THE INVOLVEMENT OF TERMINAL CARBOHYDRATES OF THE MAMMALIAN-CELL SURFACE IN THE CYTOADHESION OF TRICHOMONADS

In the present study the parental cells and glycosylation mutants of C hinese hamster ovary (CHO) cells were used to analyze the influence of surface carbohydrates on the cytoadhesion of trichomonads. Trichomona s vaginalis and Tritrichomonas foetus were allowed to interact with ho st cells for 2 h at 37 degrees C. Alternatively, CHO cells were treate d with 10 mM periodate prior to the assays. Both trichomonads adhered to all CHO cell clones tested. A remarkable difference could be observ ed between the cytoadhesion of T. vaginalis and T. foetus. Sialic acid residues present on the surface of CHO cells may favor the cytoadhesi on of T. foetus while hampering that of T. vaginalis. The specificity of the parasite cytoadhesion was further investigated. Sialic acid, ma nnose, and galactose as well as mannose, galactose, and N-acetylglucos amine added to the interaction medium at 50, 100, and 200 mM were capa ble of significantly inhibiting the cytoadhesion of each trichomonad s pecies. Periodate treatment of target cells also induced decreases in the cytoadhesion of the trichomonads. These results strongly sugest an important role for host-cell surface glycoconjugates during the cytoa dhesion of trichomonads. In addition, they also point out the presence of ''lectin-like'' molecules on the surface of both T. vaginalis and T. foetus.