Insect Immunity Against Parasitoids

小行星9504796 拟议项目的总体目标是通过研究果蝇对寄生虫Leptopilina boulardi的细胞毒性反应，更好地了解昆虫免疫系统。 当被感染时，免疫反应性昆虫通常在异物周围形成深色的黑色素胶囊，但实际上对特异性靶向和破坏包囊寄生虫的细胞毒性分子一无所知。 果蝇Leptopilina模型为系统分析昆虫免疫中的细胞和生化过程提供了一个很好的遗传系统。 使用遗传上明确的D. Nappi博士将监测寄生虫诱导的黑色素前体等潜在细胞毒性物质的产生（例如，醌，半醌），和活性氧（例如，超氧阴离子、羟基自由基和过氧化氢）。 细胞毒性分子的识别和它们产生的机制的知识将是非常有用的，在回答一些关于昆虫免疫识别的基本问题。 在已知的抗性和敏感宿主菌株以及抗氧化剂缺乏菌株中，将通过使用高压液相色谱-电化学检测、紫外/维斯光谱和荧光检测来监测寄生虫诱导的黑色素前体和抗氧化酶的变化。 这样一个全面的方法来研究细胞毒性分子的形成，有望提供有趣的见解，某些自由基和黑色素的反应前体在昆虫免疫中的重要性。 ***

9504796 Nappi The overall objective of the proposed project is to gain a better understanding of the insect immune system by studying the cytotoxic responses made by the fruit fly Drosophila melanogaster against the parasitoid Leptopilina boulardi. When infected, immune reactive insects typically form darkly colored, melanotic capsules around the foreign objects, but virtually nothing is known of the cytotoxic molecules that specifically target and destroy encapsulated parasites. The Drosophila Leptopilina model provides an excellent genetic system for the systematic analysis of the cellular and biochemical processes involved in insect immunity. Using genetically well-defined strains of D. melanogaster, Dr. Nappi will monitor the parasite-induced generation of such potentially cytotoxic substances as melanin precursors (e.g., quinones, semiquinones), and reactive oxygen species (e.g., superoxide anion, hydroxyl radical and hydrogen peroxide). The identification of cytotoxic molecules and knowledge of the mechanisms by which they are produced will be extremely useful in answering some of the fundamental questions concerning immune recognition in insects. Parasite-induced changes in melanin precursors and antioxidant enzymes will be monitored in known resistant and susceptible host strains, and in antioxidant deficient strains, by using high pressure liquid chromatography with electrochemical detection, UV/vis spectroscopy, and fluorometric detection. Such a comprehensive approach for investigation the formation of cytotoxic molecules promises to provide interesting insights into the importance of certain free radicals and reactive precursors of melanin in insect immunity. ***