An interfering activity against lymphocytic choriomeningitis virus replication associated with enhanced mutagenesis

Arenaviruses include several important human pathogens, and there are very limited options of preventive or therapeutic interventions to combat these viruses. An off-label use of the purine nucleoside analogue ribavirin (1-␤-D-ribofuranosyl-1-H-1,2,4-triazole-3-carboxamide) is the only antiviral treatment currently available for arenavirus infections. However, the ribavirin antiviral mechanism action against arenaviruses remains unknown. Here we document that ribavirin is mutagenic for the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) in cell culture. The mutagenic activity of ribavirin on LCMV was observed under single-and multiple-passage regimes and could not be accounted for by a decrease of the intracellular GTP pool promoted by ribavirin-mediated inhibition of inosine monophosphate dehydrogenase (IMPDH). Our findings suggest that the antiviral activity of ribavirin on arenaviruses might be exerted, at least partially, by lethal mutagenesis. Implications for antiarenavirus therapy are discussed.

Section: Resultsmentioning

confidence: 99%

Ribavirin Can Be Mutagenic for Arenaviruses

Moreno

Gallego

Sevilla

et al. 2011

“…Our hypothesis that lethal mutagenesis is the antiviral mechanism of T-705 was based on available data about the antiviral mechanism of nucleoside analogs against poliovirus, vesicular stomatitis virus (36,37), West Nile virus (34), foot-and-mouth disease virus (38), lymphatic choriomeningitis virus (39), and human immunodeficiency virus type 1 (35). Lethal mutagenesis is suggested when the percentage of noninfectious virus genomes is much higher after passaging with a nucleoside analog than after passaging in mocktreated cells; furthermore, incorporation of a nucleoside analog into the viral genome is known to induce hypermutation (34,38,39).…”

Section: Discussionmentioning

confidence: 99%

T-705 (Favipiravir) Induces Lethal Mutagenesis in Influenza A H1N1 Viruses In Vitro

Baranovich

Wong

Armstrong

et al. 2013

359

352

Several novel anti-influenza compounds are in various phases of clinical development. One of these, T-705 (favipiravir), has a mechanism of action that is not fully understood but is suggested to target influenza virus RNA-dependent RNA polymerase. We investigated the mechanism of T-705 activity against influenza A (H1N1) viruses by applying selective drug pressure over multiple sequential passages in MDCK cells. We found that T-705 treatment did not select specific mutations in potential target proteins, including PB1, PB2, PA, and NP. Phenotypic assays based on cell viability confirmed that no T-705-resistant variants were selected. In the presence of T-705, titers of infectious virus decreased significantly (P < 0.0001) during serial passage in MDCK cells inoculated with seasonal influenza A (H1N1) viruses at a low multiplicity of infection (MOI; 0.0001 PFU/cell) or with 2009 pandemic H1N1 viruses at a high MOI (10 PFU/cell). There was no corresponding decrease in the number of viral RNA copies; therefore, specific virus infectivity (the ratio of infectious virus yield to viral RNA copy number) was reduced. Sequence analysis showed enrichment of G¡A and C¡T transversion mutations, increased mutation frequency, and a shift of the nucleotide profiles of individual NP gene clones under drug selection pressure. Our results demonstrate that T-705 induces a high rate of mutation that generates a nonviable viral phenotype and that lethal mutagenesis is a key antiviral mechanism of T-705. Our findings also explain the broad spectrum of activity of T-705 against viruses of multiple families.

“…The analyses have involved residues 9 to 71 of the polymerase coding region. A comparison of the complexity of mutant spectra of different genomic regions of FMDV and other RNA viruses subjected to increased mutagenesis (2,44,53,65) renders it very unlikely that the complexities determined in the polymerase coding region differ substantially for other genomic regions. The dissimilar evolution of genomic complexity in the absence and presence of ribavirin (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Previous experimental and in silico studies suggested that under limited mutagenesis a class of defective interfering genomes termed "defectors" can be generated during viral replication and that they can interfere with the replication of standard virus, contributing to extinction (34,38,44,58). These observations add to an increasing wealth of evidence that indicates that opposite complementing or interfering interactions among components of the mutant spectrum of viral quasispecies can be a determinant of relevant viral traits such as fitness and virulence (10,12,30,34,43,50,58,75; reviewed in reference 57).…”

mentioning

confidence: 99%

Lethal Mutagenesis of Foot-and-Mouth Disease Virus Involves Shifts in Sequence Space

Perales

Mathieu

Domingo

et al. 2011

Lethal mutagenesis or virus transition into error catastrophe is an antiviral strategy that aims at extinguishing a virus by increasing the viral mutation rates during replication. The molecular basis of lethal mutagenesis is largely unknown. Previous studies showed that a critical substitution in the foot-and-mouth disease virus (FMDV) polymerase was sufficient to allow the virus to escape extinction through modulation of the transition types induced by the purine nucleoside analogue ribavirin. This substitution was not detected in mutant spectra of FMDV populations that had not replicated in the presence of ribavirin, using standard molecular cloning and nucleotide sequencing. Here we selectively amplify and analyze low-melting-temperature cDNA duplexes copied from FMDV genome populations passaged in the absence or presence of ribovirin Hypermutated genomes with high frequencies of A and U were present in both ribavirin -treated and untreated populations, but the major effect of ribavirin mutagenesis was to accelerate the occurrence of AU-rich mutant clouds during the early replication rounds of the virus. The standard FMDV quasispecies passaged in the absence of ribavirin included the salient transition-modulating, ribavirin resistance mutation, whose frequency increased in populations treated with ribavirin. Thus, even nonmutagenized FMDV quasispecies include a deep, mutationally biased portion of sequence space, in support of the view that the virus replicates close to the error threshold for maintenance of genetic information.