Broadly out there instrument to achieve in-depth insights into the molecular signatures of EV sub-populations on the single EV degree. Focusing on multiple markers enormously improves differentiation of EV sub-populations. The large simplicity of our process and its great adaptivity to clinical labs is going to be really effective for screening for powerful EV markers for liquid biopsy applications. Funding: NIH-NCIISEV2019 ABSTRACT BOOKSymposium Session 27: Non-mammalian EVs Chairs: Richard Ferrero; J. Max Silverman Place: Level B1, Hall B 16:007:OS27.Extracellular vesicles released by commensal Lactobacillus suppress HIV-1 infection Rogers A. Nahui Palominoa, Christophe Vanpouillea, Peter Backlundb, Carola Parolinc, Luca Laghid, Beatrice Vitalic and Leonid Margolisaa Area of Intercellular Interaction, BTLA/CD272 Proteins Biological Activity Eunice Kennedy Shriver National Institute of Child Well being and Human Growth, National Institutes of Health, Bethesda, MD, USA; bBiomedical Mass Spectrometry Facility, Eunice Kennedy Shriver National Institute of Kid Wellness and Human Improvement, Nationwide Institutes of Health, Bethesda, MD, USA; c Division of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy; dCentre of Foodomics, Division of Agro-Food Science and Technologies, University of Bologna, Bologna, Italyamino acids, alcohols, ketones and monosaccharides. Proteomic evaluation showed the presence of various bacterial proteins in EVs that may be related with all the anti-HIV result. Summary/Conclusion: Our findings demonstrate that the protective effect of Lactobacillus towards HIV transmission is, in element, mediated by EVs launched by these commensal bacteria. This getting could lead to new techniques to prevent male-to-female sexual HIV transmission.OS27.Extracellular vesicles from the human gut microbiota: do you hear me host Anna Kaisanlahtia, Anatoliy Samoylenkob, Genevieve Bartb, Johanna Korvalaa, Annastiina Rytk enc, Artem Zhyvolozhnyic, Ilkka Miinalainenc, Leo Lahtid, Seppo Vainioe and Justus Reunanenfa Biocenter Oulu/Cancer and Translational Adrenomedullin Proteins custom synthesis Medication Study Unit, University of Oulu, Oulu, Finland; bUniversity of Oulu, Biocenter Oulu, Laboratory of developmental Biology, Oulu, Finland; cBiocenter Oulu, University of Oulu, Oulu, Finland; dDepartment of Mathematics and Statistics, University of Turku, Turku, Finland; eUniversity of Oulu, Biocenter Oulu, Laboratory of Developmental Biology, Oulu, Finland; f University of Oulu, Biocenter Oulu, Cancer and Translational Medicine Analysis Unit, Oulu, FinlandIntroduction: The vaginal microbiota, generally dominated by Lactobacillus spp. plays a essential role in stopping from various uro-pathogens’ infections, specifically from HIV-1. Not long ago, we demonstrated that Lactobacillus of many strains inhibit HIV-1 replication in human cervico-vaginal and tonsillar tissues ex vivo supplying an experimental technique to review mechanisms of this phenomenon. A increasing entire body of evidences recommend that any kind of cells, together with bacteria talk to one another as a result of extracellular vesicles (EVs). Here, we investigated whether or not the protective anti-HIV result of lactobacilli is mediated by EVs launched by these bacteria. Procedures: EVs have been isolated from 4 strains of Lactobacillus cultures, previously isolated from vaginas of nutritious ladies, by ultracentrifugation. Vesicles’ sizes and concentrations had been evaluated employing NanoSight. Human cervico-vaginal and tonsillar tissues ex vivo, as well as cell lines had been handled with Lactobacillus-deri.