Fig. 6

Chronic psychological stress mobilizes spleen-derived MDSCs into the lung via CXCL1. A Gross representative images of the lung metastatic lesions after splenectomy in CUMS-treated breast cancer xenografts (n = 3). B The fluorescence intensity of lung metastases after splenectomy in CUMS-treated breast cancer xenografts (n = 6). C MDSCs population in the lung and peripheral blood for 2–4 weeks after splenectomy in CUMS-treated breast cancer xenografts. D Flow diagram for tracing the distribution of splenic-derived MDSCs and PMN formation in mice. E The distribution of mCherry-labeled MDSCs in the spleen and lung was represented by immunofluorescence (the scale bars indicate 10 μm). F Representative immunofluorescence images for PMN formation in the lungs of mice injected with exogenous MDSCs via spleen (CK19 labeled cancer cells, Gr-1 and CD11b labeled MDSCs, the scale bars indicate 10 μm). Data are represented as Mean ± SD. For statistical analysis, unpaired t-tests were applied. ^*P < 0.05, ^#P < 0.01