Skip to main content
. 2003 Dec;77(23):12865–12874. doi: 10.1128/JVI.77.23.12865-12874.2003

FIG. 6.

FIG. 6.

Binding of HIV-1 to DC is cholesterol dependent. DC were exposed to the endocytosis inhibitors and then incubated with FITC-labeled transferrin at 4°C. Cells were also stained with DAPI to help in the visualization of the cellular architecture. The images are the composite of a series of Z sections collected through the entire thickness of the cell monolayer and projected onto a two-dimensional plane. (A) At 4°C, transferrin-FITC can bind to its receptor but is not internalized, as evident from the staining observed predominantly at the plasma membrane. (B) Cells were shifted to 37°C for a period of 15 min and then monitored again for transferrin localization. Note the prominent intracellular green fluorescence indicative of uptake of transferrin-FITC. (C) Treatment with 500 μM amantadine prior to incubation with transferrin-FITC for 1 h at 37°C resulted in transferrin-FITC staining at the plasma membrane (indicated by white arrowheads) and completely abolished the intracellular staining, while treatment with 5 mM MβCD (D) had no effect on the intracellular accumulation of transferrin. (E) DC (4 × 104 cells) treated with the endocytosis inhibitors were exposed to Lai virus particles (30 ng of p24gag) for 2 h at 37°C. The mean level of virus (Lai) binding in the presence of endocytosis inhibitors was normalized to the level of virus binding in the absence of inhibitors (set at 100%). This experiment was performed at least five independent times with DC derived from five independent donors, and each experiment was performed in triplicate. The results shown are the averages of the mean percent binding (± standard deviations) observed for all the experiments. (F) DC (4 × 104 cells) were treated with amantadine (500 μM) and then exposed to Lai virus particles (30 ng of p24gag) for 2 h either at 4 or 37°C. (G) DC (4 × 104 cells) were treated with MβCD (5 mM) and then exposed to Lai virus particles (30 ng of p24gag) for 2 h either at 4 or 37°C. The percent virus (p24gag) binding values shown in panels F and G represent the means ± standard deviations of triplicate cultures. The results from one representative experiment out of three with DC derived from three independent donors are shown in panels F and G.