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Trichomonas vaginalis kills and eats – evidence for phagocytic activity as a cytopathic effect

  • V. MIDLEJ (a1) (a2) and M. BENCHIMOL (a1)

This study reports that the cytopathic effect of Trichomonas vaginalis, an important human parasite of the urogenital tract, occurs due to mechanical stress and subsequent phagocytosis of the necrotic cells. The investigation was done using a primary culture of bovine oviduct epithelial cells (BOECs), grown either in monolayers or as floating cells. Trophozoites displaying different virulence levels were co-incubated with BOECs for times varying between 1 min and 48 h. Analyses were performed using videomicroscopy, scanning and transmission electron microscopy, colourimetric assays and cytochemistry. Injury was observed as early as 1 h after incubation, while after 12 h the host cells were severely damaged when a fresh trichomonad isolate was used. Trichomonads attack the host cells by clustering around them. Mechanical stress on the microvilli of the host cells was observed and appeared to induce plasma membrane damage and cell death. After membrane injury and lysis, fragments of the necrotic cells were ingested by trichomonads. Phagocytosis occurred by trichomonads avidly eating large portions of epithelial cells containing the nucleus and other organelles, but living or intact cells were not ingested. Necrotic fragments were rapidly digested in lysosomes, as shown by acid phosphatase and ruthenium red assays where only the BOECs were labelled. The lytic capacity of the trichomonads was more pronounced in host cell suspensions.

Corresponding author
*Corresponding author: Rua Jornalista Orlando Dantas, CEP 222-31-010, Rio de Janeiro, RJ, Brazil. Tel/Fax: +55 21 2237 0440. E-mail:
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A. Affonso , M. Benchimol , K. C. Ribeiro , U. Lins and W. De Souza (1994). Further studies on the endocytic activity of Tritrichomonas foetus. Parasitology Research 80, 403413.

J. F. Alderete , M. W. Lehker and R. Arroyo (1995). The mechanisms and molecules involved in cytoadherence and pathogenesis of Trichomonas vaginalis. Parasitology Today 11, 7074.

M. Benchimol , I. De Andrade Rosa , R. Da Silva Fontes and A. J. Burla Dias (2008). Trichomonas adhere and phagocytose sperm cells: adhesion seems to be a prominent stage during interaction. Parasitology Research 102, 597604.

M. Benchimol , N. L. Da Cunha e Silva , C. A. Elias and W. De Souza (1986). Tritrichomonas foetus: ultrastructure and cytochemistry of endocytosis. Experimental Parasitology 62, 405415.

M. Benchimol and W. De Souza (1995). Carbohydrate involvement in the association of a prokaryotic cell with Trichomonas vaginalis and Tritrichomonas foetus. Parasitology Research 81, 459464.

V. L. Bonilha , M. C. Ciavaglia , W. De Souza and F. Costa e Silva Filho (1995). The involvement of the terminal carbohydrates of the mammalian cell surface in the cytoadhesion of trichomonads. Parasitology Research 81, 121126.

G. Brugerolle , G. Bricheux and G. Coffe (1996). Actin cytoskeleton demonstration in Trichomonas vaginalis and in other trichomonads. Biology of the Cell 88, 2936.

M. L. Crouch and J. F. Alderete (1999). Trichomonas vaginalis interactions with fibronectin and laminin. Microbiology 145, 28352843.

L. S. Diamond (1957). The establishment of various trichomonads of animals and man in axenic cultures. Journal of Parasitology 43, 488490.

P. L. Fiori , P. Rappelli , M. F. Addis , A. Sechi and P. Cappuccinelli (1996). Trichomonas vaginalis haemolysis: pH regulates a contact-independent mechanism based on pore-forming proteins. Microbial Pathogenesis 20, 109118.

P. L. Fiori , P. Rappelli , A. M. Rocchigiani and P. Cappuccinelli (1993). Trichomonas vaginalis haemolysis: evidence of functional pores formation on red cell membranes. FEMS Microbiology Letters 109, 1318.

R. O. Gilbert , G. Elia , D. H. Beach , S. Klaessig and B. N. Singh (2000). Cytopathogenic effects of Trichomonas vaginalis on human vaginal epithelial cells cultured in vitro. Infection and Immunity 68, 42004306.

A. González-Robles , G. Castanon , A. R. Cristóbal-Ramos , A. Lázaro-Haller , M. Omaña-Mlina , P. Bonilla and A. Martinez-Palomo (2006). Acanthamoeba castellanii: structural bases of the cytopathic mechanisms. Experimental Parasitology 114, 133140.

A. González-Robles , M. ESPINOSA-CASTELLANO Lazaro-Haller , F. A. Anaya-Velazquez and A. Martinez-Palomo (1995). Trichomonas vaginalis: ultrastructural bases of the cytopathic effect. The Journal of Eukaryotic Microbiology 42, 641651.

B. M. Honigberg (1990). Host cell-trichomonad interactions and virulence assays in vitro systems. In Trichomonads Parasitic in Humans (ed. B. M. Honigberg ), pp. 155212. Springer-Verlag, New York, USA.

J. B. Jesus , T. M. Podlyska , A. H. C. S. Lopes , M. A. Vannier-Santos and J. R. Meyer-Fernandes (2002). Characterization of an ecto-phosphatase activity in the human parasite Trichomonas vaginalis. Parasitology Research 88, 991997.

S. Kummer , G. R. Hayes , R. O. Gilbert , D. H. Beach , J. J. Lucas and B. N. Singh (2008). Induction of human host cell apoptosis by Trichomonas vaginalis cysteine proteases is modulated by parasite exposure to iron. Microbial Pathogenesis 44, 197203.

J. H. Luft (1971). Ruthenium red and violet. I. Cytochemistry, purification, methods of use for electron microscopy and mechanism of action. The Anatomical Record 171, 347368.

A. Martinez-Palomo , A. González-Robles , B. Chávez , E. Orozco , S. Fenádez-Castelo and A. Cervantes (1985). Structural basis of the cytolytic mechanisms of Entamoeba histolytica. The Journal of Protozoology 32, 166175.

M. R. Mendoza-Lopes , C. Becerril-Garcia , L. V. Fattel-Facenda , L. Ávila-Gonzales , M. E. Rutz-Tachiquin , J. Ortega-Lopes and R. Arroyo (2000). CP30, a cysteine proteinase involved in Trichomonas vaginalis cytoadherence. Infection and Immunity 68, 49074912.

A. Mirhagani and A. Warton (1996). An electron microscope study of the interaction between Trichomonas vaginalis and epithelial cells of the human amnion membrane. Parasitology Research 82, 4347.

A. Pereira-Neves and M. Benchimol (2007). Phagocytosis by Trichomonas vaginalis – new insights. Biology of the Cell 99, 87–101.

J. G. Rendón-Maldonado , M. Espinosa-Cantellano , A. González-Robles and A. Martinez-Palomo (1998). Trichomonas vaginalis: in vitro phagocytosis of lactobacilli, vaginal epithelial cells, leukocytes and erythrocytes. Experimental Parasitology 89, 241250.

I. M. Robinson and M. J. Karnovsky (1983). Ultrastructural localization of several phosphatases with cerium. The Journal of Histochemistry and Cytochemistry 31, 11971208.

B. N. Singh , J. J. Lucas , G. R. Hayes , I. Kumar , D. H. Beach , M. Frajblat , R. O. Gilbert , U. Sommer and C. E. Costello (2004). Tritrichomonas foetus induces apoptotic cell death in bovine vaginal epithelial cells. Infection and Immunity 72, 41514158.

B. N. Singh , G. R. Hayes , J. J. Lucas , D. H. Beach and R. O. Gilbert (2005). In vitro cytopathic effects of a cysteine protease of Tritrichomonas foetus on cultured bovine uterine epithelial cells. American Journal of Veterinary Research 66, 11811186.

F. Sorvillo , L. Smith , P. Kerndt and L. Ash (2001). Trichomonas vaginalis, HIV, and African-Americans. Emerging Infectious Diseases 7, 927932.

R. G. Vancini and M. Benchimol (2008). Entry and intracellular location of Mycoplasma hominis in Trichomonas vaginalis. Archives of Microbiology 189, 7–18.

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