Generation of ΔF508-CFTR T84 cell lines by CRISPR/Cas9-mediated genome editing

Objectives: To provide a simple method to make a stable Delta F508-CFTR-expressing T84 cell line that can be used as an efficient screening model system for Delta F508-CFTR rescue. Results: CFTR knockout cell lines were generated by Cas9 with a single-guide RNA (sgRNA) targeting exon 1 of the CFTR genome, which produced indels that abolished CFTR protein expressions. Next, stable Delta F508-CFTR expression was achieved by genome integration of Delta F508-CFTR via the lentivirus infection system. Finally, we showed functional rescue of Delta F508-CFTR not only by growing the cells at a low temperature, but also incubating with VX-809, a Delta F508-CFTR corrector, in the established T84 cells expressing Delta F508-CFTR. Conclusions: This cell system provides an appropriate screening platform for rescue of Delta F508-CFTR, especially related to protein folding, escaped from endoplasmic-reticulum-associated protein degradation, and membrane transport.