Science / Medicine : AIDS Research Progresses

Immunologists in San Francisco have discovered how the AIDS virus multiplies inside the body’s immune cells and eventually breaks out to spread the infection.

“This finding answers one of the major questions about the AIDS virus: How does it regulate its own genes?” said immunologist B. Matija Peterlin of the University of California, San Francisco.

With the mechanism now known in detail, drug designers can search for drugs to disrupt this genetic control to stop the multiplication of the virus and halt progression of the disease, he said. His report appears in the current issue of Nature magazine.

What they found was that the virus will multiply only if a “roadblock” that stops duplication of the virus is removed. The only thing that can remove this roadblock is a protein of the AIDS virus itself, which is produced by a gene called TAT.

Thus the AIDS virus cannot multiply unless the TAT gene is copied, but to get the TAT protein, the AIDS viral genes must be copied.

The researchers said this seeming “Catch 22” situation is violated when the virus occasionally slips around the roadblock, duplicating its genes, including TAT, so that some of the TAT protein is produced.

This protein then helps the virus get around the roadblock more often, to produce more virus and more TAT protein, until the virus is multiplying at full speed.