Trichomonas vaginalis
is a parasite of the human urogenital tract that causes trichomonosis, the most prevalent
non-viral sexually transmitted disease. Ectonucleoside triphosphate diphosphohydrolase (NTPDase) family members,
which hydrolyse extracellular ATP and ADP and ecto-5′-nucleotidase, which hydrolyses AMP, have been characterised
in
T. vaginalis. For trichomonad culture, the growth medium is supplemented with 10% serum, which is an
important source of nutrients, such as adenosine. Here, we investigated the ATP metabolism of
T. vaginalis trophozoites
from long-term cultures and clinical isolates under limited bovine serum conditions (1% serum). The specific
enzymatic activities were expressed as nmol inorganic phosphate (Pi) released/min/mg protein, the gene expression
patterns were determined by reverse transcriptase-polymerase chain reaction, the extracellular adenine nucleotide
hydrolysis was analysed by high performance liquid chromatography and the cell cycle analysis was assessed by
flow cytometry. Serum limitation led to the profound activation of NTPDase and ecto-5’-nucleotidase activities.
Furthermore, the levels of NTPDase A and B transcripts increased and extracellular ATP metabolism was activated,
which led to enhanced ATP hydrolysis and the formation of ADP and AMP. Moreover, the cell cycle was arrested
at the G0/G1 stage, which suggested adenosine uptake. Our data suggest that under conditions of serum limitation,
NTPDase and ecto-5’-nucleotidase play a role in providing the adenosine required for
T. vaginalis growth and that
this process contributes to the establishment of parasitism.
