In vitro production of baculoviruses: identifying host and virus genes associated with high productivity

Abstract

Baculoviruses are recognized as viral workhorses of biotechnology, being used for production of vaccines, complex recombinant proteins, gene delivery vectors' and safe biological pesticides. Improving production yields and understanding the interactions of the virus and its host cell are important aspects of ensuring baculovirus-based processes are commercially competitive. This study aims at potential optimization of host cells used in in vitro virus production by systemically investigating changes in host gene expression in response to virus replication and transcription inside host cells. The study focuses on in vitro interactions of the Helicoverpa armigera virus with Helicoverpa zea insect cells. We used 22 genome-wide microarrays to simultaneously measure both virus and host genes in infected cells in multiple batch suspension cultures, representing high- and low-producing infection conditions. Among 661 differentially expressed genes, we identified a core set of 59 host genes consistently overexpressed post infection, with strong overrepresentation of genes involved in retrotransposition, protein processing in the endoplasmic reticulum, and ubiquitin-mediated proteolysis. Applying a whole genome correlation network analysis to link gene expression to productivity, we revealed 18 key genes significantly associated to virus yield. In addition, this study is among the first to perform a genome-wide expression study for a major baculovirus group II strain, the H. armigera virus, extending current understanding of baculovirus-insect interactions, which mainly focuses on group I viruses.

Caracterización de baculovirus autóctonos para el control de la oruga militar tardía (<i>Spodoptera frugiperda</i>)

“…En primer lugar, la posibilidad de reproducir el ciclo replicativo viral en condiciones controladas de laboratorio permite diseñar y probar distintas perturbaciones para conocer su funcionamiento a nivel molecular. 212,213 Por otra parte, las herramientas de cultivo celular facilitan enormemente la aplicación de técnicas clásicas de ingeniería genética y virología para el estudio de baculovirus mutantes. 214,215 En particular, el estudio de mutantes que portan deleciones y los correspondientes virus reparados con una nueva copia del gen, la cual ha sido insertada en un locus distinto al original, representan el enfoque genético más empleado a la fecha para la caracterización de la función molecular de genes baculovirales no anotados.…”