Miller G, Lipman M
J Exp Med. 1973 Dec 1;138(6):1398-412. doi: 10.1084/jem.138.6.1398.
Three lymphoblastoid cell lines, of human, squirrel monkey, and marmoset origin, all transformed by the same strain of Epstein-Barr virus (EBV), differed markedly in their content of infectious virus. Single cell clones were obtained from each line to learn whether these differences were dependent upon factors shared by all cells in each line or upon factors present only in a proportion of the total cell population. A total of 17 primary clones were examined: 6 human, 6 squirrel monkey, and 5 marmoset. Cloning efficiency on human placental cell feeder layers varied from 16 to 24%. EBV antiserum, present in the cloning suspension, was shown to neutralize all extracellular virus. 15 of the 17 clones released EBV as measured by the transformation assay. Titers of infectious virus released by daughter clones paralleled titers of virus in the parent line. The median virus titers from human, squirrel monkey, and marmoset clones were respectively 10(1.5), 10(3.0), and 10(4.3) 50% transforming doses per 0.2 ml. The median yield of virus from clones of the three species was, respectively, 4, 96, and 786 transforming units per 1,000 cells containing viral capsid antigen. Two nonproducer clones (one human and one squirrel monkey) did not release infectious virus after treatment with 5'-bromodeoxyuridine, or with X ray followed by co-cultivation with marmoset leukocytes. The nonproducer clones could not be superinfected by biologically active EBV. These results show that differences in production of infectious EBV among the lines tested are reflected in the majority of cells of these lines. The data imply that the mechanism for regulation of the expression of the EBV genome is cellular rather than viral in origin. There are presumably genetic differences among primate species in this regulatory process.
三种淋巴母细胞系，分别源自人、松鼠猴和狨猴，均由同一株爱泼斯坦 - 巴尔病毒（EBV）转化而来，但其感染性病毒含量差异显著。从每个细胞系中获取单细胞克隆，以了解这些差异是取决于每个细胞系中所有细胞共有的因素，还是仅取决于总细胞群体中一部分细胞所具有的因素。总共检测了17个原代克隆：6个人类克隆、6个松鼠猴克隆和5个狨猴克隆。在人胎盘细胞饲养层上的克隆效率为16%至24%。克隆悬液中存在的EBV抗血清可中和所有细胞外病毒。通过转化试验检测，17个克隆中有15个释放EBV。子代克隆释放的感染性病毒滴度与亲代细胞系中的病毒滴度平行。人、松鼠猴和狨猴克隆的病毒滴度中位数分别为每0.2 ml 10(1.5)、10(3.0)和10(4.3)个50%转化剂量。三种物种克隆的病毒产量中位数分别为每1000个含有病毒衣壳抗原的细胞4、96和786个转化单位。两个不产生病毒的克隆（一个人类克隆和一个松鼠猴克隆）在用5'-溴脱氧尿苷处理后，或经X射线处理并与狨猴白细胞共培养后，均未释放感染性病毒。不产生病毒的克隆不能被具有生物活性的EBV超感染。这些结果表明，在所测试的细胞系中，感染性EBV产生的差异在这些细胞系的大多数细胞中都有体现。数据表明，EBV基因组表达调控机制源自细胞而非病毒。在这个调控过程中，灵长类物种之间可能存在遗传差异。
