Castelli Germano, Bruno Federica, Saieva Laura, Alessandro Riccardo, Galluzzi Luca, Diotallevi Aurora, Vitale Fabrizio
National Reference Center for Leishmaniasis (C.Re.Na.L.), Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129, Palermo, Italy.
Dipartimento di Biopatologia e Biotecnologie Mediche, sezione di biologia e genetica, University of Palermo, Palermo, Italy.
Exp Parasitol. 2019 Mar;198:39-45. doi: 10.1016/j.exppara.2019.01.014. Epub 2019 Feb 1.
In recent years, several studies demonstrated the role of exosomes in intercellular communications, several Leishmania species belonging to subgenera Leishmania and Viannia have been demonstrated to release exosomes, and their role in parasite-macrophage interactions and in leishmaniasis development has been investigated. However, the release of exosomes by Leishmania infantum has not been studied so far. The aim of this study was to isolate and characterize L. infantum exosomes, and to investigate the biological activity of these exosomes in macrophage cultures. To this end, exosomes were collected from both amastigote and promastigote L. infantum conditioned medium by ultracentrifugation. Exosomes were then characterized by monitoring the presence of HSP70, HSP83/90 and acetylcholinesterase activity. Moreover, extracellular vesicles-tracking analysis revealed that promastigote and amastigote exosomes had mean diameter of 122 ± 56 nm and 115 ± 65 nm, respectively. Human monocytic cell line U937-derived macrophages treated with promastigote and amastigote exosomes showed an increase in motility and an overproduction of interleukin IL-10 and IL-18 reduction, involved in immune response. Since L. infantum exosomes demonstrated the capacity to modulate the chemotactic behaviour of the cells studied and cytokines production, they could contribute in the disease establishment and may be considered an appropriate candidate for a vaccine therapy in prophylaxis and treatment.
近年来，多项研究证明了外泌体在细胞间通讯中的作用，已证实属于利什曼原虫亚属和维扬亚属的几种利什曼原虫会释放外泌体，并且对其在寄生虫与巨噬细胞相互作用以及利什曼病发展中的作用进行了研究。然而，迄今为止尚未研究过婴儿利什曼原虫外泌体的释放情况。本研究的目的是分离和鉴定婴儿利什曼原虫外泌体，并研究这些外泌体在巨噬细胞培养中的生物活性。为此，通过超速离心从婴儿利什曼原虫无鞭毛体和前鞭毛体的条件培养基中收集外泌体。然后通过监测热休克蛋白70、热休克蛋白83/90的存在以及乙酰胆碱酯酶活性来鉴定外泌体。此外，细胞外囊泡追踪分析显示，前鞭毛体和无鞭毛体外泌体的平均直径分别为122±56nm和115±65nm。用前鞭毛体和无鞭毛体外泌体处理的人单核细胞系U937衍生的巨噬细胞显示出运动性增加，以及参与免疫反应的白细胞介素IL-10过量产生和IL-18减少。由于婴儿利什曼原虫外泌体显示出调节所研究细胞的趋化行为和细胞因子产生的能力，它们可能在疾病发生过程中起作用，并且可能被认为是预防和治疗中疫苗疗法的合适候选者。
