Featured Research

from universities, journals, and other organizations

Unusual new HIV drug resistance mechanism revealed

Date:
February 18, 2014
Source:
Biophysical Society
Summary:
For the millions of people living with HIV/AIDS, antiretroviral drugs can be a lifeline, slowing the progress of viral infection. Unfortunately, studies have shown that these benefits can be short-lived: therapy can lead to mutations in the HIV genetic code, which can make the virus resistant to drugs. However, researchers have made some new insight into how the therapy functions and how therapy-induced point mutations actually confer drug resistance.

For the more than one million people with HIV/AIDS in the United States (and the over 34 million people living with HIV/AIDS around the world), antiretroviral drugs such as efavirenz and other so-called non-nucleoside reverse transcriptase inhibitors (NNRTIs) in combination with other antiretrovirals can be a lifeline, because they slow the progress of viral infection, prolonging life. Unfortunately, studies have shown that these benefits themselves can be short-lived in the clinic: therapy with NNRTIs can lead to single (or "point") mutations in the HIV genetic code -- mutations that make the virus resistant to the drugs.

Researchers at the University of Pittsburgh School of Medicine now have a good idea why. In work to be presented at the 58th Annual Biophysical Society Meeting, which takes place in San Francisco from Feb. 15-19, cell biologist Sanford Leuba and his colleagues offer new insight into how NNRTIs function and how therapy-induced point mutations actually confer drug resistance.

NNRTIs work by blocking the action of an enzyme called reverse transcriptase, which HIV uses to convert its own genetic material (in the form of RNA) into single-stranded copies of DNA, which can then be inserted into the genome of the human cells they've infected. Once incorporated, this DNA instructs the host to create new copies of the virus, propagating the infection to new cells and over time attacking the immune system, which can lead to full-blown AIDS.

Using a number of imaging techniques and computer modeling, Leuba and his team showed that, normally, the binding of efavirenz results in the formation of a molecule-sized "salt bridge" that holds the reverse transcriptase in an open state when it is attached to the template it uses in making DNA copies. "The reverse transcriptase can still bind the template, but it continually slides," Leuba explained, "preventing the enzyme from polymerizing nucleotides. The virus cannot replicate."

The point mutations that cause resistance to efavirenz, the researchers found, prevent that salt bridge from forming, "allowing the reverse transcriptase to function normally," he says. "This type of inhibition, which does not involve drug-binding affinity, has not been described previously."

Based on the work, Leuba said, "We have ideas about how to begin designing a new generation of NNRTIs."


Story Source:

The above story is based on materials provided by Biophysical Society. Note: Materials may be edited for content and length.


Cite This Page:

Biophysical Society. "Unusual new HIV drug resistance mechanism revealed." ScienceDaily. ScienceDaily, 18 February 2014. <www.sciencedaily.com/releases/2014/02/140218184822.htm>.
Biophysical Society. (2014, February 18). Unusual new HIV drug resistance mechanism revealed. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2014/02/140218184822.htm
Biophysical Society. "Unusual new HIV drug resistance mechanism revealed." ScienceDaily. www.sciencedaily.com/releases/2014/02/140218184822.htm (accessed April 20, 2014).

Share This



More Health & Medicine News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
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:
from the past week

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