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，而且在很大程度上已经应对了挑战。今天，过去30年来困扰疫苗行业的未得到满足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。三个主要的强化策略包括：使用细胞系而不是胚胎卵子或小鼠脑进行病毒繁殖；使细胞系适应悬浮状态，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教授有着长期合作的历史，他们与国际领先的疫苗制造商赛诺菲合作，将Vero细胞培养平台转变为可强化的前沿技术。当今疫苗市场价值约250亿美元，预计到2020年将翻一番以上，这证明了世界上对高效、大规模生产疫苗以预防与病毒感染有关的疾病的需求。在过去20年里，有记载的全球流行病的起因有四种：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、可扩展和受控生产病毒疫苗的最具吸引力的制造平台，而Vero是最被广泛接受的病毒疫苗制造平台。尽管中国仓鼠卵巢培养在生产单抗方面达到了显著的强化，但在用于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实现。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换；并开发一种(半)连续的操作模式，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.