State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
Viruses. 2021 Nov 1;13(11):2200. doi: 10.3390/v13112200.
The Madin-Darby Canine Kidney (MDCK) cell line is among the most commonly used cell lines for the production of influenza virus vaccines. As cell culture-based manufacturing is poised to replace egg-based processes, increasing virus production is of paramount importance. To shed light on factors affecting virus productivity, we isolated a subline, H1, which had twice the influenza virus A (IAV) productivity of the parent (P) through cell cloning, and characterized H1 and P in detail on both physical and molecular levels. Transcriptome analysis revealed that within a few hours after IAV infection, viral mRNAs constituted over one fifth of total mRNA, with several viral genes more highly expressed in H1 than P. Functional analysis of the transcriptome dynamics showed that H1 and P responded similarly to IAV infection, and were both subjected to host shutoff and inflammatory responses. Importantly, H1 was more active in translation and RNA processing intrinsically and after infection. Furthermore, H1 had more subdued inflammatory and antiviral responses. Taken together, we postulate that the high productivity of IAV hinges on the balance between suppression of host functions to divert cellular resources and the sustaining of sufficient activities for virus replication. Mechanistic insights into virus productivity can facilitate the process optimization and cell line engineering for advancing influenza vaccine manufacturing.
犬肾细胞（MDCK）系是用于生产流感病毒疫苗最常用的细胞系之一。随着基于细胞培养的生产方法有望取代基于鸡蛋的生产方法，提高病毒产量至关重要。为了阐明影响病毒生产效率的因素，我们通过细胞克隆分离出一个亚系 H1，其流感病毒 A（IAV）的生产效率是亲本（P）的两倍，并在物理和分子水平上对 H1 和 P 进行了详细的表征。转录组分析表明，在 IAV 感染后几个小时内，病毒 mRNA 构成了总 mRNA 的五分之一以上，H1 中几个病毒基因的表达水平高于 P。对转录组动态的功能分析表明，H1 和 P 对 IAV 感染的反应相似，均受到宿主关闭和炎症反应的影响。重要的是，H1 在感染前后的翻译和 RNA 加工过程中更活跃。此外，H1 的炎症和抗病毒反应较弱。综上所述，我们推测 IAV 的高生产效率取决于抑制宿主功能以转移细胞资源与维持病毒复制所需的足够活性之间的平衡。对病毒生产效率的机制见解可以促进流感疫苗生产的工艺优化和细胞系工程。
