FIG. 3.

Lung pathology after DNA vaccination and aerosol challenge. (A) Plasmid vector control. Severe extensive granulomatous interstitial pneumonia with centralized area of necrosis (arrow) is seen. Magnification, ×160. (B) Guinea pig vaccinated with hsp60 plasmid DNA. Severe extensive granulomatous bronchointerstitial pneumonia with polymorphonuclear leukocytes, mucus, sloughed epithelium, and necrotic cellular debris filling the airway lumen is shown. Magnification, ×160. (C) High magnification of airway in panel B. Note transepithelial migration of polymorphonuclear cells and epithelial erosion (arrowhead) and epithelial hyperplasia (arrow). Magnification, ×310. Hematoxylin and eosin staining was used.