037 Comparative chemokine secretory profiles in normal and CF polarized epithelial cells following S. aureus infection

Abstract

Introduction Staphylococcm aureus (S. aureus) is one of the most common causes of infections in human and one the first pathogens infltrating the lung in patients with cystic fibrosis. Branchial epithelial cells are actively involved in the pathogenesis of airway inflammation through the production of multiple factors such as cytokines and chemokines. Cytokines release can lead to the efflux of immune cells, involved in the innate immune response, and stimulate the adaptative immune response. The aim of our study was to analyze 1) the apical and basolateral chemokine profiles obtained by polarized normal human airway epithelial cells (MM39) and CF human airway epithelial cells KM4, 2) the effect of S. aureus interaction with polarized MM39 and KM4 on these chemokine profiles. Methods Polarized monolayer of transformed human tracheal gland cell lines were prepared by seeding 5.10 5 cells/cm 2 on the top of microporous polyester supports. The cells were maintained in a submerged System. For each experiment, confluent airway epithelial cells were apically infected with alive S. aureus . The apical and basolateral supernatants were coUected at different time points, and the chemokine profiles for each condition were analyzed. Results A number of chemokines are secreted by the MM39 and KM4 airway among them IL-8, NAP-2, MIP-1β, Eotaxin-2, RANTES. Following S. aureus contact, the secretion of these chemokines by MM39 cells is increased, while their secretion by KM4 cells is maintained in the basal level. Differences in the levels of the chemokines present in the apical or basolateral compartment of each cell line culture are observed. Looking at the time-dependent and bacteria-dependent IL-8 secretion by MM39 and KM4, we observed an increase of the apical IL-8 secretion by MM39 while the IL-8 secretion level was constant for the KM4. Conclusion Following stimulation of the cells by S. aureus , the chemokine secretion alteration by the MM39 polarized epithelium is more pronounced than for the KM4 polarized airway epithelium. Furthermore, for most of the chemokines studied, the variation is more important in the apical supernatant. This could represent an important factor to be taken into consideration in the development of the lung immune response.