Interferon needed for cells to 'remember' how to defeat a virus, UT Southwestern research...( DALLAS Dec. 3 2008 Scientists at U...),Health

DALLAS Dec. 3, 2008 Scientists at UT Southwestern Medical Center have determined that the immune-system protein interferon plays a key role in "teaching" the immune system how to fight off repeated infections of the same virus.

The findings, available online and in the Dec. 15 issue of the Journal of Immunology, have potential application in the development of more effective vaccines and anti-viral therapies.

Typically, when a person is infected with a virus, the human body immediately generates a massive number of T cells a type of immune cell that kill off the infected cells. Once the infection has cleared, most of the T cells also die off, leaving behind a small pool of central memory cells that "remember" how to fight that particular type of virus if the person is infected again.

"In this study, we have uncovered interferon's role and the key signaling protein, called IL-2, involved in generating memory T cells," said Dr. David Farrar, assistant professor of immunology at UT Southwestern and senior author of the study. "Knowing how T cells acquire this memory may help us design better strategies and vaccines to fight HIV and other infectious diseases. Further, our discovery was made using primary human CD4+ T cells, which underscores the relevance of our discovery to human immune responses."

CD4+ T cells coordinate the actions of other cells at the site of infection.

When a virus or bacterium infects a human, the infected cells secrete several molecules, including a cytokine or signaling protein called interferon alpha. The action of interferon is what makes an infected person feel run down and tired. Although scientists knew that interferon alpha prevented a virus from multiplying and spreading, they didn't know what role interferon played in the creation of memory cells.

In the current study, the UT Southwestern researchers show that both interferon alpha and another signaling prot
'/>"/>