Investigating the Human Immune Response to Ixodes scapularis Tick Bites

研究人体对肩胛硬蜱叮咬的免疫反应

• 批准号: 10927972
• 负责人: ADRIANA R MARQUES
• 金额: $ 53.78万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10927972
• 关键词: Anaplasma phagocytophilum; Anaplasmosis; Animal Model; Animals; Arthropods; Babesia microti; Babesiosis; Bacteriology; Basophils; Biological Assay; Biological Process; Biopsy; Black-legged Tick; Blood; Blood Platelets; Body Weight; Borrelia burgdorferi; Borrelia mayonii; Borrelia miyamotoi; Case Study; Cavia; Cells; Cessation of life; Clinical; Clinical Research; Coagulation Process; Diagnosis; Disease; Ehrlichia; Ehrlichiosis; Exposure to; Flow Cytometry; Future; Genes; Histopathology; Human; Immune response; Immunity; Individual; Infection; Innate Immune Response; Ixodes; Ixodidae; Laboratories; Life; Lyme Disease; Malaria; Measures; Molecular; Molecular Biology; Monitor; National Institute of Allergy and Infectious Disease; Nature; Oryctolagus cuniculus; Paraffin; Participant; Persons; Powassan virus; Process; Proteins; Proteomics; Pruritus; Public Health; RNA; Research; Resistance; Resolution; Role; Salivary; Salivary Proteins; Skin; Standardization; System; Technology; Testing; Tick-Borne Diseases; Tick-Borne Encephalitis; Ticks; Time; United States; Vaccine Design; Virus; Xenodiagnosis; adaptive immune response; anti-tick vaccine; clinical development; differential expression; experience; feeding; human disease; immunoregulation; molecular vector; nano-string; next generation sequencing; pathogen; preservation; response; skin irritation; tick bite; tick feeding; tick saliva; transcriptomics; transmission process; vector

Tick-borne diseases (TBDs) are a serious public health problem in the United States, with the number of reported cases more than doubling during 2004 to 2016. The deer tick (Ixodes scapularis) is the vector of at least 7 pathogens that cause human diseases: Lyme disease (Borrelia burgdorferi and Borrelia mayonii), anaplasmosis (Anaplasma phagocytophilum), babesiosis (Babesia microti), Borrelia miyamotoi disease (Borrelia miyamotoi), ehrlichiosis (Ehrlichia muris eauclairensis), and tick-borne encephalitis (deer tick virus/Powassan virus). Lyme disease accounts for more than 80% of the reported cases of tickborne diseases, with estimates of over 476,000 cases of Lyme disease been diagnosed and treated per year in the US. Ticks are obligate blood-feeding arthropods and require a blood meal at every active life stage. To acquire its blood meal, an ixodid tick must remain attached to the skin of a vertebrate host and complete its multi-day feeding process. Tick saliva is composed of a large variety of proteins that are differentially expressed throughout the process of tick feeding. Some of these proteins have anti-clotting, anti-platelet, vasodilatory, and immunomodulatory activities that allow successful feeding and pathogen transmission. The skin response to tick salivary proteins has been implicated in tick rejection as certain animals (e.g., rabbits, guinea pigs) that are repeatedly infested develop an immune response against tick proteins. Resistance to tick bites is manifested by reduced numbers and body weights of engorged ticks or tick death in subsequent infestations in these animal models and consequently protection against Borrelia burgdorferi transmission. Most people will not feel a tick bite, as tick bites do not tend to cause itching or immediate skin irritation. But people who have had many tick bites can become sensitized to tick bites over time, and this can protect against Lyme disease. Little is known about the nature of the protective immune response. We have combined our expertise to study the response to tick bites in a well standardized clinical setting to identify critical aspects of the human innate and adaptive immune responses in skin and blood following exposure to uninfected Ixodes scapularis ticks; and monitor the acquisition of a tick-associated skin immunity, including itch. This research could lead to the identification of tick salivary proteins that are targets of host immunity and might serve as targets for an anti-tick vaccine. The Lyme Disease Studies Unit at NIAID has been involved for many years in studies to examine the use of larval I. scapularis ticks in xenodiagnosis of B. burgdorferi infection and have extensive experience with placement of larval I. scapularis ticks in humans. The Vector Molecular Biology Section at the Laboratory of Malaria and Vector Research, and the Tick-Pathogen Transmission Unit, at the Laboratory of Bacteriology at Rocky Mountain Laboratories (RML), have extensive experience in working with the tick Ixodes scapularis, the isolation of Ixodes salivary components, molecular aspects of tick salivary proteins and the understanding of guinea pig immune responses to tick exposure, tick rejection and the role tick salivary proteins on tick rejection. Major accomplishments of the past year are the continuation of accrual of participants into the Major accomplishments of the past year are the continuation of accrual of participants into the study, which is now 65% completed. As planned in the clinical study, we continue to collect blood and skin biopsies from the participants at different time points after tick attachment. RNA from biopsies were extracted and RNA Illumina next generation sequencing is being performed. Biopsies have also been processed and preserved in paraffin for histopathology and guidance of the spatial analysis. Ticks fed on participants are being collect for RNA and protein extraction, which will be used for transcriptomic and proteomic analysis. We developed a basophil activation assay using flow cytometry to measure the activation of basophil to tick saliva in the blood of individuals exposed to tick bites. For feasibility, we tested one set of biopsies from normal skin, and skin bitten by ticks at time 24h and 48h by single cell spatial gene analysis using CosMx technology by Nanostring. This system gives single-cell resolution spatial transcriptomics and proteomics that will further our understanding of the biological processes involved in the host response.

蜱传疾病（TBD）是美国一个严重的公共卫生问题，2004年至2016年期间报告的病例数量增加了一倍多。鹿蜱（Ixodes scapularis）是至少7种引起人类疾病的病原体的载体：莱姆病（伯氏疏螺旋体和马永疏螺旋体）、无形体病（嗜吞噬细胞无形体）、巴贝虫病（Babesiosis）、宫本疏螺旋体病（Borrelia miyamotoi）、埃立克体病（Ehrlichia muris eauclairensis）和蜱传脑炎（鹿蜱病毒/波瓦桑病毒）。莱姆病占蜱传疾病报告病例的80%以上，估计美国每年诊断和治疗的莱姆病病例超过476，000例。 蜱是专性吸血节肢动物，在每个活跃的生命阶段都需要血液。为了获得它的血餐，硬蜱必须保持附着在脊椎动物宿主的皮肤上，并完成其多日的进食过程。蜱唾液由多种蛋白质组成，这些蛋白质在蜱进食的整个过程中差异表达。这些蛋白质中的一些具有抗凝血、抗血小板、血管舒张和免疫调节活性，从而允许成功进食和病原体传播。对蜱唾液蛋白的皮肤反应与蜱排斥有关，因为某些动物（例如，兔子、豚鼠）反复感染的动物产生针对蜱蛋白的免疫应答。在这些动物模型中，对蜱叮咬的抗性表现为饱食蜱的数量和体重减少或在随后的侵染中蜱死亡，从而防止伯氏疏螺旋体传播。 大多数人不会感觉到蜱虫叮咬，因为蜱虫叮咬不会引起瘙痒或立即的皮肤刺激。但是，随着时间的推移，被蜱虫叮咬过多次的人会对蜱虫叮咬变得敏感，这可以预防莱姆病。对保护性免疫反应的性质知之甚少。我们结合了我们的专业知识，在标准化的临床环境中研究蜱叮咬的反应，以确定暴露于未感染的肩胛硬蜱蜱后皮肤和血液中人类先天性和适应性免疫反应的关键方面;并监测蜱相关皮肤免疫的获得，包括瘙痒。这项研究可能导致识别蜱唾液蛋白，这些蛋白是宿主免疫的靶点，并可能作为抗蜱疫苗的靶点。 NIAID的莱姆病研究单位多年来一直参与研究，以检查幼虫I的使用。肩胛蜱在B类异种诊断中的应用并具有放置幼虫I的丰富经验。人类的肩胛蜱疟疾和病媒研究实验室的病媒分子生物学部门以及落基山实验室细菌学实验室（RML）的蜱病原体传播部门在与蜱肩突硬蜱、硬蜱唾液成分的分离、蜱唾液蛋白的分子方面以及对豚鼠对蜱暴露的免疫反应的理解方面具有丰富的经验，蜱排斥反应和蜱唾液蛋白在蜱排斥反应中的作用。 过去一年的主要成就是继续增加参与者参加研究，目前已完成65%。按照临床研究的计划，我们继续在蜱附着后的不同时间点收集参与者的血液和皮肤活检。提取来自活检组织的RNA，并进行RNA Illumina下一代测序。还对活检进行了处理并保存在石蜡中，用于组织病理学和空间分析的指导。正在收集以参与者为食的蜱虫进行RNA和蛋白质提取，这些提取物将用于转录组学和蛋白质组学分析。我们开发了一种嗜碱性粒细胞活化试验，使用流式细胞术测量暴露于蜱叮咬的个体血液中嗜碱性粒细胞对蜱唾液的活化。为了可行性，我们使用Nanostring的CosMx技术通过单细胞空间基因分析测试了来自正常皮肤和在时间24小时和48小时被蜱叮咬的皮肤的一组活检。该系统提供了单细胞分辨率的空间转录组学和蛋白质组学，这将进一步加深我们对宿主反应中所涉及的生物过程的理解。