Creation and characterization of an airway epithelial cell line for stable expression of CFTR variants

Background: Analysis of the functional consequences and treatment response of rare CFTR variants is challenging due to the limited availability of primary airways cells.

Methods: A Flp recombination target (FRT) site for stable expression of CFTR was incorporated into an immortalized CF bronchial epithelial cell line (CFBE41o-). CFTR cDNA was integrated into the FRT site. Expression was evaluated by western blotting and confocal microscopy and function measured by short circuit current. RNA sequencing was used to compare the transcriptional profile of the resulting CF8Flp cell line to primary cells and tissues.

Results: Functional CFTR was expressed from integrated cDNA at the FRT site of the CF8Flp cell line at levels comparable to that seen in native airway cells. CF8Flp cells expressing WT-CFTR have a stable transcriptome comparable to that of primary cultured airway epithelial cells, including genes that play key roles in CFTR pathways.

Conclusion: CF8Flp cells provide a viable substitute for primary CF airway cells for the analysis of CFTR variants in a native context.