Opportunities and challenges for the baculovirus expression system.

In this review background information on the baculovirus-insect cell expression system and its applications for producing protein subunits and virus-like particles for vaccine and other purposes is provided. This review will illustrate the principle structure of baculovirus vectors commonly used for heterologous gene expression in insect cells and describe adaptations that have been made over the last 10 years to improve the system in terms of quality of the protein produced and stability of the baculovirus genome. These improvements include enhanced trafficking, folding and glycosylation of the recombinant protein as well as preventing intracellular degradation. Challenges and progress in stabilizing the baculovirus genome in order not to lose the transgene cassette will also be discussed. Recent developments such as how to make multiple alterations in the baculovirus genome without accumulating marker genes are included.