Wart virus carries cholesterol gene

Early experiments suggest that a virus that causes warts in cows could help deliver gene therapy to patients with a "high cholesterol" gene.

About 12 million people worldwide have a defect which stops their livers getting rid of fats circulating in the bloodstream known as familial hypercholesterolaemia.

With high cholesterol levels they are prone to heart problems.

Approximately half of men and women with the problem suffer a heart attack before the age of 60.

The single defective gene produces the receptor on the liver cell which locks onto the cholesterol.

Scientists try by gene therapy to alter the genetic structure of the cells to get them working properly again.

The problem is finding a way of getting the correct genes into the right cells.

Cow virus

Researchers from Tartu University, in Estonia, have been using a virus called bovine papillomavirus.

Viruses work by getting into human cells, where they harness the cell's own machinery to reproduce their own genetic code.

A virus modified to contain the corrected cholesterol receptor gene would in theory insert this gene into the cell as part of this process.

The Estonian study involved cells grown in test tubes, and their cow virus was successful in correcting the gene defect in these.

The resulting cells were also described as "stable" in the following month under observation - again adding weight to the theory that it might work in humans.

Doubts remain

However, it is still unclear whether the gene therapy can work in either animal models of the disease - or humans.

UK experts told BBC News Online that fears over the use of a bovine virus in man may make this a less attractive prospect than other virus "vectors".

There have already been attempts to use gene therapy to correct familial hypercholesterolaemia in humans.

One technique involved removing a section of liver, treating it in the lab with viral gene therapy, then returning the liver cells to the organ.

Some patients found their blood cholesterol levels reduced by as much as 40% as a result of the therapy.