Heterologous expression in Tritrichomonas foetus of functional Trichomonas vaginalis AP65 adhesin

In this study, we show stable transfection and expression of the T. vaginalis ap65 gene in T. foetus from an episomal pBS-ap65-neo plasmid. Expression of the gene and protein was confirmed by RT-PCR and immunoblots, respectively. AP65 in transformed T. foetus bound to host cells. Specific mAbs revealed episomally-expressed AP65 targeted to the parasite surface and hydrogenosome organelles. Importantly, surface-expression of AP65 in T. foetus paralleled increased levels of adherence of transfected bovine trichomonads to human VECs.The T. vaginalis AP65 adhesin was stably expressed in T. foetus, and the data obtained using this heterologous system strongly supports the role of AP65 as a prominent adhesin for T. vaginalis. In addition, the heterologous expression in T. foetus of a T. vaginalis gene offers an important, new approach for confirming and characterizing virulence factors.The colonization of the urogenital tract of humans by the protozoan parasite Trichomonas vaginalis is responsible for trichomonosis [1], the most prevalent, non-viral sexually transmitted infection worldwide. Despite an estimated 8 million new cases per year in the United States alone [2], this health disparities disease [3] remains poorly studied. T. vaginalis infection is associated with adverse health consequences to both men and women, including infertility [4,5], atypical pelvic inflammatory disease [6], and increased HIV transmission [7,8]. Trichomonosis is also associated with preterm birth, low birth weight infants [9], predisposition to development of cervical neoplasia [10] in women and non-gonococcal urethritis [11] and chronic prostatitis [12] in men. T. vaginalis adherence to host VECs, a step preparatory to infection [13], is complex and involves four surface protein adhesins. Three adhesins studied to date at the molecular level share identity with metabolic enzymes of the hydrogenosome organelle [14,15]. Thus, the proteins exhibit functional diversity based on cellular locat