Avaliação da habilidade quimiotaxica e da adesão de eosinofilos de pacientes com rinite alergica : efeito da eotaxina e interleucina-5

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

In this study, we tested whether IL-5, eotaxin and dexamethasone modulate the adhesion and migration of eosinophils obtained trom allergic rhinitis subjects, in comparison with healty individuais. The chemotaxis and adhesion assays were performed with eosinophils isolated from peripheral blood using an imunomagnetic cell separator. ChemoTx-5 plates were used for the chemotaxis assays, whereas fibronectin-coated plates were used for the adhesion assays. For both assays, measurement of eosinophil peroxidase activity was used as marker for migrated or adhered eosinophils. Platelet-activated factor (PAF; 10-8 M) induced a significant eosinophil chemotaxis in both studied groups. Interleukin-5 (IL-5, 0.25 nglml) significantly increased the PAF-induced chemotaxis in eosinophils trom both healthy individuais and rhinitis subjects. However, the increase in rhinitis subjects eosinophils was 65% higher (p<0.001) compared with healthy individuais eosinophils. Eotaxin (100 ng/ml) did not alter the PAF-induced eosinophil chemotaxis in either groups studied. Dexamethasone (100 Ilg/ml) significantly reduced PAF-induced chemotaxis in cells trom both groups. Interleukin-5 (0.25 nglm!) induced a higher chemotactic response in eosinophils trom rhinitis subjects compared with healthy individuais. Eotaxin (100 ng/ml) had no effect on IL-5-induced eosinophil chemotaxis in healthy individuais, but prevented the increase in eosinophil chemotaxis induced by IL-5 in rhinitis subjects. Eotaxin (100 ng/ml) induced a higher chemotactic response in eosinophils trom rhinitis subjects compared with healthy individuais. Eotaxin-induced eosinophil chemotaxis was significantly enhanced by IL-5 (0.25 nglml) in both group studied, but this enhancement was higher in eosinophils trom rhinitis subjects. In plated coated with fibronectin (an opposite ligand for VLA-4) we studied the eosinophil adhesion. The basal (spontaneous) cell adhesion was siginificantly higher (p<0.05) using eosinophils from rhinitis subjects compared with those trom healthy individuais. However, the pattem of cell adhesion in both groups was not significantlyaffectedby eotaxin (100 ng/ml) or IL-5 (0.25 nglm!). Dexamethasone (100 Ilg/ml) significantly reduced the eosinophil adhesion in cells from both studied groups. Ours results indicate that eosinophils trom rhinitissubjects are found primed, and that can be due to previous exposition to IL-5 while in peripheral blood. It is likelythat IL-5 increases the expression andlor function01adhesion molecule VLA- 4 in eosinophils leading consequently to an enhanced cell chemotaxis

ASSUNTO(S)

rhinitis pharmacology farmacologia rinite eosinofilia quimiotaxia chemiotaxis eosinophilia

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