Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/1997
Publication Date: N/A
Interpretive Summary: Viral insecticides are currently formulated using virus produced in living caterpillars. We wanted to know if virus from a mutant virus could be grown in cell cultures and if its yield and infectivity would be comparable to the natural non-mutant virus. Our results demonstrated that the yield of the mutant virus from cell culture was lower and less infectious than that of the natural virus. Industrial producers, interested in the cell-cultur production of insect viruses, therefore, will have to consider production processes that yield virus equal to or better than the wild virus and also consider how to best stabilize the mutant virus.
Technical Abstract: In vitro production of baculoviruses may be more feasible if nonoccluded virions, instead of the usual polyhedral inclusion bodies (PIB), are used to formulate viral insecticides. The in vitro TCID-50/ml of final whole cultures (FWC) of a polyhedrin gene-deleted mutant of the Autographa californica nuclear polyhedrosis virus (P-AcMNPV) was significantly lower (ca. 2 to 15 X lower) than that of the wild type strain (WtAcMNPV). In addition the in vivo activity of the FWC, tested against larvae of Trichoplusia ni, was significantly better (ca. 10 to 26 X better) than that of the P-AcMNPV strain. In vitro produced nonoccluded virions, to be formulated as a viral product, will have to provide yields that are equal to or better than the wild type, and may have to be stabilized to withstand inactivation.