Affiliation: Department of Tumor Cell Biology, The Tokyo Metropolitan Institute of Medical Science, 3-18-22Honkomagome, Bunkyo, Tokyo 113-8613, Japan.
Toll like receptors (TLRs) function as signaling receptors for pathogen-derived molecules and provoke innate immune responses, which are preparatory for initiating acquired immunity. Each TLR triggers both common and unique signals, resulting in the activation of a specific set of transcription factors and hence the activation of common and specific target genes. Some members of the Interferon Regulatory Factor (IRF) family of transcription factors are specifically activated by TLR signaling and participate in the critical processes of innate immunity. Recently, a non-TLR receptor that recognizes viral double stranded RNA and participates in the antiviral innate responses was identified.