TLR3 and TLR4 SNP variants in the liver disease resulting from hepatitis B virus and hepatitis C virus infection

Correlation of IL-10 and IL18 with the development of liver cirrhosis associated with hepatitis B virus infection: A systematic review

BACKGROUND

Patients who have been infected with the Hepatitis B virus (HBV) are susceptible to developing liver cirrhosis (LC) and hepatocellular carcinoma (HCC). The objective of this systematic review was to comprehensively scrutinize the existing evidence concerning the association between host genetic polymorphisms and HBV-associated LC.

METHODS

We searched databases of PubMed, Scopus, and Web of Science for relevant articles published from building databases to 25 October 2023.

RESULT

We detected 104 relevant articles, relating to 84 individuals genes. Nine genes had the strong evidence of correlation, including IL-10, IL-18, IL-1B, TGF- β, TLR3, STAT4, IL-1RN, Tim3, and IFN receptors. A positive correlation was found for 33 genes but this data had not yet been replicated, 11 genes had limited or mixed evidence of a correlation, and 34 genes indicated no correlation. IL-10 and IL-18 had the most evidence of correlation. There was a notable amount of diversity in both the design and method of studies and data quality.

CONCLUSION

IL-10 and IL-18 had the most evidence of correlation. There was a notable amount of diversity in both the design and method of studies and data quality. It is of necessary to take into account the fundamental mechanism behind these associations and discern those that are confounded by the coexistence of other LC/HCC risk factors and response to therapy. These results are expected to guide future studies on the genetic susceptibility of HBV-related LC/HCC.

Toll-like receptor 4 - a multifunctional virus recognition receptor

Since the initial description of Toll receptors in Drosophila and their mammalian counterparts Toll-like receptors (TLRs), numerous fundamental and applied studies have explored their crucial role as sensors of pathogen-associated molecular patterns (PAMPs). Among the ten human TLRs, TLR4 is particularly well known for its ability to detect lipopolysaccharides (LPS), a component of the Gram-negative bacterial cell wall. In addition to its archetypal functions, TLR4 is also a versatile virus sensor. This review provides a background on the discovery of TLR4 and how this knowledge laid a foundation for characterization of its diverse roles in antiviral responses, examined through genetic, biochemical, structural, and immunological approaches. These advances have led to a deeper understanding of the molecular functions that enable TLR4 to orchestrate multi-nodal control by professional antigen-presenting cells (APCs) to initiate appropriate and regulated antiviral immune responses.

Polymorphism of the TLR3 gene in Predisposition to Chronic Viral Hepatitis B and C in the population of Turkic-speaking peoples

Background: Over the past four years, more than 19000 cases of viral hepatitis B have been registered in Kazakhstan. Mortality from liver cirrhosis as a result of chronic hepatitis B and C ranks first among gastroenterological diseases in the Republic. Toll-like receptor 3 (TLR3) is an effector of innate immune responses and plays a key role in the body's antiviral defense. The purpose of this paper is to analyze the latest scientific data regarding TLR3 polymorphism variants in Turkic-speaking countries and their influence on the predisposition and course of chronic hepatitis B and C. Materials and Methods: To achieve the goal, relevant papers over the past 5 years in scientific medical publications on academic search platforms were selected and processed. Results: The paper analyzes variants of TLR3 polymorphisms in terms of their involvement and predisposition to the development of viral hepatitis among Turkic-speaking peoples. It has been established that the Phe/Leu substitution is associated with a decrease in the activity of adaptive immunity reactions and hyperproduction of interleukins; TLR3 single nucleotide polymorphisms of the rs5743305 (T/A) and rs3775291 species among Turkic-speaking peoples do not affect the nature of progressed viral hepatitis B and C. The rs13126816 variant is associated with a predisposition to infection and the active course of the chronic form of hepatitis C. The G-allele rs13126816 TLR3 is associated with a high probability spontaneous clearance of hepatitis C. The TLR3 single nucleotide polymorphism rs3775291 may be associated with pathological immune responses during the primary development of viral hepatitis B. Conclusion: Thus, the study of the presence of TLR3 polymorphisms in patients of Turkic-speaking countries with viral hepatitis B and C, or in groups of patients with an increased risk of infection, affects the understanding peculiarities of antiviral protection in mutation carriers, the intensity of innate immunity reactions, as well as enables predicting the nature of the course of a chronic process and the risk of developing terminal complications.

Genetic variation of TLR3 gene is associated with the outcome of hepatitis b infection in mauritanian patients: case control study

BACKGROUND

Toll-Like receptors (TLRs) play an important role in the immune response during hepatitis B virus (HBV) infection. In this study, we evaluated the association between two SNP variants (TLR3 rs3775290 and TLR4 rs4986790) and susceptibility to chronic HBV infection in Mauritania.

SUBJECTS AND METHODS

A total of 188 subjects were recruited for this study: 102 chronically infected patients and 86 individuals with spontaneously resolved HBV infection who were considered controls. Targeted PCR products were sequenced using Sanger sequencing.

RESULTS

We found that TLR3 rs3775290 was significantly more frequent in patients with chronic HBV than in the control population (p = 0.03). However, no association was found between the TLR4 rs3775290 polymorphism and chronic infection.

CONCLUSION

Our results suggest that the TLR3 rs3775290 polymorphism may be a risk factor for susceptibility to chronic HBV infection in the Mauritanian population.

Recent advances in different interactions between toll-like receptors and hepatitis B infection: a review

Hepatitis B virus (HBV) B infections remain a primary global health concern. The immunopathology of the infection, specifically the interactions between HBV and the host immune system, remains somewhat unknown. It has been discovered that innate immune reactions are vital in eliminating HBV. Toll-like receptors (TLRs) are an essential category of proteins that detect pathogen-associated molecular patterns (PAMPs). They begin pathways of intracellular signals to stimulate pro-inflammatory and anti-inflammatory cytokines, thus forming adaptive immune reactions. HBV TLRs include TLR2, TLR3, TLR4, TLR7 and TLR9. Each TLR has its particular molecule to recognize; various TLRs impact HBV and play distinct roles in the pathogenesis of the disease. TLR gene polymorphisms may have an advantageous or disadvantageous efficacy on HBV infection, and some single nucleotide polymorphisms (SNPs) can influence the progression or prognosis of infection. Additionally, it has been discovered that similar SNPs in TLR genes might have varied effects on distinct populations due to stress, diet, and external physical variables. In addition, activation of TLR-interceded signaling pathways could suppress HBV replication and increase HBV-particular T-cell and B-cell reactions. By identifying these associated polymorphisms, we can efficiently advance the immune efficacy of vaccines. Additionally, this will enhance our capability to forecast the danger of HBV infection or the threat of dependent liver disease development via several TLR SNPs, thus playing a role in the inhibition, monitoring, and even treatment guidance for HBV infection. This review will show TLR polymorphisms, their influence on TLR signaling, and their associations with HBV diseases.

Interplay of Extracellular Vesicles and TLR4 Signaling in Hepatocellular Carcinoma Pathophysiology and Therapeutics

Hepatocellular carcinoma (HCC) stands as a significant contributor to global cancer-related mortality. Chronic inflammation, often arising from diverse sources such as viral hepatitis, alcohol misuse, nonalcoholic fatty liver disease (NAFLD), and nonalcoholic steatohepatitis (NASH), profoundly influences HCC development. Within this context, the interplay of extracellular vesicles (EVs) gains prominence. EVs, encompassing exosomes and microvesicles, mediate cell-to-cell communication and cargo transfer, impacting various biological processes, including inflammation and cancer progression. Toll-like receptor 4 (TLR4), a key sentinel of the innate immune system, recognizes both pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), thereby triggering diverse signaling cascades and pro-inflammatory cytokine release. The intricate involvement of the TLR4 signaling pathway in chronic liver disease and HCC pathogenesis is discussed in this study. Moreover, we delve into the therapeutic potential of modulating the TLR4 pathway using EVs as novel therapeutic agents for HCC. This review underscores the multifaceted role of EVs in the context of HCC and proposes innovative avenues for targeted interventions against this formidable disease.

Meta-analysis of the association between toll-like receptor gene polymorphisms and hepatitis C virus infection

Objective

The objective of this study is to investigate the association between toll-like receptor (TLR) 3/7 gene polymorphisms and the infection by hepatitis C virus (HCV).

Methods

PubMed, Embase, Web of Science, Scopus, CNKI, Wanfang Data, and SinoMed were searched to identify studies focusing on the association between the TLR3 rs3775290 or the TLR7 rs179008 single nucleotide polymorphisms (SNPs) and the HCV infection. All the related articles were collected from the inception of each database to 15 January 2023. Our meta-analysis was conducted using the allelic model, the dominant model, and the recessive model. Outcomes were presented by odds ratio (ORs) and 95% confidence interval (95%CI). The heterogeneity across studies was assessed by the I2 test. A subgroup analysis was performed to explore the source of heterogeneity. Funnel plots were drawn to assess the risk of publication bias. Review Manager 5.4 was used for statistical analysis.

Results

Ten articles were finally included, among which six studies were analyzed for rs3775290 and five studies were analyzed for rs179008. Studies relating to rs3775290 included 801 patients and 1,045 controls, whereas studies relating to rs179008 included 924 patients and 784 controls. The results of the meta-analysis showed that there is no significant association between rs3775290 gene polymorphism and HCV infection (T vs. C: OR = 1.12, 95%CI 0.97-1.30; TT+CT vs. CC: OR = 1.20, 95%CI 0.73-1.96; TT vs. CT+CC: OR = 1.13, 95%CI 0.68-1.89). The recessive model showed that rs179008-T allele homozygotes had an 89% increased risk of infection by HCV compared with rs179008-A allele carriers (TT vs. AT+AA: OR = 1.89, 95%CI 1.13-3.16). The results of the subgroup analysis demonstrated that the characteristics of the control population may serve as an important source of heterogeneity. In the African populations, individuals with homozygous rs179008-T alleles had a higher risk of infection by HCV than rs179008-A allele carriers (OR = 2.14, 95%CI 1.18-3.87). We did not find that this difference existed in the European populations (OR = 1.24, 95%CI 0.43-3.56).

Conclusion

There is no significant association between rs3775290 single nucleotide polymorphism and the infection by HCV. Individuals with homozygous rs179008-T alleles have a higher risk of an infection by HCV than rs179008-A allele carriers, which is statistically significant in the African populations.

A Chemically Defined TLR3 Agonist with Anticancer Activity

Toll-like receptor 3 (TLR3) agonists such as polyinosinic:polycytidylic acid (poly(I:C)) have immunostimulatory effects that can be taken advantage of to induce anticancer immune responses in preclinical models. In addition, poly(I:C) has been introduced into clinical trials to demonstrate its efficacy as an adjuvant and to enhance the immunogenicity of locally injected tumors, thus reverting resistance to PD-L1 blockade in melanoma patients. Here, we report the pharmacokinetic, pharmacodynamic, mechanistic and toxicological profile of a novel TLR3 agonist, TL-532, a chemically synthesized double-stranded RNA that is composed by blocks of poly(I:C) and poly(A:U) (polyadenylic - polyuridylic acid). In preclinical models, we show that TL-532 is bioavailable after parenteral injection, has an acceptable toxicological profile, and stimulates the production of multiple chemokines and interleukins that constitute pharmacodynamic markers of its immunostimulatory action. When given at a high dose, TL-532 monotherapy reduced the growth of bladder cancers growing on mice. In addition, in immunodeficient mice lacking formylpeptide receptor-1 (FPR1), TL-532 was able to restore the response of orthotopic subcutaneous fibrosarcoma to immunogenic chemotherapy. Altogether, these findings may encourage further development of TL-532 as an immunotherapeutic anticancer agent.

Association between TLR2, TLR4, and TLR5 genetic variants and the risk of hepatocellular carcinoma in Moroccan population

Hepatocellular carcinoma (HCC) is the fifth most common human malignancy and the fourth most frequent cause of cancer-related deaths worldwide. Toll-like receptors (TLRs), are known to play a key role in hepatocarcinogenesis through induction of inflammation. We aimed to investigate the association between TLR2 rs3804099, TLR4 rs4986790, rs4986791, and rs11536889 and TLR5 rs5744174 and HCC risk in a total of 306 Moroccan subjects, including 152 HCC patient and 154 controls using a TaqMan allelic discrimination assay. Our result showed that the frequency of TLR4 rs11536889 C allele was higher in control group than in HCC patients (OR = 0.52, 95% CI = 0.30-0.88, p = 0.01). Moreover, under the dominant model, we observed that CG/CC genotypes were protective factors against HCC risk (OR = 0.51, 95% CI = 0.28-0.91, p = 0.02). However, no significant differences were found in the allele and genotype frequencies of TLR4 rs4986790 and rs4986791, between HCC patients and controls. Similarly, genotypic frequencies of TLR2 and TLR5 polymorphisms did not differ significantly between HCC patients and controls. However, TLR4 haplotype analysis revealed that ACC haplotype may be protective of HCC risk in patients with HCC (OR = 0.53, 95% CI = 0.31-0.92, p = 0.02). In conclusion, our result suggest that TLR4 rs11536889 polymorphism and ACC haplotype may decrease risk of hepatocellular carcinoma in Moroccan population.

Pathomorphological Manifestations and the Course of the Cervical Cancer Disease Determined by Variations in the TLR4 Gene

Cervical cancer (CC) is often associated with human papillomavirus (HPV). Chronic inflammation has been described as one of the triggers of cancer. The immune system fights diseases, including cancer. The genetic polymorphism of pathogen recognition receptors potentially influences the infectious process, development, and disease progression. Many candidate genes SNPs have been contradictory demonstrated to be associated with cervical cancer by association studies, GWAS. TLR4 gene activation can promote antitumor immunity. It can also result in immunosuppression and tumor growth. Our study aimed to investigate eight selected polymorphisms of the TLR4 gene (rs10759932, rs1927906, rs11536898, rs11536865, rs10983755, rs4986790, rs4986791, rs11536897) and to determine the impact of polymorphisms in genotypes and alleles on the pathomorphological characteristics and progression in a group of 172 cervical cancer subjects with stage I-IV. Genotyping was performed by RT-PCR assay. We detected that the CA genotype and A allele of rs11536898 were significantly more frequent in patients with metastases (p = 0.026; p = 0.008). The multivariate logistic regression analysis confirmed this link to be significant. The effect of rs10759932 and rs11536898 on progression-free survival (PFS) and overall survival (OS) has been identified as important. In univariate and multivariate Cox analyses, AA genotype of rs11536898 was a negative prognostic factor for PFS (p = 0.024; p = 0.057, respectively) and OS (p = 0.008; p = 0.042, respectively). Rs11536898 C allele predisposed for longer PFS (univariate and multivariate: p = 0.025; p = 0.048, respectively) and for better OS (univariate and multivariate: p = 0.010; p = 0.043). The worse prognostic factor of rs10759932 in a univariate and multivariate Cox analysis for survival was CC genotype: shorter PFS (p = 0.032) and increased risk of death (p = 0.048; p = 0.015, respectively). The T allele of rs10759932 increased longer PFS (univariate and multivariate: p = 0.048; p = 0.019, respectively) and longer OS (univariate and multivariate: p = 0.037; p = 0.009, respectively). Our study suggests that SNPs rs10759932 and rs11536898 may have the potential to be markers contributing to the assessment of the cervical cancer prognosis. Further studies, preferably with larger groups of different ethnic backgrounds, are needed to confirm the results of the current study.

Association of TLR4 and TLR9 gene polymorphisms with the risk and progression of cervical lesions in HPV-infected women

Aim: Toll-like receptors involved in tumor-associated inflammatory response, this study aimed to investigate the role of TLR4 and TLR9 gene polymorphisms in the risk and progression of HPV-related cervical lesions. Materials & methods: A total of 220 cervical lesion patients and 227 healthy controls were enrolled. Single-nucleotide polymorphisms were genotyped using PCR-restriction fragment length polymorphism. Results: A significantly decreased risk of cervical lesions was observed to be associated with the TLR4 rs10116253 (C), rs1927911 (T) and rs10759931 (G) mutant alleles. rs187084-rs1927911-HPV-16/18 was the best interaction model to affect cervical lesion risk. Conclusion: TLR4 rs10116253, rs1927911 and rs10759931 were potential biomarkers for cervical lesion susceptibility.

Diagnostic Values of the Liver Imaging Reporting and Data System in the Detection and Characterization of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

This review was undertaken to assess the diagnostic value of the Liver Imaging Reporting and Data System (LI-RADS) in patients with a high risk of hepatocellular carcinoma (HCC). Google Scholar, PubMed, Web of Science, Embase, PROQUEST, and Cochrane Library, as the international databases, were searched with appropriate keywords. Using the binomial distribution formula, the variance of all studies was calculated, and using Stata version 16 (StataCorp LLC, College Station, TX, USA), the obtained data were analyzed. Using a random-effect meta-analysis approach, we determined the pooled sensitivity and specificity. Utilizing the funnel plot and Begg's and Egger's tests, we assessed publication bias. The results exhibited pooled sensitivity and pooled specificity of 0.80% and 0.89%, respectively, with a 95% confidence interval (CI) of 0.76-0.84 and 0.87-0.92, respectively. The 2018 version of LI-RADS showed the greatest sensitivity (0.83%; 95% CI 0.79-0.87; I ² = 80.6%; P < 0.001 for heterogeneity; T ² = 0.001). The maximum pooled specificity was detected in LI-RADS version 2014 (American College of Radiology, Reston, VA, USA; 93.0%; 95% CI 89.0-96.0; I ² = 81.7%; P < 0.001 for heterogeneity; T ² = 0.001). In this review, the results of estimated sensitivity and specificity were satisfactory. Therefore, this strategy can serve as an appropriate tool for identifying HCC.

Polymorphisms and haplotypes of TLR-4/9 associated with bacterial infection, gingival inflammation/recession and oral cancer

BACKGROUND

The expression and SNPs of innate immunity genes TLR-4/9 for bacterial infection, gingival inflammation/gingival recession (GIGR), and oral squamous cell carcinoma (OSCC) are largely unknown.

PATIENTS AND METHOD

235 specimens (120 OSCC cases, among which 85 cases with either Porphyromonas gingivalis, Fusobacterium nucleatum or Treponema denticola infection and GIGR) and 115 healthy controls were used to know the expression and polymorphisms (TLR-4: N1:rs10759931, N2:rs11536889, N3:rs1927911, N4:rs4986790; TLR-9: N5:rs5743836, N6:rs352140, N7:rs187084 and N8:rs352139) of TLR-4/9 by western blot, RT-PCR, and allele-specific (AS)-PCR followed by sequencing.

RESULTS

Increased TLR-4/9 mRNA/protein expression, bacterial infection (BI) and GIGR were associated with OSCC incidence. One of the three BI and GIGR was observed in 70.83% of OSCC cases, whereas all the HC used were free from any of these three BI/GIGR. The N3: CT-genotype (Odds Ratio hereafter as O.R.=1.811, p = 0.0338), TT-genotype (O.R.=3.094, p = 0.0124), 'T'-allele (O.R.=1.821, p = 0.003), N4: AG-genotype (O.R.=2.015, p = 0.0222) and 'G'-allele (O.R.=1.86, p = 0.018) of TLR-4 as well as the N5: CC-genotype (O.R.=3.939, p = 0.0017), 'C'-allele (O.R.=1.839, p = 0.0042), N6: AA-genotype (O.R.=2.195, p = 0.0234), 'A'-allele (O.R.=1.569, p = 0.0163), N7: TC-genotype (O.R.=2.083, p = 0.0136), CC-genotype (O.R.=2.984, p = 0.003) and 'C'-allele (O.R.=1.885, p = 0.0008) of TLR-9 were associated with increased OSCC risk. Similarly, the N2:'C'-allele (O.R.=1.615, p = 0.0382), N3: TT-genotype (O.R.=2.829, p = 0.0336), 'T'-allele (O.R.=1.742, p = 0.0115), N4: AG-genotype (O.R.=2.221, p = 0.0147) and 'G'-allele (O.R.=1.890, p = 0.0238) of TLR-4 as well as the N5: CC-genotype (O.R.=2.830, p = 0.031), N6: AA-genotype (O.R.=2.6, p = 0.0122) and 'A'-allele (O.R.=1.746, p = 0.0064), N7:CC-genotype (O.R.2.706, p = 0.0111) and 'C'-allele (O.R. 1.774, p = 0.0055) of TLR-9 were correlated with GIGR and BI. TLR-4 (N1-N2-N3-N4: A-C-T-A (O.R.=2.1, p = 0.0069) and TLR-9 (N5-N6-N7-N8: T-A-C-A (O.R.=2.019, p = 0.0263); C-A-C-A (O.R.=6.0, p = 0.0084); C-A-C-G (O.R.=4.957, p = 0.0452) haplotypes were linked with OSCC vulnerability, while the TLR-4 (N1-N2-N3-N4: G-C-C-A (O.R.=0.5752, p = 0.0131) and TLR-9 (N5-N6-N7-N8: T-G-T-A (O.R.=0.5438, p = 0.0314); T-G-T-G (O.R.=0.5241, p = 0.036) haplotypes offered protection.

CONCLUSION

TLR-4/9 expression, polymorphisms, and BI-induced GIGR could increase OSCC risk. This may be used in pathogenesis and oral cancer prediction.

The relationship between 896A/G (rs4986790) polymorphism of TLR4 and infectious diseases: A meta-analysis

Toll-like Receptors (TLRs), such as the TLR4, are genes encoding transmembrane receptors of the same name, which induce a pro- or anti-inflammatory response according to their expression as the host's first line of defense against pathogens, such as infectious ones. Single nucleotide polymorphisms (SNPs) are the most common type of mutation in the human genome and can generate functional modification in genes. The aim of this article is to review in which infectious diseases there is an association of susceptibility or protection by the TLR4 SNP rs4986790. A systematic review and meta-analysis of the literature was conducted in the Science Direct, PUBMED, MEDLINE, and SciELO databases between 2011 and 2021 based on the dominant genotypic model of this SNP for general and subgroup analysis of infectious agent type in random effect. Summary odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated for genotypic comparison. I2 statistics were calculated to assess the presence of heterogeneity between studies and funnel plots were inspected for indication of publication bias. A total of 27 articles were included, all in English. Among the results achieved, the categories of diseases that were most associated with the SNP studied were in decreasing order of number of articles: infections by bacteria (29.63%); caused by viruses (22.23%); urinary tract infection-UTI (7.4%), while 11 studies (40.74%) demonstrated a nonsignificant association. In this meta-analysis, a total of 5599 cases and 5871 controls were finalized. The present meta-analysis suggests that there is no significant association between TLR4-rs4986790 SNP and infections (OR = 1,11; 95% CI: 0,75-1,66; p = 0,59), but in the virus subgroup it was associated with a higher risk (OR = 2,16; 95% CI: 1,09-4,30; p = 0,03). The subgroups of bacteria and parasites did not show statistical significance (OR = 0,86; 95% CI: 0,56-1,30; p = 0,47, and no estimate of effects, respectively). Therefore, it has been shown that a diversity of infectious diseases is related to this polymorphism, either by susceptibility or even severity to them, and the receptor generated is also crucial for the generation of cell signaling pathways and immune response against pathogens.

Single Nucleotide Polymorphisms of Toll-like Receptor 4 in Hepatocellular Carcinoma-A Single-Center Study

Hepatocellular carcinoma (HCC) is the most common primary liver tumor leading to significant morbidity and mortality; its exact genetic background is largely unrecognized. Toll-like receptor-4 (TLR4) reacts with lipopolysaccharides, molecules found in the outer membrane of Gram-negative bacteria. In damaged liver, TLR4 expression is upregulated, leading to hepatic inflammation and injury. We tried to investigate the role of the two most common single-nucleotide polymorphisms (SNPs) of TLR4 in HCC-genesis. Aged > 18 years old, cirrhotic patients were included in this study. Exclusion criteria were non-HCC tumors and HIV co-infection. TLR4 SNPs association with HCC occurrence was the primary endpoint, and associations with all-cause and liver-related mortality, as well as time durations between diagnosis of cirrhosis and HCC development or death and diagnosis of HCC and death were secondary endpoints. A total of 52 out of 260 included patients had or developed HCC. TLR4 SNPs showed no correlation with primary or secondary endpoints, except for the shorter duration between HCC development and death in patients with TLR4 mutations. Overall, TLR4 SNPs showed no correlation with carcinogenesis or deaths in patients with liver cirrhosis; patients with TLR4 SNPs that developed HCC had lower survival rates, a finding that should be further evaluated.

Toll-like receptor-mediated innate immunity orchestrates adaptive immune responses in HBV infection

Chronic hepatitis B virus (HBV) infection remains to be a substantial global burden, especially for end-stage liver diseases. It is well accepted that HBV-specific T and B cells are essential for controlling HBV infection. Toll-like receptors (TLRs) represent one of the major first-line antiviral defenses through intracellular signaling pathways that induce antiviral inflammatory cytokines and interferons, thereby shaping adaptive immunity. However, HBV has evolved strategies to counter TLR responses by suppressing the expression of TLRs and blocking the downstream signaling pathways, thus limiting HBV-specific adaptive immunity and facilitating viral persistence. Recent studies have stated that stimulation of the TLR signaling pathway by different TLR agonists strengthens host innate immune responses and results in suppression of HBV replication. In this review, we will discuss how TLR-mediated responses shape HBV-specific adaptive immunity as demonstrated in different experimental models. This information may provide important insight for HBV functional cure based on TLR agonists as immunomodulators.

Association of toll-like receptors single nucleotide polymorphisms with HBV and HCV infection: research status

Background

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections have become increasingly severe worldwide and are a threat to public health. There have been a number of studies conducted recently on the relationship of single nucleotide polymorphisms (SNPs) to innate immune receptor genes such as toll-like receptors (TLRs). Some literature suggests that SNPs of TLRs are associated with HBV and HCV infection. We summarized the role of TLRs gene polymorphisms associated with HBV and HCV infections and explored their possible mechanisms of action.

Methodology

PubMed and Web of Science were used to perform the literature review. Related articles and references were identified and used to analyze the role of TLRs gene polymorphism in HBV and HCV infection.

Results

TLRs gene polymorphisms may have beneficial or detrimental effects in HBV and HCV infection, and some SNPs can affect disease progression or prognosis. They affect the disease state by altering gene expression or protein synthesis; however, the mechanism of action is not clearly understood.

Conclusions

Single nucleotide polymorphisms of TLRs play a role in HBV and HCV infection, but the mechanism of action still needs to be explored in future studies.

TLR3 Mediates Senescence and Immunosurveillance of Hepatic Stellate Cells

Background: Activation of hepatic stellate cells (HSCs) is an important driver of liver fibrosis, which is a health problem of global concern, and there is no effective solution for it at the present. Senescent activated HSCs are preferentially killed by natural killer cells (NK cells) to promote the regression of hepatic fibrosis. Objectives: The purpose of this study was to investigate the effect of polyinosinic-polycytidylic acid (poly I:C) on HSCs’ senescence, a trigger for NK cell-induced cytotoxicity. Methods: The senescence of HSCs was assessed by western blot, qRT-PCR, and flow cytometry, and NK cell cytotoxicity was assessed in a co-culture of NK cells with poly I:C-treated HSCs by measuring CD107a expression. Results: The expression of p16, p21, SA-β-gal, MICA/MICB, and ULBP2 increased in poly I:C-treated HSCs, rendering them significantly susceptible to NK cell cytotoxicity. Conclusions: Poly I:C induces cellular senescence in HSCs and triggers NK cell immunosurveillance, suggesting that the role of poly I:C in HSC senescence may promote fibrosis regression.

TLR3\TLR7 as Differentially Expressed Markers Among Viral, Nonviral, and Autoimmune Diseases in Egyptian Patients

Toll-like receptors (TLRs) represent the immune link between the innate and the adaptive immune signals against various pathogens. This study aimed to evaluate the TLRs3 and 7 as immune-markers in differentiating between hepatitis C virus (HCV)-infected and -uninfected patients. Also, the use of the TLR3 and TLR7 as immune markers was compared with the prevalent bio and immune markers for autoimmune diseases in HCV-infected or -uninfected patients. The levels of GPT, GOT, B cell activated factors, tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-10 were measured in plasma, while the levels of TLR3 and TLR7 were quantified in lysates of peripheral blood mononuclear cells from healthy donors, HCV-infected patients, nonalcoholic fatty liver (NAFL) patients without autoimmune diseases and with autoimmune diseases (HCV-infected patients with autoimmune diseases [HCV+auto], nonalcoholic fatty liver patients with autoimmune diseases [NAFL+auto]), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE) patients. The relative expression of TLR3, TLR7, TNF, and IL-10 in cell lysates was assessed against glyceraldehyde 3-phosphate dehydrogenase (GAPDH) by quantitative real time-polymerase chain reaction (qRT-PCR). Results showed that TLRs 3 and 7 levels were significantly higher in SLE, RA, HCV, HCV+auto, and the NAFL patients compared to the normal control. The cell lysates from SLE patients expressed TLR3 at relatively significantly higher mRNA levels compared to normal subjects or other patient groups. The NAFL+auto patients expressed TLR7 at relatively significantly high mRNA levels compared to normal subjects or other patients. The RA patients expressed TLR7 at relatively significantly higher mRNA levels when compared to HCV, HCV+auto, and NAFL+auto patients. Conclusions: At the protein level, TLR7 can differentiate between HCV and NAFL patients. In addition, both TLRs3 and 7 can serve as potent markers in differentiating between NAFL and NAFL+auto.

Single nucleotide polymorphisms of the interleukin-1 superfamily members: аssociation with viral hepatitis B and C

The review provides information on single nucleotide polymorphisms (SNPs) in genes encoding some interleukins belonging to the interleukin-1 (IL-1) superfamily and on their association with different infectious and non-infectious human diseases. It also briefs on the history of SNP discovery and the progress in the related scientific studies till the present time. It gives an insight into some mechanisms of interaction between infectious agents and the human immune system, involving SNPs in some cytokines of the IL-1 superfamily. The review provides data on relationships of SNPs in genes encoding other factors of the immune system, which are associated with the specific characteristics of natural history of chronic hepatitis B and C. It explores the significance of assessment of the SNP-proportion in proinflammatory cytokines and their antagonists of the IL-1 superfamily among the healthy population as well as the ratio of individual SNPs in specific groups of patients as a monitoring parameter for epidemiological surveillance of infectious diseases.

Associations of Hydroxysteroid 17-beta Dehydrogenase 13 Variants with Liver Histology in Chinese Patients with Metabolic-associated Fatty Liver Disease

BACKGROUND AND AIMS

In Europeans, variants in the hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) gene impact liver histology in metabolic-associated fatty liver disease (MAFLD). The impact of these variants in ethnic Chinese is unknown. The aim of this study was to investigate the potential associations in Chinese patients.

METHODS

In total, 427 Han Chinese with biopsy-confirmed MAFLD were enrolled. Two single nucleotide polymorphisms in HSD17B13 were genotyped: rs72613567 and rs6531975. Logistic regression was used to test the association between the single nucleotide polymorphisms and liver histology.

RESULTS

In our cohort, the minor allele TA of the rs72613567 variant was related to an increased risk of fibrosis [odds ratio (OR): 2.93 (1.20-7.17), p=0.019 for the additive model; OR: 3.32 (1.39-7.91), p=0.007 for the recessive model], representing an inverse association as compared to the results from European cohorts. In contrast, we observed a protective effect on fibrosis for the minor A allele carriers of the HSD17B13 rs6531975 variant [OR: 0.48 (0.24-0.98), p=0.043 for the additive model; OR: 0.62 (0.40-0.94), p=0.025 for the dominant model]. HSD17B13 variants were only associated with fibrosis but no other histological features. Furthermore, HSD17B13 rs6531975 modulated the effect of PNPLA3 rs738409 on hepatic steatosis.

CONCLUSIONS

HSD17B13 rs72613567 is a risk variant for fibrosis in a Han Chinese MAFLD population but with a different direction for allelic association to that seen in Europeans. These data exemplify the need for studying diverse populations in genetic studies in order to fine map genome-wide association studies signals.

Nucleic Acid-Induced Signaling in Chronic Viral Liver Disease

A hallmark for the development and progression of chronic liver diseases is the persistent dysregulation of signaling pathways related to inflammatory responses, which eventually promotes the development of hepatic fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The two major etiological agents associated with these complications in immunocompetent patients are hepatitis B virus (HBV) and hepatitis C virus (HCV), accounting for almost 1.4 million liver disease-associated deaths worldwide. Although both differ significantly from the point of their genomes and viral life cycles, they exert not only individual but also common strategies to divert innate antiviral defenses. Multiple virus-modulated pathways implicated in stress and inflammation illustrate how chronic viral hepatitis persistently tweaks host signaling processes with important consequences for liver pathogenesis. The following review aims to summarize the molecular events implicated in the sensing of viral nucleic acids, the mechanisms employed by HBV and HCV to counter these measures and how the dysregulation of these cellular pathways drives the development of chronic liver disease and the progression toward HCC.

Toll-like receptor 7 mRNA is reduced in hepatitis C-based liver cirrhosis and hepatocellular carcinoma, out-performs alpha-fetoprotein levels, and with age and serum aspartate aminotransferase is a new diagnostic index

BACKGROUND

Hepatitis B and C viruses are leading causes of liver cirrhosis and hepatocellular carcinoma (HCC). Toll-like receptor 7 (TLR-7) has been implicated in the pathogenesis of HCC linked to hepatitis B. We hypothesised a role of leukocyte TLR-7 mRNA in hepatitis C related liver cirrhosis and HCC, using alpha-fetoprotein (AFP) and liver function tests as comparators.

METHODS

We recruited 102 patients with HCV-related HCC, 97 with HCV-related liver cirrhosis and 60 healthy controls. Quantification of TLR-7 mRNA was performed using real-time PCR, AFP and routine LFTs by standard techniques.

RESULTS

TLR-7 mRNA levels were significantly lower in HCC patients compared to cirrhotic patients and lower again in healthy controls (p < 0.001 for trend). In multivariate analysis, age, aspartate transaminase (AST), AFP, and TLR-7 mRNA were significant predictors of HCC. The ROCC/AUC for age, AST and TLR-7 mRNA were all between 0.64 and 0.78 (all P < 0.01), but for AFP was 0.57 (95% CI 0.48-0.65, P = 0.09). We derived an index score using age, AST and TLR-7 mRNA for the diagnosis of HCC. The ROCC/AUC for the index was superior to all three root indices in the prediction of HCC. The index linked significantly with the Tokyo and Vienna liver cancer staging systems, but not with those of the CLIP and Okuda systems, in distinguishing HCC from liver cirrhosis.

CONCLUSION

The combination of TLR-7 mRNA levels with age and AST improves the performance of TLR-7 in HCC diagnosis, out-performs alpha-fetoprotein and predicts early HCC.

Genetic diversity of toll-like receptor genes in the vulnerable Chinese egret (Egretta eulophotes)

Toll-like receptor (TLR) genes have recently been employed to assess genetic diversity, as they can be used to infer both demographic history and adaptation to environments with different pathogen pressure. Here, we sampled 120 individuals of the Chinese egret (Egretta eulophotes), a globally vulnerable species, from four breeding populations across China. We assessed the levels of genetic diversity, selection pressure, and population differentiation at seven TLR loci (TLR1LB, TLR2A, TLR3, TLR4, TLR5, TLR7, and TLR15). Using a variety of metrics (SNPs, heterozygosity, nucleotides, haplotypes), our analyses showed that genetic diversity was lower at 4 of the 7 TLR loci in the vulnerable Chinese egret compared to the more common little egret (Egretta garzetta). The selection test indicated TLRs, except for TLR5, were under purifying selection in TLR evolution, suggesting that low TLR genetic diversity in the Chinese egret may be caused by purifying selection. Moreover, analysis of molecular variance indicated low but significant population differentiation among four populations at all of the TLR loci in this egret. However, some comparisons based on fixation index analyses did not show significant population differentiation, and Bayesian clustering showed admixture. Our finding suggested that these four populations of the Chinese egret in China may be considered a single unit for conservation planning. These results, the new report of TLR genetic diversity in a long-distance migratory vulnerable Ardeid species, will provide fundamental TLR information for further studies on the conservation genetics of the Chinese egret and other Ardeids.

Resveratrol prevents liver damage in MCD-induced steatohepatitis mice by promoting SIGIRR gene transcription

Persistent inflammation is one of the main reasons that nonalcoholic fatty liver disease develops into cirrhosis and liver cancer, and reducing the expression of inflammatory factors may be an effective strategy to alleviate the development of nonalcoholic steatohepatitis (NASH). SIGIRR, a member of the interleukin-1 receptor family, has been shown to inhibit the production of inflammatory cytokines, and its down-regulation or deletion has been suggested to be an important cause of inflammatory damage to organs. In this study, we identified that resveratrol efficiently induced the transcriptional activity of the SIGIRR promoter and also increased SIGIRR mRNA levels in human hepatocytes and mouse livers. Furthermore, the potential effects of resveratrol on a methionine/choline-deficient diet-induced NASH mouse model were investigated. Resveratrol maintained the expression level of SIGIRR in the mouse liver. Resveratrol intervention alleviated NASH progression; decreased the levels of alanine aminotransferase and aspartate aminotransferase; and down-regulated tumor necrosis factor-α, interleukin (IL)-6, IL-1β and transforming growth factor-β mRNA and protein levels. Additionally, increased SIGIRR potentially blocked the activity of the Toll-like receptor/nuclear factor-κB signaling pathway both in vivo and in vitro. In vitro, resveratrol pretreatment protected against hepatocyte injury caused by foamy macrophage-released inflammatory cytokines, which are involved in the development of NASH. However, resveratrol did not effectively induce hepatocyte SIGIRR gene transcription in the inflammatory cytokine microenvironment. In conclusion, resveratrol is practical and acts as an agonist of the SIGIRR protein to negatively regulate the expression of inflammatory factors in liver, suggesting that appropriate intake may be a potential way to prevent the occurrence and development of NASH.

Methylation of tumour suppressor genes RUNX3, RASSF1A and E-Cadherin in HCV-related liver cirrhosis and hepatocellular carcinoma

Background: HCV infection is related to aberrant methylation of several genes. RASSF1A, E-Cadherin and RUNX3 are tumour suppressor genes that may be inactivated by hypermethylation in many tumours including hepatocellular carcinoma (HCC). We hypothesized that methylation is a diagnostic biomarker for HCC in patients with HCV-related liver cirrhosis.Methods: We recruited 207 cases of HCV-related liver cirrhosis, 193 HCC patients and 53 healthy controls. Methylation-specific polymerase chain reaction for detection of circulating hypermethylated RASSF1A, E-Cadherinand RUNX3. Alpha fetoprotein (AFP) was measured by commercial immunoassay.Results: Significant hypermethylation of the three genes was found in the HCC group compared to both cirrhosis and healthy groups (P < 0.001), whereas no significant difference in hypermethylation was found between cirrhosis and healthy groups (P = 0.17, 0.50 and 0.14, respectively). No significant links were found between hypermethylated RASSF1A, E-Cadherin and RUNX3 and stages of Barcelona Clinic of Liver Cancer score (P =0.21, 0.63 and 0.98, respectively). No significant associations were found between AFP value and hypermethylated genes in cirrhosis and HCC groups (P = 0.82) except with E-Cadherin in HCC (P = 0.02). In multiple regression analysis, RASSF1A and E-Cadherin were predictors of HCC within cirrhosis cases, but only E-Cadherin was an independent risk factor for prediction of HCC in cases with low AFP (P = 0.01).Conclusions: The presence of hypermethylated serum RASSF1A, E-Cadherin and RUNX3 is linked to HCC in patients with HCV-related cirrhosis. Only E-Cadherin is an independent risk factor for prediction of HCC with low AFP. These findings may be of diagnostic value.

British Journal of Biomedical Science in 2019. What have we learned?

In 2019 the British Journal of Biomedical Science published 40 articles in the various disciplines that comprise biomedical science. These were one review, 22 original articles and 17 'In Brief' short reports. Of those citing original data, the majority were in cellular pathology (14 papers), clinical chemistry (9 papers), and microbiology (6 papers: 4 in bacteriology and 2 in virology). There were 3 papers in haematology and 2 in andrology, whilst 5 papers crossed traditional discipline boundaries (such as the molecular genetics of IL6, liver function tests, and hepatocellular carcinoma). Over two-thirds of papers used techniques in molecular genetics. The present report will summarise key aspects of these publications that are of greatest relevance to laboratory scientists.

Hepatitis B Virus Molecular Epidemiology, Host-Virus Interaction, Coinfection, and Laboratory Diagnosis in the MENA Region: An Update

Hepatitis B virus (HBV) is an enveloped partial double-stranded DNA virus that can cause acute and chronic hepatitis. According to the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), 257 million people are living with HBV. Moreover, 20,900 acute hepatitis B cases were reported in 2016. Hepatitis B is highly prevalent in the African, Western Pacific, Eastern Mediterranean, South-East Asia, and European regions, respectively. Due to the high mutational rate of HBV and lack of reverse transcriptase proofreading activity, ten different genotypes with different geographical distributions have been identified. HBV pathogenesis and severity of infection depend on several host and viral factors, particularly, the genetic variability of both the host and virus. Although HBV infection is a global health concern, there is a lack of adequate studies and reports in the Middle East and North Africa (MENA) region. Here, we provide a review on HBV epidemiology, pathogenesis, host-pathogen interactions, coinfection with selected viruses, and laboratory diagnosis, focusing on studies conducted in the MENA region to determine the current situation of the HBV infection and outline the future study areas.

The association of toll-like receptor 4 gene polymorphisms with primary open angle glaucoma susceptibility: a meta-analysis

Primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) cause irreversible blindness while current medications cannot completely inhibit disease progression. An understanding of immunopathogenesis is thus a keystone to develop novel drug targets and genetic markers are still required for early diagnosis. Toll-like receptor 4 (TLR4) is an essential player in inflammation in various diseases. However, the TLR4 polymorphisms have not been completely elucidated in both types of glaucoma. The aim of the present study was to identify the association between TLR4 polymorphism and glaucoma (POAG and NTG) via the use of a comprehensive review and meta-analysis. The relevant studies were collected from PubMed, Excerpta Medica Database (EMBASE), and Web of Science to identify eight included articles, assessed for quality by a modified Newcastle-Ottawa Scale (NOS) for gene association study. A meta-analysis was applied to calculate the pooled odds-ratio and 95% confidence intervals (CIs) to evaluate the association between TLR4 polymorphism and glaucoma. The results revealed that TLR4 rs1927911 A/G, rs12377632 C/T, and rs2149356 G/T significantly decrease the risk of POAG and NTG in allele contrast models 0.71-, 0.71-, and 0.67-fold, respectively. Moreover, rs4986790 A/G and rs4986791 C/T showed a stringent association with POAG in allele contrast, heterozygous, recessive, and overdominant models. In conclusion, this meta-analysis represented a significant correlation between TLR4 polymorphisms and both types of glaucoma suggesting that TLR4 might be involved in the pathogenesis of glaucoma and may be applied as a genetic marker for disease screening.

Genetic variants of XRCC1 and risk of hepatocellular carcinoma in chronic hepatitis C patients

BACKGROUND

Hepatitis C virus (HCV) related liver cirrhosis occurs in about 20% of chronically infected patients over a duration of 10-20 years, and within 5 years approximately 10-20% of these cirrhotic patients will develop hepatocellular carcinoma (HCC). Previous studies report that the X-ray repair cross-complementing group1 gene (XRCC1) is important in the risk of HCC development; however, results obtained from these studies are conflicting rather than conclusive. We hypothesised an association between single nucleotide polymorphisms (SNPs) in XRCC1 with the HCC risk on a background of chronic hepatitis C.

MATERIALS AND METHODS

We recruited 210 subjects, 70 with HCC, 70 with cirrhosis and 70 healthy controls. Two SNPs [c.1254C>T(rs2293035) and c.1517G>C(rs139599857)] in XRCC1 were genotyped using created restriction site-polymerase chain reaction (CRS-PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) methods.

RESULTS

The TT genotype, CT genotype and T-allele in c.1254C>T (rs2293035) were linked to risk of HCC compared to the CC genotype: OR 3.58 [confidence interval (CI) 95%: 1.19-10.7] p = 0.019; OR 2.16 (CI 95%: 1.04-4.47) p = 0.037 and OR 2.10 (CI 95%: 1.2-3.3) p = 0.006, respectively. Regarding c.1517G>C (rs139599857), the CC genotype, GC genotype and C-allele were linked with higher risk of developing HCC compared to GG genotype: OR 4.77 (CI 95%: 1.3-16.9), p = 0.016; OR 3.02 (CI 95%: 1.46-6.2), p = 0.002 and OR 2.4 (CI 95%: 1.4-4.0), p = 0.001, respectively.

CONCLUSION

We conclude that the T-allele of c.1254C>T (rs2293035) and the C allele of c.1517G>C (rs139599857) genetic variants may be associated with increased HCC risk among chronic hepatitis C patients.

The associations between Toll-like receptor 4 gene polymorphisms and hepatitis C virus infection: a systematic review and meta-analysis

Background and objective: The hepatitis C virus (HCV) is able to cause a life-threatening disease relating to lethal hepatocellular carcinoma. Previous, Toll-like receptor polymorphisms were proposed as promising biomarker for HCV-related hepatocellular carcinoma and disease progression. This study aimed to summarize the association of TLR4 polymorphisms and HCV infection through meta-analysis.

Methods: We applied a systematic review and meta-analysis performed by using PubMed, EMBASE and Web of Science searches. The Modified Newcastle-Ottawa scale was used for quality assessment. The odd-ratio (OR) and 95% confidence interval (CI) were calculated to assess the association. In silico analysis was applied for proposing the function as microRNA (miRNA) of non-coding polymorphism. Finally, the miRNA target was predicted and annotated to suggest the possible relationship between polymorphism and HCV infection.

Results: Our meta-analysis incorporated seven studies involving rs4986791, rs4986790 and rs2149356. No association exists between rs4986791 and HCV infection. However, the heterozygous model (AG vs GG) of rs4986790 significantly associates with HCV infection (OR = 0.33, 95% CI = 0.21–0.49, P<0.0001). Moreover, the rs2149356 TG genotype also associates with HCV infection in the over-dominant model (TG vs TT+TG: OR = 0.54, 95% CI = 0.40–0.75). In silico analysis of rs2149356G allele showed that this mutation is siRNA, which targets the set of genes, especially in the autophagy pathway.

Conclusion: We demonstrated that rs4986790 and rs2149356 are associated with HCV infection.