Immune balance in Hepatitis B Infection: Present and Future Therapies

Letter: Muddle of serum sPD-1 and sPD-L1 levels and association with HBsAg clearance in HBeAg-negative CHB patients on IFN therapy

This article is linked to Chen et al paper. To view this article, visit https://doi.org/10.1111/apt.18131.

Risk and impact of cytomegalovirus infection in lymphoma patients treated with bendamustine

Bendamustine is used to treat lymphoma with excellent efficacy but is known for its immunosuppressive effect. Cytomegalovirus (CMV) reactivation after bendamustine use has been reported. We aim to address the impact of CMV infection in lymphoma patients treated with bendamustine-containing regimens. We retrospectively analyzed lymphoma patients at Taipei Veterans General Hospital in Taiwan between September 1, 2010, and April 30, 2022. Clinically significant CMV infection (CS-CMVi) was defined as the first CMV reactivation after bendamustine use necessitating CMV therapy. Patients' baseline characteristics and laboratory data were recorded. The primary endpoint of the study was CS-CMVi. A time-dependent covariate Cox regression model was used to estimate the risk factors of CS-CMVi and mortality. A total of 211 lymphoma patients treated with bendamustine were enrolled. Twenty-seven (12.8%) had CS-CMVi. The cumulative incidence was 10.1 per 100 person-years during the three-year follow-up period. In the multivariate analysis, lines of therapy before bendamustine ≥ 1 (95% CI 1.10-24.76), serum albumin < 3.5 g/dL (95% CI 2.63-52.93), and liver disease (95% CI 1.51-28.61) were risk factors for CS-CMVi. In conclusion, CS-CMVi (95% confidence interval [CI] 1.23-10.73) was one of the major independent risk factors of mortality. Lines of therapy before bendamustine ≥ 1, hypoalbuminemia, and liver disease were risk factors for CS-CMVi in lymphoma patients treated with bendamustine.

Tumor‑associated macrophages activated in the tumor environment of hepatocellular carcinoma: Characterization and treatment (Review)

Hepatocellular carcinoma (HCC) tissue is rich in dendritic cells, T cells, B cells, macrophages, natural killer cells and cellular stroma. Together they form the tumor microenvironment (TME), which is also rich in numerous cytokines. Tumor‑associated macrophages (TAMs) are involved in the regulation of tumor development. TAMs in HCC receive stimuli in different directions, polarize in different directions and release different cytokines to regulate the development of HCC. TAMs are mostly divided into two cell phenotypes: M1 and M2. M1 TAMs secrete pro‑inflammatory mediators, and M2 TAMs secrete a variety of anti‑inflammatory and pro‑tumorigenic substances. The TAM polarization in HCC tumors is M2. Both direct and indirect methods for TAMs to regulate the development of HCC are discussed. TAMs indirectly support HCC development by promoting peripheral angiogenesis and regulating the immune microenvironment of the TME. In terms of the direct regulation between TAMs and HCC cells, the present review mainly focuses on the molecular mechanism. TAMs are involved in both the proliferation and apoptosis of HCC cells to regulate the quantitative changes of HCC, and stimulate the related invasive migratory ability and cell stemness of HCC cells. The present review aims to identify immunotherapeutic options based on the mechanisms of TAMs in the TME of HCC.

A genetic variant in the CD40 gene is related to HBV infection in the Chinese Han population

BACKGROUND

CD40 is an important immune costimulatory molecule that has recently been found to be associated with chronic hepatitis B. This study aims to explore the association between CD40 polymorphisms and HBV infection, as well as to investigate the impact of different rs1883832 genotypes on CD40 expression and its effect on the progression of chronic HBV infection.

METHODS

We genotyped rs1883832 in 3433 individuals using MassARRAY, and quantified the CD40 expression, including CD40 mRNA, sCD40, and mCD40. The CD40 and HBV infection indicators were assessed to investigate the potential function of rs1883832 in suppressing HBV replication in HepG2.2.15 and HepAD38, CD40L in cytotoxic t lymphocytes (CTLs) and interferon-γ, TNF-α, granzyme B, and perforin were measured to elucidate the mechanism by which CD40 inhibits HBV replication.

RESULTS

Our study revealed that the frequencies of CC genotype and C allele of rs1883832 were significantly higher in immune recovery compared to chronic hepatitis B. Individuals with CC genotype exhibited significantly elevated CD40 in serum and B cells compared to TT genotypes in chronic hepatitis B. Additionally, CD40 is capable of inhibiting HBV replication and transcription in hepatocytes by means of interaction with CD40L. A significant negative correlation was found between HBV DNA, HBeAg, and mCD40. Conversely, the expressions of ALT and mCD40 showed a positive correlation, which aligns with the trend of CD40L.

CONCLUSIONS

rs1883832 C allele may have a protective role in HBV immune recovery. This protective effect could potentially be attributed to the regulation of CD40 expression. The activation of the anti-HBV immune response, which occurs through binding CD40L on CTL, can suppress HBV DNA replication and potentially facilitate immune recovery in HBV infection.

Profiling of Peripheral TRBV and CD4+CD25+ Treg in CHB Patients with HBeAg SC during TDF Treatment

BACKGROUND

It is lacking that markers could predict the prognosis of chronic hepatitis B (CHB) subjects during antiviral treatment, and the related cellular immune mechanism is not fully evaluated.

AIM

To explore the comprehensive profile of T cell receptor β-chain (TRBV) and CD4+CD25+ regulatory T cell (Treg) in peripheral blood of CHB patients with HBeAg seroconverting (SC) during tenofovir disoproxil fumarate (TDF) treatment.

METHODS

The frequency of CD4+CD25high+ Treg and number of skewed TRBV in 20 HBeAg positive patients were determined at baseline and following every 12 weeks during 96-week TDF treatment. The relationship among serum alanine aminotransferase (ALT) level, HBV DNA load, Treg frequency, and the number of skewed TRBV, respectively, was analyzed for CHB patients. Receiver operative characteristic curve was applied to analyze their diagnostic value for HBeAg SC.

RESULTS

The number of skewed TRBV at week 48, Treg frequency at week 72, and ALT level at baseline could predict the HBeAg SC or non-SC in CHB patients during 96-week TDF treatment. Moreover, the positive correlation between ALT or HBV DNA and Treg levels or skewed TRBVs was significant in the SC group, but not in non-SC.

CONCLUSIONS

The predictive cutoff value of ALT for HBeAg SC was 178 U/L at baseline. Moreover, the ALT, Treg, and TRBV families would be associated with the prognosis and pathogenesis of CHB patients during TDF treatment.

Complementary Presence of HBV Humoral and T-cell Response Provides Protective Immunity after Neonatal Immunization

BACKGROUND AND AIMS

Hepatitis B vaccination is the most cost effective way to prevent hepatitis B virus (HBV) infection. Hepatitis B vaccine (HepB) efficacy is usually assessed by anti-hepatitis B surface antigen (HBsAg) level, but there are few reports of humoral and cellular immune responses to HepB in children after neonatal vaccination.

METHODS

A group of 100 children with a history of primary hepatitis B immunization were included in this study to evaluate the efficacy of HepB. Blood samples were obtained from 80 children before, and 41 children after, a single HepB booster dose. Children with low anti-HBsAg (HBs) titers of <100 mIU/mL received a booster dose after giving their informed consent. Anti-HBsAg, T-cell response and percentage of B-cell subsets were assayed before and after the booster.

RESULTS

Of the 80 children, 81.36% had positive T cell and anti-HBsAg responses at baseline. After the booster dose, the anti-HBsAg titer (p<0.0001), positive HBsAg-specific T-cell response (p=0.0036), and spot-forming cells (p=0.0003) increased significantly. Compared with pre-existing anti-HBsAg titer <10 mIU/mL, the anti-HBsAg (p=0.0005) and HBsAg-specific T-cell responses (p<0.0001) increased significantly in preexisting anti-HBsAg titer between 10 and 100 mIU/mL group. Change of the HBV-specific humoral response was the reverse of the T-cell response with age. Peripheral blood lymphocytes, B cells, and subset frequency decreased.

CONCLUSIONS

HBV immunization protection persisted at least 13 years after primary immunization because of the complementary presence of HBV-specific humoral antibodies and a T-cell immune response. One dose of a HepB booster induced protective anti-HBsAg and promoted an HBsAg-specific T-cell response. In HBV endemic regions, a HepB booster is recommended to children without anti-HBsAg because of effectiveness in HBV prevention.

Humoral Immune Responses and Hepatitis B Infection

BACKGROUND

Chronicity or seroclearance of hepatitis B virus (HBV) antigens is determined by the host immune responses. Current approaches to treat HBV patients are based on inhibition of replication using different antivirals (nucleoside or nucleotide analogs) as monotherapy, or along with immune modulators as combination therapy is being used worldwide for reducing the viral load. Understanding the role of immune cellular therapies with currently available treatments for persistent viral-mediated responses in HBV patients is unexplored. However, the generation of antibodies against a surface (HBs) and envelop (HBe) antigen of hepatitis B remains an issue for future studies and needs to be explored.

SUMMARY

Humoral immunity, specifically T follicular helper (TFh) cells, may serve as a target for therapy for HBsAg seroconversion. In this review, we have been engrossed in the importance and role of the humoral immune responses in CHBV infection and vertical transmission. Key Message: TFh cells have been suggested as the potential target of immunotherapy which lead to seroconversion of HBe and HBs antigens of HBV. HBsAg seroconversion and eradication of covalently closed circular DNA are the main challenges for existing and forthcoming therapies in HBV infection.

Expected Hepatocarcinoma Cancer Rate Due to Escape Mutant among Local Population in Thailand: The Situation after the Implementation of Universal Hepatitis B Vaccination at Birth

Background: Chronic hepatitis B infection is an etiology of hepatocellular carcinoma. The high prevalence of hepatitis B can be seen in several regions including Indochina. In Thailand, a country in Indochina, according to the local public health policies, the universal hepatitis B vaccination is freely given to any infant at birth without charge. Despite the universal vaccination, the hepatitis B seropositive rate is still observed, and it can still be a cause of hepatocellular carcinoma among the hepatitis B carriers in the future. Methods: Here, the authors try to estimate the expected hepatocarcinoma cancer rate due to escape mutant among local population in Thailand, the situation after the implementation of universal hepatitis B vaccination at birth. Results: Based on the present study, the mutant escape contributes to only a few parts of overall estimated cancer cases in the situation that there is an implementation of universal hepatitis B vaccination at birth. Conclusion: Efficacy of theuniversal hepatitis B vaccination is not improved by specific management on escape mutants.

Tim-3 regulates inflammatory cytokine expression and Th17 cell response induced by monocytes from patients with chronic hepatitis B

Tim-3 is expressed on monocytes/macrophages and is involved in the regulation of inflammatory responses. The aim of this study was to determine the effect of Tim-3 on inflammatory response triggered by peripheral monocytes from patients with chronic hepatitis B (CHB). Tim-3 expression on peripheral monocytes and frequency of Th17 cells in peripheral blood mononuclear cells (PBMCs) derived from CHB patients were detected. Followed by lipopolysaccharides (LPS) activation of circulating monocytes from CHB patients, expression of inflammatory cytokines including TNF-α，IL-1β and IL-6 were examined in the presence and absence of Galectin-9 which is the ligand for Tim-3. Subsequently, after purified CD4+T cells were cocultured with LPS-activated monocytes from CHB patients in the presence of anti-Tim-3 antibody, percentage of Th17 cells and production of IL-17 were measured. Tim-3 expression was significantly upregulated and closely correlated to the frequency of Th17 cells in patients with CHB. Expression of TNF-α，IL-1β and IL-6 increased significantly in monocytes stimulated with LPS and Galectin-9, compared to LPS stimulation alone. LPS-activated monocytes from CHB patients could drive differentiation of memory CD4+T cells to Th17 cells. However, under the blockade of Tim-3 signalling by anti-Tim-3 antibody, percentage of Th17 cells and production of IL-17 decreased significantly. Our results demonstrate that upregulated expression of Tim-3 on circulating monocytes accelerates inflammatory response by promoting production of inflammatory cytokines and Th17 responses in CHB.

Altered serum copper homeostasis suggests higher oxidative stress and lower antioxidant capability in patients with chronic hepatitis B

Copper homeostasis can be altered by inflammation. This study aimed to investigate the alteration of serum copper homeostasis and to explore its clinical significance in patients with chronic hepatitis B (CHB).Thirty-two patients with CHB and 10 aged- and sex-matched healthy controls were recruited. Analyses included serum levels of total copper (TCu), copper ions (Cu), small molecule copper (SMC), ceruloplasmin (CP), Cu/Zn superoxide dismutase 1 (SOD1), urinary copper, and the activities of serum CP and SOD1.The serum TCu and urinary copper levels in patients with CHB were significantly higher than the controls (P = .04 and .003), while the serum Cu was lower than the controls (P = .0002). CP and SOD1 activities in the serum were significantly lower in patients with CHB compared to controls (P = .005) despite higher serum concentrations. In addition, serum alanine aminotransferase inversely correlated with serum CP activity (P = .0318, r = -0.4065).Serum copper homeostasis was altered in this cohort of patients with CHB. The results suggest increased oxidative stress and impaired antioxidant capability in patients with CHB, in addition to necroinflammation. These results may provide novel insights into the diagnosis and treatment of patients with CHB.

Urinary Nucleosides and Deoxynucleosides

Urinary nucleosides and deoxynucleosides are mainly known as metabolites of RNA turnover and oxidative damage of DNA. For several decades these metabolites have been examined for their potential use in disease states including cancer and oxidative stress. Subsequent improvements in analytical sensitivity and specificity have provided a reliable means to measure these unique molecules to better assess their relationship to physiologic and pathophysiologic conditions. In fact, some are currently used as antiviral and antitumor agents. In this review we provide insight into their molecular characteristics, highlight current separation techniques and detection methods, and explore potential clinical usefulness.

Interleukin-35 Suppresses Antiviral Immune Response in Chronic Hepatitis B Virus Infection

The mechanisms of hepatitis B virus (HBV) persistent infection are not completely understood. Interleukin (IL)-35, which is a newly identified cytokine belongs to IL-12 family, has been demonstrated to induce immunotolerance. Thus, the aim of current study was to investigate the role of IL-35 during chronic HBV infection. A total of 61 patients with chronic HBV infection [37 chronic hepatitis B (CHB) and 24 asymptomatic HBV carriers (ASC)] and 20 healthy individuals were enrolled. IL-35 concentration as well as the modulatory function of IL-35 on CD4⁺CD25⁺CD127^dim/− regulatory T cells (Tregs) and on HBV antigen-specific CD8⁺ T cells was investigated. IL-35 expression was significantly increased in both CHB and ASC, and was positively correlated with the levels of HBV DNA. Inhibition of viral replication induced the reduction in serum levels of IL-35. IL-35 stimulation led to inhibition of proinflammatory cytokine productions and elevation of apoptosis in peripheral blood mononuclear cells (PBMCs), but not in HepG2.2.15 cells. Moreover, IL-35 stimulation not only robustly inhibited cellular proliferation, but also up-regulated the production of IL-10 and IL-35 in a HBV antigen-specific and non-specific manner in Tregs/CD4⁺CD25⁻ T cells coculture system, which indicated enhancement of suppressive function of Tregs. Furthermore, IL-35 also reduced both cytolytic activity (direct lysis of HepG2.2.15 cells) and noncytolytic function (IFN-γ and TNF-α production) of HBV antigen-specific CD8⁺ T cells. The current data suggested that IL-35 contributed to maintain viral persistence by suppressing antiviral immune responses and reducing inflammatory responses in chronic HBV infection.