bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronic Treatment With P2-Purinergic Receptor Agonists Induces Phenotypic Modulation of the HL-60 and U937 Human Myelogenous Leukemia Cell Lines
Authors: Cowen Daniel S , Berger Melvin , Nuttle Louise , Dubyak George R 
Published: January 2018

Abstract
In previous studies we have demonstrated that extracellular ATP (and UTP), acting through P2-purinergic receptors, can stimulate the inositol phospholipid signaling system in neutrophils and monocytes, as well as in neutrophil monocyte progenitor cells. In this study we have examined the ability of extracellular nucleotides to modulate the phenotype of myelomonocytic progenitor cells. As model systems, we utilized the established HL-60 promyelocytic and U937 promonocytic human cell lines which were cultured in the continuous presence of nucleotides known to be potent agonists for P2-purinergic receptors. When cultured for 5 days with ATPγS (a phosphatase resistant analog of ATP) plus 10% fetal bovine serum, both HL-60 cells and U937 cells expressed several (but not all) phenotypic characteristics of differentiated phagocytes. In HL-60 cells these characteristics were (1) increased intracellular calcium mobilization in response to formylated chemotactic peptides, (2) a reduction in cell size with a decreased nuclear cytoplasmic ratio, (3) a sharply reduced rate of proliferation, (4) a reduction in the percentage of cells expressing surface transferrin receptors, and (5) an increase in the percentage of cells expressing the type 1 complement receptor (CR1). In U937 cells these characteristics were (1) increased intracellular calcium mobilization in response to formylated chemotactic peptides and platelet activating factor, (2) a reduced rate of proliferation, (3) a reduction in the percentage of cells expressing surface transferrin receptors, and (4) increases in the percentage of cells expressing both type 1 (CR1) and type 3 (CR3) complement receptors. During the first 12-24 hr after exposure to ATPγS, HL-60 cells showed no obvious changes in morphology, viability, or the levels of β-actin mRNA, but did show (1) a 4-fold increase in chemotactic peptide-induced Ca2+ mobilization, and (2) a &gt;90% decrease in c-myc mRNA levels. Significantly, when HL-60 cells were treated under serum-free conditions, the ability of ATP to enhance expression of functional FMLP receptors could be dissociated from the inhibitory effects of adenine nucleotides on cell proliferation observed in serum containing media. Moreover, treatment of serum-free HL-60 cultures with UTP, another P2-purinergic receptor agonist, also resulted in enhanced expression of functional FMLP receptors.
Effect of Tumor Necrosis Factor on the Generation of Chlorinated Oxidants by Adherent Human Neutrophils
Authors: Test Samuel T 
Published: January 2018

Abstract
Human neutrophils adherent to simulated biologic surfaces undergo significant activation of the respiratory burst over prolonged periods of time in response to stimulation with the cytokines tumor necrosis factor-alpha (TNFα) or tumor necrosis factor-beta (TNFβ) or with the chemotactic peptide N-formyl-methionylleucylphenylalanine (FMLP). In this study, neutrophils were examined for their ability to generate the highly reactive and powerful oxidant hypochlorous acid (HOCI) and the longer-lived, less reactive endogenous nitrogen-chlorine (N-CI) derivatives in response to these stimuli either alone or when exposed to recombinant human TNFα (rTNFα) or β (rTNFβ) prior to addition of FMLP. Neutrophils adherent to fetal bovine serum-coated polystyrene tissue culture wells were able to generate only small quantities of HOCI when incubated with rTNFα, rTNFβ, or FMLP individually. However, when neutrophils were first incubated with either rTNFα or rTNFβ prior to addition of FMLP, there was a marked increase in HOCI generation. Neutrophils stimulated in such a manner consumed ~18% of the HOCI generated in the formation of N-CI derivatives. Further scrutiny of the response to the combination of rTNFα and FMLP revealed that HOCI release was rapid, with 80% of total HOCI accumulation occurring within 15 min after FMLP addition. The amount of HOCI generated was dependent on the number of cells added and on the concentration of both rTNFα and FMLP. Comparison of HOCI generation with superoxide anion and myeloperoxidase release showed that the amount of HOCI generated was limited primarily by the amount of myeloperoxidase released rather than by the degree of respiratory burst activation. These results demonstrate that human neutrophils stimulated with FMLP after a brief incubation with rTNFα or rTNFβ can generate cytotoxic and microbicidal concentrations of chlorinated oxidants.
Phagocytosis of Opsonized Yeast Induces Tumor Necrosis Factor-α mRNA Accumulation and Protein Release by Human Polymorphonuclear Leukocytes
Authors: Bazzoni Flavia , Cassatella Marco A , Laudanna Carlo , Rossi Filippo 
Published: January 2018

Abstract
In this report we show that phagocytosis of yeast particles opsonized with IgG (Y-IgG) by human polymorphonuclear cells (PMN) results in the selective induction of tumor necrosis factor (TNF-α) messenger RNA (mRNA) and release of its mature protein. Lipopolysaccharide (LPS) was also found able to induce TNF-α secretion by PMN, but was a less potent stimulus compared with Y-lgG. There was no evidence of interleukin-6 (IL-6) gene expression in PMN after phagocytosis of Y-lgG or in response to LPS, whereas IL-6 mRNA expression and secretion were induced by either stimulus in monocytes. These findings demonstrate that a physiological function such as phagocytosis modulates the gene expression for a cytokine in PMN and shed new light on the understanding of the pathogenesis of the inflammatory process.
Leukocyte-Endothelial Cell Adhesive Interactions: Role of Xanthine Oxidase-Derived Oxidants
Authors: Suzuki Masayuki , Grisham Matthew B , Granger D Neil 
Published: January 2018

Abstract
The objective of this study was to determine whether agents that either scavenge or inhibit the production of oxygen radicals can alter the adhesive interactions between leukocytes and venular endothelium elicited by ischemia-reperfusion. Cat mesenteric and intestinal blood flows were reduced to 20% of baseline for 1 hr, followed by 1 hr of reperfusion. Sixty minutes after reperfusion, red blood cell velocity (Vr), leukocyte rolling velocity (Vw), and the number of adherent leukocytes were measured in mesenteric venules. Then, either manganese-superoxide dismutase (Mn-SOD), catalase, desferrioxamine, or oxypurinol was administered intravascularly. Ten minutes later, repeat measurements were obtained and compared with pretreatment values. Catalase, Mn-SOD, and oxypurinol significantly attenuated neutrophil adherence while neither inactivated-catalase nor desferrioxamine altered the reperfusion-induced leukocyte adhesion. The ratio of Vw to erythrocyte velocity, an index of the fracture stress between rolling leukocytes and venular endothelium, was not altered by any of the agents studied. These results and data in the literature indicate that many of the agents that are commonly used to either scavenge or inhibit the production of oxygen radicals in postischemic tissues exert a significant inhibitory influence on leukocyte adhesion to microvascular endothelium in vivo. Our results are also consistent with the view that xanthine oxidase-derived oxidants contribute to the leukocyte-endothelial cell adhesive Interactions associated with reperfusion of ischemic tissues.
Antibodies Against Granule Proteins Activate Neutrophils In Vitro
Authors: Charles Linda A , Caldas Maria Lucia R , Falk Ronald J , Terrell Regina S , Jennette J Charles 
Published: January 2018

Abstract
Polymorphonuclear leukocyte (PMN) respiratory burst was stimulated by heterologous antibodies against PMN granule proteins but not by control antibodies. Fluorescence-activated cell sorter (FACS) analysis of activated PMN demonstrated the presence of two primary granule proteins, proteinase 3 (PR-3) and cationic protein 57 (CAP-57) at the membrane surface. The presence of myeloperoxidase (MPO) at the cell surface of primed and unprimed PMN was confirmed by immunoelectron microscopy. Priming doses of recombinant tumor necrosis alpha (rTNFα) enhanced the rate of superoxide (O2-) production by these antibodies and increased the amount of surface protein accessible to these antibodies. Anti-neutrophil cytoplasmic autoantibodies (ANCA) with specificities for PMN granule proteins are present in patients with Wegener's granulomatosis, polyarteritis nodosa, and idiopathic and crescentic glomerulonephritis. The demonstration that antibodies against granule proteins activate PMN supports the hypothesis that the vasculitis seen in these diseases is due in part to PMN mediated oxidative injury following PMN stimulation by ANCA.
Histochemical and Immunochemical Study of the Fate of Candida albicans Inside Human Neutrophil Phagolysosomes
Authors: Marquis Gabriel , Garzon Simon , Montplaisir Serge , Strykowski Henri , Benhamou Nicole 
Published: January 2018

Abstract
To further define the urtrastructural events associated with the killing of Candida albicans by human neutrophils, four methods were used: (1) the periodate-thiocarbohydrazidesilver proteinate (PA-TCH-SP) staining of vicinal-glycol-containing complex carbohydrates; (2) the localization of thermostable immunodeterminants of the yeast cell wall, mannans or mannoproteins, using monospecific antibodies and a protein A-gold complex (monAb-gold); (3) the localization of mannose residues with concanavalin A labeled with gold particles (Con A-gold); (4) the localization of chitin oligomers using wheat germ agglutinin and ovomucoid labeled with gold particles (WGA-gold). The mannan-rich cell wall layers were progressively lost as shown by altered PA-TCH-SP reactivity and a diffuse pattern of staining with Con A-gold and monAb-gold. The de novo appearance of conspicuous amounts of glycogen-like particles near the plasmalemma and in the cell wall was interpreted as evidence of a reparative process of the yeast cell wall. Chitin was seemingly unaltered and readily demonstrated by the WGA-gold in the wall remnants of ghost cells.
C-reactive protein inhibits intracellular calcium mobilization and superoxide production by guinea pig alveolar macrophages
Authors: Földes-Filep Éva , Filep János G , Sirois Pierre 
Published: January 2018

Abstract
C-reactive protein (CRP) is a prototypical acute-phase reactant, the humoral and plasma concentrations of which rise dramatically after tissue injury or inflammation. The effects of CRP on superoxide production and intracellular calcium mobilization by guinea pig alveolar macrophages challenged with platelet-activating factor (PAF), N-formyl-methionyl-leucyl-phenylalanine (fMLP), and phorbol 12-myristate 13-acetate (PMA) were studied. CRP by itself did not activate alveolar macrophages up to a concentration of 100 μg/ml, whereas it inhibited superoxide production in a time- and dose-dependent manner with median inhibitory concentration (IC50) values of 4.2 ± 0.3,3.0 ± 0.2, and 3.2 ± 0.3 μg/ml for PAF (10-7 M), fMLP (10-7 M), and PMA (10-9 M), respectively. When CRP was incubated with the agonists before addition to cells, it inhibited PMA-, PAF-, and to a lesser extent fMLP-induced superoxide production. CRP also attenuated the rise in intracellular free calcium levels evoked by fMLP or PAF in a dose-dependent manner. These findings suggest that CRP may play a role in attenuating tissue damage secondary to activation of alveolar macrophages by inhibiting superoxide generation and mobilization of intracellular free calcium.
Macrophage cytoskeleton association with CR3 and CR4 regulates receptor mobility and phagocytosis of iC3b-opsonized erythrocytes
Authors: Ross Gordon D , Reed William , Dalzell Juanita G , Becker Susanne E , Hogg Nancy 
Published: January 2018

Abstract
Alveolar macrophages (AMø) were examined for CR1 (C3b receptor, CD35), CR3 (iC3b receptor; CD11b/CD18), and CR4 (iC3b receptor; CD11c/CD18) by assays for binding of C3-opsonized sheep erythrocytes (EC3b or EC3bi) and uptake of specific monoclonal antibodies (mAbs). In AMø isolates from nine normal volunteers, 49% of cells bound EC3b and 71% bound EC3bi. Quantitation of receptors per cell with [125I]mAbs showed 8.5 × 104 CR4, 5.1 × 104 CR3, and 2.6 × 104 CR1. With most AMø preparations, CR3 was the major receptor mediating attachment of EC3bi, despite the predominance of CR4 antigens. Anti-CR3 inhibited EC3bi rosettes by ≥50%, whereas anti-CR4 blocked rosettes by ≤18%. U937 cells differentiated with phorbol myristate acetate resembled AMø in receptor expression but exhibited almost no CR4-dependent rosetting. Despite the relative inability of CR4 to mediate EC3bi attachment, AMø ingestion of [51Cr]EC3bi was blocked by either anti-CR3 or anti-CR4. Two lines of evidence indicated that CR3 were more mobile within the membrane than were CR4. Immunofluorescence staining demonstrated patching and occasional capping of CR3, whereas CR4 remained uniformly distributed. This patching and capping of CR3 required the actin cytoskeleton, as it was inhibited by cytochalasin D. Modulation experiments using surfaces coated with anti-CR3 or anti-CR4 also showed that CR3 was more mobile than was CR4. However, there was some variation among AMø isolates from different donors. In seven isolates, no CR4 modulation was produced with anti-CR4, whereas in six other isolates, CR4 was modulated by 66%. Incubation of cells in cytochalasin D increased modulation of both CR3 and CR4 on mAb-coated surfaces. Cells exhibiting increased mobility of CR4 showed an increased ability to form CR4-dependent EC3bi rosettes. The data are consistent with the hypothesis that CR3 and CR4 exhibit a variable association with the cytoskeleton that regulates their mobility and function. A relatively mobile subset of CR3 and/or CR4 mediates EC3bi attachment, whereas a relatively immobile subset of CR3 and/or CR4 fails to mediate EC3bi attachment but functions to promote ingestion of EC3bi.
Functional alterations of swine peripheral blood mononuclear cells by methadone
Authors: Molitor Thomas W , Murtaugh Michael P , Click Robert E , Gekker Genya , Chao Chun , Peterson Phillip K 
Published: January 2018

Abstract
In vitro exposure of the synthetic opiate drug methadone allowed evaluation of putative immunomodulatory activities of swine peripheral blood mononuclear cells. Respiratory burst, an index of microbicidal activity, was suppressed by methadone in a dose-dependent manner following exposure for 48 h. The suppression was blocked by the opiate antagonist naloxone. Another macrophage function phagosome-lysosome fusion was impaired by exposure to methadone. A primary lymphocyte-mediated function natural killer cell activity was also affected. In contrast, the macrophage function antibody-mediated phagocytosis was not affected. Because the functions affected by methadone are critical to host defenses against pathogenic organisms, our findings suggest that opiate-mediated immunomodulation merits further study. Moreover, our studies suggest that swine may provide an ideal model for the investigation of opiate-mediated suppression of immune cell functions.
Increase in the rat blood leukocyte counts induced by PAF-acether is suppressed by general anesthesia
Authors: Bozza Patricia T , Silva Patricia M R , Castro-Faria-Neto Hugo C , Martins Marco A , Cordeiro Renato S B 
Published: January 2018

Abstract
Blood leukocyte count alterations induced by PAF-acether in anesthetized and nonanesthetized rats were investigated. Intravenous injection of increasing amounts of PAF-acether (1.5-8 μg/kg) in nonanesthetized animals induced dose-dependent hemoconcentration and leukocytosis. The former was apparent within 10 min, peaked from 30 min to 1 h, and diminished thereafter. The leukocytosis was noted within 30 min, was maximal at 1 h, and was over 4 h after injection of PAF-acether (4 μg/kg). It was characterized by a marked increase in the blood neutrophil counts under conditions in which the number of lymphocytes, monocytes, and eosinophils remained unchanged. PAF-acether–induced leukocytosis occurred in parallel with a marked decrease in the number of bone marrow nucleated cells, suggesting that the latter phenomenon may determine the former one. Leukocytosis by PAF-acether was inhibited dose-dependently by specific PAF-acether antagonists including BN 52021 (median effective dose ED50 = 4.99 mg/kg), WEB 2086 (ED50 = 4.59 mg/kg), and 48740 RP (ED50 = 9.02 mg/kg). General anesthesia by either pentobarbital, urethane, or ether inhalation, but not by ketamine, also impaired the PAF-acether–induced blood leukocytosis under conditions in which the hemoconcentration was not modified. In addition, pentobarbital-anesthetized rats did not have reduced bone marrow nucleated cell counts after PAF-acether stimulation. These findings are consistent with the assessment that PAF-acether–induced rat leukocytosis is accounted for by a bone marrow neutrophil mobilization process that is clearly suppressed in animals anesthetized by pentobarbital.
The up- and down-modulation of immunoglobulin G Fc receptors and complement receptors on activated human neutrophils depends on the nature of activator
Authors: Leino Lasse , Lilius Esa-Matti 
Published: January 2018

Abstract
Human neutrophils were activated with soluble stimuli, fonnyl-methionyl-leucyl-phenylalanine (fMLP) or ionophore A23187, and with opsonized particles, zymosan or Streptococcus pneumoniae bacteria. Monoclonal antibodies and flow cytometry were used to assess the expression of Fc-γ receptors (FcRI, FcRII, FcRIII) and complement receptors (CR1, CR3). The role of extracellular calcium and magnesium in the modulation of receptor expression was also examined. The low-level expression of FcRI was not affected by any activator tested. fMLP and A23187 did not alter the expression of FcRII, whereas a significant, Ca2+- and Mg2+-independent down-modulation was observed upon activation with opsonized particles. All activators clearly decreased the surface expression of FcRIII in the presence of Ca2+ and Mg2+, probably as a consequence of shedding of the phosphatidylinositol-glycan–anchored receptor protein. The removal of calcium and magnesium blocked the shedding of FcRIII caused by soluble stimuli, whereas it retarded but did not abolish the fall in FcRIII expression when cells were incubated with opsonized particles. This fall was likely due to internalization of the receptor molecules while the shedding was blocked. A rapid increase in CR1 and CR3 expression was seen upon activation with soluble stimuli. The change in CR1 expression was independent of extracellular Ca2+ and Mg2+. The increase in CR3 number required an influx of divalent cations. No total up-modulation of complement receptors occurred when neutrophils were activated with opsonized particles. However, the kinetic analysis revealed a temporary up-modulation that was followed by a down-modulation. The results indicate that the expression of both Fc-γ and complement receptors on human neutrophils is changed upon activation and that the up- and down-modulation of these receptors depends on the nature of activator. We also suggest that in neutrophils the FcRIII down-modulation is the result of both receptor shedding and internalization, while FcRII is down-modulated by receptor internalization.
High deformability and motility of lymphokine-activated killer cells in vitro and in vivo
Authors: Bouwens Luc , Narayani Inna , Wisse Eddie 
Published: January 2018

Abstract
The motility and deformability of lymphokine-activated killer cells, purified by their adherence to plastic (A-LAK cells), was investigated in vivo and in vitro. In vitro, A-LAK cells were observed as intrinsically motile cells. They continuously changed their shape while forming protopods or pseudopods and crawled over the culture surface. A-LAK cells were able to migrate across micropores of 3 μm diameter, which was three times smaller than the average diameter of an A-LAK cell. Even in the absence of serum factors and of interleukin-2 (IL-2), more than half of the inoculated cells migrated across such micropore membranes within 18 h. Electron microscopic examination of these micropore membranes showed that the A-LAK cells were highly deformable. A-LAK cells also migrated across a confluent monolayer of endothelium-like 10T1/2 cells. After 24 h incubation on the monolayers, about 20% of the A-LAK cells were found underneath the monolayer. There, they actively moved in the narrow space between the monolayer and the bottom of the culture dish. In vivo IL-2-activated cells showing the large granular lymphocyte morphology accumulated in the hepatic microvasculature. Electron microscopic observations indicate that these cells did not accumulate by mechanical entrapment due to rigidity and size but rather by adherence to the endothelial lining of the sinusoidal capillaries. This also appeared to be the case for adoptively transferred A-LAK cells, which were seen to be attached to the capillary wall. These observations stress the importance of adhesive entrapment to explain the accumulation of intravenously transferred LAK cells in the vascular beds.
Synergism of interleukin 6 and 1α,25-dihydroxyvitamin D3 in induction of myeloid differentiation of human leukemic cell lines
Authors: Duits Ashley J , Dimjati Wati , van de Winkel Jan GJ , Capel Peter JA 
Published: January 2018

Abstract
Interleukin 6 (IL-6) is a multifunctional cytokine with an important role in immunity. We analyzed the effect of recombinant human IL-6 in combination with 1α,25-dihydroxyvitamin D3 (Vit. D3) on differentiation of the human myeloid leukemic cell lines U937 and HL-60 with respect to alterations in antigen expression and functional activity. Of a panel of antigens analyzed, only CD11b (the α chain of CR3), and GD14 (a cell surface protein recognizing the lipopolysaccharide-binding protein-lipopolysaccharide complex) had significantly increased expression. Expression of ICAM-1 (CD54), a ligand for LFA-1, was also found to be enhanced with a concomitant increase of ICAM-1 mRNA levels. Enhanced nonspecific esterase levels and induction of respiratory burst activity confirmed that cell differentiation was induced. Furthermore, IL-6 and Vit. D3 had a profound effect on functional activities, as shown by enhancement of rosetting between sheep erythrocytes, sensitized with C3bi (EAC), and either U937 or HL-60 cells. Also, phorbol myristate acetate–induced homotypic adhesion of U937, which is ICAM-1 dependent, was markedly induced by these agents. These results indicate an important role of IL-6 and Vit. D3 in myeloid cell Function and development.