Small-Molecule Antiviral β-d-N4-Hydroxycytidine Inhibits a Proofreading-Intact Coronavirus with a High Genetic Barrier to Resistance

Copyright © 2019 American Society for Microbiology..

Coronaviruses (CoVs) have emerged from animal reservoirs to cause severe and lethal disease in humans, but there are currently no FDA-approved antivirals to treat the infections. One class of antiviral compounds, nucleoside analogues, mimics naturally occurring nucleosides to inhibit viral replication. While these compounds have been successful therapeutics for several viral infections, mutagenic nucleoside analogues, such as ribavirin and 5-fluorouracil, have been ineffective at inhibiting CoVs. This has been attributed to the proofreading activity of the viral 3'-5' exoribonuclease (ExoN). β-d-N4-Hydroxycytidine (NHC) (EIDD-1931; Emory Institute for Drug Development) has recently been reported to inhibit multiple viruses. Here, we demonstrate that NHC inhibits both murine hepatitis virus (MHV) (50% effective concentration [EC50] = 0.17 μM) and Middle East respiratory syndrome CoV (MERS-CoV) (EC50 = 0.56 μM) with minimal cytotoxicity. NHC inhibited MHV lacking ExoN proofreading activity similarly to wild-type (WT) MHV, suggesting an ability to evade or overcome ExoN activity. NHC inhibited MHV only when added early during infection, decreased viral specific infectivity, and increased the number and proportion of G:A and C:U transition mutations present after a single infection. Low-level NHC resistance was difficult to achieve and was associated with multiple transition mutations across the genome in both MHV and MERS-CoV. These results point to a virus-mutagenic mechanism of NHC inhibition in CoVs and indicate a high genetic barrier to NHC resistance. Together, the data support further development of NHC for treatment of CoVs and suggest a novel mechanism of NHC interaction with the CoV replication complex that may shed light on critical aspects of replication.IMPORTANCE The emergence of coronaviruses (CoVs) into human populations from animal reservoirs has demonstrated their epidemic capability, pandemic potential, and ability to cause severe disease. However, no antivirals have been approved to treat these infections. Here, we demonstrate the potent antiviral activity of a broad-spectrum ribonucleoside analogue, β-d-N4-hydroxycytidine (NHC), against two divergent CoVs. Viral proofreading activity does not markedly impact sensitivity to NHC inhibition, suggesting a novel interaction between a nucleoside analogue inhibitor and the CoV replicase. Further, passage in the presence of NHC generates only low-level resistance, likely due to the accumulation of multiple potentially deleterious transition mutations. Together, these data support a mutagenic mechanism of inhibition by NHC and further support the development of NHC for treatment of CoV infections.

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:93

Enthalten in:

Journal of virology - 93(2019), 24 vom: 15. Dez.

Sprache:

Englisch

Beteiligte Personen:

Agostini, Maria L [VerfasserIn]
Pruijssers, Andrea J [VerfasserIn]
Chappell, James D [VerfasserIn]
Gribble, Jennifer [VerfasserIn]
Lu, Xiaotao [VerfasserIn]
Andres, Erica L [VerfasserIn]
Bluemling, Gregory R [VerfasserIn]
Lockwood, Mark A [VerfasserIn]
Sheahan, Timothy P [VerfasserIn]
Sims, Amy C [VerfasserIn]
Natchus, Michael G [VerfasserIn]
Saindane, Manohar [VerfasserIn]
Kolykhalov, Alexander A [VerfasserIn]
Painter, George R [VerfasserIn]
Baric, Ralph S [VerfasserIn]
Denison, Mark R [VerfasserIn]

Links:

Volltext

Themen:

5CSZ8459RP
Antiviral Agents
Antiviral resistance
C3D11PV2O4
Coronavirus
Cytidine
EC 2.1.1.56
EC 2.7.7.48
EC 3.1.-
Exoribonucleases
Journal Article
MERS-CoV
N(4)-hydroxycytidine
Nsp14 protein, SARS coronavirus
Nucleoside analogue
Pandemic
RNA-Dependent RNA Polymerase
RNA-dependent RNA polymerase
RdRp
Research Support, N.I.H., Extramural
SARS-CoV
Viral Nonstructural Proteins

Anmerkungen:

Date Completed 04.06.2020

Date Revised 14.02.2024

published: Electronic-Print

Citation Status MEDLINE

doi:

10.1128/JVI.01348-19

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM301856001