Is often transferred among neighbouring cells in mammalian tissue to handle the expression of genes in each donor and recipient cells. How the extracellular vesicle (EV)-derived miRNAs are getting internalized and turn into functional in target cells is definitely an unresolved query. Procedures: We applied mammalian cells in culture to study the EV-mediated miRNA delivery to target cells. Employing miR-122 negative HeLa cells as recipient cells and miR122 containing exososmes isolated from miR-122 optimistic cells, we have delineated the mechanistic detail from the import course of action. Final results: We have identified that, by way of a exceptional mechanism, the EV-associated miRNAs that happen to be primarily single stranded can get loaded together with the Ago gp130/CD130 Proteins manufacturer proteins present inside the target cells to turn into functional there. The loading of EV-derived miRNAs to host cells Ago proteins just isn’t dependent on the Dicer1 that otherwise needed for the loading on the Ago proteins with double stranded miRNAs before 1 strand get cleaved and dislodged from Ago2. The EV-derived miRNA loading of Ago2 happens on the endosomal membrane exactly where the pH dependent fusion of the internalized EV membrane with endosomal membrane releases the miRNAs thatJOURNAL OF EXTRACELLULAR VESICLESget loaded with unloaded Ago2 present around the endosomal membrane. This approach is depenent on memebrane dynamics and restriction of memebrane dynamics either resulting from mitochondrial depolarization or other ways impacts the loading of EV-derived miRNAs with Ago2. Leishmania donovani, a protozoan parasite impact membrane dynamics in infected macrophage cells and thus it restrict the internalization of miR-122 containing EVs that otherwise trigger an inflammatory response in mammalian macrophage-a method detrimental for the pathogen. Summary/Conclusion: as a result we conclude that Leishmania donovani Restricts Retrograde DicerIndependent Loading of Extracellular Single Stranded miR-122 in Host Cell Agos to stop Inflammatory Response. Funding: SERB, Dept of Science and Technologies, Govt. of India and Swarnajayanti Fellowship Fund, Dept of Science and Technologies, Govt. of India.OS23.Engineering of extracellular vesicles for surface display of targeting ligands Elisa L aro-Ib eza, Anders Gunnarssonb, Gwen O riscollb, Olga Shatnyevac, Xabier Osteikoetxead and Niek Dekkerba csingle particle level, making use of monomeric EGFP as a reference. Final results: The screening of EGFP fused for the N- or Cterminal of EV proteins served as a quantitative strategy to identify protein candidates for the surface display of EV-associated cargo. Fusions to CD47 and luminal EV proteins with a snorkel domain allowed the show of EGFP in the surface of EVs, with CD47 as very good candidate for surface display. Alternatively, fusions of EGFP to EV proteins with either C- or Nin topology like Tspan14 and CD63 allowed for loading of EGFP within the EV lumen. Single EV analysis using TIRF microscopy enabled the quantification of your typical variety of EGFP molecules per single engineered vesicle, which was among 15 and 136 EGFP/ EV according to the fusion protein. Summary/Conclusion: The screening of EGFP-fusions to EV proteins revealed various protein candidates for each surface display and intra-luminal cargo loading in EVs. These results contribute for the understanding of EV biogenesis and are relevant for exploiting the possible of engineered EVs as drug delivery systems.OS23.Endogenous drug loading of extracellular vesicles CD131 Proteins Synonyms applying microbubbleassisted ultrasound Yuana Yuanaa, K.