HBV Core Protein Enhances Cytokine Production

Clinical implications of hepatitis B virus core antigen-mediated immunopathologic T cell responses in chronic hepatitis B

Hepatitis B virus (HBV) infection significantly impacts Asian populations. The influences of continuous HBV antigen and inflammatory stimulation to T cells in chronic hepatitis B (CHB) remain unclear. In this study, we first conducted bioinformatics analysis to assess T-cell signaling pathways in CHB patients. In a Taiwanese cohort, we examined the phenotypic features of HBVcore -specific T cells and their correlation with clinical parameters. We used core protein overlapping peptides from the Taiwan prevalent genotype B HBV to investigate the antiviral response and the functional implication of HBV-specific T cells. In line with Taiwanese dominant HLA-alleles, we also evaluated ex vivo HBVcore -specific T cells by pMHC-tetramers targeting epitopes within HBV core protein. Compared to healthy subjects, we disclosed CD8 T cells from CHB patients had higher activation marker CD38 levels but showed an upregulation in the inhibitory receptor PD-1. Our parallel study showed HBV-specific CD8 T cells were more activated with greater PD-1 expression than CMV-specific subset and bulk CD8 T cells. Moreover, our longitudinal study demonstrated a correlation between the PD-1 fluctuation pattern of HBVcore -specific CD8 T cells and liver inflammation in CHB patients. Our research reveals the HBV core antigen-mediated immunopathologic profile of CD8 T cells in chronic HBV infection. Our findings suggest the PD-1 levels of HBVcore -specific CD8 T cells can be used as a valuable indicator of personal immune response for clinical application in hepatitis management.

Muscle Cramps in Outpatients with Liver Diseases in Tokyo, Japan

Background and Objectives: Muscle cramps are often observed in patients with liver diseases, especially advanced liver fibrosis. The exact prevalence of muscle cramps in outpatients with liver diseases in Japan is unknown. Patients and Methods: This study examined the prevalence of, and therapies for, muscle cramps in outpatients with liver diseases in Tokyo, Japan. A total of 238 outpatients with liver diseases were retrospectively examined. We investigated whether they had muscle cramps using a visual analog scale (VAS) (from 0, none, to 10, strongest), and also investigated their therapies. Results: Muscle cramps were observed in 34 outpatients with liver diseases (14.3%); their mean VAS score was 5.53. A multivariate analysis demonstrated that older age (equal to or older than 66 years) was the only significant factor as-sociated with muscle cramps. The prevalence of muscle cramps among patients with liver diseases seemed not to be higher. The problem was that only 11 (32.4%) of 34 outpatients received therapy for their muscle cramps. Conclusions: Only age is related to muscle cramps, which is rather weak, and it is possible that this common symptom may not be limited to liver disease patients.

Hepatitis B Core Antibody Level: A Surrogate Marker for Host Antiviral Immunity in Chronic Hepatitis B Virus Infections

The hepatitis B virus core protein (HBcAg) is a highly immunogenic particulate antigen. Nearly all patients with persistent or resolved hepatitis B virus (HBV) infection show seropositivity for hepatitis B core antibody (anti-HBc), which appears in the early stage of infection and is mostly present for life. Traditionally, the anti-HBc is regarded as an evidential serological marker of HBV infections. In the last ten years, several studies revealed the predictive value of quantitative anti-HBc (qAnti-HBc) level in the treatment response and clinical outcome of chronic HBV infections, implying new insights into this classic marker. Overall, qAnti-HBc should be regarded as an indicator of the host's immune response specific to HBV, which correlates with HBV-related hepatitis activity and liver pathology. This review summarized the latest understanding of the clinical values of qAnti-HBc for differentiating the CHB phase, predicting treatment response, and providing disease prognosis. Moreover, we also discussed the possible mechanism of qAnti-HBc regulation during different courses of HBV infection.

Identification of the Interaction between Minichromosome Maintenance Proteins and the Core Protein of Hepatitis B Virus

Chronic HBV infection is a major cause of cirrhosis and hepatocellular carcinoma. Finding host factors involved in the viral life cycle and elucidating their mechanisms is essential for developing innovative strategies for treating HBV. The HBV core protein has pleiotropic roles in HBV replication; thus, finding the interactions between the core protein and host factors is important in clarifying the mechanism of viral infection and proliferation. Recent studies have revealed that core proteins are involved in cccDNA formation, transcriptional regulation, and RNA metabolism, in addition to their primary functions of capsid formation and pgRNA packaging. Here, we report the interaction of the core protein with MCMs, which have an essential role in host DNA replication. The knockdown of MCM2 led to increased viral replication during infection, suggesting that MCM2 serves as a restriction factor for HBV proliferation. This study opens the possibility of elucidating the relationship between core proteins and host factors and their function in viral proliferation.

Molecular pathogenesis: Connections between viral hepatitis-induced and non-alcoholic steatohepatitis-induced hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is the sixth most common cancer in the world and is usually caused by viral hepatitis (HBV and HCV), alcoholic, and non-alcoholic fatty liver disease(NAFLD). Viral hepatitis accounts for 80% of HCC cases worldwide. In addition, With the increasing incidence of metabolic diseases, NAFLD is now the most common liver disease and a major risk factor for HCC in most developed countries. This review mainly described the specificity and similarity between the pathogenesis of viral hepatitis(HBV and HCV)-induced HCC and NAFLD-induced HCC. In general, viral hepatitis promotes HCC development mainly through specific encoded viral proteins. HBV can also exert its tumor-promoting mechanism by integrating into the host chromosome, while HCV cannot. Viral hepatitis-related HCC and NASH-related HCC differ in terms of genetic factors, and epigenetic modifications (DNA methylation, histone modifications, and microRNA effects). In addition, both of them can lead to HCC progression through abnormal lipid metabolism, persistent inflammatory response, immune and intestinal microbiome dysregulation.

A pilot study on some critical immune elements in HBV infection: evidence of Alpha-1 Antitrypsin as an immunological biomarker

Aim

This study is an attempt to screen the key immune elements that participate during HBV infection and the related pathways that are modulated.

Background

The pathogenesis of Hepatitis B virus and the corresponding clinical manifestations in the host are primarily immune-mediated.

Methods

This study utilizes a PCR array to screen immune-related genes that are differentially expressed in the presence of the virus in HBV replicating HepG2.2.15 cells as compared to control HepG2 cells. The significantly up-regulated genes were subjected to bioinformatic analysis utilizing GSEA and STRING. Additionally, ELISA was used to corroborate the levels of Alpha 1 antitrypsin (AAT) from patients' sera.

Results

The expressions of 31% of the studied genes were significantly up-regulated (> 2-fold, p<0.05) in HepG2.2.15 cells compared to controls, and this included the SERPINA1, FN1, IL1R2, LBP, LY96, LYZ and PROC genes. When they were clustered based on biological processes, signaling pathways, and disease progression, the genes related to biotic stimulus, complement-coagulation cascades, and fibrosis, respectively, showed the highest (p<0.05) enrichment. Analysis of patients' sera by ELISA revealed that the serum AAT (SERPINA1) levels were significantly higher in asymptomatic carriers and in patients with chronic liver disease than in controls (p<0.05). Moreover, SERPINA1 levels were also positively correlated with the levels of serum ALT (r=0.4495, p<0.05) among HBV infected patients.

Conclusion

The current study highlights the key immune elements and pathways that are modulated during HBV infection and proposes the possible use of AAT as a non-invasive immunological biomarker to follow the progression of liver disease.

Hepatitis B Virus Core Protein Mediates the Upregulation of C5α Receptor 1 via NF-κB Pathway to Facilitate the Growth and Migration of Hepatoma Cells

Purpose

C5α receptor 1 (C5AR1) is associated with the development of various human cancers. However, whether it is involved in the development of hepatitis B virus (HBV)–related hepatocellular carcinoma (HCC) is poorly understood. We explored the expression, biological role, and associated mechanisms of C5AR1 in HBV-related hepatoma cells.

Materials and Methods

The expression of C5AR1 mediated by HBV and HBV core protein (HBc) was detected in hepatoma cells. The function of nuclear factor κB (NF-κB) pathway in HBc-induced C5AR1 expression was assessed. The roles of C5AR1 in the activation of intracellular signal pathways, the upregulation of inflammatory cytokines, and the growth and migration of hepatoma cells mediated by HBc, were investigated. The effect of C5α in the development of HCC mediated by C5AR1 was also measured.

Results

C5AR1 expression was increased in HBV-positive hepatoma cells. Dependent on HBc, HBV enhanced the expression of C5AR1 at the mRNA and protein levels. Besides, HBc could promote C5AR1 expression via the NF-κB pathway. Based on the C5AR1, HBc facilitated the activation of JNK and ERK pathways and the expression and secretion of interleukin-6 in hepatoma cells. Furthermore, C5AR1 was responsible for enhancing the growth and migration of hepatoma cells mediated by HBc. Except these, C5α could promote the malignant development of HBc-positive HCC via C5AR1.

Conclusion

We provide new insight into the mechanisms of hepatocarcinogenesis mediated by HBc. C5AR1 has a significant role in the functional abnormality of hepatoma cells mediated by HBc, and might be utilized as a potential therapeutic target for HBV-related HCC.

Thalassemia and hepatocellular carcinoma: links and risks

The increased survival and lifespan of thalassemia patients, in the setting of better iron overload monitoring and chelation, have also however increased the incidence of diseases and complications, which were less likely to develop. Among these, one of the most worrying in recent years is hepatocellular carcinoma (HCC). Due to blood transfusions, many patients with thalassemia are or have been infected with hepatitis C virus (HCV) or hepatitis B virus (HBV), especially those born before the 1990s or in countries in which universal HBV vaccination and safe blood programs are still not completely implemented. However, HCC has also been described in nontransfused patients and in those who are HCV- and HBV-negative. Therefore, other risk factors are involved in hepatocarcinogenesis in thalassemia. The following review analyzes recent literature on the role of different risk factors in the progression of liver disease in thalassemia as well as the importance of surveillance. Treatment of HCC in thalassemia is still highly debated and requires further studies.

Association between IL-37 gene polymorphisms and risk of HBV-related liver disease in a Saudi Arabian population

Interleukin-37 (IL-37) has recently been recognized as a strong anti-inflammatory cytokine having anti-tumor activity against hepatocellular carcinoma (HCC) in hepatitis B virus (HBV)-infected patients. HCC is a typical inflammation-related cancer, and genetic variations within the IL-37 gene may be associated with the risk of HBV infection. Identification of the allelic patterns that genetically have a high disease risk is essential for the development of preventive diagnostics for HBV-mediated liver disease pathogenesis. In this study, we aimed to investigate the association between single nucleotide polymorphisms (SNPs) within the IL-37 gene and disease sequelae associated with HBV infection. We genotyped ten IL-37 SNPs in 1274 patients infected with HBV and 599 healthy controls from a Saudi Arabian population. Among the selected SNPs, two SNPs (rs2723175 and rs2708973) were strongly associated with HBV infection, and six SNPs (rs2723176, rs2723175, rs2723186, rs364030, rs28947200, rs4392270) were associated with HBV clearance, comparing healthy controls and HBV infected-patients respectively. A suggestive association of rs4849133 was identified with active HBV surface antigen (HBsAg) carrier and HBV-related liver disease progression. In conclusion, our findings suggest that variations at the IL-37 gene may be useful as genetic predictive risk factors for HBV infection and HBV-mediated liver disease progression in the Saudi Arabian population.

Molecular Mechanisms Driving Progression of Liver Cirrhosis towards Hepatocellular Carcinoma in Chronic Hepatitis B and C Infections: A Review

Almost all patients with hepatocellular carcinoma (HCC), a major type of primary liver cancer, also have liver cirrhosis, the severity of which hampers effective treatment for HCC despite recent progress in the efficacy of anticancer drugs for advanced stages of HCC. Here, we review recent knowledge concerning the molecular mechanisms of liver cirrhosis and its progression to HCC from genetic and epigenomic points of view. Because ~70% of patients with HCC have hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infection, we focused on HBV- and HCV-associated HCC. The literature suggests that genetic and epigenetic factors, such as microRNAs, play a role in liver cirrhosis and its progression to HCC, and that HBV- and HCV-encoded proteins appear to be involved in hepatocarcinogenesis. Further studies are needed to elucidate the mechanisms, including immune checkpoints and molecular targets of kinase inhibitors, associated with liver cirrhosis and its progression to HCC.

Molecular Mechanisms Driving Progression of Liver Cirrhosis towards Hepatocellular Carcinoma in Chronic Hepatitis B and C Infections: A Review

Almost all patients with hepatocellular carcinoma (HCC), a major type of primary liver cancer, also have liver cirrhosis, the severity of which hampers effective treatment for HCC despite recent progress in the efficacy of anticancer drugs for advanced stages of HCC. Here, we review recent knowledge concerning the molecular mechanisms of liver cirrhosis and its progression to HCC from genetic and epigenomic points of view. Because ~70% of patients with HCC have hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infection, we focused on HBV- and HCV-associated HCC. The literature suggests that genetic and epigenetic factors, such as microRNAs, play a role in liver cirrhosis and its progression to HCC, and that HBV- and HCV-encoded proteins appear to be involved in hepatocarcinogenesis. Further studies are needed to elucidate the mechanisms, including immune checkpoints and molecular targets of kinase inhibitors, associated with liver cirrhosis and its progression to HCC.