The dynamic changes of circulating invariant natural killer T cells during chronic hepatitis B virus infection

Bushen Formula promotes the decrease of HBsAg levels in patients with CHB by regulating Tfh cells and B-cell subsets

ETHNOPHARMACOLOGICAL RELEVANCE

Bushen Formula (BSF) is the effective traditional Chinese medicine (TCM) for chronic hepatitis B (CHB) according to our previous researches. However, the special effectiveness of BSF treating CHB patients in different stages and the immunoregulatory mechanisms remain to be explored.

AIM OF THE STUDY

To compare the therapeutic effects of BSF in both treatment-naive patients and Peg-IFN-α-treated patients, and explore the potential mechanism of immunomodulation.

MATERIALS AND METHODS

Ultra-high performance liquid chromatography-quadrupole electrostatic field-orbital trap high resolution mass spectrometry and the TCMSP database were used to determine the main components of BSF. Two hundred and sixty-six patients were enrolled in the retrospective study, and they were divided into the treatment group (T-Group, BSF plus Peg-IFN-α) and the control group (C-Group, Peg-IFN-α monotherapy). Within each group, patients were further grouped into subgroups, namely T1/C1 groups (treatment-naive patients, T1 = 34, C1 = 94) and T2/C2 groups (Peg-IFN-α-treated patients, T2 = 56, C2 = 82). Serum HBV markers, serum HBV DNA levels, serum ALT/AST and TCM symptoms were obtained from the record. Bioinformatics analysis was employed to obtain the potential immunoregulatory mechanisms of BSF treating CHB patients. Among patients in T2 and C2 group, peripheral mononuclear cells from 36 patients were used to analyze the characteristics of peripheral follicular helper T (Tfh) cells and B-cell subtypes by flow cytometry. Preparation of BSF-containing serum in rats. In vitro, the co-culture system of CXCR5+ cells and HepG2.2.15 cells was built to investigate the immunoregulatory effects of BSF.

RESULTS

A total of 14 main active compounds were detected in BSF, which were deemed critical for the treatment of CHB. Our findings indicated that the T2-Group exhibited the higher percentage of HBsAg decline ≥ 1-log10 IU/ml and rate of HBeAg seroclearance compared to the C2-Group (35.7% vs. 15.9%, P = 0.033; 33.9% vs. 11.0%, P = 0.002). Additionally, the T2-Group demonstrated the higher percentage of HBsAg decline ≥ 1-log10 IU/ml and rate of HBeAg seroclearance compared to the T1-Group (35.7% vs. 14.7%, P = 0.031; 33.9% vs. 2.9%, P = 0.000). The total effective rate based on TCM clinical syndrome in T1-Group and T2-Group were significantly greater than those in C1-Group and C2-Group (85.3% vs. 61.7%, P = 0.012; 89.1% vs. 63.4%, P = 0.000). Bioinformatics analysis indicated that the immunoregulatory mechanisms of BSF treating CHB patients were mainly linked to the growth and stimulation of B-cell, T-cell differentiation, and the signaling pathway of the B-cell receptor. Furthermore, the frequencies of Tfh cells and its IL-21 level, and the IL-21R expressed by B-cell were all increased after BSF treatment. Additionally, in the co-culture system of CXCR5+ cells and HepG2.2.15 cells, HBsAg and HBeAg levels were decreased after BSF-containing serum treatment，as well as the up-regulating of Tfh cell frequencies and down-regulating of B-cell frequencies.

CONCLUSIONS

BSF have the higher percentage of HBsAg decline and HBeAg seroclearance in Peg-IFN-α-treated patients compared with treatment-naive patients. The potential immunoregulatory mechanism may correlate with promoting the interaction between Tfh cells and B-cell through IL-21/IL-21R signaling pathway.

The Role of Interleukins in HBV Infection: A Narrative Review

Hepatitis B virus (HBV) infection is a worldwide medical issue with significant morbidity and mortality, as it is the main cause of chronic liver disease and hepatocellular carcinoma (HCC). Both innate and adaptive immune responses play a key role in HBV replication and suppression. Recently, the pathophysiological function of interleukins (IL) in the natural course of HBV has gained much attention as a result of the broad use of anti-interleukin agents for a variety of autoimmune diseases and the accompanying risk of HBV reactivation. We present a narrative review regarding the role of IL in HBV infection. Collectively, the pro-inflammatory ILs, namely IL-1, IL-5, IL-6, IL-12 and IL-21, seem to play a critical role in the suppression of HBV replication. In contrast, the anti-inflammatory cytokines IL-10, IL-23 and IL-35 probably act as HBV replication enhancers, while IL-17 has been correlated with HBV-related liver injury. Interestingly enough, IL-2, IL-4 and IL-12 have been tried as therapeutic options against HBV infection with contradictory results. Lastly, the role of IL-22 remains largely ill defined, although preliminary data suggest that it may play a significant role in HBV replication, proliferation and subsequent liver damage.

Interleukin-1 family cytokines in liver cell death: a new therapeutic target for liver diseases

INTRODUCTION

Liver cell death represents a basic biological process regulating the progression of liver diseases via distinct mechanisms. Accumulating evidence has uncovered participation of interleukin (IL)-1 family cytokines in liver cell death. Upon activation of cell death induced by hepatotoxic stimuli, IL1 family cytokines released by hepatic dead cells stimulate recruitment of immune cells, which in turn influence inflammation and subsequent liver injury, thus highlighting their potential as therapeutic targets in liver diseases. Enhancing our comprehension of mechanisms underlying IL1 family cytokine signaling in cell death responses could pave the way for novel therapeutic interventions aimed at addressing liver cell death-related liver pathologies.

AREAS COVERED

This review summarizes the recent findings reported in preclinical and clinical studies on mechanisms of liver cell death, alongside participation of IL1 family members consisting of IL1α, ILβ, IL18, and IL33 in liver cell death and their significant implications in liver diseases.

EXPERT OPINION

Discovery of new and innovative therapeutic approaches for liver diseases will need close cooperation between fundamental and clinical scientists to better understand the multi-step processes behind IL1 family cytokines' contributions to liver cell death.

Type I Natural Killer T Cells as Key Regulators of the Immune Response to Infectious Diseases

The immune system must work in an orchestrated way to achieve an optimal response upon detection of antigens. The cells comprising the immune response are traditionally divided into two major subsets, innate and adaptive, with particular characteristics for each type. Type I natural killer T (iNKT) cells are defined as innate-like T cells sharing features with both traditional adaptive and innate cells, such as the expression of an invariant T cell receptor (TCR) and several NK receptors. The invariant TCR in iNKT cells interacts with CD1d, a major histocompatibility complex class I (MHC-I)-like molecule. CD1d can bind and present antigens of lipid nature and induce the activation of iNKT cells, leading to the secretion of various cytokines, such as gamma interferon (IFN-γ) and interleukin 4 (IL-4). These cytokines will aid in the activation of other immune cells following stimulation of iNKT cells. Several molecules with the capacity to bind to CD1d have been discovered, including α-galactosylceramide. Likewise, several molecules have been synthesized that are capable of polarizing iNKT cells into different profiles, either pro- or anti-inflammatory. This versatility allows NKT cells to either aid or impair the clearance of pathogens or to even control or increase the symptoms associated with pathogenic infections. Such diverse contributions of NKT cells to infectious diseases are supported by several publications showing either a beneficial or detrimental role of these cells during diseases. In this article, we discuss current data relative to iNKT cells and their features, with an emphasis on their driving role in diseases produced by pathogenic agents in an organ-oriented fashion.

Invariant natural killer T cells: Not to be ignored in liver disease

The liver is an important immune organ. Hepatocellular injury can be caused by many factors, which further leads to chronic liver diseases by activating the immune system. Multiple immune cells, such as T lymphocytes, B lymphocytes, natural killer cells (NKs), natural killer T cells (NKTs), and γδT cells, accumulate and participate in the immune regulation of the liver. NKTs are an indispensable component of immune cells in the liver, and invariant natural killer T cells (iNKTs) are the main subpopulation of NKTs. iNKTs activated by glycolipid antigen presented on CD1d secrete a series of cytokines and also act on other immune cells through cell-to-cell contact. Studies on the relationship between iNKTs and liver immunity have provided clues to uncover the pathogenesis of liver diseases and develop a promising strategy for the diagnosis and treatment of liver diseases.

The effects of nucleoside/nucleotide analogues on host immune cells: the baseline for future immune therapy for HBV?

HBV is a non-cytopathic virus and the progression of liver fibrosis is attributed to the host immune response. Complete suppression of viral replication using nucleotide or nucleoside analogues (NUCs) can prevent most complications related to chronic HBV infection. Unfortunately, antiviral treatment has to be administered lifelong to the majority of patients as HBV persists in the hepatocytes. However, although NUCs are very frequently administered in clinical practice, their effects on vital parts of the host immune response to HBV are not well established. In this review we summarize the currently available data gathered from longitudinal studies that investigated treatment-associated alterations of HBV-specific CD4⁺ and CD8⁺ T-cells, regulatory T-cells and natural killer (NK) cells. These observations are important, as they can guide the design of studies that investigate the efficacy of new immune therapeutic agents. Novel experimental compounds will likely be added to ongoing NUC treatment, which leads to a functional cure in only a small minority of patients.

Impaired circulating CD56dim NK cells are associated with decompensation of HBV-related cirrhosis

NK cells play an important role in immune regulation and defense of infection, but their characteristics in patients with decompensated cirrhosis and their relationship with liver function remain unclear. We studied the functional properties of NK cells (including CD56dim NK and CD56bright NK cells) in patients with HBV-related decompensated liver cirrhosis (HBV-DLC) and analyzed their relationship with decompensation of liver function. Thirty patients with HBV-DLC and 25 patients with HBV-related compensated liver cirrhosis (HBV-CLC) were recruited in this study. Twenty five age- and sex-matched healthy individuals were recruited as healthy controls (HCs). The phenotypical and functional characteristics of NK cell subsets were detected by flow cytometry, and the correlation between NK cells and decompensation of liver function was analyzed. The frequency of circulating CD56bright NK cells was significantly increased while circulating CD56dim NK cells was significantly decreased in HBV-DLC patients as compared with HCs and HBV-CLC patients. Peripheral activated-CD56bright NK cells from HBV-DLC patients might express lower levels of inhibitory receptor CD158b1/2 and higher levels of activating receptor NKG2D and their expression of perforin and granzyme A/B also increased significantly compared with HCs, suggesting a high immune activation status of peripheral CD56bright NK cells in HBV-DLC patients. In HBV-DLC patients, the expression of CD107a and perforin in circulating CD56dim NK cells was positively correlated with cytolytic capacity while CD107a and perforin expression in circulating CD56dim NK cells were significantly decreased, suggesting an impaired cytolytic capacity of circulating CD56dim NK cells. Besides, we found that the perforin expression of circulating CD56dim NK cells correlated negatively with child-pugh classification in HBV-DLC patients. The functional properties of circulating NK cell subsets in HBV-DLC patients have changed significantly, especially of CD56dim NK cells which closely related to decompensation of liver function. These findings may help provide new perspectives and theoretical basis for the treatment of patients with HBV-DLC.

Interleukin-1 Family Cytokines: Keystones in Liver Inflammatory Diseases

The pyrogenic property being the first activity described, members of the interleukin-1 superfamily (IL-1α, IL-1β, IL-18, and the newest members: IL-33, IL-36, IL-37, and IL-38) are now known to be involved in several inflammatory diseases such as obesity, atherosclerosis, cancer, viral and parasite infections, and auto-inflammatory syndromes as well as liver diseases. Inflammation processes are keystones of chronic liver diseases, of which the etiology may be viral or toxic, as in alcoholic or non-alcoholic liver diseases. Inflammation is also at stake in acute liver failure involving massive necrosis, and in ischemia-reperfusion injury in the setting of liver transplantation. The role of the IL-1 superfamily of cytokines and receptors in liver diseases can be either protective or pro-inflammatory, depending on timing and the environment. Our review provides an overview of current understanding of the IL-1 family members in liver inflammation, highlighting recent key investigations, and therapeutic perspectives. We have tried to apply the concept of trained immunity to liver diseases, based on the role of the members of the IL-1 superfamily, first of all IL-1β but also IL-18 and IL-33, in modulating innate lymphoid immunity carried by natural killer cells, innate lymphoid cells or innate T-αβ lymphocytes.

Hyperactivated peripheral invariant natural killer T cells correlate with the progression of HBV-relative liver cirrhosis

Invariant NKT (iNKT) cells express markers of both T and NK cells and may produce various cytokines to regulate liver immunity. However, the role of iNKT cells in the progression of HBV-relative liver cirrhosis (HBV-LC) is incompletely understood. Here, we investigated the impact of peripheral iNKT cells on a cohort of patients with HBV-LC. The frequency, number, activation status, apoptosis and proliferation ability of peripheral iNKT cells were detected with flow cytometry. The impact of peripheral iNKT cells on the proliferation of hepatocyte cell line (MIHA) and activation of hepatic stellate cell line (LX-2) was detected with flow cytometry and PCR. In HBV-LC patients, the frequency and absolute number of peripheral iNKT cells significantly reduced, but the expression levels of CD25, interleukin (IL)-4, IL-13 and interferon (IFN)-γ increased. No difference was observed in the proliferation and apoptosis of circulating iNKT cells between patients and healthy controls (HCs). CXCR6 (CD186), known to be closely associated with iNKT cells migration from the periphery to the liver, was highly expressed on peripheral iNKT cells in HBV-LC patients. Furthermore, peripheral iNKT cells had a profound impact on MIHA cell proliferation and LX-2 cell activation through IL-4 or IL-13. Our data suggest that in HBV-LC patients, highly activated peripheral iNKT cells may migrate to the liver and affect hepatocyte cell line (MIHA) proliferation and hepatic stellate cell line (LX-2) activation through the expression of type 2 cytokines, which may result in excessive healing and contributing to the progression of fibrosis toward cirrhosis in liver.

Correlations between cytokines produced by T cells and clinical-virological characteristics in untreated chronic hepatitis B patients

Background

Hepatitis B virus (HBV) replicates non-cytopathically in the hepatocytes and HBV-related diseases are caused by immune-mediated inflammatory events. This study aimed to identify the relationship between clinical-virological characteristics and immunity in untreated chronic hepatitis B (CHB) patients.

Methods

A total of 209 CHB patients were categorized into immune tolerant (IT, n = 17), inactive carrier (IC, n = 20), immune active (IA, n = 120), and gray zone (GZ, n = 72) phases. The quantitative hepatitis B surface antigen (qHBsAg), hepatitis B e antigen (HBeAg), anti-HBeAg (HBeAb), HBV genotype, viral mutant and frequencies of interleukin (IL)-4, IL-17, IL-10 and interferon-gamma (IFN-γ) produced by CD4⁺ and CD8⁺ T cells were tested. We also correlated these cytokines with clinical-virological characteristics using a linear regression model.

Results

CD8⁺ T cells frequency were significantly decreased in IT patients. Levels of CD4⁺ T cells IL-4⁺ or IL-10⁺ were strongly negatively associated with qHBsAg titers. The frequency of IFN-γ produced by CD4⁺ and CD8⁺ T cells showed significant positive association with age and alanine aminotransferase (ALT) level, while that had negative association with qHBsAg titers. Additionally, the ratios of mutations in the HBV precore (PC) stop codon and basal core promoter (BCP) and the combined mutations were 32.5, 27.2, and 11.3%, respectively. The frequency of CD4⁺ T cells IL-17⁺ was higher in patients with a PC mutation than that in patients carrying a wild-type sequence. Finally, little associations among T cell derived IL-4, IL-10, IL-17, and IFN-γ was observed in the current untreated CHB cohort.

Conclusions

Several components of the immune system were correlated with HBV factors that influence an inflammatory process during CHB. Of particular relevance are the significant associations of between CD4⁺ T cells IL-4⁺ and qHBsAg level, and between CD4⁺ T cells IL-17⁺ and the presence of a mutation in PC.

Immunomodulatory Effects of Combination Therapy with Bushen Formula plus Entecavir for Chronic Hepatitis B Patients

Aim

To compare the clinical efficacy of the combination therapy with Bushen formula (BSF) plus entecavir (ETV) in naïve chronic hepatitis B (CHB) patients and that in CHB patients with partial virological response to ETV and explore the relevant immunoregulatory mechanism.

Materials and Methods

Two hundred and twenty CHB patients were enrolled in the historical prospective cohort study. Patients were categorized into a treatment group (T-Group: combination therapy with BSF plus ETV) and a control group (C-Group: ETV). Patients in T-Group and C-Group were grouped into T1/C1 (treatment-naïve patients) and T2/C2 (patients with partial virological response to ETV). Biochemical assessment, viral load quantitation, and HBV markers were tested. Chinese medicine symptom complex score was evaluated and recorded as well. In addition, peripheral blood mononuclear cells were separated from blood samples in 56 patients and 11 healthy donors. The frequencies of Th1, Treg, and dendritic cells (DCs) and expression levels of PD-1/PD-L1 were examined by flow cytometry.

Results

In treatment-naïve CHB patients, complete viral suppression rates in HBeAg(−) patients were higher than those in HBeAg(+) patients in both T and C groups. In patients with partial virological response to ETV, the rate of HBsAg decline ≥ 20% in HBeAg(+) patients of T2-Group was higher than that in HBeAg(+) patients of C2-Group. A significant reduction of Chinese medicine symptom complex score was only observed in T-Group. The study of mechanism showed that, compared with healthy controls, Th1 and DC frequencies were decreased in all CHB patients, while Treg frequency was increased only in treatment-naïve patients. In addition, compared with healthy controls, PD-1 expression levels on Th1 and Treg were increased in all patients and PD-L1 expression levels on DCs were increased only in treatment-naïve patients. In treatment-naïve patients, the combination therapy with BSF plus ETV increased Th1 and DC frequencies and decreased Treg frequency, which was correlated with HBsAg decline. In addition, in patients with partial virological response to ETV, the combination therapy downregulated PD-L1 levels on DCs and the frequency of Treg, which was related with HBsAg decline.

Conclusions

In patients with partial virological response to ETV, HBeAg(+) patients tend to achieve ideal effects after the combination therapy with BSF plus ETV, which may correlate with the decrease of Treg frequency and the downregulation of PD-L1 levels on DCs.

Comprehensive investigating of cytokine and receptor related genes variants in patients with chronic hepatitis B virus infection

BACKGROUND & AIMS

Chronic hepatitis B virus (HBV) infection is a global health problem and the outcome are associated with both viral factors and host genetic factors. High Throughput Sequencing (HTS) technology were used to identify variants associated with liver disease.

METHODS

Fifty-five Chronic hepatitis B (CHB) patients, fifty-three self-healing HBV (SH) patients and 53 healthy controls (HC) were recruited, 404 cytokine and cytokine receptor related genes were captured and sequenced at high depth (>900X), both variant (Fischer's exact test, P value < 0.05) and gene (SKAT-O gene level test, adjust P value < 0.05) level association were used to identify variants and genes associated with CHB.

RESULTS

Total 5083 variants have been detected, fifty-four variants were found associated with CHB, most (29/32) variants were located in HLA region, including HLA-B, HLA-C, HLA-DQA1, HLA-DQB1, HLA-DQB2, HLA-DRB1 and HLA-DRB5. Several missense variants were found associated with CHB, including p.E226K in PVR (poliovirus receptor), p.E400A and p.C431R in IL4R (interleukin 4 receptor). Four variants located in 3'UTR (untranslated region) have also been found associated with CHB.

CONCLUSION

Our study revealed that high through target region sequencing, combined with association analysis at variant and gene level, would be a good way to found variants and genes associated with CHB even at small sample size. Our data implied that chronic hepatitis B patients who carry these variants need intensive monitoring.

Slow reduction of IP-10 Levels predicts HBeAg seroconversion in chronic hepatitis B patients with 5 years of entecavir treatment

The aim of this study was to determine the correlation between dynamic changes in serum cytokine/chemokine expression levels in response to entecavir (ETV) treatment and HBV e antigen (HBeAg) seroconversion in patients with chronic hepatitis B (CHB). Four cytokines (interleukin [IL]-4, IL-6, IL-8, and interferon-γ) and five chemokines (macro-phage inflammatory protein [MIP]-1α, MIP-1β, platelet derived growth factor-BB, and interferon-inducible protein 10 [IP-10]) before ETV therapy and at 3, 6, 12, 24, 36 and 60 months during therapy in 105 CHB patients were analyzed. The results showed that the low decrease rate of IP-10 levels after 1 year of ETV treatment was an independent predictor of HBeAg seroconversion at year 5 (Hazard ratio = 0.972). The area under the receiver operating characteristic curves for the decrease rate of IP-10 levels after 1 year of treatment to discriminate a year-5 HBeAg seroconversion was 0.752 (p = 0.005). The results indicate that higher IP-10 level at year one of ETV treatment is associated with an increased probability of HBeAg seroconversion. Quantification of IP-10 during ETV treatment may help to predict long-term HBeAg seroconversion in patients with CHB.