Identification and Profiling of a Novel Bombyx mori latent virus Variant Acutely Infecting Helicoverpa armigera and Trichoplusia ni

Thomas-Wolf Verdonckt; Anton Bilsen; Filip Van Nieuwerburgh; Loes De Troij; Dulce Santos; Jozef Vanden Broeck

doi:10.3390/v15051183

Identification and Profiling of a Novel Bombyx mori latent virus Variant Acutely Infecting Helicoverpa armigera and Trichoplusia ni

Viruses. 2023 May 17;15(5):1183. doi: 10.3390/v15051183.

Authors

Thomas-Wolf Verdonckt¹, Anton Bilsen¹, Filip Van Nieuwerburgh², Loes De Troij¹, Dulce Santos¹, Jozef Vanden Broeck¹

Affiliations

¹ Molecular Developmental Physiology and Signal Transduction Research Group, Animal Physiology and Neurobiology Division, Department of Biology, KU Leuven, Naamsestraat 59 Box 2465, 3000 Leuven, Belgium.
² Laboratory of Pharmaceutical Biotechnology, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.

Abstract

Insect cell expression systems are increasingly being used in the medical industry to develop vaccines against diseases such as COVID-19. However, viral infections are common in these systems, making it necessary to thoroughly characterize the viruses present. One such virus is Bombyx mori latent virus (BmLV), which is known to be specific to Bombyx mori and to have low pathogenicity. However, there has been little research on the tropism and virulence of BmLV. In this study, we examined the genomic diversity of BmLV and identified a variant that persistently infects Trichoplusia ni-derived High Five cells. We also assessed the pathogenicity of this variant and its effects on host responses using both in vivo and in vitro systems. Our results showed that this BmLV variant causes acute infections with strong cytopathic effects in both systems. Furthermore, we characterized the RNAi-based immune response in the T. ni cell line and in Helicoverpa armigera animals by assessing the regulation of RNAi-related genes and profiling the generated viral small RNAs. Overall, our findings shed light on the prevalence and infectious properties of BmLV. We also discuss the potential impact of virus genomic diversity on experimental outcomes, which can help interpret past and future research results.

Keywords: BmN4; High Five; Maculavirus; RNAi; antiviral immunity; viral piRNA.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Bombyx*
COVID-19* / genetics
Insecta
Moths*
RNA Interference
Tymoviridae*
Viruses*

Grants and funding

This work was funded by the Research Foundation of Flanders (FWO), grant number G093119N, and the Special Research Fund of KU Leuven, grant number C14/19/069. T.-W.V. was supported by FWO with a PhD fellowship, grant number 1S83719N. A.B. was funded by the KU Leuven with a PhD fellowship, project number 3E220092. D.S. is currently supported by the FWO as a postdoctoral researcher, fellowship number 1278922N.