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H E Broxmeyer

Publications and source records attributed to H E Broxmeyer.

At least 307 records · Page 17Linked to original sources
PubMed1988

Selective and indirect modulation of human multipotential and erythroid hematopoietic progenitor cell proliferation by recombinant human activin and inhibin.

Activin and inhibin are biomolecules that, respectively, enhance and suppress the release of follicle-stimulating hormone from pituitary cells in vitro. Purified recombinant human (rhu) activin A and inhibin A were assessed for their effects on colony formation in vitro by human multipotential (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells. It was found that (i) rhu-activin A enhances colony formation by normal bone marrow erythroid and multipotential progenitor cells; (ii) purified rhu-inhibin A decreases activin, but not rhu-interleukin 3, rhu-granulocyte-macrophage colony-stimulating factor, or rhu-interleukin 4, enhancement of erythropoietin-stimulated colony formation by erythroid and multipotential progenitor cells; (iii) modulatory actions of rhu-activin and rhu-inhibin are mediated through monocytes and T lymphocytes within the marrow; (iv) actions are apparent in the absence or presence of serum; and (v) rhu-activin and rhu-inhibin have no effect on colony formation by granulocyte-macrophage progenitor cells. This defines an indirect mode of action and a specificity for activin and inhibin on multipotential and erythroid progenitor cells.

Activins↗
PubMed1988

Enhancement of release from MHC class II antigen-positive monocytes of hematopoietic colony stimulating factors CSF-1 and G-CSF by recombinant human tumor necrosis factor-alpha: synergism with recombinant human interferon-gamma.

The influence of purified recombinant human tumor necrosis factor-alpha (rhuTNF-alpha) was assessed alone and in combination with purified recombinant human interferon gamma (rhuIFN-gamma) for its effects on enhancing release from human monocytes of activities that stimulate colony formation by granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells. RhuTNF-alpha or rhuIFN-gamma enhanced release of colony stimulating factors (CSFs), which were determined by a combination of human and mouse colony assays, morphological assessment of colony types and neutralization studies with anti-human macrophage CSF (CSF-1) and anti-human granulocyte (G)-CSF to be CSF-1 and G-CSF. The activity in the uninduced and induced monocyte conditioned media (CM) for CFU-GM-type colonies and clusters was attributed to the presence of both CSF-1 and G-CSF, while the activity in the monocyte CM for BFU-E and CFU-GEMM colonies was attributed to the presence of G-CSF. Monocytes were separated by two-color fluorescence using a dye laser flow cytometry system with cells labeled with anti-leu M3 conjugated with fluorescein isothiocyanate and anti-HLA-DR conjugated with phycoerythrin. While "constitutive" release of CSFs from monocytes was apparent from both the leu M3+, HLA-DR+ and the leu M3+, HLA-DR- (low density or negative DR) fractions, enhanced release of CSFs in response to rhuTNF-alpha or rhuIFN-gamma was confined to the leu M3+, HLA-DR+ population of cells. RhuTNF-alpha and rhuIFN-gamma synergized to enhance release of CSFs such that low concentrations of each molecule, which were inactive when used alone, were active when the two molecules were used together. These studies suggest a role, at least in vitro, for TNF-alpha and IFN-gamma in the release of CSFs from cells of the mononuclear phagocytic lineage.

Animals↗
PubMed1988

Correlation between CSF-1 responsiveness and expression of (CSF-1 receptor) c-fms in purified murine granulocyte-macrophage progenitor cells (CFU-GM).

The gene product of the viral proto-oncogene v-fms, associated with the feline sarcoma virus (SM-FeSV), is a glycoprotein of 170 kd with associated tyrosine kinase activity. The murine c-fms proto-oncogene produces a similar glycoprotein of 165 kd and has been implicated as a similar, if not identical, molecule to the cell surface receptor of the hematopoietic growth factor CSF-1. Employing a v-fms probe in an in situ hybridization assay we examined the expression of c-fms transcripts in a population of purified granulocyte-macrophage progenitor cells (CFU-GM). Using this approach, which requires only 10-20 thousand cells, we demonstrate that 53% of the cells in the purified CFU-GM containing fraction (FR-28) express c-fms transcripts. In the presence of natural purified CSF-1, 51% +/- 3% of FR-28 cells form colonies or clusters in a semi-solid culture assay system. 94% of the colonies and clusters stimulated by CSF-1 were morphologically macrophage in nature. In addition, 84% +/- 4% of FR-28 cells formed colonies and clusters when stimulated with pokeweed mitogen spleen cell conditioned medium (PWMSCM) in a similar in vitro assay (35% granulocyte, 29% macrophage and 39% mixed granulocyte/macrophage colonies). These results indicate there is a correlation between the responsiveness of CFU-GM progenitor cells to CSF-1 and the expression of c-fms RNA.

Animals↗
PubMed1988

Correlation between CSF-1 responsiveness and expression of (CSF-1 receptor) c-fms in purified murine granulocyte-macrophage progenitor cells (CFU-GM).

The gene product of the viral proto-oncogene v-fms, associated with the feline sarcoma virus (SM-FeSV), is a glycoprotein of 170 kd with associated tyrosine kinase activity. The murine c-fms proto-oncogene produces a similar glycoprotein of 165 kd and has been implicated as a similar, if not identical, molecule to the cell surface receptor of the hematopoietic growth factor CSF-1. Employing a v-fms probe in an in situ hybridization assay we examined the expression of c-fms transcripts in a population of purified granulocyte-macrophage progenitor cells (CFU-GM). Using this approach, which requires only 10-20 thousand cells, we demonstrate that 53% of the cells in the purified CFU-GM containing fraction (FR-28) express c-fms transcripts. In the presence of natural purified CSF-1, 51% +/- 3% of FR-28 cells form colonies or clusters in a semi-solid culture assay system. 94% of the colonies and clusters stimulated by CSF-1 were morphologically macrophage in nature. In addition, 84% +/- 4% of FR-28 cells formed colonies and clusters when stimulated with pokeweed mitogen spleen cell conditioned medium (PWMSCM) in a similar in vitro assay (35% granulocyte, 29% macrophage and 39% mixed granulocyte/macrophage colonies). These results indicate there is a correlation between the responsiveness of CFU-GM progenitor cells to CSF-1 and the expression of c-fms RNA.

Animals↗
PubMed1988

Growth characteristics of marrow hematopoietic progenitor/precursor cells from patients on a phase I clinical trial with purified recombinant human granulocyte-macrophage colony-stimulating factor.

Bone marrow cells from patients with leukemia, myelodysplastic syndromes, cancer, and other disorders on a phase I clinical trial with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) were assessed in vitro for numbers of granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells, and for growth patterns (colony-to-cluster ratio) of CFU-GM, cycling rates of CFU-GM, and responsiveness in vitro to colony-stimulating and colony-inhibiting factors. The colony-to-cluster ratio of CFU-GM and the dose-response curves of CFU-GM to stimulation by rhGM-CSF in vitro did not change during the clinical trial. However, the percentage of CFU-GM in DNA synthesis, which is a measure of the proliferative rates of these cells, determined by the high specific activity tritiated thymidine kill technique in vitro, was markedly enhanced in a reversible fashion after administration in vivo of rhGM-CSF. The increased cycling rates of CFU-GM were consistent with the induced increase in neutrophil counts in these patients that has been reported elsewhere. Additionally, marrow CFU-GM from patients given rhGM-CSF in vivo were increased in sensitivity to inhibition in vitro by recombinant human H-subunit (acidic) ferritin in two of eight cases, and were increased in sensitivity to inhibition by lower dosages of recombinant human tumor necrosis factor alpha in all patients evaluated. The sensitivity of CFU-GM to inhibition in vitro by recombinant human interferon gamma and prostaglandin E1 did not change during the clinical trial. These studies demonstrate that the rhGM-CSF is having an effect on CFU-GM in the patients on the phase I clinical trial. This information may be of significance in planning future clinical studies combining rhGM-CSF with chemotherapy and/or other biotherapy.

Bone Marrow↗
PubMed1988

Acidic isoferritin stimulates differentiation of normal granulomonocytic progenitors.

Acidic isoferritin (AIF) has been shown to be released by cells from patients with leukemia and to have an inhibitory effect on the growth of normal granulomonocytic (GM) progenitors (leukemia-inhibitory activity) during the S phase of the cell cycle. AIF is also produced by normal mature cells of the monocyte-macrophage lineage. We studied the effects of AIF on the differentiation of normal GM progenitors and found an increase in the number of mature cells in AIF-exposed cultures. This increase did not occur when AIF was pretreated with anti-heart ferritin antiserum or when basic isoferritin was used in the place of AIF. The influence of AIF was not mimicked by removing S phase cells by pretreatment with a pulse of high specific activity tritiated thymidine. Thus, the apparent differentiation-stimulating effect of AIF is not likely to be due to selective removal of immature dividing cells. The results suggest that AIF-inhibitory activity on the proliferation of GM progenitors might at least in part be mediated by a stimulus for differentiation of the target cells, thus regulating the number of mature cells which might be formed by a single progenitor cell.

Cell Differentiation↗
PubMed1988

Interleukin-1 alpha enhances the in vitro survival of purified murine granulocyte-macrophage progenitor cells in the absence of colony-stimulating factors.

Interleukin-1 (IL-1), recently identified as hemopoietin-1, affects hematopoiesis by presumably direct and indirect mechanisms. IL-1 stimulates primitive hematopoietic stem cells to express receptors for the granulocyte-macrophage colony-stimulating factors (GM-CSFs) and stimulates CSF release from accessory cells. We used highly purified murine granulocyte-macrophage progenitor cells (CFU-GM, up to 92% cloning efficiency) to assess the effects of IL-1 alpha on the proliferation, differentiation, and survival of these cells. The results demonstrated that IL-1 alpha does not directly influence the proliferation or differentiation of purified CFU-GM in the presence of plateau concentrations of purified natural or recombinant CSFs, and IL-1 alpha lacks intrinsic CSF activity of its own. CSF deprivation studies showed that IL-1 alpha rapidly (within one hour) promoted CFU-GM survival in the absence of CSF. This enhanced survival stimulated by IL-1 alpha was observed with CFU-GM responding to purified recombinant GM-CSF, natural M-CSF, recombinant G-CSF, recombinant IL-3, or IL-3 in WEHI-conditioned medium, and no effect on the pattern of CFU-GM differentiation occurred in cultures incubated with IL-1 alpha in the absence of CSF. The IL-1 alpha effects on CFU-GM are probably due to a direct action on progenitor cells because the presence or absence of accessory cells did not alter the results and concentrations of the CSFs that were too low to stimulate the proliferation of CFU-GM could not mimic the IL-1 alpha effect on CFU-GM survival.

Animals↗
PubMed1988

Synergistic interaction of hematopoietic colony stimulating and growth factors in the regulation of myelopoiesis.

Synergistic interactions in the regulation of myelopoiesis have been noted in vitro and in vivo and are discussed. Moreover, data is presented to highlight such synergistic interactions in vitro and in vivo. It is shown that purified recombinant human B-cell stimulating factor-1/interleukin-4 (rh BSF-1/IL-4) synergizes with rh Granulocyte (G)-Colony Stimulating Factor (CSF), but not with rh Granulocyte-Macrophage (GM)-CSF, rh IL-3, or rh Macrophage CSF (CSF-1) to enhance colony formation in vitro by normal human bone marrow cells. This synergism is restricted to granulocyte progenitors. Also, it is shown that rh G-CSF or rh CSF-1 enhance the proliferation of granulocyte-macrophage progenitor cells (CFU-GM) in vivo in mice pretreated with human lactoferrin, and when added together these preparations of CSF act synergistically. It is apparent that a true understanding of how myeloid blood cell production is regulated requires insight into how molecules collaborate with or antagonise one another.

Animals↗
PubMed1988

Stimulation of hematopoiesis in patients with bone marrow failure and in patients with malignancy by recombinant human granulocyte-macrophage colony-stimulating factor.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a multipotential hematopoietin. To assess the toxicity and biological activity of recombinant human GM-CSF (rhGM-CSF) in vivo, 25 patients with malignancy or bone marrow failure were treated with rhGM-CSF (specific activity approximately 5 x 10(7) U/mg) as part of a phase 1 trial. The treatment was administered by continuous intravenous (IV) infusion daily for 2 weeks at fixed dose levels and repeated after a 2-week rest period. Over the entire dose range tested (15 to 500 micrograms/m2/d), rhGM-CSF treatment was associated with dramatic increases (two- to 70-fold) in total leukocyte counts, which consisted predominantly of neutrophils, bands, eosinophils, and monocytes. Furthermore, six of the 14 patients with one or more cytopenias that received at least two cycles of treatment had multilineage responses characterized by twofold or greater increases in platelet count to a level above 100,000, twofold or greater increases in corrected reticulocyte count, and a reduced requirement for red cell transfusions. Three of these patients became independent of both red cell and platelet transfusions for 17 to 37 weeks of follow-up. Treatment was associated also with an increase in bone marrow cellularity and frequency of cycling progenitor cells. The treatment was well tolerated; side effects included constitutional symptoms and bone pain. These results demonstrated that rhGM-CSF has a significant impact on hematopoiesis in patients with advanced malignancy and also in patients with bone marrow failure.

Adult↗
PubMed1987

Effects of recombinant human granulocyte-macrophage colony-stimulating factor in patients with myelodysplastic syndromes.

The myelodysplastic syndromes are characterized by ineffective hematopoiesis and refractory cytopenias. In an attempt to improve hematopoiesis, we administered recombinant human granulocyte--macrophage colony-stimulating factor (GM-CSF) to eight patients with myelodysplastic syndrome, as part of a Phase I trial. The GM-CSF was given by continuous intravenous infusion daily for two weeks and then again after a two-week rest period. Over the entire dose range tested (30 to 500 micrograms per square meter of body-surface area), treatment was associated with marked increases in peripheral-blood leukocytes (5- to 70-fold), including granulocytes (5- to 373-fold), in all eight patients. The absolute number of monocytes, eosinophils, and lymphocytes increased in all patients. Three of eight patients also had 2- to 10-fold increases in platelet counts and improvement in erythropoiesis, with the result that two of three patients who had required red-cell and platelet transfusions no longer needed them (at 20 to 27 weeks of follow-up). Treatment was also associated with increased marrow cellularity and a decreased percentage of blasts in the bone marrow of patients with excess blasts, resulting in an increase in the ratio of differentiated myeloid cells to immature myeloid cells. We observed relatively few side effects, but bone pain was dose-limiting when it was associated with high white-cell counts. Our results showed that GM-CSF is a potent stimulator of hematopoiesis in vivo and may produce hematologic improvement in the short term (8 to 32 weeks of observation) in patients with myelodysplastic syndrome. More experience, with longer follow-up periods, will be necessary to assess the long-term safety and efficacy of this new treatment.

Adult↗
PubMed1987

Characterization of adult human marrow hematopoietic progenitors highly enriched by two-color cell sorting with My10 and major histocompatibility class II monoclonal antibodies.

Monoclonal antibodies, My10 (HPCA-1) and major histocompatibility class II (HLA-DR), were used to enrich and phenotype normal human marrow colony-forming unit: granulocyte-macrophage (CFU-GM), burst-forming unit: erythroid (BFU-E), and multipotential colony-forming unit: granulocyte-erythroid-macrophage-megakaryocyte (CFU-GEMM) progenitor cells. Nonadherent low density T lymphocyte-depleted marrow cells were sorted on a Coulter Epics 753 dye laser flow cytometry system with the use of Texas Red-labeled anti-My10 and phycoerythrin conjugated anti-HLA-DR. Cells were separated into populations with nondetectable expression of antigens (DR-My10-) or with constant expression of one antigen and increasing densities of the other antigen. More than 98% of the CFU-GM, BFU-E, and CFU-GEMM were found in fractions containing cells expressing both HLA-DR and My10 antigens. The cloning efficiency (CE) of cells in the DR-My10- cell fraction was 0.01%. In the antigen-positive sorted fractions, the CE was highest (up to 47%) in the fractions of cells expressing high My10 and low DR (My10 DR+) antigens and was lowest (2.5%) in the fraction of cells expressing low My10 and low DR (My10+DR+) antigens. Populations of cells varying in the density of HLA-DR, but not My10, antigens varied in the proportion and types of progenitor cells present. When My10-positive cells were sorted for HLA-DR density expression, the CE for CFU-GM was similar in the DR+ and DR++ fractions, but most of the BFU-E and CFU-GEMM were found in the DR+ fraction. Within the CFU-GM compartment, most of the eosinophil progenitors were found in the DR+ fraction, whereas a greater proportion of macrophage progenitors were detected in the DR++ fraction. CFU-GM and BFU-E in the fractions of cells positive for DR and My10 were assessed for responsiveness to the effects of recombinant human tumor necrosis factor-alpha, recombinant human interferon-gamma, and prostaglandin E1. Colony formation from CFU-GM was suppressed by the three molecules, and colony formation by BFU-E was suppressed by recombinant human tumor necrosis factor-alpha and interferon-gamma and enhanced, in the presence of T lymphocyte-conditioned medium, by prostaglandin E1 in all antigen-positive fractions.(ABSTRACT TRUNCATED AT 400 WORDS)

Alprostadil↗
PubMed1987

Protective influence of lactoferrin on mice infected with the polycythemia-inducing strain of Friend virus complex.

Purified iron-saturated human lactoferrin (LF) was assessed in vivo for effects on the survival rates of C57BL X DBA/2 f1 (hereafter called BD2F1) (Fv-2sr) mice and titers of spleen focus-forming viruses (SFFV) in BD2F1 and DBA/2 (Fv-2ss) mice inoculated with the polycythemia-inducing strain of the Friend virus complex (FVC-P). LF prolonged the survival rates and decreased the titers of SFFV in mice given FVC-P. Titers of SFFV, assayed 14 days after administration of FVC-P, were measured by the spleen focus-forming unit assay in secondary mouse recipients. Decreases in titers of SFFV were apparent when LF was given in vivo as a single bolus dose of 200 micrograms within 2 h of the Friend virus complex (FVC), or as a total dosage of 200 micrograms given on days 1, 2, 4, 7, 9, and 11 after FVC-P, and to a lesser degree when LF was given as a total dosage of 200 micrograms on days 3, 4, 7, 9, and 11 after FVC-P. No decreases in titers of SFFV were detected when LF was given up to 3 days before or more than 3 days after FVC-P. LF did not appear to be directly inactivating the viruses as it did not inactivate the SFFV or the Friend murine leukemia helper virus in vitro. The results suggest that the protective effect of LF in vivo is probably due to an action on cells responding to the FVC or to an action on cells which influence the cells responding to the FVC or which influence the virus. It has been shown elsewhere that LF decreases the percentage of marrow and spleen hematopoietic progenitor cells that are in DNA synthesis in vivo and this may be the means by which the protective effect of LF is mediated in mice given the FVC.

Animals↗
PubMed1987

The influence in vivo of natural murine interleukin-3 on the proliferation of myeloid progenitor cells in mice recovering from sublethal dosages of cyclophosphamide.

Purified natural murine interleukin-3 (IL-3) was assessed for its effects in vivo in mice pretreated 7 days earlier with a sublethal dosage of cyclophosphamide. The multipotential (CFU-GEMM), erythroid (BFU-E) and granulocyte-macrophage (CFU-GM) progenitor cells in these mice were in a slowly- or non-cycling state. Three hours after the i.v. administration of 200 units IL-3 into these mice, the hematopoietic progenitor cells in the marrow and spleen were placed into rapid cell-cycle. At this time, no effects were noted on marrow or spleen nucleated cellularity, numbers of progenitor cells per organ, or peripheral blood counts. No endotoxin was detected in the IL-3 preparation, by Limulus lysate assay. Treatment of IL-3 in vitro at 100 degrees C for 20 min partially decreased its colony stimulating activity in vitro and completely inactivated its proliferation stimulating effects in vivo. These findings suggest that the effects of IL-3 in vivo were not due to contaminating endotoxin or to a non-specific protein effect. These studies do not allow us to conclude whether the effects of IL-3 in vivo are directly on the progenitors and/or are indirect effects mediated by accessory cells.

Animals↗
PubMed1987

The comparative enhancing effects of prostaglandin E1 on colony formation by erythroid progenitor (BFU-E) cells from bone marrow of mice differing in the Fv-2 locus.

Prostaglandin E1(PGE1) was assessed for its colony enhancing effects on erythroid (BFU-E) progenitor cells and for its colony suppressive effects on granulocyte-macrophage (CFU-GM) progenitor cells from bone marrows of mice differing in the Fv-2 locus. The Fv-2 locus has been reported by others to control the proportion of BFU-E, but not of CFU-GM, in DNA synthesis. PGE1 significantly enhanced erythroid colony formation by marrow cells from DBA/2 (Fv-2ss), C57BL/6 (Fv-2rr) and BDF1 (Fv-2rs) mice, but the DBA/2 cells were more sensitive to the PGE1 enhancing effects than were cells from C57BL/6 or BDF1 mice. The enhanced sensitivity of DBA/2 cells to PGE1 was associated with the higher cycling rate of DBA/2-BFU-E in comparison with C57BL/6- and BDF1-BFU-E, and removal of S-phase DBA/2-BFU-E by pulse exposure of cells to high specific activity tritiated thymidine in vitro eliminated the erythroid colony enhancing effects of PGE1. The differences in sensitivity of BFU-E from mice differing in the Fv-2 locus to the effects of PGE1 were verified using Fv-2 congenic mice. In contrast, no significant differences were noted in sensitivity of CFU-GM from these different mouse strains, including mice congenic for the Fv-2 locus, to the suppressive effects of PGE1. This correlated with the similar cycling characteristics of CFU-GM from these mice, and the non-cycle specific effects of PGE1 on mouse CFU-GM. These studies substantiate further the regulatory effects of the Fv-2 locus on mouse erythroid progenitor cells which are a manifestation of the cycling rates of these cells.

Alprostadil↗
PubMed1987

Synergistic myelopoietic actions in vivo after administration to mice of combinations of purified natural murine colony-stimulating factor 1, recombinant murine interleukin 3, and recombinant murine granulocyte/macrophage colony-stimulating factor.

Combinations of low dosages of purified murine hematopoietic colony-stimulating factors (CSFs)--L-cell CSF type 1 (CSF-1), recombinant interleukin 3 (IL-3), and recombinant granulocyte/macrophage CSF (GM-CSF)--were compared with single CSFs for their influence on the cycling rates and numbers of bone marrow granulocyte/macrophage, erythroid, and multipotential progenitor cells in vivo in mice pretreated with human lactoferrin. Lactoferrin was used to enhance detection of the stimulating effects of exogenously administered CSFs. Concentrations of CSFs that were not active in vivo when given alone were active when administered together with other types of CSF. The concentrations of CSF-1, IL-3, and GM-CSF needed to increase progenitor cell cycling rates were reduced by factors of 40-200, 10-50, and 40- greater than 400, respectively; the concentrations needed to increase progenitor cell numbers were reduced by factors of 40-500 (CSF-1), 20-80 (IL-3), and greater than 40- greater than 200 (GM-CSF) when these forms of CSFs were administered in combination with low dosages of one of the other forms of CSFs. The results demonstrate that different CSFs can synergize when administered in vivo to increase the cycling rates and numbers of marrow hematopoietic progenitor cells. These findings may be of relevance physiologically to the regulation of myeloid blood cell production by CSFs.

Animals↗