Fig 2. Western blot analysis for shRNAs in Vero cells with influenza A/WSN/33 virus infection.

The expression levels of targeted PA, PB2, and untargeted matrix (M1) protein were analyzed by Western blot analysis. We tested treatment with (a) 1 μg, (b) 2.5 μg, (c) 5 μg, (d) 8 μg, (e) 10 μg, and (f) 15 μg of PAsh1, PAsh2, and PB2sh2 shRNA plasmids. The protein expression of the three proteins decreased in a dose-dependent pattern and reached a maximal inhibitory effect at 10 μg.