Cytokine, Genotype, and Viral Load Profile in the Acute and Chronic Hepatitis B

The Culprit Behind HBV-Infected Hepatocytes: NTCP

Hepatitis B virus (HBV) is a globally prevalent human DNA virus responsible for over 250 million cases of chronic liver infections, leading to conditions such as liver inflammation, cirrhosis and hepatocellular carcinoma (HCC). Sodium taurocholate co-transporting polypeptide (NTCP) is a transmembrane protein highly expressed in human hepatocytes and functions as a bile acid (BA) transporter. NTCP has been identified as the receptor that HBV and its satellite virus, hepatitis delta virus (HDV), use to enter hepatocytes. HBV entry into hepatocytes is tightly regulated by various signaling pathways, and NTCP plays an important role as the initial stage of HBV infection. NTCP acts as an initiation signal, causing metabolic changes in hepatocytes and facilitating the entry of HBV into hepatocytes. Thus, a comprehensive understanding of NTCP's role is crucial. In this review, we will examine the regulatory mechanisms governing HBV pre-S1 binding to liver membrane NTCP, the role of NTCP in HBV internalization, and the transcriptional and translational regulation of NTCP expression. Additionally, we will discuss clinical drugs targeting NTCP, including combination therapies involving NTCP inhibitors, and consider the safety of NTCP as a therapeutic target.

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

Background and Aim

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

Methods

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

Results

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

Conclusion

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

Strategy for immunological analysis of pro-inflammatory cytokine marker studies with chronic hepatitis B virus in Southwestern region of Saudi Arabia

BACKGROUND

Hepatitis B Virus (HBV) is one of the leading causes of infectious disease in the global population, and its prevalence has been increasing globally. Human HBV infection is complex, involving both innate and adaptive immune systems. Cytokines play a role in both physiologic and pathologic processes in the liver. This study was designed to screen serum levels using an enzyme linked immunosorbent assay (ELISA) and genetic variants in the TNF-α and IL6 genes using polymerase chain reactions (PCR). The aim of this study was to screen the serum levels and genotype levels with TNF-α (C-308 T/G-308A) and IL-6 (G-174 C) genes in HBV patients and control subjects.

METHODS

In this study, we have selected 50 HBV patients and 40 control subjects from Saudi Population. Patient serum samples was used for measuring the serum levels and PCR analysis using RFLP analysis. Prior to this, HBV patients were confirmed with PCR analysis followed by Sanger sequencing analysis.

RESULTS

The current study results confirmed positive association in serum levels (p < 0.05) and negative association with both genotype and allele frequencies in TNF-α (C-308 T) and IL-6 (G-174 C) genes among HBV patients and controls (p > 0.05). Positive associations between blood levels of TNF-α and IL-6 were confirmed, while negative associations were found between PCR investigations involving the TNF-α (G-308A) and IL-6 (G-174 C) genes with the HBV prevalence in the Saudi population.

CONCLUSION

This study confirmed serum levels are strongly associated with HBV patients in the Saudi population. However, PCR studies showed the negative association with the couple of variants selected for this study.

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

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

Interleukin-17A pretreatment attenuates the anti-hepatitis B virus efficacy of interferon-alpha by reducing activation of the interferon-stimulated gene factor 3 transcriptional complex in hepatitis B virus-expressing HepG2 cells

Background

Some cytokine signaling pathways can interact with interferon (IFN)-α pathway and thus regulate cell responses to IFN-α. Levels of the pro-inflammatory cytokine interleukin-17A (IL-17A) were found to be elevated in both the peripheral blood and liver in chronic hepatitis B (CHB) patients. However, how IL-17A affects the anti-HBV activity of IFN-α remains unclear.

Methods

The effects of IL-17A on anti-HBV activity of IFN-α were evaluated in HBV-expressing HepG2 cells (HepG2-HBV1.3) with IL-17A pretreatment and IFN-α stimulation. Culture supernatant levels of HBsAg, HBeAg, and HBV DNA, or intracellular expression of HBsAg and HBcAg were detected by ELISA, real-time quantitative PCR (RT-qPCR), or western blotting (WB). The expression of canonical IFN-α signaling pathway components, including the interferon-α/β receptor (IFNAR), Janus Kinase 1 (JAK1), Tyrosine Kinase 2 (TYK2), the Interferon Stimulated Gene Factor 3 complex (ISGF3) and IFN-stimulated genes (ISGs), was also examined by RT-qPCR, Immunofluorescence or WB. The effects of IL-17A were further investigated by the suppression of the IL-17A pathway with a TRAF6 inhibitor.

Results

Compared to IFN-α stimulation alone, IL-17A pretreatment followed by IFN-α stimulation increased the levels of HBsAg, HBeAg, and HBV DNA, and decreased the levels of ISGF3 complex (phosphorylated (p)-signal transducer and activator of transcription (STAT1)/p-STAT2/IRF9) and antiviral-related ISGs (ISG15, ISG20 and Mx1). Interestingly, IL-17A pretreatment increased the expression of suppressor of cytokine signaling (SOCS) 1, SOCS3 and USP18, which were also the ISGs negatively regulating activity of ISGF3. Moreover, IFNAR1 protein expression declined more sharply in the group with IL-17A pretreatment than in the group with IFN-α stimulation alone. Blocking the IL-17A pathway reversed the effects of IL-17A on the IFN-α-induced activation of ISGF3 and anti-HBV efficacy.

Conclusions

Our results demonstrate that IL-17A pretreatment could attenuate IFN-α-induced anti-HBV activity by upregulating negative regulators of the critical transcriptional ISGF3 complex. Thus, this might be a potential target for improving response to IFN-α therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-022-01753-x.

Pathogenicity of the newly emerged Lagovirus europaeus GI.2 strain in China in experimentally infected rabbits

In April 2020, rabbit hemorrhagic virus type 2 (Lagovirus europaeus GI.2), which causes highly infectious fatal rabbit hemorrhagic disease, was emerged in China. The phylogenetic analyses of the complete genome sequence of GI.2 showed that it belonged to the non-recombinant GI.3/GI.2 genotype. However, the pathogenicity of this GI.2 strain differed from that of early typical GI.2 strains in Europe. To prevent the spread of the new strain in China, its pathogenicity urgently needs to be studied. Thus, viral shedding and distribution as well as clinical symptoms, histopathological changes, and serum cytokines were studied in experimentally GI.2/SC2020-infected rabbit adults and kits. The kit group showed a shorter survival time after the challenge than the adult group did. The mortality rate was higher in the kits (80 %) than in the adults (30 %). Viral RNA could be detected in both nasal and fecal swabs, and the main dissemination route appeared to be the fecal route. Viral RNA rapidly increased in the blood of the adults and kits at 6 h post-infection, indicating that blood viral load testing can be used for early diagnosis. The most affected organs were the liver and spleen, and the lesions were more severe in the kits than in the adults. The liver contained the highest viral RNA levels. Moreover, serum interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor-alpha levels were increased in the infected rabbits. In conclusion, our findings will help to understand the evolutionary trends and pathogenic characteristics of GI.2 strains in China.