Surface antigens of stocks and clones of Trypanosoma cruzi isolated from humans.

The total surface polypeptide pattern was analyzed after radioiodination of 12 different stocks and clones of Trypanosoma cruzi belonging to four different zymodemes isolated from humans of the region of Bambuí (M.G., Brazil). Although some minor differences were encountered, it is concluded that this pattern cannot be used as a method for classification of strains. Sera obtained from chagasic patients harboring parasites typed according to each zymodeme and from rabbits immunized with either epimastigotes or trypomastigotes from the Y strain immunoprecipitated surface antigens of apparent Mr 55 kDa, 80 kDa and 95 kDa in all the stocks (epimastigotes) tested. These antigens thus appear to be conserved among stocks of T. cruzi and to be common to epimastigotes and trypomastigotes. Immunoprecipitation of antigens of surface radioiodinated trypomastigotes (Y strain) with 16 different chagasic sera indicates a remarkable identity among the observed patterns, suggesting that the antigenic characteristics of the surface of T. cruzi infective forms are highly conserved and insensitive to the zymodeme type.