This project (part of Divide and ConqueR/INTERCEPT project coordinated by Marco Vignuzzi) pertains to the study, construction and use of defective viral genomes in order to combat viral infections. Neurotropic Flaviviruses, for which no anti-viral therapy is yet available, are indeed good models for this project. Our team is currently developing 3 aspects:
– How are defective genomes for WNV and JEV viruses generated?
ARN viruses are known to produce defective genomes during their infectious cycle, but how and why they are produced is still poorly understood. In order to produce defective genomes, WNV and JEV viruses are passaged serially at low and high multiplicity of infection (MOI) in mammalian as well as in mosquito cells. The genomic RNA from the cell culture supernatants is then extracted and will be submitted to deep sequencing (NGS).
– Are deletions in defective genomes specific for each virus?
We will examine genomic deletions of a chimeric virus (Zika/WNV virus) we produced in the lab after passaging it at high and low MOI in mammalian as well as mosquito cells using deep sequencing (NGS). Location and length of the deletions in the chimeric virus genome will be then compared to that of the parental Zika and WNV viruses.
– Do defective genomes play a role in the pathophysiology of JEV virus?
JEV virus is neurotropic as well as neuroinvasive. We have developed in the lab an in vitro system to examine neuroinvasion, ie the passage of the Blood-Brain Barrier (BBB) by JEV virus. We will examine the viral RNA genomes of the viral particles that are able to cross the BBB by NGS, and study the mechanisms involved in BBB crossing by this neuroinvasive Flavivirus.