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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 effects of recombinant human stem cell factor (SCF, a c-kit ligand) on an eosinophil lineage were examined in clonal and suspension cultures of human non-adherent light density bone marrow cells. Although interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-5 (IL-5) each exhibited eosinophil-colony stimulating activity, SCF did not do so alone. However, the addition of SCF to IL-3, GM-CSF, or IL-5 cultures led to an increase in the number of eosinophil colonies per 5 x 10(4) cells, from 8.0 +/- 1.4, 11.0 +/- 2.0, and 6.7 +/- 0.6, to 12.7 +/- 3.2, 19.0 +/- 4.4, and 12.0 +/- 2.0, respectively. A similar synergistic effect of SCF on eosinophils was also observed in the suspension cultures of bone marrow cells, although SCF alone had little proliferative effect. Moreover, although the delayed addition of IL-5 to cultures containing SCF led to a small increase in the number of mature eosinophils, the effect of SCF was less than that of either GM-CSF or IL-3. These observations suggest that SCF may have a proliferative effect on eosinophil precursor cells and may increase the number of mature eosinophils when used in combination with such other growth factors as IL-3, GM-CSF, and IL-5.
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PMID:Effect of c-kit ligand (stem cell factor) in combination with interleukin-5, granulocyte-macrophage colony-stimulating factor, and interleukin-3, on eosinophil lineage. 769 27

We have studied the effects of recombinant human interleukin-11 (rhIL-11), alone and combined with stem cell factor (SCF or c-kit ligand), IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF) on the proliferation of highly enriched human hematopoietic CD34+ and CD34+CD33-DR- progenitor cells. CD34+ cells were purified using the avidin-biotin immunoabsorption technique and CD33+DR+ cells were subsequently removed by immuno-magnetic separation. The colony assays were performed in the presence and absence of exogenous serum. IL-11, as a single agent, induced the growth of a small number of colony-forming units-granulocyte/macrophage (CFU-GM) derived from purified CD34+ cells and failed to support the colony growth of CD34+CD33-DR- cells. The addition of erythropoietin (Epo) to IL-11 induced the growth of erythroid progenitors (BFU-E) derived from CD34+ cells but not from the same population depleted of CD33+DR+ cells. The combination of IL-11 with SCF, IL-3, or GM-CSF, in the presence of Epo, resulted in a synergistic or additive increase in the number of CFU cells (CFU-C) derived from both cell fractions. Moreover, the addition of SCF to IL-11 stimulated the development of macroscopic erythroid and multilineage colonies (CFU-GEMM) containing more than 10(4) cells. A combination of three factors (IL-11, SCF, and IL-3) resulted in the increase of the number of colonies arising from CD34+ and CD34+CD33-DR- cells (but not of their size) compared to the cultures treated with IL-11 plus SCF or IL-11 plus IL-3. The pattern of proliferative response of primitive hematopoietic progenitor cells to IL-11 in serum-free conditions was very similar to the cultures grown in serum-containing medium. It is noteworthy that IL-11 and SCF yielded colony formation that was comparable to that observed in the presence of serum. The effects of IL-11 on CD34+CD33-DR- cells were also studied in a short-term suspension culture system, which was shown to be specific for evaluating the proliferation of pluripotent hematopoietic precursors (Delta assay). In this system, IL-11 had a minimal effect on its own, whereas IL-11 plus SCF acted synergistically and their proliferative activity was improved by the addition of GM-CSF. These experiments indicate that IL-11 may be considered a "permissive" cytokine, capable of initiating the proliferation of very primitive human hematopoietic cells, which are then able to respond to late-acting CSFs.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Interleukin-11 stimulates the proliferation of human hematopoietic CD34+ and CD34+CD33-DR- cells and synergizes with stem cell factor, interleukin-3, and granulocyte-macrophage colony-stimulating factor. 769 67

Murine hematopoietic cells can be transformed in vitro by recombinant retroviruses that express the myb oncogene, and hematopoietic growth factor (HGF)-dependent myeloid cell lines can be derived from these transformed primary cells. In this study, the differentiation state and responses of myb-transformed hematopoietic cells (MTHCs) have been investigated. We find that MTHCs exhibit properties of early myeloid progenitors including synergistic responses to combinations of HGFs and expression of certain surface markers. As reported previously, MTHCs respond well to granulocyte-macrophage colony-stimulating factor (GM-CSF) but can also respond to interleukin-3 (IL-3); the response to the latter factor depends on the mouse strain from which the cells are derived. Although these single factors stimulate MTHCs, combinations of these factors with colony-stimulating factor-1 (CSF-1 or M-CSF) or Steel factor (SLF or SCF) act synergistically to promote colony formation. The surface markers expressed by MTHCs include both granulocyte-macrophage lineage specific antigens Gr-1, 7/4, F4/80, and Mac-1, as well as two antigens found on early progenitors and stem cells--Thy-1 and Sca-1 (Ly6E). Expression of the latter markers is often heterogeneous and can be modulated by the growth factors to which the cells are exposed. Finally, we show that monocytic differentiation of MTHCs can be induced by exposure to tumor necrosis factor (TNF alpha). Taken together, these results suggest that MTHCs will be a useful model for studying HGF/cytokine responses in both proliferation and differentiation.
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PMID:Differentiation state and responses to hematopoietic growth factors of murine myeloid cells transformed by myb. 821 31

Recombinant human (rh) granulocyte-macrophage colony-stimulating factor (GM-SCF) is currently being tested in clinical trials for the treatment of acute myeloid leukemias with two main intentions: reduction of neutropenia and recruitment of leukemic blasts into cell cycle to enhance cytarabine (ara-C) mediated cytotoxicity. We report a case of a fatal spleen rupture in a patient with acute monocytic leukemia (AML M5b) who was treated according to a clinical phase I/II protocol with rh GM-CSF priming and standard induction chemotherapy TAD 9 (thioguanine/ara-C/daunorubicin). During treatment we observed rapidly rising peripheral blast counts and the development of an acute abdomen. Ultrasound examination revealed splenomegaly due to diffuse cellular infiltration and spleen rupture. The patient died 17 days later due to pneumonia and renewed spleen hemorrhage. Bone marrow progenitor assays before treatment showed exclusive growth of monocytoid blast cell colonies (CFU-L). Colony growth could be stimulated with rh GM-CSF and blocked dose-dependently by a monoclonal anti-GM-CSF antibody. CFU-L proliferation also increased after stimulation with rh interleukin-3 (rh IL-3) and supra-additively with rh granulocyte colony-stimulating factor (rh G-CSF) combined with rh GM-CSF. Furthermore, rh GM-CSF induced surface marker expression of CDw 65 and CD 11b on isolated CFU-L blasts. After short-term suspension culture, rh GM-CSF enhanced the expression of CD 29- and CD 11b-adhesion molecules on peripheral blast cells. In summary, this case represents a fatal spleen rupture occurring during rh GM-CSF priming and induction chemotherapy for acute monocytic leukemia. Although the etiology of this spleen rupture remains uncertain, in view of our data we suggest special caution, when further testing this therapy protocol in acute leukemias with monocytic subtype and high peripheral blast cell counts.
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PMID:Fatal spleen rupture during induction chemotherapy with rh GM-CSF priming for acute monocytic leukemia. Clinical case report and in vitro studies. 845 Jun 76

Thrombopoietin (Tpo), the ligand for c-mpl, has been shown to be the principal regulator of megakaryocytopoiesis and platelet production. The ability of Tpo to potently stimulate the growth of committed megakaryocyte (Mk) progenitor cells has been studied in detail. Murine fetal liver cells, highly enriched in primitive progenitors, have been shown to express c-mpl, but little is known about the ability of Tpo to stimulate the growth and differentiation of primitive multipotent bone marrow (BM) progenitor cells. Here, we show that Tpo alone and in combination with early acting cytokines can stimulate the growth and multilineage differentiation of Lin- Sca-1+ BM progenitor cells. In particular, Tpo potently synergized with the ligands for c-kit (stem cell factor [SCF]) and flt3 (FL) to stimulate an increase in the number and size of clones formed from Lin- Sca-1+ progenitors. When cells were plated at 1 cell per well, the synergistic effect of Tpo was observed both in fetal calf serum-supplemented and serum-depleted medium and was decreased if the addition of Tpo to cultures was delayed for as little as 24 hours, suggesting that Tpo is acting directly on the primitive progenitors. Tpo added to SCF + erythropoietin (Epo)-supplemented methylcellulose cultures potently enhanced the formation of multilineage colonies containing granulocytes, macrophages, erythrocytes, and Mks. SCF potently enhanced Tpo-stimulated production of high-ploidy Mks from Lin- Sca-1+ progenitors, whereas the increased growth response obtained when combining Tpo with FL did not translate into increased Mk production. The ability of Tpo and SCF to synergistically enhance the growth of Lin- Sca-1+ progenitors was predominantly observed in the more primitive rhodamine 123(lo) fraction. Tpo also enhanced growth of Lin- Sca-1+ progenitors when combined with interleukin-3 (IL-3) and IL-11 but not with IL-12, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, or Epo. Epo, which has high homology to Tpo, was unable to stimulate the growth of Lin- Sca-1+ progenitors alone or in combination with SCF or FL, suggesting that c-mpl is expressed on more primitive stages of progenitors than the Epo receptor. Thus, the present studies show the potent ability of Tpo to enhance the growth of primitive multipotent murine BM progenitors in combination with multiple early acting cytokines and documents its unique ability to synergize with SCF to enhance Mk production from such progenitors.
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PMID:Thrombopoietin, but not erythropoietin, directly stimulates multilineage growth of primitive murine bone marrow progenitor cells in synergy with early acting cytokines: distinct interactions with the ligands for c-kit and FLT3. 897 40

Selected CD34+ cells from mobilized apheresis products were cultured in serum-free or serum-containing media supplemented with granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and stem cell factor (SCF; c-kit ligand). We examined the emergence of a CD15+CD11b- population, which appeared morphologically to be promyelocytes. This CD15+CD11b- population can be further expanded in culture into morphologically mature granulocytes. In an attempt to characterize this culture-derived CD15+CD11b- promyelocytic population, single cells were clone sorted into wells of a Terasaki plate containing various growth factors. We compared the growth factor requirements and kinetics of this apheresis culture-derived CD15+CD11b- population to the CD15+CD11b- population from fresh bone marrow samples. Our studies indicate that the CD15+CD11b- promyelocytic population from bone marrow and blood are equivalent in their ability to proliferate and in their requirements for growth factors. The CD15+CD11b- population in vitro shows a high proliferative capacity when compared with the other CD15/CD11b populations (CD15-CD11b-, CD15+CD11b+, CD15-CD11b+). Thus, we can manipulate CD34+ cells in vitro to proliferate and differentiate toward a mature neutrophil lineage. The CD15+CD11b- promyelocytic population derived from this culture may represent the most effective cultured cell population for therapeutic reduction of neutropenia in vivo based on both its stage of differentiation and its proliferative potential.
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PMID:Characterization of a culture-derived CD15+CD11b- promyelocytic population from CD34+ peripheral blood cells. 933 18

Administration of hematopoietic growth factors is being used increasingly to obtain populations of blood progenitor/stem cells (PBPC) for clinical transplantation. Here we examined the effect of combining stem cell factor (SCF ) and granulocyte colony-stimulating factor (G-CSF ) versus G-CSF alone in a randomized clinical study involving 62 women with early-stage breast cancer. In the first patient cohorts, escalating doses of SCF were administered for 7 days with concurrent G-CSF administration. At baseline, levels of progenitor cells in the bone marrow or blood were comparable in the different patient groups. As with administration of G-CSF alone, the combination of SCF plus G-CSF did not alter the wide variation in levels of PBPC observed between individuals and did not alter the selective nature of PBPC release, with preferential release of day-14 granulocyte-macrophage colony-stimulating factor (GM-CFC) versus day-7 GM-CFC. However, SCF acted to sustain the levels of PBPC after cessation of growth factor treatment; levels of PBPC were elevated 100-fold at later timepoints compared with G-CSF alone. In addition, the maximum levels of PBPC observed were increased approximately fivefold at day 5 of growth-factor administration. The increased levels of PBPC resulted in significantly increased levels of PBPC obtained by leukapheresis. In a subsequent patient cohort, 3-days pretreatment with SCF was introduced and followed by 7 days concurrent SCF plus G-CSF. The 3-days pretreatment with SCF resulted in an earlier wave of PBPC release in response to commencement of G-CSF. In addition, maximum PBPC levels in blood and PBPC yield in leukapheresis products were further increased. Unexpectedly however, SCF pretreatment resulted in progenitor cells with enhanced self-generation potential. Recloning assays documented the ability of approximately 30% of primary granulocyte-macrophage (GM) colonies from control cell populations to generate secondary GM colonies (n = 1,106 primary colonies examined). In contrast approximately 90% of GM colonies from PBPC after SCF pretreatment generated secondary clones and 65% generated secondary colonies. The action of SCF was not explicable in terms of altered SCF, GM-CSF, or G-CSF responsiveness, but SCF pretreatment was associated with maximum serum SCF levels at the time G-CSF was commenced. These results show that PBPC populations mobilized by different growth factor regimens can differ in their functional properties and caution against solely considering number of harvested progenitor cells without regard to their function.
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PMID:Enhanced levels and enhanced clonogenic capacity of blood progenitor cells following administration of stem cell factor plus granulocyte colony-stimulating factor to humans. 934 20

The cDNAs encoding wild type (WT) human receptor tyrosine kinase c-Kit and a constitutively activated mutant, V816Kit, were introduced into granulocyte-macrophage colony-stimulating factor (GM-CSF )-dependent early murine hemopoietic cells, which had been transformed with activated Myb. WTKit cells were able to grow in the presence of the human ligand for Kit, stem cell factor (SCF ), but displayed reduced growth and clonogenic potential in either SCF or GM-CSF compared with the parental cells in GM-CSF. In contrast, V816Kit cells grew without factor at a higher rate than the parental cells in GM-CSF and displayed increased clonogenicity. Dissection of the growth characteristics in liquid culture showed that in the presence of appropriate factors, the different populations had similar proliferation rates, but that V816Kit profoundly increased cell survival compared with WTKit or parental cells. This suggests that the signals transduced by WTKit activated with SCF, and by V816Kit, were not identical. Also, WTKit and V816Kit-expressing cells both varied from the early myeloid progenitor phenotype of the parental cells and gave rise to a small number of large to giant adherent cells that expressed macrophage (alpha-naphthyl acetate) esterase and neutrophil (naphtol-AS-D-chloroacetate) esterase, were highly phagocytic and phenotypically resembled histiocytes. Thus, WTKit activated by SCF and V816Kit were able to induce differentiation in a proportion of Myb-transformed myeloid cells. The factor independent V816Kit cells, unlike the parental and WTKit expressing cells, were shown to produce tumors of highly mitotic, invasive cells at various stages of differentiation in syngeneic mice. These results imply that constitutively activated Kit can promote the development of differentiated myeloid tumors and that its oncogenic effects are not restricted to lineages (mast cell and B-cell acute lymphoblastic leukemia), which have been reported previously. Furthermore, the mixed populations of cells in culture and in the tumors phenotypically resembled the leukemic cells from patients with monocytic leukemia with histiocytic differentiation (acute myeloid leukemia-M5c), a newly proposed subtype of myeloid leukemia.
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PMID:Expression of constitutively activated human c-Kit in Myb transformed early myeloid cells leads to factor independence, histiocytic differentiation, and tumorigenicity. 937 65

Here we review our recent data addressing the role of recombinant human (rh) interleukin 9 (IL-9) in acute myeloblastic leukemia (AML). We first evaluated the proliferative response of 3 leukemic cell lines and 32 primary samples from AML patients to IL-9 alone and combined with rh-IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF) and stem cell factor (SCF, c-kit ligand). The colony forming ability of leukemic cells was assessed by a clonogenic assay in methylcellulose, whereas the cell cycle characteristics of the same samples were determined by the acridine-orange (AO) flow cytometric technique and the bromodeoxyuridine (BRDU) incorporation assay. In addition, the terminal deoxynucleotidyl transferase Assay (TDTA) and standard analysis of DNA cleavage by gel electrophoresis were used to evaluate induction or prevention of apoptosis by IL-9. IL-9, used as a single cytokine, at various concentrations stimulated the colony formation of the 3 myeloid cell lines under serum-containing and serum-free conditions and this effect was completely abrogated by anti-IL-9 monoclonal antibodies (MoAbs). When tested on fresh AML samples, optimal concentrations of IL-9 resulted in the increase of the blast colony formation in all the cases studied and was the most effective CSF for promoting leukemic cell growth among those tested in this study including SCF, IL-3, and GM-CSF. The addition of SCF to IL-9 demonstrated an additive or synergistic effect of the 2 cytokines in 5 out of 8 AML cases tested for their CFU-L growth (187 +/- 79 colonies in comparison with 107 +/- 32 CFU-L; p = 0.05). Positive interaction was also observed when IL-9 was combined with IL-3 and GM-CSF. Studies of cell cycle distribution of AML samples demonstrated that IL-9 alone significantly augmented the number of leukemic cells in S-phase in the majority of the cases evaluated. IL-9 and SCF in combination resulted in a remarkable decrease of the G0 cell fraction (38.2 +/- 24% compared to 58.6 +/- 22% of control cultures; p < 0.05) and induced an increase of G1 and S-phase cells. Conversely, neither IL-9 alone nor the combination of IL-9 and SCF had any effect on induction or prevention of apoptosis of leukemic cells. Furthermore, in this study, reverse transcriptase-polymerase chain reaction amplification (RT-PCR) did not show the constitutive expression of IL-9 mRNA in the cell lines and the AML samples studied at diagnosis. In summary, IL-9 may play a role in the development of acute myeloid leukemia by stimulating the proliferation of leukemic cells perhaps through a paracrine growth loop.
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PMID:Interleukin-9 in human myeloid leukemia cells. 938 63

The mechanism(s) underlying the release of stem/progenitor cells from bone marrow into the circulation is poorly understood. We hypothesized that matrix metalloproteinases (MMPs), especially gelatinases, which are believed to participate in the proteolysis of basement membranes and in the migration of leukocytes, may facilitate this process. First, we investigated whether CD34(+) stem/progenitor cells express gelatinases A (MMP-2) and/or B (MMP-9) and whether growth factors and cytokines (granulocyte colony-stimulating factor [G-CSF], granulocyte-macrophage colony-stimulating factor [GM-CSF], stem cell factor [SCF], macrophage colony-stimulating factor [M-CSF], interleukin-3 [IL-3], IL-6, IL-8, and tumor necrosis factor-alpha [TNF-alpha]) are able to modulate their expression. Next, we examined the transmigration of these stem/progenitor cells through reconstituted basement membrane (Matrigel) and its modulation by growth factors and cytokines. CD34(+) cells were obtained from steady-state bone marrow and peripheral blood (from leukapheresis products collected either in steady-state hematopoiesis or after mobilization with G-CSF plus chemotherapy or G-CSF alone). We found that peripheral blood CD34(+) cells, regardless of whether they were mobilized or not, strongly expressed both gelatinases (MMP-2 and MMP-9) in contrast to steady-state bone marrow CD34(+) cells, which did not. However, all the growth factors and cytokines tested could induce MMP-2 and MMP-9 secretion by the latter cells. Moreover, the stimulatory effects of G-CSF and SCF on both MMP-2 and MMP-9 secretion were found to be significantly higher in CD34(+) cells isolated from bone marrow than in those from peripheral blood. In addition TNF-alpha, GM-CSF, and IL-6 increased the secretion of a partially active form of MMP-2. Basal transmigration of bone marrow CD34(+) cells through Matrigel was lower than that of peripheral blood CD34(+) cells (P <.0001), but growth factors and cytokines increased it by 50% to 150%. Positive correlations were established between expression of gelatinases and CD34(+) cell migration (r >.9). The stimulatory effect of G-CSF was significantly greater on the migration of CD34(+) cells from bone marrow than on those from peripheral blood (P =.004). Moreover, CD34(+) cell migration was reduced to approximately 50% by antibodies to MMP-2 and MMP-9, tissue inhibitors of metalloproteinases (rhTIMP-1 and -2), and o-phenanthroline. TNF-alpha-induced gelatinase secretion and migration of CD34(+) cells and of clonogenic progenitors (colony-forming unit-granulocyte-macrophage [CFU-GM], burst-forming unit-erythroid [BFU-E], colony-forming unit granulocyte, erythroid, monocyte, megakaryocyte [CFU-GEMM], and colony-forming unit-megakaryocyte [CFU-MK]) were dose-dependent. Therefore, this study demonstrated that CD34(+) cells that are circulating in peripheral blood express both MMP-2 and MMP-9 and transmigrate through Matrigel. In contrast, CD34(+) cells from steady-state bone marrow acquire similar properties after exposure to growth factors and cytokines, which upregulate expression of gelatinases and transmigration of these cells when they enter the bloodstream. Hence, we suggest that growth factors and cytokines induce release of stem/progenitor cells from bone marrow into peripheral blood during mobilization, as well as during steady-state hematopoiesis, by signaling through gelatinase pathways.
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PMID:Growth factors and cytokines upregulate gelatinase expression in bone marrow CD34(+) cells and their transmigration through reconstituted basement membrane. 1023 90


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