FIG. 4.

Impact of tetherin expression on vesicular stomatitis virus (VSV) replication. (A) Supernatants from VSV-infected neuronal cells were assayed for infectious virus by plaque assay. Control neuronal cells or tetherin-silenced cells were incubated with the medium (solid fill or slashed fill, respectively) or with IFN-β (empty bars or cross-hatched bar fill, respectively) for 24 h before infection at 3 multiplicity of infection (moi). Supernatants from triplicate cultures were collected at 4, 6, 8, 10, and 12 h postinfection (hpi) and serially diluted before adding to L929 cells. The bars represent mean plaque forming units detected. Error bars represent 3 SD; the experiment was replicated three times. (B) Expression of VSV G, N, P, and M proteins was determined by western blot analyses performed with cell lysates (8–9 hpi) of neuroblastoma cells (lanes 1 and 2) and tetherin-silenced cells (lanes 3 and 4) pretreated with the medium (lanes 1 and 3) or with IFN-β-treated (lanes 2 and 4) for 24 h. The bands were 55 kDa for VSV G protein, 45 kDa for VSV N and P proteins, and 25 kDa for VSV M protein. Mouse GAPDH was used as loading control. Data are representative of three replicate experiments, each with triplicate cultures at each condition.