LAMP-2, a novel endocytic receptor on human monocytes derived dendritic cells (MDDC).

Abstract

Event Abstract Back to Event LAMP-2, a novel endocytic receptor on human monocytes derived dendritic cells (MDDC). Dario Leone1* 1 Medical University Vienna, Clinical Institute of Pathology, Austria LAMP-2, a novel endocytic receptor on human monocytes derived dendritic cells (MDDC). Dario Leone* Renate Kain and Andrew Rees* Clinical Institute of Pathology, Medical University of Wien. Supported by Marie Curie action (Transvir network) Keyword (Human Dendritic Cell, novel endocytic receptor, LAMP-2, uptake, antigen presentation) Lysosome-associated membrane protein-2 (LAMP-2) is a type 2 membrane-protein that is commonly used as lysosome and late endosomal marker and with essential roles in chaperone mediated autophagy and antigen presentation. LAMP-2 is also present on the cell-surface although its role was never studied. We focus on the role of LAMP-2 as a receptor on freshly isolated monocytes and iDCs with possible implication in antigen presentation. LAMP-2 was detected on the surface of immature MDDC both by FACS and confocal microscopy, its expression increased after maturation with IFN-γ LPS. The monoclonal anti-LAMP-2 antibody (H4B4) bound to LAMP-2 on the surface of MDDC and was rapidly and specifically internalized when compared to control antibodies in the presence of Fc blockade. Also the Fab fragment alone is internalized as well. Uptake was absent in MDDC from an individual with genetic LAMP-2 deficiency, Danon-disease. As expected, MDDC LAMP-2 and HLA-DR localized to partially overlapping compartments in iDC but there was no co-localization with HLA-DM. However, confocal microscopy showed that H4B4 transits into a HLA-DM positive compartment 1 hour after ligating LAMP-2 on the cell surface. Co-localization is no longer detectable after 3 hours. Finally, stimulation of immature MDDCs with H4B4 promote activation in the presence of IFN-γ indicated by up-regulation of CD80/CD83. This data suggest that when LAMP-2 is on the membrane acts as a specific receptor for internalization of extracellular molecules. H4B4 mimics natural ligands and after internalization can be found into the MIIC causing as well the maturation of DCs up-regulating CD80/83. Keywords: human dendritic cell, Antigen Presentation, Lysosomes, endocytic receptor, autoan, MHCII compartment Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Immune receptors and signaling Citation: Leone D (2013). LAMP-2, a novel endocytic receptor on human monocytes derived dendritic cells (MDDC).. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00633 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: 12 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Dario Leone, Medical University Vienna, Clinical Institute of Pathology, Vienna, 1090, Austria, bleons2.0@gmail.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 Dario Leone Google Dario Leone Google Scholar Dario Leone PubMed Dario Leone 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.