FIG. 1.
The course of M. tuberculosis infection in mice lacking components of the IFN-γ-mediated macrophage activation pathway. Mice were infected aerogenically with 100 virulent bacteria, and the numbers of bacteria detected in the lungs of C57BL/6 (solid circles), IRF-1-KO (empty circles) and NOS2-KO mice (triangles) were determined. Data represent the mean log10 number of viable bacteria per organ (n = 4) ± the standard error. ∗, means which were statistically different from the C57BL/6 values as determined by Student's t test (P ≤ 0.05). †, mice were euthanized due to morbidity. The graph reflects one experiment representative of two similar experiments.