Characterization of midgut regeneration capacity and immune responses in local Aedes albopictus mosquitoes.

Abstract

Mosquitoes transmit a variety of diseases with important impact on human health. Several mosquito species occur naturally in Lebanon. The presence of these vectors coupled with the environmental changes increase the risk of spread of infectious diseases in the region. Current control strategies comprise several disadvantages, such as insecticide resistance, high cost and the risk of releasing female mosquitoes by mistake. A better characterization of the vectors’ immunity and physiology should provide insights for the development of novel control strategies. The gut is an important component of an effective immune response against pathogens. Maintaining gut integrity is therefore very important for successful clearance of invaders. Hence, in the context of this project, we wanted to investigate how mosquito gut integrity is maintained. We established a model for inducing gut damage in Aedes albopictus mosquitoes and studied the effect of damage on gut structure and on the proliferation of mitotic cells. Aedes albopictus is one of the mosquito species constituting a major vector of diseases. Other important examples of mosquito vectors include Culex pipiens and Anopheles gambiae mosquitoes. Therefore, in the second aim we extended the analysis of gut regeneration to these disease vectors in order to establish a comparative analysis of midgut regeneration capacity and resistance to oral infection Another aim of the project was to explore the immune responses of the Lebanese Aedes albopictus strain after different microbial challenges. We investigated the ability of mosquitoes to tolerate or clear infections with different pathogens. Some previous studies had shown that insects harboring the endosymbiont Wolbachia have a better resistance to several pathogens, while other studies have claimed that in its native host, immune activation by Wolbachia might get attenuated and the protective effects of the endosymbiont become abolished. Hence, we aimed to establish a model for a comparative analysis by generating