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

蚊子是世界性的害虫和疾病媒介。 目前用于控制蚊子种群的方法主要依赖于在蚊子血腔（体腔）或肠道中发挥其杀虫功能的化学或生物制剂。 当在血腔中时，杀虫剂通过血淋巴（血液）的自然流动遍布全身，并暴露于蚊子免疫和解毒因子。 此外，由蚊子传播的病原体通过血腔进行专性迁移，在血腔中它们也必须压倒蚊子的免疫和解毒因子。 在描述蚊子心脏的结构力学时，Hillyer及其同事观察到全身性细菌感染引起免疫细胞聚集在心脏瓣膜周围的区域（口周区域），这使他们假设循环系统和免疫系统协同工作以消除全身性感染。 本研究的目的是描述免疫细胞和蚊子心脏的口周区域之间的相互作用，以揭示蚊子循环系统和免疫系统之间生理相互作用的基本方面。 目的1将采用成像方法来表征口周免疫细胞灶的结构，确定口周免疫细胞灶形成的动力学，并测试心脏收缩动力学是否响应于细菌感染而改变。 目标2将利用分子和成像技术揭示调节蚊子心脏活动的激素。 最后，目标3将测试操纵心脏收缩动力学是否改变口周免疫细胞灶形成的动力学和蚊子在全身感染中存活的能力。 从这些实验中获得的数据可以帮助开发新的害虫和疾病控制策略。 除了科学影响外，该项目还将对研究生、本科生和高中生进行生物研究方面的培训。

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.