The C-Terminal Effector Domain of Non-Structural Protein 1 of Influenza A Virus Blocks IFN-ß Production by Targeting TNF Receptor-Associated Factor 3

Qian, Wei; Wei, Xiaoqin; Guo, Kelei; Li, Yongtao; Lin, Xian; Zou, Zhong; Zhou, Hongbo; Jin, Meilin

To determine whether the replication of IAV is enhanced by the NS1/126-225 protein, A549 cells were transfected with NS1/126-225, or an empty vector, then infected with different titers of H5N1/HM or PR8 virus. Upon infection with H5N1/HM or PR8 virus, NS1/126-225 could facilitate transcription of NP of both viruses (Figure 8A) , resulting in an increase in NP and HA proteins observed in the NS1/126-225 group (Figure 8B ). This was confirmed by the titers of H5N1/HM or PR8 virus, which significantly increased by 40-and 31-fold, respectively, in NS1/126-225 overexpressing cells compared with control cells (Figure 8C) . These results demonstrate that NS1/126-225 enhances the capacity of IAV to replicate in cells.