杏吧原创

PEOPLE who fear they鈥檝e been exposed to HIV infection could soon have an
injection to prevent the AIDS virus getting a foothold.

To invade humans cells and establish infection, the virus relies on a coat
protein called gp41. This protein contorts itself into a bundle called the
鈥渢rimer of hairpins鈥� which fuses the viral coat with the human cell membrane. A
substance called 5-helix, developed by a team at the Whitehead Institute for
Biomedical Research in Cambridge, Massachusetts, blocks this process鈥攁nd
HIV鈥檚 entry to the cell.

So far, all the work has been done on cells grown in the lab. 鈥淭his is really
the first step,鈥� says team member Michael Root. He hopes to attract drug-company
funds to test the drug in monkeys.

Root says that a similar drug, called T-20, is already in clinical trials.
But he is hopeful that 5-helix will be effective at lower doses than T-20, which
can cause headaches, nausea, and fever.

However, both drugs have to be injected, so regular doses to treat those who
already have HIV would be costly and unpleasant. 鈥�5-helix needs to be converted
into an orally available drug for it to revolutionise AIDS therapy,鈥� says
Jonathan Weber, an AIDS specialist at Imperial College, London. But for anyone
exposed to HIV by a needle-stick injury, the injection would be a small price to
pay to avoid becoming infected.