CORRECTION OF THE CYSTIC-FIBROSIS DEFECT BY GENE COMPLEMENTATION IN HUMAN INTRAHEPATIC BILIARY EPITHELIAL-CELL LINES

Background/Aims: Hepatobiliary disease is the second most common cause of mortality in patients with cystic fibrosis (CF). In the liver, onl y the intrahepatic biliary epithelial (IBE) cells express cystic fibro sis transmembrane conductance regulator (CFTR) chloride channel. The a im of this study was to determine whether human CF-derived IBE cells c an be infected with adenovirus and the CF phenotype complemented. Meth ods: IBE cells were isolated from 2 patients with CF and immortalized using retrovirus transduction of SV40 large T antigen. Immortalized ce lls were infected with the adenovirus vector Ad2/CFTR2 and assayed 2-3 1 days postinfection for cyclic adenosine monophosphate (cAMP)-induced halide efflux. Halide efflux was measured in single cells using fluor escence microscopy and the fluorescent probe 6-methoxy-N(3-sulfopropyl )-quinolinium. Results: CF-derived IBE cell lines express biliary spec ific markers and express no cAMP-inducible halide efflux. Following in fection with the adenovirus vector Ad2/CFTR2, a cAMP-induced halide ef flux was observed for 31 days, although the number of responsive cells decreased with time. Conclusions: Human CF-IBE cells can be infected by adenovirus and the defective CFTR complemented. The loss of respons ive cells with time could be due to loss of construct and/ or a reduce d growth of cells that are overexpressing CFTR. These CF-IBE cell line s offer an opportunity to determine the mechanisms responsible for hep atobiliary disease in the patients with CF.