【摘要】 目的:通过对经母婴传播获得HBV感染的子女及其母亲慢性携带者体内HBV EnhII/CP/PreC基因序列研究,了解来源相同的HBV毒株在不同程度病毒血症情况下EnhII/CP/PreC基因变异特点。方法:选择15对母子AsC,根据HBV病毒血症高低分为3组,每组5对母子,即Ⅰ组(母子均为高病毒血症)、Ⅱ组(子女为高病毒血症、母亲为低病毒血症)和Ⅲ组(子女为低病毒血症、母亲为高病毒血症)。同对母子HBV亚型相同,各组中有4/5对母子为B/adw2、1/5对母子为C/adrq+亚型。应用T-A克隆技术构建重组质粒pGEM-EnhII/CP/PreC、双酶切鉴定,每个病人选2个酶切鉴定正确的克隆测序并分析。结果:高病毒血症组间或低病毒血症组间HBV EnhII/CP/PreC基因变异数目及位点均无明显差异,低病毒血症病人变异数目及位点明显高于高病毒血症。高病毒血症中16例B/adw2亚型的32个EnhII/CP共有6个变异位点;4例C/adrq+亚型的8个克隆中有4个变异位点,均无热点变异;PreC无变异。低病毒血症中8例B/adw2亚型病人的16个克隆共有26个变异位点,变异与年龄无关。结论经母婴传播获得HBV感染儿童及其母亲无症状携带者中,HBVEnhII/CP/PreC变异与病毒血症高低有关,低病毒血症病人变异明显高于高病毒血症。HBV的低复制状态是CP、EnhII及X蛋白等结构和功能改变综合影响的结果,与年龄无关。更多还原

【Abstract】 Objective: To invistigate the characteristics of mutations in EnhII/CP/PreC of HBV in AsC children infected through mother-to-infant transmission and their AsC mothers with different degrees of viremia.Methods: There were 15 pairs of children and mothers.They were divided into three groups based on the level of viremia: groupⅠ(both children and mothers presented high viremia),groupⅡ(children presented high and mothers presented low viremia) and groupⅢ(children presented low and mothers were high viremia).There were 5 pairs in each group with 4/5 of HBV being B/adw2 and 1/5 of HBV being C/adrq+ in each group.EnhII/CP/PreC was amplified and cloned into pGEM-T vector.Tow clones were selected to sequence each patient.Results: Substitution was the main model of mutations.There were no significant differences in the mutation numbers in EnhII/CP/PreC among high viremia groups or between two low viremia groups.There were significant differences between each high viremia group and each low viremia group.In patients with high viremia,there were 6 mutational positions in 32 clones in 16/20 patients with B/adw2,and there were 4 mutational positions in 8 clones in 4/20 patients with C/adrq+.In patients with low viremia(mothers of group Ⅱ and children of group Ⅲ),there were 26 mutational positions totally.Conclusion: The mutations in EnhII/CP/PreC are related to the degree of viremia in AsC children infected through mother-to-infant transmission and their AsC mothers,and no associated with age.更多还原