Figure 3

Histologic appearance of liver (A and B) and spleen (C and D) sections stained for acid phosphatase activity 4 weeks after BCG infection. A, Strong acid phosphatase activity in the BCG-granuloma of wild-type mice corresponding to activated macrophages. Granulomas were well delimited, numerous, and had strong acid phosphatase staining. B, In nos2-deficient mice, the size of granulomas was much larger, and contained many macrophages, but acid phosphatase staining was less intense. C, Acid phosphatase activity in normal splenic granulomas, which are numerous and have high enzyme activity. D, One enlarged granuloma from a nos2-deficient mice that does not show acid phosphatase activity. These results are representative of four mice per group and two experiments.