Plasmacytoid dendritic cells activated by influenza virus and CD40L drive a potent TH1 polarization.
Plasmacytoid dendritic cells (PDCs) are a subset of dendritic cells present in human blood and inflamed lymph nodes. Here we show that blood PDCs, when stimulated with influenza virus and CD40L in vitro, undergo a maturation process characterized by up-regulation of major histocompatibility complex proteins and adhesion and costimulatory molecules. In addition, PDCs down-regulate CXCR3 and L-selectin, which mediate migration and homing of these cells into the lymph node. Mature PDCs efficiently stimulate T cells and drive a potent TH1 polarization in vitro, which is mediated by the synergistic effect of interleukin 12 and type 1 interferon. In vivo, mature PDCs are found in secondary lymphoid organs, where they represent the principal source of type 1 interferon during inflammation. Thus, PDCs probably participate in antiviral and pro-inflammatory responses, rather than in TH2 polarization and tolerance induction.
Cella
M
M
Basel Institute for Immunology, CH-4005 Basel, Switzerland.
Facchetti
F
F
Lanzavecchia
A
A
Colonna
M
M
D017951:Antigen Presentation; D000956:Antigens, Viral / Q000276:immunology; D023201:CD40 Ligand / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology* / Q000821:virology; D006801:Humans; D007108:Immune Tolerance; D007251:Influenza, Human / Q000276:immunology*; D008213:Lymphocyte Activation; D009975:Orthomyxoviridae / Q000276:immunology*; D010950:Plasma Cells / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*
D000956:Antigens, Viral; D023201:CD40 Ligand