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.