Figure 11.

A schematic representation of the IEV loading mechanism in infected cells. After infection of cells, Ad replication results in the virus DNA and proteins accumulating in the cytoplasm in addition to the nucleus. The viral components are recognized by receptors in plasma membrane, endosomes and forming phagosomes (1a, b and c). EVs budding off from the plasma membrane can entrap viral components localized to the inner surface of the plasma membrane, creating microvesicles with intravesicular viral cargo (2a). Phagosomes fuse with late endosomes (2b), forming endo-phagosomes where the phagosomal contents are released into the lumen of the endo-phagosome. Endo-phagosomes mature to multivesicular bodies (MVB) (3) where additional inward budding generates ILVs with viral components in their lumen (4a). Adsorption of viral components, delivered by phagosomes, to the surface of ILVs generates vesicles with a corona of viral components. MVB contents can be degraded by its fusion with lysosomes (5a). Alternatively, MVB fusion with the plasma membrane releases ILVs as exosomes, with viral components in their lumen and on their surface, to the extracellular space (5b).