Figure 4.

Efficient and airway-specific transgene expression via aerosolized doxycycline. H2BGFP expression (green) was determined in cross sections of tracheas from R26-H2BGFP mice that were exposed to doxycycline, either by drinking water (A) or by inhalation in the aerosolized form (B). Airway-specific and efficient expression of H2BGFP was observed in mice that received doxycycline in aerosolized form, compared with doxycycline received through drinking water. Flow cytometric analysis of GFP expression was performed in papain-dissociated epithelial cell adhesion molecule airway epithelial cells from R26-H2BGFP mice that received doxycycline either by drinking water (C) or inhalation (D). Collagenase/trypsin/EDTA-dissociated nonepithelial tracheal cells from R26-H2BGFP mice that received doxycycline via either drinking water (E) or inhalation (F) were analyzed by flow cytometry. Scale bars, 20 μm.