Cystic fibrosis transmembrane conductance regulator with a shortened R domain rescues the intestinal phenotype of CFTR−/− mice

LS Ostedgaard, DK Meyerholz… - Proceedings of the …, 2011 - National Acad Sciences
LS Ostedgaard, DK Meyerholz, DW Vermeer, PH Karp, L Schneider, CD Sigmund, MJ Welsh
Proceedings of the National Academy of Sciences, 2011National Acad Sciences
Gene transfer could provide a novel therapeutic approach for cystic fibrosis (CF), and adeno-
associated virus (AAV) is a promising vector. However, the packaging capacity of AAV limits
inclusion of the full-length cystic fibrosis transmembrane conductance regulator (CFTR)
cDNA together with other regulatory and structural elements. To overcome AAV size
constraints, we recently developed a shortened CFTR missing the N-terminal portion of the
R domain (residues 708–759, CFTRΔR) and found that it retained regulated anion channel …
Gene transfer could provide a novel therapeutic approach for cystic fibrosis (CF), and adeno-associated virus (AAV) is a promising vector. However, the packaging capacity of AAV limits inclusion of the full-length cystic fibrosis transmembrane conductance regulator (CFTR) cDNA together with other regulatory and structural elements. To overcome AAV size constraints, we recently developed a shortened CFTR missing the N-terminal portion of the R domain (residues 708–759, CFTRΔR) and found that it retained regulated anion channel activity in vitro. To test the hypothesis that CFTRΔR could correct in vivo defects, we generated CFTR−/− mice bearing a transgene with a fatty acid binding protein promoter driving expression of human CFTRΔR in the intestine (CFTR−/−;TgΔR). We found that intestinal crypts of CFTR−/−;TgΔR mice expressed CFTRΔR and the intestine appeared histologically similar to that of WT mice. Moreover, like full-length CFTR transgene, the CFTRΔR transgene produced CFTR Cl currents and rescued the CFTR−/− intestinal phenotype. These results indicate that the N-terminal part of the CFTR R domain is dispensable for in vivo intestinal physiology. Thus, CFTRΔR may have utility for AAV-mediated gene transfer in CF.
National Acad Sciences