Increased clearance of Candida albicans from the peritoneal cavity of mice pretreated with concanavalin A or jacalin

We have studied the role of polymorphonuclear leukocytes and macrophages in the clearance of Candida albicans from the peritoneal cavity of Swiss mice after treatment with jacalin or concanavalin A (Con-A). Mice (25-30 g, N = 7 per group) received jacalin or Con-A (500 µg/0.5 ml PBS) intraperitoneally 96 h before intraperitoneal inoculation of 5 x 10(7) yast cell. The clearance of Candida from the peritoneal cavity was complete 24 h after inoculation for animals pretreated with jacalin and 48 h after inoculation for animals pretreated with Con-A, whereas a reduction to 4 x 10(4) yeast cells/cavity occurred in control animals 48 h after inoculation. Pretreatment with jacalin or Con-A reduced the recovery of C. albicans from spleen, kidney and liver 10- to 80-fold compared to control animals. Pretreatment with the lectins increased the number of phagocytic cells in the peritoneal exudate 5-to 10-fold and their candidacidal activity was increased 6-fold compared to controls. These data explain the increased rate of clearance and reduced yeast dissemination to the viscera of lectintreated mice

Participation of mannose receptors on the surface of stimulated macrophages in the phagocytosis of glutaraldehyde-fixed Candida albicans, in vitro

We have evaluated the participation of mannose receptors on the surface of stimulated macrophages in the phagocytosis of Candida albicans in vitro. A dose-dependent 8.6 to 88.3% reduction of phagocytosis was observed in the presence of 0.5 to 5.0 mg/ml of the mannose-rich glycoprotein invertase (either native or denatured) in the incubation medium. Macrophages plated onto substrates coated with poly-L-lysine-mannan also showed a 99% reduction of phagocytic activity toward Candida albicans, but phagocytosis of IgG-coated erytrocytes was not inhibited under the same conditions. These results indicate that mannose receptors are involved in one of the initial steps of phagocytosis of Candida albicans by macrophages