TNF-α/IFN-γ profile of HBV-specific CD4 T cells is associated with liver damage and viral clearance in chronic HBV infection

Interpretable machine learning model for prediction functional cure in chronic hepatitis B patients receiving Peg-IFN therapy: A multi-center study

BACKGROUND

Functional cure is the ideal treatment goal for chronic hepatitis B (CHB) treatment. We developed and validated machine learning (ML) models to predict functional cure in CHB patients.

METHODS

This study retrospectively recruited 534 CHB patients who received Peg-IFN treatment to construct model and 269 patients for external validation. We analyzed three strategies: baseline, week 12, week 24. Seven ML models were constructed using selected variables by Boruta and least absolute shrinkage and selection operator regression algorithm, and performance metrics, including area under the curve (AUC), sensitivity, specificity, and F1 score were applied to determine the best model. We utilized SHapley Additive exPlanation to visualize and interpret the best model and built a website to conveniently predict functional cure of CHB.

RESULTS

A total of 272 participants were cured in our study. Compared to baseline and week 12 strategies, week 24 using Support Vector Machine (SVM) model can better predict functional cure of CHB, with reliable predictive performance (AUC = 0.981), calibration and clinical applicability in external validation cohort. Age, ALT ratio at week 12, HBsAg at week 24 and HBsAg ratio at week 24 were important features. In order to enhance clinical convenience and effectiveness of the constructed model, a web-based dynamic nomogram was created (Dynamic Nomogram (shinyapps.io)).

CONCLUSION

This study developed SVM model to predict functional cure in CHB patients treated with Peg-IFN. Furthermore, we also built a website that clinicians can individualized predict the efficacy of Peg-IFN therapy in CHB patients.

Expression variation of Akt and cytokines in lamivudine-resistant HBV rare mutation that prematurely truncates the overlapping surface protein

The sW196*(Stop) mutation of HBV is the rarest variant of sW196L. It is associated with rapid progression of chronic hepatitis B to end-stage liver disease and hepatocellular carcinoma. Information on proliferative vs. apoptotic cells and immunological manifestations related to the expression of HBV-associated cytokines in the presence of the lamivudine-resistant mutation sW196L and the rarest variant of sW196L, sW196*(Stop), has been limited. Therefore, the current investigation aimed to examine the molecular and immunological basis of lamivudine-resistant mutations with the help of transfection studies carried out in cell lines of hepatic origin. sW196*(Stop) transfected HepG2 cells showed IFN-gamma was extremely downregulated by 20.96 folds, and IL-6 was upregulated by 4.5 folds which had not been seen in any of the constructs. The current study reveals for the first time the underlying immunological processes that render detrimental effects to lamivudine-resistant rare mutations, in particular sW196*(Stop) of HBV that can be explained by downregulation of IFN-gamma, a known cytokine associated with efficient viral clearance, together with upregulation of IL-6 known to be associated with disease progression and HCC. Understanding the molecular and immunological mechanisms in such HBV mutations is furthered by the choreographed event of increased TNF-alpha expression, which is known to be linked to liver damage.

Impacts of PEG-IFN-α-2b Combination Therapy on Liver Function, Immune Factors and Risk Factors in Patients With HBV Infection: A Retrospective Study

Aims/Background Hepatitis B virus (HBV) infection poses a challenge to global healthcare. Peginterferon alfa-2b (PEG-IFNα-2b) is an effective treatment for HBV infection. This study aimed to explore the efficacy of PEG-IFNα-2b combined with entecavir in the treatment of HBV infection, its effect on liver function and immune factors, and the risk factors affecting the prognosis of patients with HBV infection. Methods The clinical data of 184 patients with HBV infection who were treated at Jinhua Central Hospital from January 2021 to January 2024 were collected for retrospective analysis. Patients were divided into a control group (not receiving antiviral treatment, n = 34), a standard treatment group (receiving entecavir, n = 85), and a combination treatment group (PEG-IFNα-2b and entecavir, n = 65) according to the treatment approach. Treatment efficacy, liver function indicators (albumin [ALB], alanine aminotransferase [ALT], and aspartate aminotransferase [AST]), immune factor indexes (tumour necrosis factor alpha [TNF-α] and interferon gamma [IFN-γ]), hepatitis B surface antigen [HBsAg] and HBV DNA levels were compared among the three groups. All patients were followed up after treatment. According to their prognosis, the patients were divided into good prognosis group (n = 118) and poor prognosis group (n = 66). Logistic regression analysis was performed to explore the risk factors affecting the prognosis of HBV patients. Results The efficacy in the combination treatment group was higher (92.31%) than that in the control group (8.82%) and the standard treatment group (78.82%) (p < 0.05). After treatment, the HBsAg and HBV DNA levels were decreased in the standard treatment and combination treatment groups (p < 0.05). Compared with the control and standard treatment groups, the combination treatment group exhibited significantly lower HBsAg and HBV DNA levels after treatment (p < 0.05). Besides, the combination treatment group had lower ALT and AST levels (p < 0.05), and higher ALB level (p < 0.05), than the control and standard treatment groups after treatment. Compared with the control and standard treatment groups, the combination treatment group demonstrated decreased TNF-α level and higher IFN-γ level after treatment (p < 0.05). Multivariate logistic regression analysis identified family medical history as the risk factor affecting the prognosis of patients with HBV infection (p = 0.001, odds ratio [OR] = 3.614, 95% confidence interval [CI]: 1.685-7.750) and therapy regimen as the protective factor (p = 0.029, OR = 0.135, 95% CI: 0.022-0.815). Conclusion The PEG-IFNα-2b combination therapy in patients with HBV infection significantly improves the clinical treatment efficacy, liver function, and immune factors. In addition, this study found that therapy regimen and family medical history are independent factors affecting the prognosis of HBV infection.

Functional Cure for Hepatitis B Virus: Challenges and Achievements

The Hepatitis B Virus (HBV) presents a formidable global health challenge, impacting hundreds of millions worldwide and imposing a considerable burden on healthcare systems. The elusive nature of the virus, with its ability to establish chronic infection and evade immune detection, and the absence of curative agents have prompted efforts to develop novel therapeutic approaches beyond current antiviral treatments. This review addresses the challenging concept of a functional cure for HBV, a state characterized by the suppression of HBV and HBsAg, mitigating disease progression and transmission without a complete cure. We provide an overview of HBV epidemiology and its clinical impact, followed by an exploration of the current treatment landscape and its limitations. The immunological basis of a functional cure is then discussed, exploring the intricate interplay between the virus and the host immune response. Emerging therapeutic approaches, such as RNA interference-based interventions, entry inhibitors, nucleic acid polymers, and therapeutic vaccines, are discussed with regard to their success in achieving a functional cure. Lastly, the review underscores the urgent need for innovative strategies to achieve a functional cure for HBV.

Definition, diagnosis and epidemiology of acute-on-chronic liver failure

This narrative review addresses the definition of acute-on-chronic liver failure, a condition associated with high short-term mortality in patients with chronic liver disease and/or cirrhosis. We provide two major points of view: the East and the West perspective. Both definitions vary regarding the underlying patient population and organ failure(s) definition. Nevertheless, all the definitions have their clinical utility: from the core concept of having the "liver" as a conditio sine qua non, the syndrome cannot exist (Asian Pacific Association for the Study of the Liver); a data-driven, robust definition (European Association for the Study of the Liver); a bedside tool that can quickly identify patients at high risk of dying (North American Consortium for the Study of End-stage Liver Disease [NACSELD]). In each section, we provide the overall definitions, the criteria of organ failure(s), and some epidemiological data illustrating how these apply in each area of the world.

Immunotherapy Using HBV Vaccine Pulsed DCs and Induced T-Cells Combined Antiviral Drugs in Treatment Naive CHB Patients-A Multi-Centre Phase II Study

Dendritic cells are the most potent antigen-presenting cells in immune therapeutic approaches for chronic hepatitis B (CHB) infection. Here, we developed a clinical trial to evaluate the efficacy and safety of autologous HBV vaccine-pulsed DCs and their induced T cells (HPDCT) in CHB patients. This was a randomised, prospective, open-label, multicentre, superiority study and 309 treatment-naive CHB patients were divided into HPDCT plus nucleos(t)ide analogues (NAs) group (n = 84), NAs mono-therapy group (n = 82), HPDCT plus Peg-interferon (Peg-IFN) group (n = 69), Peg-IFN mono-therapy group (n = 74). Twelve times of HPDCT vaccinations were given intravenously, and all the patients were followed up for 72 weeks. In total, 1836 HPDCT infusions were administered with no obvious toxicity and side effect although few patients had self-limited low fever. More patients got HBsAg loss in those receiving HPDCT therapy. Patients of HPDCT plus Peg-IFN group with HBV DNA < 1 × 107 IU/mL at baseline exhibited earlier, stronger and longer lasting of viral response, especially HBV DNA < 20 IU/mL, than those patients of Peg-IFN mono-therapy group, from week 24 till week 72 (p < 0.05). Comparable efficacy was observed between the patients of HPDCT plus NAs group and NAs mono-therapy groups. In addition, CD25 on CD8+ T cells and HBV-specific CD8+ T cell increased significantly in patients of HPDCT combined antiviral drugs therapy. HPDCT combined with antiviral drugs was safe and able to enhance T cell immunity. Furthermore, HPDCT combined with Peg-IFN could provide an incremental benefit to patients with baseline levels of lower HBV DNA. Trial Registration: ClinicalTrials.gov identifier: NCT01935635.

Hepatic Flare Following Effective Antiretroviral Therapy Is Associated With HBsAg Seroclearance in HBV/HIV-1 Co-Infection

Little is known about the clinical significance of hepatic flare following effective antiretroviral therapy (ART) on HBsAg seroclearance and prognosis in HBV/HIV co-infection. This observational cohort study recruited HBV/HIV-1 co-infected patients from the China National Free Antiretroviral Treatment Program. We obtained longitudinal information on demographic characteristics, clinical indicators, and treatment outcomes. Hepatic flare was defined as an elevation of ALT of more than five times the upper limit of the normal range without an upsurge of HBV DNA or HBsAg at any time point between ART initiation and 12 months. Among the 1354 enrolled patients, 98.7% received two anti-HBV drugs containing ART and 95.1% achieved good viral control. Hepatic flare was observed in 88 (6.5%) patients and was more frequent in those with lower baseline immune function but subsequently enhanced immune reconstitution. Over a median follow-up of 4.7 years, we observed 99 HBsAg seroclearance, 9 hepatic events, 6 HIV-associated malignancy, 3 non-HIV-associated malignancy, and 3 all-cause mortality. The 3-, 5-, and 10-year cumulative incidence of HBsAg seroclearance was 6.4%, 8.9%, and 12.9%, respectively. Compared to patients without hepatic flare, patients with hepatic flare had significantly higher rates of HBsAg seroclearance (13.6% vs. 6.9%, p = 0.018) but had no recorded adverse outcome. Multivariate analysis with different models indicated that hepatic flare was independently associated with HBsAg seroclearance especially in patients with low immune function, normal ALT, and high levels of HBV DNA and HBsAg at baseline. In HBV/HIV-1 co-infection, hepatic flare following effective ART is associated with HBsAg seroclearance. HBV-specific T cells immune reconstitution may represent a potential mechanism which deserves further investigation.

Probiotics and their metabolite spermidine enhance IFN-γ+CD4+ T cell immunity to inhibit hepatitis B virus

The therapeutic potential of commensal microbes and their metabolites is promising in the functional cure of chronic hepatitis B virus (HBV) infection, which is defined as hepatitis B surface antigen (HBsAg) loss. Here, using both specific-pathogen-free and germ-free mice, we report that probiotics significantly promote the decline of HBsAg and inhibit HBV replication by enhancing intestinal homeostasis and provoking intrahepatic interferon (IFN)-γ+CD4+ T cell immune response. Depletion of CD4+ T cells or blockage of IFN-γ abolishes probiotics-mediated HBV inhibition. Specifically, probiotics-derived spermidine accumulates in the gut and transports to the liver, where it exhibits a similar anti-HBV effect. Mechanistically, spermidine enhances IFN-γ+CD4+ T cell immunity by autophagy. Strikingly, administration of probiotics in HBV patients reveals a preliminary trend to accelerate the decline of serum HBsAg. In conclusion, probiotics and their derived spermidine promote HBV clearance via autophagy-enhanced IFN-γ+CD4+ T cell immunity, highlighting the therapeutic potential of probiotics and spermidine for the functional cure of HBV patients.

HBV Biomarkers and Their Role in Guiding Treatment Decisions

Over 300 million individuals worldwide are chronically infected with hepatitis B virus and at risk for progressive liver disease. Due to the lack of a therapy that reliably achieves viral elimination and the variability of liver disease progression, treatment decisions are guided by the degree of liver disease and viral biomarkers as the viral life-cycle is well characterized and largely conserved between individuals. In contrast, the immunological landscape is much more heterogeneous and diverse and the measurement of its components is less well standardized. Due to the lack of a universal and easily measurable set of biomarkers, clinical practice guidelines remain controversial, aiming for a balance between simplifying treatment decisions by reducing biomarker requirements and using all available biomarkers to avoid overtreatment of patients with low risk for disease progression. While approved therapies such as nucleos(t)ide analogs improve patient outcomes, the inability to achieve a complete cure highlights the need for novel therapies. Since no treatment candidate has demonstrated universal efficacy, biomarkers will remain important for treatment stratification. Here, we summarize the current knowledge on virological and immunological biomarkers with a specific focus on how they might be beneficial in guiding treatment decisions in chronic hepatitis B.

Elimination of the hepatitis B virus: A goal, a challenge

The hepatitis B elimination is a goal proposed by the WHO to be achieved by 2030 through the adoption of synergistic measures for the prevention and chronic HBV infection treatment. Complete cure is characterized by the HBV elimination from the body and is the goal of the chronic hepatitis B treatment, which once achieved, will enable the hepatitis B elimination. This, today, has been a scientific challenge. The difficulty in achieving a complete cure is due to the indefinite maintenance of a covalently closed episomal circular DNA (cccDNA) reservoir and the maintenance and persistence of an insufficient and dysfunctional immune response in chronically infected patients. Among the measures adopted to eliminate hepatitis B, two have the potential to directly interfere with the virus cycle, but with limited effect on HBV control. These are conventional vaccines-blocking transmission and antiviral therapy-inhibiting replication. Vaccines, despite their effectiveness in protecting against horizontal transmission and preventing mother-to-child vertical transmission, have no effect on chronic infection or potential to eliminate the virus. Treatment with antivirals suppresses viral replication, but has no curative effect, as it has no action against cccDNA. Therapeutic vaccines comprise an additional approach in the chronic infection treatment, however, they have only a modest effect on the immune system, enhancing it temporarily. This manuscript aims to address (1) the cccDNA persistence in the hepatocyte nucleus and the immune response dysfunction in chronically infected individuals as two primary factors that have hampered the treatment and HBV elimination from the human body; (2) the limitations of antiviral therapy and therapeutic vaccines, as strategies to control hepatitis B; and (3) the possibly promising therapeutic approaches for the complete cure and elimination of hepatitis B.

Expression patterns of immune checkpoint proteins and Plasmodium falciparum-induced cytokines in chronic hepatitis B virus-infected and uninfected individuals: A cross-sectional study

Background and Aim

Chronic hepatitis B virus (CHB) infection remains a major public health problem. The American Association for the Study of Liver Diseases (AASLD) 2018 Hepatitis B Guidelines provide that CHB individuals not requiring antiviral therapy yet are monitored to determine the need for antiviral therapy in the future; however, these tests do not include measurement of cytokines and immune cell characterization. This case-control study compared the cytokine and immune checkpoint protein expression profiles between CHB individuals not yet on antiviral treatment and hepatitis B virus (HBV)-negative individuals.

Methods

CD4 and CD8 T cells from CHB and HBV-negative individuals were characterized for immune checkpoint proteins programmed cell death-1 (PD1), T cell Immunoglobulin domain and mucin domain-containing protein 3 (TIM-3), and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) (CD152), and a memory marker CXCR3 (CD183) using flow cytometry. Malaria-induced cytokine expression levels were determined by stimulating their blood cells with Plasmodium falciparum 3D7 strain antigens (CSP, AMA-1, and TRAP) in whole blood assays, and cytokine levels were measured using a 13-plex Luminex kit.

Results

HBV-negative and CHB individuals had comparable levels of CD4+ and CD8+ T cells. However, a proportion of the CD4+ and CD8+ populations from both groups, which were CXCR3+, expressed PD-1 and CD152. The ability to produce cytokines in response to malaria antigen stimulation was not significantly different between the groups.

Conclusion

These findings support excluding CHB individuals from antiviral therapy at this stage of infection. However, CHB individuals require regular monitoring to determine the need for later antiviral treatment.

Novel role of MHC class II transactivator in hepatitis B virus replication and viral counteraction

BACKGROUND/AIMS

The major histocompatibility class II (MHC II) transactivator, known as CIITA, is induced by Interferon gamma (IFN-γ) and plays a well-established role in regulating the expression of class II MHC molecules in antigen-presenting cells.

METHODS

Primary human hepatocytes (PHH) were isolated via therapeutic hepatectomy from two donors. The hepatocellular carcinoma (HCC) cell lines HepG2 and Huh7 were used for the mechanistic study, and HBV infection was performed in HepG2-NTCP cells. HBV DNA replication intermediates and secreted antigen levels were measured using Southern blotting and ELISA, respectively.

RESULTS

We identified a non-canonical function of CIITA in the inhibition of hepatitis B virus (HBV) replication in both HCC cells and patient-derived PHH. Notably, in vivo experiments demonstrated that HBV DNA and secreted antigen levels were significantly decreased in mice injected with the CIITA construct. Mechanistically, CIITA inhibited HBV transcription and replication by suppressing the activity of HBV-specific enhancers/promoters. Indeed, CIITA exerts antiviral activity in hepatocytes through ERK1/2-mediated down-regulation of the expression of hepatocyte nuclear factor 1α (HNF1α) and HNF4α, which are essential factors for virus replication. In addition, silencing of CIITA significantly abolished the IFN-γ-mediated anti-HBV activity, suggesting that CIITA mediates the anti-HBV activity of IFN-γ to some extent. HBV X protein (HBx) counteracts the antiviral activity of CIITA via direct binding and impairing its function.

CONCLUSION

Our findings reveal a novel antiviral mechanism of CIITA that involves the modulation of the ERK pathway to restrict HBV transcription. Additionally, our results suggest the possibility of a new immune avoidance mechanism involving HBx.

Interferon-γ+ Th1 activates intrahepatic resident memory T cells to promote HBsAg loss by inducing M1 macrophage polarization

The immune mechanism underlying hepatitis B surface antigen (HBsAg) loss, particularly type I inflammatory response, during pegylated interferon-α (PEG-IFN) therapy remains unclear. In this study, we aimed to elucidate such immune mechanisms. Overall, 82 patients with chronic hepatitis B (CHB), including 41 with HBsAg loss (cured group) and 41 uncured patients, received nucleos(t)ide analogue and PEG-IFN treatments. Blood samples from all patients, liver tissues from 14 patients with CHB, and hepatic perfusate from 8 liver donors were collected for immune analysis. Jurkat, THP-1 and HepG2.2.15 cell lines were used in cell experiments. The proportion of IFN-γ+ Th1 cells was higher in the cured group than in the uncured group, which was linearly correlated with HBsAg decline and alanine aminotransferase (ALT) levels during treatment. However, CD8+ T cells were weakly associated with HBsAg loss. Serum and intrahepatic levels of Th1 cell-associated chemokines (C-X-C motif chemokine ligand [CXCL] 9, CXCL10, CXCL11, IFN-γ) were significantly lower in the cured patients than in patients with a higher HBsAg quantification during therapy. Serum from cured patients induced more M1 (CD68+CD86+ macrophage) cells than that from uncured patients. Patients with chronic HBV infection had significantly lower proportions of CD86+ M1 and CD206+ M2 macrophages in their livers than healthy controls. M1 polarization of intrahepatic Kupffer cells promoted HBsAg loss by upregulating the effector function of tissue-resident memory T cells with increased ALT levels. IFN-γ+ Th1 activates intrahepatic resident memory T cells to promote HBsAg loss by inducing M1 macrophage polarization.

Tissue adaptation of CD4 T lymphocytes in homeostasis and cancer

The immune system is traditionally classified as a defense system that can discriminate between self and non-self or dangerous and non-dangerous situations, unleashing a tolerogenic reaction or immune response. These activities are mainly coordinated by the interaction between innate and adaptive cells that act together to eliminate harmful stimuli and keep tissue healthy. However, healthy tissue is not always the end point of an immune response. Much evidence has been accumulated over the years, showing that the immune system has complex, diversified, and integrated functions that converge to maintaining tissue homeostasis, even in the absence of aggression, interacting with the tissue cells and allowing the functional maintenance of that tissue. One of the main cells known for their function in helping the immune response through the production of cytokines is CD4+ T lymphocytes. The cytokines produced by the different subtypes act not only on immune cells but also on tissue cells. Considering that tissues have specific mediators in their architecture, it is plausible that the presence and frequency of CD4+ T lymphocytes of specific subtypes (Th1, Th2, Th17, and others) maintain tissue homeostasis. In situations where homeostasis is disrupted, such as infections, allergies, inflammatory processes, and cancer, local CD4+ T lymphocytes respond to this disruption and, as in the healthy tissue, towards the equilibrium of tissue dynamics. CD4+ T lymphocytes can be manipulated by tumor cells to promote tumor development and metastasis, making them a prognostic factor in various types of cancer. Therefore, understanding the function of tissue-specific CD4+ T lymphocytes is essential in developing new strategies for treating tissue-specific diseases, as occurs in cancer. In this context, this article reviews the evidence for this hypothesis regarding the phenotypes and functions of CD4+ T lymphocytes and compares their contribution to maintaining tissue homeostasis in different organs in a steady state and during tumor progression.

A Dual-domain Engineered Antibody for Efficient HBV Suppression and Immune Responses Restoration

Chronic hepatitis B (CHB) remains a major public health concern because of the inefficiency of currently approved therapies in clearing the hepatitis B surface antigen (HBsAg). Antibody-based regimens have demonstrated potency regarding virus neutralization and HBsAg clearance. However, high dosages or frequent dosing are required for virologic control. In this study, a dual-domain-engineered anti-hepatitis B virus (HBV) therapeutic antibody 73-DY is developed that exhibits significantly improved efficacy regarding both serum and intrahepatic viral clearance. In HBV-tolerant mice, administration of a single dose of 73-DY at 2 mg kg-1 is sufficient to reduce serum HBsAg by over 3 log10 IU mL-1 and suppress HBsAg to < 100 IU mL-1 for two weeks, demonstrating a dose-lowering advantage of at least tenfold. Furthermore, 10 mg kg-1 of 73-DY sustainably suppressed serum viral levels to undetectable levels for ≈ 2 weeks. Molecular analyses indicate that the improved efficacy exhibited by 73-DY is attributable to the synergy between fragment antigen binding (Fab) and fragment crystallizable (Fc) engineering, which conferred sustained viral suppression and robust viral eradication, respectively. Long-term immunotherapy with reverse chimeric 73-DY facilitated the restoration of anti-HBV immune responses. This study provides a foundation for the development of next-generation antibody-based CHB therapies.

Association of HBV serological markers with host antiviral immune response relevant hepatic inflammatory damage in chronic HBV infection

The natural progression of chronic hepatitis B virus (HBV) infection is dynamic, but the longitudinal landscape of HBV serological markers with host antiviral immune response relevant hepatic inflammatory damage remains undetermined. To this issue, we studied the association of HBV serological markers with the severity of hepatic inflammatory damage and enumerated HBV-specific T cells using the cultured enzyme-linked immune absorbent spot (ELISpot). Five hundred and twenty-four treatment-naïve chronic HBV infection patients were enrolled. The Spearman correlation analysis revealed that in hepatitis B e antigen (HBeAg)-positive patients, all HBV virologic indicators negatively correlated with liver inflammatory damage and fibrosis (p < 0.01). Stronger correlations were accessed in the subgroup of HBeAg-positive patients with HBV DNA > 2 × 106 IU/mL (p < 0.01), whereas negative correlations disappeared in patients with HBV DNA ≤ 2 × 106 IU/mL. Surprisingly, in HBeAg-negative patients, the HBV DNA level was positively correlated with the hepatic inflammatory damage (p < 0.01). The relationship between type Ⅱ interferon genes expression and HBV DNA levels also revealed a direct shift from the initial negative to positive in HBeAg-positive patients with HBV DNA declined below 2 × 106 IU/mL. The number of HBV-specific T cells were identified by interferon γ ELISpot assays and showed a significant increase from HBeAg-positive to HBeAg-negative group. The host's anti-HBV immunity remains effective in HBeAg-positive patients with HBV DNA levels exceeding 2 × 106 IU/mL, as it efficiently eliminates infected hepatocytes and inhibits HBV replication. However, albeit the increasing number of HBV-specific T cells, the host antiviral immune response shifts towards dysfunctional when the HBV DNA load drops below this threshold, which causes more pathological damage and disease progression.

Cytokines Expression Compared to the Determinants of Cellular Apoptosis Prominently Attributes to the Deleterious Effects of 'A' Determinant Surface Gene Mutations in HBV Transfected Hepatoma Cell Line

BACKGROUND

Previous studies have explored the role of AKT protein in anti-apoptotic/proliferative activities. However, there has been a lack of information regarding the role of Akt in association with cytokines expression in HBV-related (wild type HBV and HBV with mutations of 'a' determinant region) studies either in the case of HBV infection or in transfected hepatoma cells. The present study tries to determine the role of Akt and cytokines expression in the presence of small surface gene mutants in the hepatoma cell line.

METHODS

Mutations of 'a' determinant region, viz. sA128V and sG145R, were created in wild-type pHBV1.3 by site-directed mutagenesis and transfected in hepatoma cell line. Secretory levels of HBsAg in the wild type as well as in both the mutants were analyzed by ELISA. Apoptotic analysis of transfected cells was studied by flow cytometry. Expression analysis of Akt and cytokines (TNF-alpha, IL-6, and IFN-gamma) was done by qPCR.

RESULTS

The presence of significantly more alive cells in sG145R than sA128V transfected cells may be due to the up-regulation of the Akt gene expression. Cytokines expression was nearly similar between sA128V and wild-type pHBV1.3 transfected cells. Presence of sG145R showed dramatically high cytokines expression than sA128V and wild-type pHBV1.3.

CONCLUSION

Cytokines expression predominantly contributes to the detrimental effects associated with the 'a' determinant region mutations particularly sG145R mutant. It may also be inferred that mechanisms associated with cellular apoptosis apparently do not play any major role to assign the 'a' determinant small surface gene mutation(s) for their pathological outcome.

hPMSCs Regulate the Level of TNF-α and IL-10 in Th1 Cells and Improve Hepatic Injury in a GVHD Mouse Model via CD73/ADO/Fyn/Nrf2 Axis

Mesenchymal stem cells (MSCs) ameliorate graft-versus-host disease (GVHD)-induced tissue damage by exerting immunosuppressive effects. However, the related mechanism remains unclear. Here, we explored the therapeutic effect and mechanism of action of human placental-derived MSCs (hPMSCs) on GVHD-induced mouse liver tissue damage, which shows association with inflammatory responses, fibrosis accompanied by hepatocyte tight junction protein loss, the upregulation of Bax, and the downregulation of Bcl-2. It was observed in GVHD mice and Th1 cell differentiation system that hPMSCs treatment increased IL-10 levels and decreased TNF-α levels in the Th1 subsets via CD73. Moreover, hPMSCs treatment reduced tight junction proteins loss and inhibited hepatocyte apoptosis in the livers of GVHD mice via CD73. ADO level analysis in GVHD mice and the Th1 cell differentiation system showed that hPMSCs could also upregulate ADO levels via CD73. Moreover, hPMSCs enhanced Nrf2 expression and diminished Fyn expression via the CD73/ADO pathway in Th1, TNF-α+, and IL-10+ cells. These results indicated that hPMSCs promoted and inhibited the secretion of IL-10 and TNF-α, respectively, during Th1 cell differentiation through the CD73/ADO/Fyn/Nrf2 axis signaling pathway, thereby alleviating liver tissue injury in GVHD mice.

Serum vitamin D deficiency is associated with increased risk of γδ T cell exhaustion in HBV-infected patients

Previous studies have demonstrated that T cell exhaustion is associated with poor clearance of Hepatitis B virus (HBV). However, whether the expression of exhaustion markers on innate-like circulating γδ T cells derived from patients with HBV infection correlates with the serum level of vitamin D is not completely understood. In this study, we found that the frequency of circulating Vδ2+ T cell and serum levels of vitamin 25(OH)D3 were significantly decreased in patients with HBV. And serum 25(OH)D3 levels in HBV-infected patients were negatively correlated with HBV DNA load and PD-1 expression on γδ T cells. Interestingly, 1α,25(OH)2 D3 alleviated the exhaustion phenotype of Vδ2 T cells in HBV-infected patients and promoted IFN-β expression in human cytotoxic Vδ2 T cells in vitro. Collectively, these findings demonstrate that vitamin D plays a pivotal role in reversing γδ T-cell exhaustion and is highly promising target for ameliorating HBV infection.

Treatment cessation in HBeAg-negative chronic hepatitis B: clinical response is associated with increase in specific proinflammatory cytokines

Patients with HBeAg-negative chronic hepatitis B may experience an immune response after stopping nucleos(t)ide analogue (NA)therapy, which may potentially trigger HBsAg loss or off-therapy sustained viral control. The immunological mechanisms determining clinical response remain poorly understood. To identify inflammatory signatures associated with defined outcomes, we analysed plasma cytokines and chemokines from 57 HBeAg-negative patients enrolled in the Nuc-Stop Study at baseline and 12 weeks after NA cessation. Clinical response at 12 weeks was classified into four groups: immune control, viral relapse, evolving clinical relapse, and resolving clinical relapse. Twelve weeks after treatment cessation 17 patients (30%) experienced immune control, 19 (33%) viral relapse, 6 (11%) evolving clinical relapse, and 15 (26%) resolving clinical relapse. There was a significant increase in interferon-γ-induced protein 10 (IP-10; p = 0.012) and tumor necrosis factor (TNF; p = 0.032) in patients with evolving clinical relapse. Sparse partial least-squares multivariate analyses (sPLS-DA) showed higher first component values for the clinical relapse group compared to the other groups, separation was driven mainly by IP-10, TNF, IL-9, IFN-γ, MIP-1β, and IL-12. Our results demonstrate that evolving clinical relapse after NA cessation is associated with a systemic increase in the proinflammatory cytokines IP-10 and TNF.Clinical trial registration: ClinicalTrials.gov, Identifier: NCT03681132.

Hepatitis B Virus Envelope Antigen and Hepatitis B Virus Surface Antigen Both Contribute to the Innate Immune Response During Persistent Hepatitis B Virus Infection

This study aimed to investigate the changes of toll-like receptor 4 (TLR4), proinflammatory cytokine expression, hepatitis B virus surface antigen (HBsAg), and hepatitis B virus envelope antigen (HBeAg) expression as well as innate immune cell percentages in a mouse model of persistent hepatitis B virus (HBV) infection to better understand the innate immune response. Mouse models of persistent HBV infection, HBsAg expression, and HBeAg expression were developed using high-pressure tail-vein injection of recombinant adeno-associated viruses. Enzyme-linked immunosorbent assays (ELISAs) were used to determine the serum proinflammatory cytokine levels. Immunohistochemistry and western blot assays were used to detect TLR4 expression. Flow cytometric analysis was used to assess the percentage of innate immune cells in the whole blood. Persistent HBV infection, HBsAg expression, and HBeAg expression each significantly decreased the expression of TLR4. Persistent HBV infection significantly increased the percentages of T cells and monocytes, whereas it decreased the percentage of natural killer (NK) cells. Persistent HBeAg expression also decreased the percentage of NK cells, whereas persistent HBsAg expression increased the percentage of NK cells. Both persistent HBsAg and HBeAg expression increased the percentage of monocytes. However, both persistent HBsAg and HBeAg expression decreased the percentage of T cells. HBV as well as HBsAg and HBeAg showed similar effects on the expression of TLR4 and proinflammatory cytokines as well as the percentage of monocytes. Persistent HBV infection increased the percentage of T cells and decreased the percentage of NK cells, whereas only persistent HBeAg expression contributed to a decreased percentage of NK cells.

Interspecies comparison of the early transcriptomic changes associated with hepatitis B virus exposure in human and macaque immune cell populations

BACKGROUND AND AIMS

Hepatitis B virus (HBV) infection affects 300 million individuals worldwide, representing a major factor for the development of hepatic complications. Although existing antivirals are effective in suppressing replication, eradication of HBV is not achieved. Therefore, a multi-faceted approach involving antivirals and immunomodulatory agents is required. Non-human primates are widely used in pre-clinical studies due to their close evolutionary relationship to humans. Nonetheless, it is fundamental to identify the differences in immune response between humans and these models. Thus, we performed a transcriptomic characterization and interspecies comparison of the early immune responses to HBV in human and cynomolgus macaques.

METHODS

We characterized early transcriptomic changes in human and cynomolgus B cells, T cells, myeloid and plasmacytoid dendritic cells (pDC) exposed to HBV ex vivo for 2 hours. Differentially-expressed genes were further compared to the profiles of HBV-infected patients using publicly-available single-cell data.

RESULTS

HBV induced a wide variety of transcriptional changes in all cell types, with common genes between species representing only a small proportion. In particular, interferon gamma signaling was repressed in human pDCs. At the gene level, interferon gamma inducible protein 16 (IFI16) was upregulated in macaque pDCs, while downregulated in humans. Moreover, IFI16 expression in pDCs from chronic HBV-infected patients anti-paralleled serum HBsAg levels.

CONCLUSION

Our characterization of early transcriptomic changes induced by HBV in humans and cynomolgus macaques represents a useful resource for the identification of shared and divergent host responses, as well as potential immune targets against HBV.

Engineered anti-PDL1 with IFNα targets both immunoinhibitory and activating signals in the liver to break HBV immune tolerance

OBJECTIVE

The purpose of this study is to develop an anti-PDL1-based interferon (IFN) fusion protein to overcome the chronic hepatitis B virus (HBV)-induced immune tolerance, and combine this immunotherapy with a HBV vaccine to achieve the functional cure of chronic hepatitis B (CHB) infection.

DESIGN

We designed an anti-PDL1-IFNα heterodimeric fusion protein, in which one arm was derived from anti-PDL1 antibody and the other arm was IFNα, to allow targeted delivery of IFNα into the liver by anti-PDL1 antibody. The effect of the anti-PDL1-IFNα heterodimer on overcoming hepatitis B surface antigen (HBsAg) vaccine resistance was evaluated in chronic HBV carrier mice.

RESULTS

The anti-PDL1-IFNα heterodimer preferentially targeted the liver and resulted in viral suppression, the PD1/PDL1 immune checkpoint blockade and dendritic cell activation/antigen presentation to activate HBsAg-specific T cells, thus breaking immune tolerance in chronic HBV carrier mice. When an HBsAg vaccine was administered soon after anti-PDL1-IFNα heterodimer treatment, we observed strong anti-HBsAg antibody and HBsAg-specific T cell responses for efficient HBsAg clearance in chronic HBV carrier mice that received the combination treatment but not in those that received either single treatment.

CONCLUSIONS

Targeting the liver with an engineered anti-PDL1-IFNα heterodimer can break HBV-induced immune tolerance to an HBsAg vaccine, offering a promising translatable therapeutic strategy for the functional cure of CHB.

IFN-γ: A Crucial Player in the Fight Against HBV Infection?

About 0.8 million people die because of hepatitis B virus (HBV) infection each year. In around 5% of infected adults, the immune system is ineffective in countering HBV infection, leading to chronic hepatitis B (CHB). CHB is associated with hepatocellular carcinoma, which can lead to patient death. Unfortunately, although current treatments against CHB allow control of HBV infection, they are unable to achieve complete eradication of the virus. Cytokines of the IFN family represent part of the innate immune system and are key players in virus elimination. IFN secretion induces the expression of interferon stimulated genes, producing proteins that have antiviral properties and that are essential to cell-autonomous immunity. IFN-α is commonly used as a therapeutic approach for CHB. In addition, IFN-γ has been identified as the main IFN family member responsible for HBV eradication during acute infection. In this review, we summarize the key evidence gained from cellular or animal models of HBV replication or infection concerning the potential anti-HBV roles of IFN-γ with a particular focus on some IFN-γ-inducible genes.

Differential response of HBV envelope-specific CD4 + T cells is related to HBsAg loss after stopping nucleos(t)ide analogue therapy

BACKGROUND AND AIM

Long-term maintenance of viral control, even HBsAg loss, remains a challenge for chronic hepatitis B (CHB) patients undergoing nucleos(t)ide analogue (NA) discontinuation. This study aimed to investigate the relationship between HBV-specific T-cell responses targeting peptides spanning the whole proteome and clinical outcomes in CHB patients after NA discontinuation.

APPROACH AND RESULTS

Eighty-eight CHB patients undergoing NA discontinuation were classified as responders (remained relapse-free up to 96 weeks) or relapsers (relapsed patients who underwent NA retreatment for up to 48 weeks and reachieved stable viral control). HBV-specific T-cell responses were detected at baseline and longitudinally throughout the follow-up. We found responders had a greater magnitude of HBV polymerase (Pol)-specific T-cell responses than relapsers at baseline. After long-term NA discontinuation, simultaneously enhanced HBV Core-induced and Pol-induced responses were observed in responders. Particularly, responders with HBsAg loss possessed enhanced HBV Envelope (Env)-induced responses after short-term and long-term follow-up. Notably, CD4 + T cells accounted for the predominance of HBV-specific T-cell responses. Correspondingly, CD4-deficient mice showed attenuated HBV-specific CD8 + T-cell responses, reduced HBsAb-producing B cells, and delayed HBsAg loss; in contrast, in vitro addition of CD4 + T cells promoted HBsAb production by B cells. Besides, IL-9, rather than PD-1 blockade, enhanced HBV Pol-specific CD4 + T-cell responses.

CONCLUSION

HBV-specific CD4 + T-cell responses induced by the targeted peptide possess specificities for long-term viral control and HBsAg loss in CHB patients undergoing NA discontinuation, indicating that CD4 + T cells specific to distinct HBV antigens may endow with divergent antiviral potential.

Research Progress on the Role and Mechanism of IL-37 in Liver Diseases

Cytokines are important components of the immune system that can predict or influence the development of liver diseases. IL-37, a new member of the IL-1 cytokine family, exerts potent anti-inflammatory and immunosuppressive effects inside and outside cells. IL-37 expression differs before and after liver lesions, suggesting that it is associated with liver disease; however, its mechanism of action remains unclear. This article mainly reviews the biological characteristics of IL-37, which inhibits hepatitis, liver injury, and liver fibrosis by inhibiting inflammation, and inhibits the development of hepatocellular carcinoma (HCC) by regulating the immune microenvironment. Based on additional evidence, combining IL-37 with liver disease markers for diagnosis and treatment can achieve more significant effects, suggesting that IL-37 can be developed into a powerful tool for the clinical adjuvant treatment of liver diseases, especially HCC.

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.

Predictive value of Th17 and Treg cells at baseline for HBsAg loss in chronic hepatitis B patients with low HBsAg quantification treated with pegylated interferon and nucleos(t)ide analogue

Background and aims

The primary goal of chronic hepatitis B (CHB) treatment is to reduce hepatitis B surface antigen (HBsAg). T helper 17 (Th17) and regulatory T (Treg) cells are essential for the development of CHB. However, how Th17 and Treg cells contribute to HBsAg loss is still unknown. Therefore, this study aimed to search for the predictive value of Th17 and Treg cells for HBsAg loss in CHB patients with low HBsAg quantification.

Methods

The study included 99 hepatitis B e antigen (HBeAg)-negative CHB patients who had completed a year of nucleos(t)ide analogue (NA) monotherapy and had received both NA and pegylated interferon (PEG-IFN) treatment for less than 96 weeks (96 wk). In the cured group, 48 patients lost HBsAg within 48 wk, while 51 patients did not (uncured group). Blood samples and clinical data were collected for research.

Results

During PEG-IFN and NA combination therapy, the proportion of Th17 cells in the cured group increased significantly, while the proportion of Treg cells in the uncured group increased. From 0 to 24 wk, the proportion of Th17 cells in the cured group was significantly higher than in the uncured group, while the opposite was true for Treg cells. Patients with alanine aminotransferase (ALT) ≥ 2.5 upper limit of normal (ULN) at 12 wk had a higher proportion of Th17 cells and a lower proportion of Treg cells than those with ALT <2.5 ULN at 12 wk. Additionally, the proportion of Th17 cells is inversely associated with the level of HBsAg, whereas the level of Treg cells is positively related to HBsAg quantification. The clinical cure index, including age, HBsAg quantification, and the proportions of Th17 and Treg cells, had a higher area under the curve (0.957) for predicting HBsAg loss when compared to the proportions of Th17 and Treg cells and HBsAg quantification alone.

Conclusions

Combined with quantification of HBsAg, the proportions of Th17 cells and Treg cells at baseline can be used as good predictors of HBsAg loss in patients with low HBsAg quantification treated with NA and PEG-IFN.

Chronic viral infection compromises the quality of circulating mucosal-invariant T cells and follicular T helper cells via expression of both activating and inhibitory receptors

Chronic viral infection results in impaired immune responses rendering viral persistence. Here, we investigated the role of immune activation and compared the quality of T-cell responses in chronic HBV, HCV, and HIV infections. Cytokines were measured using a commercial Bio-plex Pro Human Cytokine Grp I Panel 17-plex kit (BioRad, Hercules, CA, USA). Inflammation was assessed by measuring an array of plasma cytokines, and peripheral CD4+ T cells including circulating Tfh cells, CD8+ T cells, and TCR iVα7.2+ MAIT cells in chronic HBV, HCV, and HIV-infected patients and healthy controls. The cells were characterized based markers pertaining to immune activation (CD69, ICOS, and CD27) proliferation (Ki67), cytokine production (TNF-α, IFN-γ) and exhaustion (PD-1). The cytokine levels and T cell phenotypes together with cell markers were correlated with surrogate markers of disease progression. The activation marker CD69 was significantly increased in CD4+ hi T cells, while CD8+ MAIT cells expressing IFN-γ were significantly increased in chronic HBV, HCV and HIV infections. Six cell phenotypes, viz., TNF-α+CD4+ lo T cells, CD69+CD8+ T cells, CD69+CD4+ MAIT cells, PD-1+CD4+ hi T cells, PD-1+CD8+ T cells, Ki67+CD4+ MAIT cells were independently associated with decelerating the plasma viral load (PVL). TNF-α levels showed a positive correlation with increase in cytokine levels and decrease in PVL. Chronic viral infection negatively impacts the quality of peripheral MAIT cells and TFH cells via expression of both activating and inhibitory receptors.

Impact of maternal hepatitis B carrier status on congenital abnormalities: a systematic review and meta-analysis

OBJECTIVES

This study aims to explore whether maternal hepatitis B carrier status is associated with an increased risk of congenital abnormalities.

DESIGN

A systematic review and meta-analysis of observational studies.

DATA SOURCES

PubMed, Embase (Ovid), Scopus, the China National Knowledge Infrastructure (CNKI) and the Wanfang databases.

STUDY SELECTION

Five databases were searched systematically from inception to 7 September 2021. Cohort and case-control studies that investigated the association between maternal hepatitis B virus (HBV) infection and congenital abnormalities were included. This study was conducted according to MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently collected data, as well as assessed risk of bias by using Newcastle-Ottawa Scale. We pooled crude relative risk (cRR) and adjusted OR (aOR) by DerSimonian-Laird random-effects model. Heterogeneity was explored by I ² statistics, Cochran's Q test. Several subgroup analyses and sensitivity analyses were performed.

RESULTS

In total, 14 studies involving 16 205 pregnant women exposed to HBV were included. The pooled cRR of 1.15 (95% CI: 0.92 to 1.45; 14 studies included) showed a marginal but not significant association between maternal HBV-carrier status and congenital abnormalities. However, the pooled aOR of 1.40 (95% CI: 1.01 to 1.93; 8 studies included) indicated that pregnant women with HBV infection might be associated with a higher risk of congenital abnormalities. Subgroup analyses of adjusted data showed a higher pooling cRR or aOR on high prevalence HBV infection populations, as well as studies from Asia and Oceania.

CONCLUSIONS

Maternal hepatitis B carrier status might be at potential risk for congenital abnormalities. The existing evidence was not sufficient to draw a firm conclusion. Additional studies may be warranted to confirm the association.

PROSPERO REGISTRATION NUMBER

CRD42020205459.

HBV Core-specific CD4+ T cells correlate with sustained viral control upon off-treatment in HBeAg-positive chronic hepatitis B patients

BACKGROUND & AIMS

Treatment with nucleos(t)ide analogue (NA) efficiently suppresses viral replication in patients with chronic HBV infection, yet HBV relapse frequently upon NA withdrawal; the detailed immunomodulatory compounds for sustained viral control of HBV upon NA interruption have yet to be fully clarified. This study aimed to elucidate the role of T cells specific for distinct HBV peptides in sustained response upon discontinuation of antiviral treatment.

METHODS

A total of 48 patients with HBeAg-positive chronic hepatitis B receiving NA treatment and withdrawal were included longitudinally in a retrospective and prospective cohort. Enzyme-linked immunosorbent spot (ELISpot) and intracellular cytokine staining (ICS) assays were performed to detect IFN-γ producing HBV-specific T cells following stimulation with overlapping peptides covering the whole HBV genome after 10 days of in vitro expansion.

RESULTS

ICS assays revealed that T cells specific for HBV Core and Polymerase induced more robust IFN-γ responses compared to envelope and HBx. Notably, at the time of NA discontinuation, the intensity and breadth of HBV Core peptides-induced responses, predominately targeted by CD4⁺ T cells but not CD8⁺ T cells, were associated with sustained viral control upon off-treatment. Further exploration of longitudinal features in patients with sustained viral control revealed that the breadth of HBV-specific T cell responses does not increase following treatment cessation.

CONCLUSION

This report emphasizes the essential role of HBV Core-specific CD4⁺ T cells in sustained response after therapy withdrawal, indicating it is a potential candidate for immunotherapeutic approaches in chronic HBV patients.

Studying T Cell Responses to Hepatotropic Viruses in the Liver Microenvironment

T cells play an important role in the clearance of hepatotropic viruses but may also cause liver injury and contribute to disease progression in chronic hepatitis B and C virus infections which affect millions of people worldwide. The liver provides a unique microenvironment of immunological tolerance and hepatic immune regulation can modulate the functional properties of T cell subsets and influence the outcome of a virus infection. Extensive research over the last years has advanced our understanding of hepatic conventional CD4+ and CD8+ T cells and unconventional T cell subsets and their functions in the liver environment during acute and chronic viral infections. The recent development of new small animal models and technological advances should further increase our knowledge of hepatic immunological mechanisms. Here we provide an overview of the existing models to study hepatic T cells and review the current knowledge about the distinct roles of heterogeneous T cell populations during acute and chronic viral hepatitis.

H3K9 acetylation modification and TLR9 immune regulation mechanism in patients after anti-HBV treatment

To improve the curative effect of anti-hepatitis B virus (HBV) drugs, methods such as thymosin and entecavir combination have become a focus of clinical investigation. The aim of this retrospective experimental study was to explore the potential mechanism of action of thymosin a1 (Ta1) combined with entecavir in the treatment of HBV infection. A total of 28 patients with chronic hepatitis B, 29 patients treated with thymosin a1 and entecavir combination, and 15 healthy individuals were enrolled in this study. RT-qPCR was conducted to evaluate the mRNA levels of TLR9 in peripheral blood mononuclear cells (PBMCs). The serum level of TLR9 protein was analyzed by ELISA. The binding of TLR9 gene to the protein H3K9Ac in PBMCs was assessed by chromatin immunoprecipitation, and serum inflammatory factors were detected by Luminex technology. The expression levels of TLR9 mRNA and serum TLR9 protein in patients with HBV infection were significantly lower than those in subjects in the control group before treatment but increased after treatment with the Ta1 and entecavir combination. Moreover, the acetylation protein H3K9Ac was significantly bound to the promoter region of the TLR9 gene in patients with HBV infection treated with the Ta1 and entecavir combination compared to that in patients with HBV infection without treatment. Furthermore, the expression levels of interleukin 6 (IL-6), interleukin 12 (IL-12), interferon gamma, and necrosis factor alpha in patients with HBV infection after the combination treatment were slightly decreased compared to those in patients with HBV infection without treatment. In conclusion, the histone acetylation modification of TLR9 was significantly improved in patients with HBV infection after treatment with the Ta1 and entecavir combination, which elevated the expression of TLR9 at the mRNA and protein levels and further regulated the expression of IL-6, IL-12, and other cytokines.

The immune landscape in hepatitis delta virus infection-Still an open field!

Hepatitis delta virus (HDV) is known to cause the most aggressive and severe form of viral hepatitis, yet it remained under-diagnosed but does require early diagnosis for accurate disease staging. Antibody to HDV (anti-HDV) is the primary screening tool and should be assessed in patients with hepatitis B surface antigen (HBsAg) positivity, as HDV is a satellite RNA virus of hepatitis B. Additionally, the viral load (HDV RNA) should be assessed in those with positive anti-HDV, to differentiate between active infection and resolved hepatitis delta. Data regarding immune responses in HDV are limited but show dysfunctional adaptive and innate immunity. Many studies however fail to distinguish between active and resolved infection. Limited treatments are available for HDV, but promise has been shown with the newly approved Bulevirtide, a first-in-class HBV entry inhibitor. Thus immune response during therapy requires further investigation, along with additional targets for HDV cure.

CD4+ CTLs Act as a Key Effector Population for Allograft Rejection of MSCs in a Donor MHC-II Dependent Manner in Injured Liver

Mesenchymal stromal/stem cells (MSCs) have been considered an attractive source of cytotherapy due to their promising effects on treating various diseases. Allogeneic MSCs (allo-MSCs) are extensively used in clinical trials due to their convenient preparation and credible performance. Traditionally, allo-MSCs are considered immunoprivileged with minimal immunogenicity and potent immunomodulatory capacity. However, growing evidence has suggested that allo-MSCs also induce immune response and cause rejection after transplantation, but the underlying cellular and molecular mechanisms remain to be elucidated. Here, we demonstrated that allografted MSCs upregulated MHC-II upon stimulation of IFN-γ in hepatic inflammatory environment by using mouse model of CCl4-induced liver injury. MHC-II upregulation enhanced the immunogenicity of allo-MSCs, leading to the activation of alloreactive T cells and rejection of allo-MSCs. However, MHC-II deficiency impaired the allogenic reactivity, thereby rescuing the loss of allo-MSCs. Mechanistically, CD4+ cytotoxic T lymphocytes (CTLs), rather than CD8+ CTLs, acted as the major effector for allo-MSC rejection. Under liver injury condition, the transplanted allo-MSCs upregulated CD80 and PD-L1, and CD8+ CTLs highly expressed CTLA-4 and PD-1, thereby inducing immune tolerance of CD8+ T cells to allo-MSCs. On the contrary, CD4+ CTLs minimally expressed CTLA-4 and PD-1; thus, they remain cytotoxic to allo-MSCs. Consequently, transplantation of MHC-II-deficient allo-MSCs substantially promoted their therapeutic effects in treating liver injury. This study revealed a novel mechanism of MSC allograft rejection mediated by CD4+ CTLs in injured liver, which provided new strategies for improving clinical performance of allo-MSCs in benefiting hepatic injury repair.

Plasma interleukin-7 correlation with human immunodeficiency virus RNA and CD4+ T cell counts, and interleukin-5 with circulating hepatitis B virus DNA may have implications in viral control

Chronic viral infections represent a leading cause of global morbidity and mortality. Chronic HBV, HCV, and HIV infections result in cytokine perturbations that may hold key implications in understanding the complex disease mechanisms driving virus persistence and/or resolution. Here, we determined the levels of various plasma cytokines using a commercial Bio-Plex Luminex cytokine array in chronic HBV (n = 30), HCV (n = 15), and HIV (n = 40) infections and correlated with corresponding plasma viral loads (PVLs) and liver parameters. We observed differential perturbations in cytokine profiles among the study groups. The cytokines levels positively correlated with PVL and liver transaminases. The monocyte-derived cytokines viz., MIP-1β, IL-8, and TNF-α, and Th2 cytokines like IL-4, IL-5, and IL-13 showed a better correlation with liver enzymes as compared to their corresponding PVLs. Our investigation also identified two cytokines viz., IL-5 and IL-7 that inversely correlated with HBV DNA and HIV PVLs, respectively. Regression analysis adjusted for age showed that every increase of IL-5 by one unit was associated with a reduction in HBV PVL by log10 0.4, whereas, every elevation by a unit of IL-7 was associated with decreased HIV PVL by log10 2.5. We also found that IL-7 levels correlated positively with absolute CD4+ T cell counts in HIV-infected patients. We concluded that plasma IL-5 and IL-7 may likely have a key role on viral control in HBV and HIV infections, respectively. A noteworthy increase in cytokines appears to bear protective and pathological significance, and indeed is reflective of the host's versatile immune armory against viral persistence.

Hepatitis B flare: the good, the bad and the ugly

INTRODUCTION

Hepatitis B flare, defined as an event of abrupt ALT elevation to >5x ULN, is a frequent episode during the natural course or during/after antiviral therapy of chronic HBV infection, in both HBeAg-positive and HBeAg-negative patients with chronic hepatitis B or liver cirrhosis.

AREAS COVERED

The definition, pathogenesis, clinical presentation, and management of hepatitis B flares in the published literature were reviewed. Hepatitis B flares have been considered as a result of the robust immune response of the patient to an upsurging HBV/HBV-antigen(s). 'Host-dominating flares,' reflect effective immune response, may resolve with ALT normalization and decline of HBV/ antigen(s). Contradictorily, 'virus-dominating flares,' reflect ineffective immune response, are usually followed by persistent/intermittent hepatitis and may even develop hepatic decompensation/failure.

EXPERT OPINION

Not all hepatitis B flares require antiviral therapy, and close observation with combined HBsAg/ALT kinetics along the ascending ALT during hepatitis flare may differentiate hepatitis flares for an appropriate treatment/retreatment decision. More studies are needed to verify this proposal. Further immunologic studies using multiple samples during hepatitis B flare are important to clarify the precise underlying mechanisms as the basis for further improvement in the management of hepatitis flare.

Hepatitis B virus-specific CD4 T cell responses differentiate functional cure from chronic surface antigen+ infection

BACKGROUND & AIMS

With or without antiviral treatment, few individuals achieve sustained functional cure of chronic hepatitis B virus (HBV) infection. A better definition of what mediates functional cure is essential for improving immunotherapeutic strategies. We aimed to compare HBV-specific T cell responses in patients with different degrees of viral control.

METHODS

We obtained blood from 124 HBV-infected individuals, including those with acute self-limiting HBV infection, chronic infection, and chronic infection with functional cure. We screened for HBV-specific T cell specificities by ELISpot, assessed the function of HBV-specific T cells using intracellular cytokine staining, and characterized HBV-specific CD4 T cells using human leukocyte antigen (HLA) class II tetramer staining, all directly ex vivo.

RESULTS

ELISpot screening readily identified HBV-specific CD4 and CD8 T cell responses in acute resolving infection compared with more limited reactivity in chronic infection. Applying more sensitive assays revealed higher frequencies of functional HBV-specific CD4 T cells, but not CD8 T cells, in functional cure compared to chronic infection. Function independent analysis using HLA multimers also identified more HBV-specific CD4 T cell responses in functional cure compared to chronic infection, with the emergence of CD4 T cell memory both after acute and chronic infection.

CONCLUSIONS

Functional cure is associated with higher frequencies of functional HBV-specific CD4 memory T cell responses. Thus, immunotherapeutic approaches designed to induce HBV functional cure should also aim to improve CD4 T cell responses.

LAY SUMMARY

Immunotherapy is a form of treatment that relies on harnessing the power of an individual's immune system to target a specific disease or pathogen. Such approaches are being developed for patients with chronic HBV infection, in an attempt to mimic the immune response in patients who control HBV infection spontaneously, achieving a so-called functional cure. However, what exactly defines protective immune responses remains unclear. Herein, we show that functional cure is associated with robust responses by HBV-specific CD4 T cells (a type of immune cell).

Effect of the change in antiviral therapy indication on identifying significant liver injury among chronic hepatitis B virus infections in the grey zone

OBJECTIVE

In clinical practice, a substantial proportion of chronic hepatitis B virus (HBV) infections that do not fit into any of the usual immune states are considered to be in the "grey zone (GZ)". This study aimed to investigate the effect of the change in antiviral therapy indication on identifying significant hepatic injury among GZ patients.

METHODS

Patients with chronic HBV infections and a persistent normal alanine aminotransferase (ALT) level (PNALT) who underwent ultrasonography-guided percutaneous liver biopsy were examined retrospectively. Evidenced hepatic injury (EHI) was defined as an inflammation grade ≥2 (≥G2) and/or fibrosis stage ≥2 (≥F2). Complete clinical data, liver inflammation, and fibrosis grades were collected, and the levels of cytokines were detected by the Luminex technique, all of which were analysed to investigate the immune and histopathology states of the liver.

RESULTS

A total of 347 patients with chronic HBV infections and PNALT were categorized into immune tolerant (IT, n = 108), inactive HBV surface antigen (HBsAg) carrier (IHC, n = 61), GZ-1 (HBeAg positive in GZ, n = 92), and GZ-2 (HBeAg negative in GZ, n = 68) phases. Among them, 51.3% were in the GZ phase, and 50.1% presented with EHI. The IL-6 levels were higher in the EHI group than in the non-EHI group (2.77 vs. 1.53 pg/ml, Z = -13.32, p = 0.028). The monocyte chemoattractant protein 1 (MCP-1) level was positively correlated with HBV DNA (R = 0.64, p < 0.001) and HBeAg (R = 0.5, p < 0.001) but negatively correlated with fibrosis grade (R = -0.26, p = 0.048). The ratio of EHI in the GZ phase was 60.55%, which was significantly higher than that in patients in the IT (39.8%) and IHC phases (37.7%) (χ2 = 10.4, p = 0.006). A total of 46.69% of all patients exceeded the new ALT antiviral treatment threshold (30 U/L for men and 19 U/L for women). The EHI values in the IT and IHC phases below the new ALT threshold were 32.6% and 37.8%, respectively, whereas higher EHI values of 67.4% and 68.4% were seen in GZ-1 and GZ-2 patients, respectively, exceeding the new ALT threshold, and the difference was statistically significant (χ2 = 11.13, p < 0.001; χ2 = 14.22, p = 0.002). The median age in our cohort was 38.91 years, and only 21.03% were less than 30 years old. The EHI values in the IT and IHC patients <30 years old were 32.4% and 35.8%, respectively, while the ratio of EHI increased to 43.2% once patients were older than 30 years but still in the IT and IHC stages.

CONCLUSION

Setting 30 years old as a cut-off and lowering the ALT threshold could facilitate screening for the presence of significant liver injury, especially for GZ patients. IL-6 was a good indicator of EHI, and MCP-1 was significantly positively correlated with HBV DNA but negatively correlated with liver fibrosis.

Robust antiviral responses in severe hepatitis flare persist after early retreatment cessation and lead toward hepatitis B surface antigen loss: A proof-of-concept study

AIM

Hepatitis B flare has been interpreted as result of immune response against upsurging hepatitis B virus (HBV) and its antigen(s) that may lead to HBV decline/clearance spontaneously. It has been speculated that antiviral therapy could halt the effective immune response with viral persistent as a consequence. A proof-of-concept study was conducted to investigate this issue.

METHODS

Serial biochemical, quantitative hepatitis B surface antigen (HBsAg), interferon-γ (IFN-γ) and tumor-necrosis factor-α (TNF-α) assays were performed in four patients with severe hepatitis flare who had achieved precipitous HBsAg decline within 4 weeks of antiviral therapy.

RESULTS

TNF-α and IFN-γ were found to be elevated in parallel to upsurging HBV DNA and HBsAg levels in all patients. Higher levels of TNF-α and IFN-γ and levels relative to qHBsAg were observed during and after early termination of therapy within 4 weeks in two patients and were followed by further HBsAg decline to <5 IU/ml and even achieved HBsAg loss in one patient. The patient who had stopped therapy on day 44 showed minimal HBsAg decline afterward and the patient who continued therapy showed a 10-fold rebound of qHBsAg from its nadir. The subsequent IFN-γ and TNF-α activity of these two patients was minimal.

CONCLUSIONS

The results suggest that patients with severe hepatitis flare who achieved precipitous HBsAg decline may have robust immune response to clear the virus, and early termination of antiviral therapy may allow the protective immune response to continue and accelerate HBV decline toward HBsAg loss.

Molecular clones of genetically distinct hepatitis B virus genotypes reveal distinct host and drug treatment responses

Background & Aims

HBV exhibits wide genetic diversity with at least 9 genotypes (GTs), which differ in terms of prevalence, geographic distribution, natural history, disease progression, and treatment outcome. However, differences in HBV replicative capacity, gene expression, and infective capability across different GTs remain incompletely understood. Herein, we aimed to study these crucial aspects using newly constructed infectious clones covering the major HBV GTs.

Methods

The replicative capacity of infectious clones covering HBV GTs A-E was analyzed in cell lines, primary hepatocytes and humanized mice. Host responses and histopathology induced by the different HBV GTs were characterized in hydrodynamically injected mice. Differences in treatment responses to entecavir and various HBV capsid inhibitors were also quantified across the different genetically defined GTs.

Results

Patient-derived HBV infectious clones replicated robustly both in vitro and in vivo. GTs A and D induce more pronounced intrahepatic and proinflammatory cytokine responses which correlated with faster viral clearance. Notably, all 5 HBV clones robustly produced viral particles following transfection into HepG2 cells, and these particles were infectious in HepG2-NTCP cells, primary human hepatocytes and human chimeric mice. Notably, GT D virus exhibited higher infectivity than GTs A, B, C and E in vitro, although it was comparable to GT A and B in the human liver chimeric mice in vivo. HBV capsid inhibitors were more readily capable of suppressing HBV GTs A, B, D and E than C.

Conclusions

The infectious clones described here have broad utility as genetic tools that can mechanistically dissect intergenotypic differences in antiviral immunity and pathogenesis and aid in HBV drug development and screening.

Lay summary

The hepatitis B virus (HBV) is a major contributor to human morbidity and mortality. HBV can be categorized into a number of genotypes, based on their specific genetic make-up, of which 9 are well known. We isolated and cloned the genomes of 5 of these genotypes and used them to create valuable tools for future research on this clinically important virus.

The Role of Off-Therapy Viral Kinetics in the Timing and Severity of Flares in Hepatitis B e Antigen-Negative Patients

BACKGROUND & AIMS

Hepatitis B flare occurs earlier and is more severe in patients stopping tenofovir (TDF) compared with entecavir (ETV). This study investigated relationship between hepatitis B virus (HBV) kinetics, onset timing, and the severity of flares.

METHODS

Hepatitis B e antigen-negative chronic hepatitis B patients who developed off-ETV or off-TDF hepatitis flare were recruited. Their HBV kinetics and the severity of flares were compared between patients with early (<6 months) and late (between 6 and 24 months) flares. Propensity score matching was performed at 1:1 adjusting for age, sex, cirrhosis, and end-of-treatment (EOT) hepatitis B surface antigen between off-ETV and off-TDF flares.

RESULTS

After propensity score matching, 76% and 15% of each 107 off-TDF and off-ETV patients, respectively, developed early flare. A much steeper HBV DNA upsurge (ΔHBV DNA/month) was observed in off-TDF than off-ETV flares (2.12 vs 0.73 log₁₀ IU/mL; P < .01). Greater ΔHBV DNA/month correlated with earlier timing and higher peak alanine aminotransferase levels of flares. ΔHBV DNA/month ≥2.5 log₁₀ IU/mL was an independent factor for severe off-TDF flare, and ≥1 log₁₀ IU/mL was a predictor for severe off-ETV flares.

CONCLUSIONS

Greater HBV DNA upsurge rate (ΔHBV DNA/month) ≥1 log₁₀ IU/mL is a key factor for an earlier onset and more severe flare. More frequent ΔHBV DNA/month ≥1 log₁₀ IU/mL in off-TDF than off-ETV flares may explain why off-TDF flare mostly occurred early and was more severe. More stringent monitoring in those with ΔHBV DNA/month ≥1 log₁₀ IU/mL at flare, especially ≥2.5 log₁₀ IU/mL in early off-TDF flares, is important for timely retreatment to prevent decompensation.

Arthrospira Enhances Seroclearance in Patients with Chronic Hepatitis B Receiving Nucleos(t)ide Analogue through Modulation of TNF-α/IFN-γ Profile

Chronic hepatitis B (CHB) virus infection, causing immune dysfunction and chronic hepatitis, is one of the leading risk factors for hepatocellular cancer. We investigated how Arthrospira affected hepatitis B surface antigen (HBsAg) reduction in CHB patients under continued nucleos(t)ide analogues (NA). Sixty CHB patients who had been receiving NA for at least one year with undetectable HBV DNA were randomized into three groups: control and oral Arthrospira at 3 or 6 g daily add-on therapy groups. Patients were followed up for 6 months. Oral Arthrospira-diet mice were established to investigate the possible immunological mechanism of Arthrospira against HBV. Within 6 months, mean quantitative HBsAg (qHBsAg) decreased in the oral Arthrospira add-on therapy group. Interestingly, interferon gamma (IFN-γ) increased but TNF-α, interleukin 6 (IL-6), hepatic fibrosis, and steatosis decreased in the add-on groups. In mice, Arthrospira enhanced both innate and adaptive immune system, especially natural killer (NK) cell cytotoxicity, B cell activation, and the interleukin 2 (IL-2), IFN-γ immune response. Arthrospira may modulate IL-2- and TNF-α/IFN-γ-mediated B and T cell activation to reduce HBsAg. Also, Arthrospira has the potential to restore immune tolerance and enhance HBsAg seroclearance in CHB patients through promoting T, B, and NK cell activation.

Association Between Depression or Anxiety and the Risk of Hepatitis B Flares: A Nationwide Population-Based Cohort Study

Purpose

Depression and anxiety have been reported to increase the risk of infectious diseases and reactivation of latent infection. We conducted a nationwide population-based retrospective cohort study to determine the relationship between hepatitis B flares and depression or anxiety, utilizing outpatient and inpatient data from the Taiwan National Health Insurance Research database collected from 2000 to 2015.

Patients and Methods

A total of 12,992 patients with chronic hepatitis B and newly diagnosed anxiety/depression, without advanced liver disease, were propensity score-matched for age, sex, and comorbidities in a 1:4 ratio to 51,968 controls with chronic hepatitis B without depression/anxiety or advanced liver disease. Both groups were followed-up until December 31, 2015. Cox proportional hazards regression was used to determine the risk factors for hepatitis B flares. The Log rank test and Kaplan-Meier analysis were performed to assess differences in the cumulative incidence of hepatitis B flares according to anxiety/depression status.

Results

The incidence of hepatitis B flares was higher in the depression/anxiety cohort than in the control cohort (log-rank; p < 0.001). Patients with depression/anxiety had a significantly higher incidence rate of hepatitis B flares than those without depression/anxiety (3017 per 105 person-years versus 2042 per 105 person-years, p = 0.003). After adjusting for age and comorbidities, anxiety/depression was independently associated with an increased risk of hepatitis B flares (hazard ratio, 1.173; 95% confidence interval, 1.033-1.277; p = 0.003).

Conclusion

This analysis suggests that in patients with chronic hepatitis B without advanced liver disease, those with concomitant depression or anxiety may be at higher risk of hepatitis B flares.

Serum cytokine/chemokine profiles predict hepatitis B reactivation in HBV/HCV co-infected subjects receiving direct-acting antiviral agents

BACKGROUND/PURPOSE

Direct-acting antiviral agents (DAAs) have revolutionized the paradigm for HCV treatment. However, patients with HBV and HCV co-infection receiving DAAs are at significant risk of HBV reactivation, with limited literature addressing the roles of serum chemokines/chemokines. We aimed to explore the profiles and predictive value of serum cytokines/chemokines regarding HBV reactivation in this clinical setting.

METHODS

From 2017 to 2019, 25 patients with HBV and HCV co-infection scheduled for DAA therapy were prospectively enrolled. At enrolment and after DAA treatment, serial serum cytokine/chemokine levels were examined. The baseline and dynamic levels were compared between those with versus without HBV virologic (defined by an increase of serum HBV DNA to >10 times) and clinical reactivation (defined by > 1.5-fold elevated ALT level than nadir and >100 U/L; or > 2-fold increase from nadir and greater than the upper normal limit, in addition to virologic reactivation).

RESULTS

There were 20 patients (80%) experiencing HBV virologic reactivation and 6 patients (24%) experiencing clinical reactivation. Patients with clinical reactivation had higher pre-treatment TNF-alpha (27.93 versus 18.85 pg/mL, P = 0.015), lower week-4 IFN-gamma (1.07 versus 8.74 pg/mL, P = 0.020) levels and significant declines of CCL2 and TNF-alpha (P < 0.05). Single or combination of these cytokines helped predict clinical reactivation (all P < 0.05).

CONCLUSION

Higher serum TNF-alpha at baseline and lower IFN-gamma at week 4 were associated with mild clinical reactivation of HBV in patients with HBV/HCV co-infection receiving DAAs. Combination of these cytokines reliably predicted HBV reactivation early.

Proteomic characterization of the natural history of chronic HBV infection revealed by tandem mass tag-based quantitative proteomics approach

Currently, determining when to start antiviral therapy in patients with chronic HBV infection is a controversial issue. One crucial reason is that biomarkers for distinguishing the natural history of chronic HBV infection are unmet needs. In this study, we aimed to explore novel biomarkers and therapeutic targets for the diagnosis and treatment of chronic HBV infection by using tandem mass tag (TMT)-based quantitative proteomics approach. Here, we firstly revealed the serum proteomic characterization of the natural history of chronic HBV infection using multiplex TMT labeling coupled with liquid chromatography-mass spectrometry. Then, we verified the levels of differentially expressed proteins (DEPs) across a large number of clinical samples by enzyme-linked immunosorbent assay (ELISA). We found that DEPs over the different phases of chronic HBV infection were primarily involved in the biological process of leukocyte-mediated immunity. Patients with chronic hepatitis were characterized as having an up-regulated proteasome pathway, including upregulation of proteasome activator subunit 1 (PSME1) and proteasome subunit alpha type 7 (PSMA7) levels. In addition, immune tolerant phase patients were characterized by having the lowest ephrin-B2 (EFNB2) levels and highest heat responsive protein 12 (HRSP12) levels. Moreover, inactive HBV carrier state patients were characterized by having a down-regulated glycolysis/gluconeogenesis pathway, with especially low expression of related enzymes alpha-enolase (ENO1) and fructose-1,6-bisphosphatase 1 (FBP1). What's more, HBeAg-negative chronic hepatitis patients were characterized as having the highest interleukin 18 binding protein (IL-18BP) levels. Thus, our results provide several potential diagnostic biomarkers for distinguishing the natural history of chronic HBV infection, such as PSME1, PSMA7, EFNB2, ENO1, and IL-18BP, and also present potential therapeutic interventions for chronic hepatitis B patients, such as targeting the proteasome or glycolysis/gluconeogenesis pathways. Our findings shed new light on the development of novel diagnostic biomarkers and therapeutic targets for the diagnosis and treatment of chronic HBV infection.

Screening and Identification of HBV Epitopes Restricted by Multiple Prevalent HLA-A Allotypes

Although host T cell immune responses to hepatitis B virus (HBV) have been demonstrated to have important influences on the outcome of HBV infection, the development of T cell epitope-based vaccine and T cell therapy and the clinical evaluation of specific T cell function are currently hampered markedly by the lack of validated HBV T cell epitopes covering broad patients. This study aimed to screen T cell epitopes spanning overall HBsAg, HBeAg, HBx and HBpol proteins and presenting by thirteen prevalent human leukocyte antigen (HLA)-A allotypes which gather a total gene frequency of around 95% in China and Northeast Asia populations. 187 epitopes were in silico predicted. Of which, 62 epitopes were then functionally validated as real-world HBV T cell epitopes by ex vivo IFN-γ ELISPOT assay and in vitro co-cultures using peripheral blood mononuclear cells (PBMCs) from HBV infected patients. Furthermore, the HLA-A cross-restrictions of each epitope were identified by peptide competitive binding assay using transfected HMy2.CIR cell lines, and by HLA-A/peptide docking as well as molecular dynamic simulation. Finally, a peptide library containing 105 validated epitopes which cross-binding by 13 prevalent HLA-A allotypes were used in ELISPOT assay to enumerate HBV-specific T cells for 116 patients with HBV infection. The spot forming units (SFUs) was significantly correlated with serum HBsAg level as confirmed by multivariate linear regression analysis. This study functionally validated 62 T cell epitopes from HBV main proteins and elucidated their HLA-A restrictions and provided an alternative ELISPOT assay using validated epitope peptides rather than conventional overlapping peptides for the clinical evaluation of HBV-specific T cell responses.

Hepatitis B Virus-Specific Cellular Immunity Contributes to the Outcome of Occult Hepatitis B Virus Infection

There is little known of immunologic factors leading to the occurrence of occult HBV infection (OBI). Specific cellular immune response to hepatitis B virus (HBV) core/pol peptides was compared between blood donor populations, including 37 OBIs, 53 chronic HBV infections (CHB), 47 resolved infections, and 56 non-infected controls, respectively. The rate of CD4⁺/CD8⁺ T cell proliferation in OBI or CHB carriers was higher than in HBV resolved and non-infected individuals (P < 0.05). The intensity of IFN-γ-secretion T-cell response of OBI carriers was highest, followed by CHB and resolved infections, and non-infected individuals (P < 0.05). The frequency of intracellular IFN-γ and IL-17A CD4⁺/CD8⁺ and IL-21 CD4⁺ T-cell responses was significantly higher in resolved infections than in OBI or CHB carriers (P < 0.05), while the level of extracellular IL-17A of peripheral blood mononuclear cells (PBMCs) was higher in OBI and CHB carriers than in resolved infections (P < 0.01). The frequency of intracellular IL-10 CD4⁺ T-cell response in CHB, OBI, and resolved infections was higher than in HBV non-infected individuals (P < 0.01). Intracellular IL-10 CD8⁺ T cell and extracellular IL-10 T-cell responses were higher in CHB than in OBI (P = 0.012) or HBV resolved infections (P < 0.01). In conclusion, the higher level of effective T-cell response with IFN-γ, IL-17A, and IL-21 contributes to resolved infection outcome, while higher levels of suppressive T-cell response with IL-10 result in HBV chronicity. OBI is an intermediary status between HBV resolved and chronic infections, in which IL-21 effector and IL-10 suppressor T-cell responses play an important role in directing the outcome of HBV infection.

A Systematic Review of T Cell Epitopes Defined from the Proteome of Hepatitis B Virus

Hepatitis B virus (HBV) infection remains a worldwide health problem and no eradicative therapy is currently available. Host T cell immune responses have crucial influences on the outcome of HBV infection, however the development of therapeutic vaccines, T cell therapies and the clinical evaluation of HBV-specific T cell responses are hampered markedly by the lack of validated T cell epitopes. This review presented a map of T cell epitopes functionally validated from HBV antigens during the past 33 years; the human leukocyte antigen (HLA) supertypes to present these epitopes, and the methods to screen and identify T cell epitopes. To the best of our knowledge, a total of 205 CD8⁺ T cell epitopes and 79 CD4⁺ T cell epitopes have been defined from HBV antigens by cellular functional experiments thus far, but most are restricted to several common HLA supertypes, such as HLA-A0201, A2402, B0702, DR04, and DR12 molecules. Therefore, the currently defined T cell epitope repertoire cannot cover the major populations with HLA diversity in an indicated geographic region. More researches are needed to dissect a more comprehensive map of T cell epitopes, which covers overall HBV proteome and global patients.

The therapeutic effect of IL-21 combined with IFN-γ inducing CD4+CXCR5+CD57+T cells differentiation on hepatocellular carcinoma

Introduction

Liver cancer is a malignant tumor with high incidence and short survival time. In order to increase the cure rate and disease-free survival rate of liver cancer, it is necessary to seek effective treatment methods.

Objectives

The objective of this study is to evaluate the therapeutic effects of IL-21 and IFN-γ inducing the formation of CD4+CXCR5+CD57+T cells on liver cancer.

Methods

The methods of analyze the relationship between CD4+CXCR5+CD57+T cells and the survival time of hepatocellular carcinoma (HCC), and study the effect of IL-21 combined with IFN-γ in inducing stem cells to differentiate into CD4+CXCR5+CD57+T cells. The effects of IL-21 combined with IFN-γ induced CD4+CXCR5+CD57+T cells on liver cancer were studied through animal experiments, and the regulatory mechanism, and the effect of hepatitis B virus (HBV) on it.

Results

The study found that the number of CD4+CXCR5+CD57+T cells in serum of liver cancer patients with prolonged survival time increased significantly, the expression of CD4, CD57, and CXCR5 in the tumor microenvironment increased, and the serum IL-21 and IFN-γ concentrations increased. IL-21 and IFN-γ induce stem cells to differentiate into CD4+CXCR5+CD57+T cells and induce HepG2 cells apoptosis. HBV leads to a decrease in the number of CD4+CXCR5+CD57+T cells and a chronic inflammatory response. Treg cells can regulate CD4+CXCR5+CD57+T cells. IL-21 combined with IFN-γ induced an increase in the number of CD4+CXCR5+CD57+T cells in hepatocarcinoma-bearing mice, which has an inhibitory effect on H22 liver cancer.

Conclusion

The conclusion of the study is that IL-21 combined with IFN-γ induces stem cells to differentiate into CD4+CXCR5+CD57+T cells, Treg can control the increase in their number, and HBV can cause their number to decrease, which can control the growth of liver cancer.