Premium
Structural characterization of blood group A glycolipids in blood group A 1 liver tissue in situ perfused with O blood: the dominating presence of type 1 core chain A antigens
Author(s) -
Samuelsson Bo E.,
Magnusson Stefan,
Rydberg Lennart,
Scherstén Tore,
Breimer Michael E
Publication year - 2006
Publication title -
xenotransplantation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.052
H-Index - 61
eISSN - 1399-3089
pISSN - 0908-665X
DOI - 10.1111/j.1399-3089.2006.00287.x
Subject(s) - glycolipid , abo blood group system , chemistry , biochemistry , glycoprotein , fucose , chromatography , biology , immunology
Background: Biochemical studies of organ blood group antigen expression show a mixed pattern originating from both the organ tissue and remaining blood cells trapped in the organ despite in vitro perfusion of the vascular tree. The blood group A glycolipid expression was studied in a unique case in which a human liver had been in situ perfused by recipient blood. Case history: A blood group O recipient was re‐transplanted with an ABO incompatible A 1 Le (a−b+) liver. Because of discrepancy in size, liver segments II and III were removed 2 h after re‐vascularization. Thereafter, the removed A 1 liver segment was physiologically in situ perfused with O blood, eliminating a major part of the donor blood cells/plasma. Experimental: Total neutral glycolipids were isolated from the liver tissue and separated by high‐performance liquid chromatography. Purified glycolipid fractions were stained with anti‐A monoclonal antibodies (mAbs) and structurally characterized by mass spectrometry and proton nuclear magnetic resonance (NMR) spectroscopy. Results: Two blood group A reactive glycolipid compounds were isolated. One component had a thin‐layer chromatography (TLC) mobility as a six‐sugar glycolipid and reacted with mAbs specific for A type 1 mono‐fucosyl structures. The second glycolipid fraction migrated as seven‐sugar components and reacted with mAbs specific for type 1 difucosyl (ALe b ) as well as Le b determinants. Mass spectrometry of the six‐sugar component showed a structure similar to a blood group A hexaglycosylceramide with one fucose. Mass spectrometry and proton NMR spectroscopy of the seven‐sugar fraction revealed a mixture of blood group Le b hexa‐ and ALe b hepta‐glycosylceramides, respectively. All fractions were non‐reactive with antibodies specific for A antigens based on types 3 and 4 core chain structures. In addition, TLC immunostaining of glycolipids isolated from blood group A livers, harvested for organ transplantation but discarded for various reasons, revealed trace amounts of several A glycolipids with a complex pattern. Conclusion: The in situ perfused liver tissue contains blood group A glycolipids based exclusively on type 1 core chains. The secretor gene ( Se ) codes for a fucosyltransferase acting on all core chain precursors while the H‐gene fucosyltransferase only utilizes the type 2 chain precursor. Whether this explains that only A type 1 chain compounds were found has to be established.