Gene Therapy Article

[Guest guest]

Sunday, 20 October, 2002, 23:04 GMT 00:04 UK

               Gene therapy targets cystic fibrosis

               Cystic Fibrosis is caused by a single defective gene

Scientists believe they may be able to overcome a natural body defence which

is

               hindering gene therapy for cystic fibrosis.

               Thousands in the UK are battling the lung disease, which,

without transplantation, can prove fatal before the age of 30.

               Gene therapy is one of the big hopes for future treatments, as

a mutation in just one gene causes a malfunction within cells on the lung

               surface.

               The malfunction leads to overproduction of mucus, which clogs

the lung and makes sufferers vulnerable to chronic infections.

               Because the surface of the lung is relatively accessible

compared with other internal organs, it is hoped that a  gene therapy could

be

               inserted into an inhaler to replace the mutated gene.

               However, trials of gene  therapy have only had  limited

success so far,  with the effects often proving short-lived.

               This is partly due to the natural defences of the lungs, which

are primed to defend their  surface against all sorts of allergens, dust

               particles, viruses and other foreign particles.

               This defence system proves pretty effective against the

viruses used to deliver the new gene into cells.

               Keeping therapy working

               Now a team of researchers from the Women's and Children's

Hospital in Adelaide, Australia, claim they have found a way of prolonging

the

               effect of the treatment.

               As well as the therapy, they gave a dose of a detergent-like

substance found naturally in the

               healthy lung.

               They believe this helps " condition " the surface  of the lung

and hold off the defence  mechanism.

               So far, they have only tested their theory in   the nasal

passages of mice - which react in a  similar way to the surfaces of the

lungs.

               In their experiments, cells lining these airways  not only

responded to the gene therapy, but maintained that response - so far for 110

               days.

               As nasal cells are generally replaced once  every three

months, this means it is possible  that the change is appearing in

newly-created   cells as well as existing ones.

               Helpful HIV

               The team used a modified form of HIV to carry  the therapy -

it has been rendered incapable of causing an HIV infection, but can still

enter  cells and replace the key gene with a new,   healthy sequence.

               Dr Parsons, who led the research, said:  " Airway cells

are replaced every three months so our findings are particularly exciting

               because they imply we are in fact targeting airway stem cells

through this approach.

               " Some of the therapeutic gene must have been  passed on from

these parent stem cells to  their daughter cells for the effect to persist

               beyond three months. "

               The next challenge is to take these successes  and reproduce

them in the lungs of real cystic  fibrosis patients, and the Australian

team is  fine-tuning the technique so that human  clinical trials can be

started.

Becki

YOUR FAVORITE LilGooberGirl

YOUNGLUNG EMAIL SUPPORT LIST

www.topica.com/lists/younglung

Pediatric Interstitial Lung Disease Society

http://groups.yahoo.com/group/InterstitialLung_Kids/