Function of hemolymph plasma proteins in insect immune responses

昆虫有一种天生的免疫系统，可以保护自己免受病原体和 寄生虫。这个项目的总体目标是研究昆虫血淋巴血浆中的蛋白质。 参与昆虫免疫的不同方面。这个实验室以前的工作是 建立了鳞翅目昆虫Manduca sexta，作为适合于 血淋巴蛋白复杂功能的生化表征。我们计划 研究由血浆蛋白介导的免疫的三个方面。(1)我们会 革兰氏阴性菌和革兰氏阴性菌血浆蛋白与肽聚糖相互作用的研究 一种阳性细菌，能激活丝氨酸蛋白酶，从而启动酶的级联反应 这会导致酚氧化酶和Toll途径的激活。(2)我们会调查 血淋巴的氧化还原环境在免疫反应和检测过程中受到调节 免疫蛋白可能受硫醇修饰调节的假说。(3)哺乳动物有 很好地描述了剥夺入侵微生物铁的机制；然而， 昆虫体内与免疫相关的铁抑制作用仍然知之甚少。我们将使用M.sexta作为 在昆虫中发现保守的铁抑制机制的模型。最基本的 通过这项研究获得的生物化学知识有望更好地激发 昆虫血淋巴中蛋白酶级联途径和分子调控的认识 有助于免疫过程中的氧化调节，并有助于理解铁是如何 通过昆虫媒介影响人类疾病的传播。这份副刊将资助一项 来自代表性不足群体的本科生将获得研究经验和 通过参与项目进行培训。

Insects have an innate immune system that protects against infections by pathogens and parasites. The overall goal of this project is to investigate proteins in insect hemolymph plasma that participate in different aspects of insect immunity. Previous work from this laboratory has established the lepidopteran insect, Manduca sexta, as a model system well suited for biochemical characterization of the complex functions of hemolymph proteins. We plan to investigate three aspects of immunity that are mediated by plasma proteins. (1) We will characterize interactions of plasma proteins with peptidoglycan from Gram-negative and Gram- positive bacteria that trigger activation of a serine protease, thereby initiating protease cascades that result in activation of phenoloxidase and the Toll pathway. (2) We will investigate how the redox environment of hemolymph is regulated during an immune response and test a hypothesis that immune proteins may be regulated by thiol modifications. (3) Mammals have well-characterized mechanisms for depriving invading microorganisms of iron; however, immune-related iron-withholding in insects is still poorly understood. We will use M. sexta as a model for discovering conserved iron-withholding mechanisms in insects. The fundamental biochemical knowledge gained as a result of this research is expected to stimulate better understanding of regulation of protease cascade pathways and molecules in insect hemolymph that contribute to oxidative modulation during immunity, and lead to understanding of how iron influences human disease transmission by insect vectors. This supplement will fund an undergraduate student from an underrepresented group to gain research experience and training by participating in the project.