FIG. 7.

Uninfected (A, D, and G), young (B, E, and H), and mature (C, F, and I) mice at week 4 postinfection. (A, B, and C) Lung sections were stained with PAS. Magnification, ×200. Hyperproduction of mucus (stained dark pink) is readily apparent in airways from C. neoformans-infected mice but not uninfected mice. Also note the hypertrophy of epithelial cells lining the airways in infected animals. (D to I) Lung sections stained with trichrome, which stains collagen blue. Magnification: D, E, and F, ×200; G, H, and I, ×400. Both groups (young and mature) of infected mice had much thicker collagen lining around the airways compared to uninfected mice. In addition, infected animals also had collagen in the lung matrix, as seen at higher magnification. “Uninfected” denotes uninfected young mice. There was no difference in trichrome and PAS staining of young uninfected and mature uninfected mice (data not shown).