The baculovirus expression vector system (BEVS) is one of the major platforms for recombinant protein production. Unlike mammalian expression systems that have long since transitioned to serum-free, chemically-defined culture media, relatively little innovation has taken place in insect expression systems, with insect cells continuing to rely on undefined, yeastolate-containing culture media that can exhibit significant lot-to-lot variability in terms of both cell growth and protein expression. Here, we present the development of a novel Sf9-based baculovirus expression system based on a high-density, chemically-defined culture medium, a high-expressing Sf9 cell line and expression enhancers that allow for the consistent production of recombinant proteins with two-fold or greater improvements in protein titers compared to traditional BEVS workflows.

摘要

杆状病毒表达载体系统（BEVS）是重组蛋白生产的主要平台之一。与哺乳动物表达系统早已转换为无血清，化学成分限定的培养基不同，昆虫表达系统的创新相对较少。昆虫细胞继续依赖成分不限定的含酵母提取物的培养基，而这些培养基可以显示出明显的细胞生长和蛋白质表达的批次差异。在这里，我们介绍一种新型的Sf9细胞杆状病毒表达系统的开发。此系统包括支持高细胞密度、化学成分限定的培养基，高表达Sf9细胞系，以及优化的培养辅料。此表达系统提供一致的重组蛋白生产，且比传统的BEVS提高了两倍或更多的蛋白滴度。