Properties of hepatitis B virus pre-S1 deletion mutants.
Properties of hepatitis B virus pre-S1 deletion mutants.
复制标题
乙型肝炎病毒前 S1 缺失突变体的特性。
DOI：
10.1006/viro.1994.1127
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发表时间：
1994
期刊：
影响因子：
3.7
通讯作者：
Wands,JR
中科院分区：
文献类型：
--
作者：
Melegari,M;Bruno,S;Wands,JR
10例慢性B型肝炎患者中有2例（20%）在干扰素治疗后血清中检测到B型肝炎病毒（HBV）前S蛋白缺失突变体。这些缺失的大小高达整个前S1区域的一半。在体内，发现所有HBV缺失突变体均与全长“野生型”病毒基因组共存。详细研究了HBV缺失突变体的功能特性，并在所有20个测序的克隆中揭示了前S2开放阅读框中的终止密码子。与野生型病毒相比，由于转录因子结合位点的假定丢失，几种缺失的突变体在培养上清液中产生低水平的HBsAg。在人肝癌细胞（HuH-7）中的转染实验表明，聚合酶基因的功能不受大的前S1缺失和突变的病毒基因组能够复制。然而，失能突变病毒基因组的分泌在HuH-7细胞中被阻断。用仅表达HBV前S1、前S2和S蛋白质的质粒进行共转染研究，导致活性颗粒分泌完全恢复。我们的研究结果表明，体内反式互补现象将不得不发生，以允许从肝脏分泌到血清中的核衣壳含有这些删除的病毒基因组。
Deletion mutants of hepatitis B virus (HBV) pre-S proteins were detected in serum in 2 of 10 (20%) individuals with chronic hepatitis B infection following the initiation of interferon treatment. The size of these deletions was up to one-half of the entire pre-S1 region.In vivo, all HBV deletion mutants were found to coexist with a full-length "wild-type" viral genome. The functional properties of a HBV-deleted mutant were studied in detail and revealed a stop codon in the pre-S2 open reading frame in all 20 of the clones sequenced. Several of the deleted mutants produced low-level HBsAg in culture supernatants compared to wild-type virus due to a putative loss of transcription factor binding sites. Transfection experiments in human hepatoma cells (HuH-7) demonstrated that the polymerase gene function was not affected by the large pre-S1 deletions and mutant viral genomes were capable of replication. However, secretion of incapsidated mutant viral genomes was blocked in HuH-7 cells. Cotransfection studies with a plasmid expressing only the HBV pre-S1, pre-S2, and S proteins resulted in complete restoration of vital particle secretion. Our findings suggest that anin vivotrans-complementation phenomenon would have had to occur to permit secretion from the liver into serum of the nucleocapsids containing these deleted viral genomes.