EPITHELIAL-CELL SPECIFIC PROPERTIES AND GENETIC COMPLEMENTATION IN A DELTA-F508 CYSTIC-FIBROSIS NASAL POLYP CELL-LINE

Analysis of vectorial ion transport and protein trafficking in transformed cystic fibrosis (CF) epithelial cells has been limited because the cells tend to lose their tight junctions with multiple subcultures. To elucidate ion transport and protein trafficking in CF epithelial cells, a polar cell line with apical and basolateral compartments will facilitate analysis of the efficacy of different gene therapy strategies in a ''tight epithelium'' in vitro. This study investigates the genotypic and phenotypic properties of a CF nasal polyp epithelial, Delta F508 homozygote, cell line that has tight junctions pre-crisis. The cells (Sigma CFNPE14o-) were transformed with an origin-of-replication defective SV40 plasmid. They develop transepithelial resistance in Ussing chambers and are defective in cAMP-dependent Cl- transport as measured by efflux of radioactive Cl-, short circuit current (I-se), or whole-cell patch clamp. Stimulation of the cells by bradykinin, histamine, or ATP seems to activate both K+- and Ca+2-dependent Cl- transport. Measurement of Cl-36(-) efflux following stimulation with A23187 and ionomycin indicate a Ca+2-dependent Cl- transport. Volume regulatory capacity of the cells is indicated by cell swelling conductance. Expression of the CF transmembrane conductance regulator mRNA was indicated by RT-PCR amplification. When cells are grown at 26 degrees C for 48 h there is no indication of cAMP-dependent Cl- as has been previously indicated in heterologous expression systems. Antibodies specific for secretory cell antigens indicate the presence of antigens found in goblet, serous, and mucous cells; in goblet and serous cells; or in goblet and mucous cells; but not antigens found exclusively in mucous or serous cells. Gene complementation studies with an episomal vector containing wild-type CF transmembrane conductance regulator cDNA showed correction of the cAMP-dependent Cl- transport defect. This cell line contributes unique phenotypic features to the store of transformed CF epithelial cells already available.