Correlations of gene polymorphism of interferon-induced proteins

比较29例无症状丙型肝炎病毒(ASC)携带者和60例慢性丙型肝炎(CH)患者mxA基因启动子区单核苷酸多态性(SNP)。所有患者均给予书面知情同意书。根据Hijikata等人的报告，采用基于聚合酶链式反应的限制性片段长度多态性(RFLP)方法检测MxA基因的SNP。从2 0 0μ1的全血中提取DNA。DNA经聚合酶链式反应扩增出覆盖mxA启动子区域的599个核苷酸片段(NT-567-NT+30)。聚合酶链式反应产物经HAI消化后，经5%聚丙烯酰胺凝胶电泳，MXA基因启动子nT-88位G/T杂合子在AsC组的发生率(66%)显著高于CH组(28%)(p=0.008)。G/G纯合子在ASC中的发生率(17%)显著低于CH(52%)(p=0.019)。T等位基因频率在ASC组(50%)显著高于CH组(34%)(p=0.042)，在给予干扰素后，NT-88的T携带者比G的携带者更有效地表达MxA蛋白。因此，T携带者在感染的早期，即肝炎发生和内源性干扰素释放时，可以很容易地通过MxA蛋白清除丙型肝炎病毒。这可能是ASC组T等位基因频率显著高于CH组的原因。

Single nucleotide polymorphism (SNP) in promoter region of MxA gene was compared between 29 asymptomatic carriers of hepatitis C virus (ASC) and 60 patients with chronic hepatitis C (CH). All patients gave written informed consents. SNP of MxA gene was determined by polymerase chain reaction-based restriction fragment length polymorphism (RFLP) according to the report of Hijikata et al. DNA was extracted from 200μ1 of whole blood. DNA was subjected to PCR for amplifying a 599-nt DNA fragment that covers the promoter region of MxA (nt-567-nt+30). Products of PCR were digested with HhaI and electrophoresed in 5% polyacrylamide gel.G/T heterozygote at nt-88 of promoter of MxA gene was significantly more frequently detected in ASC (66%) than in CH (28%)(p=0.008). G/G homozygote was significantly less frequently detected in ASC (17%) than in CH (52%)(p=0.019). T allele frequency was significantly higher in ASC (50%) than in CH (34%)(p=0.042).Carriers of T at nt-88 express MxA protein more efficiently than those of G when given interferon. Thus the carriers of T could easily clear hepatitis C virus by MxA protein in the early stage of infection, when hepatitis occurs and intrinsic interferon is released. This may be the reason why T allele frequency was significantly higher in ASC than in CH.