Fig 3.

MV production by eukaryotic microbes. (A) Eukaryotic microbes, including fungi (shown here) and parasites, release MVs at the cell surface, although these MVs may be derived from multiple sources. (B) Upper panel: exosome release is a conserved process in eukaryotic microbes. An endosome is created in the cytosol, which traffics through the microbial cell. In transit, the ESCRT-III homologues (also conserved in Archaea and higher eukaryotes) induce formation of intraluminal vesicles (ILVs), creating multivesicular bodies (MVBs). MVBs fuse to the cell surface and release the vesicular content as exosomes. Lower panel: electron micrograph demonstrating release of exosomes by the fungus Cryptococcus neoformans. (Reprinted from reference 75 with permission.) (C) An additional pathway for MV release in eukaryotic microbes exists, appearing to produce surface-derived MVs reminiscent of those in Bacteria and Archaea. In this process, for which mechanistic details are as yet unknown, shedding microvesicles bud directly from the cell surface. Lower panel: electron micrograph demonstrating MV release by the parasite Leishmania donovani. (Reprinted from reference 82 with permission of the publisher, BioMed Central.)