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This Article Full Text (Papers in Press[PDF]) All Versions of this Article: vir.2008.006049-0v1 90/4/833    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Adair, R. Articles by McCormick, C. J. Search for Related Content PubMed PubMed Citation Articles by Adair, R. Articles by McCormick, C. J. Agricola Articles by Adair, R. Articles by McCormick, C. J.

Expression of HCV structural proteins in trans facilitates encapsidation and transmission of HCV subgenomic RNA

¹ MRC Virology Unit, Glasgow;
² University of Leeds;
³ University of Southampton

⁴ E-mail: cjm{at}soton.ac.uk

A characteristic of many positive strand RNA viruses is that whilst replication of the viral genome is dependent on the expression of the majority of non-structural proteins in cis, virus particle formation can occur when most or all of the structural proteins are co-expressed in trans. Making use of a recently identified HCV isolate (JFH1) that can be propagated in tissue culture, we sought to establish whether this also is the case for hepaciviruses. Stable cell lines containing one of two bicistronic replicons derived from the JFH1 isolate were generated that expressed either non-structural proteins NS3-5B or NS2-5B. Release and transmission of these replicons to naïve Huh7 cells could then be demonstrated when baculovirus transduction was used to express the HCV proteins absent from the sub-genomic replicons. Transmission could be blocked by a neutralizing antibody targeted at the E2 envelope protein, consistent with this phenomenon occurring via trans-encapsidation of replicon RNA into virus-like particles. Transmission was also dependent on expression of NS2, which was most effective at promoting virus particle formation when expressed in cis on the replicon RNA compared with in trans via baculovirus delivery. Density gradient analysis of the particles revealed the presence of a broad infectious peak between 1.06 to 1.11 g/ml, comparable to that seen when propagating full-length virus in tissue culture. In summary, the trans-encapsidation system described offers a complementary and safer approach to study HCV particle formation and transmission in tissue culture.

Received 29 July 2008; accepted 1 December 2008.