Molecular Mechanisms of Trichomonas Infection

阴道毛滴虫是滴虫病的病原体，滴虫病是人类最普遍的非病毒性性传播疾病。感染涉及缺乏O2的生态位、宿主细胞识别、Fe2+的隔离、寄生虫与宿主组织接触时从鞭毛到变形虫的形态发生、对甲硝唑的抗药性以及滴虫厌氧线粒体氢小体的能量代谢和蛋白质输入。目前关于滴虫感染的分子过程和机制的知识有限。特别是，感染的早期阶段和宿主-寄生虫的相互作用在很大程度上还没有确定。在这里，我们建议两个致力于滴虫生物学的欧洲领先实验室共同努力，以揭示人类泌尿生殖道组织感染阴道毛滴虫的潜在分子过程。我们提案前景中的问题包括：i)寄生虫黏附的性质，ii)感染期间核心碳和能量代谢的变化，以及iii)寄生虫与宿主组织接触时的转录反应。我们的方法需要对早期感染期间的转录本进行深度测序，结合蛋白质组学和与氢酶体输入和功能相关的单个成分的生化特征。为此，我们成功地将感染性阴道毛滴虫T016株与人阴道上皮细胞系MS74相结合，建立了稳定的体外感染系统。该系统不仅帮助我们生成了关于感染过程的新的初步数据的丰富来源，而且还允许采用新的方法来研究含有甲硝唑治疗靶点的氢小体。

Trichomonas vaginalis is the causative agent of Trichomoniasis, the most widespread non-viral sexually transmitted disease in humans. Infection involves O2-poor niches, host cell recognition, Fe2+-sequestration, morphogenesis of the parasite from flagellate to amoeboid form upon contact with host tissue, resistance to metronidazole treatment, as well as energy metabolism in and protein import into hydrogenosomes, the anaerobic mitochondria of trichomonads. Current knowledge about the molecular processes and mechanisms of Trichomonas infection is limited. In particular the very early stages of infection and host-parasite interactions are largely uncharacterized. Here we propose a concerted effort of two leading European laboratories working on trichomonad biology to uncover the molecular processes underlying infection by Trichomonas vaginalis of human urogenital tract tissue. The questions in the foreground of our proposal include i) the nature of parasite adherence, ii) changes in core carbon and energy metabolism during infection, and iii) the parasites transcriptomic response upon contact with host tissue. Our approach entails deep-sequencing of transcriptomes during early infection, combined with proteomics and biochemical characterization of individual components associated with hydrogenosomal import and function. To this end we have successfully established a stable in vitro infection system by combining the infectious T. vaginalis strain T016 and the human vaginal epithelial cell line MS74. The system has helped us not only to generate a rich source of novel preliminary data regarding the infection process, but furthermore allows new approaches to study hydrogenosomes, which harbor the target of metronidazole treatment.