ONCOGENIC POTENTIAL OF HUMAN HERPESVIRUS-6

本研究的目的是确定人类疱疹病毒-6（HHV-6）， 分离自艾滋病患者并与某些B细胞淋巴瘤相关， 含有转化DNA序列。为了测试这一点，HHV-6基因组DNA和一个 少数亚克隆转染NIH 3 T3细胞。我们的数据表明 NIH 3 T3细胞可以通过以下方式反复进行形态学转化： 无论是完整的病毒基因组（HHV-6）或亚基因组片段， 克隆pZVH 14。病灶形成的频率明显高于对照组。 背景水平。这些焦点线表明， 裸鼠和免疫活性小鼠。此外，致瘤性 转化体也可以通过将DNA与 新霉素抗性标记通过组织病理学检查， 被鉴定为未分化纤维肉瘤。 Southern印迹杂交显示存在pZVH 14 DNA序列 在G418选择的转化细胞系和肿瘤细胞系中， 焦点来源的细胞系。G418选择的基因组DNA诱导系是 与HHV-6的另一个亚克隆pZVB 70相关的序列也呈阳性。 在焦点测定中发现该克隆具有弱的转化活性。 我们未能在焦点衍生系中检测到DNA序列可能是由于 由于8.7kb探针（pZVH 14插入物）太大而不能检测到 小片段（<500 bp），即使其存在于转化细胞系中。 pZVH 14 DNA在这些病灶中未发现以染色体外形式存在 细胞系这些数据表明，HHV-6 DNA可能是瞬时整合的 或者保留了一小段不能被检测到的DNA。二次 转化子，通过用来自 原代G418选择的转化细胞系和肿瘤细胞系，表现出许多 比原代转化体具有更高的致瘤活性。这些数据 确定HHV-6含有转化DNA序列。该项目 仍然活跃。

The purpose of this study is to determine if human herpesvirus-6 (HHV-6), isolated from AIDS patients and associated with some B-cell lymphomas, contains transforming DNA sequences. To test this, HHV-6 genomic DNA and a few subclones were transfected into NIH 3T3 cells. Our data demonstrated that the NIH 3T3 cells can be repeatedly morphologically transformed by either the complete viral genome (HHV-6) or the subgenomic fragment in clone pZVH14. The frequency of focus formation was significantly above the background level. These focal lines demonstrated tumorigenic potential in both nude mice and immunocompetent mice. Moreover, tumorigenic transformants could also be derived by cotransfection of the DNA with a neomycin resistant marker. By histopathological examination, the tumors were identified to be undifferentiated fibrosarcomas. Southern blot hybridization revealed the presence of pZVH14 DNA sequences in the G418 selected transformed and tumor cell lines but not in the focus-derived cell lines. The G418 selected genomic DNA-induced lines were also positive for sequences related to another subclone pZVB70 of HHV-6. This clone was found to have weak transforming activity in a focus assay. Our failure to detect DNA sequences in the focus-derived lines could be due to the fact that 8.7 kb probe (pZVH14 insert) is too large to detect a small fragment (< 500bp) even if it exists in the transformed cells lines. pZVH14 DNA was not found to exist as extrachromosomal forms in these focal cell lines. These data suggest that HHV-6 DNA may be transiently integrated or a small piece of DNA is retained which could not be detected. Secondary transformants, derived by transfecting NIH 3T3 cells with genomic DNAs from the primary G418 selected transformed and tumor cell lines, exhibited much higher tumorigenic activity than the primary transformants. These data establish that HHV-6 contains transforming DNA sequences. The project is still active.