Detection of pathogenic intestinal bacteria by Toll-like receptor 5 on intestinal CD11c+ lamina propria cells.
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.
Uematsu
Satoshi
S
Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Suita Osaka 565-0871, Japan.
Jang
Myoung Ho
MH
Chevrier
Nicolas
N
Guo
Zijin
Z
Kumagai
Yutaro
Y
Yamamoto
Masahiro
M
Kato
Hiroki
H
Sougawa
Nagako
N
Matsui
Hidenori
H
Kuwata
Hirotaka
H
Hemmi
Hiroaki
H
Coban
Cevayir
C
Kawai
Taro
T
Ishii
Ken J
KJ
Takeuchi
Osamu
O
Miyasaka
Masayuki
M
Takeda
Kiyoshi
K
Akira
Shizuo
S
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*
D000942:Antigens, Bacterial; D039521:CD11c Antigen; D016207:Cytokines; D051198:Toll-Like Receptor 5; D005408:Flagellin