Investigation into the potential involvement of apoptosis in the pathogenic mechanisms of the protozoan parasite Trichomonas vaginalis.

Abstract

Our hypothesis proposed that Trichomonas vaginalis would induce apoptosis in host cells as part of its pathogenic assault. This hypothesis was tested in an established co-culture system; previous research demonstrated that the parasite destroyed McCoy cell monolayers. The TUNEL assay was used to identify cells undergoing apoptotic DNA fragmentation as a result of co-incubation with T. vaginalis. Early experiments suggested that apoptosis may have been occurring in the McCoy monolayers, but this was later disproved with the help of a sandwich ELISA to detect DNA/histone fragments that characteristically result from apoptosis. Instead, the cells that had originally been identified as apoptotic were found to be adherent trichomonads. While McCoy cell apoptosis in response to co-culture with T. vaginalis was not observed, T. vaginalis did, over time, cause detachment of almost all monolayer cells, and also caused irreparable damage in a portion of these cells. Induction of McCoy monolayer detachment was determined to be contact-independent, given that trichomonad culture supernatants had a similar effect. (Abstract shortened by UMI.)