SUNDAY, SEPTEMBER 25, 2016

Flavivirus discovery may lead to new treatments, vaccines

A University of Colorado School of Medicine researcher and his colleagues recently published two papers that may help scientists develop treatments or vaccines for Dengue fever, West Nile virus, Yellow fever, Japanese encephalitis and other disease-causing flaviviruses.

Associate professor of biochemistry and molecular genetics Jeffrey S. Keift, an early career scientist with the Howard Hughes Medical Institute, and his colleagues published the articles in the journals eLife and Science.

The articles explain how flaviviruses produce a unique RNA molecule that leads to disease.

According to eLife, more than 40 percent of people globally are at risk of mosquito bites infected with the virus that causes Dengue fever and more than 100 million are infected. Other flaviviruses like West Nile virus are spreading rapidly around the globe. Flaviviruses are considered dangerous emerging pathogens.

The Dengue fever causing virus and other closely related viruses, including West Nile and Japanese encephalitis, use instructions encoded on a single RNA strand to take over an infected cell and reproduce, the eLife paper shows. Additionally, the viruses exploit an enzyme used by cells to destroy RNA to instead produce short stretches of RNA that may aid the virus in avoiding the host's immune systems.

The Science paper delineates the discovery that the resistant RNA folds into an unprecedented "knot-like" structure. The enzyme that normally breaks up the RNA structure cannot untangle the new structure. Such a structure has never been observed but has characteristics that may be amenable to targeting by new drugs.