DEVELOPMENT AND ANALYSIS OF RECOMBINANT ADENOVIRUSES FOR GENE-THERAPYOF CYSTIC-FIBROSIS

A new adenovirus-based vector (Ad2/CFTR-1) has been constructed in whi ch the cDNA encoding the cystic fibrosis transmembrane conductance reg ulator (CFTR), the cystic fibrosis (CF) gene product, replaces the ear ly region 1 coding sequences, E1a and E1b. The virus retains the E3 re gion. Ad2/CFTR-1 and a related construct encoding beta-galactosidase r eplicate in human 293 cells which provide E1 gene functions in trans. Replication of these recombinant viruses was not detected in a variety of other cells, although very limited viral DNA synthesis and transcr iption from the E4 and L5 regions could be measured. These E1-deletion vectors were also deficient in cellular transformation, shut-off of h ost cell protein synthesis, and production of cytopathic effects, even at high multiplicities of infection. Ad2/CFTR-1 produced CFTR protein in a variety of cells including airway epithelia from CF patients. Ex pression of functional CFTR protein in a CF airway epithelial monolaye r was detected by correction of the Cl- transport defect characteristi c of CF. Surprisingly low multiplicities of infection (0.1 moi) were s ufficient to generate CFTR Cl- current across a CF epithelial monolaye r in vitro. These data, together with the lack of obvious toxicity, su ggest that Ad2/CFTR-1 should be suitable for CF gene therapy.