Figure 4: In vitro induction of polarization and apoptosis in C D 4 + T cells derived from normal mice with SWA and SEA. C D 4 + T cells were purified from normal mice by MACS and preactivated overnight with anti-CD3 (2  𝜇 g/mL) and anti-CD28 (1  𝜇 g/mL) antibodies. Then the cells were stimulated with specific antigens of SEA, SWA or PBS alone for 36 hours at 3 7 C in 5% C O 2 , followed by staining with rabbit antimouse caspase-3 antibody or rabbit IgG isotype control antibody plus anti-CD4-FITC, anti-IFN- 𝛾 -PE anti-IL-4-PE mAbs, or isotype control antibodies prior to FACS analysis. The percentage of apoptotic cells in the FACS data was derived from the number of cells that were C D 4 + and IFN- 𝛾 + or C D 4 + and IL- 4 + and gated on the caspase- 3 + population. Data are expressed as the mean ± SD of 18 mice from three independent experiments. 𝑃 < . 0 5 ; 𝑃 < . 0 1 . Upper panels: One representative experiment of flow cytometric analysis with the average percentage of Th or apoptotic cells shown in the FACS data. Lower panels: The statistical analysis of 18 mice from three independent experiments.