BACULOVIRUS VECTOR-MEDIATED EXPRESSION OF HETEROLOGOUS GENES IN INSECT CELLS

The baculovirus expression system employing Autographa californica nuc lear polyhedrosis virus and Spodoptera frugiperda insect cells in cult ure has proved very popular for high level expression of heterologous genes. In this system, transcription of the foreign gene is usually dr iven by the hyperactive and temporally regulated polyhedrin gene promo ter. Replacement of the polyhedrin gene, which encodes a 29-kDa occlus ion protein (non-essential for viral replication), with a gene of inte rest leads to an occlusion negative phenotype which serves as a visual marker to select for recombinant viruses. Simultaneous expression of multiple genes can also be achieved. The heterologous proteins synthes ized in this system are antigenically, immunologically and functionall y identical in most respects to their native counterparts. This mini-r eview will aim at summarizing the potentials and utility of the baculo virus expression vector system and will address some important questio ns relating to the biology of this system.