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 erythrocytes 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.