More efficient gene targeting improves prospects for gene therapy

The Nobel prize-winning MRC scientist Sir Aaron Klug and a team from an American company, Sangamo BioSciences, have announced a new way to target genes that may revolutionise medical research and pave the way for new treatments.

Their findings are published in PNAS.

The scientists have developed a more efficient way to target genes using synthetic proteins. Many biological processes are determined by switching genes on or off. Genes give instructions for making the proteins involved in these processes. This regulation of gene expression is controlled by regulatory proteins called transcription factors.

Sir Aaron Klug, of the Medical Research Council's Laboratory of Molecular Biology in Cambridge, devised these synthetic transcription factors called zinc-finger nucleases based on a naturally occuring design. These zinc-fingered nucleases have the capacity to recognise specific sequences of DNA which makes them extremely good at targeting particular genes without affecting others.

These findings confirm that this method of gene targeting will present an efficient option for scientists to create “knock-out” animals for research. Animal trials are already under way to use the technique to knock out the receptor of HIV in T-cells of AIDS patients, so leading to a supply of non-infectable T-cells, which will combat HIV and the other infections which occur in AIDS patients. Clinical trials are also in progress for stimulating the growth of new arteries in patients suffering from obstruction of the blood vessels in the limbs.

This is a powerful technology for intervening in gene expression in health or disease and therapeutic applications are planned for other diseases by Sangamo BioSciences.