Replication of hepatitis A viruses with chimeric 5' nontranslated regions.
Replication of hepatitis A viruses with chimeric 5' nontranslated regions.
复制标题
具有嵌合 5 非翻译区的甲型肝炎病毒的复制。
DOI：
10.1128/jvi.70.5.2861-2868.1996
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Ehrenfeld,E
中科院分区：
文献类型：
--
作者：
Jia,XY;Tesar,M;Summers,DF;Ehrenfeld,E
通过分析含有脑心肌炎病毒（EMCV）内部核糖体进入片段（IRES）和不同长度（237、151和98个核苷酸[nt]）的甲型肝炎病毒（HAV）5 '端非翻译区序列的嵌合RNA的翻译和复制，研究了5'端非翻译区在HAV复制中的作用。翻译的所有嵌合RNA，截短编码衣壳蛋白序列，发生在兔网织红细胞裂解液中的效率相同，并大大增强了所表现出的HAV IRES。用亲本HAV RNA和嵌合RNA转染FRhK-4细胞产生了在连续传代中稳定的活病毒;然而，需要从HAV的5'末端超过151个nt来支持病毒复制。从亲本RNA转染和从含有HAV前237 nt下游的EMCV IRES的RNA转染回收的病毒的单步生长曲线证明了具有相似动力学和相似产率的复制。当用能产生SP 6 RNA聚合酶以扩增HAV RNA的重组牛痘病毒感染的FRhK-4细胞，用编码这些病毒RNA的质粒或仅含有亲本或嵌合5'非翻译区下游的HAV衣壳编码序列的亚克隆转染时，从HAV IRES合成病毒衣壳抗原的效率等于或大于用EMCV IRES获得的效率。这些数据表明HAV IRES的固有翻译效率可能不是HAV缓慢生长表型的主要限制性决定因素。
The role of the 5' nontranslated region in the replication of hepatitis A virus (HAV) was studied by analyzing the translation and replication of chimeric RNAs containing the encephalomyocarditis virus (EMCV) internal ribosome entry segment (IRES) and various lengths (237, 151, or 98 nucleotides [nt]) of the 5'-terminal HAV sequence. Translation of all chimeric RNAs, truncated to encode only capsid protein sequences, occurred with equal efficiency in rabbit reticulocyte lysates and was much enhanced over that exhibited by the HAV IRES. Transfection of FRhK-4 cells with the parental HAV RNA and with chimeric RNA generated a viable virus which was stable over continuous passage; however, more than 151 nt from the 5' terminus of HAV were required to support virus replication. Single-step growth curves of the recovered viruses from the parental RNA transfection and from transfection of RNA containing the EMCV IRES downstream of the first 237 nt of HAV demonstrated replication with similar kinetics and similar yields. When FRhK-4 cells infected with recombinant vaccinia virus producing SP6 RNA polymerase to amplify HAV RNA were transfected with plasmids coding for these viral RNAs or with subclones containing only HAV capsid coding sequences downstream of the parental or chimeric 5' nontranslated region, viral capsid antigens were synthesized from the HAV IRES with an efficiency equal to or greater than that achieved with the EMCV IRES. These data suggest that the inherent translation efficiency of the HAV IRES may not be the major limiting determinant of the slow-growth phenotype of HAV.