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: Predicting antibiotic resistance

add to favorites email to friend print save as pdf

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

Stem cells faulty in Duchenne muscular dystrophy

5 hours ago

Like human patients, mice with a form of Duchenne muscular dystrophy undergo progressive muscle degeneration and accumulate connective tissue as they age. Now, researchers at the Stanford University School of Medicine have ...

Here's how the prion protein protects us

10 hours ago

The cellular prion protein (PrPC) has the ability to protect the brain's neurons. Although scientists have known about this protective physiological function for some time, they were lacking detailed knowledge ...

Regulation of maternal miRNAs in early embryos revealed

11 hours ago

The Center for RNA Research at the Institute for Basic Science (IBS) has succeeded in revealing, for the first time, the mechanism of how miRNAs, which control gene expression, are regulated in the early embryonic stage.

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.