title: Combination of specific single chain antibody variable fragment and siRNA has a synergistic inhibitory effect on the propagation of avian influenza virus H5N1 in chicken cells.
abstract: BACKGROUND
  The avian influenza virus (AIV) causes frequent disease with high morbidity and mortality. RNA interference (RNAi) has been shown to provide an effective antiviral defense in animals, and several studies have focused on harnessing small interfering RNAs (siRNAs) to inhibit viral infections. In addition, single chain variable fragments (scFvs) contain the complete antigen binding site, and specific scFvs can bind to and neutralize viruses.
  
  
  RESULTS
  Fourteen positive scFvs were selected by the yeast two-hybrid system. Using molecular docking technology, we selected the three highest affinity scFvs for further functional validation. Results of indirect ELISA and IFA showed that all three scFvs could bind to FJ13 strain and had neutralizing activity, decreasing the viral infectivity markedly. Chicken fibroblastic DF-1 cells were transfected with scFvs in combination with siRNA-NP604 (an siRNA of anti-AIV NP protein previously reported). Following infection with FJ13 virus, copy numbers of the virus were significantly reduced from 12 h to at least 60 h post-infection compared to that achieved in cells transfected with scFv or siRNA-NP604 separately.
  
  
  CONCLUSIONS
  A novel combination of antiviral siRNAs expressed in chicken cells and chicken antibody single-chain variable fragments (scFvs) secreted from the cells has a synergistic inhibitory effect on the avian influenza viral proliferation in vitro. Intracellular application of scFvs and anti-viral siRNA may provide a new approach to influenza prevention and treatment.
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. wangshuang35@163.com.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. pengzhang@moon.ibp.ac.cn.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. plane83@gmail.com.
authors.forename: Fei
authors.initials: F
authors.lastname: He
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. jiguiwang1@126.com.
authors.forename: Ji-Gui
authors.initials: JG
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. sunjiazeng331@163.com.
authors.forename: Jia-Zeng
authors.initials: JZ
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. lizhilicz@163.com.
authors.forename: Zhi-Li
authors.initials: ZL
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. yibao33@163.com.
authors.forename: Bao
authors.initials: B
authors.lastname: Yi
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. Xiji19890708@163.com.
authors.forename: Ji
authors.initials: J
authors.lastname: Xi
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. maoyaping195@163.com.
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. houqiang1130@sina.com.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. rongrongydl@163.com.
authors.forename: Dao-Li
authors.initials: DL
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. zidingzhang@cau.edu.cn.
authors.forename: Zi-Ding
authors.initials: ZD
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agrobiotechnology, Department of Biochemistry and Molecular Biology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China. weiquan8@cau.edu.cn.
authors.forename: Wei-Quan
authors.initials: WQ
authors.lastname: Liu
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism*; D002460:Cell Line; D002645:Chickens; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects* / Q000254:growth & development*; D034741:RNA, Small Interfering / Q000378:metabolism*; D057127:Single-Chain Antibodies / Q000378:metabolism*; D019562:Viral Load
chemical_list: D000998:Antiviral Agents; D034741:RNA, Small Interfering; D057127:Single-Chain Antibodies