Quasispecies of Hepatitis C Virus Participate in Cell-Specific Infectivity

Takasuke Fukuhara,Daisuke Motooka,Tomokazu Tamura,Kazuaki Chayama,Michio Imamura,Asuka Sato,Satomi Yamamoto,Takeshi Kurihara,Chikako Ono,Yoshiharu Matsuura,Takashi Motomura,Yoshihiko Maehara,Toru Okamoto,Shota Nakamura,Hiroyuki Mori,Yuji Soejima,Toru Ikegami,Tomoharu Yoshizumi

doi:10.1038/srep45228

Takasuke Fukuhara, Daisuke Motooka + Show 16 more

Open Access

https://doi.org/10.1038/srep45228

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Abstract

It is well documented that a variety of viral quasispecies are found in the patients with chronic infection of hepatitis C virus (HCV). However, the significance of quasispecies in the specific infectivity to individual cell types remains unknown. In the present study, we analyzed the role of quasispecies of the genotype 2a clone, JFH1 (HCVcc), in specific infectivity to the hepatic cell lines, Huh7.5.1 and Hep3B. HCV RNA was electroporated into Huh7.5.1 cells and Hep3B/miR-122 cells expressing miR-122 at a high level. Then, we adapted the viruses to Huh7 and Hep3B/miR-122 cells by serial passages and termed the resulting viruses HCVcc/Huh7 and HCVcc/Hep3B, respectively. Interestingly, a higher viral load was obtained in the homologous combination of HCVcc/Huh7 in Huh7.5.1 cells or HCVcc/Hep3B in Hep3B/miR-122 cells compared with the heterologous combination. By using a reverse genetics system and deep sequence analysis, we identified several adaptive mutations involved in the high affinity for each cell line, suggesting that quasispecies of HCV participate in cell-specific infectivity.

Highlights

More than 160 million individuals worldwide are infected with hepatitis C virus (HCV), and cirrhosis and hepatocellular carcinoma induced by HCV infection are life-threatening diseases[1]
We previously reported that exogenous expression of miR-122 facilitates the efficient propagation of HCVcc in Hep3B cells[11]
No adaptive mutations were observed in the viruses obtained at 20 days after electroporation, suggesting that the replication fitness of JFH1-AM was high enough in Huh7.5.1 and in Hep3B/miR-122 cells (Fig. 1B)

Summary

Introduction

More than 160 million individuals worldwide are infected with hepatitis C virus (HCV), and cirrhosis and hepatocellular carcinoma induced by HCV infection are life-threatening diseases[1]. There have been no reports about the mechanistic role of quasispecies in HCV adaptation to new target cells. Development of a robust in vitro propagation system of HCV based on the genotype 2a JFH1 strain (HCVcc) has gradually clarified the mechanism of the HCV life cycle[9,10]. Several reports have shown that the expression of miR122 in hepatic cancer cell lines facilitates the efficient propagation of HCVcc[11,12]. The pattern of adaptive mutation and role of quasispecies in the infectivity of HCVcc were determined by using in vitro and in vivo models of HCVcc infection to hepatic cancer cell lines and uPA-SCID mice with human liver xenografts, respectively. The results suggested that quasispecies play crucial roles in the specific infectivity to new target cells

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Results

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