Project description:Wolbachia pipientis is an intracellular symbiotic bacterium found in insects and arthropods. Wolbachia can decrease the vectorial capacity for various pathogens, such as the dengue virus, in Aedes aegypti. The purpose of this study was to determine the effect of Wolbachia (wMel strain) on the vectorial capacity of Ae. aegypti for Dirofilaria immitis. We analyzed gene expression patterns by RNA-seq in addition to the D. immitis infection phenotype in Ae. aegypti infected with and without wMel. Four Ae. aegypti strains, MGYP2.tet, MGYP2, Liverpol (LVP)-Obihiro (OB), and LVP-OB-wMel (OB-wMel) were analyzed for transcriptome comparison in Malpighian tubule at 2 days post infection. The correlation between Wolbachia infection, D. immitis infection phenotype and immune-related genes expression in Ae. aegypti was investigated.
Project description:Certain strains of the intracellular endosymbiont Wolbachia can strongly inhibit or block the transmission of viruses such as dengue by Aedes mosquitoes, and the mechanisms responsible are still not well understood. Direct infusion and liquid chromatography FT-ICR mass spectrometry based lipidomicse DIMS and LCMS analyses were conducted using Aedes albopictus Aa23 cells that were infected with the wMel and wMelPop strains of Wolbachia compared to uninfected cells. Substantial shifts in the cellular lipid profile were apparent in the presence of Wolbachia. Most significantly, sphingolipids were depleted across all classes, and some reduction in diacylglyerol fatty acids and phosphatidylcholines was also observed. These lipid classes have previously been shown to be selectively enriched in DENV-infected mosquito cells, suggesting that Wolbachia may produce a cellular lipid environment that is antagonistic to viral replication. The data improve understanding of the intracellular interactions between Wolbachia and mosquitoes.
Project description:Wolbachia is a vertically transmitted intracellular bacteria that infect most than 60% of insect species. The strains wMelPop and wMel were introduced in the dengue virus vector Aedes aegypti, naturally not infected by Wolbachia. Recently, it was shown that those two strains inhibit dengue virus replication into their new host, A. aegypti (Moreira et al. 2009 and Walker et al. in preparation). The aim of this project is to look at the transcriptional response of Aedes aegypti to infection with wMel and wMelPop and try to find some genes or pathway potentially involved in the viral interference.Four laboratory lines of A. aegypti were used throughout this study. The PGYP1 and Mel2 lines were generated by transinfection with wMelPop and wMel strains respectively. PGYP1.tet and Mel2tet lines were treated with the antibiotic tetracycline and cured from Wolbachia infection (McMeniman et al., 2009 and Walker et al in preparation). The Mosquitoes were reared under standard laboratory conditions (26 ± 2 °C, 12:12 light/dark cycle, 75% relative humidity). Mosquito larvae were fed 0.1mg/larvae of TetraMin Tropical Tablets once a day. Adults were transferred to cages (measuring 30 x 30 x 30 cm) at emergence at 400 individuals per cage. Adults were supplied with a basic diet of 10% sucrose solution (Turley et al., 2009).
Project description:Cellular models have provided significant advances on molecular bases of bipartite interactions between either an arbovirus or a bacterial symbiont with a given arthropod vector. However, although an interference phenomenon was evidenced in tripartite interaction arbovirus-symbiont-mosquito vector very little is known regarding the mechanisms involved. Using large-scale proteome profiling, we characterized proteins differentially expressed in Aedes albopictus cells infected by the symbiotic bacterium Wolbachia and the Chikungunya virus (CHIKV). These proteins were mostly related to cellular processes involved in glycolysis process, protein metabolism, translation and amino acid metabolism. The presence of Wolbachia impacted significantly the protein profiles, including sequestration of proteins such as structural polyprotein and capsid viral proteins that may affect replication and assembly of CHIKV in cellulo. This study provides insights into the molecular pathways involved in the tripartite interaction mosquito-Wolbachia-virus and may help in defining targets for the better implementation of Wolbachia-based strategy for disease transmission control.