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：
10187515
负责人：
Dana Kathleen Shaw
金额：
$ 19.88万
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/10187515
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 Health 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向量能力的关键因素。我们最近确定了非典型免疫 ixodes肩cap虫的缺陷（IMD）途径，响应并限制了Borrelia Burgdorferi（莱姆（Lyme）疾病）和纳巴氏菌吞噬tophim（人类粒细胞杂质病）。宿主细胞应力反应是与免疫力紧密交织在一起，可以发挥增强或拮抗免疫信号传导。应力反应途径与影响载体能力的节肢动物免疫相交仍然未知。应力颗粒（SGS）是RNA和蛋白质的聚集体，它们在应激的细胞质中瞬时形成细胞，例如感染期间。 SG形成在整个真核生物中都高度保守，并且已知免疫在哺乳动物中的调节作用。一旦形成，SG就成为可以从调节细胞过程的其他途径。例如，SGS可以抑制哺乳动物的类似物 IMD途径，肿瘤坏死因子受体（TNFR）网络，通过隔离信号蛋白离开来自免疫复合物。当EIF2α（真核翻译起始因子2α）为通过应激感应激酶（例如PERK）（蛋白激酶R样性内质网激酶）磷酸化。在此R21应用中，我们报告说PERK-EIF2α信号传导促进了吞噬细胞的定植和在壁虱单元中复制。该观察结果以及已知的EIF2α诱导的SGS的免疫抑制作用提示我们在壁虱中寻找SG组。我们发现13个在唾液中诱导的SG组装基因吞噬细胞的虫的腺体和/或中肠感染的壁虱。根据我们的中心假设是 EIF2α诱导的SGS拮抗tick中的免疫信号传导，从而促进细菌病原体定植。该提案的目标1将评估细菌感染是否使用免疫荧光诱导tick细胞中的SG 显微镜，蛋白质生化和药物抑制。 AIM 2将评估SGS对使用转录敲低和药理学，细菌定植和tick免疫在体外调节器。 AIM 3将研究SG机械是否影响病原体定植和维持通过在幼虫中使用转录敲低的体内，然后是吞噬曲霉或B. burgdorferi挑战。由于SG形成是一种保守的进化机制，因此研究了这种现象节肢动物的免疫力和向量能力将为更广泛的媒介生物学界提供新颖的见解。