Figure 3: Polarization and apoptosis of Th1/Th2 cells in SWA/SEA immunized mice. Mice were injected subcutaneously in the back with 100  𝜇 l of a solution containing 50  𝜇 g of SEA, 100  𝜇 g of SWA, or PBS alone emulsified in incomplete Freund’s adjuvant (IFA). Ten days after immunization, six mice from each group were sacrificed. Splenocytes from SWA or SEA immunized mice were prepared, respectively, and then C D 4 + T cells were purified from splenocytes with MACS. The cells were stained with anticaspase-3, anti-CD4-FITC, anti-IFN- 𝛾 -PE or anti-IL-4-PE mAb prior to FACS analysis as described in Materials and Methods. 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.