Effects Of T Cell Subsets From PBMCs In Patients With Chronic HBV Infection At Different Clinical Stages

Background:Chronic HBV infection is a chronic disease that damages liver cells by inducing an immune response after being invaded by the hepatitis B virus(HBV).In recent years,immunotherapy methods have achieved remarkable therapeutic effects in the fields of anti-virus and anti-tumor.According to the clinical symptoms of patients with chronic HBV infection,they were divided into immune tolerant(IT)group,immune active(IA)group,immune control(IC)group and reactivation(RA)group.Patients with CHI in different clinical stages have different immune function states,leading to the diversification of diseases.T cell immune response plays an important role in the process of anti-HBV immune response,affecting the occurrence and development of the disease.Objective:To investigate the characteristics of T cell subpopulations,subsets and the expression of PD-1 on the surface of T cells in PBMCs from patients with chronic HBV infection at different clinical stages.Combined with the clinical laboratory data of the patient,a comprehensive analysis of the relationship between the peripheral blood T cell immune status and HBV DNA load of the patient was used to speculate the body’s T cell immune function.It provides scientific basis for staging diagnosis and predicting prognosis of clinical chronic HBV infection disease,it can also provides a new direction for the development of reasonable immunotherapy to interfere with the development of the disease at the same time.Methods:In the study,patients with chronic HBV infection were divided into IT group,IA group,IC group,RA group according to the clinical laboratory data of patients,and healthy volunteer(HD)was the control group.The patient’s venous blood was collected,and peripheral blood mononuclear cells(PBMCs)were isolated by density gradient centrifugation.Multicolor flow cytometry was used to detect the peripheral blood T cell subpopulations,CD4~+T and CD8~+T cell subsets.According to the expression of CD45RA and CCR7,the subsets of CD4~+T and CD8~+T cells are divided into:na?ve T cell(Tn),central memory T cell(Tcm),effect memory T cells(Effector memory T cell,Tem)and effector T cells(Effector T cell,Te).Tregs were labeled with CD4~+CD25~+CD127~-.The expression of PD-1 on the surface of CD4~+T and CD8~+T cells in patients’peripheral blood was detected at the same time,and comprehensively analyze the relationship between peripheral blood CD4~+T and CD8~+T cell subsets and HBV DNA load.Results:Compared with HD,there was no significant difference in T cell subpopulation in the CHI group.According to the clinical symptoms of patients,CHI patients were divided into IT,IA,IC,RA groups.The percentage of CD3~+T cell decreased significantly in RA group(P<0.05),and the percentage of CD3~+T cells in the IT,IA,and IC groups did not change significantly.For CD4~+T cell subsets,compared with HD,there was no significant difference in CD4~+Tn,CD4~+Tem,CD4~+Te between each group.The frequency of CD4~+Tcm increased in the IT and RA groups(P<0.05),and there was no significant difference in the CD4~+Tcm frequency between IA and IC groups.The frequency of Treg in each group showed an upward trend,and the frequency of Treg in the IA group increased significantly(P<0.05).The frequency of Treg is positively correlated with ALT.There was no significant difference in the CD4~+T cell subsets between each group.For CD8~+T cell subsets,compared with HD group,the frequency of CD8~+Tn in IC and RA group decreased(P<0.05),and no significant difference was found between IT and IA group.There was no significant difference in the frequency of CD8~+Tcm in each group.The frequency of CD8~+Tem in the IT group decreased(P<0.05),and no significant difference was found among the remaing three groups.The frequency of CD8~+Te in the IC group increased significantly(P<0.05),and no significant change among the other three groups.Compared with the high HBV DNA load group(IT),the frequency of CD8~+Tn decreased and the frequency of CD8~+Te increased in the low HBV DNA load group(IC)(P<0.05).The expression of PD-1 in CD4~+T cell was highest in IT group,followed by RA group(P<0.05).The expression of PD-1 in CD8~+T cell was highest in IA group,followed by IC group(P<0.05).Conclusions:There are significant differences in T cell subsets of peripheral blood from patients with CHI at different clinical stages.The frequency of CD8~+Te cells in IC group with low viral load is significantly increased,indicating a good prognosis of the disease.The expression of PD-1 on the surface of CD8~+T cells in CHI group increases,suggesting two different immune states of the body and predicting different immune outcomes of the disease.The frequency of Treg is positively correlated with the body’s ALT level,suggesting that it can be used to predict the severity of hepatitis disease.Clinical diagnostic indicators combined with the frequency of T cell subsets and immunosuppressive function detection in patients wih CHI might be considered in diagnosis of the clinical staging and the prediction of prognosis,and for treatment of chronic HBV infection.