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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 biological effects of recombinant hematopoietic factors, which are considered to stimulate megakaryocytopoiesis in vitro or in vivo, were studied utilizing purified rat megakaryocytes. Recombinant human erythropoietin (rhEPO), recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF), and recombinant murine interleukin 3 (rmIL-3) stimulated both [3H]thymidine and [3H]leucine incorporation into purified rat megakaryocytes. In contrast, recombinant human interleukin 6 (rhIL-6) did not stimulate [3H]thymidine uptake but did increase [3H]leucine incorporation into purified rat megakaryocytes. These in vitro data suggest that DNA synthesis in megakaryocytes may be regulated by EPO, GM-CSF, and IL-3, and that protein synthesis is stimulated by EPO, GM-CSF, IL-3, and IL-6 in vitro.
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PMID:Biological effects of recombinant erythropoietin, granulocyte-macrophage colony-stimulating factor, interleukin 3, and interleukin 6 on purified rat megakaryocytes. 189 46

Hematopoetic growth factors stimulate the proliferation of leukocyte precursors in bone marrow cultures, but some also augment the responsiveness of mature effector cells. For example, granulocyte-macrophage colony-stimulating factor (GM-CSF) enhances superoxide production and cytotoxicity of neutrophils stimulated by diverse agonists. We show that preexposure of neutrophils to GM-CSF is absolutely required for the induction of leukotriene B4 and platelet-activating factor (PAF) synthesis by a soluble agonist, C5a or N-formyl-methionyl-leucine-phenylalanine (FMLP). Lipid mediator synthesis occurs very rapidly after triggering with the second signal, and under identical conditions superoxide release is enhanced. Interleukin-3 (IL-3), another hematopoetic growth factor, enhances granule release and more profoundly leukotriene C4 (LTC4) synthesis in basophils stimulated by immunoglobulin-E (IgE)-dependent or -independent agonists. Sequential stimulation with IL-3 and C5a results in the production of large quantities of LTC4, while neither factor alone induces the release of lipid mediators. We conclude that a major function of these cytokines is to allow lipid mediator synthesis in effector cells after triggering with agonists which by themselves do not induce the production of bioactive lipids. We also propose that lipoxygenase metabolites and PAF represent an autocrine response amplification pathway in effector cells which might explain the enhanced responsiveness of cells primed by these cytokines.
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PMID:Growth factors, lipid mediators and effector cells. 196 12

Incubation of human bloodstream neutrophils with 50 u/ml recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) "primed" the respiratory burst (as assessed by fMet-Leu-Phe stimulated luminol-dependent chemiluminescence) and resulted in a rapid (within 15 min) up-regulation of expression of CD11b and CD18 (as measured by FACS analysis). This rapid "priming" and modulation of receptor expression was not inhibited by cycloheximide and hence appeared to be independent of de novo protein biosynthesis. When neutrophils were incubated for up to 5 h in culture, the fluorescence distributions of CD11b and CD18 declined indicating the loss of expression of these receptors as the neutrophils aged, but in rGM-CSF treated suspensions receptor expression was maintained. When neutrophils were incubated in the presence of cycloheximide, they progressively lost their ability to generate reactive oxidants in response to fMet-Leu-Phe so that by 5 h incubation with this inhibitor they could only generate about 25% of the oxidative response stimulated in untreated cells, and the expression of CD16 and CD18 was grossly impaired. Similar effects were observed in rGM-CSF treated suspensions except that cycloheximide required longer incubation times (typically 4-5 h) before impairment of function or receptor expression occurred. These data show that de novo protein biosynthesis is required for both the maintenance of neutrophil function and also for the continued expression of some plasma membrane receptors.
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PMID:Receptor expression and oxidase activity in human neutrophils: regulation by granulocyte-macrophage colony-stimulating factor and dependence upon protein biosynthesis. 197 13

The ability of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) to augment the fungicidal activity of human monocytes for Candida albicans was evaluated. Purified human monocytes cultured with [3H]leucine-labeled C. albicans caused a dose-dependent release of the [3H]leucine. The amount of [3H]leucine released correlated with a decrease in the number of viable yeast colonies. Monocyte cytotoxicity for C. albicans was reduced by superoxide dismutase and catalase and by inhibitors of myeloperoxidase and scavengers of hydroxyl radical and single oxygen, consistent with monocyte candidacidal activity being partly dependent upon products of oxidative metabolism. Monocytes incubated with rhGM-CSF produced more superoxide anion (O2-) spontaneously and after stimulation than control monocytes (P less than .05). Enhanced O2- production was dose-dependent and specific for rhGM-CSF and could be inhibited by antibody to rhGM-CSF. In association with rhGM-CSF-induced production of O2-, the cytokine enhanced cytotoxic activity for C. albicans. These findings indicate that rhGM-CSF stimulates human monocyte fungicidal activity for C. albicans.
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PMID:Granulocyte-macrophage colony-stimulating factor augments human monocyte fungicidal activity for Candida albicans. 215 74

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) both stimulates hematopoietic precursor cells to grow as well as enhances the function of mature effector cells, such as neutrophils, eosinophils and macrophages. All of the biological actions of GM-CSF appear to be mediated via binding to a single class of high-affinity receptors present on all responsive cells. Affinity cross-linking experiments demonstrate that the same 98 kDa cross-linked species seen on other GM-CSF-responsive cells is also detected on a choriocarcinoma cell line, JAR. However, JAR cells express significantly increased numbers (10,000 sites/cell) of low-affinity (Kd approximately 1.5 nM) GM receptors. The GM-CSF receptor is a glycoprotein which binds to wheat germ agglutinin-sepharose. It is dramatically downregulated on neutrophils by phorbol esters and formyl-methionyl-leucine-phenylalanine (fMLP), but not by phosphatidylinositol-dependent phospholipase C. GM-CSF primes neutrophils for enhanced response to secondary stimuli, such as ionophore and chemotactic factors. Specifically, GM-CSF enhances 3H-arachidonic acid release, synthesis of leukotriene B4 and platelet activity factor in response to fMLP and the calcium ionophores.
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PMID:GM-CSF: receptor structure and transmembrane signaling. 215 79

Colony-stimulating factors (CSFs) have important effects on mature myeloid cells in addition to their regulatory role in haemopoiesis. Exposure of neutrophils to granulocyte macrophage-CSF (GM-CSF) increases chemotaxis, phagocytosis and cytotoxicity and primes the cells for enhanced oxidative metabolism in response to stimuli, such as formylated oligopeptides derived from bacteria (f-Met-Leu-Phe) and endogenous activated complement components (C5a). GM-CSF induces time-dependent changes in neutrophil f-Met-Leu-Phe receptor number and affinity that correspond to changes in functional activity. The neutrophil IgA Fc receptor is also modulated by GM-CSF such that it develops a high affinity state and transduces a phagocytic signal. The ability to regulate the number and activity of mature myeloid effector cells in vivo establishes unique therapeutic opportunities in the area of infectious disease, cancer treatment, bone marrow transplantation and augmentation of host defence in immunodeficient patients.
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PMID:Responses of neutrophils to myeloid growth factors. 218 Jun 50

Human recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) was analysed for effects on the migration of human neutrophilic granulocytes by the Boyden chamber assay. At concentrations ranging from 0.1 to 10,000 U/ml (or 10(-12) to 10-mol/l) GM-CSF had neither chemokinetic nor chemotactic activity. When added to the cells in the upper compartment of the chamber GM-CSF dose-dependently inhibited the chemotactic migration towards the tripeptide f-Met-Leu-Phe and the complement split product C5a. Chemotaxis towards f-Met-Leu-Phe was inhibited more efficiently by GM-CSF than C5a-induced migration.
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PMID:Inhibition of chemotactic migration of human neutrophilic granulocytes by recombinant human granulocyte-macrophage colony-stimulating factor. 219 Sep 47

We have improved the expression of recombinant human granulocyte-colony-stimulating factor (G-CSF), produced by either pL or trpP expression vectors in Escherichia coli, by altering the sequence at the 5' end of the G-CSF-coding region. Initial attempts to express G-CSF resulted in neither detectable G-CSF mRNA nor protein in the trpP system, and only G-CSF mRNA was detectable in the pL system. We modified both expression vectors to decrease the G + C content of the 5' end of the coding region without altering the predicted amino acid sequence. This resulted in expression of detectable G-CSF mRNA and protein in both systems. Expression reached 17% and 6.5% of the total soluble cellular protein in the pL and trpP expression systems, respectively. The N-terminal sequence of the recombinant G-CSF from the pL system was Met-Thr-Pro-Leu-Gly-Pro-. G-CSF isolated from several human cell lines (including the LD-1 cell line reported here), does not have an N-terminal methionyl residue. Deletion of the threonine codon at the beginning of the coding region for the mature G-CSF resulted in efficient removal of the N-terminal methionine residue during expression in E. coli.
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PMID:Alteration of amino-terminal codons of human granulocyte-colony-stimulating factor increases expression levels and allows efficient processing by methionine aminopeptidase in Escherichia coli. 245 56

The addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) to human neutrophils causes a rapid increase in the basal and fMet-Leu-Phe-stimulated Na+ influx and an increase in intracellular pH. The increase can be seen as early as 5 min after the addition of GM-CSF. Changes produced by GM-CSF are totally inhibited by amiloride and are significantly reduced in pertussis toxin-treated cells. The stimulation of the Na+/H+ exchange mechanism by GM-CSF inhibits further stimulation of this system with either fMet-Leu-Phe or phorbol 12-myristate 13-acetate. In addition, membrane preparations isolated from GM-CSF-treated neutrophils have higher basal and stimulated GTPase activities. The basal and the fMet-Leu-Phe- or platelet-activating factor-stimulated GTPase activities are reduced in pertussis toxin-treated cells. Cells pretreated with GM-CSF accumulate more radioactive phosphate than control cells, and this increase is diminished by pertussis toxin treatment. In addition, GM-CSF causes a rapid increase in the tyrosine phosphorylation levels of five proteins with molecular masses of 118 kDa, 92 kDa, 78 kDa, 54 kDa, and 40 kDa. These results clearly show that GM-CSF, on its own, can initiate several changes and that these changes are mediated in part by the pertussis toxin-sensitive guanine nucleotide regulatory protein.
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PMID:Granulocyte-macrophage colony-stimulating factor and human neutrophils: role of guanine nucleotide regulatory proteins. 247 Nov 89

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates multiple differentiated functions of mature neutrophils. Increased expression of leukocyte adhesion molecules and chemotactic receptors on GM-CSF-treated neutrophils suggested that GM-CSF may stimulate neutrophil degranulation. were assessed by quantitating the release of an exclusive component of the specific granules, vitamin B12 binding protein. Incubation of neutrophils with GM-CSF alone resulted in a significant release of [57Co]-vitamin B12 binding protein quantitatively similar to that elicited by cytochalasin B or N-formyl-methionyl-leucylphenylalanine (f-Met-Leu-Phe) alone. In addition, cells preincubated with GM-CSF and subsequently stimulated with f-Met-Leu-Phe, platelet-activating factor, or the calcium ionophore, A23187, demonstrated enhanced degranulation, which greatly exceeded that produced by GM-CSF alone. These results demonstrate a small direct effect of GM-CSF on neutrophil degranulation, as well as enhanced degranulation in cells stimulated by chemotactic agents and calcium ionophore. Neutrophil degranulation in response to GM-CSF may be involved in the phlebitis associated with therapeutic administration of GM-CSF.
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PMID:Effects of human GM-CSF on neutrophil degranulation in vitro. 250 23


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