Hot-spot variations of Kaposi's sarcoma-associated herpesvirus latent nuclear antigen and application in genotyping by PCR-RFLP.
Hot-spot variations of Kaposi's sarcoma-associated herpesvirus latent nuclear antigen and application in genotyping by PCR-RFLP.
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DOI：
10.1099/0022-1317-81-8-2049
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发表时间：
2000-08
期刊：
影响因子：
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通讯作者：
Yan Jin Zhang;Jian‐Hong Deng;Charles S. Rabkin;Shou‐Jiang Gao
中科院分区：
文献类型：
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作者：
Yan Jin Zhang;Jian‐Hong Deng;Charles S. Rabkin;Shou‐Jiang Gao
卡波西肉瘤相关疱疹病毒（KSHV，人类疱疹病毒-8）在病因学上与卡波西肉瘤和其他几种淋巴组织增生性疾病相关。KSHV ORF 73编码的潜伏核抗原（latent nuclear antigen，LNA）在病毒潜伏感染中具有重要作用，并具有分子多态性。在ORF 73的内部重复结构域（IRD）中鉴定了序列变异。对KSHV感染细胞系PK-1的ORF 73进行DNA测序，结果显示，与BC-1 KSHV的ORF 73相比，IRD的ORF 73有558 bp（30.2%）的缺失和66个（3.6%）的点突变，主要位于重复区2（富含谷氨酰胺的区域）。ORF 73的相似序列变异也在另外两个分离株中鉴定。在这四个KSHV分离株中，没有一个序列变异引起任何翻译移码，表明LNA在病毒潜伏感染中具有保守的功能。26个KSHV分离株的ORF 73 IRD重复序列第2区也存在变异，提示该区域是KSHV基因变异的“热点”。每个卡波西肉瘤病变样本包含一个病毒基因型与一个独特的RFLP模式，表明在体内KSHV感染建立了单一的占主导地位的基因型，这是进一步支持的存在不变的基因型在多灶性病变从个别KS患者。根据代表ORF 73 IRD中DNA序列变异模式的RFLP模式，将KSHV分为四种亚型。PCR-RFLP基因分型技术可用于KSHV分子流行病学研究。
Kaposi's sarcoma-associated herpesvirus (KSHV, human herpesvirus-8) is aetiologically associated with Kaposi's sarcoma and several other lymphoproliferative disorders. The latent nuclear antigen (LNA) encoded by KSHV ORF73 has important functions in virus latent infection and shows molecular polymorphism. Sequence variations were identified in the internal repeat domain (IRD) of ORF73. DNA sequencing of ORF73 from one KSHV-infected cell line, PK-1, revealed that there were 558 bp (30.2%) deletions and 66 (3.6%) point mutations located mainly in repeat region 2, the glutamine-rich region of ORF73 IRD, compared with ORF73 of BC-1 KSHV. Similar sequence variations of ORF73 were also identified in two other isolates. None of the sequence variations caused any translational frame-shift in these four KSHV isolates examined, suggesting that LNA has a conservative function in virus latent infection. The frequent sequence variations in repeat region 2 of ORF73 IRD were also identified by PCR-RFLP genotyping in 26 KSHV isolates, suggesting that this region is a 'hot-spot' for genetic variations. Each Kaposi's sarcoma lesion sample contained one virus genotype with a unique RFLP pattern, indicating that in vivo KSHV infection was established with single predominate genotypes, which was further supported by the presence of invariable genotypes in multifocal lesions from individual KS patients. Four KSHV subtypes were classified based on the RFLP patterns that represent the patterns of DNA sequence variations in the ORF73 IRD. PCR-RFLP genotyping is capable of identifying LNA genetic variations and differentiating individual KSHV isolates, and thus may be useful for KSHV molecular epidemiology studies.