title: Expression of multilectin receptors and comparative FITC-dextran uptake by human dendritic cells.
abstract: Dendritic cells (DC) are potent antigen-presenting cells and understanding their mechanisms of antigen uptake is important for loading DC with antigen for immunotherapy. The multilectin receptors, DEC-205 and macrophage mannose receptor (MMR), are potential antigen-uptake receptors; therefore, we examined their expression and FITC-dextran uptake by various human DC preparations. The RT-PCR analysis detected low levels of DEC-205 mRNA in immature blood DC, Langerhans cells (LC) and immature monocyte-derived DC (Mo-DC). Its mRNA expression increased markedly upon activation, indicating that DEC-205 is an activation-associated molecule. In Mo-DC, the expression of cell-surface DEC-205 increased markedly during maturation. In blood DC, however, the cell-surface expression of DEC-205 did not change during activation, suggesting the presence of a large intracellular pool of DEC-205 or post-transcriptional regulation. Immature Mo-DC expressed abundant MMR, but its expression diminished upon maturation. Blood DC and LC did not express detectable levels of the MMR. FITC-dextran uptake by both immature and activated blood DC was 30- to 70-fold less than that of LC, immature Mo-DC and macrophages. In contrast to immature Mo-DC, the FITC-dextran uptake by LC was not inhibited effectively by mannose, an inhibitor for MMR-mediated FITC-dextran uptake. Thus, unlike Mo-DC, blood DC and LC do not use the MMR for carbohydrate-conjugated antigen uptake and alternative receptors may yet be defined on these DC. Therefore, DEC-205 may have a different specificity as an antigen uptake receptor or contribute to an alternative DC function.
authors.affiliation: Haematology/Immunology Research Group, Christchurch School of Medicine, Christchurch, New Zealand.
authors.forename: M
authors.initials: M
authors.lastname: Kato
authors.forename: T K
authors.initials: TK
authors.lastname: Neil
authors.forename: D B
authors.initials: DB
authors.lastname: Fearnley
authors.forename: A D
authors.initials: AD
authors.lastname: McLellan
authors.forename: S
authors.initials: S
authors.lastname: Vuckovic
authors.forename: D N
authors.initials: DN
authors.lastname: Hart
mesh_terms: D000818:Animals; D015703:Antigens, CD; D019556:COS Cells; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism*; D003911:Dextrans / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives* / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism; D006689:Hodgkin Disease / Q000378:metabolism; D006801:Humans; D007546:Isoquinolines / Q000378:metabolism; D007801:Langerhans Cells / Q000276:immunology / Q000378:metabolism; D037102:Lectins / Q000378:metabolism; D037181:Lectins, C-Type; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D015778:Minor Histocompatibility Antigens; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D010873:Pinocytosis / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis; D011946:Receptors, Antigen / Q000096:biosynthesis*; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D015703:Antigens, CD; C093569:DEC-205 receptor; D003911:Dextrans; D005456:Fluorescent Dyes; D007546:Isoquinolines; D037102:Lectins; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008562:Membrane Glycoproteins; D015778:Minor Histocompatibility Antigens; D012333:RNA, Messenger; D011946:Receptors, Antigen; D011956:Receptors, Cell Surface; C015219:fluorescein isothiocyanate dextran; C017475:lucifer yellow; D016650:Fluorescein-5-isothiocyanate