FIG. 6.

RID protein is sufficient to inhibit TRAIL-induced apoptosis; 14.7K protects cells from TRAIL-induced apoptosis in stable transfectants. (A) A549 cells were mock infected or infected with 5 to 20 PFU of WT Ad (rec700), Ad/E3 (expressing all E3 proteins), Ad/RID/14.7K, Ad/RID, or Ad/14.7K per cell and then treated with TRAIL (plus CHX at 25 μg/ml) at 24.5 h p.i. as indicated. After 28 h, apoptosis was determined by release of LDH. The error bars indicate standard deviations. (B) A549 cells as well as two independent stably transfected A549 clonal cell lines expressing the E3-14.7K protein, named 4-6-8F (WT 14.7K expression) and 37-2-1-2B (14.7K with point mutation of D37A, not affecting function), were treated with TRAIL (1.0 ng/ml) plus CHX (25 μg/ml). After 25 h of treatment, the percentage of viable cells was determined by trypan blue exclusion.