Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetically engineered mosquitoes show resistance to dengue fever virus

10.03.2006


Researchers create new tool against transmission of virus



Researchers have successfully created a genetically engineered mosquito that shows a high level of resistance against the most prevalent type of dengue fever virus, providing a powerful weapon against a disease that infects 50 million people each year.

Anthony James, a UC Irvine vector biologist, is one of a team of researchers who injected DNA into mosquito embryos, creating the first stable transgenic mosquito resistant to Type 2 dengue fever virus, the most prevalent strain of the disease. The mosquitoes that survived the procedure also remained fertile and were able to reproduce, a key factor for any future strategies that may involve replacing mosquito populations with their genetically modified counterparts.


The results were published this week in the early online edition of the Proceedings of the National Academy of Sciences.

“These results are very exciting because they provide us a genetic tool we can use to control mosquito-borne diseases such as dengue fever,” James said. “We have been working for some time on the individual components of creating a genetically modified mosquito that would fend off dengue infection, but this is the first time we have brought all the pieces together to create a stable model that can also reproduce.”

In the study, the researchers exploited a vulnerability of the dengue virus to make the mosquitoes resistant to infection. This vulnerability occurs when the virus replicates and its single strand of RNA – a chemical cousin of DNA – briefly becomes double–stranded. At this point, the virus is vulnerable because of a naturally occurring protein called dicer-2. This protein initially has no effect on a single strand of RNA, but acts like scissors on the double strand, chopping it up and rendering its genetic material useless. Once this process is started, the single-stranded RNA also becomes vulnerable to dicer-2 and is cut up, thereby preventing further virus replication.

On its own, this process of self-destruction happens only after the virus has already replicated and been transmitted; however, the researchers found a way to control and speed up the process. They accomplished this by cloning a section of the virus’ RNA and injected two inverse copies of it into mosquito embryos. The copies formed a double-stranded RNA, which, as expected, bound with dicer-2 and was chopped up. The virus never had the opportunity to replicate. As a result, they could “inoculate” mosquitoes with a form of the virus that would essentially be benign.

Joining James on the study, funded by a 2001 grant from the National Institutes of Health, were researchers from Colorado State University and from Virginia Polytechnic Institute and State University.

James and his colleagues performed tests on a family of mosquitoes descended from one of the original embryos that survived the procedure. They found that the vast majority of that family was highly resistant to dengue infection. They also were able to detect the engineered RNA in the mosquitoes, a sign that the genetic alteration had been successful and passed down through reproduction. Furthermore, when that genetic modification was reversed, the mosquitoes were as susceptible to the virus as they had been before the procedure.

Dengue fever is endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, Southeast Asia and the Western Pacific. The virus is transmitted to people by mosquitoes of the species Aedes aegypti. The World Health Organization estimates 50 million cases of dengue infection each year. Approximately 20,000 people die annually from the disease.

James, a professor of microbiology and molecular genetics, and of molecular biology and biochemistry, has made a number of significant advances on genetic approaches to interrupt malaria parasite and dengue virus transmission by mosquitoes. He has received a number of international awards for his research.

In 2005, he received a $19.7 million grant from the Foundation for the National Institutes of Health to lead an international effort to develop new methods to control the transmission of dengue fever. The project is among 43 groundbreaking research projects to improve health in developing countries, supported by $436 million for the Grand Challenges in Global Health Initiative, launched by the Bill and Melinda Gates Foundation.

According to James, the next step of this research will be to use the FNIH grant to explore population replacement strategies using the genetically modified mosquitoes. He stressed that no genetically altered mosquitoes will be released at any time during these studies.

About the University of California, Irvine: The University of California, Irvine is a top-ranked university dedicated to research, scholarship and community service. Founded in 1965, UCI is among the fastest-growing University of California campuses, with more than 24,000 undergraduate and graduate students and about 1,400 faculty members. The second-largest employer in dynamic Orange County, UCI contributes an annual economic impact of $3.3 billion.

Farnaz Khadem | EurekAlert!
Further information:
http://www.today.uci.edu
http://www.uci.edu

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>