부산대학교 도서관

Resident alveolar macrophages (AMø) were tested for their ability to respond to Candida albicansmannan. AMøwere found to produce tumor necrosis factor alpha (TNF‐α) in vitro in response to mannan stimulation. TNF‐α secretion was measured using ELISA and L929B cellular cytotoxicity assays. Cytotoxicity was neutralized in parallel L929B cell cultures by the addition of rabbit anti‐TNF‐α antibody. Mannan preparations were found to be free of contaminating LPS by Limulusassay. When AMøwere cultivated for 18 h at 37°, 67 μg of mannan stimulated the secretion of approximately 207 U/ml of TNF‐α. By comparison, AMøtreated with 6.7 μg of LPS secreted approximately 257 U/ml of TNF‐α. Optimal TNF‐α production occurred between 9 and 18 h after mannan stimulation. Disparate mechanisms for stimulation of TNF‐α secretion were suggested by differential sugar blockade of LPS‐ and mannan‐induced TNF‐α secretion. The addition of 2% D‐mannose or 2% alpha‐methyl‐D‐mannoside to AMøcultures blocked mannan‐but not LPS‐stimulated TNF‐α secretion. Furthermore, the addition of rabbit anti‐mannan antibody to mannan‐coated plastic culture dishes prevented TNF‐α secretion by the mannan‐sensitive RAW 264.7 cell line. Moreover, the data suggest that C. albicansmannan stimulated AMøto secrete TNF‐α by an LPS‐independent receptor mechanism which may also function as a mannose receptor. J. Leukoc. Biol.55: 161–168; 1994.