Alpha interferon inhibits hepatitis C virus replication in primary human hepatocytes infected in vitro

Chronic hepatitis C is a common cause of liver disease, the complications of which include cirrhosis and hepatocellular carcinoma. Treatment of chronic hepatitis C is based on the use of alpha interferon (IFN-alpha). Recently, indirect evidence based on mathematical modeling of hepatitis C virus (HCV) dynamics during human IFN-alpha therapy suggested that the major initial effect of IFN-alpha is to block HCV virion production or release. Here, we used primary cultures of healthy, uninfected human hepatocytes to show that: (i) healthy human hepatocytes can be infected in vitro and support HCV genome replication, (ii) hepatocyte treatment with IFN-alpha results in expression of IFN-alpha-induced genes, and (iii) IFN-alpha inhibits HCV replication in infected human hepatocytes. These results show that IFN-alpha acts primarily through its nonspecific antiviral effects and suggest that primary cultures of human hepatocytes may provide a good model to study intrinsic HCV resistance to IFN-alpha.