title: Detection of Hanganutziu-Deicher antigens in O-glycans from pig heart tissues by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
abstract: BACKGROUND
  In the α1,3-galactosyltransferase knockout (α-GalT KO) pig era, identification of the non-Gal epitopes is necessary for successful pig-to-human xenotransplantation. Recently, we successfully detected α-Gal epitopes as well as Hanganutziu-Deicher (H-D) antigens from the N-glycans in the pig heart tissues, which have been considered as promising non-Gal antigens. However, the profiling of O-glycan from pig heart tissues had not been performed owing to the difficulty of O-glycan preparation.
  
  
  METHODS
  In this study, we established the simple and sensitive method to profile O-glycans from pig heart aortic valve, aortic wall, pulmonary valve, pulmonary wall, and cardiac muscle tissues. To liberate O-glycans from the pig heart tissues, we used non-reductive β-elimination reagent and subsequently purified the glycans. After permethylation, the glycans were qualitatively analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).
  
  
  RESULTS
  The comprehensive O-glycan analysis method was successfully validated using model glycoproteins such as bovine serum fetuin (BSF) and bovine submaxillary gland mucin (BSM) glycoproteins, and their O-glycan profiles were in accordance with the data of previous studies. Next, we applied the method for O-glycan release and characterization to analysis of various pig heart tissues. As a result, total 39, 33, 24, 36, and 25 of O-glycans were detected from aortic valve, aortic wall, pulmonary valve, pulmonary wall, and cardiac muscle, respectively. Furthermore, four in aortic valve, one in aortic wall, one in pulmonary valve, one in pulmonary wall, and one in cardiac muscle were particularly determined as terminally N-glycolylneuraminic acid-linked O-glycans, which is considered to be the H-D antigens.
  
  
  CONCLUSIONS
  Here, we initially described the O-glycan structures of various pig heart tissues, and additionally, the existence of H-D antigen type O-glycans was firstly identified. These results will be fundamental information for overcoming the xenoantigenic carbohydrate-related immunological rejection in pig-to-human heart tissue xenotransplantation.
authors.affiliation: School of Chemical and Biological Engineering in College of Engineering, Seoul National University, Seoul, Korea.
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Jeong
authors.forename: Mausumi
authors.initials: M
authors.lastname: Adhya
authors.forename: Hae-Min
authors.initials: HM
authors.lastname: Park
authors.forename: Yun-Gon
authors.initials: YG
authors.lastname: Kim
authors.forename: Byung-Gee
authors.initials: BG
authors.lastname: Kim
mesh_terms: D000818:Animals; D015478:Antigens, Heterophile / Q000032:analysis* / Q000737:chemistry; D002240:Carbohydrate Sequence; D002417:Cattle; D060748:Fetuins / Q000737:chemistry; D064593:Heterografts; D006801:Humans; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009077:Mucins / Q000737:chemistry; D009206:Myocardium / Q000737:chemistry* / Q000276:immunology*; D011134:Polysaccharides / Q000737:chemistry* / Q000276:immunology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D034421:Sus scrofa / Q000276:immunology*; D014181:Transplantation Immunology
chemical_list: D015478:Antigens, Heterophile; D060748:Fetuins; D009077:Mucins; D011134:Polysaccharides
keywords: Hanganutziu-Deicher antigen; O-glycans; heart; matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; xenotransplantation