5-oxo-6,8,11,14-eicosatetraenoic acid stimulates the release of the eosinophil survival factor granulocyte/macrophage colony-stimulating factor from monocytes.
Allergic diseases such as asthma are characterized by tissue eosinophilia induced by the combined effects of chemoattractants and cytokines. Lipid mediators are a major class of endogenous chemoattractants, among which 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is the most potent for human eosinophils. In this study, we investigated the effects of 5-oxo-ETE on eosinophil survival by flow cytometry. We found that this compound could promote eosinophil survival in the presence of small numbers of contaminating monocytes, but not in their absence. The conditioned medium from monocytes treated for 24 h with 5-oxo-ETE also strongly promoted eosinophil survival, whereas the medium from vehicle-treated monocytes had no effect. An antibody against the granulocyte/macrophage colony-stimulating factor (GM-CSF) completely blocked the response of eosinophils to the conditioned medium from 5-oxo-ETE-treated monocytes, whereas an antibody against interleukin-5 had no effect. Furthermore, 5-oxo-ETE stimulated the release of GM-CSF from cultured monocytes in amounts compatible with eosinophil survival activity, with a maximal effect being observed after 24 h. This effect was concentration-dependent and could be observed at concentrations in the picomolar range. 5-Oxo-ETE and leukotriene B(4) had similar effects on GM-CSF release at low concentrations, but 5-oxo-ETE induced a much stronger response at concentrations of 10 nm or higher. This is the first report that 5-oxo-ETE can induce the release of any cytokine, suggesting that it could be an important mediator in allergic and other inflammatory diseases due both to its chemoattractant properties and to its potent effects on the synthesis of the survival factor GM-CSF.
Stamatiou
Panagiota B
PB
Meakins-Christie Laboratories, Department of Medicine, McGill University, 3626 St. Urbain Street, Montreal, Quebec H2X 2P2, Canada.
Chan
Chi-Chung
CC
Monneret
Guillaume
G
Ethier
Diane
D
Rokach
Joshua
J
Powell
William S
WS
D001095:Arachidonic Acids / Q000494:pharmacology*; D002470:Cell Survival; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000378:metabolism*; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D006801:Humans; D007975:Leukotriene B4 / Q000378:metabolism; D050356:Lipid Metabolism; D018950:Lipopolysaccharide Receptors / Q000096:biosynthesis; D009000:Monocytes / Q000378:metabolism*; D017452:Receptors, IgG / Q000096:biosynthesis; D013997:Time Factors
D001095:Arachidonic Acids; D017077:Culture Media, Conditioned; D016207:Cytokines; D018950:Lipopolysaccharide Receptors; D017452:Receptors, IgG; C080828:5-oxo-6,8,11,14-eicosatetraenoic acid; D007975:Leukotriene B4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor