Evidence against a requisite role for defective virus in the establishment of persistent hepadnavirus infections.
Evidence against a requisite role for defective virus in the establishment of persistent hepadnavirus infections.
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证据表明缺陷病毒在建立持续性肝炎病毒感染中发挥必要作用。
DOI：
10.1073/pnas.87.23.9329
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发表时间：
1990
影响因子：
11.1
通讯作者：
Purcell,RH
中科院分区：
文献类型：
--
作者：
Miller,RH;Girones,R;Cote,PJ;Hornbuckle,WE;Chestnut,T;Baldwin,BH;Korba,BE;Tennant,BC;Gerin,JL;Purcell,RH
持续性嗜肝DNA病毒感染的建立所涉及的因素知之甚少。最近的研究结果表明，B肝炎病毒（HBV）的基因组序列是可变的感染个体，在某些情况下，病毒突变体占主导地位。本研究的目的是分析土拨鼠肝炎病毒（WHV）基因组在感染动物中的变异性，并确定序列异质性是否在WHV诱导慢性感染的能力中起关键作用。我们克隆并确定了来自接种标准化WHV血清池后感染的动物的三个超螺旋基因组的完整核苷酸序列（即，WHV 7病毒库）。我们发现在三个基因组序列中有四个核苷酸替换，以及在一个重组体中有73个核苷酸缺失。DNA转染实验表明，三个重组体中只有一个能够独立复制。这些数据表明，在感染WHV的土拨鼠中，很大一部分复制模板是有缺陷的病毒基因组。接下来，我们比较了用含有均匀的可复制病毒群体的血清池接种后急性感染的结果（即，WHV 7R库）与由可变序列的WHV基因组组成的血清库。WHV 7 R血清池源自土拨鼠，该土拨鼠在用感染性WHV 7重组体体内转染肝脏后成为慢性携带者。新生土拨鼠接种5 × 106个WHV基因组当量的WHV 7库或WHV 7R库。研究中的所有动物均急性感染WHV。在感染WHV 7血清池的动物中，65%成为慢性携带者，而80%感染WHV 7R血清池的动物发展为慢性感染。因此，用含有缺陷病毒的血清池感染土拨鼠，导致慢性WHV感染率与仅含有野生型病毒的血清池的感染率相似，甚至更低。这表明接种物中存在缺陷病毒不是建立持续嗜肝DNA病毒感染的先决条件。
The factors involved in the establishment of persistent hepadnavirus infection are poorly understood. Recent findings demonstrate that the sequence of the genome of hepatitis B virus (HBV) is variable in infected individuals and that, in some cases, virus mutants predominate. Our objectives in the present study were to analyze the variability of woodchuck hepatitis virus (WHV) genomes in an infected animal and to determine whether sequence heterogeneity played a critical role in the ability of WHV to induce chronic infection. We cloned and determined the complete nucleotide sequence of three supercoiled genomes from an animal that became infected after inoculation with a standardized WHV serum pool (i.e., the WHV7 virus pool). We found that there were four nucleotide substitutions among the three genome sequences as well as a 73-nucleotide deletion in one of the recombinants. DNA transfection experiments revealed that only one of the three recombinants was capable of independent replication. These data suggest that a significant proportion of replicative templates in woodchucks that are infected with WHV are defective virus genomes. Next, we compared the outcome of acute infection after inoculation with a serum pool containing a uniform population of replication competent virus (i.e., the WHV7R pool) with a serum pool composed of WHV genomes of variable sequence. The WHV7R serum pool originated from a woodchuck that became a chronic carrier after in vivo transfection of the liver with the infectious WHV7 recombinant. Neonatal woodchucks were inoculated with 5 x 10(6) WHV genome equivalents of either the WHV7 pool or the WHV7R pool. All animals in the study became acutely infected with WHV. Of the animals infected with the WHV7 serum pool, 65% became chronic carriers, while 80% of the animals infected with the WHV7R serum pool developed chronic infection. Thus, infection of woodchucks with a serum pool containing defective virus resulted in a rate of chronic WHV infection that was similar to, or even lower than, a rate from a pool containing only wild-type virus. This suggests that the presence of defective virus in the inoculum is not a prerequisite for the establishment of persistent hepadnavirus infections.