Distribution of water soluble antigens and allergens of Candida albicans in blastospore cell extract fractions

Abstract

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.

Immunoblotting analysis of concanavalin A ‐isolated allergens of Candida albicans

“…Similar findings were observed in immunoblotting with the crude and purified protein fractions (25). This protein component was not present in pure GonA preparations but still bound human IgE-antibodies.…”

“…The glycoproteins in the crude extract have molecular weights which differ from the 70 kD component. Similar findings were observed in immunoblotting with the crude and purified protein fractions (25). The reason for the difference between the molecular weights of the glycoproteins in the crude extract and those isolated with GonA might be that the 70 kD glycoprotein contains GonA-related structures, to which the carbobydrate residues in this glycoprotein become attached.…”

Enhanced IgE response to Candida albicans in postoperative invasive candidiasis

“…A crude cytoplasmic extract was prepared by disruption of the yeast cells with a Manton-Gaulin homogenizer after extensive washing as previously described [14]. The purified protein extract was prepared in a carbohydrate-free form by Concavaiin A (ConA) affinity chromatography purification as previously described [15,16]. Mannan was prepared according to the Peat method by degradation under alkaline conditions and separation by Fehling's precipitation [17].…”

IgE‐binding components of baker's yeast (Saccharomyces cerevisiae) recognized by immunoblotting analysis. Simultaneous IgE binding to mannan and 46–48 kD allergens of Saccharomyces cerevisiae and Candida albicans

“…This procedure resulted in the mannan/mannoprotein extract and the purified protein extract. Commercially available purified S. eerevisiae enolase was purchased from Sigma chemicals (Sigma E 6126): To analyse the possible simultaneous reactivity with Candida albieans the crude extract, mannan/mannoprotein extracts and purified protein extract of C. albieans were prepared as described [5,6]. The alkaline degraded Fehling precipitated purified mannan of C. albieans was prepared according to Peat et al [7].…”