We have used mtmvitus-mediated gene transfer to dentonstrate compiementation of the cystic fibrosis (CF) defect In vitro. Amphotropic mtroviruses were used to transduce a functional cystic fibrosis transmembrane conductance regulator (CFTR) cDNA into CFPAC-1, a pancreatic adenocarcinoma ceil line derived from a patient with CF that stably expresses the chloride tram+ port abnormalities characteristic of CF. CFPAC-1 ceils were exposed to control virus (PLJ) and CFTR-exptessing virus (PLJ-CFTR); viral-transduced clones were isolated and subjected to molecular and physiologic analysis. RNA analysis detected a viral-derived CFTR transcript in ail of the PLJ-CFTR clones that contained unmarranged provirai sequences. Agents that increase intracellular cAMP stimulated l* R efflux in PLJ-CFTR clones but not PLJ clones. Whole-ceil patch-clamp performed on three responding clones showed that the anion effiux responses were due to cAMP stimulation of Cl conductance. Our findings indicate that expression of the normal CFTR gene confers cAMPdependent Cl channel regulation on CF epitheliai ceils. introduction

Cystic fibrosis (CF) is an autosomal recessive disorder characterized by abnormalities in water and electrolyte transport that lead to pancreatic and pulmonary insufficiency (Taussig, 1964). Recent progress in our understanding of the genetic and functional basis of CF has provided a foundation for better defining its molecular pathology as well as developing novel therapies based on somatic gene transfer.