Development of a baculovirus vector carrying a small hairpin RNA for suppression of sf-caspase-1 expression and improvement of recombinant protein production

作者：Xiaoyue Zhang, Keyan Xu, Yanmei Ou, Xiaodong Xu, Hongying Chen · 发表于：BMC Biotechnology · 年份：2018 · DOI：10.1186/s12896-018-0434-1 · 被引用次数：15 · 研究领域：Viral Infectious Diseases and Gene Expression in Insects、Invertebrate Immune Response Mechanisms、Transgenic Plants and Applications

BACKGROUND: The Baculovirus expression vector system (BEVS) is a transient expression platform for recombinant protein production in insect cells. Baculovirus infection of insect cells will shutoff host translation and induce apoptosis and lead to the termination of protein expression. Previous reports have demonstrated the enhancement of protein yield in BEVS using stable insect cell lines expressing interference RNA to suppress the expression of caspase-1. RESULTS: In this study, short-hairpin RNA (shRNA) expression cassettes targeting Spodoptera frugiperda caspase-1 (Sf-caspase-1) were constructed and inserted into an Autographa californica multiple nucleopolyhedrovirus (AcMNPV) vector. Using the recombinant baculovirus vectors, we detected the suppression of Sf-caspase-1 expression and cell apoptosis. Green fluorescent protein (GFP), Discosoma sp. Red (DsRed) and firefly luciferase were then expressed as reporter proteins. The results showed that suppression of apoptosis enhanced the accumulation of exogenous proteins at 2 and 3 days post infection. After 4 days post infection, the activity of the reporter proteins remained higher in BEVS using the baculovirus carrying shRNA in comparison with the control without shRNA, but the accumulated protein levels showed no obvious difference between them, suggesting that apoptosis suppression resulted in improved protein folding rather than translation efficiency at the very late stage of baculovirus infection. CONCLUSIONS: The ba...