Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM, UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155, Piso 13, Buenos Aires, Argentina.
Área de Parasitología, Departamento de Farmacia y Tecnología Farmacéutica y Parasitología, Universitat de València, Burjassot, Valencia, Spain; Joint Research Unit on Endocrinology, Nutrition and Clinical Dietetics, Health Research Institute-La Fe, Universitat de València, 46026 Valencia, Spain.
Int J Parasitol. 2017 Sep;47(10-11):675-686. doi: 10.1016/j.ijpara.2017.05.003. Epub 2017 Jun 29.
Intercellular communication is crucial in multiple aspects of cell biology. This interaction can be mediated by several mechanisms including extracellular vesicle (EV) transfer. EV secretion by parasites has been reported in protozoans, trematodes and nematodes. Here we report that this mechanism is present in three different species of cestodes, Taenia crassiceps, Mesocestoides corti and Echinococcus multilocularis. To confirm this we determined, in vitro, the presence of EVs in culture supernatants by transmission electron microscopy. Interestingly, while T. crassiceps and M. corti metacestodes secrete membranous structures into the culture media, similar vesicles were observed in the interface of the germinal and laminated layers of E. multilocularis metacestodes and were hardly detected in culture supernatants. We then determined the protein cargo in the EV-enriched secreted fractions of T. crassiceps and M. corti conditioned media by LC-MS/MS. Among the identified proteins, eukaryotic vesicle-enriched proteins were identified as expected, but also proteins used for cestode disease diagnosis, proteins related to neurotransmission, lipid binding proteins as well as host immunoglobulins and complement factors. Finally, we confirmed by capillary electrophoresis the presence of intravesicular RNA for both parasites and detected microRNAs by reverse transcription-PCR. This is the first report of EV secretion in cestode parasites and of an RNA secretion mechanism. These findings will provide valuable data not only for basic cestode biology but also for the rational search for new diagnostic targets.
细胞间通讯在细胞生物学的多个方面都至关重要。这种相互作用可以通过几种机制介导，包括细胞外囊泡 (EV) 的转移。寄生虫的 EV 分泌已在原生动物、吸虫和线虫中报道过。在这里，我们报告称，这种机制存在于三种不同的绦虫物种中，即多头绦虫、中绦期囊尾蚴和多房棘球绦虫。为了证实这一点，我们通过透射电子显微镜在体外确定了培养上清液中 EV 的存在。有趣的是，虽然多头绦虫和中绦期囊尾蚴会将膜状结构分泌到培养基中，但在多房棘球绦虫的生殖层和板层之间的界面也观察到了类似的囊泡，而在培养上清液中则很少检测到。然后，我们通过 LC-MS/MS 确定了 T. crassiceps 和 M. corti 条件培养基中 EV 富集分泌部分中的蛋白质组。在所鉴定的蛋白质中，除了预期的真核囊泡丰富蛋白外，还鉴定出了用于绦虫病诊断的蛋白、与神经传递有关的蛋白、脂质结合蛋白以及宿主免疫球蛋白和补体因子。最后，我们通过毛细管电泳证实了两种寄生虫的囊泡内 RNA 的存在，并通过逆转录-PCR 检测到了 microRNAs。这是首次报道绦虫寄生虫的 EV 分泌和 RNA 分泌机制。这些发现不仅为基础绦虫生物学提供了有价值的数据，也为合理寻找新的诊断靶点提供了依据。
