Era and Elke Pogge von Strandmannba Experimental Tumor Study, Center for Tumor Biology and Immunology, Clinic for Hematology, Oncology and Immunology, Philipps University of Marburg, Marburg, Cologne, Germany, Germany; bExperimental Tumor Analysis, Center for Tumor Biology and Immunology, Division of Hematology, Oncology and Immunology, Philipps University Marburg, Marburg, GermanySummary/Conclusion: Our findings present a conceptual advance within the understanding of the biogenesis and function of EVs, identifying BAG6 as an ESCRTassociated protein plus a molecular switch for the formation of anti- versus pro-tumourigenic EVs in tumour immune surveillance.FA1.Development of a live-cell imaging strategy for secretion activity of extracellular vesicles of person cells Yoshitaka Shirasakia, Keisuke Tsukadab, Nobutake Suzukic, Tamiko Minamisawad, Mai Yamagishie, Nobuyoshi Kosakaf, Takahiro Ochiyaf, Osamu Oharag, Kiyotaka Shibah and Sotaro UemuraiaIntroduction: Current research have highlighted the part of melanoma cell-derived EVs within the formation of premetastatic niches or, around the contrary, in tumour immune surveillance. The molecular machinery and mechanisms directing distinct cargo loading, mGluR8 manufacturer regulatory release and function of stress-induced EVs remain unknown. Procedures: EV release was quantified by NTA. EVs have been isolated by ultracentrifugation and analysed by proteomics and transcriptomics. EV function was investigated in vivo by P2X7 Receptor drug intravenous injections followed by lung transcriptomics and by using an experimental metastasis transplantation model. The mechanistic release of EVs was analysed utilizing diverse molecular, cell biological, spectroscopic and microscopic approaches. Results: Our study reveals a vital part in the chaperone and NK cell ligand BAG6 for the formation and reprogramming of pro- and anti-tumour EVs. Loss of BAG6 led to a rise in EV production as well as a reduce in EV size. In contrast for the melanosomelike protein signature observed for WT-EVs, BAG6KOEVs showed an exosome-like profile and induced a neutrophil gene signature inside the lungs of mice. Education with B-16V WT-EVs, but not BAG6KOEVs, suppressed lung metastasis concomittant with all the accumulation of anti-tumour Ly6Clow patrolling monocytes. Mechanistically, the formation of antitumour EVs was dependent on BAG6 mediating the nucleo-cytoplasmic shuttling of CBP/p300 acetyltransferases to acetylate p53. We’ve identified a late endosomal P(S/T)AP motif in BAG6 which mediated its direct recruitment for the ESCRT machinery, thereby giving a molecular link amongst the regulatory role of BAG6 to EV cargo loading.JST PRESTO, Tokyo, Japan; bThe University of Tokyo, bunkyo, Japan; cThe university of Tokyo, Bunkyo-ku, Japan; dJapanese Foundation For Cancer Study, Koto-ku, Japan; eDepartment of Biological Sciences, Graduate School of Science, The University of Tokyo, Japan; fDepartment of Molecular and Cellular Medicine, Institute of Healthcare Science, Tokyo Healthcare University, Shinjyuku-ku, Japan; gRIKEN Institute for Integrative Health-related Sciences, Yokohama, Japan; hJapaese Foundation for Cancer research, Tokyo, Japan; iThe University of Tokyo, Tokyo, JapanIntroduction: The cells in our body exchange their details employing a variety of methods to manage the expression of functions, to kind higher order systems and to sustain homeostasis. Especially in the communication involving spatially separated cells, mediation of humoral things which include cytokines is usually mentioned.