AIDS Virus Thrives in Fat City
Cholesterol is vital to HIV reproduction, says study
MONDAY, Nov. 19, 2001 (HealthDayNews) -- The AIDS virus needs an ample supply of cholesterol to reproduce itself, a finding that researchers say could add another weapon to the armory of treatments for the disease.
"Our research raises the intriguing possibility that widely used cholesterol-lowering drugs might have an effect in humans similar to what we have found in these initial laboratory studies," says Eric O. Freed, an investigator in the laboratory of molecular biology at the National Institute of Allergy and Infectious Diseases and senior author of a report in the latest Proceedings of the National Academy of Sciences.
Statins, the widely used family of cholesterol-lowering drugs, seem worth a try, says Freed.
Freed says he has had some preliminary discussions with "several clinicians who expressed an interest in looking further at a trial." But he says he and his co-worker, Akira Ono, would not take part in any such trial since their interest is in basic research on HIV, the virus that causes AIDS.
Specifically, they have been looking at the site where HIV reproduces itself. "We've known for a long time that HIV assembly takes place on the cell membrane. We have found that this takes place at discrete regions of the membrane called rafts," Freed says.
Rafts are so named because they are relatively solid structures floating on the more liquid, fatty sea that makes up most of the cell membrane, Freed says. He and Ono found that to infect a cell and reproduce, HIV must attach itself to a raft. Since rafts are rich in cholesterol, the researchers investigated what happens when cholesterol is in short supply.
Working with cell cultures, they used two compounds, one of which removes cholesterol from the cell membrane and one that inhibits cholesterol production. Each by itself reduced HIV reproduction, and using both virtually eliminated reproduction of the virus, they say.
There isn't any information about patients infected with HIV who are taking statins, so a human trial would be needed to see what the effect would be, Freed says.
That trial would have patients taking two or three times the doses of statins now recommended for cholesterol reduction, Freed says. "Since the statins are well tolerated, an appropriate group of patients could be found," he says.
Animal tests might be done before any human trial is undertaken, Freed says. The treatment could be tried in monkeys infected with a close relative of HIV, the simian immunodeficiency virus (SIV).
Meanwhile, he says the discovery "has given us a much better understanding of how HIV replicates," which can help other scientists working on prevention and treatment of AIDS.
What To Do
Be wary, Freed says: "We need to be cautious about extrapolating our in-vitro cell culture work to treatment of patients." Any treatment based on this research is still years away and may not even be useful at all, he says.