Expression and quantification of the iC3b-binding protein in different Candida albicans strains and their...

Expression and quantification of the iC3b-binding protein in yeast, germ-tube, and mycelial forms of several Candida albicans strains were studied. Ten isolates were obtained from patients with recurrent vaginal candidosis. The germ-tubes generated at 37 degrees C and the mycelial forms of all strains grown at 30 degrees C, as well as most of the mycelial forms grown at 37 degrees C, were able to bind complement-coated sheep erythrocytes (EAiC3b). ELISA results revealed that a decrease in the binding of EAiC3b by the mycelial form of strains CBS 5982 and K10 correlated with a decrease of the expression of the iC3b-binding protein, detected by cross-reaction with the monoclonal antibody OKM1, recognising the alpha chain of human CR3. Expression of the iC3b-binding protein in other strains, binding EAiC3b, was higher in the mycelial form or very similar to that of germ-tubes. The dependence of the expression of the iC3b-binding protein on the morphological stages of individual C. albicans isolates suggests a possible association with the virulence of these strains.