Featured Research

from universities, journals, and other organizations

Drug-resistant HIV patients with unimpaired immune cells

Date:
December 1, 2010
Source:
Mayo Clinic
Summary:
Researchers have shown why, in a minority of HIV patients, immune function improves despite a lack of response to standard anti-retroviral treatment.

Mayo Clinic researchers have shown why, in a minority of HIV patients, immune function improves despite a lack of response to standard anti-retroviral treatment. In these cases, researchers say, the virus has lost its ability to kill immune cells. The findings appear in the online journal PLoS Pathogens.

Related Articles


The goal of current treatments for HIV is to block the virus from reproducing, thereby allowing the immune system to repair itself. These findings show for the first time that not all HIV viruses are equally bad for the immune system. Patients who harbor these viruses do not develop certain complications of the disease because of mutations that render some HIV drugs ineffective -- but also impair the ability of the virus to cause disease.

"These findings suggest -- in contrast to how these patients have been treated in the past -- that changing treatments might not be needed in order to help the immune system," says Andrew Badley, M.D., Mayo infectious disease researcher and senior author of the study.

Background

HIV causes disease by progressively killing CD4 T cells, whose function is to orchestrate the immune system. Loss of these cells renders patients susceptible to unusual infections and cancers. Over time, HIV mutates and can become resistant to the drugs used for treatment. Mayo researchers have discovered that viruses with certain mutations that render a component of the drug cocktail used to treat HIV infection ineffective also have an impaired ability to kill CD4 T cells. Even though mutated viruses replicate as well as normal HIV, they fail to cause the infected cells to die. Not all mutant viruses share this effect; only selected mutations cause the impairment in cell killing, without effecting virus replication.

HIV has evolved many ways to cause the death of CD4 T cells, most of which involve HIV accelerating the normal cell death. One kind of cell death that is unique to HIV involves the HIV enzyme protease, whose normal job is to cut up viral proteins so they can be used. This same process also cuts a normal cell protein which creates a novel protein called Casp8p41. This protein is only created during HIV infection. Casp8p41 in turn is responsible for the death of many of the infected cells. Researchers found that cells infected with HIV that also contain the mutations, produced less Casp8p41, and therefore fewer of the infected cells died.

Significance of the Findings

The current treatment for HIV involves measuring virus levels in the blood and using drugs to stop that virus from reproducing. When drugs stop working, virus levels in the blood rise and physicians typically respond by changing medications. However, effective drugs may not always be available.

"Results from the current study suggest that if a patient is failing their current treatment, and other effective drugs are not available, then it may be best to take advantage of the virus' lessened ability to kill CD4 T cells, by staying on the same medication" says Dr. Badley. "We have begun to study whether the best approach might be instead to monitor Casp8p41 levels as opposed to measuring virus levels, and use that to determine whether or not to change treatment."

Researchers have already developed a way to measure Casp8p41 in the blood of patients, and this new knowledge may ultimately lead to a new diagnostic tool for HIV treatment, based upon predicting whether a patient's virus will deplete CD4 T cells.

Other researchers on the team are first author Sekar Natesampillai, Ph.D.; Zilin Nie M.D.; Nathan Cummins, M.D.; and Gary Bren, of Mayo Clinic; and Dirk Jochmans, Ph.D., Tibotec BVBA, Belgium; and Jonathan Angel, M.D., Ottawa Hospital, Canada. The research was supported by the National Institutes of Health.


Story Source:

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


Cite This Page:

Mayo Clinic. "Drug-resistant HIV patients with unimpaired immune cells." ScienceDaily. ScienceDaily, 1 December 2010. <www.sciencedaily.com/releases/2010/11/101130122048.htm>.
Mayo Clinic. (2010, December 1). Drug-resistant HIV patients with unimpaired immune cells. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2010/11/101130122048.htm
Mayo Clinic. "Drug-resistant HIV patients with unimpaired immune cells." ScienceDaily. www.sciencedaily.com/releases/2010/11/101130122048.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Don't Fall For Flu Shot Myths

Don't Fall For Flu Shot Myths

Newsy (Nov. 23, 2014) Misconceptions abound when it comes to your annual flu shot. Medical experts say most people older than 6 months should get the shot. Video provided by Newsy
Powered by NewsLook.com
WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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