Validating #Enterovirus D68-2Apro as an #Antiviral Drug #Target and the Discovery of #Telaprevir as a Potent D68-2Apro Inhibitor (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Validating Enterovirus D68-2Apro as an Antiviral Drug Target and the Discovery of Telaprevir as a Potent D68-2Apro Inhibitor

Rami Musharrafieh, Chunlong Ma, Jiantao Zhang, Yanmei Hu, Jessica M. Diesing, Michael T. Marty, Jun Wang

DOI: 10.1128/JVI.02221-18



Enterovirus D68 (EV-D68) is a viral pathogen that leads to severe respiratory illness and has been linked with the development of acute flaccid myelitis (AFM) in children. No vaccines or antivirals are currently available for EV-D68 infection, and treatment options for hospitalized patients are limited to supportive care. Here, we report the expression of the EV-D68 2A protease (2Apro) and characterization of its enzymatic activity. Furthermore, we discovered telaprevir, an FDA-approved drug used for the treatment of Hepatitis C virus infections, as a potent antiviral against EV-D68 by targeting the 2Apro enzyme. Using FRET-based substrate cleavage assay, we showed that the purified EV-D68 2Apro has proteolytic activity selective against a peptide sequence corresponding to the viral VP1-2A polyprotein junction. Telaprevir inhibits EV-D68 2Apro through a nearly irreversible, biphasic binding mechanism. In cell culture, telaprevir showed submicromolar to low micromolar potency against several recently circulating neurotropic strains of EV-D68 in different human cell lines. To further confirm the antiviral drug target, serial viral passage experiments were performed to select for resistance against telaprevir. An N84T mutation near the active site of 2Apro was identified in resistant viruses, and this mutation reduced the potency of telaprevir in both the enzymatic and cellular antiviral assays. Collectively, we report for the first time the in vitro enzymatic activity of EV-D68 2Aproand the identification of telaprevir as a potent EV-D68 2Apro inhibitor. These findings implicate EV-D68 2Apro as an antiviral drug target and highlight the repurposing potential of telaprevir to treat EV-D68 infection.



A 2014 EV-D68 outbreak in the United States has been linked to the development of acute flaccid myelitis in children. Unfortunately, no treatment options against EV-D68 are currently available, and the development of effective therapeutics is urgently needed. Here, we characterize and validate a new EV-D68 drug target, the 2Apro, and identify telaprevir—an FDA approved drug used to treat hepatitis C virus (HCV) infections—as a potent antiviral with a novel mechanism towards 2Apro. 2Apro functions as a viral protease that cleaves a peptide sequence corresponding to the VP1-2A polyprotein junction. Binding of telaprevir potently inhibits its enzymatic activity, and using drug resistance selection, we show that the potent antiviral activity of telaprevir was due to 2Apro inhibition. This is the first inhibitor to selectively target the 2Apro from EV-D68 and can be used as a starting point for the development of selective EV-D68 therapeutics.

Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Antivirals; Enterovirus; EV-D68; Telaprevir.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum ( in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.