Surrogate cell-based system and method for assaying the activity of hepatitis C virus NS3 protease

摘要

The application concerns the development of a cell-based assay system having improved sensitivity to HCV NS3 protease activity, which is useful for screening test compounds capable of modulating (particularly inhibiting) HCV NS3 protease activity. This system provides a first construct comprising a transactivator domain joined downstream of the NS3-5 domains of HCV under the control of a non-cytopathic viral promoter system. A second construct is also provided that comprises a reporter gene under the control of an operator sensitive to the binding of the transactivator. The NS3-5 domains encodes the NS3 polyprotein which comprises: the NS3 protease, followed by the NS4A co-factor, the NS4B and NS5A proteins (including any derivative, variant or fragment thereof), terminated by the NS5B protein (including any derivative, variant or fragment thereof) sufficient to constitute a NS5A/5B cleavage site. The transactivator, when expressed and released from the polyprotein initiates transcription and expression of the reporter gene that is measurable.