Distribution of watersoluble antigens and allergens of Candida albicans in blastospore cell extract fractions.

Watersoluble antigens of Candida albicans were sequentially extracted from intact and disrupted yeast cells grown on protein-free agar, and analysed on immunoblots after SDS-PAGE. Washing of the cells in saline before proper extraction resulted in loss of 47.2% of the total carbohydrate and 1.5% of the total protein. The protein fraction contained 14 antigenic bands when analysed with hyperimmune rabbit antisera. Four of these bound IgE when probed with a RAST-positive serum pool and beta-galactosidase-labelled anti-IgE. Extraction of the disrupted cells resulted in 15% of the total carbohydrate and 94% of the total protein. The cytoplasmic protein fraction showed 69 antigenic bands, 13 of which bound IgE. The carbohydrate fraction contained mannan, which was found in the washing solutions and in the surface extract as well as in the cytoplasmic extract. Allergens found in washing solutions were also present in cytoplasmic fraction. This study suggests that the rapid release of allergens from saprophytic C. albicans cells on mucous membranes of the body may cause continuous exposure and result in sensitization.