ONCOGENIC POTENTIAL OF HUMAN HERPESVIRUS-6

本研究的目的是确定人类疱疹病毒 6 (HHV-6) 是否 从艾滋病患者中分离出来并与某些 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 少数亚克隆被转染至 NIH 3T3 细胞中。我们的数据证明 NIH 3T3 细胞可以通过以下方法反复进行形态学转化 完整的病毒基因组 (HHV-6) 或亚基因组片段 克隆pZVH14。焦点形成频率明显高于 背景水平。这些焦线表现出致瘤潜力 裸鼠和免疫活性小鼠。此外，致瘤性 转化体也可以通过 DNA 与 新霉素抗性标记。通过组织病理学检查，肿瘤 经鉴定为未分化纤维肉瘤。 Southern 印迹杂交揭示了 pZVH14 DNA 序列的存在 在G418选择的转化细胞系和肿瘤细胞系中，但不在 焦点来源的细胞系。 G418选择的基因组DNA诱导品系是 与 HHV-6 的另一个亚克隆 pZVB70 相关的序列也呈阳性。 在焦点测定中发现该克隆具有弱转化活性。 我们未能检测到焦点衍生系中的 DNA 序列可能是由于 事实上，8.7 kb 探针（pZVH14 插入片段）太大，无法检测到 小片段（< 500bp），即使它存在于转化的细胞系中。 在这些病灶中未发现 pZVH14 DNA 以染色体外形式存在 细胞系。这些数据表明 HHV-6 DNA 可能短暂整合 或者保留一小段无法检测到的 DNA。中学 转化体，通过用基因组 DNA 转染 NIH 3T3 细胞而获得 原代G418选择的转化细胞和肿瘤细胞系，表现出很多 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。该项目是 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.