title: The double-stranded RNA bluetongue virus induces type I interferon in plasmacytoid dendritic cells via a MYD88-dependent TLR7/8-independent signaling pathway.
abstract: Dendritic cells (DCs), especially plasmacytoid DCs (pDCs), produce large amounts of alpha/beta interferon (IFN-α/β) upon infection with DNA or RNA viruses, which has impacts on the physiopathology of the viral infections and on the quality of the adaptive immunity. However, little is known about the IFN-α/β production by DCs during infections by double-stranded RNA (dsRNA) viruses. We present here novel information about the production of IFN-α/β induced by bluetongue virus (BTV), a vector-borne dsRNA Orbivirus of ruminants, in sheep primary DCs. We found that BTV induced IFN-α/β in skin lymph and in blood in vivo. Although BTV replicated in a substantial fraction of the conventional DCs (cDCs) and pDCs in vitro, only pDCs responded to BTV by producing a significant amount of IFN-α/β. BTV replication in pDCs was not mandatory for IFN-α/β production since it was still induced by UV-inactivated BTV (UV-BTV). Other inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and IL-12p40, were also induced by UV-BTV in primary pDCs. The induction of IFN-α/β required endo-/lysosomal acidification and maturation. However, despite being an RNA virus, UV-BTV did not signal through Toll-like receptor 7 (TLR7) for IFN-α/β induction. In contrast, pathways involving the MyD88 adaptor and kinases dsRNA-activated protein kinase (PKR) and stress-activated protein kinase (SAPK)/Jun N-terminal protein kinase (JNK) were implicated. This work highlights the importance of pDCs for the production of innate immunity cytokines induced by a dsRNA virus, and it shows that a dsRNA virus can induce IFN-α/β in pDCs via a novel TLR-independent and Myd88-dependent pathway. These findings have implications for the design of efficient vaccines against dsRNA viruses.
authors.affiliation: Virologie et Immunologie Moléculaires, UR892 INRA, Jouy-en-Josas, France.
authors.forename: Suzana
authors.initials: S
authors.lastname: Ruscanu
authors.forename: Florentina
authors.initials: F
authors.lastname: Pascale
authors.forename: Mickael
authors.initials: M
authors.lastname: Bourge
authors.forename: Behzad
authors.initials: B
authors.lastname: Hemati
authors.forename: Jamila
authors.initials: J
authors.lastname: Elhmouzi-Younes
authors.forename: Céline
authors.initials: C
authors.lastname: Urien
authors.forename: Michel
authors.initials: M
authors.lastname: Bonneau
authors.forename: Haru
authors.initials: H
authors.lastname: Takamatsu
authors.forename: Jayne
authors.initials: J
authors.lastname: Hope
authors.forename: Peter
authors.initials: P
authors.lastname: Mertens
authors.forename: Gilles
authors.initials: G
authors.lastname: Meyer
authors.forename: Meredith
authors.initials: M
authors.lastname: Stewart
authors.forename: Polly
authors.initials: P
authors.lastname: Roy
authors.forename: Eliane F
authors.initials: EF
authors.lastname: Meurs
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Dabo
authors.forename: Stéphan
authors.initials: S
authors.lastname: Zientara
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Breard
authors.forename: Corinne
authors.initials: C
authors.lastname: Sailleau
authors.forename: Emilie
authors.initials: E
authors.lastname: Chauveau
authors.forename: Damien
authors.initials: D
authors.lastname: Vitour
authors.forename: Bernard
authors.initials: B
authors.lastname: Charley
authors.forename: Isabelle
authors.initials: I
authors.lastname: Schwartz-Cornil
mesh_terms: D000818:Animals; D001819:Bluetongue / Q000235:genetics / Q000276:immunology* / Q000821:virology; D001820:Bluetongue virus / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology* / Q000821:virology; D005260:Female; D007113:Immunity, Innate; D007370:Interferon Type I / Q000235:genetics / Q000276:immunology*; D008562:Membrane Glycoproteins; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000276:immunology*; D017472:Receptors, Interleukin-1; D012756:Sheep / Q000276:immunology / Q000821:virology; D015398:Signal Transduction; D051199:Toll-Like Receptor 7 / Q000235:genetics / Q000276:immunology*; D051200:Toll-Like Receptor 8 / Q000235:genetics / Q000276:immunology*
chemical_list: D016207:Cytokines; D007370:Interferon Type I; D008562:Membrane Glycoproteins; D053594:Myeloid Differentiation Factor 88; D017472:Receptors, Interleukin-1; C434984:TIRAP protein, human; D051199:Toll-Like Receptor 7; D051200:Toll-Like Receptor 8