hTR knockdown induces Bim-mediated apoptosis. (A) Telomerase activity in CD4 T cells in culture with different lentiviral vectors. Representative example of 10 different experiments using cells from 8 different donors; each experiment was performed in triplicate. Error bars show standard deviation of biological triplicates. (B) hTERT mRNA and hTR RNA levels in CD4 T cells. Error bars show standard deviation of the mean of 2 experiments. (C) Live cell counts measured by trypan blue exclusion. Representative example from 10 different experiments using cells from 8 different donors. Error bars show standard deviation of biological triplicates. (D) Stages in cell cycle measured by DyeCycle Green. Error bars show standard deviation of biological triplicates. (E) Caspase-8, -9, -3/7 activity, measured by luminescence. Error bars represent standard deviation of biological triplicates. One-way ANOVA was performed for each caspase. *P < .05. (F) Western blot measuring Bim, Puma, Bad, Bid, and p53 in shScramble, shTERT, shTR1, and shTR2 cells. (G) Cell survival measured by trypan blue exclusion with Bim knockdown followed by hTR knockdown, compared with empty vector knockdown followed by hTR knockdown. Error bars represent standard deviation of biological duplicates. EV, empty vector; shScr, shScramble.