Gene/Protein Disease Symptom Drug Enzyme Compound
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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)

Previous studies suggested that the potent immunosuppressive activities of transforming growth factor-beta (TGF-beta) were mediated in part through the inhibition of IL-2-dependent S-phase progression and mitosis of activated T cells. To further investigate the mechanism of T cell growth inhibition by TGF-beta, two constitutively activated murine T cell clones were employed as defined model systems for the growth factor-dependent phase of T cell proliferation. The Th cell line, HT-2, proliferated in response to either IL-2 or IL-4, whereas the cytotoxic T cell line, CT6, exhibited strict dependence on IL-2 for growth stimulation. In both cell lines, picomolar concentrations of TGF-beta inhibited S-phase progression stimulated by IL-2 or IL-4. TGF-beta pretreatment decreased the expression of high affinity IL-2R on HT-2 cells, but not on CT6 cells. In contrast, IL-2-stimulated transferrin receptor expression was markedly inhibited by TGF-beta in both T cell lines. Analyses of growth factor-dependent specific mRNA accumulation revealed that TGF-beta exerted selective inhibitory effects on gene expression in HT-2 and CT6 cells. TGF-beta significantly reduced early (1 to 2 h) increases in c-myc mRNA levels stimulated by IL-2 or IL-4 in both cell lines. In HT-2 cells, TGF-beta pretreatment also inhibited the early increase in granulocyte-macrophage CSF mRNA stimulated by IL-2 or IL-4. The inhibition of c-myc and granulocyte-macrophage cyte-macrophage CSF gene expression by TGF-beta was explained, at least in part, by suppression of the growth factor-dependent transcriptional activation of these genes. These studies suggest that inhibition of c-myc gene transcription may play a fundamental role in the antiproliferative effect of TGF-beta on IL-2- or IL-4-stimulated T cells.
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PMID:Regulatory effects of transforming growth factor-beta on IL-2- and IL-4-dependent T cell-cycle progression. 240 83

The effects of hematopoietic growth factors on in vitro human megakaryocytopoiesis were studied using a serum-depleted culture system. Both recombinant interleukin-3 (r-IL-3) and recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) increased megakaryocyte (MK) colony formation (P less than .01) above that observed in baseline cultures. Recombinant interleukin-4 (rIL-4) and interleukin 1 alpha (rIL-1 alpha) failed either to promote MK colony formation alone or to increase rIL-3 or rGM-CSF promoted colony formation. Recombinant erythropoietin (rEpo) and purified thrombocytopoiesis-stimulating factor (TSF) did not increase (P greater than .05) MK colony formation when added alone but synergized with rIL-1 alpha, leading to a twofold increase in MK colony formation. Such a synergistic relationship was not observed between rIL-4 and rEpo. In addition, TSF enhanced the ability of rIL-3 but not rGM-CSF to promote MK colony formation. Addition of rEpo to optimal or suboptimal concentrations of rGM-CSF or suboptimal concentrations of rIL-3 resulted in a significant increase (P less than .05) in the total number of MK-containing colonies, due to the appearance of multilineage colonies containing MKs. The addition of rEpo to optimal concentrations of rIL-3 resulted in increased numbers of multilineage colonies containing MKs; however, the number of total MK-containing colonies was not significantly increased when compared to assays containing rIL-3 alone. By contrast, transforming growth factor-beta (TGF-beta) inhibited both rIL-3, and rGM-CSF promoted MK colony formation, with optimal inhibition resulting in a 35%-45% reduction of MK colony formation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interacting cytokines regulate in vitro human megakaryocytopoiesis. 264 84

Proliferation in vitro of the in vivo passaged murine B cell tumor line BCL1 has been used as a standard assay for mouse interleukin-5 (IL-5) for a number of years. We demonstrate that this line will also respond to human IL-5. The response to murine IL-5 is abrogated by transforming growth factor-beta and to a lesser extent by interferon-gamma. This suggests a possible regulatory role for these lymphokines in the proliferation of B cells induced by IL-5. Other purified recombinant lymphokines were also tested for their ability to induce BCL1 proliferation. The lymphokines IL-1, IL-2, IL-3, and IL-6 had no effect on the growth of BCL1. In contrast, IL-4 and more surprisingly granulocyte-macrophage colony-stimulating factor (GM-CSF) also induced proliferation of this cell. These effects could be inhibited by specific antibodies directed against the respective lymphokines. These data suggest that GM-CSF, as well as IL-4 and IL-5, may be yet another regulator of neoplastic and possibly even normal B-cell growth and differentiation.
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PMID:The BCL1 B lymphoma responds to IL-4, IL-5, and GM-CSF. 267 47

Previous work has shown that part of the hierarchical structure of the hematopoietic system can be described by HPP-CFC-1 (primitive high proliferative potential colony-forming cells responding to colony-stimulating factor-1 [CSF-1] + interleukin-3 [IL-3] + IL-1), HPP-CFC-2 (more mature HPP-CFC responding to CSF-1 + IL-3), and mature HPP-CFC responding to the single factors, CSF-1, granulocyte-macrophage colony-stimulating factor (GM-CSF), or IL-3. In this study, we have attempted to relate the murine HPP-CFC, stimulated by various combinations of growth factors (GFs)--CSF-1, GM-CSF, IL-3, IL-6, IL-1, stem cell factor (SCF), and transforming growth factor-beta (TGF-beta)--and by CSF-1, GM-CSF, and IL-3 on their own, to these known progenitors. Studies involving regeneration of the bone marrow after 5-fluorouracil (5-FU) treatment, generation of progenitors in liquid cultures in response to different GF combinations, and the HPP-CFC content of lineage-negative rhodamine-sorted bone marrow (BM) fractions have indicated that: 1. the combinations CSF-1 + IL-3 + IL-1 + SCF and CSF-1 + IL-3 + IL-1 + IL-6, and possibly CSF-1 + GM-CSF + IL-3 + IL-1, stimulate pre-HPP-CFC-1; 2. the combinations CSF-1 + IL-1 + GM-CSF, CSF-1 + IL-1 + IL-6, CSF-1 + IL-1 + SCF, CSF-1 + IL-3 + SCF, CSF-1 + IL-6 + SCF, and IL-3 + SCF, appear to overlap with the CSF-1 + IL-3 + IL-1 combination to stimulate the more mature cells of the HPP-CFC-1 compartment; 3. the combinations CSF-1 + GM-CSF, CSF-1 + IL-1, CSF-1 + IL-6, and CSF-1 + SCF may stimulate the more mature cells of the HPP-CFC-2 population, while the single factors CSF-1, GM-CSF, and IL-3, as suggested in other reports, may stimulate HPP-CFC that are more mature than the HPP-CFC-2; 4. the combinations IL-3 + IL-6 and SCF + IL-6 appear to stimulate HPP-CFC that overlap with the HPP-CFC-1 population, while those responding to the combination GM-CSF + TGF-beta overlap with the HPP-CFC-2 population within the hematopoietic hierarchy; and 5. CSF-1 and GM-CSF appear to be interchangeable in the combinations studied.
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PMID:The relationship between different high proliferative potential colony-forming cells in mouse bone marrow. 751 52

A number of recombinant cytokines believed to regulate normal hematopoiesis are now being used in cancer treatment protocols to reduce the myelosuppressive toxicity of intensive chemoradiotherapy regimens. It is widely assumed that such cytokines are relatively specific for hematopoietic cells, although some cell lines derived from a variety of non-hematopoietic human tumors can respond to some of these factors. However, relatively little is known about their ability to stimulate (or inhibit) the proliferation of freshly isolated normal or malignant non-hematopoietic cells. We have used a serum-free culture medium that selectively supports the growth of human breast epithelial cells (HBEC) obtained directly from normal or malignant tissue samples to evaluate potential stimulatory or inhibitory effects of eight cytokines: granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, Steel factor, interleukin-2, interleukin-3, interleukin-6, transforming growth factor-beta and macrophage inflammatory protein-1 alpha, on these cells cultured both in the presence of epidermal growth factor, a potent stimulator of HBEC growth, and in its absence. HBEC growth was assessed after 7 and 14 days using the tetrazolium-dye reduction assay. Potential effects on the well studied MCF-7 breast cancer cell line, cultured under the same conditions, were also investigated. None of the cytokines (which were tested over a wide range of concentrations) had any modulating effect on the growth of normal or malignant HBEC under the conditions used with the exception of transforming growth factor-beta, which was consistently and significantly inhibitory.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Lack of effect of hematopoietic growth factors on human breast epithelial cell growth in serum-free primary culture. 751 1

The nuclear transcription factor NF-kappa B has been identified as a critical component in signal transduction pathways. We used an electrophoretic gel mobility shift assay to examine the activation of NF-kappa B in human U-937 cells treated with tumor necrosis factor (TNF), lymphotoxin (LT), interferons (IFN)-alpha, IFN-beta, and IFN-gamma, interleukins (IL)-1 beta, IL-4, and IL-6, leukemia inhibitory factor (LIF), basic fibroblast growth factor (FGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and transforming growth factor-beta (TGF-beta). Only TNF, LT, and IL-1 activated NF-kappa B. Since interferons have been shown to induce TNF receptors and potentiate TNF-mediated cellular responses, we also measured the effect of interferons on TNF-induced activation of NF-kappa B. Under our conditions, all three IFNs potentiated the cytotoxic effects of TNF but had no effect on the TNF-dependent NF-kappa B activation. These results suggest overall that the activation of NF-kappa B is not a generalized mediator of signal transduction of most cytokines and also that NF-kappa B activation is not sufficient for antiproliferative effects mediated through certain cytokines.
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PMID:Effect of tumor necrosis factors, interferons, interleukins, and growth factors on the activation of NF-kappa B: evidence for lack of correlation with cell proliferation. 753 17

We have further characterized the biological activities, mechanism of action, and target cell populations of recombinant human and murine thrombopoietin (rhTPO and rmTPO) in in vitro human and murine model systems. Alone, hTPO or mTPO stimulated the maturation of immature murine megakaryoblasts as measured in a single cell assay. The combination of hTPO or mTPO and interleukin-6 (IL-6) resulted in a further increase in megakaryocyte differentiation in this system. Murine TPO stimulated mouse megakaryocyte progenitor development. Human megakaryocyte progenitor development was potentiated by hTPO alone and further augmented in the presence of the early-acting cytokines (IL-3) or kit ligand/stem cell factor (KL/SCF). To further define the mechanism of action of TPO, neutralization studies were performed with antisera to IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-1 beta, and IL-11. No diminution in TPO activity was observed in the presence of these antisera. Moreover, because adhesive interactions are known to modulate hematopoiesis, we studied whether hTPO might alter such interactions between human bone marrow (BM) megakaryocytes and human BM stromal fibroblasts. No changes were observed in either megakaryocyte expression of the surface molecules lymphocyte function-associated antigen-1, very late activation antigen-4, or intercellular adhesion molecule-1 or the adhesion of megakaryocytes to stromal fibroblasts after treatment with the growth factor. Furthermore, no induction of secretion of the cytokines IL-1 alpha, IL-1 beta, GM-CSF, IL-6, granulocyte-CSF, tumor necrosis factor-alpha, transforming growth factor-beta 1, or transforming growth factor-beta 2 by primary human BM megakaryocytes was noted after treatment of the cells with hTPO. To address whether TPO affects very primitive hematopoietic progenitors, we studied the residual cells from the BMs of mice treated with high doses of 5-fluorouracil. Although no effect of mTPO alone was noted on the viability or replication of such primitive murine progenitor populations, the triple combination of IL-3 + KL/SCF + TPO stimulated growth of megakaryocyte progenitors. These results indicate that TPO is a highly lineage-specific growth factor whose primary biological effects are likely to be direct modulation of the growth and maturation of committed megakaryocyte precursors and immature megakaryoblasts.
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PMID:Modulation of megakaryocytopoiesis by thrombopoietin: the c-Mpl ligand. 763 39

Human natural killer cells (NK) respond to interleukin-2 (IL-2) with augmented cytolytic activity, cytokine secretion and cell proliferation. Here we show that IL-2 protects NK cells from death by apoptosis (programmed cell death; PCD). Highly purified NK cells (CD3- CD56+) were isolated from peripheral blood lymphocytes (PBL) of either control donors or of an asymptomatic donor with 60% NK cells. Glucocorticosteroids (GCS) induced PCD in NK cells, as shown by nuclear condensation and DNA fragmentation. IL-2 completely prevented GCS-induced PCD in a dose-dependent manner without overcoming GCS-induced inhibition of NK cell proliferation. The IL-2 protective effect was mediated through the p75 beta chain of the IL-2R, as neutralizing monoclonal antibody (mAb) to the p75 beta chain but not to the p55 alpha chain completely abolished the IL-2 anti-apoptotic activity. In addition to IL-2, the cytokines IL-7 and IL-12 have been reported to regulate NK cell functions. Our present data showed that IL-7 but not IL-12 rescued NK cells from apoptosis, but to a lesser extent than IL-2. Although IL-4 had a marginal protective effect, IL-1, IL-3, IL-6, IL-8, interferon-gamma (IFN-gamma) and IFN-alpha, tumour necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta) and granulocyte-macrophage colony-stimulating factor (GM-CSF) displayed no significant activity. Finally, we report that IL-2 and IL-7 enhanced bcl-2 expression in NK cells, suggesting the existence of a bcl-2-dependent survival pathway. In addition to regulating various functions, it is concluded that IL-2 and IL-7 have the ability to prevent PCD in NK cells.
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PMID:IL-2 and IL-7 but not IL-12 protect natural killer cells from death by apoptosis and up-regulate bcl-2 expression. 764 25

Interferon-gamma (IFN-gamma) is an important immunoregulatory protein produced predominantly by T cells and large granular lymphocytes (LGL) in response to different extracellular signals. In particular, two interleukins (ILs), IL-2 and IL-12, have been shown to be potent inducers of IFN-gamma gene expression in both T cells and LGL. Although it has been reported that there are some T cell lines that produce IFN-gamma in response to IL-2 and IL-12 stimulation, there has as yet been no report of a natural killer (NK) cell line that responds in a similar manner. In this report we present evidence that the cell line NK3.3 derived from human NK cells, responds to both IL-2 and IL-12, as measured by increases in IFN-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF) cytoplasmic mRNA and protein expression. In addition, when used together IL-2 and IL-12 synergized in the induction of IFN-gamma and GM-CSF and this synergy was attributed to an increased accumulation and stability of the IFN-gamma and GM-CSF mRNAs. To investigate the signaling pathways involved in the gene induction, five inhibitors, cyclosporin A (CsA), transforming growth factor-beta, cycloheximide, genistein, and staurosporine A, were used in analyzing the effects of IL-2 and IL-12 on NK3.3 cells. The results suggest that activation of protein kinase C, but not new protein synthesis, is required for IL-2 induction of IFN-gamma and GM-CSF cytoplasmic mRNA. In contrast, IL-12 induction of IFN-gamma cytoplasmic mRNA appears to only partially depend on activation of protein kinase C. Furthermore, both transforming growth factor-beta and genistein, a tyrosine kinase inhibitor, could suppress IL-2 and IL-12 signaling but CsA was generally inactive. It also was observed that suppression of cytokine gene expression by these agents was independent of the inhibition of proliferation. In addition, IL-2 but not IL-12 induced nuclear factors NF-kappa B and AP1, and regulation of the nuclear levels of these two DNA binding protein complexes is correlated with IFN-gamma and GM-CSF gene expression. These data indicate that IL-2 and IL-12 may have distinct signaling pathways leading to the induction of IFN-gamma and GM-CSF gene expression, and that the NK3.3 cell line may serve as a novel model for dissecting the biochemical and molecular events involved in these pathways.
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PMID:Cellular and molecular mechanisms of IFN-gamma production induced by IL-2 and IL-12 in a human NK cell line. 764 15

The effects of a myeloablative sublethal 775 cGy 60C gamma radiation exposure on endogenous bone marrow (BM) and splenic granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor-beta (TGF-beta) mRNA levels were assayed in B6D2F1 female mice. BM and spleen were harvested from normal mice and irradiated mice on days 2, 4, 7, 10, and 14 after exposure. Cytokine mRNA levels were determined using reverse transcription-polymerase chain reaction. After irradiation, GM-CSF mRNA levels were significantly increased in the BM from days 2 to 10 and in the spleen from days 4 to 10. However, when BM and splenic GM-CSF protein levels were measured using Western dot blot, no increased protein levels were detected. Serum GM-CSF levels were likewise unchanged. Radiation exposure did not affect BM or splenic TGF-beta mRNA levels and this cytokine is known to be produced by cell populations similar to those that produce GM-CSF. These data suggest that radiation injury to hemopoietic tissues results in differential effects on GM-CSF and TGF-beta mRNA levels and that, in the case of GM-CSF, increased mRNA levels are not matched by increased protein production.
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PMID:Bone marrow and splenic granulocyte-macrophage colony-stimulating factor and transforming growth factor-beta mRNA levels in irradiated mice. 766 61


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