Cytokine secretion depends on Galalpha(1,3)Gal expression in a pig-to-human whole blood model

J Immunol. 2008 May 1;180(9):6346-53. doi: 10.4049/jimmunol.180.9.6346.


Transplants from alpha1,3-galactosyltransferase (Gal) gene-knockout pigs to nonhuman primates are largely protected from hyperacute but not acute humoral xenograft rejection. The present study investigates the role of Gal in cytokine responses using a novel pig-to-human whole blood in vitro model, developed for species-specific analysis of porcine and human cytokines. Porcine (n = 7) and human (n = 27) cytokines were measured using ELISA or multiplex technology, respectively. Porcine aortic endothelial cells from control (Gal(+/+)) and Gal-deficient (Gal(-/-)) pigs were incubated with human lepirudin anticoagulated whole blood from healthy donors. E-selectin expression was measured by flow cytometry. The C3 inhibitor compstatin and a C5aR antagonist were used to study the role of complement. Cytokine species specificity was documented, enabling detection of 2 of 7 porcine cytokines and 13 of 27 human cytokines in one single sample. Gal(+/+) porcine aortic endothelial cells incubated with human whole blood showed a marked complement C5b-9 dependent up-regulation of E-selectin and secretion of porcine IL-6 and IL-8. In contrast, Gal(-/-) cells responded with E-selectin and cytokine expression which was so weak that the role of complement could not be determined. Human IL-6, IL-8, IFN-gamma, MIP-1alpha, MIP-1beta, eotaxin, and RANTES were detected in the Gal(+/+) system, but virtually no responses were seen in the Gal(-/-) system (p = 0.03). The increase in human cytokine release was largely complement dependent and, in contrast to the porcine response, mediated through C5a. Species-specific analysis of cytokine release revealed a marked, complement-dependent response when Gal(+/+) pig cells were incubated with human whole blood, compared with Gal(-/-) cells which induced virtually no cytokine release.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified / genetics
  • Animals, Genetically Modified / immunology
  • Aorta / immunology
  • Blood Cells / immunology*
  • Cells, Cultured
  • Coculture Techniques
  • Complement C5a / immunology
  • Cytokines / immunology*
  • E-Selectin / immunology
  • Endothelial Cells / immunology*
  • Galactosyltransferases / genetics
  • Galactosyltransferases / immunology*
  • Gene Deletion
  • Gene Expression Regulation / immunology*
  • Humans
  • Models, Biological*
  • Species Specificity
  • Swine
  • Transplantation, Heterologous


  • Cytokines
  • E-Selectin
  • Complement C5a
  • Galactosyltransferases