Fig. 4.
Levels of Th1 cytokines produced by splenocytes of different immunized mice. Nine weeks after immunization, splenocytes were obtained from each C57BL/6 mouse of all groups. Cells (2.5 × 106 cells/well) were seeded in 24-well microtiter plates and incubated with rRv0572c (10 μg/mL), PPD (10 μg/mL, positive control), or media alone (negative control) at 37 °C for 24 h to detect (C) IL-2, and for 72 h to detect (A) IFN-γ and (B) TNF-α. The cytokine concentrations in the culture supernatant were detected using commercial ELISA kits. The results are shown as the mean ± SD (pg/mL) in each group (n = 6). This experiment was repeated twice with comparable results. *P < 0.05, **P < 0.01.