Interferon-α suppresses hepatitis B virus enhancer II activity via the protein kinase C pathway

Evaluation of the clinical efficacy of vaginal treatment options for persistent high-risk human papillomavirus infection after excisional treatment of cervical high-grade squamous intraepithelial lesions: a systematic review and Bayesian network meta-analysis

BACKGROUND

To evaluate the clinical efficacy of different vaginal administration on cervical persistent high-risk human papillomavirus (HR-HPV) infection after excisional treatment for high-grade squamous intraepithelial lesions (HSIL).

METHODS

Six databases (PubMed, EmBase, Cochrane Central, China Knowledge Network database, China Biomedical Literature Service, and WanFang database) were searched to collect randomized controlled trials (RCTs) of various types of vaginal administration compared to no treatment on persistent HR-HPV infection after HSIL excisional treatment, and comprehensive analysis of the clearance of different drugs on HR-HPV was performed using Bayesian reticulation meta-analysis.

RESULTS

The study analyzed the efficacy of eight interventions, including Interferon, Baofukang, Paiteling, Bletilla striata Sanhuang Powder, Lactobacilli vaginal capsules, Fuanning + Interferon, Interferon + Lactobacilli vaginal capsules, and Interferon + Baofukang, on the clearance of HR-HPV after excisional treatment through pooling and analyzing data from 52 RCTs. The results of the study demonstrated that Interferon + Lactobacilli vaginal capsules [OR 16.0 (95% CIs 8.1-32.0)], Interferon + Fuanning [OR 16.0 (95% CIs 1.1-52.0)], and Interferon + Baofukang [OR 14.0 (95% CIs 6.8-28.0)] were all found to significantly improve postoperative HR-HPV clearance rates when compared to no treatment. Furthermore, when studies with high-risk bias were excluded, Interferon + Lactobacilli vaginal capsules [OR 8.6 (95% CIs 4.7-19.0)] and Interferon + Baofukang [OR 22.0 (95% CIs 8.7-59.0)] were still found to be positively associated with increased postoperative HR-HPV clearance rate. Additionally, the study´s results also indicate that Interferon + Baofukang was effective in enhancing the postoperative HR-HPV clearance rates, mainly when the studies were restricted to a follow-up period of at least 12 months [OR 9.6 (95% CIs 2.9-34.0)]. However, it is important to note that the majority of the trials (29 out of 52, 51.6%) were rated as moderate to high risk of bias, and the certainty of the evidence was moderate to very low.

CONCLUSION

The application of various forms of vaginal administration, except for individual use of Lactobacilli vaginal capsules, is more efficacious than no treatment in patients with cervical persistent HR-HPV infection after excisional treatment. However, all of the estimates of the effect size for change in the efficiency of HR-HPV clearance are uncertain. Our confidence in effect estimates and ranking of treatments is low, which needs larger, more rigorous, and longer follow-up RCTs to resolve.

Molecular Basis of Functional Effects of Phosphorylation of the C-Terminal Domain of the Rabies Virus P Protein

Rabies virus P protein is a multifunctional protein with critical roles in replication and manipulation of host-cell processes, including subversion of immunity. This functional diversity involves interactions of several P protein isoforms with the cell nucleus and microtubules.

Capsid Allosteric Modulators Enhance the Innate Immune Response in Hepatitis B Virus-Infected Hepatocytes During Interferon Administration

Capsid allosteric modulators (CAMs) inhibit the encapsidation of hepatitis B virus (HBV) pregenomic RNA (pgRNA), which contains a pathogen-associated molecular pattern motif. However, the effect of CAMs on the innate immune response of HBV-infected hepatocytes remains unclear, and we examined this effect in this study. Administration of a CAM compound, BAY41-4109 (BAY41), to HBV-infected primary human hepatocytes (PHHs) did not change the total cytoplasmic pgRNA levels but significantly reduced intracapsid pgRNA levels, suggesting that BAY41 increased extracapsid pgRNA levels in the cytoplasm. BAY41 alone did not change the intracellular interferon (IFN)-stimulated gene (ISG) expression levels. However, BAY41 enhanced antiviral ISG induction by IFN-α in HBV-infected PHHs but did not change ISG induction by IFN-α in uninfected PHHs. Compared with BAY41 or IFN-α alone, coadministration of BAY41 and IFN-α significantly suppressed extracellular HBV-DNA levels. HBV-infected human liver-chimeric mice were treated with vehicle, BAY41, pegylated IFN-α (pegIFN-α), or BAY41 and pegIFN-α together. Compared with the vehicle control, pegIFN-α highly up-regulated intrahepatic ISG expression levels, but BAY41 alone did not change these levels. The combination of BAY41 and pegIFN-α further enhanced intrahepatic antiviral ISG expression, which was up-regulated by pegIFNα. The serum HBV-DNA levels in mice treated with the combination of BAY41 and pegIFN-α were the lowest observed in all the groups. Conclusion: CAMs enhance the host IFN response when combined with exogenous IFN-α, likely due to increased cytoplasmic extracapsid pgRNA.

Geranylgeranylacetone decreases the production of hepatitis B virus-related antigen by comprehensive downregulation of mRNA transcription activity

BACKGROUND AND AIM

Elimination of hepatitis B virus (HBV) is infrequently achieved with current therapies. Therefore, more effective anti-HBV therapy is needed. We previously reported that geranylgeranylacetone (GGA) showed anti-hepatitis C virus activity in human hepatoma cells. In this study, we examined the anti-HBV activity of GGA.

METHODS

We used HepG2.2.15.7 cells, PXB cells infected with HBV, Huh7 cells transfected with linear HBV, and PLC/PRF/5 cells as HBV-infected hepatocyte models. After GGA treatment, HBV-related antigen was measured by chemiluminescent immunoassay. HBV-related mRNA was examined by Northern blot. cccDNA and endoplasmic reticulum stress markers were measured by real-time polymerase chain reaction. The activities of HBV promoters and enhancer regions were examined using luciferase vectors.

RESULTS

After GGA treatment, hepatitis B surface antigen and hepatitis B e antigen secretion was decreased in all HBV-infected hepatocyte models. HBV-related mRNA was also decreased by GGA treatment, although cccDNA levels were not affected. Additionally, the activity of HBV S1 and S2 promoter region and Enhancer 1/Enhancer 2/core promoter region was reduced by GGA treatment. The mRNA expression of the main transcription factors, hepatocyte nuclear factor 3 and 4 and CCAAT/enhancer binding protein, was also decreased. Further, the expression levels of endoplasmic reticulum stress markers were increased by GGA treatment, which reflected the change in HBV-related antigen secretion.

CONCLUSIONS

Geranylgeranylacetone treatment reduces HBV-related protein levels by suppressing comprehensive downregulation of HBV promoter and enhancer activity, which might be caused by decreased hepatic transcription factor expression. GGA treatment may enhance anti-HBV effects in combination with other therapies.

Transforming growth factor β as a possible independent factor in chronic hepatitis B

To investigate the association between immune-cell-related cytokines and the development of chronic hepatitis B (CHB), patients with chronic hepatitis B virus (HBV) infection in the immunotolerant (IT) phase (n = 30) or hepatitis B envelope antigen (HBeAg)-positive CHB (n = 250) were enrolled in this study. Serological indicators and plasma cytokine levels were measured at the time of enrollment. The results showed that there were significant differences in the median age of the patients (27 vs. 31 years), alanine aminotransferase levels (ALT, 29.85 vs. 234.70 U/L), alanine aminotransferase levels (AST, 23.40 vs. 114.90 U/L), HBsAg levels (4.79 vs. 3.88 log₁₀ IU/ml), HBeAg levels (1606.36 vs. 862.47 S/CO), and the HBV DNA load (8.17 vs. 6.71 log₁₀ IU/ml) between the IT and CHB groups (all P < 0.01). The median values of Fms-like tyrosine kinase 3 ligand (FLT3-L), interferon-gamma (IFN-γ), interleukin- 17A (IL-17A), and transforming growth factor beta (TGF-β1) were significantly higher in the IT group than in the CHB group (FLT3-L, 41.62 vs. 27.47 pg/ml; IFN-γ, 42.48 vs. 33.18 pg/ml; IL-17A, 15.66 vs. 8.90 pg/ml; TGF-β1, 4921.50 vs. 2234 pg/ml; all P < 0.01). The median IFN-α2, TGF-β3 and IL-10 levels in the IT group were significantly lower than those in the CHB group (IFN-α2, 15.24 vs. 35.78 pg/ml, P = 0.000; TGF-β3, 131.69 vs. 162.61 pg/ml, P = 0.025; IL-10, 5.02 vs. 7.9 pg/ml, P = 0.012). Multivariate logistic regression analysis indicated that TGF-β 1 (OR = 0.999, 95% CI 0.999-1.000, P < 0.001) and TGF-β2 levels (OR = 1.008, 95%CI 1.004-1.012, P < 0.001) were modestly but significantly associated with the incidence of CHB. The results suggest that TGF-β level might be an independent factor related to the occurrence of CHB.

Association of cytokines with hepatitis B virus and its antigen

To investigate the characteristics of cytokines in patients with different HBV infection status and their correlation with HBV DNA, HBsAg, and HBeAg levels. Peripheral blood samples were collected from patients with chronic HBV infection in immune tolerance phase (IT), HBeAg-positive chronic hepatitis B (CHB), and acute hepatitis B (AHB) groups, and levels of cytokines were detected by Luminex technique, and analyzed by FLEXMAP 3D analyzer. The correlation between cytokines and HBV DNA load, HBsAg, HBeAg, and alanine aminotransferase (ALT) level in patients with chronic HBV infection was analyzed. In total 312 subjects (184 males and 128 females) were enrolled in the study. There were significant differences among IT, CHB, and AHB groups in Flt-3L value (P = .003; H = 12.312), IFN-γ (P = .001; H = 11.723), IL-10 (P = .001; H = 18.736), IL-17A ((P = .001; H = 12.735), and TGF-β1 (P = .001; Z = 48.571). IFN-α2 levels in CHB group were significantly higher than those in IT and AHB groups (15.24 vs 35.78 pg/mL, P = .000; Z = 3.727; 13.88 vs 35.78 pg/mL, P = .024; Z = -2.258. In CHB group, the levels of HBsAg and ALT were positively correlated with the levels of IL-10 (r = .173; P = .006; r = 0.176; P = .006, respectively), while HBeAg level was positively correlated with the IFN-α2 level (r = .153; P = .016). In AHB group, the HBsAg level was positively correlated with Flt-3L, IFN-α2, IL-10, and IL-6 (r = .402; P = .023; r = .436; P = .016; r = .524, P = .002; r = .405; P = .022, respectively). HBeAg level was positively correlated with IFN-γ and IL-17A levels (r = .400; P = .023; r = .373; P = .036, respectively), and ALT level was positively correlated with IL-6 levels (r = .367; P = .039). In either AHB or CHB group, HBV DNA load was only related to TGF-β level (r = .493; P = .004; r = -.218, P = 0.009 respectively). The correlation between Flt-3L and HBsAg (F = 7.422; P = .007); IL-17, IL-6, and HBeAg (F = 5.757; P = .017; F = 6.156; P = .014) were statistically significant. There was significant correlation between TGF-β2 and HBV DNA (F = 11.795; P = .001), and between ALT and HBsAg, HBV DNA (F = 26.089; P = .000; F = 4.724; P = .031). HBsAg, HBeAg, and HBV DNA were correlated with cytokines and ALT in patients with HBV infection. The level of IFN-α2 was significantly higher in patients with CHB. HBV DNA load was only correlated with the level of TGF-β in acute or CHB.

HBV T1719G mutation reduced HBV replication through mutant Enh II and HBx protein in vitro

It was repeatedly reported that the hepatitis B virus (HBV) T1719G mutation was very common and related to progression and malignancy of liver disease. However, its effect on viral replication efficiency remains unclear. In this study, we aimed to evaluate the function and mechanisms of the T1719G mutation on viral replication capacity. Wild-type and T1719G mutation-bearing HBV1.2× plasmids were transfected into Huh7 and HepG2 cells, respectively, and HBV total RNA, 3.5 kb RNA and supernatant HBV DNA were assessed using real-time PCR, hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) levels were measured by time-resolved fluoroimmunoassay. In order to assess Enh II activity and the binding capacity of HNF3β to Enh II sequence, dual-luciferase assay and Chromatin immunoprecipitation (ChIP)-PCR were employed, respectively. Simultaneously, the HBx or HBx-mut (T1719G) plasmid was co-transfected to evaluate the effect of HBx on viral replication. Our results showed that the T1719G mutation impaired viral replication efficacy compared with the wild type both by reducing Enh II activity and binding capacity of HNF3β with Enh II. And such reduction caused by T1719G mutation could be rescued by HBx protein. Our results show that the T1719G mutation decreases HBV viral replication capacity possibly by mutant HBx protein and altered Enh II activity.

Association of Cytokines with Alanine Aminotransferase, Hepatitis B Virus Surface Antigen and Hepatitis B Envelope Antigen Levels in Chronic Hepatitis B

Background

Cytokines play an important role in occurrence and recovery of hepatitis B virus (HBV) infection. The aim of this study was to investigate the changes of cytokines concentration and its correlation to alanine aminotransferase (ALT), HBV deoxyribonucleic acid (HBV-DNA), hepatitis B envelope antigen (HBeAg), and HBV surface antigen (HBsAg) in the development of chronic hepatitis B (CHB).

Methods

Thirteen healthy individuals (HI), 30 chronic HBV-infected patients in immune tolerant (IT) phase, and 55 CHB patients were enrolled between August 2015 and May 2017. The peripheral blood samples were collected from all individuals. The levels of interferon (IFN)-α2, interleukin (IL)-10, transforming growth factor (TGF)-β1, HBV-DNA, HBsAg, and HBeAg and liver function were measured. The quantitative determinations of cytokines levels, including IFN-α2, IL-10, and TGF-β1 were performed using Luminex multiplex technology. The correlation of cytokines to ALT, HBV-DNA, HBsAg, and HBeAg was analyzed by linear regression analysis.

Results

IFN-α2 levels were similar between HI and IT groups (15.35 [5.70, 67.65] pg/ml vs. 15.24 [4.07, 30.73] pg/ml, Z = -0.610, P = 0.542), while it elevated significantly in CHB group (35.29 [15.94, 70.15] pg/ml vs. 15.24 [4.07, 30.73] pg/ml; Z = -2.522, P = 0.012). Compared with HI group (3.73 [2.98, 11.92] pg/ml), IL-10 concentrations in IT group (5.02 [2.98, 10.11] pg/ml), and CHB group (7.48 [3.10, 18.00] pg/ml) slightly increased (χ² = 2.015, P = 0.365), and there was no significant difference between IT and CHB group (Z = -1.419, P = 0.156). The TGF-β1 levels among HI (3.59 ± 0.20 pg/ml), IT (3.62 ± 0.55 pg/ml), and CHB groups (3.64 ± 0.30 pg/ml) were similar (χ² = 2.739, P = 0.254). In all chronic HBV-infected patients (including patients in IT and CHB groups), the elevation of IFN-α2 level was significantly associated with ALT level (β= 0.389, t = 2.423, P = 0.018), and was also negatively correlated to HBV-DNA load (β = -0.358, t = -2.308, P = 0.024), HBsAg (β = -0.359, t = -2.288, P = 0.025), and HBeAg contents (β = -0.355, t = -2.258, P = 0.027). However, when both ALT level and cytokines were included as independent variable, HBV-DNA load, HBsAg, and HBeAg contents were only correlated to ALT level (β = -0.459, t = -4.225, P = 0.000; β = -0.616, t = -6.334, P = 0.000; and β = -0.290, t = -2.433, P = 0.018; respectively).

Conclusions

IFN-α2 elevation was associated with ALT level in patients with chronic HBV infection. However, in CHB patients, only ALT level was correlated to HBV-DNA, HBsAg and HBeAg contents.

Inhibitory effects of metachromin A on hepatitis B virus production via impairment of the viral promoter activity

The currently available antiviral agents for chronic infection with hepatitis B virus (HBV) are pegylated interferon-α and nucleoside/nucleotide analogues, although it has been difficult to completely eliminate covalently closed circular DNA (cccDNA) from patients. To identify an antiviral compound targeting HBV core promoter, 15 terpenes originating from marine organisms were screened using a cell line expressing firefly luciferase under the control of the HBV core promoter. Metachromin A, which is a merosesquiterpene isolated from the marine sponge Dactylospongia metachromia, inhibited the viral promoter activity at the highest level among the tested compounds, and suppressed HBV production with an EC₅₀ value of 0.8 μM regardless of interferon signaling and cytotoxicity. The analysis on the structure-activity relationship revealed that the hydroquinone moiety, and the double bonds at carbon numbers-5 and -9 in metachromin A are crucial for anti-HBV activity. Furthermore, metachromin A reduced the protein level but not the RNA level of hepatic nuclear factor 4α, which mainly upregulates the activities of enhancer I/X promoter and enhancer II/core promoter. These results suggest that metachromin A can inhibit HBV production via impairment of the viral promoter activity. Antiviral agents targeting the viral promoter may ameliorate HBV-related disorders regardless of remaining cccDNA.

Different antiviral effects of IFNα and IFNβ in an HBV mouse model

Interferons α and β (IFNα and IFNβ) are type I interferons produced by the host to control pathogen propagation. However, only a minority of chronic hepatitis B (CHB) patients generate a sustained response after treatment with recombinant IFNα. The anti-HBV effect of IFNβ and the underlying mechanism are not well-understood. Here, we compared the antiviral activities of IFNα and IFNβ by application of IFNα or IFNβ expression plasmids using the well-established HBV hydrodynamic injection (HI) mouse model. Injection of IFNα expression plasmid could significantly reduce HBV serum markers including HBsAg, HBeAg and HBV DNA as well as the number of HBcAg positive cells in the liver, while IFNβ showed only a weak inhibition of HBV replication. In contrast to IFNβ, IFNα resulted in elevated expression levels of IFN stimulated genes (ISGs) as well as the proinflammatory cytokine interleukin 6 (IL6) in the liver. Moreover, IFNβ treated mice showed higher expression levels of the anti-inflammatory cytokines IL10 and TGFβ in the liver compared to IFNα. Our results demonstrated that both IFNα and IFNβ exert antiviral activities against HBV in HI mouse model, but IFNα is more effective than IFNβ.

Antiviral activity of various interferons and pro-inflammatory cytokines in non-transformed cultured hepatocytes infected with hepatitis B virus

In HBV-infected patients, therapies with nucleoside analogues or IFNα remain ineffective in eradicating the infection. Our aim was to re-analyze the anti-HBV activity of a large panel of IFNs and cytokines in vitro using non-transformed cultured hepatocytes infected with HBV, to identify new immune-therapeutic options. HepaRG cells and primary human hepatocytes were infected with HBV and, when infection was established, treated with various concentrations of different IFNs or inflammatory cytokines. Viral parameters were evaluated by quantifying HBV nucleic acids by qPCR and Southern Blot, and secreted HBV antigens were evaluated using ELISA. The cytokines tested were type-I IFNs, IFNγ, type-III IFNs, TNFα, IL-6, IL-1β, IL-18 as well as nucleos(t)ide analogues tenofovir and ribavirin. Cytokines and drugs, with the exception of IL-18 and ribavirin, exhibited a suppressive effect on HBV replication at least as strong as, but often stronger than, IFNα. The cytokine presenting the highest effect on HBV DNA was IL-1β, which exerted its inhibition within picomolar range. Importantly, we noticed differential effects on other parameters (HBV RNA, HBeAg, HBsAg) between both IFNs and inflammatory cytokines, thus suggesting different mechanisms of action. The combination of IL-1β and already used therapies, i.e. IFNα or tenofovir, demonstrated a stronger or similar anti-HBV activity. IL-1β was found to have a very potent antiviral effect against HBV in vitro. HBV was previously shown to promptly inhibit IL-1β production in Kupffer cells. Strategies aiming at unlocking this inhibition and restoring local production of IL-1β may help to further inhibit HBV replication in vivo.

Control of hepatitis B virus replication by interferons and Toll-like receptor signaling pathways

Hepatitis B virus (HBV) infection is one of the major causes of liver diseases, affecting more than 350 million people worldwide. The interferon (IFN)-mediated innate immune responses could restrict HBV replication at the different steps of viral life cycle. Indeed, IFN-α has been successfully used for treatment of patients with chronic hepatitis B. However, the role of the innate immune response in HBV replication and the mechanism of the anti-HBV effect of IFN-α are not completely explored. In this review, we summarized the currently available knowledge about the IFN-mediated anti-HBV effect in the HBV life cycle and the possible effectors downstream the IFN signaling pathway. The antiviral effect of Toll-like receptors (TLRs) in HBV replication is briefly discussed. The strategies exploited by HBV to evade the IFN- and TLR-mediated antiviral actions are summarized.

Identification and characterization of multiple TRIM proteins that inhibit hepatitis B virus transcription

Tripartite motif (TRIM) proteins constitute a family of over 100 members that share conserved tripartite motifs and exhibit diverse biological functions. Several TRIM proteins have been shown to restrict viral infections and regulate host cellular innate immune responses. In order to identify TRIM proteins that modulate the infection of hepatitis B virus (HBV), we tested 38 human TRIMs for their effects on HBV gene expression, capsid assembly and DNA synthesis in human hepatoma cells (HepG2). The study revealed that ectopic expression of 8 TRIM proteins in HepG2 cells potently reduced the amounts of secreted HBV surface and e antigens as well as intracellular capsid and capsid DNA. Mechanistic analyses further demonstrated that the 8 TRIMs not only reduced the expression of HBV mRNAs, but also inhibited HBV enhancer I and enhancer II activities. Studies focused on TRIM41 revealed that a HBV DNA segment spanning nucleotide 1638 to nucleotide 1763 was essential for TRIM41-mediated inhibition of HBV enhancer II activity and the inhibitory effect depended on the E3 ubiquitin ligase activity of TRIM41 as well as the integrity of TRIM41 C-terminal domain. Moreover, knockdown of endogenous TRIM41 in a HepG2-derived stable cell line significantly increased the level of HBV preC/C RNA, leading to an increase in viral core protein, capsid and capsid DNA. Our studies have thus identified eight TRIM proteins that are able to inhibit HBV transcription and provided strong evidences suggesting the endogenous role of TRIM41 in regulating HBV transcription in human hepatoma cells.

Hepatitis B virus polymerase impairs interferon-α-induced STA T activation through inhibition of importin-α5 and protein kinase C-δ

Treatment with exogenous interferon (IFN)-α is not effective in the majority of patients with chronic hepatitis B virus (HBV) infection. Recent evidence suggests that HBV has evolved strategies to block the nuclear translocation of signal transducer and activator of transcription (STAT) 1 to limit IFN-α-induced cellular antiviral responses. However, it remains unclear whether STAT1 translocation is impaired in chronic hepatitis B patients and what mechanisms are involved. Here we report that the expression of HBV polymerase (Pol) in human hepatic cell lines inhibited induction of IFN-stimulated genes and resulted in a weakened antiviral activity of IFN-α. Ectopic expression of Pol suppressed IFN-α-induced STAT1 serine 727 phosphorylation and STAT1/2 nuclear accumulation, whereas STAT1 tyrosine 701 phosphorylation, and STAT1-STAT2 heterodimer formation were not affected. Further studies demonstrated that Pol interacted with the catalytic domain of protein kinase C-δ (PKC-δ) and perturbed PKC-δ phosphorylation and its association with STAT1, which resulted in the suppression of STAT1 Ser727 phosphorylation. Moreover, Pol was found to interfere with nuclear transportation of STAT1/2 by competitively binding to the region of importin-α5 required for STAT1/2 recruitment. Truncation analysis suggested that the terminal protein and RNase H domains of Pol were able to bind to PKC-δ and importin-α5, respectively, and were responsible for the inhibition of IFN-α signaling. More importantly, the inhibition of STAT1 and PKC-δ phosphorylation were confirmed in a hydrodynamic-based HBV mouse model, and the blockage of IFN-α-induced STAT1/2 nuclear translocation was observed in HBV-infected cells from liver biopsies of chronic HBV patients.

CONCLUSIONS

These results demonstrate a role for Pol in HBV-mediated antagonization of IFN-α signaling and provide a possible molecular mechanism by which HBV resists the IFN therapy and maintains its persistence.