Histochemical and Immunochemical Study of the Fate of <i>Candida albicans</i> Inside Human Neutrophil Phagolysosomes

Abstract

To further define the ultrastructural events associated with the killing of Candida albicans by human neutrophils, four methods were used: (1) the periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining of vicinal-glycol-containing complex carbohydrates; (2) the localization of thermostable immunodeterminants of the yeast cell wall, mannans or mannoproteins, using monospecific antibodies and a protein A-gold complex (monAb-gold); (3) the localization of mannose residues with concanavalin A labeled with gold particles (Con A-gold); (4) the localization of chitin oligomers using wheat germ agglutinin and ovomucoid labeled with gold particles (WGA-gold). The mannan-rich cell wall layers were progressively lost as shown by altered PA-TCH-SP reactivity and a diffuse pattern of staining with Con A-gold and monAb-gold. The de novo appearance of conspicuous amounts of glycogen-like particles near the plasmalemma and in the cell wall was interpreted as evidence of a reparative process of the yeast cell wall. Chitin was seemingly unaltered and readily demonstrated by the WGA-gold in the wall remnants of ghost cells.