FIG 4.

Inhibition of caveolin-mediated endocytosis does not block SGIV entry. (A) MβCD and nystatin do not inhibit SGIV uptake. GS cells were pretreated with various concentrations of MβCD or nystatin, followed by infection with Cy5-labeled SGIV (red) for 120 min. After the infected cells were labeled with DiO (green), more than 100 cells were examined by CLSM. (B and C) MβCD (B) and nystatin (C) have no influence on SGIV infectivity or viral protein synthesis. GS cells were pretreated with different concentrations of MβCD or nystatin for 120 min and then incubated with SGIV for 120 min. After being washed with citrate buffer to remove noninternalized viruses, the cells were harvested at 48 hpi. Infectivity was examined by IFA, and the level of infection of the treated cells was normalized to that of the untreated cells. The results are from triplicate experiments, and error bars indicate the means ± SD. The levels of SGIV viral protein and β-actin were analyzed by Western blotting. Scale bars are 10 μm. *, P < 0.05.