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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)

Culture of WEHI-3B myelomonocytic leukemic cells in semi-solid agar medium containing serum from mice injected with endotoxin serum (ES) led to the development of maturing granulocytes and macrophages in most leukemic colonies. ES contains high levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), a regulator known to stimulate differentiation of these leukemic cells, but an antiserum which neutralized greater than 85% of the GM-CSF in ES did not suppress the differentiation-inducing activity of ES on WEHI-3B cells. The active factor in endotoxin serum stimulating differentiation in WEHI-3B leukemic cells (GM-DF) was separated from most of the GM-CSF by gel filtration using Ultrogel AcA44. The residual CSF associated with the GM-DF appeared to stimulate selectively granulocytic colonies. Disproportionation of GM-DF and GM-CSF was observed in ES fractions obtained using concanavalin-A/Sepharose chromatography: none of the GM-DF bound to this matrix, whereas 40% of the GM-CSF bound and was eluted with competing alpha methylglucopyranoside. Although no separation of GM-CSF and GM-DF was obtained using DEAE-Sepharose, non-isoelectric focusing in amphoteric buffers indicated charge differences between the differentiation factor and several sub-species of GM-CSF. Sequential purification of GM-DF from ES using 40 - 70% ammonium sulfate precipitation gel filtration and phenyl-Sepharose chromatography resulted in a 25-fold purification. In all fractionation procedures used, a sub-species of GM-CSF, stimulating granulocyte colony formation, was consistently associated with partially purified GM-DF, but some subspecies of GM-CSF clearly lacked any capacity to induce differentiation in the leukemic cells. The observations suggest that the factor in post-endotoxin serum most efficient in enforcing differentiation in myelomonocytic leukemic cells may be a subset of GM-CSF molecules with a selective capacity to stimulate granulocyte colony formation by normal cells.
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PMID:Characterization of a serum factor stimulating the differentiation of myelomonocytic leukemic cells. 697 58

We describe the molecular characteristics of T cell growth factor (TCGF), T cell replacing factor (TRF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) produced by a T cell hybridoma after stimulation with concanavalin A (Con A). All three activities could be separated from Con A itself by ammonium sulfate precipitation. The TRF and TCGF activities had a m.w. of 35,000 to 40,000 on gel filtration in phosphate-buffered saline (PBS). Their m.w. were about 30,000 under dissociating conditions in guanidine hydrochloride and about 35,000 to 40,000 under disulfide reducing conditions, suggesting the molecule(s) lacked noncovalent or disulfide-linked subunit structure. GM-CSF had a m.w. of 25,000 to 30,000 by gel filtration in PBS and about 23,000 in guanidine hydrochloride. TRF and TCGF on the one hand and GM-CSF on the other could be distinguished by the criteria of m.w., relative heat sensitivity, and hydrophobic chromatography. TCGF could not be separated from TRF by any of these methods. In terms of all the above properties, factor derived from the T cell hybridoma and spleen cells appeared identical.
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PMID:Biochemical characterization of regulatory factors derived from T cell hybridomas and spleen cells. I. Separation of T cell growth factor and T cell replacing factor from granulocyte-macrophage colony-stimulating factor. 697 69

Interleukin 2 (IL-2), produced with and without co-stimulation by the Burkitt's lymphoma line Daudi, was purified 37,000-fold to apparent homogeneity from lymphocyte conditioned medium by (NH4)2SO4 precipitation, DEAE-cellulose ion-exchange chromatography, gel filtration, and chromatography on blue agarose and on Procion-red agarose. The purified IL-2 showed a 10(6) U/mg protein sp act. IL-2 produced in the absence of Daudi cells had a mol wt of 26,000 as measured by gel filtration and an isoelectric point of 6.7. This IL-2 showed a 16,000 and 17,000 mol wt in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). IL-2, produced in the presence of Daudi cells (10(6)/ml), showed a mol wt of approximately 14,000, as measured by both gel filtration and SDS-PAGE, and an isoelectric point of 8.1. The purified IL-2 lacked detectable interferon (alpha and gamma), granulocyte-macrophage colony-stimulating factor, B cell growth factor, T cell-replacing factor, and thymocyte-differentiating activity and was free of any contaminating proteins as judged by silver staining in SDS-PAGE. All three molecular forms of IL-2 were biologically active at concentrations of 10(-11) - 10(-10) M, supporting the growth of human and murine cytotoxic T cell lines.
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PMID:Purification of human interleukin 2 to apparent homogeneity and its molecular heterogeneity. 698 Feb 56

A new and quantitative liquid culture system has been developed to measure the production of megakaryocytes from megakaryocyte progenitor cells (colony-forming units-megakaryocyte [CFU-MK]). The system uses as a target population a glycoprotein (Gp) IIb/IIIa+ subpopulation of rat bone marrow cells previously demonstrated to be highly enriched for CFU-MK. GpIIb/IIIa+ cells were cultured at 5 x 10(4) cells/mL (10(4) cells/well) with test samples in 96-well tissue culture plates for 4 days at 37 degrees C. During the final 3 hours of incubation, the cells were pulsed with [14C]5-hydroxytryptamine creatinine sulfate (14C-serotonin). After incubation, the plates were washed and the cell pellets were lysed with Triton-X 100. The cell lysate was infiltrated into a commercially available solid scintillator and dried, and radioactivity was measured. In this assay system, rat interleukin-3 (IL-3) was found to be the most potent among known cytokines tested. Murine granulocyte-macrophage colony-stimulating factor (GM-CSF), human erythropoietin (Epo), human IL-6, and murine stem cell factor (SCF) each alone stimulated megakaryocyte growth but were much less active than rat IL-3. Plasma of rats rendered thrombocytopenic by injection of monoclonal antirat platelet GpIIb/IIIa antibody exhibited significant activity, and the active protein fractions partially purified from the plasma showed much higher activity, but normal rat plasma had no effect. This liquid culture system allows the measurement of a large number of test samples--including a wide variety of cytokines and unknown growth factors, alone or in combinations--and provides a simple method for evaluating the early proliferative events involving CFU-MK in the megakaryocyte differentiation pathway.
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PMID:A simple and quantitative liquid culture system to measure megakaryocyte growth using highly purified CFU-MK. 755 34

Metabolism of dehydroepiandrosterone sulfate (DHEAS) to dehydroepiandrosterone (DHEA) occurs within specific anatomical compartments in vivo through the actions of the enzyme DHEAS sulfatase. This enzymatic activity facilitates the conversion of hydrophilic DHEAS to the hydrophobic species DHEA, which can then be further metabolized to other steroid hormones. High levels of DHEAS sulfatase reside in tissues where the biological activity of DHEA or its downstream metabolites regulate cellular function. Therefore, control over the activity of DHEAS sulfatase may represent an important regulatory process for the production of DHEA and its metabolites. Homogeneous populations of macrophages from normal mice were found to effectively convert DHEAS to DHEA in vitro. DHEAS sulfatase activity could be markedly depressed after exposure of these cells to a variety of nonspecific macrophage activators [i.e. zymosan, polyinosine/cytosine, heat-killed bacteria, or bacterial lipopolysaccharide (LPS)]. Inhibition of DHEAS metabolism was found to require protein synthesis, because temporary abrogation of protein synthesis with cycloheximide eliminated the ability of LPS to depress the conversion of DHEAS to DHEA. Additionally, exposure of LPS-nonresponsive macrophages to supernatants derived from LPS-treated BALB/c macrophages inhibited their ability to convert DHEAS to DHEA. Potent inhibition of sulfatase activity could be achieved by directly exposing murine macrophages to interferon-alpha (IFN alpha), IFN beta, or tumor necrosis factor-alpha, but not interleukin-1, interleukin-6, granulocyte-macrophage colony-stimulating factor, transforming growth factor-beta, platelet-derived growth factor, or the T-cell product IFN gamma. Our results indicate that macrophage metabolism of DHEAS to DHEA is down-regulated after cellular activation. Furthermore, inhibition of DHEAS sulfatase activity appears to be mediated through the actions of the inflammatory cytokines tumor necrosis factor-alpha and IFN alpha/beta.
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PMID:Regulation of macrophage dehydroepiandrosterone sulfate metabolism by inflammatory cytokines. 801 93

Experimental studies using murine tumor models have demonstrated that potent systemic immunity can be generated using tumor vaccines engineered by gene transfer to secrete certain cytokines. The underlying physiological principle behind these strategies involves the sustained release of high doses of cytokine at the site of the tumor. In some cases, this paracrine approach appears to enhance tumor antigen presentation and avoids systemic cytokine toxicity. The widespread clinical use of autologous cytokine gene transduced tumor vaccines may be limited by the technical difficulty and labor intensity of individualized gene transfer. We have therefore explored an alternate approach to generating sustained release of cytokines local to the tumor cells. High doses of granulocyte-macrophage colony-stimulating factor encapsulated in cell-sized gelatin-chondroitin sulfate microspheres were mixed with irradiated tumor cells prior to s.c. injection. This vaccination scheme resulted in systemic anti-tumor immune responses comparable to granulocyte-macrophage colony-stimulating factor gene transduced tumor vaccines.
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PMID:Controlled release, biodegradable cytokine depots: a new approach in cancer vaccine design. 826 90

A panel of monoclonal antibodies was raised against the low-affinity human granulocyte-macrophage colony-stimulating factor (hGM-CSF) receptor alpha-chain expressed as recombinant protein on murine FDC-P1 cells. All the selected antibodies were of the IgG2A isotype and bound to protein A. They each recognized both native and recombinant receptors by indirect surface immunofluorescence and by immunoprecipitation. Several of the antibodies also recognized presumably denatured receptors as detected by immunoblotting of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Three different epitopes on the extracellular domain of the GM-CSF receptor alpha-chain were defined by these antibodies, and two of the epitopes did not appear to be involved in binding hGM-CSF or in interactions with the beta-chain of the GM-CSF receptor that are required for high-affinity binding of GM-CSF. On the other hand, the epitope recognized by antibody 2B7-17-A appeared to be critically involved in the binding of GM-CSF because this antibody completely abrogated both high- and low-affinity binding of GM-CSF to native and recombinant receptors. Antibody 2B7-17-A had a relatively high affinity for the GM-CSF receptor alpha-chain (kd = 3 nmol/L) and slow dissociation kinetics (kd = 0.002 min-1). These properties made the 2B7-17-A antibody a potent inhibitor of hGM-CSF biologic action in several different bioassays, with a half-maximal inhibitory dose of about 6 nmol/L (1 microgram/mL). This antibody could prove useful in alleviating any pathologic states mediated by excess GM-CSF levels and in defining the domains of the GM-CSF receptor required for ligand binding.
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PMID:Neutralizing and nonneutralizing monoclonal antibodies to the human granulocyte-macrophage colony-stimulating factor receptor alpha-chain. 840 Feb 29

An adult T cell leukemia cell line, HIL-3, constitutively secretes a factor which induces the phenotypical and functional eosinophilic differentiation of a human eosinophilic leukemia cell line, EoL-1. Biochemical characteristics of the factor, termed eosinophilic leukemia cell differentiation factor (ELDF), were examined. ELDF was precipitated by 35 to 65% saturated ammonium sulfate from the culture supernatants of HIL-3 cells (HIL-3 sup). ELDF was eluted in a peak corresponding to a molecular weight of 30 to 40 kd by gel filtration. Isoelectric focusing in the Rotofor showed that ELDF had isoelectric points of 5 to 6. ELDF was trypsin-sensitive and stable to heat treatment at 65 degrees C for 30 minutes but labile at 80 degrees C or pH lower than 3. Half of the activity adhered to lentil-lectin but not to Con-A, indicating that a part of ELDF is glycoprotein with an N-linked carbohydrate moiety, which did not seem to be essential for ELDF activity. The biochemical characteristics of ELDF and blocking experiments using cytokine-specific neutralizing antibodies suggest that ELDF is different from gamma-interferon (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-5 (IL-5) and interleukin-2 (IL-2), which may exist in HIL-3 sup, and that ELDF may be a previously unrecognized leukemia differentiation factor.
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PMID:Characterization of an eosinophilic leukemia cell differentiation factor (ELDF) produced by a human T cell leukemia cell line, HIL-3. 850 May 76

Megakaryocytes and endothelial cells, two important blood and vascular cells, share many similar antigens on their surfaces and in the cytoplasm. It is known that the two types of cells share several developmental regulators: fibroblast growth factors, granulocyte-macrophage colony-stimulating factor, heparin and heparan sulfate, platelet factor 4, transforming growth factor-beta, gamma-interferon, and thrombospondin. Recognition of these common factors and studies with them are broadening the understanding of the pathogenesis of megakaryocytic and angiogenic diseases and encouraging attempts to develop new therapeutic strategies for the future.
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PMID:Are megakaryocytes and endothelial cells sisters? 850 91

Connective tissue cells (myofibroblasts) from liver inflammatory granulomatous reactions to schistosome eggs are able to sustain a long-term proliferation of myeloid cells, both in vivo and in vitro. We have addressed the question of the molecular mechanisms involved in control of this extramedullar stroma-dependent production of inflammatory cells. Heparan sulfate proteoglycans (HSPGs) were purified from granuloma-derived connective tissue cells and bound to plastic or collagen substrate. Their ability to bind recombinant murine granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3), to stimulate proliferation of the FDC-P1 myeloid cell lineage, and to modify growth factor activity was monitored. The specificity of this stroma cell-derived glycosaminoglycan interaction with the myeloid growth factors was analyzed by comparing other glycosaminoglycans and sulfated polysaccharides. HSPGs could act as an artificial myelopoietic stroma; they were both required and sufficient for binding and presenting GM-CSF and IL-3 in biologically active form. Moreover, they were able to mediate an increase in the specific growth-promoting activity of GM-CSF and IL-3. This was specific for stroma-derived heparan sulfate and heparin, since heparan sulfate derived from other cells, other glycosaminoglycans and related molecules had no effect. These results indicate that HSPGs can stimulate and control the in situ proliferation of myeloid cells, modifying in both quantitative and qualitative terms the composition of inflammatory cell infiltrates in hepatic granulomas.
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PMID:GM-CSF and IL-3 activities in schistosomal liver granulomas are controlled by stroma-associated heparan sulfate proteoglycans. 860 24


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