Fig. 6: The synergetic tumor inhibition is enhanced by RT with dual antibody blockage of CD47 and HER2.

Tumor volumes (a), tumor weights at end of experiments (b), and representative images (c) were measured with mouse syngeneic breast tumors generated with radioresistant 4T1/C2 cells and treated with intratumoral injection of PBS, IgG, Herceptin (5 mg/kg), anti-CD47 antibody (5 mg/kg), or a combination both antibodies every other day starting at day 10 with radiation delivered locally to tumors of all groups with 5 Gy at days 10 and 11 (n = 6, mean ± SEM, ns not significant, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001). d Above, HE staining of 4T1/C2 tumors treated with radiation combined with indicated antibodies. Bottom, representative IHC images of CD11b⁺ macrophages in tumors; scale bar = 100 µm. e Representative images of infiltrated macrophage and macrophage-mediated phagocytosis in the syngeneic mouse orthotopic BC models repeated as in a with GFP-labeled 4T1 tumors detected with indicated antibodies; green, tumor cells; red, infiltrated macrophages; blue, cell nucleus stained with DAPI; yellow (indicated with arrows), macrophage-mediated phagocytosis with tumor cells. f Quantitation of relative richness of infiltrated CD11b⁺ macrophages. g Quantitation of macrophages-mediated phagocytosis with tumor cells counted in multiple areas in the high-power fields marked with yellow arrows (Image Pro Plus 6.0; b, c, *P < 0.05, ****P < 0.0001; ns not significant).