FIG. 2.

Tax cooperates with Tat to enhance HIV-1 LTR activity. (A) The transient cotransfection was performed with LTR-SEAP (0.4 μg), Flag-Tax (1 μg), Tat (0.05 μg), and Vpr (0.1 μg) either alone or in combination as indicated in the figure. The DNA amount used for transfection was standardized to a total of 2 μg with phEFneo vector. The data are representative of two independent experiments. (B) The dose-response activation to the LTR by costimulation of Jurkat T cells with Tax and Tat was measured by cotransfection of Tat (0.1 μg), LTR-SEAP (0.4 μg), and various amounts of Tax plasmid as indicated in the figure.