MEK/ERK MAP kinase limits poly I:C‐induced antiviral gene expression in RAW264.7 macrophages by reducing interferon‐beta expression

Toll‐like receptor 3 (TLR3) recognizes viral double‐stranded RNA (or the synthetic dsRNA analog poly I:C) and induces a signal transduction pathway that results in activation of transcription factors that induce expression of antiviral genes including type I interferon (IFN‐I). Secreted IFN‐I positively feeds back to amplify antiviral gene expression. In this report, we study the role of MEK/ERK MAP kinase in modulating antiviral gene expression downstream of TLR3. We find MEK/ERK is a negative regulator of antiviral gene expression by limiting expression of IFN‐β. However, MEK/ERK does not limit antiviral responses downstream of the type I interferon receptor. These findings provide insights into regulatory mechanisms of antiviral gene expression and reveal potential targets for modulating antiviral immunity.