Towards an in vitro model of cystic fibrosis small airway epithelium: characterisation of the human bronchial epithelial cell line CFBE41o-

The CFBE41o- cell line was generated by transformation of cystic fibrosis (CF) tracheo-bronchial cells with SV40 and has been reported to be homozygous for the Delta F508 mutation. A systematic characterisation of these cells, which however, is a pre-requisite for their use as an in vitro model, has not been undertaken so far. Here, we report an assessment of optimal culture conditions, the expression pattern of drug-transport-related proteins and the stability/presence of the CF transmembrane conductance regulator (CFTR) mutation in the gene and gene product over multiple passages. The CFBE41o- cell line was also compared with a wild-type airway epithelial cell line, 16HBE14o-, which served as model for bronchial epithelial cells in situ. The CFBE41o- cell line retains at least some aspects of human CF bronchial epithelial cells, such as the ability to form electrically tight cell layers with functional cell-cell contacts, when grown under immersed (but not air-interfaced) culture conditions. The cell line is homozygous for Delta F508-CFTR over multiple passages in culture and expresses a number of proteins relevant for pulmonary drug absorption (e.g. P-gp, LRP and caveolin-1). Hence, the CFBE41o- cell line should be useful for studies of CF gene transfer or alternative treatment with small drug molecules and for the gathering of further information about the disease at the cellular level, without the need for primary culture.