Michea, PaulaVargas, PabloDonnadieu, Marie-HélèneRosemblatt, MarioBono, María RosaDuménil, GuillaumeSoumelis, Vassili2025-05-162025-05-162013-04European Journal of Immunology. Volume 43, Issue 5, Pages 1264 - 1273. April 20131521-4141https://repositorio.unab.cl/handle/ria/64725Indexación: ScopusPlasmacytoid pre-dendritic cells (pDCs) are specialized in responding to nucleic acids, and link innate with adaptive immunity. Although the response of pDCs to viruses is well established, whether pDCs can respond to extracellular bacteria remains controversial. Here, we demonstrate that extracellular bacteria such as Neisseria meningitidis, Haemophilus influenzae, and Staphylococcus aureus activate pDCs to produce IFN-α, TNF-α, IL-6, and to upregulate CD86 expression. We observed that pDCs were present within tonsillar crypts and oro-nasopharyngeal epithelium, where they may contact extracellular bacteria, in situ. Tonsil epithelium-conditioned supernatants inhibited IFN-α, TNF-α, and IL-6 triggered by the direct contact of N. meningitidis or S. aureus with pDCs. However, pDC priming of naive T cells was not affected, suggesting that tonsil epithelium micro-environment limits local inflammation while preserving adaptive immunity in response to extracellular bacteria. Our results reveal an important and novel function of pDCs in the initiation of the mucosal innate and adaptive immunity to extracellular bacteria. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.enCytokinesExtracellular BacteriaHuman MucosaInnate ImmunityPlasmacytoid pre-dendritic cellArtículo10.1002/eji.201242990International Cooperation Inserm-Conicyt 2009/2011Conicyt Doctoral Fellowship, Conicyt PFB-16M