title: Characterization of human upper airway epithelial progenitors.
abstract: BACKGROUND
  New epithelial cells are generated through the proliferation and differentiation of resident progenitor cells in the nasal cavity. In several upper airway diseases, such as cystic fibrosis and chronic rhinosinusitis, self-renewing progenitor cells may be functionally defective, or compromised in their ability, to regenerate cells that maintain normal mucociliary clearance. Herein, we describe our early work to define and characterize a rare population of human nasal epithelial putative progenitors.
  
  
  METHODS
  Single-cell suspensions of human ethmoid sinus tissues were prepared following endoscopic sinus surgery. Cell surface antibodies were analyzed as candidate markers for detecting progenitor cells. A panel of antibodies, including epithelial cell adhesion molecule (EpCAM, epithelial cells), CD45 (hematopoietic cells), nerve growth factor receptor (NGFR/CD271), intercellular adhesion molecule-1 (ICAM1/CD54), and integrin-α6 (ITGA6/CD49f) were used to resolve epithelial progenitor candidates by high-dimensional flow cytometry and the gating technique of fluorescence minus one (FMO) controls.
  
  
  RESULTS
  A rare population of approximately 0.06% of total ethmoid cells was discriminated as EpCAM(-) CD45(-) NGFR(+) ICAM1(+) by surface markers. Use of ITGA6 was excluded based on FMO control analysis. This lineage-negative population was purified to 99% homogeneity by cell sorting and analyzed by immunofluorescence microscopy. Sorted cells were subsequently confirmed to uniformly express the transcription factor p63. Upon in vitro culture, lineage-negative clonal cells were confirmed to spontaneously differentiate into epithelial lineage-positive cells.
  
  
  CONCLUSIONS
  Using the NGFR and ICAM1 cellular coordinates, we have identified a promising population of native human nasal epithelial progenitor cells that require more formal investigation for their role in upper airway regeneration.
authors.affiliation: Department of Otolaryngology, Stanford University School of Medicine, Stanford, CA.
authors.forename: Dawn T
authors.initials: DT
authors.lastname: Bravo
authors.forename: Ethan
authors.initials: E
authors.lastname: Soudry
authors.forename: Justin A
authors.initials: JA
authors.lastname: Edward
authors.forename: Wei
authors.initials: W
authors.lastname: Le
authors.forename: Alan L
authors.initials: AL
authors.lastname: Nguyen
authors.forename: Peter H
authors.initials: PH
authors.lastname: Hwang
authors.forename: Mrinmoy
authors.initials: M
authors.lastname: Sanyal
authors.forename: Jayakar V
authors.initials: JV
authors.lastname: Nayak
mesh_terms: D000951:Antigens, Neoplasm / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002478:Cells, Cultured; D000071858:Epithelial Cell Adhesion Molecule; D004847:Epithelial Cells / Q000145:classification / Q000166:cytology*; D005005:Ethmoid Sinus / Q000166:cytology*; D005434:Flow Cytometry; D006801:Humans; D039503:Integrin alpha6 / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism; D020545:Respiratory Mucosa / Q000166:cytology*; D013234:Stem Cells / Q000145:classification / Q000166:cytology*; D014157:Transcription Factors / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; D015415:Biomarkers; D015815:Cell Adhesion Molecules; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule; C573420:ICAM1 protein, human; C588002:ITGA6 protein, human; D039503:Integrin alpha6; C484065:NGFR protein, human; D009419:Nerve Tissue Proteins; D017475:Receptors, Nerve Growth Factor; C115051:TP63 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D018799:Intercellular Adhesion Molecule-1
keywords: EpCAM; FACS; ICAM1; ITGA6; NGFR; epithelial regeneration; ethmoid sinus; flow cytometry; nasal mucosa; progenitor cells; stem cells