Medical Function of Bacterial Extracellular Vesicles

Extracellular vesicles are nanoscale particles which were identified about fifty years ago. The studies have shown that all of the gram-negative bacteria secrete extracellular vesicles during their normal growth. Today, the production of membrane vesicles has been reported by gram-positive bacteria, parasites, fungi, and mycobacteria. Since these nanoscale particles carry many of the bacterial components such as DNA, RNA, protein, endotoxin, and virulence molecules, they play a very important role in interacting with the environment and other bacteria. For this reason, many of these vesicles are considered as the transmission of pathogens, antigenic protein compounds, and the development of non-cellular vaccines, as well as drug delivery agents. The studies, have been carried in this field so far, have been focused on the pathogenic and physiological roles of these nanostructures in cross-species relationships. The focus of this article is on the role of extracellular bacterial vesicles and pathological and physiological functions which contribute to the interactions between bacteria and bacterium-host. Since these nanostructures play significant role in pathogenesis, gene transduction, regulation of gene expression, immune response regulation, and cellular signaling, further studies are needed on the medical application of these nanostructures as a new generation of vaccines, adjuvants, drug delivery agents.