基于多模态技术实现包虫病表面抗原受体特异性成像的研究

Echinococcosis is one of zoonotic infectious diseases which had being under strongly controlled by our government. The key points for cure this disease rely on early diagnosis and real-time monitoring during chemotherapy process. Unfortunately, it was still very difficult for us to make early diagnosis as well as to evaluate the chemotherapy result. Therefore, it was urgent to explore new technologies either for early diagnosis or for real-time monitoring and evaluating treatment. Based on multimodality imaging and our previous significant finding of the specific surface antigen receptor(EPC1) of the echinococcosis. This study aims to set up a specific surface antigen receptor imaging indicating system. Rat model with hepatic alveolar echinococcosis(HAE) was created for testing those new tracers which including EPC1 antigen, coupling the near-infrared fluorescence and magnetic bio-nano-particles, so as to build up multimodality imaging technology for detecting the specific surface antigen receptor expression system which integrated the MRI and fluorescence imaging for HAE. The rats, treated with albendazole, would be scanned by optical spectrum living image system and MRI to evaluate the chemotherapy changes. All of the above will be the experimental and scientific basis for exploring the growing features and early diagnosis in molecule level, as well as real-time evaluation after albendazole treatment.

包虫病是国家重点控制的人畜共患传染病之一。实现对包虫病的早期筛查和治疗中的实时监测与评价，是根治包虫病的关键环节。时下对于包虫病早期诊断仍然困难，中晚期治疗效果评价仍然缺乏有效手段。因此，急需探索新的早期诊断技术和治疗实时监测与评价技术。本研究基于多模态影像学技术，在发现包虫病重组特异性抗原EPC1的基础之上，拟构建包虫病表面抗原受体特异性影像表达系统。拟选取接种成功的肝泡球蚴大鼠作为观察对象，以EPC1抗原偶联近红外荧光素标记行活体小动物光学成像，同时以EPC1偶联纳米磁珠为示踪基团行MRI检查，再针对服用阿苯达唑治疗的大鼠进行上述两种影像的动态实时评价，以期构建基于荧光显像和磁共振成像的多模态包虫病表面抗原受体特异性检测系统，揭示包虫病发生发展过程中的影像变化规律，为包虫病早期影像诊断和治疗过程中的实时有效监测及评价提供科学依据和实验基础。

项目的背景：包虫病是人畜共患的寄生虫病，在我国主要流行于西北地区的农牧区，严重危害农牧民的健康甚至生命，本研究试想实现肝包虫病抗原抗体相结合的特异性成像。.主要研究内容：1）包虫重组表面抗原蛋白 EPC1偶联纳米磁珠的化学构建与鉴定：应用相关化学构建的技术将包虫重组表面抗原蛋白 EPC1 偶联到纳米磁珠上，形成磁珠-包虫重组表面抗原蛋白 EPC1复合体。2）近红外荧光素偶联包虫重组表面抗原蛋白 EPC1 的化学构建与鉴定：应用相关化学构建的技术将近红外荧光素偶联到包虫重组表面抗原蛋白 EPC1上，形成荧光素-包虫重组表面抗原蛋白 EPC1 复合体。3）建立泡球蚴小鼠模型，超声监测造模成功后分为对照组和实验组，对照组经尾静脉注射磁珠/荧光素，实验组以包虫表面抗原EPC1 蛋白偶联纳米磁珠/荧光素为示踪基团。4）用MRI和小动物光学成像仪检测对照组和实验组两组大鼠HAE病灶的特点，比较包虫重组表面抗体蛋白 EPC1特异性受体表达系统增敏效应。.重要结果及关键数据：1）动态光散射：羧基化Fe3O4纳米偶联EPC1抗体后的水动力尺寸，平均粒子直径Z-Average为 54.53 nm，通过光强分布占比计算的平均粒径Intensity为51.04 nm。2）羧基化 Fe3O4纳米颗粒偶联 EPC1抗体后的Zeta电位为-11.96 mV，表面羧基消耗用于偶联抗体，电位正移。3）将造膜成功的小鼠分为对照组、实验组，每组10只小鼠，对照组注射SPION示踪剂、实验组注射SPION-EPC1复合体示踪剂，两组均进行小鼠肝内病灶核磁检测及显影差异分析，结果显示SPION-EPC1实验组在注射示踪剂后1h、4h两个时间点T2信号强度、病灶SNR值均有减低，而SPION对照组仅在注射示踪剂后1h时间点T2信号强度、病灶SNR值减低，4）将造膜成功的20小鼠，采用随机数字表的方法分为对照组、实验组，每组10只小鼠，对照组采用FITC荧光显影剂、实验组采用FITC-EPC1复合体荧光显影剂，结果显示复合体示踪剂，能够与肝泡状棘球蚴内的包虫重组表面EPC1抗体相结合，增加病灶的荧光显像。.科学意义：SPION-EPC1、FITC-EPC1能够实现包虫重组表面抗原抗体EPC1的靶向成像，增加小鼠病灶的荧光显影，较早发现更小病灶。