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). Deliv ery of the CFTR gene to the airways offers a potential treatment for CF but requires improvement in efficiency to obtain clinical benefit. We have dev eloped a murine tracheal culture system that maintains tissue integrity as judged by normal histological appearance, high transepithelial resistance a nd electrophysiological responses similar to fresh tissue. This ex vivo sys tem 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 paramet ers affecting liposome-mediated gene delivery to the upper airway such as p lasmid dose. We have also found that a contact time of 1 min for the transf ection mixture is sufficient to achieve significant DNA binding and maximal reporter gene expression.