Identification of interferon-stimulated genes that attenuate Ebola virus infection

Makoto Kuroda,Yoshihiro Kawaoka,Gabriele Neumann,Makoto Ozawa,Tiago J S Lopes,John W Schoggins,Peter J Halfmann,Lindsay Hill-Batorski,Charles M Rice

doi:10.1038/s41467-020-16768-7

Abstract

The West Africa Ebola outbreak was the largest outbreak ever recorded, with over 28,000 reported infections; this devastating epidemic emphasized the need to understand the mechanisms to counteract virus infection. Here, we screen a library of nearly 400 interferon-stimulated genes (ISGs) against a biologically contained Ebola virus and identify several ISGs not previously known to affect Ebola virus infection. Overexpression of the top ten ISGs attenuates virus titers by up to 1000-fold. Mechanistic studies demonstrate that three ISGs interfere with virus entry, six affect viral transcription/replication, and two inhibit virion formation and budding. A comprehensive study of one ISG (CCDC92) that shows anti-Ebola activity in our screen reveals that CCDC92 can inhibit viral transcription and the formation of complete virions via an interaction with the viral protein NP. Our findings provide insights into Ebola virus infection that could be exploited for the development of therapeutics against this virus.

Highlights

The West Africa Ebola outbreak was the largest outbreak ever recorded, with over 28,000 reported infections; this devastating epidemic emphasized the need to understand the mechanisms to counteract virus infection
Our interferonstimulated genes (ISGs) library screen identified cellular proteins involved in the host restriction of EBOVΔVP30 infection; the potential of these proteins to inhibit wild-type EBOV still needs to be investigated
Caused a marked reduction in luciferase levels (Fig. 1a, b). Several of these 22 ISGs have established roles in the innate immune response to viruses, including interferon regulatory factor 1 (IRF1)[15,51,52], interferon regulatory factor 7 (IRF7)[53], interferon induced with helicase c domain 1 (IFIH1/MDA5)[54], and guanylate binding protein 2 (GBP2)[55]

Summary

Introduction

The West Africa Ebola outbreak was the largest outbreak ever recorded, with over 28,000 reported infections; this devastating epidemic emphasized the need to understand the mechanisms to counteract virus infection. Ebola virus is a member of the Filoviridae family, and six virus species in the genus Ebolavirus have been identified to date: Zaire, Sudan, Tai Forest (previously Cote d’Ivoire), Reston, Bundibugyo, and Bombali[2,3] Among these six species, Zaire ebolavirus (EBOV) causes the highest case fatality rates in humans, and was the species responsible for the 2014–2016 EBOV outbreak in West Africa. The ISG products may directly limit viral replication[14,15,16]; once again, EBOV has evolved countermeasures against the action of ISGs; for example, VP35 blocks PKR activation and GP blocks BST2/ tetherin-mediated restriction of viral budding[17,18] This rapid and potent attenuation of antiviral IFN responses likely contributes to the overall pathogenicity of EBOV. Our findings provide insights into Ebola virus infection that could be exploited for the development of antivirals to combat this virus

Methods

Results

Conclusion