Study Of PD-1 In Peripheral Blood Lymphocytes Of T Cell Non-Hodgkin's Lymphoma

BackgroundT cell non-Hodgkin lymphoma(T-NHL)is a heterogeneous disease of high malignancy and poor prognosis,and the 5-year overall survival rate is only 20-40%.At present the patients receiving conventional therapy is easy to get relapsed,and once relapsed,the choice of effective salvage therapy was very limited.Therefore,promoting the development of T-NHL clinical research and exploring the research on pathogenesis and drug targets,should be the key program.Recently,tumor microenvironment and tumor-related immunity are hotspots of lymphoma research,and peripheral blood circulation lymphocytes are an important part of the immune system in patients with tumor.It has been confirmed that costimulatory molecules on peripheral blood T cells are abnormally expressed in lymphoma patients,which is related to the immune escape of tumor.And the programmed death-1(PD-1)is most closely related to tumor immunity.However,in T-NHL the study of PD-1 on circulating lymphocytes is relatively few.So our research are preliminarily figure out the influence of PD-1 on the immune function of T-NHL patients.Objectives1.To identify the PD-1 and related costimulatory molecules’ expression on peripheral blood Treg cell of newly diagnosed T-NHL patients and track their changes aftertreatment.2.To investigate the functional difference of peripheral blood PD-1(+)lymphocytes between newly diagnosed T-NHL patients and healthy subjects.3.To initially reveal the molecular mechanism on the functional difference of peripheral blood PD-1(+)lymphocytes between T-NHL patients and healthy subjects.MethodsIn this study,60 patients with T-NHL were enrolled in the Peking Union Medical College Hospital from September 2015 to April 2017,and 65 healthy volunteers were enrolled from the Health Examination Center.The expression of PD-1 and related costimulatory molecules on peripheral blood Treg cells were detected by flow cytometry,and the relationship between the expression of PD-1 and the prognosis was analyzed.The expression of PD-1 and related costimulatory molecules on the peripheral blood T lymphocytes were measured again after receiving 2-6 cycles of chemotherapy.The relationship between the expression level and therapeutic efficacy was investigated.The peripheral blood PD-1(+)lymphocytes were collected using magnetic cell sorting system from 10 patients newly diagnosed of T-NHL and 10 healthy subjects.The MTT test was used to compare the function of peripheral blood PD-1(+)lymphocyte.And the gene expression profiles of peripheral blood PD-1(+)lymphocyte in patients and healthy subjects were analyzed by digital gene expression profiling technique,in order to explore the molecular basis of functional differences.Results1.1)The mean fluorescence intensities of CD279 and CD 152 on peripheral blood Treg cells in patients with T-NHL were significantly higher than that in healthy controls(P<0.001).The expression ratios of CD 152 and CD28 on peripheral blood Treg cells in T-NHL patients were significantly lower than that in healthy controls(P<0.001).2)The mean fluorescence intensities of CD279 and CD 152 on peripheral blood Treg cells in patients with intermediate/high risk were significantly higher than that in patients with low risk(P<0.05),expression ratios of CD28 were significantly lower in patients with low-risk(P<0.05).3)The mean fluorescence intensities of CD279 and CD28 on peripheral blood Treg cells in patients with vascular myocardium T lymphocytes were significantly lower than that in patients with extranodal NK/T cell lymphoma(P<0.05).4)The mean fluorescence intensities of CD279 and CD152 on peripheral blood Treg cells became significantly lower after treatment(P<0.05).The mean fluorescence intensities of CD28 became significantly higher after treatment(P<0.05).5)The expression of PD-1 and CD 152 on the peripheral blood Treg cells were correlated with the event-free survival time(P<0.05)in patients with T-NHL.2.The conversion rates of peripheral blood PD-1(+)lymphocytes in T-NHL patients were lower than that in healthy subjects(P<0.001).3.Compared with healthy controls,PD-1(+)lymphocytes in peripheral blood of T-NHL patients had distinct gene expression profiles.The biological processes associated with differential expression genes included cell proliferation/apoptosis,immune response,signal transduction,metabolism and cell adhesion,mainly related to IFN,MYD88 and Toll-like receptor-related pathways.Conclusions1.The expression of PD-1 and related costimulatory molecules on the peripheral blood in T-NHL patients were significantly different from that in healthy subjects.After treatment,the expression of PD-1 and related costimulatory molecules on peripheral blood Treg cells in T-NHL patients were closed to the expression level in healthy people.2.The function of peripheral blood PD-1(+)lymphocyte in T-NHL patients was significantly lower than that in healthy people.3.The gene expression profiles of peripheral blood PD-1(+)lymphocytes in T-NHL patients were significantly different from that in healthy human.The differentially expressed genes could be related to the occurrence of T-NHL and tumor immunity.