Mutations Abrogating VP35 Interaction with Double-Stranded RNA Render Ebola Virus Avirulent in Guinea Pigs

Journal Article · Mon Oct 11 00:00:00 EDT 2010 · J. Virol.

DOI:https://doi.org/10.1128/JVI.02459-09· OSTI ID:1002793

Prins, Kathleen C; Delpeut, Sebastien; Leung, Daisy W; Reynard, Olivier; Volchkova, Valentina A; Reid, St Patrick; Ramanan, Parameshwaran; Cárdenas, Washington B; Amarasinghe, Gaya K; Volchkov, Viktor E; Basler, Christopher F ^[1]

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1. CNRS-INSERM

Ebola virus (EBOV) protein VP35 is a double-stranded RNA (dsRNA) binding inhibitor of host interferon (IFN)-{alpha}/{beta} responses that also functions as a viral polymerase cofactor. Recent structural studies identified key features, including a central basic patch, required for VP35 dsRNA binding activity. To address the functional significance of these VP35 structural features for EBOV replication and pathogenesis, two point mutations, K319A/R322A, that abrogate VP35 dsRNA binding activity and severely impair its suppression of IFN-{alpha}/{beta} production were identified. Solution nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography reveal minimal structural perturbations in the K319A/R322A VP35 double mutant and suggest that loss of basic charge leads to altered function. Recombinant EBOVs encoding the mutant VP35 exhibit, relative to wild-type VP35 viruses, minimal growth attenuation in IFN-defective Vero cells but severe impairment in IFN-competent cells. In guinea pigs, the VP35 mutant virus revealed a complete loss of virulence. Strikingly, the VP35 mutant virus effectively immunized animals against subsequent wild-type EBOV challenge. These in vivo studies, using recombinant EBOV viruses, combined with the accompanying biochemical and structural analyses directly correlate VP35 dsRNA binding and IFN inhibition functions with viral pathogenesis. Moreover, these studies provide a framework for the development of antivirals targeting this critical EBOV virulence factor.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: USDOE
• OSTI ID: 1002793
• Journal Information: J. Virol., Vol. 84, Issue 03, 2010; ISSN 0022-538X
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ANIMALS
ATTENUATION
CRYSTALLOGRAPHY
FUNCTIONALS
GENE MUTATIONS
GUINEA PIGS
IN VIVO
INTERFERON
MUTANTS
MUTATIONS
NUCLEAR MAGNETIC RESONANCE
PATHOGENESIS
POLYMERASES
PRODUCTION
PROTEINS
RNA
SPECTROSCOPY
VIRULENCE
VIRUSES