Cystic fibrosis or mucoviscidosis is a genetic disorder that is caused by mutations in the CFTR gene. This makes the mucus in the body thick and sticky, which in turn causes clogging in, for instance, the airways and in the gastrointestinal tract. The symptoms of cystic fibrosis (CF) can be treated, but there is no cure for the disorder.
Mice studies conducted in collaboration with the University Hospitals Leuven and the universities of Paris, Utrecht, and Rotterdam have revealed that an improved gene therapy treatment can cure mice with CF. Cell cultures from CF patients have also been found to respond well to the treatment.
‘Gene therapy targeting the CFTR gene has yielded promising results both in mice with cystic fibrosis (CF) and in gut cell cultures from CF patients. Further trials involving human beings are required to study gene therapy as a cure for cystic fibrosis.’
The researchers examined an improved gene therapy treatment based on inserting the genetic material for chloride channels, coded by the CFTR gene, into the genome of a recombinant AAV viral vector, which is derived from the relatively innocent AAV virus. The team then used this vector to 'smuggle' a healthy copy of the CFTR gene into the affected cells.
Both in mice with CF and in gut cell cultures from CF patients, this approach yielded positive results. Professor Zeger Debyser said, "We administered the rAAV to the mice via their airways. Most of the CF mice recovered. In the patient-derived cell cultures, chloride and fluid transport were restored."
However, the researchers stressed that there is still a long way to go before gene therapy can be used to treat cystic fibrosis patients. Debyser said, "We must not give CF patients false hope. Developing a treatment based on gene therapy will take years of work. For one thing, our study did not involve actual human beings, only mice and patient-derived cell cultures. Furthermore, we still have to examine how long the therapy works. Repeated doses might be necessary. But gene therapy clearly is a promising candidate for further research towards a cure for cystic fibrosis."
The study was presented by the Laboratory for Molecular Virology and Gene Therapy at KU Leuven, Belgium.