Chronic infection now clearly tied to immune-system protein (w/Video)

May 14, 2009

A new study finds the cross-talk between 'killer T-cells' and 'helper T-cells' can only happen in the presence of interleukin-21, a powerful immune-system protein. UAB researchers say if interleukin-21 is missing, the immune system's anti-viral efforts fail. The study mice were treated for lymphocytic choriomeningitis.

The reason deadly infections like human immunodeficiency virus (HIV) and hepatitis C never go away is because these viruses disarm the body's defense system. Researchers at the University of Alabama at Birmingham (UAB) have discovered that a key immunity must be present for this defense system to have a chance against chronic infection.

Research up to now has tried but failed to decipher the cross-talk between 'killer T-cells' and 'helper T-cells' in the fight against viruses. The new UAB study finds this cross-talk can only happen in the presence of interleukin-21, a powerful . If interleukin-21 is missing for whatever reason, then the immune system's anti-viral efforts fail, said Allan Zajac, Ph.D., an associate professor in UAB's Department of Microbiology and lead author on the study.

This video is not supported by your browser at this time.
Cross-talk between specific T-cells needs interleukin-21 to be effective, says Allan Zajac, Ph.D., an associate professor in the UAB Department of Microbiology. He is the lead author on a Science study. Credit: UAB

The findings are published in the journal Science through its service.

"Adding interleukin-21 back in stimulates the immune response and controls the infection," Zajac said. "We demonstrate that the loss of this protein prevents the control of the infection and diminishes the function of the killer T-cells, specifically ."

The study mice were treated for lymphocytic choriomeningitis, a viral infection of the membranes surrounding the brain and spinal cord. Measurements were taken for two types of T-cells, CD4 and CD8 T-cells, before and after the mice were treated with interleuikin-21.

"Interleukin-21 served as the key messenger between the T-cells, whereas before we didn't know exactly how the two types of cells communicated with each other," Zajac said. The CD4 T-cells help the immune system do its job by boosting CD8 T-cells' ability to fight and kill viruses.

Source: University of Alabama at Birmingham (news : web)

Explore further: Nutritional supplement boosts muscle stamina in animal studies

Related Stories

Protein's new role discovered in autoimmune disease

Jan 02, 2008

Investigators at the University of Alabama at Birmingham (UAB) have identified the previously unknown role of a chemical 'messenger' leading to autoimmune disorders like rheumatoid arthritis and lupus.

Recommended for you

Organ transplant rejection may not be permanent

3 hours ago

Rejection of transplanted organs in hosts that were previously tolerant may not be permanent, report scientists from the University of Chicago. Using a mouse model of cardiac transplantation, they found that immune tolerance ...

Researchers find key mechanism that causes neuropathic pain

5 hours ago

Scientists at the University of California, Davis, have identified a key mechanism in neuropathic pain. The discovery could eventually benefit millions of patients with chronic pain from trauma, diabetes, shingles, multiple ...

Deep sea light shines on drug delivery potential

5 hours ago

A naturally occurring bioluminescent protein found in deep sea shrimp—which helps the crustacean spit a glowing cloud at predators—has been touted as a game-changer in terms of monitoring the way drugs ...

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.