Event Abstract Back to Event The functional fate of human monocytes after engagement of various pattern recognition receptors Daniela Ifrim1*, Jessica Quintin1, Leo Joosten1, Gow Neil2, David Williams3, Jos W. Van Der Meer1 and Mihai Netea1 1 Radboud University Medical Center Nijmegen, Department of Medicine, Netherlands 2 University of Aberdeen, United Kingdom 3 East Tennessee State University, United States After priming with the human commensal Candida albicans or the fungal cell wall component β-glucan, monocytes respond with an increased cytokine production upon restimulation, a phenomenon termed "trained immunity". Because the vast majority of commensal microorganisms are of the bacterial or viral phyla, we sought to determine whether similar monocyte reprogramming could be induced by recognition of bacterial or viral ligands by pattern-recognition receptors. Monocytes were functionally programmed for either an enhanced (training) or a decreased (tolerance) cytokine production, depending on the type of ligand they encountered. The training effect required p38 and JNK mediated MAPK-signalling, with specific signalling patterns directing the functional fate of the cell. The long-term effects on the function of monocytes were mediated by epigenetic events, with both histone methylation and acetylation inhibitors blocking the training effects. In conclusion, our experiments identify the ability of monocytes to acquire adaptive characteristics after prior activation with a wide variety of microbial ligands. Trained immunity and tolerance are two distinct functional programs induced by the specific microbial ligands engaging the monocytes. Acknowledgements D.C.I. received funding from the European Union’s Seventh Framework Programme [FP7/2007-2013] under grant agreement n° HEALTH-2010-260338 (Fungi in the setting of inflammation, allergy and autoimmune diseases: Translating basic science into clinical practices “ALLFUN”). M.G.N. was supported by a Vici grant of the Netherlands Organization of Scientific Research. This work was supported, in part, by NIHGM53522 to D.L.W. N.G. was supported by the Wellcome Trust. References no conflict of interest Keywords: innate immunity, host microbiota, memory monocytes, Pattern Recognition Receptors, MAPK, epigenetics Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Innate immunity Citation: Ifrim D, Quintin J, Joosten L, Neil G, Williams D, Van Der Meer JW and Netea M (2013). The functional fate of human monocytes after engagement of various pattern recognition receptors . Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00941 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 26 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Ms. Daniela Ifrim, Radboud University Medical Center Nijmegen, Department of Medicine, Nijmegen, Netherlands, daniela.ifrim@yahoo.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Daniela Ifrim Jessica Quintin Leo Joosten Gow Neil David Williams Jos W Van Der Meer Mihai Netea Google Daniela Ifrim Jessica Quintin Leo Joosten Gow Neil David Williams Jos W Van Der Meer Mihai Netea Google Scholar Daniela Ifrim Jessica Quintin Leo Joosten Gow Neil David Williams Jos W Van Der Meer Mihai Netea PubMed Daniela Ifrim Jessica Quintin Leo Joosten Gow Neil David Williams Jos W Van Der Meer Mihai Netea Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.