Figure 8.

NS1/126-225 increases virus replication in IAV-infected A549 cells. (A) A549 cells were transfected with HA-NS1/126-225 or an empty vector and infected with HM or PR8 virus at the indicated MOIs (0.001, 0.01, and 0.1) at 24 h posttransfection. Total RNA was extracted to examine the mRNA levels of NP transcripts by qPCR at the indicated time points (12 and 24 h). β-actin was used as an internal control for normalization, and the relative expression is represented as fold induction relative to the expression level in control cells (set to 1). (B) Western blotting was performed to detect protein levels of NP and HA. (C) Culture supernatants from cells infected with HM or PR8 (0.1 MOI) were collected, and viral titers was measured by TCID₅₀. Results shown are representative of three independent experiments. The data are presented as the means ± SD derived from three repeat experiments. *P < 0.05 or **P < 0.01, ***P < 0.001 (Student’s t-test).