Expression of vitronectin and fibronectin binding by Candida albicans yeast cells

Expression of binding to vitronectin (Vn or S-protein) and fibronectin (Fn) was common among clinical isolates of Candida albicans. Growth at 37 degrees C enhanced expression of both Vn and Fn binding. Some strains expressed higher binding after growth in liquid media and others after growth on solid media. Most strains expressed higher cell surface hydrophobicity after growth on agar media. Vn binding was less influenced by expression of cell surface hydrophobicity than Fn binding. Vn binding to yeast cells was optimal around pH 4 and Fn binding around pH 6. Binding to soluble Vn was inhibited by unlabelled Vn and to a lesser extent by Fn. Fn binding to the same C. albicans strain was inhibited by unlabelled Fn, Vn, fibrinogen and to some extent collagens. C. albicans strain 3248 expressed specific high binding of Vn, and high binding of Fn. Binding of both proteins was sensitive to heat and protease treatment, but in different ways. Vn binding differed significantly from the earlier reported Fn binding and may represent a novel type of tissue adherence.