MOLECULAR AND FUNCTIONAL-ANALYSIS OF PORCINE E-SELECTIN REVEALS A POTENTIAL ROLE IN XENOGRAFT REJECTION

In this study, we report the molecular and functional characterization of porcine E-selectin. Incubation of porcine endothelial cells with h uman TNF alpha but not human IL-1 resulted in a marked increase in bin ding to human neutrophils. In order to confirm that this interaction w as mediated by E-selectin, we isolated the full-length porcine E-selec tin cDNA which contained an open reading frame encoding 485 amino acid s with 75% identity to human E-selectin. Expression of recombinant por cine E-selectin in COS cells resulted in surface expression of the pro tein and increased binding to human neutrophils. Northern blot analysi s showed that treatment of porcine endothelial cells with human TNF al pha but not human IL-1 resulted in high levels of porcine-E selectin m RNA. Taken together, our data establish that porcine E-selectin mediat es adhesive interactions between porcine endothelial cells and human l eukocytes that may contribute to xenograft rejection. (C) 1994 Academi c Press, Inc.