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Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of purified recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) on the oxidative metabolism of human peripheral blood granulocytes was investigated. The respiratory burst of granulocytes was assessed in individual cells by flow cytometry utilizing the oxidation of the nonfluorescent 2',7'-dichlorofluorescein (DCFH) to the highly fluorescent DCF by hydrogen peroxide (H2O2). Treatment with GM-CSF caused granulocytes to produce H2O2 without addition of a second stimulus. The amount of H2O2 produced correlated with the concentration of GM-CSF administered. Also, GM-CSF did not prime the granulocytes for enhanced H2O2 production in response to N-formylmethionyl-leucyl-phenylalanine (f-MLP). Consecutive stimulation of granulocytes with GM-CSF and f-MLP resulted in additive production of H2O2. GM-CSF also induced granulocytes to release superoxide anion (O2-) in a dose-dependent manner, when the respiratory burst was assessed by a conventional cytochrome c reduction assay. In contrast to hydrogen superoxide production, GM-CSF significantly (p < 0.001) enhanced f-MLP-stimulated release of superoxide anion over that expected from the additive effects of the two agonists.
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PMID:Recombinant human granulocyte-macrophage colony-stimulating factor stimulates superoxide anion and hydrogen peroxide production in human neutrophils. 136 32

Most studies of antibody-dependent cellular cytotoxicity (ADCC) by polymorphonuclear leukocytes (PMN) have supported oxidative lytic processes. This may be because the studies used nonhuman or nonneoplastic cells that were highly sensitive to reactive oxygen species or were small enough to be phagocytosed by PMN. We therefore investigated whether oxygen radicals participate in PMN cytotoxicity toward human neuroectodermal solid tumor cells sensitized by 3F8, which is an anti-ganglioside GD2 murine IgG3 monoclonal antibody with documented anticancer activity in humans. A 4-h 51Cr release assay was used to assess tumor cell lysis by hydrogen peroxide, superoxide, and hypochlorite. Nine of 11 GD2(+) human melanoma and neuroblastoma cell lines had equal or greater resistance to these oxidants as compared to a GD2(-) human carcinoma line (SKBr1-III) found by others (and confirmed by us) to be significantly more resistant to oxidative lysis than a murine cell line (P388D1) representative of those commonly used in cytotoxicity assays. To facilitate detection of oxidant-mediated lysis, subsequent studies of 3F8-mediated ADCC used GD2(+) targets that were relatively sensitive and others that were relatively resistant to oxygen radicals. Normal PMN and PMN obtained from children with chronic granulomatous disease, which do not generate reactive oxygen species, were equally effective in ADCC. Granulocyte-macrophage colony-stimulating factor, which primes oxidative responses of normal but not of chronic granulomatous disease PMN, enhanced ADCC by both kinds of PMN. During ADCC of 3F8-sensitized targets, with or without granulocyte-macrophage colony-stimulating factor, GD2(-) "innocent bystander" tumor cells (including P388D1) were not lysed, a finding consistent with unimportant extracellular release of cytotoxic mediators. Finally, antioxidant and antimyeloperoxidase moieties did not block ADCC. We conclude that oxidants are not key factors in 3F8-mediated lysis by PMN of human neuroectodermal tumor cells.
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PMID:Clinically effective monoclonal antibody 3F8 mediates nonoxidative lysis of human neuroectodermal tumor cells by polymorphonuclear leukocytes. 165 2

The effects of interferon-gamma (IFN-gamma) on a highly enriched population of granulocyte-macrophage colony-forming cells (GM-CFC) were assessed. When added with myeloid growth factors (interleukin-3 [IL-3], granulocyte-macrophage colony-stimulating factor [GM-CSF], or macrophage-CSF [M-CSF]), IFN-gamma inhibited the formation of colonies in soft agar assays. Furthermore IFN-gamma stimulated an increase in the number of macrophages present in colonies formed in the presence of IL-3. IFN-gamma also inhibited M-CSF-, GM-CSF-, or IL-3-stimulated [3H]-thymidine incorporation in highly enriched GM-CFC. However, when added in the absence of hematopoietic growth factors, IFN-gamma promoted the survival of GM-CFC and had a modest stimulatory effect on DNA synthesis. The direct interaction of the IFN with GM-CFC was confirmed by showing its ability to rapidly activate the sodium/hydrogen antiport in GM-CFC, as do the mitogens GM-CSF, M-CSF, and IL-3. However, the effect of IFN-gamma on intracellular pH and DNA synthesis was transient and pretreatment with IFN markedly inhibited the ability of GM-CSF, M-CSF, and IL-3 to activate the sodium/hydrogen antiport. IFN-gamma has a dual effect on GM-CFC, decreasing the rate of cell death but also limiting the proliferative response to CSFs.
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PMID:Interferon-gamma stimulates the survival and influences the development of bipotential granulocyte-macrophage colony-forming cells. 182 54

Granulocyte-macrophage colony-stimulating factor (GM-CSF) was shown to modulate different granulocyte functions. In the present study we investigated the effect of purified and recombinant human GM-CSF, particularly on the oxidative metabolism of isolated human granulocytes. In addition, ultrastructural changes upon stimulation were evaluated. For detection of granulocyte activation the following assay systems were used: 1) lucigenin-dependent chemiluminescence (CL), 2) superoxide-dismutase (SOD) inhibitable cytochrome C-reduction (superoxide), 3) horseradish peroxidase-mediated oxidation of phenol red (hydrogen peroxide), 4) release of myeloperoxidase, 5) ultrastructural detection of hydrogen peroxide-production, and 6) scanning and transmission electron microscopy (SEM and TEM, respectively). A significant CL response was seen upon stimulation with recombinant human GM-CSF at concentrations ranging from 1 to 10(3) U/ml. The CL response started within 5-10 min with a maximum at 60-90 min and lasted more than 3 h. Thereafter granulocytes were completely deactivated to restimulation with the same mediator and with Tumor Necrosis Factor, but responded to other triggers of the oxidative burst, whereas the response to f-met-leu-phe was significantly increased. The CL signal was completely blocked by an antiserum to GM-CSF. Moreover, the response was significantly inhibited by SOD and D-Mannitol, suggesting the involvement of distinct reactive oxygen species (ROS) in generating the CL response. Significant amounts of superoxide were detected within 180 min after stimulation with GM-CSF, whereas release of hydrogen peroxide and peroxidase were only minimal as shown by functional and ultrastructural assays. Activation of granulocytes could be visualized by SEM and TEM. GM-CSF stimulated cells showed an increased adherence to the substratum developing polarized filopodia and an increased number of intracellular vesicles within 30 min after addition of the stimulus. The results clearly demonstrate that GM-CSF directly stimulates granulocytes and, particularly, their oxidative metabolism. Therefore, GM-CSF which is probably released by epidermal cells appears to be a candidate for neutrophil activation in the skin, and thereby may play a crucial role in inflammatory skin diseases.
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PMID:Human granulocyte-macrophage colony stimulating factor: an effective direct activator of human polymorphonuclear neutrophilic granulocytes. 283 54

We have previously reported that continuous intravenous (IV) administration of recombinant granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) to humans following high-dose alkylating agent chemotherapy and autologous bone marrow support (ABMS) results in myeloid bone marrow maturation, accelerated granulocyte recovery, and reduced treatment-related toxicity. However, we found that leukocyte counts declined rapidly after discontinuation of rHuGM-CSF therapy, which suggests possible growth factor effects on leukocyte margination and migration. For these reasons we studied granulocyte margination by using 111In-labeled autologous granulocytes and found similar granulocyte margination before (21.5% +/- 13.4%) and during continuous IV rHuGM-CSF infusion (23.3% +/- 9.6%). Phagocytosis of Cryptococcus neoformans and granulocyte hydrogen peroxide production was similar before and during rHuGM-CSF infusion and similar to patients treated with the same high-dose chemotherapy and ABMS but not receiving growth factor. However, migration of granulocytes to a sterile inflammatory site was markedly reduced during continuous rHuGM-CSF infusion (1.2 +/- 0.9 WBCs/cm2, 24 hr) as compared with baseline (39.6 +/- 17.7 WBCs/cm2/24 hr; P less than .0008). These findings may be of relevance when extravascular granulocytes are required for host defense.
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PMID:Neutrophil migration is defective during recombinant human granulocyte-macrophage colony-stimulating factor infusion after autologous bone marrow transplantation in humans. 304 40

Aplastic anemia is a syndrome in which pancytopenia occurs in the presence of hypocellularity of the bone marrow. To assess the biologic activities of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) in aplastic anemia, we gave GM-CSF (60 to 500 micrograms per square meter of body-surface area) to 10 patients with moderate or severe disease, by continuous intravenous infusion daily for two weeks, and repeated the treatment after a two-week rest period. The treatment increased the white-cell count (1.6- to 10-fold) in all patients, primarily because of an increase in the numbers of neutrophils (1.5 to 20-fold), eosinophils (12- to greater than 70-fold), and monocytes (2- to 32-fold). Rates of hydrogen peroxide production in purified granulocyte fractions increased during GM-CSF treatment. Increases in bone marrow cellularity, myeloid precursor cells, and myeloid:erythroid cell ratios accompanied the white-cell response. Despite the in vivo response of the white-cells, the concentration of colony-forming cells remained the same. Measurable concentrations of interleukin-2 (2 to 15 units per milliliter) were found in the serum of 8 patients, and high levels of erythropoietin (81 to 1200 IU per liter) were found in 10 patients. The predominant side effects were constitutional symptoms. These results indicate that recombinant human GM-CSF is effective in stimulating myelopoiesis in patients with severe aplastic anemia and may benefit some patients in whom the disorder is refractory to standard forms of therapy.
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PMID:Stimulation of myelopoiesis in patients with aplastic anemia by recombinant human granulocyte-macrophage colony-stimulating factor. 305 91

We examined the ability of two recombinant human cytokines, granulocyte-macrophage colony-stimulating factor (rHu-GM-CSF) and interferon-gamma (rHu-IFN-gamma) to activate antibacterial mechanisms in human pulmonary macrophages (PM) and peripheral blood monocytes (PBM). Growth of Legionella pneumophila (LP) was assessed in PM or PBM which had been exposed to either rHu-IFN-gamma (500-1000 u/ml) or rHu-GM-CSF (1 to 10,000 u/ml). In both PM and PBM exposed to 500 u/ml rHu-IFN-gamma, growth of LP was reduced compared to cells exposed to media alone. By comparison, exposure of these cell types to rHu-GM-CSF had no detectable effect on bacterial replication. In order to investigate potential mechanisms accounting for this observation, the effect of these cytokines on the hydrogen peroxide (H2O2)-releasing capacity of cells was studied. Exposure of PM and PBM to rHu-IFN-gamma (500 to 1000 u/ml) resulted in increased production of H2O2 triggered by phorbol myristate acetate; when subjected to the same experimental conditions, rHu-GM-CSF-exposed cells exhibited no increase in H2O2 production. To further clarify the role of rHu-IFN-gamma-induced augmentation of oxidative metabolism on cellular inhibition of bacterial growth, an amount of catalase capable of completely neutralizing extracellular H2O2 was added to cells before and during infection. This did not abrogate the antibacterial activity of rHu-IFN-gamma. These studies demonstrate that rHu-IFN-gamma but not rHu-GM-CSF is capable of augmenting the capacity of PM and PBM to restrict LP growth. These data suggest that the antibacterial activity of rHu-IFN-gamma in this system may involve oxidative as well as nonoxidative mechanisms.
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PMID:Cytokine activation of antibacterial activity in human pulmonary macrophages: comparison of recombinant interferon-gamma and granulocyte-macrophage colony-stimulating factor. 314 84

The ability of granulocyte-macrophage colony-stimulating factor (CSF-H) to modulate human neutrophil functions was studied by using an in vitro system in which this cell type interacted with intracellular (amastigote [AMA]) forms of Trypanosoma cruzi. The presence of CSF-H during the 30-min period of neutrophil incubation with the AMA markedly enhanced parasite internalization. This effect was evidenced by significant increases in both the percentage of neutrophils incorporating AMA and the average number of AMA per 100 neutrophils with respect to mock-treated neutrophils. Pretreatment of the neutrophils with CSF-H reproduced the enhancement effect, whereas pretreatment of the AMA had no detectable consequence. The minimal neutrophil CSF-H pretreatment period required to significantly increase the number of AMA per 100 neutrophils was 20 min--suggesting that CSF-H induced time-dependent events ultimately leading to the manifestation of the noted effect--but neutrophil treatment with CSF-H for longer periods of time (up to 60 min) caused a much greater enhancement. Consistent with the notion of a regulatory action of CSF-H on neutrophils was the fact that the enhancing effect subsided gradually after removal of the factor and was no longer detectable after 16 hr. When 3H-labeled AMA were used, CSF-H-treated neutrophils released greater amounts of radiolabeled substances than mock-treated cells, indicating a stimulatory effect of CSF-H on the killing capacity of neutrophils. This was confirmed by the fact that untreated neutrophils that had internalized 3H-AMA killed the parasites at a faster rate when subsequently incubated with CSF-H. Catalase, but not superoxide dismutase, mannitol, benzoate, or histidine, inhibited neutrophil killing of the 3H-AMA whether the granulocytes had been exposed to CSF-H or not. This indicated that the cytotoxic mechanism involved the production of hydrogen peroxide in both cases, but possibly at a higher rate in the CSF-H-treated neutrophils. These results point to a regulatory effect of CSF-H on neutrophils that promotes cellular activities that might be relevant to the mechanisms of clearance of T. cruzi in vivo.
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PMID:Effects of human colony-stimulating factor on the uptake and destruction of a pathogenic parasite (Trypanosoma cruzi) by human neutrophils. 352 88

Recent studies have shown that surface epithelial cells play a major role in the defence and inflammatory reactions of the airways. How extracellular stimuli lead to increased gene expression in these epithelial cells is not well known. In this study, we asked whether the multiunit transcription factor, nuclear factor (NF)-kappa B, which regulates the expression of genes involved in defense and immune processes, is activated in airway epithelial cells following stimulation with inflammatory mediators and hydrogen peroxide. In addition, we studied whether this would be followed by upregulation of the NF-kappa B target gene product granulocyte-macrophage colony-stimulating factor (GM-CSF). Activation of NF-kappa B in the SV40 transformed human tracheobronchial epithelial cell line 1HAEo- was measured by electrophoretic mobility shift assays. GM-CSF concentrations in cell culture supernatants were determined by enzyme-linked immunosorbent assays. NF-kappa B was rapidly activated by exposure of cells to interleukin-1 beta (IL-1 beta), phorbol myristate acetate (PMA), and tumour necrosis factor-alpha (TNF). Exposure to H2O2 platelet activating factor (PAF) and lipopolysaccharide (LPS) did not lead to increased NF-kappa B activation. Co-stimulation of IL-1 beta with H2O2 led to augmentation and prolongation of the effect on NF-kappa B activation compared to stimulation with IL-1 beta alone. GM-CSF concentrations increased following stimulation with IL-1 beta and H2O2, and the effect of IL-1 beta/H2O2 co-stimulation on GM-CSF concentrations was additive. These results suggest that NF-kappa B may represent an important transcription factor, controlling the expression of cytokine genes in airway epithelial cells.
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PMID:Activation of the transcription factor NF-kappa B in human tracheobronchial epithelial cells by inflammatory stimuli. 778 82

Single cytokine therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3) has been shown to be effective in decreasing the respective periods of neutropenia and thrombocytopenia following radiation- or drug-induced marrow aplasia. The combined administration of IL-3 and GM-CSF in normal primates suggested that a sequential protocol of IL-3 followed by GM-CSF would be more effective than that of GM-CSF alone in producing neutrophils (PMN). We investigated the therapeutic efficacy of two combination protocols, the sequential and coadministration of recombinant human IL-3 and GM-CSF relative to respective single cytokine therapy, and delayed GM-CSF administration in sublethally irradiated rhesus monkeys. Monkeys irradiated with 450 cGy (mixed fission neutron:gamma radiation) received either IL-3, GM-CSF, human serum albumin (HSA), or IL-3 coadministered with GM-CSF for days 1 through 21 consecutively postexposure, or IL-3 or HSA for days 1 through 7 followed by GM-CSF for days 7 through 21. All cytokines and HSA were injected subcutaneously at a total dose of 25 micrograms/kg/d, divided twice daily. Complete blood counts (CBC) and platelet (PLT) counts were monitored over 60 days postirradiation. The respiratory burst activity of the PMN was assessed flow cytometrically, by measuring hydrogen peroxide (H2O2) production. Coadministration of IL-3 and GM-CSF reduced the average 16-day period of neutropenia and antibiotic support in the control animals to 6 days (P = .006). Similarly, the average 10-day period of severe thrombocytopenia, which necessitated PLT transfusion in the control animals, was reduced to 3 days when IL-3 and GM-CSF were coadministered (P = .004). The sequential administration of IL-3 followed by GM-CSF had no greater effect on PMN production than GM-CSF alone and was less effective than IL-3 alone in reducing thrombocytopenia. PMN function was enhanced in all cytokine-treated animals.
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PMID:Combination protocols of cytokine therapy with interleukin-3 and granulocyte-macrophage colony-stimulating factor in a primate model of radiation-induced marrow aplasia. 821 92


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