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Synergistic effects of granulocyte-colony stimulating factor and macrophage-colony stimulating factor on recovery of donor hematopoietic cells in allogeneic bone marrow transplantation.

G-CSF and M-CSF are used clinically to augment hematopoiesis after bone marrow transplantation (BMT) and chemotherapy. In this paper, we examined the synergistic effect of G-CSF and M-CSF on hematopoietic recovery in allogeneic BMT as a model of human BMT. We performed BMT from eGFP-transgenic mice (C57BL/6 background; H-2b) into lethally-irradiated C3H (H-2k). From the day after BMT, G-CSF and/or M-CSF were injected for 5 consecutive days. Not only the numbers of day 12 CFU-S and spleen weight, but also white blood cell (WBC) counts in the peripheral blood (PB) and nuclear cells in the bone marrow (BM) increased in the mice treated with G-CSF and/or M-CSF 12 days after BMT. Moreover, the number of donor-type WBCs in the PB and donor-type nuclear cells in the BM also increased in the mice treated with G-CSF and/or M-CSF. The effects were pronounced when G-CSF and M-CSF were used together rather than independently. These results suggest that treatment with the combination of G-CSF and M-CSF has a synergistic effect on hematopoiesis in allogeneic BMT.

Animals↗

A granulocyte-colony-stimulating factor gene promoter element responsive to inflammatory mediators is functionally distinct from an identical sequence in the granulocyte-macrophage colony-stimulating factor gene.

A number of mesenchymal cells produce hemopoietic growth factors in response to inflammatory mediators in vitro and in vivo. Induced transcription from the hemopoietic growth factor genes is at least partially responsible for their increased expression. We have previously identified a sequence, cytokine (CK)-1, in the granulocyte (G)-CSF gene promoter that responds to TNF-alpha and binds a transcription factor, NF-GMa. We report here that the CK-1 sequence responds in a time- and dose-dependent manner to IL-1 beta and that the mutations which affect NF-GMa binding correlate with decreased transcriptional activity after stimulation with either TNF-alpha or IL-1 beta. The CK-1 sequence also responds to the human T lymphotrophic virus-1 transactivator, tax, so that this promoter element may contribute to the overall response of the G-CSF gene to these various agents. Although NF-GMa binding is seen in a number of cell types, the ability of the G-CSF CK-1 sequence to act as a transcriptional enhancer is specific for fibroblasts and not T cells. Furthermore, we show that an identical sequence in the granulocyte macrophage CSF gene, although apparently binding the same protein in vitro, cannot respond to any of these stimuli in either fibroblasts or T cells. Modification interference experiments, using the CK-1 region in the context of the granulocyte macrophage-CSF and G-CSF genes, indicated that the contact points for NF-GMa differ in each case and suggest that differences in sequences flanking the 10-bp CK-1 region probably leads to an altered DNA:protein conformation, which may explain the differential response of this conserved promoter element.

Base Sequence↗

Release of the cytokines colony-stimulating factor-1, granulocyte-macrophage colony-stimulating factor, and IL-6 by cloned murine vascular smooth muscle cells.

Vascular smooth muscle cells were cultured from the mesenteric arteries of MRL lpr/lpr, MRL +/+, CBA/J, or C3H/HeJ mice and evaluated for their ability to synthesize a range of cytokines. Vascular smooth muscle cells of MRL +/+, MRL lpr/lpr, and CBA/J origin released biologically significant amounts of CSF-1 and IL-6 and relatively low but detectable amounts of granulocyte macrophage-CSF (GM-CSF) but not IL-2, IL-3, or IL-4. Vascular smooth muscle cells of C3H/HeJ origin produced lower amounts of CSF-1 and IL-6, and GM-CSF was barely detectable. Production of these cytokines did not require the exogenous growth factors present in FCS and occurred, although at lower levels, in serum-free medium supplemented with insulin, transferrin, and albumin. Cloned lines of MRL +/+ vascular smooth muscle cells, with electron microscopic and immunochemical properties of vascular smooth muscle cells, produced CSF-1, IL-6, and GM-CSF, establishing that vascular smooth muscle cells were a direct source of CSF-1, IL-6, and GM-CSF. These observations highlight the need for experiments to directly address the question of whether vascular smooth muscle cells constitutively produce these cytokines under physiologic conditions in vivo and suggest that vascular smooth muscle cells may participate actively in inflammation by releasing cytokines that are active on lympho-hemopoietic and other cells.

Animals↗

Endotoxin-induced alterations in canine granulopoiesis: colony-stimulating factor, colony-forming cells in culture, and growth of cells in diffusion chambers.

Salmonella typhosa endotoxin injected into dogs produced elevated plasma CSF levels, transient leukopenia followed by leukocytosis, and stimulation of marrow granulopoiesis and mobilization of granulocyte-macrophage progenitors cells into the the peripheral circulation. The number of marrow CFU-c decreased to 65% of the control number within 6 h, returned to control levels by 24 h, and increased to 370% of the control number by 48h after endotoxin. The granulopoietic response was supported by a concomitant increase in the M:E ratio, an increased fraction of marrow-derived CFU-c susceptible to 3H-TdR suicide, and increased granulo-monocytopoietic activity of marrow- and peripheral blood-derived cells grown in diffusion chamber cultures. These results are consistent with the concept that endotoxin-induced CSF is a physiologic regulator of canine granulopoiesis, and that canine marrow responds to endotoxin with a significant increase in the concentration of marrow-derived granulocytic progenitors and with mobilization of granulocyte-macrophage progenitors into the peripheral circulation.

Animals↗

Differential regulation of metalloelastase activity in murine peritoneal macrophages by granulocyte-macrophage colony-stimulating factor and macrophage colony-stimulating factor.

We investigated the regulation of elastase activity in murine peritoneal macrophages by different cytokines and bacterial LPS. Thioglycolate-elicited mouse peritoneal exudate macrophages secrete a metalloproteinase that degrades elastin. Incubation of peritoneal exudate macrophages with LPS and IFN-gamma significantly inhibited the production of elastase by a mechanism independent of nitric oxide, superoxide, and hydrogen peroxide. The cytokines IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, TNF, TGF-alpha and -beta, basic fibroblast growth factor, monocyte chemotactic factor-1, and granulocyte CSF (G-CSF) had no significant effect on the production of elastase by macrophages. In contrast, granulocyte-macrophage CSF (GM-CSF) increased the production of elastase in a dose-dependent manner, and with macrophage CSF (M-CSF) inhibited it. Elastin zymography demonstrated that the modulation of elastolytic activity in macrophages was associated with changes in the level of metalloelastase protein. The stimulation of elastase activity by GM-CSF and the inhibition of elastase activity by LPS, IFN-gamma, and M-CSF occurred at the level of transcription. LPS and M-CSF also augmented the expression level of tissue inhibitors of metalloproteinase mRNA. The increased mRNA steady state level of murine macrophage elastase induced by GM-CSF resulted from both increased transcription and enhanced stability. The modulation of metalloelastase activity in macrophages by IFN-gamma, M-CSF, and GM-CSF suggests that these molecules may control the degradation of elastin fibers in lungs or blood vessels.

Animals↗

Advances in the clinical use of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor to intensify cancer chemotherapy.

The majority of human malignancies remain refractory to current therapeutic regimens. Several animal and human models provide evidence of a dose-response effect of many chemotherapeutic agents in a variety of malignancies. In recent years dose escalation with bone marrow transplant support has provided encouraging evidence that increased doses of antineoplastic agents may overcome clinical drug resistance. However, this approach has been limited by hematologic toxicity. This problem has been abrogated by the development and use of hematopoietic growth factors. These agents now offer the oncologist new treatment opportunities.

Chemotherapy, Adjuvant↗

Treatment of de novo acute myelogenous leukemia with recombinant granulocyte macrophage-colony-stimulating factor in combination with standard induction chemotherapy: effect of granulocyte macrophage-colony-stimulating factor on white blood cell counts.

GM-CSF is a major regulator of myelopoiesis. Recombinant human GM-CSF (250 micrograms/m2 per day i.v.) was used prior to chemotherapy ("3 + 7" scheme) to recruit leukemic blasts in vivo (de novo AML patients, n = 20) into the chemotherapy sensitive phases of the cell cycle. The stimulatory effect of GM-CSF on peripheral blood AML blasts was associated with a rapid redistribution of leukemic blood cells and with an increase in "S-phase positive" cells. Standard induction chemotherapy ("3 + 7") following GM-CSF induced complete aplasia in 19/20 patients. In the same patients, rhGM-CSF (given after chemotherapy) was found to shorten the time of complete aplasia compared to historical controls whereas post-chemotherapy- and follow-up data suggest no significant differences for CCR and survival. Together, our studies show that GM-CSF can safely be administered to AML patients in combination with induction chemotherapy to recruit leukemic cells into the cell cycle.

Adult↗