Adhesion of Candida albicans, but not Candida krusei, to salivary statherin and mimicking host molecules

The aim of the present study was to identify salivary molecules affecting adhesion of Candida albicans and Candida krusei to salivary pellicles and epithelial cells. Strains of C. albicans (GDH18, GDH3339, CA1957, ATCC 28366 and ATCC 10321), but not C. krusei (strains ATCC 14243 and Ck9), bound to saliva-coated hydroxyapatite and buccal epithelial cells. Parotid saliva fractions containing statherin, glycosylated proline-rich proteins (PRP) and as yet unidentified components mediated adhesion of strain GDH18; Fuc alpha 1-2Gal beta 1-4Glc partly inhibited the adhesion to those fractions not containing statherin. Pure statherin, but not PRP-1, mediated dose-dependent adhesion of C, albicans strain GDH18 to hydroxyapatite beads. Candida isolates (GDH18, GDH3339 and CA1957) bound somewhat more avidly to statherin/saliva relative to ATCC strains 28366 and 10321, while the opposite was true for adhesion to buccal epithelial cells. Adhesion of C, albicans strain GDH18 to saliva-coated hydroxyapatite and buccal epithelial cells was completely (93%) and partly (43%) blocked by statherin-specific immunoglobulin G (IgG) antibodies, respectively. Control IgG antibodies did not block Candida adhesion. Blockage of Candida adhesion to epithelial cells also occurred with Fuc alpha 1-2Gal beta 1-4Glc (49%) and N-acetylglucosamine (38%), while statherin specific IgG antibodies in combination with Fuc alpha 1-2Gal beta 1-4Glc almost completely eliminated Candida adhesion (79%). In addition, statherin in solution blocked the adhesion of strain GDH18 to epithelial cells by inducing aggregation of Candida cells.