title: Post-transcriptional down-regulation of Toll-like receptor signaling pathway in umbilical cord blood plasmacytoid dendritic cells.
abstract: Plasmacytoid dendritic cells (PDCs) from human umbilical cord blood (UCB) produce lower amounts of IFN-α upon TLR stimulation compared with adult counterparts. This difference may play a role in the low graft-versus-host disease rate after UCB transplantation and in the impaired immune response of the neonate to pathogens. Comparing UCB PDC to their adults counterparts, we found that they exhibited a mature surface phenotype and a normal antigen uptake. They upregulated costimulatory molecules upon activation, although with delayed kinetics. Protein, but not ARN, levels of TLR-9, MyD88, IRAK1 and IRF-7, involved in the TLR-9 signaling pathway were reduced. The expression levels of miR-146a and miR-155, known to be involved in the post-transcriptional down-regulation of immune responses, were higher. These data point out a post-transcriptional down-regulation of the TLR-9/IRF-7 signaling pathway in UCB PDC.
authors.affiliation: Groupe de Recherche En Transplantation et Immunologie du Sang de Cordon, Centre de Cancérologie Charles-Bruneau, Centre de Recherche du CHU Sainte-Justine, 3175 chemin de la Côte Sainte-Catherine, Montréal, Québec, Canada H3T 1C5.
authors.forename: Emily
authors.initials: E
authors.lastname: Charrier
authors.forename: Paulo
authors.initials: P
authors.lastname: Cordeiro
authors.forename: Martine
authors.initials: M
authors.lastname: Cordeau
authors.forename: R'Kia
authors.initials: R
authors.lastname: Dardari
authors.forename: Annie
authors.initials: A
authors.lastname: Michaud
authors.forename: Michaël
authors.initials: M
authors.lastname: Harnois
authors.forename: Natacha
authors.initials: N
authors.lastname: Merindol
authors.forename: Sabine
authors.initials: S
authors.lastname: Herblot
authors.forename: Michel
authors.initials: M
authors.lastname: Duval
mesh_terms: D002454:Cell Differentiation; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D015536:Down-Regulation; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D010641:Phenotype; D034622:RNA Interference; D015398:Signal Transduction; D051193:Toll-Like Receptors / Q000276:immunology*
chemical_list: C542542:MIRN146 microRNA, human; C524942:MIRN155 microRNA, human; D035683:MicroRNAs; D051193:Toll-Like Receptors