HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 289/6/L1123    most recent 00049.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Farmen, S. L. Articles by Welsh, M. J. Search for Related Content PubMed PubMed Citation Articles by Farmen, S. L. Articles by Welsh, M. J.

Gene transfer of CFTR to airway epithelia: low levels of expression are sufficient to correct Cl^– transport and overexpression can generate basolateral CFTR

Departments of ¹Physiology and Biophysics and ²Internal Medicine, ³Howard Hughes Medical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242; ⁴Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030; and ⁵Lung Biology Research Program, Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada

Submitted 25 January 2005 ; accepted in final form 28 July 2005

Gene transfer of CFTR cDNA to airway epithelia is a promising approach to treat cystic fibrosis (CF). Most gene transfer vectors use strong viral promoters even though the endogenous CFTR promoter is very weak. To learn whether expressing CFTR at a low level in a fraction of cells would correct Cl^– transport, we mixed freshly isolated wild-type and CF airway epithelial cells in varying proportions and generated differentiated epithelia. Epithelia with 20% wild-type cells generated 70% the transepithelial Cl^– current of epithelia containing 100% wild-type cells. These data were nearly identical to those previously obtained with CFTR expressed under control of a strong promoter in a CF epithelial cell line. We also tested high level CFTR expression using the very strong cytomegalovirus (CMV) promoter as well as the cytokeratin-18 (K18) promoter. In differentiated airway epithelia, the CMV promoter generated 50-fold more transgene expression than the K18 promoter, but the K18 promoter generated more transepithelial Cl^– current at high vector doses. Using functional studies, we found that with marked overexpression, some CFTR channels were present in the basolateral membrane where they shunted Cl^– flow, thereby reducing net transepithelial Cl^– transport. These results suggest that very little CFTR is required in a fraction of CF epithelial cells to complement Cl^– transport because transepithelial Cl^– flow is limited at the basolateral membrane. Thus they suggest a broad leeway in promoter strength for correcting the CF gene transfer, although at very high expression levels CFTR may be mislocalized to the basolateral membrane.

cystic fibrosis; gene therapy; promoter; cytomegalovirus; cytokeratin-18

This article has been cited by other articles:

				R. Robert, G. W. Carlile, C. Pavel, N. Liu, S. M. Anjos, J. Liao, Y. Luo, D. Zhang, D. Y. Thomas, and J. W. Hanrahan Structural Analog of Sildenafil Identified as a Novel Corrector of the F508del-CFTR Trafficking Defect Mol. Pharmacol., February 1, 2008; 73(2): 478 - 489. [Abstract] [Full Text] [PDF]

				O. Granio, C. Norez, K. J. D. Ashbourne Excoffon, P. H. Karp, M. Lusky, F. Becq, P. Boulanger, J. Zabner, and S.-S. Hong Cellular Localization and Activity of Ad-Delivered GFP-CFTR in Airway Epithelial and Tracheal Cells Am. J. Respir. Cell Mol. Biol., December 1, 2007; 37(6): 631 - 639. [Abstract] [Full Text] [PDF]

				E. M. Bruscia, E. C. Ziegler, J. E. Price, S. Weiner, M. E. Egan, and D. S. Krause Engraftment of Donor-Derived Epithelial Cells in Multiple Organs Following Bone Marrow Transplantation into Newborn Mice Stem Cells, October 1, 2006; 24(10): 2299 - 2308. [Abstract] [Full Text] [PDF]