Figure 3. Initiation of the pre-metastatic niche is not impaired in Ccr2^ecKO mice.

A) Flow cytometry analysis of inflammatory monocytes (CD45⁺CD11b⁺Ly6G^-Ly6C^hi) recruited to the lungs at 12 and 24 h after i.v. MC-38GFP injection of Ccr2^fl/fl and Ccr2^ecKO mice. Untreated naïve mice (n) were used as controls. B) Endothelial cells (CD45^-CD11b^-CD31⁺) sorted from lungs of Ccr2^fl/fl and Ccr2^ecKO mice 12 h after i.v. MC-38GFP injection or untreated (naive) mice were analyzed for the expression levels of E-selectin, VCAM-1, SAA1+2 and SAA3 (n = 3-6) C) Amounts of cytokines in perfused lung homogenates of Ccr2^fl/fl and Ccr2^ecKO mice at 12 and 24 h after i.v. MC-38GFP injection. Untreated mice (control) were used as controls. D) Flow cytometry analysis of myeloid cells (CD45⁺CD11b⁺), granulocytes (CD45⁺CD11b⁺Ly6G⁺), Ly6C^int monocytes (CD45⁺CD11b⁺LyG^-Ly6C^int), and inflammatory monocytes (CD45⁺CD11b⁺Ly6G^-Ly6C^hi) recruited to lungs of mice s.c.-injected with LLC1.1 cells after 7 and 14 days. E) Amounts of cytokines detected in lung homogenates of mice s.c.-injected with LLC1.1 cells after 7 and 14 days. F) Lung vascular permeability assay of Ccr2^fl/fl and Ccr2^ecKO mice 14 days after s.c. injection of LLC cells, including representative macroscopic images. Statistical significance in panels B, D, E and F was assessed using unpaired t-test; *; p<0.05; **; p<0.01; ***; p<0.001.