The Antiviral Effects of the Symbiont Bacteria Wolbachia in Insects

Abstract

Wolbachia is a maternally transmitted bacterium that lives inside arthropod cells. Historically, it was viewed primarily as a parasite that manipulates host reproduction, but more recently it was discovered that Wolbachia can also protect Drosophila species against infection by RNA viruses. Combined with Wolbachia’s ability to invade insect populations due to reproductive manipulations, this provides a way to modify mosquito populations to prevent them transmitting viruses like dengue. In this review, we discuss the main advances in the field since Wolbachia’s antiviral effect was discovered 12 years ago, identifying current research gaps and potential future developments. We discuss that the antiviral effect works against a broad range of RNA viruses and depends on the Wolbachia lineage. We describe what is known about the mechanisms behind viral protection, and that recent studies suggest two possible mechanisms: activation of host immunity or competition with virus for cellular resources. We also discuss how association with Wolbachia may influence the evolution of virus defense on the insect host genome. Finally, we investigate whether the antiviral effect occurs in wild insect populations and its ecological relevance as a major antiviral component in insects.

Insect-specific viruses regulate vector competence in Aedes aegypti mosquitoes via expression of histone H4

“…This poor diversity in A. albopictus was observed in several independent samples, which suggests it is not an artefact. It is noteworthy that A. albopictus naturally carries the endosymbiont bacteria Wolbachia that is known to provide resistance to viruses in insects (38)(39)(40).…”

Combating mosquito-borne diseases using genetic control technologies

“…This mechanistic aspect is an important design consideration, as it influences the ability to target pathogens at different developmental stages or multiple sites, which can be crucial for preventing or mitigating the emergence of pathogen resistance 60,61 . To date, there is no evidence of pathogen escape, or evasion, in Wolbachia-infected wild populations, but there have been numerous examples in laboratory studies 67 with different pathogens and different arthropod hosts underscoring the importance of continued monitoring for such an escape. For example, an elegant artificial selection and gene association study on Wolbachia-infected mosquitoes collected from the WMP program release site in Cairns, Australia, was able to quickly select pathogen blocking phenotypes and identified 61 genes associated with modulation of pathogen blocking, suggesting that breakdown of pathogen blocking could occur easily under some circumstances 68 .…”

Intracellular Interactions Between Arboviruses and Wolbachia in Aedes aegypti

“…Existing review articles on Wolbachia ’s pathogen blocking effect present a broad discussion encompassing various arthropod species ( Caragata et al., 2016 ; Kamtchum-Tatuene et al., 2017 ; Lindsey et al., 2018 ; Pimentel et al., 2021 ). On the contrary, this review focuses on Ae.…”