title: Secretory component mediates Candida albicans binding to epithelial cells.
abstract: OBJECTIVE
  Candida albicans attaches to oral surfaces via a number of mechanisms including adherence mediated by salivary components adsorbed to the C. albicans cell surface. Our goal was to identify the salivary molecules involved.
  
  
  METHODS
  Biotinylated salivary polypeptides that were bound by C. albicans were detected in extracts from washed, saliva-treated yeast cells by polyacrylamide gel electrophoresis and electroblot or immunoblot transfer analysis and purified by electroelution. Purified material was tested for the ability to promote the adherence of radiolabelled C. albicans yeast cells to cultured epithelial monolayers.
  
  
  RESULTS
  Three of the polypeptides bound by C. albicans cells were identified as components of secretory IgA, including secretory component. Using non-denaturing polyacrylamide gel electrophoresis, we demonstrated that secretory component could be detected in its free form in saliva, and was bound by yeast cells. Secretory component which was purified by electroelution from non-denaturing PAGE-separated saliva, without detectable complete IgA, promoted adherence of yeast cells to cultured epithelial monolayers in a dose-dependent fashion.
  
  
  CONCLUSIONS
  These results indicate that despite the inhibitory effect on adherence of IgA specific to C. albicans, IgA components, in particular secretory component, also promote binding to cultured epithelial monolayers.
authors.affiliation: Sir John Walsh Research Institute, University of Otago Faculty of Dentistry, Dunedin, New Zealand.
authors.forename: P A
authors.initials: PA
authors.lastname: van der Wielen
authors.affiliation: Sir John Walsh Research Institute, University of Otago Faculty of Dentistry, Dunedin, New Zealand.
authors.forename: A R
authors.initials: AR
authors.lastname: Holmes
authors.affiliation: Sir John Walsh Research Institute, University of Otago Faculty of Dentistry, Dunedin, New Zealand.
authors.forename: R D
authors.initials: RD
authors.lastname: Cannon
mesh_terms: D019921:Biotinylation; D002176:Candida albicans / Q000378:metabolism*; D002180:Candidiasis, Oral / Q000378:metabolism / Q000382:microbiology; D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells / Q000382:microbiology*; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000737:chemistry / Q000378:metabolism; D009061:Mouth Mucosa / Q000737:chemistry / Q000378:metabolism / Q000382:microbiology; D010455:Peptides / Q000737:chemistry; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000737:chemistry / Q000378:metabolism; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D012635:Secretory Component / Q000378:metabolism*
chemical_list: D007071:Immunoglobulin A, Secretory; D010455:Peptides; D019038:Platelet Glycoprotein GPIb-IX Complex; D012635:Secretory Component; C094990:adhesion receptor
keywords: adhesion receptor; immunoglobulin A; oral candidiasis; oral mucosa; saliva