Andrew Rose, Oriel College, 2001.
Naked plasmid DNA and DNA/liposome complexes are currently being considered as gene therapy treatments for cystic fibrosis (CF) pulmonary disease. Current viral and non-viral methods of gene delivery to the lung and trachea result only in the transient correction of the CF ion transport defect, and thus disease treatment will require repeated administrations of vector. Under specific circumstances, repeated administrations of DNA/liposomes can result in decreased efficacy in comparison with single administrations, due to immune responses directed against the transgene. The aim of this study was to assess the effect of repeated administrations of naked DNA and DNA/liposome formulations on gene expression. The mouse lung and trachea was used as a model system, with plasmid vectors encoding reporter proteins (bacterial chloramphenicol acetyltransferase (CAT) and firefly luciferase (Lux)) or the human and murine cystic fibrosis transmembrane conductance regulator (CFTR). After delivery or DNA formulations to the lung and trachea, vector-specific mRNA was quantitated using an Applied Biosystems ABI PRISM 7700 sequence detector (TaqMan). Results showed that vector-specific CFTR mRNA expression was not reduced upon repeated administration, and support the development of therapeutic gene therapy strategies for CF pulmonary disease.