ONCOGENIC POTENTIAL OF HUMAN HERPESVIRUS-6

本研究的目的是确定人类疱疹病毒6型(HHV-6)， 从艾滋病患者中分离出来，并与一些B细胞淋巴瘤有关， 包含转换的DNA序列。为了测试这一点，HHV-6基因组DNA和一个 很少有亚克隆被导入NIH3T3细胞。我们的数据显示 NIH3T3细胞可重复进行形态转化 病毒全基因组(HHV-6)或亚基因组片段 克隆pZVH14。病灶形成的频率明显高于 背景级别。这些焦点线显示了肿瘤发生的潜力 无论是裸鼠还是免疫活性小鼠。此外，致癌作用 转化子也可以通过将dna与 新霉素抗性标记。通过组织病理学检查，肿瘤 均为未分化纤维肉瘤。 Southern杂交显示pZVH14 DNA序列的存在 在G418所选的转化和肿瘤细胞系中，但不在 焦点来源的细胞系。G418选育的基因组DNA诱导系 与HHV-6的另一个亚克隆pZVB70相关的序列也呈阳性。 在聚焦实验中发现该克隆具有较弱的转化活性。 我们未能在焦点衍生线中检测到DNA序列可能是由于 由于8.7kb的探针(pZVH14插入)太大而无法检测到 小片段(&lt；500bp)，即使在转化的细胞系中也是如此。 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-6DNA可能是瞬时整合的 或者是保留了一小段无法被检测到的DNA。次要的 转化子，通过将基因组DNA导入NIH 3T3细胞而来 G418原代筛选转化细胞系和肿瘤细胞系，表现出许多 比原代转化子具有更高的致瘤活性。这些数据 确定HHV-6含有转化的DNA序列。该项目是 仍在使用中。

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.