Large scale expression of SARS-CoV-2 spike protein antigenic regions to aid development of kits to measure immunity to COVID-19 disease.

检测SARS-CoV-2病毒（COVID-19疾病的病原体）的存在和检测对该病毒的免疫力是制定明智的公共政策以抗击COVID-19大流行所需的关键工具。 SARS-CoV-2病毒在其表面上具有刺突蛋白，针对刺突蛋白某些区域的抗体被认为可以阻止病毒进入细胞，因此，个体中存在此类抗体表明对COVID-19疾病具有免疫力。 检测抗SARS-CoV-2抗体的任何测定的关键组分是重组刺突蛋白或刺突蛋白的重组片段。 该提案描述了一种产生重组SARS-CoV-2刺突蛋白抗体结合区的方法，其成本比使用当前方法产生刺突蛋白的成本低100至1，000倍。 我们的重组系统使用枯草芽孢杆菌将重组刺突蛋白分泌到生长培养基中，这允许从细菌细胞中简单分离刺突蛋白片段。 这种重组细菌可以在工业规模的生物反应器中使用简单、廉价的生长培养基培养。 生产廉价的刺突蛋白区域将为我们的行业合作伙伴提供竞争优势，并将成为抗击COVID-19大流行的有用工具，特别是在世界资源贫乏的地区。

Testing for the presence of the SARS-CoV-2 virus (the causative agent of COVID-19 disease) and testing for immunity to the virus are critical tools needed to create informed public policy to combat the COVID-19 pandemic. The SARS-CoV-2 virus has a spike protein on its surface, and antibodies against certain regions of the spike protein are thought to block viral entry into cells, and thus, the presence of such antibodies in an individual indicate immunity to COVID-19 disease. The critical component of any assay to detect anti-SARS-CoV-2 antibody is recombinant spike protein or recombinant fragments of the spike protein. This proposal describes an approach to generate recombinant SARS-CoV-2 spike protein antibody binding regions at cost that are 100 to 1,000 times lower than the cost of producing spike protein using current methods. Our recombinant system uses the bacterium Bacillus subtilis to secrete recombinant spike protein into the growth medium, which allows a simple separation of the spike protein fragments from the bacterial cells. This recombinant bacterium can be cultivated in industrial size bioreactors using simple, inexpensive growth medium. The production of inexpensive spike protein regions will provide a competitive advantage for our industry partner and will be a useful tool in fighting the COVID-19 pandemic, especially in resource poor regions of the world.