Figure 3

LRP blocking agents act on microglia and CRT blocking inhibits neuronal sites to prevent primary phagocytosis. (A) Schematic showing experimental design for microglial elimination/reconstitution/inhibition studies. (B) 1 μg/ml LRP-blocking antibody inhibits LPS-induced primary phagocytosis of PS-exposing ‘primed’ neurons when antibody added to microglia but not when incubated with neuronal targets prior to readdition of microglia (excess antibody was washed off cells prior to addition of microglia to neurons). Microglia were added to primed neuronal cultures for six hours followed by quantification of neuronal survival. (C) 1 μg/ml CRT-blocking antibody inhibits LPS-induced primary phagocytosis when pre-incubated with primed neurons but not when pre-incubated with microglia. (B) and (C), data represent three separate experiments with two replicates per experiment. mIgG = mouse IgG control. Error bars represent SEM. CRT, calreticulin; LPS, lipopolysaccharide; LRP, low-density lipoprotein receptor-related protein; PS, phosphatidylserine.