Dutch study sheds light on virus that causes SARS

By Michael Kahn

LONDON (Reuters) - Dutch researchers have built a three-dimensional model of a type of virus that causes SARS in a step that could one day help in the battle against the deadly disease.

The model, created using hepatitis coronavirus from mice, will help scientists understand severe acute respiratory syndrome (SARS), which appeared in China in 2002 and killed some 800 people globally before being brought under control.

"I think we can translate what we found for this virus to the SARS virus," Berend Jan Bosch, a virologist at Utrecht University who worked on the study, said in a telephone interview on Monday.

"If you are going to study the SARS virus you will basically find the same features."

The researchers reported their findings in the Proceedings of the National Academy of Sciences.

Coronaviruses cause diseases in animals and in people from the common cold to severe gastrointestinal illness. They also cause SARS which scientists believe, like influenza, initially came from an animal.

The 2002 outbreak of SARS is estimated to have cost as much as $100 billion. Quarantine and travel restrictions helped contain the disease.

Bosch and colleagues used a new type of electron microscopy to take images of the virus in a frozen state.

"Because we take so many pictures from different angles, we could combine the images to recreate the virus in 3D," Bosch said.

The researchers also discovered that the virus' outer coating or envelope, which it uses to fuse with and spread to healthy cells, is thicker than thought due to an extra internal layer.

Deciphering the structure of the mouse coronavirus is a basic finding but one that can allow researchers to better understand the human form of the virus, Bosch added.

"It is a broader understanding of the architecture of coronaviruses," he said. "It is really fundamental knowledge."

(Reporting by Michael Kahn; editing by Maggie Fox and Charles Dick)