Intensifying Animal Cell Culture for Virus Vaccine Manufacturing

过去疫苗生产的挑战可以说与规模扩大有关，在大多数情况下，挑战已经得到了解决。如今，过去30年来一直困扰疫苗行业的未解决的挑战是缺乏制造灵活性，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，而不是使用含胚卵或小鼠脑;使细胞系适应悬浮液，从而能够进行高密度培养;以及从分批操作模式转向连续操作模式。在这个项目中，Aucoin教授和Kamen教授有着长期的合作历史，他们正在与领先的国际疫苗制造商赛诺菲合作，将Vero细胞培养平台转变为一种易于强化的前沿技术。对于有效、大规模生产疫苗以预防世界上与病毒感染相关的疾病存在明确的需求，这由以下事实证明：当今的疫苗市场价值约250亿美元，并且预计到2020年将翻一番以上。在过去的二十年里，有四种病毒是全球流行病的记录原因：SARS冠状病毒;禽流感和猪流感病毒;埃博拉病毒;最近，寨卡病毒。细胞培养是最具吸引力的生产平台，用于快速，可扩展和可控的病毒疫苗生产-Vero是最广泛接受的病毒疫苗生产平台。尽管在中国人卵巢培养物中用于生产单克隆抗体达到显著强化，但在用于重组蛋白生产或病毒生产的细胞培养物中在高细胞密度下的生产性感染仍然是难以捉摸的。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细胞状态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.