Ae. aegypti in nature differs dramatically in its vector competence for viruses (the permissiveness of the mosquito to become infected and to then transmit the virus). Successful transmission of a virus critically depends on its ability to overcome infection and escape barriers imposed by co-infecting pathogens or co-habiting symbionts in the mosquito. Viruses are obligate parasites and therefore, must compete for resources (or nutrients) primarily at the initial site of replication, the midgut. Thus, they induce significant changes in the mosquito metabolic environment to benefit viral replicative needs. The metabolic environment (referred to as the metabolome) can be precisely measured and directly linked to the level of replication and transmission and thus exploited to control these events. In this project we will determine if manipulating the metabolic environment of the mosquito can interfere with the success of viral replication by creating metabolic choke-points that limit transmission of the virus from the vector. We will also evaluate how Wolbachia (an endosymbiont that has the ability to block virus transmission) might compete for or limit metabolic resources required for virus replication and if this `pathogen- blocking' phenotype is dependent on its density within the mosquito. We will also identify if and how viruses will counter the effects of Wolbachia or other metabolic interference to develop resistance or escape metabolic pressure. Through this work, we will identify how the metabolic environment of the vector can be exploited (by natural or artificial means) to create refractory environments for viral replication and transmission. This work will also provide a foundation for developing associations between metabolic reprogramming and other important vector phenotypes, such as insecticide resistance, populations structure and geographic distribution, and general mosquito biology, all of which are major determinants of vectorial capacity and pathogen transmission.
Aedes aegypti is the primary mosquito vector that transmits the arboviruses, dengue, Zika, chikungunya and yellow fever in the Western Hemisphere. These studies will identify biochemical pathways that change in the mosquito following infection with these viruses. They will also identify how the endosymbiont Wolbachia used to control virus transmission in Aedes aegypti may be metabolically competing with the virus. Identifying the biochemical pathways that are integral to mosquito biology and to transmission of these viruses provide a novel avenue to interfere with vector transmission of the virus.
