Tritrichomonas foetus: the role played by iron during parasite interaction with epithelial cells

Abstract

The aim of this work was to investigate the role played by iron during interaction of Tritrichomonas foetus with cultured epithelial cells. We have observed that the growth rate of T. foetus is influenced by the amount of iron available into culture medium. When organisms maintained for 24 h in iron-depleted medium were transferred to an iron-rich one, many protozoan cells exhibited a cytokinesis blockage. Parasites maintained in iron-depleted medium exhibited a significant increase in cytoadhesion when compared with both controls and parasites that had been cultured in medium in which iron was replaced. T. foetus collected from iron-depleted medium also exhibited a reduction in its ability to destroy epithelial cell monolayers and a reduction in the activity of several cysteine proteases. Taken together, the results presented here demonstrate that iron may be an extracellular signal, which seems to modulate the ability of T. foetus to interact with host epithelial cells. Index descriptions and Abbreviations: Tritrichomonas foetus; parasitic protozoa; iron; HeLa cells; cytoadhesion; cytotoxicity; cysteine proteases; l- trans-epoxysuccinylleucylamido-(4-guanidino) butane E-64; EDTA, ethylenediaminetetraacetic acid; FCS, fetal calf serum; Hepes, N-2-hydroxyethylpiperazine- N ′-2-ethanesulfonic acid; PAGE, polyacrylamide gel electrophoresis; PBS, phosphate-buffered saline; PFOR, pyruvate:ferredoxin oxidoreductase; PMSF, phenylmethylsulphonyl fluoride; RPMI, Roswell Park Memorial Institute medium; SDS, sodium dodecyl sulfate; SOD, superoxide dismutase; TLCK, N-α- p-tosyl- l-lisine chloromethyl ketone