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Blood, 15 April 2007, Vol. 109, No. 8, pp. 3369-3376. Prepublished online as a Blood First Edition Paper on December 7, 2006; DOI 10.1182/blood-2006-06-031484. This Article Full Text Full Text (PDF) All Versions of this Article: blood-2006-06-031484v1 109/8/3369    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Kvale, E. O. Articles by Olweus, J. Search for Related Content PubMed PubMed Citation Articles by Kvale, E. O. Articles by Olweus, J. Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  IMMUNOBIOLOGY Plasmacytoid DCs regulate recall responses by rapid induction of IL-10 in memory T cells Espen O. Kvale1,2, Yngvar Fløisand2, Fridtjof Lund-Johansen2,3, Halvor Rollag4, Lorant Farkas1, Smita Ghanekar5, Per Brandtzaeg1, Frode L. Jahnsen1, and Johanna Olweus2 1 Laboratory for Immunohistochemistry and Immunopathology, Institute of Pathology, University of Oslo, Rikshospitalet-Radiumhospitalet Medical Center, Oslo, Norway; 2 Institute of Immunology, Rikshospitalet-Radiumhospitalet Medical Center, University of Oslo, Norway; 3 Section of Hematology, Department of Medicine, University of Oslo, Rikshospitalet-Radiumhospitalet Medical Center, Oslo, Norway; 4 Institute of Medical Microbiology, University of Oslo, Rikshospitalet-Radiumhospitalet Medical Center, Oslo, Norway; 5 BD Biosciences, San Jose, CA Dendritic cells (DCs) are believed to regulate T cell-mediated immunity primarily by directing differentiation of naive T cells. Here, we show that a large fraction of CD4+ memory cells produce IL-10 within the first hours after interaction with plasmacytoid DCs (PDCs). In contrast, CD11c+ DCs induce IFN- and little IL-10. IL-10–secreting T cells isolated after 36 hours of culture with PDCs suppressed antigen-induced T-cell proliferation by an IL-10–dependent mechanism, but were distinct from natural and type 1 regulatory T cells. They proliferated strongly and continued to secrete IL-10 during expansion with PDCs, and after restimulation with immature monocyte-derived DCs or CD11c+ DCs. The IL-10–producing T cells acquired the ability to secrete high levels of IFN- after isolation and subsequent coculture with PDCs or CD11c+ DCs. Compared to CD11c+ DCs, PDCs were superior in their ability to selectively expand T cells that produced cytokines on repeated antigenic challenge. The DC-dependent differences in cytokine profiles were observed with viral recall antigen or staphylococcal enterotoxin B and were independent of extracellular type I interferon or IL-10. Our results show that DCs can regulate memory responses and that PDCs rapidly induce regulatory cytokines in effector T cells that can suppress bystander activity. CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

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