha-tocopherol is known to protect the membrane from oxidative modulation and preserve its integrity. In the present study, we investigated the effect of Cum-OOH on physiology of macrophages and evaluated the protective effect of alpha-tocopherol against Cum-OOH-induced functional impairment. An in vitro exposure to 10-200 microM Cum-OOH altered redox balance of murine peritoneal macrophages and led to a severe physiological impairment. It markedly augmented the release of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta and prostaglandin E(2)), lipopolysaccharide primed nitric oxide release and inducible nitric oxide synthase expression, and lysosomal hydrolases secretion. It mitigated respiratory burst and phagocytosis and intracellular killing of yeast (Saccharomyces cerevisiae). Mannose receptor, a major macrophage phagocytic receptor (also implicated in S. cerevisiae phagocytosis), exhibited a hampered recycling with its number being reduced to about 54% of the untreated, control cells following Cum-OOH exposure. A 24-h pretreatment of macrophages with 25 microM alpha-tocopherol preserved most of the assessed functions close to their corresponding control values. These data suggest that exposure to Cum-OOH may impair the physiology of immune cells such as macrophages and that supplementation with alpha-tocopherol can safeguard these cells against Cum-OOH toxicity.

  8. Isolation and culture of murine macrophages.

    Science.gov (United States)

    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.

  9. New model of macrophage acquisition of the lymphatic endothelial phenotype.

    Directory of Open Access Journals (Sweden)

    Kelly L Hall

    Full Text Available BACKGROUND: Macrophage-derived lymphatic endothelial cell progenitors (M-LECPs contribute to new lymphatic vessel formation, but the mechanisms regulating their differentiation, recruitment, and function are poorly understood. Detailed characterization of M-LECPs is limited by low frequency in vivo and lack of model systems allowing in-depth molecular analyses in vitro. Our goal was to establish a cell culture model to characterize inflammation-induced macrophage-to-LECP differentiation under controlled conditions. METHODOLOGY/PRINCIPAL FINDINGS: Time-course analysis of diaphragms from lipopolysaccharide (LPS-treated mice revealed rapid mobilization of bone marrow-derived and peritoneal macrophages to the proximity of lymphatic vessels followed by widespread (∼50% incorporation of M-LECPs into the inflamed lymphatic vasculature. A differentiation shift toward the lymphatic phenotype was found in three LPS-induced subsets of activated macrophages that were positive for VEGFR-3 and many other lymphatic-specific markers. VEGFR-3 was strongly elevated in the early stage of macrophage transition to LECPs but undetectable in M-LECPs prior to vascular integration. Similar transient pattern of VEGFR-3 expression was found in RAW264.7 macrophages activated by LPS in vitro. Activated RAW264.7 cells co-expressed VEGF-C that induced an autocrine signaling loop as indicated by VEGFR-3 phosphorylation inhibited by a soluble receptor. LPS-activated RAW264.7 macrophages also showed a 68% overlap with endogenous CD11b(+/VEGFR-3(+ LECPs in the expression of lymphatic-specific genes. Moreover, when injected into LPS- but not saline-treated mice, GFP-tagged RAW264.7 cells massively infiltrated the inflamed diaphragm followed by integration into 18% of lymphatic vessels. CONCLUSIONS/SIGNIFICANCE: We present a new model for macrophage-LECP differentiation based on LPS activation of cultured RAW264.7 cells. This system designated here as the "RAW model" mimics

  10. The eyeball killer: serial killings with postmortem globe enucleation.

    Science.gov (United States)

    Coyle, Julie; Ross, Karen F; Barnard, Jeffrey J; Peacock, Elizabeth; Linch, Charles A; Prahlow, Joseph A

    2015-05-01

    Although serial killings are relatively rare, they can be the cause of a great deal of anxiety while the killer remains at-large. Despite the fact that the motivations for serial killings are typically quite complex, the psychological analysis of a serial killer can provide valuable insight into how and why certain individuals become serial killers. Such knowledge may be instrumental in preventing future serial killings or in solving ongoing cases. In certain serial killings, the various incidents have a variety of similar features. Identification of similarities between separate homicidal incidents is necessary to recognize that a serial killer may be actively killing. In this report, the authors present a group of serial killings involving three prostitutes who were shot to death over a 3-month period. Scene and autopsy findings, including the unusual finding of postmortem enucleation of the eyes, led investigators to recognize the serial nature of the homicides.

  11. Chlordiazepoxide and diazepam induced mouse killing by rats.

    Science.gov (United States)

    Leaf, R C; Wnek, D J; Gay, P E; Corcia, R M; Lamon, S

    1975-10-14

    Chlordiazepoxide HCl, at dose levels from 2.5 mg/kg to 80 mg/kg, significantly increased the low base rates of mouse killing (3-9%) observed in large samples (N = 100/dose) of Holtzman strain albino male rats. Maximal killing rates were obtained at doses from 7.5 mg/kg to 20 mg/kg. Diazepam was equally effective, and several times more potent than chlordiazepoxide. Pentobarbital did not increase killing. Killing induced by chlordiazepoxide was blocked by d-amphetamine SO4, but not by l-amphetamine, at dose levels similar to those that block undrugged killing in this strain (ED50 = 1.5 mg/kg). Unlike pilocarpine-induced killing, the effects of chlordiazepoxide were not increased or decreased significantly by either peripherally or centrally active anticholinergic drugs, over wide dose ranges of these agents; nor were the effects of chlordiazepoxide increased by repeated daily administration.

  12. Susceptibility of Inbred Mice to Leishmania major Infection: Genetic Analysis of Macrophage Activation and Innate Resistance to Disease in Individual Progeny of P/J (Susceptible) and C3H/HeN (Resistant) Mice

    Science.gov (United States)

    1990-12-01

    mediated immu- ease and defective macrophage activation in Bx mice that nity in mice highly susceptible to Leishmania tropica . J. Exp. could not be...inbred mice to Leishmania tropica infec- tion: correlation of susceptibility with in vitro defective macro- LITERATURE CITED phage microbicidal...probability and phage activation to kill Leishmania tropica : characterization of statistics. Chemical Rubber Co., Cleveland. P/J mouse macrophage defects for

  13. f(R)-gravity from Killing tensors

    Science.gov (United States)

    Paliathanasis, Andronikos

    2016-04-01

    We consider f(R)-gravity in a Friedmann-Lemaître-Robertson-Walker spacetime with zero spatial curvature. We apply the Killing tensors of the minisuperspace in order to specify the functional form of f(R) and for the field equations to be invariant under Lie-Bäcklund transformations, which are linear in momentum (contact symmetries). Consequently, the field equations to admit quadratic conservation laws given by Noether’s theorem. We find three new integrable f(R)-models, for which, with the application of the conservation laws, we reduce the field equations to a system of two first-order ordinary differential equations. For each model we study the evolution of the cosmological fluid. We find that for each integrable model the cosmological fluid has an equation of state parameter, in which there is linear behavior in terms of the scale factor which describes the Chevallier, Polarski and Linder parametric dark energy model.

  14. Killing, letting die and moral perception.

    Science.gov (United States)

    Gillett, Grant

    1994-10-01

    There are a number of arguments that purport to show, in general terms, that there is no difference between killing and letting die. These are used to justify active euthanasia on the basis of the reasons given for allowing patients to die. I argue that the general and abstract arguments fail to take account of the complex and particular situations which are found in the care of those with terminal illness. When in such situations, there are perceptions and intuitions available that do not easily find propositional form but lead most of those whose practice is in the care of the dying to resist active euthanasia. I make a plea for their intuitions to be heeded above the sterile voice of abstract premises and arguments by examining the completeness of the outline form of the pro-euthanasia argument. In doing so, I make use of Nussbaum's discussion of moral perception and general claims to be found in the literature of moral particularism.

  15. Killing Symmetries in $\\mathcal{H}$-Spaces with $\\Lambda$

    CERN Document Server

    Chudecki, Adam

    2013-01-01

    All Killing symmetries in complex $\\mathcal{H}$-spaces with $\\Lambda$ in terms of the Pleba\\'nski - Robinson - Finley coordinate system are found. All $\\mathcal{H}$-metrics with $\\Lambda$ admitting a null Killing vector are explicitly given. It is shown that the problem of non-null Killing vector reduces to looking for solution of the Boyer - Finley - Pleba\\'nski (Toda field) equation

  16. The geometry of D=11 null killing spinors

    Energy Technology Data Exchange (ETDEWEB)

    Gauntlett, Jerome P.; Gutowski, Jan B. E-mail: gutowski@maths.ox.ac.uk; Stathis Pakis

    2003-12-01

    We determine the necessary and sufficient conditions on the metric and the four-form for the most general bosonic supersymmetric configurations of D=11 supergravity which admit a null Killing spinor i.e. a Killing spinor which can be used to construct a null Killing vector. This class covers all supersymmetric time-dependent configurations and completes the classification of the most general supersymmetric configurations initiated in hep-th/0212008. (author)

  17. The Geometry of D=11 Null Killing Spinors

    CERN Document Server

    Gauntlett, J P; Pakis, S

    2003-01-01

    We determine the necessary and sufficient conditions on the metric and the four-form for the most general bosonic supersymmetric configurations of D=11 supergravity which admit a null Killing spinor i.e. a Killing spinor which can be used to construct a null Killing vector. This class covers all supersymmetric time-dependent configurations and completes the classification of the most general supersymmetric configurations initiated in hep-th/0212008.

  18. Effects of linalool and eugenol on the survival of Leishmania (L.) infantum chagasi within macrophages.

    Science.gov (United States)

    Dutra, Fernando L; Oliveira, Maurício M; Santos, Reinaldo S; Silva, Wagner Seixas; Alviano, Daniela S; Vieira, Danielle P; Lopes, Angela H

    2016-12-01

    The most commonly used drugs against visceral leishmaniasis are based on pentavalent antimonial compounds, which have played a fundamental role in therapy for over 70 years. However, the treatment is painful and has severe toxic side effects that can be fatal. Antimonial resistance is spreading and reaching alarming proportions. Linalool and eugenol have been shown to kill Leishmania (L.) amazonensis and Trypanosoma cruzi at low doses. In the present study, we demonstrate the effects of linalool and eugenol, components of essential oils, on Leishmania (L.) infantum chagasi, one of the causative agents of visceral leishmaniasis. We compared the effects of those compounds to the effects of glucantime, a positive control. In L. infantum chagasi killing assays, the LD50 for eugenol was 220μg/ml, and that for linalool was 550μg/ml. L. infantum chagasi was added to cultures of peritoneal mouse macrophages for four hours prior to drug treatment. Eugenol and linalool significantly decreased the number of parasites within the macrophages. Eugenol and linalool enhanced the activities of the L. infantum chagasi protein kinases PKA and PKC. Linalool also decreased L. infantum chagasi oxygen consumption. In conclusion, both linalool and eugenol promoted a decrease in the proliferation and viability of L. infantum chagasi. These effects were more pronounced during the interaction between the parasites and peritoneal mouse macrophages.

  19. Female resistance to pneumonia identifies lung macrophage nitric oxide synthase-3 as a therapeutic target

    Science.gov (United States)

    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

  20. Antibacterial activity of silver-killed bacteria: the "zombies" effect

    Science.gov (United States)

    Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David

    2015-04-01

    We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

  1. Comparative speed of kill of sarolaner (Simparica™) and afoxolaner (NexGard®) against induced infestations of Rhipicephalus sanguineus s.l. on dogs

    OpenAIRE

    Six, Robert H.; Young, David R.; Holzmer, Susan J.; Mahabir, Sean P.

    2016-01-01

    Background The brown dog tick, Rhipicephalus sanguineus sensu lato, commonly infests dogs globally, is the major vector of the pathogen that causes canine monocytic ehrlichiosis and also transmits Babesia vogeli. A rapid speed of kill of a parasiticide is essential to reduce the direct deleterious effects of tick infestation and the risk of tick-borne pathogen transmission. The speed of kill of a novel orally administered isoxazoline parasiticide, sarolaner (Simparica™), against R. sanguineus...

  2. Comparative speed of kill of sarolaner (Simparica™) and afoxolaner (NexGard®) against induced infestations of Ctenocephalides felis on dogs

    OpenAIRE

    Six, Robert H.; Liebenberg, Julian; Honsberger, Nicole A.; Mahabir, Sean P.

    2016-01-01

    Background Fleas are the most common ectoparasite infesting dogs globally. The many possible sequellae of infestation include: direct discomfort; allergic reactions; and the transmission of pathogens. Rapid speed of kill is an important characteristic for a parasiticide in order to alleviate the direct deleterious effects of fleas, reduce the impact of allergic responses, and break the flea infestation cycle. In this study, the speed of kill of a novel orally administered isoxazoline parasiti...

  3. Burkholderia pseudomallei-induced expression of a negative regulator, sterile-alpha and Armadillo motif-containing protein, in mouse macrophages: a possible mechanism for suppression of the MyD88-independent pathway.

    Science.gov (United States)

    Pudla, M; Limposuwan, K; Utaisincharoen, P

    2011-07-01

    Burkholderia pseudomallei, a causative agent of melioidosis, is a Gram-negative facultative intracellular bacterium that can survive and multiply in macrophages. Previously, we demonstrated that B. pseudomallei failed to activate gene expression downstream of the MyD88-independent pathway, particularly the expression of beta interferon (IFN-β) and inducible nitric oxide synthase (iNOS), leading to the inability of macrophages to kill this bacterium. In the present report, we extended our study to show that B. pseudomallei was able to activate sterile-α and Armadillo motif (SARM)-containing protein, a known negative regulator of the MyD88-independent pathway. Both live B. pseudomallei and heat-killed B. pseudomallei were able to upregulate SARM expression in a time-dependent manner in mouse macrophage cell line RAW 264.7. The expression of SARM required bacterial internalization, as it could be inhibited by cytochalasin D. In addition, the intracellular survival of B. pseudomallei was suppressed in SARM-deficient macrophages. Increased expression of IFN-β and iNOS and degradation of IκBα correlated with enhanced macrophage killing capability. These results demonstrated that B. pseudomallei modulated macrophage defense mechanisms by upregulating SARM, thus leading to the suppression of IFN-β and iNOS needed for bacterial elimination.

  4. Burkholderia pseudomallei-Induced Expression of a Negative Regulator, Sterile-α and Armadillo Motif-Containing Protein, in Mouse Macrophages: a Possible Mechanism for Suppression of the MyD88-Independent Pathway ▿

    Science.gov (United States)

    Pudla, M.; Limposuwan, K.; Utaisincharoen, P.

    2011-01-01

    Burkholderia pseudomallei, a causative agent of melioidosis, is a Gram-negative facultative intracellular bacterium that can survive and multiply in macrophages. Previously, we demonstrated that B. pseudomallei failed to activate gene expression downstream of the MyD88-independent pathway, particularly the expression of beta interferon (IFN-β) and inducible nitric oxide synthase (iNOS), leading to the inability of macrophages to kill this bacterium. In the present report, we extended our study to show that B. pseudomallei was able to activate sterile-α and Armadillo motif (SARM)-containing protein, a known negative regulator of the MyD88-independent pathway. Both live B. pseudomallei and heat-killed B. pseudomallei were able to upregulate SARM expression in a time-dependent manner in mouse macrophage cell line RAW 264.7. The expression of SARM required bacterial internalization, as it could be inhibited by cytochalasin D. In addition, the intracellular survival of B. pseudomallei was suppressed in SARM-deficient macrophages. Increased expression of IFN-β and iNOS and degradation of IκBα correlated with enhanced macrophage killing capability. These results demonstrated that B. pseudomallei modulated macrophage defense mechanisms by upregulating SARM, thus leading to the suppression of IFN-β and iNOS needed for bacterial elimination. PMID:21555400

  5. Macrophage responsiveness to light therapy

    Energy Technology Data Exchange (ETDEWEB)

    Young, S.; Bolton, P.; Dyson, M.; Harvey, W.; Diamantopoulos, C. (United Medical School, London (England))

    1989-01-01

    Macrophages are a source of many important mediators of wound repair. It was the purpose of this study to see if light could stimulate the release of these mediators. In this study an established macrophage-like cell line (U-937) was used. The cells were exposed in culture to the following wavelengths of light: 660 nm, 820 nm, 870 nm, and 880 nm. The 820-nm source was coherent and polarised, and the others were non-coherent. Twelve hours after exposure the macrophage supernatant was removed and placed on 3T3 fibroblast cultures. Fibroblast proliferation was assessed over a 5-day period. The results showed that 660-nm, 820-nm, and 870-nm wavelengths encouraged the macrophages to release factors that stimulated fibroblast proliferation above the control levels, whereas the 880-nm wavelength either inhibited the release of these factors or encouraged the release of some inhibitory factors of fibroblast proliferation. These results suggest that light at certain wavelengths may be a useful therapeutic agent by providing a means of either stimulating or inhibiting fibroblast proliferation where necessary. At certain wavelengths coherence is not essential.

  6. The genetic basis of Escherichia coli pathoadaptation to macrophages.

    Directory of Open Access Journals (Sweden)

    Migla Miskinyte

    Full Text Available Antagonistic interactions are likely important driving forces of the evolutionary process underlying bacterial genome complexity and diversity. We hypothesized that the ability of evolved bacteria to escape specific components of host innate immunity, such as phagocytosis and killing by macrophages (MΦ, is a critical trait relevant in the acquisition of bacterial virulence. Here, we used a combination of experimental evolution, phenotypic characterization, genome sequencing and mathematical modeling to address how fast, and through how many adaptive steps, a commensal Escherichia coli (E. coli acquire this virulence trait. We show that when maintained in vitro under the selective pressure of host MΦ commensal E. coli can evolve, in less than 500 generations, virulent clones that escape phagocytosis and MΦ killing in vitro, while increasing their pathogenicity in vivo, as assessed in mice. This pathoadaptive process is driven by a mechanism involving the insertion of a single transposable element into the promoter region of the E. coli yrfF gene. Moreover, transposition of the IS186 element into the promoter of Lon gene, encoding an ATP-dependent serine protease, is likely to accelerate this pathoadaptive process. Competition between clones carrying distinct beneficial mutations dominates the dynamics of the pathoadaptive process, as suggested from a mathematical model, which reproduces the observed experimental dynamics of E. coli evolution towards virulence. In conclusion, we reveal a molecular mechanism explaining how a specific component of host innate immunity can modulate microbial evolution towards pathogenicity.

  7. Inflammasome sensor NLRP1 controls rat macrophage susceptibility to Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Kimberly M Cirelli

    2014-03-01

    Full Text Available Toxoplasma gondii is an intracellular parasite that infects a wide range of warm-blooded species. Rats vary in their susceptibility to this parasite. The Toxo1 locus conferring Toxoplasma resistance in rats was previously mapped to a region of chromosome 10 containing Nlrp1. This gene encodes an inflammasome sensor controlling macrophage sensitivity to anthrax lethal toxin (LT induced rapid cell death (pyroptosis. We show here that rat strain differences in Toxoplasma infected macrophage sensitivity to pyroptosis, IL-1β/IL-18 processing, and inhibition of parasite proliferation are perfectly correlated with NLRP1 sequence, while inversely correlated with sensitivity to anthrax LT-induced cell death. Using recombinant inbred rats, SNP analyses and whole transcriptome gene expression studies, we narrowed the candidate genes for control of Toxoplasma-mediated rat macrophage pyroptosis to four genes, one of which was Nlrp1. Knockdown of Nlrp1 in pyroptosis-sensitive macrophages resulted in higher parasite replication and protection from cell death. Reciprocally, overexpression of the NLRP1 variant from Toxoplasma-sensitive macrophages in pyroptosis-resistant cells led to sensitization of these resistant macrophages. Our findings reveal Toxoplasma as a novel activator of the NLRP1 inflammasome in rat macrophages.

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

    Directory of Open Access Journals (Sweden)

    Mary Philip

    2016-01-01

    Full Text Available 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.

  9. Optimisation and standardisation of functional immune assays for striped catfish (Pangasianodon hypophthalmus) to compare their immune response to live and heat killed Aeromonas hydrophila as models of infection and vaccination.

    Science.gov (United States)

    Sirimanapong, Wanna; Thompson, Kim D; Kledmanee, Kan; Thaijongrak, Prawporn; Collet, Bertrand; Ooi, Ei Lin; Adams, Alexandra

    2014-10-01

    Aquaculture production of Pangasianodon hypophthalmus is growing rapidly in South East Asia, especially in Vietnam. As it is a relatively new aquaculture species there are few reports evaluating its immune response to pathogens. Thus, functional assays for P. hypophthalmus were optimised to evaluate both innate and adaptive immune responses, and were then used to examine immune response following stimulation with live and heat-killed Aeromonas hydrophila. These were used as models of infection and vaccination, respectively. Four treatment groups were used, including a control group, a group injected intraperitonally (IP) with adjuvant only, a group injected with heat-killed A. hydrophila (1 × 10(9) cfu ml(-1) mixed with adjuvant), and a group injected with a subclinical dose of live A. hydrophila. Samples were collected at 0, 1, 3, 7, 14 and 21 days post-injection (d.p.i.) to assess their immune response. The results indicated that challenge with live or dead bacteria stimulated the immune response in P. hypophthalmus significantly above the levels observed in control groups with respect to specific antibody titre, plasma lysozyme and peroxidase activity, and phagocytosis by head kidney macrophages at 7 or/and 14 d.p.i. At 21 d.p.i., total and specific antibody (IgM) levels and plasma lysozyme activity in fish injected with either live or dead A. hydrophila were significantly different to the control groups. Differential immune responses were observed between fish injected with either live or dead bacteria, with live A. hydrophila significantly stimulating an increase in WBC counts and plasma peroxidase activity at 3 d.p.i., with the greatest increase in WBC counts noted at 21 d.p.i. and in phagocytosis at 14 d.p.i. By 21 d.p.i. only the macrophages from fish injected with dead A. hydrophila showed significantly stimulation in their respiratory burst activity. This study provides basic information on the immune response in pangasius catfish that can be useful in

  10. The kinematics of cytotoxic lymphocytes influence their ability to kill target cells.

    Science.gov (United States)

    Bhat, Purnima; Leggatt, Graham; Matthaei, Klaus I; Frazer, Ian H

    2014-01-01

    Cytotoxic lymphocytes (CTL) have been reported to show a range of motility patterns from rapid long-range tracking to complete arrest, but how and whether these kinematics affect their ability to kill target cells is not known. Many in vitro killing assays utilize cell lines and tumour-derived cells as targets, which may be of limited relevance to the kinetics of CTL-mediated killing of somatic cells. Here, live-cell microscopy is used to examine the interactions of CTL and primary murine skin cells presenting antigens. We developed a qualitative and quantitative killing assay using extended-duration fluorescence time-lapse microscopy coupled with large-volume objective software-based data analysis to obtain population data of cell-to-cell interactions, motility and apoptosis. In vivo and ex vivo activated antigen-specific cytotoxic lymphocytes were added to primary keratinocyte targets in culture with fluorometric detection of caspase-3 activation in targets as an objective determinant of apoptosis. We found that activated CTL achieved contact-dependent apoptosis of non-tumour targets after a period of prolonged attachment - on average 21 hours - which was determined by target cell type, amount of antigen, and activation status of CTL. Activation of CTL even without engagement of the T cell receptor was sufficient to mobilise cells significantly above baseline, while the addition of cognate antigen further enhanced their motility. Highly activated CTL showed markedly increased vector displacement, and velocity, and lead to increased antigen-specific target cell death. These data show that the inherent kinematics of CTL correlate directly with their ability to kill non-tumour cells presenting cognate antigen.

  11. The kinematics of cytotoxic lymphocytes influence their ability to kill target cells.

    Directory of Open Access Journals (Sweden)

    Purnima Bhat

    Full Text Available Cytotoxic lymphocytes (CTL have been reported to show a range of motility patterns from rapid long-range tracking to complete arrest, but how and whether these kinematics affect their ability to kill target cells is not known. Many in vitro killing assays utilize cell lines and tumour-derived cells as targets, which may be of limited relevance to the kinetics of CTL-mediated killing of somatic cells. Here, live-cell microscopy is used to examine the interactions of CTL and primary murine skin cells presenting antigens. We developed a qualitative and quantitative killing assay using extended-duration fluorescence time-lapse microscopy coupled with large-volume objective software-based data analysis to obtain population data of cell-to-cell interactions, motility and apoptosis. In vivo and ex vivo activated antigen-specific cytotoxic lymphocytes were added to primary keratinocyte targets in culture with fluorometric detection of caspase-3 activation in targets as an objective determinant of apoptosis. We found that activated CTL achieved contact-dependent apoptosis of non-tumour targets after a period of prolonged attachment - on average 21 hours - which was determined by target cell type, amount of antigen, and activation status of CTL. Activation of CTL even without engagement of the T cell receptor was sufficient to mobilise cells significantly above baseline, while the addition of cognate antigen further enhanced their motility. Highly activated CTL showed markedly increased vector displacement, and velocity, and lead to increased antigen-specific target cell death. These data show that the inherent kinematics of CTL correlate directly with their ability to kill non-tumour cells presenting cognate antigen.

  12. Time-kill behaviour against eight bacterial species and cytotoxicity of antibacterial monomers.

    Science.gov (United States)

    Li, Fang; Weir, Michael D; Fouad, Ashraf F; Xu, Hockin H K

    2013-10-01

    The objectives of this study were to investigate: (1) the antibacterial activity of two antibacterial monomers, dimethylaminododecyl methacrylate (DMADDM) and dimethylammoniumethyl dimethacrylate (DMAEDM), against eight different species of oral pathogens for the first time; (2) the cytotoxicity of DMAEDM and DMADDM. DMAEDM and DMADDM were synthesized by reacting a tertiary amine group with an organo-halide. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against eight species of bacteria were tested. Time-kill determinations were performed to examine the bactericidal kinetics. Cytotoxicity of monomers on human gingival fibroblasts (HGF) was assessed using a methyl thiazolyltetrazolium assay and live/dead viability assay. DMADDM showed strong bactericidal activity against all bacteria, with MIC of 1.2-9.8μg/mL. DMAEDM had MIC of 20-80mg/mL. Time-kill determinations indicated that DMADDM and DMAEDM had rapid killing effects against eight species of bacteria, and eliminated all bacteria in 30min at the concentration of 4-fold MBC. Median lethal concentration for DMADDM and DMAEDM was between 20 and 40μg/mL, which was 20-fold higher than 1-2μg/mL for BisGMA control. DMAEDM and DMADDM were tested in time-kill assay against eight species of oral bacteria for the first time. Both were effective in bacteria-inhibition, but DMADDM had a higher potency than DMAEDM. Different killing efficacy was found against different bacteria species. DMAEDM and DMADDM had much lower cytotoxicity than BisGMA. Therefore, DMADDM and DMAEDM are promising for use in bonding agents and other restorative/preventive materials to combat a variety of oral pathogens. Published by Elsevier Ltd.

  13. Target product profile choices for intra-domiciliary malaria vector control pesticide products: repel or kill?

    Directory of Open Access Journals (Sweden)

    Moore Sarah J

    2011-07-01

    Full Text Available Abstract Background The most common pesticide products for controlling malaria-transmitting mosquitoes combine two distinct modes of action: 1 conventional insecticidal activity which kills mosquitoes exposed to the pesticide and 2 deterrence of mosquitoes away from protected humans. While deterrence enhances personal or household protection of long-lasting insecticidal nets and indoor residual sprays, it may also attenuate or even reverse communal protection if it diverts mosquitoes to non-users rather than killing them outright. Methods A process-explicit model of malaria transmission is described which captures the sequential interaction between deterrent and toxic actions of vector control pesticides and accounts for the distinctive impacts of toxic activities which kill mosquitoes before or after they have fed upon the occupant of a covered house or sleeping space. Results Increasing deterrency increases personal protection but consistently reduces communal protection because deterrent sub-lethal exposure inevitably reduces the proportion subsequently exposed to higher lethal doses. If the high coverage targets of the World Health Organization are achieved, purely toxic products with no deterrence are predicted to generally provide superior protection to non-users and even users, especially where vectors feed exclusively on humans and a substantial amount of transmission occurs outdoors. Remarkably, this is even the case if that product confers no personal protection and only kills mosquitoes after they have fed. Conclusions Products with purely mosquito-toxic profiles may, therefore, be preferable for programmes with universal coverage targets, rather than those with equivalent toxicity but which also have higher deterrence. However, if purely mosquito-toxic products confer little personal protection because they do not deter mosquitoes and only kill them after they have fed, then they will require aggressive "catch up" campaigns, with

  14. Investigating CTL mediated killing with a 3D cellular automaton.

    Directory of Open Access Journals (Sweden)

    Frederik Graw

    2009-08-01

    Full Text Available Cytotoxic T lymphocytes (CTLs are important immune effectors against intra-cellular pathogens. These cells search for infected cells and kill them. Recently developed experimental methods in combination with mathematical models allow for the quantification of the efficacy of CTL killing in vivo and, hence, for the estimation of parameters that characterize the effect of CTL killing on the target cell populations. It is not known how these population-level parameters relate to single-cell properties. To address this question, we developed a three-dimensional cellular automaton model of the region of the spleen where CTL killing takes place. The cellular automaton model describes the movement of different cell populations and their interactions. Cell movement patterns in our cellular automaton model agree with observations from two-photon microscopy. We find that, despite the strong spatial nature of the kinetics in our cellular automaton model, the killing of target cells by CTLs can be described by a term which is linear in the target cell frequency and saturates with respect to the CTL levels. Further, we find that the parameters describing CTL killing on the population level are most strongly impacted by the time a CTL needs to kill a target cell. This suggests that the killing of target cells, rather than their localization, is the limiting step in CTL killing dynamics given reasonable frequencies of CTL. Our analysis identifies additional experimental directions which are of particular importance to interpret estimates of killing rates and could advance our quantitative understanding of CTL killing.

  15. Removal of hematopoietic cells and macrophages from mouse bone marrow cultures: isolation of fibroblastlike stromal cells.

    Science.gov (United States)

    Modderman, W E; Vrijheid-Lammers, T; Löwik, C W; Nijweide, P J

    1994-02-01

    A method is described that permits the removal of hematopoietic cells and macrophages from mouse bone marrow cultures. The method is based on the difference in effect of extracellular ATP4- ions (ATP in the absence of divalent, complexing cations) on cells of hematopoietic origin, including macrophages, and of nonhematopoietic origin, such as fibroblastlike stromal cells. In contrast to fibroblastlike cells, hematopoietic cells and macrophages form under the influence of ATP4- lesions in their plasma membranes, which allows the entrance of molecules such as ethidium bromide (EB) and potassium thiocyanate (KSCN), which normally do not easily cross the membrane. The lesions can be rapidly closed by the addition of Mg2+ to the incubation medium, leaving the EB or KSCN trapped in the cell. This method allows the selective introduction of cell-toxic substances such as KSCN into hematopoietic cells and macrophages. By using this method, fibroblastlike stromal cells can be isolated from mouse bone marrow cultures.

  16. Identification of polarized macrophage subsets in zebrafish.

    Science.gov (United States)

    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; Jorgensen, Christian; Djouad, Farida

    2015-07-08

    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.

  17. The Role of Macrophages in Tumor Development

    Directory of Open Access Journals (Sweden)

    Gerben J. van der Bij

    2005-01-01

    Full Text Available Macrophages constitute a large proportion of the immune cell infiltrate, which is present in many tumors. Activation state of macrophages is greatly influenced by their environment, leading to different macrophage subsets with diverse functions. Although previously regarded as potent immune cells that are capable of destroying tumor cells, recent literature focuses on the ability of macrophages to promote tumor development due to secretion of mediators, like growth and angiogenic factors. It is now becoming increasingly clear that a complicated synergistic relationship exists between macrophages and malignant cells whereby tumor cells can affect macrophage phenotype, and vice versa. As such, macrophages and their contribution in cancer development are currently subject of debate.

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

    Science.gov (United States)

    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.

  19. Nucleosome loss facilitates the chemotactic response of macrophages.

    Science.gov (United States)

    De Toma, I; Rossetti, G; Zambrano, S; Bianchi, M E; Agresti, A

    2014-11-01

    High mobility group box 1 (HMGB1) is a small nuclear protein with two functions. In the nucleus, it helps to wrap DNA around nucleosomes. When secreted, it recruits inflammatory cells and induces cytokine production. Before HMGB1 is secreted from inflammatory cells, it relocates to the cytoplasm, which partially or totally depletes cell nuclei of HMGB1. We previously showed that cells lacking HMGB1 contain 20% fewer nucleosomes and 30% more RNA transcripts levels genome-wide. We hypothesized that the depletion of nuclear HMGB1 plays a role in inflammation that can enhance or complement the role of extracellular HMGB1. We analysed the transcriptional profile of wild-type and Hmgb1-/- mouse embryonic fibroblasts (MEFs) as a proxy for cells that have lost HMGB1 from their nuclei. We explored the transcriptome of wild-type and Hmgb1-/- macrophages differentiated in the presence of granulocyte-macrophage colony-stimulating factor, before and after exposure to LPS/IFN-γ. In the same cells, histones and nuclear HMGB1 were quantified. We found that Hmgb1-/- MEFs show a transcriptional profile associated with stress and inflammation responses. Moreover, wild-type macrophages that have secreted HMGB1 because of LPS/IFN-γ exposure rapidly reduce their histone content as much as cells that genetically lack HMGB1. Importantly, unstimulated Hmgb1-/- macrophages activate transcriptional pathways associated with cell migration and chemotaxis. We suggest that nucleosome loss is an early event that facilitates transcriptional responses of macrophages to inflammation, particularly chemotaxis. HMGB1's dual roles in the nucleus and in the extracellular space appear to be complementary. © 2014 The Association for the Publication of the Journal of Internal Medicine.

  20. Autophagy in Macrophages: Impacting Inflammation and Bacterial Infection

    Directory of Open Access Journals (Sweden)

    Ali Vural

    2014-01-01

    Full Text Available Macrophages are on the front line of host defense. They possess an array of germline-encoded pattern recognition receptors/sensors (PRRs that recognize pathogen-associated molecular patterns (PAMPs and which activate downstream effectors/pathways to help mediate innate immune responses and host defense. Innate immune responses include the rapid induction of transcriptional networks that trigger the production of cytokines, chemokines, and cytotoxic molecules; the mobilization of cells including neutrophils and other leukocytes; the engulfment of pathogens by phagocytosis and their delivery to lysosome for degradation; and the induction of autophagy. Autophagy is a catabolic process that normally maintains cellular homeostasis in a lysosome-dependent manner, but it also functions as a cytoprotective response that intersects with a variety of general stress-response pathways. This review focuses on the intimately linked molecular mechanisms that help govern the autophagic pathway and macrophage innate immune responses.

  1. Metabolic and Epigenetic Coordination of T Cell and Macrophage Immunity.

    Science.gov (United States)

    Phan, Anthony T; Goldrath, Ananda W; Glass, Christopher K

    2017-05-16

    Recognition of pathogens by innate and adaptive immune cells instructs rapid alterations of cellular processes to promote effective resolution of infection. To accommodate increased bioenergetic and biosynthetic demands, metabolic pathways are harnessed to maximize proliferation and effector molecule production. In parallel, activation initiates context-specific gene-expression programs that drive effector functions and cell fates that correlate with changes in epigenetic landscapes. Many chromatin- and DNA-modifying enzymes make use of substrates and cofactors that are intermediates of metabolic pathways, providing potential cross talk between metabolism and epigenetic regulation of gene expression. In this review, we discuss recent studies of T cells and macrophages supporting a role for metabolic activity in integrating environmental signals with activation-induced gene-expression programs through modulation of the epigenome and speculate as to how this may influence context-specific macrophage and T cell responses to infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Control of Influenza and Poliomyelitis with Killed Virus Vaccines

    Science.gov (United States)

    Salk, Jonas; Salk, Darrell

    1977-01-01

    Discusses control of poliomyelitis and influenza by live and killed virus vaccines. Considered are the etiological agents, pathogenic mechanisms and epidemiology of each disease. Reviews recent scientific studies of the diseases. Recommends use of killed virus vaccines in controlling both diseases. (CS)

  3. Defective phagocyte Aspergillus killing associated with recurrent pulmonary Aspergillus infections.

    Science.gov (United States)

    Fietta, A; Sacchi, F; Mangiarotti, P; Manara, G; Gialdroni Grassi, G

    1984-01-01

    An apparently healthy boy was suffering from recurrent Aspergillus infections. No classical conditions of immunodeficiency were found. Studies on the patient's phagocytic system revealed neutrophils and monocytes to function normally except in Aspergillus killing (microbicidal activity for bacteria and Candida was normal). Aspergillus killing mechanisms may be complex and peculiarly selective, possibly involving both oxygen-dependent and independent mechanisms.

  4. Beneath the surface: killing of fish as a moral problem

    NARCIS (Netherlands)

    Bovenkerk, B.; Braithwaite, V.A.

    2016-01-01

    Are we morally justified in killing fish and if so, for what purposes? We do not focus on the suffering that is done during the killing, but on the question whether death itself is harmful for fish. We need to distinguish two questions; first, can death be considered a harm for fish? And second, if

  5. 9 CFR 113.210 - Feline Calicivirus Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... Virus. 113.210 Section 113.210 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.210 Feline Calicivirus Vaccine, Killed Virus. Feline Calicivirus...

  6. Killing day-old chicks? Public opinion regarding potential alternatives

    NARCIS (Netherlands)

    Leenstra, F.; Munnichs, G.M.; Beekman, V.; Vromans, E.; Aramyan, L.; Woelders, H.

    2011-01-01

    Throughout the world, male chicks from layer breeds are killed just after hatching, as they are not profitable as regards the production of meat. The Dutch and European parliaments have insisted on research into possible alternatives to the killing of day-old chicks. In the present study we have inv

  7. 9 CFR 113.211 - Feline Rhinotracheitis Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... Rhinotracheitis Vaccine, Killed Virus, shall be prepared from virus-bearing cell culture fluids. Only Master Seed... and individually tested on susceptible cell cultures for the presence of feline rhinotracheitis virus... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Feline Rhinotracheitis Vaccine, Killed...

  8. 9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... Virus. 113.216 Section 113.216 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.216 Bovine Rhinotracheitis Vaccine, Killed Virus. Infectious...

  9. Dynamic visualization the whole process of cytotoxic T lymphocytes killing the B16 tumor cells in vitro

    Science.gov (United States)

    Qi, Shuhong; Zhang, Zhihong

    2016-03-01

    Cytotoxic T lymphocytes (CTLs) played a key role in the immune system to destroy the tumor cells. Although some mechanisms of CTLs killing the tumor cells are revealed already, the dynamic information of CTLs interaction with tumor cells are still not known very clearly. Here we used confocal microscopy to visualize the whole process of CTLs killing the tumor cells in vitro. The imaging data showed that CTLs destroyed the target tumor cells rapidly and efficiently. Several CTLs surrounded one or some tumor cells and the average time for CTLs destroying one tumor cell is just a few minutes in vitro. The study displayed the temporal events of CTLs interacting with tumor cells at the beginning and finally killing them and directly presented the efficient tumor cell cytotoxicity of the CTLs. The results helped us to deeply understand the mechanism of the CTLs destroying the tumor cells and to develop the cancer immunotherapy.

  10. Viral infection of human lung macrophages increases PDL1 expression via IFNβ.

    Directory of Open Access Journals (Sweden)

    Karl J Staples

    Full Text Available Lung macrophages are an important defence against respiratory viral infection and recent work has demonstrated that influenza-induced macrophage PDL1 expression in the murine lung leads to rapid modulation of CD8+ T cell responses via the PD1 receptor. This PD1/PDL1 pathway may downregulate acute inflammatory responses to prevent tissue damage. The aim of this study was to investigate the mechanisms of PDL1 regulation by human macrophages in response to viral infection. Ex-vivo viral infection models using influenza and RSV were established in human lung explants, isolated lung macrophages and monocyte-derived macrophages (MDM and analysed by flow cytometry and RT-PCR. Incubation of lung explants, lung macrophages and MDM with X31 resulted in mean cellular infection rates of 18%, 18% and 29% respectively. Viral infection significantly increased cell surface expression of PDL1 on explant macrophages, lung macrophages and MDM but not explant epithelial cells. Infected MDM induced IFNγ release from autologous CD8+ T cells, an effect enhanced by PDL1 blockade. We observed increases in PDL1 mRNA and IFNβ mRNA and protein release by MDM in response to influenza infection. Knockdown of IFNβ by siRNA, resulted in a 37.5% reduction in IFNβ gene expression in response to infection, and a significant decrease in PDL1 mRNA. Furthermore, when MDM were incubated with IFNβ, this cytokine caused increased expression of PDL1 mRNA. These data indicate that human macrophage PDL1 expression modulates CD8+ cell IFNγ release in response to virus and that this expression is regulated by autologous IFNβ production.

  11. Functional drug screening reveals anticonvulsants as enhancers of mTOR-independent autophagic killing of Mycobacterium tuberculosis through inositol depletion.

    Science.gov (United States)

    Schiebler, Mark; Brown, Karen; Hegyi, Krisztina; Newton, Sandra M; Renna, Maurizio; Hepburn, Lucy; Klapholz, Catherine; Coulter, Sarah; Obregón-Henao, Andres; Henao Tamayo, Marcela; Basaraba, Randall; Kampmann, Beate; Henry, Katherine M; Burgon, Joseph; Renshaw, Stephen A; Fleming, Angeleen; Kay, Robert R; Anderson, Karen E; Hawkins, Phillip T; Ordway, Diane J; Rubinsztein, David C; Floto, Rodrigo Andres

    2015-02-01

    Mycobacterium tuberculosis (MTB) remains a major challenge to global health made worse by the spread of multidrug resistance. We therefore examined whether stimulating intracellular killing of mycobacteria through pharmacological enhancement of macroautophagy might provide a novel therapeutic strategy. Despite the resistance of MTB to killing by basal autophagy, cell-based screening of FDA-approved drugs revealed two anticonvulsants, carbamazepine and valproic acid, that were able to stimulate autophagic killing of intracellular M. tuberculosis within primary human macrophages at concentrations achievable in humans. Using a zebrafish model, we show that carbamazepine can stimulate autophagy in vivo and enhance clearance of M. marinum, while in mice infected with a highly virulent multidrug-resistant MTB strain, carbamazepine treatment reduced bacterial burden, improved lung pathology and stimulated adaptive immunity. We show that carbamazepine induces antimicrobial autophagy through a novel, evolutionarily conserved, mTOR-independent pathway controlled by cellular depletion of myo-inositol. While strain-specific differences in susceptibility to in vivo carbamazepine treatment may exist, autophagy enhancement by repurposed drugs provides an easily implementable potential therapy for the treatment of multidrug-resistant mycobacterial infection.

  12. Functional drug screening reveals anticonvulsants as enhancers of mTOR-independent autophagic killing of Mycobacterium tuberculosis through inositol depletion

    Science.gov (United States)

    Schiebler, Mark; Brown, Karen; Hegyi, Krisztina; Newton, Sandra M; Renna, Maurizio; Hepburn, Lucy; Klapholz, Catherine; Coulter, Sarah; Obregón-Henao, Andres; Henao Tamayo, Marcela; Basaraba, Randall; Kampmann, Beate; Henry, Katherine M; Burgon, Joseph; Renshaw, Stephen A; Fleming, Angeleen; Kay, Robert R; Anderson, Karen E; Hawkins, Phillip T; Ordway, Diane J; Rubinsztein, David C; Floto, Rodrigo Andres

    2015-01-01

    Mycobacterium tuberculosis (MTB) remains a major challenge to global health made worse by the spread of multidrug resistance. We therefore examined whether stimulating intracellular killing of mycobacteria through pharmacological enhancement of macroautophagy might provide a novel therapeutic strategy. Despite the resistance of MTB to killing by basal autophagy, cell-based screening of FDA-approved drugs revealed two anticonvulsants, carbamazepine and valproic acid, that were able to stimulate autophagic killing of intracellular M. tuberculosis within primary human macrophages at concentrations achievable in humans. Using a zebrafish model, we show that carbamazepine can stimulate autophagy in vivo and enhance clearance of M. marinum, while in mice infected with a highly virulent multidrug-resistant MTB strain, carbamazepine treatment reduced bacterial burden, improved lung pathology and stimulated adaptive immunity. We show that carbamazepine induces antimicrobial autophagy through a novel, evolutionarily conserved, mTOR-independent pathway controlled by cellular depletion of myo-inositol. While strain-specific differences in susceptibility to in vivo carbamazepine treatment may exist, autophagy enhancement by repurposed drugs provides an easily implementable potential therapy for the treatment of multidrug-resistant mycobacterial infection. PMID:25535254

  13. Pseudomonas aeruginosa utilises its type III secretion system to kill the free-living amoeba Acanthamoeba castellanii.

    Science.gov (United States)

    Abd, Hadi; Wretlind, Bengt; Saeed, Amir; Idsund, Eva; Hultenby, Kjell; Sandström, Gunnar

    2008-01-01

    Pseudomonas aeruginosa is a free-living and common environmental bacterium. It is an opportunistic and nosocomial pathogen causing serious human health problems. To overcome its predators, such as macrophages and environmental phagocytes, it utilises different survival strategies, such as the formation of microcolonies and the production of toxins mediated by a type III secretion system (TTSS). The aim of this study was to examine interaction of TTSS effector proteins of P. aeruginosa PA103 with Acanthamoeba castellanii by co-cultivation, viable count, eosin staining, electron microscopy, apoptosis assay, and statistical analysis. The results showed that P. aeruginosa PA103 induced necrosis and apoptosis to kill A. castellanii by the effects of TTSS effector proteins ExoU, ExoS, ExoT, and ExoY. In comparison, Acanthamoeba cultured alone and co-cultured with P. aeruginosa PA103 lacking the known four TTSS effector proteins were not killed. The results are consistent with P. aeruginosa being a strict extracellular bacterium that needs TTSS to survive in the environment, because the TTSS effector proteins are able to kill its eukaryotic predators, such as Acanthamoeba.

  14. Killing (absorption) versus survival in random motion

    Science.gov (United States)

    Garbaczewski, Piotr

    2017-09-01

    We address diffusion processes in a bounded domain, while focusing on somewhat unexplored affinities between the presence of absorbing and/or inaccessible boundaries. For the Brownian motion (Lévy-stable cases are briefly mentioned) model-independent features are established of the dynamical law that underlies the short-time behavior of these random paths, whose overall lifetime is predefined to be long. As a by-product, the limiting regime of a permanent trapping in a domain is obtained. We demonstrate that the adopted conditioning method, involving the so-called Bernstein transition function, works properly also in an unbounded domain, for stochastic processes with killing (Feynman-Kac kernels play the role of transition densities), provided the spectrum of the related semigroup operator is discrete. The method is shown to be useful in the case, when the spectrum of the generator goes down to zero and no isolated minimal (ground state) eigenvalue is in existence, like in the problem of the long-term survival on a half-line with a sink at origin.

  15. Combinatorial stresses kill pathogenic Candida species.

    Science.gov (United States)

    Kaloriti, Despoina; Tillmann, Anna; Cook, Emily; Jacobsen, Mette; You, Tao; Lenardon, Megan; Ames, Lauren; Barahona, Mauricio; Chandrasekaran, Komelapriya; Coghill, George; Goodman, Daniel; Gow, Neil A R; Grebogi, Celso; Ho, Hsueh-Lui; Ingram, Piers; McDonagh, Andrew; de Moura, Alessandro P S; Pang, Wei; Puttnam, Melanie; Radmaneshfar, Elahe; Romano, Maria Carmen; Silk, Daniel; Stark, Jaroslav; Stumpf, Michael; Thiel, Marco; Thorne, Thomas; Usher, Jane; Yin, Zhikang; Haynes, Ken; Brown, Alistair J P

    2012-10-01

    Pathogenic microbes exist in dynamic niches and have evolved robust adaptive responses to promote survival in their hosts. The major fungal pathogens of humans, Candida albicans and Candida glabrata, are exposed to a range of environmental stresses in their hosts including osmotic, oxidative and nitrosative stresses. Significant efforts have been devoted to the characterization of the adaptive responses to each of these stresses. In the wild, cells are frequently exposed simultaneously to combinations of these stresses and yet the effects of such combinatorial stresses have not been explored. We have developed a common experimental platform to facilitate the comparison of combinatorial stress responses in C. glabrata and C. albicans. This platform is based on the growth of cells in buffered rich medium at 30°C, and was used to define relatively low, medium and high doses of osmotic (NaCl), oxidative (H(2)O(2)) and nitrosative stresses (e.g., dipropylenetriamine (DPTA)-NONOate). The effects of combinatorial stresses were compared with the corresponding individual stresses under these growth conditions. We show for the first time that certain combinations of combinatorial stress are especially potent in terms of their ability to kill C. albicans and C. glabrata and/or inhibit their growth. This was the case for combinations of osmotic plus oxidative stress and for oxidative plus nitrosative stress. We predict that combinatorial stresses may be highly significant in host defences against these pathogenic yeasts.

  16. f(R)-gravity from Killing Tensors

    CERN Document Server

    Paliathanasis, Andronikos

    2015-01-01

    We consider $f\\left( R\\right) $-gravity in a Friedmann-Lema\\^{\\i}tre-Robertson-Walker spacetime with zero spatial curvature. We apply the Killing tensors of the minisuperspace in order to specify the functional form of $f\\left( R\\right) $ and the field equations to be invariant under Lie-B\\"{a}cklund transformations which are linear in the momentum (contact symmetries). Consequently, the field equations to admit quadratic conservation laws given by Noether's Theorem. We find three new integrable $f\\left( R\\right) $ models, for which with the application of the conservation laws we reduce the field equations to a system of two first-order ordinary differential equations. For each model we study the evolution of the cosmological fluid. Where we find that for the one integrable model the cosmological fluid has an equation of state parameter, in which in the latter there is a linear behavior in terms of the scale factor which describes the CPL parametric dark energy model.

  17. Novel innate cancer killing activity in humans

    Directory of Open Access Journals (Sweden)

    Lovato James

    2011-08-01

    Full Text Available Abstract Background In this study, we pilot tested an in vitro assay of cancer killing activity (CKA in circulating leukocytes of 22 cancer cases and 25 healthy controls. Methods Using a human cervical cancer cell line, HeLa, as target cells, we compared the CKA in circulating leukocytes, as effector cells, of cancer cases and controls. The CKA was normalized as percentages of total target cells during selected periods of incubation time and at selected effector/target cell ratios in comparison to no-effector-cell controls. Results Our results showed that CKA similar to that of our previous study of SR/CR mice was present in human circulating leukocytes but at profoundly different levels in individuals. Overall, males have a significantly higher CKA than females. The CKA levels in cancer cases were lower than that in healthy controls (mean ± SD: 36.97 ± 21.39 vs. 46.28 ± 27.22. Below-median CKA was significantly associated with case status (odds ratio = 4.36; 95% Confidence Interval = 1.06, 17.88 after adjustment of gender and race. Conclusions In freshly isolated human leukocytes, we were able to detect an apparent CKA in a similar manner to that of cancer-resistant SR/CR mice. The finding of CKA at lower levels in cancer patients suggests the possibility that it may be of a consequence of genetic, physiological, or pathological conditions, pending future studies with larger sample size.

  18. The equine alveolar macrophage: Functional and phenotypic comparisons with peritoneal macrophages☆

    Science.gov (United States)

    Karagianni, Anna E.; Kapetanovic, Ronan; McGorum, Bruce C.; Hume, David A.; Pirie, Scott R.

    2013-01-01

    Alveolar macrophages (AMs) constitute the first line of defence in the lung of all species, playing a crucial role in the regulation of immune responses to inhaled pathogens. A detailed understanding of the function and phenotype of AMs is a necessary pre-requisite to both elucidating their role in preventing opportunistic bacterial colonisation of the lower respiratory tract and developing appropriate preventative strategies. The purpose of the study was to characterise this important innate immune cell at the tissue level by making functional and phenotypic comparisons with peritoneal macrophages (PMs). We hypothesised that the tissue of origin determines a unique phenotype of AMs, which may constitute an appropriate therapeutic target for certain equine respiratory diseases. Macrophages isolated from the lung and the peritoneal cavity of 9 horses were stimulated with various toll like receptor (TLR) ligands and the production of nitrite, tumour necrosis factor alpha (TNFα), interleukin (IL) 10 and indoleamine 2,3-dioxygenase (IDO) were measured by the Griess reaction and enzyme linked immunosorbent assay (ELISA) and/or quantitative polymerase chain reaction, respectively. Cells were also compared on the basis of phagocytic-capacity and the expression of several cell surface markers. AMs, but not PMs, demonstrated increased TNFα release following stimulation with LPS, polyinosinic polycytidylic acid (Poly IC) and heat-killed Salmonella typhinurium and increased TNFα and IDO mRNA expression when stimulated with LPS. AMs showed high expression of the specific macrophage markers cluster of differentiation (CD) 14, CD163 and TLR4, whereas PMs showed high expression of TLR4 only. AMs, but not PMs, demonstrated efficient phagocytic activity. Our results demonstrate that AMs are more active than PMs when stimulated with various pro-inflammatory ligands, thus supporting the importance of the local microenvironment in the activation status of the macrophage. This

  19. Interaction of glucocorticoids with macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Werb, Z.; Foley, R.; Munck, A.

    1978-01-01

    The mononuclear phagocyte system plays a central role in mediating host responses in inflammation. Glucocorticoids have anti-inflammatory actions that may be of considerable importance in the therapeutic effects of these agents in chronic inflammation; it is possible that some of these effects are mediated through direct hormonal action on macrophages. Although the site of action of the glucocorticoids on macrophages has not been established, it has been shown that in many other glucocorticoid target systems the effects of glucocorticoids are mediated by specific macromolecular binding proteins, referred to as receptors. In this study we have established that monocytes and macophages contain saturable glucocorticoid-binding proteins, with specificity of binding for cortisol, corticosterone, and related synthetic steroids such as dexamethasone, and that they have dissociation constants for binding within physiological ranges.

  20. Managing Threat, Cost, and Incentive to Kill: The Short- and Long-Term Effects of Intervention in Mass Killings

    Science.gov (United States)

    Kathman, Jacob D.; Wood, Reed M.

    2011-01-01

    How do third-party interventions affect the severity of mass killings? The authors theorize that episodes of mass killing are the consequence of two factors: (1) the threat perceptions of the perpetrators and (2) the cost of implementing genocidal policies relative to other alternatives. To reduce genocidal hostilities, interveners must address…

  1. Comparative activation states of tumor-associated and peritoneal macrophages from mice bearing an induced fibrosarcoma.

    Science.gov (United States)

    Valdez, J C; de Alderete, N; Meson, O E; Sirena, A; Perdigon, G

    1990-11-01

    Balb/c mice bearing a methylcholanthrene-induced fibrosarcoma were used to compare the activation levels of tumor-associated and peritoneal macrophages. Two stages of tumor growth were examined, namely "small" and "large" tumors, with average diameters of 10 and 30 mm, respectively. The activation state, determined by measurement of both phagocytic index and beta-glucuronidase content, was found to be markedly higher in tumor-associated macrophages than in their peritoneal counterparts and it was, in addition, independent of tumor progression. The percentage of tumor-associated macrophages, which were detected on the basis of Fc receptor expression, remained constant in the growing neoplasm, at approximately 23% of total cell population. None of these parameters were affected by inoculation with an immunopotentiating dose of heat-killed Candida albicans which, on the other hand, seemed not to alter the course of the tumor. These data suggest that within the tumor microenvironment macrophages would somehow be maintained at a constant proportion and at a highly activated state, while outside the tumor they would be at a lower activation level. Our results also suggest that TAM would not possess antitumor activity in vivo, although we have found this activity in vitro.

  2. The mechanism of the anticancer function of M1 macrophages and their use in the clinic

    Institute of Scientific and Technical Information of China (English)

    Xing-Qing Pan

    2012-01-01

    M1-type macrophages are capable of inducing lysis in various types of cancer cells,but the mechanism of action is unclear.It has been noted that an "unknown protein" produced together with protease by activated macrophages is responsible for this action.Activated M1 macrophages have been recently reported to produce family 18 chitinases,all of which have been named chitotriosidase.Our experiments have demonstrated that family 18 chitinases work together with proteases and can damage various cancer cells both in vitro and in vivo.Thus,in this article,we suggest that the 50-kDa chitotriosidase is the reported "unknown protein".In addition,we discuss how to properly stimulate activated M1 macrophages to produce 50-kDa chitotriosidases and proteases for destroying cancer cells.Because family 19 chitinase has recently been reported to kill cancer cells,we also discuss the possibility of directly using human family 18 chitotriosidase and the humanized plant family 19 chitinase for cancer treatment.

  3. Aminopeptidase N (CD13 Is Involved in Phagocytic Processes in Human Dendritic Cells and Macrophages

    Directory of Open Access Journals (Sweden)

    Mónica I. Villaseñor-Cardoso

    2013-01-01

    Full Text Available Aminopeptidase N (APN or CD13 is a membrane ectopeptidase expressed by many cell types, including myelomonocytic lineage cells: monocytes, macrophages, and dendritic cells. CD13 is known to regulate the biological activity of various peptides by proteolysis, and it has been proposed that CD13 also participates in several functions such as angiogenesis, cell adhesion, metastasis, and tumor invasion. We had previously reported that, in human monocytes and macrophages, CD13 modulates the phagocytosis mediated by receptors for the Fc portion of IgG antibodies (FcγRs. In this work, we analyzed the possible interaction of CD13 with other phagocytic receptors. We found out that the cross-linking of CD13 positively modulates the phagocytosis mediated by receptors of the innate immune system, since a significant increase in the phagocytosis of zymosan particles or heat-killed E. coli was observed when CD13 was cross-linked using anti-CD13 antibodies, in both macrophages and dendritic cells. Also, we observed that, during the phagocytosis of zymosan, CD13 redistributes and is internalized into the phagosome. These findings suggest that, besides its known functions, CD13 participates in phagocytic processes in dendritic cells and macrophages.

  4. Identification and characterization of a non-interferon antileishmanial macrophage activating factor (antileishmanial MAF).

    Science.gov (United States)

    Van Niel, A; Zacks, S E; David, J R; Remold, H G; Weiser, W Y

    1988-01-01

    A non-interferon lymphokine elaborated from PHA and Con A-stimulated human T-cell hybridoma, T-CEMA, has been found to activate monocyte-derived macrophages for the intracellular killing of L. donovani (antileishmanial MAF). This T-cell hybridoma derived antileishmanial MAF which has an apparent mw of 65,000 and pI of 5.3-5.6, contains neither antiviral activity nor colony stimulating activity. Furthermore, antileishmanial MAF is not neutralized by anti-MIF, anti-IFN-gamma or anti-GM-CSF antibodies.

  5. Effects of inhaled ceramic fibres on macrophage function of rat lungs.

    OpenAIRE

    Morimoto, Y.; Yamato, H; Kido, M; Tanaka, I; Higashi, T; Fujino, A; Yokosaki, Y

    1994-01-01

    To evaluate the biological effect of ceramic fibres on the clearance function of alveolar macrophages (AMs) morphological changes and phagocytic activity of AMs were assessed. Rats were exposed to respirable ceramic fibres with a mass median aerodynamic diameter of 4.4 microns and a concentration of 20.1 mg/m3 in an exposure chamber. They were killed after one week (group A) and two weeks (group B) of exposure, and four weeks (group C) and 12 weeks (group D) after exposure for two weeks. The ...

  6. Primary Tr1 cells from metastatic melanoma eliminate tumor-promoting macrophages through granzyme B- and perforin-dependent mechanisms.

    Science.gov (United States)

    Yan, Hongxia; Zhang, Ping; Kong, Xue; Hou, Xianglian; Zhao, Li; Li, Tianhang; Yuan, Xiaozhou; Fu, Hongjun

    2017-04-01

    In malignant melanoma, tumor-associated macrophages play multiple roles in promoting tumor growth, such as inducing the transformation of melanocytes under ultraviolet irradiation, increasing angiogenesis in melanomas, and suppressing antitumor immunity. Because granzyme B- and perforin-expressing Tr1 cells could specifically eliminate antigen-presenting cells of myeloid origin, we examined whether Tr1 cells in melanoma could eliminate tumor-promoting macrophages and how the interaction between Tr1 cells and macrophages could affect the growth of melanoma cells. Tr1 cells were characterized by high interleukin 10 secretion and low Foxp3 expression and were enriched in the CD4(+)CD49b(+)LAG-3(+) T-cell fraction. Macrophages derived from peripheral blood monocytes in the presence of modified melanoma-conditioned media demonstrated tumor-promoting capacity, exemplified by improving the proliferation of cocultured A375 malignant melanoma cells. But when primary Tr1 cells were present in the macrophage-A375 coculture, the growth of A375 cells was abrogated. The conventional CD25(+) Treg cells, however, were unable to inhibit macrophage-mediated increase in tumor cell growth. Further analyses showed that Tr1 cells did not directly eliminate A375 cells, but mediated the killing of tumor-promoting macrophages through the secretion of granzyme B and perforin. The tumor-infiltrating interleukin 10(+)Foxp3(-)CD4(+) T cells expressed very low levels of granzyme B and perforin, possibly suggested the downregulation of Tr1 cytotoxic capacity in melanoma tumors. Together, these data demonstrated an antitumor function of Tr1 cells through the elimination of tumor-promoting macrophages, which was not shared by conventional Tregs.

  7. Effects of ischemia on lung macrophages.

    Directory of Open Access Journals (Sweden)

    Aigul Moldobaeva

    Full Text Available Angiogenesis after pulmonary ischemia is initiated by reactive O(2 species and is dependent on CXC chemokine growth factors, and its magnitude is correlated with the number of lavaged macrophages. After complete obstruction of the left pulmonary artery in mice, the left lung is isolated from the peripheral circulation until 5-7 days later, when a new systemic vasculature invades the lung parenchyma. Consequently, this model offers a unique opportunity to study the differentiation and/or proliferation of monocyte-derived cells within the lung. In this study, we questioned whether macrophage subpopulations were differentially expressed and which subset contributed to growth factor release. We characterized the change in number of all macrophages (MHCII(int, CD11C+, alveolar macrophages (MHCII(int, CD11C+, CD11B- and mature lung macrophages (MHCII(int, CD11C+, CD11B+ in left lungs from mice immediately (0 h or 24 h after left pulmonary artery ligation (LPAL. In left lung homogenates, only lung macrophages increased 24 h after LPAL (vs. 0 h; p<0.05. No changes in proliferation were seen in any subset by PCNA expression (0 h vs. 24 h lungs. When the number of monocytic cells was reduced with clodronate liposomes, systemic blood flow to the left lung 14 days after LPAL decreased by 42% (p<0.01 compared to vehicle controls. Furthermore, when alveolar macrophages and lung macrophages were sorted and studied in vitro, only lung macrophages secreted the chemokine MIP-2α (ELISA. These data suggest that ischemic stress within the lung contributes to the differentiation of immature monocytes to lung macrophages within the first 24 h after LPAL. Lung macrophages but not alveolar macrophages increase and secrete the proangiogenic chemokine MIP-2α. Overall, an increase in the number of lung macrophages appears to be critical for neovascularization in the lung, since clodronate treatment decreased their number and attenuated functional angiogenesis.

  8. Toxicity and antibacterial assessment of chitosan-coated silver nanoparticles on human pathogens and macrophage cells

    Directory of Open Access Journals (Sweden)

    Jena P

    2012-04-01

    Full Text Available Prajna Jena1, Soumitra Mohanty1, Rojee Mallick1, Biju Jacob2, Avinash Sonawane11School of Biotechnology, KIIT University, Bhubaneswar, Orissa, India; 2Center for Innovation, Technopark Technology Business Incubator, Bangalore, Karnataka, IndiaBackground: Pathogenic bacteria are able to develop various strategies to counteract the bactericidal action of antibiotics. Silver nanoparticles (AgNPs have emerged as a potential alternative to conventional antibiotics because of their potent antimicrobial properties. The purpose of this study was to synthesize chitosan-stabilized AgNPs (CS-AgNPs and test for their cytotoxic, genotoxic, macrophage cell uptake, antibacterial, and antibiofilm activities.Methods: AgNPs were synthesized using chitosan as both a stabilizing and a reducing agent. Antibacterial activity was determined by colony-forming unit assay and scanning electron microscopy. Genotoxic and cytotoxic activity were determined by DNA fragmentation, comet, and MTT [3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide] assays. Cellular uptake and intracellular antibacterial activity were tested on macrophages.Results: CS-AgNPs exhibited potent antibacterial activity against different human pathogens and also impeded bacterial biofilm formation. Scanning electron microscopy analysis indicated that CS-AgNPs kill bacteria by disrupting the cell membrane. CS-AgNPs showed no significant cytotoxic or DNA damage effect on macrophages at the bactericidal dose. Propidium iodide staining indicated active endocytosis of CS-AgNPs resulting in reduced intracellular bacterial survival in macrophages.Conclusion: The present study concludes that at a specific dose, chitosan-based AgNPs kill bacteria without harming the host cells, thus representing a potential template for the design of antibacterial agents to decrease bacterial colonization and to overcome the problem of drug resistance.Keywords: chitosan-silver nanoparticles, antibiofilm, cytotoxicity

  9. Psychological traits underlying different killing methods among Malaysian male murderers.

    Science.gov (United States)

    Kamaluddin, Mohammad Rahim; Shariff, Nadiah Syariani; Nurfarliza, Siti; Othman, Azizah; Ismail, Khaidzir H; Mat Saat, Geshina Ayu

    2014-04-01

    Murder is the most notorious crime that violates religious, social and cultural norms. Examining the types and number of different killing methods that used are pivotal in a murder case. However, the psychological traits underlying specific and multiple killing methods are still understudied. The present study attempts to fill this gap in knowledge by identifying the underlying psychological traits of different killing methods among Malaysian murderers. The study adapted an observational cross-sectional methodology using a guided self-administered questionnaire for data collection. The sampling frame consisted of 71 Malaysian male murderers from 11 Malaysian prisons who were selected using purposive sampling method. The participants were also asked to provide the types and number of different killing methods used to kill their respective victims. An independent sample t-test was performed to establish the mean score difference of psychological traits between the murderers who used single and multiple types of killing methods. Kruskal-Wallis tests were carried out to ascertain the psychological trait differences between specific types of killing methods. The results suggest that specific psychological traits underlie the type and number of different killing methods used during murder. The majority (88.7%) of murderers used a single method of killing. Multiple methods of killing was evident in 'premeditated' murder compared to 'passion' murder, and revenge was a common motive. Examples of multiple methods are combinations of stabbing and strangulation or slashing and physical force. An exception was premeditated murder committed with shooting, when it was usually a single method, attributed to the high lethality of firearms. Shooting was also notable when the motive was financial gain or related to drug dealing. Murderers who used multiple killing methods were more aggressive and sadistic than those who used a single killing method. Those who used multiple methods or

  10. A very rare cause of dyspnea with a unique presentation on a computed tomography scan of the chest: macrophage activation syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Brandao-Neto, Rodrigo Antonio [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas. Clinical Emergency Dept.; Santana, Alfredo Nicodemos Cruz; Danilovic, Debora Lucia Seguro; Mendonca, Berenice Bilharinho de [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina]. E-mail: alfredonicodemos@hotmail.com; Bernardi, Fabiola Del Carlo [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas. Dept. of Pathology; Barbas, Carmen Silvia Valente [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas. Dept. of Pulmonology

    2008-02-15

    Macrophage activation syndrome is a rare and potentially life-threatening disease. It occurs due to immune dysregulation manifested as excessive macrophage proliferation, typically causing hepatosplenomegaly, pancytopenia and hepatic dysfunction. Here, we report an unusual case of macrophage activation syndrome presenting as dyspnea, as well as (reported here for the first time) high resolution computed tomography findings of an excavated nodule, diffuse ground glass opacities and consolidations (mimicking severe pneumonia or alveolar hemorrhage). The patient was successfully treated with human immunoglobulin. We recommend that macrophage activation syndrome be considered in the differential diagnosis of respiratory failure. Rapid diagnosis and treatment are essential to achieving favorable outcomes in patients with this syndrome. (author)

  11. Laser Microbial Killing and Biofilm Disruption

    Science.gov (United States)

    Krespi, Yosef P.; Kizhner, Victor

    2009-06-01

    Objectives: To analyze the ability of NIR lasers to reduce bacterial load and demonstrate the capability of fiber-based Q-switched Nd:YAG laser disrupting biofilm. Study Design: NIR diode laser was tested in vitro and in vivo using pathogenic microorganisms (S. aureus, S. pneumoniae, P. aeruginosa). In addition biofilms were grown from clinical Pseudomonas isolates and placed in culture plates, screws, tympanostomy tubes and PET sutures. Methods: In the animal experiments acute rhinosinusitis model was created by packing the rabbit nose with bacteria soaked solution. The nasal pack was removed in two days and nose was exposed to laser irradiation. A 940 nm diode laser with fiber diffuser was used. Nasal cultures were obtained before and after the laser treatments. Animals were sacrificed fifteen days following laser treatment and bacteriologic/histologic results analyzed. Q-switched Nd:YAG laser generated shockwave pulses were delivered on biofilm using special probes over culture plates, screws, tubes, and PET sutures for the biofilm experiments. Results: Average of two log bacteria reduction was achieved with NIR laser compared to controls. Histologic studies demonstrated preservation of tissue integrity without significant damage to mucosa. Biofilms were imaged before, during and after treatment using a confocal microscope. During laser-generated shockwave application, biofilm was initially seen to oscillate and eventually break off. Large and small pieces of biofilm were totally and instantly removed from the surface to which they were attached in seconds. Conclusions: Significant bacterial reduction was achieved with NIR laser therapy in this experimental in vitro and animal study. In addition we disrupted Pseudomonas aeruginosa biofilms using Q-switched Nd:YAG laser and special probes generating plasma and shockwave. This new and innovative method of bacteria killing and biofilm disruption without injuring host tissue may have clinical application in the

  12. Did Vertigo Kill America's Forgotten Astronaut?

    Science.gov (United States)

    Bendrick, Gregg A.; Merlin, Peter W.

    2007-01-01

    On November 15, 1967, U.S. Air Force test pilot Major Michael J. Adams was killed while flying the X-15 rocket-propelled research vehicle in a parabolic spaceflight profile. This flight was part of a joint effort with NASA. An electrical short in one of the experiments aboard the vehicle caused electrical transients, resulting in excessive workload by the pilot. At altitude Major Adams inappropriately initiated a flat spin that led to a series of unusual aircraft attitudes upon atmospheric re-entry, ultimately causing structural failure of the airframe. Major Adams was known to experience vertigo (i.e. spatial disorientation) while flying the X-15, but all X-15 pilots most likely experienced vertigo (i.e. somatogravic, or "Pitch-Up", illusion) as a normal physiologic response to the accelerative forces involved. Major Adams probably experienced vertigo to a greater degree than did others, since prior aeromedical testing for astronaut selection at Brooks AFB revealed that he had an unusually high degree of labyrinthine sensitivity. Subsequent analysis reveals that after engine burnout, and through the zenith of the flight profile, he likely experienced the oculoagravic ("Elevator") illusion. Nonetheless, painstaking investigation after the mishap revealed that spatial disorientation (Type II, Recognized) was NOT the cause, but rather, a contributing factor. The cause was in fact the misinterpretation of a dual-use flight instrument (i.e. Loss of Mode Awareness), resulting in confusion between yaw and roll indications, with subsequent flight control input that was inappropriate. Because of the altitude achieved on this flight, Major Adams was awarded Astronaut wings posthumously. Understanding the potential for spatial disorientation, particularly the oculoagravic illusion, associated with parabolic spaceflight profiles, and understanding the importance of maintaining mode awareness in the context of automated cockpit design, are two lessons that have direct

  13. Stimulation of neoplastic mouse lung cell proliferation by alveolar macrophage-derived, insulin-like growth factor-1 can be blocked by inhibiting MEK and PI3K activation

    Directory of Open Access Journals (Sweden)

    Malkinson Alvin M

    2011-06-01

    Full Text Available Abstract Background Worldwide, lung cancer kills more people than breast, colon and prostate cancer combined. Alterations in macrophage number and function during lung tumorigenesis suggest that these immune effector cells stimulate lung cancer growth. Evidence from cancer models in other tissues suggests that cancer cells actively recruit growth factor-producing macrophages through a reciprocal signaling pathway. While the levels of lung macrophages increase during tumor progression in mouse models of lung cancer, and high pulmonary macrophage content correlates with a poor prognosis in human non-small cell lung cancer, the specific role of alveolar macrophages in lung tumorigenesis is not clear. Methods After culturing either an immortalized lung macrophage cell line or primary murine alveolar macrophages from naïve and lung-tumor bearing mice with primary tumor isolates and immortalized cell lines, the effects on epithelial proliferation and cellular kinase activation were determined. Insulin-like growth factor-1 (IGF-1 was quantified by ELISA, and macrophage conditioned media IGF-1 levels manipulated by IL-4 treatment, immuno-depletion and siRNA transfection. Results Primary macrophages from both naïve and lung-tumor bearing mice stimulated epithelial cell proliferation. The lungs of tumor-bearing mice contained 3.5-times more IGF-1 than naïve littermates, and media conditioned by freshly isolated tumor-educated macrophages contained more IGF-1 than media conditioned by naïve macrophages; IL-4 stimulated IGF-1 production by both macrophage subsets. The ability of macrophage conditioned media to stimulate neoplastic proliferation correlated with media IGF-1 levels, and recombinant IGF-1 alone was sufficient to induce epithelial proliferation in all cell lines evaluated. Macrophage-conditioned media and IGF-1 stimulated lung tumor cell growth in an additive manner, while EGF had no effect. Macrophage-derived factors increased p-Erk1/2, p

  14. Protein chlorination in neutrophil phagosomes and correlation with bacterial killing.

    Science.gov (United States)

    Green, Jessie N; Kettle, Anthony J; Winterbourn, Christine C

    2014-12-01

    Neutrophils ingest and kill bacteria within phagocytic vacuoles. We investigated where they produce hypochlorous acid (HOCl) following phagocytosis by measuring conversion of protein tyrosine residues to 3-chlorotyrosine. We also examined how varying chloride availability affects the relationship between HOCl formation in the phagosome and bacterial killing. Phagosomal proteins, isolated following ingestion of opsonized magnetic beads, contained 11.4 Cl-Tyr per thousand tyrosine residues. This was 12 times higher than the level in proteins from the rest of the neutrophil and ~6 times higher than previously recorded for protein from ingested bacteria. These results indicate that HOCl production is largely localized to the phagosomes and a substantial proportion reacts with phagosomal protein before reaching the microbe. This will in part detoxify the oxidant but should also form chloramines which could contribute to the killing mechanism. Neutrophils were either suspended in chloride-free gluconate buffer or pretreated with formyl-Met-Leu-Phe, a procedure that has been reported to deplete intracellular chloride. These treatments, alone or in combination, decreased both chlorination in phagosomes and killing of Staphylococcus aureus by up to 50%. There was a strong positive correlation between the two effects. Killing was predominantly oxidant and myeloperoxidase dependent (88% inhibition by diphenylene iodonium and 78% by azide). These results imply that lowering the chloride concentration limits HOCl production and oxidative killing. They support a role for HOCl generation, rather than an alternative myeloperoxidase activity, in the killing process.

  15. Protective role of spleen-derived macrophages in lung inflammation, injury, and fibrosis induced by nitrogen mustard.

    Science.gov (United States)

    Venosa, Alessandro; Malaviya, Rama; Gow, Andrew J; Hall, Leroy; Laskin, Jeffrey D; Laskin, Debra L

    2015-12-15

    Nitrogen mustard (NM) is a vesicant that causes lung injury and fibrosis, accompanied by a persistent macrophage inflammatory response. In these studies we analyzed the spleen as a source of these cells. Splenectomized (SPX) and sham control rats were treated intratracheally with NM (0.125 mg/kg) or PBS control. Macrophage responses were analyzed 1-7 days later. Splenectomy resulted in an increase in lung macrophages expressing CCR2, but a decrease in ATR-1α(+) cells, receptors important in bone marrow and spleen monocyte trafficking, respectively. Splenectomy was also associated with an increase in proinflammatory M1 (iNOS(+), CD11b(+)CD43(+)) macrophages in lungs of NM-treated rats, as well as greater upregulation of iNOS and COX-2 mRNA expression. Conversely, a decrease in CD11b(+)CD43(-) M2 macrophages was observed in SPX rats, with no changes in CD68(+), CD163(+), CD206(+), or YM-1(+) M2 macrophages, suggesting distinct origins of M2 subpopulations responding to NM. Macrophage expression of M2 genes including IL-10, ApoE, PTX-2, PTX-3, 5-HT2α, and 5-HT7 was also reduced in NM-treated SPX rats compared with shams, indicating impaired M2 activity. Changes in lung macrophages responding to NM as a consequence of splenectomy were correlated with exacerbated tissue injury and more rapid fibrogenesis. These data demonstrate that the spleen is a source of a subset of M2 macrophages with anti-inflammatory activity; moreover, in their absence, proinflammatory/cytotoxic M1 macrophages predominate in the lung, resulting in heightened pathology. Understanding the origin of macrophages and characterizing their phenotype after vesicant exposure may lead to more targeted therapeutics aimed at reducing toxicity and disease pathogenesis.

  16. Bone Marrow-Derived Macrophages (BMM)

    DEFF Research Database (Denmark)

    Weischenfeldt, Joachim; Porse, Bo

    2008-01-01

    INTRODUCTIONBone marrow-derived macrophages (BMM) are primary macrophage cells, derived from bone marrow cells in vitro in the presence of growth factors. Macrophage colony-stimulating factor (M-CSF) is a lineage-specific growth factor that is responsible for the proliferation and differentiation...... of committed myeloid progenitors into cells of the macrophage/monocyte lineage. Mice lacking functional M-CSF are deficient in macrophages and osteoclasts and suffer from osteopetrosis. In this protocol, bone marrow cells are grown in culture dishes in the presence of M-CSF, which is secreted by L929 cells...... and is used in the form of L929-conditioned medium. Under these conditions, the bone marrow monocyte/macrophage progenitors will proliferate and differentiate into a homogenous population of mature BMMs. The efficiency of the differentiation is assessed using fluorescence-activated cell sorting (FACS...

  17. Dexamethasone palmitate ameliorates macrophages-rich graft-versus-host disease by inhibiting macrophage functions.

    Directory of Open Access Journals (Sweden)

    Satoshi Nishiwaki

    Full Text Available Macrophage infiltration of skin GVHD lesions correlates directly with disease severity, but the mechanisms underlying this relationship remain unclear and GVHD with many macrophages is a therapeutic challenge. Here, we characterize the macrophages involved in GVHD and report that dexamethasone palmitate (DP, a liposteroid, can ameliorate such GVHD by inhibiting macrophage functions. We found that host-derived macrophages could exacerbate GVHD in a mouse model through expression of higher levels of pro-inflammatory TNF-α and IFN-γ, and lower levels of anti-inflammatory IL-10 than resident macrophages in mice without GVHD. DP significantly decreased the viability and migration capacity of primary mouse macrophages compared to conventional dexamethasone in vitro. DP treatment on day 7 and day 14 decreased macrophage number, and attenuated GVHD score and subsequent mortality in a murine model. This is the first study to provide evidence that therapy for GVHD should be changed on the basis of infiltrating cell type.

  18. DMPD: Silica binding and toxicity in alveolar macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18226603 Silica binding and toxicity in alveolar macrophages. Hamilton RF Jr, Thaku...l) Show Silica binding and toxicity in alveolar macrophages. PubmedID 18226603 Title Silica binding and toxicity in alveolar

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

    Science.gov (United States)

    Yamamoto, N; Naraparaju, V R

    1998-06-01

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

  20. HIV transcription is induced with some forms of cell killing

    Energy Technology Data Exchange (ETDEWEB)

    Woloschak, G.E. [Argonne National Lab., IL (United States); Schreck, S. [Argonne National Lab., IL (United States)][South Carolina Univ., Columbia, SC (United States). Dept. of Chemistry; Panozzo, J. [Loyola Univ. Medical Center, Maywood, IL (United States); Chang-Liu, C.-M. [Argonne National Lab., IL (United States); Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

    1996-11-01

    Using HeLa cells stably transfected with an HIV-LTR-CAT construct`, we demonstrated a peak in CAT induction that occurs in viable (but not necessarily cell-division-competent) cells 24 h following exposure to some cell-killing agents. {Gamma} rays were the only cell-killing agent which did not induce HIV transcription; this can be attributed to the fact that {gamma}-ray-induced apoptotic death requires function p53, which is missing in HeLa cells. For all other agents, HIV-LTR induction was dose-dependent and correlated with the amount of cell killing that occurred in the culture.

  1. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  2. Killing by neutrophil extracellular traps: fact or folklore?

    Science.gov (United States)

    Menegazzi, Renzo; Decleva, Eva; Dri, Pietro

    2012-02-02

    Neutrophil extracellular traps (NETs) are DNA structures released by dying neutrophils and claimed to constitute a new microbicidal mechanism. Killing by NET-forming cells is ascribed to these structures because it is prevented by preincubation with DNase, which has been shown to dismantle NETs, before addition of the target microorganisms. Curiously, the possibility that the microorganisms ensnared in NETs are alive has not been considered. Using Staphylococcus aureus and Candida albicans blastospores, we demonstrate that the microorganisms captured by NETs and thought to be killed are alive because they are released and recovered in cell medium by incubation with DNase. It is concluded that NETs entrap but do not kill microbes.

  3. Is “cooling then freezing” a humane way to kill amphibians and reptiles?

    Directory of Open Access Journals (Sweden)

    Richard Shine

    2015-07-01

    Full Text Available What is the most humane way to kill amphibians and small reptiles that are used in research? Historically, such animals were often killed by cooling followed by freezing, but this method was outlawed by ethics committees because of concerns that ice-crystals may form in peripheral tissues while the animal is still conscious, putatively causing intense pain. This argument relies on assumptions about the capacity of such animals to feel pain, the thermal thresholds for tissue freezing, the temperature-dependence of nerve-impulse transmission and brain activity, and the magnitude of thermal differentials within the bodies of rapidly-cooling animals. A review of published studies casts doubt on those assumptions, and our laboratory experiments on cane toads (Rhinella marina show that brain activity declines smoothly during freezing, with no indication of pain perception. Thus, cooling followed by freezing can offer a humane method of killing cane toads, and may be widely applicable to other ectotherms (especially, small species that are rarely active at low body temperatures. More generally, many animal-ethics regulations have little empirical basis, and research on this topic is urgently required in order to reduce animal suffering.

  4. High-resolution transcriptome of human macrophages.

    Directory of Open Access Journals (Sweden)

    Marc Beyer

    Full Text Available Macrophages are dynamic cells integrating signals from their microenvironment to develop specific functional responses. Although, microarray-based transcriptional profiling has established transcriptional reprogramming as an important mechanism for signal integration and cell function of macrophages, current knowledge on transcriptional regulation of human macrophages is far from complete. To discover novel marker genes, an area of great need particularly in human macrophage biology but also to generate a much more thorough transcriptome of human M1- and M1-like macrophages, we performed RNA sequencing (RNA-seq of human macrophages. Using this approach we can now provide a high-resolution transcriptome profile of human macrophages under classical (M1-like and alternative (M2-like polarization conditions and demonstrate a dynamic range exceeding observations obtained by previous technologies, resulting in a more comprehensive understanding of the transcriptome of human macrophages. Using this approach, we identify important gene clusters so far not appreciated by standard microarray techniques. In addition, we were able to detect differential promoter usage, alternative transcription start sites, and different coding sequences for 57 gene loci in human macrophages. Moreover, this approach led to the identification of novel M1-associated (CD120b, TLR2, SLAMF7 as well as M2-associated (CD1a, CD1b, CD93, CD226 cell surface markers. Taken together, these data support that high-resolution transcriptome profiling of human macrophages by RNA-seq leads to a better understanding of macrophage function and will form the basis for a better characterization of macrophages in human health and disease.

  5. Quantitative GPCR and ion channel transcriptomics in primary alveolar macrophages and macrophage surrogates

    Directory of Open Access Journals (Sweden)

    Groot-Kormelink Paul J

    2012-10-01

    Full Text Available Abstract Background Alveolar macrophages are one of the first lines of defence against invading pathogens and play a central role in modulating both the innate and acquired immune systems. By responding to endogenous stimuli within the lung, alveolar macrophages contribute towards the regulation of the local inflammatory microenvironment, the initiation of wound healing and the pathogenesis of viral and bacterial infections. Despite the availability of protocols for isolating primary alveolar macrophages from the lung these cells remain recalcitrant to expansion in-vitro and therefore surrogate cell types, such as monocyte derived macrophages and phorbol ester-differentiated cell lines (e.g. U937, THP-1, HL60 are frequently used to model macrophage function. Methods The availability of high throughput gene expression technologies for accurate quantification of transcript levels enables the re-evaluation of these surrogate cell types for use as cellular models of the alveolar macrophage. Utilising high-throughput TaqMan arrays and focussing on dynamically regulated families of integral membrane proteins, we explore the similarities and differences in G-protein coupled receptor (GPCR and ion channel expression in alveolar macrophages and their widely used surrogates. Results The complete non-sensory GPCR and ion channel transcriptome is described for primary alveolar macrophages and macrophage surrogates. The expression of numerous GPCRs and ion channels whose expression were hitherto not described in human alveolar macrophages are compared across primary macrophages and commonly used macrophage cell models. Several membrane proteins known to have critical roles in regulating macrophage function, including CXCR6, CCR8 and TRPV4, were found to be highly expressed in macrophages but not expressed in PMA-differentiated surrogates. Conclusions The data described in this report provides insight into the appropriate choice of cell models for

  6. SULFASALAZINE INDUCED AGRANULOCYTOSIS TREATED WITH GRANULOCYTE-MACROPHAGE COLONY STIMULATING FACTOR

    NARCIS (Netherlands)

    KUIPERS, EJ; VELLENGA, E; DEWOLF, JTM; HAZENBERG, BPC

    1992-01-01

    We report the use of granulocyte-macrophage colony stimulating factor (GM-CSF) in a case of rheumatoid arthritis with sulfasalazine induced agranulocytosis, leading to a rapid bone marrow recovery within 7 days. This case and 2 others reported in the literature emphasize the need for further researc

  7. The DNA-binding factor Ctcf critically controls gene expression in macrophages

    NARCIS (Netherlands)

    T. Nikolic (Tatjana); D. Movita (Dowty); M.E.H. Lambers (Margaretha); C. Ribeiro de Almeida (Claudia); P.J. Biesta (Paula); K. Kreefft (Kim); M.J.W. de Bruijn (Marjolein); I.M. Bergen (Ingrid); N.J. Galjart (Niels); P.A. Boonstra (André); R.W. Hendriks (Rudi)

    2014-01-01

    textabstractMacrophages play an important role in immunity and homeostasis. Upon pathogen recognition via specific receptors, they rapidly induce inflammatory responses. This process is tightly controlled at the transcriptional level. The DNA binding zinc-finger protein CCCTC-binding factor (Ctcf) i

  8. Liver macrophages in healthy and diseased liver.

    Science.gov (United States)

    Abdullah, Zeinab; Knolle, Percy A

    2017-04-01

    Kupffer cells, the largest tissue resident macrophage population, are key for the maintenance of liver integrity and its restoration after injury and infections, as well as the local initiation and resolution of innate and adaptive immunity. These important roles of Kupffer cells were recently identified in healthy and diseased liver revealing diverse functions and phenotypes of hepatic macrophages. High-level phenotypic and genomic analysis revealed that Kupffer cells are not a homogenous population and that the hepatic microenvironment actively shapes both phenotype and function of liver macrophages. Compared to macrophages from other organs, hepatic macrophages bear unique properties that are instrumental for their diverse roles in local immunity as well as liver regeneration. The diverse and, in part, contradictory roles of hepatic macrophages in anti-tumor and inflammatory immune responses as well as regulatory and regenerative processes have been obscured by the lack of appropriate technologies to specifically target or ablate Kupffer cells or monocyte-derived hepatic macrophages. Future studies will need to dissect the exact role of the hepatic macrophages with distinct functional properties linked to their differentiation status and thereby provide insight into the functional plasticity of hepatic macrophages.

  9. DMPD: Nuclear receptor signaling in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14698033 Nuclear receptor signaling in macrophages. Valledor AF, Ricote M. Biochem ...Pharmacol. 2004 Jan 15;67(2):201-12. (.png) (.svg) (.html) (.csml) Show Nuclear receptor signaling in macrop...hages. PubmedID 14698033 Title Nuclear receptor signaling in macrophages. Authors Valledor AF, Ricote M. Pub

  10. DMPD: Cellular signaling in macrophage migration and chemotaxis. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 11073096 Cellular signaling in macrophage migration and chemotaxis. Jones GE. J Leu...koc Biol. 2000 Nov;68(5):593-602. (.png) (.svg) (.html) (.csml) Show Cellular signaling in macrophage migration... and chemotaxis. PubmedID 11073096 Title Cellular signaling in macrophage migration and chemotaxis. Autho

  11. DMPD: Macrophage migration inhibitory factor and host innate immune responses tomicrobes. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14620137 Macrophage migration inhibitory factor and host innate immune responses to...microbes. Calandra T. Scand J Infect Dis. 2003;35(9):573-6. (.png) (.svg) (.html) (.csml) Show Macrophage migration... inhibitory factor and host innate immune responses tomicrobes. PubmedID 14620137 Title Macrophage migration

  12. DMPD: Macrophage differentiation and function in health and disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18251777 Macrophage differentiation and function in health and disease. Naito M. Pa...thol Int. 2008 Mar;58(3):143-55. (.png) (.svg) (.html) (.csml) Show Macrophage differentiation and function in health... and disease. PubmedID 18251777 Title Macrophage differentiation and function in health and disease

  13. DMPD: Shaping of monocyte and macrophage function by adenosine receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17056121 Shaping of monocyte and macrophage function by adenosine receptors. Hasko ...tml) (.csml) Show Shaping of monocyte and macrophage function by adenosine receptors. PubmedID 17056121 Titl...e Shaping of monocyte and macrophage function by adenosine receptors. Authors Has

  14. DMPD: Receptor tyrosine kinases and the regulation of macrophage activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14726496 Receptor tyrosine kinases and the regulation of macrophage activation. Cor...(.csml) Show Receptor tyrosine kinases and the regulation of macrophage activation. PubmedID 14726496 Title ...Receptor tyrosine kinases and the regulation of macrophage activation. Authors Co

  15. DMPD: Macrophage activation by endogenous danger signals. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18161744 Macrophage activation by endogenous danger signals. Zhang X, Mosser DM. J ...Pathol. 2008 Jan;214(2):161-78. (.png) (.svg) (.html) (.csml) Show Macrophage activation by endogenous dange...r signals. PubmedID 18161744 Title Macrophage activation by endogenous danger signals. Authors Zhang X, Moss

  16. DMPD: Regulation of endogenous apolipoprotein E secretion by macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18388328 Regulation of endogenous apolipoprotein E secretion by macrophages. Kockx ...svg) (.html) (.csml) Show Regulation of endogenous apolipoprotein E secretion by macrophages. PubmedID 18388...328 Title Regulation of endogenous apolipoprotein E secretion by macrophages. Aut

  17. DMPD: Iron regulation of hepatic macrophage TNFalpha expression. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 11841920 Iron regulation of hepatic macrophage TNFalpha expression. Tsukamoto H. Fr...ee Radic Biol Med. 2002 Feb 15;32(4):309-13. (.png) (.svg) (.html) (.csml) Show Iron regulation of hepatic macrophage TNFalpha expres...sion. PubmedID 11841920 Title Iron regulation of hepatic macrophage TNFalpha express

  18. Contagion in Mass Killings and School Shootings: e0117259

    National Research Council Canada - National Science Library

    Sherry Towers; Andres Gomez-Lievano; Maryam Khan; Anuj Mubayi; Carlos Castillo-Chavez

    2015-01-01

    ... to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts. Methods Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings...

  19. Fish Kill Investigations : St. Vincent National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This memo summarizes an investigation that took place after a massive fish kill in 5 of the 6 ponds on St. Vincent National Wildlife Refuge. Two days of field...

  20. 'Superbug' Resistant to All Antibiotics Killed Nevada Woman

    Science.gov (United States)

    ... news/fullstory_163038.html 'Superbug' Resistant to All Antibiotics Killed Nevada Woman She died after possibly picking ... September from a "superbug" infection that resisted all antibiotics, according to a report released Friday. The case ...

  1. Canada goose kill statistics: Swan Lake Public Hunting Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document discusses how the flexible kill formula for Canada goose hunting at Swan Lake Public Hunting Area was reached. Methods used to collect Canada goose...

  2. Mycobacterium leprae-induced Insulin-like Growth Factor I attenuates antimicrobial mechanisms, promoting bacterial survival in macrophages

    Science.gov (United States)

    Batista-Silva, L. R.; Rodrigues, Luciana Silva; Vivarini, Aislan de Carvalho; Costa, Fabrício da Mota Ramalho; Mattos, Katherine Antunes de; Costa, Maria Renata Sales Nogueira; Rosa, Patricia Sammarco; Toledo-Pinto, T. G.; Dias, André Alves; Moura, Danielle Fonseca; Sarno, Euzenir Nunes; Lopes, Ulisses Gazos; Pessolani, Maria Cristina Vidal

    2016-01-01

    Mycobacterium leprae (ML), the etiologic agent of leprosy, can subvert macrophage antimicrobial activity by mechanisms that remain only partially understood. In the present study, the participation of hormone insulin-like growth factor I (IGF-I) in this phenomenum was investigated. Macrophages from the dermal lesions of the disseminated multibacillary lepromatous form (LL) of leprosy expressed higher levels of IGF-I than those from the self-limited paucibacillary tuberculoid form (BT). Higher levels of IGF-I secretion by ML-infected macrophages were confirmed in ex vivo and in vitro studies. Of note, the dampening of IGF-I signaling reverted the capacity of ML-infected human and murine macrophages to produce antimicrobial molecules and promoted bacterial killing. Moreover, IGF-I was shown to inhibit the JAK/STAT1-dependent signaling pathways triggered by both mycobacteria and IFN-γ most probably through its capacity to induce the suppressor of cytokine signaling-3 (SOCS3). Finally, these in vitro findings were corroborated by in vivo observations in which higher SOCS3 expression and lower phosphorylation of STAT1 levels were found in LL versus BT dermal lesions. Altogether, our data strongly suggest that IGF-I contributes to the maintenance of a functional program in infected macrophages that suits ML persistence in the host, reinforcing a key role for IGF-I in leprosy pathogenesis. PMID:27282338

  3. Immunomodulatory Role of Ocimum gratissimum and Ascorbic Acid against Nicotine-Induced Murine Peritoneal Macrophages In Vitro

    Directory of Open Access Journals (Sweden)

    Santanu Kar Mahapatra

    2011-01-01

    Full Text Available The aim of this present study was to evaluate the immune functions and immune responses in nicotine-induced (10 mM macrophages and concurrently establish the immunomodulatory role of aqueous extract of Ocimum gratissimum (Ae-Og and ascorbic acid. In this study, nitrite generations and some phenotype functions by macrophages were studied. Beside that, release of Th1 cytokines (TNF-α, IL-12 and Th2 cytokines (IL-10, TGF-β was measured by ELISA, and the expression of these cytokines at mRNA level was analyzed by real-time PCR. Ae-Og, at a dose of 10 μg/mL, significantly reduced the nicotine-induced NO generation and iNOSII expression. Similar kinds of response were observed with supplementation of ascorbic acid (0.01 mM. The administration of Ae-Og and ascorbic acid increased the decreased adherence, chemotaxis, phagocytosis, and intracellular killing of bacteria in nicotine-treated macrophages. Ae-Og and ascorbic acid were found to protect the murine peritoneal macrophages through downregulation of Th1 cytokines in nicotine-treated macrophages with concurrent activation of Th2 responses. These findings strongly enhanced our understanding of the molecular mechanism leading to nicotine-induced suppression of immune functions and provide additional rationale for application of anti-inflammatory therapeutic approaches by O. gratissimum and ascorbic acid for different inflammatory disease prevention and treatment during nicotine toxicity.

  4. The Response of Macrophages and Neutrophils to Hypoxia in the Context of Cancer and Other Inflammatory Diseases

    Directory of Open Access Journals (Sweden)

    Antje Egners

    2016-01-01

    Full Text Available Lack of oxygen (hypoxia is a hallmark of a multitude of acute and chronic diseases and can be either beneficial or detrimental for organ restitution and recovery. In the context of inflammation, hypoxia is particularly important and can significantly influence the course of inflammatory diseases. Macrophages and neutrophils, the chief cellular components of innate immunity, display distinct properties when exposed to hypoxic conditions. Virtually every aspect of macrophage and neutrophil function is affected by hypoxia, amongst others, morphology, migration, chemotaxis, adherence to endothelial cells, bacterial killing, differentiation/polarization, and protumorigenic activity. Prominent arenas of macrophage and neutrophil function, for example, acute/chronic inflammation and the microenvironment of solid tumors, are characterized by low oxygen levels, demonstrating the paramount importance of the hypoxic response for proper function of these cells. Members of the hypoxia-inducible transcription factor (HIF family emerged as pivotal molecular regulators of macrophages and neutrophils. In this review, we will summarize the molecular responses of macrophages and neutrophils to hypoxia in the context of cancer and other chronic inflammatory diseases and discuss the potential avenues for therapeutic intervention that arise from this knowledge.

  5. FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection.

    Science.gov (United States)

    Kerr, Sheena C; Fischer, Gregory J; Sinha, Meenal; McCabe, Orla; Palmer, Jonathan M; Choera, Tsokyi; Lim, Fang Yun; Wimmerova, Michaela; Carrington, Stephen D; Yuan, Shaopeng; Lowell, Clifford A; Oscarson, Stefan; Keller, Nancy P; Fahy, John V

    2016-04-01

    The immune mechanisms that recognize inhaled Aspergillus fumigatus conidia to promote their elimination from the lungs are incompletely understood. FleA is a lectin expressed by Aspergillus fumigatus that has twelve binding sites for fucosylated structures that are abundant in the glycan coats of multiple plant and animal proteins. The role of FleA is unknown: it could bind fucose in decomposed plant matter to allow Aspergillus fumigatus to thrive in soil, or it may be a virulence factor that binds fucose in lung glycoproteins to cause Aspergillus fumigatus pneumonia. Our studies show that FleA protein and Aspergillus fumigatus conidia bind avidly to purified lung mucin glycoproteins in a fucose-dependent manner. In addition, FleA binds strongly to macrophage cell surface proteins, and macrophages bind and phagocytose fleA-deficient (∆fleA) conidia much less efficiently than wild type (WT) conidia. Furthermore, a potent fucopyranoside glycomimetic inhibitor of FleA inhibits binding and phagocytosis of WT conidia by macrophages, confirming the specific role of fucose binding in macrophage recognition of WT conidia. Finally, mice infected with ΔfleA conidia had more severe pneumonia and invasive aspergillosis than mice infected with WT conidia. These findings demonstrate that FleA is not a virulence factor for Aspergillus fumigatus. Instead, host recognition of FleA is a critical step in mechanisms of mucin binding, mucociliary clearance, and macrophage killing that prevent Aspergillus fumigatus pneumonia.

  6. Immune reaction and survivability of salmonella typhimurium and salmonella infantis after infection of primary avian macrophages.

    Science.gov (United States)

    Braukmann, Maria; Methner, Ulrich; Berndt, Angela

    2015-01-01

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

  7. A sensitive flow cytometric methodology for studying the binding of L. chagasi to canine peritoneal macrophages

    Directory of Open Access Journals (Sweden)

    Mosser David M

    2005-05-01

    Full Text Available Abstract Background The Leishmania promastigote-macrophage interaction occurs through the association of multiple receptors on the biological membrane surfaces. The success of the parasite infection is dramatically dependent on this early interaction in the vertebrate host, which permits or not the development of the disease. In this study we propose a novel methodology using flow cytometry to study this interaction, and compare it with a previously described "in vitro" binding assay. Methods To study parasite-macrophage interaction, peritoneal macrophages were obtained from 4 dogs and adjusted to 3 × 106 cells/mL. Leishmania (Leishmania chagasi parasites (stationary-phase were adjusted to 5 × 107 cells/mL. The interaction between CFSE-stained Leishmania chagasi and canine peritoneal macrophages was performed in polypropylene tubes to avoid macrophage adhesion. We carried out assays in the presence or absence of normal serum or in the presence of a final concentration of 5% of C5 deficient (serum from AKR/J mice mouse serum. Then, the number of infected macrophages was counted in an optical microscope, as well as by flow citometry. Macrophages obtained were stained with anti-CR3 (CD11b/CD18 antibodies and analyzed by flow citometry. Results Our results have shown that the interaction between Leishmania and macrophages can be measured by flow cytometry using the fluorescent dye CFSE to identify the Leishmania, and measuring simultaneously the expression of an important integrin involved in this interaction: the CD11b/CD18 (CR3 or Mac-1 β2 integrin. Conclusion Flow cytometry offers rapid, reliable and sensitive measurements of single cell interactions with Leishmania in unstained or phenotypically defined cell populations following staining with one or more fluorochromes.

  8. Immune reaction and survivability of salmonella typhimurium and salmonella infantis after infection of primary avian macrophages.

    Directory of Open Access Journals (Sweden)

    Maria Braukmann

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

  9. Moral dilemma: to kill or allow to die?

    Science.gov (United States)

    Cole, J J

    1989-01-01

    The thesis of this paper is that while allowing a person to die with care can be morally justified in particular cases, the option of mercy killing can never be morally defended. There is a significant moral difference between these two concepts. Furthermore, the wedge argument, the medical fallibility argument, and the medical care and trust argument provide cogent and convincing reasons for maintaining a legal distinction between mercy killing and letting a person die.

  10. Conformal Killing vector fields and a virial theorem

    CERN Document Server

    Cariñena, José F; Martínez, Eduardo; Santos, Patrícia

    2014-01-01

    The virial theorem is formulated both intrinsically and in local coordinates for a Lagrangian system of mechanical type on a Riemann manifold. An import case studied in this paper is that of an affine virial function associated to a vector field on the configuration manifold. The special cases of a virial function associated to a Killing, a homothetic and a conformal Killing vector field are considered and the corresponding virial theorems are established for this type of functions.

  11. Special Killing forms on toric Sasaki-Einstein manifolds

    CERN Document Server

    Slesar, Vladimir; Vilcu, Gabriel Eduard

    2014-01-01

    In this paper we study the interplay between complex coordinates of the Calabi-Yau metric cone and the special Killing forms on the toric Sasaki-Einstein manifold. In the general case we give a procedure to locally construct the special Killing forms. In the final part we exemplify the general scheme in the case of the 5-dimensional $Y^{p,q}$ spaces.

  12. Symmetry operators of Killing spinors and superalgebras in AdS_5

    OpenAIRE

    Ertem, Ümit

    2016-01-01

    We construct the first-order symmetry operators of Killing spinor equation in terms of odd Killing-Yano forms. By modifying the Schouten-Nijenhuis bracket of Killing-Yano forms, we show that the symmetry operators of Killing spinors close into an algebra in AdS_5 spacetime. Since the symmetry operator algebra of Killing spinors corresponds to a Jacobi identity in extended Killing superalgebras, we investigate the possible extensions of Killing superalgebras to include higher-degree Killing-Ya...

  13. Macrophage Migration Inhibitory Factor in Acute Adipose Tissue Inflammation.

    Directory of Open Access Journals (Sweden)

    Bong-Sung Kim

    Full Text Available Macrophage migration inhibitory factor (MIF is a pleiotropic cytokine and has been implicated in inflammatory diseases. However, little is known about the regulation of MIF in adipose tissue and its impact on wound healing. The aim of this study was to investigate MIF expression in inflamed adipose and determine its role in inflammatory cell recruitment and wound healing. Adipose tissue was harvested from subcutaneous adipose tissue layers of 24 healthy subjects and from adipose tissue adjacent to acutely inflamed wounds of 21 patients undergoing wound debridement. MIF protein and mRNA expression were measured by ELISA and RT-PCR. Cell-specific MIF expression was visualized by immunohistochemistry. The functional role of MIF in cell recruitment was investigated by a chemotaxis assay and by flow cytometry of labeled macrophages that were injected into Mif-/-and wildtype mice. Wound healing was evaluated by an in vitro scratch assay on human fibroblast monolayers. MIF protein levels of native adipose tissue and supernatants from acutely inflamed wounds were significantly elevated when compared to healthy controls. MIF mRNA expression was increased in acutely inflamed adipose tissue indicating the activation of MIF gene transcription in response to adipose tissue inflammation. MIF is expressed in mature adipocytes and in infiltrated macrophages. Peripheral blood mononuclear cell migration was significantly increased towards supernatants derived from inflamed adipose tissue. This effect was partially abrogated by MIF-neutralizing antibodies. Moreover, when compared to wildtype mice, Mif-/-mice showed reduced infiltration of labeled macrophages into LPS-stimulated epididymal fat pads in vivo. Finally, MIF antibodies partially neutralized the detrimental effect of MIF on fibroblast wound healing. Our results indicate that increased MIF expression and rapid activation of the MIF gene in fat tissue adjacent to acute wound healing disorders may play a

  14. Oxidative and nonoxidative killing of Actinobacillus actinomycetemcomitans by human neutrophils.

    Science.gov (United States)

    Miyasaki, K T; Wilson, M E; Brunetti, A J; Genco, R J

    1986-07-01

    Actinobacillus actinomycetemcomitans is a facultative gram-negative microorganism which has been implicated as an etiologic agent in localized juvenile periodontitis and in subacute bacterial endocarditis and abscesses. Although resistant to serum bactericidal action and to oxidant injury mediated by superoxide anion (O2-) and hydrogen peroxide (H2O2), this organism is sensitive to killing by the myeloperoxidase-hydrogen peroxide-chloride system (K.T. Miyasaki, M.E. Wilson, and R.J. Genco, Infect. Immun. 53:161-165, 1986). In this study, we examined the sensitivity of A. actinomycetemcomitans to killing by intact neutrophils under aerobic conditions, under anaerobic conditions, and under aerobic conditions in the presence of the heme-protein inhibitor sodium cyanide. Intact neutrophils killed opsonized A. actinomycetemcomitans under aerobic and anaerobic conditions, and the kinetics of these reactions indicated that both oxidative and nonoxidative mechanisms were operative. Oxidative mechanisms contributed significantly, and most of the killing attributable to oxidative mechanisms was inhibited by sodium cyanide, which suggested that the myeloperoxidase-hydrogen peroxide-chloride system participated in the oxidative process. We conclude that human neutrophils are capable of killing A. actinomycetemcomitans by both oxygen-dependent and oxygen-independent pathways, and that most oxygen-dependent killing requires myeloperoxidase activity.

  15. Commensal Bacteria-Induced Inflammasome Activation in Mouse and Human Macrophages Is Dependent on Potassium Efflux but Does Not Require Phagocytosis or Bacterial Viability

    Science.gov (United States)

    Chen, Kejie; Shanmugam, Nanda Kumar N.; Pazos, Michael A.; Hurley, Bryan P.; Cherayil, Bobby J.

    2016-01-01

    Gut commensal bacteria contribute to the pathogenesis of inflammatory bowel disease, in part by activating the inflammasome and inducing secretion of interleukin-1ß (IL-1ß). Although much has been learned about inflammasome activation by bacterial pathogens, little is known about how commensals carry out this process. Accordingly, we investigated the mechanism of inflammasome activation by representative commensal bacteria, the Gram-positive Bifidobacterium longum subspecies infantis and the Gram-negative Bacteroides fragilis. B. infantis and B. fragilis induced IL-1ß secretion by primary mouse bone marrow-derived macrophages after overnight incubation. IL-1ß secretion also occurred in response to heat-killed bacteria and was only partly reduced when phagocytosis was inhibited with cytochalasin D. Similar results were obtained with a wild-type immortalized mouse macrophage cell line but neither B. infantis nor B. fragilis induced IL-1ß secretion in a mouse macrophage line lacking the nucleotide-binding/leucine-rich repeat pyrin domain containing 3 (NLRP3) inflammasome. IL-1ß secretion in response to B. infantis and B. fragilis was significantly reduced when the wild-type macrophage line was treated with inhibitors of potassium efflux, either increased extracellular potassium concentrations or the channel blocker ruthenium red. Both live and heat-killed B. infantis and B. fragilis also induced IL-1ß secretion by human macrophages (differentiated THP-1 cells or primary monocyte-derived macrophages) after 4 hours of infection, and the secretion was inhibited by raised extracellular potassium and ruthenium red but not by cytochalasin D. Taken together, our findings indicate that the commensal bacteria B. infantis and B. fragilis activate the NLRP3 inflammasome in both mouse and human macrophages by a mechanism that involves potassium efflux and that does not require bacterial viability or phagocytosis. PMID:27505062

  16. Karr’s Kill Cult: Virtual Cults and Pseudo-Killing in the Digital Age

    Directory of Open Access Journals (Sweden)

    Jeremy Biles

    2012-03-01

    Full Text Available Most readers will recall the 1996 tragedy in which six-year-old beauty-pageant princess JonBenét Ramsey was found bound, gagged, and strangled in the basement of her parents’ home, inciting an orgy of media coverage. What readers may not know is that John Mark Karr—the imminently creepy individual who falsely confessed to the killing, and whose sordid past includes an arrest for possession of child pornography—has continued to make news as an alleged cyberstalker and would-be cult leader. This article claims that whereas a real serial killer is compelled to murder again and again with different victims, Karr is compelled to repeat the singular murder of JonBenét Ramsey the only way he can—in a virtual reality constituted by writing.

  17. Leishmania panamensis infection and antimonial drugs modulate expression of macrophage drug transporters and metabolizing enzymes: impact on intracellular parasite survival

    Science.gov (United States)

    Gómez, Maria Adelaida; Navas, Adriana; Márquez, Ricardo; Rojas, Laura Jimena; Vargas, Deninson Alejandro; Blanco, Victor Manuel; Koren, Roni; Zilberstein, Dan; Saravia, Nancy Gore

    2014-01-01

    Objectives Treatment failure is multifactorial. Despite the importance of host cell drug transporters and metabolizing enzymes in the accumulation, distribution and metabolism of drugs targeting intracellular pathogens, their impact on the efficacy of antileishmanials is unknown. We examined the contribution of pharmacologically relevant determinants in human macrophages in the antimony-mediated killing of intracellular Leishmania panamensis and its relationship with the outcome of treatment with meglumine antimoniate. Methods Patients with cutaneous leishmaniasis who failed (n = 8) or responded (n = 8) to treatment were recruited. Gene expression profiling of pharmacological determinants in primary macrophages was evaluated by quantitative RT–PCR and correlated to the drug-mediated intracellular parasite killing. Functional validation was conducted through short hairpin RNA gene knockdown. Results Survival of L. panamensis after exposure to antimonials was significantly higher in macrophages from patients who failed treatment. Sixteen macrophage drug-response genes were modulated by infection and exposure to meglumine antimoniate. Correlation analyses of gene expression and intracellular parasite survival revealed the involvement of host cell metallothionein-2A and ABCB6 in the survival of Leishmania during exposure to antimonials. ABCB6 was functionally validated as a transporter of antimonial compounds localized in both the cell and phagolysosomal membranes of macrophages, revealing a novel mechanism of host cell-mediated regulation of intracellular drug exposure and parasite survival within phagocytes. Conclusions These results provide insight into host cell mechanisms regulating the intracellular exposure of Leishmania to antimonials and variations among individuals that impact parasite survival. Understanding of host cell determinants of intracellular pharmacokinetics/pharmacodynamics opens new avenues to improved drug efficacy for intracellular

  18. The scavenger protein apoptosis inhibitor of macrophages (AIM potentiates the antimicrobial response against Mycobacterium tuberculosis by enhancing autophagy.

    Directory of Open Access Journals (Sweden)

    Lucía Sanjurjo

    Full Text Available Apoptosis inhibitor of macrophages (AIM, a scavenger protein secreted by tissue macrophages, is transcriptionally regulated by the nuclear receptor Liver X Receptor (LXR and Retinoid X Receptor (RXR heterodimer. Given that LXR exerts a protective immune response against M. tuberculosis, here we analyzed whether AIM is involved in this response. In an experimental murine model of tuberculosis, AIM serum levels peaked dramatically early after infection with M. tuberculosis, providing an in vivo biological link to the disease. We therefore studied the participation of AIM in macrophage response to M. tuberculosis in vitro. For this purpose, we used the H37Rv strain to infect THP-1 macrophages transfected to stably express AIM, thereby increasing infected macrophage survival. Furthermore, the expression of this protein enlarged foam cell formation by enhancing intracellular lipid content. Phagocytosis assays with FITC-labeled M. tuberculosis bacilli indicated that this protein was not involved in bacterial uptake; however, AIM expression decreased the number of intracellular cfus by up to 70% in bacterial killing assays, suggesting that AIM enhances macrophage mycobactericidal activity. Accordingly, M. tuberculosis-infected AIM-expressing cells upregulated the production of reactive oxygen species. Moreover, real-time PCR analysis showed increased mRNA levels of the antimicrobial peptides cathelicidin and defensin 4B. These increases were concomitant with greater cellular concentrations of the autophagy-related molecules Beclin 1 and LC3II, as well as enhanced acidification of mycobacterial phagosomes and LC3 co-localization. In summary, our data support the notion that AIM contributes to key macrophage responses to M. tuberculosis.

  19. Non-opsonic phagocytosis of homologous non-toxigenic and toxigenic Corynebacterium diphtheriae strains by human U-937 macrophages.

    Science.gov (United States)

    dos Santos, Cíntia Silva; dos Santos, Louisy Sanches; de Souza, Monica Cristina; dos Santos Dourado, Fernanda; de Souza de Oliveira Dias, Alexandre Alves; Sabbadini, Priscila Soares; Pereira, Gabriela Andrade; Cabral, Maulori Curié; Hirata Junior, Raphael; de Mattos-Guaraldi, Ana Luíza

    2010-01-01

    As interactions between bacteria and macrophages dictate the outcome of most infectious diseases, analyses of molecular mechanisms of non-opsonic phagocytosis should lead to new approaches for the prevention of diphtheria and systemic Corynebacterium diphtheriae infections. The present study aimed to evaluate human macrophage-bacteria interactions in the absence of opsonin antibodies and the influence of the tox gene on this process. Homologous C. diphtheriae tox+ and tox- strains were evaluated for adhesion, entering and survival within U-937 human macrophages at different incubation periods. Higher numbers of viable bacteria associated with and internalized by macrophages were demonstrated for the tox+ strain. However, viable intracellular bacteria were detected at T-24 hr only for the tox- strain. Cytoskeletal inhibitors, cytochalasin E, genistein and colchicine, inhibited intracellular viability of both strains at different levels. Bacterial replication was evidenced at T-24 hr in supernatants of monolayers infected with the tox- strain. Host cell death and nuclear alterations were evidenced by the Trypan blue exclusion assay and DAPI fluorescence microscopy. ELISA of histone-associated DNA fragments allowed detection of apoptosis and necrosis induced by tox+ and tox- strains at T-1 hr and T-3 hr. In conclusion, human macrophages in the absence of opsonins may not be promptly effective at killing diphtheria bacilli. The presence of the tox gene influences the susceptibility of C. diphtheriae to human macrophages and the outcome of non-opsonic phagocytosis. C. diphtheriae strains exhibit strategies to survive within macrophages and to exert apoptosis and necrosis in human phagocytic cells, independent of the tox gene.

  20. HIV-1-infected monocytes and monocyte-derived macrophages are impaired in their ability to produce superoxide radicals.

    Science.gov (United States)

    Howell, A L; Groveman, D S; Wallace, P K; Fanger, M W

    1997-01-01

    Monocytes and monocyte-derived macrophages play a key role in immune defense against pathogenic organisms. Superoxide anion production is a key mechanism by which phagocytes kill pathogens. We sought to determine whether human immunodeficiency virus-infected monocytes and monocyte-derived macrophages are compromised in their ability to produce the superoxide anion following stimulation with phorbol myristate acetate (PMA) or after cross-linking the type I Fc receptor for IgG (Fc gamma RI). Fc gamma RI was cross-linked by the binding of monoclonal antibody 197, which reacts with an epitope of Fc gamma RI via its Fc region. Monocytes and monocyte-derived macrophages obtained from seronegative donors were infected in vitro with human immunodeficiency virus-1JR-FL and used in effector assays that measured superoxide anion production by the reduction of nitroblue tetrazolium. Reduced nitroblue tetrazolium was measured spectrophotometrically and by microscopy in which the percentage of cells containing intracellular deposits of the dye was assessed. By spectrophotometric measurement, we found that human immunodeficiency virus-infected monocytes and monocyte-derived macrophages produced less superoxide anion following either phorbol myristate acetate stimulation or Fc gamma RI cross-linking than uninfected cells from the same donor. Using microscopy we saw no difference in the percentage of infected and uninfected macrophages containing intracellular deposits of nitroblue tetrazolium suggesting that human immunodeficiency virus-infected macrophages produce less superoxide anion on a per cell basis than uninfected macrophages. Activation of human immunodeficiency virus-infected monocytes with interferon-gamma for 72 h prior to stimulation with phorbol myristate acetate or monoclonal antibody 197 increased their ability to reduce nitroblue tetrazolium. These findings suggest that impairment in the production of reactive oxygen intermediates may, in some cases, contribute to

  1. Macrophages.com: an on-line community resource for innate immunity research.

    Science.gov (United States)

    Robert, Christelle; Lu, Xiang; Law, Andrew; Freeman, Tom C; Hume, David A

    2011-11-01

    Macrophages play a major role in tissue remodelling during development, wound healing and tissue homeostasis, and are central to innate immunity and to the pathology of tissue injury and inflammation. Given this fundamental role in many aspects of biological function, an enormous wealth of information has accumulated on these fascinating cells in the literature and other public repositories. With the escalation of genome-scale data derived from macrophages and related haematopoietic cell types, there is a growing need for an integrated resource that seeks to compile, organise and analyse our collective knowledge of macrophage biology. Here we describe a community-driven web-based resource, macrophages.com that aims to provide a portal onto various types of Omics data to facilitate comparative genomic studies, promoter and transcriptional network analyses, models of macrophage pathways together with other information on these cells. To this end, the website combines public and in-house analyses of expression data with pre-analysed views of co-expressed genes as supported by the network analysis tool BioLayout Express(3D), as well as providing access to maps of pathways active in macrophages. Macrophages.com also provides access to an extensive image library of macrophages in adult/embryonic tissue sections prepared from normal and transgenic mice. In addition, the site links to the Human Protein Atlas database so as to provide direct access to protein expression patterns in human macrophages. Finally, an integrated gene-centric portal provides the tools for rapid promoter analysis studies based on a comprehensive set of CAGE-derived transcription start site (TSS) sequences in human and mouse genomes as generated by the Functional Annotation of Mammalian genomes (FANTOM) projects initiated by the RIKEN Omics Science Center. Our aim is to continue to grow the macrophages.com resource using publicly available data, as well as in-house generated knowledge. In so doing

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

    Science.gov (United States)

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

    2014-12-01

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

  3. Macrophage diversity in renal injury and repair

    NARCIS (Netherlands)

    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 re

  4. Mycobacterium tuberculosis replicates within necrotic human macrophages

    Science.gov (United States)

    Lerner, Thomas R.; Repnik, Urska; Herbst, Susanne; Collinson, Lucy M.; Griffiths, Gareth

    2017-01-01

    Mycobacterium tuberculosis modulation of macrophage cell death is a well-documented phenomenon, but its role during bacterial replication is less characterized. In this study, we investigate the impact of plasma membrane (PM) integrity on bacterial replication in different functional populations of human primary macrophages. We discovered that IFN-γ enhanced bacterial replication in macrophage colony-stimulating factor–differentiated macrophages more than in granulocyte–macrophage colony-stimulating factor–differentiated macrophages. We show that permissiveness in the different populations of macrophages to bacterial growth is the result of a differential ability to preserve PM integrity. By combining live-cell imaging, correlative light electron microscopy, and single-cell analysis, we found that after infection, a population of macrophages became necrotic, providing a niche for M. tuberculosis replication before escaping into the extracellular milieu. Thus, in addition to bacterial dissemination, necrotic cells provide first a niche for bacterial replication. Our results are relevant to understanding the environment of M. tuberculosis replication in the host. PMID:28242744

  5. A broken krebs cycle in macrophages.

    Science.gov (United States)

    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.

  6. The Alternative Faces of Macrophage Generate Osteoclasts

    Directory of Open Access Journals (Sweden)

    N. Lampiasi

    2016-01-01

    Full Text Available The understanding of how osteoclasts are generated and whether they can be altered by inflammatory stimuli is a topic of particular interest for osteoclastogenesis. It is known that the monocyte/macrophage lineage gives rise to osteoclasts (OCs by the action of macrophage colony stimulating factor (M-CSF and receptor activator of nuclear factor-kB ligand (RANKL, which induce cell differentiation through their receptors, c-fms and RANK, respectively. The multinucleated giant cells (MGCs generated by the engagement of RANK/RANKL are typical OCs. Nevertheless, very few studies have addressed the question of which subset of macrophages generates OCs. Indeed, two main subsets of macrophages are postulated, the inflammatory or classically activated type (M1 and the anti-inflammatory or alternatively activated type (M2. It has been proposed that macrophages can be polarized in vitro towards a predominantly M1 or M2 phenotype with the addition of granulocyte macrophage- (GM- CSF or M-CSF, respectively. Various inflammatory stimuli known to induce macrophage polarization, such as LPS or TNF-α, can alter the type of MGC obtained from RANKL-induced differentiation. This review aims to highlight the role of immune-related stimuli and factors in inducing macrophages towards the osteoclastogenesis choice.

  7. Mycobacteria, metals, and the macrophage.

    Science.gov (United States)

    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.

  8. Rapidly Evolving Giant Dermatofibroma

    Directory of Open Access Journals (Sweden)

    K. J. Lang

    2010-01-01

    Full Text Available Dermatofibroma, also known as “fibrous histiocytoma”, is a benign dermal or subcutaneous poorly circumscribed proliferation of spindle-shaped fibroblasts and macrophages in the dermis. Although it is commonly present as a brownish nodule the legs of females, it may also arise on the upper extremities, trunk, and rarely on the head. The exact pathogenesis is unclear. However, it is widely believed that the originating insult to the dermis is a folliculitis, an arthropod bite, or an unspecified initial inflammatory condition. Giant dermatofibromas of greater than 5 cm in diameter are rare, with only 22 cases reported in the literature. We present a case of a rapidly evolving pedunculated mass in the groin of a male patient. Histological examination confirmed this to be a giant dermatofibroma. Though this specimen cannot is not confirmed as such, the cellular subtype is sometimes present as a larger lesion with anecdotal reports of local recurrence and distant metastases. The clinical and radiological features which were somewhat suspicious of malignancy are considered in the context of the definitive pathological diagnosis of a benign lesion.

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

    Science.gov (United States)

    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.

  10. Macrophage serum markers in pneumococcal bacteremia

    DEFF Research Database (Denmark)

    Møller, Holger Jon; Moestrup, Søren K; Weis, Nina

    2006-01-01

    OBJECTIVE: Soluble CD163 (sCD163) is a new macrophage-specific serum marker. This study investigated sCD163 and other markers of macrophage activation (neopterin, ferritin, transcobalamin, and soluble urokinase plasminogen activator receptor [suPAR]) as prognostic factors in patients with pneumoc......OBJECTIVE: Soluble CD163 (sCD163) is a new macrophage-specific serum marker. This study investigated sCD163 and other markers of macrophage activation (neopterin, ferritin, transcobalamin, and soluble urokinase plasminogen activator receptor [suPAR]) as prognostic factors in patients...... on the probability of survival when sCD163 and CRP were known (p = .25). CONCLUSIONS: Macrophage marker response in pneumococcal bacteremia was compromised in old age. In patients disease outcome....

  11. Macrophage Polarization in Health and Disease

    Directory of Open Access Journals (Sweden)

    Luca Cassetta

    2011-01-01

    Full Text Available Macrophages are terminally differentiated cells of the mononuclear phagocyte system that also encompasses dendritic cells, circulating blood monocytes, and committed myeloid progenitor cells in the bone marrow. Both macrophages and their monocytic precursors can change their functional state in response to microenvironmental cues exhibiting a marked heterogeneity. However, there are still uncertainties regarding distinct expression patterns of surface markers that clearly define macrophage subsets, particularly in the case of human macrophages. In addition to their tissue distribution, macrophages can be functionally polarized into M1 (proinflammatory and M2 (alternatively activated as well as regulatory cells in response to both exogenous infections and solid tumors as well as by systems biology approaches.

  12. Azurophil granule proteins constitute the major mycobactericidal proteins in human neutrophils and enhance the killing of mycobacteria in macrophages

    DEFF Research Database (Denmark)

    Jena, Prajna; Mohanty, Soumitra; Mohanty, Tirthankar

    2012-01-01

    and specific granules and systematically analyzed the antimycobacterial activity of some purified azurophil and specific granule proteins against M. smegmatis, M. bovis-BCG and M. tuberculosis H37Rv. Using gel overlay and colony forming unit assays we showed that the defensin-depleted azurophil granule...

  13. Helicobacter pylori phagosome maturation in primary human macrophages

    Directory of Open Access Journals (Sweden)

    Borlace Glenn N

    2011-03-01

    Full Text Available Abstract Background Helicobacter pylori (H. pylori is a micro-aerophilic, spiral-shaped, motile bacterium that is the principal cause of gastric and duodenal ulcers in humans and is a major risk factor for the development of gastric cancer. Despite provoking a strong innate and adaptive immune response in the host, H. pylori persists in the gastric mucosa, avoiding eradication by macrophages and other phagocytic cells, which are recruited to the site of infection. Here we have characterised the critical degradative process of phagosome maturation in primary human macrophages for five genotypically and phenotypically distinct clinical strains of H. pylori. Results All of the H. pylori strains examined showed some disruption to the phagosome maturation process, when compared to control E. coli. The early endosome marker EEA1 and late endosome marker Rab7 were retained on H. pylori phagosomes, while the late endosome-lysosome markers CD63, LAMP-1 and LAMP-2 were acquired in an apparently normal manner. Acquisition of EEA1 by H. pylori phagosomes appeared to occur by two distinct, strain specific modes. H. pylori strains that were negative for the cancer associated virulence factor CagA were detected in phagosomes that recruited large amounts of EEA1 relative to Rab5, compared to CagA positive strains. There were also strain specific differences in the timing of Rab7 acquisition which correlated with differences in the rate of intracellular trafficking of phagosomes and the timing of megasome formation. Megasomes were observed for all of the H. pylori strains examined. Conclusions H. pylori appeared to disrupt the normal process of phagosome maturation in primary human macrophages, appearing to block endosome fission. This resulted in the formation of a hybrid phagosome-endosome-lysosome compartment, which we propose has reduced degradative capacity. Reduced killing by phagocytes is consistent with the persistence of H. pylori in the host, and would

  14. Changing pattern of the subcellular distribution of erythroblast macrophage protein (Emp) during macrophage differentiation.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. Kinetic studies of Candida parapsilosis phagocytosis by macrophages and detection of intracellular survival mechanisms

    Directory of Open Access Journals (Sweden)

    Renata eToth

    2014-11-01

    Full Text Available Even though the number of Candida infections due to non-albicans species like C. parapsilosis has been increasing, little is known about their pathomechanisms. Certain aspects of C. parapsilosis and host interactions have already been investigated; however we lack information about the innate cellular responses towards this species. The aim of our project was to dissect and compare the phagocytosis of C. parapsilosis to C. albicans and to another Candida species C. glabrata by murine and human macrophages by live cell video microscopy. We broke down the phagocytic process into three stages: macrophage migration, engulfment of fungal cells and host cell killing after the uptake. Our results showed increased macrophage migration towards C. parapsilosis and we observed differences during the engulfment processes when comparing the three species. The engulfment time of C. parapsilosis was comparable to that of C. albicans regardless of the pseudohypha length and spatial orientation relative to phagocytes, while the rate of host cell killing and the overall uptake regarding C. parapsilosis showed similarities mainly with C. glabrata. Furthermore, we observed difference between human and murine phagocytes in the uptake of C. parapsilosis. UV-treatment of fungal cells had varied effects on phagocytosis dependent upon which Candida strain was used. Besides statistical analysis, live cell imaging videos showed that this species similarly to the other two also has the ability to survive in host cells via the following mechanisms: yeast replication, and pseudohypha growth inside of phagocytes, exocytosis of fungal cells and also abortion of host cell mitosis following the uptake. According to our knowledge this is the first study that provides a thorough examination of C. parapsilosis phagocytosis and reports intracellular survival mechanisms associated with this species.

  18. Prairie dogs increase fitness by killing interspecific competitors.

    Science.gov (United States)

    Hoogland, John L; Brown, Charles R

    2016-03-30

    Interspecific competition commonly selects for divergence in ecology, morphology or physiology, but direct observation of interspecific competition under natural conditions is difficult. Herbivorous white-tailed prairie dogs (Cynomys leucurus) employ an unusual strategy to reduce interspecific competition: they kill, but do not consume, herbivorous Wyoming ground squirrels (Urocitellus elegans) encountered in the prairie dog territories. Results from a 6-year study in Colorado, USA, revealed that interspecific killing of ground squirrels by prairie dogs was common, involving 47 different killers; 19 prairie dogs were serial killers in the same or consecutive years, and 30% of female prairie dogs killed at least one ground squirrel over their lifetimes. Females that killed ground squirrels had significantly higher annual and lifetime fitness than non-killers, probably because of decreased interspecific competition for vegetation. Our results document the first case of interspecific killing of competing individuals unrelated to predation (IK) among herbivorous mammals in the wild, and show that IK enhances fitness for animals living under natural conditions.

  19. Rotating Killing horizons in generic F( R) gravity theories

    Science.gov (United States)

    Bhattacharya, Sourav

    2016-10-01

    We discuss various properties of rotating Killing horizons in generic F( R) theories of gravity in dimension four for spacetimes endowed with two commuting Killing vector fields. Assuming there is no curvature singularity anywhere on or outside the horizon, we construct a suitable (3+1)-foliation. We show that similar to Einstein's gravity, we must have T_{ab}k^ak^b=0 on the Killing horizon, where k^a is a null geodesic tangent to the horizon. For axisymmetric spacetimes, the effective gravitational coupling ˜ F'^{-1}(R) should usually depend upon the polar coordinate and hence need not necessarily be a constant on the Killing horizon. We prove that the surface gravity of such a Killing horizon must be a constant, irrespective of whether F'(R) is a constant there or not. We next apply these results to investigate some further basic features. In particular, we show that any hairy solution for the real massive vector field in such theories is clearly ruled out, as long as the potential of the scalar field generated in the corresponding Einstein's frame is a positive definite quantity.

  20. Killing of Mycobacterium tuberculosis by neutrophils: a nonoxidative process.

    Science.gov (United States)

    Jones, G S; Amirault, H J; Andersen, B R

    1990-09-01

    To determine the role of oxygen radicals in the killing of Mycobacterium tuberculosis by neutrophils, the effects of free-radical inhibitors and enzymes, catalase, superoxide dismutase, taurine, deferoxamine, and histidine were evaluated. Changes in the viability of M. tuberculosis were determined by agar plate colony counts and a radiometric assay. No impairment in killing was seen with any of the inhibitors or enzymes. Patients with chronic granulomatous disease (CGD) have a defect in the NADPH oxidase pathway, causing their neutrophils to be unable to generate oxygen radicals. If these radicals are involved in killing, then CGD neutrophils should be less effective killers of M. tuberculosis than normal neutrophils. There was no evidence by either measure of M. tuberculosis viability that CGD neutrophils were less bactericidal than normal neutrophils. Killing by normal neutrophils was also effective in the absence of serum. These results lead to the conclusion that the mechanism by which M. tuberculosis is killed by neutrophils is independent of the oxygen metabolic burst.

  1. Rotating Killing horizons in generic $F(R)$ gravity theories

    CERN Document Server

    Bhattacharya, Sourav

    2016-01-01

    We discuss various properties of rotating Killing horizons in generic non-singular $F(R)$ theories of gravity in dimension four for spacetimes endowed with two commuting Killing vector fields. By constructing a suitable $(3+1)$-foliation, we show that similar to Einstein's gravity, we must have $T_{ab}k^ak^b=0$ on the Killing horizon, where $k^a$ is a null geodesic tangent to the horizon. For axisymmetric spacetimes, the effective gravitational coupling $\\sim\\,F'^{-1}(R)$ should usually depend upon the polar coordinate and hence need not necessarily be a constant on the Killing horizon. We prove that the surface gravity of such a Killing horizon must be a constant, irrespective of whether $F'(R)$ is a constant there or not. We next use these results to derive some simple corollaries. In particular, we point out that the no hair theorem for the real massive vector field need not necessarily hold for a generic $F(R)$, unless some additional condition is satisfied.

  2. Expression of bacterial virulence factors and cytokines during in vitro macrophage infection by enteroinvasive Escherichia coli and Shigella flexneri: a comparative study

    Directory of Open Access Journals (Sweden)

    Silvia Y Bando

    2010-09-01

    Full Text Available Enteroinvasive Escherichia coli (EIEC and Shigellaspp cause bacillary dysentery in humans by invading and multiplying within epithelial cells of the colonic mucosa. Although EIEC and Shigellashare many genetic and biochemical similarities, the illness caused by Shigellais more severe. Thus, genomic and structure-function molecular studies on the biological interactions of these invasive enterobacteria with eukaryotic cells have focused on Shigella rather than EIEC. Here we comparatively studied the interactions of EIEC and of Shigella flexneriwith cultured J774 macrophage-like cells. We evaluated several phenotypes: (i bacterial escape from macrophages after phagocytosis, (ii macrophage death induced by EIEC and S. flexneri, (iii macrophage cytokine expression in response to infection and (iv expression of plasmidial (pINV virulence genes. The results showed thatS. flexneri caused macrophage killing earlier and more intensely than EIEC. Both pathogens induced significant macrophage production of TNF, IL-1 and IL-10 after 7 h of infection. Transcription levels of the gene invasion plasmid antigen-C were lower in EIEC than in S. flexneri throughout the course of the infection; this could explain the diminished virulence of EIEC compared to S. flexneri.

  3. Enhancing effects of gamma interferon on phagocytic cell association with and killing of Trypanosoma cruzi

    Science.gov (United States)

    Wirth, J. J.; Kierszenbaum, F.; Sonnenfeld, G.; Zlotnik, A.

    1985-01-01

    Results are reported from a study of the influence gamma interferon (GIFN) and interleukin 2 (IL2) have on the capability of P388D1 cells and mouse resident peritoneal macrophages (MPM) to attach to the blood-resident parasites Trypanosoma cruzi and kill them. Cultures of trypomastigote forms of the Tulahuen strain of T. cruzi grown in bovine serum were introduced into peritoneal cells of mice, along with P388D1 cells incubated with GIFN, IL2 and both. Control cells were also maintained. Statistical analysis were then performed on data on counts of the number of dead T. Cruzi cells. The GIFN enhanced the interaction of MPM and P388D1 cells with the surface of T. Cruzi, provided the interaction was given over 12 hr to take place. A depression of the cytotoxicity of P388D1 cells was attributed to mediation by H2O2, an effect partially offset by incubation with the lymphokine GIFN.

  4. Enhancing effects of gamma interferon on phagocytic cell association with and killing of Trypanosoma cruzi

    Science.gov (United States)

    Wirth, J. J.; Kierszenbaum, F.; Sonnenfeld, G.; Zlotnik, A.

    1985-01-01

    Results are reported from a study of the influence gamma interferon (GIFN) and interleukin 2 (IL2) have on the capability of P388D1 cells and mouse resident peritoneal macrophages (MPM) to attach to the blood-resident parasites Trypanosoma cruzi and kill them. Cultures of trypomastigote forms of the Tulahuen strain of T. cruzi grown in bovine serum were introduced into peritoneal cells of mice, along with P388D1 cells incubated with GIFN, IL2 and both. Control cells were also maintained. Statistical analysis were then performed on data on counts of the number of dead T. Cruzi cells. The GIFN enhanced the interaction of MPM and P388D1 cells with the surface of T. Cruzi, provided the interaction was given over 12 hr to take place. A depression of the cytotoxicity of P388D1 cells was attributed to mediation by H2O2, an effect partially offset by incubation with the lymphokine GIFN.

  5. Macrophages and Dendritic Cells: Partners in Atherogenesis.

    Science.gov (United States)

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

    2016-02-19

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

  6. HIV-1 Latency in Monocytes/Macrophages

    Directory of Open Access Journals (Sweden)

    Amit Kumar

    2014-04-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 targets CD4+ T cells and cells of the monocyte/macrophage lineage. HIV pathogenesis is characterized by the depletion of T lymphocytes and by the presence of a population of cells in which latency has been established called the HIV-1 reservoir. Highly active antiretroviral therapy (HAART has significantly improved the life of HIV-1 infected patients. However, complete eradication of HIV-1 from infected individuals is not possible without targeting latent sources of infection. HIV-1 establishes latent infection in resting CD4+ T cells and findings indicate that latency can also be established in the cells of monocyte/macrophage lineage. Monocyte/macrophage lineage includes among others, monocytes, macrophages and brain resident macrophages. These cells are relatively more resistant to apoptosis induced by HIV-1, thus are important stable hideouts of the virus. Much effort has been made in the direction of eliminating HIV-1 resting CD4+ T-cell reservoirs. However, it is impossible to achieve a cure for HIV-1 without considering these neglected latent reservoirs, the cells of monocyte/macrophage lineage. In this review we will describe our current understanding of the mechanism of latency in monocyte/macrophage lineage and how such cells can be specifically eliminated from the infected host.

  7. Generation of dendritic cells and macrophages from human induced pluripotent stem cells aiming at cell therapy.

    Science.gov (United States)

    Senju, S; Haruta, M; Matsumura, K; Matsunaga, Y; Fukushima, S; Ikeda, T; Takamatsu, K; Irie, A; Nishimura, Y

    2011-09-01

    This report describes generation of dendritic cells (DCs) and macrophages from human induced pluripotent stem (iPS) cells. iPS cell-derived DC (iPS-DC) exhibited the morphology of typical DC and function of T-cell stimulation and antigen presentation. iPS-DC loaded with cytomegalovirus (CMV) peptide induced vigorous expansion of CMV-specific autologous CD8+ T cells. Macrophages (iPS-MP) with activity of zymosan phagocytosis and C5a-induced chemotaxis were also generated from iPS cells. Genetically modified iPS-MPs were generated by the introduction of expression vectors into undifferentiated iPS cells, isolation of transfectant iPS cell clone and subsequent differentiation. By this procedure, we generated iPS-MP expressing a membrane-bound form of single chain antibody (scFv) specific to amyloid β (Aβ), the causal protein of Alzheimer's disease. The scFv-transfectant iPS-MP exhibited efficient Aβ-specific phagocytosis activity. iPS-MP expressing CD20-specific scFv engulfed and killed BALL-1 B-cell leukemia cells. Anti-BALL-1 effect of iPS-MP in vivo was demonstrated in a xeno-transplantation model using severe combined immunodeficient mice. In addition, we established a xeno-free culture protocol to generate iPS-DC and iPS-MP. Collectively, we demonstrated the possibility of application of iPS-DC and macrophages to cell therapy.

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

    Science.gov (United States)

    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.

  9. Macrophage biology plays a central role during ionizing radiation-elicited tumor response

    Directory of Open Access Journals (Sweden)

    Qiuji Wu

    2017-08-01

    Full Text Available Radiation therapy is one of the major therapeutic modalities for most solid tumors. The anti-tumor effect of radiation therapy consists of the direct tumor cell killing, as well as the modulation of tumor microenvironment and the activation of immune response against tumors. Radiation therapy has been shown to promote immunogenic cells death, activate dendritic cells and enhance tumor antigen presentation and anti-tumor T cell activation. Radiation therapy also programs innate immune cells such as macrophages that leads to either radiosensitization or radioresistance, according to different tumors and different radiation regimen studied. The mechanisms underlying radiation-induced macrophage activation remain largely elusive. Various molecular players such as NF-κB, MAPKs, p53, reactive oxygen species, inflammasomes have been involved in these processes. The skewing to a pro-inflammatory phenotype thus results in the activation of anti-tumor immune response and enhanced radiotherapy effect. Therefore, a comprehensive understanding of the mechanism of radiation-induced macrophage activation and its role in tumor response to radiation therapy is crucial for the development of new therapeutic strategies to enhance radiation therapy efficacy.

  10. Clinically relevant concentrations of fosfomycin combined with polymyxin B, tobramycin or ciprofloxacin enhance bacterial killing of Pseudomonas aeruginosa, but do not suppress the emergence of fosfomycin resistance.

    Science.gov (United States)

    Walsh, Clare C; Landersdorfer, Cornelia B; McIntosh, Michelle P; Peleg, Anton Y; Hirsch, Elizabeth B; Kirkpatrick, Carl M; Bergen, Phillip J

    2016-08-01

    Fosfomycin resistance occurs rapidly with monotherapy. This study systematically investigated bacterial killing and emergence of fosfomycin resistance with fosfomycin combinations against Pseudomonas aeruginosa. Four clinical isolates and a reference strain of P. aeruginosa were employed. Combinations of fosfomycin plus polymyxin B, tobramycin or ciprofloxacin were examined over 24 h using time-kill studies (inocula ∼10(6) cfu/mL) incorporating clinically relevant concentrations (fosfomycin, 30, 150 or 300 mg/L; polymyxin B, 0.5, 1 or 2 mg/L; tobramycin, 0.5, 1.5 or 4 mg/L; ciprofloxacin, 0.5, 1 or 2.5 mg/L). Microbiological response was examined by log changes and population analysis profiles. Against susceptible isolates, monotherapy produced varying degrees of initial killing followed by rapid regrowth. Fosfomycin plus polymyxin B or tobramycin produced greater initial killing (up to ∼4 log10 cfu/mL) with many concentrations compared with monotherapy against fosfomycin-susceptible (FOF(S)) isolates. With these combinations, synergy or additivity was observed in 54 (67%) and 49 (60%) of 81 cases (nine combinations across three isolates at three timepoints) for polymyxin B and tobramycin, respectively. Substantial improvements in killing were absent against fosfomycin-resistant (FOF(R)) isolates. For fosfomycin/ciprofloxacin combinations, synergy or additivity was observed against FOF(R) isolates in 33 of 54 (61%) cases (nine combinations across two isolates at three timepoints), while improvements in killing were largely absent against FOF(S) isolates. No combination prevented emergence of fosfomycin resistance. Against P. aeruginosa, fosfomycin in combination with polymyxin B or tobramycin (FOF(S) isolates) or ciprofloxacin (FOF(R) isolates) increased bacterial killing, but did not suppress emergence of fosfomycin resistance. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights

  11. Maintenance of Macrophage Redox Status by ChREBP Limits Inflammation and Apoptosis and Protects against Advanced Atherosclerotic Lesion Formation

    Directory of Open Access Journals (Sweden)

    Vincent Sarrazy

    2015-10-01

    Full Text Available Enhanced glucose utilization can be visualized in atherosclerotic lesions and may reflect a high glycolytic rate in lesional macrophages, but its causative role in plaque progression remains unclear. We observe that the activity of the carbohydrate-responsive element binding protein ChREBP is rapidly downregulated upon TLR4 activation in macrophages. ChREBP inactivation refocuses cellular metabolism to a high redox state favoring enhanced inflammatory responses after TLR4 activation and increased cell death after TLR4 activation or oxidized LDL loading. Targeted deletion of ChREBP in bone marrow cells resulted in accelerated atherosclerosis progression in Ldlr−/− mice with increased monocytosis, lesional macrophage accumulation, and plaque necrosis. Thus, ChREBP-dependent macrophage metabolic reprogramming hinders plaque progression and establishes a causative role for leukocyte glucose metabolism in atherosclerosis.

  12. Conformal Killing Vectors Of Plane Symmetric Four Dimensional Lorentzian Manifolds

    CERN Document Server

    Khan, Suhail; Bokhari, Ashfaque H; Khan, Gulzar Ali; Mathematics, Department of; Peshawar, University of; Pakhtoonkhwa, Peshawar Khyber; Pakistan.,; Petroleum, King Fahd University of; Minerals,; 31261, Dhahran; Arabia, Saudi

    2015-01-01

    In this paper, we investigate conformal Killing's vectors (CKVs) admitted by some plane symmetric spacetimes. Ten conformal Killing's equations and their general forms of CKVs are derived along with their conformal factor. The existence of conformal Killing's symmetry imposes restrictions on the metric functions. The conditions imposing restrictions on these metric functions are obtained as a set of integrability conditions. Considering the cases of time-like and inheriting CKVs, we obtain spacetimes admitting plane conformal symmetry. Integrability conditions are solved completely for some known non-conformally flat and conformally flat classes of plane symmetric spacetimes. A special vacuum plane symmetric spacetime is obtained, and it is shown that for such a metric CKVs are just the homothetic vectors (HVs). Among all the examples considered, there exists only one case with a six dimensional algebra of special CKVs admitting one proper CKV. In all other examples of non-conformally flat metrics, no proper ...

  13. Human platelets efficiently kill IgG-opsonized E. coli.

    Science.gov (United States)

    Riaz, Anum H; Tasma, Brian E; Woodman, Michael E; Wooten, R Mark; Worth, Randall G

    2012-06-01

    Platelets are known contributors of hemostasis but have recently been shown to be important in inflammation and infectious diseases. Moreover, thrombocytopenia is often observed in patients with sepsis. We previously reported that platelets actively phagocytosed IgG-coated latex beads. In this study, the capacity of human platelets to participate in host defense against bacterial infections was determined by assessing their ability to kill Escherichia coli. Washed human platelets were incubated with unopsonized or IgG-opsonized E. coli and evaluated for binding and killing of E. coli. We found that although both unopsonized and IgG-opsonized E. coli were associated with platelets, only IgG-opsonized E. coli were efficiently killed unless platelets were activated by a potent agonist. The bactericidal activity was dependent on FcγRIIA, was sensitive to cytochalasin D, but was not due to reactive oxygen metabolites. These data suggest that platelets may play an important role in protection against infection.

  14. Supersymmetric backgrounds, the Killing superalgebra, and generalised special holonomy

    Energy Technology Data Exchange (ETDEWEB)

    Coimbra, André [Institut des Hautes Études Scientifiques, Le Bois-Marie,35 route de Chartres, F-91440 Bures-sur-Yvette (France); Strickland-Constable, Charles [Institut des Hautes Études Scientifiques, Le Bois-Marie,35 route de Chartres, F-91440 Bures-sur-Yvette (France); Institut de physique théorique, Université Paris Saclay, CEA, CNRS,Orme des Merisiers, F-91191 Gif-sur-Yvette (France)

    2016-11-10

    We prove that, for M theory or type II, generic Minkowski flux backgrounds preserving N supersymmetries in dimensions D≥4 correspond precisely to integrable generalised G{sub N} structures, where G{sub N} is the generalised structure group defined by the Killing spinors. In other words, they are the analogues of special holonomy manifolds in E{sub d(d)}×ℝ{sup +} generalised geometry. In establishing this result, we introduce the Kosmann-Dorfman bracket, a generalisation of Kosmann’s Lie derivative of spinors. This allows us to write down the internal sector of the Killing superalgebra, which takes a rather simple form and whose closure is the key step in proving the main result. In addition, we find that the eleven-dimensional Killing superalgebra of these backgrounds is necessarily the supertranslational part of the N-extended super-Poincaré algebra.

  15. Supersymmetric Backgrounds, the Killing Superalgebra, and Generalised Special Holonomy

    CERN Document Server

    Coimbra, André

    2016-01-01

    We prove that, for M theory or type II, generic Minkowski flux backgrounds preserving $\\mathcal{N}$ supersymmetries in dimensions $D\\geq4$ correspond precisely to integrable generalised $G_{\\mathcal{N}}$ structures, where $G_{\\mathcal{N}}$ is the generalised structure group defined by the Killing spinors. In other words, they are the analogues of special holonomy manifolds in $E_{d(d)} \\times\\mathbb{R}^+$ generalised geometry. In establishing this result, we introduce the Kosmann-Dorfman bracket, a generalisation of Kosmann's Lie derivative of spinors. This allows us to write down the internal sector of the Killing superalgebra, which takes a rather simple form and whose closure is the key step in proving the main result. In addition, we find that the eleven-dimensional Killing superalgebra of these backgrounds is necessarily the supertranslational part of the $\\mathcal{N}$-extended super-Poincar\\'e algebra.

  16. Supersymmetric backgrounds, the Killing superalgebra, and generalised special holonomy

    Science.gov (United States)

    Coimbra, André; Strickland-Constable, Charles

    2016-11-01

    We prove that, for M theory or type II, generic Minkowski flux backgrounds preserving N supersymmetries in dimensions D ≥ 4 correspond precisely to integrable generalised {G}_{N} structures, where {G}_{N} is the generalised structure group defined by the Killing spinors. In other words, they are the analogues of special holonomy manifolds in {E}_{d(d)}× {R}+ generalised geometry. In establishing this result, we introduce the Kosmann-Dorfman bracket, a generalisation of Kosmann's Lie derivative of spinors. This allows us to write down the internal sector of the Killing superalgebra, which takes a rather simple form and whose closure is the key step in proving the main result. In addition, we find that the eleven-dimensional Killing superalgebra of these backgrounds is necessarily the supertranslational part of the N -extended super-Poincaré algebra.

  17. Phagocytosis and killing of Streptococcus suis by porcine neutrophils.

    Science.gov (United States)

    Chabot-Roy, Geneviève; Willson, Philip; Segura, Mariela; Lacouture, Sonia; Gottschalk, Marcelo

    2006-07-01

    Streptococcus suis serotype 2 is an important swine pathogen responsible for diverse infections, mainly meningitis. Virulence factors and the pathogenesis of infection are not well understood. Neutrophils may play an important role in the pathogenesis of infection given that infiltration by neutrophils and mononuclear cells are frequently observed in lesions caused by S. suis. The objective of this work was to study the interactions between S. suis serotype 2 and porcine neutrophils. Results showed that suilysin is toxic to neutrophils and this could help S. suis evade innate immunity. Moreover, suilysin appears to affect complement-dependent killing by decreasing the opsonization of S. suis and the bactericidal capacity of neutrophils. Our results confirm that capsule polysaccharide protects S. suis against killing and phagocytosis by neutrophils. We also showed that the presence of specific IgG against S. suis serotype 2 promoted killing by neutrophils, indicating that the induction of a strong humoral response is beneficial for clearance of this pathogen.

  18. S. Typhimurium strategies to resist killing by cationic antimicrobial peptides.

    Science.gov (United States)

    Matamouros, Susana; Miller, Samuel I

    2015-11-01

    S. Typhimurium is a broad host range Gram-negative pathogen that must evade killing by host innate immune systems to colonize, replicate, cause disease, and be transmitted to other hosts. A major pathogenic strategy of Salmonellae is entrance, survival, and replication within eukaryotic cell phagocytic vacuoles. These phagocytic vacuoles and gastrointestinal mucosal surfaces contain multiple cationic antimicrobial peptides (CAMPs) which control invading bacteria. S. Typhimurium possesses several key mechanisms to resist killing by CAMPs which involve sensing CAMPs and membrane damage to activate signaling cascades that result in remodeling of the bacterial envelope to reduce its overall negative charge with an increase in hydrophobicity to decrease binding and effectiveness of CAMPs. Moreover Salmonellae have additional mechanisms to resist killing by CAMPs including an outer membrane protease which targets cationic peptides at the surface, and specific efflux pumps which protect the inner membrane from damage. This article is part of a Special Issue entitled: Bacterial Resistance to Antimicrobial Peptides.

  19. On Discrete Killing Vector Fields and Patterns on Surfaces

    KAUST Repository

    Ben-Chen, Mirela

    2010-09-21

    Symmetry is one of the most important properties of a shape, unifying form and function. It encodes semantic information on one hand, and affects the shape\\'s aesthetic value on the other. Symmetry comes in many flavors, amongst the most interesting being intrinsic symmetry, which is defined only in terms of the intrinsic geometry of the shape. Continuous intrinsic symmetries can be represented using infinitesimal rigid transformations, which are given as tangent vector fields on the surface - known as Killing Vector Fields. As exact symmetries are quite rare, especially when considering noisy sampled surfaces, we propose a method for relaxing the exact symmetry constraint to allow for approximate symmetries and approximate Killing Vector Fields, and show how to discretize these concepts for generating such vector fields on a triangulated mesh. We discuss the properties of approximate Killing Vector Fields, and propose an application to utilize them for texture and geometry synthesis. Journal compilation © 2010 The Eurographics Association and Blackwell Publishing Ltd.

  20. Macrophages and Uveitis in Experimental Animal Models

    Directory of Open Access Journals (Sweden)

    Salvador Mérida

    2015-01-01

    Full Text Available 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.

  1. Persistence versus escape: Aspergillus terreus and Aspergillus fumigatus employ different strategies during interactions with macrophages.

    Directory of Open Access Journals (Sweden)

    Silvia Slesiona

    Full Text Available Invasive bronchopulmonary aspergillosis (IBPA is a life-threatening disease in immunocompromised patients. Although Aspergillus terreus is frequently found in the environment, A. fumigatus is by far the main cause of IBPA. However, once A. terreus establishes infection in the host, disease is as fatal as A. fumigatus infections. Thus, we hypothesized that the initial steps of disease establishment might be fundamentally different between these two species. Since alveolar macrophages represent one of the first phagocytes facing inhaled conidia, we compared the interaction of A. terreus and A. fumigatus conidia with alveolar macrophages. A. terreus conidia were phagocytosed more rapidly than A. fumigatus conidia, possibly due to higher exposure of β-1,3-glucan and galactomannan on the surface. In agreement, blocking of dectin-1 and mannose receptors significantly reduced phagocytosis of A. terreus, but had only a moderate effect on phagocytosis of A. fumigatus. Once phagocytosed, and in contrast to A. fumigatus, A. terreus did not inhibit acidification of phagolysosomes, but remained viable without signs of germination both in vitro and in immunocompetent mice. The inability of A. terreus to germinate and pierce macrophages resulted in significantly lower cytotoxicity compared to A. fumigatus. Blocking phagolysosome acidification by the v-ATPase inhibitor bafilomycin increased A. terreus germination rates and cytotoxicity. Recombinant expression of the A. nidulans wA naphthopyrone synthase, a homologue of A. fumigatus PksP, inhibited phagolysosome acidification and resulted in increased germination, macrophage damage and virulence in corticosteroid-treated mice. In summary, we show that A. terreus and A. fumigatus have evolved significantly different strategies to survive the attack of host immune cells. While A. fumigatus prevents phagocytosis and phagolysosome acidification and escapes from macrophages by germination, A. terreus is rapidly

  2. Autocrine HBEGF expression promotes breast cancer intravasation, metastasis and macrophage-independent invasion in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z. N.; Sharma, V. P.; Beaty, B. T.; Roh-Johnson, M.; Peterson, E. A.; Van Rooijen, N.; Kenny, P. A.; Wiley, H. S.; Condeelis, J. S.; Segall, J. E.

    2014-10-13

    Increased expression of HBEGF in estrogen receptor-negative breast tumors is correlated with enhanced metastasis to distant organ sites and more rapid disease recurrence upon removal of the primary tumor. Our previous work has demonstrated a paracrine loop between breast cancer cells and macrophages in which the tumor cells are capable of stimulating macrophages through the secretion of colony-stimulating factor-1 while the tumor-associated macrophages (TAMs), in turn, aid in tumor cell invasion by secreting epidermal growth factor. To determine how the autocrine expression of epidermal growth factor receptor (EGFR) ligands by carcinoma cells would affect this paracrine loop mechanism, and in particular whether tumor cell invasion depends on spatial ligand gradients generated by TAMs, we generated cell lines with increased HBEGF expression. We found that autocrine HBEGF expression enhanced in vivo intravasation and metastasis and resulted in a novel phenomenon in which macrophages were no longer required for in vivo invasion of breast cancer cells. In vitro studies revealed that expression of HBEGF enhanced invadopodium formation, thus providing a mechanism for cell autonomous invasion. The increased invadopodium formation was directly dependent on EGFR signaling, as demonstrated by a rapid decrease in invadopodia upon inhibition of autocrine HBEGF/EGFR signaling as well as inhibition of signaling downstream of EGFR activation. HBEGF expression also resulted in enhanced invadopodium function via upregulation of matrix metalloprotease 2 (MMP2) and MMP9 expression levels. We conclude that high levels of HBEGF expression can short-circuit the tumor cell/macrophage paracrine invasion loop, resulting in enhanced tumor invasion that is independent of macrophage signaling.

  3. Cell Intrinsic Galectin-3 Attenuates Neutrophil ROS-Dependent Killing of Candida by Modulating CR3 Downstream Syk Activation

    Science.gov (United States)

    Wu, Sheng-Yang; Huang, Juin-Hua; Chen, Wen-Yu; Chan, Yi-Chen; Lin, Chun-Hung; Chen, Yee-Chun; Liu, Fu-Tong; Wu-Hsieh, Betty A.

    2017-01-01

    Invasive candidiasis is a leading cause of nosocomial bloodstream infection. Neutrophils are the important effector cells in host resistance to candidiasis. To investigate the modulation of neutrophil fungicidal function will advance our knowledge on the control of candidiasis. While recombinant galectin-3 enhances neutrophil phagocytosis of Candida, we found that intracellular galectin-3 downregulates neutrophil fungicidal functions. Co-immunoprecipitation and immunofluorescence staining reveal that cytosolic gal3 physically interacts with Syk in neutrophils after Candida stimulation. Gal3−/− neutrophils have higher level of Syk activation as well as greater abilities to generate reactive oxygen species (ROS) and kill Candida than gal3+/+ cells. While galectin-3 deficiency modulates neutrophil and macrophage activation and the recruitment of monocytes and dendritic cells, the deficiency does not affect the numbers of infiltrating neutrophils or macrophages. Galectin-3 deficiency ameliorates systemic candidiasis by reducing fungal burden, renal pathology, and mortality. Adoptive transfer experiments demonstrate that cell intrinsic galectin-3 negatively regulates neutrophil effector functions against candidiasis. Reducing galectin-3 expression or activity by siRNA or gal3 inhibitor TD139 enhances human neutrophil ROS production. Mice treated with TD139 have enhanced ability to clear the fungus. Our work unravels the mechanism by which galectin-3 regulates Syk-dependent neutrophil fungicidal functions and raises the possibility that blocking gal3 in neutrophils may be a promising therapeutic strategy for treating systemic candidiasis. PMID:28217127

  4. Misregulation of the broad-range phospholipase C activity increases the susceptibility of Listeria monocytogenes to intracellular killing by neutrophils.

    Science.gov (United States)

    Blank, Bryant S; Abi Abdallah, Delbert S; Park, Justin J; Nazarova, Evgeniya V; Pavinski Bitar, Alan; Maurer, Kirk J; Marquis, Hélène

    2014-02-01

    Listeria monocytogenes is a facultative intracellular bacterial pathogen that tightly regulates the activities of various virulence factors during infection. A mutant strain (the plcBDpro mutant) that has lost the ability to control the activity of a phospholipase C (PC-PLC) is attenuated a hundred fold in mice. This attenuation is not due to a lack of bacterial fitness, but appears to result from a modified host response to infection. The transcriptomic pattern of immune-related genes indicated that PC-PLC did not enhance the innate immune response in infected macrophages. However, it partially protected the cells from bacteria-mediated mitochondrial fragmentation. In mice, the plcBDpro mutant transiently caused an increase in liver pathology, as judged by the size of neutrophil-filled micro-abscesses. Moreover, the plcBDpro mutant was more susceptible to intracellular killing by neutrophils than wild-type L. monocytogenes. Together, these data indicate that in vivo attenuation of the plcBDpro mutant results from its reduced ability to disrupt mitochondrial homeostasis and to resist intracellular killing by neutrophils.

  5. NK cells are strongly activated by Lassa and Mopeia virus-infected human macrophages in vitro but do not mediate virus suppression.

    Science.gov (United States)

    Russier, Marion; Reynard, Stéphanie; Tordo, Noël; Baize, Sylvain

    2012-07-01

    Lassa virus (LASV) and Mopeia virus (MOPV) are closely related Arenaviruses. LASV causes hemorrhagic fever, whereas MOPV is not pathogenic. Both viruses display tropism for APCs such as DCs and macrophages. During viral infections, NK cells are involved in the clearance of infected cells and promote optimal immune responses by interacting with APCs. We used an in vitro model of human NK and APC coculture to study the role of NK cells and to characterize their interactions with APCs during LASV and MOPV infections. As expected, NK cells alone were neither infected nor activated by LASV and MOPV, and infected DCs did not activate NK cells. By contrast, LASV- and MOPV-infected macrophages activated NK cells, as shown by the upregulation of CD69, NKp30, and NKp44, the downregulation of CXCR3, and an increase in NK-cell proliferation. NK cells acquired enhanced cytotoxicity, as illustrated by the increase in granzyme B (GrzB) expression and killing of K562 targets, but did not produce IFN-γ. Contact between NK cells and infected macrophages and type I IFNs were essential for activation; however, NK cells could not kill infected cells and control infection. Overall, these findings show that MOPV- as well as pathogenic LASV-infected macrophages mediate NK-cell activation.

  6. Role of copper oxides in contact killing of bacteria.

    Science.gov (United States)

    Hans, Michael; Erbe, Andreas; Mathews, Salima; Chen, Ying; Solioz, Marc; Mücklich, Frank

    2013-12-31

    The potential of metallic copper as an intrinsically antibacterial material is gaining increasing attention in the face of growing antibiotics resistance of bacteria. However, the mechanism of the so-called "contact killing" of bacteria by copper surfaces is poorly understood and requires further investigation. In particular, the influences of bacteria-metal interaction, media composition, and copper surface chemistry on contact killing are not fully understood. In this study, copper oxide formation on copper during standard antimicrobial testing was measured in situ by spectroscopic ellipsometry. In parallel, contact killing under these conditions was assessed with bacteria in phosphate buffered saline (PBS) or Tris-Cl. For comparison, defined Cu2O and CuO layers were thermally generated and characterized by grazing incidence X-ray diffraction. The antibacterial properties of these copper oxides were tested under the conditions used above. Finally, copper ion release was recorded for both buffer systems by inductively coupled plasma atomic absorption spectroscopy, and exposed copper samples were analyzed for topographical surface alterations. It was found that there was a fairly even growth of CuO under wet plating conditions, reaching 4-10 nm in 300 min, but no measurable Cu2O was formed during this time. CuO was found to significantly inhibit contact killing, compared to pure copper. In contrast, thermally generated Cu2O was essentially as effective in contact killing as pure copper. Copper ion release from the different surfaces roughly correlated with their antibacterial efficacy and was highest for pure copper, followed by Cu2O and CuO. Tris-Cl induced a 10-50-fold faster copper ion release compared to PBS. Since the Cu2O that primarily forms on copper under ambient conditions is as active in contact killing as pure copper, antimicrobial objects will retain their antimicrobial properties even after oxide formation.

  7. Humane killing of animals for disease control purposes.

    Science.gov (United States)

    Thornber, P M; Rubira, R J; Styles, D K

    2014-04-01

    Killing for disease control purposes is an emotional issue for everyone concerned. Large-scale euthanasia or depopulation of animals may be necessary for the emergency control or eradication of animal diseases, to remove animals from a compromised situation (e.g. following flood, storm, fire, drought or a feed contamination event), to effect welfare depopulation when there is an oversupply due to a dysfunctional or closed marketing channel, or to depopulate and dispose of animals with minimal handling to decrease the risk of a zoonotic disease infecting humans. The World Organisation for Animal Health (OIE) developed international standards to provide advice on humane killing for various species and situations. Some fundamental issues are defined, such as competency of animal handling and implementation of humane killing techniques. Some of these methods have been used for many years, but novel approaches for the mass killing of particular species are being explored. Novel vaccines and new diagnostic techniques that differentiate between vaccinated and infected animals will save many animals from being killed as part of biosecurity response measures. Unfortunately, the destruction of affected livestock will still be required to control diseases whilst vaccination programmes are activated or where effective vaccines are not available. This paper reviews the principles of humane destruction and depopulation and explores available techniques with their associated advantages and disadvantages. It also identifies some current issues that merit consideration, such as legislative conflicts (emergency disease legislation versus animal welfare legislation, occupational health and safety), media issues, opinions on the future approaches to killing for disease control, and animal welfare.

  8. Endotoxin-induced enhancement of glucose influx into murine peritoneal macrophages via GLUT1.

    Science.gov (United States)

    Fukuzumi, M; Shinomiya, H; Shimizu, Y; Ohishi, K; Utsumi, S

    1996-01-01

    Hypoglycemia is among the most injurious metabolic disorders caused by endotoxemia. In experimental endotoxemia with lipopolysaccharide (LPS) in animals, a marked glucose consumption is observed in macrophage-rich organs. However, the direct effect of LPS on the uptake of glucose by macrophages has not been fully understood, and the present study was undertaken to shed light on this point. The consumption and uptake of glucose, as measured with 2-deoxy-D-[3H]glucose, by murine peritoneal exudate macrophages in culture were accelerated two- to threefold by stimulation with 3 ng of LPS per ml. The rate of glucose uptake reached a plateau after 20 min of stimulation and remained at the maximum as long as LPS was present. Northern (RNA) blot analysis with cDNA probes for five known isoforms of glucose transporter (GLUT) revealed that the expression of GLUT by macrophages was restricted to the GLUT1 isoform during LPS stimulation and the amount of GLUT1 mRNA was increased by the stimulation. These results suggest that macrophage responses to LPS are supported by a rapid and sustained glucose influx via GLUT1 and that this is a participating factor in the development of systemic hypoglycemia when endotoxemia is prolonged. PMID:8557327

  9. Protective effect of natural flavonoids on rat peritoneal macrophages injury caused by asbestos fibers.

    Science.gov (United States)

    Kostyuk, V A; Potapovich, A I; Speransky, S D; Maslova, G T

    1996-01-01

    Exposure of macrophages to asbestos fibers resulted in enhancement of the production of oxygen radicals, determined by a lucigenin enhanced chemiluminescence (LEC) assay, a formation of thiobarbituric acid reactive substances (TBARS), a LDH release into the incubation mixture, and a rapid lysis of the cells. Rutin (Rut) and quercetin (Qr) were effective in inhibiting LEC, TBARS formation, and reducing peritoneal macrophages injury caused by asbestos. The concentrations pre-treatment of antioxidants that were required to prevent the injury of peritoneal macrophages caused by asbestos by 50% (IC50) were 90 microM and 290 microM for Qr and Rut, respectively. Both flavonoids were found to be oxidized during exposure of peritoneal macrophages to asbestos and the oxidation was SOD sensitive. The efficacy of flavonoids as antioxidant agents as well as superoxide ion scavengers was also evaluated using appropriate model systems, and both quercetin and rutin were found to be effective in scavenging O2.-. These findings indicate that flavonoids are able to prevent the respiratory burst in rat peritoneal macrophages exposed to asbestos at the stage of activated oxygen species generation, mainly as superoxide scavengers. On the basis of this study it was concluded that natural flavonoids quercetin and rutin would be promising drug candidates for a prophylactic asbestos-induced disease.

  10. Macrophages facilitate the excystation and differentiation of Toxoplasma gondii sporozoites into tachyzoites following oocyst internalisation

    Science.gov (United States)

    Freppel, Wesley; Puech, Pierre-Henri; Ferguson, David J. P.; Azas, Nadine; Dubey, Jitender P.; Dumètre, Aurélien

    2016-01-01

    Toxoplasma gondii is a common parasite of humans and animals, which is transmitted via oocysts in cat faeces or tissue cysts in contaminated meat. The robust oocyst and sporocyst walls protect the infective sporozoites from deleterious external attacks including disinfectants. Upon oocyst acquisition, these walls lose their integrity to let the sporozoites excyst and invade host cells following a process that remains poorly understood. Given the resistance of the oocyst wall to digestive enzymes and the ability of oocysts to cause parenteral infections, the present study investigated the possible contribution of macrophages in supporting sporozoite excystation following oocyst internalisation. By using single cell micromanipulations, real-time and time-point imaging techniques, we demonstrated that RAW macrophages could interact rapidly with oocysts and engulfed them by remodelling of their actin cytoskeleton. Internalised oocysts were associated to macrophage acidic compartments and showed evidences of wall disruption. Sporozoites were observed in macrophages containing oocyst remnants or in new macrophages, giving rise to dividing tachyzoites. All together, these results highlight an unexpected role of phagocytic cells in processing T. gondii oocysts, in line with non-classical routes of infection, and open new perspectives to identify chemical factors that lead to oocyst wall disruption under physiological conditions. PMID:27641141

  11. [Killing Effect of Carpesium abrotanoides on Taenia asiatica Cysticercus].

    Science.gov (United States)

    Liu, Xiao-yan; Guo, Guang-wu; Wang, Heng

    2015-06-01

    The cysticerci of Taenia asiatica were cultured in vitro with different concentrations of water decoction of Carpesium abrotanoides (20, 40, and 60 mg/ml). The killing effect of C. abrotanoides on T. asiatica and the morphological change of cysticerci were observed under microscope 24 hours post-culture. The water decoction of C. abrotanoides showed significant killing effect on the cysticerci. The mortality of the parasites(95.0%, 57/60) was highest in 60 mg/ml group. The dead body of cysticercus shows shrunken with the enlarged scolex, and sucker tissue degenerated.

  12. Radiolabel release microassay for phagocytic killing of Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    Bistoni, F.; Baccarini, M.; Blasi, E.; Marconi, P. (Perugia Univ. (Italy). Inst. of Microbiology); Puccetti, P. (Perugia Univ. (Italy). Inst. of Pharmacology)

    1982-08-13

    The chromium-51 release technique for quantifying intracellular killing of radiolabelled Candida albicans particles was exploited in a microassay in which murine and human phagocytes acted as effectors under peculiarly simple conditions. At appropriate effector: target ratios and with a 4 h incubation, up to 50% specific chromium release could be detected in the supernatant with no need for opsonization or lysis of phagocytes. This simple microassay permits easy-to-perform, simultaneous testing of a variety of different phagocytes even if only available in limited amounts, and provides an objective measurement of intracellular killing of Candida albicans.

  13. Human neutrophils dump Candida glabrata after intracellular killing.

    Science.gov (United States)

    Essig, Fabian; Hünniger, Kerstin; Dietrich, Stefanie; Figge, Marc Thilo; Kurzai, Oliver

    2015-11-01

    Interaction between fungal pathogens and human phagocytes can lead to remarkably variable outcomes, ranging from intracellular killing to prolonged survival and replication of the pathogen in the host cell. Using live cell imaging we observed primary human neutrophils that release phagocytosed Candida glabrata yeast cells after intracellular killing. This process, for which we propose the name "dumping", adds a new outcome to phagocyte-fungus interaction which may be of potential immunological importance as it allows professional antigen presenting cells to take up and process neutrophil-inactivated pathogens that in their viable state are able to evade intracellular degradation in these cells.

  14. The macrophage cytoskeleton acts as a contact sensor upon interaction with Entamoeba histolytica to trigger IL-1β secretion.

    Directory of Open Access Journals (Sweden)

    Joëlle St-Pierre

    2017-08-01

    Full Text Available Entamoeba histolytica (Eh is the causative agent of amebiasis, one of the major causes of dysentery-related morbidity worldwide. Recent studies have underlined the importance of the intercellular junction between Eh and host cells as a determinant in the pathogenesis of amebiasis. Despite the fact that direct contact and ligation between Eh surface Gal-lectin and EhCP-A5 with macrophage α5β1 integrin are absolute requirements for NLRP3 inflammasome activation and IL-1β release, many other undefined molecular events and downstream signaling occur at the interface of Eh and macrophage. In this study, we investigated the molecular events at the intercellular junction that lead to recognition of Eh through modulation of the macrophage cytoskeleton. Upon Eh contact with macrophages key cytoskeletal-associated proteins were rapidly post-translationally modified only with live Eh but not with soluble Eh proteins or fragments. Eh ligation with macrophages rapidly activated caspase-6 dependent cleavage of the cytoskeletal proteins talin, Pyk2 and paxillin and caused robust release of the pro-inflammatory cytokine, IL-1β. Macrophage cytoskeletal cleavages were dependent on Eh cysteine proteinases EhCP-A1 and EhCP-A4 but not EhCP-A5 based on pharmacological blockade of Eh enzyme inhibitors and EhCP-A5 deficient parasites. These results unravel a model where the intercellular junction between macrophages and Eh form an area of highly interacting proteins that implicate the macrophage cytoskeleton as a sensor for Eh contact that leads downstream to subsequent inflammatory immune responses.

  15. The macrophage cytoskeleton acts as a contact sensor upon interaction with Entamoeba histolytica to trigger IL-1β secretion

    Science.gov (United States)

    Moreau, France; Gorman, Hayley

    2017-01-01

    Entamoeba histolytica (Eh) is the causative agent of amebiasis, one of the major causes of dysentery-related morbidity worldwide. Recent studies have underlined the importance of the intercellular junction between Eh and host cells as a determinant in the pathogenesis of amebiasis. Despite the fact that direct contact and ligation between Eh surface Gal-lectin and EhCP-A5 with macrophage α5β1 integrin are absolute requirements for NLRP3 inflammasome activation and IL-1β release, many other undefined molecular events and downstream signaling occur at the interface of Eh and macrophage. In this study, we investigated the molecular events at the intercellular junction that lead to recognition of Eh through modulation of the macrophage cytoskeleton. Upon Eh contact with macrophages key cytoskeletal-associated proteins were rapidly post-translationally modified only with live Eh but not with soluble Eh proteins or fragments. Eh ligation with macrophages rapidly activated caspase-6 dependent cleavage of the cytoskeletal proteins talin, Pyk2 and paxillin and caused robust release of the pro-inflammatory cytokine, IL-1β. Macrophage cytoskeletal cleavages were dependent on Eh cysteine proteinases EhCP-A1 and EhCP-A4 but not EhCP-A5 based on pharmacological blockade of Eh enzyme inhibitors and EhCP-A5 deficient parasites. These results unravel a model where the intercellular junction between macrophages and Eh form an area of highly interacting proteins that implicate the macrophage cytoskeleton as a sensor for Eh contact that leads downstream to subsequent inflammatory immune responses. PMID:28837696

  16. Effect of porcine reproductive and respiratory syndrome virus (PRRSV) (isolate ATCC VR-2385) infection on bactericidal activity of porcine pulmonary intravascular macrophages (PIMs): in vitro comparisons with pulmonary alveolar macrophages (PAMs).

    Science.gov (United States)

    Thanawongnuwech, R; Thacker, E L; Halbur, P G

    1997-11-01

    Porcine pulmonary intravascular macrophages (PIMs) were recovered by in situ pulmonary vascular perfusion with 0.025% collagenase in saline from six 8-week old, crossbred pigs. Pulmonary alveolar macrophages (PAMs) were recovered by bronchoalveolar lavage from the same pigs for comparisons in each assay. The macrophages were exposed to PRRSV (ATCC VR-2385) in vitro for 24 h and infection was confirmed by an indirect immunofluorescence test or transmission electron microscopy. Viral particles tended to accumulate in the vesicles of the Golgi apparatus or endoplasmic reticulum. Bactericidal function assays were performed on the recovered macrophages to determine the effects of the virus on macrophage functions. In vitro PRRSV infection reduced the bactericidal ability of PIMs from 68.3% to 56.4% (P PAMs from 69.3% to 61.0% (P > 0.1) at 24 h post-infection. The mean percentage of bacteria killed by macrophages after PRRSV infection was not significantly different among the treatment groups or between the treatment groups and non-infected controls based on colorimetric MTT bactericidal (Staphylococcus aureus) assay. PRRSV did not affect the ability of PIMs or PAMs to internalize opsonized 125I-iododeoxyuridine-labeled S. aureus (P > 0.05). PRRSV infection significantly decreased the production of superoxide anion (P PAMs. PRRSV reduced the myeloperoxidase-H2O2-halide product (P PAMs. The results suggest: (1) PIMs should be considered as an important replication site of PRRSV; (2) PRRSV may have a detrimental effect on both PIMs and PAMs; (3) loss of bactericidal function in PIMs may facilitate hematogenous bacterial infections.

  17. Surface expression of HSP72 by LPS-stimulated neutrophils facilitates gammadeltaT cell-mediated killing.

    Science.gov (United States)

    Hirsh, Mark I; Hashiguchi, Naoyuki; Chen, Yu; Yip, Linda; Junger, Wolfgang G

    2006-03-01

    During inflammation and sepsis, accumulation of activated neutrophils causes lung tissue damage and organ failure. Effective clearance of neutrophils reduces the risk of organ failure; however, its mechanisms are poorly understood. Because lungs are rich in gammadeltaT cells, we investigated the physiological role of these cells in the protection of lung tissue from infiltrating neutrophils. In a mouse model of sepsis, we found that the lungs of survivors contained significantly higher numbers of gammadeltaT cells than those of mice that died from sepsis. The number of gammadeltaT cells correlated inversely with the number of neutrophils in the lungs and with the degree of lung tissue damage. LPS rapidly elicited the expression of heat shock protein (HSP) 72 on the surface of human neutrophils. Inhibitors of transcription, protein synthesis, and intracellular protein transport blocked HSP72 expression, indicating that de novo synthesis is required. gammadeltaT cells targeted and rapidly killed LPS-treated neutrophils through direct cell-to-cell contact. Pre-treatment with neutralizing antibodies to HSP72 diminished neutrophil killing. Our data indicate that HSP72 expression on the cell surface predisposes inflamed neutrophils to killing by gammadeltaT cells. This intercellular exchange may allow gammadeltaT cells to resolve inflammation and limit host tissue damage during sepsis.

  18. Chemical and physical effects on the adhesion, maturation, and survival of monocytes, macrophages, and foreign body giant cells

    Science.gov (United States)

    Collier, Terry Odell, III

    Injury caused by biomedical device implantation initiates inflammatory and wound healing responses. Cells migrate to the site of injury to degrade bacteria and toxins, create new vasculature, and form new and repair injured tissue. Blood-proteins rapidly adsorb onto the implanted material surface and express adhesive ligands which mediate cell adhesion on the material surface. Monocyte-derived macrophages and multi-nucleated foreign body giant cells adhere to the surface and degrade the surface of the material. Due to the role of macrophage and foreign body giant cell on material biocompatibility and biostability, the effects of surface chemistry, surface topography and specific proteins on the maturation and survival of monocytes, macrophages and foreign body giant cells has been investigated. Novel molecularly designed materials were used to elucidate the dynamic interactions which occur between inflammatory cells, proteins and surfaces. The effect of protein and protein adhesion was investigated using adhesive protein depleted serum conditions on RGD-modified and silane modified surfaces. The effects of surface chemistry were investigated using temperature responsive surfaces of poly (N-isopropylacrylamide) and micropatterned surfaces of N-(2 aminoethyl)-3-aminopropyltrimethoxysilane regions on an interpenetrating polymer network of polyacrylamide and poly(ethylene glycol). The physical effects were investigated using polyimide scaffold materials and polyurethane materials with surface modifying end groups. The depletion of immunoglobulin G caused decreased levels of macrophage adhesion, foreign body giant cell formation and increased levels of apoptosis. The temporal nature of macrophage adhesion was observed with changing effectiveness of adherent cell detachment with time, which correlated to increased expression of beta1 integrin receptors on detached macrophages with time. The limited ability of the micropatterned surface, polyimide scaffold and surface

  19. Human macrophages infected with a high burden of ESAT-6-expressing M. tuberculosis undergo caspase-1- and cathepsin B-independent necrosis.

    Directory of Open Access Journals (Sweden)

    Amanda Welin

    Full Text Available Mycobacterium tuberculosis (Mtb infects lung macrophages, which instead of killing the pathogen can be manipulated by the bacilli, creating an environment suitable for intracellular replication and spread to adjacent cells. The role of host cell death during Mtb infection is debated because the bacilli have been shown to be both anti-apoptotic, keeping the host cell alive to avoid the antimicrobial effects of apoptosis, and pro-necrotic, killing the host macrophage to allow infection of neighboring cells. Since mycobacteria activate the NLRP3 inflammasome in macrophages, we investigated whether Mtb could induce one of the recently described inflammasome-linked cell death modes pyroptosis and pyronecrosis. These are mediated through caspase-1 and cathepsin-B, respectively. Human monocyte-derived macrophages were infected with virulent (H37Rv Mtb at a multiplicity of infection (MOI of 1 or 10. The higher MOI resulted in strongly enhanced release of IL-1β, while a low MOI gave no IL-1β response. The infected macrophages were collected and cell viability in terms of the integrity of DNA, mitochondria and the plasma membrane was determined. We found that infection with H37Rv at MOI 10, but not MOI 1, over two days led to extensive DNA fragmentation, loss of mitochondrial membrane potential, loss of plasma membrane integrity, and HMGB1 release. Although we observed plasma membrane permeabilization and IL-1β release from infected cells, the cell death induced by Mtb was not dependent on caspase-1 or cathepsin B. It was, however, dependent on mycobacterial expression of ESAT-6. We conclude that as virulent Mtb reaches a threshold number of bacilli inside the human macrophage, ESAT-6-dependent necrosis occurs, activating caspase-1 in the process.

  20. Macrophage Polarization in Obesity and Type 2 Diabetes: Weighing Down our Understanding of Macrophage Function?

    Directory of Open Access Journals (Sweden)

    Michael James Kraakman

    2014-09-01

    Full Text Available Obesity and type 2 diabetes are now recognized as chronic pro-inflammatory diseases. In the last decade, the role of the macrophage in particular has become increasingly implicated in their pathogenesis. Abundant literature now establishes that monocytes get recruited to peripheral tissues (ie pancreas, liver and adipose tissue to become resident macrophages and contribute to local inflammation, development of insulin resistance or even pancreatic dysfunction. Furthermore, an accumulation of evidence has established an important role for macrophage polarisation in the development of metabolic diseases. The general view in obesity is that there is an imbalance in the ratio of M1/M2 macrophages, with M1 pro-inflammatory macrophages being enhanced compared with M2 anti-inflammatory macrophages being down-regulated, leading to chronic inflammation and the propagation of metabolic dysfunction. However, there is emerging evidence revealing a more complex scenario with the spectrum of macrophage states exceeding well beyond the M1/M2 binary classification and confused further by human and animal models exhibiting different macrophage profiles. In this review we will discuss the recent findings regarding macrophage polarization in obesity and type 2 diabetes.

  1. Colonic microbiota can promote rapid local improvement of murine colitis by thioguanine independently of T lymphocytes and host metabolism.

    Science.gov (United States)

    Oancea, I; Movva, R; Das, I; Aguirre de Cárcer, D; Schreiber, V; Yang, Y; Purdon, A; Harrington, B; Proctor, M; Wang, R; Sheng, Y; Lobb, M; Lourie, R; Ó Cuív, P; Duley, J A; Begun, J; Florin, T H J

    2017-01-01

    Mercaptopurine (MP) and pro-drug azathioprine are 'first-line' oral therapies for maintaining remission in IBD. It is believed that their pharmacodynamic action is due to a slow cumulative decrease in activated lymphocytes homing to inflamed gut. We examined the role of host metabolism, lymphocytes and microbiome for the amelioration of colitis by the related thioguanine (TG). C57Bl/6 mice with or without specific genes altered to elucidate mechanisms responsible for TG's actions were treated daily with oral or intrarectal TG, MP or water. Disease activity was scored daily. At sacrifice, colonic histology, cytokine message, caecal luminal and mucosal microbiomes were analysed. Oral and intrarectal TG but not MP rapidly ameliorated spontaneous chronic colitis in Winnie mice (point mutation in Muc2 secretory mucin). TG ameliorated dextran sodium sulfate-induced chronic colitis in wild-type (WT) mice and in mice lacking T and B lymphocytes. Remarkably, colitis improved without immunosuppressive effects in the absence of host hypoxanthine (guanine) phosphoribosyltransferase (Hprt)-mediated conversion of TG to active drug, the thioguanine nucleotides (TGN). Colonic bacteria converted TG and less so MP to TGN, consistent with intestinal bacterial conversion of TG to so reduce inflammation in the mice lacking host Hprt. TG rapidly induced autophagic flux in epithelial, macrophage and WT but not Hprt(-/-) fibroblast cell lines and augmented epithelial intracellular bacterial killing. Treatment by TG is not necessarily dependent on the adaptive immune system. TG is a more efficacious treatment than MP in Winnie spontaneous colitis. Rapid local bacterial conversion of TG correlated with decreased intestinal inflammation and immune activation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. The mechanism of killing and exiting the protozoan host Acanthamoeba polyphaga by Legionella pneumophila.

    Science.gov (United States)

    Gao, L Y; Kwaik, Y A

    2000-02-01

    The ability of Legionella pneumophila to cause legionnaires' disease is dependent on its capacity to replicate within cells in the alveolar spaces. The bacteria kill mammalian cells in two phases: induction of apoptosis during the early stages of infection, followed by an independent and rapid necrosis during later stages of the infection, mediated by a pore-forming activity. In the environment, L. pneumophila is a parasite of protozoa. The molecular mechanisms by which L. pneumophila kills the protozoan cells, after their exploitation for intracellular proliferation, are not known. In an effort to decipher these mechanisms, we have examined induction of both apoptosis and necrosis in the protozoan Acanthamoeba polyphaga upon infection by L. pneumophila. Our data show that, although A. polyphaga undergoes apoptosis following treatment with actinomycin D, L. pneumophila does not induce apoptosis in these cells. Instead, intracellular L. pneumophila induces necrotic death in A. polyphaga, which is mediated by the pore-forming activity. Mutants of L. pneumophila defective in expression of the pore-forming activity are indistinguishable from the parental strain in intracellular replication within A. polyphaga. The parental strain bacteria cause necrosis-mediated lysis of all the A. polyphaga cells within 48 h after infection, and all the intracellular bacteria are released into the tissue culture medium. In contrast, all cells infected by the mutants remain intact, and the intracellular bacteria are 'trapped' within A. polyphaga after the termination of intracellular replication. Failure to exit the host cell after termination of intracellular replication results in a gradual decline in the viability of the mutant strain bacteria within A. polyphaga starting 48h after infection. Our data show that the pore-forming activity of L. pneumophila is not required for intracellular bacterial replication within A. polyphaga but is required for killing and exiting the protozoan

  3. Dakin Solution Alters Macrophage Viability and Function

    Science.gov (United States)

    2014-07-18

    crobial for wound care. DS has been shown to be toxic to host cells, but effects on immune cells are not well documented. Materials and methods: DS at 0.5...characterize the impact of DS on macrophage viability and function in vitro. 2. Materials and methods 2.1. Cell lines and reagents Murine macrophages...strainer to separate conidia from mycelium , and stored in DMEM at 4C. 2.3. Cellular viability assays Effect of DS on cellular viability was

  4. Lack of RNase L attenuates macrophage functions.

    Directory of Open Access Journals (Sweden)

    Xin Yi

    Full Text Available Macrophages are one of the major cell types in innate immunity against microbial infection. It is believed that the expression of proinflammatory genes such as tumor necrosis factor-α (TNF-α, interleukin (IL-1β, IL-6, and cyclooxygenase-2 (Cox-2 by macrophages is also crucial for activation of both innate and adaptive immunities. RNase L is an interferon (IFN inducible enzyme which is highly expressed in macrophages. It has been demonstrated that RNase L regulates the expression of certain inflammatory genes. However, its role in macrophage function is largely unknown.Bone marrow-derived macrophages (BMMs were generated from RNase L(+/+and (-/- mice. The migration of BMMs was analyzed by using Transwell migration assays. Endocytosis and phagocytosis of macrophages were assessed by using fluorescein isothiocyanate (FITC-Dextran 40,000 and FITC-E. coli bacteria, respectively. The expression of inflammatory genes was determined by Western Blot and ELISA. The promoter activity of Cox-2 was measured by luciferase reporter assays.Lack of RNase L significantly decreased the migration of BMMs induced by M-CSF, but at a less extent by GM-CSF and chemokine C-C motif ligand-2 (CCL2. Interestingly, RNase L deficient BMMs showed a significant reduction of endocytic activity to FITC-Dextran 40,000, but no any obvious effect on their phagocytic activity to FITC-bacteria under the same condition. RNase L impacts the expression of certain genes related to cell migration and inflammation such as transforming growth factor (TGF-β, IL-1β, IL-10, CCL2 and Cox-2. Furthermore, the functional analysis of the Cox-2 promoter revealed that RNase L regulated the expression of Cox-2 in macrophages at its transcriptional level. Taken together, our findings provide direct evidence showing that RNase L contributes to innate immunity through regulating macrophage functions.

  5. The Many Alternative Faces of Macrophage Activation

    OpenAIRE

    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 g...

  6. Macrophage subsets and microglia in multiple sclerosis

    OpenAIRE

    2014-01-01

    Along with microglia and monocyte-derived macrophages, macrophages in the perivascular space, choroid plexus, and meninges are the principal effector cells in neuroinflammatory and neurodegenerative disorders. These phagocytes are highly heterogeneous cells displaying spatial- and temporal-dependent identities in the healthy, injured, and inflamed CNS. In the last decade, researchers have debated on whether phagocytes subtypes and phenotypes are pathogenic or protective in CNS pathologies. In...

  7. Macrophage Efferocytosis and Prostate Cancer Bone Metastasis

    Science.gov (United States)

    2015-10-01

    AWARD NUMBER: W81XWH-14-1-0408 TITLE: Macrophage Efferocytosis and Prostate Cancer Bone Metastasis PRINCIPAL INVESTIGATOR: Jacqueline D. Jones...0408 Macrophage Efferocytosis and Prostate Cancer Bone Metastasis 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER...efferocytosis. The translation of this functional role during pathophysiological states such as tumor metastasis to the skeleton is unknown. The purpose of this

  8. Macrophage Polarization in Metabolism and Metabolic Disease

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2013-08-01

    Full Text Available BACKGROUND: Obesity is now recognized as the main cause of the worldwide epidemic of type 2 diabetes. Obesity-associated chronic inflammation is a contributing key factor for type 2 diabetes and cardiovascular disease. Numbers of studies have clearly demonstrated that the immune system and metabolism are highly integrated. CONTENT: Macrophages are an essential component of innate immunity and play a central role in inflammation and host defense. Moreover, these cells have homeostatic functions beyond defense, including tissue remodeling in ontogenesis and orchestration of metabolic functions. Diversity and plasticity are hallmarks of cells of the monocyte-macrophage lineage. In response to interferons (IFNs, toll-like receptor (TLR, or interleukin (IL-4/IL-13 signals, macrophages undergo M1 (classical or M2 (alternative activation. Progress has now been made in defining the signaling pathways, transcriptional networks, and epigenetic mechanisms underlying M1, M2 or M2-like polarized activation. SUMMARY: In response to various signals, macrophages may undergo classical M1 activation (stimulated by TLR ligands and IFN-γ or alternative M2 activation (stimulated by IL-4/IL-13; these states mirror the T helper (Th1–Th2 polarization of T cells. Pathology is frequently associated with dynamic changes in macrophage activation, with classically activated M1 cells implicate in initiating and sustaining inflammation, meanwhile M2 or M2-like activated cells associated with resolution or smoldering chronic inflammation. Identification of the mechanisms and molecules that are associated with macrophage plasticity and polarized activation provides a basis for macrophage centered diagnostic and therapeutic strategies. KEYWORDS: obesity, adipose tissue, inflammation, macrophage polarization.

  9. Bifunctional effect of E2 on macrophage

    Institute of Scientific and Technical Information of China (English)

    MinHONG; QuanZHU

    2004-01-01

    AIM: Our previous study showed that the effect of 1713-estradiol(E2) on macrophage does not strengthen when concentrationincreased. So the effect of E2 on cytokines, intracellular free Ca2+([Ca2+]i) and morphological change of macrophages at differentconcentrations were studied. METHODS: TNF-α was measured by MTT via L929 cell. Nitrate and nitrite level(NO) wasmeasured by the method of Griess. [Ca2+]i was examined by laser scanning confocal microscopy(LSCM). Fluorescent microscopy

  10. Temperature-induced protein secretion by Leishmania mexicana modulates macrophage signalling and function.

    Science.gov (United States)

    Hassani, Kasra; Antoniak, Elisabeth; Jardim, Armando; Olivier, Martin

    2011-05-03

    Protozoan parasites of genus Leishmania are the causative agents of leishmaniasis. These digenetic microorganisms undergo a marked environmental temperature shift (TS) during transmission from the sandfly vector (ambient temperature, 25-26°C) to the mammalian host (37°C). We have observed that this TS induces a rapid and dramatic increase in protein release from Leishmania mexicana (cutaneous leishmaniasis) within 4 h. Proteomic identification of the TS-induced secreted proteins revealed 72 proteins, the majority of which lack a signal peptide and are thus thought to be secreted via nonconventional mechanisms. Interestingly, this protein release is accompanied by alterations in parasite morphology including an augmentation in the budding of exovesicles from its surface. Here we show that the exoproteome of L. mexicana upon TS induces cleavage and activation of the host protein tyrosine phosphatases, specifically SHP-1 and PTP1-B, in a murine bone-marrow-derived macrophage cell line. Furthermore, translocation of prominent inflammatory transcription factors, namely NF-κB and AP-1 is altered. The exoproteome also caused inhibition of nitric oxide production, a crucial leishmanicidal function of the macrophage. Overall, our results provide strong evidence that within early moments of interaction with the mammalian host, L. mexicana rapidly releases proteins and exovesicles that modulate signalling and function of the macrophage. These modulations can result in attenuation of the inflammatory response and deactivation of the macrophage aiding the parasite in the establishment of infection.

  11. Temperature-induced protein secretion by Leishmania mexicana modulates macrophage signalling and function.

    Directory of Open Access Journals (Sweden)

    Kasra Hassani

    Full Text Available Protozoan parasites of genus Leishmania are the causative agents of leishmaniasis. These digenetic microorganisms undergo a marked environmental temperature shift (TS during transmission from the sandfly vector (ambient temperature, 25-26°C to the mammalian host (37°C. We have observed that this TS induces a rapid and dramatic increase in protein release from Leishmania mexicana (cutaneous leishmaniasis within 4 h. Proteomic identification of the TS-induced secreted proteins revealed 72 proteins, the majority of which lack a signal peptide and are thus thought to be secreted via nonconventional mechanisms. Interestingly, this protein release is accompanied by alterations in parasite morphology including an augmentation in the budding of exovesicles from its surface. Here we show that the exoproteome of L. mexicana upon TS induces cleavage and activation of the host protein tyrosine phosphatases, specifically SHP-1 and PTP1-B, in a murine bone-marrow-derived macrophage cell line. Furthermore, translocation of prominent inflammatory transcription factors, namely NF-κB and AP-1 is altered. The exoproteome also caused inhibition of nitric oxide production, a crucial leishmanicidal function of the macrophage. Overall, our results provide strong evidence that within early moments of interaction with the mammalian host, L. mexicana rapidly releases proteins and exovesicles that modulate signalling and function of the macrophage. These modulations can result in attenuation of the inflammatory response and deactivation of the macrophage aiding the parasite in the establishment of infection.

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

    Directory of Open Access Journals (Sweden)

    Katrin Paulsen

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  14. Induction of interferon and cell death in response to cytosolic DNA in chicken macrophages.

    Science.gov (United States)

    Vitak, Nazarii; Hume, David A; Chappell, Keith J; Sester, David P; Stacey, Katryn J

    2016-06-01

    Responses to cytosolic DNA can protect against both infectious organisms and the mutagenic effect of DNA integration. Recognition of invading DNA is likely to be fundamental to eukaryotic cellular life, but has been described only in mammals. Introduction of DNA into chicken macrophages induced type I interferon mRNA via a pathway conserved with mammals, requiring the receptor cGAS and the signalling protein STING. A second pathway of cytosolic DNA recognition in mammalian macrophages, initiated by absent in melanoma 2 (AIM2), results in rapid inflammasome-mediated pyroptotic cell death. AIM2 is restricted to mammals. Nevertheless, chicken macrophages underwent lytic cell death within 15 min of DNA transfection. The mouse AIM2-mediated response requires double stranded DNA, but chicken cell death was maintained with denatured DNA. This appears to be a novel form of rapid necrotic cell death, which we propose is an ancient response rendered redundant in mammalian macrophages by the appearance of the AIM2 inflammasome. The retention of these cytosolic DNA responses through evolution, with both conserved and non-conserved mechanisms, suggests a fundamental importance in cellular defence.

  15. Adipose tissue supports normalization of macrophage and liver lipid handling in obesity reversal.

    Science.gov (United States)

    Vatarescu, Maayan; Bechor, Sapir; Haim, Yulia; Pecht, Tal; Tarnovscki, Tanya; Slutsky, Noa; Nov, Ori; Shapiro, Hagit; Shemesh, Avishai; Porgador, Angel; Bashan, Nava; Rudich, Assaf

    2017-06-01

    Adipose tissue inflammation and dysfunction are considered central in the pathogenesis of obesity-related dysmetabolism, but their role in the rapid metabolic recovery upon obesity reversal is less well defined. We hypothesized that changes in adipose tissue endocrine and paracrine mechanisms may support the rapid improvement of obesity-induced impairment in cellular lipid handling. C57Bl-6J mice were fed ad libitum either normal chow (NC) or high-fat diet (HFF) for 10 weeks. A dietary obesity reversal group was fed HFF for 8 weeks and then switched to NC for 2 weeks (HFF→NC). Whole-body glucose homeostasis rapidly nearly normalized in the HFF→NC mice (fasting glucose and insulin fully normalized, glucose and insulin tolerance tests reversed 82% to the NC group levels). During 2 weeks of the dietary reversal, the liver was significantly cleared from ectopic fat, and functionally, glucose production from pyruvate, alanine or fructose was normalized. In contrast, adipose tissue inflammation (macrophage infiltration and polarization) largely remained as in HFF, though obesity-induced adipose tissue macrophage lipid accumulation decreased by ~50%, and adipose tissue MAP kinase hyperactivation was reversed. Ex vivo, mild changes in adipose tissue adipocytokine secretion profile were noted. These corresponded to partial or full reversal of the excess cellular lipid droplet accumulation induced by HFF adipose tissue conditioned media in hepatoma or macrophage cells, respectively. We propose that early after initiating reversal of nutritional obesity, rapid metabolic normalization largely precedes resolution of adipose tissue inflammation. Nevertheless, we demonstrate a hitherto unrecognized contribution of adipose tissue to the rapid improvement in lipid handling by the liver and by macrophages. © 2017 The authors.

  16. A Sigmoid Functional Response Emerges When Cytotoxic T Lymphocytes Start Killing Fresh Target Cells.

    Science.gov (United States)

    Gadhamsetty, Saikrishna; Marée, Athanasius F M; Beltman, Joost B; de Boer, Rob J

    2017-03-28

    Cytotoxic T lymphocyte (CTL)-mediated killing involves the formation of a synapse with a target cell, followed by delivery of perforin and granzymes. Previously, we derived a general functional response for CTL killing while considering that CTLs form stable synapses (i.e., single-stage) and that the number of conjugates remains at steady state. However, the killing of target cells sometimes requires multiple engagements (i.e., multistage). To study how multistage killing and a lack of steady state influence the functional response, we here analyze a set of differential equations as well as simulations employing the cellular Potts model, in both cases describing CTLs that kill target cells. We find that at steady state the total killing rate (i.e., the number of target cells killed by all CTLs) is well described by the previously derived double saturation function. Compared to single-stage killing, the total killing rate during multistage killing saturates at higher CTL and target cell densities. Importantly, when the killing is measured before the steady state is approached, a qualitatively different functional response emerges for two reasons: First, the killing signal of each CTL gets diluted over several targets and because this dilution effect is strongest at high target cell densities; this can result in a peak in the dependence of the total killing rate on the target cell density. Second, the total killing rate exhibits a sigmoid dependence on the CTL density when killing is a multistage process, because it takes typically more than one CTL to kill a target. In conclusion, a sigmoid dependence of the killing rate on the CTLs during initial phases of killing may be indicative of a multistage killing process. Observation of a sigmoid functional response may thus arise from a dilution effect and is not necessarily due to cooperative behavior of the CTLs. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  17. A type I IFN-dependent DNA damage response regulates the genetic program and inflammasome activation in macrophages

    Science.gov (United States)

    Morales, Abigail J; Carrero, Javier A; Hung, Putzer J; Tubbs, Anthony T; Andrews, Jared M; Edelson, Brian T; Calderon, Boris; Innes, Cynthia L; Paules, Richard S; Payton, Jacqueline E; Sleckman, Barry P

    2017-01-01

    Macrophages produce genotoxic agents, such as reactive oxygen and nitrogen species, that kill invading pathogens. Here we show that these agents activate the DNA damage response (DDR) kinases ATM and DNA-PKcs through the generation of double stranded breaks (DSBs) in murine macrophage genomic DNA. In contrast to other cell types, initiation of this DDR depends on signaling from the type I interferon receptor. Once activated, ATM and DNA-PKcs regulate a genetic program with diverse immune functions and promote inflammasome activation and the production of IL-1β and IL-18. Indeed, following infection with Listeria monocytogenes, DNA-PKcs-deficient murine macrophages produce reduced levels of IL-18 and are unable to optimally stimulate IFN-γ production by NK cells. Thus, genomic DNA DSBs act as signaling intermediates in murine macrophages, regulating innate immune responses through the initiation of a type I IFN-dependent DDR. DOI: http://dx.doi.org/10.7554/eLife.24655.001 PMID:28362262

  18. Macrophages - silent enemies in juvenile idiopathic arthritis.

    Science.gov (United States)

    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.

  19. Modulation of Macrophage Efferocytosis in Inflammation

    Directory of Open Access Journals (Sweden)

    Darlynn R Korns

    2011-11-01

    Full Text Available A critical function of macrophages within the inflammatory milieu is the removal of dying cells by a specialized phagocytic process called efferocytosis (to carry to the grave. Through specific receptor engagement and induction of downstream signaling, efferocytosing macrophages promote resolution of inflammation by i efficiently engulfing dying cells, thus avoiding cellular disruption and release of inflammatory contents, and ii producing anti-inflammatory mediators such as IL-10 and TGF-β that dampen pro-inflammatory responses. Evidence suggests that plasticity in macrophage programming, in response to changing environmental cues, modulates efferocytic capability. Essential to programming for enhanced efferocytosis is activation of the nuclear receptors PPARγ, PPARδ, LXR and possibly RXRα. Additionally, a number of signals in the inflammatory milieu, including those from dying cells themselves, can influence efferocytic efficacy either by acting as immediate inhibitors/enhancers or by altering macrophage programming for longer-term effects. Importantly, sustained inflammatory programming of macrophages can lead to defective apoptotic cell clearance and is associated with development of autoimmunity and other chronic inflammatory disorders. This review summarizes the current knowledge of the multiple factors that modulate macrophage efferocytic ability and highlights emerging therapeutic targets with significant potential for limiting chronic inflammation.

  20. VECTOR BUNDLE, KILLING VECTOR FIELD AND PONTRYAGIN NUMBERS

    Institute of Scientific and Technical Information of China (English)

    周建伟

    1991-01-01

    Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the Bott-Baum-Cheeger Theorem for vector bundle E.

  1. Male-killing Wolbachia in a flour beetle.

    Science.gov (United States)

    Fialho, R F; Stevens, L

    2000-01-01

    The bacteria in the genus Wolbachia are cytoplasmically inherited symbionts of arthropods. Infection often causes profound changes in host reproduction, enhancing bacterial transmission and spread in a population. The reproductive alterations known to result from Wolbachia infection include cytoplasmic incompatibility (CI), parthenogenesis, feminization of genetic males, fecundity enhancement, male killing and, perhaps, lethality Here, we report male killing in a third insect, the black flour beetle Tribolium madens, based on highly female-biased sex ratios of progeny from females infected with Wolbachia. The bias is cytoplasmic in nature as shown by repeated backcrossing of infected females with males of a naturally uninfected strain. Infection also lowers the egg hatch rates significantly to approximately half of those observed for uninfected females. Treatment of the host with antibiotics eliminated infection, reverted the sex ratio to unbiased levels and increased the percentage hatch. Typically Wolbachia infection is transmitted from mother to progeny, regardless of the sex of the progeny; however, infected T. madens males are never found. Virgin females are sterile, suggesting that the sex-ratio distortion in T. madens results from embryonic male killing rather than parthenogenesis. Based on DNA sequence data, the male-killing strain of Wolbachia in T. madens was indistinguishable from the CI-inducing Wolbachia in Tribolium confusum, a closely related beetle. Our findings suggest that host symbiont interaction effects may play an important role in the induction of Wolbachia reproductive phenotypes. PMID:10983833

  2. Denaturation of membrane proteins and hyperthermic cell killing

    NARCIS (Netherlands)

    Burgman, Paulus Wilhelmus Johannes Jozef

    1993-01-01

    Summarizing: heat induced denaturation of membrane proteins is probably related to hyperthermic cell killing. Induced resistance of heat sensitive proteins seems to be involved in the development of thermotolerance. Although many questions remain still to be answered, it appears that HSP72, when

  3. Killing for Girls: Predation Play and Female Empowerment

    Science.gov (United States)

    Bertozzi, Elena

    2012-01-01

    Predation games--games in which the player is actively encouraged and often required to hunt and kill in order to survive--have historically been the purview of male players. Females, though now much more involved in digital games than before, generally play games that stress traditionally feminine values such as socializing with others, shopping,…

  4. Karo-kari: a form of honour killing in pakistan.

    Science.gov (United States)

    Patel, Sujay; Gadit, Amin Muhammad

    2008-12-01

    Karo-Kari is a type of premeditated honour killing, which originated in rural and tribal areas of Sindh, Pakistan. The homicidal acts are primarily committed against women who are thought to have brought dishonour to their family by engaging in illicit pre-marital or extra-marital relations. In order to restore this honour, a male family member must kill the female in question. We conducted a systematic review of the published literature other sources on karo-kari and related forms of honour killing or violence against women. Media and non-governmental organization reports were utilized for case studies and analysis. Although legally proscribed, socio-cultural factors and gender role expectations have given legitimacy to karo-kari within some tribal communities. In addition to its persistence in areas of Pakistan, there is evidence that karo-kari may be increasing in incidence in other parts of the world in association with migration. Moreover, perpetrators of ;honour killings' often have motives outside of female adultery. Analysis of the socio-cultural and psycho-pathological factors associated with the practice of karo-kari can guide the development of prevention strategies.

  5. Killing Range: Explaining Lethality Variance within a Terrorist Organization.

    Science.gov (United States)

    Asal, Victor; Gill, Paul; Rethemeyer, R Karl; Horgan, John

    2015-04-01

    This paper presents an analysis of the Provisional Irish Republican Army's (PIRA) brigade level behavior during the Northern Ireland Conflict (1970-1998) and identifies the organizational factors that impact a brigade's lethality as measured via terrorist attacks. Key independent variables include levels of technical expertise, cadre age, counter-terrorism policies experienced, brigade size, and IED components and delivery methods. We find that technical expertise within a brigade allows for careful IED usage, which significantly minimizes civilian casualties (a specific strategic goal of PIRA) while increasing the ability to kill more high value targets with IEDs. Lethal counter-terrorism events also significantly affect a brigade's likelihood of killing both civilians and high-value targets but in different ways. Killing PIRA members significantly decreases IED fatalities but also significantly decreases the possibility of zero civilian IED-related deaths in a given year. Killing innocent Catholics in a Brigade's county significantly increases total and civilian IED fatalities. Together the results suggest the necessity to analyze dynamic situational variables that impact terrorist group behavior at the sub-unit level.

  6. Conformal killing vectors of plane symmetric four dimensional lorentzian manifolds

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Suhail; Hussain, Tahir; Khan, Gulzar Ali [University of Peshawar, Department of Mathematics, Peshawar, Khyber Pakhtoonkhwa (Pakistan); Bokhari, Ashfaque H. [King Fahd University of Petroleum and Minerals, Department of Mathematics and Statistics, Dhahran (Saudi Arabia)

    2015-11-15

    In this paper, we investigate conformal Killing vectors (CKVs) admitted by some plane symmetric spacetimes. Ten conformal Killing's equations and their general forms of CKVs are derived along with their conformal factor. The existence of conformal Killing symmetry imposes restrictions on the metric functions. The conditions imposing restrictions on these metric functions are obtained as a set of integrability conditions. Considering the cases of time-like and inheriting CKVs, we obtain spacetimes admitting plane conformal symmetry. Integrability conditions are solved completely for some known non-conformally flat and conformally flat classes of plane symmetric spacetimes. A special vacuum plane symmetric spacetime is obtained, and it is shown that for such a metric CKVs are just the homothetic vectors (HVs). Among all the examples considered, there exists only one case with a six dimensional algebra of special CKVs admitting one proper CKV. In all other examples of non-conformally flat metrics, no proper CKV is found and CKVs are either HVs or Killing's vectors (KVs). In each of the three cases of conformally flat metrics, a fifteen dimensional algebra of CKVs is obtained of which eight are proper CKVs. (orig.)

  7. THE KILLING FORMS AND DECOMPOSITION THEOREMS OF LIE SUPERTRIPLE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhixue; Jia Peipei

    2009-01-01

    In this article, the Killing form of a Lie supertriple system (LSTS) and that of its imbedding Lie superalgebra (LSA) are investigated, and a unique decomposition theorem for a quasiclassical LSTS with trivial center is established by means of the parallel decomposition theorem for a quasiclassical LSA.

  8. Killing for Girls: Predation Play and Female Empowerment

    Science.gov (United States)

    Bertozzi, Elena

    2012-01-01

    Predation games--games in which the player is actively encouraged and often required to hunt and kill in order to survive--have historically been the purview of male players. Females, though now much more involved in digital games than before, generally play games that stress traditionally feminine values such as socializing with others, shopping,…

  9. Illegal killing for ivory drives global decline in African elephants.

    Science.gov (United States)

    Wittemyer, George; Northrup, Joseph M; Blanc, Julian; Douglas-Hamilton, Iain; Omondi, Patrick; Burnham, Kenneth P

    2014-09-09

    Illegal wildlife trade has reached alarming levels globally, extirpating populations of commercially valuable species. As a driver of biodiversity loss, quantifying illegal harvest is essential for conservation and sociopolitical affairs but notoriously difficult. Here we combine field-based carcass monitoring with fine-scale demographic data from an intensively studied wild African elephant population in Samburu, Kenya, to partition mortality into natural and illegal causes. We then expand our analytical framework to model illegal killing rates and population trends of elephants at regional and continental scales using carcass data collected by a Convention on International Trade in Endangered Species program. At the intensively monitored site, illegal killing increased markedly after 2008 and was correlated strongly with the local black market ivory price and increased seizures of ivory destined for China. More broadly, results from application to continental data indicated illegal killing levels were unsustainable for the species between 2010 and 2012, peaking to ∼ 8% in 2011 which extrapolates to ∼ 40,000 elephants illegally killed and a probable species reduction of ∼ 3% that year. Preliminary data from 2013 indicate overharvesting continued. In contrast to the rest of Africa, our analysis corroborates that Central African forest elephants experienced decline throughout the last decade. These results provide the most comprehensive assessment of illegal ivory harvest to date and confirm that current ivory consumption is not sustainable. Further, our approach provides a powerful basis to determine cryptic mortality and gain understanding of the demography of at-risk species.

  10. Fish Kill in the Philippines—Déjà Vu

    Directory of Open Access Journals (Sweden)

    Gil Jacinto

    2011-12-01

    Full Text Available Almost ten years ago today, the country woke up toscreaming headlines— “Massive Fish Kill inPangasinan” or something akin to that. The fish killphenomenon, familiar to fishers in freshwater andcoastal bodies of water where fish farming was beingpursued, was suddenly manifested at a scale that hadheretofore not been experienced.

  11. What Is John Dewey Doing in "To Kill a Mockingbird"?

    Science.gov (United States)

    Frank, Jeff

    2015-01-01

    Harper Lee's novel "To Kill a Mockingbird" is taught in countless public schools and is beloved by many teachers and future teachers. Embedded within this novel--interestingly--is a strong criticism of an approach to education mockingly referred to as the "Dewey Decimal System." In this essay I explore Lee's criticism of…

  12. Pseudomonas Exotoxin A: optimized by evolution for effective killing

    Directory of Open Access Journals (Sweden)

    Marta eMichalska

    2015-09-01

    Full Text Available Pseudomonas Exotoxin A (PE is the most toxic virulence factor of the pathogenic bacterium Pseudomonas aeruginosa. This review describes current knowledge about the intoxication pathways of PE. Moreover, PE represents a remarkable example for pathoadaptive evolution, how bacterial molecules have been structurally and functionally optimized under evolutionary pressure to effectively impair and kill their host cells.

  13. Benzothiazinones kill Mycobacterium tuberculosis by blocking arabinan synthesis

    DEFF Research Database (Denmark)

    Makarov, Vadim; Manina, Giulia; Mikusova, Katarina

    2009-01-01

    New drugs are required to counter the tuberculosis (TB) pandemic. Here, we describe the synthesis and characterization of 1,3-benzothiazin-4-ones (BTZs), a new class of antimycobacterial agents that kill Mycobacterium tuberculosis in vitro, ex vivo, and in mouse models of TB. Using genetics...

  14. Comparison microbial killing efficacy between sonodynamic therapy and photodynamic therapy

    Science.gov (United States)

    Drantantiyas, Nike Dwi Grevika; Astuti, Suryani Dyah; Nasution, Aulia M. T.

    2016-11-01

    Biofilm is a way used by bacteria to survive from their environmental conditions by forming colony of bacteria. Specific characteristic in biofilm formation is the availability of matrix layer, known as extracellular polymer substance. Treatment using antibiotics may lead bacteria to be to resistant. Other treatments to reduce microbial, like biofilm, can be performed by using photodynamic therapy. Successful of this kind of therapy is induced by penetration of light and photosensitizer into target cells. The sonodynamic therapy offers greater penetrating capability into tissues. This research aimed to use sonodynamic therapy in reducing biofilm. Moreover, it compares also the killing efficacy of photodynamic therapy, sonodynamic therapy, and the combination of both therapeutic schemes (known as sono-photodynamic) to achieve higher microbial killing efficacy. Samples used are Staphylococcus aureus biofilm. Treatments were divided into 4 groups, i.e. group under ultrasound treatment with variation of 5 power levels, group of light treatment with exposure of 75s, group of combined ultrasound-light with variation of ultrasound power levels, and group of combined lightultrasound with variation of ultrasound power levels. Results obtained for each treatment, expressed in % efficacy of log CFU/mL, showed that the treatment of photo-sonodynamic provides greater killing efficacy in comparison to either sonodynamic and sono-photodynamic. The photo-sonodynamic shows also greater efficacy to photodynamic. So combination of light-ultrasound (photo-sonodynamic) can effectively kill microbial biofilm. The combined therapy will provide even better efficacy using exogenous photosensitizer.

  15. Nordic Noir on Television: The Killing I-III

    DEFF Research Database (Denmark)

    Agger, Gunhild

    2012-01-01

    The Nordic Noir has been applied by many countries as a slightly distorting mirror of tendencies in their own societies. On the background of its international appeal, the article analyses the prevalent genre of The Killing – the thriller – and relates it to the genres of crime fiction, political...

  16. [Hepatic manifestation of a macrophage activation syndrome (MAS)].

    Science.gov (United States)

    Nagel, Michael; Schwarting, Andreas; Straub, Beate K; Galle, Peter R; Zimmermann, Tim

    2017-05-01

    Background Elevated liver values are the most common pathological laboratory result in Germany. Frequent findings, especially in younger patients, are nutritive- or medicamentous- toxic reasons, viral or autoimmune hepatitis. A macrophage activation syndrome (MAS) may manifest like a viral infectious disease with fever, hepatosplenomegaly and pancytopenia and is associated with a high mortality. It is based on an enhanced activation of macrophages with increased cytokine release, leading to organ damage and multi-organ failure. In addition to genetic causes, MAS is commonly associated with infections and rheumatic diseases. We report the case of a 26-year-old female patient suffering from MAS as a rare cause of elevated liver enzymes. Methods Patient characteristics, laboratory values, liver histology, bone marrow and radiological imaging were documented and analyzed. Case Report After an ordinary upper airway infection with bronchitis, a rheumatic arthritis appeared and was treated with leflunomide und methotrexate. In the further course of the disease, the patient developed an acute hepatitis with fever, pancytopenia and massive hyperferritinemia. Immunohistochemistry of the liver biopsy revealed hemophagocytosis and activation of CD68-positive macrophages. In the radiological and histological diagnostics of the liver and bone marrow, an MAS was diagnosed as underlying disease of the acute hepatitis. Under therapy with prednisolone, the fever disappeared and transaminases and ferritin rapidly normalized. Conclusion Aside from the frequent causes of elevated liver values in younger patients, such as nutritive toxic, drug induced liver injury, viral or autoimmune hepatitis, especially in case of massive hyperferritinemia, a MAS should be considered as a rare cause of acute liver disease. © Georg Thieme Verlag KG Stuttgart · New York.

  17. The uptake of tocopherols by RAW 264.7 macrophages

    Directory of Open Access Journals (Sweden)

    Papas Andreas M

    2002-10-01

    Full Text Available Abstract Background Alpha-Tocopherol and gamma-tocopherol are the two major forms of vitamin E in human plasma and the primary lipid soluble antioxidants. The dietary intake of gamma-tocopherol is generally higher than that of alpha-tocopherol. However, alpha-tocopherol plasma levels are about four fold higher than those of gamma-tocopherol. Among other factors, a preferential cellular uptake of gamma-tocopherol over alpha-tocopherol could contribute to the observed higher plasma alpha-tocopherol levels. In this investigation, we studied the uptake and depletion of both alpha-tocopherol and gamma-tocopherol (separately and together in cultured RAW 264.7 macrophages. Similar studies were performed with alpha-tocopheryl quinone and gamma-tocopheryl quinone, which are oxidation products of tocopherols. Results RAW 264.7 macrophages showed a greater uptake of gamma-tocopherol compared to alpha-tocopherol (with uptake being defined as the net difference between tocopherol transported into the cells and loss due to catabolism and/or in vitro oxidation. Surprisingly, we also found that the presence of gamma-tocopherol promoted the cellular uptake of alpha-tocopherol. Mass balance considerations suggest that products other than quinone were formed during the incubation of tocopherols with macrophages. Conclusion Our data suggests that gamma-tocopherol could play a significant role in modulating intracellular antioxidant defence mechanisms. Moreover, we found the presence of gamma-tocopherol dramatically influenced the cellular accumulation of alpha-tocopherol, i.e., gamma-tocopherol promoted the accumulation of alpha-tocopherol. If these results could be extrapolated to in vivo conditions they suggest that gamma-tocopherol is selectively taken up by cells and removed from plasma more rapidly than alpha-tocopherol. This could, in part, contribute to the selective maintenance of alpha-tocopherol in plasma compared to gamma-tocopherol.

  18. Hidden symmetries and Lie algebra structures from geometric and supergravity Killing spinors

    Science.gov (United States)

    Açık, Özgür; Ertem, Ümit

    2016-08-01

    We consider geometric and supergravity Killing spinors and the spinor bilinears constructed out of them. The spinor bilinears of geometric Killing spinors correspond to the antisymmetric generalizations of Killing vector fields which are called Killing-Yano forms. They constitute a Lie superalgebra structure in constant curvature spacetimes. We show that the Dirac currents of geometric Killing spinors satisfy a Lie algebra structure up to a condition on 2-form spinor bilinears. We propose that the spinor bilinears of supergravity Killing spinors give way to different generalizations of Killing vector fields to higher degree forms. It is also shown that those supergravity Killing forms constitute a Lie algebra structure in six- and ten-dimensional cases. For five- and eleven-dimensional cases, the Lie algebra structure depends on an extra condition on supergravity Killing forms.

  19. CERN Library | Roy Calne presents: "The Ratchet of Science - Curiosity killed the cat" | 26 October

    CERN Multimedia

    CERN Library

    2015-01-01

    Sir Roy Calne will discuss his most recent book: “The Ratchet of Science - Curiosity killed the cat. Can human nature cope with the rapid and accelerated advances of science?”   Monday, 26 October - 4.30 p.m. CERN Filtration plant, Room 222-R-001 There is a limited number of seats. Please register here. The book’s premise is that huge scientific advances throughout history occur in spurts or “ratchets”. It reflects on the good and the evil consequences of discoveries. Due to the worrying nature of human beings, each ratchet in our knowledge is too often accompanied by dangerous applications. Knowledge, once established by a reliable scientific method, cannot be unlearned. The cat is out of the bag and the curiosity may kill the cat – so to speak. Professor Roy Calne illustrates this with the example of the young physicist known to all at CERN: Lise Meitner, who discovered and named nucle...

  20. Determination of Complement-Mediated Killing of Bacteria by Viability Staining and Bioluminescence

    Science.gov (United States)

    Virta, Marko; Lineri, Sanna; Kankaanpää, Pasi; Karp, Matti; Peltonen, Karita; Nuutila, Jari; Lilius, Esa-Matti

    1998-01-01

    Complement-mediated killing of bacteria was monitored by flow cytometric, luminometric, and conventional plate counting methods. A flow cytometric determination of bacterial viability was carried out by using dual staining with a LIVE/DEAD BacLight bacterial viability kit. In addition to the viable cell population, several other populations emerged in the fluorescence histogram, and there was a dramatic decrease in the total cell count in the light-scattering histogram in the course of the complement reaction. To permit luminometric measurements, Bacillus subtilis and Escherichia coli were made bioluminescent by expressing an insect luciferase gene. Addition of substrate after the complement reaction resulted in bioluminescence, the level of which was a measure of the viable cell population. All three methods gave essentially the same killing rate, suggesting that the bacteriolytic activity of serum complement can be measured rapidly and conveniently by using viability stains or bioluminescence. In principle, any bacterial strain can be used for viability staining and flow cytometric analysis. For the bioluminescence measurements genetically engineered bacteria are needed, but the advantage is that it is possible to screen automatically a large number of samples. PMID:9464386