Expression of Bombyx mori cytoplasmic polyhedrosis virus polyhedrin in insect cells by using a baculovirus expression vector, and its assembly into polyhedra.

A cDNA encoding the cytoplasmic polyhedrin of Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) strain H was introduced into an improved baculovirus expression vector which can be utilized to express foreign genes in the Spodoptera frugiperda cell line IPLB-SF-21AE (Sf21 cells) and the B. mori cell line BmN. A recombinant virus produced large, cubic inclusion body-like structures in infected Sf21 and BmN cells. Western blot analysis showed that these structures were BmCPV polyhedra. This result suggested that the supramolecular assembly of BmCPV polyhedrin is responsible for its properties.