Alteration in the Culex pipiens transcriptome reveals the implication of the mosquito immune system during Rift Valley fever phlebovirus infection

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. Overall design: Examination of the virulent RVFV infection in Cx. pipiens mosquito interaction