Glycosylation, an important protein modification that plays a crucial part in ligand-binding recognition, could influence the affinity of EVs for diverse tissues. Procedures: Purified EVs derived from Complement Component 8 beta Chain Proteins manufacturer hepatic cells were treated with a neuraminidase, an enzyme that digests the terminal sialic acid residues from glycoproteins. Afterwards, EVs were labelled with [124I]NaI and injected in mice intravenously or within the hook (the lateral tarsal area just above the ankle). The level of radioactivity in key organs was measured at diverse time points right after administration both in vivo making use of positron emission tomography and ex vivo (just after animal sacrifice) making use of dissection and gamma counting. Results: As expected, intravenous injection results in fast accumulation of EVs within the liver, contrary to [124I]NaI (no EVs, made use of as the control). Immediately after some hours, the distribution results in the presence of EVs in distinct organs, and interestingly, also in brain. Glycosidase-treated EVs showed a vital accumulation inside the lungs compared with intact EVs. This pattern was also confirmed within the animals injected by way of the hook.ISEV 2018 abstract bookSummary/Conclusion: The EVs derived from hepatic cell lines are systemically distributed in quite a few organs, despite the fact that the key accumulation occurs in the liver. The modification on the glycome that decorates the EVs surface affects the distribution of these vesicles, permitting the transformed EVs to reach far more abundantly the lungs. Further studies will assistance to establish diverse protocols to target many different organs. Funding: This operate was supported by RAMON ARECES FUNDATION along with the Spanish Ministry of Economy and Competitiveness MINECO (Plan NACIONAL).PS03.A quantitative strategy to measure EV uptake Victor Toribio1; Beatriz Carde s2; Sara Morales-Lopez3; Soraya L ezMart 4; Carlos Caba s2; Mar Y ez-M Centro de Biolog Molecular “Severo Ochoa” CSIC/UAM, Madrid, Spain; CBM-SO, CSIC, Madrid, Spain; 3Instituto de Investigaci Sanitaria Princesa (IIS-IP), Madrid, Spain; 4Molecular Biology Center Severo Ochoa (CBM), Instituto de Investigaci Sanitaria Princesa (IIS-IP), Madrid, Spain; 5 Departamento de Biolog Molecular, UAM, Madrid, Spain1Background: Because EV size lies beneath the limit of resolution of optical strategies, discrimination amongst EV binding to the target cell and uptake is usually not feasible with microscopy or cytometry strategies, top to artefactual outcomes. Our aim was to construct a appropriate and quantitative technique to analyse and discover the molecular mechanisms of EV uptake by the target cells, based on tetraspanins, classical EV-markers. Strategies: Human tetraspanins CD9 and CD63 were fused to a dual GFP-Luciferase-split vector tag. Incorporation of fusion proteins into EVs was assessed by bead-based flow cytometry and Carbonic Anhydrase 13 (CA-XIII) Proteins web Western blot. Measurement of binding and uptake was performed by a combination of classical Renilla substrates and Enduren. Final results: Dual GFP-Luciferase-split constructs of tetraspanins have been shown to present the exact same subcellular localization than endogenous proteins. Also, by each bead-based flow cytometry and Western blot they may be properly detected at EVs immediately after lentiviral infection of creating cells. Incubation of target cells that expressed the complementary domains on the dual GFP-Luciferase-split construct with transfected exosomes could not recover the fluorescence or the luciferase function. On the other hand, when EVs carried the completely reconstituted DualGFP-Lucife.