beta-1,2-linked oligomannosides from Candida albicans bind to a 32-kilodalton macrophage membrane protein homologous to the mammalian lectin galectin-3.
beta-1,2-linked oligomannoside residues are present, associated with mannan and a glycolipid, the phospholipomannan, at the Candida albicans cell wall surface. beta-1,2-linked oligomannoside residues act as adhesins for macrophages and stimulate these cells to undergo cytokine production. To characterize the macrophage receptor involved in the recognition of C. albicans beta-1,2-oligomannoside we used the J774 mouse cell line, which is devoid of the receptor specific for alpha-linked mannose residues. A series of experiments based on affinity binding on either C. albicans yeast cells or beta-1,2-oligomannoside-conjugated bovine serum albumin (BSA) and subsequent disclosure with biotinylated conjugated BSA repeatedly led to the detection of a 32-kDa macrophage protein. An antiserum specific for this 32-kDa protein inhibited C. albicans binding to macrophages and was used to immunoprecipitate the molecule. Two high-pressure liquid chromatography-purified peptides from the 32-kDa tryptic digest showed complete homology to galectin-3 (previously designated Mac-2 antigen), an endogenous lectin with pleiotropic functions which is expressed in a wide variety of cell types with which C. albicans interacts as a saprophyte or a parasite.
Fradin
C
C
Laboratoire de Mycologie Fondamentale et Appliquée, INSERM E9915, Faculté de Médecine, Pôle Recherche, 59037 Lille Cedex, France.
Poulain
D
D
Jouault
T
T
D000818:Animals; D000943:Antigens, Differentiation / Q000276:immunology / Q000378:metabolism*; D002176:Candida albicans / Q000472:pathogenicity*; D002448:Cell Adhesion; D037502:Galectin 3; D017737:Macrophages, Peritoneal / Q000378:metabolism*; D008362:Mannosides / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009844:Oligosaccharides / Q000378:metabolism*; D011975:Receptors, Mitogen / Q000276:immunology / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D013045:Species Specificity; D013237:Stereoisomerism
D000943:Antigens, Differentiation; D037502:Galectin 3; D008362:Mannosides; D008562:Membrane Glycoproteins; D009844:Oligosaccharides; D011975:Receptors, Mitogen; C028569:oligomannoside