New study identifies how ebola virus avoids the immune system

Jan 27, 2009
Scanning electron microscope image of Ebola virions (spaghetti-like filaments) on the surface of a tetherin-expressing cell (center). The other three cells seen in this image (upper right and upper and lower left) do not have the filamentous virus on their surfaces. Credit: Paul Bates, Ph.D., University of Pennsylvania School of Medicine

(PhysOrg.com) -- Researchers at the University of Pennsylvania School of Medicine have likely found one reason why the Ebola virus is such a powerful, deadly, and effective virus. Using a cell culture model for Ebola virus infection, they have discovered that the virus disables a cellular protein called tetherin that normally can block the spread of virus from cell to cell.

"Tetherin represents a new class of cellular factors that possess a very different means of inhibiting viral replication," says study author Paul Bates, PhD, Associate Professor of Microbiology at the University of Pennsylvania School of Medicine. "Tetherin is the first example of a protein that affects the virus replication cycle after the virus is fully made and prevents the virus from being able to go off and infect the next cell." These findings appear online this week in the Proceedings of the National Academy of Sciences.

When a cell is infected with a virus like Ebola, which is deadly to 90 percent of people infected, the cell is pirated by the virus and turned into a production factory that makes massive quantities on new virions. These virions are then released from that cell to infect other cells and promote the spreading infection.

Tetherin is one of the immune system's responses to a viral infection. If working properly, tetherin stops the infected cell from releasing the newly made virus, thus shutting down spread to other cells. However, this study shows that the Ebola virus has developed a way to disable tetherin, thus blocking the body's response and allowing the virus to spread.

"This information gives us a new way to study how tetherin works," says Bates. "Binding of a protein produced by Ebola to tetherin apparently inactivates this cellular factor. Understanding how the Ebola protein blocks the activity of tetherin may facilitate the design of therapeutics to inhibit this interaction, allowing the cell's natural defense systems to slow down viral replication and give the animal or person a chance to mount an effective antiviral response and recover."

Previous research had found that tetherin plays a role in the immune system's response to HIV-1, a retrovirus, and that tetherin is also disabled by HIV. These new studies reveal that human cells also use this defense against other types of viruses, such as Ebola, that are not closely related to HIV-1. "Because we see such broad classes of viruses that are affected by tetherin, it's possible that all enveloped viruses are targets of this antiviral system," says Bates. "If so, then understanding how tetherin works and how viruses escape from the effect of tetherin will be very important."

Provided by University of Pennsylvania

Explore further: US scientists make embryonic stem cells from adult skin

add to favorites email to friend print save as pdf

Related Stories

Gene removal could have implications beyond plant science

Apr 16, 2014

(Phys.org) —For thousands of years humans have been tinkering with plant genetics, even when they didn't realize that is what they were doing, in an effort to make stronger, healthier crops that endured climates better, ...

Ferns borrowed genes to flourish in low light

Apr 14, 2014

During the age of the dinosaurs, the arrival of flowering plants as competitors could have spelled doom for the ancient fern lineage. Instead, ferns diversified and flourished under the new canopy—using ...

The science of anatomy is undergoing a revival

Apr 10, 2014

Only two decades ago, when I was starting my PhD studies at the University of California in Berkeley, there was talk about the death of anatomy as a research subject. That hasn't happened. Instead the science ...

Recommended for you

Leeches help save woman's ear after pit bull mauling

Apr 18, 2014

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

New pain relief targets discovered

Apr 17, 2014

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

SgntZim
not rated yet Jan 27, 2009
Very interesting article

More news stories

Less-schooled whites lose longevity, study finds

Barbara Gentry slowly shifts her heavy frame out of a chair and uses a walker to move the dozen feet to a chair not far from the pool table at the Buford Senior Center. Her hair is white and a cough sometimes interrupts her ...

Low tolerance for pain? The reason may be in your genes

Researchers may have identified key genes linked to why some people have a higher tolerance for pain than others, according to a study released today that will be presented at the American Academy of Neurology's 66th Annual ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.