Cytopathogenic Effect of Trichomonas vaginalis on Human Vaginal Epithelial Cells Cultured In Vitro

Abstract

In this study we established human vaginal epithelial cells (hVECs) in culture and evaluated their interaction with Trichomonas vaginalis parasites to complement previous studies using other cell types. Primary cultures of hVECs were established. Contaminating fibroblasts were separated from epithelial cells by differential trypsinization. Specific antibody staining revealed that over 92% of cells in hVEC monolayers were epithelial cells. T. vaginalis adhered to hVECs and produced severe cytotoxic effects resulting in obliteration of the monolayer within 24 h. Adherence and cytotoxicity were not observed when T. vaginalis was exposed to human vaginal fibroblasts or bovine vaginal epithelial cells. Likewise, the bovine parasite Tritrichomonas foetus had no cytotoxic effects on hVECs. We concluded that the interaction between T. vaginalis and hVECs is both cell specific (limited to epithelial cells and not vaginal fibroblasts) and species specific (limited to human vaginal cells and not bovine cells). Pretreatment of T. vaginalis with metronidazole or periodate abolished the adhesion of parasites to cell monolayers and the cytotoxic effect, suggesting involvement of carbohydratecontaining molecules in these processes. Different clinical isolates of T. vaginalis caused damage to cultured cells at different rates. Parasites separated from the vaginal cell monolayer by a permeable membrane did not produce a cytopathic effect, suggesting contact-dependent cytotoxicity.

Trichomonas vaginalis and Tritrichomonas foetus: interaction with fibroblasts and muscle cells - new insights into parasite-mediated host cell cytotoxicity

“…Previous in vitro studies have addressed the interaction of T. vaginalis with human fibroblasts (Alderete & Garza 1985, Gilbert et al 2000. The authors of these studies concluded that the parasites were able to attach to the cells, but did not induce cytotoxicity (Alderete & Garza 1985, Gilbert et al 2000.…”

“…The authors of these studies concluded that the parasites were able to attach to the cells, but did not induce cytotoxicity (Alderete & Garza 1985, Gilbert et al 2000. In addition, recent work in which mice were used as a host model for T. vaginalis infection demonstrated that trichomonas causes alterations in the connective tissue (Escario et al 2010).…”

“…Another important question is whether trichomonads are restricted to interactions with epithelial cells or are invasive and able to reach deeper tissues, such as the cells of the connective and muscle tissues. In the literature, some authors have claimed that T. vaginalis adheres to fibroblast monolayers, but the parasites were unable to provoke damage to this cell type (Alderete & Garza 1985, Gilbert et al 2000. In contrast, another group reported that T. vaginalis could invade and induce changes in deep vaginal tissues (Escario et al 2010).…”

Trichomonas vaginalis perturbs the junctional complex in epithelial cells

“…Trichomonas vaginalis, a protozoan parasite, is the causative agent of trichomoniasis, the most common nonviral sexually transmitted disease in humans [1]. This parasite has a worldwide distribution and it infects 250 to 350 million people worldwide [2].…”

Comparative aspects of immunity and vaccination in human and bovine trichomoniasis: a review

“…In laboratory mice, Tritrichomonas foetus maintains its shape and flagella and adheres to and injure vaginal and endometrial epithelial cells (Singh et al 2004;Gilbert et al 2000;Midlej et al 2009;Vilela and Benchimol 2011;Pereira-Neves et al 2012). Inhibition of cell division and endometrial inflammation were detected in vitro in oviduct organ culture models (Benchimol et al 2006;Ma et al 2011) .…”