DETECTION OF VIRUSES IN CELL SUBSTRATES

CBER感兴趣的是细胞系是否用于产品生产 含有病毒或病毒样颗粒或病毒核酸序列，或 支持对人类具有传染性的病毒的生长。中国仓鼠 卵巢（CHO）细胞系被用作最近的细胞基质， 获得许可的组织纤溶酶原激活剂Activase和其他重组体 在CHO细胞中生产的产品目前正在IND. CHO下进行临床试验。 细胞含有电子可见的内源性逆转录病毒样颗粒 显微镜这些颗粒不具有传染性， 逆转录酶活性，并被认为是类似于 脑池内A颗粒通常存在于小鼠细胞基质中， 单克隆抗体生产。因此，电子显微镜研究 进行，以确定是否生长因子或细胞因子（这可能是 在CHO细胞中制造的）可能影响这些内源性颗粒。的 结果表明，在CHO处理后，颗粒增加了30- 100 细胞与几种细胞因子（GM-CSF，IFN，TNF）或与佛波酯 TPA。数据在连续细胞系会议上提出， 1988年5月26日至28日出版的《生物制品的基质》， 已提交。我们最近又展开另一项研究， 是否Sf 9细胞（用于产生重组产物的昆虫细胞系 在杆状病毒表达系统中）可以被虫媒病毒感染。 已经选择了12种虫媒病毒，目前正在进行测试， 它们感染或维持在Sf 9细胞中的能力。

It is interest to CBER whether cell lines used for product production contain virus or virus-like particles or viral nucleic acid sequences or support the growth of viruses infectious for humans. The Chinese Hamster Ovary (CHO) cell line is used as the cell substrate for the recently licensed tissue plasminogen activator Activase, and additional recombinant products made in CHO cells are currently in clinical trials under IND. CHO cells contain endogenous retroviral-like particles visible by electron microscopy. These particles are not infectious and do not demonstrate reverse transcriptase activity, and are thought to be similar to the intracisternal A particles commonly found in mouse cell substrates used for monoclonal antibody production. An electron microscopic study was therefore undertaken to determine whether growth factors or cytokines (which might be manufactured in CHO cells) might affect these endogenous particles. The results indicate increases in particles from 30-100% after treatment of CHO cells with several cytokines (GM-CSF, IFN, TNF) or with the phorbol ester TPA. Data was presented at a Conference on Continuous Cell Lines as Substrates for Biologicals, May 26-28, 1988 and a manuscript has been submitted. We have recently initiated an additional study to examine whether Sf9 cells (an insect cell line used to produce recombinant products in the Baculovirus expression system) could be infected by arboviruses. Twelve arboviruses have been selected and are currently being tested for their ability to infect or be maintained in Sf9 cells.