Development of a cell culture system based on recombinant hepatitis C virus expressing enhanced green fluorescent protein

Objective To develop a time saving and sensitive cell culture system based on hepatitis C virus chimera expressing enhanced green fluorescent protein(EGFP) and to facilitate the study on HCV pathogenesis and screening of anti-HCV drugs.Methods Enhanced green fluorescent protein reporter gene and a mutation V2440L that can yield higher virus titers were introduced into the C-terminus of non-structural protein 5A (NS5A) of the JFH1 viral genome by using recombinant PCR.The viral RNA was transfected into Huh7.5 cells.Viral RNA in supernatant of HCV RNA-transfected cells was determined after transfection by RT-PCR.HCV replication and infection were determined by immunofluorescence assay.IFN-α was used to evaluate the feasibility of this system for anti-HCV drugs screening.Results The viral RNA replicated efficiently in transfected cells.These cells can produce HCV-EGFP reporter virus.Viral RNA levels in supernatant were 3.06× 105 copies/ml and 7.96×106 copies/ml at 72 h and 9 d after transfection,respectively.The virus titer reached to 104 FFU/ml 9 d after transfection.The expression of EGFP was inhibited by IFN-α in a dose dependent manner in Huh7.5 cells infected by HCV-EGFP reporter virus.Conclusion The recombinant HCV JFH1-EGFP reporter gene system is a time saving,cost effective and sensitive method for studying viral replication cycles and screening of anti-HCV drugs. Key words: HCV; EGFP; Reporter gene; Cell culture