Toll‐Like Receptor 3: A Link between Toll‐Like Receptor, Interferon and Viruses

Abstract

Production of type I interferon (IFN‐α/β) by virus‐infected cells is the central event in their antiviral immune responses. In mammalian cells, IFN‐α/β gene transcription is induced through distinct signaling pathways by viral infection or by treatment with double‐stranded (ds) RNA, which is an intermediate of virus replication. Toll‐like receptor 3 (TLR3) was found to recognize dsRNA and transmit signals to activate NF‐κB and the IFN‐β promoter. Recent identification of the TLR3‐adaptor protein and its downstream signaling molecules, which are involved in IFN‐α/β production, revealed a novel IFN‐inducing pathway for an anti‐viral immune response. Here, we summarize the current knowledge of TLR3‐mediated immune responses.