NeuroMab™ Anti-SIRP Alpha Antibody, Clone 9C2

Figure 1 shows FACS histograms of selected SIRPA antibodies binding to rodent Chinese hamster ovary cell lines (CHO) expressing human SIRPA (HuSIRPA) or mouse SIRPA (MuSIRPA). Left panel

Figure 2 shows FACS histograms of binding of selected SIRPA antibodies to primary human macrophages.

Figure 3 shows the binding of increasing concentrations of anti-SIRPA antibodies to human SIRPA overexpressed on CHO cells. EC50 values were calculated by fitting the data to a sigmoid curve using Graph Pad Prism.

Figure 4 shows the ability of CD47-blocking and CD47-non-blocking anti-SIRPA antibodies to affect HuSIRPA-dependent luciferase expression in a cell-based reporter assay.

BWZ-HuSIRPA cells were seeded in wells with or without plate-bound CD47 protein. All CD47 blocking antibodies (1B3, 12D6, 1H11, 5F7) effectively inhibited the luminescence signal. Two CD47 non-blocking anti-SIRPA antibodies did not reduce luciferase expression. Results are expressed as background multiples. The background level is set to 1 on the y-axis.

Figure 5 shows the induction of human SIRPA-dependent or human SIRPB1-dependent luciferase expression in a cell-based reporter assay.

Figure 6 shows downregulation of SIRPA receptors in primary human macrophages in response to antibody stimulation.

Cells were treated with soluble full-length isotype control or soluble full-length anti-SIRPA antibody, followed by staining with DyLight650-conjugated anti-SIRPA reference antibody (SA56-DyL650) that binds to different epitope bins.

Figure 7 shows the enhanced phagocytic activity of macrophages treated with CD47 blocking anti-SIRPA antibodies.

Macrophages were cultured overnight in 2.5% FBS RPMI medium containing 5 μg/mL 12D6, 9C5, 1H11, 5F7, 1B3, 3F9 (CD47 non-blocker) or isotype control.