在其适应性进化过程中,SARS-CoV-2是否面临限制?
1Department of Biomedical Sciences, College of Osteopathic Medicine, Liberty University, Lynchburg, Virginia, the United States of America.
Biomolecules & biomedicine
|June 11, 2025
概括
严重急性呼吸道综合征冠状病毒2 (SARS-CoV-2) 的适应速度有所减缓,突变的益处较小. 最近的Omicron变种显示出减少复制和较温和的COVID-19结果,尽管感染率高.
科学领域:
- 病毒学 病毒学
- 进化生物学 进化生物学
- 流行病学 流行病学
背景情况:
- 严重急性呼吸系统综合征冠状病毒2 (SARS-CoV-2) 在五年内对人类群体表现出了显著的适应性.
- 关键的适应包括通过尖端 (S) 蛋白突变和上呼吸道殖民,缩短潜伏期和增加传播的增强受体结合.
- 免疫逃避突变已经出现,有时以复制性适应性为代价,驱动变体进化.
研究的目的:
- 分析SARS-CoV-2的进化轨迹.
- 研究突变对病毒适应性,传播和病原性的影响.
- 了解病毒适应的局限性,并预测未来的趋势.
主要方法:
- 对病毒遗传序列的分析,以识别突变和跟踪进化变化.
- 在体外评估受体结合亲和力和复制性适应性.
- 在动物模型和人类种群中评估免疫逃逸特性和病原性.
主要成果:
- SARS-CoV-2 的适应性,特别是在S蛋白受体结合方面,似乎在2023年底-2024年初左右停滞不前.
- 净化选择现在在Omicron血统中占主导地位,因错误突变而减少的健康益处.
- 与较早的菌株相比,Omicron亚型体现出细胞培养中的复制效率降低,动物模型中的致病性减弱.
- 在Omicron亚变体中,编码子适应指数下降,表明同名突变的效率下降.
结论:
- SARS-CoV-2 的进化能力可能正在达到功能极限,转向净化选择.
- 最近的Omicron变种显示病毒适应性和致病性降低,与COVID-19死亡率下降相关,尽管持续高感染率.
- 未来的SARS-CoV-2进化可能涉及免疫逃避和复制能力之间的权衡,可能导致不那么严重的疾病结果.
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