title: Distribution of the alpha-gal epitope on adult porcine bone tissue.
abstract: BACKGROUND
  Bone xenografts from pig to human appear to be an alternative to resolve the shortage of bone autologous and allografts. However, the major obstacle of pig-to-human xenotransplantation is the interaction between human natural anti-Gal antibody and the alpha-Gal epitope abundantly expressed on pig endothelium. It was important to investigate the expression of alpha-Gal epitopes in porcine bone tissue to look for an ideal method to remove the alpha-Gal epitopes.
  
  
  METHODS
  The cortical and trabecular bone were retrieved from five pigs. After the soft tissues and periosteum were removed, the blood and marrow cavity were cleaned with phosphate-buffered solution. All 5 mm x 5 mm x 5 mm samples were imbedded in paraffin and methyl methacrylate resin for histological sections. The mouse IgM M86 monoclonal antibody, which was highly specific for alpha-Gal epitopes, was used to document alpha-Gal epitope expression by immunostaining of tissues and immunofluorescence.
  
  
  RESULTS
  Gal-positive immunostaining and immunofluorescence were observed on the surface of osteocytes and Haversian canals. There was a significant difference in Gal expression between cortical and trabecular bone tissues. There was no Gal expression in the extracellular matrix of bone.
  
  
  CONCLUSIONS
  Major alpha-Gal epitopes were on the surface of osteocytes of porcine bone tissues. A method should be used to damage the osteocytes and eliminate the alpha-Gal epitopes to avoid the xenogenic rejection in xenotransplantation of porcine bone tissues.
authors.affiliation: Orthopaedic Department, West China Hospital, Sichuan University, Guoxuexiang 37, Chengdu 610041, P.R. China.
authors.forename: W
authors.initials: W
authors.lastname: Feng
authors.forename: Y
authors.initials: Y
authors.lastname: Lian
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
authors.forename: Y
authors.initials: Y
authors.lastname: Lu
authors.forename: S
authors.initials: S
authors.lastname: Li
authors.forename: F
authors.initials: F
authors.lastname: Pei
authors.forename: J
authors.initials: J
authors.lastname: Cheng
mesh_terms: D000818:Animals; D016025:Bone Transplantation; D001842:Bone and Bones / Q000166:cytology / Q000502:physiology*; D000939:Epitopes / Q000032:analysis; D005697:Galactosides / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D013552:Swine; D014183:Transplantation, Heterologous
chemical_list: D000939:Epitopes; D005697:Galactosides