Functional Impact of Stress Granules on Tick-Microbe Interactions

应激颗粒对蜱微生物相互作用的功能影响

基本信息

批准号：
10056116
负责人：
Dana Kathleen Shaw
金额：
$ 22.2万
依托单位：
WASHINGTON STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-06-09 至 2022-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10056116
关键词：
Anaplasma phagocytophilum Anaplasmosis Anti-Bacterial Agents Antigen-Antibody Complex Arthropods Bacterial Infections Biology Black-legged Tick Borrelia burgdorferi Case Study Cell physiology Cells Cellular Stress Communities Cytoplasm Data Disease Vectors Endoplasmic Reticulum Equilibrium Eukaryota Eukaryotic Initiation Factors Genes Genetic Transcription Human Immune Immune signaling Immunity In Vitro Incidence Infection Intercept Larva Lyme Disease Maintenance Mammals Mediating Microbe Microscopy Midgut Molecular Outcome Pathway interactions Pharmacology Phosphorylation Phosphotransferases Process Protein Biochemistry Proteins RNA Reporting Role Salivary Glands Signal Transduction Signaling Protein Stress Tick-Borne Diseases Ticks Tumor Necrosis Factor Receptor United States Vector-transmitted infectious disease analog biological adaptation to stress genetic regulatory protein granulocyte human pathogen in vivo insight knock-down novel pathogen pathogenic bacteria protein kinase R stress granule vector vector competence vector tick

项目摘要

Abstract Arthropod immunity is a key factor influencing vector competence. We recently identified an atypical Immune Deficiency (IMD) pathway in Ixodes scapularis ticks that responds to and restricts Borrelia burgdorferi (Lyme disease) and Anaplasma phagocytophilum (Human Granulocytic Anaplasmosis). Host cell stress-responses are closely intertwined with immunity and can function to either potentiate or antagonize immune signaling. Whether stress-response pathways intersect with arthropod immunity to influence vector competence remains unknown. Stress Granules (SGs) are aggregates of RNA and protein that transiently form in the cytoplasm of stressed cells, such as during infection. SG formation is highly conserved throughout eukaryotes and has known immune regulatory roles in mammals. Once formed, SGs become cell signaling hubs that can intercept molecules from other pathways to modulate cellular processes. For instance, SGs can inhibit the mammalian analogue to the IMD pathway, the Tumor Necrosis Factor Receptor (TNFR) network, by sequestering signaling proteins away from immune complexes. SGs are induced when eIF2α (eukaryotic translation initiation factor 2α) is phosphorylated by stress-sensing kinases, such as PERK (protein kinase R-like endoplasmic reticulum kinase). In this R21 application, we report that PERK-eIF2α signaling promotes A. phagocytophilum colonization and replication in tick cells. This observation together with known immune inhibitory roles of eIF2α-induced SGs prompted us to look for SG formation in ticks. We found 13 SG-assembly genes that are induced in the salivary glands and/or midguts of A. phagocytophilum-infected ticks. Accordingly, our central hypothesis is that PERK- eIF2α-induced SGs antagonize immune signaling in ticks, which promotes bacterial pathogen colonization. AIM 1 of this proposal will evaluate whether bacterial infection induces SGs in tick cells using immunofluorescent microscopy, protein biochemistry and pharmacological inhibition. AIM 2 will assess the impact of SGs on bacterial colonization and tick immunity in vitro using transcriptional knockdown and pharmacological modulators. AIM 3 will investigate whether SG machinery influences pathogen colonization and maintenance in vivo by using transcriptional knockdown in larvae followed by A. phagocytophilum or B. burgdorferi challenge. As SG formation is a conserved evolutionary mechanism, investigating this phenomenon as it relates to arthropod immunity and vector competence will provide novel insights for the broader vector biology community.

抽象的节肢动物免疫是影响媒介能力的关键因素我们最近发现了一种非典型免疫。肩胛硬蜱的缺乏（IMD）途径响应并限制伯氏疏螺旋体（莱姆病）病）和嗜吞噬细胞无形体（人粒细胞无形体病）的应激反应。与免疫密切相关，可以增强或拮抗免疫信号传导。应激反应途径与节肢动物免疫相交叉以影响媒介能力仍然未知。应激颗粒 (SG) 是在应激细胞质中短暂形成的 RNA 和蛋白质的聚集体 SG 的形成在真核生物中高度保守，并且具有已知的免疫功能。一旦形成，SG 就成为细胞信号传导中枢，可以拦截来自哺乳动物的分子。调节细胞过程的其他途径例如，SG 可以抑制哺乳动物的类似物。 IMD 通路，肿瘤坏死因子受体 (TNFR) 网络，通过隔离信号蛋白当 eIF2α（真核翻译起始因子 2α）存在时，会诱导来自免疫复合物的 SG。被压力感应激酶磷酸化，例如 PERK（蛋白激酶 R 样内质网激酶）。在此 R21 应用中，我们报告 PERK-eIF2α 信号传导促进 A. phagocytophilum 定植并该观察结果与 eIF2α 诱导的 SG 的已知免疫抑制作用一起。促使我们寻找蜱中 SG 的形成，我们发现了 13 个在唾液中诱导的 SG 组装基因。因此，我们的中心假设是 PERK-。 eIF2α 诱导的 SG 拮抗蜱中的免疫信号，从而促进细菌病原体定植。该提案的目标 1 将使用免疫荧光评估细菌感染是否会在蜱细胞中诱导 SG 显微镜、蛋白质生物化学和药理抑制 2 将评估 SG 对的影响。使用转录敲低和药理学进行体外细菌定植和蜱免疫 AIM 3 将研究 SG 机制是否影响病原体的定植和维持。通过在幼虫中使用转录敲低，然后用 A. phagocytophilum 或 B. burgdorferi 攻击来进行体内试验。由于 SG 形成是一种保守的进化机制，因此研究这种现象与节肢动物免疫和载体能力将为更广泛的载体生物学界提供新的见解。