Expression of Tissue Inhibitor of Metalloproteinases by Recombinant Baculovirus-Infected Insect Cells Cultured in an Airlift Fermentor

The recombinant baculovirus expression system, developed in the laboratories of Summers (1 ) and Miller (2 ), has been widely used for the production of heterologous proteins (3 , 4 ). In this system, the gene to be expressed is cloned into a plasmid transfer vector, downstream of a strong baculovirus gene promoter, and cotransfected with wildtype virus DNA into insect cells. An in vivo homologous recombination between viral DNA and the specific segment of the shuttle vector containing the promoter and heterologous gene occurs at a low frequency. This recombination leads to the production of a small population of recombinant viruses carrying the foreign gene under the control of the viral polyhedrin promoter. These recombinant viruses can be readily isolated from the wildtype population by plaque purification. The infection of insect cells with the recombinant virus results in the production of the foreign gene product.