Fig. 5

Septal macrophage staining and quantification. Immunohistochemistry with F4/80 antibody was done on lung sections from exposed and unexposed WT and TLR9-deficient (TLR9-) mice. Blinded counts of macrophages were done on five 400X magnification fields on 2 separate lung sections from each animal and averages of these counts used. Septal macrophages were increased in 1 day control TLR9^−/− mice compared to WT (** = p ≤ 0.01) and TLR9^−/− exposed mice (* = p ≤ 0.05). After 20 days exposure TLR9- mice had significantly more septal macrophages than exposed WT animals at 20 days (p ≤ 0.05)