FIG 2.

Sense and antisense transcription are unaffected by the transcriptional output from the opposite direction. Luciferase activities corresponding to sense and antisense transcription are represented with solid and hatched bars, respectively. (A, C, and E) The graphs show a comparison of the relative luciferase activities of sense transcription between the construct containing both LTRs (LTR/LTR), those in which the 5′ or 3′ LTR was replaced with the CMV promoter (CMV/LTR or LTR/CMV, respectively), and those with a deletion of the 5′ (−/LTR) or 3′ LTR (LTR/−) from HEK293T, CEM, and Jurkat cells as indicated. (B, D, and F) The graphs show a comparison of the relative luciferase activities of antisense transcription between the construct containing both LTRs (LTR/LTR), those in which the 5′ or 3′ LTR was replaced with the CMV promoter (CMV/LTR or LTR/CMV, respectively), and those with a deletion of the 5′ (−/LTR) or 3′ LTR (LTR/−) from HEK293T, CEM, and Jurkat cells as indicated. All graphs display mean luciferase activities relative to the β-galactosidase internal control with values normalized to luciferase activities from the reporter construct with a deletion of both LTRs (−/−; set to 1). Data from HEK293T, CEM, and Jurkat cells are from six, four, and three independent experiments, respectively. Error bars denote standard deviations. Significant results as determined by Student's t test are indicated (*, P < 0.01; **, P < 0.001).