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J F DiPersio

Publications and source records attributed to J F DiPersio.

At least 55 records · Page 3Linked to original sources
PubMed1991

Involvement of tyrosine kinases in the activation of human peripheral blood neutrophils by granulocyte-macrophage colony-stimulating factor.

The aim of the present study is to evaluate the involvement of human neutrophil tyrosine kinase(s) in the signal transduction mechanism of granulocyte-macrophage colony-stimulating factor (GM-CSF). Stimulation of neutrophils with GM-CSF resulted in a time- and dose-dependent phosphorylation of several proteins having estimated molecular weights of approximately 40, 55, 74, 97, 118, and 155 Kd, detected by immunoblot using a monoclonal antibody directed against phosphotyrosine. GM-CSF-induced tyrosine phosphorylation was inhibited in a dose- and time-dependent manner by the tyrosine kinase inhibitor erbstatin. Using this inhibitor, we were able to correlate tyrosine phosphorylation with several functional effects of GM-CSF on human neutrophils. Pretreatment of neutrophils with erbstatin before incubation with GM-CSF completely inhibited the GM-CSF-induced intracellular alkalinization, downregulation of the leukotriene B4 receptor, enhancement of fMet-Leu-Phe-induced intracellular calcium mobilization, as well as the accumulation of mRNA for the proto-oncogene c-fos. Taken together, these data suggest that tyrosine kinase activation in human neutrophils plays a critical regulatory role in both the stimulation and priming of neutrophil function by GM-CSF.

Calcium↗
PubMed1991

Identification and molecular cloning of a soluble human granulocyte-macrophage colony-stimulating factor receptor.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) plays an important role in hematopoiesis and host defense via interaction with specific cell-surface receptors in target tissues. We identified a truncated, soluble form of the low-affinity GM-CSF receptor (GMR) in chorio-carcinoma cells. Low-affinity GMR cDNAs encoding both the membrane-bound and soluble receptors were obtained by PCR using primers corresponding to the published sequence. Clones encoding the soluble receptor were identical in sequence to the membrane-bound form but contained a 97-nucleotide internal deletion. The amino acid sequence of this deleted cDNA predicts a protein that lacks the 84 C-terminal amino acids of the membrane-bound receptor, including the transmembrane and cytoplasmic domains, and contains 16 different amino acids at its C terminus. Expression of the soluble GMR cDNA in murine psi-AM cells as well as GM-CSF-dependent myeloid 32Dc13 cells produced a secreted protein that retained its capacity to bind GM-CSF in solution. RNase protection analysis indicates that this variant cDNA is derived from a naturally occurring mRNA. Soluble receptors have been identified for several other hematopoietin receptors and may be a general feature of this class. The striking similarity between the soluble form of the GMR and other hematopoietin receptors suggests that soluble binding proteins may play an important role in regulating the broad spectrum of biological responses mediated by these cytokines.

Amino Acid Sequence↗
PubMed1991

Characterization of the soluble human granulocyte-macrophage colony-stimulating factor receptor complex.

The human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor (GM-R) is expressed on both hematopoietic and non-hematopoietic tissues. Although the receptor has been identified by cross-linking studies as an 84,000-dalton protein, very little is known about its biochemistry. In this report, we describe a soluble binding assay for the human GM-R which allowed us to characterize the receptor complex from various sources, including plasma membranes of placenta, neutrophils, and human myeloid leukemia cell lines. Preparation of membranes as well as solubilization by Triton X-100 and N-octylglucoside resulted in a 5-10-fold lower affinity of the receptor for GM-CSF. The Kd decreased from 20 to 80 pM in intact cells to 200-500 pM in both intact and solubilized membranes. Binding in solution was rapid, specific for GM-CSF, and best fit a "one-site" model with an approximate Kd of 500 pM. The dissociation rate constant for the soluble GM-R was very similar to that of intact cells (k2 = 0.013 min-1 versus 0.017 min-1, respectively). As expected, solubilized membranes obtained from those cells expressing the highest number of GM-R (neutrophils and dimethyl sulfoxide-induced HL-60 cells; approximately 500-800 sites/cell) possessed the highest concentration of soluble GM-R (approximately 2-3 x 10(8) GM-R/micrograms). Cross-linking of 125I-GM-CSF to soluble GM-R resulted in the appearance of two specifically labeled complexes. A major 110-kDa receptor-ligand complex is found when cross-linking is performed with intact cells; both 110- and 200-kDa species are seen when cross-linking is performed with either intact membranes or soluble GM-R. These studies define methods by which intact GM-R can be solubilized and measured in solution, permitting a more complete biochemical characterization of the intact GM-R complex.

Cell Line↗
PubMed1991

Orthotopic liver transplantation for life-threatening veno-occlusive disease of the liver after allogeneic bone marrow transplant.

Veno-occlusive disease (VOD) of the liver is a serious and often lethal sequela to bone marrow transplantation. Although a history of prior hepatitis moderately increases the risk of VOD, reliable screening methods for identifying high risk patients are not available. New approaches to managing patients who develop serious VOD are needed. One approach may be the use of orthotopic liver transplantation in selected patients who are likely to die of the disease. In this report we describe a patient who underwent liver transplantation for life-threatening VOD following allogeneic transplantation for CML. Although this patient died early from interstitial pneumonitis, the orthotopic liver functioned well up to her death. Other reports describing successful liver transplants in patients with advanced VOD or graft-versus-host disease of the liver are discussed and the possible indications for liver transplantation for VOD after marrow transplantation are considered. Taken together, these reports suggest that orthotopic liver transplantation may be a feasible and potentially effective approach to managing select patients with life-threatening liver dysfunction after marrow transplantation.

Adult↗
PubMed1990

Human granulocyte colony-stimulating factor: biologic activities and receptor characterization on hematopoietic cells and small cell lung cancer cell lines.

Human granulocyte colony-stimulating factor (G-CSF) is a regulatory glycoprotein that stimulates the production of neutrophilic granulocytes from committed hematopoietic progenitor cells both in vitro and in vivo. In this report, we show that biosynthetic (recombinant) human G-CSF enhances colony formation by normal human bone marrow and the human myeloid leukemic cell lines, HL-60 and KG-1, as well as nonhematopoietic small cell lung cancer lines, H128 and H69. G-CSF also modulates multiple differentiated functions of human neutrophils, including enhanced oxidative metabolism in response to f-Met-Leu-Phe (f-MLP), increased antibody-dependent cell-mediated cytotoxicity (ADCC), and augmented arachidonic acid release in response to ionophore and chemotactic agents. These effects are all maximal at a concentration of 100 to 500 pmol/L. Using 125I-labeled recombinant human G-CSF, high affinity binding sites were identified on human neutrophils, the myeloid leukemia cell lines KG-1 and HL-60, and the small cell carcinoma cell lines, H128 and H69. G-CSF receptor numbers ranged between 138 and 285 sites per cell with a kd of 77 to 140 pmol/L, consistent with the concentrations of G-CSF that elicit biologic responses in vitro. Decreased specific binding of 125l-G-CSF by human neutrophils was consistently observed in the presence of excess unlabeled human granulocyte-macrophage colony-stimulating factor (GM-CSF), suggesting competition or down modulation by GM-CSF of the G-CSF receptor.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1990

GM-CSF: receptor structure and transmembrane signaling.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) both stimulates hematopoietic precursor cells to grow as well as enhances the function of mature effector cells, such as neutrophils, eosinophils and macrophages. All of the biological actions of GM-CSF appear to be mediated via binding to a single class of high-affinity receptors present on all responsive cells. Affinity cross-linking experiments demonstrate that the same 98 kDa cross-linked species seen on other GM-CSF-responsive cells is also detected on a choriocarcinoma cell line, JAR. However, JAR cells express significantly increased numbers (10,000 sites/cell) of low-affinity (Kd approximately 1.5 nM) GM receptors. The GM-CSF receptor is a glycoprotein which binds to wheat germ agglutinin-sepharose. It is dramatically downregulated on neutrophils by phorbol esters and formyl-methionyl-leucine-phenylalanine (fMLP), but not by phosphatidylinositol-dependent phospholipase C. GM-CSF primes neutrophils for enhanced response to secondary stimuli, such as ionophore and chemotactic factors. Specifically, GM-CSF enhances 3H-arachidonic acid release, synthesis of leukotriene B4 and platelet activity factor in response to fMLP and the calcium ionophores.

Cell Membrane↗
PubMed1990

Colony-stimulating factors: enhancement of effector cell function.

Haemopoietic growth factors both stimulate the growth and maturation of marrow precursor cells and enhance the functional activities of mature myelomonocytic effector cells. These biological effects are consistent with the expression of functional colony stimulating factor receptors on granulocytes and monocytes as well as on those immature marrow cells with proliferative potential. As the number of defined haemopoietic growth factors increases, both general perspectives of effector cell function and pathways of growth factor-induced signal transduction become more complex and less clearly understood. Although most known haemopoietic growth factors are briefly discussed, an effort has been made to focus on granulocyte-macrophage colony stimulating factor as a prototypic inducer of enhanced neutrophil, eosinophil and macrophage effector cell function.

Animals↗
PubMed1989

Effects of human GM-CSF on neutrophil degranulation in vitro.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates multiple differentiated functions of mature neutrophils. Increased expression of leukocyte adhesion molecules and chemotactic receptors on GM-CSF-treated neutrophils suggested that GM-CSF may stimulate neutrophil degranulation. were assessed by quantitating the release of an exclusive component of the specific granules, vitamin B12 binding protein. Incubation of neutrophils with GM-CSF alone resulted in a significant release of [57Co]-vitamin B12 binding protein quantitatively similar to that elicited by cytochalasin B or N-formyl-methionyl-leucylphenylalanine (f-Met-Leu-Phe) alone. In addition, cells preincubated with GM-CSF and subsequently stimulated with f-Met-Leu-Phe, platelet-activating factor, or the calcium ionophore, A23187, demonstrated enhanced degranulation, which greatly exceeded that produced by GM-CSF alone. These results demonstrate a small direct effect of GM-CSF on neutrophil degranulation, as well as enhanced degranulation in cells stimulated by chemotactic agents and calcium ionophore. Neutrophil degranulation in response to GM-CSF may be involved in the phlebitis associated with therapeutic administration of GM-CSF.

Calcimycin↗
PubMed1989

Involvement of guanine nucleotide binding proteins in neutrophil activation and priming by GM-CSF.

Pre-incubation of human neutrophils with pertussis toxin significantly inhibited the neutrophil-directed biologic actions of granulocyte-macrophage colony-stimulating factor (GM-CSF) in three separate assays: the induction of c-fos mRNA, the enhancement of both platelet-activating factor-induced mobilization of intracellular calcium, and stimulation of leukotriene synthesis by the calcium ionophore A23187. Cholera toxin did not have an effect on the latter two assays. Pre-treatment of human neutrophils with pertussis toxin did not affect the binding of GM-CSF to its surface receptor. These results provide the first evidence that a pertussis toxin substrate plays an important mediatory role in the mechanism of action of GM-CSF.

Calcimycin↗
PubMed1989

Nonhematopoietic tumor cells express functional GM-CSF receptors.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates the colony growth of myeloid progenitors in semisolid media, and enhances the function of mature effector cells, including neutrophils, monocytes, and eosinophils. Small cell carcinoma lines (SCCL) have properties of amine precursor uptake and decarboxylation (APUD) cells and express high levels of the enzyme, L-aromatic amino acid decarboxylase. We looked for possible expression of GM-CSF receptors on nonhematopoietic cells and found specific high-affinity binding of human GM-CSF to SCCL and to the SV40-transformed African green monkey kidney cell line, COS. The small cell carcinoma lines responded to GM-CSF with enhanced proliferation, and both small cells and COS cells were found to express authentic 84,000 dalton GM-CSF receptor protein. These findings indicate that nonhematopoietic cells can bind and respond to GM-CSF, suggesting additional biological activities as well as the possibility of tumor responses when GM-CSF is used therapeutically in humans. Since preliminary clinical trials using CSFs as adjunctive treatment in patients with solid tumors are underway, it will be important to consider the possible responsiveness of nonhematopoietic tumor cells to CSFs.

Carcinoma, Small Cell↗
PubMed1988

Human granulocyte-macrophage colony-stimulating factor and other cytokines prime human neutrophils for enhanced arachidonic acid release and leukotriene B4 synthesis.

Human recombinant granulocyte-macrophage CSF (GM-CSF) "primes" neutrophils for enhanced biologic responses to a number of secondary stimuli. Here, we examined the properties of neutrophil priming by GM-CSF and other growth factors such as human rTNF and granulocyte CSF. Although GM-CSF has a negligible direct effect on [3H]arachidonic acid release, it enhances or "primes" neutrophils for three- to fivefold increased release of [3H]arachidonic acid, induced by 1.0 microM A23187 and the chemotactants FMLP, platelet-activating factor, and leukotriene B4 (LTB4) (all 0.1 microM). The priming effects of GM-CSF were concentration- and time-dependent (maximum 100 pM, 1 h at 23 degrees C), and consistent with the determined dissociation constant of the human GM-CSF receptor. Indomethacin (10(-8) M), cycloheximide (100 micrograms/ml), and pertussis toxin (200 ng/ml, 2 h at 37 degrees C) had no effect on GM-CSF-, A23187, or platelet-activating factor-induced [3H]arachidonic acid release. The lipoxygenase inhibitor, nordihydroguaiaretic acid, however, totally abolished A23187-induced [3H]arachidonic acid release from both diluent- and GM-CSF-treated neutrophils. Consistent with this observation, we found that GM-CSF-pretreated neutrophils synthesize increased levels of LTB4 after stimulation with A23187 and chemotactic factors. GM-CSF enhances neutrophil arachidonic acid release and LTB4 synthesis, and thereby may amplify the inflammatory response to chemotactic factors and other physiologically relevant stimuli.

Arachidonic Acid↗
PubMed1988

Granulocyte-macrophage colony-stimulating factor modulates the excitation-response coupling sequence in human neutrophils.

We have investigated the effects of granulocyte-macrophage (GM) CSF on two biochemical responses thought to play internal signaling roles in the neutrophils, namely the increase in the concentration of free calcium and the changes in the internal pH. The changes in the right-angle light scatter of the cell suspensions were also examined. GM-CSF was found not to affect the resting levels of calcium or the internal pH of the cells. However, pre-incubation of the neutrophils with the growth factor resulted in an increase in the magnitude of the calcium transients that follow the stimulation of the cells with chemotactic factors as well as a profound depression of the cell alkalinization that is induced by fMet-Leu-Phe, leukotriene B4, and platelet-activating factor, as well as by phorbol esters. The rapid cytoplasmic acidification elicited by these agents was apparently magnified. GM-CSF did not directly affect the Na+/H+ antiport as GM-CSF-treated cells were as capable as untreated cells of recovering from an acid load. The right-angle light scatter responses of the cells to the chemotactic factors were found not to be affected by GM-CSF. These results provide an initial description of the effects of GM-CSF on the cellular physiology of the neutrophils and insights into the mechanism of action of this factor as well as into the excitation-response coupling sequence activated by chemotactic factors.

Calcium↗
PubMed1988

Characterization of the priming effects of human granulocyte-macrophage colony-stimulating factor on human neutrophil leukotriene synthesis.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) is an in vitro and in vivo stimulator of human bone marrow myelomonocytic precursor cells and mature granulocyte and macrophage effector cells. We have compared the effect of GM-CSF on the synthesis of 5-lipoxygenase products induced by the chemotactic peptide fMet-Leu-Phe and the calcium ionophore A23187 in human neutrophils. Although GM-CSF alone did not stimulate detectable synthesis of products of the 5-lipoxygenase pathway, pre-incubation of neutrophils with 200 pM GM-CSF for 1 hour at 23 degrees C enhanced synthesis of leukotriene B4, its all-trans isomers and omega-oxidation products, and 5-hydroxyeicosatetraenoic acid in response to both the calcium ionophore A23187 (1.5 microM), and the chemotactic peptide fMet-Leu-Phe (0.1 microM). This priming effect of GM-CSF was maximal after a 60 min incubation at 23 degrees C, or after a 30 min preincubation at 37 degrees C. The effect of GM-CSF was maximal using a concentration of 1 nM. Enhancement of the leukotriene synthesis stimulated by A23187 was only observed when the cells were stimulated by the ionophore for periods of 3 minutes or less. In contrast, the enhancing effect of GM-CSF was still apparent when cells were exposed to fMet-Leu-Phe for as long as 15 minutes. Furthermore, the enhancing effect of GM-CSF was ablated when neutrophils were stimulated with A23187 and exogenous arachidonic acid. However, co-addition of exogenous arachidonic acid with fMet-Leu-Phe did not entirely mask the effect of GM-CSF. Possible mechanisms of action of GM-CSF are discussed.

Arachidonate 5-Lipoxygenase↗
PubMed1986

Enhancement of human eosinophil cytotoxicity and leukotriene synthesis by biosynthetic (recombinant) granulocyte-macrophage colony-stimulating factor.

Culture medium conditioned by activated human T lymphocytes enhances the in vitro cytotoxicity of purified human eosinophils toward Schistosoma mansoni larvae, suggesting the existence of a mechanism for T lymphocyte regulation of eosinophil function. Here we show that purified biosynthetic (recombinant) human T lymphocyte granulocyte-macrophage colony-stimulating factor (GM-CSF) enhanced markedly two eosinophil functions: cytotoxicity toward schistosomula by a mean of 676%, and calcium ionophore A23187-induced generation of leukotriene C4 (LTC4) by a mean of 135%. Augmentation of each eosinophil function by GM-CSF was time- and dose-dependent, with a dose-response relationship at concentrations between 1 and 20 pM. Tumor necrosis factor (TNF) enhanced eosinophil cytotoxicity with slower kinetics, a different dose-dependence relationship, and to a lower maximum, as compared with GM-CSF. There was no detectable effect of TNF on calcium ionophore A23187-induced generation of LTC4. The effect of GM-CSF on arachidonic acid metabolism to LTC4 reached a plateau with 60 min of incubation before stimulation with ionophore, and was characterized by an initial augmentation of the intracellular level of LTC4 and a subsequent increment in extracellular LTC4. Thus, GM-CSF can serve as a mediator for T lymphocyte regulation of functions of mature eosinophils. It is also the first defined macromolecule known to enhance metabolism of membrane-derived arachidonic acid via the 5-lipoxygenase pathway.

Calcimycin↗
PubMed1981

Autostimulation of growth by human myelogenous leukemia cells (HL-60).

We have studied the effects of medium conditioned by the human progranulocytic leukemia cell line, HL-60, on the subsequent growth of new inocula of HL-60 cells. When HL-60 cells were cultured at high cell density, optimal growth rate occurred in liquid suspension and confluent colony growth was observed in viscous medium without the addition of conditioned medium. However, when cells were cultured at lower cell density, growth rate was reduced and colony growth was nil unless conditioned medium from HL-60 culture was added. All HL-60 populations studied, including the earliest available passage, 9, both elaborated and responded to HL-60 CM. HL-60 CM did not stimulate normal human or mouse granulocyte-monocyte colony-forming cell (CFU-GM) growth. Conditioned media from other human cell lines varied in the ability to stimulate HL-60 cell and CFU-GM proliferation. Some, such as GCT CM, stimulated both HL-60 cells and normal CFU-GM, whereas others, like HL-60 CM, stimulated only HL-60 growth. The majority of cell line CMs tested did not stimulate either HL-60 or CFU-GM. Chromatography of HL-60 CM on Ultrogel AcA54 showed a single peak of HL-60 stimulating activity of apparent molecular weight 13,000. The ability of HL-60 cells to elaborate this activity provides a possible explanation for their proliferation at higher cell densities. Autostimulation may prove to be important in the high growth potential of other cell populations that undergo unrepressed proliferation.

Animals↗
PubMed1980

Erythropoietic enhancing activity (EEA) secreted by the human cell line, GCT.

Medium conditioned by the monocyte-like cell line GCT contains colony-stimulating activity (CSA), a mediator of in vitro granulopoiesis. Also, the conditioned medium (CM) contains erythroid-enhancing activity (EEA), which can be demonstrated in a system utilizing either nonadherent marrow or blood mononuclear cells, erythropoietin (1-2 units/ml), and 20 ml/dl fetal calf serum. Under these conditions, GCT CM enhances the growth of CFU-E and BFU-E. Attempts were made to characterize the molecular features of EEA. Serum-free GCT cell CM was fractionated on Sephacryl S200 and Ultrogel AcA54. EEA and CSA cochromatographed with apparent molecular weights of approximately 40,000 daltons on Sephacryl and approximately 30,000 daltons on Ultrogel. Fractionation on DEAE Sephacel led to an apparent separation of CSA from EEA; however, when diluted, the fractions containing CSA and EEA. Undiluted fractions containing potent CSA inhibited erythropoiesis; however, dilution of these fractions resulted in marked EEA. Diluted crude GCT CM and DEAE Sephacel fractions enriched in EEA were also capable of sustaining BFU-E in liquid culture and mediating erythropoietin-independent colony growth. CSA could not be unequivocally separated from EEA on concanavalin A-Sepharose, since the diluted void volume containing CSA also had EEA. EEA was present in CM boiled for 60 minutes, whereas CSA was markedly reduced but not abolished. The inverse relationship between CSA concentration and EEA mandates dilution of fractions when bioassayed for these two activities. Although CSA and EEA are similar in molecular weight, they appear to be partially separable by ion-exchange chromatography and heat stability.

Cell Line↗