Adaptation of two flaviviruses results in differences in genetic heterogeneity and virus adaptability
Adaptation of two flaviviruses results in differences in genetic heterogeneity and virus adaptability
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DOI：
10.1099/vir.0.83061-0
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发表时间：
2007-09-01
影响因子：
3.8
通讯作者：
Kramer, Laura D.
中科院分区：
文献类型：
--
作者：
Ciota, Alexander T.;Lovelace, Amy O.;Kramer, Laura D.
西尼罗河病毒（WNV）是一种蚊媒黄病毒，于1999年首次在纽约市地区传入美国。自推出以来，西尼罗河病毒稳步增加其主机和地理范围。密切相关的黄病毒，圣路易斯脑炎病毒（SLEV），在美国周期性发生，但活动水平和宿主范围比WNV更受限制。了解驱动arbovinus适应和进化的选择压力在不同的蚊子和鸟类宿主中对于预测它们的生存和重新出现的能力至关重要。在这里，我们评估了蚊子细胞适应的WNV和SLEV的体内表型。结果表明，在体外适应并没有转化为在体内适应任一病毒，但SLEV显示衰减的蚊子和鸡的生长，而西尼罗河病毒一般没有。体外生长分析还表明，西尼罗河病毒的适应可以推广到其他蚊子物种的细胞培养物，而SLEV不能。传代SLEV的遗传多样性分析显示，一个高度同质的人口，显着不同，从以前的结果，高水平的多样性在西尼罗河。我们假设，这种遗传多样性的差异与病毒在实验室中新的和不断变化的环境中的成功直接相关，并且病毒在自然界中产生和维持异质群体的能力的差异在某些情况下可以解释虫媒病毒中观察到的不同水平的成功。
West Nile virus (WNV) is a mosquito-borne flavivirus that was first introduced into the USA in the New York City area in 1999. Since its introduction, WNV has steadily increased both its host and geographical ranges. Outbreaks of the closely related flavivirus, St. Louis encephalitis virus (SLEV), occur in the USA periodically, but levels of activity and host range are more restricted than those of WNV. Understanding the selective pressures that drive arbovinus adaptation and evolution in their disparate mosquito and avian hosts is crucial to predicting their ability to persist and re-emerge. Here, we evaluated the in vivo phenotypes of mosquito cell-adapted WNV and SLEV. Results indicated that in vitro adaptations did not translate to in vivo adaptations for either virus, yet SLEV displayed attenuated growth in both mosquitoes and chickens, while WNV generally did not. In vitro growth analyses also indicated that WNV adaptations could be generalized to cell cultures derived from other mosquito species, while SLEV could not. Analysis of genetic diversity for passaged SLEV revealed a highly homogeneous population that differed significantly from previous results of high levels of diversity in WNV. We hypothesize that this difference in genetic diversity is directly related to the viruses' success in new and changing environments in the laboratory and that differences in a viruses' ability to produce and maintain heterogeneous populations in nature may in some instances explain the variable levels of success seen among arboviruses.