Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New understanding of dengue virus points way to possible therapies for dengue fever

24.04.2009
Doctors have no specific drugs to treat dengue fever, a viral illness spread by mosquitoes that sickens 50 million to 100 million people worldwide each year. Instead, the only treatments they can recommend for this painful and sometimes fatal illness (20,000 deaths globally each year) are fluids, rest and non-aspirin pain and fever reducers.

Now, researchers have identified cellular components in mosquitoes and in humans that dengue virus uses to multiply inside these hosts after infecting them. Their findings could lead to the development of anti-dengue drugs that would inhibit one or more of these host factors, thus curtailing infection and the development of disease.

The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, funded the research, which was led by Mariano Garcia-Blanco, M.D., Ph.D., of Duke University Medical Center. The research appears in the current issue of the journal Nature.

"In this important study, Dr. Garcia-Blanco and his collaborators have greatly expanded the list of candidate targets for dengue drug development," says NIAID Director Anthony S. Fauci, M.D. "Their discovery should spur a better understanding of how dengue virus causes illness and open new avenues for developing specific treatments for a disease that exacts a huge global burden."

All viruses co-opt parts of the cells they invade, but dengue virus is believed to require many such host factors because it has very little of its own genetic material, says Dr. Garcia-Blanco. Yet only a handful of mosquito or human dengue virus host factors (DVHF) have been identified to date, he adds, because researchers lack the tools for determining the functions of mosquito genes.

To overcome this barrier, the researchers turned to a familiar lab animal, the fruit fly. Mosquitoes and fruit flies (Drosophila melanogaster) are closely related, and researchers have multiple tools for determining Drosophila gene functions, notes Dr. Garcia-Blanco.

The Duke researchers screened test-tube-grown Drosophila cells to find any fly gene components used by dengue virus. They employed a technique called RNA interference (RNAi) to selectively turn off, or silence, Drosophila gene segments and identify those that dengue virus requires for efficient growth. The screen turned up 116 DVHFs, of which 111 had not previously been identified as host factors.

The scientists also used RNAi and live mosquitoes to test whether silencing select DVHFs impaired the ability of dengue virus to infect the gut tissue of the insects. They found that silencing a specific mosquito gene greatly impaired the capacity of the virus to multiply in the mosquito. This finding, though preliminary, raises the possibility of selectively inhibiting dengue virus growth in mosquitoes, says Dr. Garcia-Blanco. For example, a spray containing inhibitory chemicals might be developed that would be used not to kill the mosquitoes, he says, but to make them a less effective carrier of dengue virus. Because these envisioned drugs would not target the virus directly, but rather a host factor, the virus would have less opportunity to develop drug resistance, Dr. Garcia-Blanco adds.

The 116 DVHFs discovered through the Drosophila screen included 42 that the investigators found to have counterparts in humans. Like the mosquito DVHFs, these newly discovered human DVHFs may serve as targets for new kinds of RNAi-based drugs, says Dr. Garcia-Blanco.

"Our research is motivated in part by a desire to understand how these tiny viruses manage to live in two such unrelated organisms as mosquitoes and humans," says Dr. Garcia-Blanco. "But we should also keep in the front of our minds—not the back—the magnitude of suffering caused by dengue fever to millions around the world. Our study is a big leap in terms of the amount of information we have about dengue host factors and this information could, we hope, be applied in ways that will help people."

Dr. Garcia-Blanco's collaborators included NIAID grantee George Dimopoulos, Ph.D., and others from Johns Hopkins University's Bloomberg School of Public Health. NIAID grantee Priscilla Yang, Ph.D., and others from Harvard Medical School also contributed to the new research.

NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.

The National Institutes of Health (NIH)—The Nation's Medical Research Agency—includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

Reference: OM Sessions et al. Discovery of insect and human dengue virus host factors. Nature DOI: 10.1038/nature07969 (2009).

Visit NIAID's Dengue Fever page for more information on this disease (http://www3.niaid.nih.gov/topics/DengueFever/default.htm).

Anne A. Oplinger | EurekAlert!
Further information:
http://www.niaid.nih.gov

More articles from Health and Medicine:

nachricht Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine

nachricht Flexible sensors can detect movement in GI tract
11.10.2017 | Massachusetts Institute of Technology

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>