October 22, 2010

Researchers Find Potentially Rare Virus Has Weakness

(Ivanhoe Newswire) -- The JC polyomavirus doesn't strike very often, but when it does, this mean bug can leave a devastating path.

The JC polyomavirus is an opportunistic viral infection of the central nervous system. It usually preys on people with weakened immune systems, including people with AIDS, and almost always kills them. Researchers at Brown University, the University of Tubingen in Germany and Imperial College in London got together to study the precise structure and biology of how the virus binds to host.

The JC virus causes the brain-wasting disease known as PML. It's a rare and usually fatal viral disease that is characterized by progressive damage or inflammation of the white matter of the brain at multiple locations.

"The overall goal is to get these 'plans' and then design small molecules "” drugs that will fit in this receptor, binding and preventing infection," Walter Atwood, professor of molecular biology, cell biology, and biochemistry at Brown and a senior author of the new study was quoted saying.

They found that the virus must bind to a very specific sugar molecule dangling from the side of the brain cells it attacks. It will float towards a cell then encounter a metaphorical cityscape of sugary molecule on its surface. They also found that the virus strongly preferred to bind to a sialic acid on the end of the molecule called LSTc.

They came to this conclusion after pre-mixing the virus in some cases with LSTc and in others with the very similar molecule LSTb. Then they exposed each to glial cells. The virus pre-mixed with LSTc did not infect the cells, because they had already bound to LSTc in incubation.

The next step is to find a small-molecule drug that will cross the blood-brain barrier and bind the virus so that it can't bind with LSTc.

"Drug development is a very long-term process," researcher Christian Nelson at Brown University was quoted saying. "But the data in this paper provides the platform for rational drug design and opens the door to begin the process of screening compounds."

SOURCE: Cell Host & Microbe, October 2010