Fig. 2.

Induction of cytokine mRNA and protein in primary human macrophages does not enhanced by the PB2-D253N mutation of H9N2/Y280 virus. Primary human macrophages were infected at an MOI of 2 with the H9N2/Y280 virus or the PB2 variant. mRNA was collected at 0, 3, and 6 h postinfection. The gene copy numbers of (A) IFN-β, (B) TNF-α, and (C) IP-10 were analyzed by real-time PCR. The data are shown based on the results of a representative donor. Mock: uninfected cells. GAPDH was used as internal control. The supernatants were collected at 6 and 24 h postinfection. The protein levels of (D) TNF-α (6 h), (E) TNF-α (24 h), (F) IP-10 (6 h), and (G) IP-10 (24 h) were analyzed using an ELISA-based cytomix detection kit. Results are expressed as means ± standard deviations of three independent experiments. Mock: uninfected cells.