Fig. 4
Effects of the PB1-S216G mutation on influenza A/H1N1 virus replication capability and adaptability in cells treated with ribavirin. The replication capability of the PR8 and PR8PB1(S216G) viruses was measured in the presence of ribavirin. HEK293 cells were transfected with RT2AF-transfected for 4 h, and the cells were infected with PR8, PR8PB1(S216G), or PR8PB1(I563R) virus in the presence of the indicated concentrations of ribavirin. At 48 h post-infection, cell lysates were prepared, and the Rluc and Flu luciferase activities were measured. The relative replication capability was determined by Rluc/Rluc (without ribavirin) ratio. Error bars, standard error of the mean of three independent experiments; NS, not significant (p > 0.05) by Student’s two-tailed unpaired t-test; ****p < 0.0001; and **p = 0.0024