Ceramide glycosylation and fatty acid hydroxylation influence serological reactivity in Trypanosoma cruzi glycosphingolipids

Ceramide mono (CMH) or dihexoside (CDH) fractions from Trypanosoma cruzi (Dm28c clone) were identified as glucosyl and lactosylceramides containing non-hydroxylated fatty acids. The di-glycosylated form was much more efficiently recognized by sera from T. cruzi-immunized rabbits, indicating that glycosylation influences antigenicity. Fatty acid hydroxylation was also a determinant of serological reactivity, since an alpha-hydroxylated CMH, only present at the Y clone, was recognized by the hyperimmune sera. In summary, these data indicate that T. cruzi CMHs with non-hydroxylated fatty acids are unable to induce antibody responses in animal hosts, which is reverted by the addition of a sugar residue or an alpha-hydroxyl group.