ACS Sens. 2018 Sep 28;3(9):1616-1621. doi: 10.1021/acssensors.8b00360. Epub 2018 Aug 31.
Parasite extracellular vesicles (EVs) are potential biomarkers that could be exploited for the diagnosis of infectious disease. This paper reports a rapid bioassay to discriminate parasite and host EVs. The EV detection assay utilizes a label-free photonic crystal (PC) biosensor to detect the EVs using a host-specific transmembrane protein (CD63), which is present on EV secreted by host cells (modeled by murine macrophage cell line J774A.1) but is not expressed on EV secreted by parasitic nematodes such as the gastrointestinal nematode Ascaris suum. The surface of PC is functionalized to recognize CD63, and is sensitive to the changes in refractive index caused by the immobilization of EVs. The biosensor demonstrates a detection limit of 2.18 × 10 EVs/mL and a capability to characterize the affinity constants of antibody-host EV bindings. The discrimination of murine host EVs from parasite EVs indicates the capability of the sensor to differentiate EVs from different origins. The label-free, rapid EV assay could be used to detection parasite infection and facilitate the exosome-based clinic diagnosis and exosome research.
寄生虫细胞外囊泡 (EVs) 是一种有潜力的生物标志物，可以用于传染病的诊断。本文报道了一种快速的生物测定法，用于区分寄生虫和宿主 EVs。该 EV 检测测定法利用无标记的光子晶体 (PC) 生物传感器，通过宿主特异性跨膜蛋白 (CD63) 检测 EVs，该蛋白存在于宿主细胞分泌的 EV 中（以鼠巨噬细胞系 J774A.1 为模型），但不存在于寄生线虫（如胃肠道线虫 Ascaris suum）分泌的 EV 中。PC 的表面经过功能化处理，以识别 CD63，并且对 EV 固定引起的折射率变化敏感。该生物传感器的检测限为 2.18×10 EVs/mL，并且能够表征抗体-宿主 EV 结合的亲和常数。从寄生虫 EVs 中区分出鼠源宿主 EVs 表明该传感器有能力区分来自不同来源的 EVs。这种无标记、快速的 EV 测定法可用于检测寄生虫感染，并促进基于外泌体的临床诊断和外泌体研究。
