Influence of hypothermia and cardioplegic solutions on expression of alpha-Gal epitope on porcine aortic endothelial cells.
OBJECTIVE
The Galalpha1-3Galbeta1-4GlcNAc-R is the major antigen on pig tissue bound by human xenoreactive natural antibodies in xenotransplant. We have investigated in vitro the influence of hypothermic storage with cardioplegic solutions on expression of Galalpha1-3Galbeta1-4GlcNAc-Rs and hyperacute xenograft rejection.


METHODS
To analyze effects of hypothermia on the Galalpha1-3Galbeta1-4GlcNAc-Rs, cultured porcine aortic endothelial cells were exposed to a temperature of 4 degrees C for 1 hour, 4 hours, and 6 hours. Cell cultures of the control groups were incubated at the same time at 38 degrees C. To investigate the influence of cardioplegic solutions on the Galalpha1- 3Galbeta1-4GlcNAc-Rs, porcine aortic endothelial cells were exposed to 4 degrees C for 4 hours in the presence of University of Wisconsin solution or histidinetryptophan- ketoglutarate solution. Cells of the control groups were cooled at 4 degrees C for 4 hours without cardioplegic solution. After treatment, porcine aortic endothelial cells were submitted to fluorescence-activated cell sorter.


RESULTS
Hypothermia of 4 degrees C showed no significant effect on the quantity of Galalpha1-3Galbeta1-4GlcNAc-Rs. However, the treatment of porcine aortic endothelial cells with University of Wisconsin solution resulted in a highly significant reduction of Galalpha1-3Galbeta1- 4GlcNAc-Rs by 50% (P = .006). Treatment of porcine aortic endothelial cells with histidine-tryptophanketoglutarate solution decreased Alpha-Gal quantity significantly by 32% (P = .011).


CONCLUSIONS
Our data offer new perspectives in the prevention of hyperacute, humoral xenograft rejection by reducing the Galalpha1-3Galbeta1-4GlcNAc-Rs after exposure to different cardioplegic solutions.
Keller
Miriam
M
Department of Cardiac Surgery, University Hospital Grosshadern, Ludwig- Maximilians-University, Munich, Germany.
Beiras-Fernandez
Andres
A
Schmoeckel
Michael
M
Reichart
Bruno
B
Brenner
Paolo
P
D000241:Adenosine / Q000494:pharmacology; D000493:Allopurinol / Q000494:pharmacology; D000818:Animals; D015478:Antigens, Heterophile / Q000378:metabolism*; D001011:Aorta / Q000187:drug effects* / Q000276:immunology; D002314:Cardioplegic Solutions / Q000494:pharmacology*; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D015536:Down-Regulation; D042783:Endothelial Cells / Q000187:drug effects* / Q000276:immunology; D005434:Flow Cytometry; D005947:Glucose / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control; D007036:Hypothermia, Induced; D056724:Immunity, Humoral / Q000187:drug effects; D007328:Insulin / Q000494:pharmacology; D008353:Mannitol / Q000494:pharmacology; D019188:Organ Preservation Solutions / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D011343:Procaine / Q000494:pharmacology; D011887:Raffinose / Q000494:pharmacology; D013552:Swine; D013997:Time Factors; D014312:Trisaccharides / Q000378:metabolism*
D015478:Antigens, Heterophile; C039984:Bretschneider cardioplegic solution; D002314:Cardioplegic Solutions; D007328:Insulin; D019188:Organ Preservation Solutions; D014312:Trisaccharides; C055206:University of Wisconsin-lactobionate solution; C076569:alpha-galactosyl epitope; D008353:Mannitol; D011343:Procaine; D000493:Allopurinol; D011189:Potassium Chloride; D005978:Glutathione; D005947:Glucose; D000241:Adenosine; D011887:Raffinose