Figure 4.

Immunostaining for AMCase expression. A) Immunostaining for AMCase expression revealed minimal reactivity in the lungs of controls. B) Intense signal was demonstrated in airway epithelium (black arrow), particularly after 2 months of infection. C) Similar expression patterns in the airway epithelium (black arrow) and alveolar macrophages (white arrow) were also seen at 2 weeks. Original magnification 200× for all photomicrographs. Inset shows high magnification (original magnification 1000×) of immunoreactive cells that appear to be alveolar macrophages.