Study On Expression Characteristics Of T Lymphocyte Surface Factors PD1 And PDL1 In Peripheral Blood Of Patients With Non-small Cell Lung Cancer

BackgroundAt present,among all malignant tumors,lung cancer-related deaths were high,which were the first and second causes of cancer-related deaths in men and women respectively.With the development of cell biology and gene detection technology,there were more and more methods for the diagnosis and treatment of lung cancer,including surgery,radiotherapy and chemotherapy,and targeted drug therapy.At present,immunotherapy had become an important part of integrated therapy for lung cancer.More and more studies showed that the monitoring function of immune system was closely related to the occurrence and development of lung cancer.Studies had confirmed that programmed death receptor-1(PD1)and its ligand PDLl(programmed death-ligand 1)could induce and maintain the immune tolerance of peripheral tissues under normal physiological conditions,and could down-regulate the secretion of immune stimulating cytokines of T cells in pathological conditions such as malignant tumors,and promote the increase of immunosuppressive cytokines,thus inhibiting the immune response of T cells.However,the expression of PD1 and PDL1 in peripheral blood T lymphocytes and their relationship with clinicopathological parameters and prognosis of lung cancer patients were still unclear.ObjectivesTo detect the distribution of PD1 and PDL1 in Treg CD25+,Th CD4+ and Ts CD28+lymphocytes in peripheral blood of patients with non-small cell lung cancer,observe the relationship between PD1 and PDL1 distribution and T lymphocyte types in peripheral blood,and analyze the relationship between PD1 and PDL1 distribution and clinicopathological parameters of patients with non-small cell lung cancer,and the influence of PD1 and PDL1 distribution on the survival of patients with non-small cell lung cancer.To find biomarkers that could predict the biological characteristics of lung cancer cells and the prognosis of patients with non-small cell lung cancer,understand the possible mechanism of immunosuppression in patients with non-small cell lung cancer,and provide basic theoretical basis for clinical immunotherapy,so as to improve the survival of patients with non-small cell lung cancer.MethodsThe fresh blood samples of 85 hospitalized patients with non-small cell lung cancer from January 2016 to December 2018 in Nanyang First People’s Hospital were collected,and the fresh blood samples of 25 healthy volunteers who took physical examination in the same period were collected.Flowcytometry,FCM)was used to detect the distribution of PD1 and PDL1 on the peripheral blood Treg CD25+,Th CD4+ and Ts CD28+ lymphocytes.T test,χ2test,pearson rank correlation test,Kaplan-Meier survival analysis and multivariate Cox regression model were used to analyze the expression of PD1 and PDL1 on the surface of various T lymphocytes in peripheral blood and their relationship with clinicopathological parameters and prognosis of lung cancer patients.Results1.The percentages of PD1 and PDL1 in Treg CD25+,Th CD4+,Ts CD28+ cell surface in peripheral blood of patients with non-small cell lung cancer were higher than those of healthy people,with significant difference(P<0.01).2.the percentages of PD1 and PDL1 in Treg CD25+,Th CD4+,Ts CD28+T cell surface in peripheral blood of patients with non-small cell lung cancer were related to lymph node metastasis,histological grade and clinical stage(P<0.05),but had no significant correlation with age,sex and tumor size(P>0.05).3.The overall survival rate of non-small cell lung cancer patients with high percentage of PD1 and PDL1 on T cell surface in peripheral blood was lower than that of patients with low expression rate of PD1 and PDL1(P<0.05).4.Cox univariate and multivariate analysis showed that PDL1 and PDL 1 were the prognostic factors of patients with non-small cell lung cancer.ConclusionsThe distribution of Treg CD25+,Th CD4+,Ts CD28+ cell surface PD1 and PDL1 in peripheral blood of patients with non-small cell lung cancer is significantly related to the degree of tumor differentiation,lymph node metastasis,distant metastasis and pathological stage.The higher the malignant degree of tumor,the higher the percentage of PD1 and PDL1,and the higher the expression with the progress of the disease,which is a risk factor for poor prognosis.