Recent contributions of in vitro models to our understanding of hepatitis C virus life cycle

Abstract

In vitro HCV infection models M. Ré geard et al.

An Assessment of the Use of Chimpanzees in Hepatitis C Research Past, Present and Future: 2. Alternative Replacement Methods

“…The identification, isolation and use of highly permissive cell lines have also facilitated the use of the replicon system by increasing efficiency. Examples of these cell lines include the Huh7.5 (85), Huh7.5.1 (33) and Huh7-Lunet (86) lines.…”

“…As relatively long ago as 2001, reviews cited dozens of systems that had been assessed and that had succeeded to varying degrees (25). More recently, many good reviews have outlined developments in this field and have illustrated the major breakthroughs these represent and the insights and progress they should deliver (1,27,(32)(33)(34).…”

“…The importance of replicons is reflected in their citation, alongside full recombinant HCV culture, in discussions of the crucial contributions in vitro approaches have made to HCV research (6,27). These contributions include, for example, the elucidation of the roles of specific HCV genome segments and proteins in replication, the determination of intracellular HCV protein localisation, the characterisation of virus-host interactions, and the identification of anti-viral agents (20,(32)(33)(34)(73)(74)(75). Many more examples, too numerous to discuss here, are summarised in a recent very detailed and comprehensive review, including, for example, the importance of the HCV untranslated regions (UTRs) and other cis-acting elements in viral replication, the elucidation of roles, functions and criticality of HCV viral proteins and protein domains, the involvement of various host proteins with the endoplasmic reticulum, the association of the HCV core protein with host lipids, and the screening and testing of viral inhibitors (1).…”

“…The first subgenomic replicon for HCV was based on a consensus genotype 1b sequence derived from a chronically infected patient, and exhibited efficient replication when transfected into Huh7 human hepatoma cell lines (26). Subsequent in vitro analyses revealed the evolution of various adaptive mutations in the subgenomes, which further increased their replicative capacities by several orders of magnitude, even up to 10,000-fold (33,79,80). Knowledge of these adaptive mutations permitted the development of extremely efficient in vitro replicon systems, which rendered the inclusion of selectable marker genes redundant.…”

“…There are a number of detailed and extensive recent reviews of the application of these methods to HCV research, and of the data they can provide with regard to HCV binding, membrane fusion and entry, antibody-mediated neutralisation, screening of anti-HCV agents and vaccine development, and other aspects of the HCV life-cycle (1,27,33). Briefly, the techniques range from the simple expression of the HCV envelope glycoproteins (E1 and E2) in cell culture, through the expression of HCV structural proteins by using recombinant baculovirus, to the creation of HCVpp in which the HCV envelope proteins are incorporated into other enveloped viruses, in place of their own envelope proteins.…”