Baculovirus Expression Vector System
Today, recombinant baculoviruses are commonly used for the expression of heterologous genes in cultivated insect cells and insect larvae. Since its introduction by Smith et al. in 1983, the Baculovirus Expression Vector System (BEVS) has developed into the most important technology for protein expression based on eukaryotic vectors.
Cell lines based on Spodoptera frugiperda (e.g. Sf9, Sf-21) or Trichoplusia ni (e.g. Tn-368) are used most frequently. Both easy to cultivate in suspension, they are thus ideal for use in bioreactors. Since the recombinant proteins produced by BEVS are generally easily soluble, they can be expressed up to a very late stage of infection and thus deliver high volumes per cell.
Unlike proteins produced from bacteria, proteins produced in this way show a post-translational modification pattern very similar to that of mammalian cells.
Baculoviruses are not pathogenic for mammalian and plant cells and generally possess a very limited range of potential host cells limited to invertebrates. In addition, insect cells are never transformed by viruses which are pathogenic for mammalian cells. Both these features are important for the product's ease of use and for the reproducible scale-up of insect cell cultures.