Effect of carbohydrates, periodate and enzymes in the process of endocytosis of Trypanosoma cruzi by macrophages.

The effect of mild enzyme (trypsin, neuraminidase) treatment, periodate treatment and addition of carbohydrates (mono, di-, and polysaccharides) on the ingestion of Trypanosoma cruzi epimastigotes and trypomastigotes by mouse macrophages was studied. Trypsin treatment did not interfere with the ingestion of epimastigotes but did, however, increase the ingestion of trypomastigotes by mouse peritoneal macrophages. Neuraminidase and periodate treatment of the parasites increased the uptake of epi- and trypomastigote forms. The neuraminidase effect was partially blocked by galactose or N-acetylgalactosamine. Galactose, mannose, fucose, N-acetylglucosamine, and N-acetylgalactosamine had an influence on the ingestion of T. cruzi by macrophages. This effect was dependent on the strain of parasite tested, and the medium used to cultivate the epimastigotes. The results obtained, in conjunction with the work of others, suggest that glycoproteins and/or glycolipids on the parasite and/or macrophage surface are involved in the T. cruzi-macrophage interaction.