CD56bright natural killer cells induce HBsAg reduction via cytolysis and cccDNA decay in long-term entecavir-treated patients switching to peginterferon alfa-2a

Long-term effects of peginterferon-based therapy versus nucleos(t)ide analogue monotherapy in non-cirrhotic HBeAg-positive chronic hepatitis B patients

BACKGROUND & AIMS

The long-term clinical benefits of interferon (IFN)-based therapy compared to nucleos(t)ide analogue (NA) monotherapy in HBeAg-positive chronic hepatitis B (CHB) have not been well defined. This study aimed to evaluate the cumulative incidence of new-onset cirrhosis, serological responses, and hepatocellular carcinoma (HCC) development between these treatment strategies.

METHODS

Two independent cohorts of non-cirrhotic, HBeAg-positive CHB patients were analyzed: a treatment-naïve cohort (n = 686) and an NA-experienced cohort (n = 531). Patients received either IFN-based therapy or NA monotherapy. Propensity score matching (PSM) was employed to minimize intergroup heterogeneity. The primary endpoint was the cumulative incidence of new-onset cirrhosis.

RESULTS

After PSM, the 10-year cumulative incidence of new-onset cirrhosis was significantly lower in the IFN-based therapy group compared to the NA monotherapy group in both the treatment-naïve (3.3 % vs 20.0 %, p = 0.005) and NA-experienced (4.9 % vs 20.9 %, p = 0.034) cohorts. IFN-based therapy also resulted in significantly higher serological response rates across both cohorts, including HBeAg loss (treatment-naïve: 84.7 % vs 55.6 %; NA-experienced: 60.4 % vs 43.6 %, both p < 0.001) and HBsAg loss (treatment-naïve: 14.3 % vs 5.7 %, p = 0.006; NA-experienced: 10.2 % vs 1.3 %, p < 0.001). Subgroup analysis showed that patients receiving IFN-based therapy who achieved HBeAg loss within 96 weeks had the greatest long-term benefits, with lower cirrhosis incidence and higher HBsAg loss rates. Although the incidence of HCC was lower in the IFN-based group, the difference did not reach statistical significance (both p > 0.05).

CONCLUSIONS

IFN-based therapy provides superior long-term benefits over NA monotherapy in reducing cirrhosis risk and enhancing serological responses in HBeAg-positive CHB patients.

Immune response and treatment targets of chronic hepatitis B virus infection: innate and adaptive immunity

Chronic hepatitis B virus (HBV) infection is a major global public health risk that threatens human life and health, although the number of vaccinated people has increased. The clinical outcome of HBV infection depends on the complex interplay between viral replication and the host immune response. Innate immunity plays an important role in the early stages of the disease but retains no long-term immune memory. However, HBV evades detection by the host innate immune system through stealth. Therefore, adaptive immunity involving T and B cells is crucial for controlling and clearing HBV infections that lead to liver inflammation and damage. The persistence of HBV leads to immune tolerance owing to immune cell dysfunction, T cell exhaustion, and an increase in suppressor cells and cytokines. Although significant progress has been made in HBV treatment in recent years, the balance between immune tolerance, immune activation, inflammation, and fibrosis in chronic hepatitis B remains unknown, making a functional cure difficult to achieve. Therefore, this review focuses on the important cells involved in the innate and adaptive immunity of chronic hepatitis B that target the host immune system and identifies treatment strategies.

Functional molecular expression of nature killer cells correlated to HBsAg clearance in HBeAg-positive chronic hepatitis B patients during PEG-IFN α-2a therapy

OBJECTIVE

To explore whether the frequencies and functional molecules expression of Natural Killer cells (NK cells) are related to hepatitis B surface antigen (HBsAg) disappearance in hepatitis B e envelope antigen (HBeAg)-positive patients with chronic hepatitis B (CHB) throughout peginterferon alpha-2a (PEG-IFN α-2a) treatment.

METHODS

In this prospective research, HBeAg-positive patients with CHB received PEG-IFN α-2a treatment, completing 4-year follow-up. After PEG-IFN α-2a treatment, undetectable HBV DNA, HBsAg loss, and HBeAg disappearance were defined as functional cure. Proportions of NK, CD56dim, CD56bright, NKp46+, NKp46dim, NKp46high, and interferon alpha receptor 2 (IFNAR2)+ NK cells, and the mean fluorescence intensity (MFI) of NK cell surface receptors IFNAR2 and NKp46 were detected.

RESULTS

66 patients were enrolled into the study in which 17 patients obtained functional cure. At baseline, hepatitis B virus desoxyribose nucleic acid (HBV DNA) titer in patients with functional cure was remarkably lower than that in Non-functional cure group. Compared with baseline, HBV DNA levels, HBsAg levels, and HBeAg levels significantly declined at week 12 and 24 of therapy in patients with functional cure. At baseline, the negative correlation between CD56bright NK% and HBV DNA and the negative correlation between CD56dim NK% and HBV DNA was showed; CD56bright NK% and IFNAR2 MFI in patients with functional cure were remarkably higher than those in patients without functional cure. After therapy, CD56bright NK% and NKp46high NK% in patients with functional cure were higher than those in patients without functional cure. In Functional cure group, after 24 weeks of treatment NK%, CD56bright NK%, IFNAR2 MFI weakly increased, and NKp46high NK% and NKp46 MFI significantly increased, meanwhile, CD56dim NK% and NKp46dim NK% decreased. Only NKp46 MFI increased after therapy in patients without functional cure.

CONCLUSION

The lower HBV DNA load and the higher CD56bright NK% before therapy, and the higher the post-treatment CD56bright NK%, IFNAR2 MFI, NKp46high NK%, the easier to achieve functional cure.

Interleukin-2 promotes pegylated interferon alpha for hepatitis B surface antigen loss: A retrospective pragmatic clinical study at the Fourth Affiliated Hospital of Zhejiang University Medical College

Background and Aims

Interleukin-2 (IL-2) can be used as an adjuvant therapy when pegylated interferon alpha (Peg-IFN-α) does not effectively promote hepatitis B surface antigen (HBsAg) loss, but the relevant timing, kinetic patterns, and prognostic associations of this intervention are unclear.

Methods

A total of 115 patients with chronic hepatitis B (CHB) treated at our institution between October 2018 and March 2021 were included in this retrospective analysis. They were divided into two kinetic patterns by using K-medoids cluster analysis. Profile and prognostic associations were statistically analyzed between the two patterns.

Results

After baseline standardization, before the intervention, the relative HBsAg level showed a continuously increasing trend, but after the intervention, it showed a continuously decreasing trend. Based on the relative change in the HBsAg level, two kinetic patterns, namely, a fluctuation platform pattern and a stepwise growth pattern, were identified by using K-medoids cluster analysis for all 115 patients before IL-2 intervention. Profile analysis showed that there were statistically significant differences between the two patterns before IL-2 intervention (p < 0.05), but their profiles showed the same trend after 2 weeks of IL-2 intervention. Prognostic association analysis showed that CD8+ T cells, alanine transaminase (ALT), age, natural killer (NK) cells, neutrophils, and course of treatment before IL-2 intervention were the six main indicators affecting the relative decrease in the HBsAg level.

Conclusion

For CHB patients who have received continuous Peg-IFN-α treatment, IL-2 intervention should be given as early as possible when the HBsAg level has not decreased for four consecutive weeks or a fluctuation platform pattern is observed. After the intervention, a downward relative change in the HBsAg level can be maintained over 4 weeks. CD8+ T cells, ALT, NK cells, and neutrophils are baseline indicators closely related to the prognosis of this intervention.

APASL guidance on stopping nucleos(t)ide analogues in chronic hepatitis B patients

Chronic hepatitis B virus (HBV) infection is currently incurable. Long-term treatment with potent and safe nucleos(t)ide analogs (NAs) can reduce hepatocellular carcinoma (HCC) and cirrhosis-related complications through profound viral suppression. However, indefinite therapy raises several crucial issues with pros and cons. Because seroclearance of hepatitis B surface (HBsAg) as functional cure is not easily achievable, a finite therapy including sequential 48-week pegylated interferon therapy may provide an opportunity to facilitate HBsAg seroclearance by the rejuvenation of exhausted immune cells. However, the cost of stopping NA is the high incidence of virological relapse and surge of alanine aminotransferase (ALT) levels, which may increase the risk of adverse outcomes (e.g., decompensation, fibrosis progression, HCC, or liver-related mortality). So far, the APASL criteria to stop NA treatment is undetectable HBV DNA levels with normalization of ALT; however, this criterion for cessation of treatment is associated with various incidence rates of virological/clinical relapse and more than 40% of NA-stoppers eventually receive retreatment. A very intensive follow-up strategy and identification of low-risk patients for virological/clinical relapse by different biomarkers are the keys to stop the NA treatment safely. Recent studies suggested that decreasing HBsAg level at the end-of-treatment to < 100-200 IU/mL seems to be a useful marker for deciding when to discontinue NAs therapy. In addition, several viral and host factors have been reviewed for their potential roles in predicting clinical relapse. Finally, the APASL guidance has proposed rules to stop NA and the subsequent follow-up strategy to achieve a better prognosis after stopping NA. In general, for both HBeAg-positive and HBeAg-negative patients who have stopped treatment, these measurements should be done every 1-3 months at the minimum until 12 months.

Interferon-Induced Macrophage-Derived Exosomes Mediate Antiviral Activity Against Hepatitis B Virus Through miR-574-5p

BACKGROUND

Interferon alfa (IFN-α) has been proved effective in treating chronic hepatitis B (CHB), owing to its ability to suppress hepatitis B surface antigen and hepatitis B virus (HBV) covalently closed circular DNA. However, the underlying mechanisms are unclear.

METHODS

We investigated the antiviral activities of exosomes from responders and nonresponders to pegylated IFN-α (PegIFN-α) as well as the supernatants of IFN-α-treated macrophages derived from THP-1 (the human leukemia monocyte cell line). Then the expression profiles of exosomal microRNAs (miRNAs) were analyzed using miRNA sequencing. The luciferase reporter assay was used to locate the binding position of HBV genomic sequence targeted by the identified miRNA.

RESULTS

Exosomes from PegIFN-α-treated patients, particularly responders, as well as the supernatants of IFN-α-treated macrophages exhibited anti-HBV activities, as manifested by the suppression of hepatitis B surface antigen, hepatitis B e antigen, HBV DNA, and covalently closed circular DNA levels in HBV-related cell lines. PegIFN-α treatment up-regulated exosomal hsa-miR-193a-5p, hsa-miR-25-5p, and hsa-miR-574-5p, which could partially inhibit HBV replication and transcription, and hsa-miR-574-5p reduced pregenomic RNA and polymerase messenger RNA levels by binding to the 2750-2757 position of the HBV genomic sequence.

CONCLUSIONS

Exosomes can transfer IFN-α-related miRNAs from macrophages to HBV-infected hepatocytes, and they exhibit antiviral activities against HBV replication and expression.

Safety, pharmacokinetics and pharmacodynamics of TQ-A3334, an oral toll-like receptor 7 agonist in healthy individuals

BACKGROUND & AIMS

TQ-A3334, a selective, oral toll-like receptor (TLR)-7 agonist, is being developed to treat chronic hepatitis B (CHB). This study evaluated the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of TQ-A3334 in healthy participants.

RESEARCH DESIGN AND METHODS

The effects of a single-ascending dose of TQ-A3334 (0.2-1.8 mg) combined with food (1.2 mg) were evaluated in 48 healthy participants.

RESULTS

No serious adverse events or discontinuations occurred in the study. The most common adverse reactions were lymphocyte count decreased and headache, which were generally consistent with IFN-α exposure and the mechanism of action of a TLR7 agonist. TQ-A3334 was rapidly absorbed, with a time to maximum plasma concentration of 0.42-0.5 h. Systemic exposure (C_max and AUC) to TQ-A3334 increased with a slight saturation proportion to dose. Food reduced the exposure of TQ-A3334. The concentrations of MCP-1, ISG-15, MX-1, and OAS-1 were observed to be slightly dose-dependent, ranging from 1.0 to 1.8 mg TQ-A3334.

CONCLUSIONS

Oral doses of 0.2-1.8 mg appeared to be safe and tolerated. PD activity was seen at doses ranging from 1.0 to 1.8 mg, indicating its possible future use to treat CHB.

TRIAL REGISTRATION

The trial is registered at the Chinese Clinical Trial website (http://www.chinadrugtrials.org.cn/index.html # CTR20182248).

Contribution of NK cells to HBsAg seroconversion in inactive HBsAg carriers following pegylated IFN therapy

Our recent study showed a high rate of HBsAg seroconversion in inactive HBsAg carriers (IHCs) treated with pegylated IFN (PEG-IFN). To understand the immune-mediated component of the HBsAg seroconversion better, this study investigated the role of NK cells. A total of 44 IHCs were given 48 wk of PEG-IFN. Fifteen cases achieved HBsAg seroconversion (R group), whereas 29 failed (NR group). The proportion and activity (CD107α and IFN-γ production) of NK cells were measured before and during treatment. We found that the proportion of NK cells in the R group was higher than in the NR group at baseline and during PEG-IFN treatment, even when patients were matched for age, sex and treatment period. IFN- γ secretion and CD107α expression from NK cells in cases who achieved HBsAg seroconversion were significantly higher than patients matched for age, sex, HBsAg and treatment period in the NR group at baseline and during PEG-IFN treatment. We also found that in HBsAg seroconversion cases, NK cells activity increased after PEG-IFN treatment, especially before HBsAg seroconversion. These effects were not found in non-responders. In conclusion, we demonstrated that the increase of NK cells accompanied by enhanced activity during PEG-IFN treatment favoured HBsAg seroconversion for IHC, and that NK cells may play a role in HBV seroconversion.

Combination of pegylated interferon-alpha and nucleos(t)ide analogue treatment enhances the activity of natural killer cells in nucleos(t)ide analogue experienced chronic hepatitis B patients

A combination of pegylated interferon-alpha (peg-IFN-α) and nucleos(t)ides analogue (NA) therapy can effectively reduce hepatitis B surface antigen (HBsAg), especially in NA-experienced chronic hepatitis B (CHB) patients. However, the immune mechanism of this therapy is unclear. Forty NA-experienced CHB patients were enrolled into this study. The frequencies of peripheral blood natural killer (NK) cells, dendritic cells (DCs), CD4⁺ T cells, CD8⁺ T cells, T helper (Th) cells, regulatory T cells (T_reg ), B cells and follicular T helper (Tfh) cells were evaluated by flow cytometry. Seven of the 40 patients converted to peg-IFN-α combined with NA treatment, while the other 33 continued to NA therapy. The decrease in HBsAg was more pronounced in the combination treatment group, and only patients receiving combination treatment achieved HBsAg loss. The frequency and absolute number of CD56^bright NK cells in the combination treatment group increased significantly compared with the NA treatment group, whereas the CD56^dim NK cells were decreased. In the NA treatment group, the proportions of CD4⁺ T_N , CD8⁺ T_N , CD19⁺ B and cytotoxic T lymphocyte antigen-4 (CTLA-4)⁺ CD4⁺ T cells were increased, while the proportions of CD4⁺ T_EM , CD8⁺ T_EM , CD25⁺ CD4⁺ T_reg , CD25^high CD4⁺ T_reg , CD127^low CD25⁺ T_reg , programmed cell death 1 (PD-1)⁺ CD4⁺ T, PD-1⁺ CD8⁺ T, CTLA-4⁺ CD8⁺ T, CCR4⁺ CD25⁺ T_reg and CCR4⁺ CD25^high T_reg cells were decreased after therapy. For NA-experienced CHB patients who achieved low HBsAg levels, combination treatment is more likely to result in HBsAg decline and HBsAg clearance by increasing the activity of CD56^bright NK cells.

NKG2C+ natural killer cell function improves the control of HBV replication in individuals with acute HIV infection coinfected with HBV

Individuals infected with hepatitis B virus (HBV) are often coinfected with human immunodeficiency virus (HIV). However, individuals with chronic HBV infection living with acute HIV infection have a significantly lower HBV viral load, along with higher HBeAg and HBsAg loss than HBV-infected individuals alone. Here, we investigated the possible role of natural killer cells (NK cell) function in this progressive course to explore the relationship between phenotypic/functional changes in NK cells during acute HIV infection and HBV clearance in patients with HIV/HBV coinfection.Peripheral blood NK cells from 38 patients with primary HIV infection, including 20 with untreated HIV infection and 18 treatment-naïve patients with HIV/HBV coinfection and 16 patients with chronic HBV infection, were enrolled in this study.We found that the HIV/HBV-coinfected individuals had higher levels of NK cells than the HBV-infected individuals, due to expansion of the CD56 NK cell population. The proportion of NK cells in CD56 and CD56 NK subsets was not found significant difference between HIV/HBV-coinfected and HBV-infected individuals. However, NKG2C levels on NK cells and subsets were significantly higher in HIV/HBV-coinfected individuals than in HBV-infected individuals, whereas NKG2A levels were unaffected or decreased. In addition, the levels of degranulation CD107a, cytotoxicity and IFN-γ production of NK cells were increased in HIV/HBV-coinfected individuals than in HBV-infected individuals. The level of IL-10 production of NK cells was decreased in HIV/HBV-coinfected individuals than in HBV-infected individuals. Furthermore, the level of HBV-DNA was inversely correlated with the proportion of NKG2C and NKG2CNKG2A NK cells, while positively correlated with the proportion of NKG2A and NKG2CNKG2A NK cells. IFN-γ production was inversely correlated with levels of HBV-DNA, but the CD107a expression and IL-10 production of NK cells were not correlated with HBV-DNA levels.These results demonstrate that the upregulation of NKG2C expression, but not of NKG2A expression on the surface of NK cells increases cytolytic capacity and the amounts of cytokines produced and may play a crucial role in HBV clearance during HIV/HBV-coinfection.

Strategies to eliminate HBV infection: an update

Chronic hepatitis B (CHB) is a widespread global infection and a leading cause of hepatocellular carcinoma and liver failure. Current approaches to treat CHB involve the suppression of viral replication with either interferon or nucleos(t)ide analog therapy, but neither of these approaches can reliably induce viral eradication, immunologic control or long-lived viral suppression in the absence of continued therapy. In this update, we explore the major obstacles of CHB cure and review new therapeutic strategies and drug candidates.

Roadmap to functional cure of chronic hepatitis B: An expert consensus

Hepatitis B virus (HBV) infection continues to be a major public health issue worldwide. HBsAg loss is associated with functional remission and improved long-term outcome, and is considered to be a 'functional cure' (also referred to as clinical or immunologic cure) for chronic hepatitis B. This ideal goal of therapy can be achieved using optimized combination regimens with direct-acting antivirals [eg nucleos(t)ide analogues (NAs)] and immunomodulators [eg pegylated interferon alpha2a (Peg-IFN)] in selected patients with chronic hepatitis B. Among different combination therapies currently available, those with NA lead-in followed by Peg-IFN in virally suppressed patients has been demonstrated to be effective. This review provides an updated overview of the evidence supporting the use of combination therapies and summarizes expert consensus on the roadmap to attain functional cure for chronic hepatitis B patients.

Sequential combination therapy with interferon, interleukin-2 and therapeutic vaccine in entecavir-suppressed chronic hepatitis B patients: the Endeavor study

BACKGROUND

Switching from nucleos(t)ide analogues to interferon (IFN) improves hepatitis B surface antigen (HBsAg) loss. We aimed to evaluate whether combining immunomodulators such as interleukin-2 (IL-2) and therapeutic vaccine with IFN enhances HBsAg loss in entecavir (ETV)-suppressed patients.

METHODS

Ninety-four patients exhibiting virological suppression and hepatitis B e antigen (HBeAg) loss following ETV treatment were randomized 1:1:1 to receive ETV (group I) or IFN (group II) for 48 weeks, or IFN and vaccine for 48 weeks plus IL-2 for 12 weeks (group III). The primary endpoint was HBsAg loss at week 48. Peripheral natural killer (NK) cells and regulatory T cells (Treg) were measured as immune checkpoint indicators.

RESULTS

Mean HBsAg decline at week 48 was significantly greater in group III (0.85 log 10 IU/mL) and group II (0.74 log 10 IU/mL), than in group I (0.13 log 10 IU/mL). At week 48, 9.38%, 3.03%, and 3.70% of subjects in group III, II, and I, respectively, achieved HBsAg loss. Among patients with baseline HBsAg titers ranging from 100 to 1500 IU/mL, HBsAg loss rate was 27.3, 7.1, and 0% in group III, II, and I, respectively. Responders in group III showed a significantly higher increase in CD56^bright CD16^-NK cells from week 24 to 36, and a significant decline in Treg from week 12 to 24 than non-responders.

CONCLUSION

For ETV-suppressed patients, particularly those with low baseline HBsAg levels, combination therapy with IFN and other immunomodulators may enhance HBsAg loss, while successful response correlates with partial restoration of NK cells and Tregs.

The impact of currently licensed therapies on viral and immune responses in chronic hepatitis B: Considerations for future novel therapeutics

Despite the availability of a preventative vaccine, chronic hepatitis B (CHB) remains a global healthcare challenge with the risk of disease progression due to cirrhosis and hepatocellular carcinoma. Although current treatment strategies, interferon and nucleos(t)ide analogues have contributed to reducing morbidity and mortality related to CHB, these therapies are limited in providing functional cure. The treatment paradigm in CHB is rapidly evolving with a number of new agents in the developmental pipeline. However, until novel agents with functional cure capability are available in the clinical setting, there is a pressing need to optimize currently licensed therapies. Here, we discuss current agents used alone and/or in combination strategies along with the impact of these therapies on viral and immune responses. Novel treatment strategies are outlined, and the potential role of current therapies in the employment of pipeline agents is discussed.