Ze-Qi-Tang Formula Induces Granulocytic Myeloid-Derived Suppressor Cell Apoptosis via STAT3/S100A9/Bcl-2/Caspase-3 Signaling to Prolong the Survival of Mice with Orthotopic Lung Cancer

Figure 4

ZQT attenuated the immunosuppressive effect of MDSCs on T cells in the tumor microenvironment. (a, b) CD3⁺ T cells isolated from the tumor tissue of tumor-bearing C57BL/6 mice treated with normal saline or ZQT were cocultured with LLC cells for 4 h before incubating with CD3, CD8, and CD107α antibodies. Events shown were finally gated on CD3 and CD8. (c) ELISA analysis for the expression of IFN-γ in cells from the tumor tissue. (d, e) RT-qPCR quantitative analysis of Granzyme B, Perforin 1, Arg-1, iNOS, and S100A9 gene expression. (f) ROS assay for ROS production in tumor tissue from ZQT-treated mice or normal saline-treated mice. (g, h) T-lymphocyte in the spleen of wild-type C57BL/6 mice and MDSCs in tumor tissue of tumor-bearing mice treated with normal saline or ZQT were isolated using the MojoSort Mouse Isolation Kit. T-lymphocyte proliferation assay was used to show dose-dependent suppression of T cell proliferation by MDSCs isolated from tumor tissue of tumor-bearing mice treated with normal saline or with ZQT. CD3⁺ T cells isolated from tumor tissue stained with 5 μM CFSE were incubated with MDSCs for 72 h. Meanwhile, CD3 and CD28 antibodies were added for CD3⁺ T cell stimulation. Flow cytometry analysis was performed to quantify 72 h CFSE dilution. . Data are expressed as the . n/s: nonstatistical significance. ; ; .

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