E to efficiently switch the Cre-LoxP reporter program in injected embryos, resulting within a large variation of fluorescent cells distributed in the total zebrafish inside a mosaic pattern. In contrast, injected EVs derived from cells with higher Cre expression have been in a position to colour switch cells in only 1 out of 60 injected zebrafish. The low efficiency in EV-mediated Creprotein or RNA transfer is correlated with tiny quantity of Cre-mRNA Gag-Pol Polyprotein Proteins Species present in the 4 nL EV isolate that contained around 30 10-14 pg in comparison with the 50 pg present within the 4 nL synthetic Cre-mRNA solution. Summary/Cathepsin K Proteins Gene ID Conclusion: The Zebrabow Cre-LoxP reporter system is an efficient reporter for Cre activity and could thus be a perfect model system to study EV-transfer in vivo. Nonetheless, the volume of EVmediated transfer of Cre-mRNA is also low with a single injection of 4 nL of purified EVs from Cre-expressing cell lines. This very low efficacy can properly be explained by the relative low Cre-mRNA quantity in EVs as well as the compact volume that could maximally be injected within the yolk of zebrafish embryos.OF11.Pre-metastatic cancer exosomes induce immune surveillance by patrolling monocytes Michael P. Plebanek1; Nicholas Angeloni1; Elena Vinokour1; Anna Henkin2; Dalia Martinez-Marin3; Stephanie Filleur3; Reshma Bhowmick4; Jack Henkin5; Stephen Miller1; Igal Ifergan1; Yesung Lee6; Iman Osman6; Shad Thaxton1; Olga Volpert7 Northwestern University, Chicago, IL, USA; 2Massachusetts Institute of Technology, Boston, MA, USA; 3Texas Tech University, Lubbock, TX, USA; four University of Texas MD Anderson Cancer Center, Houston, TX, USA; 5 Northwestern University, Evanston, IL, USA; 6New York University, New York, NY, USA; 7MD Anderson Cancer Center, Houston, TX, USAOF11.Zebrabow as in vivo model system to monitor vesicles mediated transfer in cancer Martin E. van Royen1; Wilma Teubel2; Thomas A. Hartjes3; Tjakko van Ham4; Guido W. Jenster1 Division of Pathology, Erasmus Optical Imaging Centre, Erasmus MC, Rotterdam, The Netherlands; 2Department of Urology, Erasmus MC, Rotterdam, The Netherlands; 3Erasmus Medical Center, Rotterdam, The Netherlands; 4Department of Clinical genetics, Erasmus MC, Rotterdam, The NetherlandsBackground: Cancer exosomes are usually involved in the suppression of innate immune responses. Monocytes and macrophages are essential inside the metastatic microenvironments, in tumour-promoting or tumour-suppressive capacities. Non-classical or patrolling Ly6C low monocytes (PMo) have been identified for the ability to get rid of broken cells and rely on nuclear receptor Nr4a1 for survival. Not too long ago, Nr4a1-positive PMo were implicated in scavenging metastatic tumour cells inside the lungs. However, the events that manage PMo at the metastatic niche remain unknown.ISEV 2018 abstract bookMethods: We isolated and tested exosomes from spontaneously occurring and artificially generated metastatic/ non-metastatic melanoma cells and tested them in vivo for altering metastatic capacity of human and mouse cells. The impact on bone marrow myeloid cells was examined by FACS and dependence on particular cell kinds was determined working with clodronate liposomes and neutralizing antibodies. The effects on macrophages had been examined in functional and biochemical assays. The relevance on the findings was assessed by a functional and biomarker evaluation of patient exosomes. Final results: Exosomes from non-metastatic melanoma cells (ExoNM) are taken up by myeloid cells inside the bone marrow and cause an expansion of Ly6C low mo.
