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)

The cell-surface expression and the functional status of the CD95/Fas antigen on primitive hematopoietic progenitors (PHPs) freshly isolated from human fetal liver (FL) were studied. PHPs were phenotypically defined as CD34++ CD38 -/+ cells. The most immature subfractions of PHPs, CD34++CD38- and CD34+2CD38+ FL cells, expressed CD95, whereas the more mature CD34++CD38++ and CD34+CD38++2 FL cells displayed low CD95 expression. Combinations of cytokines, such as kit ligand (KL) + interleukin-3 or KL + granulocyte-macrophage colony-stimulating factor (GM-CSF) upregulated the expression of CD95 on PHPs upon in vitro culture. Tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) further increased the CD95 expression induced by KL+GM-CSF. The hematopoietic potential of sorted CD34++lineage (lin)- CD95+ versus CD34++ lin-CD95-FL cells was compared by colony-forming unit-culture (CFU-C) assays performed in serum-deprived medium. Lin+ cells were composed of erythrocytes, monocytes, T cells, B cells, and natural killer cells. Our results indicated that both CD95- and CD95+ subsets contained pluripotent progenitors, generating myeloid and erythroid progenitors. The functional status of CD95 and the effects of TNF-alpha and IFN-gamma, cytokines known to induce CD95-mediated apoptosis, were analyzed by incubation of PHPs in the presence of anti-CD95 monoclonal antibodies (MoAbs). The effect of anti-CD95 MoAbs was measured by viable cell counting, flow cytometry, and CFU-C assays. A decrease of CFU-C numbers was observed in the presence of anti-CD95 MoAbs and TNF-alpha and/or IFN-gamma. However, whereas growth factor deprivation induced apoptosis of PHPs, cross-linking of CD95 did not lead to apoptosis of PHPs measured by flow cytometry and viable cell counting. The correlation of increased intracytoplasmic levels of bcl-2 with high levels of cell-surface CD34 and the presence of CD95 on fresh FL cells suggests that bcl-2 may be involved in protecting against CD95-mediated apoptosis of FL PHPs.
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PMID:Expression of Fas/CD95 and Bcl-2 by primitive hematopoietic progenitors freshly isolated from human fetal liver. 882 20

Most juvenile chronic myelogenous leukemia (JCML) cells have limited long-term proliferative capacity, and only a minority of immature cells give rise to colonies in semisolid cultures. Clonogenic JCML progenitors cannot be maintained in culture because they differentiate, and within a few weeks the leukemic clone is lost. This makes it difficult to identify the cell that initiates and maintains the disease in patients. To determine the proliferative capacity of JCML cells in vivo, bone marrow (BM), peripheral blood, or spleen cells from eight patients with JCML either at diagnosis or during treatment were transplanted into sublethally irradiated severe combined immune deficient (SCID) mice. JCML cells from all patients homed to the murine BM and proliferated extensively in response to exogenous stimulation with granulocyte-macrophage colony-stimulating factor. Within a few weeks, highly engrafted mice became ill and cachectic due to infiltration of leukemic cells and secretion of tumor necrosis factor-alpha. Murine BM, spleen, and liver were infiltrated with leukemic blasts, and typical JCML colony-forming progenitors could be recovered. Kinetic experiments demonstrated that only a small minority of transplanted cells homed to the murine BM, and that these cells initiated and maintained the disease in vivo by extensive proliferation and differentiation. To characterize the cell-surface phenotype of the JCML initiating cell (JCML-IC), JCML blood or spleen cells were fractionated on the basis of CD34/CD38 marker expression and transplanted into SCID mice. Only immature CD34+ cells could initiate the disease, while mature CD34- cells did not engraft. Within the CD34+ compartment, there was enrichment for JCML-ICs by immature cells with a CD34+/CD38- stem-cell-like phenotype. Mice transplanted with more mature CD34+/CD38+ populations that also contained clonogenic JCML progenitors were poorly engrafted. These results indicate that the JCML-IC is an earlier stage of development than clonogenic JCML progenitors. Additional evidence that the JCML-IC has stem-cell properties comes from secondary transplant experiments that test the self-renewal capacity. The JCML-IC from all three patients tested could successfully reinitiate the disease in secondary murine recipients. Thus, we have developed a functional in vivo model that replicates many aspects of human JCML, and have used this model to identify and characterize JCML-ICs and their stem-cell properties.
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PMID:Identification of human juvenile chronic myelogenous leukemia stem cells capable of initiating the disease in primary and secondary SCID mice. 883 60

Human CD38, a surface glycoprotein expressed by different immunocompetent cells, is associated with distinct transmembrane signaling molecules and plays a key role in the synthesis of cyclic ADP-ribose, a calcium-mobilizing compound. This study reports that CD38 ligation by specific monoclonal antibodies (mAb) in purified peripheral blood T cells is followed by secretion of discrete cytokines. IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), IFN-gamma, and IL-10 mRNA expression were constant findings. Low levels of IL-2 mRNA were also detected in CD38-activated T lymphocyte cultures of all subjects studied. Low levels of IL-4 and IL-5 mRNA were detected in the majority of CD38-activated T cultures. Moreover, CD38 mediated cytokine induction does not require T cell proliferation or the addition of antigen presenting cells. In conclusion, human CD38 runs an activation pathway in purified T cells which operates through the induction of a cytokine profile shared by Th1 or Th2 cells.
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PMID:Secretion of IFN-gamma, IL-6, granulocyte-macrophage colony-stimulating factor and IL-10 cytokines after activation of human purified T lymphocytes upon CD38 ligation. 891 76

CD34+ cord blood (CB) cells were expanded in stromal cell-free long-term culture (LTC), in the presence of various combinations of interleukin-3 (IL-3), stem cell factor (SCF), IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), and anti-transforming growth factor-beta (anti-TGF-beta) antibody. The progenitor cell expansion was evaluated by monitoring the increase of CD34+ and CD34 + CD38- cells over a period of 21 days. The expansion of immature (B1-CFC, HPP-CFC) and of more committed progenitors (CFU-GM, CFU-GEMM, BFU-E) was also evaluated in specific samples. Our results show that (a) CD34+ cell expansion is highly variable depending on the cord blood samples studied, (b) significant correlations between B1-CFC and CD34 + CD38- and between total CFU and CD34+ cell expansion are observed, (c) SCF in combination with IL-3 appears to expand cell subsets that continue to express their CD34 + CD38- phenotype and that generate both immature and committed progenitors, and (d) the addition of IL-6, GM-CSF, or anti-TGF-beta does not significantly improve these expansions.
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PMID:Ex vivo expansion of CD34 + CD38- cord blood cells. 913 38

We report here on a novel stromal cell line, AGM-S3, derived from the aorta-gonad-mesonephros (AGM) region of a 10.5 days postcoitum (dpc) mouse embryo. The AGM-S3 cells promoted production of hematopoietic progenitors and day-12 spleen colony-forming cells from Lin-c-Kit+Sca-1(+) murine primitive hematopoietic cells. They also supported for 6 weeks generation of human multipotential progenitors from cord blood CD34(+)CD38(-) primitive hematopoietic cells. Human long-term repopulating hematopoietic stem cells (LTR-HSC) with the potential to reconstitute hematopoiesis in NOD/SCID mice were maintained on AGM-S3 cells for at least 4 weeks. Flow cytometric analysis showed that CD13, vascular cellular adhesion molecule-1, and Sca-1 were expressed on AGM-S3 cells. Because stem cell factor, interleukin-6 (IL-6), and oncostatin M, but not IL-3, IL-11, leukemia- inhibitory factor, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, thrombopoietin, and Flk2 ligand were detected in reverse transcription-polymerase chain reaction analysis of AGM-S3 cells, the cells seem to express species-cross reactive molecule(s) other than the cytokines examined and which act on primitive hematopoietic progenitor/stem cells. This cell line is expected to elucidate molecular mechanisms regulating early hematopoiesis and pave the way for developing strategies for expansion of human transplantable HSC.
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PMID:Stimulation of mouse and human primitive hematopoiesis by murine embryonic aorta-gonad-mesonephros-derived stromal cell lines. 973 Oct 61

In the present study, we investigated the effects of stem cell factor (SCF) and/or thrombopoietin (TPO) on the cell production by cord blood CD34(+) cells using a serum-deprived liquid culture system. Although SCF alone supported a modest production of neutrophilic cells and a remarkable generation of mast cells, the addition of TPO to the culture containing SCF caused an apparent generation of neutrophilic cells, identified by immunocytochemical staining and flow cytometric analysis. The significant production of neutrophilic cells by SCF and TPO was persistently observed from 2 weeks to 2 to 3 months of culture. The interaction between SCF and TPO on the neutrophilic cell generation was greater than the combined effects of SCF with granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF). The addition of neutralizing antibody against G-CSF or GM-CSF did not influence the SCF + TPO-dependent neutrophilic cell production. A single-cell culture study showed that not only CD34(+)CD38(+) c-kit+ cells but also CD34(+)CD38(-)c-kit+ cells were responsible for the neutrophilic cell generation. In clonal cell cultures, GM progenitors as well as erythroid progenitors and multipotential progenitors expanded in the cultures supplemented with SCF and TPO. The neutrophilic cells grown by SCF + TPO were at myeloblast to band cell stages, and scarcely matured to segmented neutrophils. In addition, the cells generated by SCF + TPO were stained with monoclonal antibodies against myeloperoxidase, elastase, lactoferrin, and CD11b, but they had negligible levels of alkaline phosphatase (ALP) and CD35. The replating of the CD34(-)c-kit-/low CD15(+) cells grown by SCF + TPO into a culture containing SCF + G-CSF permitted both the terminal maturation into segmented cells and the appearance of ALP and CD35. These results indicate the existence of a G-CSF/GM-CSF-independent system of neutrophilic cell production.
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PMID:Neutrophilic cell production by combination of stem cell factor and thrombopoietin from CD34(+) cord blood cells in long-term serum-deprived liquid culture. 988 12

Ex vivo stroma-free static liquid cultures of granulocyte colony-stimulating factor (G-CSF)/chemotherapy-mobilized CD34+ cells were established from patients with epithelial solid tumors. Different culture conditions were generated by adding G-CSF, granulocyte-macrophage colony-stimulating factor (GM-CSF), Flt3 ligand (Flt3), megakaryocyte growth and development factor (Peg-rHuMGDF), GM-CSF/erythropoietin (EPO) hybrid protein (MEN11303), and interleukin-15 (IL-15) to the basic stem cell factor (SCF) + interleukin-3 (IL-3) + EPO combination. This study showed that, among the nine different combinations tested in our 5% autologous plasma-containing cultures, only those containing IL-3/SCF/Flt3/MEN11303 and IL-3/SCF/Flt3/MEN11303/IL-15 significantly expanded colony-forming unit granulocyte-macrophage (CFU-GM), burst-forming unit erythroid (BFU-E), long-term culture-initiating cells (LTC-IC), CD34+, and CD34+/CD38- cells after 14 days of culture. Particularly, the addition of IL-15 to IL-3/SCF/Flt3/MEN11303 combination produced a significant increase of LTC-IC, with an average 26-fold amplification as compared to input cells, without any detrimental effect on CFU-GM and BFU-E expansion. This combination also produced a statistically significant 3.6-fold expansion of primitive CD34+/CD38- cells. Moreover, this study confirms the previously described erythropoietic effect of MEN11303, which, in our experience, was the only factor capable of expanding BFU-E. Compared to equimolar concentrations of GM-CSF and EPO, MEN11303 hybrid protein showed a significantly higher capacity of expanding CFU-GM, BFU-E, LTC-IC, CD34+, and CD34+/CD38- cells when these cytokines were tested in combination with IL-3/SCF/Flt3. These cultures indicated that Peg-rHuMGDF addition to IL-3/SCF/EPO/Flt3 does not affect CFU-GM and BFU-E expansion but, unlike G-CSF or GM-CSF, it does not decrease the ability of Flt3 to expand primitive LTC-IC. These studies indicate that, starting from G-CSF/chemotherapy-mobilized CD34+ cells, concomitant expansion of primitive LTC-IC, CFU-GM, BFU-E, CD34+, and CD34+/CD38- cells is feasible in simple stroma-free static liquid cultures, provided IL-3/SCF/Flt3/MEN11303/IL-15 combination is used as expanding cocktail in the presence of 5% autologous plasma.
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PMID:Expansion of granulocyte colony-stimulating factor/chemotherapy-mobilized CD34+ hematopoietic progenitors: role of granulocyte-macrophage colony-stimulating factor/erythropoietin hybrid protein (MEN11303) and interleukin-15. 1008 3

Evidence has been provided recently that shows that high concentrations of cytokines can fulfill functions previously attributed to stromal cells, such as promote the survival of, and led to a net increase in human primitive progenitors initiating long-term cultures in vitro (LTC-IC) or engrafting NOD-SCID (nonobese diabetic severe-combined immunodeficient) recipients in vivo. These data prompted us to re-evaluate whether stromal cells will further alter the properties of primitive progenitor cells exposed to cytokines. Single CD34(+)CD38(low) and CD38(neg) cells were incubated 10 days in serum-containing or serum-free medium in the presence or in the absence of murine marrow-derived stromal cells (MS-5). Recombinant human cytokines stem cell factor (SCF), pegylated-megakaryocyte growth and differentiation factor (PEG-MGDF), FLT3-L, Interleukin (IL)-3, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were systematically added at various concentrations (10 to 300 ng/mL). Cell proliferation and LTC-IC potential were evaluated in each clone after 10 days. A striking and consistent observation was the retention of a high LTC-IC potential in clones exposed to cytokines in the presence of stromal feeders, whereas clones exposed to cytokines alone in the absence of stromal feeders rapidly lost their LTC-IC potential as they proliferated. This was reflected both by the higher proportion of wells containing LTC-IC and by the high numbers of CFC produced after 5 weeks in clones grown with MS-5 during the first 10 days. We further showed by analyzing multiple replicates of a single clone at day 10 that MS-5 cells promoted a net increase in the LTC-IC compartment through self-renewal divisions. Interestingly, these primitive LTC-IC were equally distributed among small and large clones, as counted at day 10, indicating that active proliferation and loss of LTC-IC potential could be dissociated. These observations show that, in primitive cells, stromal cells counteract differentiation events triggered by cytokines and promoted self-renewal divisions. Furthermore, the almost identical distribution of the size of the clones with or without MS-5 suggests that proliferation and function of human primitive cells may be independently regulated by external signals, and that the former is primarily under the control of cytokines.
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PMID:Murine stromal cells counteract the loss of long-term culture-initiating cell potential induced by cytokines in CD34(+)CD38(low/neg) human bone marrow cells. 1039 20

We have developed a stromal-based in vitro culture system that facilitates ex vivo expansion of transplantable CD34(+) thy-1(+) cells using long-term hematopoietic reconstitution in severe combined immunodeficient-human (SCID-hu) mice as an in vivo assay for transplantable human hematopoietic stem cells (HSCs). The addition of leukemia inhibitory factor (LIF) to purified CD34(+) thy-1(+) cells on AC6.21 stroma, a murine bone marrow-derived stromal cell line, caused expansion of cells with CD34(+) thy-1(+) phenotype. Addition of other cytokines, including interleukin-3 (IL-3), IL-6, granulocyte-macrophage colony-stimulating factor, and stem cell factor, to LIF in the cultures caused a 150-fold expansion of cells retaining the CD34(+) thy-1(+) phenotype. The ex vivo-expanded CD34(+) thy-1(+) cells gave rise to multilineage differentiation, including myeloid, T, and B cells, when transplanted into SCID-hu mice. Both murine LIF (cannot bind to human LIF receptor) and human LIF caused expansion of human CD34(+) thy-1(+) cells in vitro, suggesting action through the murine stroma. Furthermore, another human HSC candidate, CD34(+) CD38(-) cells, shows a similar pattern of proliferative response. This suggests that ex vivo expansion of transplantable human stem cells under this in vitro culture system is a general phenomenon and not just specific for CD34(+) thy-1(+) cells.
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PMID:Long-term ex vivo maintenance and expansion of transplantable human hematopoietic stem cells. 1096 Feb 42

We have developed a time-lapse camera system to follow the replication history and the fate of hematopoietic stem cells (HSC) at a single-cell level. Combined with single-cell culture, we correlated the early replication behavior with colony development after 14 days. The membrane dye PKH26 was used to monitor cell division. In addition to multiple, synchronous, and symmetric divisions, single-sorted CD34(+)/CD38(-) cells derived from fetal liver (FLV) also gave rise to a daughter cell that remained quiescent for up to 8 days, whereas the other daughter cell proliferated exponentially. Upon separation and replating as single cells onto medium containing a cytokine cocktail, 60.6% +/- 9.8% of the initially quiescent cells (PKH26 bright) gave rise again to colonies and 15.8% +/- 7.8% to blast colonies that could be replated. We have then determined the effects of various regulatory molecules on symmetry of initial cell divisions. After single-cell sorting, the CD34(+)/CD38(-) cells derived from FLV were exposed to flt3-ligand, thrombopoietin, stem cell factor (SCF), or medium containing a cytokine cocktail (with SCF, interleukin-3, interleukin-6, granulocyte-macrophage colony-stimulating factor, and erythropoietin). Whereas mitotic rate, colony efficiency, and asymmetric divisions could be altered using various regulatory molecules, the asymmetric division index, defined as the number of asymmetric divisions versus the number of dividing cells, was not altered significantly. This observation suggests that, although lineage commitment and cell proliferation can be skewed by extrinsic signaling, symmetry of early divisions is probably under the control of intrinsic factors.
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PMID:Symmetry of initial cell divisions among primitive hematopoietic progenitors is independent of ontogenic age and regulatory molecules. 1051 63


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