Send to

Choose Destination
Antiviral Res. 2013 Aug;99(2):91-9. doi: 10.1016/j.antiviral.2013.05.001. Epub 2013 May 13.

Human 4F5 single-chain Fv antibody recognizing a conserved HA1 epitope has broad neutralizing potency against H5N1 influenza A viruses of different clades.

Author information

Key Laboratory of Antibody Technique, Ministry of Health, Nanjing Medical University, Nanjing 210029, China.


Influenza A viruses present a significant threat to public health worldwide. High-affinity human scFv antibodies against a conserved epitope can potentially provide immunity to diverse viruses and protect against future pandemic viruses. A library of phage-displayed human scFv containing 6.0×10(8) members was generated from lymphocytes of H5N1 virus vaccinated individuals. Using the recombinant H5N1 virus hemagglutinin ectodomain (HA1), 4F5 scFv was identified with neutralizing activity against both clade 2 and 9 H5N1 viruses. In embryonated chicken eggs, the antiviral activity of 4F5 scFv conferred a 100% survival rate and at least a 62.5% survival rate against different clades of H5N1 viruses by pre-treatment and post-treatment, respectively. 4F5 scFv belongs to the VH-3-43 family according to the IMGT database, and a peptide (76)WLLGNP(81) containing half of an α-helix in HA1 was identified as the binding pocket. The conserved binding epitope of this novel broadly neutralizing scFv may become key in the design and implementation of vaccines or RNA interference against H5N1 viruses.


Antiviral effect; Broad neutralization; Conserved epitope; H5N1 influenza A viruses; α-Helix

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center