Abstract

Using colloidal gold immunocytochemistry - monoclonal antibody gal-13 (specific for lipid-linked galactosyl (alfa 1-3) galactose residues, anti-Iaminin, and anti-nidogen antibodies - and lectin cytochemistry (Bandeiraea simplicifolia IB4 ), both techniques specific for demonstrating galactosyl (alfa 1-3) galactose residues we have found terminal disaccharide residues on the Trypanosoma cruzi external surface of mouse blood - and Vero cell-derived trypomastigotes. Although intact epimastigotes moderately stained only with human antibodies, disrupted epimastigotes strongly immunoreacted with humans as well as with rabbit antibodies. Staining was also detected in the lips of the flagellar pocket, and on the parasitic side exactly opposite to the flagellar pocket in amastigote and promastigote forms of American Leishmania. The presence of abundant galactosyl (alfa 1-3) galactose residues on Trypanosomatid family members suggests a specific unknown role in parasite physiology for this terminal disaccharide.