Figure 4

Inhibition of caveolar uptake increased HIV-1 infection. LCs were incubated for 2 hours with HIV-1NL4.3/Vpr-BlaM and viral fusion to the host membrane was measured by BlaM assay as described by [31] (A). MUTZ-LCs were incubated with HIV-1 NL4.3-BaL (MOI = 0.2, B) or with VSV-G pseudotyped HIV-1 (MOI = 0.2, C) in the absence or presence of filipin (1 μg/ml) and integration of HIV-1 DNA was analyzed by Alu-PCR. MUTZ-LCs were treated with small interfering RNA (siRNA) of caveolin-1-specific (Cav-1 siRNA) or with non-target control (Control siRNA). Cells were incubated for 18 hours with HIV-1 NL4.3-BaL (D) or HIV-1 NL4.3 (E). Integration of HIV-1 DNA was determined by Alu-PCR. At day 8 post-infection, HIV-1 infection was measured by intracellular p24 staining. Percentage of CD1a⁺p24⁺ cells are depicted here as % of HIV-1 infection. MUTZ-LCs were incubated with HIV-1 for 4 h in the absence or presence of the clathrin inhibitor monodansylcadaverine (MDC, 10 or 50 μM). Cells were treated with Trypsin-EDTA (0.05%) or left untreated as control. HIV-1 uptake was quantified by permeabilizing cells and measuring subsequent HIV-1-p24 content by flow cytometry (F). MUTZ-LCs were incubated for 18 hours with HIV-1 NL4.3-BaL in the absence or presence of monodansylcadaverine (MDC, 10 or 50 μM) and integration of HIV-1 DNA was analyzed by Alu-PCR (G). n = 3 paired students t-test; *p < 0.05; SD and mean are depicted (A, B, F, G). One representative experiment out of two is shown (C). n = 4 paired students t-test; *p < 0.05; SD and mean are depicted (D, E).