FIG 4.

Retroviral particles bearing HERV-K ENV require endosomal acidification and dynamin. (A) Schematic of the experimental procedure. CRFK cells were treated with inhibitors and infected with pseudotyped lentiviruses bearing the indicated glycoproteins. The cells were washed 6 h postinfection, and medium with ammonium chloride was added to prevent entry of any surface-bound particles. Cells were collected 3 days postinfection, and GFP expression was analyzed by flow cytometry. (B) Effects of endocytic inhibitors on infection by pseudotyped lentiviruses. The percentage of GFP-positive infected cells was normalized to vehicle control (DMSO)-treated cells. Approximately 5% of the cells were infected in the DMSO-treated cells for each virus. The error bars represent standard errors of the mean.