Endocytosis of alpha 1-acid glycoprotein variants and of neoglycoproteins containing mannose derivatives by a mouse hybridoma cell line (2C11-12). Comparison with mouse peritoneal macrophages.
Macrophages from various origins are known to express membrane lectins that mediate the endocytosis of mannose-bearing glycoconjugates. Most macrophage tumor cell-lines lack such receptors. In this paper we show by flow cytometry analysis that a newly generated macrophage hybridoma (2C11-12), which displays several macrophage characteristics, also expresses mannose membrane lectins, resulting in the internalization of fluoresceinylated neoglycoproteins into acidic compartments. Thioglycolate elicited mouse peritoneal macrophages and the 2C11-12 hybridomas were compared by flow cytometry with regard to the binding and endocytosis of alpha 1-acid glycoprotein (AGP) variants separated by affinity chromatography on immobilized concanavalin A. AGP C eluted specifically with methyl alpha-mannopyranoside, which contains two bi-antennary oligosaccharides, was endocytosed as mannosylated serum albumin (Man-BSA). In both types of macrophages, the fluoresceinylated ligands were internalized in acidic compartments as demonstrated by the fluorescence intensity increase upon monensin post-incubation. However the behaviour of the internalized ligands was found to be quite different. AGP C and Man-BSA were rapidly degraded by thioglycolate elicited peritoneal macrophages and excreted in the medium as small peptide fragments; conversely they remained a longer time in the 2C11-12 hybridoma.
Pimpaneau
V
V
Département de Biochimie des glycoconjugués et lectines endogènes, INSERM, Orléans, France.
Midoux
P
P
Durand
G
G
De Baetselier
P
P
Monsigny
M
M
Roche
A C
AC
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004705:Endocytosis; D017127:Glycation End Products, Advanced; D006023:Glycoproteins / Q000378:metabolism*; D006031:Glycosylation; D006825:Hybridomas / Q000378:metabolism*; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism*; D008358:Mannose; D051379:Mice; D008815:Mice, Inbred Strains; D009961:Orosomucoid / Q000031:analogs & derivatives* / Q000378:metabolism*; D012709:Serum Albumin / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000378:metabolism; D000093423:Glycated Serum Albumin
D017127:Glycation End Products, Advanced; D006023:Glycoproteins; D009961:Orosomucoid; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D008358:Mannose; D000093423:Glycated Serum Albumin