TNF-α polymorphisms affect persistence and progression of HBV infection

Multifunctional roles of inflammation and its causative factors in primary liver cancer: A literature review

Primary liver cancer is a severe and complex disease, leading to 800000 global deaths annually. Emerging evidence suggests that inflammation is one of the critical factors in the development of hepatocellular carcinoma (HCC). Patients with viral hepatitis, alcoholic hepatitis, and steatohepatitis symptoms are at higher risk of developing HCC. However, not all inflammatory factors have a pathogenic function in HCC development. The current study describes the process and mechanism of hepatitis development and its progression to HCC, particularly focusing on viral hepatitis, alcoholic hepatitis, and steatohepatitis. Furthermore, the roles of some essential inflammatory cytokines in HCC progression are described in addition to a summary of future research directions.

The hepatitis B virus pre-core protein p22 suppresses TNFα-induced apoptosis by regulating the NF-κB pathway

OBJECTIVE

Cell apoptosis is strongly associated with hepatocellular carcinoma (HCC) progress. Thus, gaining a comprehensive understanding of the virus interfering with the apoptotic process is important for the development of effective anti-tumor therapies. The objective of this study is to explore the potential involvement of HBeAg-p22 (HBV-p22) in TNFα-induced apoptosis.

METHODS

Protein expression was detected using western blot. Cell viability and apoptosis were assessed by employing Cell Counting Kit-8 (CCK8) and flow cytometry, respectively. Evaluation of protein-protein interactions was accomplished through co-immunoprecipitation and glutathione-S-transferase (GST) pull-down assays.

RESULTS

In this study, it was shown that HBV-p22 inhibited apoptosis of human hepatoma cell lines after tumor necrosis factor-alpha (TNF-α) stimulation. Mechanistically, HBV-p22 suppressed Jun N-terminal kinases (JNK) signaling and enhanced nuclear factor kappa-B (NF-κB) signaling. Moreover, HBV-p22 interacted with I-kappa B kinase α (IKKα) and increased its phosphorylation.

CONCLUSIONS

Collectively, HBV-p22, whereby the mechanism contributing to anti-apoptotic effect was regulation of the NF-κB pathway via enhancing the phosphorylation of IKKα.

Host Factors in the Natural History of Chronic Hepatitis B: Role of Genetic Determinants

BACKGROUND

The host immune system plays an important role in hepatitis B virus (HBV) infection manifestation. Genetic polymorphisms of several inflammatory cytokines, including TNF-α and IL-10, have been associated with chronic hepatitis B (CHB) progression, although with contradicting results. CHB progression can be categorized into four phases, immune tolerance (IT), immune clearance (IC), low/no replicative (LR), and e-negative hepatitis (ENH), with HBeAg seroconversion as an important milestone. Here, we determined the association of TNF-α (rs1800629) and IL-10 (rs1800896 and rs1800872) SNPs in the context of CHB natural history progression, particularly to HBeAg seroconversion, in Indonesian CHB patients.

METHODS

A total of 287 subjects were recruited and categorized into distinct CHB phases based on HBeAg, viral load, and ALT levels. TNF-α and IL-10 SNPs were determined using PCR-RFLP and confirmed with direct sequencing. The association between SNP genotypes with CHB dynamics was determined using logistic regression presented as odds ratio (OR) with 95% CI.

RESULTS

No significant association was found between IL-10 -592A/C polymorphism and progression of IT and IC to LR, IT and IC to ENH, and LR to ENH phases in all the gene models. IL-10 rs1800896 and TNF-α rs1800629 could not be analyzed using logistic regression. Subjects' age (≥40 years old) was significantly associated with IT and IC to LR (OR: 2.191, 95% CI 1.067-4.578, P = 0.034), IT and IC to ENH (OR: 7.460, 95% CI 3.316-18.310, P < 0.001), and LR to ENH (OR: 5.252, 95% CI 2.010-14.858, P = 0.001). Male gender was associated with LR to ENH (OR: 4.077, 95% CI 1.605-11.023, P = 0.004).

CONCLUSIONS

Age and male gender were associated with CHB phase progression instead of the TNF-α and IL-10 polymorphisms. It would be beneficial to study not only the effect of host determinants but also the viral factor to understand the mechanisms of CHB phase progression.

Relationships between IL-1β, TNF-α genetic polymorphisms and HBV infection: A meta-analytical study

BACKGROUND

IL-1β and TNF-α have been demonstrated as pro-inflammatory cytokines to participate in the innate immune response and suppression of HBV infection. However, the exact relationship between IL-1β, TNF-α gene polymorphisms and HBV infection remains unknown. Our study aims to assess the associations between IL-1β, TNF-α gene polymorphisms and HBV infection.

METHODS

A systematic literature search of PubMed and Embase databases was conducted through February 2020, and studies that were included in the present meta-analysis should fulfil the following conditions: (1) case-control studies focusing on the associations between IL-1β, TNF-α polymorphisms and HBV infection; (2) patients in the case group should be tested positive for the HBsAg and/or HBV-DNA without liver cirrhosis or hepatocellular carcinoma; (3) the control group including healthy population or HBV spontaneous clearance population; (4) odds ratios (ORs) and their 95% confidence intervals (CIs) could be calculated based on the allele and genotype frequencies provided in articles. The quality of included studies was assessed according to the Newcastle-Ottawa scale (NOS) assessment system. Pooled ORs and 95% CIs were used to analyze the strength of associations. Subgroup analysis was performed according to ethnicity and control type.

RESULTS

In the present meta-analysis, 49 articles including 10,218 cases and 9,557 controls were enrolled and seven polymorphisms (IL-1β rs16944, rs1143634, TNF-α rs1799724, rs1799964, rs1800629, rs1800630, rs361525) were studied. In overall meta-analysis, significant associations were found in IL-1β rs1143634, TNF-α rs1799724 and TNF-α rs1799964. For subgroup analysis under ethnicity, TNF-α rs1799724 and rs1800630 were markedly related to HBV infection in both Asian and Caucasian populations. In terms of control type subgroup, TNF-α rs1799724, rs1799964, rs1800630 were significantly associated with HBV persistence in HBV spontaneous clearance group.

CONCLUSION

In the present study, we identified that three polymorphisms (IL-1β rs1143634, TNF-α rs1799724, rs1799964) might serve as potential genetic biomarkers in HBV infection.

CCL19 enhances CD8+ T-cell responses and accelerates HBV clearance

BACKGROUND

Chemokine (C-C motif) ligand 19 (CCL19) is a leukocyte chemoattractant that plays a crucial role in cell trafficking and leukocyte activation. Dysfunctional CD8⁺ T cells play a crucial role in persistent HBV infection. However, whether HBV can be cleared by CCL19-activated immunity remains unclear.

METHODS

We assessed the effects of CCL19 on the activation of PBMCs in patients with HBV infection. We also examined how CCL19 influences HBV clearance and modulates HBV-responsive T cells in a mouse model of chronic hepatitis B (CHB). In addition, C-C chemokine-receptor type 7 (CCR7) knockdown mice were used to elucidate the underlying mechanism of CCL19/CCR7 axis-induced immune activation.

RESULTS

From in vitro experiments, we found that CCL19 enhanced the frequencies of Ag-responsive IFN-γ⁺ CD8⁺ T cells from patients by approximately twofold, while CCR7 knockdown (LV-shCCR7) and LY294002 partially suppressed IFN-γ secretion. In mice, CCL19 overexpression led to rapid clearance of intrahepatic HBV likely through increased intrahepatic CD8⁺ T-cell proportion, decreased frequency of PD-1⁺ CD8⁺ T cells in blood and compromised suppression of hepatic APCs, with lymphocytes producing a significantly high level of Ag-responsive TNF-α and IFN-γ from CD8⁺ T cells. In both CCL19 over expressing and CCR7 knockdown (AAV-shCCR7) CHB mice, the frequency of CD8⁺ T-cell activation-induced cell death (AICD) increased, and a high level of Ag-responsive TNF-α and low levels of CD8⁺ regulatory T (T_reg) cells were observed.

CONCLUSIONS

Findings in this study provide insights into how CCL19/CCR7 axis modulates the host immune system, which may promote the development of immunotherapeutic strategies for HBV treatment by overcoming T-cell tolerance.

Clinical and molecular characterization of COVID-19 hospitalized patients

Clinical and molecular characterization by Whole Exome Sequencing (WES) is reported in 35 COVID-19 patients attending the University Hospital in Siena, Italy, from April 7 to May 7, 2020. Eighty percent of patients required respiratory assistance, half of them being on mechanical ventilation. Fiftyone percent had hepatic involvement and hyposmia was ascertained in 3 patients. Searching for common genes by collapsing methods against 150 WES of controls of the Italian population failed to give straightforward statistically significant results with the exception of two genes. This result is not unexpected since we are facing the most challenging common disorder triggered by environmental factors with a strong underlying heritability (50%). The lesson learned from Autism-Spectrum-Disorders prompted us to re-analyse the cohort treating each patient as an independent case, following a Mendelian-like model. We identified for each patient an average of 2.5 pathogenic mutations involved in virus infection susceptibility and pinpointing to one or more rare disorder(s). To our knowledge, this is the first report on WES and COVID-19. Our results suggest a combined model for COVID-19 susceptibility with a number of common susceptibility genes which represent the favorite background in which additional host private mutations may determine disease progression.

Unraveling the susceptibility of paracoccidioidomycosis: Insights towards the pathogen-immune interplay and immunogenetics

Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis caused by Paracoccidioides spp. This disease comprises three clinical forms: symptomatic acute and chronic forms (PCM disease) and PCM infection, a latent form without clinical symptoms. PCM disease differs markedly according to severity, clinical manifestations, and host immune response. Fungal virulence factors and adhesion molecules are determinants for entry, latency, immune escape and invasion, and dissemination in the host. Neutrophils and macrophages play a paramount role in first-line defense against the fungus through the recognition of antigens by pattern recognition receptors (PRRs), activating their microbicidal machinery. Furthermore, the clinical outcome of the PCM is strongly associated with the variability of cytokines and immunoglobulins produced by T and B cells. While the mechanisms that mediate susceptibility or resistance to infection are dictated by the immune system, some genetic factors may alter gene expression and its final products and, hence, modulate how the organism responds to infection and injury. This review outlines the main findings relative to this topic, addressing the complexity of the immune response triggered by Paracoccidioides spp. infection from preclinical investigations to studies in humans. Here, we focus on mechanisms of fungal pathogenesis, the patterns of innate and adaptive immunity, and the genetic and molecular basis related to immune response and susceptibility to the development of the PCM and its clinical forms. Immunogenetic features such as HLA system, cytokines/cytokines receptors genes and other immune-related genes, and miRNAs are likewise discussed. Finally, we point out the occurrence of PCM in patients with primary immunodeficiencies and call attention to the research gaps and challenges faced by the PCM field.

TNF-α polymorphisms affect persistence and progression of HBV infection

Background

Hepatitis B virus (HBV) infections are a major threat worldwide. Disease progression and outcome is diverse and depends on host genetic background. Recently, a high rate of HBV reactivation in individuals receiving tumor necrosis factor‐α (TNF‐α) antagonists showed the importance of this cytokine in HBV infection control. Here, we investigated the influence of TNF‐α promoter polymorphisms on susceptibility to chronic HBV infection (CHB), liver injury progression and outcomes.

Methods

A total of 231 patients with CHB constituted the study group and 100 healthy volunteers—the local control group. TNF‐α −1031T/C, −863C/A, −857C/T, −308G/A, and −238G/A were genotyped using MALDI‐TOF mass spectrometry.

Results

TNF‐α −1031C and −863A alleles were observed more frequently in CHB group than in healthy controls. Carriers of TNF‐α −1031C and −863A variant alleles had lower baseline levels of serum HBV DNA and lower liver necroinflammatory activity than dominant homozygotes. A −857CT genotype predisposed to higher necroinflammatory activity. No associations between TNF‐α variants and liver fibrosis were found.

Conclusion

This study indicates that TNF‐α −863A and −1031C alleles are associated with increased susceptibility to CHB in individuals from northern Poland. The same variants determine the course of CHB, lowering viremia and reducing necroinflammatory activity of the liver.