Caco-2 monolayer as a model for transepithelial migration of the fungal pathogen Candida albicans

A model for transepithelial migration of human fungal pathogens was established, in which Candida albicans was shown to migrate across a monolayer of Caco-2 intestinal cells in a two-chamber system. Electron microscopy revealed typical stages of epithelial penetration by C. albicans including phagocytosis at the apical side, intra- and intercellular migration and exit on the basolateral side of the monolayer. Hyphal growth forms appeared particularly involved in penetration of the Caco-2 monolayer. The model was examined using defined C. albicans mutants defective in hyphal development (efg1/efg1) or growth (ura3/ura3). Transmigration of the efg1/efg1 mutant strain was reduced, while transmigration of the ura3/ura3 strain was blocked completely in the absence of uridine. Because these results parallel virulence characteristics of the mutants the Caco-2 monolayer system appears a useful model for the study of fungal-human host cell interactions.