Figure 2.

Granulocyte–macrophage colony-stimulating factor (GM-CSF) expression after intratracheal (i.t.) administration of different doses of adenoviruses encoding GM-CSF (AdGM-CSF). (a) Groups of healthy mice were treated with the indicated dose of AdGM-CSF (black bars) or the control adenoviruses Addl70-3 (white bars, undetectable levels), and euthanized after 1 and 7 days; the lungs were used to determine the expression of GM-CSF reverse transcription–polymerase chain reaction (RT–PCR), values are means ± standard deviation (s.d.) from two independent experiments with five mice per group; *P < 0·05. (b) GM-CSF protein expression was detected by immunohistochemistry; the mouse lung after 1 day of 1 × 10⁸ plaque-forming units (pfu) i.t. administration shows strong immunostaining in the airways epithelium in bronchioles (B) and negative immunostaining in alveolar walls (A). (c) In contrast, the mouse lung treated with the same dose of control adenovirus Addl70-3 does not show immunostaining (scale bar represents 60 μm) (207 × 386 mm; 300 × 300 DPI).