A new discovery from the University of Alberta’s Faculty of Medicine & Dentistry could open the door to one day treat or prevent diseases caused by West Nile virus and Dengue virus infections.
The research, published and featured in the Spot Light section of the December edition of the Journal of Virology, examines a previously unknown connection between flaviviruses–a classification of viruses that include West Nile virus, Dengue virus and tick-borne encephalitis virus–and organelles (a specialized subunit within a cell) known as peroxisomes that help coordinate the body’s immune responses. Postdoctoral fellow Jaehwan You and PhD student Shangmei Hou, the lead authors on the study, found that flaviviruses induce degradation of a protein called Pex19, which is essential for the building of new peroxisomes, setting off a chain reaction that could leave the body more vulnerable to viral infection.
“Peroxisomes, as it turns out, are required for production of an antiviral molecule called interferon lambda,” says Tom Hobman, senior author and professor of cell biology at the U of A. “Interferon lambda is produced by infected cells and has been shown to inhibit replication of multiple viruses. We hypothesized that loss of peroxisomes results in the loss of the ability of the cells to produce this interferon, which indeed was found to be the case.
“It looks like the virus may be targeting peroxisomes to prevent antiviral defense by the cell.”
The study found that in infected cells, about 35 per cent of the peroxisomes had disappeared. Production of interferon was also down by approximately 80 per cent. Richard Rachubinski, a study co-author and one of the world’s leading authorities on peroxisomes, says that while the team set out to find how viruses manipulate host cells, the link to peroxisomes was completely unexpected.
“You can’t plan this. You just cannot,” says Rachubinski, who is also chair of the U of A’s Department of Cell Biology. “It goes to show the unexpected avenues one finds in discovery research that you’d never anticipate.”
Read the rest of the University of Alberta news release HERE