Analysis Of Th17 Cell,IL-21 And Other Cytokines In Peripheral Blood From The Different Clinical Types Of Patients Infected With Hepatitis B Virus

hChronic HBV infection remains a significant global health problem. So far, the detailed pathogenesis of persistent HBV infection hasn't been clarified, which is an impediment to effective treatment. HBV is believed indirectly damage the liver cells and the mechanism of liver injury is mainly mediated by the immune system and continue to rely on the virus replication. Recently, studies show that, T cell subsets mediated cellular immunity and the regulation of cytokines network play an important role in the immunopathogenesis damage of hepatitis B liver cells. Presently, CD4~+T cells can be divided into Th1, Th2, Treg, Th17, Tfh, Th9, Th22 and other cell subsets, which can produce IFN-γ, IL-2, TNF-α, IL-4, IL-10, IL-17, IL-21, IL-22 and many other important cytokines. IL-21, likely produced by CD4~+ T cells, directly influences the generation of polyfunctional CD8+ T cells. IL-21 maintains the CD8+ T cell effector activity required to control infection and thus provides a mechanism for CD4~+T cell help in response to chronic viral infection. This study has completed the following work: 1 The levels of IL-21 and Th17 cell of peripheral blood from the different types of patients infected with hepatitis B virus (HBV) and their relationship.In order to observe the expression of IL-21 , Th17 cell of peripheral blood from the different types of patients infected with hepatitis B virus and their relationship with clinical parameters,we used density gradient centrifugation to collect peripheral blood mononuclear cells (PBMC)of 76 cases of HBV infection in different clinical manifestations and 13 healthy controls. Flow cytometry was performed to assess CD3~+CD4~+IL-17A~+T cell subset(Th17 cell),CD3~+CD4~+IL-21~+T cell and CD3~+CD4~+IL-17A~+IL-21~+T cell.Results:1) Without PMA and ionomycin stimulated, few CD4~+ T cells can produce IL-21 (0.15%)and IL-17(0.08%); After stimulated with PMA and ionomycin , CD4~+T cell can produce IL-21 and II-17.2) IL-17A~+IL-21 +CD4~+ T cells were almost undetected.3) The frequencies of IL-21~+CD4~+T cells in acute hepatitis B(1.58±1.10%) and chronic asymptomatic HBV carriers(1.80±1.33%) were higher than healthy controls(0.82±0.70%) and chronic severe hepatitis B patients(0.76±0.52%), There were all significant differences, P<0.05; The frequencies in chronic hepatitis B(1.05±0.74%) and inactive chronic HBsAg carriers(1.13±0.65%) were also higher than healthy controls and chronic severe hepatitis B patients, but there wasn't a significant difference.4) The frequencies of Th17 cell subsets were no significant difference in all groups.5) Except acute hepatitis B patients (r = 0.178, P = 0.60), IL-21~+CD4~+T cell ratio and the proportion of Th17 cell subsets in the normal control (r = 0.787, P = 0.001), hepatitis B virus carrier (r=0.783,P=0.007),chronic hepatitis B(r=0.699,P=0.001),inactive HBsAg carrier(r=0.657,P=0.002),chronic severe hepatitis B(r=0.724,P=0.005), have good correlation. 6) There isn't correlation between experimental parameters and clinical parameters.2 Concentrations of IL-21,IL-2,IL-4,IL-6,IL-8(CXCL8),IL-10,IL-17,IFN-γ,TNF-αin plasma from different types of patients infected with hepatitis B virus.In order to observe concentrations of IL-21 in plasma and preliminary understanding the relationship of Th1, Th2, Treg, Tfh and other cell subsets with HBV infection between different clinical manifestations, we collected 122 patients with different HBV infections and 15 healthy controls of plasma. We used ELISA to detect IL-21 levels and multiple microsphere cytokine immunoassay to detect IL-2,IL-4,IL-6,IL-8(CXCL8),IL-10,IL-17,IFN-γ,TNF-αlevels.Results:1) IL-4,IL-6,IL-10,IL-17,IFN-γ,TNF-αin plasma were almost undetectable.2) The concentrations of IL-21 and IL-2 in plasma were no statistical difference in all groups.3) Chemokine IL-8(CXCL8) in chronic severe hepatitis B(60.01±88.10) compared with normal controls(l7.13±2.49) , acute hepatitis B(5.21±1.95), chronic asymptomatic HBV carriers(3.62±2.27),chronic hepatitis B(8.57±5.73), inactive HBsAg carriers (3.91±3.92) were significantly higher and the difference was statistically significant (P <0.01).Coclusions:IL-21 may be a factor in the control of HBV infection and may play a role with Th17 cell subsets through paracrine or through direct interactions between cells. IL-8(CXCL8)and other chemokines caused excessive hepatic inflammation may be critical for chronic severe hepatitis B patients and the specific mechanism needs further research.