Differential transcriptional responses to interferon-α and interferon-γ in primary human hepatocytes

Interferon (IFN) plays a central role in the innate and adaptive antiviral immune responses. While IFN-α is currently approved for treating chronic hepatitis B and hepatitis C, in limited studies, IFN-γ has not been shown to be effective for chronic hepatitis B or C. To identify the potential mechanism underlying the differential antiviral effects of IFN-α and IFN-γ, we used cDNA microarray to profile the global transcriptional response to IFN-α and IFN-γ in primary human hepatocytes, the target cell population of hepatitis viruses. Our results reveal distinct patterns of gene expression induced by these 2 cytokines. Overall, IFN-α induces more genes than IFN-γ at the transcriptional level. Distinct sets of genes were induced by IFN-α and IFN-γ with limited overlaps. IFN-α induces gene transcription at an early time point (6 h) but not at a later time point (18 h), while the effects of IFN-γ are more prominent at 18 h than at 6 h, suggesting a delayed transcriptional response to IFN-γ in the hepatocytes. These findings indicate differential actions of IFN-α and IFN-γ in the context of therapeutic intervention for chronic viral infections in the liver.