Figure 4

S212P mutation of H7N9 NS1 results in a reduction in the viral replication. A 293T cells transfected with plasmids expressing H7N9 NS1-WT (WT), NS1-S212P (S212P) or EV were infected with WSN (MOI = 1) for 12 h, followed by Western blotting to detect viral NP expression. B NP levels in (A) were quantitated by densitometry, and normalized to β-actin levels. In each experiment, the NP level in NS1-WT transfected cells is 100. C 293T cells transfected with plasmids expressing H7N9 NS1-WT (WT), NS1-S212P (S212P) or EV were infected with PR8 delNS1 virus (MOI = 1) for 12 h, followed by Western blotting to detect viral NP expression. D NP levels in (C) were quantitated by densitometry, and normalized to β-actin levels. In each experiment, the NP level in NS1-WT transfected cells is 100. E, F 293T cells transfected with plasmids expressing H7N9 NS1-WT (WT), NS1-S212P (S212P) or EV were infected with WSN (E) or PR8 delNS1 virus (F) (MOI = 1) for 12 h, and viral titers in the supernatants of the cells were examined by plaque assay. ^**P < 0.01.