Selenium may slow march of AIDS

Nov 28, 2008

Increasing the production of naturally occurring proteins that contain selenium in human blood cells slows down multiplication of the AIDS virus, according to biochemists.

"We have found that increasing the expression of proteins that contain selenium negatively affects the replication of HIV," said K. Sandeep Prabhu, Penn State assistant professor of immunology and molecular toxicology. "Our results suggest a reduction in viral replication by at least 10-fold."

Selenium is a micronutrient that the body needs to maintain normal metabolism. Unlike other nutrients, which bind to certain proteins and modulate the protein's activity, selenium gets incorporated into proteins in the form of an amino acid called selenocysteine.

These proteins – selenoproteins – are especially important in reducing the stress caused by an infection, thereby slowing its spread.

Upon infecting a person, the virus quickly degrades selenoproteins so that it can replicate efficiently. It is unclear just how the virus is able to silence these proteins but Prabhu and his colleagues believe that stress inflicted on cells by the rapidly dividing virus, which produces a key protein known as Tat, is the likely culprit.

Tat is one of about 14 odd proteins produced by HIV during the first stage of infection. The job of these proteins is to trigger the expression of all the other genes that the virus needs to sustain itself. In addition, Tat also plays a key role in helping the virus replicate.

One of the proteins that targets Tat is a selenoprotein known as TR1.

"Since HIV targets the selenoproteins, we thought that the logical way to deal with the virus is to increase the expression of such proteins in the body," explained Prabhu, whose team's findings are outlined this week (Nov. 28) in the Journal of Biological Chemistry.

Researchers first isolated blood cells from healthy human volunteers who did not have HIV, and infected those cells with the virus. Next, they added tiny amounts of a selenium compound – sodium selenite – into the cell culture to see the effect on viral replication.

Results from the tests indicate that the addition of selenium inhibits the replication of HIV at least 10-fold, compared to cell cultures in which no selenium is added. When the researchers selectively reduced production of the selenium containing TR1 protein, they observed a 3.5-fold increase in viral replication.

"This confirms that while increasing the expression of TR1 has a negative impact on the replication of HIV, reducing it helps the virus replicate more efficiently," explained Prabhu. He believes that TR1 works by upsetting the chemical structure of Tat, which in turn reduces the virus' ability to replicate.

"Once we fully understand the function of these selenium proteins, it will give us a handle to come up with more effective drugs," said Prabhu, whose work is partly funded by the National Institutes of Health.

Source: Penn State

Explore further: HIV testing yields diagnoses in Kenya but few seek care

add to favorites email to friend print save as pdf

Related Stories

Professor sheds light on DNA mechanisms

Jul 17, 2009

By manipulating individual atoms in DNA and forming unique molecules, a Georgia State University researcher hopes to open new avenues in research towards better understanding the mechanisms of DNA replication and transcription, ...

Recommended for you

HIV testing yields diagnoses in Kenya but few seek care

18 hours ago

Between December 2009 and February 2011, health workers with the AMPATH Consortium sought to test and counsel every adult resident in the Bunyala subcounty of Kenya for HIV. A study in the journal Lancet HIV reports that the campaign yielded more than 1,300 new positive diagnoses, but few of those new ...

The adaptability of pathogens

Jan 28, 2015

Drug-resistant HIV viruses can spread rapidly. This is the conclusion of a study conducted as part of the SWISS HIV Cohort Study, which is supported by the SNSF. Only the continuous introduction of new drugs can stop the ...

User comments : 0

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.