METHODS: Human respiratory epithelial cells were serially passaged using a co-culture system and a conventional dispase-dissociation technique. The growth kinetics and gene expression levels of the cultured respiratory epithelial cells were compared. Four genes were investigated, namely cytokeratin-18, a marker for ciliated and secretory epithelial cells; cytokeratin-14, a marker for basal epithelial cells; MKI67, a proliferation marker; and MUC5B, a marker for mucin secretion. Immunocytochemical analysis was performed using monoclonal antibodies against the high molecular-weight cytokeratin 34 beta E12, cytokeratin 18, and MUC5A to investigate the protein expression from cultured respiratory epithelial cells.

RESULTS: Respiratory epithelial cells cultured using both methods maintained polygonal morphology throughout the passages. At passage 1, co-cultured respiratory epithelial showed a 2.6-times higher growth rate compared to conventional dispase dissociation technique, and 7.8 times higher at passage 2. Better basal gene expression was observed by co-cultured respiratory epithelial cells compared to dispase dissociated cells. Immunocytochemical analyses were positive for the respiratory epithelial cells cultured using both techniques.