Influence of Time and Multiplicity of Infection on the Batch Production of Anticarsia gemmatalis Nuclear Polyhedrosis Virus in Lepidopteran Insect Cell Cultures

Abstract

The influence of the time and the multiplicity of infection was investigated on the production of polyhedra of Anticarsia gemmatalis nuclear polyhedrosis virus (AgNPV) in batch suspension cultures of IPLB-Sf-21 insect cells. Several cultures were infected at various multiplicities of infection, either in the early or in the late growth phase. While the dynamics of the infection process was clearly determined by the multiplicity of infection (affecting the cell growth, the viability evolution, the kinetics of virus synthesis and indirectly the virus yield), final virus yields were strongly influenced by the actual time of cellular infection. Early infected cells showed to be more permissive to replicate AgNPV than late infected cells. Such a higher permissivity of early infected cells determined the maximum polyhedra productivity obtained in early and synchronal infected cultures, despite the fact that late infected cultures showed to be more efficient than early infected ones to perform the final step in the process of polyhedra synthesis: the occlusion of enveloped viruses.