Figure 4. Effect of SSRP1 partial knockdown on HIV-1 infection.

(a and b) SupT1 cells were transduced at different MOIs with a lentiviral vector expressing a Scrambled or SSRP1-specific shRNA and three days later were infected with single-round HIV-1 expressing luciferase. Three days post-infection luciferase and ATP levels were measured. Luciferase readings in control cells infected with Hluc in (a) and (b) were around 5×10³ relative light untis (RLU)/ml and background readings were approximately 0.02 RLU/ml. Luciferase was normalized to ATP content in the same samples. Standard deviations in (a) represent the variability in luciferase readings of single experiments and in (b) the variability of three independent experiments at MOI 0.1. (c) The levels of SSRP1 in one of the experiments represented in (b) were determined by immunoblot analysis. α-tubulin was measured as a loading control. The level of knockdown achieved is representative of the other two infection experiments. The vertical line separating the lanes indicates that the samples were in the same electrophoresis gel and immunoblot membrane but not in adjacent positions. (d) SupT1 cells were transduced with either the scrambled or SSRP1-specific shRNA expressing lentiviral virus and three days later were infected with HIV-1_NL4-3. After twenty-four hours, infected cells were extensively washed to remove input HIV-1_NL4-3 virus and 96 hours post-infection the supernatant was harvested and HIV-1 p24 quantified by ELISA. Standard deviations represent data from three different experiments.