Characterization of human trophoblastic extracellular vesicles

Primary human trophoblasts release a repertoire of extracellular vesicles (EVs). Among them are nano-sized exosomes, which we found to suppress the replication of a wide range of DNA and RNA viruses. We report here our investigation of protein cargo of placental EVs including exosomes, microvesicles, and apoptotic blebs. We isolated EVs using ultracentrifugation and defined their purity using western analysis, electron microscopy, and nanoparticle tracking. We found that trophoblastic exosomes harbor a protein profile that is distinct from that of microvesicles or apoptotic blebs. Functionally, trophoblastic exosomes exhibit the highest anti-viral activity among the EVs. Our work suggests that human trophoblastic EVs may play a key role in maternal-placental-fetal communication.