Featured Research

from universities, journals, and other organizations

'Secret weapon' of retroviruses that cause cancer

Date:
February 17, 2010
Source:
CNRS (Délégation Paris Michel-Ange)
Summary:
Oncogenic retroviruses are a particular family of viruses that can cause some types of cancer. Scientists have now identified a "virulence factor" that inhibits the host immune response and allows the virus to spread throughout the body. This factor is a sequence of amino acids that is located in the envelope protein of the virus.

Oncogenic retroviruses are a particular family of viruses that can cause some types of cancer. Thierry Heidmann and his colleagues in the CNRS-Institut Gustave Roussy-Université Paris Sud 11 "Rétrovirus endogènes et éléments rétroïdes des eucaryotes supérieurs" Laboratory have studied these viruses. They have identified a "virulence factor" that inhibits the host immune response and allows the virus to spread throughout the body. This factor is a sequence of amino acids that is located in the envelope protein of the virus.

These scientists have also shown that once mutated to lose its immunosuppressive capability, this envelope protein could serve as a basis for the development of vaccines.

These findings have been published online in the Proceedings of the National Academy of Sciences USA.

Retroviruses are viruses whose genome is made up of RNA. These viruses are unique in possessing an enzyme that enables synthesis from this RNA of a DNA molecule capable of integrating into the DNA of a host cell. The retrovirus then utilizes the cell machinery to replicate. HIV is one of the best-known retroviruses. Oncogenic retroviruses (or oncoretroviruses) are cancer-causing viruses. Numerous oncoretroviruses are associated with animal diseases. In humans, two retroviruses, called HTLV and XMRV, have been associated with a type of leukemia and with prostate cancer.

Researchers in the Rétrovirus Endogènes et Eléments Rétroïdes des Eucaryotes Supérieurs Laboratory (1), headed by Thierry Heidmann, CNRS Senior Researcher at Institut Gustave Roussy, have been working on the ability of retroviruses to propagate and persist in their hosts by escaping the immune system. They have studied the molecular basis of this process, and have shown that it is driven by the envelope protein of these viruses. First of all, this protein has an essential "mechanical" role, as it induces the fusion of viral particles with the target cell membrane, thus allowing them to penetrate into the cell. Using a mouse model of infection with a murine leukemia virus, the researchers showed that this envelope protein also has a second role that is equally essential to viral propagation in the body: it is immunosuppressive, or in other words it inhibits the host immune response in a radical manner, affecting both the "innate" and "adaptive" immune responses.

The researchers succeeded in locating the domain responsible for this property within the amino acid sequence of the envelope protein. This domain, an authentic virulence factor, is a crucial element in the arsenal that enables retroviruses to invade their host and produce their pathogenic effect. It thus becomes a target of choice for the design of novel antiretroviral therapeutic strategies, including vaccines. The results obtained by these scientists mean it will be possible to follow this path.

hey were able to introduce targeted point mutations into the envelope protein that could suppress its ability to inhibit the immune system which, as expected, reacted much more effectively than with the non-mutated protein, producing a high level of antibodies and inducing antiviral cellular immunity. By working on this mutated protein, it should be possible to develop vaccines for the future. Indeed, after the mouse model, the researchers were able to show that the HTLV and XMRV retroviruses associated with human diseases were both endowed with an immunosuppressive domain in their envelope protein.

(1) CNRS/ Université Paris-Sud 11/Institut Gustave Roussy)


Story Source:

The above story is based on materials provided by CNRS (Délégation Paris Michel-Ange). Note: Materials may be edited for content and length.


Journal Reference:

  1. Schlecht-Louf et al. Retroviral infection in vivo requires an immune escape virulence factor encrypted in the envelope protein of oncoretroviruses. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.0913122107

Cite This Page:

CNRS (Délégation Paris Michel-Ange). "'Secret weapon' of retroviruses that cause cancer." ScienceDaily. ScienceDaily, 17 February 2010. <www.sciencedaily.com/releases/2010/02/100215130341.htm>.
CNRS (Délégation Paris Michel-Ange). (2010, February 17). 'Secret weapon' of retroviruses that cause cancer. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2010/02/100215130341.htm
CNRS (Délégation Paris Michel-Ange). "'Secret weapon' of retroviruses that cause cancer." ScienceDaily. www.sciencedaily.com/releases/2010/02/100215130341.htm (accessed October 23, 2014).

Share This



More Plants & Animals News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) — Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) — One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Working Mother DIY: Pumpkin Pom-Pom

Working Mother DIY: Pumpkin Pom-Pom

Working Mother (Oct. 22, 2014) — How to make a pumpkin pom-pom. Video provided by Working Mother
Powered by NewsLook.com
Goofy Dinosaur Blends Barney and Jar Jar Binks

Goofy Dinosaur Blends Barney and Jar Jar Binks

AP (Oct. 22, 2014) — A collection of dinosaur bones reveal a creature that is far more weird and goofy-looking than scientists originally thought when they found just the arm bones nearly 50 years ago, according to a new report in the journal Nature. (Oct. 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins