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The Capital Region of Denmark - a part of Copenhagen University Hospital
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Characterization of hepatitis C virus recombinants with chimeric E1/E2 envelope proteins and identification of single amino acids in the E2 stem region important for entry

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DOI

  1. CO-HEP; Copenhagen Hepatitis C Program

    Project: Types of projects

  1. Replicons of a rodent hepatitis C model virus permit selection of highly permissive cells

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. IDENTIFICATION OF PIPERAZINYLBENZENESULFONAMIDES AS NEW INHIBITORS OF CLAUDIN-1 TRAFFICKING AND HEPATITIS C VIRUS ENTRY

    Research output: Contribution to journalJournal articleResearchpeer-review

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The hepatitis C virus (HCV) envelope proteins E1 and E2 play a key role in host cell entry and represent important targets for vaccine and drug development. Here, we characterized HCV recombinants with chimeric E1/E2 complexes in vitro. Using genotype 1a/2a JFH1-based recombinants expressing 1a core-NS2, we exchanged E2 with functional isolate sequences of genotypes 1a (alternative isolate), 1b, and 2a. While the 1a-E2 exchange did not impact virus viability, the 2a-E2 recombinant was nonviable. After E2 exchange from three 1b isolates, long delays were observed before spread of infection. For recovered 1b-E2 recombinants, single E2 stem region amino acid changes were identified at residues 706, 707, and 710. In reverse genetic studies, these mutations increased infectivity titers by ~100-fold, apparently without influencing particle stability or cell binding although introducing slight decrease in particle density. In addition, the 1b-E2 exchange led to a decrease in secreted core protein of 25 to 50%, which was further reduced by the E2 stem region mutations. These findings indicated that compensatory mutations permitted robust infectious virus production, without increasing assembly/release. Studies of E1/E2 heterodimerization showed no differences in intracellular E1/E2 interaction for chimeric constructs with or without E2 stem region mutations. Interestingly, the E2 stem region mutations allowed efficient entry, which was verified in 1a-E1/1b-E2 HCV pseudoparticle assays. A CD81 inhibition assay indicated that the mutations influenced a late step of the HCV entry pathway. Overall, this study identified specific amino acids in the E2 stem region of importance for HCV entry and for production of infectious virus particles.
Original languageEnglish
JournalJournal of Virology
Volume87
Issue number3
Pages (from-to)1385-99
Number of pages15
ISSN0022-538X
DOIs
Publication statusPublished - 2013

ID: 36883123