The Expression Of Negative Costimulatory MoleculePD-1/PD-L1in The Peripheral Blood Of SLE Patientsand Its Clinical Significance

Part The expression and clinical signficance of PD-1/PD-L1molecular on thePBMC of SLE patientsObjective: To investigate the level of lymphocyte subsets in the peripheral bloodof systemic lupus erythematosus (SLE) patients in different active stages,and theexpression of PD-1/PD-L1on peripheral T lymphocyte,monocyte and B lymphocyte.Methods: Immunofluorescence staining and flow cytometry method were used todetect the level of CD4+T lymphocyte,CD8+T lymphocyte,CD19+B lymphocyte subsetsand the expression of PD-1/PD-L1on peripheral T lymphocyte,monocyte and Blymphocyte in periphera1blood which from50active SLE patients,69inavtive SLEpatients and40health controls. Data were dealt with statistics analysis, quantitative datawere expressed in (x±s) processed with statistical software SPSS13.0,chart and graphwere drawn with GraphPad Prism5.0.Results:(1) The percentage of CD4+T lymphocytes and the ratio of CD4+/CD8+was downregulated with the severity of SLE; The percentage of CD8+T lymphocyteswas upregulated with the severity of SLE; The percentage of CD19+B lymphocytes washigher than that in control group and inactive group.(2) The expression of PD-1wasupregulated on the membrane of T lymphocytes and B lymphocytes respectively in theperipheral blood of SLE patients with the severity of the disease.(3) The expression ofPD-L1was upregulated on the membrane of CD19+B lymphocytes with the severity ofSLE.(4) The expression of PD-L1was upregulated on the membrane of CD14+monocytes,but the expression in active group was lower than that in inactive group.Conclusion: The level of lymphocyte subsets was changed in peripheral blood ofSLE, The expression of PD-1and PD-L1was abnormally increased on the membrane ofPBMC,that may involve in PD-1/PD-L1inhibitory pathway and participate inautoimmune response and immunological pathogenesis.It will have potential value in clinical medicine.Part П The expression of soluble PD-L1in peripheral serum of SLE patientsObjective: To investigate the expression level of sPD-L1in serum of SLE patientsin different active stages,and analysis the change of the expression after treatment.Method: Mouse anti-human PD-L1mAb (2H11) used as coating antibody, wasprecoated in the ELISA plate with the CBS.Another biotin-anti-PD-L1mAb (10D7)was used as detecting antibody to recognize the sPD-L1protein in serum of88activeSLE patients,73inavtive SLE patients and75health controls. Then theStreptavidin-HRP was added to the reaction system. Finally, TMB substrate was addedfor colorable reaction. The absorbance was measured by the microplate reader. Datawere dealt with GraphPad Prism5.0.Results:(1) The results of ELISA for detecting sPD-L1was that the expression ofsPD-L1was upregulated with the severity of SLE.(2) There was an uptrend of the levelof sPD-L1with deterioration,and a downtrend in a improved condition.Conclusion: The expression of sPD-L1in serum of SLE patients wasincreased,and was correlated with SLEDAI and efficacy, sPD-L1might play aimportant role in the progression of SLE.The level of sPD-L1maybe provide a basis fordisease process and treatment evaluation.In summary,this paper has successfully accomplished the investigation as follows:(1) Lymphocyte subsets was changed in peripheral blood of SLE. The expression ofPD-1and PD-L1was abnormally increased with the severity of SLE.(2) The level ofsPD-L1in serum of SLE patients was increased,and was correlated with SLEDAI andefficacy. sPD-L1might play a much broader role in blocking the interaction ofPD-1/PD-L1. Because of the lack of negative control signal, T cells and B cells wouldbe excessive activation in autoimmune response. Dynamic analysis of the expression ofPD-1/PD-L1on the surface of peripheral blood cells, as well as the level of sPD-L1inserum of SLE patients had potential clinical value. The mechanism of PD-1/PD-L1pathway in the immunological pathogenesis of SLE was worthy of further study.