(Monterotondo, Italy) Nearly fifty years ago, researchers discovered that when cells in laboratory cultures are infected by a virus, they secrete a substance that protects other cells from infection. In 1957 Alick Issaks and Jean-Jacques Lindenmann traced this effect to a protein called interferon, a molecule now known to play a key role in the immune system. Human and animal cells produce it in a rapid first wave response to infections. Since its discovery, scientists have sought to use this natural substance to cure all sorts diseases, and clinical trials have demonstrated interferons potential to combat diseases as different as hepatitis C, blood cancers, and multiple sclerosis. Yet many aspects of interferon biology remain a mystery including what initially prompts the body to produce it. Now Ulrich Kalinke and Winfried Barchet at the European Molecular Biology Laboratory (EMBL) station in Monterotondo, Italy, have identified specific cells in the body able to launch a massive, initial round of interferon production. Their work, reported in the current issue of the Journal of Experimental Medicine, is changing how researchers think of the interferon system and adds a key element to our understanding of how the immune system works.

Interferons have the ability to put the cell on hold; they slow down a lot of processes that would otherwise help viruses reproduce very quickly. While many deadly viruses have evolved the means to evade these measures, most are slowed down enough for other phases of the bodys immune system to kick into high gear and eradicate them. Animals that are born without the ability to mount an interferon defense are unable to survive even mild infections and they quickly die.

Until now, scientists have generally believed that the body produces most of its interferon through a sort of feedback
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Contact: Russ Hodge
hodge@embl-heidelberg.de
49-6221-387252
European Molecular Biology Laboratory
18-Feb-2002