[Gene therapy perspectives in cystic fibrosis]

Cystic fibrosis (CF) is a frequent autosomal recessive genetic disease. The isolation of the gene at the CF locus assigned to the long arm of chromosome 7 band q 31 and defining description of its protein named CFTR (cystic fibrosis transmembrane conductance regulator) promoted understanding the basic biochemical defect. Brief review of relevant literature demonstrates that glycoprotein CFTR is a chloride channel and is activated by a combination of phosphorylation by protein kinase A and binding of ATP. Most common mutation of CF gene, a deletion of the three nucleotides encoding phenylalanine (Delta F508) results in disturbance of chloride transport through membrane of epithelial cells involved in pathomechanism of CF. The way for gene therapy in CF is open, however therapeutic progress is noted on both pharmacologic arena and on the gene cure front. Recombinant vectors utilizing the adenovirus system with high efficiency of CFTR gene transfer to airway epithelium demonstrated in a rat model look promising. The use of retroviruses for CFTR transfer is also advanced mode of somatic gene therapy. An alternative approach suggesting the use of germ line cells is prerequisite of the development of the preimplantation/preconception genetic CF diagnosis. A number of safety and efficacy issues have to be addressed for all approaches before human trials can be implemented.