FIG. 2.

Time courses of caspase 3, 8, and 9 activities in IBDV-infected cells. CEF cells were mock infected or infected with GLSTC virus at an MOI of 10 PFU per cell, and cell lysates were prepared at the indicated times postinfection. The enzymatic activities of caspases 3, 8, and 9 were quantified as described in Materials and Methods. (A) Caspase 3-like activity at the indicated times after infection. (B) Caspase 8- and 9-like activities at the indicated times after infection. P values were calculated using an unpaired t test. By conventional criteria, the differences in caspase 3 activities (A) and caspase 8 and 9 activities (2) between control and GLSTC-infected CEF cells at different time points were evaluated, and the results are marked (* or **). (C) As a positive control for caspase 8 and 9 activation, 2 μg or 12 μg of the synthetic dsRNA poly(I · C) was transfected into CEF cells by using Lipofectin. At 3 hours posttransfection, cell lysates were prepared, and the enzymatic activities of caspases 8 and 9 were determined.