Fig. 5: B-BMSCs induce the expansion of PMN-MDSCs in the bone marrow.

LLCs and BMSCs were subcutaneously injected in C57BL/6 mice. a The ratio of Gr-1⁺/CD11b⁺ cells in the bone marrow of tumour-bearing mice measured by flow cytometry. b The ratio of CD11b⁺Ly6G⁺in the bone marrow of tumour-bearing mice measured by flow cytometry. Column bar chart was presented to show the ratio of CD11b⁺Ly6G⁺in the bone marrow. c The ratio of CD11b⁺Ly6G⁺ cells in the bone marrow measured by flow cytometry. Tumour-free mice were given intracavitary injections of BMSCs. d Bone marrow Ly6G⁺granulocytic cells inhibited CD4⁺ and CD8⁺ T-cell proliferation in vitro. Ly6G⁺ MDSC subpopulations were isolated by magnetic activated cell sorting. T cells were isolated from bone marrow by magnetic activated cell sorting from tumour-free mice. Ly6G⁺ MDSCs were co-culture with T cells isolated from bone marrow in different ratio. After were stimulated by anti-CD3⁺ antibody and anti-CD28⁺ antibody, cells were subjected to flow cytometry to measure the ratio of CD4⁺ and CD8⁺ T cells. e CD4⁺ and CD8⁺ T cells in bone marrow were measured by flow cytometry. Bone marrow from mice with co-injection of LLC cells and BMSCs and LLC cells alone were collected. Column bar chart was presented to show the ratio of CD8⁺ T cells in the bone marrow. Data were presented as the mean ± SD and analyzed with Student’s t-test. *p < 0.05; **p < 0.01; ***p < 0.001.