The mechanisms of serum-treated zymosan (STZ)-induced oxidative metabolism by human eosinophils and the effects of IL-5 priming.
Allergy
; 56(7): 639-45, 2001 Jul.
Article
en En
| MEDLINE
| ID: mdl-11421922
ABSTRACT
BACKGROUND:
The aim of this work was to study the mechanisms of action of IL-5 on the subsequent stimulation of the oxidative metabolism of blood eosinophils by serum-treated zymosan (STZ), in terms of signal transduction characteristics, and by comparing the response of cells from healthy and allergic subjects during environmental exposure to birch pollen.METHODS:
Eosinophils from healthy controls and allergic patients were purified to over 95% by Percoll gradients and the MACS system. Oxidative metabolism was measured by a lucigenin-enhanced chemiluminescence (CL) assay. Eosinophils were primed with IL-5 and subsequently stimulated with STZ. The signal transduction mechanisms of IL-5 priming were studied with the MEK inhibitor PD 98059,the PkC inhibitors staurosporine and Ro 318220, and the PI3 kinase inhibitor wortmannin.RESULTS:
IL-5 increased the maximum radical production (P=0.0079) and reduced the t(1/2) rise (0.000018) of the CL reactions. The t(1/2) rise was PkC dependent and MEK independent, while the maximum radical production was PkC, MEK, and PI3 kinase dependent. During the pollen season, IL-5 reduced the total STZ-induced CL response in the patients' cells (P=0.016), but not in the control cells, whereas it primed the response to STZ of both cell populations in terms of the t(1/2) rise (P=0.012 and 0.00066, respectively).CONCLUSION:
STZ-induced oxidative metabolism consists of different stages. The initial stage (t(1/2) rises of the curves) is PkC dependent and MEK independent, while the end stage (maximum radical production) is PkC, MEK, and PI3 kinase dependent. IL-5 shortened the initial stage, and increased the end stage. During allergen exposure, however, the end stage was reduced by IL-5. This could be due to increased amounts of hypodense eosinophils and/or some abnormality in cell responses.
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Bases de datos:
MEDLINE
Asunto principal:
Oxidación-Reducción
/
Zimosan
/
Interleucina-5
/
Péptidos y Proteínas de Señalización Intracelular
/
Eosinófilos
/
Hipersensibilidad
Idioma:
En
Revista:
Allergy
Año:
2001
Tipo del documento:
Article
País de afiliación:
Suecia