Recognition of pathogen-associated molecular patterns by TLR family.
Toll-like receptors (TLRs) are type I transmembrane proteins involved in innate immunity by recognizing microbial conserved structures. Recent studies have shown that TLR3 recognizes dsRNA, a viral product, whereas TLR9 recognizes unmethylated CpG motifs frequently found in the genome of bacteria and viruses, but not vertebrates. TLR7 recognizes small synthetic immune modifiers including imiquimod, R-848, loxoribine, and bropirimine, all of which are already applied or promising for clinical use against viral infections and cancers. Plasmacytoid dendritic cells express TLR7 and TLR9, and respond to TLR7 and TLR9 ligands by producing a large amount of interferon (IFN-alpha). These results indicate that TLR3, TLR7 and TLR9 may play an important role in detecting and combating viral infections.
Akira
Shizuo
S
Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, SORST of Japan Science and Technology Corporation, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan. sakira@biken.osaka-u.ac.jp
Hemmi
Hiroaki
H
D000818:Animals; D001419:Bacteria / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D008024:Ligands; D008070:Lipopolysaccharides / Q000276:immunology; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D051196:Toll-Like Receptor 3; D051199:Toll-Like Receptor 7; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; D014780:Viruses / Q000276:immunology
D008024:Ligands; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C495344:TLR3 protein, human; C495348:TLR7 protein, human; C495371:TLR9 protein, human; D051196:Toll-Like Receptor 3; D051199:Toll-Like Receptor 7; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors