Novel mechanism that Trypanosoma cruzi uses to adhere to the extracellular matrix mediated by human galectin-3

Binding of Trypanosoma cruzi trypomastigotes to laminin is enhanced by galectin-3, a beta-galactoside binding lectin. The galectin-3 enhanced binding of trypanosomes to laminin is inhibited by lactose. Co-immunoprecipitations indicate that galectin-3 binds to the 45, 32 and 30 kDa trypanosome surface proteins. Binding of galectin-3 to the 45, 32 and 30 kDa surface proteins is inhibited by lactose. Polyclonal and a monoclonal antibodies to galectin-3 immunoprecipitated a major 64 kDa trypanosome surface protein. T. cruzi monoclonal antibody to mucin recognized the 45 kDa surface protein. The 45, 32 and 30 kDa surface proteins interact with galectin-3 in order to enhance trypanosome adhesion to laminin.