Inhibition of caveolae/lipid raft-mediated endocytosis fails to reduce the entry and trafficking of KSHV particles to the perinuclear region.

(A, D and G) HUVEC were treated with chemicals to deplete membrane cholesterol and inhibit caveolae/lipid raft-mediated endocytosis at the indicated doses for 1 h. Cells were inoculated with KSHV in the presence of inhibitors, fixed at 8 hpi, and stained for Orf65+ viral particles (red) and nuclei (blue). (B, E and H) The total number of nuclei bearing at least one Orf65+ viral particle was determined. (C, F and I) The total number of Orf65+ viral particles docked at each nucleus was determined. (J) Inhibition of caveolae/lipid raft-mediated endocytosis reduces the internalization of AlexaFluor 488-CTB. HUVEC were pretreated with inhibitors of caveolae/lipid raft-mediated endocytosis for 1 h prior to exposure to AlexaFluor 488-CTB. The reduced internalization and increased membrane accumulation of CTB (green) compared to untreated control cells demonstrates the effective inhibition of caveolae/lipid raft-mediated endocytosis.