IN VITRO TRANSLATION AS A PROBE FOR THE MECHANISM OF POLIOVIRUS ATTENUATION

脊髓灰质炎病毒神经毒力的减弱是有限数量的结果 脊髓灰质炎病毒基因组的核苷酸变化。一个主要的网站 3型脊髓灰质炎病毒(第472位)的减弱发生在非编码区 参与病毒翻译调控的基因组。 翻译的改变究竟如何(以及是否)导致脊髓灰质炎病毒减毒 仍有待确定。 Mola、Paul和Wimmer最近的一份报告，《科学》，254,1647-1651(1991) 表明从未感染的HeLa衍生的体外翻译系统 翻译的细胞以一种与脊髓灰质炎病毒RNA非常相似的方式添加了脊髓灰质炎病毒RNA 病毒在人类细胞中的完整复制周期。最近，巴顿和 Flanegan，J.of Virroology，67,822-831，(1993)提供了额外的 有关此系统的信息。我们正在使用这个系统来确定 降低神经毒力的基因组变化是否表现出 关于病毒粒子RNA的体外翻译。HeLa细胞的反应 加入野生型脊髓灰质炎病毒RNA的提取物正在进行评估 将被用来比较从衰减的RNA中提取的反应 沙宾菌株。 该项目的目标是获得有关 核苷酸变化的功能，导致细胞的功能减弱 脊髓灰质炎病毒基因组。理解这些序列与 病毒和宿主因素可能会导致减毒的进一步变化 将导致减毒表型稳定性增加的基因组

Attenuation of poliovirus neurovirulence is the result of a limited number of nucleotide changes in the poliovirus genome. A major site for attenuation of Type 3 poliovirus (position 472) occurs in a noncoding regio of the genome that is involved in the regulation of viral translation. Exactly how (and if) changes in translation result in poliovirus attenuatio remain to be established. A recent report by Mola, Paul, and Wimmer, Science, 254, 1647-1651(1991) indicated that an in vitro translation system derived from uninfected HeLa cells translated added poliovirus RNA in a manner that closely mimics the full viral replicative cycle in human cells. More recently, Barton and Flanegan, J. of Virology, 67, 822-831, (1993), have provided additional information about this system. We are using this system to determine whether the genomic changes that decrease neurovirulence exhibit an effect on the in vitro translation of virion RNA. The response of HeLa cell extracts to the addition of wild-type poliovirus RNA are being evaluated an will be used to compare the response to RNA derived from the attenuated Sabin strain. The goal of this project is to obtain further information concerning the function of the nucleotide changes that result in attenuation of the poliovirus genome. Understanding the interaction of these sequences with viral and host factors could lead to further changes in the attenuated genome that would result in increased stability of the attenuated phenotype