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Progressive multifocal leukoencephalopathy, Central nervous system infections, Extracellular vesicle, Polyomavirus, Virus receptor


The endemic human JC polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy in immune-suppressed patients. The mechanisms of virus infection in vivo are not understood because the major target cells for virus in the brain do not express virus receptors and do not bind virus. We found that JCPyV associates with extracellular vesicles (EVs) and can infect target cells independently of virus receptors. Virus particles were found packaged inside extracellular vesicles and attached to the outer side of vesicles. Anti-JCPyV antisera reduced infection by purified virus but had no effect on infection by EV-associated virus. Treatment of cells with the receptor-destroying enzyme neuraminidase inhibited infection with purified virus but did not inhibit infection by EV-associated virus. Mutant pseudoviruses defective in sialic acid receptor binding could not transduce cells as purified pseudovirions but could do so when associated with EVs. This alternative mechanism of infection likely plays a critical role in the dissemination and spread of JCPyV both to and within the central nervous system.

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Work in the Atwood laboratory was supported by grants from the National Institute of Neurological Disease and Stroke (R01NS043097 and P01NS065719).



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Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.


© 2019 Morris-Love et al.