The temporary or long-term xenotransplantation of pig organs into people would save thousands of lives each year if not for the robust human antibody response to pig carbohydrates. Genetically engineered pigs deficient in galactose-alpha-1,3-galactose (gene modified: GGTA1) and N-glycolylneuraminic acid (gene modified: CMAH) have significantly improved cell survival when challenged by human antibody and complement in vitro. There remains, however, a significant portion of human antibody binding. To uncover additional xenoantigens we compared the asparagine-linked (N-linked) glycome from serum proteins of humans, domestic pigs, GGTA1 knockout pigs and GGTA1/CMAH knockout pigs. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) analysis of reduced and solid-phase permethylated glycans resulted in the detection of high-mannose, hybrid, and complex type N-linked glycans in the 1000 to 4500 m/z ion range. Carbohydrate structures were determined with assistance from GlycoWorkbench, Cartoonist, and SimGlycan software by comparison to existing database entries and collision-induced dissociation fragmentation data. GGTA1/CMAH knockout pig samples had increased relative amounts of high-mannose and incomplete N-linked glycans. All pig samples had significantly higher amounts of core and possibly antennae fucosylation. We provide for the first time the serum protein glycomes of the human and domestic pig in comparison to genetically modified pigs important to xenotransplantation.

N-linked glycan profiling of GGTA1/CMAH knockout pigs identifies new potential carbohydrate xenoantigens

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.