The influence of surface carbohydrates on the interaction of Fonsecaea pedrosoi with Chinese hamster ovary glycosylation mutant cells.

In order to better understand the role played by surface glycoconjugates during cell adhesion and endocytosis by the dematiaceous fungi Fonsecaea pedrosoi, we analyzed the interaction between this microorganism and five mutants of Chinese Hamster Ovary (CHO) cells, which differ from each other in the exposition of carbohydrate residues on the cell surface. Five clones (Gat-2 parental, and the clones: Lec1, Lec2, Lec8 and ldlLec1) were tested and the adhesion and endocytic indexes were determined after 2 hours of interaction. The Lec1 and ldlLec1 clones, which present exposed mannose residues, showed the greater adhesion index (AI). On the other hand, the Lec8 clone, which exposes N-acetylglucosamine on the cell surface, presented the greater endocytic index. The role played by surface-exposed carbohydrate residues was further analyzed by addition of mannose or N-acetylglucosamine to the interaction medium and by previous incubation of the cells in the presence of the lectins Concanavalin A (ConA) and wheat germ agglutinin (WGA). The results obtained suggest that mannose residues are involved in the first step of adhesion of F. pedrosoi to the cell surface, while N-acetylglucosamine residues are involved on its ingestion process.