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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)
Mast cell growth factor (MGF, the ligand for
c-kit
receptor) can stimulate proliferation of factor dependent myeloid cell line, M07e, and MGF synergizes with
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) or IL-3 in this effect. The effect of MGF on protein tyrosine kinase activity in M07e cells was investigated by immunoblotting with anti-phosphotyrosine mAb and this was compared with effects of
GM-CSF
. MGF stimulation rapidly induced or enhanced at least 12 tyrosine phosphorylated bands. Major bands had molecular weights of 145, 120, 110, 98, 62, 55 and 42 kD. P145, the most prominent phosphorylated protein, was identified as
c-kit
product using anti-
c-kit
-mAb (YB5.B8), suggesting ligand-dependent receptor autophosphorylation. Five of six tyrosine phosphorylated bands induced or enhanced by
GM-CSF
stimulation comigrated with those tyrosine phosphorylated by MGF (138, 120, 76, 55 and 42 kD). P42 was identified, at least in part, as mitogen-activated protein (MAP) kinase. MGF induced tyrosine phosphorylation of a complex of GTPase-activating protein (GAP, 120 kD) and GAP associated proteins (p62/p190) as detected by anti-GAP Ab immunoprecipitation followed by immunoblotting with anti-phosphotyrosine mAb.
GM-CSF
also stimulated slightly but consistently tyrosine phosphorylation of GAP and p190 but not p62. Both MGF and
GM-CSF
enhanced Raf-1 phosphorylation and increased Raf-1 associated kinase activity in vitro. Phosphoamino acid analysis revealed Raf-1 phosphorylation by these two growth factors occurred almost exclusively on serine residues. No tyrosine phosphorylation of Raf-1 protein was detected. These data suggest shared and unshared components of signaling pathways of both factors, which may be involved in cell proliferation.
...
PMID:Comparative analysis of signaling pathways between mast cell growth factor (c-kit ligand) and granulocyte-macrophage colony-stimulating factor in a human factor-dependent myeloid cell line involves phosphorylation of Raf-1, GTPase-activating protein and mitogen-activated protein kinase. 172 91
Recombinant human stem cell factor (SCF) is homologous with recombinant rat SCF (rrSCF) and is a ligand for
c-kit
. We determined the influence of SCF on hematopoiesis in vitro and in vivo in baboons. In vitro, SCF alone stimulated little growth of hematopoietic colony-forming cells from baboon marrow, but did increase the number of colonies formed in response to erythropoietin (Epo), interleukin-3 (IL-3), and
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
). In vivo, SCF caused an increase in the peripheral blood of the number of erythrocytes, neutrophils, lymphocytes, monocytes, eosinophils, and basophils. In marrow, it caused an increase in marrow cellularity and in the absolute number of colony-forming unit-granulocyte-monocyte (CFU-GM) and burst-forming unit-erythroid (BFU-E) in marrow following infusion of SCF. The in vivo stimulation of multiple lymphohematopoietic lineages corroborates previous in vitro studies and suggests a potentially important clinical role for SCF.
...
PMID:Recombinant human stem cell factor, a c-kit ligand, stimulates hematopoiesis in primates. 191 79
The regenerative potential of bone marrow following exposure to relatively high doses of ionizing radiation, as well as the efficacy of hemopoietic growth factor treatment, are dependent on the residual number of hemopoietic stem cells. From studies in mice in particular, evidence has been obtained that immature hemopoietic stem cells are heterogenous with respect to repopulating capacity, with one subset being capable of short-term, transient hemopoietic reconstitution and another subset of sustained reconstitution. In rhesus monkeys, CD34+, RhLA-DRdull cells were identified as the small fraction of a bone marrow cell that contains reconstituting hemopoietic stem cells. The growth factor receptor phenotype of this immature cell fraction has been determined for
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
), interleukin 3 (IL-3), and IL-6 as well as for kit-ligand, making
c-kit
an especially strong growth factor receptor marker for reconstituting stem cells. In addition, it is demonstrated that CD34+ cells appear in peripheral blood after exposure to radiation and are correlated to numbers of CD34+ cells in bone marrow. This finding suggests that circulating CD34+ cells may be used as a cellular marker with prognostic significance for both the number of residual stem cells as well as regeneration of immature hemopoietic cells in bone marrow.
...
PMID:Surface markers and growth factor receptors of immature hemopoietic stem cell subsets. 748 42
By employing a monoclonal antibody against the stem cell factor receptor (SCF-R),
c-kit
oncogene product, we analysed in flow cytometric technique the density of SCF-R on GM/SO cells which were incubated under various culture conditions. These experiments revealed that there is an inverse correlation between the SCF-R density on the cells and the doses of
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) in culture medium; the lower the dose, the higher the density of SCF-R on the cells. More detailed analyses showed that, in contrast to SCF which rapidly downregulates its own receptor,
GM-CSF
does not alter the measurable level of SCF-R in an exposition period of 60 minutes, which suggests that the internalization or shedding of the receptor is not the mechanism of action. Since the most striking difference regarding density of SCF-R between
GM-CSF
-treated and untreated cells was observed on day 2, the modulation of
c-kit
oncogene protein by
GM-CSF
likely occur prior to expression of protein onto the cell surface. In order to exclude the possibility that altered cell viability due to insufficient
GM-CSF
content in culture medium might be responsible for the increased SCF-R densities on
GM-CSF
-dependent cells, we subsequently generated a
GM-CSF
-independent subclone which still responded to
GM-CSF
as well as the dependent did. The experiments carried out with this subclone confirmed the results presented above. Thus our data suggest that
GM-CSF
is directly involved in the regulation of SCF receptor density on GM/SO cells.
...
PMID:Granulocyte-macrophage colony-stimulating factor (GM-CSF) reduces the density of stem cell factor receptors (c-kit oncogene product) on a GM-CSF-dependent human myeloid cell line. 750 37
The clinical symptoms of allergy are caused by cellular (IgE-triggered) responses to an allergen. Effector cells of allergy include eosinophil and basophil granulocytes, as well as tissue mast cells. Growth and accumulation, as well as IgE-dependent and independent functions of these cells are regulated by distinct proteohormones and peptides. The hemopoietic cytokines IL-3 (interleukin-3), IL-5 and GM-CSF (
granulocyte-macrophage colony-stimulating factor
) are involved in the regulation of basophils (and eosinophils), whereas the ligand for
c-kit
, SCF (stem cell factor) is a mast cell-specific agonist. Basophils and mast cells express high-affinity IgE-binding sites. Allergen binding to IgE on mast cells and basophils, and consecutive cross-linking of IgE receptors is followed by production and/or secretion of inflammatory mediator substances. Specific activation and deactivation of mast cells/basophils in vitro has been demonstrated by use of recombinant cytokines and allergens, and specific haptens or by use of novel drugs, and should lead to epitope-specific diagnosis and better management of allergic diseases in the future.
...
PMID:[Effector cells in allergy: biological principles and new pharmacologic concepts]. 750 62
In long-term human bone marrow cultures, stromal cells of human origin are usually used on the assumption that human primitive progenitor cells do not respond to cytokines produced by stromal cells from other species. There is accumulating evidence, however, that murine stromal cells also promote maintenance and differentiation of very primitive human stem cells, which suggests the existence of novel stromal activities that cross species barriers. In this study, we show that a murine bone marrow-derived stromal cell line, MS-5, allows the proliferation of the human leukemic cell line UT-7. The long-term growth of UT-7 is usually supported only by human interleukin-3 (IL-3),
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
), or erythropoietin (Epo). None of these three cytokines was involved in the observed effect, since murine
GM-CSF
and IL-3 do not act on human cells and MS-5 cells do not produce Epo. Soluble stem cell factor (SCF) induced UT-7 cell proliferation. However, S1/S1 mutant fibroblasts also supported UT-7 cell growth and anti-
c-kit
antibodies only partially abolished UT-7 cell proliferative response to MS-5 cells. These observations excluded a major role of SCF in this system. MS-5-derived growth-promoting activity was diffusible, but attempts to grow UT-7 cells in high levels of known soluble murine stromal-derived cytokines active on human cells showed no or minimal response, suggesting that MS-5's proliferative effect was not mediated by known cytokines. Finally, involvement of an autocrine loop of activation induced by MS-5 was excluded: RT-PCR analysis did not detect increased transcripts for
GM-CSF
, IL-3, IL-6, SCF, or Epo in UT-7 cells cocultured for 2 to 6 days with MS-5. In addition, UT-7 cell proliferation on MS-5 was not inhibited by neutralizing antibodies against the human GM-CSF receptor or the human IL-6 receptor alpha chain. Whether UT-7 cell proliferation triggered by MS-5 reflects the existence of novel stromal cytokines or results from synergistic interactions on the MS-5 cell surface between extracellular matrix proteins and cytokines will require further investigation.
...
PMID:A murine stromal cell line promotes the proliferation of the human factor-dependent leukemic cell line UT-7. 751 51
High proliferative-potential colony-forming cells (HPP-CFC) have been identified in the bone marrow of mice and adult humans, and have been characterized as a compartment of primitive progenitors possibly including stem cells. In this report we describe the human fetal liver (FL) as a source of HPP-CFC. These FL HPP-CFC develop in clonal cultures in the presence of
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) and interleukin-3 (IL-3) within 3 to 4 weeks. The median frequency of HPP-CFC in FL tissues between 16 and 21 weeks of gestational age was 1 in 3,000 total FL cells. After 4 weeks of growth, FL HPP-CFC grew to a median colony size of 8.3 x 10(4) cells/colony. Using cell-sorting techniques FL HPP-CFC were shown to be predominantly contained in the CD34+ CD33+ CD38- fraction of FL cells. FL HPP-CFC were heterogeneous for HLA-DR expression, and no differences in proliferative capacities were observed between HLA-DR+ and HLA-DR- HPP-CFC. The CD34+ CD33-HLA-DR- CD38- population, previously suggested to contain stem cells, was observed to be very rare in the FL, representing approximately 1 in 1.7 x 10(5) light-density FL cells and containing almost no CFC. Therefore, it is possible that stem cells are contained in the CD33+ fraction of FL cells. Phenotypic characterization of CD34+ CD33+ CD38- lin -LDFL cells showed that these cells are also CD13+, predominantly Thy-1+, CD45RA-, CD45RO-, CD71-, and heterogenoeous for
c-kit
expression. These data suggest that FL HPP-CFC represent a heterogeneous compartment of primitive myeloid progenitors that may include stem cells.
...
PMID:Expression of CD33, CD38, and HLA-DR on CD34+ human fetal liver progenitors with a high proliferative potential. 751 3
It might be possible to facilitate engraftment after transplantation of purified hematopoietic progenitor cells if the cells are stimulated ex vivo prior to transplantation. The aim of this study was to analyze the potential of
c-kit
ligand (CKL) combined with
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) and/or interleukin-3 (IL-3) to induce proliferation and differentiation of human bone marrow CD34+ cells in vitro. Particular attention was paid to the ability to expand populations that could maintain progenitor characteristics, i.e. CD34 expression and generation of colony forming cells (CFC), for a considerable period of time. Purified CD34+ cells were cultured in liquid medium for 42 days interrupted by immunophenotyping and CFC assays. In the presence of CKL combined with
GM-CSF
and/or IL-3, the total number of cells expressing CD34 increased significantly for several weeks after an initial decline. Further, CFC were continually recovered in these cultures. Based on the kinetics and the flow cytometry analysis, the expanding populations that continued to express CD34 probably originated from noncommitted, immature CD34+ cell subsets. CKL combined with
GM-CSF
and/or IL-3 also induced strong cell proliferation. The majority of the proliferating cells lost CD34 expression and acquired a series of mature myeloid cell surface markers associated with the monocytic, granulocytic and megakaryocytic lineages. These cells probably originated from committed CD34+ cell subsets. We conclude that CKL combined with
GM-CSF
and/or IL-3 can stimulate noncommitted, immature as well as committed CD34+ cell populations to expand and to differentiate. This property might be useful in a short-term ex vivo pretransplant stimulation of CD34+ cells in an attempt to facilitate rapid and stable engraftment after stem cell transplantation.
...
PMID:c-kit ligand combined with GM-CSF and/or IL-3 can expand CD34+ hematopoietic progenitor subsets for several weeks in vitro. 751 97
We have studied the effects of recombinant human interleukin-9 (IL-9), alone and combined with stem cell factor (SCF,
c-kit
ligand), IL-3, and
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) on the clonogenic proliferation of highly enriched human hematopoietic CD34+ and CD34+CD33-DR- progenitor cells. Colony assays were performed under serum-containing and serum-free conditions. IL-9, as a single agent, did not support colony formation. The addition of erythropoietin (Epo) to IL-9 induced the growth of erythroid progenitors (BFU-E) derived from both CD34+ and CD34+CD33-DR- cells. The IL-9-dependent growth of BFU-E derived from CD34+ cells was increased in an additive manner by SCF and, to a lesser extent, by IL-3, whereas CD34+CD33-DR- erythroid precursors were also responsive to
GM-CSF
in combination with IL-9. The addition of SCF to IL-9 did stimulate the development of CD34+ and CD34+CD33-DR- macroscopic, multicentered BFU-E and multilineage colonies (CFU-GEMM). When IL-9 was used in serum-free conditions, the growth of CD34+ and CD34+CD33-DR- BFU-E was observed in the presence of Epo. Moreover, a marked synergy on BFU-E colony formation was evident when IL-9 was combined with SCF, and their activity was enhanced by the addition of IL-3. IL-9 showed a negligible proliferative activity on colony-forming units-granulocyte/macrophage (CFU-GM). However, it increased the number of CD34+CD33-DR- CFU-GM responsive to IL-3 (37% of the colonies generated by phytohemagglutinin-stimulated lymphocyte conditioned medium [PHA-LCM]). The effects of IL-9 on CD34+CD33-DR- cells were also studied in a short-term suspension culture system, which evaluates the proliferation of progenitors earlier than day 14 CFU-C (Delta assay). In this system, IL-9 had a minimal activity on its own. In combination with SCF, however, it induced a nine-fold expansion of CD34+CD33-DR- cells, which generated a greater number of CFU-GM than BFU-E in secondary methylcellulose cultures. These experiments indicate that IL-9 induces the proliferation of very primitive human erythroid cells, and this effect is potentiated by SCF and other cytokines. Furthermore, IL-9 synergizes in vitro with the
c-kit
ligand in expanding the pool of early pluripotent hematopoietic progenitor cells.
...
PMID:Stem cell factor (c-kit ligand) enhances the interleukin-9-dependent proliferation of human CD34+ and CD34+CD33-DR- cells. 752 Mar 94
In the presence of hemopoietic cytokines such as
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) and interleukin-3 (IL-3), mast cell growth factor (MGF; also known as steel factor, stem cell factor, and
c-kit
ligand) has proven to be a potent hemopoietic regulator in vitro. In these studies, we examined the in vivo effects of MGF in combination with
GM-CSF
or
GM-CSF
plus IL-3. Effects were based on the ability of these cytokines to stimulate recovery from radiation-induced hemopoietic aplasia. Female B6D2F1 mice were exposed to a sublethal 7.75-Gy dose of 60Co radiation followed by subcutaneous administration of either saline, recombinant murine (rm) MGF (100 micrograms/kg/day), rmGM-CSF (100 micrograms/kg/day), rmIL-3 (100 micrograms/kg/day), or combinations of these cytokines on days 1-17 postirradiation. Recoveries of bone marrow and splenic spleen colony-forming units (CFU-s), granulocyte macrophage colony-forming cells (GM-CFC), and peripheral white blood cells (WBC), red blood cells (RBC) and platelets (PLT) were determined on days 14 and 17 during the postirradiation recovery period. MGF administered in combination with
GM-CSF
or in combination with
GM-CSF
plus IL-3 either produced no greater response than
GM-CSF
alone or down-regulated the
GM-CSF
-induced recovery. These results sharply contrasted results of in vitro studies evaluating the effects of these cytokines on induction of GM-CFC colony formation from bone marrow cells obtained from normal or irradiated B6D2F1 mice, in which MGF synergized with
GM-CSF
or
GM-CSF
plus IL-3 to increase both GM-CFC colony numbers and colony size. These studies demonstrate a dichotomy between MGF-induced effects in vivo and in vitro and emphasize that caution should be taken in attempting to predict cytokine interactions in vivo in hemopoietically injured animals based on in vitro cytokine effects.
...
PMID:Mast cell growth factor (C-kit ligand) in combination with granulocyte-macrophage colony-stimulating factor and interleukin-3: in vivo hemopoietic effects in irradiated mice compared to in vitro effects. 752 Jul 25
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