FIG. 2.

Lung histopathology in C57BL/6, IL-4^−/−, and IFN-γ^−/− mice. C57BL/6, IL-4^−/−, and IFN-γ^−/− mice were immunized and injected i.v. with 200,000 live Mf as described above. One week later, animals were sacrificed, lungs were fixed in formalin, and 5-μm sections were stained with hematoxylin and eosin. Shown are representative lung sections from similar sites in the left lobe for naïve mice (A), immunized, Mf-challenged C57BL/6 mice (B), IL-4^−/− mice (C), and IFN-γ^−/− mice (D). Peribronchial and perivascular cell infiltrates can be detected in panels B and D. In panel D, normal lung architecture is also lost. Sections are representative of five mice per group from two repeat experiments.