Human single chain-transbodies that bound to domain-I of non-structural protein 5A (NS5A) of hepatitis C virus

Sci Rep. 2017 Nov 8;7(1):15042. doi: 10.1038/s41598-017-14886-9.

Abstract

A safe and broadly effective direct acting anti-hepatitis C virus (HCV) agent that can withstand the viral mutation is needed. In this study, human single chain antibody variable fragments (HuscFvs) to conserved non-structural protein-5A (NS5A) of HCV were produced by phage display technology. Recombinant NS5A was used as bait for fishing-out the protein bound-phages from the HuscFv-phage display library. NS5A-bound HuscFvs produced by five phage transfected-E. coli clones were linked molecularly to nonaarginine (R9) for making them cell penetrable (become transbodies). The human monoclonal transbodies inhibited HCV replication in the HCVcc infected human hepatic cells and also rescued the cellular antiviral immune response from the viral suppression. Computerized simulation verified by immunoassays indicated that the transbodies used several residues in their multiple complementarity determining regions (CDRs) to form contact interface with many residues of the NS5A domain-I which is important for HCV replication complex formation and RNA binding as well as for interacting with several host proteins for viral immune evasion and regulation of cellular physiology. The human monoclonal transbodies have high potential for testing further as a new ramification of direct acting anti-HCV agent, either alone or in combination with their cognates that target other HCV proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Cell Surface Display Techniques
  • Hepacivirus / drug effects
  • Hepacivirus / genetics
  • Hepacivirus / metabolism*
  • Hepatitis C / metabolism
  • Hepatitis C / prevention & control
  • Hepatitis C / virology
  • Humans
  • Peptide Library
  • Protein Binding
  • Single-Chain Antibodies / metabolism*
  • Single-Chain Antibodies / pharmacology
  • Viral Nonstructural Proteins / antagonists & inhibitors
  • Viral Nonstructural Proteins / genetics
  • Viral Nonstructural Proteins / metabolism*
  • Virus Replication*

Substances

  • Peptide Library
  • Single-Chain Antibodies
  • Viral Nonstructural Proteins
  • NS-5 protein, hepatitis C virus