"For the first time, people are beginning to think about a cure" as a real possibility, said Dr. John Zaia, head of the government panel that oversees gene therapy experiments. Even if the new approach doesn't get rid of HIV completely, it may repair patients' immune systems enough that they can control the virus and not need AIDS medicines -- "what is called a functional cure," he said.
Carl Dieffenbach, AIDS chief at the National Institute of Allergy and Infectious Diseases, agreed.
"We're hopeful that this is sufficient to give the level of immune reconstitution similar to what was seen with the patient from Germany," he said.
This is the first time researchers have permanently deleted a human gene and infused the altered cells back into patients. Other gene therapy attempts tried to add a gene or muffle the activity of one, and have not worked against HIV.
The virus can damage the immune system for years before people develop symptoms and are said to have AIDS -- acquired immune deficiency syndrome. The virus targets special immune system soldiers called T-cells. It usually enters these cells through a protein receptor, or "docking station," called CCR5.
The cell transplant appears to have cured both problems, but finding such donors for everyone with HIV is impossible, and transplants are medically risky.
So scientists wondered: Could a patient's own cells be used to knock out the CCR5 gene and create resistance to HIV?
A California biotechnology company, Sangamo (SANG-uh-moh) BioSciences Inc., makes a treatment that can cut DNA at precise locations and permanently "edit out" a gene.
Dr. Jacob Lalezari, director of Quest Clinical Research of San Francisco, led the first test of this with the company and colleagues at the University of California in San Francisco and Los Angeles.