In vivo targeting of CCR1 in a syngeneic lymphoma mouse model. (A) Typical photos of syngeneic mouse tumors bearing murine MCL cell line FC-muMCL1 on day 21 from untreated and BX-471 (50 mg/kg) treated early (day 1) and late (day 7) groups. (B) Tumor weight was assessed among the indicated groups. Treatment with BX-471 decreased tumor weight when measured at day 21 (n = 6 mice) (∗P < .05; ∗∗∗P < .001) (C). Tumor volume was assessed among the indicated groups. BX-471 treatment decreased tumor volume when measured at day 21 (n = 6 mice) (∗P < .05; ∗∗∗P < .001). (D) IF was performed on the syngeneic mouse tumors using Gr-1 (green) and CD11b (red) antibodies. The experiment was repeated on 3 mouse tumors. (E) Immunofluorescent staining was performed on the syngeneic mouse tumors using F4/80 (red) and CD206 (green) antibodies. Nuclei were stained with DAPI (blue). (F) Immunofluorescent staining was performed on the syngeneic mouse tumor using a CD8 antibody (red). (G-H) Bar diagram of the relative percentage of CD206⁺ to F4/80⁺ cells in control and CCR1 inhibitor–treated groups (G); Bar diagram representing the percentage of CD8⁺ T cell infiltration (H). Data represent the mean of the 5 to 10 microscopic fields. All staining was performed on at least 3 mouse tumors and a representative image is shown.