Researchers discover how dengue suppresses the human immune system

July 16, 2014

Scientists have discovered a new pathway the dengue virus takes to suppress the human immune system. This new knowledge deepens our understanding of the virus and could contribute to the development of more effective therapeutics.

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.

Fortunately a new study, published in the prestigious journal PLOS Pathogens, has given us fresh insight into the virus. Researchers from the Program 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 .

"These findings were surprising because in 30 years of RNA and dengue related research this new mechanism was never discovered," explained 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 () 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."

These findings highlight new steps that regulate our immune response, and in the case of dengue, how the virus has learnt how to avoid these defenses. It also highlights the differences between the four dengue strains and how more research is needed to understand this highly complex virus.

"The dengue virus employs multiple strategies to evade our immune responses. These strategies provide the virus with redundancies so that if one approach fails, it has others to provide it with the necessary means to thrive," commented Associate Professor Eng Eong Ooi, Deputy Director of EID.

"Prof Garcia-Blanco's lab describes a novel way in which dengue virus is able to avoid being killed by our antiviral response. It produces fragments of its own genome to act like a sponge to soak up those factors needed to produce the virus killing machinery. This work is an important contribution to our overall understanding of the evasive strategies employed by , which is important for devising new and effective methods for treating dengue patients."

Explore further: Researchers determine how mosquitoes survive dengue virus infection

Related Stories

Mechanism of dengue virus entry into cells revealed

February 17, 2014

Dengue fever, an infectious tropical disease caused by a mosquito-borne virus, afflicts millions of people each year, causing fever, headache, muscle and joint pains and a characteristic skin rash. In some people the disease ...

How the Dengue virus circulates in the wild

February 20, 2014

Science has come a long way in containing infectious diseases over the past five decades. Despite this progress, the incidence of dengue fever has increased thirty-fold, with 390 million people infected annually worldwide.

Researchers discover target for treating dengue fever

April 17, 2014

Two recent papers by a University of Colorado School of Medicine researcher and colleagues may help scientists develop treatments or vaccines for Dengue fever, West Nile virus, Yellow fever, Japanese encephalitis and other ...

Recommended for you

In sub-Saharan Africa, cancer can be an infectious disease

August 26, 2016

In 1963, Irish surgeon Denis Parson Burkitt airmailed samples of an unusual jaw tumor found in Ugandan children to his colleague, Anthony Epstein, at Middlesex Hospital in London. Epstein, an expert in chicken viruses and ...

Zika virus may persist in the vagina days after infection

August 25, 2016

The Zika virus reproduces in the vaginal tissue of pregnant mice several days after infection, according to a study by Yale researchers. From the genitals, the virus spreads and infects the fetal brain, impairing fetal development. ...

Team discovers how Zika virus causes fetal brain damage

August 24, 2016

Infection by the Zika virus diverts a key protein necessary for neural cell division in the developing human fetus, thereby causing the birth defect microcephaly, a team of Yale scientists reported Aug. 24 in the journal ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.