Seeing through HIV's disguises: Researchers identify 25 human proteins that may be crucial for HIV-1 infection

Seeing through HIV's disguises
This image shows new HIV particles exiting an infected T-cell. Credit: National Institutes of Health

Studying HIV-1, the most common and infectious HIV subtype, Johns Hopkins scientists have identified 25 human proteins "stolen" by the virus that may be critical to its ability to infect new cells. HIV-1 viruses capture many human proteins from the cells they infect but the researchers believe these 25 proteins may be particularly important because they are found in HIV-1 viruses coming from two very different types of infected cells. A report on the discovery, published online in the Journal of Proteome Research on Feb. 22, could help in building diagnostic tools and novel treatment strategies to fight HIV infection.

When a new HIV particle emerges from an infected human cell, it wraps itself in membrane and proteins from the , effectively disguising itself from the immune system's sentinels. Scientists believe that some of these proteins are specifically "chosen" by the virus in order to enhance its ability to survive, while other proteins may be just randomly caught up in the viral packaging.

"Human proteins incorporated into viruses could potentially be used to find, and selectively kill, harboring HIV, but the problem is that HIV can steal hundreds of different proteins unique to each cell type that it infects, leaving too many targets for researchers and drug companies to chase after," according to David Graham, Ph.D., the senior author of the study report and assistant professor of molecular and comparative at the Johns Hopkins University School of Medicine. The new research, he says, narrows the target pool to a small number of proteins that may be most important for and survival.

This video is not supported by your browser at this time.
David Graham, Ph.D., Johns Hopkins University, is an assistant professor of molecular and comparative pathobiology in the School of Medicine. In this two-minute video, he discusses the results of his latest paper, which reports the finding of 25 human proteins incorporated into HIV-1 particles that may be crucial for its ability to survive and infect other cells. Credit: Johns Hopkins Medicine

HIV infects several types of cells throughout the body, most notably CD4+ T-cells and macrophages, both major parts of the immune system. Graham and his team suspected that a comparison of human proteins incorporated into HIV particles from different cell types could lead them to the human proteins important to the virus' disease activity.

After isolating HIV-1 particles from lab-grown human CD4+ T-cells, Graham and his team used powerful protein sequencing and bioinformatics tools to identify all of the associated human proteins. They then used the same bioinformatics tools to re-analyze protein content information from HIV-1 particles isolated from lab-grown human macrophages, data previously published by another group of researchers.

With the help of sophisticated computing, the team identified 279 proteins taken up by HIV-1 particles from one or the other cell type. Of these, only 25 were shared by viruses from both cell types.

One protein the research team identified that could be particularly important to diagnosis and treatment is CD44, because it appears to be the only one of the 25 capable of binding to other cells. It helps the viruses attach themselves to sites of inflammation. Graham suggests that "this makes a lot of sense for a virus that likes to infect T-cells and macrophages because both types of cells migrate to sites of inflammation to help out. Little do they know that HIV viruses are lying in wait."

More information: dx.doi.org/10.1021/pr300918r

Related Stories

How sneaky HIV escapes cells

Jun 05, 2007

Like hobos on a train, HIV, the virus that causes AIDS, uses a pre-existing transport system to leave one infected cell and infect new ones, Hopkins scientists have discovered. Their findings, published in the June issue ...

Exhausted B cells fail to fight HIV

Jul 14, 2008

HIV tires out the cells that produce virus-fighting proteins known as antibodies, according to a human study that will be published online July 14 in the Journal of Experimental Medicine.

Hide-and-seek: Altered HIV can't evade immune system

Sep 28, 2011

(Medical Xpress) -- Researchers at Johns Hopkins have modified HIV in a way that makes it no longer able to suppress the immune system. Their work, they say in a report published online September 19 in the journal Blood, could ...

Recommended for you

Cambodia orders probe into mass HIV infection

Dec 18, 2014

Cambodian Prime Minister Hun Sen on Thursday ordered a probe into an apparent mass HIV infection believed to have been spread by contaminated needles, as the number of suspected cases passed 100.

A fresh setback for efforts to cure HIV infection

Dec 17, 2014

Researchers are reporting another disappointment for efforts to cure infection with the AIDS virus. Six patients given blood-cell transplants similar to one that cured a man known as "the Berlin patient" have ...

User comments

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.