Involvement of commensal bacteria in thymic Aire expression

Event Abstract Back to Event Involvement of commensal bacteria in thymic Aire expression Akihito Nakajima1 and Sonoko Habu1* 1 Juntendo University, Japan Autoimmune regulator (Aire) expression in thymic epithelial cells (TECs) is involved in negative selection of self-antigen reactive T cells. However, little is known about how Aire expression is regulated. In this study, we found that Aire expression is reduced in TECs in germ-free (GF) mice in which commensal bacteria are absent, in comparison to specific pathogen-free (SPF) mice, allowing us to predict that components of commensal bacteria are involved in promoting Aire expression in TECs. Mutant mice lacking Nod1, an intracellular pattern recognition receptor of bacteria-derived molecules, also revealed reduced Aire expression in TECs. In the organ culture system of fetal thymus (FTOC) of wild type mice in the presence of synthetic ligand of Nod1, Aire expression was reciprocally increased in TECs. Staphylococcal enterotoxin B (SEB) produced from Staphylococcus aureus also induced Aire up-regulation in FTOC, which was reduced when thymic lobes were co-cultured with blocking antibody against the cytokine RANK ligand (RANKL). These observations indicate that intestinal bacterial components are involved in promoting Aire expression in TECs in vivo and in vitro, suggesting the novel possibility that commensal bacteria contribute to intrathymic negative selection through Aire induction. Keywords: AIRE, Autoimmune Diseases, commensal bacteria, NOD1, Superantigens Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Adaptive Immunity Citation: Nakajima A and Habu S (2013). Involvement of commensal bacteria in thymic Aire expression. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00869 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: 24 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Sonoko Habu, Juntendo University, Tokyo, Japan, sonoko-h@juntendo.ac.jp 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 Akihito Nakajima Sonoko Habu Google Akihito Nakajima Sonoko Habu Google Scholar Akihito Nakajima Sonoko Habu PubMed Akihito Nakajima Sonoko Habu 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.