A proctolin‐like peptide is regulated after baculovirus infection and mediates in caterpillar locomotion and digestion

Abstract

Baculoviruses constitute a large group of invertebrate DNA viruses, predominantly infecting larvae of the insect order Lepidoptera. During a baculovirus infection, the virus spreads throughout the insect body producing a systemic infection in multiple larval tissues, included the central nervous system (CNS). As a main component of the CNS, neuropeptides are small protein-like molecules functioning as neurohormones, neurotransmitters, or neuromodulators. These peptides are involved in regulating animal physiology and behavior and could be altered after baculovirus infection. In this study, we have investigated the effect of Spodoptera exigua multiple nucleopolyhedrovirus (SeM-NPV) infection on expression of Spodoptera exigua neuropeptides and neuropeptide-like genes. Expression of the gene encoding a polypeptide that resembles the well-known insect neuropeptide proctolin and named as proctolin-like peptide (PLP), was downregulated in the larval brain following infection and was chosen for further analysis. A recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) overexpressing the Cterminal part of the PLP was generated and used in bioassays using S. exigua larvae to study its influence on the viral infection and insect behavior. AcMNPV-PLP-infected larvae showed less locomotion activity and a reduction in growth compared to larvae infected with wild type AcMNPV or mock-infected larvae. These results are indicative of this new peptide as a neuromodulator that regulates visceral and skeletal muscle contractions and offers a novel effector involved in the behavioral changes during baculovirus infection.

The Role of Exosome and the ESCRT Pathway on Enveloped Virus Infection

“…After oral ingestion of ODV in arthropods, the alkaline environment in their intestines causes the ODV shell to fall off, releasing infectious virions, which initiate infection from insect intestinal epithelial cells. Then the nucleocapsid enters the midgut cells for replication, and the newly formed nucleocapsid buds out of the midgut cells to form the second virion blastomavirus (BV), which invades cells through receptor-mediated endocytosis and mediates systemic infection between cells [106,110]. More than 600 species of baculoviruses have been found, among which Autographa californica multiple nucleopolyhedrovirus (ACMNPV) has been extensively studied as a model baculovirus [111].…”

Influence of RVFV Infection on Olfactory Perception and Behavior in Drosophila melanogaster

“…Viral induced behavior changes regarding olfaction were also observed in other insect species. Infection with Baculoviruses changes the expression of specific odorant receptors in Lepidoptera causing an altered olfactory-driven behavioral response to food related odors or influencing the production of neuropeptides reducing locomotor activity and growth [47,48]. Additionally, infection state of planthoppers can alter their preferences in an olfactometer test setup regarding infected versus non-infected host plants [49].…”