Dissociation of inflammatory and epithelial responses in a murine model of chronic asthma

Date

2000

Authors

Foster, Paul S
Yang, Ming
Matthaei, Klaus
Young, I M
Temelkovski, J
Kumar, Rakesh K

Journal Title

Journal ISSN

Volume Title

Publisher

Lippincott Williams & Wilkins

Abstract

To study pathogenetic mechanisms in chronic asthma, we employed a novel experimental model that replicates characteristic features of the human disease. Chronic inflammation and epithelial changes, specifically localized to the airways, were induced by repeated exposure of systemically sensitized BALB/c mice to low mass concentrations of aerosolized ovalbumin for 6 weeks. The contribution of Th2 cytokine-driven inflammation to the development of airway lesions and hyperreactivity was assessed in cytokine-deficient mice. In interleukin-5-deficient animals, intraepithelial eosinophils and chronic inflammatory cells in the lamina propria of the airways were markedly decreased; however, these animals developed epithelial hypertrophy and subepithelial fibrosis comparable with that observed in sensitized wild type mice. Airway hyperreactivity to inhaled methacholine did not develop in interleukin-5-deficient mice. In contrast, interleukin-4-deficient mice exhibited no decrease in airway inflammation, but had significantly greater epithelial hypertrophy and subepithelial fibrosis, as well as exaggerated hyperreactivity to methacholine. We conclude that interleukin-5, but not interleukin-4, plays a central role in the development of chronic inflammation of the airways and the induction of airway hyperreactivity. Furthermore, chronic epithelial and fibrotic changes occur independently of interleukin-5 and are not required for the development of airway hyperreactivity. The dissociation between airway wall remodeling and airway hyperreactivity has important implications for therapeutic approaches to chronic asthma.

Description

Keywords

Keywords: cytokine; interleukin 4; interleukin 5; methacholine; animal experiment; animal model; animal tissue; article; asthma; bronchus hyperreactivity; chronic inflammation; controlled study; cytokine release; eosinophil; experimental model; fibrosis; hypertroph

Citation

Source

Laboratory Investigation

Type

Journal article

Book Title

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DOI

Restricted until

2037-12-31