In vitro infectivity of Spodoptera frugiperda multiple nucleopolyhedrovirus to different insect cell lines

Abstract

The objective of this work was to evaluate the response of an in vitro host range to Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), a pathogenic virus to the fall armyworm (Spodoptera frugiperda, Lepidoptera: Noctuidae), for the further development of a biopesticide based on cell culture systems. The cell lines from Bombyx mori (BM-5), Lymantria dispar (IPLB-LD-625Y), Trichoplusia ni (BTI-Tn-5B1-4), Anticarsia gemmatalis (UFL-AG-286), and S. frugiperda (IPLB-SF-21AE and Sf9) were tested for their susceptibility to a highly-virulent Brazilian isolate of SfMNPV. The cytopathic effects induced by the virus, the production of viral particles, and the synthesis of viral polypeptides were examined and compared. Both S. frugiperda cell lines showed hypertrophy of cell nuclei and production of many polyhedra. The SDS-Page of radiolabed proteins showed that the cell protein synthesis was shutoff, while an intense band of about 30 kDa, recognized as polyhedrin, was synthesized. The other cell lines did not show polyhedra production, although some of them underwent morphological changes and protein synthesis shutdown in response to virus infection. The SF-21 and Sf9 cell lines are recommended for further in vitro production of SfMNPV.

Bioreactor Production Process of Spodoptera frugiperda multiple nucleopolyhedrovirus Biopesticide

“…There are several studies focused on the bioreactor culture of baculoviruses aiming to achieve recombinant protein production [ 26 , 27 , 28 , 29 ], although only a few studies have been conducted regarding the in vitro production of baculoviruses for pest control [ 30 , 31 , 32 ]. Advances were achieved in the selection of suitable cell lines for high OBs production [ 15 , 33 ]. However, there are still challenges to be overcome in the scale-up process for large-scale in vitro production.…”

“…(CVI code BRM5023). The virus stock suspension of 4.65 × 10 6 pfu/mL was previously obtained from static culture [ 15 ]. All cell cultures used Sf-900™ III Serum Free Medium (Gibco, Waltham, MA, USA).…”

“…However, baculovirus multiplication in cell culture has the potential to overcome these limitations during large-scale production [ 13 ]. The SF-21 and Sf9 cell lines support the wild SfMNPV isolates’ replication both in suspension and in static culture [ 14 , 15 ]. One of the downsides of the serial passage of virus in insect cell culture is the occurrence of Few-Polyhedra (FP) mutants that produce low yields of occlusion bodies (OBs), which have an advantageous rate of virus replication [ 16 ] but show a low virulence of SfMNPV produced in SF-21 cells [ 17 ].…”

Viruses of the Fall Armyworm Spodoptera frugiperda: A Review with Prospects for Biological Control

“…However, a major concern of this technology is the mutation of the isolates since several passages in insect cell cultures might lead to deletions in some parts of the genome, which might render the isolates less virulent [32,64,76] or even loss of oral infectivity [114]. Nonetheless, ongoing studies on the optimization of the production of baculovirus OBs in cell culture [158][159][160] showed that the propagation of SfMNPV in Sf9 and Sf21 cells in both static and suspension cultures results in a higher OB production in comparison to other cell types [159,160]. Further optimization of in vitro production in cell culture might lead to a successful commercial mass production.…”