cells challenged with the species-specific baculovirus Se MNPV as well as with a generalist baculovirus, Ac MNPV. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. Many immune-related genes, including pattern recognition proteins, genes involved in signalling and immune pathways as well as immune effectors and genes coding for proteins involved in the melanization cascade were found to be down-regulated after baculovirus infection.
We therefore asked whether the down-regulation that occurs after baculovirus infection affects the amount of gut microbiota.
An increase in the gut bacterial load was observed and we hypothesize this to be as a consequence of viral infection.
Humoral responses include identifying the invading microbes by pattern recognition proteins and subsequently synthesizing antimicrobial peptides (AMPs).
The production of AMPs in insects is regulated by the signalling pathways Toll, Imd and JAK-STAT.
A series of bioassays showed that the baculovirus performs better in the presence of microbiota in the gut.
Our study shows that baculovirus infection leads to increase of microbiota loads in the gut and that the gut microbiota play a significant role in insect immunity and susceptibility to viral infections.These findings suggest that gut microbiota can be manipulated to improve biocontrol strategies that employ baculoviruses.Baculoviruses are large DNA viruses that infect arthropods, mainly insects from the orders, Lepidoptera, Diptera and Hymenoptera.Subsequent experiments on virus performance in the presence and absence of gut microbiota revealed that gut bacteria enhanced baculovirus virulence, pathogenicity and dispersion.We discuss the host immune response processes and pathways affected by baculoviruses, as well as the role of gut microbiota in viral infection.Antiviral responses include the RNA interference (RNAi) machinery, which is especially active against RNA viruses; though recent studies show that it also contributes to fighting DNA viral infections , .