EVALUATION OF THE RESPIRATORY EPITHELIUM OF NORMALS AND INDIVIDUALS WITH CYSTIC-FIBROSIS FOR THE PRESENCE OF ADENOVIRUS E1A SEQUENCES RELEVANT TO THE USE OF E1A(-) ADENOVIRUS VECTORS FOR GENE-THERAPY FOR THE RESPIRATORY MANIFESTATIONS OF CYSTIC-FIBROSIS

Lung disease associated with disorders such as cystic fibrosis (CF) ma y be amenable to somatic gene therapy in which there is delivery of th e normal gene directly to the respiratory epithelium using E1a(-) aden ovirus (Ad) type 2- or 5-based vectors. For safety reasons, the Ad vec tors are rendered replication deficient by deletion of the E1a region. Because there is the theoretical possibility of an E1a(-) replication -deficient vector replicating as a result of recombination or compleme ntation with Ad 2/5 E1a sequences present in the target cell, this stu dy is directed toward evaluating respiratory epithelium of normals and individuals with CF for the presence of E1a sequences. Using Ad 2/5 E 1a-specific primers and the polymerase chain reaction to evaluate DNA recovered from freshly isolated nasal and bronchial epithelium recover ed by brushing, E1a sequences were detected in respiratory epithelium of 19 of 91 normals (21%). In the E1a-positive samples, the average of E1a copy number was 55 +/- 18/10(3) recovered cells. In CF individual s, 7 of 52 (13%) had detectable E1a sequences in the respiratory epith elium, with E1a copy number in the positive samples of 80 +/- 21/10(3) recovered cells. These results demonstrate that there are detectable Ad 2/5 E1a sequences in the respiratory epithelium of a small percenta ge of normals and individuals with CF. Because of the theoretical pote ntial of such sequences supporting replication of E1a(-) Ad vectors, h uman gene therapy protocols for CF utilizing such vectors should consi der evaluating study individuals for the presence of Ad 2/5 E1a sequen ces in the respiratory epithelium.