TRYPANOSOMA-CRUZI - DIFFERENT SURFACE-ANTIGENS OF TRYPOMASTIGOTES ARETARGETS OF LYTIC ANTIBODIES

Polyclonal antisera were obtained in rabbits following immunization wi th disrupted epimastigote or trypomastigote forms; 8-methoxypsoralen-i nactivated trypomastigotes; and surface trypomastigote antigens shed i nto the medium. High antibody levels were induced by all preparations as observed by indirect immunofluorescence and ELISA. However, antibod ies promoting complement-mediated lysis of bloodstream forms were only detected in animals immunized with inactivated living trypomastigotes and shed surface antigens. Immunoprecipitation of radioiodinated para sites showed that sera with lytic antibodies bound strongly to a wide range of membrane polypeptides from 72 to 160 kDa. Immunoadsorption of antibodies from a serum with high lytic activity on specific classes of trypomastigote polypeptides indicated that independent antigens are targets of lytic antibodies and that common epitopes may exist in dif ferent trypomastigote components.