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

The HPAI H5N1 virus strain, A/duck/Hubei/hangmei01/2006 (H5N1; designated H5N1/HM) was isolated from a duck. Influenza A virus (strain A/Puerto Rico/8/1934 H1N1), A/ PR/8/34, was grown in our laboratories and stored until use. rNS1-SD30 was constructed as previously described (24) . Influenza virus stocks of H5N1/HM, PR8, and rNS1-SD30 strains were amplified using 10-day-old embryonic chicken eggs and then titrated by determining log10 TCID50/ml values in MDCK cells. All cell experiments with H5N1 virus were performed in an Animal Biosafety Level 3 laboratory (BSL-3). This study was carried out in accordance with the recommendations of BSL-3, Huazhong Agricultural University (HZAU). The protocol was approved by the BSL-3 of HZAU. The recombinant vesicular stomatitis virus (VSV) encoding green fluorescence protein (VSV-GFP) was a gift from the Harbin Veterinary Research Institute (Harbin, China). Sendai virus (Sev) was grown in 10-day-old embryonic chicken eggs and titrated using a hemagglutination assay as previously described (25) .