A mutation in the puff region of VP2 attenuates the myocarditic phenotype of an infectious cDNA of the Woodruff variant of coxsackievirus B3
A mutation in the puff region of VP2 attenuates the myocarditic phenotype of an infectious cDNA of the Woodruff variant of coxsackievirus B3
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DOI：
10.1128/jvi.70.11.7811-7818.1996
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发表时间：
1996-11-01
影响因子：
5.4
通讯作者：
Huber, S
中科院分区：
文献类型：
--
作者：
Knowlton, KU;Jeon, ES;Huber, S
柯萨奇病毒B3（CVB 3）感染可诱导人类和小鼠心肌炎。关于CVB 3激活负责心脏炎症的细胞免疫的分子特征知之甚少。先前的实验已经鉴定了CVB 3（H3）的心肌炎变体的抗体逃逸突变体（H310 A1），其减弱病毒在小鼠中的心肌炎潜力，尽管病毒在心脏中持续复制。我们已经克隆了CVB 3的野生型心肌炎H3变体和抗体逃逸突变体H310 A1的病毒基因组的全长感染性cDNA拷贝。子代病毒保持了亲本病毒H3和H310 A1的心肌炎和减弱的心肌炎潜力。H3病毒的cDNA的全序列的报告，并与先前公布的CVB 3变种。H3和H310 A1病毒的全序列的比较确定了一个单一的非保守性突变（A至G）在P1多蛋白区的核苷酸1442导致在氨基酸165的VP 2的天冬酰胺天冬氨酸突变。该突变位于对应于VP 2的puff区域的区域中。将病毒基因组的H3和H310 A1 cDNA拷贝的核苷酸1442突变以将VP 2的氨基酸165分别改变为天冬氨酸和天冬酰胺。在VP 2的氨基酸165处存在天冬酰胺与心肌炎表型相关，而在同一位点的天冬氨酸降低了病毒的心肌炎潜力。此外，感染的BALB/c单核细胞产生的高水平肿瘤坏死因子α与VP 2的氨基酸165处的天冬酰胺相关，如先前对H3病毒所证明的。这些发现确定了CVB 3的H3变体与其他先前发表的CVB 3变体之间的潜在重要差异。此外，数据表明，VP 2的puff区域中的点突变可以显著改变CVB 3诱导小鼠心肌炎的能力和感染的BALB/c单核细胞分泌肿瘤坏死因子α的能力。
Coxsackievirus B3 (CVB3) infections induce myocarditis in humans and mice. Little is known about the molecular characteristics of CVB3 that activate the cellular immunity responsible for cardiac inflammation. Previous experiments have identified an antibody escape mutant (H310A1) of a myocarditic variant of CVB3 (H3) that attenuates the myocarditic potential of the virus in mice in spite of ongoing viral replication in the heart. We have cloned full-length infectious cDNA copies of the viral genome of both the wild-type myocarditic H3 variant of CVB3 and the antibody escape mutant H310A1. Progeny viruses maintained the myocarditic and attenuated myocarditic potential of the parent viruses, H3 and H310A1. The full sequence of the H3 viral cDNA is reported and compared with those of previously published CVB3 variants. Comparison of the full sequences of H3 and H310A1 viruses identified a single nonconserved mutation (A to G) in the P1 polyprotein region at nucleotide 1442 resulting in an asparagine-to-aspartate mutation in amino acid 165 of VP2. This mutation is in a region that corresponds to the puff region of VP2. Nucleotide 1442 of the H3 and H310A1 cDNA copies of the viral genome was mutated to change amino acid 165 of VP2 to aspartate and asparagine, respectively. The presence of asparagine at amino acid 165 of VP2 is associated with the myocarditic phenotype, while an aspartate at the same site reduces the myocarditic potential of the virus. In addition, high-level production of tumor necrosis factor alpha by infected BALB/c monocytes is associated with asparagine at amino acid 165 of VP2 as has been previously demonstrated for the H3 virus. These findings identify potentially important differences between the H3 variant of CVB3 and other previously published CVB3 variants. In addition, the data demonstrate that a point mutation in the puff region of VP2 can markedly alter the ability of CVB3 to induce myocarditis in mice and tumor necrosis factor alpha secretion from infected BALB/c monocytes.