Abstract
The discovery that extracellular vesicles (EVs) serve as carriers of virus particles calls for a reevaluation of the release strategies of non-enveloped viruses. Little is currently known about the molecular mechanisms that determine the release and composition of EVs produced by virus-infected cells, as well as conservation of these mechanisms among viruses. We previously described an important role for the Leader protein of the picornavirus encephalomyocarditis virus (EMCV) in the induction of virus-carrying EV subsets with distinct molecular and physical properties. EMCV L acts as a 'viral security protein' by suppressing host antiviral stress and type-I interferon (IFN) responses. Here, we tested the ability of functionally related picornavirus proteins of Theilers murine encephalitis virus (TMEV L), Saffold virus (SAFV L), and coxsackievirus B3 (CVB3 2Apro), to rescue EV and EV-enclosed virus release when introduced in Leader-deficient EMCV. We show that all viral security proteins tested were able to promote virus packaging in EVs, but that only the expression of EMCV L and CVB3 2Apro increased overall EV production. We provide evidence that one of the main antiviral pathways counteracted by this class of picornaviral proteins, i.e. the inhibition of PKR-mediated stress responses, affected EV and EV-enclosed virus release during infection. Moreover, we show that the enhanced capacity of the viral proteins EMCV L and CVB3 2Apro to promote EV-enclosed virus release is linked to their ability to simultaneously promote the activation of the stress kinase P38 MAPK. Taken together, we demonstrate that cellular stress pathways involving the kinases PKR and P38 are modulated by the activity of non-structural viral proteins to increase the release EV-enclosed viruses during picornavirus infections. These data shed new light on the molecular regulation of EV production in response to virus infection.
Original language | English |
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Article number | e1012133 |
Journal | PLoS Pathogens |
Volume | 20 |
Issue number | 4 |
Early online date | 25 Apr 2024 |
DOIs | |
Publication status | Published - 2024 |
Bibliographical note
Publisher Copyright:© 2024 Defourny et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding
This work was supported by The Netherlands Organisation for Scientific Research (NWO-ALW grant number ALWOP.351 to ENMN'tH) (https://www.nwo.nl/en) and the China Scholarship Council (CSC, to XP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank prof. dr. Thomas Michiels for providing RSK TKO and reconstituted cells. We are grateful to prof. dr. Marca Wauben for making available the BD Influx tailored for EV-analysis and to dr. Ger Arkesteijn for help with high resolution flow cytometric analysis of EVs, as well as the Center for Cell Imaging Utrecht for allowing access to their facility for confocal imaging and training.
Funders | Funder number |
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China Scholarship Council | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | ALWOP.351 |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek |