Hepatitis E virus infection activates signal regulator protein α to down-regulate type I interferon.

Hepatitis E virus (HEV) is a major cause of enterically transmitted acute hepatitis worldwide. However, the mechanism of HEV replication is unclear. Type I interferon is the first defense line of host against viral infection. Signal regulator protein α (SIRP-α) plays an important role in negative regulation of innate immunity. In the present study, HEV infection significantly activated the expression of SIRP-α and down-regulated phosphorylation of IRF3, consequently resulted in suppression of type I interferon (IFN-β). In conclusion, HEV exploited SIRP-α to negative regulated IFN-β of the host innate immune system to promote viral infection. It suggested that interfering with the functions of SIRP-α should be considered as a potential therapeutic approach to the prevention and treatment of HEV infection.