20000105

How polio, cold

viruses enter

cells discovered

WASHINGTON: A team of researchers had discovered how viruses that cause polio and the common cold enter cells to cause infections, according to a US study to be released.

The report in Proceedings of the National Academy of Sciences, explains the strategies used by the two viruses, both members of the picornavirus family, to access cells.

"A virus and its receptor must be perfect complements, like a lock and a key, in order for infection to occur," said the report by researchers at Purdue University in Indiana and State University of New York at Stony Brook.

Rhinoviruses (the common cold virus) and polio viruses each have shells that contain deep crevices or canyons, and this is the site at which binding occurs," wrote research leader Michael Rossmann, a distinguished professor of biological sciences at Purdue.

Though the polio virus Ñ causing the central nervous system disease poliomyelitis Ñ and the common cold use different "receptors" to enter the cell, scientists found that they have a similar "footprint" to interact with the virus at similar sites on its shell, he said.

Rossmann added: "These viruses have evolved to recognise molecules on the cell receptor that just fit them, and we can now see the reason for that".

The new findings could lead to development of drugs to prevent illness caused by viral pathogens.ÑAFP