Project description:PIWI-interacting (pi) RNAs are a class of small RNAs that have diverse functions in mosquitoes. In order to uncover novel components involved in biogenesis or function of the piRNA pathway in Aedes aegypti mosquitoes, we performed mass spectrometry analyses on immunoprecipitated PIWI proteins and their interactors.
Project description:Plasmodium parasites within mosquitoes are exposed to various physiological processes, such as blood meal digestion activity, the gonotrophic cycle, and host responses preventing the entry of parasites into the midgut wall. However, when in vitro-cultured ookinetes are injected into the hemocoel of mosquitoes, Plasmodium parasites are not affected by the vertebrate host’s blood contents and do not pass through the midgut epithelial cells. This infection method might aid in identifying mosquito-derived factors affecting Plasmodium development within mosquitoes. This study investigated novel mosquito-derived molecules related to parasite development in Anopheles mosquitoes. We injected in vitro-cultured Plasmodium berghei (ANKA strain) ookinetes into female and male Anopheles stephensi (STE2 strain) mosquitoes and found that the oocyst number was significantly higher in males than in females, suggesting that male mosquitoes better support the development of parasites. Next, RNA-seq analysis was performed on the injected female and male mosquitoes to identify genes exhibiting changes in expression. Five genes with different expression patterns between sexes and greatest expression changes were identified as being potentially associated with Plasmodium infection. Two of the five genes also showed expression changes with infection by blood-feeding, indicating that these genes could affect the development of Plasmodium parasites in mosquitoes.
Project description:Efficient virus replication in its vector, Aedes mosquitoes, is essential for the transmission of arboviral diseases like dengue virus (DENV) in populations. In order to identify RNA-independent host factors involved in DENV replication in mosquitoes, we established a system expressing all non-structural proteins within the context of the macro protein complex as observed during viral infections. We GFP-tagged Loqs to purify it's interactors by label-free mass spectrometry.
Project description:Efficient virus replication in its vector, Aedes mosquitoes, is essential for the transmission of arboviral diseases like dengue virus (DENV) in populations. In order to identify RNA-independent host factors involved in DENV replication in mosquitoes, we established a system expressing all non-structural proteins within the context of the macro protein complex as observed during viral infections. Mosquito host factors interacting with 3xFLAGED-tagged DENV non-structural proteins NS1 or NS5 proteins were identified by label-free mass spectrometry.
Project description:Rift valley fever (RVF) is an emerging zoonotic disease and it is caused by Rift valley fever phlebovirus (RVFV). This virus is commonly transmitted in endemic areas between wild ruminants and mosquitoes, mainly by mosquitoes of Culex and Aedes genus. Starting from 2000, several outbreaks have been reported outside the African continent, in countries facing the Mediterranean Sea, such as Saudi Arabia. The available vaccines for ruminants present limited efficacy or residual pathogenic effects. Consequently, new strategies are urgently required to limit the expansion of this zoonotic virus. The main objective of this work is to investigate the molecular responses of Culex pipiens to RVFV focusing mainly on genes implicated in the classical innate immunity pathways, RNAi mechanism and apoptosis process in order to elucidate the implicated genes in viral infection. The immune altered genes here described could be potential targets to control RVFV infection in mosquitoes. Some of the genes related to the immune defense response were previously described in others mosquito-arbovirus models, as also in Drosophila and human. To our knowledge, this study elucidates for the first time the Cx. pipiens-RVFV interaction in terms of defense infection-response, which was largely under studied and provides information to develop new approaches to prevent and control the expansion of the virus in the future.
Project description:In recent years, arboviral infections have surged dramatically due to the geographic expansion of Aedes and Culex mosquitoes, their main vector mosquitoes. Despite significant efforts to uncover arbovirus–host interactions and viral protein effector functions in mammals, systematic studies aiming to characterize virus–vector interactions in arthropods are largely missing, and the functions and cellular targets of many arboviral proteins in mosquitoes remain elusive. Here, we applied a multi-omic approach to systematically evaluate the ability of arboviral capsids to interact with the Ae. aegypti proteome. This extensive multi-modal atlas across 12 pathogenic arboviral species spanning three viral genera revealed shared and distinct host factor specificities, uncovering species-, genus- and vector preference-specific patterns of host usage in mosquitoes. Functional phenotypic screening of 110 newly discovered host proteins across three prototypic arboviruses (La Crosse virus, dengue virus and West Nile virus) identified several novel host dependency factors, including a new role for the chromatin-remodeling Brahma complex in orthoflavivirus replication. Using a combination of biochemical and sequencing approaches, we characterized the cellular determinants of these interactions and profiled their functional consequences on the chromatin landscape. Altogether, this study provides a multi-layered repository to categorize and characterize arboviral capsid effector functions in invertebrates, providing important cues on novel mechanisms of transcriptional regulation via capsid-mediated modulation of chromatin accessibility in insects.