Enhanced in vivo airway gene transfer via transient modification of host barrier properties with a surface-active agent

Effective adenoviral gene therapy requires efficient viral vector entry int o epithelial cells. Injured airway epithelia display enhanced gene transfer , reflecting in part increased vector access to protected cell populations and/or protected basolateral membranes. We tested whether adenoviral gene t ransfer is enhanced by modification of the epithelial barrier in mouse nasa l airways with a nonionic detergent (polidocanol, PDOC). In C57BL/6 mice, 1 .6 x 10(9) PFU of Ad5CMV LacZ (AdLacZ) instilled into the right nostril pro duced negligible gene transfer to the nasal epithelium 2 days after dosing, but significant, dose-dependent increases in gene transfer were achieved b y pretreatment with PDOC. Permeation of the electron-dense tracer lanthanum into the intercellular junctions of PDOC (0.1%)-treated murine nasal epith elium, but not into intercellular junctions of vehicle controls, is consist ent with PDOC-mediated increases in tight junctional permeability. In CF(-/ -) mice, significant gene expression was not detectable after exposure to A d5CBCFTR alone (1.4 x 10(9) PFU in 20 mu l; AdCFTR), but PDOC pretreatment prior to AdCFTR instillation produced functional expression of CFTR (measur ed as Delta PD) 5 days after instillation. Because the development and test ing of lung gene therapy will principally occur in children and adults with airway disease, AdLacZ gene transfer with and without PDOC pretreatment wa s examined in infected nasal airways. Gene expression was significantly red uced in infected as compared with uninfected airways. We conclude that the use of adjuvant surface-active and/or membrane-perturbing agents, synthetic or naturally derived, may provide a novel approach to enhancing the effici ency of adenoviral gene transfer.