Functions of toll-like receptors: lessons from KO mice.
The innate immune response is a first-line defense system in which individual Toll-like receptors (TLRs) recognize distinct pathogen-associated molecular patterns (PAMPs) and exert subsequent immune responses against a variety of pathogens. TLRs are composed of an extracellular leucine-rich repeat (LRR) domain and a cytoplasmic domain that is homologous to that of the IL-IR family. Upon stimulation, TLR recruits a cytoplasmic adaptor molecule MyD88, then IL-IR-associated kinase (IRAK), and finally induces activation of NF-kappaB and MAP kinases. However, the responses to TLR ligands differ, indicating the diversity of TLR signaling pathways. Besides MyD88, several novel adaptor molecules have recently been identified. Differential utilization of these adaptor molecules may provide the specificity in the TLR signaling.
Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Japan. sakira@biken.osaka-u.ac.jp
Shizuo
S
Akira
Kiyoshi
K
Takeda
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000943:Antigens, Differentiation / Q000235:genetics / Q000276:immunology; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout / Q000276:immunology*; D053594:Myeloid Differentiation Factor 88; D011956:Receptors, Cell Surface / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology; D051193:Toll-Like Receptors
D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation; D008562:Membrane Glycoproteins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D051193:Toll-Like Receptors