Can be transferred between 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 obtaining internalized and turn out to be functional in target cells is an unresolved query. Approaches: We utilised mammalian cells in culture to study the EV-mediated miRNA delivery to target cells. Employing miR-122 damaging HeLa cells as recipient cells and miR122 containing exososmes isolated from miR-122 good cells, we’ve delineated the mechanistic detail with the import process. Final results: We’ve identified that, by way of a exclusive mechanism, the EV-associated miRNAs which might be mainly single stranded can get loaded with the Ago CD147 Proteins site proteins present within the target cells to become functional there. The loading of EV-derived miRNAs to host cells Ago proteins is not dependent around the Dicer1 that otherwise necessary for the loading of your Ago proteins with double stranded miRNAs ahead of a single strand get cleaved and dislodged from Ago2. The EV-derived miRNA loading of Ago2 takes place on the endosomal membrane exactly where the pH dependent fusion with the internalized EV membrane with endosomal membrane releases the miRNAs thatJOURNAL OF EXTRACELLULAR VESICLESget loaded with unloaded Ago2 present on the endosomal membrane. This method is depenent on memebrane dynamics and restriction of memebrane dynamics either as a consequence of mitochondrial depolarization or other ways affects the loading of EV-derived miRNAs with Ago2. Leishmania donovani, a protozoan parasite influence membrane dynamics in infected macrophage cells and therefore it restrict the internalization of miR-122 containing EVs that otherwise bring about an inflammatory response in mammalian macrophage-a procedure detrimental for the pathogen. Summary/Conclusion: thus 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 show of targeting ligands Elisa L aro-Ib eza, Anders Gunnarssonb, Gwen O riscollb, Olga Shatnyevac, Xabier Osteikoetxead and Niek Dekkerba csingle particle level, applying monomeric EGFP as a reference. Benefits: The screening of EGFP fused to the N- or Cterminal of EV proteins served as a quantitative process 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 great 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 inside the EV lumen. Single EV evaluation using TIRF microscopy enabled the quantification in the typical number of EGFP molecules per single engineered vesicle, which was among 15 and 136 EGFP/ EV based on the fusion protein. Summary/Conclusion: The screening of EGFP-fusions to EV proteins revealed numerous protein candidates for both surface show and intra-luminal cargo loading in EVs. These benefits contribute for the understanding of EV biogenesis and are relevant for exploiting the potential of engineered EVs as drug delivery systems.OS23.Endogenous drug loading of extracellular vesicles working with microbubbleassisted Testicular Receptors Proteins Molecular Weight ultrasound Yuana Yuanaa, K.