FIG. 2.

Regulation of M. tuberculosis whiB3 and acr in wild-type C57BL/6 and immunodeficient mice. RNA was isolated from M. tuberculosis in lungs of infected mice at the indicated time points. Quantitative RT-PCR was performed for whiB3 (a) and acr (b) and normalized to 16S rRNA in the same sample. Fold induction, defined as a ratio of normalized expression in mouse lung to mid-log broth culture, was calculated. The inset shows CFU equivalents calculated based on the 16S rRNA copy numbers. TNF-α^−/− mice did not survive beyond week 4. Bars show mean induction plus standard deviations of quadruplicates. Wild-type and IFN-γR^−/− data are representative of three independent experiments. The difference in whiB3 induction at 2 weeks was not reproducible. *, P < 0.05 compared to same time point in the wild-type; **, P < 0.0001 compared to same time point in the wild-type. wk, week; WT, wild type; eq., equivalent.