Fig. 3.

Replication kinetics of avian influenza A H7N9 virus in human astrocytes, neuronal cells, and primary monocyte-derived macrophages. a Differentiated human astrocytes (T98G), neuronal cells (SH-SY5Y) cells, and human primary monocyte-derived macrophages (Mϕ) were infected by avian H7N9 virus and pdmH1N1 viruses at MOI of 2. Mock-infected cells served as controls. Total RNA was extracted from the infected cells at the indicated times. Influenza A viral matrix mRNA expression was measured by real-time PCR and normalized to that of β-actin. b DifferentiatedT98G and SH-SY5Y cells were infected with influenza A viruses at MOI of 2 for 24 h. Copy number of influenza M gene vRNA was measured by real-time PCR and normalized per microgram of total RNA. c Kinetics of influenza progeny virus production. Differentiated T98G, SH-SY5Y cells or human Mϕ were infected with different influenza A viruses at MOI of 0.001. The culture supernatants were collected at the indicated times, and the viral titers were determined by TCID₅₀ assay. Viral titers of different strains at different time points were compared to that at 3 h post-infection. Data are mean ± standard deviation of representative results from at least three independent experiments. *p ≤ 0.05, **p ≤ 0.005