Single nucleotide polymorphisms of toll-like receptor 7 in hepatitis C virus infection patients from a high-risk chinese population.

Hepatitis C virus (HCV) infection varies in the outcomes depending on both viral and host factors. This study aims to investigate the associations of three single nucleotide polymorphisms (SNPs) of Toll-like receptor 7 (TLR7), rs179016, rs5743733, and rs1634323, with susceptibility to HCV infection and clearance. The three SNPs were genotyped in a high-risk Chinese population, including 444 HCV spontaneous clearance cases, 732 persistent infection cases, and 1107 healthy controls. The G allele of rs1634323 was related to the protection from persistent infection among females (dominant model: odds ratio (OR) = 0.558, 95 % confidence interval (CI) = 0.348-0.894, P = 0.015). This protective effect was more evident in blood donation and HCV non-1 genotype-infected subgroups (all P < 0.05). The carriage of rs179016 C allele was more prone to develop persistent infection (OR = 1.444, 95 % CI = 1.096-1.903, P = 0.009) in males, and the risk effect remained significant among older (>50 years), hemodialysis (HD), and HCV-1 and HCV non-1 genotypes-infected subjects (all P < 0.05). Haplotype analyses showed that CCA haplotype among females was correlated with the elevated risk of HCV susceptibility while the carriage of GGA was more prone to be infected with HCV and CCA was more likely to develop persistent infection (all P < 0.05) among males. Our results first demonstrated that the carriage of rs179016 C allele had a negative effect on spontaneous clearance of HCV among males while rs1634323 G allele conferred a protective effect against persistent infection among female subjects.

Meta-analysis of associations of IL1 receptor antagonist and estrogen receptor gene polymorphisms with systemic lupus erythematosus susceptibility.

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects a number of different organs and tissues. Interleukin-1 (IL1) and estrogen are considered potential elements in the pathology of SLE. Recently, the variable number of tandem repeats (VNTR) polymorphism in the IL1 receptor antagonist gene (IL1-RN) and PvuII (rs2234693) and XbaI (rs9340799) polymorphisms in the estrogen receptor 1 gene (ESR1) have been associated with a predisposition to SLE. However, the evidence for these associations is inconclusive. We therefore conducted a meta-analysis to validate the roles of these polymorphisms in SLE susceptibility. We searched four databases and identified a total of 17 eligible articles comprising 24 studies. The Newcastle-Ottawa quality assessment scale was used to assess the qualities of the selected studies. We assessed the strengths of the associations using odds ratios (ORs) with 95% confidence intervals (95% CIs). Regarding the IL-1RN VNTR, the 2 allele significantly increased SLE susceptibility (2 vs. L: OR = 1.34, 95% CI = 1.03-1.73, P = 0.03). The ESR1 PvuII CC/CT genotype was also associated with SLE susceptibility (CC/CT vs. TT: OR = 1.25, 95% CI = 1.06-1.47, P = 0.01), and the difference was especially pronounced among Asians (CC/CT vs. TT: OR = 1.33, 95% CI = 1.04-1.69, P = 0.02). No significant association between the ESR1 XbaI polymorphism and SLE susceptibility was observed in the overall analysis. However, a marginally significant association between the GG/GA genotype was found in individuals of Asian descent (GG/GA vs. AA: OR = 1.30, 95% CI = 1.01-1.67, P = 0.04). These results indicate that the IL1-RN VNTR 2 allele, ESR1 PvuII CC/CT genotype and ESR1 XbaI GG/GA genotype may increase SLE susceptibility, especially in Asian individuals.

Toll-like receptor 7 variations are associated with the susceptibility to HCV infection among Chinese females.

Toll-like receptors 7 (TLR7) play a crucial role in provoking an immune response in HCV infection. We aimed to investigate whether single nucleotide polymorphisms (SNPs) of TLR7, including rs179009, rs179010 and rs179012, affect the outcomes of HCV infection among the Chinese population. A total of 1767 Chinese Han individuals were enrolled. The distribution of SNP frequencies among three groups with different outcomes of HCV infection was assessed, including healthy controls, cases with spontaneous clearance and cases with viral persistence. Then TLR7 mRNA expression and the production of IFN-α and IL-6 after TLR7 agonist Imiquimod stimulation in vitro were determined. Our results suggested that rs179009 GG genotype was significantly associated with a higher risk of the susceptibility to HCV infection among female subjects (OR=2.42, 95% CI=1.24-4.71, P=0.01). Haplotype GCG was significantly associated with a high risk for HCV susceptibility (OR=1.50, 95% CI=1.11-2.03, P=0.01) as compared with the reference haplotype ACG among females. In the functional research of rs179009, a lower IFN-α level was observed in GG genotype than in AA genotype (P=0.032). Our data indicate that TLR7 rs179009 GG genotype and haplotype GCG were associated with an increased risk of the susceptibility to HCV infection among Chinese females, which may be due to the impaired IFN-α response.

Sex-specific association between X-linked Toll-like receptor 7 with the outcomes of hepatitis C virus infection.

Toll-like receptor 7 (TLR7) senses hepatitis C virus (HCV) infection and drives the host specific innate and adaptive immune response. The aim of this study was to estimate the distributions of TLR7 single nucleotide polymorphisms (SNPs), including rs179019 and rs3853839, as well as the effect of TLR7 gene variants on TLR7 mRNA expression and cytokine production in response to TLR7 agonist in vitro. TLR7 SNP genotyping was performed among a Chinese sample population of 418 patients with persistent HCV infection, 317 patients with HCV spontaneous clearance, and 989 healthy controls. TLR7 mRNA expression and TLR7-specific IFN-α and IL-6 secretion in peripheral blood mononuclear cells, derived from 60 healthy individuals in vitro, were then quantified. We identified the association of TLR7 rs3853839C allele, haplotype CC and haplotype AC (rs179019/rs3853839) with protection against HCV persistence in Chinese females (OR=0.49, 95% CI=0.29-0.81, P=0.01 for rs3853839 GC; OR=0.29, 95% CI=0.11-0.75, P=0.01 for rs3853839 CC; OR=0.51, 95% CI=0.38-0.77, P<0.01 for haplotype CC; OR=0.29, 95% CI=0.10-0.88, P=0.03 for haplotype AC). In addition, the rs3853839 CC genotype among female carriers had significantly low TLR7 mRNA expression (P=0.006 for GG vs. CC, P=0.021 for GC vs. CC), along with decreased IFN-α (P=0.002 for GG vs. CC, P=0.021 for GC vs. CC) and increased antiviral IL-6 production (P=0.002 for GG vs. CC, P=0.030 for GC vs. CC), after treatment with Imiquimod in vitro. The cytokine profile among rs3853839 CC genotype female carriers may indicate a pronounced protective effect against persistent HCV infection. The functional polymorphism of TLR7 rs3853839C allele was found to be sex-specific and associated with protection against HCV persistence among Chinese females, which may be due to specific IFN-α and IL-6 secretion profiles.