Immune Function And Expression Of G-MDSCs In Gastric Adenocarcinoma

Background MDSCs is a group of heterogeneous cell populations of immunosuppressive effect,on the basis of the expression of CD14 or not,divided into CD33+CD11b+(M-MDSCs)HLA-DR-/low CD14+MDSCs and CD33+CD11b+HLA-DR-/low CD14-MDSCs(G-MDSCs)two major subsets.Recent studies have found that the occurrence of tumor is related to MDSCs,and the function of this group of cells in gastric cancer needs further study.Objective To investigate the expression of CD33+CD11b+HLA-DR-/low CD14-in MDSCs and its immune function in patients with adenocarcinoma of stomach.Methods: First part: According to the standard,patients and healthy controls were randomly enrolled in the study series,then establish a statistical table data,general data collected from patients and healthy people;The levels of G-MDSCs and M-MDSCs in peripheral blood of patients with gastric cancer were detected by flow cytometry,and the expression levels of G-MDSCs and M-MDSCs in tissues of patients with gastric cancer were compared.The difference of expression frequencies in peripheral blood and tissues was analyzed.Second part: the influence MDSCs on the proliferation of CD4+T cells and CD8+T cells were detected by CSFE;effect on apoptosis of CD4+T cells and CD8+T cells were detected by A5 and 7AAD;effects of MDSCs on Secreting IFN-γ of CD8+T cells and CD4+T cell function were detected by ELISA.The third part: the expression of serum Arg-1,i NOS-2,TGF-beta and IL-10 in patients with gastric cancer The expression of STAT3 on the surface of GMDSCs were detected.Results: The expression of G-MDSCs in peripheral blood,peripheral blood and tumor tissues of gastric cancer patients was increased,and the expression in tumor tissues was higher than that in tumor adjacent tissues.G-MDSCs can inhibit the proliferation of CD4+T cells and CD8+T cells.They can promote the apoptosis of CD4+T cells and CD8+T cells.G-MDSCs inhibited the secretion of IFN-γ by CD4+T cells and CD8+T cells.Functional experiments showed that G-MDSCs might play an immunosuppressive role through cytokines such as Arg-1,i NOS,TGF-β,IL-10 and STAT3 pathway.Conclusion: G-MDSCs can promote the immune escape of gastric cancer cells by inhibiting the killing effect of CD4+T cells and CD8+T cells on gastric cancer cells.