title: CFTR expression analysis in human nasal epithelial cells by flow cytometry.
abstract: BACKGROUND
  Unbiased approaches that study aberrant protein expression in primary airway epithelial cells at single cell level may profoundly improve diagnosis and understanding of airway diseases. We here present a flow cytometric procedure to study CFTR expression in human primary nasal epithelial cells from patients with Cystic Fibrosis (CF). Our novel approach may be important in monitoring of therapeutic responses, and better understanding of CF disease at the molecular level.
  
  
  OBJECTIVE
  Validation of a panel of CFTR-directed monoclonal antibodies for flow cytometry and CFTR expression analysis in nasal epithelial cells from healthy controls and CF patients.
  
  
  METHODS
  We analyzed CFTR expression in primary nasal epithelial cells at single cell level using flow cytometry. Nasal cells were stained for pan-Cytokeratin, E cadherin, and CD45 (to discriminate epithelial cells and leukocytes) in combination with intracellular staining of CFTR. Healthy individuals and CF patients were compared.
  
  
  RESULTS
  We observed various cellular populations present in nasal brushings that expressed CFTR protein at different levels. Our data indicated that CF patients homozygous for F508del express varying levels of CFTR protein in nasal epithelial cells, although at a lower level than healthy controls.
  
  
  CONCLUSIONS
  CFTR protein is expressed in CF patients harboring F508del mutations but at lower levels than in healthy controls. Multicolor flow cytometry of nasal cells is a relatively simple procedure to analyze the composition of cellular subpopulations and protein expression at single cell level.
authors.affiliation: Department of Pediatric Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Marit A
authors.initials: MA
authors.lastname: van Meegen
authors.forename: Suzanne W J
authors.initials: SW
authors.lastname: Terheggen-Lagro
authors.forename: Cornelis K
authors.initials: CK
authors.lastname: van der Ent
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Beekman
mesh_terms: D000818:Animals; D001980:Bronchi / Q000378:metabolism; D015820:Cadherins / Q000096:biosynthesis; D016022:Case-Control Studies; D002460:Cell Line; D045744:Cell Line, Tumor; D006224:Cricetinae; D003550:Cystic Fibrosis / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000378:metabolism*; D005434:Flow Cytometry / Q000379:methods; D005786:Gene Expression Regulation; D006720:Homozygote; D006801:Humans; D007633:Keratins / Q000096:biosynthesis; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D009297:Nasal Mucosa / Q000378:metabolism*
chemical_list: C505032:CFTR protein, human; D015820:Cadherins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D007633:Keratins; D017493:Leukocyte Common Antigens