小柯机器人

美国洛斯阿拉莫斯国家实验室B. Korber等研究人员合作发现，新冠病毒（SARS-CoV-2）突刺蛋白D614G突变增加了病毒的感染性。这一研究成果于2020年7月2日在线发表在《细胞》上。

通过动态跟踪变体频率，研究人员发现G614在多个地理级别（国家、地区和市政）的反复增加。甚至在引入G614变体之前就已经存在原始D614形式的地方也发生了这种变化。该模式的一致性在统计学高度显著，这表明G614变体可能具有适应性优势。

研究人员发现，G614变体作为假型病毒颗粒具有更高的滴度。在受感染的个体中，G614与较低的RT-PCR循环阈值相关，从而提示了较高的上呼吸道病毒载量，尽管与疾病的严重程度无关。这些发现阐明了对病毒机制理解的重要变化，并表明对突刺蛋白突变的持续监测能够帮助开发免疫学干预措施。

据悉，携带突刺蛋白氨基酸变化D614G的SARS-CoV-2变体已成为全球大流行中最普遍的形式。

附：英文原文

Title: Tracking changes in SARS-CoV-2 Spike: evidence that D614G increases infectivity of the COVID-19 virus

Author: B. Korber, W.M. Fischer, S. Gnanakaran, H. Yoon, J. Theiler, W. Abfalterer, N. Hengartner, E.E. Giorgi, T. Bhattacharya, B. Foley, K.M. Hastie, M.D. Parker, D.G. Partridge, C.M. Evans, T.M. Freeman, T.I. de Silva, C. McDanal, L.G. Perez, H. Tang, A. Moon-Walker, S.P. Whelan, C.C. LaBranche, E.O. Saphire, D.C. Montefiori, Adrienne Angyal, Rebecca L. Brown, Laura Carrilero, Luke R. Green, Danielle C. Groves, Katie J. Johnson, Alexander J. Keeley, Benjamin B. Lindsey, Paul J. Parsons, Mohammad Raza, Sarah Rowland-Jones, Nikki Smith, Rachel M. Tucker, Dennis Wang, Matthew D. Wyles

Issue&Volume: 2020-07-02

Abstract: A SARS-CoV-2 variant carrying the Spike protein amino acid change D614G has become the most prevalent form in the global pandemic. Dynamic tracking of variant frequencies revealed a recurrent pattern of G614 increase at multiple geographic levels: national, regional and municipal. The shift occurred even in local epidemics where the original D614 form was well established prior to the introduction of the G614 variant. The consistency of this pattern was highly statistically significant, suggesting that the G614 variant may have a fitness advantage. We found that the G614 variant grows to higher titer as pseudotyped virions. In infected individuals G614 is associated with lower RT-PCR cycle thresholds, suggestive of higher upper respiratory tract viral loads, although not with increased disease severity. These findings illuminate changes important for a mechanistic understanding of the virus, and support continuing surveillance of Spike mutations to aid in the development of immunological interventions.

DOI: 10.1016/j.cell.2020.06.043

Source: https://www.cell.com/cell/fulltext/S0092-8674(20)30820-5