Original Article
Open Access
Miki Taniguchi, Megumi Tasaka-Fujita, Mina Nakagawa, Takako Watanabe, Fukiko Kawai-Kitahata, Satoshi Otani, Fumio Goto, Hiroko Nagata, Shun Kaneko, Sayuri Nitta, Miyako Murakawa, Yuki Nishimura-Sakurai, Seishin Azuma, Yasuhiro Itsui, Kenichi Mori, Shintaro Yagi, Sei Kakinuma, Yasuhiro Asahina, Mamoru Watanabe
Published online March 28, 2016
Journal of Clinical and Translational Hepatology.
doi:10.14218/JCTH.2015.00047
Abstract
Background and Aims: The hepatitis C virus (HCV) genotype 1b is known to exhibit treatment resistance with respect to interferon (IFN) therapy. Substitution of amino acids 70 and
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Background and Aims: The hepatitis C virus (HCV) genotype 1b is known to exhibit treatment resistance with respect to interferon (IFN) therapy. Substitution of amino acids 70 and 91 in the core region of the 1b genotype is a significant predictor of liver carcinogenesis and poor response to pegylated-IFN-α and ribavirin therapy. However, the molecular mechanism has not yet been clearly elucidated because of limitations of the HCV genotype 1b infectious model. Recently, the TPF1-M170T HCV genotype 1b cell culture system was established, in which the clone successfully replicates and infects Huh-7-derived Huh7-ALS32.50 cells. Therefore, the purpose of this study was to compare IFN resistance in various HCV clones using this system. Methods: HCV core amino acid substitutions R70Q and L91M were introduced to the TPF1-M170T clone and then transfected into Huh7-ALS32.50 cells. To evaluate the production of each virus, intracellular HCV core antigens were measured. Results were confirmed with Western blot analysis using anti-NS5A antibodies, and IFN sensitivity was subsequently measured. Results: Each clone was transfected successfully compared with JFH-1, with a significant difference in intracellular HCV core antigen (p < 0.05), an indicator of continuous HCV replication. Among all clones, L91M showed the highest increase in the HCV core antigen and HCV protein. There was no significant resistance against IFN treatment in core substitutions; however, IFN sensitivity was significantly different between the wildtype core and JFH-1 (p < 0.05). Conclusions: A novel genotype 1b HCV cell culture was constructed with core amino acid substitutions, which demonstrated IFN resistance of genotype 1b. This system will be useful for future analyses into the mechanisms of HCV genotype 1b treatment.
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