Analysis Of The Expression Of BTLA And Its Ligand HVEM On T Cells From Peripheral Blood Of Patients With Chronic Hepatitis Virus B Infection And Its Relation To Clinic Baseline

Hepatitis B virus is a kind of addicted to sex liver virus DNA which do not directlycause cellular damage. It is one of the most important reason lead to chronic hepatitisB(CHB), liver cirrhosis and liver cancer.Chronic hepatitis B infected by Hepatitis Bvirus (HBV) is a worldwide disease and serious threat to human health. HBV specific Tcells in the immune system can recognize and kill the infected liver cells by combiningwith HBV antigen peptide. This is thought to be the mechanism which cause of livercell injury and virus remove. Some high quality of HBV specific CD4+T and CD8+T areclosely related to HBV virus remove. Some study found T cell depletion in patients withchronic HBV infection and the number and quality of HBV specific CD4+T and CD8+Tcells becameabnormal. For this reason the HBV virus can not be removed, it is the mainreason lead to virus persistent infection and inflammation of the liver.T cell activation and function perfectly normal play need double signal commonstimulation, these include TCR-Ag signals which provide the first signals, and alsosome co-stimulatory molecules provide the second signals. In recent years, some studyhad found that these co-stimulatory moleculesnot only includepositive stimulusmolecule which conductpositive signals but also include some negative stimulusmolecule play a role for immune cells appropriate activation and proliferation.Someresearch found that negative stimulus moleculeabnormal high express on the surface ofdepletion of T cells, such as: PD-1, CTLA-4, Tim-3and so on. B and T lymphocyteattenuator is the new found negative stimulus molecule in2003. Interestingly, as amember of CD28superfamily, BTLA interacts with the unique ligand herpesvirus entrymediator (HVEM), a member of TNF superfamily. When BTLA interacts with HVEM,the cytoplasm area three tyrosine residues of BTLA can be phosphorylated, then ITIMrecruiting tyrosine phosphatase SHP-1and SHP-2and further mediated inhibit T cell activation and proliferation of negative signals.Some studies have preliminary revealedthat BTLA/HVEM signaling pathways in T cell depletion may play an important role.In summary, our study report the BTLA/HVEM expression pattern on CD4+andCD8+T cells and its association with clinic baseline characteristics in peripheral bloodof patients with chronic hepatitis virus B infection. The exposure of dynamic change ofBTLA/HVEM expression and the correlations with clinic baseline characteristics notonly make BTLA/HVEM itself another valuable clinic indicator, but also provide animportant theoretic base for BTLA/HVEM blockade.Part I: Detect and analysis the expression of BTLA and its ligandHVEM on T cells from peripheral blood of patients with chronichepatitis virus B infectionObjective: The BTLA and HVEM molecular expression level on the surface ofCHB patient peripheral blood CD4+T and CD8+T cells were detected by Flow cytometry.Explore the BTLA/HVEM possible role in the pathogenesis of CHB and providefurthertheoretical basis for effective treatment of CHB.Methods: Peripheral blood samples were collected from44CHB patients and40healthy subjects (HC). Then detect the BTLA/HVEM expression on the CD4+T andCD8+T by flow cytometry. Compare the different expression of BTLA/HVEM onCD4+T and CD8+T cells between CHB and HC groups and analyze its significance byGraphPad Prism5.0.Results: The results illustrated that compared with HC, the percentage ofcirculating CD4+BTLA+and CD4+HVEM+T cells was significantly increased in CHB.Also the percentage of circulating CD8+BTLA+and CD8+HVEM+T cells weremoresignificantly increased in CHB compared with HC. In the study, we also find that theexpression of BTLA on CD4+and CD8+T cells was positively correlated with theexpression of HVEMConclusion: When compared with HC, the expression of BTLA/HVEM on theCD4+T and CD8+T cells all high in CHB group, the expression of BTLAwas positivelycorrelated with the expression of HVEM, and this may be one factor that participate thedepletion of T cells. Part II: Analysis of correlations between BTLA/HVEM expression onT cells from HBV-infected patients and clinic indicatorsObjective: Analyze the expression of BTLA and HVEM on CD4+T and CD8+Tcells from CHB patients and its correlations with clinical indicators. Investigate theregulatory effect of BTLA/HVEM inhibitory signals on T cells and the influence onCHB, and lay theoretical foundation to clinical diagnoses and intervenes.Methods: Determine serum markers of HBsAg, HBsAb, HBeAg, HBeAb andHBcAb all via ELISA. Check HBV DNA by Realtime PCR and the positiveconsequences should more than5×102copies/ml. Check liver function indicator usingRoche automatic biochemistry analysis meter.Results: The results showed that the expression of BTLA and HVEM on CD4+andCD8+T cells of CHB patients were all have no positively correlated with HBV viralload. However, the expression of these two molecule on CD4+and CD8+T cells of CHBpatients were all positively correlated with ALTand AST levels.Date statistics andcorrelation analysis by GraphPad Prism5.0software.Conclusion: In our study, we find that the expression of BTLA/HVEM had nopositively correlated with HBV DNA load. The result showed that expression ofBTLA/HVEM on CD4+and CD8+T cells of CHB patients were all positively correlatedwith ALT and AST. The level of ALT and AST could reflect Liver tissue damage degree,when Liver tissue damage is serious the level of ALT and AST become high. T cellcracking HBV infection of the liver cell is the main reason cause of liver damage, thehigh expression of BTLA/HVEM could lead T cell exhaustion. Thereby, it can protectliver tissue from excessive damage and also lead to HBV Long-term presence in thebody to form a chronic HBV infection.In summary, our study report the BTLA and HVEM molecular expression level onthe surface of CHB patient peripheral blood CD4+T and CD8+T cells were allsignificant high than HC group. Also the expression of BTLA/HVEM on CD4+andCD8+T cells of CHB patients were all positively correlated with ALT and AST whichcould reflect Liver tissue damage degree. Thereby indicate that BTLA/HVEM can be a new clinical immune index, it will be very helpful for the diagnosis of the disease andprognosis judgement.BTLA/HVEM signaling pathway may be involved in the immunepathological process of CHB, its specific mechanism remains to be further research.