Figure 1

H7N9 NS1 protein impairs host innate immune response. A 293T cells transfected with plasmids expressing H7N9 NS1 or empty vector (EV) were infected with WSN virus (MOI = 1) for 12 h, followed by quantitative real-time PCR to detect the mRNA levels of the indicated genes. In each experiment, the value observed in mock-infected cells was normalized to 1. Plotted are the average levels from three independent experiments. The error bars represent the s.e.m. **P < 0.01. B–D 293T cells transfected with plasmids expressing H7N9 NS1 or EV were infected with WSN virus as described in (A). Then the cells were harvested and cell extracts were prepared for Western blotting using indicated antibodies. Shown are representative data of three independent experiments with similar results. E 293T cells transfected with plasmids expressing H7N9 NS1 or EV were treated as described in (A), and viral titers in the supernatants of the cells were examined by plaque assay.