Interleukin-5 modulates interleukin-8 secretion in eosinophilic inflammation

• Main Authors: L. H. Faccioli (Author), A. I. Medeiros (Author), A. Malheiro (Author), R. C. L. R. Pietro (Author), A. Januário (Author), B. B. Vargaftig (Author)
• Format: Book
• Published: Hindawi Limited, 1998-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Serum and BALF (bronchoalveolar lavage fluid) IL-8 levels and serum levels were investigated in Tox ocara canis infected guinea-pigs and the role of IL-5 as a modulator of cytokine secretion was studied. Serum levels increased early in infected animals, exceeding control levels 4 h after infection, peaked between days 6 and 18, and continued to exceed control levels after 48 days of infection. Serum and BALF IL-8 levels showed the same profile as blood eosinophilia, increasing 6 days post-infection and peaking between days 18 and 24. Treatment of infected animals with anti-IL-5 Ab suppressed eosinophilia with a parallel increase in blood IL-8 levels, whereas no change was found in levels. To support our in vivo observation we carried out experiments in vitro using guinea-pig LPS-stimulated adherent peritoneal cells which release large amounts of IL-8 into the supernatants. When rIL-5 was added to LPS-stimulated cells, 65% inhibition of IL-8 release into the supernatants was observed. Pre-incubation of cells with anti-IL-5 Ab prevented the inhibition of IL-8 release into the supernatants induced by rIL-5. Our results demonstrate for the first time that TNF- α and IL-8 are released concomitant with or after IL-5 in the eosinophilic inflammation induced by T. canis . Moreover, in addition to showing that IL-5 is fundamental for the induction of blood eosinophilia, the present results suggest that this cytokine may play a new biological role by acting as modulator of IL-8 secretion.

Item Description

0962-9351
1466-1861
10.1080/09629359891379