Effect ofS. aureussupernatant on CFTR localisation and expression. (A, B) Immunolocalisation of CFTR (green staining) and Dapi nuclei staining (blue) in lateral view of successive z level images. In control cells, we noticed an apical staining of CFTR (arrow heads in A). In 2%S. aureus supernatant-treated cells (B), the CFTR staining was more diffuse in the cytoplasm. (C) Western blotting analysis of airway glandular cell membrane proteins showed the presence of CFTR in control cells and in fewer amount in cells incubated with 2%S. aureus supernatant. (D) Quantitative measurement showed a significant (*, p < 0.05) decrease in CFTR expression in cell membranes when cells were incubated with 2% S. aureus supernatant. Data represent the mean ± SEM of 5 different experiments.