Controversial issues regarding the roles of IL-10 and IFN-γ in active/inactive chronic hepatitis B

According to the important roles played by cytokines in induction of appropriate immune responses against hepatitis B virus(HBV),Dimitropoulou et al have examined the important cytokines in their patients.They showed that the serum levels of interleukin 10(IL-10)and interferon-γ(IFN-γ)were decreased in patients with HBeAg-negative chronic active hepatitis B compared with the inactive hepatitis B virus carriers(Dimitropoulou et al 2013).The controversy can be considered regarding the decreased serum levels of IFN-γin the HBeAg-negative chronic active hepatitis B patients.They concluded that subsequent to decreased expression of IFN-γ,the process of HBV proliferation led to liver diseases.Previous studies stated that HBV is not directly cytopathic for the infected hepatocytes and immune responses are the main reason for destruction of hepatocytes(Chisari et al,2010).Scientists believe that immune responses against HBV are stronger in active forms of chronic HBV infected patients than inactive forms(Zhang et al,2012).Therefore,the findings from Dimitropoulou et al may deserve further attention and discussion.Additionally,downregulation of IL-10 inchronically active hepatitis B infected patients has also confirmed our claim.IL-10 is an anti-inflammatory cytokine and its expression is increased in inactive forms in order to downregulate immune responses(Arababadi et al,2012).Thus,based on the results from Dimitropoulou et al,it can be concluded that increased immune responses in chronically active hepatitis B infected patients are related to declined expression of IL-10 and interestingly IFN-γis not involved in induction of immune responses in these patients.

Dysfunction of peripheral blood dendritic cells from patients with chronic hepatitis B virus infection

AIM: To identify the property of dendritic cells (DCs) of peripheral blood monocytes (PBMC) in patients with chronic HBV infection. METHODS: Twenty patients with persistent HBV infection were included in this study, 10 healthy subjects being used as a control group. The peripheral blood mononuclear cells (PBMC) of T cell-depleted populations were incubated and induced into mature dendritic cells in the RPMI-1640 medium in the presence of cytokines GM-CSF, IL-4, FLt-3,TNF-alpha and 100mL.L(-1 )of fetal calf serum for a total of 10-12 days. The expressions of surface markers on DCs were evaluated using flow cytometric analysis. ELISA method was used to determine the cytokine levels of interleukin-12 (IL-12) and IL-10 in the supernatant produced by DCs. For detection of the stimulatory capacity of DCs to T cell proliferation, mytomycin C-treated DC were incubated with allogenic T cells. RESULTS: A typical morphology of mature DCs from healthy subjects and HBV-infected patients was induced in in vitro incubation, but the proliferation ability and cellular number of DCs from HBV-infected patients significantly decreased compared with healthy individuals. In particular, the expression levels of HLA-DR, CD80 (B7-1) and CD86 (B7-2) on DC surface from patients were also lower than that from healthy individuals (0.46 vs 0.92 for HLA-DR, 0.44 vs 0.88 for CD80 and 0.44 vs 0.84 for CD86,P【0.05). The stimulatory capacity and production of IL-12 of DCs from patients in allogenic mixed lymphocyte reaction (AMLR) significantly decreased, but the production level of nitric oxide (NO) by DCs simultaneously increased compared with healthy subjects (86 +/- 15 vs 170 +/- 22 micromol.L(-1), P 【0.05). CONCLUSION: The patients with chronic HBV infection have the defective function and immature phenotype of dendritic cells, which may be associated with the inability of efficient presentation of HBV antigens to host immune system for the clearance of HBV.

HCV-specific cytokine induction in monocytes of patients with different outcomes of hepatitis C

AIM:Cytokine release by macrophages critically determines the type of immune response to an antigen.Therefore,we studied hepatitis C virus(HCV)-specific induction of interleukins-1β,-10,-12(IL-1β,IL-10,IL-12),and tumor necrosis factor-α(TNF-α)in monocytes. METHODS:Intracallular cytokine expression was studied by flow cytometry in 23 patients with chronic hepatitis C,14 anti-HCV seropositives without viremia and 11 controls after stimulation of peripheral blood mononuclear calls with recombinant core,NS3,NS4,NSSa and NSSb proteins. RESULTS:Patients with HCV viremia revealed greater spontaneous expression of IL-1β,TNF-α,and IL-10. Furthermore,greater than twofold higher IL-10 expression was induced by the HCV antigens in chronic hepatitis C than in the other two groups(P<0.05).In contrast,neither IL- 12 nor TNF-α was induced preferentially. CONCLUSION:In chronic hepatitis C antigen-specific cytokine induction in monocytes is apparently shifted towards predominant IL-10 induction-not counterbalanced by antiviral type 1 cytokines.This may contribute to persistent viral replication.

Plasmacytoid Dendritic Cell Function and Cytokine Network Profiles in Patients with Acute or Chronic Hepatitis B Virus Infection

Background： Plasmacytoid dendritic cells （pDCs） and cytokines play an important role in occurrence and recovery of hepatitis B virus （HBV） infection. The aim of this study was to explore the frequency and function ofpDC and serum cytokine network profiles in patients with acute or chronic HBV infection. Methods： The healthy individuals （HI group）, hepatitis B envelope antigen （HBeAg）-positive chronic HBV patients in immune tolerance （IT） phase （IT group）, HBeAg-positive chronic HBV patients （CHB group）, and acute HBV patients （AHB group） were enrolled in this study. The frequency of cluster of differentiation antigen 86 （CD86） ＋ pDC and the counts of CD86 molecular expressed on surface ofpDC were tested by flow cytometer. The quantitative determinations ofcytokines, including Fins-like tyrosine kinase 3 ligand （FIt-3L）, interferon （1FN）-α2, IFN-γ, interleukin （IL）-17A, IL-6, IL-10, transforming growth factor （TGF）-β1 and TGF-β2, were performed using Luminex multiplex technology. Results： In this study, there were 13 patients in HI group, 30 in IT group, 50 in CHB group, and 32 in AHB group. Compared with HI group, HBV infected group （including all patients in IT, CHB and AHB groups） had significantly higher counts of CD86 molecular expressed on the surface ofpDC （4596.5 ± 896.5 vs. 7097.7 ± 3124.6; P 〈 0.001）. The counts of CD86 molecular expressed on the surface of pDC in CriB group （7739.2 ±4125.4） was significantly higher than that of IT group （6393.4 ± 1653.6, P=0.043）. Compared with IT group, the profile of cytokines of FIt-3L, IFN-γ, and IL-17A was decreased, IFN-α2 was significantly increased （P =0.012） in CH B group. The contents of IL-10, TGF-{31, and TGF-132 in AHB group were significantly increased compared with IT and CHB groups （all P 〈 0.05）. Conclusions： This study demonstrated that the function of pDC was unaffected in HBV infection. The enhanced function of pDC and IFN-α2 might involve triggering the immune response from IT to hepatitis active phase in H BV infection. Acute patients mainly presented as down-regulation of the immune response by enhanced IL-10 and TGF-β.

A New Vaccine Strategy of Dendritic Cell Presented Kinetoplastid Membrane(KMP-11)as Immunogen for Control against Experimental Visceral Leishmaniasis

Available reports suggest that, Leishmania donovani antigen KMP-11 may be significant in the modulation of immune responses in visceral leishmaniasis (VL). This study evaluated vaccine prospect of presentation of KMP-11 antigen through murine dendritic cells against VL in infected BALB/c mice. We report here that immunization with KMP-11 delivered through bone marrow derived dendritic cells can lead to killing of L. donovani in infected BALB/c mice. Furthermore, the strategy to use KMP-11 as vaccine delivered through DCs can stimulate the production of IFN-g, IL-12, IL-2R and TNF-α with concomitant down-regulation of IL-10 and IL-4. Furthermore, anti-leishmanial defence function (ROS) of splenocytes was observed increased in the presence of DC-delivered KMP-11 vaccination accompanied with an increased p38-MAPK signalling in vaccinated splenocytes. We summarized from our data that KMP-11 delivered through DCs has potential for eliciting protective immunity through pro-inflammatory cytokines (IFN-γ, IL-12, IL-2, TNF-α) following an up-regulation in signalling event of p38-MAPK. Therefore the study suggests a new control strategy against VL in future.