Molecular mechanisms of HBeAg in persistent HBV infection

Switching to tenofovir alafenamide versus continued therapy in chronic hepatitis B patients who were treated with entecavir: A prospective, multicenter, randomized controlled study

BACKGROUNDS

Entecavir (ETV) and tenofovir alafenamide fumarate (TAF) have been used widely to treat patients with chronic hepatitis B virus (HBV) infection, but it is still unclear how best to use these drugs. Although some studies compared the efficacies of treatment switch from ETV to TAF, there has been no randomized study.

METHODS

We performed a prospective multicenter randomized controlled study in which subjects were enrolled from April 2018 to June 2019 and observed for 2 years until March 2021 to clarify the efficacy and safety of switching from ETV to TAF.

RESULTS

Thirty-three patients were enrolled and randomized into 2 groups, and a total of 30 patients were evaluated; a TAF-switching group (n = 16) and an ETV-continuing group (n = 14). The mean age of the 30 patients was 61 years old and 18 patients (60%) were male. The serum HBV DNA in all patients were below detection limit. The mean change in hepatitis B surface antigen (HBsAg) levels after 2 years was not significantly different between the TAF and ETV groups (-0.08 vs -0.20 log IU/mL, P = .07). Comparing the group with a HBsAg decline (≤ -0.1 log IU/mL) and a group without a HBsAg decline in an overall analysis, the prior ETV duration was significantly shorter in the HBsAg-declined group (49 vs 92 months, P = .03). Although the eGFR levels tended to decrease in the TAF group compared to ETV (-6.15 vs -2.26 mL/min/1.73 m2, P = .09), no significant differences were observed in patients with baseline eGFR < 60 (-2.49 vs 0.40 mL/min/1.73 m2, P = .25).

CONCLUSION

The efficacy and safety were comparable in the TAF-switching group and the ETV-continuing group. Because the present study was conducted in limited patients, a larger study will be required.

The positive feedback loop of furin and TGFβ1 enhances the immune responses of Tregs to hepatocellular carcinoma cells and hepatitis B virus in vitro

Regulatory T cells (Tregs) can exert immunosuppressive activity. Furin can regulate Treg functions, hepatitis B virus (HBV) persistent infection, and hepatocellular carcinoma (HCC) development. However, it remains unknown whether furin can regulate the immune responses of Tregs to HBV and HCC cells. Here, coculture systems of HBV1.3P-HepG2.3P-HepG2 cells and Tregs transduced with or without lentiviral particles that could overexpress furin or knockdown furin/transforming growth factor β1 (TGFβ1) were established to investigate the regulatory relationship between furin and TGFβ1 and the effect of furin/TGFβ1 on Treg activity. Also, the effects of furin overexpression or furin/TGFβ1 knockdown in Tregs on the immunological activity of effector T cells (Teffs)/cytotoxic T lymphocytes (CTLs) and HBV replication/expression were explored in the coculture system of Teff/CTL, Treg, and HBV1.3P-HepG2 cells. Our results showed that furin expression and TGFβ1 secretion were notably increased in Tregs, and Furin and TGFβ1 formed a positive feedback loop to activate Tregs in the coculture system of Tregs and HBV1.3P-HepG2 cells. Furin or TGFβ1 knockdown in Tregs promoted Teff cell proliferation, stimulated interleukin-2 and interferon-γ secretion, and inhibited HBV replication/gene expression in the coculture system of Teff, Treg, and HBV1.3P-HepG2 cells. Moreover, furin or TGFβ1 depletion in Tregs enhanced the killing activity of CTLs against HBV1.3P-HepG2 cells and curbed HBV replication/gene expression in the coculture system of Tregs, CTLs, and HBV1.3P-HepG2 cells. In conclusion, the positive feedback loop of furin and TGFβ1 enhanced the immune responses of Tregs to HCC cells and HBV in vitro.

Host Innate Immunity Against Hepatitis Viruses and Viral Immune Evasion

Hepatitis viruses are primary causative agents of hepatitis and represent a major source of public health problems in the world. The host innate immune system forms the first line of defense against hepatitis viruses. Hepatitis viruses are sensed by specific pathogen recognition receptors (PRRs) that subsequently trigger the innate immune response and interferon (IFN) production. However, hepatitis viruses evade host immune surveillance via multiple strategies, which help compromise the innate immune response and create a favorable environment for viral replication. Therefore, this article reviews published findings regarding host innate immune sensing and response against hepatitis viruses. Furthermore, we also focus on how hepatitis viruses abrogate the antiviral effects of the host innate immune system.

Switching to tenofovir disoproxil fumarate in entecavir-treated chronic hepatitis B patients: A pilot randomized controlled study

Although hepatitis B surface antigen (HBsAg) removal is considered the goal of chronic hepatitis B treatment, it can rarely be achieved with nucleos(t)ide analogues (NAs). It has been reported that tenofovir disoproxil fumarate (TDF) is superior in reducing HBsAg compared with entecavir (ETV) in treatment-naïve patients; however, the effect of TDF in patients who have received NAs is still unclear. The aim of the present study was to evaluate the efficacy of switching from ETV to TDF in patients who were already receiving ETV. A pilot randomized controlled study for 2 years in patients who had been treated with ETV for >1 year and did not exhibit drug resistance was performed (Clinical trial registration: UMIN000021948, UMIN-CTR, May 1, 2016). A total of 20 patients were enrolled and 19 patients were randomized into 2 groups, a TDF-switching group (n=12) or an ETV-continuing group (n=7). The mean change in HBsAg levels after 2 years was greater in the TDF group compared with the ETV group, but the difference was not significant (-0.25 vs. -0.06 log IU/ml). In the TDF group, hepatitis B e antigen (HBeAg)-positive patients at baseline showed significantly greater changes in HBsAg (-0.63 vs. -0.03 log IU/ml; P=0.030). In contrast, no difference between HBeAg-positive and HBeAg-negative patients was observed in the ETV group. No significant differences of estimated glomerular filtration rate and inorganic phosphorus changes were observed among the TDF and ETV groups. In conclusion, a significant HBsAg decrease was not achieved after switching from ETV to TDF in the overall analysis, but HBeAg-positive patients showed a larger HBsAg decrease after switching treatment.

Increasing Imbalance of Treg/Th17 Indicates More Severe Glucose Metabolism Dysfunction in Overweight/obese Patients

BACKGROUND

Chronic low-grade inflammation and dysfunction of metabolism has been reported to be involved in obesity. Regulatory T cell (Treg) and helper T cell 17 (Th17) are involved in chronic inflammatory diseases. Impaired balance of Treg/Th17 is one of the major factors contributing to inflammatory status in obesity.

METHODS

Overweight/obese patients (n = 80) were recruited and classified into three subgroups: normal glucose tolerance group (NGT, n = 32), impaired glucose regulation group (IGR, n = 19) and type two diabetes mellitus group (T2DM, n = 29). Healthy individuals were paired as normal control group (NC, n = 37). We used flow cytometry to test the frequencies of circulating Treg and Th17 cells of all subjects. Serum IL-6, IL-10, TNF-α, IL-17A levels were detected by cytometric bead array and clinical information was extracted from medical records.

RESULTS

In group IGR and T2DM, we revealed a severe decrease in peripheral ratio of Treg/Th17 compared with NC, but no significant difference was seen in group NGT. The serum level of IL-6 in group NGT and T2DM was higher than healthy subjects. The FPG and HbA1c levels were negatively correlated with the ratio of Treg/Th17 in overweight/obese patients. ROC curve analysis revealed that peripheral Treg/Th17 ratio <1.255 was a risk factor for prediabetes and diabetes in overweight/obese patients.

CONCLUSION

Peripheral Treg/Th17 imbalance exists in overweight/obese patients with IGR or T2DM and peripheral Treg/Th17 imbalance might be a risk factor for prediabetes and diabetes in overweight/obese patients.

Hepatitis Flares Are Associated With Better Outcomes Than No Flare in Patients With Decompensated Cirrhosis and Chronic Hepatitis B Virus Infection

BACKGROUND & AIMS

Little is known about the effects of baseline hepatitis flares (level of alanine aminotransferase ≥5-fold above the upper limit of normal) on the outcomes of patients with chronic hepatitis B virus (HBV) infection with decompensated cirrhosis treated with nucleos(t)ide analogues. We aimed to investigate these effects.

METHODS

We performed a cohort study of 511 consecutive patients (78.1% men; 58.7% with flares at baseline) with chronic HBV infection and decompensated cirrhosis who were treated with nucleos(t)ide analogues as soon as decompensation was noted. Patients were enrolled from January 2002 to March 2018 at a tertiary care center in Taiwan and followed up for 16 years.

RESULTS

Patients with hepatitis flares had higher mean baseline levels of HBV DNA (6.44 ± 1.52 vs 6.08 ± 1.46 log₁₀ IU/mL; P = .003), hepatitis B surface antigen, and total bilirubin; prolonged prothrombin time; higher platelet counts (108.0 ± 42.9 vs 83.6 ± 44.7 103/μL; P < .001); and a higher proportion were infected with HBV genotype B, compared with patients without flares. Patients with flares had lower ratios of neutrophils to lymphocytes than patients with flares (6.14 ± 9.18 vs 9.12 ± 1.36; P = .019); were less likely than patients without flares to be positive for hepatitis B e antigen, ascites, esophageal varices, or splenomegaly; and a lower proportion died or underwent liver transplantation (46.5% vs 73.2% of patients without flares; P < .001), even though the patients without flares had similar short-term (<3 mo) outcomes. Factors associated independently with baseline flares were esophageal varices (odds ratio [OR], 0.165; 95% CI, 0.067-0.406), ascites (OR, 0.415; 95% CI, 0.178-0.969), levels of total bilirubin (OR, 1.158; 95% CI, 1.041-1.269), prolonged prothrombin time (OR, 1.095; 95% CI, 1.033-1.168), and higher platelet counts (OR, 1.009; 95% CI, 1.00-1.018). After we used propensity score matching to match patients with and without baseline flares, factors associated with the cumulative incidence of death or liver transplantation were flares (hazard ratio [HR], 0.491; 95% CI, 0.317-0.76), ratio of neutrophils to lymphocytes (HR, 1.278; 95% CI, 1.027-1.591), and prolonged prothrombin time (HR, 1.223; 95% CI, 1.052-1.423).

CONCLUSIONS

In a 16-year study of patients with chronic HBV infection and decompensated cirrhosis treated with nucleos(t)ide analogues, a baseline flare of hepatitis was associated independently with better long-term (≥3 mo) outcomes than no flare.

Progress of research on the immune tolerance of chronic HBV infection

Immune tolerance is a specific lack or negative response of T and B lymphocytes to antigen. According to different formation periods, immune tolerance can be divided into central and peripheral tolerances. The immune tolerance of the body to hepatitis B virus (HBV) after infection is the main cause of chronic HBV infection. In this paper, the functional defects of hepatitis B virus e antigen and dendritic cells, hyporesponsiveness of cytotoxic T lymphocyte, variation of helper T lymphocytes and cytokines, HBV genotype and genome, and the role of host gene polymorphism in the formation of immune tolerance in chronic HBV infection and its related research progress are introduced briefly.

Design, synthesis and biological evaluation of seco-A-pentacyclic triterpenoids-3,4-lactone as potent non-nucleoside HBV inhibitors

A series of seco-A-pentacyclic triterpenoids-3,4-lactone were synthesized and the anti-HBV activities were evaluated in vitro. Several compounds inhibited the secretion of HBV antigen and the replication of HBV DNA in micromolar level. Compounds D7 and D10, seco-A-oleanane-3,4-lactone, suppressed the HBeAg secretion with IC₅₀ values of 0.14 μM and 0.86 μM respectively, and the inhibitory activities were also confirmed by detecting the fluorescence intensity of FITC-labeled monoclonal mouse HBeAg antibody via flow cytometry. Compounds D7 and D10 as well as B4, ring-A cleaved 3,30-dioic acid, also displayed remarkable inhibition on both HBV DNA replication at the concentration of 25 μM and HBV cccDNA (covalently closed circularDNA) replication with IC₅₀ values of 33.5 μM, 32.7 μM and 12.3 μM respectively.

Analysis of epitope-based vaccine candidates against the E antigen of the hepatitis B virus based on the B genotype sequence: An in silico and in vitro approach

Chronic hepatitis B virus infection is a worldwide health problem with no current effective strategy to achieve a cure. The Hepatitis B virus (HBV) E antigen (HBeAg) has a negative effect on the immune system and a therapeutic vaccine is a promising strategy in order to treat chronic virus infection. In this study, we analyzed and identified the MHC-I, MHC-II and B cell epitopes of the HBeAg based on a B genotype sequence of HBV using a bioinformatic approach and in vitro experiments. The computational approach provided us with four epitopes (LLWFHISCL, YLVSFGVWI, MQLFHLCLI, TVLEYLVSF) of the specific MHC-I allele HLA-A0201 that conformed to all criteria. Molecular docking and a peptide binding assay showed that epitope TVLEYLVSF had the lowest binding energy and epitope LLWFHISCL had the highest binding affinity to the HLA-A0201 molecule. An interferonγenzyme-linked immunospot assay and cytotoxicity assay revealed that epitope LLWFHISCL had the highest ability to induce and stimulate T cells. Furthermore, we determined four core peptides of MHC-II epitopes and a region of the B cell epitope. The epitopes and region identified in this research may be helpful in designing epitope-based vaccines and boosting the mechanism research of HBeAg and its effect on the immune system.

CD45RO+ T Cells and T Cell Activation in the Long-Lasting Immunity after Leishmania infantum Infection

Manifestations of Leishmania infantum infection range from asymptomatic to symptomatic visceral leishmaniasis (VL). People with symptomatic VL (sVL) have suppressed immune responses against Leishmania antigens that are reversed after clinical cure. The intradermal leishmanin skin test (LST) is negative during sVL, but it becomes positive after treatment. The aim of this study was to compare T cell responses in individuals with sVL, recovered VL (RecVL), and endemic controls. Endemic controls were household contacts of a VL case and they were grouped by their LST results, either positive (LST+) or negative (LST-). Mononuclear cells were studied ex vivo or after stimulation with soluble Leishmania antigens (SLA); cell surface markers and cytokines were determined. T cells, ex vivo, from individuals with sVL and from LST+ individuals presented a higher activation for CD4⁺ and CD8⁺ cells expressing CD69. However, lymphocytes from sVL stimulated with SLA had lower percentages of CD4⁺ and CD8⁺ cells expressing CD69 and CD8⁺ cells expressing CD25, with no release of interferon-γ or tumor necrosis factor. sVL subjects had lower percentage of memory cells (CD4⁺ CD45RO+), ex vivo, without SLA stimulation than RecVL, LST+, or LST- (P = 0.0022). However, individuals with sVL had fewer regulatory cells after SLA stimulation (CD4⁺ CD25^HIGH, P = 0.04 and CD4⁺ FOXP3+, P = 0.02) than RecVL. The decrease in specific memory and activated CD4⁺ and CD8⁺ cells, as in response to Leishmania antigens, could explain, in part, the immune impairment during sVL. Finally, protective T cell responses are long lasting because both RecVL or LST+ individuals maintain a specific protective response to Leishmania years after the primary infection.