Scientists have genetically engineered key cells in the immune system to resist infection by HIV.
Stanford researchers used molecular scissors to cut and paste HIV-resistance genes into T-cells, the specialized immune cells that are targeted by the AIDS virus.
The genetic editing prevented HIV from entering the cells and then going on to destroy the immune system, according to the study published in the journal Molecular Therapy.
Sara Sawyer, an assistant professor at the University of Texas-Austin and co-author of the study, said: "Providing an infected person with resistant T-cells would not cure their viral infection.
"However, it would provide them with a protected set of T-cells that would ward off the immune collapse that typically gives rise to AIDS."
The work was done in a laboratory and clinical trials would be needed to confirm that gene therapy was safe and effective in patients.