Washington: An unknown virus from a mosquito sample collected 30 years ago in Israel’s Negev Desert happens to be closely related to some of the world’s most dangerous mosquito-borne pathogens.
Discovery of the Eilat virus could possibly open way to the development of new alphavirus vaccines, therapies and diagnostic techniques.
Alphaviruses are a genus of largely mosquito-borne pathogens, say researchers from the University of Texas Medical Branch, Galveston (UTMBG).
The group includes the viruses responsible for chikungunya, Venezuelan equine encephalitis, western equine encephalitis and eastern equine encephalitis, journal Proceedings of the National Academy of Sciences reports.
“This virus is unique — it is related to all of these mosquito-borne viruses that cause disease and cycle between mosquitoes and animals, and yet it is incapable of infecting vertebrate cells,” said UTMBG graduate student Farooq Nasar, who led the study.
“It’s a gift, really, because we can compare it to other alphaviruses and figure out the basis of their ability to infect a variety of animals, including humans,” added Nasar, according to an UTMBG statement.
Eilat was discovered in a virus sample that Joseph Peleg of Hebrew University sent to UTMBG’s Robert Tesh, study co-author and director of World Reference Centre for Emerging Viruses and Arboviruses.
The collection holds over 5,000 identified viruses and dozens of unidentified samples like the one contributed by Peleg.
All the researchers knew about Peleg’s specimen was that it killed insect cells while leaving animal cells untouched, a very unusual behaviour. So they sent it to a lab at Columbia University that specialises in doing highly intensive searches for the genetic material of viruses, a process called “deep sequencing.”
As it turned out, there were two new viruses in the sample. One virus killed insect cells, and the other — Eilat virus — infected them without doing any harm.
“We were extraordinarily lucky to have that other virus in our sample, because without the cell death it caused, we never would have done the work that led us to Eilat,” Nasar said.
“Essentially, we found it by accident.”
Eilat’s inability to grow in animal cells makes it unique among alphaviruses, and it also makes it likely that the virus could be uniquely valuable to researchers who study alphaviruses and work to protect humans and domestic animals from them.
For example, UTMBG researchers say, Eilat could be transformed into a vaccine against one of its dangerous relatives.