New way dengue evades our immune responses discovered

Scientists have discovered a new pathway the dengue takes to suppress the human immune system, an advance that may lead to new treatments and vaccines to fight the virus.
For years, the conventional approach to target the dengue virus was through vector control, which was regarded to be the most effective method.
This is because the mechanics of the virus have been elusive, which in turn hampered the development of effective treatments and vaccines.
Researchers from the Programme in Emerging Infectious Diseases (EID) at Duke-NUS Graduate Medical School Singapore (Duke-NUS) have discovered a new way that dengue virus-2 (DENV-2) uses to evade the human defense system.

Typically, when a virus enters the body and infects cells, it induces the production and release of interferons (IFNs), which are proteins that raise the bodies' anti-viral defense mechanisms.
The dengue virus enters the cell and produces large quantities of a non-coding, highly-structured viral RNA termed sfRNA, which is part of the genetic material of the dengue virus.

The team found that sfRNA attaches itself to G3BP1, G3BP2 and CAPRIN1, proteins in the cell that typically help in producing antiviral proteins in response to IFNs.
Because of this interaction, the cell is unable to mount its antiviral defenses and protect itself against virus replication.

"These findings were surprising because in 30 years of RNA and dengue related research this new mechanism was never discovered," said senior author Professor Mariano Garcia-Blanco from EID.
"We not only found a new way in which the pathogen (dengue virus) interferes with the host response (human immune system) we also uncovered the first mechanistic insight into how this non-coding RNA works. This discovery opens the door to explore therapeutics through this channel," Garcia-Blanco said.
The study was published in the journal PLOS Pathogens.