Rous-Whipple Award Lecture. Viruses, immunity, and cancer: lessons from hepatitis B

Knowledge, Attitudes, and Practices Toward the Prevention of Hepatitis B Virus Infection Among Medical Students in Medina City, Kingdom of Saudi Arabia

INTRODUCTION

This study focuses on assessing the knowledge, attitudes, and practices related to Hepatitis B virus (HBV) prevention among medical students in Medina, Saudi Arabia. HBV is a significant global health concern, with a high prevalence in Saudi Arabia. Medical students due to their field, are at higher risk of exposure. Prior studies in Saudi Arabia show varied levels of awareness. This research aims to provide insights that can inform educational initiatives for this specific population.

METHODS

This was a cross-sectional study conducted from June 2023 to September 2023 by using a pre-designed online questionnaire that was distributed among medical students in Medina. Data was analyzed using IBM Corp. Released 2020. IBM SPSS Statistics for Windows, Version 27.0. Armonk, NY: IBM Corp.

RESULTS

This study included 307 participants. 67.8% of the participants correctly identified the link between HBV and liver cancer, and 77.5% recognized the transmission risk from carriers. 91.9% acknowledged the transmission via contaminated blood and fluids, and 88.9% recognized the risk from unsterilized instruments. Positive attitudes were observed, with 92.2% agreeing that following infection control guidelines would protect them at work. Practice scores were generally positive, including high rates of screening (57.3%) and adherence to infection control measures (90.2%). Knowledge scores correlated positively with attitude (rho = 0.204) and practice scores (rho = 0.390).

CONCLUSION

A significant proportion of participants had a strong understanding of HBV transmission and the importance of infection control measures. Positive attitudes towards infection control were prevalent, although some reluctance to provide care to HBV-infected individuals was noted.

Function and autophagy of monocyte-derived dendritic cells is affected by hepatitis B virus infection

BACKGROUND

The role of dendritic cells and the autophagy state of dendritic cells in the immune response of hepatitis B virus (HBV) infection was still controversial. In this study, we carefully examined the phenotype, function and autophagy pathway of dendritic cells in HBV infection.

METHODS

Monocyte-derived dendritic cells from healthy blood donors and patients with chronic HBV infection were stimulated by lipopolysaccharide, supernatant of HepG2.2.15 cells or supernatant of HepG2 cells respectively. Phenotype of dendritic cells was examined by flow cytometry and cytokines secretion was detected by enzyme-linked immunosorbent assay. Autophagy related proteins were detected by western blot and immunofluorescence analysis.

RESULTS

Our results showed that the expression of both major histocompatibility complex II molecules and co-stimulated molecules including cluster of differentiation antigen 80, cluster of differentiation antigen 86 in the monocyte-derived dendritic cells from patients with chronic HBV infection was significantly higher than that from healthy donors when cultured with supernatant of HepG2.2.15 cells. The amount of cytokines, including tumour necrosis factor-α, interleukin-10 and interleukin-12, secreted by monocyte-derived dendritic cells from patients with chronic HBV infection was also significantly higher than that from healthy donors when stimulate by HBV. Interestingly, the expression level of autophagy-related proteins including autophagy-related protein5 and associated protein 1 light chain in dendritic cells from patients with chronic HBV infection was significantly increased when compared with that from healthy donors when re-exposed to HBV.

CONCLUSIONS

Our results indicated that dendritic cells from patients with chronic HBV infection could intensively present antigen and express co-stimulatory molecules. The increased activation of dendritic cells might be related to the enhanced autophagy of dendritic cells in HBV infection.

Trinity of inflammation, innate immune cells and cross-talk of signalling pathways in tumour microenvironment

Unresolved inflammation is a pathological consequence of persistent inflammatory stimulus and perturbation in regulatory mechanisms. It increases the risk of tumour development and orchestrates all stages of tumorigenesis in selected organs. In certain cancers, inflammatory processes create the appropriate conditions for neoplastic transformation. While in other types, oncogenic changes pave the way for an inflammatory microenvironment that leads to tumour development. Of interest, hallmarks of tumour-promoting and cancer-associated inflammation are striking similar, sharing a complex network of stromal (fibroblasts and vascular cells) and inflammatory immune cells that collectively form the tumour microenvironment (TME). The cross-talks of signalling pathways initially developed to support homeostasis, change their role, and promote atypical proliferation, survival, angiogenesis, and subversion of adaptive immunity in TME. These transcriptional and regulatory pathways invariably contribute to cancer-promoting inflammation in chronic inflammatory disorders and foster "smouldering" inflammation in the microenvironment of various tumour types. Besides identifying common target sites of numerous cancer types, signalling programs and their cross-talks governing immune cells' plasticity and functional diversity can be used to develop new fate-mapping and lineage-tracing mechanisms. Here, we review the vital molecular mechanisms and pathways that establish the connection between inflammation and tumour development, progression, and metastasis. We also discussed the cross-talks between signalling pathways and devised strategies focusing on these interaction mechanisms to harness synthetic lethal drug combinations for targeted cancer therapy.

The Complex Role of HBeAg and Its Precursors in the Pathway to Hepatocellular Carcinoma

Hepatitis B virus (HBV) is one of the seven known human oncogenic viruses and has adapted to coexist with a single host for prolonged periods, requiring continuous manipulation of immunity and cell fate decisions. The persistence of HBV infection is associated with the pathogenesis of hepatocellular carcinoma, and various HBV proteins have been implicated in promoting this persistence. The precursor of hepatitis e antigen (HBeAg), is translated from the precore/core region and is post-translationally modified to yield HBeAg, which is secreted in the serum. HBeAg is a non-particulate protein of HBV and can act as both a tolerogen and an immunogen. HBeAg can protect hepatocytes from apoptosis by interfering with host signalling pathways and acting as a decoy to the immune response. By evading the immune response and interfering with apoptosis, HBeAg has the potential to contribute to the hepatocarcinogenic potential of HBV. In particular, this review summarises the various signalling pathways through which HBeAg and its precursors can promote hepatocarcinogenesis via the various hallmarks of cancer.

Association of HLADQ-B1 polymorphisms in three generations of chronic hepatitis B patients

The presence of polymorphisms in the human leukocyte antigen (HLA)-DQB1 gene, along with its expression, has been demonstrated to be correlated with spontaneous clearance and susceptibility to HBV infection. The present study aimed to evaluate the possible role of genetic polymorphisms in HLA-DQB1 in three generations of patients with chronic hepatitis B (CHB). Based on the inclusion criteria, 90 CHB patients, 18 individuals recovered from HBV infection, and 40 healthy subjects were chosen. The DNA contents of the whole blood samples were extracted in order to perform HLA-DQB1 typing by the PCR technique. Besides whole blood samples, sera were applied to measure liver function tests (LFTs), as well as the titers of anti-HDV and anti-HCV. Also, in all CHB patients were measured liver stiffness (LSM) by Fibro Scan. The results of HLA-DQB1 polymorphisms (rs2856718 and rs7453920) demonstrated that the majority of polymorphisms in CHB patients were HLA-DQB1*03, HLA-DQB1*05, HLA-DQB1*04:01 and HLA-DQB1*03:01 that associated with HBV persistence and chronicity. Among the patients who showed these polymorphisms, the mean±SD, LSM was 4±1.57 KPa and most of them, F grade was reported as F2, which was a sign of disease progression towards chronicity. HLA polymorphisms imputation revealed that HLA-DQB1*06:04 (3.4%, P-Value= 0.2) was detected only in healthy subjects as protective polymorphism, while the allele HLA-DQB1*03:03 was reported in both healthy subjects (P-Value= 0.06) and recovered patients (P-Value= 0.1) as suppressor of CHB formation. The allele HLA-DQB1*05:02 was found in both healthy subjects (3.4%) and CHB patients (4.5%) which was associated with risk to liver cirrhosis (P-Value= 0, OR: 0.002 0.95CI: 0.000-0.15). HLA polymorphism analysis indicated that 17.39% of patients who were seropositive for anti-HCV carried the HLA-DQB1*03:01. HBV resistance or infection risk could be assessed by DBQ1 typing. The existence of polymorphisms in HLA gene could influence the clearance (HLA-DQB1*03:03) or susceptibility and persistence of infection (HLA-DQB1*03, HLA-DQB1*05, HLA-DQB1*04:01 and HLA-DQB1*03:01). These results have the potential to improve personalized therapy and prognosis for HBV infection.

Conversion of hepatitis B virus relaxed circular to covalently closed circular DNA is supported in murine cells

Background & Aims

HBV has a narrow host restriction, with humans and chimpanzees representing the only known natural hosts. The molecular correlates of resistance in species that are commonly used in biomedical research, such as mice, are currently incompletely understood. Expression of human NTCP (hNTCP) in mouse hepatocytes enables HBV entry, but subsequently covalently closed circular (cccDNA) does not form in most murine cells. It is unknown if this blockade in cccDNA formation is due to deficiency in repair of relaxed circular DNA (rcDNA) to cccDNA.

Methods

Here, we deployed both in vivo and in vitro virological and biochemical approaches to investigate if murine cells contain a complete set of repair factors capable of converting HBV rcDNA to cccDNA.

Results

We demonstrate that HBV cccDNA does form in murine cell culture or in mice when recombinant rcDNA without a protein adduct is directly introduced into cells. We further show that the murine orthologues of core components in DNA lagging strand synthesis, required for the repair of rcDNA to cccDNA in human cells, can support this crucial step in the HBV life cycle. It is worth noting that recombinant HBV rcDNA substrates, either without a protein adduct or containing neutravidin to mimic HBV polymerase, were used in our study; it remains unclear if the HBV polymerase removal processes are the same in mouse and human cells.

Conclusions

Collectively, our data suggest that the HBV life cycle is blocked post entry and likely before the repair stage in mouse cells, which yields critical insights that will aid in the construction of a mouse model with inbred susceptibility to HBV infection.

Lay summary

Hepatitis B virus (HBV) is only known to infect humans and chimpanzees in nature. Mouse models are often used in modeling disease pathogenesis and preclinical research to assess the efficacy and safety of interventions before they are then tested in human participants. However, because mice are not susceptible to HBV infection it is difficult to accurately model human infection (and test potential treatments) in mouse models. Herein, we have shown that mice are able to perform a key step in the HBV life cycle, tightening the net around the possible reason why HBV can not efficiently infect and replicate in mice.

Dysregulation of Liver Regeneration by Hepatitis B Virus Infection: Impact on Development of Hepatocellular Carcinoma

The liver is unique in its ability to regenerate in response to damage. The complex process of liver regeneration consists of multiple interactive pathways. About 2 billion people worldwide have been infected with hepatitis B virus (HBV), and HBV causes 686,000 deaths each year due to its complications. Long-term infection with HBV, which causes chronic inflammation, leads to serious liver-related diseases, including cirrhosis and hepatocellular carcinoma. HBV infection has been reported to interfere with the critical mechanisms required for liver regeneration. In this review, the studies on liver tissue characteristics and liver regeneration mechanisms are summarized. Moreover, the inhibitory mechanisms of HBV infection in liver regeneration are investigated. Finally, the association between interrupted liver regeneration and hepatocarcinogenesis, which are both triggered by HBV infection, is outlined. Understanding the fundamental and complex liver regeneration process is expected to provide significant therapeutic advantages for HBV-associated hepatocellular carcinoma.

Hepatitis B virus reactivation: overview and management

Hepatitis B virus (HBV) can hide in the liver in the form of covalently closed circular DNA. When the body’s immunity changes, HBV reactivation (HBV-R) can occur. The risk of HBV-R is determined by the complex interaction among virological factors, medication factors and host factors. However, many patients do not know that they are infected with HBV, and doctors often do not invest enough time to systematically evaluate the patient’s HBV-R risk factors before immunosuppressive treatment. Therefore, HBV clinical screening should be vigorously promoted to achieve early detection and early prevention for patients with high risk of HBV-R. The mechanism, clinical features, risk factors, HBV-R under different disease etiologies, prevention and treatment of HBV-R were summarized to improve the in-depth understanding and awareness.

Current impact of viral hepatitis on liver cancer development: The challenge remains

Chronic infections due to hepatitis B and hepatitis C viruses are responsible for most cases of hepatocellular carcinoma (HCC) worldwide, and this association is likely to remain during the next decade. Moreover, viral hepatitis-related HCC imposes an important burden on public health in terms of disability-adjusted life years. In order to reduce such a burden, some major challenges must be faced. Universal vaccination against hepatitis B virus, especially in the neonatal period, is probably the most relevant primary preventive measure against the development of HCC. Moreover, considering the large adult population already infected with hepatitis B and C viruses, it is also imperative to identify these individuals to ensure their access to treatment. Both hepatitis B and C currently have highly effective therapies, which are able to diminish the risk of development of liver cancer. Finally, it is essential for individuals at high-risk of HCC to be included in surveillance programs, so that tumors are detected at an early stage. Patients with hepatitis B or C and advanced liver fibrosis or cirrhosis benefit from being followed in a surveillance program. As hepatitis B virus is oncogenic and capable of leading to liver cancer even in individuals with early stages of liver fibrosis, other high-risk groups of patients with hepatitis B are also candidates for surveillance. Considerable effort is required concerning these strategies in order to decrease the incidence and the mortality of viral hepatitis-related HCC.

Association of an IFN-γ variant with susceptibility to chronic hepatitis B by the enhancement of HBV DNA replication

Interferon gamma (IFN-γ) is a crucial cytokine in host immune response to hepatitis B virus (HBV) infection. This study aimed to determine whether a functional polymorphism +874T/A in IFN-γ gene linked to high and low producer phenotypes [IFN-γ (+874T^high → A^low)] may alter the outcomes of chronic HBV infection in Tunisian population. The +874T/A was analysed by ARMS-PCR method in the group of 200 patients chronically infected with HBV and 200 healthy controls. We observed that minor +874A allele, minor +874AA and +874TA genotypes were significantly more frequent in the chronic hepatitis B group in comparison to the control group [49 vs. 31%, P < 10^-4; 24 vs. 13%, P < 10^-4; 52 vs. 38%, P < 10^-4; respectively]. Besides, they were associated with susceptibility to hepatitis B infection [OR = 2.15, 3.87 and 2.84, respectively]. The minor +874A allele and +874AA genotype were statistically more representative in the sub-group of patients with high viral DNA load when compared with the sub-group of patients with low HBV DNA load [(57% vs. 43%, P = 0.003, OR = 1.79); (33% vs. 14%, P = 0.003, OR = 3.59), respectively]. Collectively, our study suggests an association between the IFN-γ +874T/A SNP and persistence of HBV by the enhancement of HBV DNA replication.

Risk Factors and Biomarkers for Chronic Hepatitis B Associated Hepatocellular Carcinoma

Globally, hepatitis B virus (HBV) related hepatocellular carcinoma (HCC) is one of the major causes of cancer-related mortality. This is, in part, due to delayed diagnosis and limited therapeutic options with more advanced stages of the disease. Given the prognostic importance of early diagnosis, novel methods for early detection are in need. Unlike most other cancer types, tissue is not required to diagnose HCC and is frequently avoided given the inherent risks of liver biopsy, so less invasive methods of obtaining tumor material are currently under investigation. Material shed from tumors into the periphery are being investigated for their potential to both surveil and diagnose patients for HCC. These materials include circulating tumor cells, DNA, RNA, and exosomes, and are collectively termed a “liquid biopsy”. In this review article, we discuss the evolving literature regarding the different risk factors for HCC and the types of emerging novel biomarkers that show promise in the prevention and early diagnosis of HCC within the context of HBV infection.

Heterogeneity of Antiviral Responses in the Upper Respiratory Tract Mediates Differential Non-lytic Clearance of Influenza Viruses

Influenza viruses initiate infection in the upper respiratory tract (URT), but early viral tropism and the importance of cell-type-specific antiviral responses in this tissue remain incompletely understood. By infecting transgenic lox-stop-lox reporter mice with a Cre-recombinase-expressing influenza B virus, we identify olfactory sensory neurons (OSNs) as a major viral cell target in the URT. These cells become infected, then eliminate the virus and survive in the host post-resolution of infection. OSN responses to infection are characterized by a strong induction of interferon-stimulated genes and more rapid clearance of viral protein relative to other cells in the epithelium. We speculate that this cell-type-specific response likely serves to protect the central nervous system from infection. More broadly, these results highlight the importance of evaluating antiviral responses across different cell types, even those within the same tissue, to more fully understand the mechanisms of viral disease.

The Crosstalk Between Hippo-YAP Pathway and Innate Immunity

Recognition of pathogen-associated molecular patterns (PAMPs) triggers expression of antiviral interferons and proinflammatory cytokines, which functions as the frontier of host defense against microbial pathogen invasion. Hippo-YAP pathway regulates cell proliferation, survival, differentiation and is involved in diverse life processes, including tissue homeostasis and tumor suppression. Emerging discoveries elucidated that the components of Hippo-YAP pathway, such as MST1/2, NDR1/2, and YAP/TAZ played crucial regulatory roles in innate immunity. Meanwhile the innate immune signaling also exhibited regulatory effect on Hippo-YAP pathway. As for the importance of these two pathways, it would be interesting to figure out the deeper biological implications of their interplays. This review focuses on the regulation between Hippo-YAP pathway and innate immune signaling. We also propose the possible contribution of these interplays to tumor development.

Interaction of the microbiota with the human body in health and diseases

The human body contains many microorganisms, including a large number of bacteria, viruses, fungi, and protozoa, which are referred to as the microbiota. Compared with the number of cells comprising the human body, that of the microbiota has been found to be much larger. The microbiome is defined as microorganisms and their genomes have been shown to contain about 100 times more genes than the human genome. The microbiota affects many vital functions in the human body. It contributes to regulation of the immune system, digestion of food, production of vitamins such as B12 and K, metabolization of xenobiotic materials, and many other tasks. Many factors affect the microbiota biodiversity, such as diet, medicines including antibiotics, relationships with the environment, pregnancy, and age. Studies have shown that the lack of microbiota diversity leads to many diseases like autoimmune diseases such as diabetes type I, rheumatism, muscular dystrophy, problems in blood coagulation due to lack of vitamin K, and disturbances in the transfer of nerve cells due to lack of vitamin B12, in addition to its involvement in a number of conditions such as cancer, memory disorders, depression, stress, autism, and Alzheimer's disease. The aim of this review is to summarize the latest studies discussing the relationship between the microbiota and the human body in health and diseases.

DNA mismatch repair is required for the host innate response and controls cellular fate after influenza virus infection

Despite the cytopathic nature of influenza A virus (IAV) replication, we recently reported that a subset of lung epithelial club cells is able to intrinsically clear virus and survive infection. However, the mechanisms that drive cell survival during a normally lytic infection remained unclear. Using a loss-of-function screening approach, we discovered that the DNA mismatch repair (MMR) pathway is essential for club cell survival of IAV infection. Repair of virally-induced oxidative damage by the DNA MMR pathway not only allowed cell survival of infection but also facilitated host gene transcription, including the expression of antiviral and stress response genes. Enhanced viral suppression of the DNA MMR pathway prevented club cell survival and increased the severity of viral disease in vivo. Altogether, these results identify previously unappreciated roles for DNA MMR as a central modulator of cellular fate and a contributor to the innate antiviral response, which together, control influenza viral disease severity.

Clinical Outcome and Viral Genome Variability of Hepatitis B Virus-Induced Acute Liver Failure

Acute hepatitis B virus (HBV) infection remains a frequent cause of acute liver failure (ALF) worldwide. ALF occurs in 0.1%-0.5% of infected patients. The aim of this study was to scrutinize the outcome of patients with HBV-induced ALF and mutational patterns of HBV variants, which might contribute to ALF. From 2005 to 2016, 42 patients were treated for HBV-induced ALF in the University Hospital Essen, Germany. Clinical and virological data from these patients were collected. As a control, 38 patients with acute hepatitis B (AHB) without liver failure were included. The HBV genome was sequenced by next-generation sequencing (NGS). Mutations that were found by NGS were analyzed in vitro. Of 42 patients, 8 had ALF without spontaneous recovery (NSR): Seven patients underwent liver transplantation (LT) and one patient died before LT. Of 42 patients, 34 (81%) had spontaneous recovery (SR) and cleared the infection, achieving either anti-HBs seroconversion or hepatitis B surface antigen (HBsAg) loss. HBV genotype (GT)-D was the most frequent GT in patients with ALF. Mutations in HBV core, preS2, and small hepatitis B surface antigen (SHB) were more frequent in patients with ALF-NSR compared with those with ALF-SR or AHB. Amino acid deletions (del; 16-22 and 20-22) in preS2 and SHB mutation L49R were exclusively detected in patients with ALF-NSR. In vitro analyses reveal that these mutations did not influence HBsAg secretion or infectivity. Conclusion: HBV GT-D and increased variability in HBV core, preS2 region, and SHB are associated with a worse clinical outcome of acute HBV infection.

Type I Interferon Signaling Prevents Hepatitis B Virus-Specific T Cell Responses by Reducing Antigen Expression

Robust virus-specific CD8+ T cell responses are required for the clearance of hepatitis B virus (HBV). However, the factors that determine the magnitude of HBV-specific CD8+ T cell responses are poorly understood. To examine the impact of genetic variations of HBV on HBV-specific CD8+ T cell responses, we introduced three HBV clones (Aa_IND [Aa], C_JPN22 [C22], and D_IND60 [D60]) that express various amounts of HBV antigens into the livers of C57BL/6 (B6) (H-2b) mice and B10.D2 (H-2d) mice. In B6 mice, clone C22 barely induced HBV-specific CD8+ T cell responses and persisted the longest, while clone D60 elicited strong HBV-specific CD8+ T cell responses and was rapidly cleared. These differences between HBV clones largely diminished in H-2d mice. Interestingly, the magnitude of HBV-specific CD8+ T cell responses in B6 mice was associated with the HB core antigen expression level during the early phase of HBV transduction. Surprisingly, robust HBV-specific CD8+ T cell responses to clone C22 were induced in interferon-α/β receptor-deficient (IFN-αβR-/-) (H-2b) mice. The induction of HBV-specific CD8+ T cell responses to C22 in IFN-αβR-/- mice reflects enhanced HBV antigen expression because the suppression of antigen expression by HBV-specific small interfering RNA (siRNA) attenuated HBV-specific T cell responses in IFN-αβR-/- mice and prolonged HBV expression. Collectively, these results suggest that HBV genetic variation and type I interferon signaling determine the magnitude of HBV-specific CD8+ T cell responses by regulating the initial antigen expression levels.IMPORTANCE Hepatitis B virus (HBV) causes acute and chronic infection, and approximately 240 million people are chronically infected with HBV worldwide. It is generally believed that virus-specific CD8+ T cell responses are required for the clearance of HBV. However, the relative contributions of genetic variation and innate immune responses to the induction of HBV-specific CD8+ T cell responses are not fully understood. In this study, we discovered that different clearance rates between HBV clones after hydrodynamic transduction were associated with the magnitude of HBV-specific CD8+ T cell responses and initial HB core antigen expression. Surprisingly, type I interferon signaling negatively regulated HBV-specific CD8+ T cell responses by reducing early HBV antigen expression. These results show that the magnitude of the HBV-specific CD8+ T cell response is regulated primarily by the initial antigen expression level.

Intrahepatic Cross-Presentation and Hepatocellular Antigen Presentation Play Distinct Roles in the Induction of Hepatitis B Virus-Specific CD8+ T Cell Responses

CD8+ T cells are the key cellular effectors mediating the clearance of hepatitis B virus (HBV) infections. However, early immunological events surrounding the priming of HBV-specific CD8+ T cell responses remain poorly understood. This study examined the importance of priming location and the relative contribution of endogenous antigen presentation by hepatocytes versus cross-presentation by bone marrow-derived cells to the induction of functional HBV-specific CD8+ T cell responses using the animal models of acute and chronic HBV infection. Functional HBV-specific CD8+ T cell responses could be induced to intrahepatically expressed HBV even when T cell homing to the lymphoid tissues was severely suppressed, suggesting that functional priming could occur in the liver. The expansion of HBV-specific CD8+ T cells was significantly reduced in the mice whose major histocompatibility complex (MHC) class I expression was mostly restricted to nonhematopoietic cells, suggesting the importance of cross-presentation by hematopoietic cells in the induction of HBV-specific CD8+ T cells. Strikingly, the expansion and cytolytic differentiation of HBV-specific CD8+ T cells were reduced even more severely in the mice whose MHC class I expression was restricted to hematopoietic cells. Collectively, these results indicate that cross-presentation is required but relatively inefficient in terms of inducing the cytolytic differentiation of HBV-specific CD8+ T cells by itself. Instead, the expansion and functional differentiation of HBV-specific CD8+ T cells are primarily dependent on hepatocellular antigen presentation.IMPORTANCE Hepatitis B virus (HBV) causes acute and chronic hepatitis. Approximately 260 million people are chronically infected with HBV and under an increased risk of developing cirrhosis and hepatocellular carcinoma. Host immune responses, particularly HBV-specific CD8+ T cell responses, largely determine the outcome of HBV infection. It is widely accepted that antigen inexperienced CD8+ T cells should be initially activated by professional antigen-presenting cells (pAPCs) in lymphoid tissues to differentiate into effector CD8+ T cells. However, this notion has not been tested for HBV-specific CD8+ T cells. In this study, we show that HBV-specific CD8+ T cell responses can be induced in the liver. Surprisingly, antigen presentation by hepatocytes is more important than cross-presentation by hematopoietic cells for the induction of HBV-specific CD8+ T cell responses. These results revealed a previously unappreciated role of antigen presentation by hepatocytes in the induction of HBV-specific CD8+ T cell responses.

Herbal management of hepatocellular carcinoma through cutting the pathways of the common risk factors

Hepatocellular carcinoma (HCC) is considered the most frequent tumor that associated with high mortality rate. Several risk factors contribute to the pathogenesis of HCC, such as chronic persistent infection with hepatitis C virus or hepatitis B virus, chronic untreated inflammation of liver with different etiology, oxidative stress and fatty liver disease. Several treatment protocols are used in the treatment of HCC but they also associated with diverse side effects. Many natural products are helpful in the co-treatment and prevention of HCC. Several mechanisms are involved in the action of these herbal products and their bioactive compounds in the prevention and co-treatment of HCC. They can inhibit the liver cancer development and progression in several ways as protecting against liver carcinogens, enhancing effects of chemotherapeutic drugs, inhibiting tumor cell growth and metastasis, and suppression of oxidative stress and chronic inflammation. In this review, we will discuss the utility of diverse natural products in the prevention and co-treatment of HCC, through its capturing of the common risk factors known to lead to HCC and shed the light on their possible mechanisms of action. Our theory assumes that shutting down the risk factor to cancer development pathways is a critical strategy in cancer prevention and management. We recommend the use of these plants side by side to recent chemical medications and after stopping these chemicals, as a maintenance therapy to avoid HCC progression and decrease its global incidence.

The Correlation Between Hepatitis B Virus Precore/Core Mutations and the Progression of Severe Liver Disease

Viral mutations acquired during the course of chronic hepatitis B virus (HBV) infection are known to be associated with the progression and severity of HBV-related liver disease. This study of HBV-infected Saudi Arabian patients aimed to identify amino acid substitutions within the precore/core (preC/C) region of HBV, and investigate their impact on disease progression toward hepatocellular carcinoma (HCC). Patients were categorized according to the severity of their disease, and were divided into the following groups: inactive HBV carriers, active HBV carriers, liver cirrhosis patients, and HCC patients. Two precore mutations, W28^* and G29D, and six core mutations, F24Y, E64D, E77Q, A80I/T/V, L116I, and E180A were significantly associated with the development of cirrhosis and HCC. Six of the seven significant core mutations that were identified in this study were located within immuno-active epitopes; E77Q, A80I/T/V, and L116I were located within B-cell epitopes, and F24Y, E64D, and V91S/T were located within T-cell epitopes. Multivariate risk analysis confirmed that the core mutations A80V and L116I were both independent predictors of HBV-associated liver disease progression. In conclusion, our data show that mutations within the preC/C region, particularly within the immuno-active epitopes, may contribute to the severity of liver disease in patients with chronic hepatitis. Furthermore, we have identified several distinct preC/C mutations within the study population that affect the clinical manifestation and progression of HBV-related disease. The specific identity of HBV mutations that are associated with severe disease varies between different ethnic populations, and so the specific preC/C mutations identified here will be useful for predicting clinical outcomes and identifying the HBV-infected patients within the Saudi population that are at high risk of developing HCC.

A STAT4 variant increases liver fibrosis risk in Caucasian patients with chronic hepatitis B

BACKGROUND

Host genetic modifiers of the natural history of chronic hepatitis B (CHB) remain poorly understood. Recently, a genome-wide association study (GWAS)-identified polymorphism in the STAT4 gene that contributes to the risk for hepatocellular carcinoma (HCC) was shown to be associated with the full spectrum of hepatitis B virus (HBV) outcomes in Asian patients. However, the functional mechanisms for this effect are unknown and the role of the variant in modulating HBV disease in Caucasians has not been investigated.

AIMS

To determine whether STAT4 genetic variation is associated with liver injury in Caucasian patients with CHB and to investigate potential mechanisms mediating this effect.

METHODS

STAT4 rs7574865 was genotyped in 1085 subjects (830 with CHB and 255 healthy controls). STAT4 expression in liver, PBMCs and NK cells, STAT4 phosphorylation and secretion of interferon-gamma (IFN-γ) according to STAT4 genetic variation was examined.

RESULTS

STAT4 rs7574865 genotype was independently associated with hepatic inflammation (OR: 1.42, 95% CI: 1.07-2.06, P = 0.02) and advanced fibrosis (OR: 1.83, 95% CI: 1.19-2.83, P = 0.006). The minor allele frequency of rs7574865 was significantly lower than that in healthy controls. rs7574865 GG risk carriers expressed lower levels of STAT4 in liver, PBMCs and in NK cells, while NK cells from patients with the risk genotype had impaired STAT4 phosphorylation following stimulation with IL-12/IL-18 and a reduction in secretion of IFN-γ.

CONCLUSION

Genetic susceptibility to HBV persistence, hepatic inflammation and fibrosis in Caucasians associates with STAT4 rs7574865 variant. Downstream effects on NK cell function through STAT4 phosphorylation-dependent IFN-γ production likely contribute to these effects.

Activation of intrahepatic CD4+CXCR5+ T and CD19+ B cells is associated with viral clearance in a mouse model of acute hepatitis B virus infection

The role of immunity in the pathogenesis of acute hepatitis B virus (HBV) infection is poorly understood. The purpose of this research was to define the intrahepatic immune factors responsible for viral clearance during acute HBV infection. The model of acute HBV infection was established by hydrodynamically transfecting mice with pCDNA3.1-HBV1.3 plasmids which contained a supergenomic HBV1.3-length transgene. The frequency of CD4⁺ CXCR5⁺ T cells, CD19⁺ B cells and their surface molecules in livers, spleens and peripheral blood were detected using flow cytometry. The lymphomononuclear cells isolated from the livers of transfected mice were further stimulated by HBc-derived peptides and then the frequency and cytokine secretion of HBV-specific CD4⁺CXCR5⁺ T cells were detected. We found that the frequency of CXCR5⁺ in CD4⁺ T cells was specifically increased; the expression of PD-1 was decreased while the expression of ICOS was increased on intrahepatic CD4⁺CXCR5⁺ T cells. Although the frequency of CD19⁺ B cells was not affected, the expression of PDL-1, ICOSL and IL-21R on B cells was increased in the livers of mice. The frequency of HBV-specific CD4⁺CXCR5⁺ T cells and the production of IL-21 by intrahepatic CD4⁺CXCR5⁺ T cells of mice with acute HBV infection were increased after stimulation. Furthermore, the expression of function-related molecules of intrahepatic CD4⁺CXCR5⁺ T, including Bcl-6, CXCR5, IL-6, IL-6R, IL-21 and IL-4 in the liver was increased during acute HBV infection. In conclusion, the activation of intrahepatic CD4⁺CXCR5⁺ T cells and B cells was associated with the clearance of HBV during acute infection.

Quantitative assessment of HLA-DQ gene polymorphisms with the development of hepatitis B virus infection, clearance, liver cirrhosis, and hepatocellular carcinoma

Hepatitis B is one of the most common infectious diseases, which leads to public health problems in the world, especially in Asian counties. In recent years, extensive human genetic association studies have been carried out to identify susceptible genes and genetic polymorphisms to understand the genetic contributions to the disease progression of HBV infection. HLA-DQ gene variations have been reported to be associated with HBV infection/clearance, disease progression and the development of hepatitis B-related complications, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC). However, the results are either inconclusive or controversial. Therefore, to derive a more precise estimation of the association, a meta-analysis was performed. Our data revealed that the HLA-DQ alleles rs2856718-G, rs7453920-A and rs9275319-G were significantly associated with decreased risk of HBV infection and HBV natural clearance. Logistic regression analyses showed that HLA-DQ alleles rs9275572-A significantly increased HBV infection clearance, and decreased HBV natural clearance. However, rs2856718-G and rs9275572-A were not associated with development of cirrhosis. The HLA-DQ polymorphisms (rs2856718 and rs9275572) were associated with a decreased HBV-related HCC risk in all genetic models, but rs9272105-A increased the risk of HBV-related HCC. In addition, no significant association was observed between HLA-DQ rs9275319-G polymorphism and HBV-related HCC. These stratified analyses were limited due to relatively modest size of correlational studies. In future, further investigation on a large population and different ethnicities are warranted. Our findings contribute to the personalized care and prognosis in hepatitis B.

The Role of Infected Cell Proliferation in the Clearance of Acute HBV Infection in Humans

Around 90-95% of hepatitis B virus (HBV) infected adults do not progress to the chronic phase and, instead, recover naturally. The strengths of the cytolytic and non-cytolytic immune responses are key players that decide the fate of acute HBV infection. In addition, it has been hypothesized that proliferation of infected cells resulting in uninfected progeny and/or cytokine-mediated degradation of covalently closed circular DNA (cccDNA) leading to the cure of infected cells are two major mechanisms assisting the adaptive immune response in the clearance of acute HBV infection in humans. We employed fitting of mathematical models to human acute infection data together with physiological constraints to investigate the role of these hypothesized mechanisms in the clearance of infection. Results suggest that cellular proliferation of infected cells resulting in two uninfected cells is required to minimize the destruction of the liver during the clearance of acute HBV infection. In contrast, we find that a cytokine-mediated cure of infected cells alone is insufficient to clear acute HBV infection. In conclusion, our modeling indicates that HBV clearance without lethal loss of liver mass is associated with the production of two uninfected cells upon proliferation of an infected cell.

Association of human leukocyte antigen polymorphisms with occult hepatitis B virus infection in a Shaanxi Han population

BACKGROUND

Occult hepatitis B virus (HBV) infection (OBI) is defined as HBV DNA detection in serum or in the liver by sensitive diagnostic tests in HBV surface antigen (HBsAg) negative patients with or without serologic markers of previous HBV exposure. Because the human leukocyte antigen (HLA) system is an integral component of the immune response, we hypothesized that the highly polymorphic HLA genes were the key determinants of HBV persistence and clearance. The present study aimed to calculate the allelic frequency of HLA loci and investigate the association between HLA alleles and the outcome of OBI in Shaanxi Han population in the northwest of China.

METHODS

We conducted a case-control study between 107 OBI subjects and 280 healthy control individuals from blood donors of Shaanxi Blood Center. Five HLA loci, including HLA-A,-B,-C,-DRB1 and -DQB1, were selected and further genotyped using a polymerase chain reaction sequence-based typing (SBT) method.

RESULTS

Using the chi-squared test, we found that the allele frequencies of HLA-B*44:03 [odds ratios (OR) = 2.146, 95% confidence interval (CI) = 1.070-4.306, p = 0.028]; C*07:01 (OR = 4.693, CI = 1.822-12.086, p = 0.000); DQB1*02:02 (OR = 1.919, CI = 1.188-3.101, p = 0.007); and DRB1*07:01 (OR = 2.012, CI = 1.303-3.107, p = 0.001) were markedly higher in the OBI group compared to the healthy control group. The allele frequencies of HLA-DRB1*08:03 (OR = 0.395, CI = 0.152-1.027, p = 0.049); DRB1*15:01 (OR = 0.495, CI = 0.261-0.940, p = 0.029); and DQB1*06:02 (OR = 0.500, CI = 0.249-1.005, p = 0.048) were obviously lower in the OBI group compared to the healthy control group. These data indicated that HLA-B*44:03, C*07:01, DQB1*02:02 and DRB1*07:01 were related to OBI infection, whereas HLA-DRB1*08:03, DRB1*15:01 and DQB1*06:02 alleles were associated with HBV DNA clearance in a Shaanxi Han population.

CONCLUSIONS

The results of the present study suggest that host HLA gene is an important influencing factor for OBI pathogenesis.

Halofuginone ameliorates inflammation in severe acute hepatitis B virus (HBV)-infected SD rats through AMPK activation

The hepatitis B virus (HBV) has caused acute and chronic liver diseases in ~350 million infected people worldwide. Halofuginone (HF) is a plant alkaloid which has been demonstrated to play a crucial role in immune regulation. Our present study explored the function of HF in the immune response of HBV-infected Sprague Dawley (SD) rats. Plasmid containing pCDNA3.1-HBV1.3 was injected in SD rats for the construction of an acute HBV-infected animal model. Our data showed that HF reduced the high concentrations of serum hepatitis B e-antigen, hepatitis B surface antigen, and HBV DNA induced by HBV infection. HF also reduced the number of T helper (Th)17 cells and the expression of interleukin (IL)-17 compared with the pCDNA3.1-HBV1.3 group. Moreover, pro-inflammatory cytokine levels (IL-17, IL-23, interferon-γ, and IL-2) were downregulated and anti-inflammatory cytokine levels (IL-4 and IL-13) were upregulated by HF. Through further research we found that the expression of AMP-activated protein kinase (AMPK) and IKBA which suppressed NF-κB activation was increased while the expression of p-NF-κB P65 was decreased in pCDNA3.1-HBV1.3+HF group compared with pCDNA3.1-HBV1.3 group, indicating that HF may work through the activation of AMPK. Finally, our conjecture was further verified by using the AMPK inhibitor compound C, which counteracted the anti-inflammation effect of HF, resulting in the decreased expression of AMPK, IKBA and increased expression of p-NF-κB P65 and reduced number of Th17 cells. In our present study, HF was considered as an anti-inflammatory factor in acute HBV-infected SD rats and worked through AMPK-mediated NF-κB p65 inactivation. This study implicated HF as a potential therapeutic strategy for hepatitis B.

Analysis of immunological mechanisms exerted by HBsAg-HBIG therapeutic vaccine combined with Adefovir in chronic hepatitis B patients

An HBsAg-HBIG therapeutic vaccine (Yeast-derived Immune Complexes, YIC) for chronic hepatitis B (CHB) patients has undergone a series of clinical trials. The HBeAg sero-conversion rate of YIC varied from 21.9% to 14% depending on the immunization protocols from 6 to 12 injections. To analyze the immunological mechanisms exerted by 6 injections of YIC, 44 CHB patients were separately immunized with YIC, alum as adjuvant control or normal saline as blank control, with add on of antiviral drug Adefovir in all groups. Kinetic increase in Th1 and Th2 cells CD4⁺ T cell sub-populations with association in decrease in Treg cells and increase of Tc1 and Tc17 cells in CD8⁺ T cells were observed in YIC immunized group. No such changes were found in the other groups. By multifunctional analysis of cytokine profiles, significant increase of IL-2 levels was observed, both in CD4⁺ and CD8⁺ T cells in the YIC immunized group, accompanied by increase in IFN-gamma and decrease of inhibitory factors (IL-10, TGF-β and Foxp3) in CD4⁺ T cells. In the alum immunized group, slight increase of IL-10, TGF-β and Foxp3 in CD4⁺ T cells was found after the second injection, but decreased after more injections, suggesting that alum induced early inflammatory responses to a certain extent. Similar patterns of responses of IL-17A and TNF-α in CD8⁺T cells were shown between YIC and the saline group. Results indicate that add on of Adefovir, did not affect host specific immune responses.

Elimination of Hepatitis B: Is It a Mission Possible?

Chronic hepatitis B virus (HBV) infection is a global public health issue. Although the disease cannot be cured effectively, disease management has been improved over the past decade. The introduction of potent nucleos(t)ide analogues (NAs) to suppress viral replication represented a giant leap in the control of this disease. It has been shown that tenofovir treatment, a potent NA, complements current immunoprophylaxis to diminish mother-to-infant transmission in pregnant women with a high viral load. For patients with chronic HBV infection, quantitative hepatitis B surface antigen is a useful tool to define inactive carriers and to guide antiviral therapy. Quantification of HBV mutants is also useful in predicting long-term outcomes more precisely than ever. The next challenge is how to achieve an HBV cure; although immunotherapy is a promising strategy, the current results from two clinical trials using therapeutic vaccines to induce HBV-specific immune response in patients with chronic HBV infection are disappointing. In the coming years, we are expecting to see a combination of therapeutic agents with various modes of action to complete the mission of HBV elimination.

Modelling the Impact of Cell-To-Cell Transmission in Hepatitis B Virus

Cell-free virus is a well-recognized and efficient mechanism for the spread of hepatitis B virus (HBV) infection in the liver. Cell-to-cell transmission (CCT) can be a more efficient means of virus propagation. Despite experimental evidence implying CCT occurs in HBV, its relative impact is uncertain. We develop a 3-D agent-based model where each hepatocyte changes its viral state according to a dynamical process driven by cell-free virus infection, CCT and intracellular replication. We determine the relative importance of CCT in the development and resolution of acute HBV infection in the presence of cytolytic (CTL) and non-CTL mechanisms. T cell clearance number is defined as the minimum number of infected cells needed to be killed by each T cell at peak infection that results in infection clearance within 12 weeks with hepatocyte turnover (HT, number of equivalent livers) ≤3. We find that CCT has very little impact on the establishment of infection as the mean cccDNA copies/cell remains between 15 to 20 at the peak of the infection regardless of CCT strength. In contrast, CCT inhibit immune-mediated clearance of acute HBV infection as higher CCT strength requires higher T cell clearance number and increases the probability of T cell exhaustion. An effective non-CTL inhibition can counter these negative effects of higher strengths of CCT by supporting rapid, efficient viral clearance and with little liver destruction. This is evident as the T cell clearance number drops by approximately 50% when non-CTL inhibition is increased from 10% to 80%. Higher CCT strength also increases the probability of the incidence of fulminant hepatitis with this phenomenon being unlikely to arise for no CCT. In conclusion, we report the possibility of CCT impacting HBV clearance and its contribution to fulminant hepatitis.

Hepatocarcinogenesis associated with hepatitis B, delta and C viruses

Globally, over half a billion people are persistently infected with hepatitis B (HBV) and/or hepatitis C viruses. Chronic HBV and HCV infection frequently lead to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Co-infections with hepatitis delta virus (HDV), a subviral satellite requiring HBV for its propagation, accelerates the progression of liver disease toward HCC. The mechanisms by which these viruses cause malignant transformation, culminating in HCC, remain incompletely understood, partially due to the lack of adequate experimental models for dissecting these complex disease processes in vivo.

Absence of CD66a expression is associated with high microvessel density and high histologic grade in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver. Patients with HCC usually have poor prognosis and high mortality. It has been shown that carcinoembryonic antigen-related cell adhesion molecule 1 (CD66a) regulates cell signaling, proliferation, and tumor growth. The aim of this study is to analyze the expression and possible role of CD66a in HCC. Immunohistochemical staining of CD66a was performed on 86 HCC cases, and microvessel density was evaluated by CD34 immunostaining. The results were further correlated with clinicopathological parameters. For 47 of 86 HCC cases, the CD66a expression showed diffuse membrane or cytoplasmic staining. The other 39 HCC cases revealed loss of CD66a expression. Loss of CD66a expression was statistically significantly associated with large tumor size (p=0.016), fatty change (p=0.039), patients with transcatheter arterial embolization (p=0.007), and high microvessel density (p=0.036). CD34 expression had no significant association with tumor size, virus infection, histological grade, and capsular invasion. The diffuse and cytoplasmic expression of CD66a may involve the early stage of the HCC, and the loss of CD66a expression indicates tumor progression.

Association between interleukin-21 gene polymorphisms (rs12508721) and HBV-related hepatocellular carcinoma

Interleukin-21 (IL-21), as a multifunctional cytokine, plays an important role in many diseases, such as cancer, inflammatory and autoimmune diseases. We aimed to investigate the relationship between polymorphisms of IL-21 gene and susceptibility of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) in a Chinese population. Studied subjects were divided into three groups: 100 patients with HBV-related HCC, 115 patients with chronic HBV infection and 127 healthy controls. Genomic DNA was isolated from peripheral blood, and the polymerase chain reaction-ligase detection reaction (PCR-LDR) method was used to genotype the SNPs (rs2221903, rs907715 and rs12508721) within IL-21 gene. Our results showed that IL-21 polymorphisms were associated with the risk of HCC and chronic HBV infection when compared with healthy controls. The rs2221903A/G AG genotype was associated with a higher risk of chronic HBV infection when compared with healthy controls [AG versus AA + GG, P = 0.036, OR = 1.898, 95%CI = 1.038-3.471]. The rs12508721C/T TT genotype was related with a lower risk of chronic HBV infection and HBV-related HCC than in healthy controls [TT versus CT + CC, P = 0.026, OR = 0.451, 95%CI = 0.221-0.920; P = 0.049, OR = 0.482, 95%CI = 0.231-1.005]. No significant difference in the genotype and allele distrubutions of rs907715G/A SNP was observed in the HBV-related HCC group, chronic HBV-infected group and the healthy control group when compared to each other. Our findings suggest that the rs12508721T/C and rs2221903A/G polymorphisms of IL-21 gene are associated with the susceptibility of HBV-related HCC and chronic HBV infection. The genetic variant may in fact cause protection against the HBV-related HCC. However, the function in these SNPs of IL-21 gene needs to clarify the mechanisms involved in the pathogenesis of HBV-related HCC further.

Host genetic variants influencing the clinical course of hepatitis B virus infection

The clinical course of hepatitis B virus (HBV) infection greatly differs in individuals. Various viral, host, and environmental factors influence the natural history of HBV infection. Recent genome-wide association studies identified several host genetic factors influencing the clinical course of HBV infection. Genetic variations in HLA class II loci were significantly associated with susceptibility to persistent HBV infection. Other polymorphisms in or near the genes EHMT2, TCF19, and HLA-C, located near HLA class II loci, and UBE2L3 were also associated with persistent HBV infection. Meanwhile, polymorphisms in KIF1B, GRIK1, and STAT4 were associated with HBV-related hepatocellular carcinoma (HCC). Interestingly, HLA class II genetic variations were strongly associated with not only persistent HBV infection, but also disease progression and HBV-related HCC in chronic hepatitis B. Understanding the various genetic factors associated with the clinical course of HBV infection is essential for personalized treatment and surveillance of disease progression and HCC.

Expression of MicroRNA-155 is Downregulated in Peripheral Blood Mononuclear Cells of Chronic Hepatitis B Patients

BACKGROUND

Persistent hepatitis B virus (HBV) infection is sustained by inadequate immune responses, either natural or acquired. Recent studies have suggested that immune responses to viral infection may be affected by microRNA (miR)-155, via its involvement in immune cell differentiation and maturation. However, little is known on the specific interaction between miR-155 and HBV in host antiviral immunity.

OBJECTIVES

This study evaluated the levels of miR-155 in peripheral blood mononuclear cells (PBMCs) of chronic hepatitis B (CHB) patients, relative to that of healthy subjects, and investigated an association between miR-155 levels and HBV DNA or alanine aminotransferase (ALT).

PATIENTS AND METHODS

Total RNA was extracted from peripheral venous blood samples of 90 treatment-naive patients with chronic HBV infection and 20 healthy volunteers. The levels of miR-155 in the PBMCs were measured by real-time quantitative polymerase chain reaction. Serum HBV DNA and liver enzymes were estimated using standard clinical laboratory methods.

RESULTS

In the HBV-infected patients, the miR-155 levels were significantly lower than in the healthy controls (P = 0.001). Chronic HBV-infected patients with elevated ALT had higher levels of miR-155 compared with patients with normal ALT (P = 0.014). No correlations were found between miR-155 and ALT or HBV DNA.

CONCLUSIONS

The miR-155 appeared to be suppressed during HBV infection. The significantly higher miR-155 levels in ALT-elevated patients infected with HBV suggest that miR-155 levels in PBMCs correlate with the immune state of patients with chronic HBV infection.

Genetic variants in IL12 influence both hepatitis B virus clearance and HBV-related hepatocellular carcinoma development in a Chinese male population

IL12 plays a major role not only in inducing appropriate immune responses against viral infections (including HBV) but also in the antitumor immune response. This study was conducted to investigate the relationships of genetic variants in IL12 with hepatitis B virus (HBV) clearance and development of HBV-related hepatocellular carcinoma (HCC). We genotyped three single nucleotide polymorphisms (SNPs) of the IL12A (rs568406 and rs2243115) and IL12B (rs3212227) in 395 HBV-positive HCC patients, 293 persistent HBV carriers and 686 subjects with HBV natural clearance from southern China, using the improved multiplex ligase detection reaction (iMLDR) method. Logistic regression analysis adjusted for age, smoking, and alcohol consumption status showed that rs568408 variant genotypes were significantly associated with host HBV-related HCC risk when compared with persistent HBV carriers, and carriers of the GA + AA genotype decreased the HCC risk in comparison with GG carriers (adjusted OR = 0.53, 95 % CI 0.35-0.80, P = 0.002). No relationships between the rs2243115 and rs3212227 SNPs and HCC risk were observed (all P > 0.05). Besides, rs568408 showed an approaching significant effect on susceptibility to HBV persistent infection (adjusted OR = 1.34, 95 % CI 0.99-1.81, P = 0.057 in dominant genetic models). Furthermore, the TG haplotype was observed to be associated with a significantly increased risk of HBV-related HCC (OR = 1.42, 95 % CI 1.10-1.83, P = 0.006), while TA haplotype was associated with a decreased risk of HBV-related HCC (OR = 0.61, 95 % CI 0.45-0.83, P = 0.002). Our results reveal that the IL12A rs568408 variant may be a marker SNP for risk of both HBV clearance and HBV-related HCC development.

Fatal reactivation of hepatitis B virus infection in a patient with adult T-cell leukemia-lymphoma receiving the anti-CC chemokine receptor 4 antibody mogamulizumab

We report an adult T-cell leukemia-lymphoma (ATL) patient suffering from fatal reactivation of hepatitis B virus (HBV) infection after treatment with the anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, mogamulizumab. HBV reactivation occurred without liver damage in this hepatitis B surface antigen (HBsAg) negative patient, who was seropositive for antibodies against the viral core and surface antigens at baseline, after two cycles of CHOP regimen (cyclophosphamide, doxorubicin, vincristine and prednisolone) followed by six cycles of THP-COP regimen (cyclophosphamide, pirarubicin, vincristine and prednisolone). Unexpectedly, mogamulizumab monotherapy for relapsed CCR4 positive ATL induced sudden and fatal liver failure due to HBV reactivation, despite antiviral prophylaxis with entecavir. This clinical course may not only offer important suggestions to prevent critical HBV reactivation in HBsAg positive cancer patients who receive immune-enhancing drugs such as anti-CCR4 antibody, but also provide a clue to understanding the pathogenesis of HBV reactivation following systemic chemotherapy.

Infection and cancer: global distribution and burden of diseases

BACKGROUND

Infection is one of the main risk factors for cancer.

OBJECTIVES

Epidemiology, pathogenesis, and disease burden of infection-related cancers were reviewed by infectious agents.

FINDINGS

Chronic infection with Epstein-Barr virus, hepatitis B and C viruses, Kaposi sarcoma herpes virus, human immunodeficiency virus (HIV) type 1, human papillomavirus (HPV), human T-cell lymphotropic virus type 1, Helicobacter pylori, Clonorchis sinensis, Opisthorchis viverrini, and Schistosoma haematobium are associated with nasopharyngeal carcinoma; lymphoma and leukemia, including non-Hodgkin lymphoma, Hodgkin lymphoma, and Burkitt lymphoma; hepatocellular carcinoma; Kaposi sarcoma; oropharyngeal carcinoma; cervical carcinoma and carcinoma of other anogential sites; adult T-cell leukemia/lymphoma; gastric carcinoma; cholangiocarcinoma; and urinary bladder cancer. In 2008, approximately 2 million new cancer cases (16%) worldwide were attributable to infection. If these infections could be prevented and/or treated, it is estimated that there would be about 23% fewer cancers in less developed regions of the world, and about 7% fewer cancers in more developed regions.

CONCLUSION

Widespread application of existing public health methods for the prevention of infection, such as vaccination, safer injection practices, quality-assured screening of all donated blood and blood components, antimicrobial treatments, and safer sex practices, including minimizing one's lifetime number of sexual partners and condom use, could have a substantial effect on the future burden of cancer worldwide.

Hepatitis B virus infection and risk of nasopharyngeal carcinoma in southern China

BACKGROUND

Whether or not hepatitis B virus (HBV) infection plays a role in the development of nasopharyngeal carcinoma (NPC) is largely unknown. Our study aimed to assess the association between HBV infection and the risk of NPC in Southern China.

METHODS

We conducted a case-control study including 711 NPC cases and two groups of controls. The first control group consisted of 656 individuals with other benign tumors unrelated to HBV infection and the second group consisted of 680 healthy population controls. Multivariable ORs and corresponding 95% confidence intervals (CI) for NPC were estimated by logistic regression.

RESULTS

Patients with NPC had higher prevalence of antibodies against hepatitis B core antigen-positive [anti-HBc-(+); 47.26%] compared with either benign tumor controls (39.33%; P < 0.01) or healthy controls (41.18%; P = 0.04). In multivariable models adjusting for a set of risk factors for NPC, anti-HBc-(+) was significantly associated with a higher risk of NPC [adjusted OR (AOR), 1.40; 95% CI, 1.12-1.74 compared with the benign tumor controls and AOR, 1.48; 95% CI, 1.05-2.08 compared with the healthy controls]. The association was not modified by hepatitis B surface antigen (HBsAg) status. Finally, compared with the healthy controls, individuals with both anti-HBc-(+) and EBV antibodies had largely increased risk of NPC (AOR, 141.82; 95% CI, 68.73-292.62).

CONCLUSION

Our study suggests that HBV infection is associated with NPC risk in Southern China.

IMPACT

Prevention for HBV infection may play a role in the development of NPC.

Complement C4a inhibits the secretion of hepatitis B virus screened by surface-enhanced laser desorption ionization time-flight mass spectrometry-based ProteinChip analysis

PURPOSE

Chronic hepatitis B (CHB) is a kind of chronic liver disease caused by persistent hepatitis B virus (HBV) infection. The study aims to seek the factors of host resistance to HBV and investigate their roles.

EXPERIMENTAL DESIGN

Protein profiles of 58 healthy controls and 121 CHB patients were obtained by SELDI-TOF/MS. Predicted protein was validated by ELISA. Protein expression was evaluated by Western blot in the persistently HBV expressing cell line HepG2.2.15 and non-HBV expressing cell line HepG2. The level of HBV DNA was subsequently detected by quantitative real-time PCR in HepG2.2.15 cells with complement C4a treatment.

RESULTS

Significantly altered protein peaks were found through statistical analysis, and m/z 4300 was predicted by databases and successfully matched with the fragment of complement C4a. According to ELISA, serum complement C4a was found to be significantly lower in CHB patients compared with healthy controls (p < 0.001) and the area under receiver operating characteristics curve is 0.78. Furthermore, complement C4a showed lower expression in HepG2.2.5 cells and the secretion of HBV DNA was inhibited by complement C4a.

CONCLUSIONS AND CLINICAL RELEVANCE

The present study implied the important role of complement C4a in inhibiting the HBV DNA secretion in CHB.

Medical students' awareness of and compliance with the hepatitis B vaccine in a tertiary care academic hospital: An epidemiological study

BACKGROUND

The hepatitis B virus (HBV) poses a health risk to healthcare workers who are in close proximity to infected individuals. Medical students are a particularly high-risk group due to the lack of an obligatory vaccination program and a post-vaccination screening program to determine immunity status, which results in a lack of awareness of and compliance with the HBV vaccine.

METHODS

This cross-sectional survey was conducted in King Khalid University Hospital (KKUH), a tertiary care academic hospital in Riyadh, Saudi Arabia, from November 2013 to March 2014. Medical students in their second to fifth years (n=444; 213 men and 231 women) completed a self-administered questionnaire regarding awareness of HBV and compliance with the HBV vaccination program in KKUH.

RESULTS

Medium to low knowledge levels were present in 53.5% of the participants, and 44.3% reported that they were not compliant with the vaccination program provided by KKUH. While 93.9% received the HBV vaccine upon entry to medical school, only 59.5% received all 3 doses, citing forgetfulness and a busy schedule as common reasons for the low compliance. There was no association between the knowledge and awareness of the participants and their compliance (p=0.988).

CONCLUSION

Medical students had a low level of compliance with the HBV vaccination program, regardless of their knowledge and awareness of the disease and vaccination. We recommend that programs and campaigns be developed to increase the overall awareness of this disease. We also suggest that a mandatory HBV vaccination program should be implemented to improve the compliance rate among medical students.

Genogeography and Immune Epitope Characteristics of Hepatitis B Virus Genotype C Reveals Two Distinct Types: Asian and Papua-Pacific

Distribution of hepatitis B virus (HBV) genotypes/subgenotypes is geographically and ethnologically specific. In the Indonesian archipelago, HBV genotype C (HBV/C) is prevalent with high genome variability, reflected by the presence of 13 of currently existing 16 subgenotypes. We investigated the association between HBV/C molecular characteristics with host ethnicity and geographical distribution by examining various subgenotypes of HBV/C isolates from the Asia and Pacific region, with further analysis on the immune epitope characteristics of the core and surface proteins. Phylogenetic tree was constructed based on complete HBV/C genome sequences from Asia and Pacific region, and genetic distance between isolates was also examined. HBV/C surface and core immune epitopes were analyzed and grouped by comparing the amino acid residue characteristics and geographical origins. Based on phylogenetic tree and geographical origins of isolates, two major groups of HBV/C isolates—East-Southeast Asia and Papua-Pacific—were identified. Analysis of core and surface immune epitopes supported these findings with several amino acid substitutions distinguishing the East-Southeast Asia isolates from the Papua-Pacific isolates. A west-to-east gradient of HBsAg subtype distribution was observed with adrq+ prominent in the East and Southeast Asia and adrq- in the Pacific, with several adrq-indeterminate subtypes observed in Papua and Papua New Guinea (PNG). This study indicates that HBV/C isolates can be classified into two types, the Asian and the Papua-Pacific, based on the virus genome diversity, immune epitope characteristics, and geographical distribution, with Papua and PNG as the molecular evolutionary admixture region in the switching from adrq+ to adrq-.

Determinants of hepatitis B and delta virus host tropism

Hepatitis B virus (HBV) infections are a global health problem afflicting approximately 360 million patients. Of these individuals, 15-20 million are co-infected with hepatitis delta virus (HDV). Progress toward curative therapies has been impeded by the highly restricted host tropism of HBV, which is limited to productive infections in humans and chimpanzees. Here, we will discuss different approaches that have been taken to study HBV and HDV infections in vivo. The development of transgenic and humanized mice has lead to deeper insights into HBV pathogenesis. An improved understanding of the determinants governing HBV and HDV species tropism will aid in the construction of a small animal model with inheritable susceptible to HBV/HDV.

Expression profile and clinical significance of miRNAs at different stages of chronic hepatitis B virus infection

OBJECTIVE

To study the expression profile and clinical significance of microRNAs (miRNAs) at different stages of chronic hepatitis B virus (HBV) infection.

METHODS

The miRNA expression profiles of peripheral blood mononuclear cells (PBMCs) at different stages of chronic HBV infection were screened using miRNA microarray and validated using real-time quantitative polymerase chain reaction (qPCR).

RESULTS

Significant differences in miRNA expression profiles of PBMCs were observed between patients in IA and IT phases of CHB. Expression was significantly down-regulated in the former but up-regulated in the latter group. No significant differences in inactive hepatitis B surface antigen carriers were observed. Changes in expression of six miRNAs determined by real-time qPCR were consistent with those determined by microarray. Areas under the receiver operation characteristic curve of the six miRNAs distinguishing immune tolerance and clearance of chronic HBV infection were 99.4%, 98.4%, 96.7%, 100%, 100%, and 99.6%. Positive correlation was found between the levels of hsa- miR-146a and ALT (r = 0.56, P < 0.01) while negative correlation was found between the levels of hsa-miR-548ah-5p and HBV DNA (r = -0.73, P < 0.01).

CONCLUSIONS

Abnormal expression of miRNAs and the resulting gradual decline in the various immune states of patients with chronic HBV infection may play important roles in maintenance of the immune homeostatic mechanisms of chronic HBV infection. Hsa-miR-548ah-5p, hsa-miR-3191-5p and hsa-miR-4711-3p can be used as potential molecular markers to distinguish among different stages of chronic HBV infection.

Safety and immunogenicity of therapeutic DNA vaccine with antiviral drug in chronic HBV patients and its immunogenicity in mice

BACKGROUND & AIMS

Here, we evaluated the safety and immunogenicity of hepatitis B virus (HBV) DNA vaccine, HB-110, in mice and Korean patients with chronic hepatitis B (CHB) undergoing adefovir dipivoxil (ADV) treatment.

METHODS

For animal study, mice (BALB/c or HBV transgenic) were immunized with mHB-110, and T-cell and antibody responses were evaluated. For clinical study, 27 patients randomly received either ADV alone or ADV in combination with HB-110. Liver function tests, serum HBV DNA levels and the presence of HBeAg/anti-HBe were analysed. T-cell responses were estimated by ELISPOT and FACS analysis.

RESULTS

mHB-110 induced higher T-cell and antibody responses than mHB-100 in mice. No adverse effects were observed by HB-110 cotreated with ADV. HBV-specific T-cell responses were induced in a portion of patients in medium to high dose of HB-110. Interestingly, HB-110 exhibited positive effects on ALT normalization and maintenance of HBeAg seroconversion. One patient, who received high dose of HB-110 exhibited HBeAg seroconversion during vaccination, which correlated with vaccine-induced T-cell responses without ALT elevation.

CONCLUSIONS

HB-110 was safe and tolerable in CHB patients. In contrast to results in animal models, HB-110 in Korean patients exhibited weaker capability of inducing HBV-specific T-cell responses and HBeAg seroconversion than HB-100 in Caucasian patients. As Asian patients, who are generally infected via vertical transmission, appeared to have higher level of immune tolerance than Caucasian, novel approaches for breaking immune tolerance rather than enhancing immunogenicity may be more urgently demanded to develop effective therapeutic HBV DNA vaccines.

Woodchuck hepatitis virus core gene deletions and proliferative responses of peripheral blood mononuclear cells stimulated by an immunodominant epitope: a viral immune escape in the woodchuck model of chronic hepatitis B?

Marmota monax and its natural infection by woodchuck hepatitis virus (WHV) could be used as a predictive model for evaluating mechanisms of viral persistence during chronic hepatitis B virus (HBV) infection. The aim of this study was to investigate the presence of viral variants in the core gene of chronically WHV-infected woodchucks that showed two different patterns of peripheral blood mononuclear cells' (PBMCs') responses after stimulation with a specific WHV core peptide. Sequences' analysis of the WHV core region from eight WHV chronically infected woodchucks have been performed after in vitro stimulation with an immunodominant epitope of the WHV core protein (amino acids [aa] 96-110). Following this stimulation, positive PBMC responses at each point of follow-up were observed for four animals (group A), and weak immune responses at one or a few points of follow-up were observed for the remaining four animals (group B). The WHV core gene sequences contained amino acid deletions (aa 84-126, aa 84-113) in three of four group A animals and in none of group B animals. In the group A animals, the same deletions were observed in liver specimens and in two of four tumor specimens. Hepatocellular carcinoma (HCC) was diagnosed in all group A animals and in one group B animal. In conclusion, internal deletions in the core region correlated with a sustained PBMC response to the immunogenic peptide (96-110) of the core protein. A possible role of this relationship in hepatocarcinogenesis could be hypothesized; however, this needs to be investigated in patients with chronic HBV infection. The evaluation of virus-specific T-cell responses and T-cell epitopes that are possibly related to the mechanisms of viral evasion should be further investigated in order to design combined antiviral and immune approaches to control chronic HBV infection.