Correction of the cystic fibrosis defect by gene complementation in human intrahepatic biliary epithelial cell lines

Hepatobiliary disease is the second most common cause of mortality in patients with cystic fibrosis (CF). In the liver, only the intrahepatic biliary epithelial (IBE) cells express cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. The aim of this study was to determine whether human CF-derived IBE cells can be infected with adenovirus and the CF phenotype complemented.

IBE cells were isolated from 2 patients with CF and immortalized using retrovirus transduction of SV40 large T antigen. Immortalized cells were infected with the adenovirus vector Ad2/CFTR2 and assayed 2-31 days postinfection for cyclic adenosine monophosphate (cAMP)-induced halide efflux. Halide efflux was measured in single cells using fluorescence microscopy and the fluorescent probe 6-methoxy-N-(3-sulfopropyl)-quinolinium.

CF-derived IBE cell lines express biliary specific markers and express no cAMP-inducible halide efflux. Following infection with the adenovirus vector Ad2/CFTR2, a cAMP-induced halide efflux was observed for 31 days, although the number of responsive cells decreased with time.

Human CF-IBE cells can be infected by adenovirus and the defective CFTR complemented. The loss of responsive cells with time could be due to loss of construct and/or a reduced growth of cells that are overexpressing CFTR. These CF-IBE cell lines offer an opportunity to determine the mechanisms responsible for hepatobiliary disease in the patients with CF.