FIG 4.

CD4⁺ T cells producing protection-related cytokines in the lungs and spleens of M. tuberculosis Beijing/K-infected mice in response to MTBK_24820. At 4 and 9 weeks postinfection, cells from the lungs and spleens were stimulated with MTBK_24820 (5 μg/ml) for 24 h, and the percentage of IFN-γ-positive CD4⁺ T cells in the lungs (A) and spleens (B) and IL-17-positive CD4⁺ T cells in the lungs (C) and spleens (D) were determined. Data are presented as means ± SD from two independent experiments with five mice. Significant differences between multiple groups were analyzed by unpaired t tests (**, P < 0.01).