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 Cholesterol-lowering drugs may fight infectious disease
22.08.2017 | Duke University

nachricht Once invincible superbug squashed by 'superteam' of antibiotics
22.08.2017 | University at Buffalo

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>