Featured Research

from universities, journals, and other organizations

NIAID Researchers Identify HIV-Induced Changes In B Cells

Date:
August 16, 2001
Source:
NIH/National Institute Of Allergy And Infectious Diseases
Summary:
One of HIV's most insidious properties is its ability to influence virtually every part of the human immune system. Antibody-producing B cells, for example, begin to malfunction early after people become infected with HIV, for reasons that have been poorly understood. In a study released this week, however, researchers identify specific alterations that occur in B cells when HIV levels are high-changes that disappear when patients are treated with antiretroviral drugs.

August 14, 2001 -- One of HIV's most insidious properties is its ability to influence virtually every part of the human immune system. Antibody-producing B cells, for example, begin to malfunction early after people become infected with HIV, for reasons that have been poorly understood. In a study released today, however, researchers identify specific alterations that occur in B cells when HIV levels are high-changes that disappear when patients are treated with antiretroviral drugs. The study, which appears in the current Proceedings of the National Academy of Sciences Early Edition online, is the first to define a unique subset of B cells in people infected with HIV.

Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID) and a principal author of the paper, is all too familiar with HIV's effects on his patients' immune systems. "Their B cells produce excessive amounts of nonessential antibodies, fail to respond properly to normal physiologic signals, and are at increased risk of becoming cancerous," he explains. "Because their B cells do not work properly, people with HIV are left with fewer means to fight off the opportunistic infections that we see in full-blown AIDS."

B cells produce antibodies, proteins that specifically recognize and attach to foreign molecules, or antigens, such as those found on the surface of an invading virus or bacterium. Once they've hitched themselves to an antigen, antibodies either directly block the microbe from spreading or act as chemical beacons, signaling other immune system components to eliminate the captured organism.

To learn how HIV affects B cells, researchers from Dr. Fauci's laboratory studied the immune systems of people who were infected with the virus. Susan Moir, Ph.D., Angela Malaspina, Ph.D., and colleagues looked at B cells both before and after patients were treated with antiretroviral therapy. The researchers found consistent changes in B cells that occurred when HIV levels in the blood were high.

"At high virus levels, people had a large number of totally dysfunctional B cells," says Dr. Moir. "When we treated the patients to reduce their virus levels, the B cells reverted to their typical ways." When the researchers analyzed the B cells in detail, they found a specific change that might help explain the cells' loss of function: decreased amounts of a protein called CD21.

CD21 is a molecule on the surface of B cells that attaches to an immune system protein called complement. Dr. Moir and colleagues studied the cells with low amounts of CD21 and found these cells were unable to respond to many different B-cell stimuli in test tubes, yet spontaneously produced large quantities of irrelevant antibodies. Both of these properties are seen in the B cells of people with HIV. The researchers had previously shown HIV can hitch a ride on B cells by attaching to CD21, providing further support for the protein's possible role in HIV-induced B-cell malfunction (see news release at http://www.niaid.nih.gov/newsroom/hivbcell.htm).

"When we studied the cells further, they looked something like plasma cells that couldn't quite make up their minds," says Dr. Moir. Plasma cells are B cells that, upon recognizing an antigen, rapidly divide and pump out thousands of antibody molecules to attack a microbial invader. As B cells become plasma cells they change shape, lose their CD21 and stop responding to many B cell stimuli. "The B cells in patients with high virus levels look like plasma cells under the microscope, have very little CD21, and don't divide in response to chemical signals," Dr. Moir continues, "but in other respects they retain features of their parent B cells."

The researchers believe HIV causes changes to occur in B cells that either partially transition them to plasma cells or stimulate them to undergo changes along a completely different biochemical pathway. By identifying a specific change that links HIV levels with B-cell malfunction, Drs. Moir, Malaspina and colleagues have a key tool to further investigate how the virus is causing B cells to go awry.

"We know it happens, we know what drives it, and we know what the consequences are," says Dr. Moir. "This is the very first step in learning how we might be able to prevent it and improve the care of people infected with HIV."

The study was funded by NIAID and the National Cancer Institute (NCI). Researchers from NCI and the George Washington University also assisted in the study.

NIAID is a component of the National Institutes of Health (NIH). NIAID supports basic and applied research to prevent, diagnose, and treat infectious and immune-mediated illnesses, including HIV/AIDS and other sexually transmitted diseases, tuberculosis, malaria, autoimmune disorders, asthma and allergies.


Story Source:

The above story is based on materials provided by NIH/National Institute Of Allergy And Infectious Diseases. Note: Materials may be edited for content and length.


Cite This Page:

NIH/National Institute Of Allergy And Infectious Diseases. "NIAID Researchers Identify HIV-Induced Changes In B Cells." ScienceDaily. ScienceDaily, 16 August 2001. <www.sciencedaily.com/releases/2001/08/010815080956.htm>.
NIH/National Institute Of Allergy And Infectious Diseases. (2001, August 16). NIAID Researchers Identify HIV-Induced Changes In B Cells. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2001/08/010815080956.htm
NIH/National Institute Of Allergy And Infectious Diseases. "NIAID Researchers Identify HIV-Induced Changes In B Cells." ScienceDaily. www.sciencedaily.com/releases/2001/08/010815080956.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. 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