title: Structural characterization of Schistosoma mansoni adult worm glycosphingolipids reveals pronounced differences with those of cercariae.
abstract: Immune responses induced by glycans upon infection with Schistosoma mansoni may be mediated by either schistosomal glycoproteins or glycosphingolipids. In this study, we have elucidated the structural features of both carbohydrate moieties and respective ceramide units of complex glycosphingolipids from adult S. mansoni. Obtained data revealed a vast structural heterogeneity due to manifold combinations of different oligosaccharides and ceramide entities. Observed carbohydrate moieties included Lewis(X) (Le(X); Gal(β1-4)[Fuc(α1-3)]GlcNAc) as well as, in part, multiply fucosylated LacdiNAc (LDN; GalNAc(β1-4)GlcNAc) carbohydrate epitopes. Corresponding lipid portions comprised predominantly C18-sphingosine as well as C18- and C20-phytosphingosine derivatives. Intriguingly, glycosphingolipids carrying an Le(X) epitope contained predominantly C18-sphingosine, whereas LDN-based species exhibited mostly phytosphingosine derivatives, in addition to C18-sphingosine, indicating that the two classes of glycosphingolipids might be synthesized via different biosynthetic routes. Compared with literature data, adult worm glycosphingolipids with Le(X) epitopes revealed clear structural differences in comparison to corresponding cercarial species which have been shown to exhibit mainly sphinganine bases with 18-21 carbon atoms. Therefore, it may be hypothesized that the divergent structural features of the respective ceramide moieties are responsible for the published observation that only adult worm, but not cercarial glycosphingolipids are able to induce dendritic cell activation skewing the T-cell response toward a Th1 profile.
authors.affiliation: Institute of Biochemistry, Faculty of Medicine,  Justus-Liebig-University Giessen, Friedrichstrasse 24, D-35392 Giessen,  Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Frank
authors.forename: Irma
authors.initials: I
authors.lastname: van Die
authors.forename: Rudolf
authors.initials: R
authors.lastname: Geyer
mesh_terms: D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004797:Enzyme-Linked Immunosorbent Assay; D006028:Glycosphingolipids / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D012550:Schistosoma mansoni / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D006028:Glycosphingolipids