Expression and localization of CFTR in the rhesus monkey surface airway epithelium

The Rhesus monkey has been used as a model for evaluating the possibility of introducing the CFTR gene into the airway epithelium in vivo. We addressed the question of whether the simian airway surface epithelium exhibits a CFTR distribution and functional activity (ciliary beating frequency) similar to that of human airway surface epithelium. Expression of CFTR mRNA was demonstrated on Rhesus monkey tracheobronchial tissue by reverse transcription polymerase chain reaction (RT-PCR) analysis. By immunofluorescent light microscopy, CFTR was localized on the apical plasma membrane of ciliated cells as we previously described for human tracheobronchial surface epithelium. The ciliary beat frequency (CBF) measured on the explant of Rhesus monkey tracheobronchial tissue appeared to be similar to that of the CBF of human tracheobronchial ciliated cells. To compare the Rhesus monkey CFTR gene with that of the human, we sequenced parts of exon 13 (encoding the R domain) and exon 24 (encoding the C terminal part of the protein) of the Rhesus monkey CFTR gene. The nucleotide sequence identity with the human counterpart was found to be 98% and 94% respectively, although restriction enzyme differences allow discrimination between Rhesus monkey and human CFTR cDNA. Taken together, these results suggest that the airway epithelium of the Rhesus monkey is a suitable model of human respiratory epithelium for analyzing the effect of human CFTR gene transfer.