Protein discovered that prevents HIV from spreading

January 18, 2008
Protein discovered that prevents HIV from spreading
Sticky situation. HIV-1 particles (dark circles) lacking Vpu are unable to extricate themselves from the surface of their host cell. Instead, tetherin keeps them locked to the surface of the cell’s outer membrane, or causes them to be sucked back in and digested by the cell’s endosomes. Credit: Rockefeller University

In a study that could open up the field of virology to an entirely new suite of possibilities and that paves the way for future drug research, scientists at Rockefeller University and the Aaron Diamond AIDS Research Center have pinned down a molecule on the surface of human cells that helps keep particles of mutant strains of HIV from spreading.

Rather than floating off to infect more cells, the protein contains the virus particles by keeping them attached to the parent cell’s outer membrane, as if stuck there with glue.

Two years ago, Paul Bieniasz — head of the Laboratory of Retrovirology and ADARC scientist — discovered that normal HIV-1 particles are able to extricate themselves from the sticky membrane surface using a protein called Vpu. Bieniasz has been searching for the source of the glue itself ever since. Now, in an advanced online publication in Nature, he and his colleagues report that they found it: a protein they dubbed “tetherin” for its ability to keep viruses tied to a cell.

“All we knew when we started this two and a half years ago was that a virus lacking Vpu was released less efficiently from cells.” Bieniasz says. “And we had some electron micrographs that showed virus particles stuck there on the surface and clustered inside cells.” Once they started looking carefully at the reasons behind this, they found an antiviral mechanism keeping the HIV-1 mutant particles tethered to the cell. And it wasn’t just HIV — the glue appeared to interfere with the spread of other membrane-encapsulated (or “enveloped”) viruses, too.

To track down the cause of stickiness — and the likely reason HIV evolved Vpu — Bieniasz and his team looked at gene activity across all known human genes, making comparisons between cells that require Vpu for HIV-1 release and those that don’t. Ultimately, they narrowed it down to one very likely candidate. And the candidate, the tetherin protein, passed all the tests the researchers threw at it: When Vpu was not present but tetherin was, large numbers of virus particles piled up on the cell surface. When tetherin was missing, however, even the Vpu-deficient viruses were able to escape.

“We’ve discovered a new way that cells defend themselves against viruses,” Bieniasz says. “I think this will open up a new area of study in virology: how this protein antagonizes other viruses, and how viruses learn to get around it.” Going forward, his lab will focus on how broad tetherin’s antiviral activity is, and whether variations of it exist that might confer additional immunity or sensitivity to HIV and other viruses. And, he notes, if drug researchers are able to interfere with the interaction between tetherin and Vpu, their newly discovered protein might even provide a potential therapeutic target.

Source: Rockefeller University

Explore further: HIV uses the immune system's own tools to suppress it

Related Stories

HIV uses the immune system's own tools to suppress it

July 15, 2015
A Canadian research team at the IRCM in Montreal, led by molecular virologist Eric A. Cohen, PhD, made a significant discovery on how HIV escapes the body's antiviral responses. The team uncovered how an HIV viral protein ...

Why human body cannot fight HIV infection? Study results could lead to new drug therapies

July 12, 2012
University of Washington researchers have made a discovery that sheds light on why the human body is unable to adequately fight off HIV infection.

Scientists 'un-can' the HIV virus

May 4, 2015
If the human immunodeficiency virus (HIV) is a bit like a hermetically sealed tin can no one has yet been able to break open, the good news is that researchers at the CHUM Research Centre, affiliated with the University of ...

Study of patients infected with both HIV and hepatitis shows how the drug interferon works to suppress virus

February 29, 2012
A drug once taken by people with HIV/AIDS but long ago shelved after newer, modern antiretroviral therapies became available has now shed light on how the human body uses its natural immunity to fight the virus—work ...

Recommended for you

Scientists find where HIV 'hides' to evade detection by the immune system

October 19, 2017
In a decades-long game of hide and seek, scientists from Sydney's Westmead Institute for Medical Research have confirmed for the very first time the specific immune memory T-cells where infectious HIV 'hides' in the human ...

National roll-out of PrEP HIV prevention drug would be cost-effective

October 18, 2017
Providing pre-exposure prophylaxis (PrEP) medication to men who have sex with men who are at high risk of HIV infection (equivalent to less than 5% of men who have sex with men at any point in time) in England would be cost-effective, ...

Regulatory T cells harbor HIV/SIV virus during antiviral drug treatment

October 17, 2017
Scientists at Yerkes National Primate Research Center, Emory University have identified an additional part of the HIV reservoir, immune cells that survive and harbor the virus despite long-term treatment with antiviral drugs.

New research opens the door to 'functional cure' for HIV

October 17, 2017
In findings that open the door to a completely different approach to curing HIV infections, scientists from the Florida campus of The Scripps Research Institute (TSRI) have for the first time shown that a novel compound effectively ...

Researchers create molecule that could 'kick and kill' HIV

October 5, 2017
Current anti-AIDS drugs are highly effective at making HIV undetectable and allowing people with the virus to live longer, healthier lives. The treatments, a class of medications called antiretroviral therapy, also greatly ...

A sixth of new HIV patients in Europe 50 or older: study

September 27, 2017
People aged 50 and older comprise a growing percentage of HIV patients in Europe, accounting for one in six new cases in 2015, researchers said Wednesday.


Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) Jan 18, 2008
Ahem. Since the viruses were mutants lacking an important protein, tetherin does not prevent the type of HIV that people are infected with from spreading. Also this knowledge may aid therapy but its role on prevention is much less certain.
not rated yet Jan 18, 2008
if you think the drug companies are working for a cure think again... only thing thats gonna get us anywhere are prizes offered for breakthroughs made by individuals, such prizes as the X prize.

It`ll be a freaking disgusting shame on the drug companies, if a small team of researchers find the cure within 5 years of so, meanwhile they been crackin at it for what seems like eternity, and then the drug companies should be held liable for all the AIDS-related deaths dating back 20 eyars of so, because of their unwillingness to actually work on a cure... always slow this, suppress that. give me a freaking cure already
not rated yet Jan 18, 2008
even if the big pharmie corps are as you say, I don't believe that it is just prizes. University research also plays a huge factor as well.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.