E to efficiently switch the Cre-LoxP reporter system in Brutons Tyrosine Kinase (BTK) Proteins Gene ID injected embryos, resulting inside 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 were able 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 smaller quantity of Cre-mRNA present in the four nL EV isolate that contained around 30 10-14 pg compared to the 50 pg present inside the 4 nL synthetic Cre-mRNA option. Summary/Conclusion: The Zebrabow Cre-LoxP reporter system is definitely an efficient reporter for Cre activity and could consequently be an ideal model method to study EV-transfer in vivo. Nonetheless, the volume of EVmediated transfer of Cre-mRNA is too low using a single injection of four nL of purified EVs from Cre-expressing cell lines. This quite low efficacy can effectively be explained by the relative low Cre-mRNA quantity in EVs and the tiny volume which will 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 Carboxypeptidase D Proteins Accession Technologies, Boston, MA, USA; 3Texas Tech University, Lubbock, TX, USA; 4 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 program 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 generally involved inside the suppression of innate immune responses. Monocytes and macrophages are critical inside the metastatic microenvironments, in tumour-promoting or tumour-suppressive capacities. Non-classical or patrolling Ly6C low monocytes (PMo) had been identified for the capability to get rid of damaged cells and depend on nuclear receptor Nr4a1 for survival. Recently, Nr4a1-positive PMo were implicated in scavenging metastatic tumour cells in the lungs. Having said that, the events that control 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 effect on bone marrow myeloid cells was examined by FACS and dependence on certain cell kinds was determined applying clodronate liposomes and neutralizing antibodies. The effects on macrophages were examined in functional and biochemical assays. The relevance of the findings was assessed by a functional and biomarker evaluation of patient exosomes. Outcomes: Exosomes from non-metastatic melanoma cells (ExoNM) are taken up by myeloid cells within the bone marrow and bring about an expansion of Ly6C low mo.