Agglutination of Trypanosoma cruzi by Concanavalin A*

SYNOPSIS Epimastigotes of Trypanosoma cruzi obtained in culture agglutinate readily with low concentrations of concanavalin A (Con A). Agglutination was linear with time up to 10 min providing that the initial cell density was greater than 1 × 108 cells/ml. Under these conditions, the percentage agglutination was dependent on the Con A concentration. Agglutination was inhibited by α‐methyl D‐mannoside, α‐D‐mannose, and α‐D‐glucose. Pretreatment of cells with trypsin had no effect on the epimastigote agglutinations. Blood forms (trypomastigotes) of T. cruzi did not agglutinate even in the presence of 100 times more Con A. Results suggest differences in membrane structure between blood forms and cultured epimastigotes of T. cruzi. These membrane differences might be related to the different pathogenic properties of both cell forms of T. cruzi.