June 29 (Bloomberg) -- Sangamo Biosciences Inc.'s gene technique can protect infection-fighting cells from the AIDS virus, according to a study in mice.

Immune cells genetically altered with Sangamo's zinc-finger proteins resisted infection with the human immunodeficiency virus, or HIV, that causes AIDS, scientists from Richmond, California-based Sangamo and the Children's Hospital of Philadelphia said today in a study in the journal Nature Biotechnology.

Many strains of HIV depend on a protein found on the surface of immune T-cells, called CCR5, to gain entry and take over their protein-making machinery. Sangamo's technology can break the gene that makes CCR5, potentially rendering T-cells resistant, and perhaps protecting patients from rare infections that afflict AIDS patients, scientists said.

``We may be able not only to reconstitute the immune system, but protect the cells that are able to fight the HIV virus itself,'' said Philip Gregory, Sangamo's vice president for research, in a telephone interview on June 27.

Sangamo gained 65 cents, or 7.2 percent, to $9.69 June 27 in Nasdaq stock market composite trading, and has gained 19 percent in the past 12 months. The company plans to begin human studies of the treatment before the end of this year, Gregory said.

HIV infects more than 33 million people worldwide and has killed more than 25 million patients since it was discovered a quarter of a century ago. The virus mutates rapidly to avoid the immune system and destroys the T-cells that would normally attack it.

Cell Invasion

The virus must invade cells to replicate and to do so all strains bind to a protein called CD4. HIV must simultaneously latch onto another cell surface protein, and most choose CCR5.

Elena Perez led researchers at the Children's Hospital who treated human immune cells with zinc-finger proteins that were designed to find the gene that makes CCR5. The proteins found and cut through the gene, making the virus incapable of attaching to the surface protein.

Later, the cells were put into mice. When the mice were infected with HIV, the virus was unable to enter the genetically altered cells. The immune cells continued to grow even in the presence of HIV, Gregory said.

-- Editors: Angela Zimm, Theresa Barry

To contact the reporter on this story: John Lauerman in Boston at jlauerman@bloomberg.net.

Last Updated: June 29, 2008 13:00 EDT