Coordinated role of RIG-I, MDA5, and TLR7 in the innate immune response to duck hepatitis A virus 3.

Abstract

The roles of RIG-I, MDA5, and TLR7 in duck hepatitis A virus genotype 3 (DHAV-3) infection were investigated using duck embryo fibroblasts (DEFs). DHAV-3 infection induced significant upregulation of RIG-I, MDA5, and TLR7 and high IFN-β, IL-6, and OASL responses. Overexpression and knockdown of RIG-I, MDA5, and TLR7 exerted significant effects on DHAV-3-induced IFN-β, IL-6, and OASL expression and DHAV-3 replication. Overexpression and inhibition of TLR7 altered DHAV-3-induced RIG-I and MDA5 expression. Together, these findings suggest that TLR7 and RIG-I/MDA5 play a coordinated role in detection and initiation of innate immunity against DHAV-3 infection.