title: Normal proportion and expression of maturation markers in migratory dendritic cells in the absence of germs or Toll-like receptor signaling.
abstract: Dendritic cells (DCs) play major roles in immunosurveillance. In peripheral tissues, 'immature' DCs are dedicated to capturing antigens. Detection of pathogens through Toll-like receptors (TLRs) triggers DC migration to the lymph nodes (LNs), where they acquire a 'mature' phenotype specialized at presenting antigens. However, DCs migrate from tissues and mature even in the absence of overt infections. This has been attributed to detection of commensal flora in the skin, the gut or other peripheral tissues in the steady state. To test this assumption, we have analyzed the DCs contained in the lymphoid organs of germ-free mice and of mice lacking the TLR adapter molecules, MyD88 and TRIF. We show that the proportion and expression of maturation markers in DC immigrants in the LNs of these mice are similar to those in normal mice. These results suggest that DC migration from tissues, followed by their phenotypic maturation, is regulated in the steady state by an inherent program of DC differentiation or by the release of low levels of inflammatory signals from normal tissues.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Wilson
authors.forename: Louise J
authors.initials: LJ
authors.lastname: Young
authors.forename: Fiona
authors.initials: F
authors.lastname: Kupresanin
authors.forename: Shalin H
authors.initials: SH
authors.lastname: Naik
authors.forename: David
authors.initials: D
authors.lastname: Vremec
authors.forename: William R
authors.initials: WR
authors.lastname: Heath
authors.forename: Shizuo
authors.initials: S
authors.lastname: Akira
authors.forename: Ken
authors.initials: K
authors.lastname: Shortman
authors.forename: Jeff
authors.initials: J
authors.lastname: Boyle
authors.forename: Eugene
authors.initials: E
authors.lastname: Maraskovsky
authors.forename: Gabrielle T
authors.initials: GT
authors.lastname: Belz
authors.forename: José A
authors.initials: JA
authors.lastname: Villadangos
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000172:deficiency / Q000276:immunology / Q000378:metabolism; D000818:Animals; D001419:Bacteria / Q000276:immunology; D002465:Cell Movement; D003713:Dendritic Cells / Q000276:immunology / Q000382:microbiology / Q000502:physiology*; D005856:Germ-Free Life; D051379:Mice; D008810:Mice, Inbred C57BL; D053594:Myeloid Differentiation Factor 88 / Q000172:deficiency / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction; D051193:Toll-Like Receptors / Q000276:immunology* / Q000378:metabolism
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D053594:Myeloid Differentiation Factor 88; D051193:Toll-Like Receptors; C507780:Myd88 protein, mouse; C476286:Ticam1 protein, mouse