Figure 7.

Schematic Model of IFITM3-Mediated Inhibition of Viral Entry

Schematic model represents viral infection in the absence (left panel) or presence (right panel) of IFITM induction. Virions (depicted as stars) enter the cell by endocytosis, are subsequently transferred to early endosome (EE), and are finally transferred to late endosome/multivesicular body (LE/MVB). In the absence of IFITM induction under normal cholesterol (depicted as its chemical shape) homeostasis conditions, the intraluminal virion-cargo-containing vesicles or virion particles finally fuse with the limiting membrane to release viral genome or nucleocapsid to the cytosol. In the presence of IFITM induction, IFITM-VAPA interaction disturbs intracellular cholesterol homeostasis, leading to the accumulation of cholesterol in LE/MVB. This consequently blocks the fusion of the intraluminal virion-cargo-containing vesicles or virion particles with the limiting membrane of LE/MVB compartments.