NUCLEOTIDE-SEQUENCE AND BIOLOGICAL PROPERTIES OF A PATHOGENIC PROVIRAL MOLECULAR CLONE OF NEUROVIRULENT VISNA VIRUS
NUCLEOTIDE-SEQUENCE AND BIOLOGICAL PROPERTIES OF A PATHOGENIC PROVIRAL MOLECULAR CLONE OF NEUROVIRULENT VISNA VIRUS
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DOI：
10.1006/viro.1993.1106
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发表时间：
1993-03-01
期刊：
影响因子：
3.7
通讯作者：
PETURSSON, G
中科院分区：
文献类型：
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作者：
ANDRESSON, OS;ELSER, JE;PETURSSON, G
用visna病毒KV1514脑内连续传代3只冰岛羊，筛选神经毒力增强的毒株。获得了一株神经致病性增强的菌株KV1772。我们从一个斑块纯化的KV1772生物克隆中分离出几个原病毒分子克隆，这些克隆在幼羊中诱导了典型的visna病毒病理。其中一个克隆（kv72）具有传染性，而其他克隆含有突变或被置换，需要与其他原病毒克隆基因重组才能在转染后产生传染性病毒。利用原病毒分子克隆构建了含有功能完整的visna病毒KV1772基因组的稳定质粒。来自这些克隆的病毒的卵细胞病变作用因感染细胞的组织来源而异。山羊细胞系持续感染分子克隆KV1772病毒这些细胞抵抗了细胞杀伤效应，并不断释放出高水平的传染性病毒。我们确定了KV1772原病毒的完整核苷酸序列；它包含先前在visna病毒基因组中鉴定的所有结构和辅助基因的开放阅读框，并且与其他已发表的visna病毒序列高度同源。分子克隆的KV1772病毒的后代在实验感染的冰岛幼羊中迅速引起明显的神经病理和意想不到的强烈中和抗体反应。现在，具有复制能力和致病性的visna病毒原病毒分子克隆的稳定质粒的可用性，将使研究visna病毒发病机制中神经毒性的遗传决定因素及其与宿主免疫系统的相互作用成为可能。
Intracerebral serial passage of visna virus KV1514 through three icelandic sheep was used to select for strains with increased neurovirulence. A strain (KV1772) with increased neuropathogenicity was obtained. We isolated several proviral molecular clones from a plaque-purified biological clone of KV1772 that induced typical visna virus pathology in young sheep. One of the clones (kv72) was infectious, while others contained mutations or were permuted and required gene recombination with other proviral clones to generate infectious virus after transfection. Stable plasmids containing functional, full-length, visna virus KV1772 genomes were constructed from the proviral molecular clones. Thein vitrocytopathic effects of virus derived from these clones varied depending upon the tissue origin of the infected cells. A goat cell line became persistently infected with molecularly cloned KV1772 virus; these cells resisted the cell-killing effects and continuously shed high levels of infectious virus. We determined the complete nucleotide sequence of a KV1772 provirus; it contains open reading frames for all structural and accessory genes previously identified in the visna virus genome and is highly homologous to other published visna virus sequences. Progeny of molecularly cloned KV1772 virus rapidly induced both a pronounced neuropathology and an unexpected, strong, neutralizing antibody response in experimentally infected young Icelandic sheep. The availability of stable plasmids of replication-competent and pathogenic proviral molecular clones of visna virus should now enable the study of the genetic determinants of neurovirulence and their interaction with the host immune system in visna virus pathogenesis.