Anaplasma phagocytophilum modulate tick gene expression for its survival and transmission from the vector host

嗜吞噬细胞无形体调节蜱基因表达以使其存活并从载体宿主传播

• 批准号: 9398343
• 负责人: Girish Neelakanta
• 金额: $ 38.75万
• 依托单位: OLD DOMINION UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-18 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9398343
• 关键词: Actins; Address; Adult; Affect; Anaplasma phagocytophilum; Antibodies; Antifreeze; Area; Arthropod Vectors; Arthropods; Bacteria; Binding; Biochemical; Biological Assay; Biology; Black-legged Tick; Bovine Anaplasmosis; Cells; Confocal Microscopy; Data; Development; Disease; EMSA; Electrophoretic Mobility Shift Assay; Enzymes; Female; Gene Expression; Genes; Goals; Human; Immunization; In Vitro; Interruption; Kynurenine-oxoglutarate aminotransferase; Lead; Mammalian Cell; Mammals; Medical; Microbe; Modeling; Molecular; Molecular Analysis; Neuromodulator; OATP Transporters; Oxidative Stress; Pathway interactions; Phosphorylation; Promoter Regions; RNA Interference; Regulation; Reproduction; Research; Rickettsia; Rickettsiales; Role; Salivary Glands; Signal Pathway; Signal Transduction; Tick-Borne Diseases; Ticks; Tryptophan; Tryptophan Metabolism Pathway; United States; Vertebrates; Xanthurenic Acid; base; design; egg; experimental study; field study; in vivo; insight; knock-down; male; mouse model; neutrophil; novel; pathogen; transmission process; vector; vector transmission

Project Summary/Abstract Human anaplasmosis, caused by the obligate intracellular bacterium Anaplasma phagocytophilum, is one of the most common tick-borne diseases in the United States. In mammals and ticks, A. phagocytophilum resides in neutrophils and in salivary glands, respectively. Despite numerous studies that have focused on understanding strategies that A. phagocytophilum uses to survive in the mammalian cells, relatively few studies have clearly defined the molecular strategies that A. phagocytophilum uses to survive in ticks. In this project, we will be performing a comprehensive molecular analysis on Ixodes scapularis organic anion transporting polypeptides (OATPs) and genes involved in the tryptophan metabolism pathway in A. phagocytophilum-tick interactions. This study is build upon our efforts in showing how A. phagocytophilum modulates gene expression and cell signaling for its survival in the vector. As an example, our previous studies has shown that A. phagocytophilum modulate tick antifreeze gene expression and actin phosphorylation for its survival in the vector. Here, we provide strong preliminary in vitro and in vivo data showing that A. phagocytophilum induces expression of a specific OATP (OATP4056) and kynurenine aminotransferase (KAT), a gene involved in the tryptophan pathway. We now hypothesize that interplay between OATP4056 and KAT not only facilitates A. phagocytophilum survival in the vector but also aid in the transmission of this bacterium to a vertebrate host. RNAi analysis revealed that knockdown of OATP4056 has no effect on A. phagocytophilum acquisition but affected its survival and transmission from these ticks. Electrophoretic mobility shift assays with promoter region and total lysates prepared from uninfected and A. phagocytophilum-infected ticks provide further evidence that the presence of this bacterium influences expression of OATP4056 in these ticks. In addition, we found evidence that a metabolite from tryptophan pathway regulates A. phagocytophilum survival and OATP4056 gene expression in these ticks. These results provide important insights for our proposed studies to define molecular basis of the relationship of A. phagocytophilum with ticks. Based on our strong preliminary results and the experiments proposed, we believe that this could be a transformative study that not only serves as a model to study intimate relationships established by pathogens with their arthropod vectors but may also lead in the development of new strategies to interrupt the transmission of this and perhaps other Rickettsial species of medical importance.

项目概要/摘要 人类无形体病，由专性细胞内细菌嗜吞噬细胞无形体引起， 是美国最常见的蜱传疾病之一。在哺乳动物和蜱中，A. 吞噬细胞分别存在于中性粒细胞和唾液腺中。尽管大量研究表明 专注于了解 A. phagocytophilum 在哺乳动物中生存的策略 细胞，相对较少的研究明确定义了 A. phagocytophilum 用于 在蜱虫中生存。在这个项目中，我们将对硬蜱进行全面的分子分析 肩胛肌有机阴离子转运多肽（OATP）和色氨酸相关基因 嗜吞噬细胞蜱相互作用中的代谢途径。这项研究是建立在我们努力的基础上的 显示 A. phagocytophilum 如何调节基因表达和细胞信号传导以使其在 向量。例如，我们之前的研究表明，A. phagocytophilum 可以调节蜱的抗冻剂 基因表达和肌动蛋白磷酸化以使其在载体中生存。在这里，我们提供强有力的 初步的体外和体内数据表明，A. phagocytophilum 诱导特定的表达 OATP (OATP4056) 和犬尿氨酸转氨酶 (KAT)（一种参与色氨酸途径的基因）。 我们现在假设 OATP4056 和 KAT 之间的相互作用不仅促进了 A. 吞噬细胞在载体中存活，而且还有助于将该细菌传播到 脊椎动物宿主。 RNAi 分析表明 OATP4056 的敲低对 A. 吞噬细胞的获得，但影响了其在这些蜱中的生存和传播。电泳 使用启动子区域和从未感染的和 A. 制备的总裂解物进行迁移率变化测定。 嗜吞噬细胞感染的蜱提供了进一步的证据，证明这种细菌的存在影响 OATP4056 在这些蜱中的表达。此外，我们发现证据表明色氨酸的代谢物 途径调节这些蜱中嗜吞噬细胞 A. 的存活和 OATP4056 基因表达。这些 结果为我们提出的研究提供了重要的见解，以定义以下关系的分子基础： A. 吞噬细胞与蜱。基于我们强有力的初步结果和提出的实验，我们 相信这可能是一项变革性的研究，不仅可以作为研究亲密关系的模型 病原体与其节肢动物载体建立的关系，但也可能导致发展 阻断这种立克次体以及其他医学立克次体物种传播的新策略 重要性。