Attenuation of the 2’-O-methylation mutant depends on IFN competence of the infected cell.

<p>(<b>A</b>) Comparison of the measured time courses of susceptible, infected and protected cells (data from <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005345#ppat.1005345.g006" target="_blank">Fig 6B</a> and <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005345#ppat.1005345.g008" target="_blank">Fig 8B</a> for DENV-faR and the DENV-faR E217A mutant, respectively), showing large persisting reservoirs of susceptible cells. (<b>B</b>) Release of infectious DENV from A549 cells (IFN-competent) and BHK-21 cells (IFN-incompetent). Cells were transfected with DENV RNA genomes and harvested 48 and 72 h later. Titers of infectious virus were determined by limiting-dilution assay. Arrows and numbers refer to fold mean difference of extracellular virus titers. A representative result of three independent experiments is shown. (<b>C</b>) Ratio of wildtype- to E217A mutant-infected cells with and without IFN response. A549 cells (IFN-competent) and BHK-21 cells (IFN-incompetent) were infected with DENV-faR wildtype or the DENV-faR E217A mutant at low MOI. The number of faR-positive cells was analyzed by flow cytometry at 72 h p.i. and the ratio between DENV wildtype and E217A mutant-infected cells was calculated.