Identification of pattern recognition receptors participating in the innate immune response to Tembusu virus

The pattern recognition receptors (PRRs) participating in the innate immune response to Tembusu virus (TMUV) were investigated using duck embryo fibroblasts (DEFs). TMUV infection induced significant upregulation of RIG-I and MDA5 and strong IFN-α, IFN-β, IL-6, and Mx responses. Overexpression of RIG-I or MDA5 resulted in increased IFN-α, IFN-β, IL-6, and Mx expression and decreased TMUV replication. Conversely, knockdown of RIG-I or MDA5 resulted in decreased IFN-α, IFN-β, IL-6, and Mx expression and increased TMUV replication. These findings demonstrate that RIG-I and MDA5 are essential sensors in the innate immune defense against TMUV, orchestrating cytokine production and restricting viral replication.