title: IL-5 as a strong secretagogue for human eosinophils.
abstract: The ability of IL-5 to induce eosinophil degranulation was investigated. Peripheral blood eosinophils from patients with mildly allergic individuals were isolated with CD16- selection method. Eosinophils were then incubated with interleukin-5 (IL-5) (0.1-100 ng/ml) for 1-48 h and EPX in the supernatants were measured with RIA. We found that IL-5 induced significant amount of eosinophil protein X in a concentration-dependent manner at 24 h. Eosinophil viability was about 90% either in the presence or absence of IL-5 at 24 h. Eosinophils stimulated with IL-5 adhered to the plate. Anti-CD18 mAb blocked adhesion and degranulation induced by IL-5. Dexamethasone and TGFbeta significantly inhibited degranulation in a concentration-dependent manner. These results suggest that IL-5 may be a strong secretagogue for eosinophils, that adhesion via beta2 integrin is a requisite for degranulation, and that the anti-inflammatory effect of corticosteroids and TGFbeta may be exerted at least in part, through the inhibition of eosinophil degranulation.
authors.affiliation: Department of Pediatrics, Mie National Hospital, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fujisawa
authors.forename: A
authors.initials: A
authors.lastname: Terada
authors.forename: J
authors.initials: J
authors.lastname: Atsuta
authors.forename: K
authors.initials: K
authors.lastname: Iguchi
authors.forename: H
authors.initials: H
authors.lastname: Kamiya
authors.forename: M
authors.initials: M
authors.lastname: Sakurai
mesh_terms: D018821:CD18 Antigens; D002448:Cell Adhesion; D015550:Cell Degranulation; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D015848:Interleukin-5 / Q000494:pharmacology*
chemical_list: D018821:CD18 Antigens; D015848:Interleukin-5