Figure 5. Comparison of the Tax inductibility of the HTLV-1 promoters in non episomal and episomal reporter vectors.

Jurkat T cells were transiently cotransfected with 600 ng of either pREP-LTRwt_sense-luc ((a) lanes 1 to 6), pREP∆-LTRwt_sense-luc ((a) lanes 7 to 12), pREP-LTRwt_antisense-luc ((b) lanes 1 to 6) or pREP∆-LTRwt_antisense-luc ((b) lanes 7 to 12) and increasing amounts of a HTLV-1 Tax expression vector pRSV-Tax (0, 25, 50, 100, 200 and 400 ng of plasmid DNA). To maintain the same amount of transfected DNA and to avoid squelching artifacts, the different amounts of pRSV-Tax cotransfected were complemented to 400 ng of DNA by using the corresponding empty plasmid. Each transfection included 10 ng of the internal control Renilla luciferase plasmid, pRL-TK. Luciferase activities (Firefly and Renilla) and protein concentrations were measured in cell lysates 48 h after transfection. The results are expressed as luciferase_firefly/luciferase_Renilla/[protein] and presented as histograms indicating the induction by Tax (in fold) with respect to the activity of each LTR reporter construct in the absence of Tax, which was arbitrarily assigned a value of 1. Means and standard errors of the means from triplicate samples are presented. An experiment representative of three independent experiments is shown. ns corresponds to a p value > 0.05, ***Corresponds to a p value < 0.001 in ANOVA test.