Candida albicans Adheres to Chitin by Recognizing N-acetylglucosamine (GlcNAc)

The binding of Candida albicans cells to chitin was examined in a cell-binding assay. Microscopic observations indicated that both living and heat-killed Candida cells bound to chitin-coated substrates. C. albicans preferentially bound to chitin-coated plastic plates over chitosan-coated and uncoated plates. We prepared ¹²⁵I-labeled Candida cells for quantitative analysis of their binding to chitin. Heat-killed ¹²⁵I-labeled Candida cells bound to chitin-coated plates in a time-dependent manner until 1.5 hours after start of incubation at 4℃. The binding of ¹²⁵I-labeled Candida cells to chitin-coated plates was inhibited by adding unlabeled living or unlabeled heat-killed Candida cells. The binding of Candida to chitin was also reduced by addition of 25 mg/ml chitin or chitosan up to 10%. N-acetylglucosamine (GlcNAc), which is a constituent of chitin, inhibited binding of Candida to chitin in a dose-dependent manner between 12.5 and 200 mM. Glucosamine, which is a constituent of chitosan, showed no such inhibitory effect. These findings suggest that the binding of Candida to chitin may be mediated by recognition of GlcNAc.