Bandobashi K, Daibata M, Kamioka M, Tanaka Y, Kubonishi I, Taguchi H, Ohtsuki Y, Miyoshi I
Department of Medicine, Kochi Medical School, Japan.
Blood. 1997 Aug 1;90(3):1200-7.
Human herpesvirus 6 (HHV-6) DNA has been detected in several human lymphoproliferative disorders. We report a case of HHV-6-infected Burkitt's lymphoma, from which a cell line, designated Katata, has been established. Katata cells had an immature B-cell phenotype with an L3 morphology and carried a t(8;14)(q24;q32) chromosomal abnormality. The HHV-6 DNA sequences were detected in both the patient's tumor cells and Katata cell line by polymerase chain reaction using three sets of primers that target different regions of HHV-6 DNA. The presence of HHV-6 DNA in Katata cells was also shown by Southern blot hybridization with the BamHI fragment of HHV-6. It is likely that the virus is in a latent state, since (1) virion-associated protein was not expressed in Katata cells, (2) transcriptional level of the immediate-early gene was very low, and (3) no viral particles were observed by electron microscopy. Katata cells were highly tumorigenic in nude mice and the tumor cells also contained HHV-6 DNA. We have successfully obtained several clonal lines by allowing the cells to form colonies in soft agarose and by the limiting dilution method. HHV-6 DNA was detectable in all 13 clones analyzed, suggesting that virtually all Katata cells are infected with HHV-6. This is the first report of a case of HHV-6+ Burkitt's lymphoma in the absence of Epstein-Barr virus. Furthermore, there has been no report of lymphoma cell lines that are persistently and nonproductively infected with HHV-6. The Katata Burkitt's lymphoma cell line, therefore, would provide a useful tool for studies of the mechanisms of HHV-6 latency and reactivation.
在几种人类淋巴增殖性疾病中已检测到人类疱疹病毒6型（HHV-6）DNA。我们报告了一例HHV-6感染的伯基特淋巴瘤病例，并从中建立了一个名为Katata的细胞系。Katata细胞具有未成熟B细胞表型，呈L3形态，并携带t(8;14)(q24;q32)染色体异常。使用针对HHV-6 DNA不同区域的三组引物，通过聚合酶链反应在患者的肿瘤细胞和Katata细胞系中均检测到HHV-6 DNA序列。用HHV-6的BamHI片段进行Southern印迹杂交也显示Katata细胞中存在HHV-6 DNA。病毒可能处于潜伏状态，因为（1）Katata细胞中未表达病毒体相关蛋白，（2）即刻早期基因的转录水平非常低，（3）电子显微镜未观察到病毒颗粒。Katata细胞在裸鼠中具有高度致瘤性，肿瘤细胞中也含有HHV-6 DNA。通过使细胞在软琼脂糖中形成集落以及采用有限稀释法，我们成功获得了几个克隆系。在所分析的所有13个克隆中均检测到HHV-6 DNA，这表明几乎所有Katata细胞都感染了HHV-6。这是首例无爱泼斯坦-巴尔病毒的HHV-6阳性伯基特淋巴瘤病例报告。此外，尚无关于持续且非生产性感染HHV-6的淋巴瘤细胞系的报道。因此，Katata伯基特淋巴瘤细胞系将为研究HHV-6潜伏和激活机制提供一个有用的工具。
