Annexin-A1 identified as the oral epithelial cell anti-Candida effector moiety

Mol Oral Microbiol. 2010 Aug;25(4):293-304. doi: 10.1111/j.2041-1014.2010.00579.x.

Abstract

Innate and adaptive immunity are considered critical to protection against mucosal candidal infections. Among innate anti-Candida mechanisms, oral and vaginal epithelial cells have antifungal activity. The mechanism is fungistatic, acid-labile and includes a requirement for cell contact by intact, but not necessarily live, epithelial cells. The purpose of this study was to use the acid-labile property to further characterize the effector moiety. Surface material extracted from phosphate-buffered saline (PBS) -treated, but not acid-treated, epithelial cells significantly inhibited the growth of Candida blastoconidia in a dose-dependent manner which was abrogated by prior heat and protease treatment. Proteins extracted from PBS-treated cells bound blastoconidia and hyphae more intensely than those from acid-treated cells. Proteins from PBS-treated cells eluted from Candida revealed two unique bands of approximately 33 and 45 kDa compared with acid-treated cells. Mass spectrometry identified these proteins as Annexin-A1 and actin, respectively. Oral epithelial cells stained positive for Annexin-A1, but not actin. Western blots showed reduced Annexin-A1 in proteins from acid-treated epithelial cells compared with those from PBS-treated epithelial cells. Lastly, it was demonstrated that immunoprecipitation of Annexin-A1 from proteins extracted from PBS-treated oral epithelial cells resulted in abrogation of inhibitory activity. Taken together, these results indicate that Annexin-A1 is a strong candidate for the epithelial cell anti-Candida effector protein.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Annexin A1 / analysis
  • Annexin A1 / physiology*
  • Antimicrobial Cationic Peptides / analysis
  • Antimicrobial Cationic Peptides / physiology*
  • Blotting, Western
  • Candida albicans / growth & development
  • Candida albicans / immunology*
  • Candida albicans / metabolism
  • Cells, Cultured
  • Epithelial Cells / drug effects
  • Epithelial Cells / immunology*
  • Epithelial Cells / microbiology*
  • Humans
  • Immunoenzyme Techniques
  • Membrane Proteins / analysis
  • Membrane Proteins / physiology
  • Mouth Mucosa / cytology
  • Mouth Mucosa / microbiology*
  • Periodic Acid / pharmacology
  • Protein Binding

Substances

  • Annexin A1
  • Antimicrobial Cationic Peptides
  • Membrane Proteins
  • Periodic Acid