Fig 6.

Effect of exposure of HOS^low and HOS^high cells to HIV-1 R5 on LTR expression. (A) HOS^low and HOS^high cells were transfected with a luciferase gene driven by a minimal promoter containing three NF-κB boxes, and exposed or not (empty bars) to 100 ng/ml tumor necrosis factor α (filled bars), or to 100 ng of p24 of the Ada-M strain (hashed bars). (B) HOS^low and HOS^high cells were transfected with an HIV-1 LTR-driven luciferase gene and exposed or not (empty bars) to 100 ng of p24 of the Ada-M strain (hatched bars); as a positive control, cells were cotransfected with a tat-expressing plasmid (filled bars). Luciferase activity was measured, and the induction of gene expression was calculated.