To characterize
Autographa californica nucleopolyhedrovirus (AcMNPV) infection of the cells derived from
Bombyx mori, cytopathology, cellular viability and metabolic activity, viral DNA replication, viral polypeptide synthesis, and polyhedrin gene expression were examined. AcMNPV-infected
Bombyx cells displayed cytopathology and were impaird in their ability of proliferation. Immunoblot analysis showed that viral capsid polypeptides were produced in AcMNPV-infected
Bombyx cells in a large quantity that was comparable to that in conventional permissive Sf21 cells, while there was a striking decrease in the production of envelope fusion protein GP64 and viral genomic DNA in
Bombyx cells as compared to that in Sf21 cells.
Bombyx cells supported the production of budded virions (BVs) into culture medium, although BV yield in AcMNPV-infected
Bombyx cells was lower by one to two orders of magnitude than that in AcMNPV-infected Sf21 cells. No detectable amount of polyhedrin protein was produced in AcMNPV-infected
Bombyx cells, and northern blot analysis demonstrated that the defect in polyhedrin production in AcMNPV-infected
Bombyx cells was due to the transcriptional restriction of polyhedrin gene expression. These results indicate that in AcMNPV-infected
Bombyx cells, virus replication cycle proceeds to yield a limited number of progeny BVs into culture medium, without an optimal expression of polyhedrin gene. The present study thus demonstrates that AcMNPV-infected
Bombyx cells provide a unique model system to define cellular factors responsible for host-dependent viral gene expression.
抄録全体を表示