title: The effects of GM-CSF on myeloperoxidase release in normal and myelodysplastic neutrophils.
abstract: When purified control neutrophils were primed with GM-CSF, a significant increase in FMLP-induced MPO release was observed (mean +/- S.E.M., 3.4 +/- 0.8 mU/10(7) unprimed cells compared to 6.5 +/- 1.1 mU/10(7) primed cells, p < 0.001). This MPO release was greatly augmented by Cytochalasin B (Cy B), but after the addition of Cy B the priming effects of GM-CSF became less obvious. Exposure to GM-CSF without FMLP did not enhance MPO release. Within whole blood, FMLP produced negligible MPO release, but priming with GM-CSF prior to FMLP always resulted in a significant increase in MPO release. Myelodysplastic neutrophils released similar amounts of MPO in response to FMLP, compared with control cells (3.4 +/- 0.8 mU/10(7) control cells compared to 2.7 +/- 0.3 mU/10(7) MDS cells, p > 0.05). Priming with GM-CSF produced an increase in FMLP-stimulated MPO release comparable with control cells. In terms of total MPO content, although some MDS patients exhibited low levels, as a group there was no significant difference from controls (169 +/- 21 mU/10(7) control cells compared with 157 +/- 19 mU/10(7) MDS cells). These findings suggest that MPO activity is not a universal defect in MDS and cannot account for the defects in respiratory burst activity in these neutrophils.
authors.affiliation: University Department of Haematology, Royal Liverpool University Teaching Hospital, U.K.
authors.forename: Y
authors.initials: Y
authors.lastname: Dang
authors.forename: G M
authors.initials: GM
authors.lastname: Lowe
authors.forename: S W
authors.initials: SW
authors.lastname: Edwards
authors.forename: D W
authors.initials: DW
authors.lastname: Galvani
mesh_terms: D000740:Anemia / Q000097:blood / Q000201:enzymology; D003571:Cytochalasin B / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D015477:Leukemia, Myelomonocytic, Chronic / Q000097:blood / Q000201:enzymology; D008163:Luminescent Measurements; D009190:Myelodysplastic Syndromes / Q000097:blood* / Q000201:enzymology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*; D009195:Peroxidase / Q000097:blood*; D011994:Recombinant Proteins / Q000494:pharmacology; D012016:Reference Values; D013481:Superoxides / Q000097:blood; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D011994:Recombinant Proteins; D013481:Superoxides; D003571:Cytochalasin B; D009240:N-Formylmethionine Leucyl-Phenylalanine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D009195:Peroxidase; D013755:Tetradecanoylphorbol Acetate