Transduction of well-differentiated airway epithelium by recombinant adeno-associated virus is limited by vector entry

The limitations of adeno-associated virus (AAV)-mediated vectors for lung-d irected gene transfer were investigated by using differentiated human respi ratory epithelium in air-liquid interface cultures. Transduction efficiency was high in undifferentiated cells and was enhanced in well-differentiated cells after basolateral application of the vector or after apical applicat ion following disruption of tight junctions or pretreatment of the cultures with glycosidases. These results indicate that transduction of airway epit helia by AAV vectors is limited by entry and reinforce the importance of a physical barrier on the airway surface.