Fig. 3.

hSIRPα.40A promotes tumor cell uptake in all SIRPA genotypes. a Illustration of tumor cell uptake by human macrophages upon engagement of FcγR and blockade of the SIRPα/CD47 axis. b Picture showing a human macrophage binding to a Raji cell opsonized with anti-tumor antibodies (in green; left) resulting in tumor cell uptake (right). Scale bar, 10 μm. c hSIRPα.40A promotes rituximab (RTX)-mediated macrophage tumor cell uptake in both homozygous and heterozygous SIRPA genotypes. (Mean ± SD; representative of n = 2 (hSIRPαV1), 4 (hSIRPαV1/V2) or 6 (hSIRPαV2) donors is shown). d Chimeric hSIRPα.40A promotes optimal macrophage-mediated tumor cell uptake on a human IgG2 (.40.C2) but not on a IgG1 (.40.C1) or IgG4 (.40.C4) Fc backbone. (Mean ± SD; representative of n = 2 is shown). Data were analyzed by unpaired two-sided Student’s t-test. The asterisks (*) indicate statistical differences compared to the RTX control group: *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001; ns, not significant