title: Inhibition of hepatitis C virus infection by DNA aptamer against envelope protein.
abstract: Hepatitis C virus (HCV) envelope protein (E1E2) is essential for virus binding to host cells. Aptamers have been demonstrated to have strong promising applications in drug development. In the current study, a cDNA fragment encoding the entire E1E2 gene of HCV was cloned. E1E2 protein was expressed and purified. Aptamers for E1E2 were selected by the method of selective evolution of ligands by exponential enrichment (SELEX), and the antiviral actions of the aptamers were examined. The mechanism of their antiviral activity was investigated. The data show that selected aptamers for E1E2 specifically recognize the recombinant E1E2 protein and E1E2 protein from HCV-infected cells. CD81 protein blocks the binding of aptamer E1E2-6 to E1E2 protein. Aptamers against E1E2 inhibit HCV infection in an infectious cell culture system although they have no effect on HCV replication in a replicon cell line. Beta interferon (IFN-β) and IFN-stimulated genes (ISGs) are not induced in virus-infected hepatocytes with aptamer treatment, suggesting that E1E2-specific aptamers do not induce innate immunity. E2 protein is essential for the inhibition of HCV infection by aptamer E1E2-6, and the aptamer binding sites are located in E2. Q412R within E1E2 is the major resistance substitution identified. The data indicate that an aptamer against E1E2 exerts its antiviral effects through inhibition of virus binding to host cells. Aptamers against E1E2 can be used with envelope protein to understand the mechanisms of HCV entry and fusion. The aptamers may hold promise for development as therapeutic drugs for hepatitis C patients.
authors.affiliation: Department of Molecular Medicine, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China.
authors.forename: Darong
authors.initials: D
authors.lastname: Yang
authors.forename: Xianghe
authors.initials: X
authors.lastname: Meng
authors.forename: Qinqin
authors.initials: Q
authors.lastname: Yu
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Ying
authors.initials: Y
authors.lastname: Long
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Fang
authors.forename: Haizhen
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D052157:Aptamers, Nucleotide / Q000494:pharmacology*; D002460:Cell Line; D016174:Hepacivirus / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D014759:Viral Envelope Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*
chemical_list: D000998:Antiviral Agents; D052157:Aptamers, Nucleotide; D014759:Viral Envelope Proteins