Featured Research

from universities, journals, and other organizations

HIV Drug Leaves Key Part Of Immune System Vulnerable

Date:
November 30, 2000
Source:
Ohio State University
Summary:
A drug that helps to slow the progression of HIV - the virus that causes AIDS - does not seem to prevent virus-related damage to an organ critical to the development of the immune system. This organ, called the thymus, is especially important early in life when the human immune system is developing.

COLUMBUS, Ohio - A drug that helps to slow the progression of HIV - the virus that causes AIDS - does not seem to prevent virus-related damage to an organ critical to the development of the immune system.

Related Articles


This organ, called the thymus, is especially important early in life when the human immune system is developing.

Infants who contract the virus from their mothers are particularly prone to developing immune system problems because of the damage HIV ultimately causes to the thymus.

Pregnant mothers who are HIV-positive are often given AZT, a drug that helps prevent the fetus from contracting the virus. In children and adults with HIV, AZT helps control and even reduces the proliferation of the virus in the blood.

Researchers at Ohio State University tested the effect of the drug AZT on the thymuses of young cats infected with FIV -- a virus which behaves similar to HIV and one that causes an AIDS-like disease in cats. They found that although AZT helped control and even reduce the amount of FIV in the blood and inthe thymus, the virus still was able to cause significant physical damage to the thymus.

"This lack of protection surprised us," said Larry Mathes, a study co-author and a professor of veterinary biosciences at Ohio State. "It suggests that antiviral therapy in infants may need to be combined with other treatments - such as other drugs - in order to restore thymic function."

The study appears in a recent issue of the journal Antimicrobial Agents and Chemotherapy.

The researchers already knew that AZT reduces the levels of FIV and HIV in blood outside of the thymus. (AZT is also called zidovudine (ZDV) or Retrovir.) Cats were placed into one of four groups: in the first, cats were infected with FIV and treated with AZT. In a second, the animals were infected with FIV and treated with placebo. The third contained uninfected, AZT-treated cats and in the fourth, the cats remained uninfected and received only a placebo instead of AZT.

The cats received daily doses of AZT for 12 weeks. Treatment began two days before the cats were infected with the virus, so researchers could compare the levels of certain immune system cells - T cells - in the infected and uninfected groups. The virus attacks and kills T cells, which mature in the thymus.

Levels of virus present in the blood samples were determined at four, eight and 12 weeks after the initial infection. The experiments ended after 12 weeks and the researchers examined the animal's thymus glands for signs of infection.

Animals receiving the AZT treatment showed significantly reduced (by 75 to 85 percent) levels of virus in the blood and also in the thymus (by about 74 percent) when compared to animals which were infected but not treated. Yet the FIV had ultimately caused similar physical damage and inflammation to the thymuses of the cats in both of the infected groups.

Inflammation is a typical immune response to a virus or an injury - it's part of the healing process. The immune system tried to get rid of the virus in the thymus, so it launched an attack, which caused the inflammation. But reducing the virus level didn't cause the inflammation to subside. "We're not sure why it didn't," Mathes said.

"It would make sense that a decrease in virus levels would mean that the inflammation would subside and that the thymus would improve," he said. "Since that didn't happen, we assumed that it was the immune response that ended up damaging the thymus.

"Our long-term goal is to develop a therapeutic strategy to protect the thymus," Mathes said. "We want to find how we can protect it."

The research was supported by grants from the National Institutes of Health and the National Institute of Allergy and Infectious Diseases. The study was co-authored by Kathleen Hayes, of the department of veterinary biosciences at Ohio State, and former Ohio State graduate research assistants Andrew Phipps, currently at Battelle Memorial Institute, and Sabine Francke, currently at Novartis Pharmaceuticals.


Story Source:

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


Cite This Page:

Ohio State University. "HIV Drug Leaves Key Part Of Immune System Vulnerable." ScienceDaily. ScienceDaily, 30 November 2000. <www.sciencedaily.com/releases/2000/11/001129074858.htm>.
Ohio State University. (2000, November 30). HIV Drug Leaves Key Part Of Immune System Vulnerable. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2000/11/001129074858.htm
Ohio State University. "HIV Drug Leaves Key Part Of Immune System Vulnerable." ScienceDaily. www.sciencedaily.com/releases/2000/11/001129074858.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. 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