FIG. 5.

Stimulation of naïve CD4 T cells by lung dendritic cells infected with M. tuberculosis (M. tb.). Lung dendritic cells were infected overnight with M. tuberculosis at a ratio of 0, 1, 2, 5, or 10 CFU per cell and were overlaid with purified naïve CD4⁺ T cells. After 72 h of culture, supernatants were assayed by ELISA for murine IFN-γ and IL-12 total and IL-12 p70 bioactive form. IL-12 p70 was not detected by ELISA (, lung dendritic cells plus M. tuberculosis; and , lung dendritic cells plus M. tuberculosis overlaid with naïve CD4⁺ T cells). Results are from one representative experiment of three experiments.