Association of Toll-Like Receptor 3 and Toll-Like Receptor 9 Single Nucleotide Polymorphisms with Hepatitis C Virus Infection and Hepatic Fibrosis in Egyptian Patients

Association of polymorphisms in TLR3 and TLR7 genes with susceptibility to COVID-19 among Iranian population: a retrospective case-control study

Background and Objectives

Host genetic changes like single nucleotide polymorphisms (SNPs) are one of the main factors influencing susceptibility to viral infectious diseases. This study aimed to investigate the association between the host SNP of Toll-Like Receptor3 (TLR3) and Toll-Like Receptor7 (TLR7) genes involved in the immune system and susceptibility to COVID-19 in a sample of the Iranian population.

Materials and Methods

This retrospective case-control study evaluated 244 hospitalized COVID-19 patients as the case group and 156 suspected COVID-19 patients with mild signs as the control group. The genomic DNA of patients was genotyped for TLR7 (rs179008 and rs179009) and TLR3 (rs3775291 and rs3775296) SNPs using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results

A significant association between rs179008 SNP in the TLR7 gene and the susceptibility of COVID-19 was found between case and control groups. The AT genotype (Heterozygous) of TLR7 rs179008 A>T polymorphism showed a significant association with a 2.261-fold increased odds of COVID-19 (P=0.003; adjusted OR: 2.261; 99% CI: 1.117-4.575). In addition, a significant association between TC genotype of TLR7 rs179009 T>C polymorphism and increased odds of COVID-19 (P<0.0001; adjusted OR: 6.818; 99% CI: 3.149-14.134) were determined. The polymorphism frequency of TLR3 rs3775291 and rs3775296 genotypes were not significantly different between the case and control groups (P> 0.004167).

Conclusion

SNPs in TLR7 rs179008 and rs179009 genotypes are considered host genetic factors that could be influenced individual susceptibility to COVID-19. The SNPs in TLR3 (rs3775296 and rs3775291) showed no significant association with COVID-19 in Iranian population.

Analysis of associations between the TLR3 SNPs rs3775291 and rs3775290 and COVID-19 in a cohort of professionals of Belém-PA, Brazil

The objective of this article was to verify associations between the SNPs rs3775291 (Cytosine [C]>Thymine [T]) and rs3775290 (C>T) of TLR3 in professionals from Health Institutions (HI) who worked during the first pandemic wave and COVID-19. A case-control study was carried out with workers from HI in Belém-PA, Brazil, divided into symptomatology groups (Asymptomatic-AS, n=91; and Symptomatic-SI, n=121), and severity groups, classified by Chest CT scan (symptomatic with lung involvement - SCP, n=34; symptomatic without lung involvement - SSP, n=8). Genotyping was performed by Sanger sequencing and statistical analysis was performed using the SPSS program. In the analysis of SNP rs3775291, the homozygous recessive genotype (T/T) was not found and the frequency of the mutant allele (T) was less than 2% in the cohort. For the rs3775290 SNP, the frequency of the mutant allele (T) was greater than 42% in the cohort. No significant associations were found for these SNPs in this cohort (N= 212 individuals). The scientific community and physicians can use these facts to find new methods of managing COVID-19.

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.

Association of TLR-4 896A/G, TLR-4 1196C/T, and TLR-9 C/T polymorphism with schizophrenia in Indian Bengalee patient

Background

Chronic low-grade inflammation triggered by viral agents is a suggested etiological factor for schizophrenia. However, the underlying mechanism of inflammation and genetic predisposition to schizophrenia is poorly understood. Toll-like receptor (TLR) is a potential candidate gene to understand the inflammatory process and genetic predisposition to schizophrenia as they are known to express widely in brain cells and can modulate cytokine synthesis through recognition of pathogen-associated molecular patterns. To date, no TLR mutations or single nucleotide polymorphisms have been established as accepted risk factors for schizophrenia.

Aim

Therefore, the present investigation was undertaken to study the role of single nucleotide polymorphisms (SNPs) within the TLR genes in the etiopathology of schizophrenia.

Methods

A total of 120 India-born Bengalee schizophrenia patients fulfilling diagnostic and statistical manual of mental disorders-V criteria, and 145 age, sex, and ethnicity-matched healthy controls were included in the study. Previous virally associated SNPs in TLR genes were genotyped by Polymerase chain reaction-restriction fragment length polymorphism assay. The allele frequency was compared using the odds ratio, and the association was studied under five inheritance models using the SNPStats program.

Results

The frequencies of G allele (OR = 2.68, P = 0.01) and A/G genotype of TLR-4 rs4986790 (P = 0.04), T allele (OR = 4.09, P = 0.01) and C/T genotype of TLR-4 rs4986791 (P = 0.05), and T allele of TLR-9 rs352140 (OR = 1.77; P = 0.00) were found to be significantly high in patients. The dominant model was the optimum genetic model for TLR-4 rs4986790 (OR = 3.24, P = 0.01) and TLR-9 rs352140 (OR = 2.88, P = 0.005).

Conclusion

The findings suggest that SNPs in TLR genes rs4986790, rs4986791, and rs352140 may confer susceptibility to schizophrenia among Indian Bengalee patients.

Genetic Polymorphism in Toll-Like Receptor 3 and Interferon Regulatory Factor 3 in Hepatitis C Virus-Infected Patients: Correlation with Liver Cirrhosis

Host genetic factors could play a primary role in determining the risk for cirrhosis development in chronic hepatitis C virus (HCV)-infected patients. We designed this work to study the effect of single-nucleotide polymorphism (SNP) in Toll-like receptor 3 (TLR3) and interferon regulatory factor (IRF) on the risk of HCV-related cirrhosis. This study enrolled 139 Egyptian HCV-infected patients. They were divided into patients with cirrhotic (56) and noncirrhotic (83) liver. Genotyping of rs3775291 F459F (+1234C/T) and rs3775290 L412F (+1377C/T) in TLR3 and IRF3 rs2304204 (-925A/G) was performed by restriction fragment length polymorphism-polymerase chain reaction. Although there is no significant difference in genotype and allele distribution of +1377C/T of TLR3 gene between cirrhotic and noncirrhotic subjects, CC (odds ratio [OR] = 1.572, 95% confidence interval [CI]: 0.781-3.164); TT (OR = 1.463, 95% CI: 0.351-6.104) genotypes might be considered as risk factors for liver cirrhosis. On the contrary, the analysis revealed that only one genotype (CC) and one allele (C) were detected in +1234C/T SNP, with the total disappearance of CT/TT genotypes and T allele in all subjects. On the contrary, lower frequency has been found for the AG genotype of the IRF3 (-925A/G) gene in cirrhotic patients compared with noncirrhotic ones, indicating that AG is a protective genotype (OR = 0.509, 95% CI: 0.256-1.012). Our data stressed the association of AG genotype SNP in IRF3 (-925A/G) in protection against the worth outcome of HCV infection.

Investigating the association of toll-like receptor 9 rs5743836, rs352140, and rs187084 gene polymorphisms and their mRNA levels with different hepatic fibrosis stages of non-alcoholic fatty liver patients compared to healthy controls

Recent studies have shown that the level of hepatocyte-derived mitochondrial DNA is elevated in plasma samples obtained from mice and NASH patients, and it has the ability to toll-like receptor 9 (TLR9) activation resulting in steatosis, hepatocyte injury, and fibrosis. In this study, we explored the association between TLR9 rs5743836, rs352140, and rs187084 polymorphism and its plasma mRNA level in non-alcoholic fatty liver (NAFL) patients with different liver fibrosis scores compared to healthy controls. Seventy Iranian patients diagnosed with NAFL, based on fibroscan testing results, were divided into F0-F1 (N=33), F2-F3 (N=19), and F4 (N=18) hepatic fibrosis groups and compared to 22 healthy controls. Genotyping was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the mRNA expression level of TLR9 was determined using Real-Time PCR analysis. Results showed no significant association between allelic and genotypic distribution frequency of TLR9 rs5743836, rs352140, and rs187084 polymorphisms in NAFL patients with hepatic fibrosis compared to healthy controls (P>0.05). However, the mRNA level of TLR9 was significantly elevated in correlation with hepatic fibrosis progression in NAFL patients compared to healthy controls (P<0.05). As a preliminary study, our data showed a correlative overexpression of TLR9 mRNA with hepatic fibrosis progression in NAFL patients without the effectiveness of TLR9 gene polymorphisms.

Study of Single Nucleotide Polymorphisms in Endosomal Toll-Like Receptors-3, 7, and 9 Genes in Patients With Dengue: A Case-Control Study

Introduction The endosomal toll-like receptors (TLR) TLR3, TLR7, and TLR9 are localized in immune cells, recognize the viral pattern associated molecular pattern (PAMPs), and start signaling cascades for immune defense response and genetic factor is known to affect the dengue virus infection therefore in our study we study the association of endosomal Toll-like receptors 3 polymorphism rs3775291, rs3775290, and rs3775296 with rs179008 A/T and rs179009C/T polymorphisms of TLR7 and rs187084 (C/T), rs5743836 (C/T) of TLR9 gene with dengue and controls. Materials and methods Ninety-eight cases of dengue virus (DV) infection and 98 healthy controls were enrolled. Clinical details were recorded and cases were classified as severe or non-severe dengue, based on WHO 2009 classification. Genotypes were determined by Sanger sequencing using the genetic analyzer. Results An increased risk of DV infection was observed in cases as compared to controls, with TLR 3 rs3775291 CT genotype (OR = 4.34, P-value: 0.031, CI = 1.14-16.5), Likewise in TLR7 rs179008 AT (OR = 2.12, P-value: 0.034, CI = 1.06-4.26) and rs179009 CT (OR = 2.04, P-value: 0.040, CI = 1.03-4.05) same as in TLR9 rs187084 CT (OR = 1.97, P-value: 0.046, CI = 1.013-3.84) and rs5743836 (OR = 2.38, P-value: 0.009, CI = 1.24-5.57). In the above polymorphisms, mutant allele was observed in a significantly higher number in cases. The values are: for TLR3 rs3775291 T allele (OR 2.167, CI = 1.3-3.61, P-value: 0.003). TLR7 rs179008 T allele (OR 1.90, P-value: 0.021, CI = 1.07-3.35) and in TLR9 rs187084 (OR 1.91, P-value: 0.014, CI = 1.137-3.24) rs5743836 (OR 2.29, P-value: 0.0018, CI = 1.36-3.87). No significant association was observed in the genotypic frequency of severe versus non-severe dengue. Conclusion TLR3, 7, and 9 gene polymorphism might confer host genetic susceptibility to dengue in the North Indian population.

The Association of rs1898830 in Toll-Like Receptor 2 with Lipids and Blood Pressure

BACKGROUND AND OBJECTIVE

Toll-like receptors (TLRs) are important components of the innate immune system, involved in establishing immunity to infections. Apart from being implicated in immunity, numerous studies have reported that many TLRs, including TLR2, are involved in the pathogenesis of cardiovascular diseases and their risk factors. Since rs1898830 is associated with TLR2-mediated cellular activation, we aimed to study its association with CVD risk factors, such as lipid levels and hypertension.

METHODS

A cross-sectional study was conducted on 460 individuals free from chronic diseases. Clinical and biological data were collected and DNA was extracted and genotyped using Kompetitive allele specific PCR (KASP™). Multiple logistic regression models, adjusted for six covariates, were used. A power calculation analysis was also performed.

RESULTS

We found that rs1898830 in TLR2 was positively associated with hypertension (OR = 2.18, p = 0.03) and negatively associated with high-density lipoprotein cholesterol (OR = 0.66, p = 0.05). In contrast, no relation was found with total cholesterol and low-density lipoprotein cholesterol.

CONCLUSION

The present results provide additional evidence supporting the implication of TLR2 in CVD risk factors.

Association of TLR3 single nucleotide polymorphisms with susceptibility to HTLV-1 infection in Iranian asymptomatic blood donors

INTRODUCTION:

The human T-lymphotropic virus type 1 (HTLV-1) has a single-stranded RNA genome and expresses specific proteins that have oncogenic potential. Approximately 15 to 20 million people worldwide have been infected by this virus. Changes in protein or gene expression are the effects of single nucleotide polymorphisms (SNPs) within the Toll-like receptor 3 (TLR3) gene. The function and efficacy of signal transduction also lead to modified immune responses. The present study aimed to investigate the association of SNPs within TLR3 (rs3775291 and rs3775296) with susceptibility to HTLV-1 infection in Iranian asymptomatic blood donors.

METHODS:

This study was performed on 100 HTLV-1-infected asymptomatic blood donors and 118 healthy blood donors. Genomic DNA from all participants was purified and then amplified using specific PCR primers. SNPs within TLR3 were evaluated using the restriction fragmentation length polymorphism technique, and the results were analyzed using SPSS software (version 22).

RESULTS:

The frequencies of the TLR3 (rs3775296) CC, CA, AA genotypes were 70%, 24%, and 6% in the patient group, and 50.8%, 44.9%, and 4.2% in the control group, respectively. There was a significant difference in the frequency distribution of TLR3 (rs3775296) genotypes and alleles, but not in the frequency distribution of TLR3 (rs3775291) genotypes between the patient and control groups.

CONCLUSIONS:

The TLR3 SNP rs3775296 was significantly associated with HTLV-1 infection and may be a protective factor against this viral infection.

Evaluation of variants in IL6R, TLR3, and DC-SIGN genes associated with dengue in sampled Colombian population

INTRODUCTION

Host genetics is recognized as an influential factor for the development of dengue disease.

OBJECTIVE

This study evaluated the association of dengue with the polymorphisms rs8192284 for gene IL6R, rs3775290 for TLR3, and rs7248637 for DC-SIGN.

MATERIALS AND METHODS

Of the 292 surveyed subjects, 191 were confirmed for dengue fever and the remaining 101 were included as controls. The genotypes were resolved using polymerase chain reaction and restriction fragment length polymorphism (PCRRFLP). In an attempt to determine the risk (Odds Ratio) of suffering dengue fever, data were analyzed using chi-square for alleles and logistic regression for both genotypes and allelic combinations. Confidence intervals were set to 95% for all tests regardless of the adjustment by either self-identification or ancestry.

RESULTS

For Afro-Colombians, the allele rs8192284 C offered protection against dengue [OR=0.425,(0.204-0.887), p=0.020]. The alleles rs7248637 A and rs3775290 A posed, respectively, an increased risk of dengue for Afro-Colombians [OR=2.389, (1.170-4.879), p=0.015] and Mestizos [OR=2.329, (1.283-4.226), p=0.005]. The reproducibility for rs8192284 C/C [OR=2.45, (1.05-5.76), p=0.013] remained after adjustment by Amerindian ancestry [OR=2.52, (1.04-6.09), p=0.013]. The reproducibility for rs3775290 A/A [OR=2.48, (1.09-5.65), p=0.033] remained after adjustment by European [OR=2.34, (1.02-5.35), p=0.048], Amerindian [OR=2.49, (1.09-5.66), p=0.035], and African ancestry [OR=2.37, (1.04-5.41), p=0.046]. Finally, the association of dengue fever with the allelic combination CAG [OR=2.07, (1.06-4.05), p=0.033] remained after adjustment by Amerindian ancestry [OR=2.16, (1.09-4.28), p=0.028].

CONCLUSIONS

Polymorphisms rs8192284 for IL6R, rs3775290 for TLR3, and rs7248637 for DC-SIGN were associated with the susceptibility to suffer dengue fever in the sampled Colombian population.