Salvador-Membreve Daile Meek C, Jacinto Sonia D, Rivera Windell L
Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines.
Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines; Molecular Protozoology Laboratory, Natural Sciences Research Institute, University of the Philippines, Diliman, Quezon City 1101, Philippines.
Exp Parasitol. 2014 Dec;147:33-40. doi: 10.1016/j.exppara.2014.10.003. Epub 2014 Oct 13.
Trichomonas vaginalis, the causative agent of trichomoniasis is generally known to inhabit the genitourinary tract. However, several case reports with supporting molecular and immunological identifications have documented its occurrence in the respiratory tract of neonates and adults. In addition, the reports have documented that its occurrence is associated with respiratory failures. The medical significance or consequence of this association is unclear. Thus, to establish the possible outcome from the interaction of T. vaginalis with lung cells, the cytopathic effects of the parasites were evaluated using monolayer cultures of the human lung alveolar basal carcinoma epithelial cell line A549. The possible effect of association of T. vaginalis with A549 epithelial cells was analyzed using phase-contrast, scanning electron microscopy and fluorescence microscopy. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), crystal-violet and TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick-end labelling) assays were conducted for cytotoxicity testing. The results demonstrate that T. vaginalis: (1) adheres to A549 epithelial cells, suggesting a density-dependent parasite-cell association; (2) adherence on A549 is through flagella, membrane and axostyle; (3) causes cell detachment and cytotoxicity (50-72.4%) to A549 and this effect is a function of parasite density; and (4) induces apoptosis in A549 about 20% after 6 h of incubation. These observations indicate that T. vaginalis causes cytopathic effects on A549 cell. To date, this is the first report showing a possible interaction of T. vaginalis with the lung cells using A549 monolayer cultures. Further studies are recommended to completely elucidate this association.
阴道毛滴虫是滴虫病的病原体，通常已知其寄生于泌尿生殖道。然而，一些有分子和免疫学鉴定支持的病例报告记录了它在新生儿和成人呼吸道中的出现。此外，报告还记录了其出现与呼吸衰竭有关。这种关联的医学意义或后果尚不清楚。因此，为了确定阴道毛滴虫与肺细胞相互作用可能产生的结果，使用人肺肺泡基底癌上皮细胞系A549的单层培养物评估了寄生虫的细胞病变效应。使用相差显微镜、扫描电子显微镜和荧光显微镜分析了阴道毛滴虫与A549上皮细胞结合的可能影响。进行了MTT（3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐）、结晶紫和TUNEL（末端脱氧核苷酸转移酶介导的dUTP缺口末端标记）试验以进行细胞毒性测试。结果表明，阴道毛滴虫：（1）粘附于A549上皮细胞，表明寄生虫与细胞的结合具有密度依赖性；（2）通过鞭毛、细胞膜和轴柱粘附于A549；（3）导致A549细胞脱离和细胞毒性（50%-72.4%），且这种效应是寄生虫密度的函数；（4）孵育6小时后，诱导A549细胞约20%凋亡。这些观察结果表明，阴道毛滴虫对A549细胞产生细胞病变效应。迄今为止，这是第一份使用A549单层培养物显示阴道毛滴虫与肺细胞可能相互作用的报告。建议进一步研究以完全阐明这种关联。
