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J Hepatol. 2015 Apr;62(4):779-84. doi: 10.1016/j.jhep.2014.11.009. Epub 2014 Nov 21.

Hepatitis C virus variants resistant to macrocyclic NS3-4A inhibitors subvert IFN-β induction by efficient MAVS cleavage.

Author information

1
Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany; Max-Planck-Institute for Informatics, Computational Biology & Applied Algorithmics, D-66123 Saarbrücken, Germany.
2
Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany.
3
Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois, University of Lausanne, CH-1011 Lausanne, Switzerland.
4
Technical University Munich, Center for Integrated Protein Science Munich (CIPS(M)) and Department of Life Science, D-85354 Freising-Weihenstephan, Germany.
5
Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany. Electronic address: Christian.Lange@kgu.de.

Abstract

BACKGROUND & AIMS:

The hepatitis C virus (HCV) NS3-4A protease is essential for the HCV life cycle and a prime target of antiviral treatment strategies. Protease inhibitors, however, are limited by emergence of resistance-associated amino acid variants (RAVs). The capacity to cleave and inactivate mitochondrial antiviral-signaling protein (MAVS) in the RIG-I-signaling pathway is a cardinal feature of NS3-4A, by which HCV blocks induction of interferon-(IFN)-β, thereby promoting viral persistence. Here, we aimed to investigate the impact of NS3-4A RAVs on MAVS cleavage.

METHODS:

The impact of NS3-4A RAVs on MAVS cleavage was assessed using immunoblot analyses, luciferase reporter assays and molecular dynamics simulations to study the underlying molecular principles. IFN-β was quantified in serum from patients with different NS3-4A RAVs.

RESULTS:

We show that macrocyclic NS3-4A RAVS with substitutions at residue D168 of the protease result in an increased capacity of NS3-4A to cleave MAVS and suppress IFN-β induction compared with a comprehensive panel of RAVs and wild type HCV. Mechanistically, we show the reconstitution of a tight network of electrostatic interactions between protease and the peptide substrate that allows much stronger binding of MAVS to D168 RAVs than to the wild-type protease. Accordingly, we could show IFN-β serum levels to be lower in patients with treatment failure due to the selection of D168 variants compared to R155 RAVs.

CONCLUSIONS:

Our data constitutes a proof of concept that the selection of RAVs against specific classes of direct antivirals can lead to the predominance of viral variants with possibly adverse pathogenic characteristics.

KEYWORDS:

All-oral therapy; Cardif; Direct-acting antiviral agent; Innate immunity; RIG-I signaling

PMID:
25463536
DOI:
10.1016/j.jhep.2014.11.009
[Indexed for MEDLINE]

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