Active caspase-3 assay for apoptosis in human adult immature DCs. Comparing with mock-infected adult immature DCs, no significant induction of active caspase-3–positive cells was observed at 6 hours, 12 hours, and 24 hours after infection (n = 4; P > .05). Data are shown as mean ± SEM of DCs from 4 independent donors. The percentage of active caspase-3–positive Jurkat cells in the positive control at 3 hours and 24 hours after addition of anti-Fas antibodies were 15% and 35%, respectively.