has an affinity to mannose residues exposed on many microbial cell surfaces and triggers complement activation by the lectin pathway

important in opsonization (immune phagocytosis after antibody binding to microorganism's cell wall) of a pulmonary pathogen unicellular fungus Pneumocystis jirovecii, formerly known as Pneumocystis carinii

binds to the phosphorylcholine moiety of certain bacteria and unicellular fungi cell walls, opsonizes them and activates the complement system by the classical pathway