title: Heterologous expression in Tritrichomonas foetus of functional Trichomonas vaginalis AP65 adhesin.
abstract: BACKGROUND
  Trichomonosis, caused by Trichomonas vaginalis, is the number one, nonviral sexually transmitted infection that has adverse consequences for the health of women and children. The interaction of T. vaginalis with vaginal epithelial cells (VECs), a step preparatory to infection, is mediated in part by the prominent surface protein AP65. The bovine trichomonad, Tritrichomonas foetus, adheres poorly to human VECs. Thus, we established a transfection system for heterologous expression of the T. vaginalis AP65 in T. foetus, as an alternative approach to confirm adhesin function for this virulence factor.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Microbiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229-3900, USA. kucknoor@uthscsa.edu
authors.forename: Ashwini S
authors.initials: AS
authors.lastname: Kucknoor
authors.forename: Vasanthakrishna
authors.initials: V
authors.lastname: Mundodi
authors.forename: J F
authors.initials: JF
authors.lastname: Alderete
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002448:Cell Adhesion / Q000235:genetics; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000502:physiology; D002458:Cell Fractionation / Q000379:methods; D002461:Cell Line, Transformed / Q000737:chemistry; D002462:Cell Membrane / Q000737:chemistry; D004274:DNA, Recombinant; D004847:Epithelial Cells / Q000469:parasitology*; D005260:Female; D015870:Gene Expression; D006801:Humans; D015151:Immunoblotting; D008856:Microscopy, Fluorescence / Q000379:methods; D010957:Plasmids / Q000235:genetics; D021381:Protein Transport; D015800:Protozoan Proteins / Q000235:genetics* / Q000502:physiology; D014162:Transfection; D014246:Trichomonas vaginalis / Q000235:genetics* / Q000502:physiology; D016835:Tritrichomonas foetus / Q000235:genetics; D014621:Vagina / Q000166:cytology / Q000469:parasitology*
chemical_list: C096723:AP65-1 protein, Trichomonas vaginalis; D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D004274:DNA, Recombinant; D015800:Protozoan Proteins