Original Research ARTICLE
Monosodium urate crystals induce extracellular DNA traps in neutrophils, eosinophils, and basophils but not in mononuclear cells
- Department of Internal Medicine 3, Institute for Clinical Immunology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
Neutrophil extracellular traps (NETs) are fibers of extracellular DNA released from neutrophils due to overwhelming phagocytic stimuli. The function of NETs is to trap and kill microbes to avoid spreading of potential pathogens. NETs are formed after encounter with various gram-positive and -negative bacteria but also in response to mediators causing sterile inflammation like interleukin-8 (IL-8), tumor necrosis factor (TNF), and phorbol myristate acetate (PMA). Here we show the formation of NETs (NETting) in response to monosodium urate (MSU) crystals as further model for sterile inflammation. We identified monocytes, neutrophils, and eosinophils as MSU phagocytosing cells. Basophils did not take up the crystals, instead they upregulated their activation marker CD203c after contact with MSU. Nevertheless, MSU crystals induced extracellular trap formation also in basophils, like in eosinophils and neutrophils, which phagocytose the crystals. In contrast, monocytes do not form NETs despite uptake of the MSU crystals. In contrast to the canonical stimuli like bacteria and PMA, MSU-induced NETosis was not abrogated by plasma. Our data show that MSU crystals induce extracellular DNA trap formation in all three granulocytes lineages (NETs, EETs, and BETs) but not in monocytes, and DNA externalization does not necessitate the uptake of the crystals.
Keywords: neutrophil extracellular traps, NETs, MSU, granulocytes, bacteria, PMA, inflammation
Citation: Schorn C, Janko C, Latzko M, Chaurio R, Schett G and Herrmann M (2012) Monosodium urate crystals induce extracellular DNA traps in neutrophils, eosinophils, and basophils but not in mononuclear cells. Front. Immun. 3:277. doi: 10.3389/fimmu.2012.00277
Received: 13 June 2012; Paper pending published: 04 July 2012;
Accepted: 15 August 2012; Published online: 03 September 2012.
Edited by:Angelo A. Manfredi, Vita Salute San Raffaele University, Italy
Reviewed by:Angelo A. Manfredi, Vita Salute San Raffaele University, Italy
Kirsten Lauber, Ludwig Maximilian University Munich, Germany
Ian Dransfield, University of Edinburgh, UK
Copyright © 2012 Schorn, Janko, Latzko, Chaurio, Schett and Herrmann. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Martin Herrmann, Department of Internal Medicine 3, Institute for Clinical Immunology, University of Erlangen-Nuremberg, Krankenhausstr. 12, 91054 Erlangen, Germany. e-mail: email@example.com
†These authors equally contributed to this work.