Dynamic expression of cell-surface antigens probed with Candida albicans-specific monoclonal antibodies

Abstract

IgG hybridomas were produced which preferentially reacted with cell-surface antigens of either yeast cells or hyphae of Candida albicans. Four mAbs were used in an immunostaining procedure to follow the expression dynamics of these antigens in media supplemented with glucose or galactose. Yeast cell growth was analysed during the lag phase, the early-and late-exponential phases and the stationary phase, and mycelium formation was analysed between 0 5 and 24 h induction a t 37 "C. It appears that yeast cell-surface antigens 5 C l l and 2 E l l are expressed throughout all phases of yeast cell growth as well as on young hyphae after up to 1 h induction. Longer hyphae only faintly react with these two mAbs as they switch to hyphal cell-surface antigens 268 and 4E1 after 3 h induction. The reactivity to mAbs 268 and 4 E l was induced after a 3 h temperature shift and was confined to the terminal third of growing mycelia. Growth and hyphae induction in galactose prolonged the reactivity of young hyphae with the two anti-yeast-cell mAbs, whereas the expression of surface antigens 268 and 2 E l l appeared delayed and desynchronized on hyphae. Whereas a similar reactivity was found with ten ATCC strains of C. albicans, four clinical isolates had a unique pattern of reactivity. lmmunoblot analyses of DTT extracts of cell-surface constituents indicated that the antigens were proteinaceous in nature and showed that yeast-cell antigens 5 C l l and 2 E l l are detected in four bands between 68 and 104 kDa, whereas mycelial antigens 4E1 and 268 are detected in 117 kDa and 104 kDa bands found in mycelial but not in yeast-cell extracts. Present data support the concept of a dynamic balance in the expression of phase-specific antigens in C. albicans.

Candida albicans Expresses an Unusual Cytoplasmic Manganese-containing Superoxide Dismutase (SOD3 Gene Product) upon the Entry and during the Stationary Phase

“…Identification and Sequence Analysis of a Third SOD Gene from C. albicans-The CSA1 gene, which encodes an abundant mycelial surface antigen in C. albicans (11), was recently sequenced from a 7.4-kilobase genomic DNA fragment cloned into plasmid YEp24 (10). Further sequencing reactions of this plasmid (p4E1) revealed the presence of an incomplete open reading frame in the opposite direction relative to CSA1.…”

“…Media and Growth Conditions-The C. albicans blastospores were routinely cultured at 28°C in Iscove's modified Dulbecco's medium (IMDM) supplemented with glucose as described previously (11). For the Northern analyses performed with the yeast and mycelial forms of C. albicans, blastospores were first grown overnight at 28°C in the following media: 1% yeast extract, 2% peptone, and 2% glucose (YPD); YPD supplemented with 10% serum; IMDM, pH 6.5; and Lee's medium at either pH 4.5 or 6.5.…”

Role of Hyphal Formation in Interactions of Candida albicans with Endothelial Cells

“…Our present results suggest that the candidal factors that induce endothelial cell endocytosis are expressed by C. albicans cells shortly after they germinate. Because the yeast-to-hypha transition is accompanied by a significant alteration in the candidal cell surface (4,31), it is probable that the germinated organisms express molecules on their surfaces that trigger the process of endocytosis.…”

Cell Wall and Secreted Proteins ofCandida albicans: Identification, Function, and Expression

“…There is a growing body of experimental evidence indicating that the properties-expression, distribution, and chemical characteristics-of cell wall proteins and glycoproteins observed in vitro and in vivo are dependent on multiple factors. These include growth conditions, organism-related factors (such as growth state, morphology of the cells, strain and serotype, phenotypic switching, cell surface hydrophobic or hydrophilic status), and the nature of the biological specimens (intact cells or isolated wall preparations) that are subjected to analysis (5,7,24,44,57,63,106,159,190,191,195,210,284,297,301,326,416,422,477,513,529). Iron availability, which has been shown to be important for pathogens in establishing infection (46,400,566), affects the cell surface (529).…”