title: Dual phase priming by IL-3 for leukotriene C4 generation in human basophils: difference in characteristics between acute and late priming effects.
abstract: Previous studies have suggested that enhancement of mediator release from human basophils by IL-3 occurs in at least two phases, and the current studies further characterize the signaling changes that accompany these two phases of the basophil in response to IL-3. The test stimulus for these studies was anaphylatoxin split product of C component (C5a), which does not induce leukotriene C4 release without prior IL-3 treatment. Functionally, IL-3 priming occurs after 5 min, disappears by 2 h, and returns by 18 h. In contrast, the kinetics of cytosolic phospholipase A2 (cPLA2) and extracellular signal-regulated kinase (ERK1/2) phosphorylation, induced by IL-3, do not show the second rise by 18 h. The kinetics of cPLA2 and ERK1/2 phosphorylation following stimulation with C5a are the same for cells that were not treated with IL-3 as for those treated for 18 h, i.e., a lag in phosphorylation of cPLA2 and ERK1/2 lasting 30 s before its eventual rise. Previous studies showed that a 5-min treatment with IL-3 induced little change in the C5a-induced cytosolic calcium response, while 24 h of treatment resulted in a marked and sustained cytosolic calcium elevation during the C5a-induced response. The first phase of the IL-3 priming effect (5-15 min of treatment) was unaffected by cycloheximide, while the second phase (18 h) was inhibited. These data suggest that early IL-3 priming results from preconditioning cPLA2, i.e., causing its phosphorylation, while late priming results from a qualitative change in the cytosolic calcium response.
authors.affiliation: Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
authors.forename: K
authors.initials: K
authors.lastname: Miura
authors.forename: D W
authors.initials: DW
authors.lastname: MacGlashan
mesh_terms: D001491:Basophils / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D015936:Complement C5a / Q000276:immunology; D003513:Cycloheximide / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D004533:Egtazic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D007377:Interleukin-3 / Q000276:immunology*; D007424:Intracellular Fluid / Q000378:metabolism; D007700:Kinetics; D017997:Leukotriene C4 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism; D054467:Phospholipases A2; D010766:Phosphorylation / Q000187:drug effects; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D005419:Flavonoids; D007377:Interleukin-3; D017997:Leukotriene C4; D004533:Egtazic Acid; D015936:Complement C5a; D003513:Cycloheximide; D019950:Mitogen-Activated Protein Kinase 1; D020928:Mitogen-Activated Protein Kinases; D010741:Phospholipases A; D054467:Phospholipases A2; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D002118:Calcium