Complement receptor 3 (CD11b/CD18) is implicated in the elimination of β-amyloid peptides.
Microglia are the professional phagocytes of the brain and express phagocytic receptors such as complement receptor 3 (CR3 or CD11b/CD18). Using mimics of the amyloid deposit made of heat-killed yeasts coated with either Aβ 1-40 or Aβ 1-42, we were able to study how microglia interacted with and ingested these particles in vitro. We have shown previously that the low density lipoprotein receptor-related protein (LRP) is largely implied in the phagocytosis of Aβ 1-42-opsonized heat-killed yeasts and partly in that of Aβ 1-40-opsonized heat-killed yeasts. Here, we report that antibodies against CD11b or CD18 reduced the uptake of the artificial amyloid deposit by microglial cell showing that CR3 is involved in the mechanism. Moreover, a concomitant inhibition of LRP and CR3 completely blocked the ingestion of both kinds of particles suggesting that no other receptors participate to this mechanism.
Choucair-Jaafar
Nada
N
UMR 7213, Université de Strasbourg, CNRS, 74 route du Rhin, 67401 Illkirch, France. choucair@neurochem.u-strasbg.fr
Laporte
Vincent
V
Levy
Rachel
R
Poindron
Philippe
P
Lombard
Yves
Y
Gies
Jean-Pierre
JP
D016229:Amyloid beta-Peptides / Q000378:metabolism; D000818:Animals; D039481:CD11b Antigen / Q000276:immunology*; D018821:CD18 Antigens / Q000276:immunology*; D002460:Cell Line; D007795:Laminaria / Q000378:metabolism; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000378:metabolism; D016177:Macrophage-1 Antigen / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D017628:Microglia / Q000276:immunology / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism
D016229:Amyloid beta-Peptides; D039481:CD11b Antigen; D018821:CD18 Antigens; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D016177:Macrophage-1 Antigen; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)