IFN-γ+874位点单核苷酸多态性和蛋白表达水平与肠道病毒71感染关系

RELATIONSHIP BETWEEN THE PLASMA LEVEL OF IFN-γ AND THE POLYMORPHISM OF IFN-γ SINGLE NUCLEOTIDE WITH ENTEROVIRUS 71 INFECTION

目的研究干扰素Ⅱ型(IFN-γ)基因+874位点单核苷酸多态性及IFN-γ在血清中表达水平与肠道病毒71(EV71)感染的关系,探讨EV71感染的遗传易感因素。方法取急性期手足口病病儿粪便进行病毒分离,序列特异性引物-聚合酶链反应(PCR-SSP)技术检测EV71感染者及正常对照儿童IFN-γ基因第一内含子+874位点T/A单核苷酸多态性;ELISA法测定血清中IFN-γ的表达水平。结果 78例手足口病病儿中有43例为EV71感染。EV71感染病儿血清中IFN-γ的水平显著高于正常对照组(t=6.477,P<0.01)。EV71感染病儿IFN-γ基因型与对照组比较差异有显著性(2χ=6.149,P<0.05)。EV71感染病儿等位基因频率与对照组比较差异有显著性(2χ=7.486,P<0.05)。EV71一般感染组IFN-γ基因型分布与脑炎组相比,差异无显著意义(P>0.05),脑炎组IFN-γ等位基因A频率明显高于一般感染组(χ2=6.211,P<0.05)。结论 IFN-γ表达水平和其基因第一内含子+874位点多态性与EV71感染有关,与是否发生EV71脑炎有一定相关性。

Objective To study the relationship between the plasma level of interferon-gamma（IFN-γ） and the polymorphism of IFN-γ single nucleotide（SNP） with the enterovirus71（EV71） infection. Methods Reverse transcription polymerase chain reaction（RT-PCR） was used to detect the specific primers of EV71 in the faeces of patients with hand,foot and mouth disease（HFMD）.The plasma levels of IFN-γ were detected by enzyme-linked immunosorbent assay. Results EV71 was positive in 43 specimens from 78 children with HFMD.Compared with that of the normal children,the plasma levels of IFN-γ of the patients were significantly increased（t=6.477,P0.01）.In EV71 group AA genotype was more common than in the normal group（χ2=6.149,P0.05）.In EV71 group,the IFN-γ A allele was more common than in normal immune group（χ2=7.486,P0.05）.In EV71 group,there was no significant difference in the distribution of frequency of IFN-γ gene＋874 site between encephalitis children and non-encephalitis children（P0.05）,but A allele frequency was higher in encephalitis（χ2=6.211,P0.05）. Conclusion Plasma level of IFN-γ expression and the polymorphism of IFN-γ ＋874A/T single nucleotide may co-relate with the enterovirus71 infection,and,with the susceptibility of individual to encephalitis.