Dynamics of the Mosquito Heart: Hemolymph Flow and Associated Immune Cells

Vanderbilt University, Nashville TN

Investigators

Abstract

Mosquitoes are cosmopolitan pests and disease vectors. Current methods for the control of mosquito populations rely primarily on chemical or biological agents that exert their insecticidal function in the mosquito hemocoel (body cavity) or in the gut. When in the hemocoel, insecticidal agents are spread throughout the body by the natural flow of hemolymph (blood) and are exposed to mosquito immune and detoxifying factors. In addition, pathogens transmitted by mosquitoes undergo an obligate migration through the hemocoel where they must also overpower mosquito immune and detoxifying factors. While characterizing the structural mechanics of the mosquito heart, Hillyer and colleagues observed that systemic bacterial infection elicited immune cells to aggregate in areas surrounding the valves of the heart (periostial regions), leading them to hypothesize that the circulatory and immune systems work in concert to eliminate systemic infections. The goal of this research is to characterize the interaction between immune cells and the periostial regions of the mosquito heart in an effort to uncover fundamental aspects of the physiological interaction between the mosquito circulatory and immune systems. Objective 1 will employ imaging methodologies to structurally characterize periostial immune cell foci, determine the kinetics of periostial immune cell foci formation, and test whether heart contraction dynamics change in response to bacterial infection. Objective 2 will employ molecular and imaging methodologies to uncover hormones that regulate mosquito heart activity. Finally, objective 3 will test whether manipulating heart contraction dynamics alters the kinetics of periostial immune cell foci formation and the ability of mosquitoes to survive a systemic infection. Data arising from these experiments could aid in the development of novel pest and disease control strategies. In addition to its scientific impact, this project will result in the training of graduate, undergraduate and high school students in biological research.