Cellular immune response in patients with chronic hepatitis B virus infection

CD32 Expression by CD4+ T and CD8+ T Lymphocytes Is Increased in Patients with Chronic Hepatitis B Virus Infection

FcγR is expressed by many immune cells and plays an important role in the immune response to hepatitis B virus (HBV) infection. CD32 belongs to the FcγR family. This study aimed to observe changes in CD32 expression by CD4+ T and CD8+ T lymphocytes in chronic HBV infection patients and evaluate the clinical utility of CD4+ T and CD8+ T CD32 expression to assess the severity of liver injury in chronic HBV-infected patients. A total of 68 chronic HBV patients and 40 healthy individuals were recruited, and the median fluorescence intensity (MFI) of CD32 expression on CD4+ T, CD8+ T lymphocytes was measured using flow cytometry and the CD4+ T, CD8+ T CD32 index was calculated. The reactivity of the healthy individual lymphocytes to mixed patients' plasma containing HBV was observed. Finally, the correlation between CD4+ T, CD8+ T lymphocytes CD32 MFI and liver function indicator levels was analyzed. The CD4+ T, CD8+ T CD32 MFI and index were significantly elevated in HBV patient groups than in normal control group (p < 0.001, for all). Furthermore, the CD32 MFI of healthy persons' CD4+ T and CD8+ T lymphocytes were remarkably increased when stimulated with mixed patients' plasma containing high HBV copies (p < 0.001; P < 0.001). More importantly, in HBV patients, there was a significant positive correlation between CD4+ T, CD8+ T CD32 MFI and the level of serum aspartate aminotransferase (p < 0.05, p < 0.05). In conclusion, the increased expression of CD32 on CD4+ T and CD8+ T lymphocytes might be potential promising biomarkers for the severity of liver function impairment in chronic HBV patients.

Antigen Recognition and Immune Response to Acute and Chronic Hepatitis B Virus Infection

The antigen recognition and immune response to acute and chronic hepatitis B virus (HBV) infections are the result of both the innate and adaptive immune response. The innate immune response comprises Dendritic Cells (DCs), which served as professional antigen-presenting cells and a bridge between innate and adaptive immunity, Kupffer cells and inflammatory monocytes for the continuous inflammation of hepatocyte, neutrophils for hepatic tissue damage due to acute inflammation, type I interferons (IFN), which induce an antiviral state on infected cells, directs natural killer (NK) cells to kill virally infected cells, reduces the population of infected cells, and promotes the effective maturation and site recruitment of adaptive immunity through the production of pro-inflammatory cytokines and chemokines. Through stimulating B cells, T-helper, and cytotoxic T cells, the adaptive immune system also protects against hepatitis B infection. During HBV infection, a network of cell types that can either play protective or harmful functions creates the anti-viral adaptive immune response. These many elements, such as ‎Cluster of differentiation four (CD4) T cells (traditionally known as helper T cells), are potent cytokine producers and necessary for the effective maturation of effector cytotoxic cluster of differentiation eight (CD8) T cells and B cell antibody production. By cytolytic and non-cytolytic processes, CD8 T cells are able to eliminate HBV-infected hepatocytes and directly detect virus-infected cells, and circulating CD4+ CD25+ regulatory T cells for the modulation of immune system. In order to avoid reinfection, B cells can produce antibodies that destroy free viral particles. Moreover, by presenting HBV antigens to helper T cells, B cells may also influence how well these cells operate.

JNK/c-Jun pathway activation is essential for HBx-induced IL-35 elevation to promote persistent HBV infection

BACKGROUND

Immunoregulation plays pivotal roles during chronic hepatitis B virus (HBV) infection. Studies have shown that Interleukin (IL)-35 is an important molecule associated with inadequate immune response against HBV. However, the mechanisms involved in the up-regulation of IL-35 expression during persistent HBV infection remain unknown.

METHODS

In this study, we constructed a plasmid expressing the HBV X protein (pCMV-HBx) to evaluate the relationship between HBx and IL-35. Activation of the JNK/c-Jun pathway was analyzed and chromatin immunoprecipitation followed by sequencing and luciferase reporter assays were performed to determine whether c-Jun could regulate IL-35 transcription.

RESULTS

HBx can significantly activate IL-35 promoter in both LO2 and HepG2 cells compared to the control plasmid (pCMV-Tag2) using the dual-luciferase assay. Whereas other viral proteins, such as S, preS1, the core protein, had no significant effect on IL-35 expression. Similarly, WB and qRT-PCR also showed that HBx can significantly promote IL-35 expression at protein and mRNA levels in the aforementioned cells. The relevant pathway mechanism showed that the expression of JNK and c-Jun genes was significantly higher in transfected cells carrying pCMV-HBx than in the pCMV-Tag2-transfected and -untransfected cells. WB analysis revealed that phosphorylated JNK and c-Jun were overexpressed after HBx action. Conversely, the addition of the JNK/c-Jun signaling pathway inhibitor could significantly suppress HBx-induced IL-35 expression in a dose-dependent manner.

CONCLUSIONS

A novel molecular mechanism of HBV-induced IL-35 expression was revealed, which involves JNK/c-Jun signaling in up-regulating IL-35 expression via HBx, resulting in transactivation of the IL-35 subunit EBI3 and p35 promoter.

Cytokine profiles and CD8+ T cells in the occurrence of acute and chronic hepatitis B

OBJECTIVE

We explore the expression of functional molecules on CD8+ T lymphocytes, cytokines concentration, and their correlation to occurrence of hepatitis B and hepatitis B virus (HBV) desoxyribose nucleic acid (DNA), hepatitis B surface antigen (HBsAg), hepatitis B envelope antigen (HBeAg), and alanine aminotransferase (ALT) in patients infected with HBV.

METHODS

This is a single center study. 32 patients with acute hepatitis B (AHB), 30 patients with immune tolerant (IT) phase chronic HBV infected, and 50 patients with chronic hepatitis B (CHB) were enrolled. The activation molecules (CD69) and the apoptosis-inducing molecules (CD178) on surface of CD8+ T lymphocytes were tested by the flow cytometry. Fms-like tyrosine kinase 3 ligand (Flt-3L), interleukin 17A (IL-17A), interferon γ (IFN-γ), and Interferon α2 (IFN-α2) were quantitated by Luminex assay. We use linear regression analysis to analyze their correlations to ALT, HBV DNA, HBsAg, and HBeAg.

RESULTS

The frequency of CD69+CD8+ T lymphocytes in CHB and AHB groups were increased significantly compared with IT group (4.19[3.01, 6.18]% and 4.45[2.93, 6.71]% vs. 3.02[2.17, 3.44]%; H=26.207, P=0.001; H=28.585, P=0.002), and the mean fluorescence intensity (MFI) of CD69 in AHB group was significantly higher than IT and CHB groups (27.35[24.88, 32.25] vs. 20.45[19.05, 27.75] and 23.40[16.78, 28.13]; H=25.832, P=0.005 and H=22.056, P=0.008). In IT group, HBsAg levels and HBV DNA loads were negatively correlated with CD69MFI (β=-0.025, t=-2.613, P=0.014; β=-0.021, t=-2.286, P=0.030), meanwhile, HBeAg was negatively related to the frequency of CD69+CD8+ T lymphocytes (β=-61.306, t=-2.116, P=0.043). In AHB group, IFN-α2 was positively related to the frequency of CD8+ T lymphocytes (β=6.798, t=2.629, P=0.016); however, in CHB group, IFN-α2 was negatively associated with frequency of CD8+ T lymphocytes (β=-14.534, t=-2.085, P=0.043). In CHB group, HBeAg was positively associated with frequency of CD69+CD8+ T lymphocytes (β=43.912, t=2.027, P=0.048). In AHB group, ALT was positively related to CD69MFI (β=35.042, t=2.896, P=0.007), but HBsAg was negatively related to CD178MFI (β=-0.137, t=-3.273, P=0.003).

CONCLUSIONS

The activation of CD8+ T lymphocytes was associated with the occurrence of AHB and CHB. However, due to the insufficient expression of functional molecules of CD8+ T lymphocytes and the depletion of CD8+ T lymphocytes, CHB patients were difficult to recover from HBV infection.

Identification of the association of CD28+ CD244+ Tc17/IFN-γ cells with chronic hepatitis C virus infection

CD8+ T cells play multiple and complex immunological roles including antiviral, regulatory, and exhaustive effects in hepatitis C virus (HCV) infected patients. Some CD8+ T-cell subsets were confirmed to be closely related to HCV infection such as TCM , TEM , TEM RA, Tc17, and CD8+ Treg. Herein, we report a new subset of interleukin (IL)-17/interferon (IFN)-γ producing CD8+ T (Tc17/IFN-γ) cells that markedly correlate with CD28+ CD244+ cells, IL-17 levels, and HCV RNA in HCV patients. During early treatment with peg-IFN-a2a plus ribavirin, the imbalance of these Tc17/IFN-γ cells could be partially restored, together with normalized serum alanine aminotransferase but not aspartate transaminase. Also, we analyzed the dynamic change of the percentage of this T cells subset in patients with different outcome after 4-week course of treatment with peg-IFN-a2a plus ribavirin and found that the percentage of CD8+ CD28+ CD244+ T cells significantly decreased in recovered patients but not in nonrecovered patients. In vitro, CD28+ CD244+ T cells were the only CD8+ T-cell group that secreted both IL-17 and IFN-γ in this axis and blockade with anti-CD244 antibodies significantly reduced cytokine production. Taken together, this study demonstrates that the frequency and regulatory functions of CD28+ CD244+ Tc17/IFN-γ cells may play an important role in persistent HCV infection.

JAK/STAT signaling is involved in IL-35-induced inhibition of hepatitis B virus antigen-specific cytotoxic T cell exhaustion in chronic hepatitis B

AIMS

Interleukin-35 (IL-35) is a new member of the interleukin-12 family and is composed of the P35 and EB virus-inducible gene 3 subunits. The aims of this study were to examine the roles of IL-35 in the exhaustion of HBV-specific CTLs, as little as known on the subject.

MAIN METHODS

The relative levels of serum HBV markers were detected using automated biochemical techniques. The HBV DNA copies were measured by RT-qPCR. The expression of inhibitory receptors and the cell cytokines on the surface of CTLs were determined by flow cytometry. The pSTAT1-pSTAT4 protein levels expression was determined by flow cytometry, confocal microscopy and Western blot.

KEY FINDINGS

Our results showed that IL-35 can activate the Janus kinase 1 (JAK1)/tyrosine kinase 2 (TYK2)/signal transducer and activator of transcription 1 (STAT1)/STAT4 pathway in CTLs in vitro. Interferon-γ and tumor necrosis alpha-α expression increased in CTLs in the presence of a JAK/STAT-pathway blocker. In addition, we evaluated the expression of the exhaustion-associated molecules programmed death-1, cytotoxic T lymphocyte-associated protein-4, and lymphocyte activation gene-3 in CTLs after adding the JAK-STAT inhibitor The results showed that the expression of exhaustion-associated molecules on the CTL surface decreased after blocking the JAK-STAT pathway. IL-35 inhibited the function of HBV-specific CTLs through the JAK1/TYK2/STAT1/STAT4 pathway, and the function of CTLs was recovered after blocking the JAK/STAT pathway.

SIGNIFICANCE

These data provide a new experimental basis for immunotherapy for chronic hepatitis B.

CD4+ T cell exhaustion revealed by high PD-1 and LAG-3 expression and the loss of helper T cell function in chronic hepatitis B

Background

Immune inhibitory receptors play an important role in chronic infections. However, little is known about their role in hepatitis B virus (HBV) infection. Here, we analyzed the relationship between programmed death-1 (PD-1) and lymphocyte activation gene-3 (LAG-3) expression on CD4⁺ T cells and HBV disease progression.

Results

PD-1 and LAG-3 expression was significantly higher on CD4⁺ T cells from HBV patients than on those from the HCs. In addition, a significant positive correlation was found between the PD-1 and LAG-3 expression levels and the ALT(alanine aminotransferase) level. CD4⁺ T cell function was inhibited by high PD-1 and LAG-3 levels, and CD4⁺ T cells with high PD-1 and LAG-3 expression lost the ability to secrete IFN-γ, IL-2 and TNF-α. Furthermore, blockade of the PD-1 and LAG-3 pathways reversed the damage to CD4⁺ T cell proliferation and cytokine secretion.

Conclusions

CD4⁺ T cell exhaustion during chronic HBV had high PD-1 and LAG-3 expression and the absence of helper T cell cytokines, including IFN-γ, IL-2 and TNF-α. After blocking PD-L1 and LAG-3, CD4⁺ T cell function in chronic hepatitis B patients was partially restored.

HBV antigen and DNA loss from mouse serum is associated with novel vaccine-induced HBV surface antigen-specific cell-mediated immunity and cytokine production

Therapeutic vaccination is a promising strategy for controlling chronic hepatitis B virus (HBV). Here, we tested whether several novel vaccination strategies could be used to induce HBV-specific adaptive immune responses and control/eradicate HBV in a mouse model. Robust HBV antigen-specific antibody responses were elicited by several vaccination strategies using a novel particle vaccine (HBSS1), which expresses a fusion of the S (amino acids [aa] 1-223) and preS1 (aa 21-47) antigens, and/or a recombinant adenovirus rAdSS1 vaccine. However, antigen-specific cell-mediated immunity and high levels of production of multiple cytokines were elicited only by heterologous prime-boost immunization; i.e., priming with the HBSS1 vaccine followed by a rAdSS1 boost. Furthermore, the most rapid loss of serum HBsAg, HBeAg and DNA was achieved by the novel vaccination regimen (priming with HBSS1 formulated with adjuvants [alum plus PolyI:C]), which was strongly associated with more potent and functional HBsAg-specific CD4⁺ and CD8⁺ T-cell responses and increased production of interleukin (IL)-2, interferon (IFN)-γ, tumor necrosis factor-α, IL-12, and IFN-γ-induced protein (IP)-10. Thus, our novel heterogeneous prime-boost vaccine regimen shows promise as a therapeutic strategy against HBV.

Multiple Functions of Cellular FLIP Are Essential for Replication of Hepatitis B Virus

Hepatitis B virus (HBV) infection is a leading cause of liver diseases; however, the host factors which facilitate the replication and persistence of HBV are largely unidentified. Cellular FLICE inhibitory protein (c-FLIP) is a typical antiapoptotic protein. In many cases of liver diseases, the expression level of c-FLIP is altered, which affects the fate of hepatocytes. We previously found that c-FLIP and its cleaved form interact with HBV X protein (HBx), which is essential for HBV replication, and regulate diverse cellular signals. In this study, we investigated the role of endogenous c-FLIP in HBV replication and its underlying mechanisms. The knockdown of endogenous c-FLIP revealed that this protein regulates HBV replication through two different mechanisms. (i) c-FLIP interacts with HBx and protects it from ubiquitin-dependent degradation. The N-terminal DED1 domain of c-FLIP is required for HBx stabilization. (ii) c-FLIP regulates the expression or stability of hepatocyte nuclear factors (HNFs), which have critical roles in HBV transcription and maintenance of hepatocytes. c-FLIP regulates the stability of HNFs through physical interactions. We verified our findings in three HBV infection systems: HepG2-NTCP cells, differentiated HepaRG cells, and primary human hepatocytes. In conclusion, our results identify c-FLIP as an essential factor in HBV replication. c-FLIP regulates viral replication through its multiple effects on viral and host proteins that have critical roles in HBV replication.IMPORTANCE Although the chronic hepatitis B virus (HBV) infection still poses a major health concern, the host factors which are required for the replication of HBV are largely uncharacterized. Our studies identify cellular FLICE inhibitory protein (c-FLIP) as an essential factor in HBV replication. We found the dual roles of c-FLIP in regulation of HBV replication: c-FLIP interacts with HBx and enhances its stability and regulates the expression or stability of hepatocyte nuclear factors which are essential for transcription of HBV genome. Our findings may provide a new target for intervention in persistent HBV infection.

Ratios of T-helper 2 Cells to T-helper 1 Cells and Cytokine Levels in Patients with Hepatitis B

BACKGROUND

Hepatitis B is an immune response-mediated disease. The aim of this study was to explore the differences of ratios of T-helper (Th) 2 cells to Th1 cells and cytokine levels in acute hepatitis B (AHB) patients and chronic hepatitis B virus (HBV)-infected patients in immune-tolerance and immune-active phases.

METHODS

Thirty chronic HBV-infected patients in the immune-tolerant phase (IT group) and 50 chronic hepatitis B patients in the immune-active (clearance) phase (IC group), 32 AHB patients (AHB group), and 13 healthy individuals (HI group) were enrolled in the study. Th cell proportions in peripheral blood, cytokine levels in plasma, and serum levels of HBV DNA, hepatitis B surface antigen, and hepatitis B e antigen were detected.

RESULTS

The Th1 cell percentage and Th2/Th1 ratio in the HBV infection group (including IT, IC, and AHB groups) were significantly different from those in HI group (24.10% ± 8.66% and 1.72 ± 0.61 vs. 15.16% ± 4.34% and 2.40 ± 0.74, respectively; all P < 0.001). However, there were no differences in the Th1 cell percentages and Th2/Th1 ratios among the IT, IC, and AHB groups. In HBV infection group, the median levels of Flt3 ligand (Flt3L), interferon (IFN)-γ, and interleukin (IL)-17A were significantly lower than those in HI group (29.26 pg/ml, 33.72 pg/ml, and 12.27 pg/ml vs. 108.54 pg/ml, 66.48 pg/ml, and 35.96 pg/ml, respectively; all P < 0.05). IFN-α2, IL-10, and transforming growth factor (TGF)-β2 median levels in hepatitis group (including patients in AHB and IC groups) were significantly higher than those in IT group (40.14 pg/ml, 13.58 pg/ml, and 557.41 pg/ml vs. 16.74 pg/ml, 6.80 pg/ml, and 419.01 pg/ml, respectively; all P < 0.05), while patients in hepatitis group had significant lower Flt3L level than IT patients (30.77 vs. 59.96 pg/ml, P = 0.021). Compared with IC group, patients in AHB group had significant higher median levels of IL-10, TGF-β1, and TGF-β2 (22.77 pg/ml, 10,447.00 pg/ml, and 782.28 pg/ml vs. 8.66 pg/ml, 3755.50 pg/ml, and 482.87 pg/ml, respectively; all P < 0.05).

CONCLUSIONS

Compared with chronic HBV-infected patients in immune-tolerance phase, chronic HBV-infected patients in immune-active phase and AHB patients had similar Th2/Th1 ratios, significantly higher levels of IFN-α2, IL-10, and TGF-β. AHB patients had significantly higher IL-10 and TGF-β levels than chronic HBV-infected patients in immune-active phase.

Decreased frequency of circulating Th9 cells in patients with chronic hepatitis B infection

BACKGROUND

Chronic hepatitis B (CHB) is one of the major infectious diseases in which CD4+ T helper (Th) cells play a crucial role. Th9 cells are a distinct subset of CD4+ Th cells with important physiological functions.

OBJECTIVE

The study aimed to assess the potential involvement of Th9 cells in the inadequate immune response leading to chronic HBV infection.

PATIENTS AND METHODS

Peripheral blood samples were collected from 22 CHB patients and 16 healthy controls (HC). The frequencies of circulating Th9, Tc9, Th1, and Tc1 cells were determined by flow cytometry. Serum levels of IL-9 and IL-10 were analyzed by ELISA. Serum biochemical indices of liver function were measured using an automated analyzers. Serum HBV DNA loads were analyzed by real-time PCR. The potential association of the frequency of Th9, Tc9, Th1 or Tc1 cells with clinical parameters was assessed.

RESULTS

The frequency of circulating Th9 cells was significantly lower in CHB patients than those in HC. However, no significant differences in the frequency of Tc9, Th1 or Tc1 cells were observed between the two groups. The percentages of Th9 cells, but not Tc9 cells, were negatively correlated with HBV DNA loads, whereas the percentages of Tc1 cells were positively correlated with viral loads in CHB patients. Moreover, there was a positive correlation between serum levels of IL-9 and IL-10 and HBV DNA loads in patients with chronic HBV infection.

CONCLUSION

The depletion of Th9 cells is associated with the development of chronic HBV infection.

Individualized Immunosuppressive Protocol of Liver Transplant Recipient Should be Made Based on Splenic Function Status

BACKGROUND

Lymphocyte subsets play important roles in rejection in liver transplant recipients, and the effect of splenic function on these roles remains unknown. The aim of this study was to explore the feasibility to adjust immunosuppressive agents based on splenic function status through detecting the lymphocyte subsets in liver transplantBeijing recipients.

METHODS

The lymphocyte subsets of 49 liver transplant recipients were assessed in the 309th Hospital of Chinese People's Liberation Army between June 2014 and August 2015. The patients were divided into splenectomy group (n = 9), normal splenic function group (n = 24), and hypersplenism group (n = 16). The percentages and counts of CD4+ T, CD8+ T, natural killer (NK) cell, B-cell, regulatory B-cell (Breg), and regulatory T-cell (Treg) were detected by flow cytometer. In addition, the immunosuppressive agents, histories of rejection and infection, and postoperative time of the patients were compared among the three groups.

RESULTS

There was no significant difference of clinical characteristics among the three groups. The percentage of CD19+CD24+CD38+ Breg was significantly higher in hypersplenism group than normal splenic function group and splenectomy group (3.29 ± 0.97% vs. 2.12 ± 1.08% and 1.90 ± 0.99%, P = 0.001). The same result was found in CD4+CD25+FoxP3+ Treg percentage (0.97 ± 0.39% vs. 0.54 ± 0.31% and 0.56 ± 0.28%, P = 0.001). The counts of CD8+ T-cell, CD4+ T-cell, and NK cell were significantly lower in hypersplenism group than normal splenic function group (254.25 ± 149.08 vs. 476.96 ± 225.52, P= 0.002; 301.69 ± 154.39 vs. 532.50 ± 194.42, P= 0.000; and 88.56 ± 63.15 vs. 188.33 ± 134.51, P = 0.048). Moreover, the counts of CD4+ T-cell and NK cell were significantly lower in hypersplenism group than splenectomy group (301.69 ± 154.39 vs. 491.89 ± 132.31, P= 0.033; and 88.56 ± 63.15 vs. 226.00 ± 168.85, P = 0.032).

CONCLUSION

Splenic function status might affect the immunity of liver transplant recipients, that should be considered when we make immunosuppressive protocols.

Regulatory T-cells promote hepatitis B virus infection and hepatocellular carcinoma progression

Regulatory T-cells (Tregs), known for their immune suppressive function, have been reported in higher numbers, with activated phenotypes and greater potency, in hepatitis B virus (HBV)-related liver diseases than in normal conditions. The numbers, phenotypes, and function of intrahepatic and/or tumor-infiltrating Tregs in HBV-related liver diseases also differ from those of Tregs in the peripheral blood. By inhibiting the function of effector T-cells (Teffs), Tregs play a substantial role in the formation and maintenance of the liver's suppressive microenvironment, which might account for the progression of HBV-related hepatitis and hepatocellular carcinoma (HCC). In acute hepatitis B virus infection, Tregs can safeguard the liver from damage at the cost of prolonged antiviral processes, which results in chronic HBV infection in the liver. Furthermore, Tregs play a role in the development of cirrhosis, the transformation of cirrhosis to HCC, and the progression and metastasis of HCC. Higher levels of Tregs in the peripheral blood and/or tumor sites signify a poorer prognosis in HBV-related liver conditions, and observational data from mouse models and human patients support the theory that depleting Tregs may be therapeutic in HBV-related liver diseases by inducing antiviral and antitumor immunity.

Deltex1 Polymorphisms Are Associated with Hepatitis B Vaccination Non-Response in Southwest China

Background

Hepatitis B vaccination is the most important tool available for preventing hepatitis B virus (HBV) infection and reducing the prevalence of infection. However, epidemiological studies have demonstrated that morethan 5% of patients exhibit a non- or hypo-response to the HBV vaccine. Genetic variations associated with T cell immunity contribute to the immune response to HBV vaccination. The deltex 1 (DTX1) gene is involved in T cell anergy, which may also be associated with the immune response to the HBV vaccination.

Methods

We detected 10 single nucleotide polymorphisms (SNPs) in or around the DTX1 gene in 601 infants out of a population from Southwest China, including 299 high responders(HRs; HBsAb > 100 mIU/mL) and 302 non-responders (NRs; HBsAb < 10 mIU/mL). An additional validation study was performed, comprising 230 adult patients(135 HRs and 95 NRs) from Southwest China.

Results

This study found that the minor allele ‘G’ of rs2384077 (adjusted p = 2.63E^-04,) and the minor allele ‘C’ of rs10744794 (adjusted p = 3.69E^-04) in the first intron of the DTX1 gene were remarkably associated with the immune response to HBV vaccination in both infant and adult populations. Moreover, a subsequent analysis indicated that haplotypes (A-T, G-C) of the two SNPs were significantly associated with the immune response to HBV vaccination.

Conclusions

Two SNPs (rs2384077 and rs10744794) in an intron of DTX1 and the linkage disequilibrium (LD) block are significantly associated with the immune response to HBV vaccination. The functional element annotation of the LD block between the two SNPs contains four transcriptional regulatory elements. The results suggest that these two SNPs may be involved in the immune response to HBV vaccination.

The Role of Immune Cells in Chronic HBV Infection

Hepatitis B virus (HBV) infection is a major cause of chronic liver diseases that may progress to liver cirrhosis and hepatocellular carcinoma. Host immune responses are important factors that determine whether HBV infection is cleared or persists. After infection, viral replication occurs inside hepatocytes, and the secretion of infectious virions can take place at high rates for decades. Consequently, HBV DNA and viral proteins, like HBV early antigen (HBeAg) and HBV surface antigen (HBsAg), can be easily detected in serum. Chronic infection with HBV is the result of an ineffective antiviral immune response towards the virus. In this review, we discuss the role of immune cells in chronic HBV infection.

Therapeutic Potential of Cell Penetrating Peptides (CPPs) and Cationic Polymers for Chronic Hepatitis B

Chronic hepatitis B virus (HBV) infection remains a major health problem worldwide. Because current anti-HBV treatments are only virostatic, there is an urgent need for development of alternative antiviral approaches. In this context, cell-penetrating peptides (CPPs) and cationic polymers, such as chitosan (CS), appear of particular interest as nonviral vectors due to their capacity to facilitate cellular delivery of bioactive cargoes including peptide nucleic acids (PNAs) or DNA vaccines. We have investigated the ability of a PNA conjugated to different CPPs to inhibit the replication of duck hepatitis B virus (DHBV), a reference model for human HBV infection. The in vivo administration of PNA-CPP conjugates to neonatal ducklings showed that they reached the liver and inhibited DHBV replication. Interestingly, our results indicated also that a modified CPP (CatLip) alone, in the absence of its PNA cargo, was able to drastically inhibit late stages of DHBV replication. In the mouse model, conjugation of HBV DNA vaccine to modified CS (Man-CS-Phe) improved cellular and humoral responses to plasmid-encoded antigen. Moreover, other systems for gene delivery were investigated including CPP-modified CS and cationic nanoparticles. The results showed that these nonviral vectors considerably increased plasmid DNA uptake and expression. Collectively promising results obtained in preclinical studies suggest the usefulness of these safe delivery systems for the development of novel therapeutics against chronic hepatitis B.

The role of DCs in the immunopathogenesis of chronic HBV infection and the methods of inducing DCs maturation

Chronic hepatitis B virus (HBV) infection is the result of an inadequate immune response towards the virus. Dendritic cells (DCs), as the most efficient professional antigen-presenting cells (APCs), possess the strongest antigen presenting the effect in the body and can stimulate the initial T cell activation and proliferation. DCs of patients with chronic HBV infection are impaired, resulting in more tolerogenic rather than immunogenic responses, which may contribute to viral persistence. Recently, numerous methods have been developed to induce DCs maturation. To date, recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) combined with interleukin-4 (rhIL-4) has been a classic culture combination to DCs. The recently classified type III interferon group interferon-λ (IFN-λ) displays antiviral, antitumor, and immunoregulatory activity. In our laboratory, we demonstrate that IFN-λ1 combined with rhGM-CSF and rhIL-4 can significantly increase the expression of DC surface molecules and the secretion of interleukin-12 (IL-12) and interferon-γ (IFN-γ) in patients with chronic hepatitis B infection. In this review, we emphasize on the role of DCs in the immunopathogenesis of chronic HBV infection. Importantly, we systematic review that the latest update in the current status of knowledge on the methods of inducing DCs maturation in anti-HBV immunity. What's more, we conclude that IFN-λ1 combined with GM-CSF and IL-4 can induce DCs maturation, which could become a possibility to be applied to the autologus dendritic cell vaccine to treat chronic hepatitis B.

Anti-duck virus hepatitis mechanisms of Bush Sophora Root polysaccharide and its sulfate verified by intervention experiments

In our previous study, Bush Sophora Root polysaccharide (BSRPS) and its sulfate (sBSRPS) exhibited anti-duck virus hepatitis (DVH) abilities as well as anti-oxidative and immuno-enhancement effects. The aim of this paper was to ulteriorly investigate the exact anti-DVH mechanisms of BSRPS and sBSRPS by intervention experiments. Hinokitiol and FK506 were used as the pro-oxidant and immunosuppressant, respectively. The dynamic deaths, oxidative and immune evaluation indexes and hepatic pathological change scores were detected. When was intervened by hinokitiol, sBSRPS still possessed therapeutic effect while BSPRS was useless. Under the condition of immunosuppression, BSRPS lost a part role in treating DVH; however such a role of sBSRPS completely exhausted. These results suggested both anti-oxidative and immuno-enhancement effects of BSRPS played roles in healing DVH, and the former was more crucial; unlike BSRPS, only immuno-enhancement ability of sBSRPS was imperative for its curative effect on DVH.

APC targeted micelle for enhanced intradermal delivery of hepatitis B DNA vaccine

Chronic hepatitis B is a serious liver disease and puts people at high risk of death from cirrhosis and liver cancer. Although DNA vaccination has been emerged as a potential immunotherapeutic strategy for the treatment of chronic hepatitis B, the efficiencies were not adequate in clinical trials. Here we describe the design, synthesis, and evaluation of mannosylated phenylalanine grafted chitosan (Man-CS-Phe) as a DNA delivery vector for direct transfection of antigen presenting cells to improve cellular and humoral immunity to plasmid-coded antigen. The cationic Man-CS-Phe micelles condense plasmid DNA into nanoscale polyplexes and provide efficient protection of complexed DNA from nuclease degradation. The mannose receptor-mediated enhanced cell uptake and high in vitro transfection efficiency of the polyplexes were demonstrated in RAW 264.7 and DC 2.4 cells using GFP-expressing plasmid DNA. Furthermore, intradermal immunization of BALB/c mice indicated that hepatitis B DNA vaccine/Man-CS-Phe polyplexes not only induced multi-fold higher serum antibody titer in comparison to all other formulations including FuGENE HD, but also significantly stimulated T-cell proliferation and skewed T helper toward Th1 polarization. These results illustrate that the Man-CS-Phe can serve as a promising DNA delivery vector to harness both cellular and humoral arms of immune system.