Contribution of Phospholipomannan to the Surface Expression of β-1,2-Oligomannosides in Candida albicans and Its Presence in Cell Wall Extracts

β-1,2-Oligomannosides (β-1,2-Man) derived from Candida albicans mannan have been shown to act as adhesins and to induce protective antibodies. We used monoclonal antibodies specific for β-1,2-Man in electron, confocal, and fluorescence microscopy to study the surface expression of β-1,2-Man epitopes. These monoclonal antibodies were also used for Western blotting of cell surface extracts to study the nature of the molecules expressing the β-Man epitopes. Evidence was obtained for the contribution of a glycolipid, phospholipomannan (PLM), to the complex expression of β-1,2-Man epitopes at the cell wall surfaces of yeasts grown on solid media. PLM was present in intercellular matrixes of colonies grown on agar and was detected as a contaminant in mannan batches prepared by conventional methods.