Use of an animal model of trichomoniasis as a basis for understanding this disease in women.

Studies of host-parasite relationships in bovine trichomoniasis are presented as a basis for understanding mechanisms of pathogenesis and protection in trichomoniasis in women. The bovine infection is caused by Trichomonas foetus, a trichomonad species closely related to the human pathogen Trichomonas vaginalis. An estrogenized murine model infected with T. vaginalis is useful for the study of virulence factors, but the bovine model has advantages for the study of immunity because T. foetus infection is common in this natural host. In vitro, several virulence factors similar to those of T. vaginalis have been studied, including cysteine proteinases, binding of host cell proteins, and factors involved in attachment to vaginal cells. The biggest advantage of the bovine model, however, is that an efficacious systemic vaccination has been demonstrated to both prevent and treat T. foetus infection. The specificity and isotype of antibodies involved in protection have also been defined. These findings provide encouragement for the development of vaccines against trichomoniasis in humans.