Event Abstract Back to Event Orai1-mediated Ca2+ influx independent of SOCE is essential for LPS and C5a-induced neutrophil migration in acute inflammation Georgios Sogkas1, Timo Vögtle2, Bernhard Nieswandt2, Reinhold Ernst Schmidt1 and Johannes Engelbert Gessner1* 1 Hannover Medical School, Clinic for Immunology and Rheumatology, Germany 2 University Hospital and Rudolf Virchow Center, DFG Research Center for Experimental Biomedicine, Chair of Experimental Biomedicine, Germany The pattern of Ca2+ mobilization serving neutrophil migration is distinct in case of different chemoattractants. Migration, elicited by chemoattractants such as C5a and fMLP, depends on extracellular Ca2+. However, this is not the case with MIP2-elicited migration. In vitro, Orai1 is required for C5a and fMLP-elicited migration but not for the Ca2+ influx independent MIP2-elicited migration. Elevation of the cytosolic levels of calcium post stimulation with C5a, which is due to Ca2+ influx, was substantially reduced in Orai1 deficient neutrophils. These data suggest the involvement of Orai1 in Ca2+ influx, serving neutrophil chemotaxis. These findings were recapitulated in vivo, in Orai1-/- bone marrow chimeric mice, in the context of agonist-induced peritoneal recruitment of neutrophils. Moreover, in case of LPS-induced peritonitis, where neutrophil recruitment largely depends on C5a, reduced numbers of neutrophils were thrived from the peritoneal cavity of Orai1-/- bone marrow chimeric mice as compared to wild type transplanted mice. Dispelling the strongly entrenched perception of Orai1 as a store-operated Ca2+ entry (SOCE) mediator, we provide several lines of evidence demonstrating that Orai1 requirement comes in a non-SOCE manner. We show that Orai1 is not involved in neutrophil SOCE. Although STIM1 is the master mediator of neutrophil SOCE, STIM1 deficient neutrophils exhibited efficient migration in vitro and in vivo. Finally, application of YM58483, with a regiment abrogating SOCE, was of no consequence in neutrophil migration. Acknowledgements Funded by the DFG and the International HRBS PhD program in Molecular Medicine. Keywords: Orai1, Neutrophils, Chemotaxis, C5a, fMLP, MIP2, Calcium, YM58483 Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Innate immunity Citation: Sogkas G, Vögtle T, Nieswandt B, Schmidt R and Gessner J (2013). Orai1-mediated Ca2+ influx independent of SOCE is essential for LPS and C5a-induced neutrophil migration in acute inflammation. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00476 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: 02 Apr 2013; Published Online: 22 Aug 2013. * Correspondence: Prof. Johannes Engelbert Gessner, Hannover Medical School, Clinic for Immunology and Rheumatology, Hannover, Germany, Gessner.Johannes@mh-hannover.de 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 Georgios Sogkas Timo Vögtle Bernhard Nieswandt Reinhold Ernst Schmidt Johannes Engelbert Gessner Google Georgios Sogkas Timo Vögtle Bernhard Nieswandt Reinhold Ernst Schmidt Johannes Engelbert Gessner Google Scholar Georgios Sogkas Timo Vögtle Bernhard Nieswandt Reinhold Ernst Schmidt Johannes Engelbert Gessner PubMed Georgios Sogkas Timo Vögtle Bernhard Nieswandt Reinhold Ernst Schmidt Johannes Engelbert Gessner 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.