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.