FIG. 2.

CD28 cosignal increases the Fas-mediated apoptotic pathway. Beads were coated with the anti-Fas (7C11) and the indicated antibody and then incubated with target Jurkat 77 cells at a 10:1 (beads/cell) ratio for 2 h before the cells were lysed. (A) DNA fragmentation was analyzed by agarose gel electrophoresis as described in Materials and Methods. (B) Activation of caspase 8 and caspase 3 was analyzed by immunoblotting. The results shown are representative of three independent experiments.