Fig. 10.

Effects of iron and iron chelators on HIV-1 LTR transactivation in U87MG cells stably transduced with HIV-1 Tat-GFP. To determine effects of iron and iron chelators on HIV-1 transactivation induced by intracellularly produced HIV-1 Tat, we first generated a stable HIV-1 Tat-GFP cell line. U87MG-LTR cells were transduced with a Tat-GFP lentivirus plasmid at an MOI of 1.0 followed by puromycin selection pressure (5.0 μg/ml). A Using confocal microscopy, stably transduced cells exhibited robust staining for HIV-1 Tat that co-distributed in DAPI-positive nuclei. B Western blot analysis of HIV-1 Tat showed high levels of Tat-GFP in the stably transduced cells. C Levels of HIV-1 LTR transactivation were significantly (p < 0.001) higher in stably transduced Tat-GFP cells than in control-GFP U87MG-LTR cells (n = 3, ***p < 0.001). D Intracellular Tat expression-mediated HIV-1 LTR transactivation was not affected significantly when stably transduced cells were incubated for 24 h with 20 μM FeCl₂, FeCl₃, NH₄–Fe–citrate or iron dextran. E Intracellular Tat expression-mediated HIV-1 LTR transactivation was significantly (p < 0.001) increased when stably transduced cells were incubated for 24 h with 25 μM of the iron chelators deferoxamine (DFO), 2–2 bipyridyl (2–2-BP), and deferiprone (DPO). (n = 3, ***p < 0.001)