Figure 3.

The protection in the lung and spleen by vaccination following M. tuberculosis H37Rv infection.

Mice were immunized with PBS, Ag85B and TAT-Ag85B three times 2 weeks apart. Three months later, the immunized mice were challenged intravenously with 1 × 105 CFU M. tuberculosis H37Rv bacilli. At week 24, the bacterial loads (CFU ± SEM) were determined in the lung A or spleen B. Furthermore, M. tuberculosis in lung slice was detected by acid-fast staining as indicated by black arrowheads, 20 fields per slice were examined C. The differences of the bacterial growth between two groups of immunized mice were analysed by non-parametric Mann–Whitney test. Data, means ± SD (*p < 0.05).