Since recombinant PIV can be re-engineered to express large transgene inserts [18], we used PIV to: (1) generate PIV-expressing CFTR as an additional gene (PIVCFTR); (2) test whether delivery of CFTR to CF ciliated cells restored mechanical innate defense, i.e., MCT, to human CF airway epithelia; and (3) determine the numbers of CF epithelial cells requiring CFTR to restore MCT rates to normal non-CF HAE levels. Here, CFTR is linked to cystic fibrosis.