Cell Death Research Uncloaks Deadly Virus Action

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Death is vital to life, especially when your body needs to get rid of worn-out or unneeded cells. This essential housekeeping job is performed by an elaborate biochemical process called apoptosis, or programmed cell death. However, under certain conditions, apoptosis can go awry, leading to life-threatening illnesses.

Scientists studying fruit flies have discovered various proteins involved in apoptosis, including the aptly named Grim and Reaper proteins. To find out what proteins with similar functions exist in other species, pharmacologist Sally Kornbluth, Ph.D., of Duke University Medical Center in Durham, North Carolina, searched through databases cataloging the DNA sequences of proteins. What she found was a protein resembling Reaper in a family of infectious agents called Bunyaviruses.

It was an important finding, since Bunyaviruses are the major cause of two potentially fatal insect-transmitted diseases in humans: hemorrhagic fever and pediatric encephalitis. Like Reaper, the Bunyavirus protein dubbed appears to deal its deadly blow in part by promoting apoptosis. Studies in mice by Kornbluth's team show that causes massive death of brain cells—an observation that could help explain the severe brain inflammation in people with hemorrhagic fever and pediatric encephalitis.

Interestingly, the discovery of these potent proteins could also shed light on why viral encephalitis is so serious in infants. Based on her studies, Kornbluth suggests that Bunyaviruses may hijack the normal processes of cell death that are particularly active during the early wiring of young nervous systems. Further research is now under way in her lab to figure out the precise mechanism by which proteins act. By understanding these mechanisms, scientists hope they can one day develop better ways to treat viral encephalitis and other dangerous diseases in which these proteins may be involved.