Lease of EVs per cell, high purity EVs.OF11.Prolongation of allograft survival via donor MHC chimerism induced by extracellular vesicles Bruno Adonai Gonzalez Nolascoa, Mengchuan Wanga, William Orenta, Aurore Prunevieillea, Jane Oa, Kaitlan Ahrensa, Joren C Madsenb and Gilles BenichouaISEV2019 ABSTRACT BOOKa Division of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Healthcare School, Boston, USA; bDepartment of Surgery, Center for Transplantation Sciences and Division of Cardiac Surgery, Massachusetts Basic Hospital and Harvard Healthcare School, Boston, USAOF11.Proteomic and transcriptomic characterization of exosomes-mimetic nanovesicles reveals their relevance as a therapeutic delivery method Amirmohammad Nasiri Kenaria, Kenneth Kastaniegaardb, Mitch C. Shambrooka, David Greeninga, Allan Stensballeb, Lesley Chenga and Andrew HillcaIntroduction: Attaining robust and sturdy host immune tolerance of allogeneic transplants could be the ultimate target in clinical transplantation. Mixed chimerism induced by way of donor bone marrow transplantation and host non-myeloablative conditioning has reliably accomplished tolerance of allogeneic organ transplants in mice and humans. Tolerance within this model is believed to rely primarily around the presentation of donor MHC molecules within the host’s thymus. In this study, we GITRL Proteins MedChemExpress investigated no matter if donor MHC chimerism may very well be achieved by means of donor extracellular vesicles (EVs) injections and subsequent cross-dressing of recipient cells inside the host’s thymus. Methods: Conditioned SJL (CD45.1+, H2-Ks+) recipient mice received a single IV dose of purified bone marrow derived exosome-enriched EVs (BM-EVs) isolated from C57BL/6 (CD45.2+, H2-Kb+) donors by way of sequential centrifugation or employing a commercially readily available exosome isolation kit. Nanoparticle tracking showed vesicles of around 100nm in size inside the BM-EVs preparation and Western Blot showed the presence of MHCI. Image flow cytometry was applied to detect the presence of cross-dressed cells from day 10 via one hundred after exosome injection. For NHP studies, MHC class I H38+ BM-EVs were injected into a H38- conditioned cynomolgus macaque before a combined heart and kidney transplant. PBMCs, thymus, spleen and mesenteric lymph nodes have been collected for image flow cytometry. Benefits: Intravenous injection of BM-EVs into conditioned mice resulted within the presentation of donor MHC and CD45.1 molecules by host’s thymic and splenic cells. Similarly, H38+cross-dressed cells were detected at D33 right after exosome injection in all of the NHP recipient tissues collected. In mice, donor but not syngeneic or third-party BM-EVs drastically prolonged skin allograft survival (median survival = 17 VS 11 days, p 0.001). Summary/Conclusion: These final results show that delivery of donor-derived extracellular vesicles can induce donor MHC chimerism through cross-dressing of recipient APCs with allogeneic MHC molecules in the host’s thymus. This suggests that donor EVs could possibly be utilised in spot of bone marrow cells to induce chimerism and allograft survival with minimal conditioning and no threat of graft versus host illness (GVHD). Funding: NIH R01DK115618.bDepartment of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia; Division of Well being Science and Technology, Faculty of Medicine, Aalborg University, Siglec-5/CD170 Proteins medchemexpress Denmark, Aalborg, Denmark; cThe Division of Biochemistry and Genetics, La Trobe Institute for Molec.