title: Coxiella burnetii Induces Inflammatory Interferon-Like Signature in Plasmacytoid Dendritic Cells: A New Feature of Immune Response in Q Fever.
abstract: Plasmacytoid dendritic cells (pDCs) play a major role in antiviral immunity via the production of type I interferons (IFNs). There is some evidence that pDCs interact with bacteria but it is not yet clear whether they are protective or contribute to bacterial pathogenicity. We wished to investigate whether Coxiella burnetii, the agent of Q fever, interacts with pDCs. The stimulation of pDCs with C. burnetii increased the expression of activation and migratory markers (CD86 and CCR7) as determined by flow cytometry and modulated gene expression program as revealed by a microarray approach. Indeed, genes encoding for pro-inflammatory cytokines, chemokines, and type I INF were up-regulated. The up-regulation of type I IFN was correlated with an increase in IFN-α release by C. burnetii-stimulated pDCs. We also investigated pDCs in patients with Q fever endocarditis. Using flow cytometry and a specific gating strategy, we found that the number of circulating pDCs was significantly lower in patients with Q fever endocarditis as compared to healthy donors. In addition, the remaining circulating pDCs expressed activation and migratory markers. As a whole, our study identified non-previously reported activation of pDCs by C. burnetii and their modulation during Q fever.
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, UMR 63, Centre National de la Recherche Scientifique 7278, INSERM U1095, IRD 198, Aix-Marseille UniversitéMarseille, France; INSERM UMR 1068, Centre de Recherche en Cancérologie de MarseilleMarseille, France.
authors.forename: Mignane B
authors.initials: MB
authors.lastname: Ka
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, UMR 63, Centre National de la Recherche Scientifique 7278, INSERM U1095, IRD 198, Aix-Marseille Université Marseille, France.
authors.forename: Soraya
authors.initials: S
authors.lastname: Mezouar
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, UMR 63, Centre National de la Recherche Scientifique 7278, INSERM U1095, IRD 198, Aix-Marseille Université Marseille, France.
authors.forename: Amira
authors.initials: A
authors.lastname: Ben Amara
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, UMR 63, Centre National de la Recherche Scientifique 7278, INSERM U1095, IRD 198, Aix-Marseille Université Marseille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, UMR 63, Centre National de la Recherche Scientifique 7278, INSERM U1095, IRD 198, Aix-Marseille Université Marseille, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Ghigo
authors.affiliation: INSERM UMR 1068, Centre de Recherche en Cancérologie de Marseille Marseille, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Olive
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses Tropicales et Emergentes, UMR 63, Centre National de la Recherche Scientifique 7278, INSERM U1095, IRD 198, Aix-Marseille Université Marseille, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Mege
mesh_terms: D016997:Coxiella burnetii / Q000276:immunology*; D016207:Cytokines / Q000032:analysis*; D003713:Dendritic Cells / Q000276:immunology* / Q000382:microbiology*; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006801:Humans; D007370:Interferon Type I / Q000032:analysis*; D046228:Microarray Analysis; D011778:Q Fever / Q000276:immunology*
chemical_list: D016207:Cytokines; D007370:Interferon Type I
keywords: Coxiella burnetii; Q fever; infection; interferon; plasmacytoid dendritic cells