Heat-Shock Mannoproteins as Targets of Secretory IgA in Candida albicans

The expression of Candida albicans antigenic determinants reacting with secretory IgA from patients with oral and vaginal candidiasis was investigated under different in vitro conditions. Reversible antigenic transitions were inducible in synthetic medium by temperature shifts, as the yeast cells were positive by an indirect immunofluorescence assay after being incubated at 37 degrees C but not at 25 degrees C. In vitro temperature-inducible C. albicans antigenic determinants reactive with secretory IgA were characterized by radioimmune Western blot as mannoproteins with molecular masses of 180-200, 130-150, 90-110, and 60-70 kDa. This is the first report on the expression of mannoproteins regulated by temperature involved in the secretory immune response during mucosal candidiasis.