title: Detection of pathogenic intestinal bacteria by Toll-like receptor 5 on intestinal CD11c+ lamina propria cells.
abstract: Toll-like receptors (TLRs) recognize distinct microbial components and induce innate immune responses. TLR5 is triggered by bacterial flagellin. Here we generated Tlr5-/- mice and assessed TLR5 function in vivo. Unlike other TLRs, TLR5 was not expressed on conventional dendritic cells or macrophages. In contrast, TLR5 was expressed mainly on intestinal CD11c+ lamina propria cells (LPCs). CD11c+ LPCs detected pathogenic bacteria and secreted proinflammatory cytokines in a TLR5-dependent way. However, CD11c+ LPCs do not express TLR4 and did not secrete proinflammatory cytokines after exposure to a commensal bacterium. Notably, transport of pathogenic Salmonella typhimurium from the intestinal tract to mesenteric lymph nodes was impaired in Tlr5-/- mice. These data suggest that CD11c+ LPCs, via TLR5, detect and are used by pathogenic bacteria in the intestinal lumen.
authors.affiliation: Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Suita Osaka 565-0871, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Uematsu
authors.forename: Myoung Ho
authors.initials: MH
authors.lastname: Jang
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chevrier
authors.forename: Zijin
authors.initials: Z
authors.lastname: Guo
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Kumagai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kato
authors.forename: Nagako
authors.initials: N
authors.lastname: Sougawa
authors.forename: Hidenori
authors.initials: H
authors.lastname: Matsui
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kuwata
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Hemmi
authors.forename: Cevayir
authors.initials: C
authors.lastname: Coban
authors.forename: Taro
authors.initials: T
authors.lastname: Kawai
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Ishii
authors.forename: Osamu
authors.initials: O
authors.lastname: Takeuchi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyasaka
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Takeda
authors.forename: Shizuo
authors.initials: S
authors.lastname: Akira
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D039521:CD11c Antigen / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D005408:Flagellin / Q000276:immunology; D005455:Fluorescent Antibody Technique; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology* / Q000382:microbiology*; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012480:Salmonella Infections / Q000276:immunology*; D012486:Salmonella typhimurium / Q000276:immunology; D051198:Toll-Like Receptor 5 / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D039521:CD11c Antigen; D016207:Cytokines; D051198:Toll-Like Receptor 5; D005408:Flagellin