FIG 3.
PS-specific mutations and IRES-mediated capsid expression differentially affect infectious titers and structural protein expression. Totals of 5 × 105 NIH 3T3, Vero, and BHK-21 cells in six-well Costar plates were infected with the indicated viruses at an MOI of 20 PFU/cell. At 22 h postinfection, both cells and media were harvested. (A) Accumulation of VEEV structural proteins in the cells was evaluated by Western blotting with VEEV-specific Abs. Quantitative data were generated on a LI-COR imager. (B) Viral particles were pelleted from 0.8 ml of medium by ultracentrifugation (see Materials and Methods for details) and analyzed by Western blotting with VEEV-specific Abs. Quantitative data were generated on a LI-COR imager. Signals in the capsid and glycoprotein bands were determined in three independent experiments. The means and standard deviations were calculated. (C) Titers of the viruses in the same harvested media were determined by plaque assay on BHK-21 cells.