Yamashita Yoriko, Tsurumi Tatsuya, Mori Naoyoshi, Kiyono Tohru
Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Pathol Int. 2006 Nov;56(11):659-67. doi: 10.1111/j.1440-1827.2006.02026.x.
The genes required for immortalization of human B cells infected by Epstein-Barr virus are multiple, and the precise mechanism of this process remains to be elucidated. In the present study HPV16 E6 and E7 were retrovirally transduced into human primary B cells stimulated by CD40-CD40L interaction, thereby establishing an Epstein-Barr virus negative immortalized human B cell line, which continued to proliferate for more than 2 years (100 population doublings). The established cell line had a high telomerase activity from the beginning of the culture period, and no shortening of the telomere length was observed. A chromosomal analysis revealed that a large portion of the HPV16E6E7 transduced cells had retained a normal karyotype. Similar to human epithelial cells, human B lymphocytes seem to require two steps for immortalization, namely, the inactivation of the p16/Rb pathway and the activation of telomerase, the latter that can be induced by the CD40-CD40L interaction. Furthermore, using this system, it is possible to analyze the role of individual genes in human B lymphocyte immortalization without the influence of a pre-existing Epstein-Barr virus genome.
爱泼斯坦-巴尔病毒感染的人B细胞永生化所需的基因是多样的，这一过程的确切机制仍有待阐明。在本研究中，通过逆转录病毒将人乳头瘤病毒16型（HPV16）E6和E7基因转导至由CD40-CD40L相互作用刺激的人原代B细胞中，从而建立了一种爱泼斯坦-巴尔病毒阴性的永生化人B细胞系，该细胞系持续增殖超过2年（100次群体倍增）。所建立的细胞系从培养期开始就具有较高的端粒酶活性，并且未观察到端粒长度缩短。染色体分析显示，大部分转导了HPV16E6E7的细胞保留了正常核型。与人类上皮细胞类似，人B淋巴细胞的永生化似乎需要两个步骤，即p16/Rb通路的失活和端粒酶的激活，后者可由CD40-CD40L相互作用诱导。此外，利用该系统，可以在不存在预先存在的爱泼斯坦-巴尔病毒基因组影响的情况下，分析单个基因在人B淋巴细胞永生化中的作用。
