engleski

Altering mumps virus polymerase fidelity

Mumps virus (MuV) is an RNA virus that causes respiratory infection. In most cases patients naturally recover in two weeks. Due to highly neurotropic nature of this virus encephalitis or meningitis can occur in less than 1% and 10% of mumps cases, respectively. Mumps vaccines are in use, but there are some concerns that indicate a need for development of more efficient ones. Altering viral population diversity rate, a main factor in RNA viruses virulence severity, has been described as a valid approach to design attenuated RNA viruses with vaccine potential. The aim of this study was to isolate a variant containing polymerase of changed fidelity (lower or higher) from mumps virus population by passaging virus in vitro in the presence of mutagen. This was expected to result in increased or decreased population diversity and potentially attenuated phenotype. We subcultivated wild-type MuV over the course of 21 passages in A549 cells in the presence of ribavirin and determined population content for control and treated samples from 6 different passages and for a parental virus, by next-generation sequencing (NGS). Analysis of the sequencing data showed accumulation of ribavirin specific mutations in treated viruses. Diversity in ribavirin treated viral populations was approximately 2 – 4 fold higher than in control or parental virus depending on passage. Despite this high rate of mutations, virus was still able to replicate to high levels in the presence of ribavirin. We hypothesize that obtained viral population is resistant to ribavirin treatment which points to its very high adaptive capability. Our next step is to determine what are biological characteristics of obtained viral population. Also, we need to determine if there is a specific viral variant present in this population that could be solely resistant to ribavirin.

mumps, vaccine, population diversity, mutagen treatment

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