Inhibition of phagocytic activity by the N-acetyl-D-galactosamine-specific lectin from Amaranthus leucocarpus.
Amaranthus leucocarpus lectin (ALL), specific for N-acetyl-D-galactosamine, induces inhibition of the erythrophagocytic activity of resident murine peritoneal macrophages and of the macrophage-like cell line J-774. This effect was observed only in macrophages that were Mac-2 (CD11c/CD18 or CR4) negative, indicating that macrophage activation induces important modification to the glycosylation (mainly O-glycosylation) of the membrane. Receptors for IgM and C3b remain unaltered after lectin treatment. Ultrastructural analysis revealed (a) that ALL induced the formation of pinocytic vacuoles, and (b) a regular distribution over the macrophage membrane as well as endosomal vesicles of the gold labeled ALL. Our results suggest that macrophage membrane glycoproteins with constitutive N-acetyl-D-galactosamine residues participate in the regulation of pinocytic-phagocytic vacuole formation.
Maldonado
G
G
Departamento de Bioquímica, Facultad de Medicina UNAM, México.
Gorocica
P
P
Agundis
C
C
Pérez
A
A
Molina
J
J
Zenteno
E
E
D000116:Acetylgalactosamine / Q000378:metabolism*; D000818:Animals; D002448:Cell Adhesion; D002460:Cell Line; D003208:Concanavalin A / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D037102:Lectins / Q000378:metabolism / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology / Q000648:ultrastructure; D051379:Mice; D008854:Microscopy, Electron; D010587:Phagocytosis / Q000187:drug effects*; D037121:Plant Lectins; D010944:Plants / Q000378:metabolism*; D012397:Rosette Formation
D037102:Lectins; D037121:Plant Lectins; D003208:Concanavalin A; D000116:Acetylgalactosamine