Project description:Use of the bacterium Wolbachia is an innovative new strategy designed to break the cycle of dengue transmission. There are two main mechanisms by which Wolbachia could achieve this: by reducing the level of dengue virus in the mosquito and/or by shortening the host mosquito's lifespan. However, although Wolbachia shortens the lifespan, it also gives a breeding advantage which results in complex population dynamics. This study focuses on the development of a mathematical model to quantify the effect on human dengue cases of introducing Wolbachia into the mosquito population. The model consists of a compartment-based system of first-order differential equations; seasonal forcing in the mosquito population is introduced through the adult mosquito death rate. The analysis focuses on a single dengue outbreak typical of a region with a strong seasonally-varying mosquito population. We found that a significant reduction in human dengue cases can be obtained provided that Wolbachia-carrying mosquitoes persist when competing with mosquitoes without Wolbachia. Furthermore, using the Wolbachia strain WMel reduces the mosquito lifespan by at most 10% and allows them to persist in competition with non-Wolbachia-carrying mosquitoes. Mosquitoes carrying the WMelPop strain, however, are not likely to persist as it reduces the mosquito lifespan by up to 50%. When all other effects of Wolbachia on the mosquito physiology are ignored, cytoplasmic incompatibility alone results in a reduction in the number of human dengue cases. A sensitivity analysis of the parameters in the model shows that the transmission probability, the biting rate and the average adult mosquito death rate are the most important parameters for the outcome of the cumulative proportion of human individuals infected with dengue.
Project description:Wolbachia, an endosymbiotic bacterium, is being investigated as a vector control agent in several insect species. Along with the well known classical reproductive parasitism Wolbachia employs against its host to spread within the population, it is emerging that the bacteria can protect the host against pathogens and reduced pathogen transmission. Anopheles mosquitoes, which transmit malaria, have never been found to harbour Wolbachia in nature, and despite numerous transinfection attempts, no stable line has been developed. However recently, two strains of Wolbachia, wAlbB from Aedes albopictus, and wRi from Drosophila simulans were cultured in Anopheles gambiae Sua5B cells. These cell lines provides an amenable system to study Wolbachia-Anopheles interaction in the absence of a stable transinfected line. It has been proposed that the compromised vector competence of Wolbachia infected insects is due to an up regulation of the basal immune state. We therefore completed a genome wide expression profile of Wolbachia infected Anopheles, assessing both wAlbB and wRi infected cells in parallel against uninfected Sua5B cells.
Project description:Using microarray-based comparative genome hybridizations (mCGH), the genomic content of Wolbachia pipientis wMel from Drosophila melanogaster was compared to the Wolbachia from D. innubila (wInn), D. santomea (wSan), and three strains from D. simulans (wAu, wRi, wSim).
Project description:The following dataset is a Wolbachia proteome derived from protein extractions of infected ovaries of the mosquito host Culex pipiens.
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.
Project description:Lymphatic filarial nematodes maintain a mutualistic association with the intracellular bacterium Wolbachia. Wolbachia populations expand following infection of the mammalian host, to support larval growth and development. Utilizing transcriptomic data from Brugia malayi over the first two weeks post-infection, we present an analysis of the biochemical pathways that are involved in Wolbachia population growth and regulation in support of larval development. In Wolbachia, we observe coordinated regulation of carbon metabolism with an alternating pattern of glycolysis and TCA cycle pathways reminiscent of the ‘Warburg effect’. Wolbachia's purine, pyrimidine and haem biosynthesis and Type IV secretion pathways are also upregulated and correlate with the upregulation of the nematode’s DNA replication pathway. In the nematode we observe up-regulation of the autophagy pathway, a key regulator of Wolbachia populations. These findings support a key role for nucleotide and haem provisioning from Wolbachia in support of the larval growth and development of its nematode host.
Project description:Zika virus is a global public health emergency due to its association with microcephaly, Guillain-Barré syndrome, neuropathy, and myelitis in children and adults. A total of 87 countries have had evidence of autochthonous mosquito-borne transmission of Zika virus, distributed across four continents, and no antivirus therapy or vaccines are available. Therefore, several strategies have been developed to target the main mosquito vector, Aedes aegypti, to reduce the burden of different arboviruses. Among such strategies, the use of the maternally-inherited endosymbiont Wolbachia pipientis has been applied successfully to reduce virus susceptibility and decrease transmission. However, the mechanisms by which Wolbachia orchestrate resistance to ZIKV infection remains to be elucidated. In this study, we apply quantitative isobaric mass spectrometry-based proteomics to quantify proteins and identify pathways altered during ZIKV infection; Wolbachia infection; co-infection with Wolbachia/ZIKV in the Ae. aegypti. We show that Wolbachia regulates proteins involved in ROS production, regulates humoral immune response, and antioxidant production. The reduction of ZIKV polyprotein in the presence of Wolbachia in the mosquitoes was determined by mass spectrometry and corroborates the idea that Wolbachia helps to block ZIKV infections in Ae. aegypti. The present study offers a rich resource of data to help elucidate mechanisms by which Wolbachia orchestrate resistance to ZIKV infection in Ae. aegypti.
Project description:Wolbachia, an endosymbiotic bacterium, is being investigated as a vector control agent in several insect species. Along with the well known classical reproductive parasitism Wolbachia employs against its host to spread within the population, it is emerging that the bacteria can protect the host against pathogens and reduced pathogen transmission. Anopheles mosquitoes, which transmit malaria, have never been found to harbour Wolbachia in nature, and despite numerous transinfection attempts, no stable line has been developed. However recently, two strains of Wolbachia, wAlbB from Aedes albopictus, and wRi from Drosophila simulans were cultured in Anopheles gambiae Sua5B cells. These cell lines provides an amenable system to study Wolbachia-Anopheles interaction in the absence of a stable transinfected line. It has been proposed that the compromised vector competence of Wolbachia infected insects is due to an up regulation of the basal immune state. We therefore completed a genome wide expression profile of Wolbachia infected Anopheles, assessing both wAlbB and wRi infected cells in parallel against uninfected Sua5B cells. Two strains of Wolbachia, wRi from Drosophila simulans and wAlbB from Aedes albopictus were transfered into Anopheles gambiae Sua5B cells via the shell vial technique. After over 30 passages, these Wolbachia infected cells lines were then compared, in parallel, to the original uninfected Sua5B cells using Affymetrix microarrays.
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.