Adapted HCV JFH1 variant is capable of accommodating a large foreign gene insert and allows lower level HCV replication and viral production

Wang, Qi; Hagedorn, Curt; Liu, Shuanghu

Infectious HCV carrying reporter genes have further applications in understanding the HCV life cycle including replication, viral assembly and release. In this study, a full-length 3039bp LacZ gene was inserted into the derivative of JFH1-AM120 to develop an additional reporter virus. The results showed that the recombinant reporter virus JFH1-AM120-LacZ can replicate and produce lower titers of infectious virus. However, insertion of the LacZ gene in the C-terminal region of the NS5A in HCV JFH1-AM120-LacZ decreased viral replication and dramatically impaired the production of infectious viral particles. Moreover, the JFH1-AM120-LacZ reporter virus lost the LacZ gene after serial passage. Nevertheless, the JFH1-AM120-LacZ reporter virus displayed the entire life cycle of HCV, from replication to production of infectious virus, in Huh7.5 cells. This study demonstrates that the NS5A region of HCV JFH1-AM120 has the capacity to accommodate large foreign genes up to 3,039 bp and suggests that other relatively large gene inserts can be accommodated at this site.