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Type I Interferons Block Extracellular Vesicle‐Mediated Cargo Transfer
Author(s) -
Hantak Michael P,
Qing Enya,
Gallagher Tom
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.lb234
Subject(s) - microbiology and biotechnology , endocytosis , cytosol , transmembrane protein , luciferase , chemistry , cell , fusion protein , extracellular vesicle , lipid bilayer fusion , transport protein , vesicle , membrane , microvesicles , biology , transfection , biochemistry , receptor , microrna , gene , enzyme , recombinant dna
Extracellular vesicles (EVs) transfer transmembrane and cytosolic macromolecules between cells. EVs must fuse with target cell membranes to deliver cargo, either at the plasma membrane or after endocytosis, in a manner analogous to enveloped virus entry. The factors mediating and regulating EV‐cell fusion are unknown. We hypothesized that EV‐cell and virus‐cell fusions are similarly regulated. To address this hypothesis, we developed a novel assay to monitor EV membrane fusions. In the assay, EVs and target cells are loaded with complementary split luciferase fragments, such that EV‐cell fusion is required for fragment complementation and luciferase formation, which can be easily measured. Using this assay, we discovered that the antiviral type I interferon response, through its induction of i nter f eron – i nduced t ransme m brane protein 3 (IFITM3), potently inhibited EV‐cell fusions. IFITM3 was incorporated into EVs, which prevented the EVs from fusing with themselves, and also with target cells. These findings demonstrated that IFITM3 regulates EV‐mediated inter‐cellular protein transport. Notably, the e ndosomal s orting c omplexes r equired for t ransport (ESCRT) were required to incorporate IFITM3 into EVs, and were also required more generally for EV‐mediated inter‐cellular protein transport. These findings demonstrated that ESCRT – generated EVs are the agents of inter‐cellular protein transport. These results identify regulators of EV‐mediated cargo transfer and reveal machinery necessary to produce cargo transfer‐competent EVs. The findings may translate into more effective methodologies for controlled delivery of hydrophilic macromolecules into cells.