Myelin phagocytosis is augmented in the presence of anti-CD47and anti-SIRPα function-blocking mAbs (see also Fig. 1). Myelin phagocytosis is augmented in (A) microglia and (B) macrophages in the presence of function-blocking anti-SIRPα and anti-CD47 mAbs. Phagocytosis was assayed using different paradigms for each mAb (see text). (i) Microglia and macrophages were pre-incubated in the presence of anti-SIRPα or matched control IgG (Cont-IgG), myelin was added and phagocytosis was assayed. Phagocytosis in the presence of anti-SIRPα was calculated as a percentage of the phagocytosis in control IgG, which was defined as 100%. (ii) Anti-CD47 or matched control IgGs that had their Fc-segments coated/blocked by anti-Fc Fab2 fragments (Fab2-anti-CD47 and Cont-Fab2-IgG, respectively) were used to opsonize myelin that was added to phagocytes. Phagocytosis of myelin opsonized by Fab2-anti-CD47 was calculated as a percentage of phagocytosis in the presence of Cont-Fab2-IgG, which was defined as 100%. Values of individual experiments, each performed in triplicates, as well as averages ± SE are given; two tailed p-values of significance are *** p < 0.001.