EaeJOURNAL OF EXTRACellular VESICLESPT01: Cellular and Organ Targeting Thursday Poster Session Chairs: Charles Lai; Ikuhiko Nakase Location: Level 3, Hall A 15:306:PT01.Role of IgG2C Proteins Purity & Documentation circulating extracellular vesicles in brain function and behaviour Eisuke Dohi, Indigo Rose, Takashi Imai, Rei Mitani, Eric Choi, Dillon Muth, Zhaohao Liao, Kenneth Witwer and Shinichi Kano Johns Hopkins University School of Medicine, Baltimore, USAPT01.In vivo tracking and monitoring of extracellular vesicles having a new non-lipophilic dye Sam Noppena, Gareth R Willisb, Antonios Fikatasa, Archana Guptac, Amirali Afsharic, Christophe Pannecouquea and Dominique ScholsaaIntroduction: Accumulating proof suggests that extracellular vesicles (EVs) circulate within the blood and affect cellular functions in an organ distant from their origins. In neuroscience, systemic circulating elements like cytokines/chemokines, hormones and metabolites have been shown to modulate brain function and behaviour. They’re also utilized as biomarkers to reflect brain illness status. Nonetheless, it remains unclear irrespective of whether circulating EVs modulate brain function and behaviour. Methods: We utilised mouse models to study the effects of EVs from precise cell forms on brain function and behaviour. Simply because circulating EVs are very heterogeneous, we focused on immunodeficient mice that lack particular lymphocytes (T and B cells). We assessed the changes in their circulating EVs and examined their possible effect around the corresponding behavioural and neuronal dysregulation. Outcomes: As expected, immunodeficient mice lack the expression of T and B cell-related markers in the EV containing fractions in the peripheral blood. Immunodeficient mice also displayed social behavioural deficits, accompanying by enhance c-Fos immunoreactivity in the excitatory neurons within the medial prefrontal cortex (mPFC). Notably, transfer of splenocytes from wild-type (WT) rescued the behavioural deficits, serum EVs and brain c-Fos expression patterns in immunodeficient mice. Further analysis on the molecular mechanisms is in progress. Summary/Conclusion: Our study has revealed a prospective periphery-brain communication by means of EVs below physiological situation. Future research are needed to Muscarinic Acetylcholine Receptor Proteins Source recognize the cellular targets of circulating EVs and their ascending routes in the brain. Funding: NIMH R01.Laboratory of Virology and Chemotherapy, Rega Institute, KU Leuven, Leuven, Belgium; bDepartment of Pediatrics, Harvard Health-related School, MA, Boston, USA; cSystem Biosciences (SBI), Palo Alto, CA, USAIntroduction: Extracellular vesicles (EVs) are gaining escalating interest as drug delivery vehicles. Nevertheless, there is nonetheless a lack of understanding regarding the in vivo fate of exogenous delivered EVs. Noninvasive optical imaging is an critical tool to analyse the biodistribution of EVs. At present, probably the most well known techniques is always to straight label EVs with fluorescent lipophilic dyes. A significant drawback is the fact that the dye itself instead of EVs is detected. Hence, there’s a will need for other dyes that overcome these limitations. A new non-lipophilic near infrared (NIR) dye, ExoGlow-Vivo (SBI), was tested in vivo in mice. Solutions: EVs from human PBMC, HEK and MCF7 cells were labelled with ExoGlow-Vivo, precipitated with Exoquick-TC (SBI) and injected intravenously (i.v.) in adult SCID mice. Human mesenchymal stem cell (MSC)-derived EVs have been labelled with ExoGlow-Vivo dye, washed by way of ultracentrifugation and injected i.v. in post-natal day-.