Figure 2.

In isolated thymocytes, CPP32 is activated during apoptosis induced by crosslinking of CD3 or exposure to dexamethasone. Time course of CPP32 activation (A) and cleavage of PARP (B) in thymocytes cultured at 4°C, or at 37°C alone, with immobilized anti-CD3 mAb or with dexamethasone for the indicated time. Cell lysates were electrophoresed, and substrate cleavage was visualized by immunoblotting as described in Materials and Methods. The results presented in this figure are representative of two independent experiments.