Early gene expression events in ferrets in response to SARS coronavirus infection versus direct interferon-alpha2b stimulation

Type I interferons (IFNs) are essential to the clearance of viral diseases, however, a clear distinction between genes upregulated by direct virus–cell interactions and genes upregulated by secondary IFN production has not been made. Here, we investigated differential gene regulation in ferrets upon subcutaneous administration of IFN-α2b and during SARS-CoV infection. In vivo experiments revealed that IFN-α2b causes STAT1 phosphorylation and upregulation of abundant IFN response genes (IRGs), chemokine receptors, and other genes that participate in phagocytosis and leukocyte transendothelial migration. During infection with SARS-CoV not only a variety of IRGs were upregulated, but also a significantly broader range of genes involved in cell migration and inflammation. This work allowed dissection of several molecular signatures present during SARS-CoV which are part of a robust IFN antiviral response. These signatures can be useful markers to evaluate the status of IFN responses during a viral infection and specific features of different viruses.