In a bold new approach ultimately aimed at trying to cure AIDS, scientists have used genetic engineering in six patients to develop blood cells that are resistant to HIV, the virus that causes the disease.

It's far too early to know if this scientific first will prove to be a cure, or even a new treatment. The research was only meant to show that, so far, it seems feasible and safe.

The concept was based on the astonishing case of an AIDS patient who seems to be cured after getting blood cells from a donor with natural immunity to HIV nearly four years ago in Berlin.

Researchers are seeking a more practical way to achieve similar immunity using patients' own blood cells.

The result, announced Monday, at a conference in Boston left experts cautiously excited.