Induction of multifunctional T cells in the lungs of mice after challenge with the <i>M</i>. <i>tuberculosis</i> HN878 strain.

<p>Five and ten weeks post-infection, mice from each group (n = 5) were euthanized and their lung cells (2 × 10⁶ cells) were stimulated with PPD (2 μg/ml) for 12 h at 37°C in the presence of GolgiStop. The percentage of antigen-specific CD4⁺CD62L^- and CD8⁺CD62L^- T cells producing IFN-γ, TNF-α, and/or IL-2 in the cells isolated from the lungs of each group of mice were analyzed by multicolor flow cytometry by gating for CD4⁺ and CD8⁺ lymphocytes (A). Pie charts (B) show the mean frequencies of cells coexpressing IFN-γ, TNF-α, and/or IL-2. The data are presented as the mean ± SD from five mice in each group. An unpaired <i>t</i>-test was used to determine the significance of differences. A value of <i>p</i><0.05 was considered to be statistically significant. ^#<i>p</i><0.05, ^##<i>p</i><0.01, and ^###<i>p</i><0.001 compared to G2. * <i>p</i><0.05, ** <i>p</i><0.01, and *** <i>p</i><0.001 compared to G3.