is an extracellular flagellate protozoan and the etiological agent of human trichomoniasis, a sexually transmitted infection (STI) with a high incidence. Several reports have shown that this protozoan releases microvesicles into the culture medium, which show high potential in modulating cell-to-cell communication and the host response to infections. However, the biogenesis of these vesicles has not been analyzed in detail. In the present study, high-resolution ion scanning microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the surface of control cells and cells incubated in the presence of Ca alone or with A 23187 calcium ionophore. Two different strains of were analyzed. Most control cells displayed relatively smooth surfaces, whereas cells incubated with Ca had many surface projections of variable shape and size (from 40 nm to around 1 μm). Quantitative analyses were performed directly in the scanning electron microscope and showed a significant increase in the number of cells with surface projections after incubation in the presence of calcium. TEM showed that treated cells presented several cytoplasmic multivesicular structures, suggesting membrane fusion and exosomes in the extracellular medium. The amount and size of the released vesicles were quantitatively analyzed using light scattering and TEM on negatively stained samples.

中文翻译：

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刺激阴道毛滴虫微泡分泌

是一种细胞外鞭毛原生动物，是人类滴虫病的病原体，滴虫病是一种发病率很高的性传播感染 (STI)。一些报告表明，这种原生动物将微泡释放到培养基中，这在调节细胞间通讯和宿主对感染的反应方面显示出巨大的潜力。然而，这些囊泡的生物发生尚未得到详细分析。在本研究中，使用高分辨率离子扫描显微镜 (SEM) 和透射电子显微镜 (TEM) 来分析对照细胞和在单独 Ca 存在或与 A 23187 钙离子载体存在下孵育的细胞的表面。分析了两种不同的菌株。大多数对照细胞显示相对光滑的表面，而用 Ca 孵育的细胞具有许多形状和大小可变的表面投影（从 40 nm 到约 1 μm）。直接在扫描电子显微镜中进行定量分析，结果显示在钙存在的情况下孵育后，具有表面突起的细胞数量显着增加。 TEM 显示处理的细胞呈现出几种细胞质多囊泡结构，表明细胞外介质中存在膜融合和外泌体。使用光散射和 TEM 对负染色样品定量分析释放的囊泡的数量和大小。