Projects per year
Abstract
Wolbachia are a genus of insect endosymbiotic bacteria which includes strains wMel and wAlbB that are being utilized as a biocontrol tool to reduce the incidence of Aedes aegypti-transmitted viral diseases like dengue. However, the precise mechanisms underpinning the antiviral activity of these Wolbachia strains are not well defined. Here, we generated a panel of Ae. aegypti-derived cell lines infected with antiviral strains wMel and wAlbB or the non-antiviral Wolbachia strain wPip to understand host cell morphological changes specifically induced by antiviral strains. Antiviral strains were frequently found to be entirely wrapped by the host endoplasmic reticulum (ER) membrane, while wPip bacteria clustered separately in the host cell cytoplasm. ER-derived lipid droplets (LDs) increased in volume in wMel- and wAlbB-infected cell lines and mosquito tissues compared to cells infected with wPip or Wolbachia-free controls. Inhibition of fatty acid synthase (required for triacylglycerol biosynthesis) reduced LD formation and significantly restored ER-associated dengue virus replication in cells occupied by wMel. Together, this suggests that antiviral Wolbachia strains may specifically alter the lipid composition of the ER to preclude the establishment of dengue virus (DENV) replication complexes. Defining Wolbachia's antiviral mechanisms will support the application and longevity of this effective biocontrol tool that is already being used at scale.IMPORTANCEAedes aegypti transmits a range of important human pathogenic viruses like dengue. However, infection of Ae. aegypti with the insect endosymbiotic bacterium, Wolbachia, reduces the risk of mosquito to human viral transmission. Wolbachia is being utilized at field sites across more than 13 countries to reduce the incidence of viruses like dengue, but it is not well understood how Wolbachia induces its antiviral effects. To examine this at the subcellular level, we compared how different strains of Wolbachia with varying antiviral strengths associate with and modify host cell structures. Strongly antiviral strains were found to specifically associate with the host endoplasmic reticulum and induce striking impacts on host cell lipid droplets. Inhibiting Wolbachia-induced lipid redistribution partially restored dengue virus replication demonstrating this is a contributing role for Wolbachia's antiviral activity. These findings provide new insights into how antiviral Wolbachia strains associate with and modify Ae. aegypti host cells.
Original language | English |
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Article number | e0249523 |
Number of pages | 20 |
Journal | mBio |
Volume | 15 |
Issue number | 2 |
DOIs | |
Publication status | Published - 14 Feb 2024 |
Keywords
- Aedes aegypti
- antiviral
- arbovirus
- dengue
- flavivirus
- Wolbachia
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Defining the antiviral effects of Wolbachia in Aedes aegypti mosquitoes
Fraser, J., Mackenzie, J., Simmons, C. & Adelman, Z.
Australian Research Council (ARC)
1/03/23 → 31/12/25
Project: Research
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Dengue virus resistance to Wolbachia
Fraser, J. & Eyre, N. S.
National Health and Medical Research Council (NHMRC) (Australia)
1/01/20 → 31/12/23
Project: Research
Equipment
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Monash Micro Imaging
Stephen Firth (Manager), Alex Fulcher (Operator), Oleks Chernyavskiy (Operator), Margaret Rzeszutek (Other), David Potter (Manager), Volker Hilsenstein (Operator), Juan Nunez-Iglesias (Other), Stephen Cody (Manager), Irena Carmichael (Operator), Betty Kouskousis (Other), Sarah Creed (Manager) & Giulia Ballerin (Operator)
Faculty of Medicine Nursing and Health Sciences Research PlatformsFacility/equipment: Facility
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Ramaciotti Centre for Cryo-Electron Microscopy
Georg Ramm (Manager), Simon Andrew Crawford (Operator), Hariprasad Venugopal (Operator), Joan Marea Clark (Operator) & Gediminas Gervinskas (Operator)
Faculty of Medicine Nursing and Health Sciences Research PlatformsFacility/equipment: Facility