Fig. 1. CD95 capping occurs by different mechanisms dependent on cell type. (A) Jurkat and (B) H9 cells were labeled with CD95 for 30 minutes on ice. After washing, the cells were incubated with a fluorescent secondary antibody on ice. The labeled cells were then stimulated by incubation at 37°C for the indicated time (0-10 minutes) to induce CD95 capping. In C,D, Jurkat and H9 cells were preincubated with cytD or zIETD for 1 hour to determine the requirement for actin or caspase-8 activation for CD95 capping. Fixed samples were then analyzed by confocal laser scanning microscopy. Maximum projections were generated from z-sections and representative fields from at least three separate experiments are shown.