Glycosphingolipid expression in pig aorta: identification of possible target antigens for human natural antibodies

Total non-acid glycosphingolipids were isolated from the aortas of morethan 80 pigs. The glycolipids were separated by HPLC, analysed by thin-layer chromatography, and tested for reactivity with monoclonal anti- bloodgroup antibodies. The fractions were structurally characterized by NMRspectroscopy and mass spectrometry. Reactivity with both anti- blood groupA and H antibodies was seen. The major glycosphingolipid constituents wereglobotri- and globotetraosylceramides and blood group Hpentaglycosylceramides based on type 1 and type 2 core saccharide chains.Globopentaosylceramides, blood group H hexaglycosylceramides based on type4 chain, and blood group A hexaglycosylceramides based on type 1 core chainwere also present. Two structures, that may be important targets for humanantibodies initiating hyperacute rejection following pig to humanxenotransplantation, were present as minor constituents compared to theblood group components. These were Galalpha1,3neolactotetraosylceramide anda Galalpha1, 3Lexstructure. A Leb/Y hexaglycosylceramide was also present.