Single-chain intracellular antibodies inhibit influenza virus replication by disrupting interaction of proteins involved in viral replication and transcription.
Influenza A virus is responsible for influenza epidemics in avian and human populations and poses a great threat to human health. Many researches have been focused on the prevention and treatment of influenza A virus infection. The nucleoprotein (NP) of the virus is an important protein due to its ability to interact with a variety of viral and cellular factors and its role in the viral RNA synthesis. In this study, we have used the influenza A virus nucleoprotein as target for anti-viral therapy through a new approach. By screening a human single-chain intracellular antibody (intrabody) cDNA library using nucleoprotein as bait in a yeast antigen-antibody two-hybrid system, we have identified several intrabodies that specifically interact with the viral nucleoprotein. Interaction between nucleoprotein and anti-nucleoprotein intrabodies was further confirmed by mammalian two-hybrid analysis. Results showed that anti-nucleoprotein intrabodies changed their cellular distribution in association with the viral nucleoprotein. Further studies indicated that anti-nucleoprotein intrabodies abolished the accumulation of not only the complementary RNA and virion RNA but also messenger RNA of influenza virus. In addition, anti-nucleoprotein intrabodies significantly inhibited influenza A virus transcription and replication through blocking the interaction of nucleoprotein with the viral polymerase proteins, polymerase basic protein 1 and polymerase basic protein 2. Thus, this study not only provides a powerful tool for the study of viral protein's functions, but also opens a new potential avenue for the prevention and treatment of influenza virus infections.
Mukhtar
Muhammad Mahmood
MM
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China.
Li
Shengfeng
S
Li
Wei
W
Wan
Ting
T
Mu
Yongxin
Y
Wei
Wei
W
Kang
Lei
L
Rasool
Sahibzada T
ST
Xiao
Yibei
Y
Zhu
Ying
Y
Wu
Jianguo
J
D000914:Antibodies, Viral / Q000276:immunology / Q000378:metabolism*; D000956:Antigens, Viral / Q000276:immunology; D015723:Gene Library; D006801:Humans; D009980:Influenza A virus / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology* / Q000517:prevention & control; D009698:Nucleoproteins / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D021381:Protein Transport / Q000276:immunology; D012367:RNA, Viral / Q000032:analysis; D012324:RNA-Dependent RNA Polymerase / Q000037:antagonists & inhibitors; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000037:antagonists & inhibitors; D014779:Virus Replication / Q000276:immunology*
D000914:Antibodies, Viral; D000956:Antigens, Viral; D009698:Nucleoproteins; C057027:PB2 protein, Influenzavirus A; D012367:RNA, Viral; D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1; D012324:RNA-Dependent RNA Polymerase