Fig. 2

mTAMs facilitates metastatic colonization. a Schema of 4T1-BALB/c orthotopic syngeneic model in mice receiving depletion of pulmonary macrophages through intratracheal injection of liposomal clodronate. b Representative result for confirming the effect of macrophages depletion. IHC for staining F4/80 was performed in lungs of mice receiving intratracheal liposomal clodronate or vehicle control (PBS). LPF low power field; Scale bar, 100 μm. HPF high power field; Scale bar, 50 μm. c Quantification of F4/80⁺ macrophages in lungs of mice receiving intratracheal liposomal clodronate or vehicle control (PBS). The result is present as the fold change of the percentage of F4/80⁺ macrophages in six representative fields. n = 5 for each group. d, e Photos (d) and quantification (e) of primary tumors. n.s. non-significance. f, g Photos (f) and quantification (g) of lung nodules of mice receiving intratracheal liposomal clodronate or control PBS. Red arrows indicate the metastatic tumors in lung. Scale bar, 1 cm. n = 5 for each group. h Schema of metastatic colonization experiments. 4T1 cells co-injected with CD11b⁺F4/80⁺Ly6C⁻ pTAMs or mTAMs through tail vein of BALB/C mice. i IVIS for visualizing tumor dissemination 11 days after tumor cells injection. n = 7 for each group. j Quantification of bioluminescent imaging of i experiment 2 weeks after tumor cells injection. k Quantification of metastatic lung nodules of i experiment 2 weeks after tumor cells injection. n = 6 for each group. l Representative photos of lungs of mice 2 weeks after injection of the 4T1 cells with/without Mrc1⁺ TAMs or F4/80⁻ myeloid cell from metastatic tumors. m Quantification of metastatic lung nodules. n = 6 for each group. Data represent mean ± S.E.M. *p < 0.05, **p < 0.01, ***p < 0.001. Statistical analysis: Student’s t-test (c, e, g, j, k, m). See also Supplementary Figure 2