A murine tracheal culture system to investigate parameters affecting gene therapy for cystic fibrosis

Cystic fibrosis (CF) is a life-threatening condition caused by mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). Delivery of the CFTR gene to the airways offers a potential treatment for CF but requires improvement in efficiency to obtain clinical benefit. We have developed a murine tracheal culture system that maintains tissue integrity as judged by normal histological appearance, high transepithelial resistance and electrophysiological responses similar to fresh tissue. This ex vivo system allows precise control of gene delivery parameters to a structure that retains the in vivo cellular architecture. We have demonstrated correction of CFTR-dependent Cl- secretion following ex vivo delivery of the CFTR gene to tracheas from CF null mice. We have used this system to examine parameters affecting liposome-mediated gene delivery to the upper airway such as plasmid dose. We have also found that a contact time of 1 min for the transfection mixture is sufficient to achieve significant DNA binding and maximal reporter gene expression.