AJP - Cell Physiology, Vol 263, Issue 6 C1147-C1151, Copyright © 1992 by American Physiological Society
Antisense oligonucleotides to CFTR confer a cystic fibrosis phenotype on B lymphocytes
R. D. Krauss, G. Berta, T. A. Rado and J. K. Bubien
Gregory Fleming James Cystic Fibrosis Research Center, Department of Microbiology, University of Alabama, Birmingham 35294.
Cystic fibrosis transmembrane conductance regulator (CFTR) is expressed at
low levels in nonepithelial cells. Recently, we demonstrated that CFTR is
responsible for cell cycle-dependent adenosine 3',5'-cyclic
monophosphate-responsive Cl- permeability in lymphocytes. Agonist
responsiveness of cystic fibrosis (CF) lymphocytes was restored by
transfection with plasmid containing wild type CFTR cDNA. CFTR mRNA is
expressed in the B lymphoid cell line GM03299; however, quantitative
reverse transcriptase-polymerase chain reaction indicates that the level of
CFTR mRNA is at least 1,000 times lower than in T84 cells. CFTR protein
could not be detected by Western blot or by immunoprecipitation of in vitro
phosphorylated protein. However, antisense oligonucleotides representing
codons 1-12 of CFTR caused a complete inhibition of cell cycle-dependent
Cl-permeability [as determined by 6-methoxy-N-(3-sulfopropyl)-quinolinium
fluorescence digital-imaging microscopy], thereby inducing normal cells to
acquire a "CF phenotype." These studies provide direct evidence that a
CFTR-associated Cl- permeability is present and measurable in lymphocytes,
even though CFTR mRNA and protein are expressed at low levels.
