Fig. 1.

Pathways and factors involved in EV biogenesis in host cells during an infection. Host factors required for microvesicle and exosome production and release, including the generation of MVBs and their transport to the plasma membrane for fusion and exosome release, are shown. For each type of EV, factors known to be involved in their biogenesis are indicated; these include ceramide and components of the ESCRT complex, which are involved in generating both exosomes and microvesicles. Also indicated are the types of macromolecules that are released from bacteria and are trafficked and packaged into EVs. These macromolecules can be released either from cytosolic bacteria or from bacteria within a phagosomal compartment. ERK, extracellular signal-regulated kinases; GPR30, G-protein-coupled receptor 30; MLC, myosin light chain; PADs, peptidylarginine deiminases.