Production of IL-8 and release of eosinophil-derived neurotoxin by normal peripheral blood eosinophils.
To study the regulation of IL-8 production and release of eosinophil-derived neurotoxin (EDN) by normal blood eosinophils, we isolated eosinophils from healthy individuals and stimulated them with immobilized secretory IgA with or without exogenous IL-5 for 3, 12, and 24 h, and with different concentrations of ionomycin for 24 h. Eosinophils cultured with secretory IgA for 3 and 12 h showed strong expression of mRNA for IL-8 by reverse transcription polymerase chain reaction. Exogenous IL-5 enhanced mRNA for IL-8 expression by eosinophils after 24 h of incubation. IL-8 secretion increased in a time-dependent manner throughout the 24 h of observation; in contrast, EDN release reached a plateau value after 12 h. Furthermore, at least 2 microM ionomycin was necessary for induction of IL-8 secretion, whereas 0.5 microM induced detectable EDN release by eosinophils. These results suggest that the mechanism of eosinophil degranulation may be different from those of cytokine secretion.
Nakajima
H
H
Department of Internal Medicine and Clinical Immunology, Dokkyo University School of Medicine, Shimotuga, Tochigi, Japan. kazu@dokkyomed.ac.jp
Gleich
G J
GJ
Fukuda
T
T
Makino
S
S
Kita
H
H
D004305:Dose-Response Relationship, Drug; D047208:Eosinophil-Derived Neurotoxin; D004804:Eosinophils / Q000276:immunology*; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000276:immunology; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D015759:Ionomycin / Q000494:pharmacology; D009498:Neurotoxins / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D012260:Ribonucleases
D007071:Immunoglobulin A, Secretory; D016209:Interleukin-8; D009498:Neurotoxins; D012333:RNA, Messenger; D015759:Ionomycin; D047208:Eosinophil-Derived Neurotoxin; D012260:Ribonucleases