DNA security system found

A MOLECULAR "security system" has been discovered in cells that neutralises and removes potentially harmful foreign DNA.

The finding could pave the way to improvements in genetic engineering and gene therapy technologies, scientists believe.

Researchers in the US found an enzyme in human immune cells that disables double-stranded foreign DNA by altering one of its chemical elements.

By understanding how the mechanism works, scientists may be able to develop ways to manipulate it. This could lead to more effective methods of swapping bad genes for good ones.