Doyle M G, Crawford D H
Department of Clinical Sciences, London School of Hygiene and Tropical Medicine, UK.
Intervirology. 1994;37(5):236-44. doi: 10.1159/000150384.
Epstein-Barr virus (EBV) infection of the EBV-negative Burkitt lymphoma (BL) cell line BL2 has been studied in vitro, to assess the efficiency of stable infection and the state of the viral genome in these cells. Expression of the EBV nuclear antigen complex (EBNA 1-6) was detected by 24 h post-infection, but expression of the latent membrane protein (LMP) and of the B cell activation antigen CD23 were delayed until 8 days post-infection, and were then only detectable in a subpopulation of EBNA-positive cells. Separation of cells into CD23-positive and -negative fractions 8 days after infection showed that the CD23-positive cells expressed EBNA 1-6 and LMP and contained viral episomes, whereas the CD23-negative cells were EBNA 1-6 positive, LMP negative and had very low levels of episomal viral genome. Cloning of the CD23-positive and -negative populations showed that EBV infection in the majority of clones was lost, with only 29 out of the 164 investigated still EBNA positive after 6 months of culture. Stable infection correlated with expression of EBNA 1-6, LMP, CD23 and the presence of viral episomes. One clone stably expressed EBNA 1-6 and LMP in the absence of detectable linear or episomal viral genome; this clone was assumed to have a viral genome integrated into the cellular chromosomes. Thus integration of the viral genome following in vitro infection of BL2 cells is a rare event.
已在体外研究了EBV阴性的伯基特淋巴瘤（BL）细胞系BL2的爱泼斯坦-巴尔病毒（EBV）感染情况，以评估稳定感染的效率以及这些细胞中病毒基因组的状态。感染后24小时即可检测到EBV核抗原复合物（EBNA 1-6）的表达，但潜伏膜蛋白（LMP）和B细胞活化抗原CD23的表达延迟至感染后8天，且仅在EBNA阳性细胞亚群中可检测到。感染8天后将细胞分离为CD23阳性和阴性部分，结果显示CD23阳性细胞表达EBNA 1-6和LMP，并含有病毒附加体，而CD23阴性细胞EBNA 1-6阳性、LMP阴性且附加体病毒基因组水平极低。对CD23阳性和阴性群体进行克隆显示，大多数克隆中的EBV感染消失，在培养6个月后，164个被研究的克隆中只有29个仍为EBNA阳性。稳定感染与EBNA 1-6、LMP、CD23的表达以及病毒附加体的存在相关。一个克隆在无可检测的线性或附加体病毒基因组的情况下稳定表达EBNA 1-6和LMP；该克隆被认为有一个病毒基因组整合到了细胞染色体中。因此，BL2细胞体外感染后病毒基因组的整合是一个罕见事件。
