Ozone-induced bronchial epithelial cytokine expression differs between healthy and asthmatic subjects

Bosson, J., Stenfors, N., Bucht, A., Helleday, R., Pourazar, J., Holgate, S.T., Kelly, F.J., Sandström, T., Wilson, S., Frew, A.J. and Blomberg, A. (2003) Ozone-induced bronchial epithelial cytokine expression differs between healthy and asthmatic subjects. Clinical & Experimental Allergy, 33 (6), 777-782. (doi:10.1046/j.1365-2222.2003.01662.x).

Abstract

Background Ozone (O₃) is a common air pollutant associated with adverse health effects. Asthmatics have been suggested to be a particularly sensitive group.

Objective This study evaluated whether bronchial epithelial cytokine expression would differ between healthy and allergic asthmatics after ozone exposure, representing an explanatory model for differences in susceptibility.

Methods Healthy and mild allergic asthmatic subjects (using only inhaled β2‐agonists prn) were exposed for 2h in blinded and randomized sequence to 0.2ppm of O₃ and filtered air. Bronchoscopy with bronchial mucosal biopsies was performed 6 h after exposure. Biopsies were embedded in GMA and stained with mAbs for epithelial expression of IL‐4, IL‐5, IL‐6, IL‐8, IL‐10, TNF‐α, GRO‐α, granulocyte–macrophage colony‐stimulating factor (GM–CSF), fractalkine and ENA‐78.

Results When comparing the two groups at baseline, the asthmatic subjects showed a significantly higher expression of IL‐4 and IL‐5. After O₃ exposure the epithelial expression of IL‐5, GM–CSF, ENA‐78 and IL‐8 increased significantly in asthmatics, as compared to healthy subjects.

Conclusion The present study confirms a difference in epithelial cytokine expression between mild atopic asthmatics and healthy controls, as well as a differential epithelial cytokine response to O₃. This O₃‐induced upregulation of T helper type 2 (Th2)‐related cytokines and neutrophil chemoattractants shown in the asthmatic group may contribute to a subsequent worsening of the airway inflammation, and help to explain their differential sensitivity to O³ pollution episodes.

This record has no associated files available for download.

Contributors

Author: S. Wilson

Download statistics