Of your LP and HP EVs revealed that the vast majority in the identified proteins had been the truth is connected with EVs. One of the most abundant proteins in LP and HP EVs shared comparable but not identical functional characteristics, as well as the proteins showing substantial differential expression in between HP and LP EVs had been predicted to become enriched in Gene Ontology biological approach terms primarily related to transport and secretion and to pathways regulating cellular morphology, growth/proliferation and development. Both LP and HP EVs promoted MSC survival and proliferation in autocrine and paracrine manners, plus the degree of proliferation was dependent around the applied EV dose and connected together with the traits on the recipient cells. Summary/conclusion: The above-described benefits demonstrate that in vitro ageing influences the secretion of EVs by MSCs, particularly the number and protein cargoes with the EVs.OF20.Novel function of BCR-ABL-containing leukemic extracellular vesicles in controlling the function of regulatory T cells Julian Swatlera, Wioleta Dudka-Ruszkowskaa, Lukasz Bugajskib, Ewa Kozlowskac and Katarzyna Piwockaaa Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland; bLaboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Science, Warsaw, Poland; cDepartment of Immunology, Faculty of Biology, University of Warsaw, Warsaw, Polandexpress Foxp3 and EGFP. Treg in blood of CML patients have been analysed using 13-colour flow cytometry. Results: Leukemic EVs potentiate suppressive function of regulatory T cells. This impact is driven by EVmediated upregulation of Foxp3 a transcription aspect accountable for Treg suppressive phenotype. Proteomic analyses revealed that CML-5-HT6 Receptor Modulator Biological Activity derived EVs contain BCR-ABL oncoprotein. Interestingly, further functional research revealed that inhibition of kinase activity of BCR-ABL in EVs has abolished the boost in Foxp3 level in EVs-treated Treg. Similarly to our in vitro findings, also Treg in CML sufferers appear to possess extra suppressive phenotype, as demonstrated by e.g. larger level of highly suppressive CD39+ Tregs. Summary/conclusion: CML-derived EVs seem to modulate immunosuppression in leukemia, by rising suppressive activity of regulatory T cells. This effect is largely driven by BCR-ABL contained in leukemic EVs. Even so, precise mechanism of this regulatory pathway is but to be dissected. Funding: Grants from National Science Centre: 2013/ 10/E/NZ3/00673 to KP, 2018/29/N/NZ3/01754 to JS and Foundation for Polish Science grant Group TECH Core Facility Plus/2017-2/2 to KP.OF20.Immunomodulatory function of human mesenchymal stromal cells (MSC)-derived extracellular vesicles (EVs) on type-i interferon response in human plasmacytoid dendritic cells (pDCs) and its therapeutic effect on RGS8 supplier murine lupus model Lin Kuia, Godfrey Chanb and Pamela PW Leeaa Division of Paediatrics and Adolescent Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong; bThe University of Hong Kong, Hong Kong, Hong KongIntroduction: BCR-ABL-positive chronic myeloid leukemia (CML) has only lately been recognized as a malignancy associated with an immunosuppressive microenvironment, which includes improved amount of Foxp3+ regulatory T cells (Treg). Nevertheless, mechanisms driving Treg differentiation and function in CML are mainly unknown. We hypothesize that extracellular vesicles (EVs) released by leukemic cells might be engaged in.
