Engineering cellular stress for enhanced extracellular bioproduction

重组蛋白的生产是一项强大的技术，广泛应用于世界各地的生物学研究实验室，并用于工业规模生产治疗蛋白和工业酶。在制药行业，基于蛋白质的生物制药产品占10大畅销产品中的8个，2017年全球基于蛋白质的生物制药市场销售额为1200亿美元。这些产品的制造成本的一个主要组成部分与从宿主生产细胞中提取产品以及分离和纯化程序有关。这对生物药品的可负担性和全球公平获取产生了重大影响，因为与小分子仿制药相比，高制造成本限制了可能的降价。因此，采用新的方法来促进高纯度和高质量产品的分离，将在降低成本和挑战方面带来巨大的利益，从而造福社会。寄主细胞外分泌的蛋白质通过特定信号肽的存在被引导到分泌途径。然而，在最近的一项研究中，我们证明了在应激条件下，通常用于重组蛋白生产的细菌细胞经历了一种排泄现象，即蛋白质被转移到细胞外环境中，即使没有信号肽。因此，确认其他转运/排泄途径的存在并了解其功能和调控对于基础微生物学和生物技术非常重要。在这项研究中，我们将寻求理解和利用这种排泄现象，以生物技术生产基于蛋白质的生物制药。更有效地生产这些用于治疗糖尿病或某些癌症的药物的潜力可以降低治疗费用，从而减轻保健提供者（例如国民保健制度）的负担。在这项研究中，我们将试图了解大肠杆菌细胞分泌和生产具有更高生产力的生物药物的能力。该研究项目将产生有助于保持英国竞争优势的技术和知识，并将培养训练有素、技术熟练的研究人员。

The production of recombinant protein is powerful technique widely employed in biology research labs around the world and for the industrial-scale production of therapeutic proteins and industrial enzymes. Within the pharmaceutical sector, protein-based biopharmaceuticals constitute 8 out of the 10-bestselling products, and the global protein-based biopharmaceutical market had sales worth $120b in 2017. A major component of the manufacturing cost of these products is associated with extraction of the product from the host production cells, and isolation and purification procedures. This has a major impact upon the affordability and equitable global access to biologic-medicines once off patent, as the high manufacturing cost limits possible price reductions when compared to small-molecule generic medicines. As such, adoption of new methods to facilitate the isolation of high purity and quality product, would offer great benefit in reducing the cost and challenges, and hence benefit society. Proteins destined for secretion out of host cells are directed toward the secretion pathways by the presence of specific signal peptides. However, in a recent study we demonstrated that under conditions of stress bacterial cells, which are commonly used for recombinant protein production, undergo an excretion phenomenon whereby proteins are translocated into the extracellular environment, even without a signal peptide. Confirming the presence of alternative translocation/excretion pathways and understanding their function and regulation are thus important for fundamental microbiology and biotechnology. In this study we will seek to understand and harness this excretion phenomenon for the biotechnological production of protein-based biopharmaceuticals. The potential to more effectively produce these medicines, used in the treatment of diabetes or certain cancers, could lower the cost of the therapy and so reduce the burden upon healthcare providers, e.g. the NHS. Within this study will seek to understand the ability of E. coli cells to excrete and produce biopharmaceuticals with enhanced productivity. This research project will generate technology and knowledge that will help maintain the UK's competitive edge, and will produce highly trained and skilled research personnel.