Fig. 3. Expression of PARP as well as cleavage of nuclear target proteins during apoptosis in human-derived cell lines are decreased by T. gondii. After infection of HL-60 and U937 cells at a parasite to host ratio of 30:1, infected and uninfected control cells were treated with 5 µg/ml actinomycin D or 40 ng/ml TNF- in combination with 2 µg/ml cycloheximide as indicated. Eight hours after infection, antigenic lysates were prepared and separated by SDS-PAGE under reducing conditions. Proteins were transferred to nitrocellulose membranes and PARP (A) and PKC (B) were detected by immunostaining using enhanced chemiluminescence detection.