RELEASE OF CANDIDA-ALBICANS YEAST ANTIGENS UPON INTERACTION WITH HUMAN NEUTROPHILS IN-VITRO

Candida albicans is the leading cause of invasive candidosis. As conve ntional tests do not reliably detect invasive infection, attention has turned to the detection of C. albicans antigens circulating in blood, As antigen tests for invasive candidosis could be improved if C. albi cans antigens released upon phagocytosis were defined, this study was undertaken to characterise antigens released during the interaction of yeasts and human neutrophils in vitro. An enzyme immunoassay develope d previously to detect what were believed to be predominantly C. albic ans cytoplasmic antigens in patients with invasive candidosis was used to follow the neutrophil-mediated release of yeast antigens, Serum op sonisation enhanced antigen release, which was rapid and essentially c omplete by 1 h. When fresh C. albicans yeasts were added to medium fro m cultures of neutrophils plus yeasts or neutrophils plus latex beads, additional yeast antigens were released, Medium from neutrophils plus yeasts or from yeasts alone had similar immunoblot patterns with rabb it antibodies to a C. albicans cytoplasmic antigen preparation, with t he reactive antigens generally being of higher mel. wt than the reacti ve antigens in the antigen mixture used for preparation of the antiser um, The two supernates also had similar immunoblot patterns with rabbi t anti-C, albicans cell-wail mannan antibodies, These results suggest that yeast surface antigens are released quickly during phagocytosis b y neutrophils, Detection of such yeast surface antigens, possibly toge ther with selected yeast cytoplasmic antigens, should improve the sens itivity of C. albicans antigen assays.