Piccone M E, Chen H H, Roos R P, Grubman M J
USDA, ARS, NAA, Plum Island Animal Disease Center, Greenport, New York 11944, USA.
Virology. 1996 Dec 1;226(1):135-9. doi: 10.1006/viro.1996.0637.
The foot-and-mouth disease virus (FMDV) leader coding region (Lb) was cloned into a full-length cDNA of the DA strain of Theiler's murine encephalomyelitis virus (TMEV) replacing the complete L coding region of TMEV. This construct, pDAFSSC1-Lb, was engineered to contain cleavage sites, at the 3' end of the Lb coding region, for both the FMDV Lb and the TMEV 3C proteases. Transcripts derived from this construct were translated in a cell-free system. Analysis of the translation products showed efficient synthesis and processing of TMEV structural and nonstructural proteins as well as a major band that comigrated with FMDV Lb and was reactive with Lb antiserum. A small plaque virus was recovered from BHK-21 cells transfected with RNA derived from pDAFSSC1-Lb. RT-PCR of RNA isolated from DAFSSC1-Lb virus demonstrated a product corresponding in size and sequence to FMDV Lb. DAFSSC1-Lb virus grew slower than parental virus, DAFSSC1, and to a lower titer. The pattern of viral proteins synthesized in DAFSSC1-Lb virus-infected cells was very similar to the pattern in DAFSSC1 virus-infected cells except that significant amounts of FMDV Lb were produced. In addition, extracts from DAFSSC1-Lb-virus-infected cells cleaved an exogenous source of the translation initiation factor, p220, while DAFSSC1-virus-infected extracts did not. Chimeric viruses that contain coding regions from different picornaviral genera may be valuable tools in investigating the function of particular viral proteins and in studying disease pathogenesis.
将口蹄疫病毒（FMDV）前导编码区（Lb）克隆到泰勒氏鼠脑脊髓炎病毒（TMEV）DA株的全长cDNA中，取代TMEV完整的L编码区。构建体pDAFSSC1-Lb经设计，在Lb编码区的3'端含有FMDV Lb和TMEV 3C蛋白酶的切割位点。源自该构建体的转录本在无细胞系统中进行翻译。对翻译产物的分析表明，TMEV结构蛋白和非结构蛋白能高效合成与加工，还有一条与FMDV Lb迁移率相同且能与Lb抗血清发生反应的主要条带。从用源自pDAFSSC1-Lb的RNA转染的BHK-21细胞中获得了一种小斑病毒。对从DAFSSC1-Lb病毒分离的RNA进行逆转录聚合酶链反应（RT-PCR），结果显示出一个大小和序列与FMDV Lb对应的产物。DAFSSC1-Lb病毒的生长速度比亲本病毒DAFSSC1慢，且滴度更低。在感染DAFSSC1-Lb病毒的细胞中合成的病毒蛋白模式与感染DAFSSC1病毒的细胞中的模式非常相似，只是产生了大量的FMDV Lb。此外，感染DAFSSC1-Lb病毒的细胞提取物能切割翻译起始因子p220的外源来源，而感染DAFSSC1病毒的提取物则不能。含有来自不同小RNA病毒属编码区的嵌合病毒可能是研究特定病毒蛋白功能和疾病发病机制的有价值工具。
