title: Heterogeneity in extracellular nucleotide hydrolysis among clinical isolates of Trichomonas vaginalis.
abstract: Trichomonas vaginalis is a parasitic protozoan that causes trichomonosis, a sexually-transmitted disease, with serious sequelae to women and men. As the host-parasite relationship is complex, it is important to investigate biochemical aspects of the parasite that contribute to our understanding of trichomonal biology and pathogenesis. Nucleoside triphosphate diphosphohydrolase 1 (NTPDase 1), which hydrolyses extracellular ATP and ADP, and ecto-5'-nucleotidase, which hyrolyses AMP, have been characterized in laboratory isolates of T. vaginalis. Here we show that the extracellular ATP: ADP hydrolysis ratio varies among fresh clinical isolates, which presented higher ATPase and ADPase activities than long-term-grown isolates. Growth of parasites in iron-replete and iron-depleted medium resulted in different, albeit minor, patterns in extracellular ATP and ADP hydrolysis among isolates. Importantly, some isolates had low or absent ecto-5'-nucleotidase activity, regardless of environmental conditions tested. For isolates with ecto-5'-nucleotidase activity, high- and low-iron trichomonads had increased and decreased levels of activity, respectively, compared to organisms grown in normal TYM-serum medium. This suggests a regulation in expression of either the enzyme amounts and/or activity under the control of iron. Finally, we found no correlation between the presence or absence of dsRNA virus infection among trichomonad isolates and NTPDase and ecto-5'-nucleotidase activities.
authors.affiliation: Department of Microbiology, MC7758, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
authors.forename: T
authors.initials: T
authors.lastname: Tasca
authors.forename: C D
authors.initials: CD
authors.lastname: Bonan
authors.forename: G A
authors.initials: GA
authors.lastname: De Carli
authors.forename: J J F
authors.initials: JJ
authors.lastname: Sarkis
authors.forename: J F
authors.initials: JF
authors.lastname: Alderete
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D001081:Apyrase / Q000378:metabolism*; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D007501:Iron / Q000494:pharmacology; D014246:Trichomonas vaginalis / Q000201:enzymology*
chemical_list: D015703:Antigens, CD; D003470:Culture Media; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D007501:Iron; D015720:5'-Nucleotidase; D001081:Apyrase; C067869:CD39 antigen