A carbohydrate-containing antigen from Trypanosoma cruzi and its detection in the circulation of infected mice.

A polysaccharide-containing fraction has been prepared from the water-soluble material of a phenol-water extract of epimastigote forms of Trypanosoma cruzi. Sera from rabbits immunized with this material have been used to detect trypanosome-derived polysaccharide in plasma of mice acutely infected with this parasite. The polysaccharide nature of the circulating antigen is suggested by its heat stability, resistance to proteinase and nucleases, and destruction by sodium metaperiodate, as well as by its periodic acid-Schiff staining and precipitation with concanavalin A. The antigen appears to be present in different strains of the parasite and in different stages in the life cycle of the parasite.