Human LPLUNC1 is a secreted product of goblet cells and minor glands of the respiratory and upper aerodigestive tracts

Histochem Cell Biol. 2010 May;133(5):505-15. doi: 10.1007/s00418-010-0683-0. Epub 2010 Mar 18.


Long PLUNC1 (LPLUNC1, C20orf114) is a member of a family of poorly described proteins (PLUNCS) expressed in the upper respiratory tract and oral cavity, which may function in host defence. Although it is one of the most highly expressed genes in the upper airways and has been identified in sputum and nasal secretions by proteomic studies, localisation of LPLUNC1 protein has not yet been described. We developed affinity purified antibodies and localised the protein in tissues of the human respiratory tract, oro- and nasopharynx. We have complemented these studies with analysis of LPLUNC1 expression in primary human lung cell cultures and used Western blotting to study the protein in cell culture secretions and in BAL. LPLUNC1 is a product of a population of goblet cells in the airway epithelium and nasal passages and is also present in airway submucosal glands and minor glands of the oral and nasal cavities. The protein is not expressed in peripheral lung epithelial cells. LPLUNC1 is present in bronchoalveolar lavage fluid as two glycosylated isoforms and primary airway epithelial cells produce identical proteins as they undergo mucociliary differentiation. Our results suggest that LPLUNC1 is an abundant, secreted product of goblet cells and minor mucosal glands of the respiratory tract and oral cavity and suggest that the protein functions in the complex milieu that protects the mucosal surfaces in these locations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies / immunology
  • Bronchoalveolar Lavage Fluid / chemistry
  • Cell Differentiation / physiology
  • Cells, Cultured
  • Elafin / genetics
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism
  • Exocrine Glands / metabolism*
  • Gene Expression / genetics
  • Glycoproteins / analysis
  • Glycoproteins / genetics
  • Glycoproteins / immunology
  • Glycoproteins / metabolism*
  • Glycosylation
  • Goblet Cells / metabolism*
  • Humans
  • Mouth / metabolism*
  • Mucin 5AC / metabolism
  • Palatine Tonsil / metabolism
  • Phosphoproteins / analysis
  • Phosphoproteins / genetics
  • Phosphoproteins / immunology
  • Phosphoproteins / metabolism*
  • Respiratory Mucosa / cytology
  • Respiratory Mucosa / metabolism
  • Respiratory System / metabolism*
  • Secretory Leukocyte Peptidase Inhibitor / genetics
  • Tongue / metabolism
  • Uteroglobin / genetics


  • Antibodies
  • BPIFA1 protein, human
  • Elafin
  • Glycoproteins
  • MUC5AC protein, human
  • Mucin 5AC
  • PI3 protein, human
  • Phosphoproteins
  • SCGB1A1 protein, human
  • SLPI protein, human
  • Secretory Leukocyte Peptidase Inhibitor
  • Uteroglobin