Apoptotic activity of LaDR5 in Jurkat cells by DISC formation and downstream caspase-8 activation. A: Giemsa’s staining observation. Jurkat cells were incubated with 10 μg/ml of LaDR5 and sprayed on glass slides. After being fixed, slides were stained with Giemsa’s staining solution for 15 minutes. The samples were examined in light microscopy at 40× magnification, which showed that Jurkat cells displayed typical features of apoptosis. B: LaDR5 induces DR5 clustering and DISC activation only in Jurkat cells. Daudi and Jurkat Cells were treated with 10 μg/ml LaDR5, and cell lysates were analyzed first directly by western blot and then immunoprecipitation for FADD/caspase-8 activation, which indicating that only LaDR5 could induce DR5 crosslinking, DISC formation and downstream caspase-8 signals in Jurkat cells. Normal cell, isotype IgG treated cells and DR5-binding Antibody 366EC (with no apoptosis-inducing activity) were set as negative controls.