In vivo transfection of murine lungs with a functioning prokaryotic gene using a liposome vehicle.

The authors report successful in vivo transfection of lungs of mice with a functioning prokaryotic gene encoding the intracellular enzyme, chloramphenicol acetyltransferase (CAT). Transfection was accomplished by injecting a plasmid containing the coding region for CAT driven by the SV40 early promoter (pSV2CAT) complexed to specially synthesized cationic liposomes. Intravenous or intratracheal injection of DNA-liposomes resulted in expression of the CAT gene in the lungs, persisting for at least a week, with little enzyme activity detectable in systemic organs. This method should permit either transient or stable in vivo transfection of the lungs with a gene encoding any protein of interest, providing a powerful experimental tool and potentially a novel and broadly applicable clinical therapeutic technique.