Characterization of the Fibronectin Binding Properties of Trypanosoma cruzi Epimastigotes

Interactions between parasites and host sells play an important role in the infection process. The adhesive protein fibronectin has been shown to be involved in the interaction between Trypanosoma cruzi and host cells. Trypanosoma cruzi epimastigotes grown in axenic culture bound 125I-fibro-nictin in an energy-dependent manner. Initial binding induced the expression/activation of further fibronectin receptors or activation of a fibronectin-specific uptake system. This binding could be inhibited by fixing the parasites with formalin, metabolic inhibitors (e.g. dinitrophenol), changes in temperature and by an excess of unlabeled fibronectin. The binding was not inhibited by EDTA nor by the peptide Arg-Gly-Asp-Ser (RGDS), which is the recognition sequence from the major cell binding domain of fibronectin.