Ith concentrate on the evaluation of their impact on CLL immune escape. Altogether, this study will give insight into the specific immune and stromal cells involved in CLL improvement, with emphasis on their involvement in Fc Receptor-like A Proteins site tumour-derived little Ev-mediated tumour immune escape. Funding: This project is funded by the Fonds National de la Recherche (FNR) INTER/DFG/16/11509946/EVRNA/Moussay. Sandrine Pierson and J e Paggetti are supported by the FNR INTER/DFG/16/11509946/EV-RNA/ Moussay. Ernesto Gargiulo is supported by the grant FNR Luxembourg PRIDE15/10675146/CANBIO.PT06.Interaction by means of exosome miRNAs among myelodysplatic cell and regular Treg Tatsuki Shibuta, Yukichi Takada and Tsukuru Umemura International University of Health and Welfare, Okawa City, Japanregulatory T cells (Treg) that had been sorted from regular peripheral blood. The exosomes were detected in cytosol of Treg by fluorescent microscopy. Microarray evaluation of miRNAs in Treg intaking MDS-exosomes showed that considerable increases of 9 miRNAs in MDS-exosomes. The conditioned medium of MDSexosomes treated Treg culture decreased the population of activated CD4 cells (CD38 good cells was 39 ; control 68). Summary/Conclusion: Our information suggested that exosomes from MDS cells impacted the function of regulatory T cells via miRNA transfer. MDS exosomes could impact on immune cells to avoid the exclusion from cancer-immune system, and may be a target for the new therapies or diagnostic approaches. Funding: This function was supported in component by a grant from the Japan Society for the Promotion of Science (JSPS KAKENHI Grant Quantity: JP17K09020 and 17H07059).PT06.Mechanism of antitumor immunity activation by `artificial neoantigen’-presenting exosomes Yoshiyuki Koyamaa, Tomoko Itoa, Masazumi Eriguchia, Aya Hasegawab, Wakana Ouchic, Toshio Inabab and Kikuya SugiurabaIntroduction: Myelodysplastic Syndrome (MDS) can be a clonalhematopoietic illness and develops leukaemia in some instances. As a result, MDS is usually a malignant hematopoietic illness and its prevalence ratio is increasing in Japan. Hematopoietic microenvironment like bone marrow niche is actually a important issue for maintaining leukaemic stem cells. To understand mechanisms of interactions between leukaemic stem cells and microenvironment is vital for the treatment of hematopoietic malignancies. In this study, to create the new therapies and diagnostic methods for MDS, we focused on the impact of exosomes released from MDS cells on peripheral T lymphocytes. Strategies: MDS cell line (MDS-L) was kindly supplied by Kasawaki Healthcare University and typical peripheral blood mononuclear cells have been obtained from wholesome volunteer donors. Exosomes from MDS cells were purified by using miRCURY Exosome Cell/Urine/CSF Kit and labelled by PKH67. Extracted miRNAs were analysed by microarray technique (Genopal, Mitsubishi Chemical, Japan). Cell surface antigens were analysed by FACS Aria II and fluorescence conjugated antibodies. Final results: CD117/c-KIT Proteins Gene ID miRNA-microarray evaluation showed that nine miRNAs have been abundant in exosomes from MDS cells and had been not detected in MDS cells. Exosomes labelled with PKH67 dye have been added to liquid culture ofJapan Anti-tuberculosis Association, Shin-Yamanote Hospital, Tokyo, Japan; Osaka Prefecture University, Osaka, Japan; cOsaka Prefecture University, Tokyo, JapanbIntroduction: Tumour-derived exosomes are known to have similar antigens as the parent tumour cells, and had been anticipated as cancer vaccines. Nonetheless, therapy with these exosomes often failed to elicit.