Fig 1.

The VEEV variant with a mutated capsid gene persistently replicates in IFN-α/βR^−/− MEFs but is cleared from IFN-competent cells. (A) Schematic representation of the VEEV genomes encoding wt and mutated capsid proteins. The mutated amino acids are presented in red. The NLS and the carboxy terminus of the supra-NES are indicated by boxes (3). Underlined amino acids indicate connecting peptide. nsP1 to -4 indicate nonstructural genes. C, E2, and E1 indicate structural genes. SG indicates the subgenomic RNA promoter. (B) NIH 3T3 cells and IFN-α/βR^−/− MEFs were infected with the indicated viruses at an MOI of 20 PFU/cell. Media were replaced at the indicated time points, and titers of the released viruses were measured by plaque assay on BHK-21 cells. (C) Concentrations of IFN-β were measured in the samples (see panel B) harvested from the infected NIH 3T3 cells.