Measurement of Antiviral Effect and Innate Immune Response During Treatment of Primary Woodchuck Hepatocytes.

An estimated 350 million people are chronically infected with hepatitis B virus (HBV), and over one million people die each year due to HBV-associated liver diseases, such as cirrhosis and liver cancer. Current therapeutics for chronic HBV infection are limited to nucleos(t)ide analogs and interferon. These anti-HBV drugs in general reduce viral load and improve the long-term outcome of infection but very rarely lead to a cure. Thus, new therapies for chronic HBV infection need to be developed by utilizing liver cell lines and primary cultures and small laboratory animals capable of replicating HBV or surrogate hepadnaviruses for antiviral testing. Natural infection with woodchuck hepatitis virus (WHV), a hepadnavirus closely related to HBV, occurs in woodchucks. Chronic WHV infection has been established over decades as a suitable model for evaluating direct-acting antivirals as well as vaccines, vaccine adjuvants, and immunotherapeutics because animals are fully immunocompetent. Before HBV-specific compounds are applied to woodchucks, they are usually tested in primary woodchuck hepatocytes (PWHs) replicating WHV at high levels for confirming drug specificity against viral or host targets. Here we describe a protocol for the isolation of PWHs from liver of WHV-infected woodchucks, maintenance in culture, and use in assays for determining antiviral efficacy, safety, and associated host innate immune response of new experimental drugs. Exemplary assays were performed with the nucleoside analog, lamivudine, and the immunomodulator, interferon-alpha.