Advance in gene therapy for cystic fibrosis

The results of a study carried out at the University of California, Berkeley and the University of Iowa, US have reported significant development in the field of gene therapy. Published this week in the online journal Proceedings of the National Academy of Sciences, the research documents the successful treating of cystic fibrosis (CF) in human lung tissue by using a highly infectious virus to deliver healthier genes into the affected cells.

Previously scientists had been successful in 'turning off' the faulty gene which causes CF by replacing it with a healthy gene, but the effects were short lived as the virus used to carry the healthy genes was being attacked by the immune system. In the recent study the stronger adeno-associated virus was adapted to make it possible for it to bind to different and more plentiful receptors and also to proceed past the cell's surface membrane and so into the cell proper.

CF is a fairly common hereditary disease affecting about 8000 people in the UK with about one in 25 people being carriers. The disease affects the body's mucus membranes causing the build up of sticky mucus in the lungs and pancreas which causes a variety of complications including difficulty breathing, digestive problems and serious infections. Currently, therapies used to treat CF only ease symptoms of the condition and those affected will typically die from lung or organ failure before the age of 40.

The successful developments published by the US research teams are still at a laboratory stage. However, David Schaffer, a co-author of the paper from the University of California, Berkeley said of this latest success: 'I think it is worthwhile thinking about clinical therapy at the levels of infection we are achieving'.

Joseph Zabner, a co-author from the University of Iowa Hospital and Clinics, supported this sentiment in an e-mail in which he said: 'If we are able to show that efficient gene transfer can result in gene therapy, if we can cure the lung disease of pigs that have been genetically engineered to have cystic fibrosis lung disease, we should have a real chance of curing cystic fibrosis in humans'.

However, a spokeswoman from the UK Cystic Fibrosis Consortium was careful not to raise expectations too high as she commented on the new developments: 'The techniques used in this research are innovative, but more work is needed before this could be translated into clinical benefit for people with CF', she said.

The UK hopes to proceed with the first large scale trials of gene therapy for cystic fibrosis this year.