脊髓灰质炎病毒部署基因组协奏曲,以快速适应宿主抗病毒防御
Nels C Elde1, Stephanie J Child, Michael T Eickbush
1Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. nelde@genetics.utah.edu
Cell
|August 21, 2012
概括
像vaccinia这样的双链DNA病毒使用基因放大,称为"基因协奏曲",尽管基因突变率低,但能够快速适应宿主防御. 这种机制允许快速适应和保持有益突变.
科学领域:
- 病毒学 病毒学
- 分子生物学分子生物学
- 进化生物学 进化生物学
背景情况:
- 双链DNA病毒具有较低的突变率,但需要快速适应以克服宿主免疫反应.
- 脊髓灰质炎疫苗的抗宿主因子K3L对人体蛋白激酶R (PKR) 无效,这给适应性带来了挑战.
研究的目的:
- 调查病毒,特别是疫苗,适应新宿主环境并克服抗病毒防御的机制.
- 了解低突变率的病毒如何实现快速的健康增长.
主要方法:
- 疫苗病毒在人体细胞中的连续传播以模拟适应性压力.
- 对病毒基因组大小变化和基因放大,特别是K3L基因的分析.
- 评估K3L基因放大和突变对PKR对抗性的功能影响.
主要成果:
- 疫苗病毒通过K3L基因的反复放大,迅速获得了增加的适应性,导致基因组大小增加7%-10%.
- 这些短暂的基因扩张对于对抗人类PKR至关重要,并使K3L中的适应性氨基酸替代成为可能.
- 在适应之后,病毒减少了基因放大,以减轻更大的基因组的能量成本,同时保持适应性突变.
结论:
- 病毒"基因协奏曲" (短暂的基因放大) 代表了病毒快速病毒适应的新机制.
- 这一过程使病毒能够有效地击败宿主防御,并获得适应性突变,尽管基因突变率低.
- 这些发现揭示了病毒和宿主之间的红皇后进化动态中以前未知的中间体.
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