Induction And Biological Significance Of PD-1/PD-L1 Signaling On Regulatory B Cells In Invasive Breast Cancer

Part ? Expression and biological significance of CD 19 and PD-1 molecules in invasive breast cancerObjective:To study the expression of CD19 and PD-1 in invasive breast cancer and its biological significance.Methods:Immunohistochemical staining was used to detect the expression of CD 19 and PD-1 in tumor tissues of patients with breast tumor.and analyze its relationship with clinical pathological parameters of invasive breast cancer and the co-expression between them.Results:(1)In invasive breast cancer tissues,the expression of CD 19 and PD-1 in tumor infiltrating lymphocytes was significantly higher than that in breast fibroadenomas,the difference was statistically significant(P=0.003;P<0.0001);(2)In invasive breast cancer tumor tissues,CD19 and PD-1 molecules were significantly co-expressed(P=0.011,Kappa=0.177).Conclusion:The expression of CD19 and PD-1 molecules in breast cancer tissues were significantly higher than that in breast fibroadenoma tissues,and they had significant co-expressionPart II Expression and biological significance of CD 19,PD-1,Bregs in peripheral blood and sPD-L1,IL-10 in serum of patients with breast tumorObjective:To study the percentage of CD 19+B cells,PD-1+B cells and Bregs in peripheral blood of patients with breast tumor and the level of sPD-L1 and IL-10 in serum.Methods:Flow cytometry was used to detect the difference of CD19+B,PD-1+B cells and Bregs in peripheral blood of healthy people and patients with breast tumor.The level of sPD-L1 and IL-10 in serum of patients with breast tumor was detected by enzyme-linked immunosorbent assay(ELISA).The correlation between the level of sPD-L1 and IL-10 in serum and the subsets of B cells in peripheral blood of invasive breast cancer were analyzed.Results:(1)The percentage of PD-1+B cells and Bregs in peripheral blood of invasive breast cancer were significantly higher than that of breast fibroadenomas(P<0.001;P<0.0001);(2)The level of sPD-L1 and IL-10 in serum of patients with invasive breast cancer were higher than that of breast fibroadenoma(P<0.05;P<0.0001);the level of both was positively correlated(r=0.267,P=0.005);(3)There was a positive correlation between Bregs in peripheral blood and sPD-L1 and IL-10 in serum of invasive breast cancer(r=0.205,P=0.041;r=0.206,P=0.037),while CD19+B,PD-1+B cells were negatively correlated with sPD-L1 and IL-10 in serum respectively(r=-0.295,P=0.002;r=-0.223,P=0.022).Conclusion:The expression of PD-1+ B cells,Bregs in peripheral blood and sPD-L1,IL-10 in serum of invasive breast cancer were high,and the sPD-L1 is closely related to the differentiation of Bregs in invasive breast cancer.Part ? Induction of PD-1/PD-L1 signaling on regulatory B cellsObjective:The effects of PD-1/PD-L1 signaling on the differentiation of Bregs and the effects on proliferation and apoptosis of breast cancer cell lines were further investigated.Methods:T cell,B cell were used to co-culture with breast cancer cell lines,then we studied the effects of PD-1/PD-L1 signaling on the differentiation of Bregs and the expression of IL-10 mRNA,and compared the effects of T and B cells on tumor cells proliferation and apoptosis under different co-culture conditions.Results:(1)Different concentrations of sPD-Ll protein could induce Bregs differentiation and IL-10 mRNA up-regulation in a dose-dependent manner(P<0.0001,P<0.0001);(2)T cell and B cell co-culture experiments showed that the proportion of Tregs and the expression of transcription factor Foxp3 in sPD-L1 pre-stimulation group were higher than other groups(P<0.05);(3)Co-culture experiments of T cells,B cells and tumor cell lines showed that the proliferation of tumor cells was significantly promoted by sPD-L1 pre-stimulation group(P<0.05);The apoptosis of tumor cells in sPD-L1 pre-stimulation group was significantly lower than that in other co-culture groups(P<0.05).Conclusion:PD-1/PD-L1 signal could induce the differentiation of Bregs and up-regulate the expression of IL-10 mRNA,and promote the proliferation and anti-apoptosis of tumor cells by increasing the expression of Tregs.