Interplays between physiology and arbovirus infection in mosquito vectors
Supervisor: Dr Emilie Pondeville, School of Infection & Immunity
Rotation project:
Male and female mosquitoes feed on plant nectar to get sugars, which are required for their energy and survival. In addition, females from many mosquito species, such as Aedes aegypti, must get a blood meal from a vertebrate host to obtain the necessary proteins to develop their eggs. This requirement for a blood meal results in Ae. aegypti being a vector of numerous arthropod-borne viruses (arboviruses; e.g. dengue [DENV], chikungunya [CHIKV], Zika [ZIKV] viruses), which are global public health threats and economic burdens. Control of mosquito vectors remains the most important tool to fight mosquito-borne diseases. Therefore, basic and applied research in entomology and vector control are on the list of the World Health Organization’s priority agenda to tackle mosquito-borne diseases.
Our recent findings uncovered a crucial role of sugar feeding in protecting Ae. aegypti mosquitoes against arboviral infection (ZIKV and SFV) by enhancing gut immunity (1). Since Ae. aegypti almost exclusively feed on blood in some natural settings, our findings suggest that this lack of sugar intake could increase the spread of mosquito-borne arboviral diseases and that basic sugar baits could constitute an environmentally friendly, sustainable, and cost-effective method to control arbovirus transmission. While sugar feeding increases antiviral immunity and protects Ae. aegypti mosquitoes against arboviral infection, we have shown that this positive action of sugar is partly inhibited by the gut microbiota, specifically gut bacteria (1). Our data suggest that the mosquito microbiota may limit sugar response and metabolism following a sugar meal to promote further blood proteins digestion and therefore reproductive output. While microbiota could be beneficial to the mosquito female’s physiology, this would be detrimental to humans by driving and increasing arbovirus transmission by mosquitoes. We now want to explore how the mosquito microbiota influences host nutrition and metabolism and how this in turn affects physiology (immunity and reproduction) and vector competence in Ae. aegypti.
To this aim, you will conduct experiments to characterize the commensal bacteria diversity in our Ae. aegypti strain and identify the bacteria responsible for the increase in arbovirus susceptibility, and to determine how mosquito microbiota limits sugar response and metabolism - and therefore sugar-induced immunity and resistance to arboviruses - to further promote reproductive output.
During your Ph.D. studies, you will have access and get training as required in state-of-the-art facilities at the CVR, including CL2 and CL3 insectaries (infection of mosquitoes with arboviruses), imaging facilities, sequencing and bioinformatics. The student will benefit from the supervision and guidance of Dr Pondeville, an expert in mosquito biology and arbovirus interactions as well mosquito genetics, and from our collaborators, experts in mosquito microbiota and bioinformatics analyses. You will use various techniques such as molecular biology techniques, immunostaining and confocal microscopy, mosquito manipulation including dissection, mosquito infection with arboviruses, injection, microbiology, virology and cell culture, analysis of sequencing datasets etc.
1. Almire F, Terhzaz S, Terry S, McFarlane M, Gestuveo RJ, Szemiel AM, Varjak M, McDonald A, Kohl A, Pondeville E. Sugar feeding protects against arboviral infection by enhancing gut immunity in the mosquito vector Aedes aegypti. PLoS Pathogens 2021. 17(9): e1009870.
Watch a film about the CVR Insectaries: https://vimeo.com/473912713
https://www.gla.ac.uk/schools/infectionimmunity/staff/emiliepondeville/
https://www.gla.ac.uk/research/az/cvr/aboutus/people/researchgroups/pondevillegroup/
https://www.gla.ac.uk/research/az/cvr/facilities/insectaries/