Fig. 3

Functional MDSCs persist in the lungs after primary tumor resection and are associated with increased tumor growth in the lungs. a G-CSF in the peripheral blood of mice with 4T1 tumors or mice with 4T1 tumors resected 2 weeks after implantation. b Number of CD11b⁺Gr1⁺ cells in the lungs of mice with 4T1 primary tumors or mice with 4T1 tumors resected 2 weeks after implantation. c Proportion of CD11b⁺Gr1⁺ recovered from the lungs of mice with 4T1 primary tumors or mice with 4T1 tumors resected 2 weeks after implantation. Data are mean ± SEM with 4–8 mice per time point in the excised group. For the “tumor excised data”, stars above the curve indicate comparison to the unresected 2-week data point; stars below the curve indicate comparison to naïve mice. d CD11b⁺Gr1⁺ cells isolated from the spleens or lungs of mice 2 or 10 days after 4T1 tumor excision retain immunosuppressive function. Data are normalized to the fraction of stimulated T cell proliferation in the absence of CD11b⁺Gr1⁺ cells (Ctrl) and are mean ± SEM of two independent experimental repeats. Significance compared to Ctrl or as indicated. e Experimental outline for (f); mouse tissues were harvested 8 days after iv injection of 4T1 tumor cells, 10 days after resection of 4T1 primary tumors, or 8 days after iv injection of 4T1 tumor cells into mice with 4T1 primary tumors resected. f Total number of 4T1 tumor cells in the lungs of mice from (e). Data are mean ± SEM from 6 to 8 mice per group