University first to grow common food poisoning cause in lab

Washington University researchers are the first to grow a common cause of diarrhea, vomiting and other stomach problems in a lab, a move that one expert said could speed along development of a vaccine, the university said Monday.

Food poisoning caused by the norovirus sickens an estimated 23 million Americans each year, according to the Atlanta-based Centers for Disease Control and Prevention. About 50,000 people are hospitalized and an estimated 400 die, epidemiologists believe.

Washington University scientists showed that the mouse norovirus MNV-1 could be grown inside cells from mice with defective immune systems. The university said those findings could ease the way for further research about the mouse virus and may help researchers seeking to duplicate the accomplishment with human forms.

"By looking at the mouse virus we'd grown in the lab, we were able to identify a part of the capsid, the virus' protective shell, that is essential to its ability to cause disease," said Skip Virgin, professor of pathology, immunology and molecular microbiology.

"If this part of the capsid has an equivalent in human noroviruses, altering or disabling it may give us a way to produce forms of the viruses that are weak enough to serve as vaccines."

It is most commonly spread through eating contaminated food, touching contaminated surfaces and having direct contact with infected people. The illness tends to last 24 to 48 hours.

Though deaths are rare in industrialized nations, infections spread rapidly, are difficult to prevent from spreading, and can create significant discomfort. In developing nations, noroviruses are a major cause of human illness.

Last year, Christianne Wobus and Stephanie Karst, postdoctoral fellows in Virgin's lab, identified MNV-1, the first known mouse norovirus. In tests in mice, researchers found that the virus thrived in macrophages - immune system cells that normally engulf and destroy pathogens - and in dendritic cells, or sentry-like cells that pick up and display proteins from pathogens.

"We think there may be dendritic cells just beneath the lining of the human gut that are providing the gateway the virus needs to cause disease," Virgin said.

•	University first to grow common food poisoning cause in lab Associated Press State & Local Wire, Monday, Nov. 29, 2004 Byline: Jim Salter, Associated Press Writer

•	WU grows virus that may help battle bug in people Researchers find clues for potential vaccine St. Louis Post-Dispatch, Tuesday, Nov. 30, 2004 Byline: Eli Kintisch, of the Post-Dispatch

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