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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)

Many problems obviously continue to exist in gene transfer using retroviruses as a means of inserting foreign DNA into hematopoietic stem cells, especially with regulated genes such as the human beta globin genes. First, it is unclear whether the available retroviral vectors will infect enough stem cells for gene transfer to be successful over the long term. Second, there may be sequences necessary for normal beta globin gene expression that may also inhibit the normal retroviral life cycle, thus decreasing the efficiency of gene transfer or gene expression. It seems clear that in order to optimize the success of gene transfer, the highest possible titer of viral production is necessary. New approaches are aimed at increasing viral titer. The transfect/infect method appears useful. Growth factors may also be useful by increasing stem cell proliferation. Single growth factors may not be sufficient to optimize stem cell cycling. To date, interleukin-3 seems to be the single most useful growth factor, although interleukin-3 with interleukin-6 or other combinations of growth factors including interleukin-1 and granulocyte-macrophage colony-stimulating factor (GM-CSF) appear to have potential. Future work also is required to optimize the number of marrow stem cells needed for successful transplantation. Long-term bone marrow culture and stromal cell cultures may provide new and improved marrow culture conditions for achieving this goal. Improvements in the efficiency of both gene transfer and gene expression are necessary before we can consider the concept of gene transfer for the treatment of various hematologic genetic diseases in humans.
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PMID:Somatic gene therapy. 186 17

Megakaryocytes are responsive to several nonlineage-specific cytokines in vitro. In this study, we examined the in vivo effects of recombinant human granulocyte-macrophage colony-stimulating factor (rh GM-CSF) on late stages of megakaryocytopoiesis in the rhesus monkey. Four rhesus monkeys were given 10 micrograms/kg body weight/day of rh GM-CSF s.c. in two divided doses daily for 8 days. Megakaryocyte maturation was evaluated serially by measuring nuclear ploidy and cytoplasmic size. GM-CSF-treated monkeys developed significant shifts in ploidy distribution from days 3 through 15 (p less than or equal to 0.001), with increased frequencies of 64N and 128N megakaryocytes. Mean megakaryocyte size increased 92.5% on day 9, paralleling the increase in DNA content, although megakaryocyte size within ploidy groups did not increase. Megakaryocyte number remained unchanged following rh GM-CSF treatment. The platelet count responses were variable, and mean platelet volume did not change. The present study demonstrates that therapeutic doses of rh GM-CSF stimulate megakaryocyte endomitosis and increase mean size. The data indicate that GM-CSF is effective in promoting the maturation stage of megakaryocyte development but does not result in a consistent thrombopoietic response.
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PMID:Recombinant human granulocyte-macrophage colony-stimulating factor promotes megakaryocyte maturation in nonhuman primates. 186 95

Erythropoietin mediates the rapid phosphorylation of Raf-1 in the murine cell lines HCD-57 and FDC-P1/ER, which proliferate in response to this cytokine. Phosphorylation occurs at both serine and tyrosine residues and as such is similar to the Raf-1 phosphorylation seen after interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor, and interleukin-2 stimulation in other murine cell lines. Such data suggest that these growth factors may share a common mechanism(s) of Raf-1 phosphorylation. Furthermore, in association with Raf-1 phosphorylation, erythropoietin induces a 2-3-fold increase in Raf-1 kinase activity as measured in immune complex kinase assays in vitro. Finally, a c-raf antisense oligodeoxyribonucleotide, which specifically decreases intracellular Raf-1 levels, also substantially inhibits both erythropoietin and IL-3-directed DNA synthesis. Together, these results provide evidence that activated Raf-1 is a necessary component of erythropoietin and IL-3 growth signaling pathways.
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PMID:Erythropoietin induces Raf-1 activation and Raf-1 is required for erythropoietin-mediated proliferation. 186 34

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

The role of placental cells in transplacental transmission of human immunodeficiency virus type 1 (HIV 1) was investigated. Placental macrophages and trophoblasts, which together represent the main cell components of the placenta, were cultivated separately and then compared to foetal monocyte-derived macrophages for susceptibility to HIV 1 infection. Placental macrophages treated with granulocyte-macrophage colony-stimulating factor (GM-CSF) were less easily infected with HIV 1 than were GM-CSF-treated foetal monocyte-derived macrophages. HIV 1 replication in cocultures consisting of infected placental macrophages together with a highly HIV 1-permissive cell line (CEM) was detected persistently for at least 6 weeks by reverse transcriptase assay, even though placental macrophages expressed no detectable CD4 receptor, as indicated by indirect immunofluorescence. HIV 1-specific DNA sequences were also detected in infected placental macrophages. Trophoblasts exhibited no detectable CD4 expression and did not support the replication of HIV 1, although low levels of HIV 1-specific DNA sequences could be detected in infected trophoblasts. Placental macrophages or trophoblasts (or both) may thus play an important role in transplacental HIV 1 transmission.
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PMID:Replication of human immunodeficiency virus type 1 in primary cultured placental cells. 189 50

Interleukin 2 (IL-2)-activated lymphocytes (lymphokine-activated killer [LAK] cells) have been shown to inhibit the formation of autologous human granulocyte-macrophage hemopoietic progenitors (granulocyte-macrophage colony-forming units, CFU-GM) in vitro. Effects of LAK cells on these progenitors may include a number of different mechanisms. LAK cells are potent cytotoxic lymphocytes capable of lysing certain normal autologous cells. They also produce cytokines known to inhibit hemopoiesis (interferon gamma [IFN-gamma] and tumor necrosis factor alpha [TNF-alpha]) or enhance it (granulocyte-macrophage colony-stimulating factor, GM-CSF). In our current study we analyzed the mechanism of suppression of autologous CFU-GM by LAK cells. Our results suggest that LAK cells are not directly cytotoxic to normal CFU-GM. We show that it is possible to abolish the hemopoiesis-inhibiting activity of LAK cells without abrogating their cytotoxicity against tumor cell lines using inhibitors of DNA synthesis, namely hydroxyurea or irradiation.
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PMID:Mechanism of suppression of normal hemopoietic activity by lymphokine-activated killer cells and their products. 190 68

Activation of T cells by antigen, lectin, or a combination of phorbol-12-myristate acetate (PMA) and calcium ionophore (A23187) leads to the induction of genes for a set of lymphokines, including granulocyte-macrophage colony-stimulating factor (GM-CSF). We demonstrated in earlier studies that the upstream region of the mouse GM-CSF promoter at positions between -95 and -73 is essential for transcriptional activation in response to PMA/A23187. This region contains two DNA-binding motifs, GM2 and GC-box. The GM2 sequence (GGTAGTTCCC) is recognized by an inducible factor NF-GM2; the other (CCGCCC) by constitutive factors A1, A2, and B. To elucidate the mechanism of GM-CSF gene activation, we have purified the inducible factor NF-GM2 from the nuclear extract of stimulated Jurkat cells on the basis of specific DNA-binding activity. The purified NF-GM2 consists of 50 (p50) and 65 kDa (p65) polypeptides and has a binding activity specific for both the GM-CSF and immunoglobulin kappa (GGAAAGTCCC) enhancers. Electrophoretically purified p50 alone can form a protein-DNA complex, but in the mixture, p50 associates preferentially with p65 to form the NF-GM2 complex. In addition, p65 gave per se, with low affinity, a protein-DNA complex that migrated more slowly than native NF-GM2 complex. Furthermore, an antiserum against KBF1 (identical to 50 kDa NF-kappa B protein) reacted with the p50 of NF-GM2, indicating that the NF-GM2 polypeptide cannot be immunologically differentiated from the 50 kDa subunit of NF-kappa B. The purified NF-GM2 activated in vitro transcription from the kappa B enhancer, while it failed to stimulate transcription from the GM-CSF promoter harboring the GM2 sequence. This suggests that the activation mechanism of the GM-CSF gene through the GM2/GC-box sequence is different from that of genes carrying the kappa B enhancer alone.
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PMID:A nuclear factor NF-GM2 that interacts with a regulatory region of the GM-CSF gene essential for its induction in responses to T-cell activation: purification from human T-cell leukemia line Jurkat cells and similarity to NF-kappa B. 191 48

The region extending from -40 to -54 of the 5'-flanking region of the mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) gene shows homology to sequences found in the 5'-flanking regions of other cytokine genes, those encoding interleukin-4 (IL-4), IL-5, and granulocyte colony-stimulating factor (G-CSF). This sequence element is referred to as conserved lymphokine element 0 (CLE0). Saturation mutagenesis of the CLE0 element indicates that in addition to the previously mapped region between -73 and -91 (CLE2+ GC box), the CLE0 element is necessary for induction of the mouse GM-CSF gene by phorbol myristate acetate/Ca ionophore (A23187) stimulation in T cells. The presence of the CLE0 element is necessary to observe stimulation of the transcription activity of the mouse GM-CSF promoter in vitro. Mobility shift assays revealed that this region forms an inducible DNA-protein complex, NF-CLE0, which consists of two complexes of similar mobility, NF-CLE0a and NF-CLE0b. NF-CLE0a and NF-CLE0b recognize the 3' half and 5' half of the CLE0 element, respectively, with an overlapping region recognized by both proteins. The recognition sequence of NF-CLE0a corresponds to the region required for induction by phorbol myristate acetate/A23187, while the recognition sequence of NF-CLE0b contains bases that have inhibitory activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of the mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) gene promoter: nuclear factors that interact with an element shared by three lymphokine genes--those for GM-CSF, interleukin-4 (IL-4), and IL-5. 194 68

Hematopoietic growth factors have recently been well characterized by complementary DNA cloning. For human epidermal growth factor, granulocyte-macrophage colony-stimulating factor recombinant proteins have been expressed in Escherichia coli. To reduce the toxic side effects of chemotherapy on the bone marrow, recombinant human granulocyte-macrophage colony-stimulating factor and recombinant human interleukin 3 were applied to patients suffering of gastrointestinal cancers. To determine the influence of recombinant human granulocyte-macrophage colony-stimulating factor and recombinant human interleukin 3 on human pancreas and gastric cancer cell cells in vitro, a sensitive microculture test system was established that allows precise quantification of proliferation. A more than twofold enhancement of proliferation was observed by interleukin 3 and granulocyte-macrophage colony-stimulating factor in two of two cell cultures derived from gastric carcinoma cells, while two of nine cultures from pancreas carcinoma cells have shown enhanced cell growth in the presence of recombinant human interleukin 3 or recombinant human granulocyte-macrophage colony-stimulating factor. In comparison, recombinant human epidermal growth factor increased cell growth in two of two gastric and in five of nine pancreas carcinoma cultures. In general, 1-10 ng/mL of the growth factors yielded the highest growth rate, but even 1-pg amounts produced increased cell growth. Expression of messenger RNA for granulocyte-macrophage colony-stimulating factor, interleukin 3, and the oncogene HER2/neu remained undetectable in all of the tested cell lines, while the various abundance of messenger RNA for the epidermal growth factor receptor was different in each cell line. The reported results imply that the hematopoietic growth factors interleukin 3 and granulocyte-macrophage colony-stimulating factor influence cellular growth of pancreas and gastric carcinoma cells by a paracrine mechanism and may possess a more general regulatory function than originally anticipated.
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PMID:Stimulation of pancreas and gastric carcinoma cell growth by interleukin 3 and granulocyte-macrophage colony-stimulating factor. 201 78

A liquid culture technique was used to study regulation of human megakaryocytopoiesis in vitro. Low-density cells from adult bone marrow were cultured in the presence of normal plasma, plasma from patients with aplastic marrows (AP), recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and interleukin-3 (IL-3). Megakaryocytes (MK) were studied at day 10 of culture by a two-color staining technique using a pool of monoclonal antibodies for their identification and propidium iodide to label DNA. Their ploidy distribution was analyzed by flow cytometry. In some experiments cytoplasmic maturation was also studied by ultrastructural techniques. Normal plasma provides a low number of MK with a ploidy distribution including 8 N and 16 N MK. AP promoted in a dose-dependent manner proliferation of MK and some batches favored endoreplication. This effect was clearly demonstrated when ploidy distribution was compared between normal plasma and AP on parallel marrow cultures. However, ploidy distribution was shifted toward low values compared with uncultured MK. rhGM-CSF had no significant effect on these two parameters. In contrast, rhIL-3 from 0.1 U/mL to 100 U/mL had a proliferative effect but was unable to induce endoreplication. Furthermore, when associated with AP it totally abrogated the effect of AP on endoreplication because in most experiments more than 90% of MK were 2 N and 4 N. This effect was also observed when rhIL-3 was added after 7 days of culture (when it has little proliferative effects). Studies of the maturation of MK grown with rhIL-3 indicate that the majority were small mature cells synthesizing alpha-granules and demarcation membranes. The effect of AP on MK proliferation and endoreplication was not related to IL-6 because its IL-6 content was identical to that of normal plasma and its neutralization did not modify these parameters. In conclusion, this study indicates that liquid culture technique in association with flow cytometry could be a powerful tool in identifying the humoral regulators of human megakaryocytopoiesis.
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PMID:In vitro effects of hematopoietic growth factors on the proliferation, endoreplication, and maturation of human megakaryocytes. 203 16


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