[Innate immune recognition of viral infection].
Toll-like receptors (TLRs) are key molecules of the innate immune systems, which detect conserved structures found in a broad range of pathogens and triggers innate immune responses. A subset of TLRs recognize viral components and induce antiviral responses by producing type I interferons. Whereas TLR2 and TLR4 recognize viral components at the cell surface, TLR3, TLR7, TLR8 and TLR9 are exclusively expressed in endosomal compartments. After phagocytes internalize viruses or virus-infected apoptotic cells, viral nucleic acids are released in phagolysosomes and are recognized by these TLRs. Recent reports have shown that hosts also have a mechanism to detect replicating viruses in the cytoplasm in a TLR-independent manner. In this review, we focus on the viral recognition by innate immunity and the signaling pathways.
Uematsu
Satoshi
S
Department of Host defense, Research Institute for Microbial Diseases, Osaka University, Japan. uemattsu@biken.osaka-u.ac.jp
Akira
Shizuo
S
D000818:Animals; D007113:Immunity, Innate / Q000276:immunology*; D007370:Interferon Type I / Q000235:genetics / Q000502:physiology; D010586:Phagocytes / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D051193:Toll-Like Receptors / Q000276:immunology*; D014157:Transcription Factors / Q000502:physiology; D014158:Transcription, Genetic; D014777:Virus Diseases / Q000276:immunology*; D014780:Viruses / Q000276:immunology*
D007370:Interferon Type I; D051193:Toll-Like Receptors; D014157:Transcription Factors