The Effect of Dexamethasone on Respiratory Syncytial Virus Induced RANTES and IL-8 Production of a Human Bronchial Epithelial Cell Line

Kim, Sang Yong; Lee, Joon Sung; Chun, Chung Sik

Abstract

PURPOSE
Besides being a structural barriers for infectious pathogens, bronchial epithelium also participates actively in the modulation of airway inflammatory reactions through the synthesis of a variety of proinflammatory mediators such as RANTES and IL-8 which are important chemokines for chemotaxis of eosinophils and neutrophils, and their activation. Respiratory syncytial virus(RSV) is the most common cause of bronchiolitis in infants, is an important trigger of asthma exacerbation, and stimulates chemokine production of human airway epithelial cells in vitro. We tested RSV-stimulated production of RANTES and IL-8, and the effects of the dexamethasone(DX) on the production of chemokines of human bronchial epithelial cell line, BEAS-2B. METHOD: SConfluent BEAS-2B culture were inoculated with RSV at various multiplicity of infection(MOI 0.1, 1, 10), and supernatants were collected at 12, 24, 48hr intervals. Concentrations of RANTES and IL-8 were measured in supernatants using ELISA. The effect of DX at varying concentrations(10-9, 10-8, 10-7, 10-6 M) on RSV(MOI 1)-induced chemokine production was determined. RESULT: The production of RANTES and IL-8 were increased in RSV infected group than non-infected group at each time and each MOI. The production of RANTES and IL-8 were decreased in DX-treated RSV infected group than non-treated RSV infected group and this tendency was prominent in higher concentration of DX.
CONCLUSION
DX can modulate the inflammatory response of the airway in RSV bronchiolitis and asthma exacerbation through the inhibition of virus-induced chemokine production by bronchial epithelial cells.