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Biomedical subjects

D Metcalf

Publications and source records attributed to D Metcalf.

At least 199 records · Page 11Linked to original sources
PubMed1989

Nonneoplastic hematopoietic myeloproliferative syndrome induced by dysregulated multi-CSF (IL-3) expression.

Post 5-fluorouracil-treated murine marrow cells were infected with a retroviral vector (MPZen) bearing a multi-potential colony stimulating factor (Multi-CSF) cDNA insert and then transplanted into lethally irradiated syngeneic recipients to study the effects of autocrine production of Multi-CSF in normal hematopoietic cells. Extremely high levels (14,000 U/mL) of Multi-CSF were detected in the sera and in media conditioned by various hematopoietic tissues of the transplanted animals. While spleen, peritoneal, and peripheral blood cellularity increased approximately 10-fold, 10-fold, and 50-fold, respectively, bone marrow cellularity decreased twofold. Progenitor numbers were depressed twofold in the bone marrow but elevated more than 100-fold in the spleen and peritoneum. The majority (80%) of transplanted mice died within 5 weeks of transplantation and showed extensive neutrophilic infiltration of the spleen, lung, liver, and muscle, often with mast cell foci; a phenomenon also seen in the skin and intestine. Neither the infected cells from hematopoietic tissues of the primary mice, nor autonomous mast cell-lines that grew from these cells in liquid culture produced any overt disease when transplanted into normal or sublethally irradiated secondary recipients. In contrast, injection into mice of autonomous FDC-P1 cells transformed by the same retroviral construct led to tumor formation in vivo within 4 weeks. Thus, dysregulated Multi-CSF expression by normal hematopoietic cells produces a fatal but nonneoplastic myeloproliferative syndrome.

Animals↗
PubMed1989

Effects of bacterially synthesized recombinant human granulocyte-macrophage colony-stimulating factor in patients with advanced malignancy.

STUDY OBJECTIVE: To define the clinical and hematologic effects of subcutaneously administered bacterially synthesized recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF). DESIGN: Single arm nonrandomized dose escalation study. PATIENTS: Twenty-one patients with advanced malignancy who were not receiving concurrent myelosuppressive therapy. INTERVENTIONS: Subcutaneous administration of rhGM-CSF by once-daily injection to groups of two to four patients at doses of 0.3 to 30 micrograms/kg body weight.d for 10 consecutive days. Some patients received a second 10-day period of daily rhGM-CSF treatment after a 10-day nontreatment interval followed by alternate-day treatment. Clinical status and hematologic values were monitored frequently. MEASUREMENTS AND MAIN RESULTS: All doses of rhGM-CSF caused an immediate transient fall of 84% to 99% in circulating neutrophils, eosinophils, and monocytes. Continued daily dosing caused a leukocytosis of up to 10-fold with increases in numbers of circulating neutrophils, eosinophils, monocytes, and lymphocytes. There appeared to be a plateau in the increase in neutrophils in the dose range 3 to 15 micrograms/kg.d. Marrow aspirates showed increased proportions of promyelocytes and myelocytes. Alternate-day injection of 15 micrograms/kg maintained a leukocytosis. At doses up to 15 micrograms/kg.d, rhGM-CSF was well tolerated but adverse effects included bone pains, myalgias, rashes, and liver dysfunction. At doses exceeding 15 micrograms/kg.d, pericarditis was a dose-limiting toxicity. Idiopathic thrombocytopenic purpura was reactivated by rhGM-CSF in one patient. CONCLUSIONS: Bacterially synthesized rhGM-CSF induces a leukocytosis in the dose range of 3 to 15 micrograms/kg.d. These doses are appropriate for phase II studies.

Adult↗
PubMed1989

A lethal myeloproliferative syndrome in mice transplanted with bone marrow cells infected with a retrovirus expressing granulocyte-macrophage colony stimulating factor.

Murine bone marrow cells infected with a novel recombinant retrovirus, MPZen(GM-CSF), were engrafted into lethally irradiated recipients. The transplanted animals developed extremely high circulating levels of GM-CSF (up to 3 x 10(5) units/ml), and greatly elevated peripheral nucleated cell counts (up to 110 x 10(6) per ml). Their haemopoietic tissues contained GM-CSF proviral DNA and produced substantial levels of GM-CSF. The mice died within 4 weeks of transplantation with extensive neutrophil and macrophage infiltration of the spleen, lung, liver and peritoneal cavity and significant infiltration of both heart and skeletal muscle by neutrophils, macrophages and eosinophils. The thymus and lymph nodes were deficient in lymphoid cells. No disease occurred when infected cells from haemopoietic tissues of the primary transplanted animals were injected into normal or sub-lethally irradiated mice. Dysregulated GM-CSF expression by haemopoietic cells thus produces a fatal albeit non-neoplastic myeloproliferative syndrome.

Animals↗
PubMed1989

LIF: a molecule with divergent actions on myeloid leukaemic cells and embryonic stem cells.

We have previously characterized, purified and cloned a novel murine and human regulator [leukaemia inhibitory factor, LIF] which induces the differentiation of certain murine and human myeloid leukaemic cells. Recently we have shown that there are specific LIF receptors on murine embryonic stem [ES] and embryonal carcinoma [EC] cells and that purified recombinant LIF can substitute for feeder cells and crude sources of differentiation inhibiting activity [DIA] [such as BRL-cell-conditioned medium] in the maintenance of ES cells in a pluripotential state in vitro. Furthermore, ES cells maintained in culture in recombinant LIF for a prolonged period can give rise to germline chimaeric mice. Thus, based on a number of biochemical and biological similarities, it is likely that LIF and DIA are the same molecule. The identification of LIF as a molecule, necessary and sufficient for the maintenance of ES cells in culture, should have a profound impact on the use of these cells for genetic manipulations.

Amino Acid Sequence↗
PubMed1989

Fatal syndrome in mice engrafted with cells producing high levels of the leukemia inhibitory factor.

Cells of the murine hemopoietic cell line FDC-P1 were multiply infected with a retroviral construct containing cDNA encoding the leukemia inhibitory factor (LIF) to produce cells secreting high levels of LIF. Injection of these cells to unirradiated or irradiated syngeneic DBA/2 mice resulted in animals engrafted with LIF-producing cells in the marrow, spleen, and lymph nodes and with elevated serum LIF levels. These mice developed within 12-70 days a fatal syndrome characterized by cachexia, excess new bone formation, calcification in heart and skeletal muscle, pancreatitis, thymus atrophy, and abnormalities in the adrenal cortex and ovarian corpora lutea. Injection of mice with control FDC-P1 cells led to comparable organ engraftment, but the mice developed none of these lesions. The observations suggest that LIF may be a potent cachexia-inducing agent and may have marked effects on osteoblasts and calcium metabolism.

Animals↗
PubMed1989

Induction of macrophage colony-stimulating factor-dependent growth and differentiation after introduction of the murine c-fms gene into FDC-P1 cells.

A system has been established for analyzing the functions of the c-fms/macrophage colony-stimulating factor (M-CSF) receptor gene product in hematopoietic growth and differentiation. The murine c-fms gene was introduced into the factor-dependent murine hematopoietic cell line FDC-P1 by retroviral infection, and conversion to M-CSF-dependent growth was assayed in agar cultures. Expression of the c-fms gene in FDC-P1 cells, which normally do not express this gene, resulted in the conversion of resultant FD(c-fms) cells to M-CSF-dependent growth. Stimulation of FD(c-fms) cells by M-CSF led to the formation of colonies of altered morphology and produced reversible morphological changes suggestive of myeloid differentiation. M-CSF also induced expression of mature myeloid surface marker proteins in the FD(c-fms) cells. Neither multi-CSF nor granulocyte-macrophage CSF induced similar phenotypic changes but remained able to stimulate the proliferation of undifferentiated FD(c-fms) cells. These results indicate that the c-fms gene was expressed functionally in FDC-P1 cells and transmitted signals for growth. Also, the interaction of M-CSF with the c-fms gene product generated an additional signal for myeloid differentiation but did not irreversibly commit FD(c-fms) cells to terminal differentiation. This system can be used for molecular analysis of the growth- and differentiation-promoting activities of the c-fms proto-oncogene.

Cell Differentiation↗
PubMed1989

Long-term exposure to retrovirally expressed granulocyte-colony-stimulating factor induces a nonneoplastic granulocytic and progenitor cell hyperplasia without tissue damage in mice.

Murine marrow cells infected with a retroviral vector (MPZen) bearing a granulocyte-colony-stimulating factor (G-CSF) cDNA insert were transplanted into lethally irradiated recipients to study the effects of autocrine production of G-CSF in normal hemopoietic cells. Most animals remained healthy with no evidence of tissue damage throughout the observation period (4-30 wk) despite high circulating G-CSF levels (range 2,000-26,000,000 U/ml). A dramatic neutrophilic granulocytosis was observed in all hemopoietic tissues with neutrophilic infiltration occurring in the lung and liver. Spleen, peritoneal, and peripheral blood cellularity increased approximately three-, two-, and eightfold, respectively, but total bone marrow cell counts remained unchanged. Progenitor cell numbers granulocyte-macrophage colony-forming cell (GM-CFC), granulocyte colony-forming cell (G-CFC), burst-forming unit-erythroid (BFU-E), colony-forming unit-erythroid (CFU-E) and mixed colony-forming cells (Mix-CFC) were elevated between 10-100-fold in the spleen, peritoneal cavity, and peripheral blood, but were unaffected or slightly depressed in the marrow. No tumors developed in syngeneic recipients transplanted with bone marrow or spleen cells from such mice, confirming the nonneoplastic nature of the hyperplasia induced by chronic G-CSF stimulation. These experiments also indicated the stable integration of MPZen vectors in infected cells, as evident from the continuous expression of the inserted gene for at least 6 mo, and from the ability of infected stem cells from the primary recipients to express the gene in lethally irradiated secondary recipients.

Animals↗
PubMed1989

Clonal suppression of HL60 and U937 cells by recombinant human leukemia inhibitory factor in combination with GM-CSF or G-CSF.

The in vitro actions of recombinant human leukemia inhibitory factor (LIF) were studied on the human leukemia cell lines HL60 and U937. Parameters analyzed were the suppression of stem cell generation using sequential clonal cultures, alterations of surface antigen expression, and morphological changes. When acting alone, LIF had no observable effects on the number, size, or morphology of colonies formed by HL60 or U937 cells, surface phenotype expression, or recloning capacity of cells of either line. In combination with GM-CSF and G-CSF, however, LIF significantly reduced the number of colonies formed in agar respectively by HL60 and U937 cells. GM-CSF alone greatly reduced the clonogenicity of U937 cells. Using sequential recloning, marked suppression of clonogenicity was observed using combinations of LIF with GM-CSF in HL60 cultures and with G-CSF in U937 cultures. These results suggest that human LIF may have some capacity to suppress human leukemia cells with loss of clonogenicity, at least in combination with G-CSF or GM-CSF.

Antigens, Surface↗
PubMed1989

Actions and interactions of G-CSF, LIF, and IL-6 on normal and leukemic murine cells.

Purified recombinant granulocyte colony stimulating factor (G-CSF) and interleukin-6 (IL-6) stimulated the formation of similar numbers of colonies in cultures of normal mouse marrow cells. LIF and IL-6 induced comparable differentiation in clonal cultures of murine M1 leukemic cells and exhibited enhanced actions in combination. However, LIF was 16-25-fold more active than IL-6. Induction of differentiation in M1 leukemic colonies by both LIF and IL-6 was enhanced by the addition of G-CSF or M-CSF but not by GM-CSF or Multi-CSF. Both G-CSF and IL-6, but not LIF, were able to induce differentiation in murine WEHI-3B leukemic colonies, but G-CSF was 10-fold more efficient than IL-6. Both G-CSF and IL-6 were able to stimulate the proliferation of cells of the NFS-60 continuous cell line, but G-CSF was 30-fold more efficient. M1 cells constitutively produced low levels of IL-6 and production was enhanced by LIF, but the general characteristics of the actions of LIF, IL-6, and G-CSF suggested that each operates independently as a direct differentiation inducer of leukemic cells. The similarities in the biology and actions of G-CSF, LIF, and IL-6 suggest that they may be designed to exhibit coordinated biological functions in certain situations.

Animals↗
PubMed1989

A myelosclerotic syndrome in mice engrafted with cells producing high levels of leukemia inhibitory factor (LIF).

DBA/2 mice engrafted with FDC-P1 cells producing high levels of the leukemia-inhibitory factor (LIF) developed high circulating levels of LIF and a fatal syndrome including the accumulation of excess osteoblasts in the marrow and new bone formation. The mice developed a neutrophil leucocytosis, an enlarged spleen, and excess numbers of hemopoietic cells in the spleen and liver. Marrow cellularity was reduced with selective survival of granulocytic cells, but the frequency of hemopoietic progenitor cells in both the marrow and spleen was higher than in control mice. Megakaryocyte numbers were reduced in marrows with pronounced sclerosis. The disease state may represent a useful model of myelosclerosis, but it remains to be established whether the hemopoietic abnormalities in these mice are direct effects of LIF or secondary changes following occlusion of the marrow by osteosclerotic tissue.

Animals↗
PubMed1989

Hemopoietic growth factors and marrow transplantation: an overview.

Current clinical trials suggest that use of G-CSF and GM-CSF is likely to benefit marrow transplant patients by significantly reducing the duration of post-transplant leukopenia. It remains to be determined whether the use of megakaryocyte-active growth factors (e.g., Multi-CSF) will prove of value in elevating platelet levels in such patients.

Animals↗
PubMed1989

Hemopoietic growth factor gene transfer.

Introduction of hemopoietic growth factor genes into hemopoietic cells using retroviral vectors or by the generation of transgenic mice has been a valuable approach in analyzing the role of these growth factors in leukemia development and in determining the pathological consequences of stimulation by excess levels of growth factors.

Animals↗
PubMed1989

Elevated levels of GM-CSF and IL-1 in the serum, peritoneal and pleural cavities of GM-CSF transgenic mice.

Levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the peritoneal and pleural cavity fluid of two lines of GM-CSF transgenic mice were abnormally high (up to 120,000 U/ml), often exceeded the elevated serum GM-CSF levels in these mice and correlated with the increased number of macrophages present. In the peritoneal fluid, the only significant elevations of IL-1 levels were seen in moribund male-line transgenic mice. In contrast, IL-1 levels in pleural cavity fluid of male-line transgenic mice were clearly higher than those in littermate control mice or female-line transgenic mice. In male-line transgenic mice, IL-1 levels in both peritoneal and pleural cavities correlated with local macrophage numbers. Endotoxin was detectable in the peritoneal cavity fluid from some mice of all types but did not correlate with elevated IL-1 levels. No correlation was observed between levels of GM-CSF or IL-1 in the peritoneal cavity and the development of fibrotic nodules in the peritoneal cavity or gut congestion, two lesions common in male-line GM-CSF transgenic mice. The data suggest that the elevated levels of IL-1 in GM-CSF transgenic mice may be the consequence of stimulation by GM-CSF of IL-1 production by the elevated numbers of macrophages in these mice.

Animals↗
PubMed1989

PGM-1: a transplantable murine leukemia of granulocyte-macrophage progenitor cells.

PGM-1 is a transplantable leukemia of C3H/HeJ mice growing as a population of undifferentiated blast cells with a predisposition to form subcutaneous tumors and to grow in lymphoid organs. Cell survival and proliferation in vitro are absolutely dependent on stimulation by hemopoietic growth factors, and up to 100% of tumor cells can form colonies of mature granulocytes and/or macrophages in semisolid cultures, the colonies containing no clonogenic cells. Most clonogenic cells in the leukemic population respond to stimulation by multi-colony-stimulating factor (IL-3) or GM-CSF, but some respond also to M-CSF, G-CSF, IL-4, IL-5, or IL-6. In their surface phenotype and proliferative characteristics in vitro, PGM-1 leukemic cells resemble normal granulocyte-macrophage progenitor cells, and the leukemia may be a useful model for human chronic myeloid leukemia.

Animals↗