Inhibition of basophil histamine release by tyrosine kinase and phosphatidylinositol 3-kinase inhibitors.
It has been demonstrated that tyrosine kinase (TK) and phosphatidylinositol 3-kinase (PI3-K) are involved in IgE-mediated stimulation of human basophils; conversely, little is known about the biochemical pathways activated by IL-3 and GM-CSF. The aim of this study was to evaluate the effects of TK and PI3-K inhibitors on basophil histamine release induced by anti-IgE, IL-3 and GM-CSF. Since IL-3 and GM-CSF cause histamine release from normal human basophils only when the inhibitory effect of extracellular Na(+) has been removed, peripheral blood leukocytes were suspended in isotonic solutions containing either 140 mM NaCl or 140 mM N-methyl-D-glucamine(+). After stimulation with anti-IgE, IL-3 or GM-CSF, histamine release was measured by an automated fluorometric method. The effects of preincubation with four different TK inhibitors (AG-126, genistein, lavendustin A, tyrphostin 51) and one PI3-K inhibitor (wortmannin) were evaluated. AG-126, genistein and lavendustin A exerted a significant dose-dependent inhibitory effect on basophil histamine release induced by anti-IgE (either in high or in low Na(+) medium), IL-3 and GM-CSF. Among the TK inhibitors, lavendustin A exerted the most potent activity, followed by AG-126 and genistein. Tyrphostin 51 caused a weak inhibition of histamine release induced by IL-3, GM-CSF and anti-IgE in a low Na(+) medium, but not in a physiological Na(+)-containing medium. The PI3-K inhibitor wortmannin exerted the most effective inhibitory activity on the histamine release induced by the three agonists. The combined effects of lavendustin A and wortmannin were less than additive, suggesting that TK and PI3-K are involved in the same activation pathway in human basophils. These results suggest a possible role of TK and PI3-K in basophil histamine release induced by anti-IgE, IL-3 and GM-CSF. TK and PI3-K are indeed potential therapeutic targets for antiallergic drugs.
Tedeschi
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Allergy and Immunopharmacology Unit, Third Division of Internal Medicine, IRCCS Ospedale Maggiore Policlinico, Padiglione Granelli, Via Sforza 35, I-20122, Milan, Italy. albited@tin.it
Lorini
M
M
Galbiati
S
S
Gibelli
S
S
Miadonna
A
A
D000730:Androstadienes / Q000494:pharmacology; D001491:Basophils / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D019833:Genistein / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D066298:In Vitro Techniques; D007377:Interleukin-3 / Q000494:pharmacology; D010636:Phenols / Q000494:pharmacology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D000077191:Wortmannin
D000730:Androstadienes; D004791:Enzyme Inhibitors; D007377:Interleukin-3; D010636:Phenols; D000081082:Phosphoinositide-3 Kinase Inhibitors; D007073:Immunoglobulin E; C062898:lavendustin A; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D000077191:Wortmannin