Prokaryotes and eukaryotes produce extracellular vesicles (EVs) whose key role is cell-to-cell communication. Bacterial EVs range in size from 20-300 nm and bud off from cells dividing during growth. It is now clear that bacteria exploit EVs as a form of secretion system to deliver their cargo of proteins, toxins and other components in a packaged and protected form to host cells. Bacterial EVs have been detected in many host tissues, including the gastrointestinal tract, and share the physicochemical properties needed by nanoparticles to penetrate mucus. Thus, it is likely that EVs can deliver cargo to host cells in the gut and independently of direct bacterial contact with these cells. Indeed, EVs can enter polarised epithelial cells with barrier functions like those of the gut epithelium and are internalised via endocytosis and traffic to the early endosome. Although there is evidence of bacterial EVs localising to the nuclear compartment, the significance of this observation is currently unclear. Interestingly, bacterial EVs harbour a range of nuclear-targeting proteins, called nucleomodulins, some of which have been reported to cause tumourigenesis in plant and human hosts. We hypothesise that EVs represent a novel mechanism by which bacteria transport these proteins to the nucleus of eukaryotic cells, thereby subverting host cell functions and promoting carcinogenesis during infection. The presentation will focus on recent work from our laboratory investigating nuclear targeting by EVs from the gut pathogens, Helicobacter pylori and Campylobacter jejuni.
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https://doi.org/10.1002/jex2.84