AUTHOR=Bekeredjian-Ding Isabelle , Greil Johann , Ammann Sandra , Parcina Marijo TITLE=Plasmacytoid Dendritic Cells: Neglected Regulators of the Immune Response to Staphylococcus aureus JOURNAL=Frontiers in Immunology VOLUME=Volume 5 - 2014 YEAR=2014 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2014.00238 DOI=10.3389/fimmu.2014.00238 ISSN=1664-3224 ABSTRACT=Plasmacytoid dendritic cells (pDC) are a rare subset of leukocytes equipped with Fcgamma and Fcepsilon receptors, which exert contrary effects on sensing of microbial nucleic acids by endosomal Toll-like receptors. In this article we explain how pDC contribute to the immune response to Staphylococcus aureus. Under normal circumstances the pDC participates in the memory response to the pathogen: pDC activation is initiated by uptake of staphylococcal immune complexes with IgG or IgE. However, protein A-expressing S. aureus strains additionally trigger pDC activation in the absence of immunoglobulin. In this context staphylococci exploit the pDC to induce antigen-independent differentiation of IL-10 producing plasmablasts, an elegant means to propagate immune evasion. We further discuss the role of type I interferons in infection with S. aureus and the implications of these findings for the development of immune based therapies and vaccination.