title: Down-regulation of Toll-like receptor expression in monocyte-derived Langerhans cell-like cells: implications of low-responsiveness to bacterial components in the epidermal Langerhans cells.
abstract: In the skin, there are unique dendritic cells called Langerhans cells, however, it remains unclear why this particular type of dendritic cell resides in the epidermis. Langerhans cell-like dendritic cells (LCs) can be generated from CD14(+) monocytes in the presence of GM-CSF, IL-4, and TGF-beta1. We compared LCs with monocyte-derived dendritic cells (DCs) generated from CD14(+) monocytes in the presence of GM-CSF and IL-4 and examined the effect of exposure to two distinct bacterial stimuli via Toll-like receptors (TLRs), such as peptidoglycan (PGN) and lipopolysaccharide (LPS) on LCs and DCs. Although stimulation with both ligands induced a marked up-regulation of CD83 expression on DCs, PGN but not LPS elicited up-regulation of expression CD83 on LCs. Consistent with these results, TLR2 and TLR4 were expressed on DCs, whereas only TLR2 was weakly detected on LCs. These findings suggest the actual feature of epidermal Langerhans cells with low-responsiveness to skin commensals.
authors.affiliation: Department of Microbiology and Immunology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8602, Tokyo, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Takeuchi
authors.forename: Eiji
authors.initials: E
authors.lastname: Watari
authors.forename: Eiji
authors.initials: E
authors.lastname: Shinya
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Norose
authors.forename: Misako
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Seya
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sugita
authors.forename: Seiji
authors.initials: S
authors.lastname: Kawana
authors.forename: Hidemi
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D048429:Cell Size; D002478:Cells, Cultured; D003594:Cytoplasmic Granules / Q000378:metabolism; D015536:Down-Regulation; D000078404:Epidermal Cells; D004817:Epidermis / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D007801:Langerhans Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D010457:Peptidoglycan / Q000494:pharmacology; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors
chemical_list: D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D010457:Peptidoglycan; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D016753:Interleukin-10; D018664:Interleukin-12