Human lymphocytes transcribe the cystic fibrosis transmembrane conductance regulator gene and exhibit CF-defective cAMP-regulated chloride current

T. V. McDonald, P. T. Nghiem, P. Gardner, C. L. Martens

Research output: Contribution to journalArticle

59 Scopus citations

Abstract

Cystic fibrosis (CF) is the most common lethal genetic disease among Caucasians, primarily affecting epithelial tissues of the lung and gut. Mutations in a single gene, the cystic fibrosis transmembrane conductance regulator (CFTR), are responsible for this disease. Whether a physiological defect exists in the immune system of CF patients has remained controversial. A chloride ion transport defect has been described in human CF-derived lymphocytes; however, it has not been possible to detect CFTR mRNA in lymphocytes. We report here that normal human B-lymphoblasts display whole cell Cl- conductances induced by calcium-mediated pathways, volume regulation, and cAMP which are equivalent to currents described in epithelial cells. B-lymphoblasts from CF-affected humans demonstrated defective Cl- conductance regulation by cAMP but preserved regulation by calcium-mediated and volume regulation mechanisms. CFTR involvement in cAMP regulation of Cl- conductance in lymphocytes is further supported by our demonstration of the presence of appropriately spliced CFTR mRNA segments in human B and T lymphocytes as detected by an optimized reverse-transcription and polymerase chain reaction approach. The identity of the amplified products was confirmed by hybridization to CFTR-specific probes and DNA sequencing. Furthermore, the 3'-end of the gene was found in a T cell cDNA library. We conclude that CFTR mRNA is expressed in lymphocytes, consistent with the cAMP regulation of chloride transport present in normal lymphocytes but defective in CF-derived lymphocytes.

Original languageEnglish (US)
Pages (from-to)3242-3248
Number of pages7
JournalJournal of Biological Chemistry
Volume267
Issue number5
Publication statusPublished - Jan 1 1992

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this