Intensifying Animal Cell Culture for Virus Vaccine Manufacturing

可以说，过去疫苗生产的挑战与扩大规模有关，在很大程度上，挑战已经得到了解决。今天，过去30年来一直困扰着疫苗工业的未应对的挑战是缺乏生产灵活性，特别是在病毒突然爆发的情况下，以及未能加强病毒的生产。三种主要的强化策略包括：使用细胞系进行病毒繁殖，而不是胚胎卵或小鼠脑；细胞系对悬浮液的适应，可以实现高密度培养；从批处理到连续操作的转变。在这个项目中，有着长期合作历史的Aucoin教授和Kamen教授将与国际领先的疫苗制造商赛诺菲（Sanofi）合作，将Vero细胞培养平台转变为可强化的前沿技术。世界上对有效、大规模生产疫苗以预防与病毒感染有关的疾病有明确的需要和需求，今天的疫苗市场价值约为250亿美元，预计到2020年将增加一倍以上。在过去的二十年里，有四种病毒被记录为全球流行病的原因：SARS冠状病毒；禽流感和猪流感病毒；埃博拉病毒;以及最近的寨卡病毒。细胞培养是快速、可扩展和可控生产病毒疫苗的最具吸引力的制造平台，而Vero是最广泛接受的病毒疫苗制造平台。尽管在中国仓鼠卵巢培养中单克隆抗体的产生显著增强，但在重组蛋白生产或病毒制造的细胞培养中，高细胞密度的生产性感染仍然难以捉摸。这项工作的目标是加强对Vero细胞系的遗传理解；确定峰值细胞密度效应的遗传和代谢基础以及从贴壁到悬浮细胞状态的表型转化；并开发一种（半）连续操作模式，以实现更高的体积生产率。

Past challenges of vaccine manufacturing have arguably been related to scale-up, and for the most part the challenge has been met. Today, the unmet challenges, which have dogged the vaccine industry for the past 30 years, are the lack of manufacturing flexibility, especially in cases of sudden virus outbreaks, and the failure to intensify the production of viruses. Three major intensification strategies include: the use of cell lines for virus propagation instead of embryonated eggs or mouse brains; the adaptation of cell lines to suspension that can enable high density cultures; and the move from batch to continuous modes of operating the process. In this project, Profs Aucoin and Kamen, who have a long history of working collaboratively together, are partnering with Sanofi, a leading international vaccine manufacturer, to transform the Vero cell culture platform into a leading edge technology amenable to intensification. There is a clear need and demand for efficient, large scale production of vaccines to prevent disease related to viral infection in the world, evidenced by the fact that today's vaccine market is worth ~25 billion dollars and is expected to more than double by 2020. In the last two decades, four viruses have been the documented cause of global epidemics: SARS coronavirus; avian and swine influenza viruses; Ebola virus; and recently, Zika virus. Cell culture is the most attractive manufacturing platform for rapid, scalable and controlled production of viral vaccines - and Vero is the most widely accepted platform for viral vaccine manufacturing. Despite reaching significant intensification in Chinese Hamster Ovary cultures for the production of monoclonal antibodies, productive infections at high cell densities in cell culture for recombinant protein production or virus manufacture remains elusive. The goals of this work are to enhance the genetic understanding of the Vero cell line; determine the genetic and metabolic underpinnings of the peak cell density effect and the phenotypic transformation from adherent to suspension cell state; and develop a (semi)-continuous mode of operation that enables higher volumetric productivity.