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Sample records for stimulated human neutrophils

  1. NFκB Is Persistently Activated in Continuously Stimulated Human Neutrophils

    PubMed Central

    Miskolci, Veronika; Rollins, Janet; Vu, Hai Yen; Ghosh, Chandra C; Davidson, Dennis; Vancurova, Ivana

    2007-01-01

    Increased activation of the transcription factor NFκB in the neutrophils has been associated with the pathogenesis of sepsis, acute lung injury (ALI), bronchopulmonary dysplasia (BPD), and other neutrophil-mediated inflammatory disorders. Despite recent progress in analyzing early NFκB activation in human neutrophils, activation of NFκB in persistently stimulated neutrophils has not been previously studied. Because it is the persistent NFκB activation that is thought to be involved in the host response to sepsis and the pathogenesis of ALI and BPD, we hypothesized that continuously stimulated human neutrophils may exhibit a late phase of NFκB activity. The goal of this study was to analyze the NFκB activation and expression of IκB and NFκB proteins during neutrophil stimulation with inflammatory signals for prolonged times. We demonstrate that neutrophil stimulation with lipopolysaccharide (LPS) and tumor necrosis factor-α (TNFα) induces, in addition to the early activation at 30–60 min, a previously unrecognized late phase of NFκB activation. In LPS-stimulated neutrophils, this NFκB activity typically had a biphasic character, whereas TNFα-stimulated neutrophils exhibited a continuous NFκB activity peaking around 9 h after stimulation. In contrast to the early NFκB activation that inversely correlates to the nuclear levels of IκBα, however, in continuously stimulated neutrophils, NFκB is persistently activated despite considerable levels of IκBα present in the nucleus. Our data suggest that NFκB is persistently activated in human neutrophils during neutrophil-mediated inflammatory disorders, and this persistent NFκB activity may represent one of the underlying mechanisms for the continuous production of proinflammatory mediators. PMID:17592547

  2. Neutrophil kinetics of recombinant human granulocyte colony-stimulating factor-induced neutropenia in rats

    SciTech Connect

    Okada, Yuji; Kawagishi, Mayumi; Kusaka, Masaru )

    1990-01-01

    Single injection of recombinant human granulocyte colony-stimulating factor (rhG-CSF) immediately induced a decrease in the number of circulating neutrophils in rats. This neutropenia occurred 10 minutes after the injection but disappeared 40 minutes after injection. This transient neutropenia was dose-dependently induced by rhG-CSF and also induced by repeated injections. We studied the kinetics of circulating neutrophils in transient neutropenia. rhG-CSF markedly decreased the number of {sup 3}H-diisopropylfluorophosphate ({sup 3}H-DFP) labeled neutrophils in the circulation 10 minutes after injection but the labeled neutrophils recovered to near the control level 40 minutes after the injection. These results indicate that the neutrophil margination accounts for the neutrophenia and the marginated neutrophils return to the circulation.

  3. Myeloperoxidase Stimulates Neutrophil Degranulation.

    PubMed

    Grigorieva, D V; Gorudko, I V; Sokolov, A V; Kostevich, V A; Vasilyev, V B; Cherenkevich, S N; Panasenko, O M

    2016-08-01

    Myeloperoxidase, heme enzyme of azurophilic granules in neutrophils, is released into the extracellular space in the inflammation foci. In neutrophils, it stimulates a dose-dependent release of lactoferrin (a protein of specific granules), lysozyme (a protein of specific and azurophilic granules), and elastase (a protein of azurophilic granules). 4-Aminobenzoic acid hydrazide, a potent inhibitor of peroxidase activity of myeloperoxidase, produced no effect on neutrophil degranulation. Using signal transduction inhibitors (genistein, methoxyverapamil, wortmannin, and NiCl2), we demonstrated that myeloperoxidase-induced degranulation of neutrophils resulted from enzyme interaction with the plasma membrane and depends on activation of tyrosine kinases, phosphatidylinositol 3-kinases (PI3K), and calcium signaling. Myeloperoxidase modified by oxidative/halogenation stress (chlorinated and monomeric forms of the enzyme) lost the potency to activate neutrophil degranulation. PMID:27597056

  4. Tumor-associated neutrophils stimulate T cell responses in early-stage human lung cancer

    PubMed Central

    Eruslanov, Evgeniy B.; Bhojnagarwala, Pratik S.; Quatromoni, Jon G.; Stephen, Tom Li; Ranganathan, Anjana; Deshpande, Charuhas; Akimova, Tatiana; Vachani, Anil; Litzky, Leslie; Hancock, Wayne W.; Conejo-Garcia, José R.; Feldman, Michael; Albelda, Steven M.; Singhal, Sunil

    2014-01-01

    Infiltrating inflammatory cells are highly prevalent within the tumor microenvironment and mediate many processes associated with tumor progression; however, the contribution of specific populations remains unclear. For example, the nature and function of tumor-associated neutrophils (TANs) in the cancer microenvironment is largely unknown. The goal of this study was to provide a phenotypic and functional characterization of TANs in surgically resected lung cancer patients. We found that TANs constituted 5%–25% of cells isolated from the digested human lung tumors. Compared with blood neutrophils, TANs displayed an activated phenotype (CD62LloCD54hi) with a distinct repertoire of chemokine receptors that included CCR5, CCR7, CXCR3, and CXCR4. TANs produced substantial quantities of the proinflammatory factors MCP-1, IL-8, MIP-1α, and IL-6, as well as the antiinflammatory IL-1R antagonist. Functionally, both TANs and neutrophils isolated from distant nonmalignant lung tissue were able to stimulate T cell proliferation and IFN-γ release. Cross-talk between TANs and activated T cells led to substantial upregulation of CD54, CD86, OX40L, and 4-1BBL costimulatory molecules on the neutrophil surface, which bolstered T cell proliferation in a positive-feedback loop. Together our results demonstrate that in the earliest stages of lung cancer, TANs are not immunosuppressive, but rather stimulate T cell responses. PMID:25384214

  5. Impact of simultaneous stimulation of 5-lipoxygenase and myeloperoxidase in human neutrophils.

    PubMed

    Zschaler, Josefin; Arnhold, Jürgen

    2016-04-01

    Human neutrophil 5-lipoxygenase (5-LOX) oxidizes arachidonic acid (AA) to 5S-hydro(pero)xy-6E,8Z,11Z, 14Z-eicosatetraenoic acid (5-H(p)ETE) and leukotriene (LT)A4, which is further converted to the chemoattractant LTB4. These cells contain also the heme enzyme myeloperoxidase (MPO) producing several potent oxidants such as hypochlorous acid (HOCl). Previously, it was shown that MPO-metabolites influence 5-LOX product formation. Here, we addressed the question, whether a simultaneous activation of MPO and 5-LOX in neutrophils results in comparable changes of 5-LOX activity. Human neutrophils were stimulated with H2O2 or phorbol 12-myristate 13-acetate (PMA) for MPO activation and subsequently treated with calcium ionophore A23187 inducing 5-LOX product formation on endogenous AA. Special attention was drawn to neutrophil vitality, formation of MPO-derived metabolites and redox status. The pre-stimulation with H2O2 resulted in a concentration-dependent increase in the ratio of 5-HETE to the sum of LTB4+6-trans-LTB4 in consequence of MPO activation. Thereby no impairment of cell vitality and only a slightly reduction of total glutathione level was observed. An influence of MPO on 5-LOX product formation could be suggested using an MPO inhibitor. In contrast, the pre-stimulation with PMA resulted in different changes of 5-LOX product formation leading to a reduced amount of 5-HETE unaffected by MPO inhibition. Furthermore, impaired cell vitality and diminished redox status was detected after PMA stimulation. Nevertheless, a MPO-induced diminution of LTB4 was obvious. Further work is necessary to define the type of 5-LOX modification and investigate the effect of physiological MPO activators. PMID:27033421

  6. Recombinant human granulocyte-macrophage colony-stimulating factor stimulates in vitro mature human neutrophil and eosinophil function, surface receptor expression, and survival.

    PubMed Central

    Lopez, A F; Williamson, D J; Gamble, J R; Begley, C G; Harlan, J M; Klebanoff, S J; Waltersdorph, A; Wong, G; Clark, S C; Vadas, M A

    1986-01-01

    A purified recombinant human granulocyte-macrophage colony stimulating factor (rH GM-CSF) was a powerful stimulator of mature human eosinophils and neutrophils. The purified rH GM-CSF enhanced the cytotoxic activity of neutrophils and eosinophils against antibody-coated targets, stimulated phagocytosis of serum-opsonized yeast by both cell types in a dose-dependent manner, and stimulated neutrophil-mediated iodination in the presence of zymosan. In addition, rH GM-CSF enhanced N-formylmethionylleucylphenylalanine(FMLP)-stimulated degranulation of Cytochalasin B pretreated neutrophils and FMLP-stimulated superoxide production. In contrast, rH GM-CSF did not promote adherence of granulocytes to endothelial cells or plastic surfaces. rH GM-CSF selectively enhanced the surface expression of granulocyte functional antigens 1 and 2, and the Mo1 antigen. rH GM-CSF induced morphological changes and enhanced the survival of both neutrophils and eosinophils by 6 and 9 h, respectively. These experiments show that granulocyte-macrophage colony stimulating factor can selectively stimulate mature granulocyte function. PMID:3021817

  7. Mechanism of arachidonic acid liberation in platelet-activating factor-stimulated human polymorphonuclear neutrophils

    SciTech Connect

    Nakashima, S.; Suganuma, A.; Sato, M.; Tohmatsu, T.; Nozawa, Y. )

    1989-08-15

    Upon stimulation of human polymorphonuclear neutrophils with platelet-activating factor (PAF), arachidonic acid (AA) is released from membrane phospholipids. The mechanism for AA liberation, a key step in the synthesis of biologically active eicosanoids, was investigated. PAF was found to elicit an increase in the cytoplasmic level of free Ca2+ as monitored by fluorescent indicator fura 2. When (3H) AA-labeled neutrophils were exposed to PAF, the enhanced release of AA was observed with a concomitant decrease of radioactivity in phosphatidylinositol and phosphatidylcholine fractions. The inhibitors of phospholipase A2, mepacrine and 2-(p-amylcinnamoyl)-amino-4-chlorobenzoic acid, effectively suppressed the liberation of (3H)AA from phospholipids, indicating that liberation of AA is mainly catalyzed by the action of phospholipase A2. The extracellular Ca2+ is not required for AA release. However, intracellular Ca2+ antagonists, TMB-8 and high dose of quin 2/AM drastically reduced the liberation of AA induced by PAF, indicating that Ca2+ is an essential factor for phospholipase A2 activation. PAF raised the fluorescence of fura 2 at concentrations as low as 8 pM which reached a maximal level about 8 nM, whereas more than nM order concentrations of PAF was required for the detectable release of (3H)AA. Pretreatment of neutrophils with pertussis toxin resulted in complete abolition of AA liberation in response to PAF. However, the fura 2 response to PAF was not effectively inhibited by toxin treatment. In human neutrophil homogenate and membrane preparations, guanosine 5'-O-(thiotriphosphate) stimulated AA release and potentiated the action of PAF. Guanosine 5'-O-(thiodiphosphate) inhibited the effects of guanosine 5'-O-(thiotriphosphate).

  8. Iron-chelating agent desferrioxamine stimulates formation of neutrophil extracellular traps (NETs) in human blood-derived neutrophils.

    PubMed

    Völlger, Lena; Akong-Moore, Kathryn; Cox, Linda; Goldmann, Oliver; Wang, Yanming; Schäfer, Simon T; Naim, Hassan Y; Nizet, Victor; von Köckritz-Blickwede, Maren

    2016-07-01

    Neutrophil extracellular trap (NET) formation is a significant innate immune defense mechanism against microbial infection that complements other neutrophil functions including phagocytosis and degranulation of antimicrobial peptides. NETs are decondensed chromatin structures in which antimicrobial components (histones, antimicrobial peptides and proteases) are deployed and mediate immobilization of microbes. Here we describe an effect of iron chelation on the phenotype of NET formation. Iron-chelating agent desferrioxamine (DFO) showed a modest but significant induction of NETs by freshly isolated human neutrophils as visualized and quantified by immunocytochemistry against histone-DNA complexes. Further analyses revealed that NET induction by iron chelation required NADPH-dependent production of reactive oxygen species (ROS) as well as protease and peptidyl-arginine-deiminase 4 (PAD4) activities, three key mechanistic pathways previously linked to NET formation. Our results demonstrate that iron chelation by DFO contributes to the formation of NETs and suggest a target for pharmacological manipulation of NET activity. PMID:27129288

  9. Effects of granulocyte-macrophage colony-stimulating factor and cyclic AMP interaction on human neutrophil apoptosis.

    PubMed Central

    Tortorella, C; Piazzolla, G; Spaccavento, F; Antonaci, S

    1998-01-01

    The current study was undertaken to evaluate the effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) and cyclic AMP (cAMP) signaling interaction on human neutrophil apoptosis, either occurring spontaneously or induced by Fas antigen activation. Results show that GM-CSF, dibutyryl cAMP (a cAMP analog) and forskolin (an adenylate cyclase activator) are all able to suppress spontaneous neutrophil cell death. Of note however, when GM-CSF is used in combination with cAMP-elevating agents, an additive effect on neutrophil survival is observed with dibutyryl cAMP only, whereas supplementation of cell cultures with GM-CSF and forskolin results in a progressive reduction of antiapoptotic effects exerted by the single compounds. Moreover, although dibutyryl cAMP and forskolin do not affect Fas-triggered apoptotic events, they are still able to modulate the GM-CSF capacity to prolong neutrophil survival following anti-Fas IgM cell challenge, with effects similar to those respectively exerted on spontaneous neutrophil apoptosis. The data indicate that GM-CSF may negatively modulate the cAMP-mediated antiapoptotic pathway in human neutrophils, likely via the inhibition of adenylate cyclase activity. This would prevent an abnormal neutrophil survival as a result of cAMP signaling stimulation, which provides a novel insight into the role of GM-CSF as a physiological regulator of myeloid cell turnover. PMID:9927231

  10. SC-41930: An inhibitor of leukotriene B4-stimulated human neutrophil functions

    SciTech Connect

    Tsai, B.S.; Villani-Price, D.; Keith, R.H.; Zemaitis, J.M.; Bauer, R.F.; Leonard, R.; Djuric, S.W.; Shone, R.L. )

    1989-12-01

    SC-41930 was evaluated for effects on human neutrophil chemotaxis and degranulation. At concentrations up to 100 microM, SC-41930 alone exhibited no effect on neutrophil migration, but dose-dependently inhibited neutrophil chemotaxis induced by leukotriene B4 (LTB4) in a modified Boyden chamber. Concentrations of SC-41930 from 0.3 microM to 3 microM competitively inhibited LTB4-induced chemotaxis with a pA2 value of 6.35. While inactive at 10 microM against C5a-induced chemotaxis, SC-41930 inhibited N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced chemotaxis, with 10 times less potency than against LTB4-induced chemotaxis. SC-41930 inhibited (3H)LTB4 and (3H)fMLP binding to their receptor sites on human neutrophils with KD values of 0.2 microM and 2 microM, respectively. SC-41930 also inhibited neutrophil chemotaxis induced by 20-OH LTB or 12(R)-HETE. At concentrations up to 10 microM, SC-41930 alone did not cause neutrophil degranulation, but inhibited LTB4-induced degranulation in a noncompetitive manner. SC-41930 also inhibited fMLP- or C5a-induced degranulation, but was about 8 and 10 times less effective for fMLP and C5a, respectively. The results indicate that SC-41930 is a human neutrophil LTB4 receptor antagonist with greater specificity for LTB4 than for fMLP or C5a receptors.

  11. Changes in the subcellular distribution of the cytochrome b-245 on stimulation of human neutrophils.

    PubMed Central

    Garcia, R C; Segal, A W

    1984-01-01

    Cytochrome b-245 of neutrophils has a bimodal distribution in sucrose density gradients. The lighter component (d = 1.14) is shown to be associated with the plasma membrane by the similarity between its density and that of markers of this organelle, as well as a parallel increase in the density of the cytochrome and plasma membrane after treatment with digitonin or dimethyl suberimidate. The cytochrome b-245 of monocytes and cytoplasts, the latter produced by the removal of nuclei and granules from neutrophils, was located only in the plasma membrane. The denser peak of cytochrome (d = 1.19), which contained approximately half of the cytochrome b of neutrophils, had a similar density-distribution profile to the specific granules. After hypo-osmotic disruption of this denser material, the cytochrome distributed with the density of membranes, suggesting an original location within the membrane of the intracellular structure. Redistribution of the cytochrome from the granules to the membranes was observed after stimulation of respiratory activity with soluble agents or opsonized particles. This translocation is not responsible for activation of the oxidase system. There was poor agreement between the kinetics of the transfer of cytochromes from the dense component to the membranes, and degranulation of specific-granule contents, suggesting that the cytochrome may be located in another intracellular structure or that its localization becomes further modified after granule fusion. PMID:6721852

  12. Mobilization of sialidase from intracellular stores to the surface of human neutrophils and its role in stimulated adhesion responses of these cells.

    PubMed Central

    Cross, A S; Wright, D G

    1991-01-01

    Desialation of cell surfaces has been associated with the initiation or modification of diverse cellular functions. In these studies we have examined the subcellular distribution of sialidase (SE) in human neutrophils as well as the mobilization of this enzyme following neutrophil activation. Separation of subcellular fractions by density gradient centrifugation showed that SE is present not only in neutrophil primary and secondary granule populations, like lysozyme, but also in plasma membrane fractions. Neutrophil activation was associated with a redistribution of SE from secondary granule-enriched fractions to the plasma membrane. Furthermore, SE activity detected on the surface of intact neutrophils with a fluorescent SE substrate increased rapidly after activation with kinetics that matched both the loss of total cell-associated sialic acid and release of free sialic acid from the cells. These activation-dependent events were in each case blocked by incubation of neutrophils with the SE inhibitor, 2-deoxy-N-acetyl-neuraminic acid. Aggregation responses of neutrophils as well as adhesion responses to nylon and plastic surfaces were also inhibited by 2-deoxyNANA. Our findings indicate that the activation-dependent desialation of the neutrophil surface is associated with mobilization of an endogenous SE to the plasma membrane and has a role in stimulated adhesion responses of these cells. Images PMID:1721626

  13. Granulocyte colony-stimulating factor does not enhance phagocytosis or microbicidal activity of human mature polymorphonuclear neutrophils in vitro.

    PubMed Central

    Shimono, N; Okada, K; Takeda, D; Eguchi, K; Misumi, H; Sawae, Y; Niho, Y

    1994-01-01

    The direct effects of human granulocyte colony-stimulating factor (hG-CSF) on mature polymorphonuclear neutrophils (PMNs) in vitro were studied with regard to chemotaxis, superoxide production, and phagocytosis and microbicidal activity against the following viable microorganisms: Staphylococcus aureus, serum-resistant Pseudomonas aeruginosa, and Candida albicans. Recombinant hG-CSF (rhG-CSF) acted as a chemoattractant for human PMNs in a dose-dependent manner. The chemotactic response of PMNs to N-formyl-methionyl-leucyl-phenylalanine (FMLP) was not enhanced by rhG-CSF at any of the concentrations used. rhG-CSF did not induce the generation of superoxide by itself. However, rhG-CSF was able to prime human PMNs and to enhance O2- release stimulated by FMLP in a dose-dependent manner. rhg-CSF did not enhance phagocytosis or killing of the three species of microorganisms by normal PMNs. With PMNs obtained from patients who had hematological disorders or solid tumors, no enhancement of the microbicidal activity was observed in most cases. Microbial killing mediated by PMNs depended on the ratio of PMNs to target organisms. We concluded from these facts that the most important effect of rhG-CSF was to increase the number of the peripheral PMNs and not to enhance the functions of mature PMNs. PMID:8556501

  14. Sulfur mustard primes human neutrophils for increased degranulation and stimulates cytokine release via TRPM2/p38 MAPK signaling

    SciTech Connect

    Ham, Hwa-Yong; Hong, Chang-Won; Lee, Si-Nae; Kwon, Min-Soo; Kim, Yeon-Ja; Song, Dong-Keun

    2012-01-01

    Sulfur mustard (2,2′-bis-chloroethyl-sulfide; SM) has been a military threat since the World War I. The emerging threat of bioterrorism makes SM a major threat not only to military but also to civilian world. SM injury elicits an inflammatory response characterized by infiltration of neutrophils. Although SM was reported to prime neutrophils, the mechanism has not been identified yet. In the present study, we investigated the mechanism of SM-induced priming in human neutrophils. SM increased [Ca{sup 2+}]{sub i} in human neutrophils in a concentration-dependent fashion. Transient receptor potential melastatin (TRPM) 2 inhibitors (clotrimazole, econazole and flufenamic acid) and silencing of TRPM2 by shRNA attenuated SM-induced [Ca{sup 2+}]{sub i} increase. SM primed degranulation of azurophil and specific granules in response to activation by fMLP as previously reported. SB203580, an inhibitor of p38 MAPK, inhibited SM-induced priming. Neither PD98057, an ERK inhibitor, nor SP600215, a JNK inhibitor, inhibited SM-induced priming. In addition, SM enhanced phosphorylation of NF-kB p65 and release of TNF-α, interleukin (IL)-6 and IL-8. SB203580 inhibited SM-induced NF-kB phosphorylation and cytokine release. These results suggest the involvement of TRPM2/p38 MAPK pathway in SM-induced priming and cytokines release in neutrophils. -- Highlights: ► SM increased [Ca{sup 2+}]{sub i} in human neutrophils through TPRM2-mediated calcium influx. ► SM primed degranulation of azurophil and specific granules. ► SM enhanced p38 MAPK and NF-κB p65 phosphorylation in human neutrophils. ► SM enhanced release of TNF-α, interleukin (IL)-6 and IL-8 from human neutrophils. ► SB203580 inhibited SM-induced priming, NF-κB p65 phosphorylation and cytokine release.

  15. Human neutrophils contain and bind high molecular weight kininogen.

    PubMed Central

    Gustafson, E J; Schmaier, A H; Wachtfogel, Y T; Kaufman, N; Kucich, U; Colman, R W

    1989-01-01

    Because plasma kallikrein activates human neutrophils, and in plasma prekallikrein (PK) circulates complexed with high molecular weight kininogen (HMWK), we determined whether HMWK could mediate kallikrein's association with neutrophils. HMWK antigen (237 +/- 61 ng HMWK/10(8) neutrophils) was present in lysates of washed human neutrophils. Little if any plasma HMWK was tightly bound and nonexchangeable with the neutrophil surface. Human neutrophils were found to possess surface membrane-binding sites for HMWK but no internalization was detected at 37 degrees C. 125I-HMWK binding to neutrophils was dependent upon Zn2+. Binding of 125I-HMWK to neutrophils was specific and 90% reversible. 125I-HMWK binding to neutrophils was saturable with an apparent Kd of 9-18 nM and 40,000-70,000 sites per cell. Upon binding to neutrophils, 125I-HMWK was proteolyzed by human neutrophil elastase (HNE) into lower relative molecular mass derivatives. Furthermore, HMWK found in neutrophils also served as a cofactor for HNE secretion because neutrophils deficient in HMWK have reduced HNE secretion when stimulated in plasma deficient in HMWK or with purified kallikrein. These studies indicate that human neutrophils contain a binding site for HMWK that could serve to localize plasma or neutrophil HMWK on their surface to possibly serve as a receptor for kallikrein and to participate in HNE secretion by this enzyme. Images PMID:2738152

  16. A variable immunoreceptor in a subpopulation of human neutrophils

    PubMed Central

    Puellmann, Kerstin; Kaminski, Wolfgang E.; Vogel, Mandy; Nebe, C. Thomas; Schroeder, Josef; Wolf, Hans; Beham, Alexander W.

    2006-01-01

    Neutrophils are thought to rely solely on nonspecific immune mechanisms. Here we provide molecular biological, immunological, ultrastructural, and functional evidence for the presence of a T cell receptor (TCR)-based variable immunoreceptor in a 5–8% subpopulation of human neutrophils. We demonstrate that these peripheral blood neutrophils express variable and individual-specific TCRαβ repertoires and the RAG1/RAG2 recombinase complex. The proinflammatory cytokine granulocyte colony-stimulating factor regulates expression of the neutrophil immunoreceptor and RAG1/RAG2 in vivo. Specific engagement of the neutrophil TCR complex protects from apoptosis and stimulates secretion of the neutrophil-activating chemokine IL-8. Our results, which also demonstrate the presence of the TCR in murine neutrophils, suggest the coexistence of a variable and an innate host defense system in mammalian neutrophils. PMID:16983085

  17. NET amyloidogenic backbone in human activated neutrophils.

    PubMed

    Pulze, L; Bassani, B; Gini, E; D'Antona, P; Grimaldi, A; Luini, A; Marino, F; Noonan, D M; Tettamanti, G; Valvassori, R; de Eguileor, M

    2016-03-01

    Activated human neutrophils produce a fibrillar DNA network [neutrophil extracellular traps (NETs)] for entrapping and killing bacteria, fungi, protozoa and viruses. Our results suggest that the neutrophil extracellular traps show a resistant amyloidogenic backbone utilized for addressing reputed proteins and DNA against the non-self. The formation of amyloid fibrils in neutrophils is regulated by the imbalance of reactive oxygen species (ROS) in the cytoplasm. The intensity and source of the ROS signal is determinant for promoting stress-associated responses such as amyloidogenesis and closely related events: autophagy, exosome release, activation of the adrenocorticotrophin hormone/α-melanocyte-stimulating hormone (ACTH/α-MSH) loop and synthesis of specific cytokines. These interconnected responses in human activated neutrophils, that have been evaluated from a morphofunctional and quantitative viewpoint, represent primitive, but potent, innate defence mechanisms. In invertebrates, circulating phagocytic immune cells, when activated, show responses similar to those described previously for activated human neutrophils. Invertebrate cells within endoplasmic reticulum cisternae produce a fibrillar material which is then assembled into an amyloidogenic scaffold utilized to convey melanin close to the invader. These findings, in consideration to the critical role played by NET in the development of several pathologies, could explain the structural resistance of these scaffolds and could provide the basis for developing new diagnostic and therapeutic approaches in immunomediated diseases in which the innate branch of the immune system has a pivotal role. PMID:26462606

  18. Chlorination of Taurine by Human Neutrophils

    PubMed Central

    Weiss, Stephen J.; Klein, Roger; Slivka, Adam; Wei, Maria

    1982-01-01

    The model hydrogen peroxide-myeloperoxidase-chloride system is capable of generating the powerful oxidant hypochlorous acid, which can be quantitated by trapping the generated species with the β-amino acid, taurine. The resultant stable product, taurine chloramine, can be quantitated by its ability to oxidize the sulfhydryl compound, 5-thio-2-nitro-benzoic acid to the disulfide, 5,5′-dithiobis(2-nitroben-zoic acid) or to oxidize iodide to iodine. Using this system, purified myeloperoxidase in the presence of chloride and taurine converted stoichiometric quantities of hydrogen peroxide to taurine chloramine. Chloramine generation was absolutely dependent on hydrogen peroxide, myeloperoxidase, and chloride and could be inhibited by catalase, myeloperoxidase inhibitors, or chloride-free conditions. In the presence of taurine, intact human neutrophils stimulated with either phorbol myristate acetate or opsonized zymosan particles generated a stable species capable of oxidizing 5-thio-2-nitrobenzoic acid or iodide. Resting cells did not form this species. The oxidant formed by the stimulated neutrophils was identified as taurine chloramine by both ultraviolet spectrophotometry and electrophoresis. Taurine chloramine formation by the neutrophil was dependent on the taurine concentration, time, and cell number. Neutrophil-dependent chloramine generation was inhibited by catalase, the myeloperoxidase inhibitors, azide, cyanide, or aminotriazole and by chloride-free conditions, but not by superoxide dismutase or hydroxyl radical scavengers. Thus, it appears that stimulated human neutrophils can utilize the hydrogen peroxide-myeloperoxidase-chloride system to generate taurine chloramine. Based on the demonstrated ability of the myeloperoxidase system to generate free hypochlorous acid we conclude that neutrophils chlorinate taurine by producing this powerful oxidant. The biologic reactivity and cytotoxic potential of hypochlorous acid and its chloramine derivatives

  19. Lipoxin A4 and lipoxin B4 stimulate the release but not the oxygenation of arachidonic acid in human neutrophils: Dissociation between lipid remodeling and adhesion

    SciTech Connect

    Nigam, S.; Fiore, S.; Luscinskas, F.W.; Serhan, C.N. )

    1990-06-01

    The profiles of actions of lipoxin A4 (LXA4) and lipoxin B4 (LXB4), two lipoxygenase-derived eicosanoids, were examined with human neutrophils. At nanomolar concentrations, LXA4 and LXB4 each stimulated the release of (1-14C)arachidonic acid from esterified sources in neutrophils. Lipoxin-induced release of (1-14C)arachidonic acid was both dose- and time-dependent and was comparable to that induced by the chemotactic peptide f-met-leu-phe. Time-course studies revealed that lipoxin A4 and lipoxin B4 each induced a biphasic release of (1-14C)arachidonic acid, which was evident within seconds (5-15 sec) in its initial phase and minutes (greater than 30 sec) in the second phase. In contrast, the all-trans isomers of LXA4 and LXB4 did not provoke (1-14C)AA release. Lipoxin-induced release of arachidonic acid was inhibited by prior treatment of the cells with pertussis toxin but not by its beta-oligomers, suggesting the involvement of guaninine nucleotide-binding regulatory proteins in this event. Dual radiolabeling of neutrophil phospholipid classes with (1-14C)arachidonic acid and (3H)palmitic acid showed that phosphatidylcholine was a major source of lipoxin-induced release of (1-14C)arachidonic acid. They also demonstrated that lipoxins rapidly stimulate both formation of phosphatidic acid as well as phospholipid remodeling. Although both LXA4 and LXB4 (10(-8)-10(-6) M) stimulated the release of (1-14C)arachidonic acid, neither compound evoked its oxygenation by either the 5- or 15-lipoxygenase pathways (including the formation of LTB4, 20-COOH-LTB4, 5-HETE, or 15-HETE). LXA4 and LXB4 (10(-7) M) each stimulated the elevation of cytosolic Ca2+ as monitored with Fura 2-loaded cells, albeit to a lesser extent than equimolar concentrations of FMLP. Neither lipoxin altered the binding of (3H)LTB4 to its receptor on neutrophils.

  20. Acetaminophen prevents oxidative burst and delays apoptosis in human neutrophils.

    PubMed

    Freitas, Marisa; Costa, Vera M; Ribeiro, Daniela; Couto, Diana; Porto, Graça; Carvalho, Félix; Fernandes, Eduarda

    2013-05-23

    Acetaminophen is a frequently prescribed over-the-counter drug to reduce fever and pain in the event of inflammatory process. As neutrophils are relevant cells in inflammatory processes, the putative interaction of acetaminophen with these cells, if present, would be of paramount importance. The present study was undertaken to evaluate the effect of acetaminophen in human neutrophils' oxidative burst and lifespan in vitro. The obtained results demonstrate that acetaminophen efficiently modulates neutrophils' oxidative burst in phorbol myristate acetate-activated neutrophils, in a concentration-dependent manner, at in vivo relevant concentrations. It was clearly demonstrated that acetaminophen is a strong scavenger of HOCl and H2O2, which probably contributed to the effect observed in neutrophils. Acetaminophen also induced the depletion of glutathione in stimulated neutrophils, suggesting its transformation into a reactive intermediate. Obtained results further revealed that acetaminophen affects programmed cell death of human neutrophils, resulting in a delay of previously stimulated neutrophils-mediated apoptosis. Overall, our data suggested that acetaminophen has considerable potential to be included in anti-inflammatory therapeutic strategies, by preventing biological damage induced by an excessive production of reactive species generated in activated neutrophils and by extending the lifespan of neutrophils, favoring the elimination of pathogens, thus contributing to tissue healing and resolution of inflammation. PMID:23518321

  1. Differential effects of nylon fibre adherence on the production of superoxide anion by human polymorphonuclear neutrophilic granulocytes stimulated with chemoattractants, ionophore A23187 and phorbol myristate acetate.

    PubMed Central

    Kownatzki, E; Uhrich, S

    1987-01-01

    Human polymorphonuclear neutrophilic granulocytes were made adherent by passing them over protein-coated nylon fibre columns and compared with suspended cells for their production of superoxide anion as measured by cytochrome C reduction. The cells were stimulated with chemotactic factors, the ionophore A 23187, and the tumour promoter phorbol myristate acetate. There was no increased O2-. production by adherent cells in the absence of a stimulus. Adherent cells produced considerably higher amounts of superoxide than suspended cells when stimulated with formyl-methionyl-leucyl-phenylalanine, ionophore A 23187, C5a, C5adesArg, and the platelet activating factor 1-o-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine. In contrast, stimulation with phorbol myristate acetate did not result in higher superoxide release from adherent than from suspended cells, and leukotriene B4 and a mononuclear cell-derived chemotaxin did not stimulate either cell to release significant amounts of superoxide. It is suggested that the augmented production of oxygen radicals with certain stimuli contributes to inflammatory symptoms in situations involving adherent granulocytes. PMID:2820637

  2. Tyrosine phosphorylation and activation of a new mitogen-activated protein (MAP)-kinase cascade in human neutrophils stimulated with various agonists.

    PubMed Central

    Nahas, N; Molski, T F; Fernandez, G A; Sha'afi, R I

    1996-01-01

    The presence of a novel 38 kDa protein that is tyrosine phosphorylated in human neutrophils, a terminally differentiated cell, upon stimulation of these cells with low concentrations of lipopolysaccharide (LPS) in combination with serum has been demonstrated. This 38 kDa protein was identified as the mammalian homologue of HOG1 in yeast, the p38 mitogen-activated protein (MAP) kinase. This conclusion is based on the experimental findings that anti-phosphotyrosine (anti-PY) antibody immunoprecipitates a 38 kDa protein that is recognized by anti-p38 MAP kinase antibody, and conversely, anti-p38 MAP kinase antibody immunoprecipitates a 38 kDa protein that can be recognized by anti-PY antibody. Moreover, this tyrosine phosphorylated protein is found associated entirely with the cytosol. It was also found that this p38 MAP kinase is activated following stimulation of these cells with low concentrations of LPS in combination with serum. This conclusion is based on three experimental findings. First, soluble fractions isolated from LPS-stimulated cells phosphorylate heat shock protein 27 (hsp27) in an in vitro assay, and this effect is not inhibited by protein kinase C and protein kinase A inhibitor peptides. This effect is similar to the effect produced by the commercially available phosphorylated and activated MAPKAP kinase-2 (MAP kinase activated protein kinase-2). Secondly, a 27 kDa protein that aligns with a protein recognized by anti-hsp27 antibody is phosphorylated upon LPS stimulation of intact human neutrophils prelabelled with radioactive phosphate. Lastly, immune complex protein kinase assays, using [gamma-32P]ATP and activating transcription factor 2 (ATF2) as substrates, showed increased p38 MAP kinase activity from LPS-stimulated human neutrophils. The phosphorylation and activation of this p38 MAP kinase can be affected by both G-protein-coupled receptors such as platelet-activating factor (PAF) and non-G-protein-coupled receptors such as the cytokine

  3. Natural Product Anacardic Acid from Cashew Nut Shells Stimulates Neutrophil Extracellular Trap Production and Bactericidal Activity.

    PubMed

    Hollands, Andrew; Corriden, Ross; Gysler, Gabriela; Dahesh, Samira; Olson, Joshua; Raza Ali, Syed; Kunkel, Maya T; Lin, Ann E; Forli, Stefano; Newton, Alexandra C; Kumar, Geetha B; Nair, Bipin G; Perry, J Jefferson P; Nizet, Victor

    2016-07-01

    Emerging antibiotic resistance among pathogenic bacteria is an issue of great clinical importance, and new approaches to therapy are urgently needed. Anacardic acid, the primary active component of cashew nut shell extract, is a natural product used in the treatment of a variety of medical conditions, including infectious abscesses. Here, we investigate the effects of this natural product on the function of human neutrophils. We find that anacardic acid stimulates the production of reactive oxygen species and neutrophil extracellular traps, two mechanisms utilized by neutrophils to kill invading bacteria. Molecular modeling and pharmacological inhibitor studies suggest anacardic acid stimulation of neutrophils occurs in a PI3K-dependent manner through activation of surface-expressed G protein-coupled sphingosine-1-phosphate receptors. Neutrophil extracellular traps produced in response to anacardic acid are bactericidal and complement select direct antimicrobial activities of the compound. PMID:27226531

  4. Effect of perfluorochemical blood substitutes on human neutrophil function.

    PubMed

    Virmani, R; Fink, L M; Gunter, K; English, D

    1984-01-01

    This investigation was undertaken to determine the influence of perfluorochemical blood substitutes (PFCs) on human neutrophil function. Neutrophils isolated from blood of healthy donors were incubated at 37 degrees C for 1 hour with 25 percent Oxypherol (perfluorotributylamine) or Fluosol-DA (perfluorodecalin and perfluorotripropylamine) in the presence of fresh autologous serum. In comparison to cells incubated with Hank's balanced salt solution (buffer), neutrophils exposed to PFCs were markedly inhibited in their chemotactic and phagocytic responses. With 25 percent PFCs, chemotaxis to zymosan-activated serum was inhibited to approximately 25 percent of control by Fluosol-DA and 11 percent by Oxypherol. Phagocytosis of polystyrene beads in the presence of fresh serum was decreased to 52 and 50 percent of control by both Oxypherol and Fluosol-DA, respectively. Neutrophils exposed to PFCs aggregated slower and with an extended activation time upon addition of phorbol myristate acetate (PMA). When activated with n-formyl-methionyl-leucyl-phenylalanine (FMLP), neutrophils exposed to PFCs aggregated at a faster rate but with a longer lag phase in comparison to control cells. Neutrophil superoxide (O-2) release stimulated by PMA also was depressed by prior exposure of cells to Oxypherol (6 nmoles O-2/1.5 X 10(6) neutrophils) compared to buffer (32 nmoles O-2/1.5 X 10(6) neutrophils). PMA-stimulated neutrophil adherence was depressed significantly by prior exposure to Fluosol-DA compared to control. In contrast, Oxypherol had insignificant influence on stimulated adherence. Since PFCs have a profound influence on several important neutrophil functions, patients receiving PFC should be monitored closely for possible infectious complications. PMID:6087518

  5. Human resistin promotes neutrophil proinflammatory activation and neutrophil extracellular trap formation and increases severity of acute lung injury.

    PubMed

    Jiang, Shaoning; Park, Dae Won; Tadie, Jean-Marc; Gregoire, Murielle; Deshane, Jessy; Pittet, Jean Francois; Abraham, Edward; Zmijewski, Jaroslaw W

    2014-05-15

    Although resistin was recently found to modulate insulin resistance in preclinical models of type II diabetes and obesity, recent studies also suggested that resistin has proinflammatory properties. We examined whether the human-specific variant of resistin affects neutrophil activation and the severity of LPS-induced acute lung injury. Because human and mouse resistin have distinct patterns of tissue distribution, experiments were performed using humanized resistin mice that exclusively express human resistin (hRTN(+/-)(/-)) but are deficient in mouse resistin. Enhanced production of TNF-α or MIP-2 was found in LPS-treated hRtn(+/-/-) neutrophils compared with control Rtn(-/-/-) neutrophils. Expression of human resistin inhibited the activation of AMP-activated protein kinase, a major sensor and regulator of cellular bioenergetics that also is implicated in inhibiting inflammatory activity of neutrophils and macrophages. In addition to the ability of resistin to sensitize neutrophils to LPS stimulation, human resistin enhanced neutrophil extracellular trap formation. In LPS-induced acute lung injury, humanized resistin mice demonstrated enhanced production of proinflammatory cytokines, more severe pulmonary edema, increased neutrophil extracellular trap formation, and elevated concentration of the alarmins HMGB1 and histone 3 in the lungs. Our results suggest that human resistin may play an important contributory role in enhancing TLR4-induced inflammatory responses, and it may be a target for future therapies aimed at reducing the severity of acute lung injury and other inflammatory situations in which neutrophils play a major role. PMID:24719460

  6. Human plasma kallikrein releases neutrophil elastase during blood coagulation.

    PubMed Central

    Wachtfogel, Y T; Kucich, U; James, H L; Scott, C F; Schapira, M; Zimmerman, M; Cohen, A B; Colman, R W

    1983-01-01

    Elastase is released from human neutrophils during the early events of blood coagulation. Human plasma kallikrein has been shown to stimulate neutrophil chemotaxis, aggregation, and oxygen consumption. Therefore, the ability of kallikrein to release neutrophil elastase was investigated. Neutrophils were isolated by dextran sedimentation, and elastase release was measured by both an enzyme-linked immunosorbent assay, and an enzymatic assay using t-butoxy-carbonyl-Ala-Ala-Pro-Val-amino methyl coumarin as the substrate. Kallikrein, 0.1-1.0 U/ml, (0.045-0.45 microM), was incubated with neutrophils that were preincubated with cytochalasin B (5 micrograms/ml). The release of elastase was found to be proportional to the kallikrein concentration. Kallikrein released a maximum of 34% of the total elastase content, as measured by solubilizing the neutrophils in the nonionic detergent Triton X-100. A series of experiments was carried out to determine if kallikrein was a major enzyme involved in neutrophil elastase release during blood coagulation. When 10 million neutrophils were incubated in 1 ml of normal plasma in the presence of 30 mM CaCl2 for 90 min, 2.75 micrograms of elastase was released. In contrast, neutrophils incubated in prekallikrein-deficient or Factor XII-deficient plasma released less than half of the elastase, as compared with normal plasma. The addition of purified prekallikrein to prekallikrein-deficient plasma restored neutrophil elastase release to normal levels. Moreover, release of elastase was enhanced in plasma deficient in C1-inhibitor, the major plasma inhibitor of kallikrein. This release was not dependent upon further steps in the coagulation pathway, or on C5a, since levels of elastase, released in Factor XI- or C5-deficient plasma, were similar to that in normal plasma, and an antibody to C5 failed to inhibit elastase release. These data suggest that kallikrein may be a major enzyme responsible for the release of elastase during blood

  7. Effects of phosphodiester and phosphorothioate ODN2216 on leukotriene synthesis in human neutrophils and neutrophil apoptosis.

    PubMed

    Viryasova, Galina M; Golenkina, Ekaterina A; Galkina, Svetlana I; Gaponova, Tatjana V; Romanova, Yulia M; Sud'ina, Galina F

    2016-06-01

    Polymorphonuclear leukocytes (PMNLs, neutrophils) play a major role in the initiation and resolution of the inflammatory response, and neutrophil apoptosis is a critical step in resolving inflammation. We examined the effects of oligodeoxynucleotide (ODN) species with different numbers of phosphodiester and phosphorothioate bonds on leukotriene synthesis in PMNLs and on neutrophil apoptosis. Our modifications were based on the well-known ODN2216 molecule (Krug et al., 2001). Treatment of cultured human neutrophils with ODN2216 accelerated apoptosis except in the case of a species with only phosphodiester bonds. The ODNs with poly(g) (phosphorothioate) sequences at both ends and a phosphodiester inner core had maximal effects on leukotriene synthesis in neutrophils and inhibited formation of 5-lipoxygenase metabolites. Addition of phosphodiester and phosphorothioate ODNs to PMNLs produced distinct effects on superoxide and nitric oxide formation: phosphorothioate-containing ODNs concomitantly stimulated production of nitric oxide and superoxide, which may rapidly combine to generate peroxynitrite. Altogether, our results describe strong activation of neutrophil's cellular responses by phosphorothioate ODN2216. We propose that phosphorothioate modification of ODNs represents a potential mechanism of PMNL activation. PMID:27036535

  8. Stimulus-dependent secretion of plasma proteins from human neutrophils.

    PubMed Central

    Borregaard, N; Kjeldsen, L; Rygaard, K; Bastholm, L; Nielsen, M H; Sengeløv, H; Bjerrum, O W; Johnsen, A H

    1992-01-01

    In search for matrix proteins released from secretory vesicles of human neutrophils, a prominent 67-kD protein was identified in the extracellular medium of neutrophils stimulated by the chemotactic peptide, FMLP. The protein was purified to apparent homogeneity and partially sequenced. The sequence of the first 32 NH2-terminal amino acids was identical to the sequence of albumin. mRNA for human albumin could not be detected in bone marrow cells, nor could biosynthetic labeling of albumin be demonstrated in bone marrow cells during incubation with [14C]leucine. Immunofluorescence studies on single cells demonstrated the presence of intracellular albumin in fixed permeabilized neutrophils. Light microscopy of immunogold-silver-stained cryosections visualized albumin in cytoplasmic "granules." The morphology of these was determined by immunoelectron microscopy as vesicles of varying form and size. Subcellular fractionation studies on unstimulated neutrophils demonstrated the presence of albumin in the low density pre-gamma and gamma-regions that contain secretory vesicles, but are devoid of specific granules and azurophil granules. Albumin was readily released from these structures during activation of neutrophils with inflammatory mediators. Immunoblotting demonstrated the presence of immunoglobulin and transferrin along with albumin in exocytosed material from stimulated neutrophils. This indicates that secretory vesicles are unique endocytic vesicles that can be triggered to exocytose by inflammatory stimuli. Images PMID:1378856

  9. Granulocyte colony-stimulating factor delays neutrophil apoptosis by inhibition of calpains upstream of caspase-3

    PubMed Central

    Drewniak, Agata; Groenewold, Vincent; van den Berg, Timo K.; Kuijpers, Taco W.

    2008-01-01

    Neutrophils have a very short life span and undergo apoptosis within 24 hours after leaving the bone marrow. Granulocyte colony-stimulating factor (G-CSF) is essential for the recruitment of fresh neutrophils from the bone marrow but also delays apoptosis of mature neutrophils. To determine the mechanism by which G-CSF inhibits neutrophil apoptosis, the kinetics of neutrophil apoptosis during 24 hours in the absence or presence of G-CSF were analyzed in vitro. G-CSF delayed neutrophil apoptosis for approximately 12 hours and inhibited caspase-9 and -3 activation, but had virtually no effect on caspase-8 and little effect on the release of proapoptotic proteins from the mitochondria. However, G-CSF strongly inhibited the activation of calcium-dependent cysteine proteases calpains, upstream of caspase-3, via apparent control of Ca2+-influx. Calpain inhibition resulted in the stabilization of the X-linked inhibitor of apoptosis (XIAP) and hence inhibited caspase-9 and -3 in human neutrophils. Thus, neutrophil apoptosis is controlled by G-CSF after initial activation of caspase-8 and mitochondrial permeabilization by the control of postmitochondrial calpain activity. PMID:18524991

  10. Differential Use of Human Neutrophil Fcγ Receptors for Inducing Neutrophil Extracellular Trap Formation

    PubMed Central

    Alemán, Omar Rafael; Mora, Nancy; Cortes-Vieyra, Ricarda; Uribe-Querol, Eileen; Rosales, Carlos

    2016-01-01

    Neutrophils (PMN) are the most abundant leukocytes in the blood. PMN migrate from the circulation to sites of infection, where they are responsible for antimicrobial functions. PMN use phagocytosis, degranulation, and formation of neutrophil extracellular traps (NETs) to kill microbes. NETs are fibers composed of chromatin and neutrophil-granule proteins. Several pathogens, including bacteria, fungi, and parasites, and also some pharmacological stimuli such as phorbol 12-myristate 13-acetate (PMA) are efficient inducers of NETs. Antigen-antibody complexes are also capable of inducing NET formation. However the particular Fcγ receptor involved in triggering this function is a matter of controversy. In order to provide some insight into what Fcγ receptor is responsible for NET formation, each of the two human Fcγ receptors was stimulated individually by specific monoclonal antibodies and NET formation was evaluated. FcγRIIa cross-linking did not promote NET formation. Cross-linking other receptors such as integrins also did not promote NET formation. In contrast FcγRIIIb cross-linking induced NET formation similarly to PMA stimulation. NET formation was dependent on NADPH-oxidase, PKC, and ERK activation. These data show that cross-linking FcγRIIIb is responsible for NET formation by the human neutrophil. PMID:27034964

  11. Differential Use of Human Neutrophil Fcγ Receptors for Inducing Neutrophil Extracellular Trap Formation.

    PubMed

    Alemán, Omar Rafael; Mora, Nancy; Cortes-Vieyra, Ricarda; Uribe-Querol, Eileen; Rosales, Carlos

    2016-01-01

    Neutrophils (PMN) are the most abundant leukocytes in the blood. PMN migrate from the circulation to sites of infection, where they are responsible for antimicrobial functions. PMN use phagocytosis, degranulation, and formation of neutrophil extracellular traps (NETs) to kill microbes. NETs are fibers composed of chromatin and neutrophil-granule proteins. Several pathogens, including bacteria, fungi, and parasites, and also some pharmacological stimuli such as phorbol 12-myristate 13-acetate (PMA) are efficient inducers of NETs. Antigen-antibody complexes are also capable of inducing NET formation. However the particular Fcγ receptor involved in triggering this function is a matter of controversy. In order to provide some insight into what Fcγ receptor is responsible for NET formation, each of the two human Fcγ receptors was stimulated individually by specific monoclonal antibodies and NET formation was evaluated. FcγRIIa cross-linking did not promote NET formation. Cross-linking other receptors such as integrins also did not promote NET formation. In contrast FcγRIIIb cross-linking induced NET formation similarly to PMA stimulation. NET formation was dependent on NADPH-oxidase, PKC, and ERK activation. These data show that cross-linking FcγRIIIb is responsible for NET formation by the human neutrophil. PMID:27034964

  12. Simplified Human Neutrophil Extracellular Traps (NETs) Isolation and Handling.

    PubMed

    Najmeh, Sara; Cools-Lartigue, Jonathan; Giannias, Betty; Spicer, Jonathan; Ferri, Lorenzo E

    2015-01-01

    Neutrophil Extracellular Traps (NETs) have been recently identified as part of the neutrophil's antimicrobial armamentarium. Apart from their role in fighting infections, recent research has demonstrated that they may be involved in many other disease processes, including cancer progression. Isolating purified NETs is a crucial element to allow the study of these functions. In this video, we demonstrate a simplified method of cell free NET isolation from human whole blood using readily available reagents. Isolated NETs can then be used for immunofluorescence staining, blotting or various functional assays. This enables an assessment of their biologic properties in the absence of the potential confounding effects of neutrophils themselves. A density gradient separation technique is employed to isolate neutrophils from healthy donor whole blood. Isolated neutrophils are then stimulated by phorbol 12-myristate 13-acetate (PMA) to induce NETosis. Activated neutrophils are then discarded, and a cell-free NET stock is obtained. We then demonstrate how isolated NETs can be used in an adhesion assay with A549 human lung cancer cells. The NET stock is used to coat the wells of a 96 well cell culture plate O/N, and after ensuring an adequate NET monolayer formation on the bottom of the wells, CFSE labeled A549 cells are added. Adherent cells are quantified using a Nikon TE300 fluorescent microscope. In some wells, 1000U DNAse1 is added 10 min before counting to degrade NETs. PMID:25938591

  13. Effects of Staphylococcal Enterotoxins on Human Neutrophil Functions and Apoptosis

    PubMed Central

    Moulding, Dale A.; Walter, Catherine; Hart, C. Anthony; Edwards, Steven W.

    1999-01-01

    Staphylococcal enterotoxins have marked effects on the properties of T cells and monocytes and have recently been reported to affect neutrophil function. In this study, we investigated the abilities of staphylococcal enterotoxins A and B and toxic shock syndrome toxin 1 to affect respiratory burst activity and to delay apoptosis in human neutrophils. When cultures containing approximately 97% neutrophils were tested, the toxins all delayed neutrophil apoptosis in a dose-dependent manner and induced the expression of FcγRI on the neutrophil cell surface. These effects on apoptosis and expression of FcγRI were largely abrogated by the addition of a neutralizing anti-gamma interferon antibody. Similarly, the effects of these toxins on phorbol ester-induced chemiluminescence were decreased after neutralization of gamma interferon. These effects on neutrophil function were mimicked by the addition of conditioned medium from peripheral blood mononuclear cells incubated with the toxins, and again, neutralizing anti-gamma interferon antibodies largely negated the effects. However, when highly purified neutrophils prepared by immunodepletion of T cells and major histocompatibility complex class II-expressing cells were analyzed, the toxins were without effect on apoptosis and FcγRI expression, but granulocyte-macrophage colony-stimulating factor and gamma interferon could still delay apoptosis. These data indicate that these toxins have no direct effect on neutrophil apoptosis but can act indirectly via the production of T-cell-derived and monocyte-derived cytokines. It is noteworthy that such effects are detected in neutrophil suspensions containing only 3% contamination with T cells and other mononuclear cells. PMID:10225889

  14. Interactions of human neutrophils with leukotoxic streptococci.

    PubMed Central

    Sullivan, G W; Mandell, G L

    1980-01-01

    Most strains of Streptococcus pyogenes contain a toxin which can kill neutrophils. Previous workers failed to show any correlation between leukotoxin content and virulence of animals or humans. We examined the in vitro interactions of a leukotoxic streptococcus and a nonleukotoxic variant with human neutrophils. At ratios of 200 streptococcal colony-forming units per neutrophil, the toxic strain killed 92.8 +/- 2.0% of neutrophils, and the nontoxic strain killed only 9.0 +/- 1.2%. Despite this, ingestion of the two strains was equal. Postphagocytic oxidative metabolism was equivalent with low numbers of either toxic or nontoxic streptococci but depressed with high numbers of leukotoxic streptococci. At 20 min, neutrophils were able to kill leukotoxic (99.6 +/- 0.3% killed) and nonleukotoxic streptococci (99.5 +/- 0.2% killed) equally efficiently (P = 0.42). Thus, leukotoxicity does not interfere with the ability of neutrophils to destroy streptococci. This may explain why leukotoxicity does not appear to be an important factor in streptococcal virulence. Images Fig. 1 PMID:7002789

  15. Human filarial Wolbachia lipopeptide directly activates human neutrophils in vitro.

    PubMed

    Tamarozzi, F; Wright, H L; Johnston, K L; Edwards, S W; Turner, J D; Taylor, M J

    2014-10-01

    The host inflammatory response to the Onchocerca volvulus endosymbiont, Wolbachia, is a major contributing factor in the development of chronic pathology in humans (onchocerciasis/river blindness). Recently, the toll-like pattern recognition receptor motif of the major inflammatory ligands of filarial Wolbachia, membrane-associated diacylated lipoproteins, was functionally defined in murine models of pathology, including mediation of neutrophil recruitment to the cornea. However, the extent to which human neutrophils can be activated in response to this Wolbachia pattern recognition motif is not known. Therefore, the responses of purified peripheral blood human neutrophils to a synthetic N-terminal diacylated lipopeptide (WoLP) of filarial Wolbachia peptidoglycan-associated lipoprotein (PAL) were characterized. WoLP exposure led to a dose-dependent activation of healthy, human neutrophils that included gross morphological alterations and modulation of surface expressed integrins involved in tethering, rolling and extravasation. WoLP exposure induced chemotaxis but not chemokinesis of neutrophils, and secretion of the major neutrophil chemokine, interleukin 8. WoLP also induced and primed the respiratory burst, and enhanced neutrophil survival by delay of apoptosis. These results indicate that the major inflammatory motif of filarial Wolbachia lipoproteins directly activates human neutrophils in vitro and promotes a molecular pathway by which human neutrophils are recruited to sites of Onchocerca parasitism. PMID:24909063

  16. Cationic liposomes evoke proinflammatory mediator release and neutrophil extracellular traps (NETs) toward human neutrophils.

    PubMed

    Hwang, Tsong-Long; Hsu, Ching-Yun; Aljuffali, Ibrahim A; Chen, Chun-Han; Chang, Yuan-Ting; Fang, Jia-You

    2015-04-01

    Cationic liposomes are widely used as nanocarriers for therapeutic and diagnostic purposes. The cationic components of liposomes can induce inflammatory responses. This study examined the effect of cationic liposomes on human neutrophil activation. Cetyltrimethylammonium bromide (CTAB) or soyaethyl morpholinium ethosulfate (SME) was incorporated into liposomes as the cationic additive. The liposomes' cytotoxicity and their induction of proinflammatory mediators, intracellular calcium, and neutrophil extracellular traps (NETs) were investigated. The interaction of the liposomes with the plasma membrane triggered the stimulation of neutrophils. CTAB liposomes induced complete leakage of lactate dehydrogenase (LDH) at all concentrations tested, whereas SME liposomes released LDH in a concentration-dependent manner. CTAB liposomes proved to more effectively activate neutrophils compared with SME liposomes, as indicated by increased superoxide anion and elastase levels. Calcium influx increased 9-fold after treatment with CTAB liposomes. This influx was not changed by SME liposomes compared with the untreated control. Scanning electron microscopy (SEM) and immunofluorescence images indicated the presence of NETs after treatment with cationic liposomes. NETs could be quickly formed, within minutes, after CTAB liposomal treatment. In contrast to this result, NET formation was slowly and gradually increased by SME liposomes, within 4h. Based on the data presented here, it is important to consider the toxicity of cationic liposomes during administration in the body. This is the first report providing evidence of NET production induced by cationic liposomes. PMID:25731102

  17. Translocation of annexin I to plasma membranes and phagosomes in human neutrophils upon stimulation with opsonized zymosan: possible role in phagosome function.

    PubMed Central

    Kaufman, M; Leto, T; Levy, R

    1996-01-01

    Annexin I in the cytosol of resting neutrophils was translocated to the plasma membranes upon addition of opsonized zymosan (OZ). Maximum translocation could be detected 1 min after stimulation with OZ, and decreased thereafter. Subcellular fractionation studies demonstrated that annexin I could not be detected in the granule fractions in either resting or activated cells, but was found in association with the phagosome fraction. The marked translocation of annexin I was unique to OZ, since formyl-Met-Leu-Phe induced only slight translocation of annexin I to the plasma membranes, and phorbol 12-myristate 13-acetate had no effect at all. The mechanism regulating the translocation of annexin I is not clear. Annexin I is not phosphorylated in resting or stimulated cells. The correlation between the elevation in the intracellular calcium ion concentration ([Ca2+]i) and the degree of translocation of annexin I to the plasma membranes induced by the different stimuli, together with the inhibition of these processes by the addition of EGTA, indicate that the translocation of annexin I can probably be attributed to the rise in [Ca2+]i. However, this cannot be the sole mechanism since ionomycin, which caused an increase in [CA2+]i similar to that induced by OZ, was less efficient than OZ in inducing translocation of annexin I. The induction of annexin I translocation to the plasma membrane by OZ, which was the only agent that induced phagosome formation, and the detection of annexin I in the phagosome fraction, suggest that annexin I participates in phagosome function. PMID:8645229

  18. Proteome Mapping of Adult Zebrafish Marrow Neutrophils Reveals Partial Cross Species Conservation to Human Peripheral Neutrophils

    PubMed Central

    Singh, Sachin Kumar; Sethi, Sachin; Aravamudhan, Sriram; Krüger, Marcus; Grabher, Clemens

    2013-01-01

    Neutrophil granulocytes are pivotal cells within the first line of host defense of the innate immune system. In this study, we have used a gel-based LC-MS/MS approach to explore the proteome of primary marrow neutrophils from adult zebrafish. The identified proteins originated from all major cellular compartments. Gene ontology analysis revealed significant association of proteins with different immune-related network and pathway maps. 75% of proteins identified in neutrophils were identified in neutrophils only when compared to neutrophil-free brain tissue. Moreover, cross-species comparison with human peripheral blood neutrophils showed partial conservation of immune-related proteins between human and zebrafish. This study provides the first zebrafish neutrophil proteome and may serve as a valuable resource for an understanding of neutrophil biology and innate immunity. PMID:24019943

  19. Transendothelial migration enhances integrin-dependent human neutrophil chemokinesis.

    PubMed

    Gonzalez, Anjelica L; El-Bjeirami, Wafa; West, Jennifer L; McIntire, Larry V; Smith, C Wayne

    2007-03-01

    Transendothelial migration of neutrophils induces phenotypic changes that influence the interactions of neutrophils with extravascular tissue components. To assess the influence of transmigration on neutrophil chemokinetic motility, we used polyethylene glycol hydrogels covalently modified with specific peptide sequences relevant to extracellular matrix proteins. We evaluated fMLP-stimulated human neutrophil motility on peptides Arg-Gly-Asp-Ser (RGDS) and TMKIIPFNRTLIGG (P2), alone and in combination. RGDS is a bioactive sequence found in a number of proteins, and P2 is a membrane-activated complex-1 (Mac-1) ligand located in the gamma-chain of the fibrinogen protein. We evaluated, via video microscopy, cell motility by measuring cell displacement from origin and total accumulated distance traveled and then calculated average velocity. Results indicate that although adhesion and shape change were supported by hydrogels containing RGD alone, motility was not. Mac-1-dependent motility was supported on hydrogels containing P2 alone. Motility was enhanced through combined presentation of RGD and P2, engaging Mac-1, alpha(V)beta(3), and beta(1) integrins. Naïve neutrophil motility on combined peptide substrates was dependent on Mac-1, and alpha(4)beta(1) while alpha(6)beta(1) contributed to speed and linear movement. Transmigrated neutrophil motility was dependent on alpha(v)beta(3) and alpha(5)beta(1), and alpha(4)beta(1), alpha(6)beta(1), and Mac-1 contributed to speed and linear motion. Together, the data demonstrate that efficient neutrophil migration, dependent on multi-integrin interaction, is enhanced after transendothelial migration. PMID:17164427

  20. Myeloperoxidase in human neutrophil host defence.

    PubMed

    Nauseef, William M

    2014-08-01

    Human neutrophils represent the predominant leucocyte in circulation and the first responder to infection. Concurrent with ingestion of microorganisms, neutrophils activate and assemble the NADPH oxidase at the phagosome, thereby generating superoxide anion and hydrogen peroxide. Concomitantly, granules release their contents into the phagosome, where the antimicrobial proteins and enzymes synergize with oxidants to create an environment toxic to the captured microbe. The most rapid and complete antimicrobial action by human neutrophils against many organisms relies on the combined efforts of the azurophilic granule protein myeloperoxidase and hydrogen peroxide from the NADPH oxidase to oxidize chloride, thereby generating hypochlorous acid and a host of downstream reaction products. Although individual components of the neutrophil antimicrobial response exhibit specific activities in isolation, the situation in the environment of the phagosome is far more complicated, a consequence of multiple and complex interactions among oxidants, proteins and their by-products. In most cases, the cooperative interactions among the phagosomal contents, both from the host and the microbe, culminate in loss of viability of the ingested organism. PMID:24844117

  1. Basal neutrophil function in human aging: Implications in endothelial cell adhesion.

    PubMed

    Nogueira-Neto, Joes; Cardoso, André S C; Monteiro, Hugo P; Fonseca, Fernando L A; Ramos, Luiz Roberto; Junqueira, Virginia B C; Simon, Karin A

    2016-07-01

    Much attention has been drawn to the pro-inflammatory condition that accompanies aging. This study compared parameters from non-stimulated neutrophils, obtained from young (18-30 years old [y.o.]) and elderly (65-80 y.o.) human volunteers. Measured as an inflammatory marker, plasmatic concentration of hs-CRP was found higher in elderly individuals. Non-stimulated neutrophil production of ROS and NO was, respectively, 38 and 29% higher for the aged group. From the adhesion molecules evaluated, only CD11b expression was elevated in neutrophils from the aged group, whereas no differences were found for CD11a, CD18, or CD62. A 69% higher non-stimulated in vitro neutrophil/endothelial cell adhesion was observed for neutrophils isolated from elderly donors. Our results suggest that with aging, neutrophils may be constitutively producing more reactive species in closer proximity to endothelial cells of vessel walls, which may both contribute to vascular damage and reflect a neutrophil intracellular disrupted redox balance, altering neutrophil function in aging. PMID:27109745

  2. Priming of Human Neutrophils Is Necessary for Their Activation by Extracellular DNA.

    PubMed

    Prikhodko, A S; Vitushkina, M V; Zinovkina, L A; Popova, E N; Zinovkin, R A

    2016-06-01

    Extracellular plasma DNA is thought to act as a damage-associated molecular pattern causing activation of immune cells. However, purified preparations of mitochondrial and nuclear DNA were unable to induce neutrophil activation in vitro. Thus, we examined whether granulocyte-macrophage colony-stimulating factor (GM-CSF) acting as a neutrophil priming agent can promote the activation of neutrophils by different types of extracellular DNA. GM-CSF pretreatment greatly increased p38 MAPK phosphorylation and promoted CD11b/CD66b expression in human neutrophils treated with mitochondrial and, to a lesser extent, with nuclear DNA. Our experiments clearly indicate that GM-CSF-induced priming of human neutrophils is necessary for their subsequent activation by extracellular DNA. PMID:27301289

  3. Energy Metabolism of Human Neutrophils during Phagocytosis

    PubMed Central

    Borregaard, Niels; Herlin, Troels

    1982-01-01

    Detailed quantitative studies were performed on the generation and utilization of energy by resting and phagocytosing human neutrophils. The ATP content was 1.9 fmol/cell, was constant during rest, and was not influenced by the presence or absence of glucose in the medium. The intracellular content of phosphocreatine was less than 0.2 fmol/cell. In the presence of glucose, ATP was generated almost exclusively from lactate produced from glucose taken up from the surrounding medium. The amount of lactate produced could account for 85% of the glucose taken up by the cells, and the intracellular glycosyl store, glycogen, was not drawn upon. The rate of ATP generation as calculated from the rate of lactate production was 1.3 fmol/cell/min. During phagocytosis, there was no measurable increase in glucose consumption or lactate production, and the ATP content fell rapidly to 0.8 fmol/cell. This disappearance of ATP was apparently irreversible since no corresponding increase in ADP or AMP was observed. It therefore appears that this phagocytosis-induced fall in ATP concentration represents all the extra energy utilized in human neutrophils in the presence of glucose. In the absence of glucose, the rate of ATP generation in the resting cell was considerably smaller, 0.75 fmol/cell per min, as calculated from the rate of glycolysis, which is sustained exclusively by glycogenolysis. Under this condition, however, phagocytosis induces significant enhancement of glycogenolysis and the rate of lactate production is increased by 60%, raising the rate of ATP generation to 1.2 fmol/cell per min. Nonetheless, the ATP content drops significantly from 1.9 to 1.0 fmol/cell. Neutrophils from patients with chronic granulomatous disease have the same rate of glycolysis and the same ATP content as normal cells, thus confirming that the defective respiration of these cells does not affect their energy metabolism. PMID:7107894

  4. Commensal microbiota stimulate systemic neutrophil migration through induction of serum amyloid A.

    PubMed

    Kanther, Michelle; Tomkovich, Sarah; Xiaolun, Sun; Grosser, Melinda R; Koo, Jaseol; Flynn, Edward J; Jobin, Christian; Rawls, John F

    2014-07-01

    Neutrophils serve critical roles in inflammatory responses to infection and injury, and mechanisms governing their activity represent attractive targets for controlling inflammation. The commensal microbiota is known to regulate the activity of neutrophils and other leucocytes in the intestine, but the systemic impact of the microbiota on neutrophils remains unknown. Here we utilized in vivo imaging in gnotobiotic zebrafish to reveal diverse effects of microbiota colonization on systemic neutrophil development and function. The presence of a microbiota resulted in increased neutrophil number and myeloperoxidase expression, and altered neutrophil localization and migratory behaviours. These effects of the microbiota on neutrophil homeostasis were accompanied by an increased recruitment of neutrophils to injury. Genetic analysis identified the microbiota-induced acute phase protein serum amyloid A (Saa) as a host factor mediating microbial stimulation of tissue-specific neutrophil migratory behaviours. In vitro studies revealed that zebrafish cells respond to Saa exposure by activating NF-κB, and that Saa-dependent neutrophil migration requires NF-κB-dependent gene expression. These results implicate the commensal microbiota as an important environmental factor regulating diverse aspects of systemic neutrophil development and function, and reveal a critical role for a Saa-NF-κB signalling axis in mediating neutrophil migratory responses. PMID:24373309

  5. Activation of human neutrophils by mycobacterial phenolic glycolipids

    PubMed Central

    Fäldt, J; Dahlgren, C; Karlsson, A; Ahmed, A M S; Minnikin, D E; Ridell, M

    1999-01-01

    The interaction between mycobacterial phenolic glycolipids (PGLs) and phagocytes was studied. Human neutrophils were allowed to interact with each of four purified mycobacterial PGLs and the neutrophil production of reactive oxygen metabolites was followed kinetically by luminol-/isoluminol-amplified chemiluminescence. The PGLs from Mycobacterium tuberculosis and Mycobacterium kansasii, respectively, were shown to stimulate the production of oxygen metabolites, while PGLs from Mycobacterium marinum and Mycobacterium bovis BCG, respectively, were unable to induce an oxidative response. Periodate treatment of the M. tuberculosis PGL decreased the production of oxygen radicals, showing the importance of the PGL carbohydrate moiety for the interaction. The activation, however, could not be inhibited by rhamnose or fucose, indicating a complex interaction which probably involves more than one saccharide unit. This is in line with the fact that the activating PGLs from M. tuberculosis and M. kansasii contain tri- and tetrasaccharides, respectively, while the nonactivating PGLs from M. marinum and M. bovis BCG each contain a monosaccharide. The complement receptor 3 (CR3) has earlier been shown to be of importance for the phagocyte binding of mycobacteria, but did not appear to be involved in the activation of neutrophils by PGLs. The subcellular localization of the reactive oxygen metabolites formed was related to the way in which the glycolipids were presented to the cells. PMID:10540187

  6. Human neutrophil-pulmonary microvascular endothelial cell interactions in vitro: differential effects of nitric oxide vs. peroxynitrite.

    PubMed

    Shelton, Jennifer L; Wang, Lefeng; Cepinskas, Gediminas; Inculet, Richard; Mehta, Sanjay

    2008-08-01

    Sepsis-induced acute lung injury is characterized by activation and injury of pulmonary microvascular endothelial cells (PMVEC), increased neutrophil-PMVEC adhesion and migration, and trans-PMVEC high-protein edema. Inducible NO synthase (iNOS) inhibits septic murine neutrophil migration in vivo and in vitro. The effects of NO in human neutrophil-PMVEC interactions are not known. We isolated human PMVEC using magnetic bead-bound anti-PECAM antibody. Confluent PMVEC at passage 3-4 were co-cultured with human neutrophils for assessment of neutrophil-PMVEC adhesion, and trans-PMVEC neutrophil migration and Evans-Blue dye-labeled albumin leak. Two NO donors (spermine-NONOate, S-nitroso-N-acetylpenicillamine) attenuated both cytomix-enhanced neutrophil-PMVEC adhesion by 64+/-14% (p<0.01) and 32+/-3% (p<0.05), respectively, and cytomix-induced trans-PMVEC neutrophil migration by 85+/-16% (p<0.01) and 43+/-5% (p<0.01), respectively. Correspondingly, iNOS inhibition with 1400W enhanced cytomix-stimulated neutrophil migration by 52+/-3% (p<0.01), but had no effect on neutrophil-PMVEC adhesion. Conversely, a peroxynitrite donor (SIN-1) increased both neutrophil-PMVEC adhesion (38+/-2% vs. 14+/-1% control, p<0.01) and trans-PMVEC neutrophil migration; with both effects were completely inhibited by scavenging of NO, superoxide, or peroxynitrite (p<0.05 for each). Scavenging of peroxynitrite also eliminated cytomix-induced neutrophil adhesion and migration. Blocking CD18-dependent neutrophil adhesion prevented cytomix-stimulated trans-PMVEC EB-albumin leak (p<0.05), while inhibiting neutrophil migration paradoxically enhanced cytomix-stimulated EB-albumin leak (11+/-1% vs. 7+/-0.5%, p<0.01). FMLP-induced neutrophil migration had no effect on trans-PMVEC EB-albumin leak. In summary, we report differential effects, including the inhibitory action of NO and stimulatory effect of ONOO(-) on human neutrophil-PMVEC adhesion and trans-PMVEC migration under cytomix stimulation

  7. Human Neutrophils Are Primed by Chemoattractant Gradients for Blocking the Growth of Aspergillus fumigatus.

    PubMed

    Jones, Caroline N; Dimisko, Laurie; Forrest, Kevin; Judice, Kevin; Poznansky, Mark C; Markmann, James F; Vyas, Jatin M; Irimia, Daniel

    2016-02-01

    The contribution of human neutrophils to the protection against fungal infections by Aspergillus fumigatus is essential but not fully understood. Whereas healthy people can inhale spores of A. fumigatus without developing disease, neutropenic patients and those receiving immunosuppressive drugs have a higher incidence of invasive fungal infections. To study the role of neutrophils in protection against A. fumigatus infections, we developed an in vitro assay in which the interactions between human neutrophils and A. fumigatus were observed in real time, at single-cell resolution, in precisely controlled conditions. We measured the outcomes of neutrophil-fungus interactions and found that human neutrophils have a limited ability to migrate toward A. fumigatus and block the growth of A. fumigatus conidia (proportion with growth blocked, 69%). The blocking ability of human neutrophils increased to 85.1% when they were stimulated by uniform concentrations of fMLP and was enhanced further, to 99.4%, in the presence of chemoattractant gradients. Neutrophils from patients receiving immunosuppressive treatment after transplantation were less effective against the fungus than those from healthy donors, and broader heterogeneity exists between patients, compared with healthy individuals. Further studies using this microfluidic platform will help understand the relevance of innate immune deficiencies responsible for the higher risk of fungal infections in patients with immunosuppressive disease. PMID:26272935

  8. A Simple and Efficient Method to Detect Nuclear Factor Activation in Human Neutrophils by Flow Cytometry

    PubMed Central

    García-García, Erick; Uribe-Querol, Eileen; Rosales, Carlos

    2013-01-01

    Neutrophils are the most abundant leukocytes in peripheral blood. These cells are the first to appear at sites of inflammation and infection, thus becoming the first line of defense against invading microorganisms. Neutrophils possess important antimicrobial functions such as phagocytosis, release of lytic enzymes, and production of reactive oxygen species. In addition to these important defense functions, neutrophils perform other tasks in response to infection such as production of proinflammatory cytokines and inhibition of apoptosis. Cytokines recruit other leukocytes that help clear the infection, and inhibition of apoptosis allows the neutrophil to live longer at the site of infection. These functions are regulated at the level of transcription. However, because neutrophils are short-lived cells, the study of transcriptionally regulated responses in these cells cannot be performed with conventional reporter gene methods since there are no efficient techniques for neutrophil transfection. Here, we present a simple and efficient method that allows detection and quantification of nuclear factors in isolated and immunolabeled nuclei by flow cytometry. We describe techniques to isolate pure neutrophils from human peripheral blood, stimulate these cells with anti-receptor antibodies, isolate and immunolabel nuclei, and analyze nuclei by flow cytometry. The method has been successfully used to detect NF-κB and Elk-1 nuclear factors in nuclei from neutrophils and other cell types. Thus, this method represents an option for analyzing activation of transcription factors in isolated nuclei from a variety of cell types. PMID:23603868

  9. Regulation of catalase in Neisseria gonorrhoeae. Effects of oxidant stress and exposure to human neutrophils.

    PubMed

    Zheng, H Y; Hassett, D J; Bean, K; Cohen, M S

    1992-09-01

    We studied the effects of oxidant stress on the catalase activity and hydrogen peroxide sensitivity of Neisseria gonorrhoeae. N. gonorrhoeae is an obligate pathogen of man that evokes a remarkable but ineffective neutrophil response. Gonococci make no superoxide dismutase but express high catalase activity. Gonococcal catalase activity increased threefold when organisms were subjected to 1.0 mM hydrogen peroxide. This increase in catalase activity was marked by a parallel increase in protein concentration recognized by a rabbit polyclonal antibody raised against the purified gonococcal enzyme. Catalase was primarily localized to the gonococcal cytoplasm in the presence or absence of stress; only a single isoenzyme of catalase could be identified. Exposure of gonococci to neutrophil-derived oxidants was accomplished by stimulating neutrophils with phorbol myristate acetate or by using gonococcal Opa variants that interacted with neutrophils with different degrees of efficiency. Gonococci exposed to neutrophils demonstrated a twofold increase in catalase activity in spite of some reduction in viability. Exposure of gonococci to 1.0 mM hydrogen peroxide made the organisms significantly more resistant to higher concentrations of hydrogen peroxide and to neutrophils than control organisms. These results suggest that catalase is an important defense for N. gonorrhoeae during attack by human neutrophils. The rapid response of this enzyme to hydrogen peroxide should be taken into consideration in studies designed to evaluate the interaction between neutrophils and gonococci. PMID:1522209

  10. Cytokine induced expression of programmed death ligands in human neutrophils

    PubMed Central

    Bankey, Paul E.; Banerjee, Sanjib; Zucchiatti, Andrea; De, Mita; Sleem, Rami W.; Lin, Chuen-Fu L.; Miller-Graziano, Carol L.; De, Asit K.

    2010-01-01

    1. Summary Recent evidence indicates that human neutrophils can serve as non-professional antigen presenting cells (APC). Although expression of MHC class II and co-stimulatory molecules on human neutrophils is limited, these molecules can be significantly induced following in vitro exposure to the cytokines IFNγ and GM-CSF. Since professional APCs such as dendritic cells express both co-stimulatory and co-inhibitory molecules for activation and regulation of adaptive immunity, we determined whether cytokines induce increased expression of specific co-signaling molecules on human neutrophils. We report here that circulating human neutrophils express co-inhibitory molecules such as immunoglobulin–like transcript (ILT) 4 and 5, and also comparatively low and highly variable levels of ILT2 and 3, but the expression of these ILTs was not significantly changed by cytokine treatment. In contrast, we demonstrate for the first time that human peripheral blood neutrophils, although do not express the co-inhibitory molecule, programmed death ligand (PD-L) 1 on their surface, can express this molecule at moderate levels following cytokine exposure. Although moderate PD-L1 levels on healthy volunteers’ neutrophils were not inhibitory to T cells, our findings do not exclude a possible robust increase in neutrophil PD-L1 expression in pathological conditions with immunosuppressive functions. These results suggest a possible immunoregulatory role for human neutrophils in adaptive immunity. PMID:20123111

  11. p38 MAPK is involved in human neutrophil chemotaxis induced by L-amino acid oxidase from Calloselasma rhodosthoma.

    PubMed

    Pontes, Adriana S; Setúbal, Sulamita da S; Nery, Neriane Monteiro; da Silva, Francisquinha Souza; da Silva, Silvana D; Fernandes, Carla F C; Stábeli, Rodrigo G; Soares, Andreimar M; Zuliani, Juliana P

    2016-09-01

    The action of LAAO, an L-amino acid oxidase isolated from Calloselasma rhodosthoma snake venom, on isolated human neutrophil function was investigated. Cr-LAAO showed no toxicity on neutrophils. Cr-LAAO in its native form induced the neutrophil chemotaxis, suggesting that its primary structure is essential for stimulation the cell. p38 MAPK and PI3K have a role as signaling pathways of CR-LAAO induced chemotaxis. This toxin also induced the production of hydrogen peroxide and stimulated phagocytosis in neutrophils. Furthermore, Cr-LAAO was able to stimulate neutrophils to release IL-6, IL-8, MPO, LTB4 and PGE2. Together, the data showed that the Cr-LAAO triggers relevant proinflammatory events. PMID:27242041

  12. Ethylmercury and Hg2+ induce the formation of neutrophil extracellular traps (NETs) by human neutrophil granulocytes.

    PubMed

    Haase, Hajo; Hebel, Silke; Engelhardt, Gabriela; Rink, Lothar

    2016-03-01

    Humans are exposed to different mercurial compounds from various sources, most frequently from dental fillings, preservatives in vaccines, or consumption of fish. Among other toxic effects, these substances interact with the immune system. In high doses, mercurials are immunosuppressive. However, lower doses of some mercurials stimulate the immune system, inducing different forms of autoimmunity, autoantibodies, and glomerulonephritis in rodents. Furthermore, some studies suggest a connection between mercury exposure and the occurrence of autoantibodies against nuclear components and granulocyte cytoplasmic proteins in humans. Still, the underlying mechanisms need to be clarified. The present study investigates the formation of neutrophil extracellular traps (NETs) in response to thimerosal and its metabolites ethyl mercury (EtHg), thiosalicylic acid, and mercuric ions (Hg(2+)). Only EtHg and Hg(2+) triggered NETosis. It was independent of PKC, ERK1/2, p38, and zinc signals and not affected by the NADPH oxidase inhibitor DPI. Instead, EtHg and Hg(2+) triggered NADPH oxidase-independent production of ROS, which are likely to be involved in mercurial-induced NET formation. This finding might help understanding the autoimmune potential of mercurial compounds. Some diseases, to which a connection with mercurials has been shown, such as Wegener's granulomatosis and systemic lupus erythematosus, are characterized by high prevalence of autoantibodies against neutrophil-specific auto-antigens. Externalization in the form of NETs may be a source for exposure to these self-antigens. In genetically susceptible individuals, this could be one step in the series of events leading to autoimmunity. PMID:25701957

  13. Monoclonal antibodies to antigens on human neutrophils, activated T lymphocytes, and acute leukemia blast cells

    SciTech Connect

    Miterev, G.Yu.; Burova, G.F.; Puzhitskaya, M.S.; Danilevich, S.V.; Bulycheva, T.I.

    1987-11-01

    The authors describe the production of two mouse hybridomas secreting monoclonal antibodies to antigenic determinants of the surface membranes of human neutrophils, activated T lymphocytes, and acute leukemic blast cells. The degree of lymphocyte stimulation was estimated from incorporation of /sup 3/H-thymidine with parallel microculture. Monoclonal antibodies of supernatants of hybridoma cultures shown here reacted in both immunofluorescence test and cytotoxicity test with surface membrane antigens on the majority of neutrophils and PHA-activated peripheral blood lymphocytes from healthy subjects, but did not give positive reactions with unactivated lymphocytes, adherent monocytes, erythrocytes, and alloantigen-stimulated lymphocytes.

  14. P-selectin mediates neutrophil rolling on histamine-stimulated endothelial cells.

    PubMed Central

    Jones, D. A.; Abbassi, O.; McIntire, L. V.; McEver, R. P.; Smith, C. W.

    1993-01-01

    In postcapillary venules, marginating neutrophils (PMNs) are often seen rolling along the vessel wall prior to stopping and emigrating. There is substantial evidence in vitro and in vivo that the adhesion receptors E- and L-selectin participate in this phenomenon on cytokine-stimulated endothelium, and recent evidence has shown that a closely related adhesion receptor, P-selectin, is capable of mediating neutrophil rolling on an artificial membrane. Here we demonstrate and characterize PMN rolling on monolayers of human umbilical vein endothelial cells (HUVECs) stimulated with histamine to induce surface expression of P-selectin. Peak association of PMNs with the HUVECs occurs 10 min after histamine stimulation, and at a postcapillary venular wall shear stress of 2.0 dyn/cm2 the rolling velocity is 14 microns/s. Approximately 95% of the PMNs roll on the endothelial cells, 5% adhere firmly, and none migrate beneath the endothelial monolayer. Monoclonal antibody (MAb) G1, which binds P-selectin and blocks its adhesive function, completely prevents association of the PMNs with histamine-stimulated HUVEC, whereas the nonblocking anti-P-selectin MAb S12 does not. Treatment of PMNs with the anti-L-selectin MAb DREG56 reduces PMN adherence by approximately 50%. Anti-CD54 MAb R6.5 and anti-CD18 MAb R15.7 have little effect on the number of PMNs rolling on the HUVECs but completely prevent PMNs from stopping and significantly increase rolling velocity. Nonblocking control MAbs for R6.5 (CL203) and R15.7 (CL18/1D1) lack these effects. Rolling adhesion of PMNs on histamine-stimulated HUVECs therefore appears to be completely dependent on endothelial cell P-selectin, with a minor adhesion-stabilizing contribution from intercellular adhesion molecule 1 and beta 2 integrins. The partial inhibition of rolling with DREG56 suggests that L-selectin may also play a role in neutrophil interactions with histamine-stimulated endothelium. We further characterize these interactions by

  15. Identification of a novel neutrophil population: proangiogenic granulocytes in second-trimester human decidua.

    PubMed

    Amsalem, Hagai; Kwan, Melissa; Hazan, Aleah; Zhang, Jianhong; Jones, Rebecca L; Whittle, Wendy; Kingdom, John C P; Croy, B Anne; Lye, Stephen J; Dunk, Caroline E

    2014-09-15

    The maternal leukocytes of the first-trimester decidua play a fundamental role in implantation and early development of the fetus and placenta, yet little is known regarding the second-trimester decidual environment. Our multicolor flow cytometric analyses of human decidual leukocytes detected an elevation in tissue resident neutrophils in the second trimester. These cells in both human and murine samples were spatially restricted to decidua basalis. In comparison with peripheral blood neutrophils (PMNs), the decidual neutrophils expressed high levels of neutrophil activation markers and the angiogenesis-related proteins: vascular endothelial growth factor-A, Arginase-1, and CCL2, similarly shown in tumor-associated neutrophils. Functional in vitro assays showed that second-trimester human decidua conditioned medium stimulated transendothelial PMN invasion, upregulated VEGFA, ARG1, CCL2, and ICAM1 mRNA levels, and increased PMN-driven in vitro angiogenesis in a CXCL8-dependent manner. This study identified a novel neutrophil population with a physiological, angiogenic role in human decidua. PMID:25135830

  16. Effects of Anti-Human Neutrophil Antibodies In Vitro. QUANTITATIVE STUDIES

    PubMed Central

    Boxer, Laurence A.; Stossel, Thomas P.

    1974-01-01

    Opsonic, antiphagocytic, cytotoxic, and metabolic effects of homologous and heterologous antibodies against human neutrophils were analyzed by means of quantitative assays to facilitate detection of antibody activity, and to probe membrane function of these cells. Normal human neutrophils were purified by gradient centrifugation, sensitized with heat-inactivated antineutrophil antisera, and incubated with rabbit alveolar macrophages in balanced salt solution containing nitroblue tetrazolium. The macrophages engulfed sensitized neutrophils and reduced nitroblue tetrazolium to formazan in phagocytic vacuoles. The initial rate of nitroblue tetrazolium reduction by macrophages ingesting the neutrophils was measured spectrophotometrically. Neutrophils treated with rabbit anti-human leukocyte antiserum or IgG, with sera from mothers of infants with neonatal isoimmune neutropenia, and with 27% of sera from frequently transfused patients promoted rapid rates of nitroblue tetrazolium reduction by alveolar macrophages. This indicates that antineutrophil antibodies without added complement opsonized neutrophils for ingestion by the macrophages. Some sera from frequently transfused patients with opsonic activity for certain donors' neutrophils did not agglutinate these neutrophils (44%), did not lyse them in the presence of fresh plasma (47%), and did not inhibit phagocytosis of particles by the neutrophils (26%). The reverse was not observed. The opsonic activity of antineutrophil antiserum appears to be the most sensitive and a quantitative means of detecting antibody activity in vitro. Low concentrations of rabbit anti-human leukocyte antisera or IgG stimulated the ingestion rate of unopsonized or opsonized particles by human neutrophils, and, as previously reported by others, enhanced rates of oxidation of [1-14C]glucose by the cells. High concentrations of the antisera or IgG inhibited ingestion. All concentrations of homologous antineutrophil antisera tested only

  17. Trace element landscape of resting and activated human neutrophils on the sub-micrometer level.

    PubMed

    Niemiec, M J; De Samber, B; Garrevoet, J; Vergucht, E; Vekemans, B; De Rycke, R; Björn, E; Sandblad, L; Wellenreuther, G; Falkenberg, G; Cloetens, P; Vincze, L; Urban, C F

    2015-06-01

    Every infection is a battle for trace elements. Neutrophils migrate first to the infection site and accumulate quickly to high numbers. They fight pathogens by phagocytosis and intracellular toxication. Additionally, neutrophils form neutrophil extracellular traps (NETs) to inhibit extracellular microbes. Yet, neutrophil trace element characteristics are largely unexplored. We investigated unstimulated and phorbol myristate acetate-stimulated neutrophils using synchrotron radiation X-ray fluorescence (SR-XRF) on the sub-micron spatial resolution level. PMA activates pinocytosis, cytoskeletal rearrangements and the release of NETs, all mechanisms deployed by neutrophils to combat infection. By analyzing Zn, Fe, Cu, Mn, P, S, and Ca, not only the nucleus but also vesicular granules were identifiable in the elemental maps. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) revealed a neutrophil-specific composition of Zn, Fe, Cu, and Mn in comparison with J774 and HeLa cells, indicating a neutrophil-specific metallome complying with their designated functions. When investigating PMA-activated neutrophils, the SR-XRF analysis depicted typical subcellular morphological changes: the transformation of nucleus and granules and the emergence of void vacuoles. Mature NETs were evenly composed of Fe, P, S, and Ca with occasional hot spots containing Zn, Fe, and Ca. An ICP-MS-based quantification of NET supernatants revealed a NETosis-induced decrease of soluble Zn, whereas Fe, Cu, and Mn concentrations were only slightly affected. In summary, we present a combination of SR-XRF and ICP-MS as a powerful tool to analyze trace elements in human neutrophils. The approach will be applicable and valuable to numerous aspects of nutritional immunity. PMID:25832493

  18. Immune complex stimulation of neutrophil apoptosis: investigating the involvement of oxidative and nonoxidative pathways.

    PubMed

    Ottonello, L; Frumento, G; Arduino, N; Dapino, P; Tortolina, G; Dallegri, F

    2001-01-15

    Neutrophils are involved in the pathogenesis of various inflammatory diseases. One of the mechanisms by which neutrophilic inflammation is generated is immune complex (IC) deposition in tissue. As the clearance of apoptotic neutrophils from inflamed sites is considered a crucial determinant for the resolution of inflammation, we investigated the effects of IC-induced neutrophil activation on apoptosis and the mechanisms regulating neutrophil survival. Our results show that IC stimulated apoptosis efficiently. The percentage of apoptotic neutrophils was reduced by the anti-FcgammaRII mAb IV.3, but not by anti-FcgammaRIII mAb 3G8. The spontaneous apoptosis was completely inhibited by the antioxidant compound catalase, which in turn prevented only partially the apoptosis in presence of IC. The oxidative metabolism triggered by IC was inhibited only blocking both FcgammaRII and FcgammaRIII. Neutrophils from patients with chronic granulomatous disease, congenitally incapable of producing oxidants, showed low level of spontaneous apoptosis, but underwent a nearly 3-fold increment in the apoptosis rate when incubated with IC. In conclusion, neutrophil apoptosis appears to be a process governed by multiple pathways, some of which are strictly ROS-dependent, others acting in a nonoxidative manner. In particular, the herein shown FcgammaRII-dependent, ROS-independent, signal-inducing neutrophil apoptosis may uncover new pharmacological targets for the promotion of cell removal from sites of inflammation, thereby favoring the resolution of the inflammatory process. PMID:11163533

  19. Various Molecular Species of Diacylglycerol Hydroperoxide Activate Human Neutrophils via PKC Activation

    PubMed Central

    Kambayashi, Yasuhiro; Takekoshi, Susumu; Tanino, Yutaka; Watanabe, Keiichi; Nakano, Minoru; Hitomi, Yoshiaki; Takigawa, Tomoko; Ogino, Keiki; Yamamoto, Yorihiro

    2007-01-01

    We have proposed that diacylglycerol hydroperoxide-induced unregulated signal transduction causes oxidative stress-related diseases. In this study, we investigated which molecular species of diacylglycerol hydroperoxide activated human peripheral neutrophils. All diacylglycerol hydroperoxides, diacylglycerol hydroxides, and diacyglycerols tested in the present study induced superoxide production by neutrophils. The ability to activate neutrophils among molecular species containing the same fatty acid composition was as follows; diacylglycerol hydroperoxide>diacylglycerol hydroxide≥diacylglycerol. The diacylglycerol hydroperoxide composed of linoleate was a stronger activator for neutrophils than that composed of arachidonate. 1-Palmitoyl-2-linoleoylglycerol hydroperoxide (PLG-OOH) was the strongest stimulator for neutrophils. We reconfirmed that PLG-OOH activated protein kinase C (PKC) in neutrophils. PLG-OOH induced the phosphorylation of p47phox, a substrate of PKC and a cytosolic component of NADPH oxidase, in neutrophils, as did N-formyl-methionyl-leucyl-phenylalanine or 4β-phorbol-12β-myristate-13α-acetate. Moreover, the time course of p47phox phosphorylation was comparable to that of superoxide production. These results suggest that PLG-OOH activated intracellular protein kinase C. PLG-OOH, produced via an uncontrolled process, can act as a biological second messenger to cause inflammatory disease from oxidative stress. PMID:18392102

  20. 7-Hydroxycoumarin modulates the oxidative metabolism, degranulation and microbial killing of human neutrophils.

    PubMed

    Kabeya, Luciana M; Fuzissaki, Carolina N; Taleb-Contini, Silvia H; da C Ferreira, Ana Maria; Naal, Zeki; Santos, Everton O L; Figueiredo-Rinhel, Andréa S G; Azzolini, Ana Elisa C S; Vermelho, Roberta B; Malvezzi, Alberto; Amaral, Antonia T-do; Lopes, João Luis C; Lucisano-Valim, Yara Maria

    2013-10-25

    In the present study, we assessed whether 7-hydroxycoumarin (umbelliferone), 7-hydroxy-4-methylcoumarin, and their acetylated analogs modulate some of the effector functions of human neutrophils and display antioxidant activity. These compounds decreased the ability of neutrophils to generate superoxide anion, release primary granule enzymes, and kill Candida albicans. Cytotoxicity did not mediate their inhibitory effect, at least under the assessed conditions. These coumarins scavenged hypochlorous acid and protected ascorbic acid from electrochemical oxidation in cell-free systems. On the other hand, the four coumarins increased the luminol-enhanced chemiluminescence of human neutrophils stimulated with phorbol-12-myristate-13-acetate and serum-opsonized zymosan. Oxidation of the hydroxylated coumarins by the neutrophil myeloperoxidase produced highly reactive coumarin radical intermediates, which mediated the prooxidant effect observed in the luminol-enhanced chemiluminescence assay. These species also oxidized ascorbic acid and the spin traps α-(4-pyridyl-1-oxide)-N-tert-butylnitrone and 5-dimethyl-1-pyrroline-N-oxide. Therefore, 7-hydroxycoumarin and the derivatives investigated here were able to modulate the effector functions of human neutrophils and scavenge reactive oxidizing species; they also generated reactive coumarin derivatives in the presence of myeloperoxidase. Acetylation of the free hydroxyl group, but not addition of the 4-methyl group, suppressed the biological effects of 7-hydroxycoumarin. These findings help clarify how 7-hydroxycoumarin acts on neutrophils to produce relevant anti-inflammatory effects. PMID:23994743

  1. Cinnoline derivatives as human neutrophil elastase inhibitors.

    PubMed

    Giovannoni, Maria Paola; Schepetkin, Igor A; Crocetti, Letizia; Ciciani, Giovanna; Cilibrizzi, Agostino; Guerrini, Gabriella; Khlebnikov, Andrei I; Quinn, Mark T; Vergelli, Claudia

    2016-08-01

    Compounds that can effectively inhibit the proteolytic activity of human neutrophil elastase (HNE) represent promising therapeutics for treatment of inflammatory diseases. We present here the synthesis, structure-activity relationship analysis, and biological evaluation of a new series of HNE inhibitors with a cinnoline scaffold. These compounds exhibited HNE inhibitory activity but had lower potency compared to N-benzoylindazoles previously reported by us. On the other hand, they exhibited increased stability in aqueous solution. The most potent compound, 18a, had a good balance between HNE inhibitory activity (IC50 value = 56 nM) and chemical stability (t1/2 = 114 min). Analysis of reaction kinetics revealed that these cinnoline derivatives were reversible competitive inhibitors of HNE. Furthermore, molecular docking studies of the active products into the HNE binding site revealed two types of HNE inhibitors: molecules with cinnolin-4(1H)-one scaffold, which were attacked by the HNE Ser195 hydroxyl group at the amido moiety, and cinnoline derivatives containing an ester function at C-4, which is the point of attack of Ser195. PMID:26194018

  2. Capsular polysaccharides from Cryptococcus neoformans modulate production of neutrophil extracellular traps (NETs) by human neutrophils.

    PubMed

    Rocha, Juliana D B; Nascimento, Michelle T C; Decote-Ricardo, Debora; Côrte-Real, Suzana; Morrot, Alexandre; Heise, Norton; Nunes, Marise P; Previato, José Osvaldo; Mendonça-Previato, Lucia; DosReis, George A; Saraiva, Elvira M; Freire-de-Lima, Célio G

    2015-01-01

    In the present study, we characterized the in vitro modulation of NETs (neutrophil extracellular traps) induced in human neutrophils by the opportunistic fungus Cryptococcus neoformans, evaluating the participation of capsular polysaccharides glucuronoxylomanan (GXM) and glucuronoxylomannogalactan (GXMGal) in this phenomenon. The mutant acapsular strain CAP67 and the capsular polysaccharide GXMGal induced NET production. In contrast, the wild-type strain and the major polysaccharide GXM did not induce NET release. In addition, C. neoformans and the capsular polysaccharide GXM inhibited PMA-induced NET release. Additionally, we observed that the NET-enriched supernatants induced through CAP67 yeasts showed fungicidal activity on the capsular strain, and neutrophil elastase, myeloperoxidase, collagenase and histones were the key components for the induction of NET fungicidal activity. The signaling pathways associated with NET induction through the CAP67 strain were dependent on reactive oxygen species (ROS) and peptidylarginine deiminase-4 (PAD-4). Neither polysaccharide induced ROS production however both molecules blocked the production of ROS through PMA-activated neutrophils. Taken together, the results demonstrate that C. neoformans and the capsular component GXM inhibit the production of NETs in human neutrophils. This mechanism indicates a potentially new and important modulation factor for this fungal pathogen. PMID:25620354

  3. Granulopoiesis and granules of human neutrophils.

    PubMed

    Cowland, Jack B; Borregaard, Niels

    2016-09-01

    Granules are essential for the ability of neutrophils to fulfill their role in innate immunity. Granule membranes contain proteins that react to environmental cues directing neutrophils to sites of infection and initiate generation of bactericidal oxygen species. Granules are densely packed with proteins that contribute to microbial killing when liberated to the phagosome or extracellularly. Granules are, however, highly heterogeneous and are traditionally subdivided into azurophil granules, specific granules, and gelatinase granules in addition to secretory vesicles. This review will address issues pertinent to formation of granules, which is a process intimately connected to maturation of neutrophils from their precursors in the bone marrow. We further discuss possible mechanisms by which decisions are made regarding sorting of proteins to constitutive secretion or storage in granules and how degranulation of granule subsets is regulated. PMID:27558325

  4. Methotrexate inhibits neutrophil function by stimulating adenosine release from connective tissue cells

    SciTech Connect

    Cronstein, B.N.; Eberle, M.A.; Levin, R.I. ); Gruber, H.E. )

    1991-03-15

    Although commonly used to control a variety of inflammatory diseases, the mechanism of action of a low dose of methotrexate remains a mystery. Methotrexate accumulates intracellularly where it may interfere with purine metabolism. Therefore, the authors determined whether a 48-hr pretreatment with methotrexate affected adenosine release from ({sup 14}C)adenine-labeled human fibroblasts and umbilical vein endothelial cells. Methotrexate significantly increased adenosine release by fibroblasts. The effect of methotrexate on adenosine release was not due to cytotoxicity since cells treated with maximal concentrations of methotrexate took up ({sup 14}C)adenine and released {sup 14}C-labeled purine (a measure of cell injury) in a manner identical to control cells. Methotrexate treatment of fibroblasts dramatically inhibited adherence to fibroblasts by both unstimulated neutrophils and stimulated neutrophils. One hypothesis that explains the effect of methotrexate on adenosine release is that, by inhibition of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) transformylase, methotrexate induces the accumulation of AICAR, the nucleoside precursor of which has previously been shown to cause adenosine release from ischemic cardiac tissue. The observation that the antiinflammatory actions of methotrexate are due to the capacity of methotrexate to induce adenosine release may form the basis for the development of an additional class of antiinflammatory drugs.

  5. Identification of dipeptidyl peptidase III in human neutrophils.

    PubMed

    Hashimoto, J; Yamamoto, Y; Kurosawa, H; Nishimura, K; Hazato, T

    2000-07-01

    We have found activity of dipeptidyl peptidase (DPP) III, one of the most important enkephalin-degrading enzymes in the central nervous system, in human neutrophils. HPLC analysis of the peptide fragments produced by treatment of leucine-enkephalin with isolated neutrophils in the presence of inhibitors of other enkephalin-degrading enzymes revealed that the enzyme in human neutrophils cleaved dipeptides from the NH(2) terminus of leucine-enkephalin, suggesting the presence of DPPIII activity in human neutrophils. Using a specific synthesized substrate and proteinase inhibitors, it was found that the neutrophils have 19.2 +/- 3.6 microM/h/5 x 10(6) cells of beta-naphthylamine for the enzyme. It was also confirmed that spinorphin and tynorphin, both reported to inhibit the activities of enkephalin-degrading enzymes, had potent inhibitory activities (IC(50): 4.0 and 0.029 microg/ml, respectively) against the enzyme. The presence of DPPIII activity in human neutrophils suggests that the biologically active peptides which are associated with enkephalin play a physiological role in regulating enkephalin or inflammatory mechanisms in peripheral tissues. PMID:10873616

  6. Selective inhibition of leukotriene C/sub 4/ synthesis in human neutrophils by ethacrynic acid

    SciTech Connect

    Leung, K.H.

    1986-05-29

    Addition of glutathione S-transferase inhibitors, ethyacrynic acid (ET), caffeic acid (CA), and ferulic acid (FA) to human neutrophils led to inhibition of leukotriene C/sub 4/ (LTC/sub 4/) synthesis induced by calcium ionophore A23187. ET is the most specific of these inhibitors for it had little effect on LTB/sub 4/, PGE/sub 2/, and 5-HETE synthesis. The inhibition of LTC/sub 4/ was irreversible and time dependent. ET also had little effect on /sup 3/H-AA release from A23187-stimulated neutrophils.

  7. Faropenem enhances superoxide anion production by human neutrophils in vitro.

    PubMed

    Sato, K; Sato, N; Shimizu, H; Tsutiya, T; Takahashi, H; Kakizaki, S; Takayama, H; Takagi, H; Mori, M

    1999-09-01

    Neutrophils are important cellular components in the defence against infections and many studies in vitro have shown that some antibiotics affect neutrophil function. We examined the effect of faropenem, a new oral penem antibiotic on neutrophil killing function by determining the generation of superoxide anion in vitro. The production of superoxide anion was measured by chemiluminescence amplified by a Cypridina luciferin analogue in the presence of N-formyl-Met-Leu-Phe (fMLP). Faropenem significantly enhanced chemiluminescence in a dose-dependent manner. The effect of faropenem was maximal at 5 min of incubation time and continued for at least 30 min. The effect of faropenem was also observed when neutrophils were stimulated by a calcium ionophore (ionomycin), while the effect of faropenem did not change in the presence of 12-O-tetra-decanoylphorbolmyristate acetate. Cytosol Ca2+ concentration ([Ca2+]i) monitored with Fura-2 increased in response to fMLP, however, faropenem did not influence the response of [Ca2+]i to fMLP. Our results suggest that faropenem enhanced the generation of superoxide anion by neutrophils, probably at the site where cytosol Ca2+ regulates NADPH oxidase. Faropenem might be potentially advantageous in the treatment of infections because a synergic interaction of antibodies and cytocidal neutrophils is necessary for the early eradication of the pathogenic bacteria. PMID:10511400

  8. Human neutrophil kinetics: modeling of stable isotope labeling data supports short blood neutrophil half-lives

    PubMed Central

    Lahoz-Beneytez, Julio; Elemans, Marjet; Zhang, Yan; Ahmed, Raya; Salam, Arafa; Block, Michael; Niederalt, Christoph; Macallan, Derek

    2016-01-01

    Human neutrophils have traditionally been thought to have a short half-life in blood; estimates vary from 4 to 18 hours. This dogma was recently challenged by stable isotope labeling studies with heavy water, which yielded estimates in excess of 3 days. To investigate this disparity, we generated new stable isotope labeling data in healthy adult subjects using both heavy water (n = 4) and deuterium-labeled glucose (n = 9), a compound with more rapid labeling kinetics. To interpret results, we developed a novel mechanistic model and applied it to previously published (n = 5) and newly generated data. We initially constrained the ratio of the blood neutrophil pool to the marrow precursor pool (ratio = 0.26; from published values). Analysis of heavy water data sets yielded turnover rates consistent with a short blood half-life, but parameters, particularly marrow transit time, were poorly defined. Analysis of glucose-labeling data yielded more precise estimates of half-life (0.79 ± 0.25 days; 19 hours) and marrow transit time (5.80 ± 0.42 days). Substitution of this marrow transit time in the heavy water analysis gave a better-defined blood half-life of 0.77 ± 0.14 days (18.5 hours), close to glucose-derived values. Allowing the ratio of blood neutrophils to mitotic neutrophil precursors (R) to vary yielded a best-fit value of 0.19. Reanalysis of the previously published model and data also revealed the origin of their long estimates for neutrophil half-life: an implicit assumption that R is very large, which is physiologically untenable. We conclude that stable isotope labeling in healthy humans is consistent with a blood neutrophil half-life of less than 1 day. PMID:27136946

  9. Human neutrophil kinetics: modeling of stable isotope labeling data supports short blood neutrophil half-lives.

    PubMed

    Lahoz-Beneytez, Julio; Elemans, Marjet; Zhang, Yan; Ahmed, Raya; Salam, Arafa; Block, Michael; Niederalt, Christoph; Asquith, Becca; Macallan, Derek

    2016-06-30

    Human neutrophils have traditionally been thought to have a short half-life in blood; estimates vary from 4 to 18 hours. This dogma was recently challenged by stable isotope labeling studies with heavy water, which yielded estimates in excess of 3 days. To investigate this disparity, we generated new stable isotope labeling data in healthy adult subjects using both heavy water (n = 4) and deuterium-labeled glucose (n = 9), a compound with more rapid labeling kinetics. To interpret results, we developed a novel mechanistic model and applied it to previously published (n = 5) and newly generated data. We initially constrained the ratio of the blood neutrophil pool to the marrow precursor pool (ratio = 0.26; from published values). Analysis of heavy water data sets yielded turnover rates consistent with a short blood half-life, but parameters, particularly marrow transit time, were poorly defined. Analysis of glucose-labeling data yielded more precise estimates of half-life (0.79 ± 0.25 days; 19 hours) and marrow transit time (5.80 ± 0.42 days). Substitution of this marrow transit time in the heavy water analysis gave a better-defined blood half-life of 0.77 ± 0.14 days (18.5 hours), close to glucose-derived values. Allowing the ratio of blood neutrophils to mitotic neutrophil precursors (R) to vary yielded a best-fit value of 0.19. Reanalysis of the previously published model and data also revealed the origin of their long estimates for neutrophil half-life: an implicit assumption that R is very large, which is physiologically untenable. We conclude that stable isotope labeling in healthy humans is consistent with a blood neutrophil half-life of less than 1 day. PMID:27136946

  10. Human Neutrophil Peptides Mediate Endothelial-Monocyte Interaction, Foam Cell Formation, and Platelet Activation

    PubMed Central

    Quinn, Kieran L.; Henriques, Melanie; Tabuchi, Arata; Han, Bing; Yang, Hong; Cheng, Wei-Erh; Tole, Soumitra; Yu, Hanpo; Luo, Alice; Charbonney, Emmanuel; Tullis, Elizabeth; Lazarus, Alan; Robinson, Lisa A.; Ni, Heyu; Peterson, Blake R.; Kuebler, Wolfgang M.; Slutsky, Arthur S.; Zhang, Haibo

    2016-01-01

    Objective Neutrophils are involved in the inflammatory responses during atherosclerosis. Human neutrophil peptides (HNPs) released from activated neutrophils exert immune modulating properties. We hypothesized that HNPs play an important role in neutrophil-mediated inflammatory cardiovascular responses in atherosclerosis. Methods and Results We examined the role of HNPs in endothelial-leukocyte interaction, platelet activation, and foam cell formation in vitro and in vivo. We demonstrated that stimulation of human coronary artery endothelial cells with clinically relevant concentrations of HNPs resulted in monocyte adhesion and transmigration; induction of oxidative stress in human macrophages, which accelerates foam cell formation; and activation and aggregation of human platelets. The administration of superoxide dismutase or anti-CD36 antibody reduced foam cell formation and cholesterol efflux. Mice deficient in double genes of low-density lipoprotein receptor and low-density lipoprotein receptor–related protein (LRP), and mice deficient in a single gene of LRP8, the only LRP phenotype expressed in platelets, showed reduced leukocyte rolling and decreased platelet aggregation and thrombus formation in response to HNP stimulation. Conclusion HNPs exert proatherosclerotic properties that appear to be mediated through LRP8 signaling pathways, suggesting an important role for HNPs in the development of inflammatory cardiovascular diseases. PMID:21817096

  11. Degradation of basement membrane laminin by human neutrophil elastase and cathepsin G.

    PubMed Central

    Heck, L. W.; Blackburn, W. D.; Irwin, M. H.; Abrahamson, D. R.

    1990-01-01

    To determine the susceptibility of laminin to proteolytic degradation by inflammatory cells, soluble laminin was incubated with supernatants from phorbol 12-myristate 13-acetate (PMA)-stimulated human neutrophils. The appearance of laminin cleavage fragments was then detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Treatment of supernatants with diisopropylfluorophosphate (DFP), anti-human neutrophil elastase (HNE), and anti-human neutrophil cathepsin G (HNCG) IgGs effectively blocked the degradation of laminin. In contrast, treatment of supernatants with EDTA failed to inhibit laminin digestion, indicating that neutrophil metalloproteinases had little laminin-degrading activity. In additional experiments, laminin was incubated with purified HNE and HNCG. Both enzymes extensively cleaved laminin in a dose- and time-dependent manner yielding similar products, but HNE was generally more potent. Immunofluorescence microscopy of cryostat sections of mouse kidney treated with HNE or HNCG also showed widespread loss of laminin epitopes from basement membranes. The proteolytic degradation of laminin by neutrophil elastase and cathepsin G indicates an important role for these enzymes in basement membrane damage during inflammation. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:2356859

  12. Inhibition of human neutrophil responses by alpha-cyano-3,4-dihydroxythiocinnamamide; a protein-tyrosine kinase inhibitor.

    PubMed Central

    Dryden, P.; Duronio, V.; Martin, L.; Hudson, A. T.; Salari, H.

    1992-01-01

    1. Activation of neutrophils results in increased tyrosine phosphorylation of several proteins that may have important roles in receptor/effector coupling. In this study, the effect of a protein tyrosine kinase inhibitor on receptor-mediated neutrophil activation by platelet-activating factor (PAF), leukotriene, B4 (LTB4) and N-formylmethionylleucylphenylalanine (FMLP) is investigated. 2. alpha-Cyano-3,4-dihydroxythiocinnamamide dose-dependently inhibited intracellular calcium release and superoxide generation from human neutrophils activated by 1 microM LTB4, PAF, and FMLP. 3. In the presence of cytochalasin B, FMLP stimulated elastase release from neutrophils was also inhibited to unstimulated levels by 5 min pretreatment with alpha-cyano-3,4-dihydroxythiocinnamamide. 4. The inhibitory action of alpha-cyano-3,4-dihydroxythiocinnamamide was found to be at or upstream of phospholipase C activation, blocking both phosphatidylinositol hydrolysis and protein kinase C activation. alpha-Cyano-3,4-dihydroxythiocinnamamide did not affect agonist receptor binding sites or receptor affinity in neutrophils. 5. Immunoblot analysis demonstrated the tyrosine phosphorylation of proteins of 41, 56, 66, and 104 kDa in neutrophils treated with agonists. Treatment of neutrophils with alpha-cyano-3,4-dihydroxythiocinnamamide prior to stimulation with chemoattractants reduced tyrosine phosphorylation of the above phosphoproteins. 6. These results indicate that alpha-cyano-3,4-dihydroxythiocinnamamide might be a useful agent in characterizing the essential proteins and biochemical pathways that regulate neutrophil activation. PMID:1504749

  13. Stimulation of Fas signaling down-regulates activity of neutrophils from major trauma patients with SIRS.

    PubMed

    Paunel-Görgülü, Adnana; Lögters, Tim; Flohé, Sascha; Cinatl, Jindrich; Altrichter, Jens; Windolf, Joachim; Scholz, Martin

    2011-03-01

    Posttrauma apoptosis resistance of neutrophils (PMN) is related to overshooting immune responses, systemic inflammatory response syndrome (SIRS) and multiple organ failure (MOF). Recently, we have shown that the apoptosis resistance in circulating PMN from severely injured patients which is known to be mediated by high serum levels of pro-inflammatory cytokines can be overcome by the activation of Fas death receptor. Here, we aimed to study whether stimulation of surface Fas leads to the inactivation of hyperactivated PMN from critically ill patients with SIRS. PMN from 23 multiple trauma patients (mean injury severity score (ISS) 34±1.9) were isolated at day 1 after admission to the trauma center. PMN from 17 volunteer blood donors served as controls. Neutrophil activity has been determined after ex vivo short (1 h) and long-term (4 h) stimulation of freshly isolated PMN with immobilized agonistic anti-Fas antibodies. We found neutrophil chemotactic migration in response to IL-8, phagocytosis and oxidative burst to be significantly inhibited in control cells already after short-term (1 h) Fas stimulation. In contrast, inactivation of trauma PMN by agonistic anti-Fas antibodies was found to be efficient only after long-term (4 h) incubation of cells with agonistic antibodies. Thus, in trauma PMN down-regulation of neutrophil activity seems to be delayed when compared to cells isolated from healthy controls, suggesting impaired susceptibility for Fas stimulation in these cells. Interestingly, whereas Fas-mediated inhibition of phagocytosis and oxidative burst could be prevented by the broad range caspase inhibitor t-butoxycarbonyl-aspartyl(O-methyl)-fluoromethyl ketone (BocD-fmk), the chemotactic activity in response to IL-8 was unaffected. In conclusion, we demonstrate that stimulation of neutrophil Fas does not only initiate apoptosis but also induces inhibition of neutrophil functions, partially by non-apoptotic signaling. PMID:20832139

  14. FMLP activates Ras and Raf in human neutrophils. Potential role in activation of MAP kinase.

    PubMed Central

    Worthen, G S; Avdi, N; Buhl, A M; Suzuki, N; Johnson, G L

    1994-01-01

    Chemoattractants bind to seven transmembrane-spanning, G-protein-linked receptors on polymorphonuclear leukocytes (neutrophils) and induce a variety of functional responses, including activation of microtubule-associated protein (MAP) kinase. Although the pathways by which MAP kinases are activated in neutrophils are unknown, we hypothesized that activation of the Ras/Raf pathway leading to activation of MAP/ERK kinase (MEK) would be induced by the chemoattractant f-met-leu-phe. Human neutrophils exposed to 10 nM FMLP for 30 s exhibited an MAP kinase kinase activity coeluting with MEK-1. Immunoprecipitation of Raf-1 kinase after stimulation with FMLP revealed an activity that phosphorylated MEK, was detectable at 30 s, and peaked at 2-3 min. Immunoprecipitation of Ras from both intact neutrophils labeled with [32P]orthophosphate and electropermeabilized neutrophils incubated with [32P]GTP was used to determine that FMLP treatment was associated with activation of Ras. Activation of both Ras and Raf was inhibited by treatment of neutrophils with pertussis toxin, indicating predominant linkage to the Gi2 protein. Although phorbol esters activated Raf, activation induced by FMLP appeared independent of protein kinase C, further suggesting that Gi2 was linked to Ras and Raf independent of phospholipase C and protein kinase C. Dibutyryl cAMP, which inhibits many neutrophil functional responses, blocked the activation of Raf by FMLP, suggesting that interruption of the Raf/MAP kinase pathway influences neutrophil responses to chemoattractants. These data suggest that Gi2-mediated receptor regulation of the Ras/Raf/MAP kinase pathway is a primary response to chemoattractants. Images PMID:8040337

  15. Spin trapping evidence for myeloperoxidase-dependent hydroxyl radical formation by human neutrophils and monocytes

    SciTech Connect

    Ramos, C.L.; Pou, S.; Britigan, B.E.; Cohen, M.S.; Rosen, G.M. )

    1992-04-25

    Using the electron spin resonance/spin trapping system, 4-pyridyl 1-oxide N-tert-butylnitrone (4-POBN)/ethanol, hydroxyl radical was detected as the alpha-hydroxyethyl spin trapped adduct of 4-POBN, 4-POBN-CH(CH3)OH, from phorbol 12-myristate 13-acetate-stimulated human neutrophils and monocytes without the addition of supplemental iron. 4-POBN-CH(CH3)OH was stable in the presence of a neutrophil-derived superoxide flux. Hydroxyl radical formation was inhibited by treatment with superoxide dismutase, catalase, and azide. Treatment with a series of transition metal chelators did not appreciably alter 4-POBN-CH(CH3)OH, which suggested that hydroxyl radical generation was mediated by a mechanism independent of the transition metal-catalyzed Haber-Weiss reaction. Kinetic differences between transition metal-dependent and -independent mechanisms of hydroxyl radical generation by stimulated neutrophils were demonstrated by a greater rate of 4-POBN-CH(CH3)-OH accumulation in the presence of supplemental iron. Detection of hydroxyl radical from stimulated monocyte-derived macrophages, which lack myeloperoxidase, required the addition of supplemental iron. The addition of purified myeloperoxidase to an enzymatic superoxide generating system resulted in the detection of hydroxyl radical that was dependent upon the presence of chloride and was inhibited by superoxide dismutase, catalase, and azide. These findings implicated the reaction of hypochlorous acid and superoxide to produce hydroxyl radical. 4-POBN-CH(CH3)OH was not observed upon stimulation of myeloperoxidase-deficient neutrophils, whereas addition of myeloperoxidase to the reaction mixture resulted in the detection of hydroxyl radical. These results support the ability of human neutrophils and monocytes to generate hydroxyl radical through a myeloperoxidase-dependent mechanism.

  16. Myeloperoxidase deficiency induces MIP-2 production via ERK activation in zymosan-stimulated mouse neutrophils.

    PubMed

    Tateno, N; Matsumoto, N; Motowaki, T; Suzuki, K; Aratani, Y

    2013-05-01

    Myeloperoxidase (MPO), a major constituent of neutrophils, catalyzes the production of hypochlorous acid (HOCl) from hydrogen peroxide (H2O2) and chloride anion. We have previously reported that MPO-deficient (MPO(-/-)) neutrophils produce greater amount of macrophage inflammatory protein-2 (MIP-2) in vitro than do wild type when stimulated with zymosan. In this study, we investigated the molecular mechanisms governing the up-regulation of MIP-2 production in the mutant neutrophils. Interestingly, we found that zymosan-induced production of MIP-2 was blocked by pre-treatment with U0126, an inhibitor of mitogen-activated protein kinase/extracellular-signal-regulated kinase (ERK), and with BAY11-7082, an inhibitor of nuclear factor (NF)-κB. Western blot analysis indicated that U0126 also inhibited the phosphorylation of p65 subunit of NF-κB (p65), indicating that MIP-2 was produced via the ERK/NF-κB pathway. Intriguingly, we found that ERK1/2, p65, and alpha subunit of inhibitor of κB (IκBα) in the MPO(-/-) neutrophils were phosphorylated more strongly than in the wild type when stimulated with zymosan. Exogenous H2O2 treatment in addition to zymosan stimulation enhanced the phosphorylation of ERK1/2 without affecting the zymosan-induced MIP-2 production. In contrast, exogenous HOCl inhibited the production of MIP-2 as well as IκBα phosphorylation without affecting ERK activity. The zymosan-induced production of MIP-2 in the wild-type neutrophils was enhanced by pre-treatment of the MPO inhibitor 4-aminobenzoic acid hydrazide. Collectively, these results strongly suggest that both lack of HOCl and accumulation of H2O2 due to MPO deficiency contribute to the up-regulation of MIP-2 production in mouse neutrophils stimulated with zymosan. PMID:23438680

  17. Peptide secreted by human alveolar macrophages releases neutrophil granule contents

    SciTech Connect

    MacArthur, C.K.; Miller, E.J.; Cohen, A.B.

    1987-11-15

    A monoclonal antibody was developed against an 8000-kDa enzyme-releasing peptide (ERP) released from human alveolar macrophages. ERP was isolated on an immunoaffinity column containing the antibody bound to staphylococcal protein A-Sepharose, and by autoradiography. Release of ERP from the macrophages is not changed by plastic adherence, phagocytosis, calcium ionophore, or phorbol esters. The peptide was not antigenically similar to interferon-..gamma.., tumor necrosis factor, or interleukin l..cap alpha.. or 1..beta... The release of constituents from azurophilic and specific granules was the main identified biologic function of ERP. ERP was a more effective secretagogue in the untreated neutrophils and f-met-leu-phe was more effective in the cytochalasin B-treated neutrophils. Absorption of ERP from macrophage-conditioned medium removed a small amount of the chemotactic activity; however, the immunopurified peptide was not chemotactic or chemokinetic for neutrophils, and at high concentrations, it suppressed base line chemokinesis. Treatment of washed macrophages with trypsin released active ERP of approximately the same m.w. of spontaneously secreted ERP. These studies showed that human alveolar macrophages release a peptide which is a secretagogue for human neutrophils under conditions which may be encountered in the lungs during certain disease states. Proteolytic enzymes which are free in the lungs may release the peptide and lead to the secretion of neutrophil enzymes.

  18. Bioactivation of myelotoxic xenobiotics by human neutrophil myeloperoxidase

    SciTech Connect

    Roy, R.R.

    1989-01-01

    Many environmental pollutants and drugs are toxic to the bone marrow. Some of these xenobiotics may initiate toxicity after undergoing bioactivation to free radicals and/or other reactive electrophiles. Peroxidases are a group of enzymes that catalyze the one-electron oxidative bioactivation of a variety of xenobiotics in vitro. Myeloperoxidase (MPO) is a peroxidative enzyme found in very high concentration in the neutrophils of human bone marrow. In this study, human MPO was evaluated to determine its ability to catalyze the in vitro bioactivation of known bone marrow toxicants that contain the aromatic hydroxyl (Ar-OH), aromatic amine (Ar-N-R{sub 2}), or heterocyclic tertiary amine ({double bond}N-R) moieties. The formation of free radical metabolites during the MPO-catalyzed bioactivation of hydroquinone and catechol (benzene metabolites), mitoxantrone and ametantrone (antitumor drugs), and chlorpromazine and promazine (antipsychotic drugs) was demonstrated by EPR spectroscopy. The reactivity of the products formed during the MPO catalyzed bioactivation of ({sup 14}C)hydroquinone and ({sup 14}C)catechol was shown by their covalent binding to protein and DNA in vitro. The covalently binding metabolite in each case is postulated to be the quinone form of the xenobiotic. In addition, both GSH and NADH were oxidized by the reactive intermediate(s) formed during the MPO-catalyzed bioactivation of many of the bone marrow toxicants tested. It was also shown that p,p-biphenol stimulated the MPO catalyzed bioactivation of both hydroquinone and catechol, while p-cresol stimulated the MPO-catalyzed bioactivation of catechol.

  19. Oxidative Autoactivation of Latent Collagenase by Human Neutrophils

    NASA Astrophysics Data System (ADS)

    Weiss, S. J.; Peppin, G.; Ortiz, X.; Ragsdale, C.; Test, S. T.

    1985-02-01

    The pathological destruction of collagen plays a key role in the development of inflammatory disease states affecting every organ system in the human body. Neutrophils localized at inflammatory sites can potentially degrade collagen by releasing a metalloenzyme, collagenase, which is stored in a latent inactive form. Triggered human neutrophils were shown to release and simultaneously activate their latent collagenase. The activation of the latent enzyme was coupled to an oxidative process that required the generation of a highly reactive oxygen metabolite, hypochlorous acid. Oxidative regulation of latent collagenase activity may be important in the pathogenesis of connective tissue damage in vivo.

  20. The impact of cationic solid lipid nanoparticles on human neutrophil activation and formation of neutrophil extracellular traps (NETs).

    PubMed

    Hwang, Tsong-Long; Aljuffali, Ibrahim A; Hung, Chi-Feng; Chen, Chun-Han; Fang, Jia-You

    2015-06-25

    Cationic solid lipid nanoparticles (cSLNs) are extensively employed as the nanocarriers for drug/gene targeting to tumors and the brain. Investigation into the possible immune response of cSLNs is still lacking. The aim of this study was to evaluate the impact of cSLNs upon the activation of human polymorphonuclear neutrophil cells (PMNs). The cytotoxicity, pro-inflammatory mediators, Ca(2+) mobilization, mitogen-activated protein kinases (MAPKs), and neutrophil extracellular traps (NETs) as the indicators of PMN stimulation were examined in this work. The cSLNs presented a diameter of 195 nm with a zeta potential of 44 mV. The cSLNs could interact with the cell membrane to produce a direct membrane lysis and the subsequent cytotoxicity according to lactate dehydrogenase (LDH) elevation. The interaction of cSLNs with the membrane also triggered a Ca(2+) influx, followed by the induction of oxidative stress and degranulation. The cationic nanoparticles elevated the levels of superoxide anion and elastase by 24- and 9-fold, respectively. The PMN activation by cSLNs promoted the phosphorylation of p38 and Jun-N-terminal kinases (JNK) but not extracellular signal-regulated kinases (ERK). The imaging of scanning electron microscopy (SEM) and immunofluorescence demonstrated the production of NETs by cSLNs. This phenomenon was not significant for the neutral SLNs (nSLNs), although histones in NETs also increased after treatment of nSLNs. Our results suggest an important role of cSLNs in governing the activation of human neutrophils. PMID:25920576

  1. Inhibitory effect of salmeterol on the respiratory burst of adherent human neutrophils.

    PubMed

    Ottonello, L; Morone, P; Dapino, P; Dallegri, F

    1996-10-01

    Human neutrophils, plated in fibronectin-coated wells and stimulated with N-formyl-methionylleucyl-phenylalanine (fMLP), were found to undergo a massive and prolonged respiratory burst, as measured by monitoring superoxide production. The beta 2-agonist salmeterol inhibited the respiratory burst in a dose-dependent manner. In contrast, salbutamol was ineffective. Moreover, the neutrophil respiratory burst was partially suppressed by prostaglandin E2 (PGE2) and the phosphodiesterase type IV (PDE-IV) inhibitor RO 20-1724. When salmeterol was used in combination with PGE2 or RO 20-1724, additive inhibitory effects were observed. The inhibitory activity of salmeterol was not reversed in the presence of the beta-blocker propranolol, and did not correlate with its ability of increasing cyclic AMP (cAMP) levels. Finally, the compounds used did not affect neutrophil adherence to fibronectin-coated wells. The results suggest that salmeterol is capable of down-regulating the neutrophil oxidative response to fMLP, also of co-operating with PGE2 and PDE-IV inhibitor RO 20-1724 in a manner not related to its beta 2-receptor binding activity. In other words, salmeterol displays neutrophil-directed effects, susceptible to be amplified by natural mediators such as PGE2 or PDE-IV inhibitors, consistent with possible anti-inflammatory properties of the drug. PMID:8870705

  2. Inhibitory effect of salmeterol on the respiratory burst of adherent human neutrophils

    PubMed Central

    OTTONELLO, L; MORONE, P; DAPINO, P; DALLEGRI, F

    1996-01-01

    Human neutrophils, plated in fibronectin-coated wells and stimulated with n-formyl-methionyl-leucyl-phenylalanine (fMLP), were found to undergo a massive and prolonged respiratory burst, as measured by monitoring superoxide production. The β2-agonist salmeterol inhibited the respiratory burst in a dose-dependent manner. In contrast, salbutamol was ineffective. Moreover, the neutrophil respiratory burst was partially suppressed by prostaglandin E2 (PGE2) and the phosphodiesterase type IV (PDE-IV) inhibitor RO 20-1724. When salmeterol was used in combination with PGE2 or RO 20-1724, additive inhibitory effects were observed. The inhibitory activity of salmeterol was not reversed in the presence of the β-blocker propranolol, and did not correlate with its ability of increasing cyclic AMP (cAMP) levels. Finally, the compounds used did not affect neutrophil adherence to fibronectin-coated wells. The results suggest that salmeterol is capable of down-regulating the neutrophil oxidative response to fMLP, also of co-operating with PGE2 and PDE-IV inhibitor RO 20-1724 in a manner not related to its β2-receptor binding activity. In other words, salmeterol displays neutrophil-directed effects, susceptible to be amplified by natural mediators such as PGE2 or PDE-IV inhibitors, consistent with possible anti-inflammatory properties of the drug. PMID:8870705

  3. Quantitation of intracellular Mac-1 (CD11b/CD18) pools in human neutrophils.

    PubMed

    Jones, D H; Anderson, D C; Burr, B L; Rudloff, H E; Smith, C W; Krater, S S; Schmalstieg, F C

    1988-12-01

    The adhesive glycoprotein Mac-1 (CD11b/CD18) of the CD11/CD18 complex contributes to multiple neutrophil inflammatory functions. Activation of neutrophils by chemotactic stimuli results in a rapid, protein synthesis-independent increase in surface Mac-1 derived from incompletely defined intracellular compartments. Therefore, we developed a novel quantitative lectin immunoblot technique to define intracellular pools of Mac-1 in subcellular neutrophil fractions resolved on discontinuous Percoll gradients. In cavitates of unstimulated neutrophils, 30% and 26% of total Mac-1 was identified in beta [1.10 gm/ml; vitamin B12 binding protein (vit B12 B.P.)-rich] or pre-gamma (1.07 gm/ml; vit B12 B.P.-poor) granular fractions, respectively, whereas 24% was associated with the plasma membrane-rich gamma (1.06 gm/ml) fractions. N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation (10(-8) M, 15 min, 37 degrees C) significantly diminished Mac-1 in pre-gamma (-18% of total, P less than 0.05) but not beta fractions (+6% of total). Under these conditions, the content of Mac-1 in gamma fractions increased 13% in association with four- to eightfold increase in surface Mac-1 expression (OKM-1 binding). These findings suggest that chemotactic stimuli increase plasma membrane and/or surface Mac-1 on human neutrophils by mobilizing a novel intracellular granule pool. PMID:2903896

  4. In vitro inhibition of human neutrophil histotoxicity by ambroxol: evidence for a multistep mechanism

    PubMed Central

    Ottonello, Luciano; Arduino, Nicoletta; Bertolotto, Maria; Dapino, Patrizia; Mancini, Marina; Dallegri, Franco

    2003-01-01

    Neutrophils are major culprits for the protease/antiprotease imbalance during various lung diseases, that is, chronic obstructive pulmonary disease, cystic fibrosis, idiopathic pulmonary fibrosis and adult respiratory distress syndrome. Thus, these cells are presently considered an ideal target for the pharmacologic control of tissue injury during these diseases. This study was planned in order to investigate if ambroxol and its precursor bromhexine are actually capable of preventing alpha-1-antitrypsin (A1AT) inactivation by stimulated neutrophils and possibly to look into the mechanisms underlying this event. Ambroxol inhibited the production of superoxide anion by activated neutrophils, whereas bromhexine had no inhibitory effect. Ambroxol decreased the production of hypochlorous acid (HOCl) from activated neutrophils with high efficiency, whereas bromhexine had a modest activity. Ambroxol and bromhexine were capable of limiting the chlorination of monochlorodimedon by HOCl, displaying the capacity of directly scavenging the oxidant. Ambroxol decreased the release of elastase and myeloperoxidase from activated neutrophils, whereas bromhexine was ineffective. Ambroxol prevented the A1AT inactivation by neutrophils, whereas bromhexine was completely ineffective. Among drugs currently available for in vivo use in humans, ambroxol is unique by virtue of its ability to prevent neutrophil-mediated A1AT inactivation via inhibition of HOCl production as well as HOCl scavenging. Also taking into account its capacity for curbing elastase release, the drug displays the potential to lessen the burden of oxidants/proteases and to increase the antiprotease shield at the site of inflammation. Thus, ambroxol appears to be a good candidate for raising attempts to develop new therapeutic histoprotective approaches to inflammatory bronchopulmonary diseases. PMID:14534155

  5. In vitro inhibition of human neutrophil histotoxicity by ambroxol: evidence for a multistep mechanism.

    PubMed

    Ottonello, Luciano; Arduino, Nicoletta; Bertolotto, Maria; Dapino, Patrizia; Mancini, Marina; Dallegri, Franco

    2003-10-01

    Neutrophils are major culprits for the protease/antiprotease imbalance during various lung diseases, that is, chronic obstructive pulmonary disease, cystic fibrosis, idiopathic pulmonary fibrosis and adult respiratory distress syndrome. Thus, these cells are presently considered an ideal target for the pharmacologic control of tissue injury during these diseases. This study was planned in order to investigate if ambroxol and its precursor bromhexine are actually capable of preventing alpha-1-antitrypsin (A1AT) inactivation by stimulated neutrophils and possibly to look into the mechanisms underlying this event. Ambroxol inhibited the production of superoxide anion by activated neutrophils, whereas bromhexine had no inhibitory effect. Ambroxol decreased the production of hypochlorous acid (HOCl) from activated neutrophils with high efficiency, whereas bromhexine had a modest activity. Ambroxol and bromhexine were capable of limiting the chlorination of monochlorodimedon by HOCl, displaying the capacity of directly scavenging the oxidant. Ambroxol decreased the release of elastase and myeloperoxidase from activated neutrophils, whereas bromhexine was ineffective. Ambroxol prevented the A1AT inactivation by neutrophils, whereas bromhexine was completely ineffective. Among drugs currently available for in vivo use in humans, ambroxol is unique by virtue of its ability to prevent neutrophil-mediated A1AT inactivation via inhibition of HOCl production as well as HOCl scavenging. Also taking into account its capacity for curbing elastase release, the drug displays the potential to lessen the burden of oxidants/proteases and to increase the antiprotease shield at the site of inflammation. Thus, ambroxol appears to be a good candidate for raising attempts to develop new therapeutic histoprotective approaches to inflammatory bronchopulmonary diseases. PMID:14534155

  6. 2-Arachidonoyl-glycerol- and arachidonic acid-stimulated neutrophils release antimicrobial effectors against E. coli, S. aureus, HSV-1, and RSV

    PubMed Central

    Chouinard, François; Turcotte, Caroline; Guan, Xiaochun; Larose, Marie-Chantal; Poirier, Samuel; Bouchard, Line; Provost, Véronique; Flamand, Louis; Grandvaux, Nathalie; Flamand, Nicolas

    2016-01-01

    The endocannabinoid 2-AG is highly susceptible to its hydrolysis into AA, which activates neutrophils through de novo LTB4 biosynthesis, independently of CB activation. In this study, we show that 2-AG and AA stimulate neutrophils to release antimicrobial effectors. Supernatants of neutrophils activated with nanomolar concentrations of 2-AG and AA indeed inhibited the infectivity of HSV-1 and RSV. Additionally, the supernatants of 2-AG- and AA-stimulated neutrophils strongly impaired the growth of Escherichia coli and Staphylococcus aureus. This correlated with the release of a large amount (micrograms) of α-defensins, as well as a limited amount (nanograms) of LL-37. All the effects of AA and 2-AG mentioned above were prevented by inhibiting LTB4 biosynthesis or by blocking BLT1. Importantly, neither CB2 receptor agonists nor antagonists could mimic nor prevent the effects of 2-AG, respectively. In fact, qPCR data show that contaminating eosinophils express ~100-fold more CB2 receptor mRNA than purified neutrophils, suggesting that CB2 receptor expression by human neutrophils is limited and that contaminating eosinophils are likely responsible for the previously documented CB2 expression by freshly isolated human neutrophils. The rapid conversion of 2-AG to AA and their subsequent metabolism into LTB4 promote 2-AG and AA as multifunctional activators of neutrophils, mainly exerting their effects by activating the BLT1. Considering that nanomolar concentrations of AA or 2-AG were sufficient to impair viral infectivity, this suggests potential physiological roles for 2-AG and AA as regulators of host defense in vivo. PMID:23242611

  7. In Vitro Oxidation of Collagen Promotes the Formation of Advanced Oxidation Protein Products and the Activation of Human Neutrophils.

    PubMed

    Bochi, Guilherme Vargas; Torbitz, Vanessa Dorneles; de Campos, Luízi Prestes; Sangoi, Manuela Borges; Fernandes, Natieli Flores; Gomes, Patrícia; Moretto, Maria Beatriz; Barbisan, Fernanda; da Cruz, Ivana Beatrice Mânica; Moresco, Rafael Noal

    2016-04-01

    The accumulation of advanced oxidation protein products (AOPPs) has been linked to several pathological conditions. Here, we investigated collagen as a potential source for AOPP formation and determined the effects of hypochlorous acid (HOCl)-treated collagen (collagen-AOPPs) on human neutrophil activity. We also assessed whether alpha-tocopherol could counteract these effects. Exposure to HOCl increased the levels of collagen-AOPPs. Collagen-AOPPs also stimulated the production of AOPPs, nitric oxide (NO), superoxide radicals (O2 (-)), and HOCl by neutrophils. Collagen-AOPPs induced apoptosis and decreased the number of viable cells. Alpha-tocopherol prevented the formation of collagen-AOPPs, strongly inhibited the collagen-AOPP-induced production of O2 (-) and HOCl, and increased the viability of neutrophils. Our results suggest that collagen is an important protein that interacts with HOCl to form AOPPs, and consequently, collagen-AOPP formation is related to human neutrophil activation and cell death. PMID:26920846

  8. Human neutrophil elastase inhibitors in innate and adaptive immunity.

    PubMed

    Fitch, P M; Roghanian, A; Howie, S E M; Sallenave, J-M

    2006-04-01

    Recent evidence shows that human neutrophil elastase inhibitors can be synthesized locally at mucosal sites. In addition to efficiently targeting bacterial and host enzymes, they can be released in the interstitium and in the lumen of mucosa, where they have been shown to have antimicrobial activities, and to activate innate immune responses. This review will address more particularly the pleiotropic functions of low-molecular-mass neutrophil elastase inhibitors [SLPI (secretory leucocyte proteinase inhibitor) and elafin] and, more specifically, their role in the development of the adaptive immune response. PMID:16545094

  9. T(H)2 cytokines modulate the IL-9R expression on human neutrophils.

    PubMed

    Dragon, Stéphane; Takhar, Manrit Kaur; Shan, Lianyu; Hayglass, Kent T; Simons, F Estelle; Gounni, Abdelilah S

    2009-06-26

    Interleukin (IL)-9 is associated with key pathological features of asthma such as airway hyperresponsiveness, bronchoconstriction and mucus production. Inflammatory responses mediated by IL-9 rely on the expression of the IL-9R which has been reported on lung epithelial cells, T lymphocytes and recently on airway granulocyte infiltrates. In this study, we assessed the regulatory and constitutive cell surface expression of the IL-9Ralpha in unfractionated and purified human neutrophils from atopic asthmatics, atopic non-asthmatics and healthy normal controls. We demonstrate that T(H)2 cytokines (IL-4 or IL-13) and granulocyte macrophage-colony stimulating factor (GM-CSF) up-regulated mRNA and cell surface expression levels of the IL-9Ralpha in primary human and HL-60 differentiated neutrophils. Pharmacological inhibition of NF-kappaB did not affect T(H)2-mediated IL-9Ralpha expression in human neutrophils although IFN-gamma and IL-10 down-regulated IL-9Ralpha expression when co-incubated with IL-4, IL-13 or GM-CSF. Collectively, our results reveal a regulatory function for IFN-gamma and IL-10 on modulating the inducible IL-9Ralpha expression levels on peripheral blood neutrophils by T(H)2 cytokines. PMID:19401191

  10. Entamoeba histolytica induces human neutrophils to form NETs.

    PubMed

    Ventura-Juarez, J; Campos-Esparza, Mr; Pacheco-Yepez, J; López-Blanco, J A; Adabache-Ortíz, A; Silva-Briano, M; Campos-Rodríguez, R

    2016-08-01

    Entamoeba histolytica invades the intestine and other organs during the pathogenesis of amoebiasis. In the early stages, the host organism responds with an inflammatory infiltrate composed mostly of neutrophils. It has been reported that these immune cells, activated by E. histolytica, exert a protective role by releasing proteolytic enzymes and generating reactive oxygen/nitrogen species (ROS/RNS) and antimicrobial peptides. It is now known that neutrophils also produce neutrophil extracellular traps (NETs), which are able to damage and kill pathogens. Studies have shown that intracellular protozoan pathogens, including Toxoplasma gondi, Plasmodium falciparum and Leishmania spp, induce neutrophils to release NETs and are damaged by them. However, the action of this mechanism has not been explored in relation to E. histolytica trophozoites. Through scanning electron, epifluorescence microscopy and viability assays, we show for first time that during in vitro interaction with E. histolytica trophozoites, human neutrophils released NETs that covered amoebas and reduced amoebic viability. These NETs presented histones, myeloperoxidase and decondensed chromatin. The results suggest that NETs participate in the elimination of the parasite. PMID:27138813

  11. Human neutrophil elastase: mediator and therapeutic target in atherosclerosis.

    PubMed

    Henriksen, Peter A; Sallenave, Jean-Michel

    2008-01-01

    Human neutrophil elastase (HNE) is present within atherosclerotic plaques where it contributes to matrix degradation and weakening of the vessel wall associated with the complications of aneurysm formation and plaque rupture. It is joined by other extracellular proteases in these actions but the broad range of substrates and potency of HNE coupled with the potential for rapid increases in HNE activity associated with neutrophil degranulation in acute coronary syndromes single this disruptive protease out as therapeutic target in atherosclerotic disease. This review summarises the role of HNE in neutrophil-mediated endothelial injury and the evidence for HNE as a mediator of atherosclerotic plaque development. The therapeutic potential of HNE neutralising antiproteases, alpha-1-antitrypsin and elafin, in atherosclerosis, is discussed. PMID:18289916

  12. Alpha-melanocyte-stimulating hormone down-regulates CXC receptors through activation of neutrophil elastase.

    PubMed

    Manna, Sunil K; Sarkar, Abira; Sreenivasan, Yashin

    2006-03-01

    Considering the role of interleukin-8 (IL-8) in a large number of acute and chronic inflammatory diseases, the regulation of IL-8-mediated biological responses is important. Alpha-melanocyte-stimulating hormone (alpha-MSH), a tridecapeptide, inhibits most forms of inflammation by an unknown mechanism. In the present study, we have found that alpha-MSH interacts predominantly with melanocortin-1 receptors and inhibits several IL-8-induced biological responses in macrophages and neutrophils. It down-regulated receptors for IL-8 but not for TNF, IL-4, IL-13 or TNF-related apoptosis-inducing ligand (TRAIL) in neutrophils. It down-regulated CXCR type 1 and 2 but not mRNA levels. alpha-MSH did not inhibit IL-8 binding in purified cell membrane or affinity-purified CXCR. IL-8 or anti-CXCR Ab protected against alpha-MSH-mediated inhibition of IL-8 binding. The level of neutrophil elastase, a specific serine protease, but not cathepsin G or proteinase 3 increased in alpha-MSH-treated cells, and restoration of CXCR by specific neutrophil elastase or serine protease inhibitors indicates the involvement of elastase in alpha-MSH-induced down-regulation of CXCR. These studies suggest that alpha-MSH inhibits IL-8-mediated biological responses by down-regulating CXCR through induction of serine protease and that alpha-MSH acts as a potent immunomodulator in neutrophil-driven inflammatory distress. PMID:16479540

  13. Local rheology of human neutrophils investigated using atomic force microscopy.

    PubMed

    Lee, Yong J; Patel, Dipika; Park, Soyeun

    2011-01-01

    During the immune response, neutrophils display localized mechanical events by interacting with their environment through the micro-vascular transit, trans-endothelial, and trans-epithelial migration. Nano-mechanical studies of human neutrophils on localized nano-domains could provide the essential information for understanding their immune responsive functions. Using the Atomic Force Microscopy (AFM)-based micro-rheology, we have investigated rheological properties of the adherent human neutrophils on local nano-domains. We have applied the modified Hertz model to obtain the viscoelastic moduli from the relatively thick body regions of the neutrophils. In addition, by using more advanced models to account for the substrate effects, we have successfully characterized the rheological properties of the thin leading and tail regions as well. We found a regional difference in the mechanical compliances of the adherent neutrophils. The central regions of neutrophils were significantly stiffer (1,548 ± 871 Pa) than the regions closer to the leading edge (686 ± 801 Pa), while the leading edge and the tail (494 ± 537 Pa) regions were mechanically indistinguishable. The frequency-dependent elastic and viscous moduli also display a similar regional difference. Over the studied frequency range (100 to 300 Hz), the complex viscoelastic moduli display the partial rubber plateau behavior where the elastic moduli are greater than the viscous moduli for a given frequency. The non-disparaging viscous modulus indicates that the neutrophils display a viscoelastic dynamic behavior rather than a perfect elastic behavior like polymer gels. In addition, we found no regional difference in the structural damping coefficient between the leading edge and the cell body. Thus, we conclude that despite the lower loss and storage moduli, the leading edges of the human neutrophils display partially elastic properties similar to the cell body. These results suggest that the lower elastic moduli

  14. Human Tissue Stimulator

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Neurodyne Corporation Human Tissue Stimulator (HTS) is a totally implantable system used for treatment of chronic pain and involuntary motion disorders by electrical stimulation. It was developed by Pacesetter Systems, Inc. in cooperation with the Applied Physics Laboratory. HTS incorporates a nickel cadmium battery, telemetry and command systems technologies of the same type as those used in NASA's Small Astronomy Satellite-3 in microminiature proportions so that the implantable element is the size of a deck of cards. The stimulator includes a rechargeable battery, an antenna and electronics to receive and process commands and to report on its own condition via telemetry, a wireless process wherein instrument data is converted to electrical signals and sent to a receiver where signals are presented as usable information. The HTS is targeted to nerve centers or to particular areas of the brain to provide relief from intractable pain or arrest involuntary motion. The nickel cadmium battery can be recharged through the skin. The first two HTS units were implanted last year and have been successful. Extensive testing is required before HTS can be made available for general use.

  15. JAK/STAT regulation of Aspergillus fumigatus corneal infections and IL-6/23-stimulated neutrophil, IL-17, elastase, and MMP9 activity.

    PubMed

    Taylor, Patricia R; Roy, Sanhita; Meszaros, Evan C; Sun, Yan; Howell, Scott J; Malemud, Charles J; Pearlman, Eric

    2016-07-01

    IL-6 and IL-23 (IL-6/23) induce IL-17A (IL-17) production by a subpopulation of murine and human neutrophils, resulting in autocrine IL-17 activation, enhanced production of reactive oxygen species, and increased fungal killing. As IL-6 and IL-23 receptors trigger JAK1, -3/STAT3 and JAK2/STAT3 phosphorylation, respectively, we examined the role of this pathway in a murine model of fungal keratitis and also examined neutrophil elastase and gelatinase (matrix metalloproteinase 9) activity by IL-6/23-stimulated human neutrophils in vitro. We found that STAT3 phosphorylation of neutrophils in Aspergillus fumigatus-infected corne as was inhibited by the JAK/STAT inhibitor Ruxolitinib, resulting in impaired fungal killing and decreased matrix metalloproteinase 9 activity. In vitro, we showed that fungal killing by IL-6/23-stimulated human peripheral blood neutrophils was impaired by JAK/STAT inhibitors Ruxolitinib and Stattic, and by the retinoic acid receptor-related orphan receptor γt inhibitor SR1001. This was also associated with decreased reactive oxygen species, IL-17A production, and retinoic acid receptor-related orphan receptor γt translocation to the nucleus. We also demonstrate that IL-6/23-activated neutrophils exhibit increased elastase and gelatinase (matrix metalloproteinase 9) activity, which is inhibited by Ruxolitinib and Stattic but not by SR1001. Taken together, these observations indicate that the regulation of activity of IL-17-producing neutrophils by JAK/STAT inhibitors impairs reactive oxygen species production and fungal killing activity but also blocks elastase and gelatinase activity that can cause tissue damage. PMID:27034404

  16. Proteome profiling of human neutrophil granule subsets, secretory vesicles, and cell membrane: correlation with transcriptome profiling of neutrophil precursors.

    PubMed

    Rørvig, Sara; Østergaard, Ole; Heegaard, Niels H H; Borregaard, Niels

    2013-10-01

    Neutrophils are indispensable in the innate immune defense against invading microorganisms. Neutrophils contain SVs and several subsets of granules that are essential for their function. Proteins present in neutrophil SVs and granules are synthesized during terminal granulopoiesis in the bone marrow. The heterogeneity of granules, as determined by marker proteins characteristic of each granule subset, is thought to result from differences in the biosynthetic windows of major classes of granule proteins, a process referred to as targeting by timing. Qualitative proteomic analysis of neutrophil granules, SVs, and plasma membrane has been performed before. Here, we performed subcellular fractionation on freshly isolated human neutrophils by nitrogen cavitation and density centrifugation on a four-layer Percoll gradient. Granule subsets were pooled and subjected to SDS-PAGE, and gel pieces were in-gel-digested with trypsin. The resulting peptides were analyzed using LTQ Orbitrap XL tandem MS. A total of 1292 unique proteins were identified and grouped, according to the neutrophil fraction, in which they displayed maximal expression. In addition to various known neutrophil proteins, several uncharacterized proteins were found, as well as proteins not described previously in neutrophils. To study the correlation between mRNA expression in neutrophil precursors and the localization of their cognate proteins, the distribution of 126 identified proteins was compared with their mRNA expression profiles. The neutrophil subcellular proteome profiles presented here may be used as a database in combination with the mRNA array database to predict and test the presence and localization of proteins in neutrophil granules and membranes. PMID:23650620

  17. Chemoattractant-Regulated Mobilization of a Novel Intracellular Compartment in Human Neutrophils

    NASA Astrophysics Data System (ADS)

    Borregaard, N.; Miller, L. J.; Springer, T. A.

    1987-09-01

    A novel mobilizable intracellular compartment was identified in human neutrophils by latent alkaline phosphatase activity. This compartment is mobilized to the plasma membrane much more readily than any identified granule subset and has kinetics of up-regulation in the membrane similar to those reported for a variety of receptor proteins. Triton X-100 permeabilization of both intact human neutrophils and subcellular fractions obtained by density-gradient centrifugation revelaed that 70 percent of the alkaline phosphatase is located in an intracellular compartment distinct from primary, secondary, and gelatinase granules and from the plasma membrane. This compartment fully translocates to the plasma membrane after stimulation with nanomolar concentrations of the chemotactic peptide N-formylmethionylleucylphenylalanine.

  18. Annexin II mediates the neutrophil elastase-stimulated exocytosis of mucin 5ac.

    PubMed

    Xu, Rui; Li, Qi; Zhou, Xiangdong; Perelman, Juliy M; Kolosov, Victor P

    2014-01-01

    The overexpression and hypersecretion of mucus is a hallmark of several chronic pulmonary inflammatory diseases, including chronic obstructive pulmonary disease (COPD), asthma and cystic fibrosis. Mucin 5ac (MUC5AC) is a major component of airway mucus. Annexin II (ANXII) has been reported to be expressed in various cells and is associated with the fusion of secretory vesicles. Neutrophil elastase (NE) is present at high concentrations in the airway surface fluid in patients with cystic fibrosis and various other severe diseases. However, the role of ANXII in NE-induced secretion of MUC5AC granules remains unclear. It was determined that NE upregulates the transcription and protein synthesis of ANXII in 16HBE human bronchial epithelial cells. Following stimulation with NE, ANXII is recruited to the cell membrane, as visualised by cell immunochemistry and laser confocal microscopy, and the redistribution of ANXII is inhibited by the protein kinase-C (PKC) inhibitor bisindolylmaleimide I. Conversely, depleting endogenous ANXII decreases MUC5AC secretion into the cell culture supernatant and increases the levels of intracellular MUC5AC protein. The data indicated that ANXII is associated with the secretion of MUC5AC granules. PMID:24247640

  19. Modulation of human neutrophil oxidative metabolism and degranulation by extract of Tamarindus indica L. fruit pulp.

    PubMed

    Paula, Fabiana S; Kabeya, Luciana M; Kanashiro, Alexandre; de Figueiredo, Andréa S G; Azzolini, Ana Elisa C S; Uyemura, Sérgio A; Lucisano-Valim, Yara Maria

    2009-01-01

    The tamarind (Tamarindus indica L.) is indigenous to Asian countries and widely cultivated in the American continents. The tamarind fruit pulp extract (ExT), traditionally used in spices, food components and juices, is rich in polyphenols that have demonstrated anti-atherosclerotic, antioxidant and immunomodulatory activities. This study evaluated the modulator effect of a crude hydroalcoholic ExT on some peripheral human neutrophil functions. The neutrophil reactive oxygen species generation, triggered by opsonized zymosan (OZ), n-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol myristate acetate (PMA), and assessed by luminol- and lucigenin-enhanced chemiluminescence (LumCL and LucCL, respectively), was inhibited by ExT in a concentration-dependent manner. ExT was a more effective inhibitor of the PMA-stimulated neutrophil function [IC50 (in microg/10(6)cells)=115.7+/-9.7 (LumCL) and 174.5+/-25.9 (LucCL)], than the OZ- [IC50=248.5+/-23.1 (LumCL) and 324.1+/-34.6 (LucCL)] or fMLP-stimulated cells [IC50=178.5+/-12.2 (LumCL)]. The ExT also inhibited neutrophil NADPH oxidase activity (evaluated by O2 consumption), degranulation and elastase activity (evaluated by spectrophotometric methods) at concentrations higher than 200 microg/10(6)cells, without being toxic to the cells, under the conditions assessed. Together, these results indicate the potential of ExT as a source of compounds that can modulate the neutrophil-mediated inflammatory diseases. PMID:19022329

  20. Acute hypoxemia in humans enhances the neutrophil inflammatory response.

    PubMed

    Tamura, Douglas Y; Moore, Ernest E; Partrick, David A; Johnson, Jeffrey L; Offner, Patrick J; Silliman, Christopher C

    2002-04-01

    The neutrophil (PMN) is regarded as a key component in the hyperinflammatory response known as the systemic inflammatory response syndrome. Acute respiratory distress syndrome (ARDS) and subsequent multiple organ failure (MOF) are related to the severity of this hyperinflammation. ICU patients who are at highest risk of developing MOF may have acute hypoxic events that complicate their hospital course. This study was undertaken to evaluate the effects of acute hypoxia and subsequent hypoxemia on circulating PMNs in human volunteers. Healthy subjects were exposed to a changing O2/N2 mixture until their O2 saturation (SaO2) reached a level of 68% saturation. These subjects were then exposed to room air and then returned to their baseline SaO2. PMNs were isolated from pre- and post-hypoxemic arterial blood samples and were then either stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP) or PMA alone, or they were primed with L-alpha-phosphatidylcholine, beta-acetyl-gamma-O-alkyl (PAF) followed by fMLP activation. Reactive oxygen species generation as measured by superoxide anion production was enhanced in primed PMNs after hypoxemia. Protease degranulation as measured by elastase release was enhanced in both quiescent PMNs and primed PMNs after fMLP activation following the hypoxemic event. Adhesion molecule upregulation as measured by CD11b/CD18, however, was not significantly changed after hypoxemia. Apoptosis of quiescent PMNs was delayed after the hypoxemic event. TNFalpha, IL-1, IL-6, and IL-8 cytokine levels were unchanged following hypoxemia. These results indicate that relevant acute hypoxemic events observed in the clinical setting enhance several PMN cytotoxic functions and suggest that a transient hypoxemic insult may promote hyperinflammation. PMID:11954825

  1. Opa+ Neisseria gonorrhoeae Exhibits Reduced Survival in Human Neutrophils Via Src Family Kinase-Mediated Bacterial Trafficking Into Mature Phagolysosomes

    PubMed Central

    Johnson, M. Brittany; Ball, Louise M.; Daily, Kylene P.; Martin, Jennifer N.; Columbus, Linda; Criss, Alison K.

    2015-01-01

    Summary During gonorrheal infection, there is a heterogeneous population of Neisseria gonorrhoeae (Gc) varied in their expression of opacity-associated (Opa) proteins. While Opa proteins are important for bacterial attachment and invasion of epithelial cells, Opa+ Gc has a survival defect after exposure to neutrophils. Here, we use constitutively Opa- and OpaD+ Gc in strain background FA1090 to show that Opa+ Gc is more sensitive to killing inside adherent, chemokine-treated primary human neutrophils due to increased bacterial residence in mature, degradative phagolysosomes that contain primary and secondary granule antimicrobial content. Although Opa+ Gc stimulates a potent oxidative burst, neutrophil killing of Opa+ Gc was instead attributable to non-oxidative components, particularly neutrophil proteases and the bactericidal/permeability-increasing protein. Blocking interaction of Opa+ Gc with carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) or inhibiting Src family kinase signaling, which is downstream of CEACAM activation, enhanced the survival of Opa+ Gc in neutrophils. Src family kinase signaling was required for fusion of Gc phagosomes with primary granules to generate mature phagolysosomes. Conversely, ectopic activation of Src family kinases or coinfection with Opa+ Gc resulted in decreased survival of Opa- Gc in neutrophils. From these results, we conclude that Opa protein expression is an important modulator of Gc survival characteristics in neutrophils by influencing phagosome dynamics and thus bacterial exposure to neutrophils’ full antimicrobial arsenal. PMID:25346239

  2. Butyric acid stimulates bovine neutrophil functions and potentiates the effect of platelet activating factor.

    PubMed

    Carretta, M D; Hidalgo, A I; Burgos, J; Opazo, L; Castro, L; Hidalgo, M A; Figueroa, C D; Taubert, A; Hermosilla, C; Burgos, R A

    2016-08-01

    Increased short-chain fatty acid (SCFA) production is associated with subacute ruminal acidosis (SARA) and activation of inflammatory processes. In humans and rodents, SCFAs modulate inflammatory responses in the gut via free fatty acid receptor 2 (FFA2). In bovines, butyric acid is one of the most potent FFA2 agonists. Its expression in bovine neutrophils has recently been demonstrated, suggesting a role in innate immune response in cattle. This study aimed to evaluate if butyric acid modulates oxidative and non-oxidative functions or if it can potentiate other inflammatory mediators in bovine neutrophils. Our results showed that butyric acid can activate bovine neutrophils, inducing calcium (Ca(2+)) influx and mitogen-activated protein kinase (MAPK) phosphorylation, two second messengers involved in FFA2 activation. Ca(2+) influx induced by butyric acid was dependent on the extracellular and intracellular Ca(2+) source and phospholipase C (PLC) activation. Butyric acid alone had no significant effect on reactive oxygen species (ROS) production and chemotaxis; however, a priming effect on platelet-activating factor (PAF), a potent inflammatory mediator, was observed. Butyric acid increased CD63 expression and induced the release of neutrophil granule markers matrix metalloproteinase-9 (MMP-9) and lactoferrin. Finally, we observed that butyric acid induced neutrophil extracellular trap (NET) formation without affecting cellular viability. These findings suggest that butyric acid, a component of the ruminal fermentative process, can modulate the innate immune response of ruminants. PMID:27288853

  3. IFNα enhances the production of IL-6 by human neutrophils activated via TLR8

    PubMed Central

    Zimmermann, Maili; Arruda-Silva, Fabio; Bianchetto-Aguilera, Francisco; Finotti, Giulia; Calzetti, Federica; Scapini, Patrizia; Lunardi, Claudio; Cassatella, Marco A.; Tamassia, Nicola

    2016-01-01

    Recently, we reported that human neutrophils produce biologically active amounts of IL-6 when incubated with agonists activating TLR8, a receptor recognizing viral single strand RNA. In this study, we demonstrate that IFNα, a cytokine that modulates the early innate immune responses toward viral and bacterial infections, potently enhances the production of IL-6 in neutrophils stimulated with R848, a TLR8 agonist. We also show that such an effect is not caused by an IFNα-dependent induction of TLR7 and its consequent co-activation with TLR8 in response to R848, but, rather, it is substantially mediated by an increased production and release of endogenous TNFα. The latter cytokine, in an autocrine manner, leads to an augmented synthesis of the IkBζ co-activator and an enhanced recruitment of the C/EBPβ transcription factor to the IL-6 promoter. Moreover, we show that neutrophils from SLE patients with active disease state, hence displaying an IFN-induced gene expression signature, produce increased amounts of both IL-6 and TNFα in response to R848 as compared to healthy donors. Altogether, data uncover novel effects that type I IFN exerts in TLR8-activated neutrophils, which therefore enlarge our knowledge on the various biological actions which type I IFN orchestrates during infectious and autoimmune diseases. PMID:26790609

  4. Inhibition of Human Neutrophil Responses by Essential Oil of Artemisia kotuchovii and Its Constituents

    PubMed Central

    Schepetkin, Igor A.; Kushnarenko, Svetlana V.; Özek, Gulmira; Kirpotina, Liliya N.; Utegenova, Gulzhakhan A.; Kotukhov, Yuriy A.; Danilova, Alevtina N.; Özek, Temel; Başer, K. Hüsnü Can; Quinn, Mark T.

    2015-01-01

    Essential oils were obtained by hydrodistillation of the flowers+leaves and stems of Artemisia kotuchovii Kupr. (AKEOf+l and AKEOstm, respectively) and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). The primary components of the oils were estragole, (E)- and (Z)-β-ocimenes, methyl eugenol, limonene, spathulenol, β-pinene, myrcene, and (E)-methyl cinnamate. Seventy four constituents were present at concentrations from 0.1 to 1.0%, and 34 compounds were identified in trace (<0.1%) amounts in one or both plant components. Screening of the essential oils for biological activity showed that AKEOstm, but not AKEOf+l, inhibited N-formyl-Met-Leu-Phe (fMLF)-stimulated Ca2+ flux and chemotaxis and phorbol-12-myristate-13-acetate (PMA)-induced reactive oxygen species (ROS) production in human neutrophils. Selected pure constituents, representing >96% of the AKEOstm composition, were also tested in human neutrophils and HL-60 cells transfected with N-formyl peptide receptor 1 (FPR1). We found that one component, 6-methyl-3,5-heptadien-2-one (MHDO), inhibited fMLF- and interleukin 8 (IL-8)-stimulated Ca2+ flux, fMLF-induced chemotaxis, and PMA-induced ROS production in human neutrophils. MHDO also inhibited fMLF-induced Ca2+ flux in FPR1-HL60 cells. These results suggest that MHDO may be effective in modulating some innate immune responses, possibly by an inhibition of neutrophil migration and ROS production. PMID:25959257

  5. Human Platelets Utilize Cycloxygenase-1 to Generate Dioxolane A3, a Neutrophil-activating Eicosanoid*

    PubMed Central

    Hinz, Christine; Aldrovandi, Maceler; Uhlson, Charis; Marnett, Lawrence J.; Longhurst, Hilary J.; Warner, Timothy D.; Alam, Saydul; Slatter, David A.; Lauder, Sarah N.; Allen-Redpath, Keith; Collins, Peter W.; Murphy, Robert C.; Thomas, Christopher P.; O'Donnell, Valerie B.

    2016-01-01

    Eicosanoids are important mediators of fever, pain, and inflammation that modulate cell signaling during acute and chronic disease. We show by using lipidomics that thrombin-activated human platelets generate a new type of eicosanoid that both stimulates and primes human neutrophil integrin (Mac-1) expression, in response to formylmethionylleucylphenylalanine. Detailed characterization proposes a dioxolane structure, 8-hydroxy-9,11-dioxolane eicosatetraenoic acid (dioxolane A3, DXA3). The lipid is generated in nanogram amounts by platelets from endogenous arachidonate during physiological activation, with inhibition by aspirin in vitro or in vivo, implicating cyclooxygenase-1 (COX). Pharmacological and genetic studies on human/murine platelets revealed that DXA3 formation requires protease-activated receptors 1 and 4, cytosolic phospholipase A2 (cPLA2), Src tyrosine kinases, p38 MAPK, phospholipase C, and intracellular calcium. From data generated by purified COX isoforms and chemical oxidation, we propose that DXA3 is generated by release of an intermediate from the active site followed by oxygenation at C8. In summary, a new neutrophil-activating platelet-derived lipid generated by COX-1 is presented that can activate or prime human neutrophils, suggesting a role in innate immunity and acute inflammation. PMID:27129261

  6. Human Platelets Utilize Cycloxygenase-1 to Generate Dioxolane A3, a Neutrophil-activating Eicosanoid.

    PubMed

    Hinz, Christine; Aldrovandi, Maceler; Uhlson, Charis; Marnett, Lawrence J; Longhurst, Hilary J; Warner, Timothy D; Alam, Saydul; Slatter, David A; Lauder, Sarah N; Allen-Redpath, Keith; Collins, Peter W; Murphy, Robert C; Thomas, Christopher P; O'Donnell, Valerie B

    2016-06-24

    Eicosanoids are important mediators of fever, pain, and inflammation that modulate cell signaling during acute and chronic disease. We show by using lipidomics that thrombin-activated human platelets generate a new type of eicosanoid that both stimulates and primes human neutrophil integrin (Mac-1) expression, in response to formylmethionylleucylphenylalanine. Detailed characterization proposes a dioxolane structure, 8-hydroxy-9,11-dioxolane eicosatetraenoic acid (dioxolane A3, DXA3). The lipid is generated in nanogram amounts by platelets from endogenous arachidonate during physiological activation, with inhibition by aspirin in vitro or in vivo, implicating cyclooxygenase-1 (COX). Pharmacological and genetic studies on human/murine platelets revealed that DXA3 formation requires protease-activated receptors 1 and 4, cytosolic phospholipase A2 (cPLA2), Src tyrosine kinases, p38 MAPK, phospholipase C, and intracellular calcium. From data generated by purified COX isoforms and chemical oxidation, we propose that DXA3 is generated by release of an intermediate from the active site followed by oxygenation at C8. In summary, a new neutrophil-activating platelet-derived lipid generated by COX-1 is presented that can activate or prime human neutrophils, suggesting a role in innate immunity and acute inflammation. PMID:27129261

  7. Protrusive and Contractile Forces of Spreading Human Neutrophils.

    PubMed

    Henry, Steven J; Chen, Christopher S; Crocker, John C; Hammer, Daniel A

    2015-08-18

    Human neutrophils are mediators of innate immunity and undergo dramatic shape changes at all stages of their functional life cycle. In this work, we quantified the forces associated with a neutrophil's morphological transition from a nonadherent, quiescent sphere to its adherent and spread state. We did this by tracking, with high spatial and temporal resolution, the cell's mechanical behavior during spreading on microfabricated post-array detectors printed with the extracellular matrix protein fibronectin. Two dominant mechanical regimes were observed: transient protrusion and steady-state contraction. During spreading, a wave of protrusive force (75 ± 8 pN/post) propagates radially outward from the cell center at a speed of 206 ± 28 nm/s. Once completed, the cells enter a sustained contractile state. Although post engagement during contraction was continuously varying, posts within the core of the contact zone were less contractile (-20 ± 10 pN/post) than those residing at the geometric perimeter (-106 ± 10 pN/post). The magnitude of the protrusive force was found to be unchanged in response to cytoskeletal inhibitors of lamellipodium formation and myosin II-mediated contractility. However, cytochalasin B, known to reduce cortical tension in neutrophils, slowed spreading velocity (61 ± 37 nm/s) without significantly reducing protrusive force. Relaxation of the actin cortical shell was a prerequisite for spreading on post arrays as demonstrated by stiffening in response to jasplakinolide and the abrogation of spreading. ROCK and myosin II inhibition reduced long-term contractility. Function blocking antibody studies revealed haptokinetic spreading was induced by β2 integrin ligation. Neutrophils were found to moderately invaginate the post arrays to a depth of ∼1 μm as measured from spinning disk confocal microscopy. Our work suggests a competition of adhesion energy, cortical tension, and the relaxation of cortical tension is at play at the onset of

  8. Transendothelial migration enhances integrin-dependent human neutrophil chemokinesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transendothelial migration of neutrophils induces phenotypic changes that influence the interactions of neutrophils with extravascular tissue components. To assess the influence of transmigration on neutrophil chemokinetic motility, we used polyethylene glycol hydrogels covalently modified with spec...

  9. Human Neutrophils Convert the Sebum-derived Polyunsaturated Fatty Acid Sebaleic Acid to a Potent Granulocyte Chemoattractant*

    PubMed Central

    Cossette, Chantal; Patel, Pranav; Anumolu, Jaganmohan R.; Sivendran, Sashikala; Lee, Gue Jae; Gravel, Sylvie; Graham, François D.; Lesimple, Alain; Mamer, Orval A.; Rokach, Joshua; Powell, William S.

    2008-01-01

    Sebaleic acid (5,8-octadecadienoic acid) is the major polyunsaturated fatty acid in human sebum and skin surface lipids. The objective of the present study was to investigate the metabolism of this fatty acid by human neutrophils and to determine whether its metabolites are biologically active. Neutrophils converted sebaleic acid to four major products, which were identified by their chromatographic properties, UV absorbance, and mass spectra as 5-hydroxy-(6E,8Z)-octadecadienoic acid (5-HODE), 5-oxo-(6E,8Z)-octadecadienoic acid (5-oxo-ODE), 5S,18-dihydroxy-(6E,8Z)-octadecadienoic acid, and 5-oxo-18-hydroxy-(6E,8Z)-octadecadienoic acid. The identities of these metabolites were confirmed by comparison of their properties with those of authentic chemically synthesized standards. Both neutrophils and human keratinocytes converted 5-HODE to 5-oxo-ODE. This reaction was stimulated in neutrophils by phorbol myristate acetate and in keratinocytes by oxidative stress (t-butyl-hydroperoxide). Both treatments dramatically elevated intracellular levels of NADP+, the cofactor required by 5-hydroxyeicosanoid dehydrogenase. In keratinocytes, this was accompanied by a rapid increase in intracellular GSSG levels, consistent with the involvement of glutathione peroxidase. 5-Oxo-ODE stimulated calcium mobilization in human neutrophils and induced desensitization to 5-oxo-6,8,11,14-eicosatetraenoic acid but not leukotriene B4, indicating that this effect was mediated by the OXE receptor. 5-Oxo-ODE and its 8-trans isomer were equipotent with 5-oxo-6,8,11,14-eicosatetraenoic acid in stimulating actin polymerization and chemotaxis in human neutrophils, whereas 5-HODE, 5-oxo-18-hydroxy-(6E,8Z)-octadecadienoic acid, and 5S,18-dihydroxy-(6E,8Z)-octadecadienoic acid were much less active. We conclude that neutrophil 5-lipoxygenase converts sebaleic acid to 5-HODE, which can be further metabolized to 5-oxo-ODE by 5-hydroxyeicosanoid dehydrogenase in neutrophils and keratinocytes. Because of

  10. Modulation of human neutrophil polymorphonuclear leucocyte migration by human plasma alpha-globulin inhibitors and synthetic esterase inhibitors.

    PubMed Central

    Goetzl, E J

    1975-01-01

    The exposure of isolated washed human neutrophils to purified human alpha1-antitrypsin resulted in a transient 2-fold enhancement of random migration and concomitant 70-90 per cent inhibition of chemotactic responsiveness to C5a or C3a, while treatment with alpha2-macroglobulin gave a less pronounced brief enhancement of random migration and prolonged 40-60 per cent suppression of chemotaxis. Peak effects occurred with concentrations of 1 mug/ml of alpha1-antitrypsin and 10 mug/ml of alpha2-macroglobulin. In contrast, the inhibitor of the activated first component of complement, at the highest concentration studied of 100/mug/ml, slightly enhanced chemotactic migration in response to C5a without influencing random migration. Preincubation of neutrophils with either L-1-tosylamide-2-phenylethyl-chloromethyl ketone (TPCK) or N-alpha-p-tosyl-L-lysine-chloromethyl ketone (TLCK) at concentrations of 10-8-10-4M suppressed chemotaxis with concomitant inhibition of random migration by TPCK and enhancement of random migration by TLCK. All agents worked directly and irreversibly on the cells but caused only slight stimulation of the activity of the hexose monophosphate shunt of layers of adherent neutrophils. The results suggest that interaction of the plasma alpha-globulins or synthetic esterase inhibitors with surface receptors on neutrophils can influence both the random migration and responsiveness to chemotactic factors of these cells. PMID:49293

  11. Passive mechanical behavior of human neutrophils: effect of cytochalasin B.

    PubMed Central

    Tsai, M. A.; Frank, R. S.; Waugh, R. E.

    1994-01-01

    Actin is a ubiquitous protein in eukaryotic cells. It plays a major role in cell motility and in the maintenance and control of cell shape. In this article, we intend to address the contribution of actin to the passive mechanical properties of human neutrophils. As a framework for assessing this contribution, the neutrophil is modeled as a simple viscous fluid drop with a constant cortical ("surface") tension. The reagent cytochalasin B (CTB) was used to disrupt the F-actin structure, and the neutrophil cortical tension and cytoplasmic viscosity were evaluated by single-cell micropipette aspiration. The cortical tension was calculated by simple force balance, and the viscosity was calculated according to a numerical analysis of the cell entry into the micropipette. CTB reduced the cell cortical tension in a dose-dependent fashion: by 19% at a concentration of 3 microM and by 49% at 30 microM. CTB also reduced the cytoplasmic viscosity by approximately -25% at a concentration of 3 microM and by approximately 65% at a concentration of 30 microM when compared at the same aspiration pressures. All three groups of neutrophils, normal cells, and cells treated with either 3 or 30 microM CTB, exhibited non-Newtonian behavior, in that the apparent viscosity decreased with increasing shear rate. The dependence of the cytoplasmic viscosity on deformation rate can be described empirically by mu = mu c(gamma m/gamma c)-b, where mu is cytoplasmic viscosity, gamma m is mean shear rate, mu c is the characteristic viscosity at the characteristic shear rate gamma c, and b is a material coefficient. The shear rate dependence of the cytoplasmic viscosity was reduced by CTB treatment. This is reflected by the changes in the material coefficients. When gamma c was set to 1 s-1, pc = 130 +/- 23 Pa.s and b = 0.52 +/- 0.09 for normal neutrophils and pc = 54 +/- 15 Pa.S and b = 0.26 +/- 0.05 for cells treated with 30 micro M CTB. These results provide the first quantitative assessment of

  12. Anti-inflammatory effects of Perilla frutescens in activated human neutrophils through two independent pathways: Src family kinases and Calcium.

    PubMed

    Chen, Chun-Yu; Leu, Yann-Lii; Fang, Yu; Lin, Chwan-Fwu; Kuo, Liang-Mou; Sung, Wei-Che; Tsai, Yung-Fong; Chung, Pei-Jen; Lee, Ming-Chung; Kuo, Yu-Ting; Yang, Hsuan-Wu; Hwang, Tsong-Long

    2015-01-01

    The leaves of Perilla frutescens (L.) Britt. have been traditionally used as an herbal medicine in East Asian countries to treat a variety diseases. In this present study, we investigated the inhibitory effects of P. frutescens extract (PFE) on N-formyl-Met-Leu-Phe (fMLF)-stimulated human neutrophils and the underlying mechanisms. PFE (1, 3, and 10 μg/ml) inhibited superoxide anion production, elastase release, reactive oxygen species formation, CD11b expression, and cell migration in fMLF-activated human neutrophils in dose-dependent manners. PFE inhibited fMLF-induced phosphorylation of the Src family kinases (SFKs), Src (Tyr416) and Lyn (Tyr396), and reduced their enzymatic activities. Both PFE and PP2 (a selective inhibitor of SFKs) reduced the phosphorylation of Burton's tyrosine kinases (Tyr223) and Vav (Tyr174) in fMLF-activated human neutrophils. Additionally, PFE decreased intracellular Ca(2+) levels ([Ca(2+)]i), whereas PP2 prolonged the time required for [Ca(2+)]i to return to its basal level. Our findings indicated that PFE effectively regulated the inflammatory activities of fMLF-activated human neutrophils. The anti-inflammatory effects of PFE on activated human neutrophils were mediated through two independent signaling pathways involving SFKs (Src and Lyn) and mobilization of intracellular Ca(2+). PMID:26659126

  13. Anti-inflammatory effects of Perilla frutescens in activated human neutrophils through two independent pathways: Src family kinases and Calcium

    PubMed Central

    Chen, Chun-Yu; Leu, Yann-Lii; Fang, Yu; Lin, Chwan-Fwu; Kuo, Liang-Mou; Sung, Wei-Che; Tsai, Yung-Fong; Chung, Pei-Jen; Lee, Ming-Chung; Kuo, Yu-Ting; Yang, Hsuan-Wu; Hwang, Tsong-Long

    2015-01-01

    The leaves of Perilla frutescens (L.) Britt. have been traditionally used as an herbal medicine in East Asian countries to treat a variety diseases. In this present study, we investigated the inhibitory effects of P. frutescens extract (PFE) on N-formyl-Met-Leu-Phe (fMLF)-stimulated human neutrophils and the underlying mechanisms. PFE (1, 3, and 10 μg/ml) inhibited superoxide anion production, elastase release, reactive oxygen species formation, CD11b expression, and cell migration in fMLF-activated human neutrophils in dose-dependent manners. PFE inhibited fMLF-induced phosphorylation of the Src family kinases (SFKs), Src (Tyr416) and Lyn (Tyr396), and reduced their enzymatic activities. Both PFE and PP2 (a selective inhibitor of SFKs) reduced the phosphorylation of Burton’s tyrosine kinases (Tyr223) and Vav (Tyr174) in fMLF-activated human neutrophils. Additionally, PFE decreased intracellular Ca2+ levels ([Ca2+]i), whereas PP2 prolonged the time required for [Ca2+]i to return to its basal level. Our findings indicated that PFE effectively regulated the inflammatory activities of fMLF-activated human neutrophils. The anti-inflammatory effects of PFE on activated human neutrophils were mediated through two independent signaling pathways involving SFKs (Src and Lyn) and mobilization of intracellular Ca2+. PMID:26659126

  14. TARM1 is a novel LRC-encoded ITAM receptor that co-stimulates pro-inflammatory cytokine secretion by macrophages and neutrophils

    PubMed Central

    Radjabova, Valeria; Mastroeni, Piero; Skjødt, Karsten; Zaccone, Paola; de Bono, Bernard; Goodall, Jane C; Chilvers, Edwin R; Juss, Jatinder K; Jones, Des C; Trowsdale, John; Barrow, Alexander David

    2015-01-01

    We identified a novel, evolutionarily conserved receptor encoded within the human Leukocyte Receptor Complex (LRC) and syntenic region of mouse chromosome 7, named T cell-interacting, activating receptor on myeloid cells-1 (TARM1). The transmembrane region of TARM1 contained a conserved arginine residue, consistent with association with a signaling adaptor. TARM1 associated with the ITAM adaptor Fc receptor common γ chain but not with DAP10 or DAP12. In healthy mice, TARM1 is constitutively expressed on the cell-surface of mature and immature CD11b+ Gr-1+ neutrophils within the bone marrow. Following intraperitoneal lipopolysaccharide (LPS) treatment or systemic bacterial challenge TARM1 expression was upregulated by neutrophils and inflammatory monocytes and TARM1+ cells were rapidly recruited to sites of inflammation. TARM1 expression was also upregulated by bone marrow-derived macrophages and dendritic cells following stimulation with TLR agonists in vitro. Ligation of TARM1 receptor in the presence of TLR ligands, such as LPS, enhanced the secretion of pro-inflammatory cytokines by macrophages and primary mouse neutrophils, whereas TARM1 stimulation alone had no effect. Finally, an immobilized TARM1-Fc fusion protein suppressed CD4+ T cell activation and proliferation in vitro. These results suggest that a putative T cell ligand can interact with TARM1 receptor resulting in bi-directional signaling, raising the T cell activation threshold whilst co-stimulating the release of pro-inflammatory cytokines by macrophages and neutrophils. PMID:26311901

  15. Role of gelsolin in actin depolymerization of adherent human neutrophils.

    PubMed Central

    Wang, J S; Coburn, J P; Tauber, A I; Zaner, K S

    1997-01-01

    Human neutrophils generally function adherent to an extracellular matrix. We have previously reported that upon adhesion to laminin- or fibronectin-coated, but not uncoated, plastic there is a depolymerization of actin in neutrophils. This phenomenon was not affected by inhibitors of the more well-studied components of the signal transduction pathway, specifically, pertussis toxin, an inhibitor of G-proteins, H-7 or staurosporine, inhibitors of protein kinase C, or herbimycin A, an inhibitor of nonreceptor tyrosine kinase. We therefore focused our attention on actin-binding proteins and measured the changes in the partitioning of gelsolin between the Triton X-100-soluble and -insoluble cellular fractions which occur upon neutrophil adhesion by means of quantitating anti-gelsolin antibody binding to aliquots of these fractions. It was found that approximately 90% of the total cellular gelsolin was found in the Triton X-100-soluble fraction in suspended cells, but that upon adherence to either fibronectin- or laminin-coated plastic about 40% of the soluble gelsolin could be detected in the insoluble fraction. This effect was not observed in cells adherent to uncoated plastic, wherein more than 90% of the gelsolin was found in the soluble fraction. Results of immunofluorescence microscopy of these cell preparations was consistent with this data. A gelsolin translocation to the insoluble cellular actin network may account for a part of the observed actin depolymerization. Images PMID:9017600

  16. Protrusive and Contractile Forces of Spreading Human Neutrophils

    PubMed Central

    Henry, Steven J.; Chen, Christopher S.; Crocker, John C.; Hammer, Daniel A.

    2015-01-01

    Human neutrophils are mediators of innate immunity and undergo dramatic shape changes at all stages of their functional life cycle. In this work, we quantified the forces associated with a neutrophil’s morphological transition from a nonadherent, quiescent sphere to its adherent and spread state. We did this by tracking, with high spatial and temporal resolution, the cell’s mechanical behavior during spreading on microfabricated post-array detectors printed with the extracellular matrix protein fibronectin. Two dominant mechanical regimes were observed: transient protrusion and steady-state contraction. During spreading, a wave of protrusive force (75 ± 8 pN/post) propagates radially outward from the cell center at a speed of 206 ± 28 nm/s. Once completed, the cells enter a sustained contractile state. Although post engagement during contraction was continuously varying, posts within the core of the contact zone were less contractile (−20 ± 10 pN/post) than those residing at the geometric perimeter (−106 ± 10 pN/post). The magnitude of the protrusive force was found to be unchanged in response to cytoskeletal inhibitors of lamellipodium formation and myosin II-mediated contractility. However, cytochalasin B, known to reduce cortical tension in neutrophils, slowed spreading velocity (61 ± 37 nm/s) without significantly reducing protrusive force. Relaxation of the actin cortical shell was a prerequisite for spreading on post arrays as demonstrated by stiffening in response to jasplakinolide and the abrogation of spreading. ROCK and myosin II inhibition reduced long-term contractility. Function blocking antibody studies revealed haptokinetic spreading was induced by β2 integrin ligation. Neutrophils were found to moderately invaginate the post arrays to a depth of ∼1 μm as measured from spinning disk confocal microscopy. Our work suggests a competition of adhesion energy, cortical tension, and the relaxation of cortical tension is at play at the

  17. Activation of TAK1 by Chemotactic and Growth Factors, and Its Impact on Human Neutrophil Signaling and Functional Responses.

    PubMed

    Sylvain-Prévost, Stéphanie; Ear, Thornin; Simard, François A; Fortin, Carl F; Dubois, Claire M; Flamand, Nicolas; McDonald, Patrick P

    2015-12-01

    The MAP3 kinase, TAK1, is known to act upstream of IKK and MAPK cascades in several cell types, and is typically activated in response to cytokines (e.g., TNF, IL-1) and TLR ligands. In this article, we report that in human neutrophils, TAK1 can also be activated by different classes of inflammatory stimuli, namely, chemoattractants and growth factors. After stimulation with such agents, TAK1 becomes rapidly and transiently activated. Blocking TAK1 kinase activity with a highly selective inhibitor (5z-7-oxozeaenol) attenuated the inducible phosphorylation of ERK occurring in response to these stimuli but had little or no effect on that of p38 MAPK or PI3K. Inhibition of TAK1 also impaired MEKK3 (but not MEKK1) activation by fMLF. Moreover, both TAK1 and the MEK/ERK module were found to influence inflammatory cytokine expression and release in fMLF- and GM-CSF-activated neutrophils, whereas the PI3K pathway influenced this response independently of TAK1. Besides cytokine production, other responses were found to be under TAK1 control in neutrophils stimulated with chemoattractants and/or GM-CSF, namely, delayed apoptosis and leukotriene biosynthesis. Our data further emphasize the central role of TAK1 in controlling signaling cascades and functional responses in primary neutrophils, making it a promising target for therapeutic intervention in view of the foremost role of neutrophils in several chronic inflammatory conditions. PMID:26491199

  18. Macrophage-derived neutrophil chemotactic factor is involved in the neutrophil recruitment inhibitory activity present in the supernatants of LPS-stimulated macrophages

    PubMed Central

    Tavares-Murta, B. M.; Cunha, F. Q.; Dias-Baruffi, M.; Roque-Barreira, M. C.

    1996-01-01

    In a previous study, we demonstrated the presence of a neutrophil recruitment inhibitory factor (NRIF) in the supernatants of LPS-stimulated macrophages. Recently, the purification of a 54 kDa protein, identified as the macrophage-derived neutrophil chemotactic factor (MNCF) was reported. Since NRIF and MNCF are obtained under the same conditions, and, since the intravenous administration of TNF-α and IL-8 inhibits neutrophil migration, we have investigated whether MNCF could be responsible for this inhibitory activity. After affinity chromatography of the macrophage supernatants on a D-galactose column, the inhibitory activity was recovered in both the unbound (D-gal−) and bound (D-gal+) fractions, with MNCF being found in the D-gal+ fraction. Further gel filtration of the latter on Superdex 75 yielded a single peak containing both activities. In a cytotoxicity assay, most of the TNF found in the crude supernatants was recovered in the D-gal− fraction. Furthermore, the incubation of the D-gal− fraction with anti-TNF-α plus anti-IL-8 antisera partially prevents its inhibitory effect on neutrophil migration, but had no effect on the D-gal+ activity. Overall, these results suggest that the D-gal− inhibitory effect is partially mediated by TNF-α and IL-8, and that MNCF accounts for the inhibition of neutrophil migration in vivo by the D-gal+ fraction. PMID:18475709

  19. Staphylococcus epidermidis strategies to avoid killing by human neutrophils.

    PubMed

    Cheung, Gordon Y C; Rigby, Kevin; Wang, Rong; Queck, Shu Y; Braughton, Kevin R; Whitney, Adeline R; Teintze, Martin; DeLeo, Frank R; Otto, Michael

    2010-01-01

    Staphylococcus epidermidis is a leading nosocomial pathogen. In contrast to its more aggressive relative S. aureus, it causes chronic rather than acute infections. In highly virulent S. aureus, phenol-soluble modulins (PSMs) contribute significantly to immune evasion and aggressive virulence by their strong ability to lyse human neutrophils. Members of the PSM family are also produced by S. epidermidis, but their role in immune evasion is not known. Notably, strong cytolytic capacity of S. epidermidis PSMs would be at odds with the notion that S. epidermidis is a less aggressive pathogen than S. aureus, prompting us to examine the biological activities of S. epidermidis PSMs. Surprisingly, we found that S. epidermidis has the capacity to produce PSMδ, a potent leukocyte toxin, representing the first potent cytolysin to be identified in that pathogen. However, production of strongly cytolytic PSMs was low in S. epidermidis, explaining its low cytolytic potency. Interestingly, the different approaches of S. epidermidis and S. aureus to causing human disease are thus reflected by the adaptation of biological activities within one family of virulence determinants, the PSMs. Nevertheless, S. epidermidis has the capacity to evade neutrophil killing, a phenomenon we found is partly mediated by resistance mechanisms to antimicrobial peptides (AMPs), including the protease SepA, which degrades AMPs, and the AMP sensor/resistance regulator, Aps (GraRS). These findings establish a significant function of SepA and Aps in S. epidermidis immune evasion and explain in part why S. epidermidis may evade elimination by innate host defense despite the lack of cytolytic toxin expression. Our study shows that the strategy of S. epidermidis to evade elimination by human neutrophils is characterized by a passive defense approach and provides molecular evidence to support the notion that S. epidermidis is a less aggressive pathogen than S. aureus. PMID:20949069

  20. Human mast cell chymase induces the accumulation of neutrophils, eosinophils and other inflammatory cells in vivo

    PubMed Central

    He, Shaoheng; Walls, Andrew F

    1998-01-01

    The roles of chymase in acute allergic responses are not clear, despite the relative abundance of this serine proteinase in the secretory granules of human mast cells. We have isolated chymase to high purity from human skin tissue by heparin-agarose affinity chromatography and Sephacryl S-200 gel filtration procedures, and have investigated the ability of human mast cell chymase to stimulate cell accumulation following injection into laboratory animals.Injection of chymase provoked marked neutrophilia and eosinophilia in the skin of Dunkin Hartley guinea-pigs. Compared with saline injected control animals, there were some 60 fold more neutrophils and 12 fold more eosinophils present at the injection site.Following injection of chymase into the peritoneum of BALB/c mice, there were up to 700 fold more neutrophils, 21 fold more eosinophils, 19 fold more lymphocytes and 7 fold more macrophages recovered than from saline injected controls at 16 h. Doses of chymase as low as 5 ng (1.7×10−13 mole) stimulated an inflammatory infiltrate, and significant neutrophilia was elicited within 3 h.The chymase induced cell accumulation in both the guinea-pig and mouse models was dependent on an intact catalytic site, being reduced by co-injection of proteinase inhibitors or heat inactivation of the enzyme.Co-injection of histamine or heparin significantly reduced the chymase induced neutrophil accumulation, whereas neither histamine nor heparin by themselves had any effect on the accumulation of nucleated cells. No synergistic or antagonist interactions between chymase and tryptase were observed when these two major mast cell proteinases were co-injected into the mouse peritoneum.Our findings suggest that chymase may provide an potent stimulus for inflammatory cell recruitment following mast cell activation. PMID:9884078

  1. Chemiluminescence of neutrophiles stimulated by opsonized Zymosan in children with bronchial asthma and pneumonia

    NASA Astrophysics Data System (ADS)

    Lewandowicz-Uszynska, A.; Jankowski, A.

    2004-08-01

    Oxygen metabolism of neutrophils after stimulation with opsonized zymosan was examined using chemiluminescence test (in the presence of the patient serum or pooled serum). Into the study 37 children aged from 2 to 12 years were enrolled (20 girls and 17 boys). 10 healthy volunteers comprised the control group (group III). Two groups of patients were established: group I -- children with bronchial asthma (without infection), group II -- children with pneumonia. The examination in both groups was performed twice -- in acute phase and in remission period. The group I in acute phase comprised 16 children and in remission phase 9 children, group II - 21 children in acute phase and 9 children in remission phase, respectively. The following parameters of CL were estimated average value of so called spontaneous CL, maximal excitation of neutrophils after stimulation by zymogen (CLmax), time of zymosan opsonization. The following results were obtained: increased spontaneous CL and CLmax (at the presence of both sera) in acute phase of bronchial asthma and pneumonia in comparison to the control group. In the period of remission both these parameters were insignificantly decreased. The longest time of zymosan opsonization in acute period of disease was observed in children with pneumonia (18 min.). This time did not change during remission phase. Only slightly longer time of opsonization was observed in the patients from group I (in exacerbation) (15 min) than in the control group (13,1 min). This time was prolonged in the clinical remission (20 min).

  2. Quantification of heterotypic granule fusion in human neutrophils by imaging flow cytometry

    PubMed Central

    Björnsdottir, Halla; Welin, Amanda; Dahlgren, Claes; Karlsson, Anna; Bylund, Johan

    2015-01-01

    Human neutrophils are filled with intracellular storage organelles, called granules and secretory vesicles, which differ in their content of soluble matrix proteins and membrane-bound molecules. To date, at least four distinct granule/vesicle subsets have been identified. These organelles may secrete their content extracellularly following mobilization to and fusion with the plasma membrane, but some of them may also fuse with internal membrane-enclosed organelles, typically a plasma membrane-derived phagosome. There are also instances where different granules appear to fuse with one another, a process that would enable mixing of their matrix and membrane components. Such granule fusion enables e.g., myeloperoxidase-processing of intragranular oxygen radicals, a key event in the formation of neutrophil extracellular traps (Björnsdottir et al., 2015) [1]. Described herein are data that show the quantification of such heterotypic granule–granule fusion by the use of imaging flow cytometry, a technique that combines flow cytometry with microscopy. The analysis described is based on immunofluorescent staining of established granule markers (lactoferrin and/or NGAL for one granule subset; the specific granules, and CD63 for another granule subset, the azurophil granules) and calculation of a colocalization score for resting and PMA-stimulated neutrophils. PMID:26862586

  3. Bacterial lipopolysaccharides prime human neutrophils for enhanced production of leukotriene B4.

    PubMed Central

    Doerfler, M E; Danner, R L; Shelhamer, J H; Parrillo, J E

    1989-01-01

    Neutrophils can be "primed" for an enhanced respiratory burst by lipopolysaccharide (LPS) in concentrations measurable in patients with septic shock. Leukotriene B4 (LTB4) is the primary eicosanoid product of neutrophils and is felt to be a mediator of host defense and inflammation. We investigated the in vitro effects of LPS on neutrophil production of LTB4 and the omega-oxidation metabolites of LTB4. Incubation of neutrophils with LPS in concentrations ranging from 0.01 to 100 ng/ml did not result in production of LTB4 or metabolites in the absence of a second stimulus. Priming neutrophils with LPS and then stimulating with opsonized zymosan, phorbol-myristate-acetate or a low concentration of the calcium ionophore A23187 resulted in enhanced production of LTB4. LPS priming of neutrophils occurred in a concentration dependent manner. LPS did not result in LTB4 production in response to the chemoattractant peptide FMLP. LPS priming of neutrophils had no effect on cytosolic calcium concentrations of resting or zymosan-stimulated cells. These results suggest that LPS might effect host defense and tissue injury by potentiating the effect of other stimulants on neutrophil production of LTB4. This LPS induced enhancement may represent an important pathogenetic pathway in patients with gram negative sepsis. PMID:2537852

  4. Kinetics of Neutrophils in Mice Exposed to Radiation and/or Granulocyte Colony-Stimulating Factor Treatment

    PubMed Central

    Romero-Weaver, A. L.; Wan, X. S.; Diffenderfer, E. S.; Lin, L.; Kennedy, A. R.

    2014-01-01

    Astronauts have the potential to develop the hematopoietic syndrome as a result of exposure to radiation from a solar particle event (SPE) during exploration class missions. This syndrome is characterized by a reduction in the number of circulating blood cells (cytopenias). In the present study the effects of SPE-like proton and γ radiation on the kinetics of circulating neutrophils were evaluated during a one-month time period using mice as a model system. The results revealed that exposure to a 2 Gy dose of either SPE-like proton or γ radiation significantly decreased the number of circulating neutrophils, with two nadirs observed on day 4 and day 16 postirradiation. Low circulating neutrophil count (neutropenia) is particularly important because it can increase the risk of astronauts developing infections, which can compromise the success of the mission. Thus, two granulocyte colony-stimulating factors (G-CSFs), filgrastim and pegfilgrastim were evaluated as countermeasures for this endpoint. Both forms of G-CSF significantly increased neutrophil counts in irradiated mice, however, the effect of pegfilgrastim was more potent and lasted longer than filgrastim. Using the expression of CD11b, CD18 and the production of reactive oxygen species (ROS) as markers of neutrophil activation, it was determined that the neutrophils in the irradiated mice treated with pegfilgrastim were physiologically active. Thus, these results suggest that pegfilgrastim could be a potential countermeasure for the reduced number of circulating neutrophils in irradiated animals. PMID:23829559

  5. A Lipid Mediator Hepoxilin A3 Is a Natural Inducer of Neutrophil Extracellular Traps in Human Neutrophils

    PubMed Central

    Douda, David N.; Grasemann, Hartmut; Pace-Asciak, Cecil

    2015-01-01

    Pulmonary exacerbations in cystic fibrosis airways are accompanied by inflammation, neutrophilia, and mucous thickening. Cystic fibrosis sputum contains a large amount of uncleared DNA contributed by neutrophil extracellular trap (NET) formation from neutrophils. The exact mechanisms of the induction of NETosis in cystic fibrosis airways remain unclear, especially in uninfected lungs of patients with early cystic fibrosis lung disease. Here we show that Hepoxilin A3, a proinflammatory eicosanoid, and the synthetic analog of Hepoxilin B3, PBT-3, directly induce NETosis in human neutrophils. Furthermore, we show that Hepoxilin A3-mediated NETosis is NADPH-oxidase-dependent at lower doses of Hepoxilin A3, while it is NADPH-oxidase-independent at higher doses. Together, these results demonstrate that Hepoxilin A3 is a previously unrecognized inducer of NETosis in cystic fibrosis lungs and may represent a new therapeutic target for treating cystic fibrosis and other inflammatory lung diseases. PMID:25784781

  6. Type I IFNs induce anti-tumor polarization of tumor associated neutrophils in mice and human.

    PubMed

    Andzinski, Lisa; Kasnitz, Nadine; Stahnke, Stephanie; Wu, Ching-Fang; Gereke, Marcus; von Köckritz-Blickwede, Maren; Schilling, Bastian; Brandau, Sven; Weiss, Siegfried; Jablonska, Jadwiga

    2016-04-15

    The importance of tumor associated neutrophils (TANs) in cancer development is in the meantime well established. Numerous of clinical data document the adverse prognostic effects of neutrophil infiltration in solid tumors. However, certain tumor therapies need functional neutrophils to be effective, suggesting altered neutrophil polarization associated with different outcomes for cancer patients. Therefore, modulation of neutrophilic phenotypes represents a potent therapeutic option, but factors mediating neutrophil polarization are still poorly defined. In this manuscript we provide evidence that type I IFNs alter neutrophilic phenotype into anti-tumor, both in mice and human. In the absence of IFN-β, pro-tumor properties, such as reduced tumor cytotoxicity with low neutrophil extracellular traps (NETs) expression, low ICAM1 and TNF-α expression, dominated neutrophil phenotypes in primary lesion and premetastatic lung. Interestingly, such neutrophils have significantly prolonged life-span. Notably, interferon therapy in mice altered TAN polarization towards anti-tumor N1. Similar changes in neutrophil activation could be observed in melanoma patients undergoing type I IFN therapy. Altogether, these data highlight the therapeutic potential of interferons, suggesting optimization of its clinical use as potent anti-tumor agent. PMID:26619320

  7. Tumor-Associated Neutrophils Show Phenotypic and Functional Divergence in Human Lung Cancer.

    PubMed

    Saha, Shilpi; Biswas, Subhra K

    2016-07-11

    Studies in murine cancer models have demonstrated the phenotypic and functional divergence of neutrophils; however, their role in pro- or anti-tumor responses in human remains elusive. In this issue of Cancer Cell, Singhal et al. report the existence of specialized subsets of neutrophils in human lung cancer with diverging functions. PMID:27411583

  8. Effects of budlein A on human neutrophils and lymphocytes

    PubMed Central

    KNOB, Carollinie Dias; SILVA, Milena; GASPAROTO, Thaís Helena; OLIVEIRA, Carine Ervolino; AMÔR, Nádia Ghinelli; ARAKAWA, Nilton Syogo; COSTA, Fernando Batista; CAMPANELLI, Ana Paula

    2016-01-01

    ABSTRACT Sesquiterpene lactones (SLs) are the active constituents of a variety of medicinal plants used in traditional medicine for the treatment of inflammatory diseases and other ailments. Objective In this study, we evaluated whether budlein A modulates the activation of innate and adaptive immune cells such as neutrophils and lymphocytes. Material and Methods Our research group has investigated several plant species and several compounds have been isolated, identified, and their medical potential evaluated. Budlein A is a SL isolated from the species Aldama buddlejiformis and A. robusta (Asteraceae) and shows anti-inflammatory and anti-nociceptive activities. Advances in understanding how plant-derived substances modulate the activation of innate and adaptive immune cells have led to the development of new therapies for human diseases. Results Budlein A inhibited MPO activity, IL-6, CXCL8, IL-10, and IL-12 production and induces neutrophil apoptosis. In contrast, budlein A inhibited lymphocyte proliferation and IL-2, IL-10, TGF-β, and IFN-γ production, but it did not lead to cell death. Conclusions Collectively, our results indicate that budlein A shows distinct immunomodulatory effects on immune cells. PMID:27383709

  9. Arbutin and decrease of potentially toxic substances generated in human blood neutrophils

    PubMed Central

    Pečivová, Jana; Nosál', Radomír; Sviteková, Klára

    2014-01-01

    Neutrophils, highly motile phagocytic cells, constitute the first line of host defense and simultaneously they are considered to be central cells of chronic inflammation. In combination with standard therapeutic procedures, natural substances are gaining interest as an option for enhancing the effectiveness of treatment of inflammatory diseases. We investigated the effect of arbutin and carvedilol and of their combination on 4β-phorbol-12β-myristate-13α-acetate- stimulated functions of human isolated neutrophils. Cells were preincubated with the drugs tested and subsequently stimulated. Superoxide (with or without blood platelets, in the rate close to physiological conditions [1:50]) and HOCl generation, elastase and myeloperoxidase release were determined spectrophotometrically and phospholipase D activation spectrofluorometrically. The combined effect of arbutin and carvedilol was found to be more effective than the effect of each compound alone. Our study provided evidence supporting the potential beneficial effect of arbutin alone or in combination with carvedilol in diminishing tissue damage by decreasing phospholipase D, myeloperoxidase and elastase activity and by attenuating the generation of superoxide and the subsequently derived reactive oxygen species. The presented data indicate the ability of arbutin to suppress the onset and progression of inflammation. PMID:26109900

  10. Arbutin and decrease of potentially toxic substances generated in human blood neutrophils.

    PubMed

    Pečivová, Jana; Nosál', Radomír; Sviteková, Klára; Mačičková, Tatiana

    2014-12-01

    Neutrophils, highly motile phagocytic cells, constitute the first line of host defense and simultaneously they are considered to be central cells of chronic inflammation. In combination with standard therapeutic procedures, natural substances are gaining interest as an option for enhancing the effectiveness of treatment of inflammatory diseases. We investigated the effect of arbutin and carvedilol and of their combination on 4β-phorbol-12β-myristate-13α-acetate- stimulated functions of human isolated neutrophils. Cells were preincubated with the drugs tested and subsequently stimulated. Superoxide (with or without blood platelets, in the rate close to physiological conditions [1:50]) and HOCl generation, elastase and myeloperoxidase release were determined spectrophotometrically and phospholipase D activation spectrofluorometrically. The combined effect of arbutin and carvedilol was found to be more effective than the effect of each compound alone. Our study provided evidence supporting the potential beneficial effect of arbutin alone or in combination with carvedilol in diminishing tissue damage by decreasing phospholipase D, myeloperoxidase and elastase activity and by attenuating the generation of superoxide and the subsequently derived reactive oxygen species. The presented data indicate the ability of arbutin to suppress the onset and progression of inflammation. PMID:26109900

  11. Neutrophil-mediated damage to human vascular endothelium. Role of cytokine activation.

    PubMed Central

    Westlin, W. F.; Gimbrone, M. A.

    1993-01-01

    Cytokine activation of cultured human vascular endothelial cells renders them hyperadhesive for blood leukocytes. Co-incubation of freshly isolated, unstimulated human blood neutrophils with confluent cytokine-activated human endothelial monolayers for 90 minutes results in extensive endothelial detachment and destruction of monolayer integrity. In contrast, unactivated endothelial monolayers remain intact. Using this in vitro model, we have explored the neutrophil-effector mechanisms involved in this injury. Coincubation in the presence of a serine protease inhibitor (phenylmethylsulfonyl fluoride) or specific elastase inhibitors (Ala-Ala-Pro-Val-chloromethyl ketone or alpha-1-protease inhibitor) markedly diminished injury. In contrast, scavengers or inhibitors of oxygen-derived free radicals (superoxide dismutase, catalase, mannitol, or sodium azide) were not protective. Purified human neutrophil elastase mimicked the effect of the neutrophils suggesting a key role for elastase in the neutrophil-mediated injury in this model. Interfering with direct neutrophil-endothelial cell contact by interposing a microporous barrier insert prevented endothelial cell detachment. Furthermore, this neutrophil-mediated detachment could be inhibited with interleukin-8, an action correlated with a decrease in neutrophil adhesion to activated endothelial monolayers. By defining the role of endothelial activation in neutrophil-mediated injury, this in vitro model may provide useful insights into potential therapeutic interventions designed to prevent disruption of the endothelial barrier function. Images Figure 1 Figure 6 PMID:8424450

  12. GMP-140 binds to a glycoprotein receptor on human neutrophils: Evidence for a lectin-like interaction

    SciTech Connect

    Moore, K.L.; Varki, A.; McEver, R.P. )

    1991-02-01

    GMP-140 is a rapidly inducible receptor for neutrophils and monocytes expressed on activated platelets and endothelial cells. It is a member of the selectin family of lectin-like cell surface molecules that mediate leukocyte adhesion. We used a radioligand binding assay to characterize the interaction of purified GMP-140 with human neutrophils. Unstimulated neutrophils rapidly bound (125I)GMP-140 at 4 degrees C, reaching equilibrium in 10-15 min. Binding was Ca2+ dependent, reversible, and saturable at 3-6 nM free GMP-140 with half-maximal binding at approximately 1.5 nM. Receptor density and apparent affinity were not altered when neutrophils were stimulated with 4 beta-phorbol 12-myristate 13-acetate. Treatment of neutrophils with proteases abolished specific binding of (125I)GMP-140. Binding was also diminished when neutrophils were treated with neuraminidase from Vibrio cholerae, which cleaves alpha 2-3-, alpha 2-6-, and alpha 2-8-linked sialic acids, or from Newcastle disease virus, which cleaves only alpha 2-3- and alpha 2-8-linked sialic acids. Binding was not inhibited by an mAb to the abundant myeloid oligosaccharide, Lex (CD15), or by the neoglycoproteins Lex-BSA and sialyl-Lex-BSA. We conclude that neutrophils constitutively express a glycoprotein receptor for GMP-140, which contains sialic acid residues that are essential for function. These findings support the concept that GMP-140 interacts with leukocytes by a lectin-like mechanism.

  13. EGCG reverses human neutrophil elastase-induced migration in A549 cells by directly binding to HNE and by regulating α1-AT

    NASA Astrophysics Data System (ADS)

    Xiaokaiti, Yilixiati; Wu, Haoming; Chen, Ya; Yang, Haopeng; Duan, Jianhui; Li, Xin; Pan, Yan; Tie, Lu; Zhang, Liangren; Li, Xuejun

    2015-07-01

    Lung carcinogenesis is a complex process that occurs in unregulated inflammatory environment. EGCG has been extensively investigated as a multi-targeting anti-tumor and anti-inflammatory compound. In this study, we demonstrated a novel mechanism by which EGCG reverses the neutrophil elastase-induced migration of A549 cells. We found that neutrophil elastase directly triggered human adenocarcinoma A549 cell migration and that EGCG suppressed the elevation of tumor cell migration induced by neutrophil elastase. We observed that EGCG directly binds to neutrophil elastase and inhibits its enzymatic activity based on the CDOCKER algorithm, MD stimulation by GROMACS, SPR assay and elastase enzymatic activity assay. As the natural inhibitor of neutrophil elastase, α1-antitrypsin is synthesized in tumor cells. We further demonstrated that the expression of α1-antitrypsin was up-regulated after EGCG treatment in neutrophil elastase-treated A549 cells. We preliminarily discovered that the EGCG-mediated induction of α1-antitrypsin expression might be correlated with the regulatory effect of EGCG on the PI3K/Akt pathway. Overall, our results suggest that EGCG ameliorates the neutrophil elastase-induced migration of A549 cells. The mechanism underlying this effect may include two processes: EGCG directly binds to neutrophil elastase and inhibits its enzymatic activity; EGCG enhances the expression of α1-antitrypsin by regulating the PI3K/AKT pathway.

  14. EGCG reverses human neutrophil elastase-induced migration in A549 cells by directly binding to HNE and by regulating α1-AT

    PubMed Central

    Xiaokaiti, Yilixiati; Wu, Haoming; Chen, Ya; Yang, Haopeng; Duan, Jianhui; Li, Xin; Pan, Yan; Tie, Lu; Zhang, Liangren; Li, Xuejun

    2015-01-01

    Lung carcinogenesis is a complex process that occurs in unregulated inflammatory environment. EGCG has been extensively investigated as a multi-targeting anti-tumor and anti-inflammatory compound. In this study, we demonstrated a novel mechanism by which EGCG reverses the neutrophil elastase-induced migration of A549 cells. We found that neutrophil elastase directly triggered human adenocarcinoma A549 cell migration and that EGCG suppressed the elevation of tumor cell migration induced by neutrophil elastase. We observed that EGCG directly binds to neutrophil elastase and inhibits its enzymatic activity based on the CDOCKER algorithm, MD stimulation by GROMACS, SPR assay and elastase enzymatic activity assay. As the natural inhibitor of neutrophil elastase, α1-antitrypsin is synthesized in tumor cells. We further demonstrated that the expression of α1-antitrypsin was up-regulated after EGCG treatment in neutrophil elastase-treated A549 cells. We preliminarily discovered that the EGCG-mediated induction of α1-antitrypsin expression might be correlated with the regulatory effect of EGCG on the PI3K/Akt pathway. Overall, our results suggest that EGCG ameliorates the neutrophil elastase-induced migration of A549 cells. The mechanism underlying this effect may include two processes: EGCG directly binds to neutrophil elastase and inhibits its enzymatic activity; EGCG enhances the expression of α1-antitrypsin by regulating the PI3K/AKT pathway. PMID:26177797

  15. N-acetyl-L-cysteine and cysteine increase intracellular calcium concentration in human neutrophils

    PubMed Central

    Hasan, Md. Ashraful; Ahn, Won-Gyun

    2016-01-01

    N-acetyl-L-cysteine (NAC) and cysteine have been implicated in a number of human neutrophils' functional responses. However, though Ca2+ signaling is one of the key signalings contributing to the functional responses of human neutrophils, effects of NAC and cysteine on intracellular calcium concentration ([Ca2+]i) in human neutrophils have not been investigated yet. Thus, this study was carried out with an objective to investigate the effects of NAC and cysteine on [Ca2+]i in human neutrophils. We observed that NAC (1 µM ~ 1 mM) and cysteine (10 µM ~ 1 mM) increased [Ca2+]i in human neutrophils in a concentration-dependent manner. In NAC pre-supplmented buffer, an additive effect on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced increase in [Ca2+]i in human neutrophils was observed. In Ca2+-free buffer, NAC- and cysteine-induced [Ca2+]i increase in human neutrophils completely disappeared, suggesting that NAC- and cysteine-mediated increase in [Ca2+]i in human neutrophils occur through Ca2+ influx. NAC- and cysteine-induced [Ca2+]i increase was effectively inhibited by calcium channel inhibitors SKF96365 (10 µM) and ruthenium red (20 µM). In Na+-free HEPES, both NAC and cysteine induced a marked increase in [Ca2+]i in human neutrophils, arguing against the possibility that Na+-dependent intracellular uptake of NAC and cysteine is necessary for their [Ca2+]i increasing activity. Our results show that NAC and cysteine induce [Ca2+]i increase through Ca2+ influx in human neutrophils via SKF96365- and ruthenium red-dependent way. PMID:27610031

  16. N-acetyl-L-cysteine and cysteine increase intracellular calcium concentration in human neutrophils.

    PubMed

    Hasan, Md Ashraful; Ahn, Won-Gyun; Song, Dong-Keun

    2016-09-01

    N-acetyl-L-cysteine (NAC) and cysteine have been implicated in a number of human neutrophils' functional responses. However, though Ca(2+) signaling is one of the key signalings contributing to the functional responses of human neutrophils, effects of NAC and cysteine on intracellular calcium concentration ([Ca(2+)]i) in human neutrophils have not been investigated yet. Thus, this study was carried out with an objective to investigate the effects of NAC and cysteine on [Ca(2+)]i in human neutrophils. We observed that NAC (1 µM ~ 1 mM) and cysteine (10 µM ~ 1 mM) increased [Ca(2+)]i in human neutrophils in a concentration-dependent manner. In NAC pre-supplmented buffer, an additive effect on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced increase in [Ca(2+)]i in human neutrophils was observed. In Ca(2+)-free buffer, NAC- and cysteine-induced [Ca(2+)]i increase in human neutrophils completely disappeared, suggesting that NAC- and cysteine-mediated increase in [Ca(2+)]i in human neutrophils occur through Ca(2+) influx. NAC- and cysteine-induced [Ca(2+)]i increase was effectively inhibited by calcium channel inhibitors SKF96365 (10 µM) and ruthenium red (20 µM). In Na(+)-free HEPES, both NAC and cysteine induced a marked increase in [Ca(2+)]i in human neutrophils, arguing against the possibility that Na(+)-dependent intracellular uptake of NAC and cysteine is necessary for their [Ca(2+)]i increasing activity. Our results show that NAC and cysteine induce [Ca(2+)]i increase through Ca(2+) influx in human neutrophils via SKF96365- and ruthenium red-dependent way. PMID:27610031

  17. Formation of Reactive Sulfite-Derived Free Radicals by the Activation of Human Neutrophils: An ESR Study

    PubMed Central

    Ranguelova, Kalina; Rice, Annette B.; Khajo, Abdelahad; Triquigneaux, Mathilde; Garantziotis, Stavros; Magliozzo, Richard S.; Mason, Ronald P.

    2012-01-01

    The objective of the present study is to determine the effect of (bi)sulfite (hydrated sulfur dioxide) on human neutrophils and the ability of these immune cells to produce reactive free radicals due to (bi)sulfite oxidation. Myeloperoxidase (MPO) is an abundant heme protein in neutrophils that catalyzes the formation of cytotoxic oxidants implicated in asthma and inflammatory disorders. In the present study sulfite (•SO3−) and sulfate (SO4•−) anion radicals are characterized with the ESR spin-trapping technique using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) in the reaction of (bi)sulfite oxidation by human MPO and human neutrophils via sulfite radical chain reaction chemistry. After treatment with (bi)sulfite, PMA-stimulated neutrophils produced DMPO-sulfite anion radical, -superoxide, and -hydroxyl radical adducts. The latter adduct probably resulted, in part, from the conversion of DMPO-sulfate to DMPO-hydroxyl radical adduct via a nucleophilic substitution reaction of the radical adduct. This anion radical (SO4•−) is highly reactive and, presumably, can oxidize target proteins to protein radicals, thereby initiating protein oxidation. Therefore, we propose that the potential toxicity of (bi)sulfite during pulmonary inflammation or lung-associated diseases such as asthma may be related to free radical formation. PMID:22326772

  18. Neutrophilic granulocytes modulate invariant NKT cell function in mice and humans.

    PubMed

    Wingender, Gerhard; Hiss, Marcus; Engel, Isaac; Peukert, Konrad; Ley, Klaus; Haller, Hermann; Kronenberg, Mitchell; von Vietinghoff, Sibylle

    2012-04-01

    Invariant NKT (iNKT) cells are a conserved αβTCR(+) T cell population that can swiftly produce large amounts of cytokines, thereby activating other leukocytes, including neutrophilic granulocytes (neutrophils). In this study, we investigated the reverse relationship, showing that high neutrophil concentrations suppress the iNKT cell response in mice and humans. Peripheral Vα14 iNKT cells from spontaneously neutrophilic mice produced reduced cytokines in response to the model iNKT cell Ag α-galactosyl ceramide and expressed lower amounts of the T-box transcription factor 21 and GATA3 transcription factor than did wild-type controls. This influence was extrinsic, as iNKT cell transcription factor expression in mixed chimeric mice depended on neutrophil count, not iNKT cell genotype. Transcription factor expression was also decreased in primary iNKT cells from the neutrophil-rich bone marrow compared with spleen in wild-type mice. In vitro, the function of both mouse and human iNKT cells was inhibited by coincubation with neutrophils. This required cell-cell contact with live neutrophils. Neutrophilic inflammation in experimental peritonitis in mice decreased iNKT cell T-box transcription factor 21 and GATA3 expression and α-galactosyl ceramide-induced cytokine production in vivo. This was reverted by blockade of neutrophil mobilization. Similarly, iNKT cells from the human peritoneal cavity expressed lower transcription factor levels during neutrophilic peritonitis. Our data reveal a novel regulatory axis whereby neutrophils reduce iNKT cell responses, which may be important in shaping the extent of inflammation. PMID:22387552

  19. Neutrophilic granulocytes modulate invariant natural killer T cell function in mice and humans

    PubMed Central

    Wingender, Gerhard; Hiss, Marcus; Engel, Isaac; Peukert, Konrad; Ley, Klaus; Haller, Hermann; Kronenberg, Mitchell; von Vietinghoff, Sibylle

    2012-01-01

    Invariant natural killer T (iNKT) cells are a conserved αβTCR+ T cell population that can swiftly produce large amounts of cytokines, thereby activating other leukocytes, including neutrophilic granulocytes (neutrophils). Here we investigated the reverse relationship, showing that high neutrophil concentrations suppress the iNKT cell response in mice and humans. Peripheral Vα14i NKT cells from spontaneously neutrophilic mice produced reduced cytokines in response to the model iNKT cell antigen αGalCer and expressed lower amounts of the T-bet and GATA3 transcription factors than did wild-type controls. This influence was extrinsic, as iNKT cell transcription factor expression in mixed chimeric mice depended on neutrophil count, not iNKT cell genotype. Transcription factor expression was also decreased in primary iNKT cells from the neutrophil rich bone marrow compared to spleen in wild-type mice. In vitro, the function of both mouse and human iNKT cells was inhibited by co-incubation with neutrophils. This required cell-cell contact with live neutrophils. Neutrophilic inflammation in experimental peritonitis in mice decreasediNKT cell T-bet and GATA3 expression and αGalCer induced cytokine production in vivo. This was reverted by blockade of neutrophil mobilization. Similarly, iNKT cells from the human peritoneal cavity expressed lower transcription factor levels during neutrophilic peritonitis. Our data reveal a novel regulatory axis whereby neutrophils reduce iNKT cell responses, which may be important in shaping the extent of inflammation. PMID:22387552

  20. IL-4 induces adherence of human eosinophils and basophils but not neutrophils to endothelium. Association with expression of VCAM-1.

    PubMed

    Schleimer, R P; Sterbinsky, S A; Kaiser, J; Bickel, C A; Klunk, D A; Tomioka, K; Newman, W; Luscinskas, F W; Gimbrone, M A; McIntyre, B W

    1992-02-15

    The present studies were performed to explore potentially selective mechanisms of leukocyte adhesion in an attempt to understand how preferential recruitment of eosinophils and basophils might occur during allergic and other inflammatory reactions. Stimulation of human vascular endothelial cells for 24 h with IL-4 (30 to 1,000 U/ml) induced adhesion for eosinophils (up to approximately four-fold of control) and basophils (up to approximately twofold of control) but not neutrophils (less than 125% of control). Analysis of endothelial expression of adhesion molecules by flow cytometry revealed that IL-4 treatment induced vascular cell adhesion molecule-1 (VCAM-1) expression without significantly affecting the expression of other adhesion molecules, namely endothelial-leukocyte adhesion molecule-1 (ELAM-1) or intercellular adhesion molecule-1 (ICAM-1). The concentration-response curve for IL-4-induced VCAM-1 expression paralleled that for adhesion. Endothelial cells stimulated with IL-4 expressed adhesive properties for eosinophils by 3 h; the response increased steadily during a 24-h time course study. Eosinophils and basophils adhered to plates coated with a recombinant form of VCAM-1. This adhesion was blocked with antibodies to VCAM-1 but not ELAM-1. mAb directed against either VCAM-1 or VLA-4 inhibited (by approximately 75%) the binding of eosinophils and basophils to IL-4-stimulated endothelial cells. Because VLA-4 and VCAM-1 have been demonstrated to bind to each other in other adhesion systems, these results suggest that IL-4 stimulates eosinophil and basophil adhesion by inducing endothelial cell expression of VCAM-1 which binds to eosinophil and basophil VLA-4. The lack of expression of VLA-4 on neutrophils and the failure of IL-4 to stimulate neutrophil adherence support this conclusion. It is proposed that local release of IL-4 in vivo in allergic diseases or after experimental allergen challenge may partly explain the enrichment of eosinophils and

  1. Effects of Alchornea cordifolia on elastase and superoxide anion produced by human neutrophils.

    PubMed

    Kouakou-Siransy, Gisèle; Sahpaz, Sevser; Nguessan, G Irié; Datté, Jacques Yao; Brou, Jérome Kablan; Gressier, Bernard; Bailleul, François

    2010-02-01

    The ability of Alchornea cordifolia (Schum. and Thonn.) Müll. Arg. (Euphorbiaceae) leaves to inhibit human neutrophil elastase (HNE) and superoxide anion (O(2)(*-)) activities was evaluated on aqueous and ethyl acetate extracts as they allow for a targeted extraction of polyphenols. The direct effect of A. cordifolia extracts on HNE and O(2)(*-) was assessed in an acellular system. Results showed that extracts scavenge HNE and O(2)(*-) in a dose-dependent manner. Better activity was exhibited by the ethyl acetate extract with lower IC(50) (2.2 and 4. 1 mg/L for HNE and O(2)(*-), respectively) than for the aqueous extract. Cellular systems including isolated human polymorphonuclear neutrophils (PMN) were investigated to assess the effect of extracts on PMN metabolism. PMN were stimulated with 4beta-phorbol-12-myristate-13-acetate (PMA), calcium ionophore (CaI), or N-formyl-methionyl-leucine-phenylalanine (fMLP), each stimulant having its own stimulation pathway. From the IC(50) obtained, it can be concluded that A. cordifolia reduces HNE and O(2)(*-) liberation. Furthermore it was demonstrated that A. cordifolia extracts have no cytotoxic activity on PMN by measuring release of the cytosolic enzyme lactate dehydrogenase. As the ethyl acetate extract offers a higher rate of total phenols than the aqueous extract as well as better scavenging activity, it can be supposed that polyphenols, which are well known for their potent antioxidant and antielastase activity, are implicated in the activity of the plant. Phenolic substances such as quercetin, myricetin-3-glucopyranoside, myricetin-3-rhamnopyranoside, and proanthocyanidin A2 were identified in the ethyl acetate extract. In conclusion, the study provides proof of ethnomedical claims and partly explains the mechanisms of the anti-inflammatory action of A. cordifolia leaves. PMID:20645828

  2. Characterization of Neutrophil Function in Human Cutaneous Leishmaniasis Caused by Leishmania braziliensis

    PubMed Central

    Conceição, Jacilara; Davis, Richard; Carneiro, Pedro Paulo; Giudice, Angela; Muniz, Aline C.; Wilson, Mary E.; Carvalho, Edgar M.; Bacellar, Olívia

    2016-01-01

    Infection with different Leishmania spp. protozoa can lead to a variety of clinical syndromes associated in many cases with inflammatory responses in the skin. Although macrophages harbor the majority of parasites throughout chronic infection, neutrophils are the first inflammatory cells to migrate to the site of infection. Whether neutrophils promote parasite clearance or exacerbate disease in murine models varies depending on the susceptible or resistant status of the host. Based on the hypothesis that neutrophils contribute to a systemic inflammatory state in humans with symptomatic L. braziliensis infection, we evaluated the phenotype of neutrophils from patients with cutaneous leishmaniasis (CL) during the course of L. braziliensis infection. After in vitro infection with L. braziliensis, CL patient neutrophils produced more reactive oxygen species (ROS) and higher levels of CXCL8 and CXCL9, chemokines associated with recruitment of neutrophils and Th1-type cells, than neutrophils from control healthy subjects (HS). Despite this, CL patient and HS neutrophils were equally capable of phagocytosis of L. braziliensis. There was no difference between the degree of activation of neutrophils from CL versus healthy subjects, assessed by CD66b and CD62L expression using flow cytometry. Of interest, these studies revealed that both parasite-infected and bystander neutrophils became activated during incubation with L. braziliensis. The enhanced ROS and chemokine production in neutrophils from CL patients reverted to baseline after treatment of disease. These data suggest that the circulating neutrophils during CL are not necessarily more microbicidal, but they have a more pro-inflammatory profile after parasite restimulation than neutrophils from healthy subjects. PMID:27167379

  3. Characterization of Neutrophil Function in Human Cutaneous Leishmaniasis Caused by Leishmania braziliensis.

    PubMed

    Conceição, Jacilara; Davis, Richard; Carneiro, Pedro Paulo; Giudice, Angela; Muniz, Aline C; Wilson, Mary E; Carvalho, Edgar M; Bacellar, Olívia

    2016-05-01

    Infection with different Leishmania spp. protozoa can lead to a variety of clinical syndromes associated in many cases with inflammatory responses in the skin. Although macrophages harbor the majority of parasites throughout chronic infection, neutrophils are the first inflammatory cells to migrate to the site of infection. Whether neutrophils promote parasite clearance or exacerbate disease in murine models varies depending on the susceptible or resistant status of the host. Based on the hypothesis that neutrophils contribute to a systemic inflammatory state in humans with symptomatic L. braziliensis infection, we evaluated the phenotype of neutrophils from patients with cutaneous leishmaniasis (CL) during the course of L. braziliensis infection. After in vitro infection with L. braziliensis, CL patient neutrophils produced more reactive oxygen species (ROS) and higher levels of CXCL8 and CXCL9, chemokines associated with recruitment of neutrophils and Th1-type cells, than neutrophils from control healthy subjects (HS). Despite this, CL patient and HS neutrophils were equally capable of phagocytosis of L. braziliensis. There was no difference between the degree of activation of neutrophils from CL versus healthy subjects, assessed by CD66b and CD62L expression using flow cytometry. Of interest, these studies revealed that both parasite-infected and bystander neutrophils became activated during incubation with L. braziliensis. The enhanced ROS and chemokine production in neutrophils from CL patients reverted to baseline after treatment of disease. These data suggest that the circulating neutrophils during CL are not necessarily more microbicidal, but they have a more pro-inflammatory profile after parasite restimulation than neutrophils from healthy subjects. PMID:27167379

  4. Systemic hypoxia enhances exercise-mediated bactericidal and subsequent apoptotic responses in human neutrophils.

    PubMed

    Wang, Jong-Shyan; Chiu, Ya-Ting

    2009-10-01

    Phagocytosis and oxidative burst are critical host defense mechanisms in which neutrophils clear invading pathogens. Clearing phagocytic neutrophils by triggering apoptosis is an essential process for controlling inflammation. This study elucidates how various exercise bouts with/without hypoxia affected neutrophil bactericidal activity and subsequent apoptosis in humans. Fifteen sedentary males performed six distinct experimental tests in an air-conditioned normobaric hypoxia chamber: two normoxic exercises [strenuous exercise (SE; up to maximal O2 consumption) and moderate exercise (ME; 50% maximal O2 consumption for 30 min) while exposed to 21% O2], two hypoxic exercises (ME for 30 min while exposed to 12% and 15% O2), and two hypoxic exposures (resting for 30 min while exposed to 12% and 15% O2). The results showed that 1) plasma complement-C3a desArg/C4a desArg/C5a concentrations were increased, 2) expressions of L-selectin/lymphocyte functin-associated antigen-1/Mac-1/C5aR on neutrophils were enhanced, 3) phagocytosis of neutrophils to Esherichia coli and release of neutrophil oxidant products by E. coli were elevated, and 4) E. coli-induced phosphotidylserine exposure or caspase-3 activation of neutrophils were promoted immediately and 2 h after both 12% O2 exposure at rest and with ME as well as normoxic SE. Although neither normoxic ME nor breathing 15% O2 at rest influenced these complement- and neutrophil-related immune responses, ME at both 12% and 15% O2 resulted in enhanced complement activation in the blood, expressions of opsonic/complement receptors on neutrophils, or the bactericidal activity and apoptosis of neutrophils. Moreover, the increased neutrophil oxidant production and apoptosis by normoxic SE and hypoxic ME were ameliorated by treating neutrophils with diphenylene iodonium (a NADPH oxidase inhibitor). Therefore, we conclude that ME at 12-15% O2 enhances bactericidal capacity and facilitates the subsequent apoptosis of neutrophils. PMID

  5. Bruton’s Tyrosine Kinase Mediates FcγRIIa/Toll-Like Receptor–4 Receptor Crosstalk in Human Neutrophils

    PubMed Central

    Krupa, Agnieszka; Fudala, Rafal; Florence, Jon M.; Tucker, Torry; Allen, Timothy C.; Standiford, Theodore J.; Luchowski, Rafal; Fol, Marek; Rahman, Moshiur; Gryczynski, Zygmunt; Gryczynski, Ignacy

    2013-01-01

    Previous observations by our laboratory indicate that the presence of anti–IL-8 autoantibody:IL-8 immune complexes in lung fluids from patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) comprises an important prognostic indicator in the development and ultimate outcome of ALI/ARDS. We also showed that these complexes display proinflammatory activity toward neutrophils through the engagement of FcγRIIa receptors. Because sepsis is one of the most common risk factors for ALI/ARDS, the initial goal of our present study involved investigating the effects of LPS on the expression of FcγRIIa receptors in neutrophils. Our results indicate that LPS triggers an increase in the expression of FcγRIIa on the neutrophil surface, which leads to shortening of the molecular distance between FcγRIIa and Toll-like receptor–4 (TLR4). When such neutrophils are stimulated with anti–IL-8:IL-8 complexes, the TLR4 cascade becomes activated via the engagement of FcγRIIa. The underlying molecular mechanism has been subsequently examined and involves Bruton’s tyrosine kinase (Btk). In conclusion, our study reveals the existence of Btk-dependent molecular cooperation between FcγRIIa and TLR4 signaling cascades in LPS-“primed” human neutrophils. Furthermore, we used fluorescence lifetime imaging to study the interactions between TLR4 and FcγRIIa in human alveolar neutrophils from patients with ALI/ARDS. The results from these experiments confirm the existence of the molecular cooperation between TLR4 and FcγRIIa. PMID:23239500

  6. Hevein, an allergenic lectin from rubber latex, activates human neutrophils' oxidative burst.

    PubMed

    Rojas, E; Llinas, P; Rodríguez-Romero, A; Hernández, C; Linares, M; Zenteno, E; Lascurain, R

    2001-04-01

    Hevein is an N-acetyl-D-glucosamine (GlcNAc) specific lectin that has been hypothesized to participate in the IgE-mediated allergic reactions in patients with latex allergy. In this work we assessed the specificity and biological effect of hevein purified from rubber latex on human leukocytes, using epifluorescence microscopy and flow cytometry. Purified human granulocytes were stimulated in vitro with hevein, and production of oxidative radicals was measured by reduction of nitroblue tetrazolium formazan. Histochemical staining and flow cytometry showed that hevein recognizes specifically monocytes (CD14+) and neutrophils (CD16+), but not lymphoid cells. Hevein induced oxidative response in purified granulocytes; this effect was 1.3-1.5-fold higher than the effect observed with the lectin WGA (wheat germ agglutinin), or other lectins with different sugar specificity. The induced reactions and cellular recognition by hevein were inhibited with GlcNAc and its oligomers; as well as by glycoproteins containing tri-and tetra-antennary N-glycosydically linked glycans. Our findings suggest that neutrophils are the main target for latex hevein; this lectin induces production of oxidative radicals, which seem to play an important role in tissue damage during latex allergy. PMID:11788802

  7. Neutrophil-Derived MMP-8 Drives AMPK-Dependent Matrix Destruction in Human Pulmonary Tuberculosis.

    PubMed

    Ong, Catherine W M; Elkington, Paul T; Brilha, Sara; Ugarte-Gil, Cesar; Tome-Esteban, Maite T; Tezera, Liku B; Pabisiak, Przemyslaw J; Moores, Rachel C; Sathyamoorthy, Tarangini; Patel, Vimal; Gilman, Robert H; Porter, Joanna C; Friedland, Jon S

    2015-05-01

    Pulmonary cavities, the hallmark of tuberculosis (TB), are characterized by high mycobacterial load and perpetuate the spread of M. tuberculosis. The mechanism of matrix destruction resulting in cavitation is not well defined. Neutrophils are emerging as key mediators of TB immunopathology and their influx are associated with poor outcomes. We investigated neutrophil-dependent mechanisms involved in TB-associated matrix destruction using a cellular model, a cohort of 108 patients, and in separate patient lung biopsies. Neutrophil-derived NF-kB-dependent matrix metalloproteinase-8 (MMP-8) secretion was up-regulated in TB and caused matrix destruction both in vitro and in respiratory samples of TB patients. Collagen destruction induced by TB infection was abolished by doxycycline, a licensed MMP inhibitor. Neutrophil extracellular traps (NETs) contain MMP-8 and are increased in samples from TB patients. Neutrophils lined the circumference of human pulmonary TB cavities and sputum MMP-8 concentrations reflected TB radiological and clinical disease severity. AMPK, a central regulator of catabolism, drove neutrophil MMP-8 secretion and neutrophils from AMPK-deficient patients secrete lower MMP-8 concentrations. AMPK-expressing neutrophils are present in human TB lung biopsies with phospho-AMPK detected in nuclei. These data demonstrate that neutrophil-derived MMP-8 has a key role in the immunopathology of TB and is a potential target for host-directed therapy in this infectious disease. PMID:25996154

  8. Immobilized immune complexes induce neutrophil extracellular trap release by human neutrophil granulocytes via FcγRIIIB and Mac-1.

    PubMed

    Behnen, Martina; Leschczyk, Christoph; Möller, Sonja; Batel, Tobit; Klinger, Matthias; Solbach, Werner; Laskay, Tamás

    2014-08-15

    Canonical neutrophil antimicrobial effector mechanisms, such as degranulation, production of reactive oxygen species, and release of neutrophil extracellular traps (NETs), can result in severe pathology. Activation of neutrophils through immune complexes (ICs) plays a central role in the pathogenesis of many autoimmune inflammatory diseases. In this study, we report that immobilized ICs (iICs), which are hallmarks of several autoimmune diseases, induce the release of NETs from primary human neutrophils. The iIC-induced NET formation was found to require production of reactive oxygen species by NADPH oxidase and myeloperoxidase and to be mediated by FcγRIIIb. Blocking of the β2 integrin macrophage-1 Ag but not lymphocyte function-associated Ag-1 abolished iIC-induced NET formation. This suggests that FcγRIIIb signals in association with macrophage-1 Ag. As intracellular signaling pathways involved in iIC-induced NET formation we identified the tyrosine kinase Src/Syk pathway, which downstream regulates the PI3K/Akt, p38 MAPK, and ERK1/2 pathways. To our knowledge, the present study shows for the first time that iICs induce NET formation. Thus, we conclude that NETs contribute to pathology in autoimmune inflammatory disorders associated with surface-bound ICs. PMID:25024378

  9. Naturally appearing N-feruloylserotonin isomers suppress oxidative burst of human neutrophils at the protein kinase C level.

    PubMed

    Nosáĺ, Rado; Perečko, Tomáš; Jančinová, Viera; Drábiková, Katarína; Harmatha, Juraj; Sviteková, Klara

    2011-01-01

    N-feruloylserotonin (N-f-5HT) isomers, isolated from seeds of Leuzea carthamoides (Wild) DC, inhibited dose-dependent oxidative burst in human whole blood and isolated neutrophils in vitro, which were measured by luminol- and/or isoluminol-enhanced chemiluminescence in the following rank order of stimuli: PMA > OpZ > calcium ionophore A23187. In isolated neutrophils that were stimulated with PMA, N-f-5HT isomers were effective against extracellular and intracellular reactive oxygen species. Liberation of ATP, analysis of apoptosis, and recombinant caspase-3 activity revealed that N-f-5HT isomers, used in concentrations up to 100 μM, did not alter the viability and integrity of isolated neutrophils. Western blot analysis documented that in concentrations of 10 and 100 μM, N-f-5HT isomers significantly decreased PMA-induced phosphorylation of PKC α/β II. The results suggest that N-f-5HT isomers are an effective, naturally occurring substance with a potent pharmacological effect on the oxidative burst of human neutrophils. It should be further investigated for its pharmacological activity against oxidative stress in ischemia-reperfusion, inflammation and other pathological conditions. PMID:21857090

  10. Neutrophil Elastase-Generated Fragment of Vascular Endothelial Growth Factor-A Stimulates Macrophage and Endothelial Progenitor Cell Migration

    PubMed Central

    Kurtagic, Elma; Rich, Celeste B.; Buczek-Thomas, Jo Ann; Nugent, Matthew A.

    2015-01-01

    Elastase released from neutrophils as part of the innate immune system has been implicated in chronic diseases such as emphysema and cardiovascular disease. We have previously shown that neutrophil elastase targets vascular endothelial growth factor-A (VEGF) for partial degradation to generate a fragment of VEGF (VEGFf) that has distinct activities. Namely, VEGFf binds to VEGF receptor 1 but not to VEGF receptor 2 and shows altered signaling compared to intact VEGF. In the present study we investigated the chemotactic function of VEGF and VEGFf released from cells by neutrophil elastase. We found that endothelial cells migrated in response to intact VEGF but not VEGFf whereas RAW 264.7 macrophages/monocytes and embryonic endothelial progenitor cells were stimulated to migrate by either VEGF or VEGFf. To investigate the role of elastase-mediated release of VEGF from cells/extracellular matrices, a co-culture system was established. High or low VEGF producing cells were co-cultured with macrophages, endothelial or endothelial progenitor cells and treated with neutrophil elastase. Elastase treatment stimulated macrophage and endothelial progenitor cell migration with the response being greater with the high VEGF expressing cells. However, elastase treatment led to decreased endothelial cell migration due to VEGF cleavage to VEGF fragment. These findings suggest that the tissue response to NE-mediated injury might involve the generation of diffusible VEGF fragments that stimulate inflammatory cell recruitment. PMID:26672607

  11. Human neutrophil leukocyte elastase activity is inhibited by Phenol Red

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neutrophil elastase (NE) activity in urine, sputum and nasal mucous is used as an indicator of inflammation due to viral or bacterial infection. However, bovine nasal mucous neutrophils collected, lysed and stored in Dulbecco's minimal medium containing Phenol Red, showed no NE activity with methox...

  12. Phagocytosis and Killing of Carbapenem-Resistant ST258 Klebsiella pneumoniae by Human Neutrophils.

    PubMed

    Kobayashi, Scott D; Porter, Adeline R; Dorward, David W; Brinkworth, Amanda J; Chen, Liang; Kreiswirth, Barry N; DeLeo, Frank R

    2016-05-15

    Carbapenem-resistantKlebsiella pneumoniaestrains classified as multilocus sequence type 258 (ST258) are among the most widespread multidrug-resistant hospital-acquired pathogens. Treatment of infections caused by these organisms is difficult, and mortality is high. The basis for the success of ST258, outside of antibiotic resistance, remains incompletely determined. Here we tested the hypothesis that ST258K. pneumoniaehas enhanced capacity to circumvent killing by human neutrophils, the primary cellular defense against bacterial infections. There was limited binding and uptake of ST258 by human neutrophils, and correspondingly, there was limited killing of bacteria. On the other hand, transmission electron microscopy revealed that any ingested organisms were degraded readily within neutrophil phagosomes, thus indicating that survival in the neutrophil assays is due to limited phagocytosis, rather than to microbicide resistance after uptake. Our findings suggest that enhancing neutrophil phagocytosis is a potential therapeutic approach for treatment of infection caused by carbapenem-resistant ST258K. pneumoniae. PMID:26768252

  13. Comparison of human eosinophil and neutrophil adhesion to endothelial cells under nonstatic conditions. Role of L-selectin.

    PubMed

    Knol, E F; Tackey, F; Tedder, T F; Klunk, D A; Bickel, C A; Sterbinsky, S A; Bochner, B S

    1994-09-01

    To simulate adhesion that occurs under conditions of flow, we investigated the attachment of eosinophils to endothelium under rotational conditions. Tissue-culture plates containing monolayers of HUVEC were placed on a horizontal rotator (80 revolutions per minute (rpm)), and equal numbers of purified human eosinophils or neutrophils were added to separate wells at 4 degrees C. Binding of eosinophils and neutrophils to unstimulated endothelial cells was 15 +/- 3 and 31 +/- 11 cells/four high power fields (HPF), respectively. After preincubation of HUVEC with IL-1 beta (1 ng/ml, 4 h, 37 degrees C), adhesion increased to 56 +/- 4 and 290 +/- 26 cells/four HPF, respectively (p < 0.0002 for both, n = 8-14). Eosinophils with reduced levels of L-selectin (blood eosinophils activated in vitro or eosinophils obtained from bronchoalveolar lavage (BAL) performed after segmental lung allergen challenge of allergic subjects) demonstrated reduced binding under rotating conditions. Several L-selectin Abs inhibited adhesion of eosinophils and neutrophils (e.g., LAM1-3: 43 +/- 14% vs 63 +/- 3% inhibition; LAM1-6: 73 +/- 5% vs 36 +/- 6% inhibition, respectively, n > or = 6). Interestingly, one additional L-selectin Ab, LAM1-11, inhibited eosinophil but not neutrophil adhesion (51 +/- 2% vs 1 +/- 7% inhibition, respectively, n > or = 5). We conclude that eosinophils, like neutrophils, use L-selectin to bind to activated endothelial cells under conditions of flow, although mAb LAM1-11 can selectively inhibit eosinophil attachment to stimulated endothelial cells in vitro, suggesting different functional epitopes on L-selectin among eosinophils and neutrophils. PMID:7519643

  14. New Selective Peptidyl Di(chlorophenyl) Phosphonate Esters for Visualizing and Blocking Neutrophil Proteinase 3 in Human Diseases*

    PubMed Central

    Guarino, Carla; Legowska, Monika; Epinette, Christophe; Kellenberger, Christine; Dallet-Choisy, Sandrine; Sieńczyk, Marcin; Gabant, Guillaume; Cadene, Martine; Zoidakis, Jérôme; Vlahou, Antonia; Wysocka, Magdalena; Marchand-Adam, Sylvain; Jenne, Dieter E.; Lesner, Adam; Gauthier, Francis; Korkmaz, Brice

    2014-01-01

    The function of neutrophil protease 3 (PR3) is poorly understood despite of its role in autoimmune vasculitides and its possible involvement in cell apoptosis. This makes it different from its structural homologue neutrophil elastase (HNE). Endogenous inhibitors of human neutrophil serine proteases preferentially inhibit HNE and to a lesser extent, PR3. We constructed a single-residue mutant PR3 (I217R) to investigate the S4 subsite preferences of PR3 and HNE and used the best peptide substrate sequences to develop selective phosphonate inhibitors with the structure Ac-peptidylP(O-C6H4-4-Cl)2. The combination of a prolyl residue at P4 and an aspartyl residue at P2 was totally selective for PR3. We then synthesized N-terminally biotinylated peptidyl phosphonates to identify the PR3 in complex biological samples. These inhibitors resisted proteolytic degradation and rapidly inactivated PR3 in biological fluids such as inflammatory lung secretions and the urine of patients with bladder cancer. One of these inhibitors revealed intracellular PR3 in permeabilized neutrophils and on the surface of activated cells. They hardly inhibited PR3 bound to the surface of stimulated neutrophils despite their low molecular mass, suggesting that the conformation and reactivity of membrane-bound PR3 is altered. This finding is relevant for autoantibody binding and the subsequent activation of neutrophils in granulomatosis with polyangiitis (formerly Wegener disease). These are the first inhibitors that can be used as probes to monitor, detect, and control PR3 activity in a variety of inflammatory diseases. PMID:25288799

  15. Cytotoxicity towards human endothelial cells, induced by neutrophil myeloperoxidase: protection by ceftazidime

    PubMed Central

    Deby-Dupont, G.; Deby, C.; Jadoul, L.; Vandenberghe, A.; Lamy, M.

    1995-01-01

    We investigated the effects of the antibiotic ceftazidime (CAZ) on the cytolytic action of the neutrophil myeloperoxidase–hydrogen peroxide–chloride anion system (MPO/H2O2/Cl−). In this system, myeloperoxidase catalyses the conversion of H2O2 and CI− to the cytotoxic agent HOCl. Stimulated neutrophils can release MPO into the extracellular environment and then may cause tissue injury through direct endothelial cells lysis. We showed that human umbilical vein endothelial cells (HUVEC) were capable of taking up active MPO. In presence of H2O2 (10−4 M), this uptake was accompanied by cell lysis. The cytolysis was estimated by the release of 51Cr from HUVEC and expressed as an index of cytotoxicity (IC). Dose dependent protection was obtained for CAZ concentrations ranging from 10−5 to 10−3 M;this can be attributed to inactivation of HOCl by the drug. This protection is comparable to that obtained with methionine and histidine, both of which are known to neutralize HOCl. This protection by CAZ could also be attributed to inactivation of H2O2, but when cytolysis was achieved with H2O2 or O2- generating enzymatic systems, no protection by CAZ was observed. Moreover, the peroxidation activity of MPO (action on H2O2) was not affected by CAZ, while CAZ prevented the chlorination activity of MPO (chlorination of monochlorodimedon). So, we concluded that CAZ acts via HOCl inactivation. These antioxidant properties of CAZ may be clinically useful in pathological situations where excessive activation of neutrophils occurs, such as in sepsis. PMID:18475677

  16. Assessment of biological activity of immunoglobulin preparations by using opsonized micro-organisms to stimulate neutrophil chemiluminescence.

    PubMed Central

    Munro, C S; Stanley, P J; Cole, P J

    1985-01-01

    We have used the ability of opsonised bacteria to stimulate luminol enhanced chemiluminescence of human neutrophils to examine the opsonic capabilities of normal and hypogammaglobulinaemic sera for four common bacterial pathogens. Preparations of human immunoglobulin modified for i.v. use have then been compared with unmodified Cohn Fraction II for their effectiveness in improving opsonization when added to antibody deficient sera in vitro. Hypogammaglobulinaemic sera exhibited impaired opsonisation of Haemophilus influenzae, and severely antibody deficient sera also opsonized Streptococcus pneumoniae and Pseudomonas aeruginosa poorly. The opsonization of these organisms was improved by Cohn Fraction II, and by pH 4 and beta-propionolactone treated immunoglobulins, in descending order of effectiveness. Pepsin digested immunoglobulin was inactive, and in some cases impaired opsonic capacity. The opsonisation of Staphylococcus aureus by hypogammaglobulinaemic sera was near normal, and was not improved by any immunoglobulin. This technique, which assesses biological activity of immunoglobulin, is useful in comparing preparations, and may help to establish appropriate dosage and frequency for intravenous immunoglobulin replacement therapy. PMID:3930107

  17. Involvement of Neutrophil Hyporesponse and the Role of Toll-Like Receptors in Human Immunodeficiency Virus 1 Protection

    PubMed Central

    Hernandez, Juan C.; Giraldo, Diana M.; Paul, Stephane; Urcuqui-Inchima, Silvio

    2015-01-01

    Objectives Neutrophils contribute to pathogen clearance through pattern recognition receptors (PRRs) activation. However, the role of PRRs in neutrophils in both HIV-1-infected [HIV-1(+)] and HIV-1-exposed seronegative individuals (HESN) is unknown. Here, a study was carried out to evaluate the level of PRR mRNAs and cytokines produced after activation of neutrophils from HIV-1(+), HESN and healthy donors. Methods The neutrophils were stimulated with specific agonists for TLR2, TLR4 and TLR9 in the presence of HIV-1 particles. Pro-inflammatory cytokine production, expression of neutrophil activation markers and reactive oxygen species (ROS) production were analyzed in neutrophils from HESN, HIV-1(+) and healthy donors (controls). Results We found that neutrophils from HESN presented reduced expression of PRR mRNAs (TLR4, TLR9, NOD1, NOD2, NLRC4 and RIG-I) and reduced expression of cytokine mRNAs (IL-1β, IL-6, IL-18, TNF-α and TGF-β). Moreover, neutrophils from HESN were less sensitive to stimulation through TLR4. Furthermore, neutrophils from HESN challenged with HIV-1 and stimulated with TLR2 and TLR4 agonists, produced significantly lower levels of reactive oxygen species, versus HIV-1(+). Conclusions A differential pattern of PRR expression and release of innate immune factors in neutrophils from HESN is evident. Our results suggest that lower neutrophil activation can be involved in protection against HIV-1 infection. PMID:25785697

  18. Translational control of human neutrophil responses by MNK1.

    PubMed

    Fortin, Carl F; Mayer, Thomas Z; Cloutier, Alexandre; McDonald, Patrick P

    2013-10-01

    A growing number of inflammatory and immune processes in vivo have been shown to be influenced by neutrophil-derived cytokines. Whereas the underlying transcriptional mechanisms are increasingly well understood, the translational regulation of this neutrophil response remains largely unexplored. Here, we show that the MNK1, which participates in translational control in several cell types, is activated in response to physiological neutrophil agonists (LPS, TNF-α) in the cytoplasmic and nuclear compartments. With the use of various pharmacological inhibitors, we found that MNK1 activation takes place downstream of the TAK1-p38 MAPK axis in neutrophils, whereas the MEK/ERK, JNK, PI3K, and PKC pathways are not involved. Pharmacological blockade of MNK1, as well as overexpression experiments, established that cytokine protein synthesis (but not gene expression) is under the control of MNK1 in neutrophils. Likewise, MNK1 inhibition reversed the antiapoptotic effect of LPS and TNF-α in neutrophils, and this was accompanied by a decreased expression of the antiapoptotic protein Mcl-1. Thus, MNK1 appears to be an important regulator of neutrophil responses. Although MNK1 inhibition did not affect protein recruitment to mRNA caps, it decreased the phosphorylation of molecules implicated in translation initiation control, such as S6K, S6, and hyperphosphorylated 4E-BP1. These molecular targets of MNK1 are shared with those of PI3K in neutrophils, and accordingly, MNK1 inhibition partially impaired the belated PI3K/Akt activation elicited by LPS or TNF in these cells. Given the importance of neutrophils and their products in numerous chronic inflammatory disorders, MNK1 could represent an attractive therapeutic target. PMID:23401599

  19. Regulation of platelet-activating factor synthesis in human neutrophils by MAP kinases.

    PubMed

    Baker, Paul R S; Owen, John S; Nixon, Andrew B; Thomas, Leslie N; Wooten, Rhonda; Daniel, Larry W; O'Flaherty, Joseph T; Wykle, Robert L

    2002-10-21

    Human neutrophils (PMN) are potentially a major source of platelet-activating factor (PAF) produced during inflammatory responses. The stimulated synthesis of PAF in PMN is carried out by a phospholipid remodeling pathway involving three enzymes: acetyl-CoA:lyso-PAF acetyltransferase (acetyltransferase), type IV phospholipase A(2) (cPLA(2)) and CoA-independent transacylase (CoA-IT). However, the coordinated actions and the regulatory mechanisms of these enzymes in PAF synthesis are poorly defined. A23187 has been widely used to activate the remodeling pathway, but it has not been shown how closely its actions mimic those of physiological stimuli. Here we address this important problem and compare responses of the three remodeling enzymes and PAF synthesis by intact cells. In both A23187- and N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMN, acetyltransferase activation is blocked by SB 203580, a p38 MAP kinase inhibitor, but not by PD 98059, which blocks activation of the ERKs. In contrast, either agent attenuated cPLA(2) activation. Correlating with these results, SB 203580 decreased stimulated PAF formation by 60%, whereas PD 98059 had little effect. However, the combination of both inhibitors decreased PAF formation to control levels. Although a role for CoA-IT in PAF synthesis is recognized, we did not detect activation of the enzyme in stimulated PMN. CoA-IT thus appears to exhibit full activity in resting as well as stimulated cells. We conclude that the calcium ionophore A23187 and the receptor agonist fMLP both act through common pathways to stimulate PAF synthesis, with p38 MAP kinase regulating acetyltransferase and supplementing ERK activation of cPLA(2). PMID:12379481

  20. Entamoeba histolytica Trophozoites and Lipopeptidophosphoglycan Trigger Human Neutrophil Extracellular Traps.

    PubMed

    Ávila, Eva E; Salaiza, Norma; Pulido, Julieta; Rodríguez, Mayra C; Díaz-Godínez, César; Laclette, Juan P; Becker, Ingeborg; Carrero, Julio C

    2016-01-01

    Neutrophil defense mechanisms include phagocytosis, degranulation and the formation of extracellular traps (NET). These networks of DNA are triggered by several immune and microbial factors, representing a defense strategy to prevent microbial spread by trapping/killing pathogens. This may be important against Entamoeba histolytica, since its large size hinders its phagocytosis. The aim of this study was to determine whether E. histolytica and their lipopeptidophosphoglycan (EhLPPG) induce the formation of NETs and the outcome of their interaction with the parasite. Our data show that live amoebae and EhLPPG, but not fixed trophozoites, induced NET formation in a time and dose dependent manner, starting at 5 min of co-incubation. Although immunofluorescence studies showed that the NETs contain cathelicidin LL-37 in close proximity to amoebae, the trophozoite growth was only affected when ethylene glycol tetra-acetic acid (EGTA) was present during contact with NETs, suggesting that the activity of enzymes requiring calcium, such as DNases, may be important for amoeba survival. In conclusion, E. histolytica trophozoites and EhLPPG induce in vitro formation of human NETs, which did not affect the parasite growth unless a chelating agent was present. These results suggest that NETs may be an important factor of the innate immune response during infection with E. histolytica. PMID:27415627

  1. Oxidation of methionine residues in proteins of activated human neutrophils.

    PubMed Central

    Fliss, H; Weissbach, H; Brot, N

    1983-01-01

    A simple assay for the detection of 35S-labeled methionine sulfoxide residues in proteins is described. The assay, which is based on the ability of CNBr to react with methionine but not with methionine sulfoxide, requires the prelabeling of cellular proteins with [35S]methionine. The assay was used to study the extent of methionine oxidation in newly synthesized proteins of both activated and quiescent human neutrophils. In cells undergoing a phorbol 12-myristate 13-acetate-induced respiratory burst, about 66% of all methionine residues in newly synthesized proteins were oxidized to the sulfoxide derivative, as compared with 9% in cells not treated with the phorbol ester. In contrast, quantitation of methionine sulfoxide content in the total cellular protein by means of amino acid analysis showed that only 22% of all methionine residues were oxidized in activated cells as compared with 9% in quiescent cells. It is proposed that methionine residues in nascent polypeptide chains are more susceptible to oxidation than those in completed proteins. PMID:6580633

  2. Inhibition of Human Neutrophil Elastase by Pentacyclic Triterpenes

    PubMed Central

    Feng, Li; Liu, Xiaoyu; Zhu, Weiliang; Guo, Fujiang; YingchunWu; Wang, Rui; Chen, Kaixian; Huang, Cheng; Li, Yiming

    2013-01-01

    Scope Inhibiting human neutrophil elastase (HNE) is a promising strategy for treating inflammatory lung diseases, such as H1N1 and SARS virus infections. The use of sivelestat, the only clinically registered synthesized HNE inhibitor, is largely limited by its risk of organ toxicity because it irreversibly inhibits HNE. Therefore, potent reversible HNE inhibitors are promising alternatives to sivelestat. Methods and Results An in vitro HNE inhibition assay was employed to screen a series of triterpenes. Six pentacyclic triterpenes, but not tetracyclic triterpenes, significantly inhibited HNE. Of these pentacyclic triterpenes, ursolic acid exhibited the highest inhibitory potency (IC50 = 5.51 µM). The HNE inhibitory activity of ursolic acid was further verified using a mouse model of acute smoke-induced lung inflammation. The results of nuclear magnetic resonance and HNE inhibition kinetic analysis showed that the pentacyclic triterpenes competitively and reversibly inhibited HNE. Molecular docking experiments indicated that the molecular scaffold, 28-COOH, and a double bond at an appropriate location in the pentacyclic triterpenes are important for their inhibitory activity. Conclusion Our results provide insights into the effects of pentacyclic triterpenes on lung inflammatory actions through reversible inhibition of HNE activity. PMID:24376583

  3. Entamoeba histolytica Trophozoites and Lipopeptidophosphoglycan Trigger Human Neutrophil Extracellular Traps

    PubMed Central

    Ávila, Eva E.; Rodríguez, Mayra C.; Díaz-Godínez, César; Laclette, Juan P.; Becker, Ingeborg; Carrero, Julio C.

    2016-01-01

    Neutrophil defense mechanisms include phagocytosis, degranulation and the formation of extracellular traps (NET). These networks of DNA are triggered by several immune and microbial factors, representing a defense strategy to prevent microbial spread by trapping/killing pathogens. This may be important against Entamoeba histolytica, since its large size hinders its phagocytosis. The aim of this study was to determine whether E. histolytica and their lipopeptidophosphoglycan (EhLPPG) induce the formation of NETs and the outcome of their interaction with the parasite. Our data show that live amoebae and EhLPPG, but not fixed trophozoites, induced NET formation in a time and dose dependent manner, starting at 5 min of co-incubation. Although immunofluorescence studies showed that the NETs contain cathelicidin LL-37 in close proximity to amoebae, the trophozoite growth was only affected when ethylene glycol tetra-acetic acid (EGTA) was present during contact with NETs, suggesting that the activity of enzymes requiring calcium, such as DNases, may be important for amoeba survival. In conclusion, E. histolytica trophozoites and EhLPPG induce in vitro formation of human NETs, which did not affect the parasite growth unless a chelating agent was present. These results suggest that NETs may be an important factor of the innate immune response during infection with E. histolytica. PMID:27415627

  4. Genomic modulators of gene expression in human neutrophils.

    PubMed

    Naranbhai, Vivek; Fairfax, Benjamin P; Makino, Seiko; Humburg, Peter; Wong, Daniel; Ng, Esther; Hill, Adrian V S; Knight, Julian C

    2015-01-01

    Neutrophils form the most abundant leukocyte subset and are central to many disease processes. Technical challenges in transcriptomic profiling have prohibited genomic approaches to date. Here we map expression quantitative trait loci (eQTL) in peripheral blood CD16+ neutrophils from 101 healthy European adults. We identify cis-eQTL for 3281 neutrophil-expressed genes including many implicated in neutrophil function, with 450 of these not previously observed in myeloid or lymphoid cells. Paired comparison with monocyte eQTL demonstrates nuanced conditioning of genetic regulation of gene expression by cellular context, which relates to cell-type-specific DNA methylation and histone modifications. Neutrophil eQTL are markedly enriched for trait-associated variants particularly autoimmune, allergy and infectious disease. We further demonstrate how eQTL in PADI4 and NOD2 delineate risk variant function in rheumatoid arthritis, leprosy and Crohn's disease. Taken together, these data help advance understanding of the genetics of gene expression, neutrophil biology and immune-related diseases. PMID:26151758

  5. Genomic modulators of gene expression in human neutrophils

    PubMed Central

    Naranbhai, Vivek; Fairfax, Benjamin P.; Makino, Seiko; Humburg, Peter; Wong, Daniel; Ng, Esther; Hill, Adrian V. S.; Knight, Julian C.

    2015-01-01

    Neutrophils form the most abundant leukocyte subset and are central to many disease processes. Technical challenges in transcriptomic profiling have prohibited genomic approaches to date. Here we map expression quantitative trait loci (eQTL) in peripheral blood CD16+ neutrophils from 101 healthy European adults. We identify cis-eQTL for 3281 neutrophil-expressed genes including many implicated in neutrophil function, with 450 of these not previously observed in myeloid or lymphoid cells. Paired comparison with monocyte eQTL demonstrates nuanced conditioning of genetic regulation of gene expression by cellular context, which relates to cell-type-specific DNA methylation and histone modifications. Neutrophil eQTL are markedly enriched for trait-associated variants particularly autoimmune, allergy and infectious disease. We further demonstrate how eQTL in PADI4 and NOD2 delineate risk variant function in rheumatoid arthritis, leprosy and Crohn's disease. Taken together, these data help advance understanding of the genetics of gene expression, neutrophil biology and immune-related diseases. PMID:26151758

  6. Suilysin Stimulates the Release of Heparin Binding Protein from Neutrophils and Increases Vascular Permeability in Mice.

    PubMed

    Chen, Shaolong; Xie, Wenlong; Wu, Kai; Li, Ping; Ren, Zhiqiang; Li, Lin; Yuan, Yuan; Zhang, Chunmao; Zheng, Yuling; Lv, Qingyu; Jiang, Hua; Jiang, Yongqiang

    2016-01-01

    Most of the deaths that occurred during two large outbreaks of Streptococcus suis infections in 1998 and 2005 in China were caused by streptococcal toxic shock syndrome (STSS), which is characterized by increased vascular permeability. Heparin-binding protein (HBP) is thought to mediate the vascular leakage. The purpose of this study was to investigate the detailed mechanism underlying the release of HBP and the vascular leakage induced by S. suis. Significantly higher serum levels of HBP were detected in Chinese patients with STSS than in patients with meningitis or healthy controls. Suilysin (SLY) is an exotoxin secreted by the highly virulent strain 05ZYH33, and it stimulated the release of HBP from the polymorphonuclear neutrophils and mediated vascular leakage in mice. The release of HBP induced by SLY was caused by a calcium influx-dependent degranulation. Analyses using a pharmacological approach revealed that the release of HBP induced by SLY was related to Toll-like receptor 4, p38 mitogen-activated protein kinase, and the 1-phosphatidylinositol 3-kinase pathway. It was also dependent on a G protein-coupled seven-membrane spanning receptor. The results of this study provide new insights into the vascular leakage in STSS associated with non-Group A streptococci, which could lead to the discovery of potential therapeutic targets for STSS associated with S. suis. PMID:27617009

  7. Suilysin Stimulates the Release of Heparin Binding Protein from Neutrophils and Increases Vascular Permeability in Mice

    PubMed Central

    Chen, Shaolong; Xie, Wenlong; Wu, Kai; Li, Ping; Ren, Zhiqiang; Li, Lin; Yuan, Yuan; Zhang, Chunmao; Zheng, Yuling; Lv, Qingyu; Jiang, Hua; Jiang, Yongqiang

    2016-01-01

    Most of the deaths that occurred during two large outbreaks of Streptococcus suis infections in 1998 and 2005 in China were caused by streptococcal toxic shock syndrome (STSS), which is characterized by increased vascular permeability. Heparin-binding protein (HBP) is thought to mediate the vascular leakage. The purpose of this study was to investigate the detailed mechanism underlying the release of HBP and the vascular leakage induced by S. suis. Significantly higher serum levels of HBP were detected in Chinese patients with STSS than in patients with meningitis or healthy controls. Suilysin (SLY) is an exotoxin secreted by the highly virulent strain 05ZYH33, and it stimulated the release of HBP from the polymorphonuclear neutrophils and mediated vascular leakage in mice. The release of HBP induced by SLY was caused by a calcium influx-dependent degranulation. Analyses using a pharmacological approach revealed that the release of HBP induced by SLY was related to Toll-like receptor 4, p38 mitogen-activated protein kinase, and the 1-phosphatidylinositol 3-kinase pathway. It was also dependent on a G protein-coupled seven-membrane spanning receptor. The results of this study provide new insights into the vascular leakage in STSS associated with non-Group A streptococci, which could lead to the discovery of potential therapeutic targets for STSS associated with S. suis. PMID:27617009

  8. Prostaglandin E2 inhibits apoptosis in human neutrophilic polymorphonuclear leukocytes: role of intracellular cyclic AMP levels.

    PubMed

    Ottonello, L; Gonella, R; Dapino, P; Sacchetti, C; Dallegri, F

    1998-08-01

    Human neutrophilic polymorphonuclear leukocytes (neutrophils) are terminally differentiated cells that die by undergoing apoptosis. At present, the intracellular pathways governing this process are only partially known. In particular, although the adenylate cyclase-dependent generation of cyclic AMP (cAMP) has been implicated in the triggering of apoptosis in lymphoid cells, the role of the intracellular cAMP pathway in neutrophil apoptosis remains controversial. In the present study, we found that two cAMP-elevating agents, prostaglandin E2 (PGE2) and the phosphodiesterase type IV inhibitor RO 20-1724, inhibit neutrophil apoptosis without inducing cell necrosis. When administered in combination, PGE2 and RO 20-1724 displayed additive effects. Moreover, neutrophil apoptosis was inhibited by a membrane-permeable analog of cAMP, dibutyryl-cAMP, in a dose-dependent manner. Finally, treatment of neutrophils with the protein kinase A inhibitor H-89 prevented PGE2- and RO 20-1724-induced inhibition of cell apoptosis. In conclusion, taking into account that PGE2 and other cAMP-elevating agents are well known downregulators of neutrophil functions, our results suggest that conditions favoring a state of functional rest, such as intracellular cAMP elevation, prolong the life span of neutrophils by delaying apoptosis. PMID:9694511

  9. Morphological evidence of neutrophil-tumor cell phagocytosis (cannibalism) in human gastric adenocarcinomas.

    PubMed

    Caruso, R A; Muda, A O; Bersiga, A; Rigoli, L; Inferrera, C

    2002-01-01

    The phenomenon of neutrophil-tumor cell emperipolesis or phagocytosis has been documented by light microscopy in various human carcinomas, but little is known about the cellular pathological processes and the morphological changes involved. In an attempt to clarify the nature of this phenomenon, the authors' ultrastructural studies on the relationships among neutrophils and tumor cells in human gastric carcinomas are reviewed and analyzed. At the electron microscopy level, apoptotic neutrophils were found within vacuoles of adenocarcinoma cells in 2 cases. They showed either early apoptotic morphology with perinuclear chromatin aggregation but cytoplasm integrity or late apoptotic morphology with uniform, collapsed nucleus and tightly packed cytoplasmic granules. A light microscopy review of 200 cases of resected gastric carcinomas identified 22 cases (11%) that were characterized by neutrophil-tumor cell phagocytosis (cannibalism). TUNEL staining confirmed the presence of apoptotic neutrophils within the cytoplasm of the tumor cells. This study provides light and electron microscopic evidence of apoptotic neutrophils phagocytosed by gastric adenocarcinoma cells. The morphological features of neutrophil-tumor cell phagocytosis (cannibalism) would suggest a particular mechanism of tumor-immune escape in human gastric carcinoma. PMID:12396242

  10. Origin and Role of a Subset of Tumor-Associated Neutrophils with Antigen-Presenting Cell Features in Early-Stage Human Lung Cancer.

    PubMed

    Singhal, Sunil; Bhojnagarwala, Pratik S; O'Brien, Shaun; Moon, Edmund K; Garfall, Alfred L; Rao, Abhishek S; Quatromoni, Jon G; Stephen, Tom Li; Litzky, Leslie; Deshpande, Charuhas; Feldman, Michael D; Hancock, Wayne W; Conejo-Garcia, Jose R; Albelda, Steven M; Eruslanov, Evgeniy B

    2016-07-11

    Based on studies in mouse tumor models, granulocytes appear to play a tumor-promoting role. However, there are limited data about the phenotype and function of tumor-associated neutrophils (TANs) in humans. Here, we identify a subset of TANs that exhibited characteristics of both neutrophils and antigen-presenting cells (APCs) in early-stage human lung cancer. These APC-like "hybrid neutrophils," which originate from CD11b(+)CD15(hi)CD10(-)CD16(low) immature progenitors, are able to cross-present antigens, as well as trigger and augment anti-tumor T cell responses. Interferon-γ and granulocyte-macrophage colony-stimulating factor are requisite factors in the tumor that, working through the Ikaros transcription factor, synergistically exert their APC-promoting effects on the progenitors. Overall, these data demonstrate the existence of a specialized TAN subset with anti-tumor capabilities in human cancer. PMID:27374224

  11. Neutrophil activation during acetaminophen hepatotoxicity and repair in mice and humans

    SciTech Connect

    Williams, C. David; Bajt, Mary Lynn; Sharpe, Matthew R.; McGill, Mitchell R.; Farhood, Anwar; Jaeschke, Hartmut

    2014-03-01

    Following acetaminophen (APAP) overdose there is an inflammatory response triggered by the release of cellular contents from necrotic hepatocytes into the systemic circulation which initiates the recruitment of neutrophils into the liver. It has been demonstrated that neutrophils do not contribute to APAP-induced liver injury, but their role and the role of NADPH oxidase in injury resolution are controversial. C57BL/6 mice were subjected to APAP overdose and neutrophil activation status was determined during liver injury and liver regeneration. Additionally, human APAP overdose patients (ALT: > 800 U/L) had serial blood draws during the injury and recovery phases for the determination of neutrophil activation. Neutrophils in the peripheral blood of mice showed an increasing activation status (CD11b expression and ROS priming) during and after the peak of injury but returned to baseline levels prior to complete injury resolution. Hepatic sequestered neutrophils showed an increased and sustained CD11b expression, but no ROS priming was observed. Confirming that NADPH oxidase is not critical to injury resolution, gp91{sup phox}−/− mice following APAP overdose displayed no alteration in injury resolution. Peripheral blood from APAP overdose patients also showed increased neutrophil activation status after the peak of liver injury and remained elevated until discharge from the hospital. In mice and humans, markers of activation, like ROS priming, were increased and sustained well after active liver injury had subsided. The similar findings between surviving patients and mice indicate that neutrophil activation may be a critical event for host defense or injury resolution following APAP overdose, but not a contributing factor to APAP-induced injury. - Highlights: • Neutrophil (PMN) function increases during liver repair after acetaminophen overdose. • Liver repair after acetaminophen (APAP)-overdose is not dependent on NADPH oxidase. • Human PMNs do not appear

  12. Ozone effects on inhibitors of human neutrophil proteinases

    SciTech Connect

    Smith, C.E.; Stack, M.S.; Johnson, D.A.

    1987-02-15

    The effects of ozone on human alpha 1-proteinase inhibitor (A-1-PI), alpha 1-antichymotrypsin (A-1-Achy), bronchial leukocyte proteinase inhibitor (BLPI), and Eglin C were studied using in vitro exposures in phosphate-buffered solutions. Following ozone exposure, inhibitory activities against human neutrophil elastase (HNE) and/or cathepsin G (Cat G) were measured. Exposure of A-1-PI to 50 mol O3/mol protein resulted in a complete loss of HNE inhibitory activity, whereas A-1-Achy lost only 50% of its Cat G inhibitory activity and remained half active even after exposure to 250 mol of O3. At 40 mol O3/mol protein, BLPI lost 79% of its activity against HNE and 87% of its Cat G inhibitory activity. Eglin C, a leech-derived inhibitor, lost 81% of its HNE inhibitory activity and 92% of its ability to inhibit Cat G when exposed to 40 mol O3/mol. Amino acid analyses of ozone-exposed inhibitors showed destruction of Trp, Met, Tyr, and His with as little as 10 mol O3/mol protein, and higher levels of O3 resulted in more extensive oxidation of susceptible residues. The variable ozone susceptibility of the different amino acid residues in the four proteins indicated that oxidation was a function of protein structure, as well as the inherent susceptibility of particular amino acids. Exposure of A-1-PI and BLPI in the presence of the antioxidants, Trolox C (water soluble vitamin E) and ascorbic acid (vitamin C), showed that antioxidant vitamins may protect proteins from oxidative inactivation by ozone. Methionine-specific modification of BLPI reduced its HNE and Cat G inhibitory activities. Two moles of N-chlorosuccinimide per mole of BLPI methionine caused an 80% reduction in activity against Cat G, but only a 40% reduction in HNE inhibitory activity.

  13. Subcellular location and properties of bactericidal factors from human neutrophils.

    PubMed

    Gabay, J E; Heiple, J M; Cohn, Z A; Nathan, C F

    1986-11-01

    We examined the subcellular location of bactericidal factors (BF) in human neutrophils, using an efficient fractionation scheme. Nitrogen bomb cavitates of DIFP-treated PMN were centrifuged through discontinuous Percoll gradients, each fraction extracted with 0.05 M glycine, pH 2.0, and tested for the killing of Escherichia coli. greater than 90% of BF coisolated with the azurophil granules. After lysis of azurophils, 98% of azurophil-derived BF (ADBF) sedimented with the membrane. ADBF activity was solubilized from azurophil membrane with either acid or nonionic detergent (Triton X-100, Triton X-114). Bactericidal activity was linear with respect to protein concentration over the range 0.3-30 micrograms/ml. 0.1-0.3 microgram/ml ADBF killed 10(5) E. coli within 30 min at 37 degrees C. At 1.4 micrograms/ml, 50% of 2 X 10(5) bacteria were killed within 5 min. ADBF was effective between pH 5-8, with peak activity at pH 5.5. Glucose (20 mM), EDTA (1-25 mM), and physiologic concentrations of NaCl or KCl had little or no inhibitory effect on ADBF. ADBF killed both Gram-positive and Gram-negative virulent clinical isolates, including listeria, staphylococci, beta-hemolytic streptococci, and Pseudomonas aeruginosa. Thus, under these conditions of cell disruption, fractionation, extraction, and assay, almost all BF in human PMN appeared to be localized to the membrane of azurophilic granules as a highly potent, broad-spectrum, rapidly acting protein(s) effective in physiologic medium. Some of these properties appear to distinguish ADBF from previously described PMN bactericidal proteins. PMID:3772295

  14. Detection of Human Neutrophil Elastase with Fluorescent Peptide Sensors Conjugated to Nanocellulosic Solid Supports Targeting Wound Care Diagnostics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human neutrophil elastase (HNE) is a biomarker for chronic wounds and a therapeutic target for certain diseases. An unchecked influx of neutrophils, which contain about one pictogram of elastase per neutrophil, is responsible for degrading growth factors and collagen formation, indefinitely delaying...

  15. Gamma-melanocyte-stimulating hormone-like immunoreactivity in blood cells of human eosinophilic patients.

    PubMed

    Johansson, O; Virtanen, M; Hilliges, M; Hansson, L O

    1991-01-01

    The immunohistochemical localization of the peptide gamma-melanocyte-stimulating hormone (gamma-MSH) within human polymorphonuclear leucocytes of blood from eosinophilic patients is described. The gamma-MSH immunoreactivity was observed only in neutrophilic granulocytes leaving all other cell types immuno-negative. PMID:1805488

  16. Human neutrophil elastase regulates the expression and secretion of elafin (elastase-specific inhibitor) in type II alveolar epithelial cells.

    PubMed

    Reid, P T; Marsden, M E; Cunningham, G A; Haslett, C; Sallenave, J M

    1999-08-20

    Elafin is a low molecular weight antiproteinase believed to be important in the regulation of elastase mediated tissue damage. The expression of elafin is known to be regulated by proinflammatory cytokines such as interleukin-1 beta and tumour necrosis factor but little was known regarding the effect of human neutrophil elastase (HNE). Employing a chloramphenicol acetyltransferase reporter construct of the human elafin gene, reverse transcription PCR from total cellular RNA and ELISA techniques, we have examined the effect of human neutrophil elastase on the transcription and secretion of human elafin in the pulmonary epithelial A549 cell line. Stimulation with HNE at concentrations of 10(-10) and 10(-11) M resulted in a significant upregulation of elafin promoter activity. Similarly, transcription of the endogenous human elafin gene was upregulated with HNE concentrations ranging from 10(-10) to 10(-12) M. In addition, we demonstrate that stimulation with HNE at concentrations ranging from 10(-9) and 10(-12) M resulted in a significant reduction in the secreted elafin protein as measured in the cell supernatant. These results provide further evidence for a role of elafin in the regulation of HNE driven proteolysis of the extracellular matrix. PMID:10486558

  17. Macrophages cultured in vitro release leukotriene B4 and neutrophil attractant/activation protein (interleukin 8) sequentially in response to stimulation with lipopolysaccharide and zymosan.

    PubMed Central

    Rankin, J A; Sylvester, I; Smith, S; Yoshimura, T; Leonard, E J

    1990-01-01

    The capacity of lipopolysaccharide (LPS), zymosan, and calcium ionophore A23187 to induce neutrophil chemotactic activity (NCA), leukotriene B4 (LTB4), and neutrophil attractant/activation protein (NAP-1) release from human alveolar macrophages (AM) retrieved from normal nonsmokers was evaluated. LPS induced a dose-dependent release of LTB4 that began by 1 h, 4.0 +/- 3.2 ng/10(6) viable AM; peaked at 3 h, 24.7 +/- 13.5 ng/10(6) viable AM; and decreased by 24 h, 1.2 +/- 1.0 ng/10(6) viable AM (n = 8). Quantities of LTB4 in cell-free supernatants of AM stimulated with LPS were determined by reverse-phase high-performance liquid chromatography and corresponded well with results obtained by radioimmunoassay. By contrast, NAP-1 release began approximately 3-5 h after stimulation of AM with LPS, 197 +/- 192 ng/ml, and peaked at 24 h, 790 +/- 124 ng/ml. Release of NAP-1 was stimulus specific because A23187 evoked the release of LTB4 but not NAP-1, whereas LPS and zymosan induced the release of both LTB4 and NAP-1. The appearance of neutrophil chemotactic activity in supernatants of AM challenged with LPS for 3 h could be explained completely by the quantities of LTB4 present. After stimulation with LPS or zymosan for 24 h, AM had metabolized almost all generated LTB4. Preincubation of AM with nordihydroguiaretic acid (10(-4) M) completely abolished the appearance of NCA, LTB4, and NAP-1 in supernatants of AM challenged with LPS. Therefore, LPS and zymosan particles were potent stimuli of the sequential release of LTB4 and NAP-1 from AM. PMID:2173722

  18. Recognition of an endothelial determinant for CD 18-dependent human neutrophil adherence and transendothelial migration.

    PubMed Central

    Smith, C W; Rothlein, R; Hughes, B J; Mariscalco, M M; Rudloff, H E; Schmalstieg, F C; Anderson, D C

    1988-01-01

    Human neutrophil (PMN) attachment to human umbilical vein endothelial cells (HUVEC) was evaluated in vitro using two MAbs, R6-5-D6 and RR1/1, that recognize intercellular adhesion molecule-1 (ICAM-1), and one MAb, TS1/18, that recognizes CD18. Pretreatment of the HUVEC with anti-ICAM-1 MAbs produced greater than 50% inhibition of attachment to HUVEC, and IL-1 (0.5 U/ml)- or lipopolysaccharide (LPS) (10 ng/ml)-stimulated HUVEC, and greater than 99% inhibition of f-Met-Leu-Phe (0.5 nM) enhanced adherence. Anti-ICAM-1 MAbs also inhibited by greater than 85% the transendothelial migration induced by 4-h IL-1 (0.5 U/ml) and LPS (10 ng/ml) activation of the HUVEC. That these effects involved a CD18-dependent mechanism is supported by the following results: pretreatment of PMN with TS1/18 produced the same degree of inhibition of attachment and migration as seen with R6-5-D6. In addition, the use of both MAbs together did not further increase the inhibition of cell attachment to stimulated HUVEC. The attachment of PMN from patients with CD18 deficiency to stimulated HUVEC was not reduced by R6-5-D6, and both R6-5-D6 and TS1/18 revealed the same time course for appearance and disappearance of an adherence component on stimulated HUVEC not blocked by either MAb. These results demonstrate that attachment and transendothelial migration of PMN in vitro depend substantially on both CD18 on the PMN and ICAM-1 on the endothelial cell. Images PMID:2903180

  19. B–helper neutrophils stimulate immunoglobulin diversification and production in the marginal zone of the spleen

    PubMed Central

    Puga, Irene; Cols, Montserrat; Barra, Carolina M.; He, Bing; Cassis, Linda; Gentile, Maurizio; Comerma, Laura; Chorny, Alejo; Shan, Meimei; Xu, Weifeng; Magri, Giuliana; Knowles, Daniel M.; Tam, Wayne; Chiu, April; Bussel, James B; Serrano, Sergi; Lorente, José Antonio; Bellosillo, Beatriz; Lloreta, Josep; Juanpere, Nuria; Alameda, Francesc; Baró, Teresa; de Heredia, Cristina Díaz; Torán, Núria; Català, Albert; Torrebadell, Montserrat; Fortuny, Claudia; Cusi, Victoria; Carreras, Carmen; Diaz, George A.; Blander, J. Magarian; Farber, Claire-Michèle; Silvestri, Guido; Cunningham-Rundles, Charlotte; Calvillo, Michaela; Dufour, Carlo; Notarangelo, Lucia Dora; Lougaris, Vassilios; Plebani, Alessandro; Casanova, Jean-Laurent; Ganal, Stephanie C.; Diefenbach, Andreas; Aróstegui, Juan Ignacio; Juan, Manel; Yagüe, Jordi; Mahlaoui, Nizar; Donadieu, Jean; Chen, Kang; Cerutti, Andrea

    2011-01-01

    Neutrophils utilize immunoglobulins (Igs) to clear antigen, but their role in Ig production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T-independent Ig responses to circulating antigen. Neutrophils colonized peri-MZ areas after post-natal mucosal colonization by microbes and enhanced their B-helper function upon receiving reprogramming signals from splenic sinusoidal endothelial cells, including interleukin 10 (IL-10). Splenic neutrophils induced Ig class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism involving the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and less preimmune Igs to T-independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial Ig defense by interacting with MZ B cells. PMID:22197976

  20. Ticagrelor potentiates adenosine-induced stimulation of neutrophil chemotaxis and phagocytosis.

    PubMed

    Alsharif, Khalaf F; Thomas, Mark R; Judge, Heather M; Khan, Haroon; Prince, Lynne R; Sabroe, Ian; Ridger, Victoria C; Storey, Robert F

    2015-08-01

    In the PLATO study, ticagrelor was associated with fewer pulmonary infections and subsequent deaths than clopidogrel. Neutrophils are a first-line defence against bacterial lung infection; ticagrelor inhibits cellular uptake of adenosine, a known regulator of neutrophil chemotaxis and phagocytosis. We assessed whether the inhibition of adenosine uptake by ticagrelor influences neutrophil chemotaxis and phagocytosis. Neutrophils and erythrocytes were isolated from healthy volunteers. Concentration-dependent effects of adenosine on IL-8-induced neutrophil chemotaxis were investigated and the involved receptors identified using adenosine receptor antagonists. The modulatory effects of ticagrelor on adenosine-mediated changes in neutrophil chemotaxis and phagocytosis of Streptococcus pneumoniae were determined in the presence of erythrocytes to replicate physiological conditions of cellular adenosine uptake. Low-concentration adenosine (10(-8)M) significantly increased IL-8-induced neutrophil chemotaxis (% neutrophil chemotaxis: adenosine 28.7%±4.4 vs. control 22.6%±2.4; p<0.01) by acting on the high-affinity A1 receptor. Erythrocytes attenuated the effect of adenosine, although this was preserved by ticagrelor and dipyridamole (another inhibitor of adenosine uptake) but not by control or by cangrelor. Similarly, in the presence of erythrocytes, a low concentration of adenosine (10(-8)M) significantly increased neutrophil phagocytic index compared to control when ticagrelor was present (37.6±6.6 vs. 28.0±6.6; p=0.028) but had no effect in the absence of ticagrelor. We therefore conclude that the inhibition of cellular adenosine reuptake by ticagrelor potentiates the effects of a nanomolar concentration of adenosine on neutrophil chemotaxis and phagocytosis. This represents a potential mechanism by which ticagrelor could influence host defence against bacterial lung infection. PMID:25869515

  1. Ticagrelor potentiates adenosine-induced stimulation of neutrophil chemotaxis and phagocytosis

    PubMed Central

    Alsharif, Khalaf F.; Thomas, Mark R.; Judge, Heather M.; Khan, Haroon; Prince, Lynne R.; Sabroe, Ian; Ridger, Victoria C.; Storey, Robert F.

    2015-01-01

    In the PLATO study, ticagrelor was associated with fewer pulmonary infections and subsequent deaths than clopidogrel. Neutrophils are a first-line defence against bacterial lung infection; ticagrelor inhibits cellular uptake of adenosine, a known regulator of neutrophil chemotaxis and phagocytosis. We assessed whether the inhibition of adenosine uptake by ticagrelor influences neutrophil chemotaxis and phagocytosis. Neutrophils and erythrocytes were isolated from healthy volunteers. Concentration-dependent effects of adenosine on IL-8-induced neutrophil chemotaxis were investigated and the involved receptors identified using adenosine receptor antagonists. The modulatory effects of ticagrelor on adenosine-mediated changes in neutrophil chemotaxis and phagocytosis of Streptococcus pneumoniae were determined in the presence of erythrocytes to replicate physiological conditions of cellular adenosine uptake. Low-concentration adenosine (10− 8 M) significantly increased IL-8-induced neutrophil chemotaxis (% neutrophil chemotaxis: adenosine 28.7% ± 4.4 vs. control 22.6% ± 2.4; p < 0.01) by acting on the high-affinity A1 receptor. Erythrocytes attenuated the effect of adenosine, although this was preserved by ticagrelor and dipyridamole (another inhibitor of adenosine uptake) but not by control or by cangrelor. Similarly, in the presence of erythrocytes, a low concentration of adenosine (10− 8 M) significantly increased neutrophil phagocytic index compared to control when ticagrelor was present (37.6 ± 6.6 vs. 28.0 ± 6.6; p = 0.028) but had no effect in the absence of ticagrelor. We therefore conclude that the inhibition of cellular adenosine reuptake by ticagrelor potentiates the effects of a nanomolar concentration of adenosine on neutrophil chemotaxis and phagocytosis. This represents a potential mechanism by which ticagrelor could influence host defence against bacterial lung infection. PMID:25869515

  2. Whole blood human neutrophil trafficking in a microfluidic model of infection and inflammation.

    PubMed

    Hamza, Bashar; Irimia, Daniel

    2015-06-21

    Appropriate inflammatory responses to wounds and infections require adequate numbers of neutrophils arriving at injury sites. Both insufficient and excessive neutrophil recruitment can be detrimental, favouring systemic spread of microbes or triggering severe tissue damage. Despite its importance in health and disease, the trafficking of neutrophils through tissues remains difficult to control and the mechanisms regulating it are insufficiently understood. These mechanisms are also complex and difficult to isolate using traditional in vivo models. Here we designed a microfluidic model of tissue infection/inflammation, in which human neutrophils emerge from a droplet-size samples of whole blood and display bi-directional traffic between this and micro-chambers containing chemoattractant and microbe-like particles. Two geometrical barriers restrict the entrance of red blood cells from the blood to the micro-chambers and simulate the mechanical function of the endothelial barrier separating the cells in blood from cells in tissues. We found that in the presence of chemoattractant, the number of neutrophils departing the chambers by retrotaxis is in dynamic equilibrium with the neutrophils recruited by chemotaxis. We also found that in the presence of microbe-like particles, the number of neutrophils trapped in the chambers is proportional to the number of particles. Together, the dynamic equilibrium between migration, reversed-migration and trapping processes determine the optimal number of neutrophils at a site. These neutrophils are continuously refreshed and responsive to the number of microbes. Further studies using this infection-inflammation-on-a-chip-model could help study the processes of inflammation resolution. The new in vitro experimental tools may also eventually help testing new therapeutic strategies to limit neutrophil accumulation in tissues during chronic inflammation, without increasing the risk for infections. PMID:25987163

  3. Mechanism Underlying Levofloxacin Uptake by Human Polymorphonuclear Neutrophils

    PubMed Central

    Vazifeh, Doina; Bryskier, André; Labro, Marie-Thérèse

    1999-01-01

    The mechanism of radiolabeled levofloxacin ([3H]levofloxacin) uptake by human polymorphonuclear neutrophils (PMNs) was investigated by a classical velocity centrifugation technique. PMNs were incubated with levofloxacin for 5 to 180 min under various conditions before centrifugation through an oil cushion. Radioactivity was measured in the cell pellet to determine the amount of cell-associated drug. The uptake of levofloxacin was moderate with a cellular concentration/extracellular concentration ratio of about 4 to 6. Levofloxacin accumulated in PMNs parallel to the extracellular concentration, without saturation, over the range of 2.5 to 200 mg/liter (linear regression analysis: r = 0.92; P < 0.001). The activation energy was low (36 ± 7.2 kJ/mol). Levofloxacin uptake was increased in Ca2+-depleted, EGTA-containing medium by approximately 33% (P = 0.022), while Ni2+, a Ca2+ channel inhibitor, inhibited it in a concentration-dependent manner, with the concentration that inhibited 50% of control uptake being approximately 2.65 mM. Verapamil (an l-type Ca2+ channel inhibitor) and other pharmacologic agents which modify Ca2+ homeostasis did not modify levofloxacin uptake. Interestingly, Ca2+ and Mg2+ inhibited levofloxacin uptake in a concentration-dependent manner. EGTA, Ni2+, and verapamil did not modify levofloxacin efflux; thapsigargin, a Ca2+ pool-releasing agent, modestly increased the intracellular retention of levofloxacin. In addition, contrary to other fluoroquinolones, probenecid at 1 to 10 mM did not modify either levofloxacin uptake or efflux. These data are consistent with a mechanism of passive accumulation of levofloxacin in PMNs. Extracellular Ca2+ and Mg2+ may influence the structural conformation of levofloxacin or the lipophilicity of PMN membranes, thus explaining their effect on levofloxacin uptake. PMID:9925513

  4. NSP4, an elastase-related protease in human neutrophils with arginine specificity.

    PubMed

    Perera, Natascha C; Schilling, Oliver; Kittel, Heike; Back, Walter; Kremmer, Elisabeth; Jenne, Dieter E

    2012-04-17

    Neutrophil serine proteases (NSPs) in cytoplasmic granules of neutrophils are regarded as important antimicrobial defense weapons after engulfment and exposure of pathogens to the content of primary granules. Despite intensive studies on neutrophils during the last three decades, only three active serine proteases, neutrophil elastase (NE), cathepsin G (CG), and proteinase 3 (PR3) have been identified in these short-lived cells. Here, we report on the identification of a fourth serine protease (NSP4) with 39% identity to NE and PR3, but arginine specificity, yet sharing features like propeptide processing by dipeptidyl peptidase I, storage, and release as an active enzyme with the three active proteases. We established monoclonal antibodies against NSP4, excluded cross-reactivity to human granzymes, NE, CG, PR3, and azurocidin, and screened for NSP4 protein expression in various human tissues and blood leukocyte populations. Only granulocyte precursors and neutrophil populations from peripheral blood were positive. The content of NSP4 in neutrophil lysates, however, was about 20-fold lower compared with CG. Upon neutrophil activation, NSP4 was released into the supernatant. Profiling its specificity with peptide libraries from Escherichia coli revealed a preference for arginine in P1; it cleaved Tyr-Arg-Phe-Arg-AMC and Ala-Pro-Nva-thiobenzyl esters. NSP4 was inhibited by α(1)-proteinase inhibitor (α(1)-antitrypsin), C1 inhibitor, and most efficiently by antithrombin-heparin, but not by elafin, secretory leukocyte protease inhibitor, α(1)-antichymotrypsin, and monocyte-neutrophil elastase inhibitor. Functional specialization and preferred natural substrates of NSP4 remain to be determined to understand the biological interplay of all four NSPs during neutrophil responses. PMID:22474388

  5. Secretory leukocyte proteinase inhibitor is a major leukocyte elastase inhibitor in human neutrophils.

    PubMed

    Sallenave, J M; Si Tahar, M; Cox, G; Chignard, M; Gauldie, J

    1997-06-01

    Secretory leukocyte proteinase inhibitor (SLPI) is the main neutrophil elastase (HLE) inhibitor found in the upper airways during pulmonary inflammation. It has been shown to be synthesized and secreted in vitro by epithelial cells and has been localized in tracheal glands and bronchiolar epithelial cells by immunocytochemistry. In this study, using immunodetection and immunopurification techniques with specific anti-SLPI immunoglobulin G (IgG), we show that SLPI is present as a native 14-kDa molecule in neutrophil cytosol. In addition, we demonstrate that SLPI is the major inhibitor of HLE present in neutrophil cytosol because pre-incubation with specific anti-SLPI IgG was able to inhibit completely the anti-HLE activity of the cytosol. SLPI can be secreted (probably in an inactive form) by neutrophils and its secretion is enhanced when the cells are stimulated with phorbol myristate acetate (PMA). Elafin, an elastase-specific inhibitor, is also present in minute amounts in neutrophil cytosol and its secretion can be up-regulated. The presence of SLPI in the cytosol of neutrophils may serve as a protective screen against proteinases spilling from azurophilic granules. An alternative or supplementary role may be the maintenance of a differentiated phenotype. PMID:9201260

  6. Infectious Progeny of 2009 A (H1N1) Influenza Virus Replicated in and Released from Human Neutrophils.

    PubMed

    Zhang, Zhang; Huang, Tao; Yu, Feiyuan; Liu, Xingmu; Zhao, Conghui; Chen, Xueling; Kelvin, David J; Gu, Jiang

    2015-01-01

    Various reports have indicated that a number of viruses could infect neutrophils, but the multiplication of viruses in neutrophils was abortive. Based on our previous finding that avian influenza viral RNA and proteins were present in the nucleus of infected human neutrophils in vivo, we investigated the possibility of 2009 A (H1N1) influenza viral synthesis in infected neutrophils and possible release of infectious progeny from host cells. In this study we found that human neutrophils in vitro without detectable level of sialic acid expression could be infected by this virus strain. We also show that the infected neutrophils can not only synthesize 2009 A (H1N1) viral mRNA and proteins, but also produce infectious progeny. These findings suggest that infectious progeny of 2009 A (H1N1) influenza virus could be replicated in and released from human neutrophils with possible clinical implications. PMID:26639836

  7. Infectious Progeny of 2009 A (H1N1) Influenza Virus Replicated in and Released from Human Neutrophils

    PubMed Central

    Zhang, Zhang; Huang, Tao; Yu, Feiyuan; Liu, Xingmu; Zhao, Conghui; Chen, Xueling; Kelvin, David J.; Gu, Jiang

    2015-01-01

    Various reports have indicated that a number of viruses could infect neutrophils, but the multiplication of viruses in neutrophils was abortive. Based on our previous finding that avian influenza viral RNA and proteins were present in the nucleus of infected human neutrophils in vivo, we investigated the possibility of 2009 A (H1N1) influenza viral synthesis in infected neutrophils and possible release of infectious progeny from host cells. In this study we found that human neutrophils in vitro without detectable level of sialic acid expression could be infected by this virus strain. We also show that the infected neutrophils can not only synthesize 2009 A (H1N1) viral mRNA and proteins, but also produce infectious progeny. These findings suggest that infectious progeny of 2009 A (H1N1) influenza virus could be replicated in and released from human neutrophils with possible clinical implications. PMID:26639836

  8. Autocrine enhancement of leukotriene synthesis by endogenous leukotriene B4 and platelet-activating factor in human neutrophils.

    PubMed Central

    McDonald, P. P.; McColl, S. R.; Braquet, P.; Borgeat, P.

    1994-01-01

    1. Platelet-activating factor (PAF) and leukotriene B4 (LTB4), two potent lipid mediators synthesized by activated neutrophils, are known to stimulate several neutrophil functional responses. In this study, we have determined that endogenous LTB4 and PAF exert autocrine effects on LT synthesis, as well as the underlying mechanism involved. 2. Pretreatment of neutrophils with either pertussis toxin (PT), or with receptor antagonists for LTB4 and PAF, resulted in an inhibition of LT synthesis induced by calcium ionophore, A23187. This inhibition was most marked at submaximal (100-300 nM) A23187 concentrations, whilst it was least at ionophore concentrations which induce maximal LT synthesis (1-3 microM). Thus newly-synthesized PAF and LTB4 can enhance LT synthesis induced by A23187 under conditions where the LT-generating system is not fully activated. 3. In recombinant human (rh) granulocyte-macrophage colony-stimulating factor (GM-CSF)-primed neutrophils, LT synthesis in response to chemoattractants (fMet-Leu-Phe or rhC5a) was also significantly inhibited by the LTB4 receptor antagonist, and to a lesser extent by PAF receptor antagonists. 4. Further investigation revealed that LTB4 and/or PAF exert their effects on LT synthesis via an effect on arachidonic acid (AA) availability, as opposed to 5-lipoxygenase (5-LO) activation. Indeed, the receptor antagonists, as well as PT, inhibited LT synthesis and AA release to a similar extent, whereas 5-LO activation (assessed with an exogenous 5-LO substrate) was virtually unaffected under the same conditions. Accordingly, we showed that addition of exogenous LTB4 could enhance AA availability in response to chemoattractant challenge in rhGM-CSF-primed cells, without significantly affecting the 5-LO activation status.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8019762

  9. Human neutrophils: Their role in cancer and relation to myeloid-derived suppressor cells.

    PubMed

    Moses, Katrin; Brandau, Sven

    2016-04-01

    Increased frequencies of peripheral blood neutrophils as well as tumor-infiltrating (associated) neutrophils (TAN) have been observed in many tumor entities. Although the most frequent cell type in the peripheral blood, neutrophils are outnumbered by other leukocyte subsets in the tumor microenvironment. Nevertheless, a number of recent meta-analyses identified TAN as well as high neutrophil-lymphocyte ratio in the blood as one of the most powerful immunologic prognostic parameters in human oncology. This clinical impact is based on an intense bidirectional crosstalk of neutrophils and tumor cells resulting in changes in neutrophil as well as tumor cell biology. These changes eventually lead to TAN equipped with various tumor promoting features, which enhance angiogenesis, cancer cell invasion and metastasis. Many of the pro-tumor features of TAN are shared with PMN-MDSC (myeloid-derived suppressor cells). Consequently, the distinction of these two cell populations is a matter of intensive debate and also specifically discussed in this article. The importance of neutrophils in cancer progression has triggered numerous efforts to therapeutically target these cells. Current strategies in this area focus on the inhibition of either TAN recruitment or pro-tumorigenic function. PMID:27067179

  10. Influence of minor thermal injury on expression of complement receptor CR3 on human neutrophils.

    PubMed Central

    Nelson, R. D.; Hasslen, S. R.; Ahrenholz, D. H.; Haus, E.; Solem, L. D.

    1986-01-01

    Thermal injury is well known to inhibit functions of the circulating neutrophil related to its role in host defense against infection, but the mechanism(s) of this phenomenon are not fully understood. To gain further clues to these mechanisms, the authors have studied patients with thermal injury in terms of altered expression of neutrophil cell membrane receptors for the opsonic complement-derived ligand C3bi--complement receptor Type 3, or CR3. CR3 expression was selected for study because an increase in the number of receptors on the cell surface can be stimulated by products of complement activation known to accumulate after thermal injury and because of the role of CR3 in phagocytic and adherence functions of the neutrophil. Expression of CR3 was monitored semiquantitatively by flow cytometry with the use of a murine monoclonal antibody (OKM1) specific for an antigen (CD11) associated with this receptor. Patients evaluated were limited in this study to those with minor degrees of thermal injury (second-degree burn involving less than 20% of total body surface area) so that possible confounding effects of major injury and its complications could be eliminated. It was observed that patient neutrophil CR3 becomes significantly up-regulated during the first week, as early as 1 day after injury. The maximum level of expression of CR3 averaged greater than 150% (range, 70-314%) of the respective minimum level observed for each patient. The minimum levels of expression of CR3 on patient neutrophils, reached 11-37 days after injury for 7 of 8 patients, were comparable to the level of expression of CR3 on unstimulated control neutrophils. Such temporal up-regulation of patient neutrophil CR3 suggests the early generation of stimuli of CR3 mobilization in response to thermal injury. Increased numbers of CR3 on patient neutrophils may augment microbicidal function and enhance or inhibit delivery of cells to the burn site. PMID:3541642

  11. Activation of human neutrophil nicotinamide adenine dinucleotide phosphate, reduced (triphosphopyridine nucleotide, reduced) oxidase by arachidonic acid in a cell-free system.

    PubMed Central

    Curnutte, J T

    1985-01-01

    Sonicates from unstimulated human neutrophils produce no measurable superoxide since the superoxide-generating enzyme, NADPH oxidase, is inactive in these preparations. Previous attempts to activate the oxidase in disrupted cells with conventional neutrophil stimuli have been unsuccessful. This report describes a cell-free system in which arachidonic acid (82 microM) was able to activate superoxide generation that was dependent upon the presence of NADPH and the sonicate. For activation to occur, both the particulate and supernatant fractions of the sonicate must be present. Calcium ions, which are required for activation of intact neutrophils by arachidonate, were not necessary in the cell-free system. In quantitative terms, the superoxide-generating activity in the cell-free system could account for at least 20-50% of the superoxide rate observed in intact neutrophils stimulated with arachidonate. Sonicates from patients with chronic granulomatous disease (CGD) could not be activated by arachidonic acid in the cell-free system. In three patients representing both genetic forms of CGD, the defect appeared to reside in the particulate fraction. The soluble cofactor was normal in all three patients and could be used to activate normal neutrophil pellets in the presence of arachidonic acid. Thus, at least a portion of the activation mechanism in the neutrophil, that residing in the soluble phase, appeared to be normal in patients with CGD. PMID:2987311

  12. Characterization of the PGE receptor subtype mediating inhibition of superoxide production in human neutrophils.

    PubMed Central

    Talpain, E; Armstrong, R A; Coleman, R A; Vardey, C J

    1995-01-01

    1. The aims of this study were to characterize the EP receptor subtype mediating the inhibition of superoxide anion generation by formyl methionyl leucine phenylalanine (FMLP)-stimulated human neutrophils, and to test the hypothesis that adenosine 3':5'-cyclic monophosphate (cyclic AMP) is the second messenger mediating the inhibition of the neutrophil by prostaglandin (PG)E2. 2. PGE2 (0.001-10 microM) inhibited FMLP (100 nM)-induced O2-generation from human peripheral blood neutrophils in a concentration-dependent manner, with an EC50 of 0.15 +/- 0.03 microM, and a maximum effect ranging from 36-84% (mean inhibition of 68.7 +/- 2.5%, n = 32). 3. The EP2-receptor agonists, misoprostol, 11-deoxy PGE1, AH13205 and butaprost, all at 10 microM, inhibited O2- generation, causing 95.5 +/- 2.9%, 56.8 +/- 5.2%, 37.1 +/- 6.6% and 18.9 +/- 4.4% inhibition respectively, the latter two being much less effective than PGE2. Similarly, the EP1-receptor agonist, 17-phenyl PGE2 (10 microM), and the EP3/EP1-receptor agonist, sulprostone (10 microM), also inhibited O2- generation, causing 32.2 +/- 7.0% and 15.3 +/- 3.4% inhibition respectively. 4. The non-selective phosphodiesterase inhibitor, isobutyl methylxanthine (IBMX, 0.25 mM) inhibited the FMLP response by 54.5 +/- 5.0%. In addition, IBMX shifted concentration-effect curves for PGE2, misoprostol, 11-deoxy PGE1, butaprost, and AH 13205 to the left, to give EC50s of 0.04 +/- 0.03 (n = 13), 0.07 +/- 0.03 (n = 4), 0.08 +/- 0.03 (n = 4), 0.33 +/- 0.13 (n = 4) and 0.41 +/- 0.2 microM (n = 3) respectively, allowing equieffective concentration-ratios (EECs, PGE2 = 1) of 11.5, 5.3, 50.7 and 12.7 to be calculated.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7606349

  13. Subcellular fractionation of human neutrophils and analysis of subcellular markers.

    PubMed

    Clemmensen, Stine Novrup; Udby, Lene; Borregaard, Niels

    2014-01-01

    The neutrophil has long been recognized for its impressive number of cytoplasmic granules that harbor proteins indispensable for innate immunity. Analysis of isolated granules has provided important information on how the neutrophil grades its response to match the challenges it meets on its passage from blood to tissues. Nitrogen cavitation was developed as a method for disruption of cells on the assumption that sudden reduction of the partial pressure of nitrogen would lead to aeration of nitrogen dissolved in the lipid bilayer of plasma membranes. We find that cells are broken by the shear stress that is associated with passage through the outlet valve under high pressure and that this results in disruption of the neutrophil cell membrane while granules remain intact. The unique properties of Percoll as a sedimentable density medium with no inherent tonicity or viscosity are used for creation of continuous density gradients with shoulders in the density profile created to optimize the physical separation of granule subsets and light membranes. Immunological methods (sandwich enzyme-linked immunosorbent assays) are used for quantitation of proteins that are characteristic constituents of the granule subsets of neutrophils. PMID:24504946

  14. On the pharmacology of oxidative burst of human neutrophils.

    PubMed

    Nosáľ, R; Drábiková, K; Jančinová, V; Mačičková, T; Pečivová, J; Perečko, T; Harmatha, J; Šmidrkal, J

    2015-01-01

    The effect of three therapeutically used drugs and five polyphenolic compounds on the mechanism of oxidative burst was compared in whole blood and isolated neutrophils at cellular and molecular level. In 10 microM concentration, the compounds investigated decreased the oxidative burst of whole blood in the rank order of potency: N-feruloylserotonin (N-f-5HT) > curcumin (CUR) > quercetin (QUER) > arbutin (ARB) > resveratrol (RES) > dithiaden (DIT) > carvedilol (CARV) > brompheniramine (BPA). The ratio between the percentage inhibition of extracellular versus intracellular chemiluminescence (CL) followed the rank order QUER > N-f-5HT > RES > CUR > DIT and is indicative of the positive effect of the compounds tested against oxidative burst of neutrophils, demonstrating suppression of reactive oxygen species extracellularly with minimal alteration of intracellular reactive oxygen species (ROS). Activation of protein kinase C was significantly decreased by DIT, CUR, QUER and N-f-5HT. CARV, DIT, QUER and ARB reduced activated neutrophil myeloperoxidase release more significantly compared with the effect on superoxide anion generation. All compounds tested increased the activity of caspase-3 in cell-free system. It is suggested that other regulatory mechanisms than protein kinase C might participate in the inhibition of neutrophil activation with the compounds tested. Different mechanisms are concerned in controlling the assembly of NADPH oxidase and the regulatory role of calcium ions is suggested. Compounds decreasing the amount of extracellular ROS generation, yet affecting but minimally intracellular ROS generation, are promising for further investigation in vivo. PMID:26681073

  15. ACTIVATED NEUTROPHILS INHIBIT PHAGOCYTOSIS BY HUMAN MONOCYTE CELLS IN VITRO

    EPA Science Inventory

    We have previously reported the correlation of decreased phagocytosis of opsonized zymosan by sputum monocytic cells with the increase in sputum neutrophils in volunteers 6h after inhalation of endotoxin (20,000 EU) (Alexis, et al. JACI, 2003;112:353). To define whether an intrin...

  16. Neutrophil apoptosis: impact of granulocyte macrophage colony stimulating factor on cell survival and viability in chronic kidney disease and hemodialysis patients

    PubMed Central

    Zahran, Nariman; Sayed, Azza; William, Iman; Sabry, Omar; Rafaat, Manar

    2013-01-01

    Introduction Altered neutrophil apoptosis might be responsible for recurrent bacterial infections encountered in hemodialysis (HD) and chronic kidney disease (CKD) patients. This work was designed to assess the neutrophil apoptotic activity and the impact of implementation of granulocyte macrophage colony stimulating factor (GM-CSF), as a survival factor, on neutrophil apoptosis among these patients. Material and methods Twenty-five patients on regular HD along with 34 CKD patients on conservative treatment, as well as 15 healthy controls, were investigated for apoptotic rate via assessment of neutrophil expression of Annexin-V by flow cytometry, before and after 20 h culture in absence and presence of GM-CSF. Neutrophil viability was determined using light microscopy. The preservation of neutrophil activation in these patients was analyzed by flow cytometric CD18 neutrophil expression. Chronic inflammatory state was evaluated by estimating C-reactive protein (CRP) and soluble intercellular adhesion molecule-1 (sICAM-1). Obtained data were statistically analyzed. Results Compared to controls, both HD and CKD groups had a significant increase of Annexin-V and CD18 expression and significant decrease in neutrophil viability. Culture of their neutrophils with GM-CSF showed significant decrease of apoptosis accompanied by improvement of neutrophil viability compared to their cultured cells without GM-CSF. These patients also showed significant elevation of CRP and sICAM-1. Conclusions Granulocyte macrophage colony stimulating factor demonstrated an evident impact on improving in vitro neutrophil survival and viability in HD and CKD patients. Therefore, this may represent promising preventive and/or therapeutic strategies against infection frequently observed in these patients and causing morbidity and mortality. PMID:24482640

  17. Neutrophil stimulation with Mycobacterium bovis bacillus Calmette-Guérin (BCG) results in the release of functional soluble TRAIL/Apo-2L

    PubMed Central

    Kemp, Troy J.; Ludwig, Aaron T.; Earel, James K.; Moore, Jill M.; VanOosten, Rebecca L.; Moses, Bonita; Leidal, Kevin; Nauseef, William M.; Griffith, Thomas S.

    2005-01-01

    Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been used to treat bladder cancer for almost 30 years; however, the effector mechanism of the BCG-induced antitumor response remains enigmatic. Most BCG research has focused on the mononuclear-cell infiltrate, but growing evidence supports a role for neutrophils in the antitumor response. Previously, we demonstrated increased urinary tumor necrosis factor (TNF)–related apoptosis-inducing ligand (TRAIL/Apo-2L) levels from BCG-responsive patients compared to nonresponders. Interestingly, neutrophils isolated from the urine expressed TRAIL/Apo-2L, leading us to investigate the neutrophil response to BCG. BCG-stimulated neutrophils expressed surface-bound and released functional soluble TRAIL/Apo-2L. Whereas neither interferon α (IFN-α) nor IFN-γ directly induced TRAIL/Apo2L expression by neutrophils, IFN-α did stimulate TRAIL gene transcription, and IFN-primed neutrophils contained and released more TRAIL/Apo-2L after BCG stimulation than did unprimed neutrophils. In unstimulated neutrophils TRAIL/Apo-2L was present predominantly in the azurophilic granules and plasma-membrane–enriched/secretory-granule fraction. Finally, we observed that killed BCG, Toll-like receptor 2 (TLR2) and TLR4 agonists, and an M tuberculosis cell-wall fraction were each capable of inducing the release of soluble TRAIL/Apo-2L from neutrophils. These results further characterize the potential role neutrophils may play in initiating the antitumor response described with BCG treatment for superficial bladder cancer. PMID:16037389

  18. Human Neutrophils Use Different Mechanisms To Kill Aspergillus fumigatus Conidia and Hyphae: Evidence from Phagocyte Defects.

    PubMed

    Gazendam, Roel P; van Hamme, John L; Tool, Anton T J; Hoogenboezem, Mark; van den Berg, J Merlijn; Prins, Jan M; Vitkov, Ljubomir; van de Veerdonk, Frank L; van den Berg, Timo K; Roos, Dirk; Kuijpers, Taco W

    2016-02-01

    Neutrophils are known to play a pivotal role in the host defense against Aspergillus infections. This is illustrated by the prevalence of Aspergillus infections in patients with neutropenia or phagocyte functional defects, such as chronic granulomatous disease. However, the mechanisms by which human neutrophils recognize and kill Aspergillus are poorly understood. In this work, we have studied in detail which neutrophil functions, including neutrophil extracellular trap (NET) formation, are involved in the killing of Aspergillus fumigatus conidia and hyphae, using neutrophils from patients with well-defined genetic immunodeficiencies. Recognition of conidia involves integrin CD11b/CD18 (and not dectin-1), which triggers a PI3K-dependent nonoxidative intracellular mechanism of killing. When the conidia escape from early killing and germinate, the extracellular destruction of the Aspergillus hyphae needs opsonization by Abs and involves predominantly recognition via Fcγ receptors, signaling via Syk, PI3K, and protein kinase C to trigger the production of toxic reactive oxygen metabolites by the NADPH oxidase and myeloperoxidase. A. fumigatus induces NET formation; however, NETs did not contribute to A. fumigatus killing. Thus, our findings reveal distinct killing mechanisms of Aspergillus conidia and hyphae by human neutrophils, leading to a comprehensive insight in the innate antifungal response. PMID:26718340

  19. An adenosine triphosphate-dependent calcium uptake pump in human neutrophil lysosomes.

    PubMed Central

    Klemper, M S

    1985-01-01

    Regulation of the cytosolic free calcium concentration is important to neutrophil function. In these studies, an ATP-dependent calcium uptake pump has been identified in human neutrophil lysosomes. This energy-dependent Ca++ uptake pump has a high affinity for Ca++ (Michaelis constant [Km] Ca++ = 107 nM) and a maximum velocity (Vmax) of 5.3 pmol/mg of protein per min. ATP was the only nucleotide that supported Ca++ uptake by lysosomes. The Km for ATP was 177 microM. ATP-dependent Ca++ uptake by neutrophil lysosomes was temperature- and pH-sensitive with optimal Ca++ pump activity at 37 degrees C and pH 7.0-7.5. Mg++ was also essential for ATP-dependent Ca++ uptake by lysosomes. Azide and antimycin A had no effect on the energy-dependent uptake of Ca++ by neutrophil lysosomes. The chemotactic peptide formyl-methionyl-leucyl-phenylalanine inhibited ATP-dependent Ca++ accumulation by isolated lysosomes. Butoxycarbonyl-phenylalanine-leucine-phenylalanine-leucine-phenylalanine , a competitive antagonist of the chemotactic peptide, blocked this inhibitory effect. These studies demonstrate the presence of an ATP-dependent Ca++ uptake pump in human neutrophil lysosomes that functions at physiologic intracellular concentrations of Ca++, ATP, and H+ and may be important to regulating neutrophil function by modulating cytosolic Ca++. PMID:3926820

  20. Neutrophil Elastase, Proteinase 3, and Cathepsin G as Therapeutic Targets in Human Diseases

    PubMed Central

    Horwitz, Marshall S.; Jenne, Dieter E.; Gauthier, Francis

    2010-01-01

    Polymorphonuclear neutrophils are the first cells recruited to inflammatory sites and form the earliest line of defense against invading microorganisms. Neutrophil elastase, proteinase 3, and cathepsin G are three hematopoietic serine proteases stored in large quantities in neutrophil cytoplasmic azurophilic granules. They act in combination with reactive oxygen species to help degrade engulfed microorganisms inside phagolysosomes. These proteases are also externalized in an active form during neutrophil activation at inflammatory sites, thus contributing to the regulation of inflammatory and immune responses. As multifunctional proteases, they also play a regulatory role in noninfectious inflammatory diseases. Mutations in the ELA2/ELANE gene, encoding neutrophil elastase, are the cause of human congenital neutropenia. Neutrophil membrane-bound proteinase 3 serves as an autoantigen in Wegener granulomatosis, a systemic autoimmune vasculitis. All three proteases are affected by mutations of the gene (CTSC) encoding dipeptidyl peptidase I, a protease required for activation of their proform before storage in cytoplasmic granules. Mutations of CTSC cause Papillon-Lefèvre syndrome. Because of their roles in host defense and disease, elastase, proteinase 3, and cathepsin G are of interest as potential therapeutic targets. In this review, we describe the physicochemical functions of these proteases, toward a goal of better delineating their role in human diseases and identifying new therapeutic strategies based on the modulation of their bioavailability and activity. We also describe how nonhuman primate experimental models could assist with testing the efficacy of proposed therapeutic strategies. PMID:21079042

  1. Heterogeneity of Human Neutrophil CD177 Expression Results from CD177P1 Pseudogene Conversion

    PubMed Central

    Liang, Rong; Ohnesorg, Thomas; Cho, Vicky; Abhayaratna, Walter P.; Gatenby, Paul A.; Perera, Chandima; Zhang, Yafei; Whittle, Belinda; Sinclair, Andrew; Goodnow, Christopher C.; Field, Matthew; Andrews, T. Daniel; Cook, Matthew C.

    2016-01-01

    Most humans harbor both CD177neg and CD177pos neutrophils but 1–10% of people are CD177null, placing them at risk for formation of anti-neutrophil antibodies that can cause transfusion-related acute lung injury and neonatal alloimmune neutropenia. By deep sequencing the CD177 locus, we catalogued CD177 single nucleotide variants and identified a novel stop codon in CD177null individuals arising from a single base substitution in exon 7. This is not a mutation in CD177 itself, rather the CD177null phenotype arises when exon 7 of CD177 is supplied entirely by the CD177 pseudogene (CD177P1), which appears to have resulted from allelic gene conversion. In CD177 expressing individuals the CD177 locus contains both CD177P1 and CD177 sequences. The proportion of CD177hi neutrophils in the blood is a heritable trait. Abundance of CD177hi neutrophils correlates with homozygosity for CD177 reference allele, while heterozygosity for ectopic CD177P1 gene conversion correlates with increased CD177neg neutrophils, in which both CD177P1 partially incorporated allele and paired intact CD177 allele are transcribed. Human neutrophil heterogeneity for CD177 expression arises by ectopic allelic conversion. Resolution of the genetic basis of CD177null phenotype identifies a method for screening for individuals at risk of CD177 isoimmunisation. PMID:27227454

  2. Heterogeneity of Human Neutrophil CD177 Expression Results from CD177P1 Pseudogene Conversion.

    PubMed

    Wu, Zuopeng; Liang, Rong; Ohnesorg, Thomas; Cho, Vicky; Lam, Wesley; Abhayaratna, Walter P; Gatenby, Paul A; Perera, Chandima; Zhang, Yafei; Whittle, Belinda; Sinclair, Andrew; Goodnow, Christopher C; Field, Matthew; Andrews, T Daniel; Cook, Matthew C

    2016-05-01

    Most humans harbor both CD177neg and CD177pos neutrophils but 1-10% of people are CD177null, placing them at risk for formation of anti-neutrophil antibodies that can cause transfusion-related acute lung injury and neonatal alloimmune neutropenia. By deep sequencing the CD177 locus, we catalogued CD177 single nucleotide variants and identified a novel stop codon in CD177null individuals arising from a single base substitution in exon 7. This is not a mutation in CD177 itself, rather the CD177null phenotype arises when exon 7 of CD177 is supplied entirely by the CD177 pseudogene (CD177P1), which appears to have resulted from allelic gene conversion. In CD177 expressing individuals the CD177 locus contains both CD177P1 and CD177 sequences. The proportion of CD177hi neutrophils in the blood is a heritable trait. Abundance of CD177hi neutrophils correlates with homozygosity for CD177 reference allele, while heterozygosity for ectopic CD177P1 gene conversion correlates with increased CD177neg neutrophils, in which both CD177P1 partially incorporated allele and paired intact CD177 allele are transcribed. Human neutrophil heterogeneity for CD177 expression arises by ectopic allelic conversion. Resolution of the genetic basis of CD177null phenotype identifies a method for screening for individuals at risk of CD177 isoimmunisation. PMID:27227454

  3. Characterization of a receptor for human monocyte-derived neutrophil chemotactic factor/interleukin-8

    SciTech Connect

    Grob, P.M.; David, E.; Warren, T.C.; DeLeon, R.P.; Farina, P.R.; Homon, C.A. )

    1990-05-15

    Monocyte-derived neutrophil chemotactic factor/interleukin-8 (MDNCF/IL-8) is an 8,000-dalton protein produced by monocytes which exhibits activity as a chemoattractant for neutrophils with maximal activity achieved at a concentration of 50 ng/ml. This polypeptide has been iodinated by chloramine-T methodology (350 Ci/mM), and specific receptors for MDNCF/IL-8 have been detected on human neutrophils, U937 cells, THP-1 cells, and dimethyl sulfoxide-differentiated HL-60 cells. The binding of MDNCF/IL-8 to human neutrophils is not inhibited by interleukin-1 alpha, tumor necrosis factor-alpha, insulin, or epidermal growth factor. In addition, chemoattractants such as C5a, fMet-Leu-Phe, leukotriene B4, and platelet-activating factor fail to inhibit binding, suggesting that MDNCF/IL-8 utilizes a unique receptor. The receptor for MDNCF/IL-8 is apparently glycosylated since ligand binding is inhibited by the presence of wheat germ agglutinin, a lectin with a binding specificity for N-acetylglucosamine and neuraminic acid. Steady state binding experiments indicate Kd values of 4 and 0.5 nM and receptor numbers of 75,000 and 7,400 for human neutrophils and differentiated HL-60 cells, respectively. 125I-MDNCF/IL-8 bound to human neutrophils is rapidly internalized and subsequently released from cells as trichloroacetic acid-soluble radioactivity. Affinity labeling experiments suggest that the human neutrophil MDNCF/IL-8 receptor exhibits a mass of approximately 58,000 daltons.

  4. Neutrophil activation during acetaminophen hepatotoxicity and repair in mice and humans.

    PubMed

    Williams, C David; Bajt, Mary Lynn; Sharpe, Matthew R; McGill, Mitchell R; Farhood, Anwar; Jaeschke, Hartmut

    2014-03-01

    Following acetaminophen (APAP) overdose there is an inflammatory response triggered by the release of cellular contents from necrotic hepatocytes into the systemic circulation which initiates the recruitment of neutrophils into the liver. It has been demonstrated that neutrophils do not contribute to APAP-induced liver injury, but their role and the role of NADPH oxidase in injury resolution are controversial. C57BL/6 mice were subjected to APAP overdose and neutrophil activation status was determined during liver injury and liver regeneration. Additionally, human APAP overdose patients (ALT: >800 U/L) had serial blood draws during the injury and recovery phases for the determination of neutrophil activation. Neutrophils in the peripheral blood of mice showed an increasing activation status (CD11b expression and ROS priming) during and after the peak of injury but returned to baseline levels prior to complete injury resolution. Hepatic sequestered neutrophils showed an increased and sustained CD11b expression, but no ROS priming was observed. Confirming that NADPH oxidase is not critical to injury resolution, gp91(phox)⁻/⁻ mice following APAP overdose displayed no alteration in injury resolution. Peripheral blood from APAP overdose patients also showed increased neutrophil activation status after the peak of liver injury and remained elevated until discharge from the hospital. In mice and humans, markers of activation, like ROS priming, were increased and sustained well after active liver injury had subsided. The similar findings between surviving patients and mice indicate that neutrophil activation may be a critical event for host defense or injury resolution following APAP overdose, but not a contributing factor to APAP-induced injury. PMID:24440789

  5. Neutrophil Activation During Acetaminophen Hepatotoxicity and Repair in Mice and Humans

    PubMed Central

    Williams, C. David; Bajt, Mary Lynn; Sharpe, Matthew R.; McGill, Mitchell R.; Farhood, Anwar; Jaeschke, Hartmut

    2014-01-01

    Following acetaminophen (APAP) overdose there is an inflammatory response triggered by release of cellular contents from necrotic hepatocytes into systemic circulation which initiates the recruitment of neutrophils into the liver. It has been demonstrated that neutrophils do not contribute to APAP-induced liver injury, but their role and the role of NADPH oxidase in injury resolution is controversial. C57BL/6 mice were subjected to APAP overdose and neutrophil activation status was determined during liver injury and liver regeneration. Additionally, human APAP overdose patients (ALT: >800U/L) had serial blood draws during the injury and recovery phases for determination of neutrophil activation. Neutrophils in the peripheral blood of mice showed increasing activation status (CD11b expression and ROS priming) during and after the peak of injury but returned to baseline levels prior to complete injury resolution. Hepatic sequestered neutrophils showed an increased and sustained CD11b expression, but no ROS priming was observed. Confirming that NADPH oxidase is not critical to injury resolution, gp91phox-/- mice following APAP overdose displayed no alteration in injury resolution. Peripheral blood from APAP overdose patients also showed increased neutrophil activation status after the peak of liver injury and remained elevated until discharge from the hospital. In mice and humans, markers of activation, like ROS priming, were increased and sustained well after active liver injury had subsided. The similar findings between surviving patients and mice indicate neutrophil activation may be a critical event for host defense or injury resolution following APAP overdose, but not a contributing factor to APAP-induced injury. PMID:24440789

  6. Coccidioides Endospores and Spherules Draw Strong Chemotactic, Adhesive, and Phagocytic Responses by Individual Human Neutrophils

    PubMed Central

    Lee, Cheng-Yuk; Thompson III, George R.; Hastey, Christine J.; Hodge, Gregory C.; Lunetta, Jennine M.; Pappagianis, Demosthenes; Heinrich, Volkmar

    2015-01-01

    Coccidioides spp. are dimorphic pathogenic fungi whose parasitic forms cause coccidioidomycosis (Valley fever) in mammalian hosts. We use an innovative interdisciplinary approach to analyze one-on-one encounters between human neutrophils and two forms of Coccidioides posadasii. To examine the mechanisms by which the innate immune system coordinates different stages of the host response to fungal pathogens, we dissect the immune-cell response into chemotaxis, adhesion, and phagocytosis. Our single-cell technique reveals a surprisingly strong response by initially quiescent neutrophils to close encounters with C. posadasii, both from a distance (by complement-mediated chemotaxis) as well as upon contact (by serum-dependent adhesion and phagocytosis). This response closely resembles neutrophil interactions with Candida albicans and zymosan particles, and is significantly stronger than the neutrophil responses to Cryptococcus neoformans, Aspergillus fumigatus, and Rhizopus oryzae under identical conditions. The vigorous in vitro neutrophil response suggests that C. posadasii evades in vivo recognition by neutrophils through suppression of long-range mobilization and recruitment of the immune cells. This observation elucidates an important paradigm of the recognition of microbes, i.e., that intact immunotaxis comprises an intricate spatiotemporal hierarchy of distinct chemotactic processes. Moreover, in contrast to earlier reports, human neutrophils exhibit vigorous chemotaxis toward, and frustrated phagocytosis of, the large spherules of C. posadasii under physiological-like conditions. Finally, neutrophils from healthy donors and patients with chronic coccidioidomycosis display subtle differences in their responses to antibody-coated beads, even though the patient cells appear to interact normally with C. posadasii endospores. PMID:26070210

  7. Human neutrophil peptides upregulate expression of cyclooxygenase-2 and endothelin-1 by inducing oxidative stress

    PubMed Central

    Syeda, Farisa; Tullis, Elizabeth; Slutsky, Arthur S.; Zhang, Haibo

    2016-01-01

    The human neutrophil peptides (HNP) bind to vascular smooth muscle cells and regulate vascular tone. We hypothesized that HNP act on endothelial cells to modulate the expression of vasoactive byproducts. We observed a time- and dose-dependent increase in the expression of cyclooxygenase-2 (COX-2) by human umbilical vein endothelial cells (HUVEC) in response to HNP stimulation, while COX-1 levels remained unchanged. Despite an upregulated expression of COX-2, HNP did not significantly enhance the production of the COX-2-derived prostaglandins PGI2 and PGE2. HNP significantly induced the release of endothelin-1 (ET-1) as well as the formation of nitrotyrosine. The HNP-induced COX-2 and ET-1 production was attenuated by the treatment with the oxygen free radical scavenger N-acetyl-L-cysteine, and the inhibitors of p38 MAPK and NF-κB, respectively. We conclude that HNP may play an important role in the regulation of the course of cardiovascular diseases by activating endothelial cells to produce vasoactive byproducts. PMID:18441204

  8. Neutrophil-mediated protection of cultured human vascular endothelial cells from damage by growing Candida albicans hyphae

    SciTech Connect

    Edwards, J.E. Jr.; Rotrosen, D.; Fontaine, J.W.; Haudenschild, C.C.; Diamond, R.D.

    1987-05-01

    Interactions were studied between human neutrophils and cultured human umbilical vein endothelial cells invaded by Candida albicans. In the absence of neutrophils, progressive Candida germination and hyphal growth extensively damaged endothelial cell monolayers over a period of 4 to 6 hours, as determined both by morphological changes and release of /sup 51/Cr from radiolabeled endothelial cells. Monolayers were completely destroyed and replaced by hyphae after 18 hours of incubation. In contrast, when added 2 hours after the monolayers had been infected with Candida, neutrophils selectively migrated toward and attached to hyphae at points of hyphal penetration into individual endothelial cells (observed by time-lapse video-microscopy). Attached neutrophils spread over hyphal surfaces both within and beneath the endothelial cells; neutrophil recruitment to initial sites of leukocyte-Candida-endothelial cell interactions continued throughout the first 60 minutes of observation. Neutrophil spreading and stasis were observed only along Candida hyphae and at sites of Candida-endothelial cell interactions. These events resulted in 58.0% killing of Candida at 2 hours and subsequent clearance of Candida from endothelial cell monolayers, as determined by microcolony counts and morphological observation. On introduction of additional neutrophils to yield higher ratios of neutrophils to endothelial cells (10 neutrophils:1 endothelial cell), neutrophil migration toward hyphal elements continued. Despite retraction or displacement of occasional endothelial cells by invading Candida and neutrophils, most endothelial cells remained intact, viable, and motile as verified both by morphological observations and measurement of /sup 51/Cr release from radiolabeled monolayers.

  9. Osmotically induced cytosolic free Ca(2+) changes in human neutrophils.

    PubMed

    Morris, M R; Doull, I J; Hallett, M B

    2001-02-01

    Cytosolic free Ca(2+) concentration in neutrophils was measured by ratiometric fluorometry of intracellular fura2. Increasing the extracellular osmolarity, by either NaCl (300-600 mM) or sucrose (600-1200 mM), caused a rise in cytosolic free Ca(2+) (Delta(max) approximately equal to 600 nM). This was not due to cell lysis as the cytosolic free Ca(2+) concentration was reversed by restoration of isotonicity and a second rise in cytosolic free Ca(2+) could be provoked by repeating the change in extracellular osmolarity. Furthermore, the rise in cytosolic free Ca(2+) concentration occurred in the absence of extracellular Ca(2+), demonstrating that release of intracellular fura2 into the external medium did not occur. The osmotically-induced rise in cytosolic free Ca(2+) was not inhibited by either the phospholipase C-inhibitor U73122, or the microfilament inhibitor cytochalasin B, suggesting that neither signalling via inositol tris-phosphate or the cytoskeletal system were involved. However, the rise in cytosolic free Ca(2+) may have resulted from a reduction in neutrophil water volume in hyperosmotic conditions. As these rises in cytosolic Ca(2+) (Delta(max) approximately equal to 600 nM) were large enough to provoke changes in neutrophil activity, we propose that conditions which removes cell water may similarly elevate cytosolic free Ca(2+) to physiologically important levels. PMID:11341979

  10. Effects of polychlorinated biphenyls, hexachlorocyclohexanes, and mercury on human neutrophil apoptosis, actin cytoskelton, and oxidative state

    USGS Publications Warehouse

    Sweet, L.I.; Passino-Reader, D. R.; Meier, P.G.; Omann, G.M.

    2006-01-01

    Apoptosis, or programmed cell death, has been proposed as a biomarker for environmental contaminant effects. In this work, we test the hypothesis that in vitro assays of apoptosis are sensitive indicators of immunological effects of polychlorinated biphenyls, hexachlorocyclohexanes, and mercury on human neutrophils. Apoptosis, necrosis, and viability as well as the related indicators F-actin levels, and active thiol state were measured in purified human neutrophils after treatment with contaminants. Effective concentrations observed were 0.3 μM (60 μg/L) mercury, 750 μg/L Aroclor 1254, and 50 μM (14,500 μg/L) hexachlorocylcohexanes. Concentrations of contaminants that induced apoptosis also decreased cellular F-actin levels. Active thiols were altered by mercury, but not organochlorines. Comparison of these data with levels of contaminants reported to be threats to human health indicate neutrophil apoptosis is a sensitive indicator of mercury toxicity.

  11. αVβ3 Integrin Regulation of Respiratory Burst in Fibrinogen Adherent Human Neutrophils

    PubMed Central

    Kim, Hye-Yeong; Skokos, Eleni A.; Myer, Deborah J.; Agaba, Perez; Gonzalez, Anjelica L.

    2015-01-01

    In response to inflammatory stimuli, microvascular endothelial cells become activated, initiating the capture and exit of neutrophils from the blood vessel and into the extravascular extracellular matrix (ECM). In the extravascular space, neutrophils bind to ECM proteins, regulating cellular functions via signaling through adhesion molecules known as integrins. The αVβ3 integrin is an important mediator of neutrophil adhesion to ECM proteins containing the Arg-Gly-Asp (RGD) peptide sequence, including fibrinogen and fibronectin. Despite the abundance of RGD sequence in the ECM, adhesion molecule-mediated neutrophil activity has been focused on the β2 (Mac-1, CD11b/CD18) and β1 integrin response to matrix proteins. Here we investigated αVβ3 integrin-mediated reactive oxidant suppression as a consequence of human neutrophil adhesion to RGD containing proteins. Using integrin ligand-modified (poly)ethylene glycol hydrogels and reactive oxygen species (ROS) sensitive fluorescent probes (dihydrotetramethylrhosamine, H2TMRos), we evaluated integrin–peptide interactions that effectively regulate ROS generation. This study demonstrates that neutrophil adhesion suppresses ROS production in an αVβ3-dependent manner. Additionally, we determine that p38 mitogen-activated protein kinase in the respiratory burst signaling pathway is interrupted by integrin-mediated adhesion. These data indicate that ECM/integrin interactions can induce αVβ3-mediated adhesion dependent downstream signaling of ROS regulation via a Mac-1 independent mechanism. PMID:25632307

  12. Human neutrophil calmodulin-binding proteins: identification of the calmodulin-dependent protein phosphatase

    SciTech Connect

    Blackburn, W.D.; Tallant, E.A.; Wallace, R.W.

    1986-05-01

    The molecular events in linking neutrophil activation and ligand binding to specific membrane receptors are mediated in part by an increase in intracellular Ca/sup 2 +/. One mechanism by which Ca/sup 2 +/ may trigger neutrophil activation is through Ca/sup 2 +//calmodulin (CaM)-regulated proteins and enzymes. To determine which Ca/sup 2 +//CaM-regulated enzymes may be present in the neutrophil, they have used Western blotting techniques and /sup 125/I-CaM to identify neutrophil CaM-binding proteins. Eleven proteins with molecular weights ranging from 230K to 13.5K bound /sup 125/I-CaM in a Ca/sup 2 +/-dependent manner. One predominant region of /sup 125/I-Cam binding was to a 59K protein; a protein with an identical mobility was labeled by an antisera against brain CaM-dependent phosphatase. Ca/sup 2 +/-dependent phosphatase activity, which was inhibited by the CaM antagonist trifluoperazine, was detected in a neutrophil extract; a radioimmunoassay for the phosphatase indicated that it was present in the extract at approximately 0.2 ..mu..g/mg protein. Most of the CaM-binding proteins, including the 59K protein, were rapidly degraded upon lysis of the neutrophil. There was a close correlation between the degradation of the 59K protein and the loss of Ca/sup 2 +/-dependent phosphatase activity in the neutrophil extract. Thus, human neutrophils contain numerous CaM-binding proteins which are presumably Ca/sup 2 +//calmodulin-regulated enzymes and proteins; the 59K protein is a CaM-dependent phosphatase.

  13. Monoclonal LYM-1 antibody-dependent cytolysis by human neutrophils exposed to GM-CSF: auto-regulation of target cell attack by cathepsin G.

    PubMed

    Ottonello, Luciano; Epstein, Alan L; Mancini, Marina; Dapino, Patrizia; Dallegri, Franco

    2004-01-01

    Murine monoclonal antibody (mAb) Lym-1 is an immunoglobulin G2a specific for certain human leukocyte antigen-DR variants expressed on the surface of malignant B cells. It has been proposed for serotherapy in patients with B lymphomas. We have previously shown that mAb Lym-1 synergizes with granulocyte macrophage-colony stimulating factor to promote Raji B-lymphoid cell lysis by human neutrophils via the intervention of neutrophil Fc receptors type II and D-mannose-inhibitable interactions between CD11b-CD18 integrins and CD66b glycoproteins. Here, we provide evidence that the process is oxygen-independent by inference related to the release of primary granules and is regulated by cathepsin G activity. The lysis was indeed reproduced by replacing normal neutrophils with cells from three patients suffering from chronic granulomatous disease, i.e., neutrophils genetically incapable of generating oxidants. Moreover, the lysis was inhibited by the serine protease inhibitor 3,4-dichloroisocoumarin and by Z-glycyl-leucyl-phenyl-chloromethyl ketone (Z-Gly-Leu-Phe-CMK), which blocks cathepsin G. Conversely, the lysis was unaffected by N-methoxysuccinyl-alanyl-alanyl-prolyl-alanyl-CMK (MeOSuc-Ala-Ala-Pro-Ala-CMK; elastase inhibitor) and MeOSuc-Ala-Ala-Pro-valine (Val)-CMK, which inhibits elastase and proteinase 3. The ability of neutrophils, engaged in cytolysis, to release cathepsin G was proved by detecting this enzymatic activity spectrophotometrically and immunocytochemically. Moreover, inhibition of cathepsin G activity by concentrations of Z-Gly-Leu-Phe-CMK, incapable of affecting elastase activity, was found to reduce the release of elastase and myeloperoxidase from neutrophils under conditions similar to those used for cytolytic assays. These findings suggest that neutrophils auto-regulate their lytic efficiency by controlling the exocytosis of primary granules via their cathepsin G activity. PMID:14525961

  14. Activation of NLRP3 inflammasome in human neutrophils by Helicobacter pylori infection.

    PubMed

    Pérez-Figueroa, Erandi; Torres, Javier; Sánchez-Zauco, Norma; Contreras-Ramos, Alejandra; Alvarez-Arellano, Lourdes; Maldonado-Bernal, Carmen

    2016-02-01

    TLRs and NLRs participate in the immune system recognition of Helicobacter pylori. However, little is known about the mechanisms leading to inflammasome activation by H. pylori and if NLRs in neutrophils are involved in the process. We studied how NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome components are involved in IL-1β maturation in human neutrophils in response to the infection and if they are dependent on T4SS (type IV secretion system) and TLRs. Human neutrophils were cultured and infected with the 26695 or the VirD4- H. pylori strains; the IL-1β concentration was analyzed by ELISA, and we also evaluated the activation of TLRs 2 and 4. The infection of neutrophils with both strains of H. pylori induced production of IL-1β and expression of the NLRP3 inflammasome components such as apoptosis-associated speck-like protein with CARD domain and NLRP3 protein. The infection also increased the activity of caspase-1, which is required for the maturation of IL-1β. Our study shows, for the first time, that H. pylori infection induces the expression and activation of components of NLRP3 inflammasomes in human neutrophils and that the activation is independent of a functional T4SS and TLR2 and TLR4. PMID:26610398

  15. Chromatin remodelling and autocrine TNFα are required for optimal interleukin-6 expression in activated human neutrophils.

    PubMed

    Zimmermann, Maili; Aguilera, Francisco Bianchetto; Castellucci, Monica; Rossato, Marzia; Costa, Sara; Lunardi, Claudio; Ostuni, Renato; Girolomoni, Giampiero; Natoli, Gioacchino; Bazzoni, Flavia; Tamassia, Nicola; Cassatella, Marco A

    2015-01-01

    Controversy currently exists about the ability of human neutrophils to produce IL-6. Here, we show that the chromatin organization of the IL-6 genomic locus in human neutrophils is constitutively kept in an inactive configuration. However, we also show that upon exposure to stimuli that trigger chromatin remodelling at the IL-6 locus, such as ligands for TLR8 or, less efficiently, TLR4, highly purified neutrophils express and secrete IL-6. In TLR8-activated neutrophils, but not monocytes, IL-6 expression is preceded by the induction of a latent enhancer located 14 kb upstream of the IL-6 transcriptional start site. In addition, IL-6 induction is potentiated by endogenous TNFα, which prolongs the synthesis of the IκBζ co-activator and sustains C/EBPβ recruitment and histone acetylation at IL-6 regulatory regions. Altogether, these data clarify controversial literature on the ability of human neutrophils to generate IL-6 and uncover chromatin-dependent layers of regulation of IL-6 in these cells. PMID:25616107

  16. Activated human valvular interstitial cells sustain interleukin-17 production to recruit neutrophils in infective endocarditis.

    PubMed

    Yeh, Chiou-Yueh; Shun, Chia-Tung; Kuo, Yu-Min; Jung, Chiau-Jing; Hsieh, Song-Chou; Chiu, Yen-Ling; Chen, Jeng-Wei; Hsu, Ron-Bin; Yang, Chia-Ju; Chia, Jean-San

    2015-06-01

    The mechanisms that underlie valvular inflammation in streptococcus-induced infective endocarditis (IE) remain unclear. We previously demonstrated that streptococcal glucosyltransferases (GTFs) can activate human heart valvular interstitial cells (VIC) to secrete interleukin-6 (IL-6), a cytokine involved in T helper 17 (Th17) cell differentiation. Here, we tested the hypothesis that activated VIC can enhance neutrophil infiltration through sustained IL-17 production, leading to valvular damage. To monitor cytokine and chemokine production, leukocyte recruitment, and the induction or expansion of CD4(+) CD45RA(-) CD25(-) CCR6(+) Th17 cells, primary human VIC were cultured in vitro and activated by GTFs. Serum cytokine levels were measured using an enzyme-linked immunosorbent assay (ELISA), and neutrophils and Th17 cells were detected by immunohistochemistry in infected valves from patients with IE. The expression of IL-21, IL-23, IL-17, and retinoic acid receptor-related orphan receptor C (Rorc) was upregulated in GTF-activated VIC, which may enhance the proliferation of memory Th17 cells in an IL-6-dependent manner. Many chemokines, including chemokine (C-X-C motif) ligand 1 (CXCL1), were upregulated in GTF-activated VIC, which might recruit neutrophils and CD4(+) T cells. Moreover, CXCL1 production in VIC was induced in a dose-dependent manner by IL-17 to enhance neutrophil chemotaxis. CXCL1-expressing VIC and infiltrating neutrophils could be detected in infected valves, and serum concentrations of IL-17, IL-21, and IL-23 were increased in patients with IE compared to healthy donors. Furthermore, elevated serum IL-21 levels have been significantly associated with severe valvular damage, including rupture of chordae tendineae, in IE patients. Our findings suggest that VIC are activated by bacterial modulins to recruit neutrophils and that such activities might be further enhanced by the production of Th17-associated cytokines. Together, these factors can amplify

  17. Neutrophil function of neonatal foals is enhanced in vitro by CpG oligodeoxynucleotide stimulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhodococcus equi is an intracellular bacterium that causes pneumonia in foals and immunocompromised adult horses. Evidence exists that foals become infected with R. equi early in life, a period when innate immune responses are critically important for protection against infection. Neutrophils are i...

  18. Neutrophil chemokines in epithelial inflammatory processes of human tonsils

    PubMed Central

    Sachse, F; Ahlers, F; Stoll, W; Rudack, C

    2005-01-01

    CXC chemokines are thought to play an important role at sites of inflammation. Because ELR+ CXC chemokines are expressed in different types of tonsillitis we investigated the role of the surface/crypt epithelium of human tonsils in producing ELR+ CXC chemokines: interleukin (IL)-8 (CXCL8), ENA-78 (CXCL5), GRO-α (CXCL1) and GCP-2 (CXCL6). Tonsillar tissue was obtained from patients undergoing tonsillectomy and chemokine expression was investigated by means of immunohistochemistry. A549 cells were used as a model to study kinetics of chemokine expression in epithelial cells. Cells were stimulated with tumour necrosis factor (TNF)-α, lipopolysaccharide (LPS) and supernatants derived from aerobic/anaerobic Staphylococcus aureus strains. Chemokine expression was measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). We observed epithelial expression of IL-8, GRO-α and GCP-2 in different types of tonsillitis, whereas ENA-78 was rarely expressed. In A549 cells abundant expression of ENA-78 was detected. IL-8 and GCP-2 are expressed in an acute type of tonsillitis whereas GRO-α was frequently detectable both in chronically and acutely inflamed tonsils. ENA-78 does not seem to play a pivotal role in tonsillitis in vivo. PMID:15807854

  19. Treatment with recombinant granulocyte colony-stimulating factor (Filgrastin) stimulates neutrophils and tissue macrophages and induces an effective non-specific response against Mycobacterium avium in mice.

    PubMed Central

    Bermudez, L E; Petrofsky, M; Stevens, P

    1998-01-01

    A role of neutrophils in the host response against Mycobacterium avium (MAC) has recently been suggested. To investigate this matter further, we determined the effect of granulocyte colony-stimulating factor (G-CSF) on the outcome of MAC infection in mice. C57BL/6bg+/bg- black mice were intravenously infected with 1 x 10(7) MAC and then divided into four experimental groups to receive G-CSF as follows: (i) 10 micrograms/kg/day; (ii) 50 micrograms/kg/day; (iii) 100 micrograms/kg/day; (iv) placebo control. Mice were killed at 2 and 4 weeks of treatment to determine the bacterial load of liver and spleen. Treatment with G-CSF at both 10 and 50 micrograms/kg/day doses significantly decreased the number of viable bacteria in liver and spleen after 2 weeks (approximately 70.5% and 69.0%, respectively), and after 4 weeks (approximately 53% and 52%, respectively, P < 0.05 compared with placebo control). Treatment with 100 micrograms/kg/day did not result in decrease of bacterial colony-forming units in the liver and spleen after 4 weeks. Administration of G-CSF induced interleukin-10 (IL-10) and IL-12 production by splenocytes. To examine if the protective effect of G-CSF was accompanied by the activation of phagocytic cells, blood neutrophils and splenic macrophages were purified from mice receiving G-CSF and their ability to kill MAC was examined ex vivo. Neutrophils and macrophages from G-CSF-treated mice were able to inhibit the growth of or to kill MAC ex vivo, while phagocytic cells from untreated control mice had no anti-MAC effect. These results suggest that activation of neutrophils appears to induce an effective non-specific host defence against MAC, and further studies should aim for better understanding of the mechanisms of protection. Images Figure 3 Figure 4 Figure 5 PMID:9767410

  20. Methionine Sulfoxide Reductases Protect against Oxidative Stress in Staphylococcus aureus Encountering Exogenous Oxidants and Human Neutrophils

    PubMed Central

    Pang, Yun Yun; Schwartz, Jamie; Bloomberg, Sarah; Boyd, Jeffrey M; Horswill, Alexander R.; Nauseef, William M.

    2013-01-01

    To establish infection successfully, S. aureus must evade clearance by polymorphonuclear neutrophils (PMN). We studied the expression and regulation of the methionine sulfoxide reductases (Msr) that are involved in the repair of oxidized staphylococcal proteins and investigated their influence over the fate of S. aureus exposed to oxidants or PMN. We evaluated a mutant deficient in msrA1 and msrB for susceptibility to hydrogen peroxide, hypochlorous acid and PMN. The expression of msrA1 in wild-type bacteria ingested by human PMN was assessed by real-time PCR. The regulation of msr was studied by screening a library of two-component regulatory system (TCS) mutants for altered msr responses. Relative to the wild-type, bacteria deficient in Msr were more susceptible to oxidants and to PMN. Upregulation of staphylococcal msrA1 occurred within the phagosomes of normal PMN and PMN deficient in NADPH oxidase activity. Furthermore, PMN granule-rich extract stimulated the upregulation of msrA1. Modulation of msrA1 within PMN was shown to be partly dependent on the VraSR TCS. Msr contributes to staphylococcal responses to oxidative attack and PMN. Our study highlights a novel interaction between the oxidative protein repair pathway and the VraSR TCS that is involved in cell wall homeostasis. PMID:24247266

  1. Absence of granulocyte colony-stimulating factor signaling and neutrophil development in CCAAT enhancer binding protein alpha-deficient mice.

    PubMed

    Zhang, D E; Zhang, P; Wang, N D; Hetherington, C J; Darlington, G J; Tenen, D G

    1997-01-21

    Transcription factors are master regulatory switches of differentiation, including the development of specific hematopoietic lineages from stem cells. Here we show that mice with targeted disruption of the CCAAT enhancer binding protein alpha gene (C/EBP alpha) demonstrate a selective block in differentiation of neutrophils. Mature neutrophils and eosinophils are not observed in the blood or fetal liver of mutant animals, while other hematopoietic lineages, including monocytes, are not affected. Instead, most of the white cells in the peripheral blood of mutant mice had the appearance of myeloid blasts. We also observed a selective loss of expression of a critical gene target of CCAAT enhancer binding protein alpha, the granulocyte colony-stimulating factor receptor. As a result, multipotential myeloid progenitors from the mutant fetal liver are unable to respond to granulocyte colony-stimulating factor signaling, although they are capable of forming granulocyte-macrophage and macrophage colonies in methylcellulose in response to other growth factors. Finally, we demonstrate that the lack of granulocyte development results from a defect intrinsic to the hematopoietic system; transplanted fetal liver from mutant mice can reconstitute lymphoid but not neutrophilic cells in irradiated recipients. These studies suggest a model by which transcription factors can direct the differentiation of multipotential precursors through activation of expression of a specific growth factor receptor, allowing proliferation and differentiation in response to a specific extracellular signal. In addition, the c/ebp alpha -/- mice may be useful in understanding the mechanisms involved in acute myelogenous leukemia, in which a block in differentiation of myeloid precursors is a key feature of the disease. PMID:9012825

  2. Characterization of Neutrophil Subsets in Healthy Human Pregnancies

    PubMed Central

    Ssemaganda, Aloysius; Kindinger, Lindsay; Bergin, Philip; Nielsen, Leslie; Mpendo, Juliet; Ssetaala, Ali; Kiwanuka, Noah; Munder, Markus; Teoh, Tiong Ghee; Kropf, Pascale; Müller, Ingrid

    2014-01-01

    We have previously shown that in successful pregnancies increased arginase activity is a mechanism that contributes to the suppression of the maternal immune system. We identified the main type of arginase-expressing cells as a population of activated low-density granulocytes (LDGs) in peripheral blood mononuclear cells and in term placentae. In the present study, we analyzed the phenotype of LDGs and compared it to the phenotype of normal density granulocytes (NDGs) in maternal peripheral blood, placental biopsies and cord blood. Our data reveal that only LDGs but no NDGs could be detected in placental biopsies. Phenotypically, NDGs and LDGs from both maternal and cord blood expressed different levels of maturation, activation and degranulation markers. NDGs from the maternal and cord blood were phenotypically similar, while maternal, cord and placental LDGs showed different expression levels of CD66b. LDGs present in cord blood expressed higher levels of arginase compared to maternal and placental LDGs. In summary, our results show that in maternal and cord blood, two phenotypically different populations of neutrophils can be identified, whereas in term placentae, only activated neutrophils are present. PMID:24551035

  3. Silver nanoparticles rapidly induce atypical human neutrophil cell death by a process involving inflammatory caspases and reactive oxygen species and induce neutrophil extracellular traps release upon cell adhesion.

    PubMed

    Liz, Rafael; Simard, Jean-Christophe; Leonardi, Laurien Bruna Araújo; Girard, Denis

    2015-09-01

    Inflammation is one of the major toxic effects reported in response to in vitro or in vivo nanoparticle (NP) exposure. Among engineered NPs, silver nanoparticles (AgNPs) are very attractive for the development of therapeutic strategies, especially because of their antimicrobial properties. In humans, neutrophils, key players in inflammation, are the most abundant blood leukocytes that spontaneously undergo apoptosis, a central cell death mechanism regulating inflammation. The aim of this study was to evaluate the effect of AgNPs on neutrophil apoptosis. Transmission electronic microscopy reveals that AgNPs rapidly penetrate inside neutrophils. AgNPs induced atypical cell death where the cell volume increased and the cell surface expression of CD16 remained unaltered unlike apoptotic neutrophils where cell shrinkage and loss of CD16 are typically observed. The AgNP-induced atypical cell death is distinct from necrosis and reversed by a pancaspase inhibitor or by inhibitors of the inflammatory caspase-1 and caspase-4. In addition, AgNPs induced IL-1β production inhibited by caspase-1 and caspase-4 inhibitors and also induced caspase-1 activity. Reactive oxygen species (ROS) production was increased by AgNPs and the atypical cell death was inhibited by the antioxidant n-acetylcysteine. Under similar experimental conditions, adhesion of neutrophils leads to neutrophil extracellular trap (NET) release induced by AgNPs. However, this process was not reversed by caspase inhibitors. We conclude that AgNPs rapidly induced an atypical cell death in neutrophils by a mechanism involving caspase-1, -4 and ROS. However, in adherent neutrophils, AgNPs induced NET release and, therefore, are novel agents able to trigger NET release. PMID:26241783

  4. Microfluidic assay for precise measurements of mouse, rat, and human neutrophil chemotaxis in whole-blood droplets.

    PubMed

    Jones, Caroline N; Hoang, Anh N; Martel, Joseph M; Dimisko, Laurie; Mikkola, Amy; Inoue, Yoshitaka; Kuriyama, Naohide; Yamada, Marina; Hamza, Bashar; Kaneki, Masao; Warren, H Shaw; Brown, Diane E; Irimia, Daniel

    2016-07-01

    Animal models of human disease differ in innate immune responses to stress, pathogens, or injury. Precise neutrophil phenotype measurements could facilitate interspecies comparisons. However, such phenotype comparisons could not be performed accurately with the use of current assays, as they require the separation of neutrophils from blood using species-specific protocols, and they introduce distinct artifacts. Here, we report a microfluidic technology that enables robust characterization of neutrophil migratory phenotypes in a manner independent of the donor species and performed directly in a droplet of whole blood. The assay relies on the particular ability of neutrophils to deform actively during chemotaxis through microscale channels that block the advance of other blood cells. Neutrophil migration is measured directly in blood, in the presence of other blood cells and serum factors. Our measurements reveal important differences among migration counts, velocity, and directionality among neutrophils from 2 common mouse strains, rats, and humans. PMID:26819316

  5. Reactive oxygen species (ROS) production in human peripheral blood neutrophils exposed in vitro to static magnetic field.

    PubMed

    Poniedziałek, Barbara; Rzymski, Piotr; Karczewski, Jacek; Jaroszyk, Feliks; Wiktorowicz, Krzysztof

    2013-12-01

    The aim of this study was to determine the effect of gradient static magnetic field (SMF) on reactive oxygen species (ROS) production in human neutrophils in peripheral blood in vitro. Blood samples collected from healthy individuals were incubated in an inhomogeneous SMF (in a south or north pole of the field) for 15, 30 or 45 minutes. The maximum value of induction (B max) amounted to ≈ 60 mT. To determine the strength of the ROS production, dihydrorhodamine (123DHR) as fluorophore and phorbol 12-myristate 13-acetate (PMA) as respiratory burst stimulator were used. 123DHR oxidation by ROS was measured by flow cytometry. The exposure of blood samples to SMF induced statistically significant changes in ROS production in unstimulated and PMA-stimulated neutrophils. The observed effects were highly correlated with the exposure time and depended on the orientation of the field. Although intracellular mechanisms underlying such interactions are not thoroughly understood, it could be presumed that SMF affects ROS metabolic oscillations and their formation and inactivation. This study emphasizes the importance of proper adjustment of exposure time to SMF for any potential therapeutic applications. PMID:23631724

  6. Specificity of antibodies against Neisseria gonorrhoeae that stimulate neutrophil chemotaxis. Role of antibodies directed against lipooligosaccharides.

    PubMed Central

    Densen, P; Gulati, S; Rice, P A

    1987-01-01

    Five strains each of Neisseria gonorrhoeae sensitive or resistant to complement (C) dependent killing by normal human serum (NHS) were examined for their ability to stimulate chemotaxis of polymorphonuclear leukocytes (PMNs) after preincubation with NHS; or IgM or IgG derived from NHS. Serum-sensitive N. gonorrhoeae stimulated C-dependent chemotaxis when opsonized with IgM, but not IgG, however, serum-resistant strains, taken as a whole, failed to promote chemotaxis when opsonized with either isotype. IgM titers in NHS against lipooligosaccharide (LOS) antigens from individual serum-sensitive, but not serum-resistant strains, correlated with the magnitude of chemotaxis generated by the corresponding opsonized strains (r = 0.99). Western blots demonstrated that IgM and IgG from NHS recognized different antigenic determinants on LOS from serum-sensitive gonococci. IgM from NHS immunopurified against serum-sensitive LOS accounted for two-thirds of the chemotaxis promoting activity present in whole serum. IgG titers in NHS against LOS antigens from individual serum-resistant strains also correlated with magnitude of chemotaxis generated by the corresponding opsonized strains (r = 0.87), although most opsonized serum-resistant strains did not generate significantly higher magnitudes of chemotaxis than controls. In contrast, a serum-resistant isolate from a patient with disseminated gonococcal infection (DGI) stimulated chemotaxis when opsonized with IgG obtained from the patient's convalescent serum. By Western blot, convalescent IgG antibody recognized an additional determinant on serum-resistant LOS not seen by normal IgG. Images PMID:2439546

  7. Inhibition of the lymphocyte metabolic switch by the oxidative burst of human neutrophils.

    PubMed

    Kramer, Philip A; Prichard, Lynn; Chacko, Balu; Ravi, Saranya; Overton, E Turner; Heath, Sonya L; Darley-Usmar, Victor

    2015-09-01

    Activation of the phagocytic NADPH oxidase-2 (NOX-2) in neutrophils is a critical process in the innate immune system and is associated with elevated local concentrations of superoxide, hydrogen peroxide (H2O2) and hypochlorous acid. Under pathological conditions, NOX-2 activity has been implicated in the development of autoimmunity, indicating a role in modulating lymphocyte effector function. Notably, T-cell clonal expansion and subsequent cytokine production requires a metabolic switch from mitochondrial respiration to aerobic glycolysis. Previous studies demonstrate that H2O2 generated from activated neutrophils suppresses lymphocyte activation but the mechanism is unknown. We hypothesized that activated neutrophils would prevent the metabolic switch and suppress the effector functions of T-cells through a H2O2-dependent mechanism. To test this, we developed a model co-culture system using freshly isolated neutrophils and lymphocytes from healthy human donors. Extracellular flux analysis was used to assess mitochondrial and glycolytic activity and FACS analysis to assess immune function. The neutrophil oxidative burst significantly inhibited the induction of lymphocyte aerobic glycolysis, caused inhibition of oxidative phosphorylation and suppressed lymphocyte activation through a H2O2-dependent mechanism. Hydrogen peroxide and a redox cycling agent, DMNQ, were used to confirm the impact of H2O2 on lymphocyte bioenergetics. In summary, we have shown that the lymphocyte metabolic switch from mitochondrial respiration to glycolysis is prevented by the oxidative burst of neutrophils. This direct inhibition of the metabolic switch is then a likely mechanism underlying the neutrophil-dependent suppression of T-cell effector function. PMID:25951298

  8. A lack of confirmation with alternative assays questions the validity of IL-17A expression in human neutrophils using immunohistochemistry.

    PubMed

    Tamarozzi, Francesca; Wright, Helen L; Thomas, Huw B; Edwards, Steven W; Taylor, Mark J

    2014-12-01

    We identified IL-17A-positive neutrophils in Wolbachia-positive Onchocerca volvulus nodules using an antibody that has previously reported IL-17A-positive neutrophils in several inflammatory conditions. However, we could not detect IL-17A using a range of alternative assays. Our data question the IL-17A antibody specificity and the ability of human neutrophils to express IL-17A. PMID:25445614

  9. Staphylococcus aureus Panton-Valentine Leukocidin Is a Very Potent Cytotoxic Factor for Human Neutrophils

    PubMed Central

    Löffler, Bettina; Hussain, Muzaffar; Grundmeier, Matthias; Brück, Michaela; Holzinger, Dirk; Varga, Georg; Roth, Johannes; Kahl, Barbara C.; Proctor, Richard A.; Peters, Georg

    2010-01-01

    The role of the pore-forming Staphylococcus aureus toxin Panton-Valentine leukocidin (PVL) in severe necrotizing diseases is debated due to conflicting data from epidemiological studies of community-associated methicillin-resistant S. aureus (CA-MRSA) infections and various murine disease-models. In this study, we used neutrophils isolated from different species to evaluate the cytotoxic effect of PVL in comparison to other staphylococcal cytolytic components. Furthermore, to study the impact of PVL we expressed it heterologously in a non-virulent staphylococcal species and examined pvl-positive and pvl-negative clinical isolates as well as the strain USA300 and its pvl-negative mutant. We demonstrate that PVL induces rapid activation and cell death in human and rabbit neutrophils, but not in murine or simian cells. By contrast, the phenol-soluble modulins (PSMs), a newly identified group of cytolytic staphylococcal components, lack species-specificity. In general, after phagocytosis of bacteria different pvl-positive and pvl-negative staphylococcal strains, expressing a variety of other virulence factors (such as surface proteins), induced cell death in neutrophils, which is most likely associated with the physiological clearing function of these cells. However, the release of PVL by staphylococcal strains caused rapid and premature cell death, which is different from the physiological (and programmed) cell death of neutrophils following phagocytosis and degradation of virulent bacteria. Taken together, our results question the value of infection-models in mice and non-human primates to elucidate the impact of PVL. Our data clearly demonstrate that PVL acts differentially on neutrophils of various species and suggests that PVL has an important cytotoxic role in human neutrophils, which has major implications for the pathogenesis of CA-MRSA infections. PMID:20072612

  10. 4-Methylcoumarin Derivatives Inhibit Human Neutrophil Oxidative Metabolism and Elastase Activity

    PubMed Central

    Fuzissaki, Carolina N.; Andrade, Micássio F.; Azzolini, Ana Elisa C.S.; Taleb-Contini, Silvia H.; Vermelho, Roberta B.; Lopes, João Luis C.; Lucisano-Valim, Yara Maria

    2013-01-01

    Abstract Increased neutrophil activation significantly contributes to the tissue damage in inflammatory illnesses; this phenomenon has motivated the search for new compounds to modulate their effector functions. Coumarins are natural products that are widely consumed in the human diet. We have evaluated the antioxidant and immunomodulator potential of five 4-methylcoumarin derivatives. We found that the 4-methylcoumarin derivatives inhibited the generation of reactive oxygen species by human neutrophils triggered by serum-opsonized zymosan or phorbol-12-myristate-13-acetate; this inhibition occurred in a concentration-dependent manner, as revealed by lucigenin- and luminol-enhanced chemiluminescence assays. Cytotoxicity did not mediate this inhibitory effect. The 7,8-dihydroxy-4-methylcoumarin suppressed the neutrophil oxidative metabolism more effectively than the 6,7- and 5,7-dihydroxy-4-methylcoumarins, but the 5,7- and 7,8-diacetoxy-4-methylcoumarins were less effective than their hydroxylated counterparts. An analysis of the biochemical pathways suggested that the 6,7- and 7,8-dihydroxy-4-methylcoumarins inhibit the protein kinase C-mediated signaling pathway, but 5,7-dihydroxy-4-methylcoumarin, as well as 5,7- and 7,8-diacetoxy-4-methylcoumarins do not significantly interfere in this pathway of the activation of the human neutrophil oxidative metabolism. The 4-methylcoumarin derivatives bearing the catechol group suppressed the elastase and myeloperoxidase activity and reduced the 1,1-diphenyl-2-picrylhydrazyl free radical the most strongly. Interestingly, the 5,7-dihydroxy-4-methylcoumarin scavenged hypochlorous acid more effectively than the o-dihydroxy-substituted 4-methylcoumarin derivatives, and the diacetoxylated 4-methylcoumarin derivatives scavenged hypochlorous acid as effectively as the 7,8-dihydroxy-4-methylcoumarin. The significant influence of small structural modifications in the inhibitory potential of 4-methylcoumarin derivatives on the

  11. A Bio-Sensor for Human Neutrophil Elastase Employs Peptide-p-nitroanilide Cellulose Conjugates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High levels of human neutrophil elastase (HNE) in chronic wounds have been associated with degradation of cytokine growth factors necessary for normal wound healing. Thus, accurate clinical detection and quantification of HNE will be important to the therapeutic management of chronic wounds. Colorim...

  12. Activity determination, kinetic analyses and isoenzyme identification of gamma glutamyltransferase in human neutrophils.

    PubMed

    Sener, Azize; Yardimci, Turay

    2005-05-31

    Gamma-glutamyltransferase (GGT, EC 2.3.2.2) which hydrolyzes glutathione (GSH), is required for the maintenance of normal intracellular GSH concentration. GGT is a membrane enzyme present in leukocytes and platelets. Its activity has also been observed in human neutrophils. In this study, GGT was purified from Triton X-100 solubilized neutrophils and its kinetic parameters were determined. For kinetic analyses of transpeptidation reaction, gamma-glutamyl p-nitroanilide was used as the substrate and glycylglycine as the acceptor. Apparent K(m) values were determined as 1.8 mM for gamma-glutamyl p-nitroanilide and 16.9 mM for glycylglycine. The optimum pH of GGT activity was 8.2 and the optimum temperature was 37 degrees C. It had thermal stability with 58 % relative activity at 56 degrees C for 30 min incubation. L-serine, in the presence of borate, was detected as the competitive inhibitor. Bromcresol green inhibited neutrophil GGT activity as a noncompetitive inhibitor. The neutrophils seem to contain only the isoenzyme that is present in platelets. We characterized the kinetic properties and compared the type of the isoenzyme of neutrophil GGT with platelet GGT via polyacrylamide gel electrophoresis (PAGE) under a standard set of conditions. PMID:15943911

  13. Apolipoprotein B mediates the capacity of low density lipoprotein to suppress neutrophil stimulation by particulates.

    PubMed

    Terkeltaub, R; Martin, J; Curtiss, L K; Ginsberg, M H

    1986-11-25

    Low density lipoprotein (LDL) inhibits phagocytosis of certain negatively charged particulates and also inhibits subsequent cellular secretory and oxidative responses to these particulates. In the present work, we have defined the structural features of LDL involved in this activity. Starch-heptane extraction depleted greater than 95% of neutral lipids but had little effect on the capacity of LDL to inhibit monosodium urate crystal- or polystyrene latex bead-induced neutrophil chemiluminescence (CL). Liposomes containing gamma-palmitoyl-beta-oleoylphosphatidylcholine (PC) with unesterified cholesterol (PC:cholesterol = 2:1), PC and sphingomyelin (PC:sphingomyelin = 2.3:1), or PC alone lacked the capacity to inhibit urate-induced CL. However, incorporation of apoB-100 into liposomes via cholate dialysis rendered them nearly as inhibitory for urate-induced neutrophil CL as LDL on a protein weight basis. Moreover, delipidated apoB-100, containing less than 3% residual phospholipid, inhibited neutrophil responses to urate crystals or latex beads (degranulation and superoxide anion release) in a stimulus-specific manner. Modifications of the lysine residues of apoB (e.g. acetylation) reduced both the capacity of LDL to inhibit urate crystal-induced CL and to bind to urate crystals. The effects of apoB lysine residue modification were reversible, proportional to the extent of modification, and were not attributable to alteration of the net charge of apoB. Thus, the apoB-100 of LDL both mediates and shares the capacity of native LDL to inhibit certain neutrophil responses to particulates. PMID:3096995

  14. Design of a Selective Substrate and Activity Based Probe for Human Neutrophil Serine Protease 4.

    PubMed

    Kasperkiewicz, Paulina; Poreba, Marcin; Snipas, Scott J; Lin, S Jack; Kirchhofer, Daniel; Salvesen, Guy S; Drag, Marcin

    2015-01-01

    Human neutrophil serine protease 4 (NSP4), also known as PRSS57, is a recently discovered fourth member of the neutrophil serine proteases family. Although its biological function is not precisely defined, it is suggested to regulate neutrophil response and innate immune reactions. To create optimal substrates and visualization probes for NSP4 that distinguish it from other NSPs we have employed a Hybrid Combinatorial Substrate Library approach that utilizes natural and unnatural amino acids to explore protease subsite preferences. Library results were validated by synthesizing individual substrates, leading to the identification of an optimal substrate peptide. This substrate was converted to a covalent diphenyl phosphonate probe with an embedded biotin tag. This probe demonstrated high inhibitory activity and stringent specificity and may be suitable for visualizing NSP4 in the background of other NSPs. PMID:26172376

  15. Motile Human Neutrophils Sense Ligand Density Over Their Entire Contact Area.

    PubMed

    Henry, Steven J; Crocker, John C; Hammer, Daniel A

    2016-04-01

    Neutrophils are key components of the immune system and motility is central their function during the inflammatory response. We have previously demonstrated that neutrophils are capable of switching their motile phenotype between amoeboid-like and keratocyte-like in response to the ligand density of adhesion molecules (Henry et al. in Int Biol 6:348-356, 2014). In this study, we engineered planar micropatterned surfaces that presented adhesion molecules in local islands of high density, separated by regions largely devoid of ligands. By controlling the geometry of islands we made arrays in which the local (on island) adhesion density was high but the global (multi-island) adhesion density over the entire cell-substrate interface was low. Neutrophils in contact with these island arrays assumed a well-spread and directionally-persistent motile phenotype (keratocyte-like) in contrast to the classical amoeboid morphology they display on uniform fields of high adhesion density. By virtue of our rationally designed substrates, we were able to conclude that neutrophils were integrating the stimulation received across their entire contact interface; furthermore, they were able to mount this whole cell response on the timescale of seconds. This work demonstrates the capacity of adhesive microenvironments to direct the phenotype of cell motility, which has broader implications in physiologic processes such as inflammation and cancer metastasis. PMID:26219404

  16. Neutrophils extracellular traps damage Naegleria fowleri trophozoites opsonized with human IgG.

    PubMed

    Contis-Montes de Oca, A; Carrasco-Yépez, M; Campos-Rodríguez, R; Pacheco-Yépez, J; Bonilla-Lemus, P; Pérez-López, J; Rojas-Hernández, S

    2016-08-01

    Naegleria fowleri infects humans through the nasal mucosa causing a disease in the central nervous system known as primary amoebic meningoencephalitis (PAM). Polymorphonuclear cells (PMNs) play a critical role in the early phase of N. fowleri infection. Recently, a new biological defence mechanism called neutrophil extracellular traps (NETs) has been attracting attention. NETs are composed of nuclear DNA combined with histones and antibacterial proteins, and these structures are released from the cell to direct its antimicrobial attack. In this work, we evaluate the capacity of N. fowleri to induce the liberation of NETs by human PMN cells. Neutrophils were cocultured with unopsonized or IgG-opsonized N. fowleri trophozoites. DNA, histone, myeloperoxidase (MPO) and neutrophil elastase (NE) were stained, and the formation of NETs was evaluated by confocal microscopy and by quantifying the levels of extracellular DNA. Our results showed N. fowleri induce the liberation of NETs including release of MPO and NE by human PMN cells as exposure interaction time is increased, but N. fowleri trophozoites evaded killing. However, when trophozoites were opsonized, they were susceptible to the neutrophils activity. Therefore, our study suggests that antibody-mediated PMNs activation through NET formation may be crucial for antimicrobial responses against N. fowleri. PMID:27189133

  17. Assessment of Antioxidant Activity of Spray Dried Extracts of Psidium guajava Leaves by DPPH and Chemiluminescence Inhibition in Human Neutrophils

    PubMed Central

    Fernandes, M. R. V.; Azzolini, A. E. C. S.; Martinez, M. L. L.; Souza, C. R. F.; Lucisano-Valim, Y. M.; Oliveira, W. P.

    2014-01-01

    This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and β-cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH• method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells. PMID:24822200

  18. Complement factor H modulates the activation of human neutrophil granulocytes and the generation of neutrophil extracellular traps.

    PubMed

    Schneider, Andrea E; Sándor, Noémi; Kárpáti, Éva; Józsi, Mihály

    2016-04-01

    Factor H (FH) is a major inhibitor of the alternative pathway of complement activation in plasma and on certain host surfaces. In addition to being a complement regulator, FH can bind to various cells via specific receptors, including binding to neutrophil granulocytes through complement receptor type 3 (CR3; CD11b/CD18), and modulate their function. The cellular roles of FH are, however, poorly understood. Because neutrophils are important innate immune cells in inflammatory processes and the host defense against pathogens, we aimed at studying the effects of FH on various neutrophil functions, including the generation of extracellular traps. FH co-localized with CD11b on the surface of neutrophils isolated from peripheral blood of healthy individuals, and cell-bound FH retained its cofactor activity and enhanced C3b degradation. Soluble FH supported neutrophil migration and immobilized FH induced cell spreading. In addition, immobilized but not soluble FH enhanced IL-8 release from neutrophils. FH alone did not trigger the cells to produce neutrophil extracellular traps (NETs), but NET formation induced by PMA and by fibronectin plus fungal β-glucan were inhibited by immobilized, but not by soluble, FH. Moreover, in parallel with NET formation, immobilized FH also inhibited the production of reactive oxygen species induced by PMA and by fibronectin plus β-glucan. Altogether, these data indicate that FH has multiple regulatory roles on neutrophil functions. While it can support the recruitment of neutrophils, FH may also exert anti-inflammatory effects and influence local inflammatory and antimicrobial reactions, and reduce tissue damage by modulating NET formation. PMID:26938503

  19. Regulation of surface expression of the granulocyte/macrophage colony-stimulating factor receptor in normal human myeloid cells

    SciTech Connect

    Cannistra, S.A.; Groshek, P.; Griffin, J.D. ); Garlick, R.; Miller, J. )

    1990-01-01

    Recombinant human granulocyte/macrophage colony-stimulating factor (GM-CSF) exerts stimulatory effects on hematopoietic cells through binding to specific, high-affinity receptors. By using radiolabeled GM-CSF with high specific activity, the authors have investigated the factors and mechanisms that regulate GM-CSF receptor expression in normal human neutrophils, monocytes, and partially purified bone marrow myeloid progenitor cells. The neutrophil GM-CSF receptor was found to rapidly internalize in the presence of ligand through a mechanism that required endocytosis. Out of a large panel of naturally occurring humoral factors tested, only GM-CSF itself, tumor necrosis factor, and formyl-Met-Leu-Phe were found to down-regulate neutrophil GM-CSF receptor expression after a 2-hr exposure at biologically active concentrations. Since formyl-Met-Leu-Phe is known to stimulate neutrophil protein kinase C activity, they also tested the ability of protein kinase C agonists to modulate GM-CSF receptor expression. Phorbol 12-myristate 13-acetate, bryostatin-1, and 1,2-dioctanoylglycerol were found to induce rapid down-regulation of the GM-CSF receptor in neutrophils, monocytes, and partially purified myeloid progenitor cells, suggesting that this effect may be at least partially mediated by protein kinase C. These data suggest that certain activators of neutrophil function may negatively regulate their biological effects by inducing down-regulation of the GM-CSF receptor.

  20. Human Neutrophil Elastase Induce Interleukin-10 Expression in Peripheral Blood Mononuclear Cells through Protein Kinase C Theta/Delta and Phospholipase Pathways

    PubMed Central

    Kawata, Jin; Yamaguchi, Rui; Yamamoto, Takatoshi; Ishimaru, Yasuji; Sakamoto, Arisa; Aoki, Manabu; Kitano, Masafumi; Umehashi, Misako; Hirose, Eiji; Yamaguchi, Yasuo

    2016-01-01

    Objective Neutrophils have an important role in the rapid innate immune response, and the release or active secretion of elastase from neutrophils is linked to various inflammatory responses. Purpose of this study was to determine how the human neutrophil elastase affects the interleukin-10 (IL-10) response in peripheral blood mononuclear cells (PBMC). Materials and Methods In this prospective study, changes in IL-10 messenger RNA (mRNA) and protein expression levels in monocytes derived from human PBMCs were investigated after stimulation with human neutrophil elastase (HNE). A set of inhibitors was used for examining the pathways for IL-10 production induced by HNE. Results Reverse transcription polymerase chain reaction (RT-PCR) showed that stimulation with HNE upregulated IL-10 mRNA expression by monocytes, while the enzyme-linked immunosorbent assay (ELISA) revealed an increase of IL-10 protein level in the culture medium. A phospholipase C inhibitor (U73122) partially blunt- ed the induction of IL-10 mRNA expression by HNE, while IL-10 mRNA expression was significantly reduced by a protein kinase C (PKC) inhibitor (Rottlerin). A calcium chelator (3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester: TMB-8) inhibited the response of IL-10 mRNA to stimulation by HNE. In addition, pretreatment with a broad-spectrum PKC inhibitor (Ro-318425) partly blocked the response to HNE. Finally, an inhibitor of PKC theta/delta abolished the increased level of IL-10 mRNA expression. Conclusion These results indicate that HNE mainly upregulates IL-10 mRNA ex- pression and protein production in moncytes via a novel PKC theta/delta, although partially via the conventional PKC pathway. PMID:26862528

  1. [Roles of intracellular calcium and monomeric G-proteins in regulating exocytosis of human neutrophils].

    PubMed

    Zhu, Ying; Wang, Jun-Han; Wu, Jian-Min; Xu, Tao; Zhang, Chun-Guang

    2003-12-25

    Neutrophils play a major role in host defense against microbial infection. There are some clues indicate that neutrophils may also play a role in the pathophysiology of the airway obstruction in chronic asthma. We studied the roles of intracellular calcium and GTP gamma S in the regulation of neutrophils exocytosis using pipette perfusion and membrane capacitance measurement technique in whole cell patch clamp configuration. The results showed that the membrane capacitance increase induced by calcium revealed a biphasic process. The first phase occurred when the calcium level was between 0.2-14 micromol/L with a plateau amplitude of 1.23 pF and a calcium EC50 of 1.1 micromol/L. This phase might correspond to the release of the tertiary granules. The second phase occurred when the calcium concentration was between 20-70 micromol/L with a plateau increment of 6.36 pF, the calcium EC50 being about 33 micromol/L. This phase might represent the release of the primary and secondary granules. Intracellular calcium also simultaneously increased the exocytotic rate and the eventual extent in neutrophils. On the other hand, GTP gamma S can increase the exocytotic rate in a dose-dependent manner but had no effect on the eventual extent of membrane capacitance increment (>6 pF) if the cell was stimulated for a long period (>20 min). GTP gamma S (ranging from 20 to 100 micromol/L) induced the neutrophils to release all four types of the granules at very low intracellular calcium level. PMID:14695488

  2. The effect of leptin on the respiratory burst of human neutrophils cultured in synovial fluid

    PubMed Central

    Rzodkiewicz, Przemysław; Gajewska, Joanna; Wojtecka-Łukasik, Elżbieta

    2015-01-01

    Objectives Leptin is a hormone responsible for nutritional status and immune competence coordination. In rheumatoid arthritis (RA) increased leptin levels were observed in both serum and synovial fluid. Its influence on development of the disease still remains unclear. So far, research on leptin's influence on the emission of reactive oxygen intermediates (ROI) measured with chemiluminescence (CL) has provided unclear and contradictory results. In this study, we evaluated the influence of leptin on oxidative activity of neutrophils isolated from blood of healthy volunteers and cultured in different amounts of synovial fluid (SF) from patients with RA. Material and methods Neutrophils’ oxidative metabolism was measured by two types of CL. The first one, luminol-dependent CL (CL-lum), allows one to determine phagocytic activity and the level of ROI generated in a myeloperoxidase-dependent manner. The second method used was lucigenin-dependent CL (CL-luc), which monitors ROI production dependent on the NADPH oxidase enzyme complex located in the cell membranes of neutrophils and enables one to determine the scope of extracellular ROI emission. Results Neutrophils stimulated by opsonized zymosan show a decrease in the level of CL-lum, proportional to the increasing concentration of both SF and serum collected from healthy donors. The observed effect of decreased CL-lum may, therefore, be dependent on the physical conditions (viscosity of fluids used). None of these experiments showed any effect of leptin on the level of CL-lum. Conclusions The present study showed that leptin does not affect the level of any of the CL types in inactive neutrophils incubated in normal serum, and it does not affect the level of oxidative activity in resting neutrophils incubated with SF. However, leptin influences extracellular ROI emission (measured by CL-luc). Leptin reduces extracellular emission of ROI, and this effect is dependent on concentration and duration of exposure to

  3. Comparative oxidation of loxapine and clozapine by human neutrophils.

    PubMed

    Jegouzo, A; Gressier, B; Frimat, B; Brunet, C; Dine, T; Luyckx, M; Kouach, M; Cazin, M; Cazin, J C

    1999-01-01

    The clozapine-induced agranulocytosis could be due to the formation of a reactive intermediate formed in polymorphonuclear neutrophils and granulocyte precursors with the myeloperoxidase-hydrogen peroxide system. On the contrary, no case of agranulocytosis has been described for loxapine, an other neuroleptic drug with a very close structural analogy. We have compared the clozapine and loxapine interaction with the oxidative burst and particularly with this enzymatic complex. On the one hand, the assay of the oxidative species demonstrated a different impact for the two neuroleptics. The 50% inhibitory concentration was 92 microM for hydrogen peroxide and 40 microM for hypochlorous acid for loxapine. The loxapine target is located before the myeloperoxidase-hydrogen peroxide system in the oxidative stream, whereas clozapine diverts the chlorination pathway of the enzyme. On the other hand, the in vitro metabolism of drugs by the myeloperoxidase-hydrogen peroxide system has been investigated by mass spectrometry. Loxapine remains inert but clozapine undergoes the oxidation. The glutathione or ascorbate addition in the medium leads to a removal of the oxidation. Glutathione is able to trap the toxic intermediate and could avoid its formation. PMID:10027097

  4. Granulocyte-macrophage colony-stimulating factor amplifies lipopolysaccharide-induced bronchoconstriction by a neutrophil- and cyclooxygenase 2-dependent mechanism.

    PubMed

    Wollin, L; Uhlig, S; Nüsing, R; Wendel, A

    2001-02-01

    Granulocyte-macrophage colony-stimulating factor (GM-CSF) is used to ameliorate neutropenia in patients after antineoplastic treatment. It has also been suggested as an adjunct treatment in septic patients; however, the recruitment and priming of leukocytes by GM-CSF bears the hazard of a hyperinflammatory response. In particular, the role of GM-CSF in pulmonary functions in septic lungs is still unclear. Therefore, we pretreated rats in vivo with GM-CSF (50 microg/kg, intravenous) and assessed the pulmonary functions of their subsequently prepared isolated perfused lungs when exposed to subtoxic concentrations of lipopolysaccharide (LPS, 2 microg/ml). These lungs showed enhanced expression of cyclooxygenase 2 (COX-2), a significant increase in thromboxane (TX) and tumor necrosis factor (TNF) release into the venous perfusate, and bronchoconstriction. COX-2 inhibition or blocking of the TX receptor abolished the GM-CSF/LPS-induced bronchoconstriction, but not the TNF release. Neutralizing antibodies against TNF did not prevent GM-CSF/LPS-induced bronchoconstriction. After GM-CSF pretreatment, massive neutrophil invasion into the lung occurred. Neutropenic rats were protected against GM-CSF/ LPS-induced lung injury. Similar results were obtained in rats pretreated with G-CSF instead of GM-CSF. We conclude that GM-CSF pretreatment exacerbates pulmonary injury by low-dose LPS via COX-2 expression, TX release, and bronchoconstriction by initiating neutrophil invasion and activation. PMID:11179120

  5. Hypohalous acid-modified human serum albumin induces neutrophil NADPH oxidase activation, degranulation, and shape change.

    PubMed

    Gorudko, Irina V; Grigorieva, Daria V; Shamova, Ekaterina V; Kostevich, Valeria A; Sokolov, Alexey V; Mikhalchik, Elena V; Cherenkevich, Sergey N; Arnhold, Jürgen; Panasenko, Oleg M

    2014-03-01

    Halogenated lipids, proteins, and lipoproteins formed in reactions with myeloperoxidase (MPO)-derived hypochlorous acid (HOCl) and hypobromous acid (HOBr) can contribute to the regulation of functional activity of cells and serve as mediators of inflammation. Human serum albumin (HSA) is the major plasma protein target of hypohalous acids. This study was performed to assess the potency of HSA modified by HOCl (HSA-Cl) and HOBr (HSA-Br) to elicit selected neutrophil responses. HSA-Cl/Br were found to induce neutrophil degranulation, generation of reactive oxygen intermediates, shape change, and actin cytoskeleton reorganization. Thus HSA-Cl/Br can initially act as a switch and then as a feeder of the "inflammatory loop" under oxidative stress. In HSA-Cl/Br-treated neutrophils, monoclonal antibodies against CD18, the β subunit of β2 integrins, reduced the production of superoxide anion radicals and hydrogen peroxide as well as MPO exocytosis, suggesting that CD18 contributed to neutrophil activation. HSA-Cl/Br-induced neutrophil responses were also inhibited by genistein, a broad-specificity tyrosine kinase inhibitor, and wortmannin, a phosphoinositide 3-kinase (PI3K) inhibitor, supporting the notion that activation of both tyrosine kinase and PI3K may play a role in neutrophil activation by HSA modified in MPO-dependent reactions. These results confirm the hypothesis that halogenated molecules formed in vivo via MPO-dependent reactions can be considered as a new class of biologically active substances potentially able to contribute to activation of myeloid cells in sites of inflammation and serve as inflammatory response modulators. PMID:24384524

  6. Potent inhibition of human neutrophil activations by bractelactone, a novel chalcone from Fissistigma bracteolatum

    SciTech Connect

    Wu, Yang-Chang; Sureshbabu, Munisamy; Fang, Yao-Ching; Wu, Yi-Hsiu; Lan, Yu-Hsuan; Chang, Fang-Rong; Chang, Ya-Wen; Hwang, Tsong-Long

    2013-02-01

    Fissistigma bracteolatum is widely used in traditional medicine to treat inflammatory diseases. However, its active components and mechanisms of action remain unclear. In this study, (3Z)-6,7-dihydroxy-4-methoxy-3-(phenylmethylidene)-5-(3-phenylpropanoyl) -1-benzofuran-2(3H) (bractelactone), a novel chalcone from F. bracteolatum, showed potent inhibitory effects against superoxide anion (O{sub 2}{sup ·−}) production, elastase release, and CD11b expression in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-induced human neutrophils. However, bractelactone showed only weak inhibition of phorbol myristate acetate-caused O{sub 2}{sup ·−} production. The peak cytosolic calcium concentration ([Ca{sup 2+}]{sub i}) was unaltered by bractelactone in FMLP-induced neutrophils, but the decay time of [Ca{sup 2+}]{sub i} was significantly shortened. In a calcium-free solution, changes in [Ca{sup 2+}]{sub i} caused by the addition of extracellular Ca{sup 2+} were inhibited by bractelactone in FMLP-activated cells. In addition, bractelactone did not alter the phosphorylation of p38 MAPK, ERK, JNK, or AKT or the concentration of cAMP. These results suggest that bractelactone selectively inhibits store-operated calcium entry (SOCE). In agreement with this concept, bractelactone suppressed sustained [Ca{sup 2+}]{sub i} changes in thapsigargin-activated neutrophils. Furthermore, bractelactone did not alter FMLP-induced formation of inositol 1,4,5-triphosphate. Taken together, our results demonstrate that the anti-inflammatory effects of bractelactone, an active ingredient of F. bracteolatum, in human neutrophils are through the selective inhibition of SOCE. Highlights: ► Bractelactone isolated from Fissistigma bracteolatum. ► Bractelactone inhibited FMLP-induced human neutrophil activations. ► Bractelactone had no effect on IP3 formation. ► Bractelactone did not alter MAPKs, AKT, and cAMP pathways. ► Bractelactone inhibited store-operated calcium entry.

  7. Activated human neutrophil response to perfluorocarbon nanobubbles: oxygen-dependent and -independent cytotoxic responses.

    PubMed

    Hwang, Tsong-Long; Fang, Chia-Lang; Al-Suwayeh, Saleh A; Yang, Li-Jia; Fang, Jia-You

    2011-06-10

    Nanobubbles, a type of nanoparticles with acoustically active properties, are being utilized as diagnostic and therapeutic nanoparticles to better understand, detect, and treat human diseases. The objective of this work was to prepare different nanobubble formulations and investigate their physicochemical characteristics and toxic responses to N-formyl-methionyl-leucyl-phenylalanine (fMLP)-activated human neutrophils. The nanobubbles were prepared using perfluoropentane and coconut oil as the respective core and shell, with soybean phosphatidylcholine (SPC) and/or cationic surfactants as the interfacial layers. The cytotoxic effect of the nanobubbles on neutrophils was determined by extracellular O₂(.)⁻ release, intracellular reactive oxygen species (ROS), lactate dehydrogenase (LDH), and elastase release. Particle sizes of the nanobubbles with different percentages of perfluorocarbon, oil, and surfactants in ranged 186-432 nm. The nanobubbles were demonstrated to inhibit the generation of superoxide and intracellular ROS. The cytotoxicity of nanobubbles may be mainly associated with membrane damage, as indicated by the high LDH leakage. Systems with Forestall (FE), a cationic surfactant, or higher SPC contents exhibited the greatest LDH release by 3-fold compared to the control. The further addition of an oil component reduced the cytotoxicity induced by the nanobubbles. Exposure to most of the nanobubble formulations upregulated elastase release by activated neutrophils. Contrary to this result, stearylamine (SA)-containing systems slightly but significantly suppressed elastase release. FE and SA in a free form caused stronger responses by neutrophils than when they were incorporated into nanobubbles. In summary, exposure to nanobubbles resulted in a formulation-dependent toxicity toward human neutrophils that was associated with both oxygen-dependent and -independent pathways. Clinicians should therefore exercise caution when using nanobubbles in patients

  8. Two Pathways through Cdc42 Couple the N-Formyl Receptor to Actin Nucleation in Permeabilized Human Neutrophils

    PubMed Central

    Glogauer, M.; Hartwig, J.; Stossel, T.

    2000-01-01

    We developed a permeabilization method that retains coupling between N-formyl-methionyl-leucyl-phenylalanine tripeptide (FMLP) receptor stimulation, shape changes, and barbed-end actin nucleation in human neutrophils. Using GTP analogues, phosphoinositides, a phosphoinositide-binding peptide, constitutively active or inactive Rho GTPase mutants, and activating or inhibitory peptides derived from neural Wiskott-Aldrich syndrome family proteins (N-WASP), we identified signaling pathways leading from the FMLP receptor to actin nucleation that require Cdc42, but then diverge. One branch traverses the actin nucleation pathway involving N-WASP and the Arp2/3 complex, whereas the other operates through active Rac to promote actin nucleation. Both pathways depend on phosphoinositide expression. Since maximal inhibition of the Arp2/3 pathway leaves an N17Rac inhibitable alternate pathway intact, we conclude that this alternate involves phosphoinositide-mediated uncapping of actin filament barbed ends. PMID:10953003

  9. Genetic Mechanism of Human Neutrophil Antigen 2 Deficiency and Expression Variations

    PubMed Central

    Li, Yunfang; Mair, David C.; Schuller, Randy M.; Li, Ling; Wu, Jianming

    2015-01-01

    Human neutrophil antigen 2 (HNA-2) deficiency is a common phenotype as 3–5% humans do not express HNA-2. HNA-2 is coded by CD177 gene that associates with human myeloproliferative disorders. HNA-2 deficient individuals are prone to produce HNA-2 alloantibodies that cause a number of disorders including transfusion-related acute lung injury and immune neutropenia. In addition, the percentages of HNA-2 positive neutrophils vary significantly among individuals and HNA-2 expression variations play a role in human diseases such as myelodysplastic syndrome, chronic myelogenous leukemia, and gastric cancer. The underlying genetic mechanism of HNA-2 deficiency and expression variations has remained a mystery. In this study, we identified a novel CD177 nonsense single nucleotide polymorphism (SNP 829A>T) that creates a stop codon within the CD177 coding region. We found that all 829TT homozygous individuals were HNA-2 deficient. In addition, the SNP 829A>T genotypes were significantly associated with the percentage of HNA-2 positive neutrophils. Transfection experiments confirmed that HNA-2 expression was absent on cells expressing the CD177 SNP 829T allele. Our data clearly demonstrate that the CD177 SNP 829A>T is the primary genetic determinant for HNA-2 deficiency and expression variations. The mechanistic delineation of HNA-2 genetics will enable the development of genetic tests for diagnosis and prognosis of HNA-2-related human diseases. PMID:26024230

  10. Chimaeric Lym-1 monoclonal antibody-mediated cytolysis by neutrophils from G-CSF-treated patients: stimulation by GM-CSF and role of Fc gamma -receptors.

    PubMed

    Ottonello, L; Epstein, A L; Mancini, M; Tortolina, G; Dapino, P; Dallegri, F

    2001-08-01

    Chimaeric Lym-1 (chLym-1) is a monoclonal antibody generated by fusing the variable region genes of murine Lym-1 to human gamma1 and kappa constant regions. Owing to its selectivity and avidity for human malignant B cells, it is an attractive candidate for developing immune-interventions in B-lymphomas. In the attempt to identify rational bases for optimizing potential chLym-1 related therapeutic approaches, we studied the ability of this ch-mAb to trigger neutrophil-mediated Raji cell cytolysis in cooperation with two neutrophil-related cytokines, G-CSF and GM-CSF. ChLym-1 triggered low levels of cytolysis by normal neutrophils but induced consistent cytolysis in neutrophils from individuals treated with G-CSF. When exposed to GM-CSF, neutrophils from subjects treated with G-CSF became potent effectors, also leading to 75% lysis. By using mAbs specific for distinct FcgammaRs, normal neutrophils were inhibited by mAb IV.3, suggesting the intervention of FcgammaRII, constitutively expressed on the cells. On the other hand, neutrophils from patients treated with G-CSF were inhibited by mAb IV.3 plus mAb 197, a finding consistent with a cooperative intervention of FCgammaRII and G-CSF-induced FcgammaRI. The anti-FcgammaRIII mAb 3G8 promoted significant enhancement of the neutrophil cytolytic efficiency. Therefore, neutrophil FcgammaRIII behaves as a down-regulator of the cytolytic potential. The present findings suggest new attempts to develop mAb-based and G-CSF/GM-CSF combined immune-interventions in B lymphomas. PMID:11487281