Canine adipose mesenchymal stem cell secretome right after various priming situations that would mimic an inflammatory environment. In unique, we wondered irrespective of whether conditioned medium (CM) would possess a advantageous impact on inflammation. Approaches: The very first step of this investigation was to establish a proteomic profile with the MSC CM, to locate the presence of certain cytokines and characterize the population of secreted extracellular vesicles (EV). Proteomic profiling from the MSC secretome was made by electrophoresis coupled with mass spectrometry and have been confirmed by ELISA. Then, to assess the CM impact on inflammation, a canine macrophage cell line DH82 was activated by LPS and treated with concentrated canine adipose MSC-derived CM. The level of TNF, IL1, IL10, IL6 and IL8 cytokines have been quantified by ELISA. Results: The initial results showed that MSC secreted far more proteins and EV immediately after diverse priming circumstances. Furthermore, CM down-regulates macrophage secretion of TNF and IL1 pointing that MSC-derived CM exhibits an anti-inflammatory impact. Summary/Conclusion: These information indicate that CM containing EV delivered by canine adipose MSC could be a fantastic option for the treatment of canine inflammatory diseases. Finally, the priming optimization of MSC secretome could potentially bring about optimize the antiinflammatory impact of CM.Friday, 04 MayPF04: EVs plus the Immune System Chairs: Martin van Herwijnen; Mar Vales-Gomez Location: Exhibit Hall 17:158:PF04.01 = OWP1.Immunomodulatory function of human mesenchymal stromal cellsderived extracellular vesicles on type-I interferon response in human plasmacytoid dendritic cells and lupus murine pDCs Lin Kui1; Godfrey CF Chan2; Pamela PW Lee1 Division of CDK4 Inhibitor manufacturer Paediatrics and Caspase 8 Inhibitor web Adolescent Medicine, The University of Hong Kong, Hong Kong, Hong Kong; 2Department of Paediatrics Adolescent Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong; 3Department of Paediatrics and Adolescent Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong KongInstitute of Pharmaceutical Biotechnology, Faculty of Pharmacy, University of Pecs, Pecs, Hungary; 2Institute of Physical Education and Sport Sciences, Faculty of Science, University of Pecs, Hungary; 3Szentagothai Study Center, University of Pecs, HungaryBackground: Immunoregulatory impact of Mesenchymal stem cell (MSC) is attributed to Extracellular vesicles (EVs) secretion. Given its effectiveness in preclinical research of autoimmune illness, no one has examined its effect on SLE pathogenesis, signify by excessive type-I IFN production by pDCs and animal models. We found that TSG-6, a essential anti-inflammatory protein secreted by activated MSC, downregulates TLR7 and TLR9 activation in human pDC. Herein, we investigate the impact of MSC and MSC-EVs on regulating cytokines production in pDCs, and no matter if such impact is mediated by TSG-6. Procedures: htMSC (immortalized human MSCs), was cultured in CDPF medium for 48 hours. EV had been isolated by ultracentrifugation at 100,000g, 3hr, at four and were characterized by Transmission electron microscopy, Nanosight, and western-blot. Comparison of immunosuppressive function amongst htMSC-EV and TSG-6 knockdown htMSC on TLR9-mediated cytokine production in pDC was determined with GEN2.2, a human pDC cell-line, following activation by CpG-A, and evaluation by qPCR and ELISA. Ultimately, we compared the IFN- and TNF intracellular expression in pDCs of htMSC-EV treated NZB W/F1 mi.