An antigen-capture assay to screen donated blood for Babesia microti

项目总结 在美国，每年约有500万人接受输血。越来越多地，这些接受者被 面临感染微小巴贝斯虫的风险，这是一种驻留在红色血液中的壁虱传播的血液寄生虫 细胞(红细胞)，并导致巴贝斯虫病。B.Microti代表着对美国血液的重大威胁 在血库程序和储存条件下幸存下来的血液供应，可以通过输血传播。 输血传播巴贝斯虫病(TTB)是与输血相关的疾病中比例最高的 向FDA报告的传染病死亡人数。存在对一种敏感和 特异性、成本效益和高通量，以筛查捐献的血液中的这种病原体。我们建议 检测血液中低水平寄生虫的EIA抗原捕获试验的建立 可能没有意识到自己被感染的捐赠者(例如，无症状、慢性携带者)。我们生成了一个 用微小杆菌感染小鼠的抗体库，然后对这个抗体库进行筛选，以鉴定特异性抗体 以寄生表面表达/分泌的蛋白质。使用这些方法，我们已经识别出了针对 七种微小芽孢杆菌蛋白在哺乳动物感染过程中表达。在本研究中，我们将生成一个优化的 使用针对一种或多种寄生虫分泌的/表面靶抗原的抗体对进行抗原捕获试验 已经在初步研究中发现。在具体目标1中，我们将优化捕获和报告抗体对 用于检测微小芽孢杆菌的抗原捕获试验，并确认其特异性和敏感性 这些捕获-报告抗体对。在特定目标2中，我们将使用血液进行检测 从巴贝斯虫病患者那里获得，并鉴定出最终的抗原捕获试验，以进入临床 与我们的商业化合作伙伴在第二阶段应用中进行化验筛选。

PROJECT SUMMARY In the U.S. ~5 million individuals receive blood transfusions annually. Increasingly, these recipients are being put at risk of infection with Babesia microti, a tick-transmitted blood-borne parasite that resides in red blood cells (RBCs) and causes the disease babesiosis. B. microti represents a significant threat to the US blood supply as it survives blood banking procedures and storage conditions, and can be transmitted via transfusion. Transfusion transmitted babesiosis (TTB) is responsible for the highest percentage of transfusion-related infectious fatalities reported to the FDA. There is a critical unmet need for a method that is sensitive and specific, cost-effective, and high-throughput to screen donated blood for this pathogen. We propose the development of an EIA-based antigen-capture assay capable of detecting low levels of parasites in blood donors who are likely unaware that they are infected (e.g., asymptomatic, chronic carriers). We generated a library of antibodies using B. microti infected mice, and then screened this library to identify antibodies specific to parasite surface-expressed/secreted proteins. Using these methods, we have identified antibodies to seven B. microti proteins expressed during mammalian infection. In this study, we will generate an optimized antigen-capture assay using antibody pairs to one or more parasite secreted/surface target antigens that we have identified in preliminary studies. In Specific Aim 1, we will optimize capture and reporter antibody pairs for use in an antigen capture assay for the detection of B. microti, and confirm the specificity and sensitivity of these capture-reporter antibody pairs. In Specific Aim 2, we will performance our assay using blood obtained from patients with babesiosis, and identify a finalized antigen-capture assay to proceed to clinical assay screening with our commercialization partner in a phase II application.