Project description:TLR3 and IL-10 play a crucial role in antiviral defence. However, there is a controversy between TLR3 rs3775291 and IL-10 rs1800871 polymorphisms and the risk of hepatitis B virus (HBV) infection. The purpose of this study is to explore the relationship between the two single nucleotide mutations and the risk of HBV infection by meta-analysis. Medline, EMBASE, Web of Science, CNKI, China Wanfang database were searched for the case-control studies on the relationship between TLR3 rs3775291 and IL-10 rs1800871 polymorphism and susceptibility to HBV, updated to June 2020. The data were analysed by Stata 15.0 software. A total of 22 articles were included. The results showed that in the analysis of IL10 rs1800871 polymorphism and the risk of HBV infection, the pooled OR was 1.21 (95% CI 1.06-1.37), 1.28 (95% CI 1.04-1.56) and 1.20 (95% CI 1.06-1.37) and 1.40 (95% CI 1.07-1.83) in the allele model (C vs. T), dominant model (CC+CT vs. TT), recessive model (CC vs. CT+TT) and homozygous model (CC vs. TT), respectively. There was no statistical significance in the heterozygote model. A subgroup analysis of the Asian population showed similar results. The analysis of TLR3 rs3775291 polymorphism and the risk of HBV showed that in the allele model (T vs. C), the pooled OR was 1.30 (95% CI 1.05-1.61). Except for the recessive model, no significances were found in other genetic models. In conclusion, TLR3 rs3775291 and IL-10 rs1800871 polymorphisms are associated with the risk of HBV. Allele C and genotype CC at IL10 rs1800871 loci, as well as allele T and genotype TT at TLR rs3775291 loci, may increase susceptibility to Hepatitis B infection.
Project description:BackgroundTLR3 recognizes dsRNA and triggers immune responses against RNA and DNA viruses. A polymorphism in TLR3, rs3775291 (Leu412Phe), has been associated with the increased susceptibility to enteroviral myocarditis, protection against tick-borne encephalitis virus and HIV-1 infection. We investigated Caucasian intravenous drug users (IDUs) and blood donors in order to evaluate the associations between TLR3 genotypes and susceptibility to HIV infection.Materials and methodsA total of 345 Caucasian IDUs were recruited, 50% of them were HIV positive, 89% HCV and 77% HBV positive. Based on their history of needle sharing, 20 of the HIV negative IDUs were classified as highly exposed HIV seronegatives (HESNs), 68 as non-HESNs and 85 as unexposed. The control group consisting of 497 blood donors tested negative for all three viruses. TLR3 rs3775291 were determined by using TaqMan Allelic Discrimination Assay.ResultsThe TLR3 rs3775291 T allele frequency was similar among the HIV negative and HIV positive IDUs and blood donors - 36%, 31% and 34%, respectively. The frequency of persons possessing at least one TLR3 rs3775291 T allele was significantly higher in HESNs compared with blood donors and HIV positive IDUs (80% vs. 55%; p=0.037 and 80% vs. 53%; p=0.031, respectively). In the univariate analysis, persons who possessed at least one T allele had reduced odds of being HIV seropositive (OR=0.29, 95% CI=0.09-0.90). This association remained significant (OR=0.25, 95% CI=0.07-0.87) after the adjustment for other co-variates (HCV, HBV serostatus and duration of intravenous drug use).ConclusionsThe TLR3 rs3775291 T allele has a protective effect against HIV infection among HESNs IDUs.
Project description:BackgroundSingle-nucleotide polymorphisms in microRNAs play important roles in oncogenesis and cancer development. Objective. We aim to explore whether miR-646 rs6513497 is associated with the risk of hepatocellular carcinoma.MethodsTotal 997 HCC patients and 993 cancer-free controls were enrolled in this study. Genotyping was performed using MassARRAY method.ResultsCompared with the T allele of rs6513497, the G allele was associated with a significantly decreased risk of HCC (OR = 0.788, 95% CI = 0.631-0.985, P = 0.037); moreover, a more protective effect of the G allele was shown in males (OR = 0.695, 95% CI = 0.539-0.897, P = 0.005 in HCC and OR = 0.739, 95% CI = 0.562-0.972, P = 0.030 in HBV-related HCC), basically in a dominant manner (HCC: OR = 0.681, 95% CI = 0.162-0.896, P = 0.006; HBV-related HCC: OR = 0.715, 95% CI = 0.532-0.962, P = 0.027).ConclusionsOur findings support the view that the miR-646 SNP rs6513497 may contribute to the susceptibility of HCC.
Project description:Advances in next-generation sequencing technology have enabled systematic exploration of the contribution of rare variation to Mendelian and complex diseases. Although it is well known that population stratification can generate spurious associations with common alleles, its impact on rare variant association methods remains poorly understood. Here, we performed exhaustive coalescent simulations with demographic parameters calibrated from exome sequence data to evaluate the performance of nine rare variant association methods in the presence of fine-scale population structure. We find that all methods have an inflated spurious association rate for parameter values that are consistent with levels of differentiation typical of European populations. For example, at a nominal significance level of 5%, some test statistics have a spurious association rate as high as 40%. Finally, we empirically assess the impact of population stratification in a large data set of 4,298 European American exomes. Our results have important implications for the design, analysis, and interpretation of rare variant genome-wide association studies.
Project description: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.
Project description:As the host's first line of defense against pathogens, Toll-like receptors (TLRs), such as the TLR3, are genes encoding transmembrane receptors of the same name. Depending on their expression, TLRs cause a pro- or anti-inflammatory response. The purpose of the article was to determine whether there is an association between the Toll-like receptor 3 (TLR3) rs3775291 Single Nucleotide Polymorphism-SNP and susceptibility to infections. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and was registered in PROSPERO under the code CRD42023429533. A systematic search for relevant studies was performed using PubMed, Scopus, SciELO, Google Scholar, and Science Direct by the MeSH descriptors and the Boolean Operator "AND": "Infections"; "TLR3"; "SNP", between January 2005 and July 2022. Summary odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated for genotypic comparison assuming a dominant genetic model (CT + TT vs. CC). A meta-analysis of 18 studies consisting of 3118 cases and 4368 controls found a significant association for risk between the presence of the TLR3 SNP rs3775291 and infections as part of the general analysis (OR = 1.16, 95% CI = 1.04-1.28, p = 0.004). In the subgroups of continents, the SNP had a protective role in Europe for 1044 cases and 1471 controls (OR = 0.83, 95% CI = 0.70-0.99, p = 0.04); however, the Asian (for 1588 patients and 2306 controls) and American (for 486 patients and 591 controls) continents had an increase in infectious risk (OR = 1.37, 95% CI = 1.19-1.58, p < 0.001; OR = 1.42, 95% CI = 1.08-1.86, and p = 0.01, respectively). Heterogeneity between studies was detected (I2 = 58%) but was explained in meta-regression by the subgroup of continents itself and publication bias was not evident. The results of the meta-analysis suggest a significant association between the TLR3 rs3775291 polymorphism and susceptibility to infections. Thus, when analyzing subgroups, the Asian and American continents showed that this SNP confers a higher risk against infections in a dominant genotypic model. Therefore, more studies are necessary to fully elucidate the role of TLR3 rs3775291 in infections.
Project description:Population stratification is a well-known confounding factor in both common and rare variant association analyses. Rare variants tend to be more geographically clustered than common variants, because of their more recent origin. However, it is not yet clear if population stratification at a very fine scale (neighboring administrative regions within a country) would lead to statistical bias in rare variant analyses. As the inclusion of convenience controls from external studies is indeed a common procedure, in order to increase the power to detect genetic associations, this problem is important. We studied through simulation the impact of a fine scale population structure on different rare variant association strategies, assessing type I error and power. We showed that principal component analysis (PCA) based methods of adjustment for population stratification adequately corrected type I error inflation at the largest geographical scales, but not at finest scales. We also showed in our simulations that adding controls obviously increased power, but at a considerably lower level when controls were drawn from another population.
Project description:Toll-like receptor 3 (TLR3) is a pattern recognition receptor mainly known for its role in innate immune response to infection. Indeed, binding of double-stranded RNA (dsRNA) to TLR3 triggers a pro-inflammatory cascade leading to cytokine release and immune cell activation. Its anti-tumoral potential has emerged progressively, associated with a direct impact on tumor cell death induction and with an indirect action on immune system reactivation. Accordingly, TLR3 agonists are currently being tested in clinical trials for several adult cancers. Meanwhile, TLR3 variants have been linked to auto-immune disorders, and as risk factors of viral infection and cancers. However, aside from neuroblastoma, TLR3 role in childhood cancers has not been evaluated. Here, by integrating public transcriptomic data of pediatric tumors, we unveil that high TLR3 expression is largely associated with a better prognosis in childhood sarcomas. Using osteosarcomas and rhabdomyosarcomas as models, we show that TLR3 efficiently drives tumor cell death in vitro and induces tumor regression in vivo. Interestingly, this anti-tumoral effect was lost in cells expressing the homozygous TLR3 L412F polymorphism, which is enriched in a rhabdomyosarcomas cohort. Thus, our results demonstrate the therapeutic potential associated with the targeting of TLR3 in pediatric sarcomas, but also the need to stratify patients eligible for this clinical approach with respect to the TLR3 variants expressed.