Dscam function in innate immunity

描述(申请人提供)：冈比亚按蚊和其他昆虫利用各种策略来对抗微生物入侵者。PIS研究的长期目标是表征和了解蚊子对微生物使用的天然免疫机制。这项建议侧重于唐氏综合征细胞黏附分子(DSCAM)作为高变量免疫监视受体的特殊作用。Dscam复杂的基因组结构和显著的特性表明，它在免疫防御中发挥着多种作用：在冈比亚按蚊中，AgDscam基因的选择性剪接产生具有不同黏附特性和特异性的&gt；31,920种选择性剪接形式的受体。AgDscam在免疫攻击时产生微生物特异性剪接体，参与抗菌和抗疟原虫防御。这里概述的研究将进一步检验这一假设，即正如之前对有限数量的细菌的挑战所显示的那样，AgDscam基因的这种表型可塑性使其能够产生具有强大的抗菌活性和对细菌和疟原虫高亲和力的受体分子。为了验证这一假说，拟议的研究将使用RNAi沉默、免疫组织化学染色、微阵列分析和相互作用分析来确定(特定目标1)微生物挑战和先天性免疫途径对AgDscam剪接和剪接体产生的调节，以及(目标2)参与这些防御和与微生物相互作用的特定剪接体。最后，我们将在过度表达病原体特定剪接形式的转基因蚊系中测试AgDscam的抗疟原虫防御特异性和有效性(在特定目标3中)。这些分析将阐明昆虫先天性免疫系统中最引人注目的参与者之一，该系统使其能够通过微生物挑战模式识别受体的特异性产生来应对广泛的微生物。这项研究还将评估使用AgDscam产生抗疟原虫蚊子的可行性，这些蚊子可用于制定疟疾控制战略。 与公共卫生相关：按蚊利用其先天免疫系统与包括疟原虫在内的多种微生物病原体作斗争。本研究旨在研究高变量模式识别受体AgDscam，以了解其免疫相关调节，并评估其杀灭疟原虫的能力。

DESCRIPTION (provided by applicant): Anopheles gambiae and other insects utilize a variety of strategies to combat microbial invaders. The long-term goal of the PIs research is to characterize and understand the mechanisms of innate immunity used by the mosquito against microbes. This proposal focuses on the particular role of the Down syndrome cell adhesion molecule (Dscam) as a hypervariable immune surveillance receptor. Dscam's complex genomic organization and remarkable properties suggest that it plays multiple roles in immune defense: In A. gambiae, alternative splicing of the AgDscam gene produces >31,920 alternative splice- form receptors with different adhesive characteristics and specificities. AgDscam produces microbe-specific splice-form repertoires upon immune challenge and is involved in both antibacterial and anti-Plasmodium defense. The studies outlined here will further test the hypothesis that, as previously shown for challenge with a limited number of bacteria, this phenotypic plasticity of the AgDscam gene allows it to produce receptor molecules with potent antimicrobial activity and high affinity for bacteria and the Plasmodium parasite. To test this hypothesis, the proposed studies will use RNAi silencing, immunohistochemical staining, microarray analyses, and interaction analyses to determine (in Specific Aim 1) the regulation of AgDscam splicing and production of splice form repertoire by microbe challenge and the innate immune pathways, and (in Aims 2) the specific splice-form repertoires involved in these defenses and interactions with microbes. We will finally test the anti-Plasmodium defense specificity and efficacy of AgDscam in genetically modified mosquito lines that over-express pathogen specific splice forms (in Specific Aim 3). These analyses will elucidate one of the most remarkable players of the insect innate immune system, which allows it to cope with a broad spectrum of microbes through the microbe challenge specific production of pattern recognition receptors. The study will also assess the feasibility to use AgDscam for the generation of Plasmodium resistant mosquitoes that could be used for the development of a malaria control strategy. PUBLIC HEALTH RELEVANCE: The Anopheles mosquito uses its innate immune system to fight against a broad spectrum of microbial pathogens including the Plasmodium parasite. This research proposal aims at the study of a hypervariable pattern recognition receptor, AgDscam, to understand its immune related regulation and assess its capacity to kill Plasmodium.