title: Prostaglandin E2 inhibits IFN-alpha secretion and Th1 costimulation by human plasmacytoid dendritic cells via E-prostanoid 2 and E-prostanoid 4 receptor engagement.
abstract: Plasmacytoid dendritic cell (PDC)-derived IFN-alpha plays a central role in antiviral defense and in Th1-driven autoimmune diseases, such as systemic lupus erythematosus (SLE). In the current study, we explored how PGE2 effects the phenotype of PDCs from healthy and SLE subjects. Although PGE2 is considered to mediate mainly proinflammatory effects, we show that PGE2 and PG analogs potently inhibit secretion of IFN-alpha by TLR-activated PDCs. This effect is mainly mediated by PG receptors E-prostanoid 2 and E-prostanoid 4 and involves inhibition of IFN regulatory factor 7 expression. Of note, profound IFN-alpha inhibition by PGE2 is also seen in PDCs from SLE subjects, independent of age, disease activity, and therapy. We show that TLR9-activated PDCs treated with PGE2 exhibit DC2-like characteristics with enhanced expression of CD86 and CD62L, and decreased expression of CD80 and MHC class I. Consequently, PGE2-treated PDCs suppress secretion of Th1 cytokines by T cells while increasing the secretion of Th2 cytokines. Prevention of CpG-induced CD62L downregulation by PGE2 suggests that it may induce the retreat of PDCs from inflamed tissues. Our data on the effects of PGE2 on PDCs may explain occasional reports about the induction of SLE-like symptoms by cyclooxygenase inhibitors as well as improvement of such symptoms by treatment with PG analogs. In conclusion, our data suggest that PGE2 and certain PG analogs, some of which are already in clinical use, should be evaluated as a novel and inexpensive treatment approach for patients with SLE and other IFN-alpha-dependent, Th1-driven autoimmune diseases.
authors.affiliation: Department of Pediatrics, University of Ulm, Ulm, Germany. dorit.fabricius@uni-ulm.de
authors.forename: Dorit
authors.initials: D
authors.lastname: Fabricius
authors.forename: Marina
authors.initials: M
authors.lastname: Neubauer
authors.forename: Birgit
authors.initials: B
authors.lastname: Mandel
authors.forename: Catharina
authors.initials: C
authors.lastname: Schütz
authors.forename: Andreas
authors.initials: A
authors.lastname: Viardot
authors.forename: Angelika
authors.initials: A
authors.lastname: Vollmer
authors.forename: Bernd
authors.initials: B
authors.lastname: Jahrsdörfer
authors.forename: Klaus-Michael
authors.initials: KM
authors.lastname: Debatin
mesh_terms: D016022:Case-Control Studies; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology*; D015232:Dinoprostone / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D016898:Interferon-alpha / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D018078:Receptors, Prostaglandin E / Q000378:metabolism*; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype; D018417:Th1 Cells / Q000378:metabolism*
chemical_list: D016207:Cytokines; D016898:Interferon-alpha; C545644:PTGER2 protein, human; C545650:PTGER4 protein, human; D018078:Receptors, Prostaglandin E; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype; D015232:Dinoprostone