title: Annexin-A1 identified as the oral epithelial cell anti-Candida effector moiety.
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.
authors.affiliation: Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center and School of Dentistry, New Orleans, LA 70119, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Lilly
authors.forename: J
authors.initials: J
authors.lastname: Yano
authors.forename: P L
authors.initials: PL
authors.lastname: Fidel
mesh_terms: D017305:Annexin A1 / Q000032:analysis / Q000502:physiology*; D023181:Antimicrobial Cationic Peptides / Q000032:analysis / Q000502:physiology*; D015153:Blotting, Western; D002176:Candida albicans / Q000254:growth & development / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008565:Membrane Proteins / Q000032:analysis / Q000502:physiology; D009061:Mouth Mucosa / Q000166:cytology / Q000382:microbiology*; D010504:Periodic Acid / Q000494:pharmacology; D011485:Protein Binding
chemical_list: D017305:Annexin A1; D023181:Antimicrobial Cationic Peptides; D008565:Membrane Proteins; D010504:Periodic Acid