Again, as noted with mice, restoration of Cl' transport is effected by Ad5-CB- 
CFTR. 
Experiments were performed to test the feasibility of detecting recombinant 
derived CFTR in primary isolates of CF airway epithelial cells. Cells removed from 
the main stem bronchus of a CF patient were plated in culture and exposed to either 
Ad5-CMV-lacZ or Ad5-CB-CFTR at an MOI of 500. High levels of recombinant 
derived CFTR were clearly detected in 100% of the Ad5-CB-CFTR cells (data not 
shown). 
IVA.2.C. Complementation in human CF xenografts: 
In order to assess the feasibility of gene therapy it is important to determine 
the level of genetic reconstitution that is necessary for detectable improvement in 
the electrophysiological properties of the human airway. Furthermore, it is 
important to determine if this level of correction is possible with the virus under 
consideration for human trials (Ad5-CB-CFTR). This issue was initially addressed 
by Johnson et al. (49) and is discussed above. 
We studied this question in CF xenografts exposed to Ad5-CB-CFTR virus. 
CF grafts were exposed to either Ad5-CMV-lacZ or Ad5-CB-CFTR and 
subsequently evaluated in situ for correction of cAMP transport across the 
epithelium using a modification of the procedure described by Knowles et al. 
(17,58). Nu/nu mice that carried xenografts were anesthetized with 
Recombinant DNA Research, Volume 17 
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