Evaluation of Spim Insect Cells Using a Novel Baculovirus Expression Vector System Employing the Hyphantria Cunea NPV

Abstract

Using a lepidopteran insect cell line, FRI-SpIm-1229 (Splm), and the Hyphantria cunea nucleopolyhedrovirus (HycuNPV), we have developed a novel baculovirus expression vector system. When SpIm cell suspension culture was adapted to a serum-free medium, Sf-900 II, and scaled up to 50 ml by the simple shaker culture, no significant reduction in the cell growth as well as HycuNPV replication was observed. We have constructed a HycuNPV polyhedrin promoter-basedtransfer vector plasmid, pHcMU1, and obtained a recombinantHycuNPVexpressing an insect peptide hormone (PTTH). The recombinantPTTH was N-glycosylated and secreted in the culture supernatant, suggesting that SpIm cells could recognize and process correctly both of the N-glycosylation and signalsequences. The expression level of PTTH in HycuNPV/SpIm cell system using serum-free Sf-900 II medium was comparable to that in the BmNPV/BmN4 cell system using TC-100 medium with 10% fetal bovine serum.