Cells from all three domains of life, Archaea, Bacteria and Eukarya, produce extracellular vesicles (EVs) which are sometimes associated to filamentous structures known as nanopods or nanotubes. The mechanisms of EV biogenesis in the three domains remain poorly understood, although studies in Bacteria and Eukarya indicate that the regulation of lipid composition plays a major role in initiating membrane curvature. EVs are increasingly recognized as important mediators of intercellular communication via transfer of a wide variety of molecular cargoes. They have been implicated in many aspects of cell physiology such as stress response, inter-cellular competition, lateral gene transfer (via RNA or DNA), pathogenicity, and detoxification. Their role in various human pathologies and aging has aroused much interest in recent years. EVs can be used as decoys against viral attack but virus infected cells also produce EVs that boost viral infection. Here, researchers from the Université Paris-Sud review current knowledge on EVs in the three domains of life and their interactions with the viral world.
Biogenesis of extracellular vesicles in the three domains of life
Vesicle budding indicated with arrows (a) TEM showing hypervesiculation in the bacterium Salmonella typhimurium . Figure kindly provided by Mario F. Feldman (University of Alberta, Canad a ). (b) SEM showing microvesicles budding from the eukaryote Leishmania donovani. Figure reprinted from Silverman et al. 2018 . (c) Cryo – TEM of vesicle budding from the archaeon Thermococcus kodakaerensis. The protrusion of the S layer can also be observed clearly. (d) TEM of ultrathin cell sections of vesicle budding from T. kodakaerensis . Figures (c) and (d) provided by the authors