Figure 2.
GrzB fails to initiate the release of mitochondrial proapoptotic factors. (A) Control L1309 B cells, Jurkat T cells, and L428 or L540 HL cells (all 106) were treated with adenovirus at an moi of 100 with or without 600 ng/mL grzB and incubated for 2 hours at 37°C. Smac and cytochrome c were detected in cytosolic extracts by respective specific antibodies. Reprobing for actin ensured equal loading of cytosolic extracts. (B) Isolated postnuclear fractions (cytoplasm and mitochondria) from Jurkat T cells and L540 and L428 HL cells were treated for 30 minutes at 30°C with grzB (200 ng) or 200 nM recombinant Bax. After centrifugation, supernatants were analyzed by Western blotting with monoclonal antibodies specific for cytochrome c, Smac, and actin.