Sulfated lipids represent common antigens on the surface of Trypanosoma cruzi and mammalian tissues

Abstract

Cross-reacting lipid antigens were isolated from Trypanosoma cruzi and the mammalian brain with the monoclonal antibody VESP 6.2. Chemical reactions indicated that the sulfate group of the lipids is an important part of the epitope recognized by the monoclonal antibody. Lipid extracts of mouse brain contained all the antigenic species present in the parasite. One of the antigens isolated from brain extracts was identified as sulfo-galactosyl-ceramide. The specificity of VESP 6.2 for these isolated lipid antigens was demonstrated by three different methods: (i) high performance thin layer chromatography immunostaining, (ii) solid phase radioimmunoassay, (iii) lysis of artificial liposomes. The T. cruzi sulfated lipid antigens were shown to be of parasite origin rather than scavenged from the culture medium. They could be radiolabelled with [ 35S]sulfate. Furthermore, lipid extracts from two T. cruzi strains grown in different media contained the same antigens while the media contained either no antigens or different species.