Fig 8. Wild type, but not tissue culture-adapted, alphaviruses are resistant to IFIT1-mediated replication inhibition and induce IFN-β in IFIT1-expressing cells.

(A). Wt MEFs and IFIT1 KI/3 cells were infected with the indicated viruses at an MOI of 5 PFU/cell. Media were harvested at 24 h PI, and cells were stained with Crystal violet at 48 h PI. Virus titers were determined by plaque assay on BHK-21 cells. (B) Concentration of IFN-β was determined in the same harvested samples as described in the Materials and Methods. The experiments were performed two times and in triplicates. Statistical analyses were performed using unpaired T-test. *:p<0.05, **:p<0.01, ***:p<0.001. Means and SD of three experiments are presented