The major transient expression platforms for recombinant therapeutic proteins (RTPs) are Chinese hamster ovary (CHO) cells. Most improving strategies have been focused on expression promotion at the transcriptional level in CHO cells. How to promote RTPs yields through translation regulation remains unclear. This study investigated the effects of the 5’ untranslated region (UTR) characteristics on the recombinant protein expression of CHO cells. And used Ribo-seq to characterize regions on the 5’UTR that can promote translation initiation efficiency by complementary pairing with ribosomal RNA. Some elements located in 5’UTR and its characteristics differentially affected the translation of main ORF, resulting in a 1.5-fold increase in protein expression in CHO cells. This study presents a 5’UTR sequence analysis method and provides a new idea to break the bottleneck of RTPs yield from the rarely considered translation enhancement.

Chinese hamster ovary cells (CHO) are the main cell line used for mass production of recombinant therapeutic proteins (RTPs), especially recombinant therapeutic antibodies (RTAs). In order to increase the yield and quality of RTPs produced by CHO cells, it is essential to optimize the production process and scale of CHO cells. Perfusion culture is an important process for mammalian cell culture that has emerged in recent years. It offers several advantages, including increased levels of protein expression, reduced risk of bacterial infection, simplified downstream processing, lower production costs, support for industrial production, and improved understanding of cell metabolism. It can increase the yield of antibodies and improve four key quality attributes. This review introduces the culture process of CHO cell expressed antibody and the effect of perfusion culture process on the yield and quality of antibody expression.