Research Of The TLR7Polymorphisms And Antiviral Immunity In Children With EV71Infection

Objective: To explore the relationship within the Toll-like receptor7(TLR7) and it’spolymorphisms in sever children with enterovirus type71(EV71) infection and theantiviral immunity, conditions and prognosis of the disease.Methods:115children with enterovirus71infection and120age-matched healthychildren were enrolled in the study. The patients were divided into two groups according tothe critical degree, severe group and critical group. All came from The ShenZhenChildren’s Hospital, from2012through2013. Genomic DNA was extracted fromperipheral blood leukocytes. PCR assays were performed to amplify the three exons andtheir promoter sequences of TLR7gene, and then subjected to direct DNA sequencing. Themean fluorescent intensity of TLR7on MC was analyzed by flow cytometry. Theconcentrations of cytokines(IFN-α、IL-6、IL-10、IL-12) were measured by cytometric beadarray (CBA).Results:(1)The c.371T>A mutation of TLR7gene exon3was found in18cases withEV71infection, the genotype is hemizygote.(2)The MFI of TLR7on MC of criticalpatients infection with EV71was significantly higher than that in healthy children(p<0.01)and there was no significant difference compared with sever group(p>0.05).(3)Theexpression levers of IL-12and IFN-a in patients infection with EV71was remarkablyhigher than normal group(p<0.01), and the concentration of other cytokines(IL-6、IL-10)had no evident change(p>0.05).Conclusion: The polymorphism of TLR7might be involved in the EV71infection, andthe c.371T>A mutation of TLR7exon3may be the predisposing genes.TLR7mediated the immune dysfunction induced by EV71, make the concentration of the IL-12increased inpatients.