title: Characterization of the priming effects of human granulocyte-macrophage colony-stimulating factor on human neutrophil leukotriene synthesis.
abstract: 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.
authors.affiliation: Division of Haematology-Oncology, UCLA School of Medicine.
authors.forename: J F
authors.initials: JF
authors.lastname: DiPersio
authors.forename: P H
authors.initials: PH
authors.lastname: Naccache
authors.forename: P
authors.initials: P
authors.lastname: Borgeat
authors.forename: J C
authors.initials: JC
authors.lastname: Gasson
authors.forename: M H
authors.initials: MH
authors.lastname: Nguyen
authors.forename: S R
authors.initials: SR
authors.lastname: McColl
mesh_terms: D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood; D000001:Calcimycin / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003115:Colony-Stimulating Factors / Q000502:physiology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D015289:Leukotrienes / Q000096:biosynthesis / Q000097:blood* / Q000302:isolation & purification; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology*
chemical_list: D001095:Arachidonic Acids; D003115:Colony-Stimulating Factors; D006133:Growth Substances; D015289:Leukotrienes; D011994:Recombinant Proteins; D016718:Arachidonic Acid; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D001094:Arachidonate 5-Lipoxygenase