Fig. 3.

Autophagy induced by H9N2 influenza virus is involved in the presence of oxidative stress. A549 cells were pre-treated with rapamycin, LY294002, 3-MA, control siRNA or Atg5 siRNA, followed by infection with H9N2 influenza virus. (a) SOD1 activity, (b) ROS generation and (c) MDA contents were measured in the cells. A549 cells were pretreated with 3-MA, followed by infection with H9N2 influenza virus at an MOI of 0.2, 1 or 5. (d) SOD1 activity, (e) ROS generation and (f) MDA contents were measured in the cells. The data are presented as means ± SD (n = 5). **P < 0.01 relative to control, ^##P < 0.01 relative to H9N2