title: Inhibition of hepatitis C virus RNA replicons by peptide aptamers.
abstract: OBJECTIVE
  Hepatitis C virus infection is a major worldwide health problem, causing chronic hepatitis, cirrhosis and primary liver cancer. In addition to its role in the viral polyprotein-processing, the viral NS3 serine protease has been implicated in interactions with various cell constituents resulting in phenotypic changes including malignant transformation. NS3 is currently regarded a prime target for anti-viral drugs thus specific inhibitors of its activities should be important. With the aim of inhibiting NS3 protease activity as a means to inhibit HCV replication we used a novel bacterial genetic screen to isolate NS3-inhibiting peptide aptamers.
  
  
  METHODS
  We have isolated and characterized seven NS3-inhibiting peptide aptamers. We investigated the phenotypic changes that SEAP-secreting subgenomic RNA replicons undergo upon intracellular expression of these peptide aptamers, assayed by real-time RT-PCR and inhibition of SEAP secretion by transfected replicon cells.
  
  
  CONCLUSIONS
  The peptide aptamers inhibited NS3 protease activity in vitro with an IC50 in the low micromolar range. Upon transfection, aptamers inhibited the replication of SEAP-secreting genotype 1b subgenomic RNA replicons. Aptamer-based intracellular immunization may emerge as a promising antiviral approach to interfere with the life cycle and pathogenicity of HCV.
authors.affiliation: Department of Molecular Microbiology and Biotechnology, The George S. Wise Faculty of Life Sciences, Green Building, Tel-Aviv University, 69978 Ramat Aviv, Israel.
authors.forename: Alla
authors.initials: A
authors.lastname: Trahtenherts
authors.forename: Meital
authors.initials: M
authors.lastname: Gal-Tanamy
authors.forename: Romy
authors.initials: R
authors.lastname: Zemel
authors.forename: Larisa
authors.initials: L
authors.lastname: Bachmatov
authors.forename: Shelly
authors.initials: S
authors.lastname: Loewenstein
authors.forename: Ran
authors.initials: R
authors.lastname: Tur-Kaspa
authors.forename: Itai
authors.initials: I
authors.lastname: Benhar
mesh_terms: D000998:Antiviral Agents / Q000302:isolation & purification / Q000494:pharmacology*; D052158:Aptamers, Peptide / Q000302:isolation & purification / Q000494:pharmacology*; D002460:Cell Line; D004353:Drug Evaluation, Preclinical / Q000379:methods; D016174:Hepacivirus / Q000187:drug effects*; D006801:Humans; D011480:Protease Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D012367:RNA, Viral / Q000032:analysis* / Q000096:biosynthesis*; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors; D014779:Virus Replication / Q000187:drug effects*; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D000998:Antiviral Agents; D052158:Aptamers, Peptide; D011480:Protease Inhibitors; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases