PAUL-NEUMANN-PRIZE 1994 - HUMAN PERIPHERAL-BLOOD LYMPHOCYTE ADHESION TO XENOGENEIC PORCINE AORTIC ENDOTHELIAL-CELLS - PREFERENTIAL ADHESION OF CD3- CD16+ NK CELLS

Xenotransplantation, the transplantation of tissues or organs between species find renewal interest because of human organ shortage. As the xenogeneic transplantation leads immediately to an humoral mediated rejection with graft necrosis, the study of the cellular response is not possible in vivo. So we developped an in vitro model to study the adhesion of human peripheral blood lymphocytes (PBL) to porcine aortic endothelial cells (PAEC). We showed that PBL were able to bind to PAEC, and that this adhesion was increased when PAEC were stimulated with human recombinant TNF-alpha. The action of TNF-alpha is maximal when PAEC were stimulated during 6 hours with 100 U/ml TNF-alpha. This adhesion involved preferentially CD3-CD16+ NK cells compared with CD3+CD26- T lymphocytes. Finally monoclonal antibodies directed against PBL adhesion molecules decreased PBL adhesion to PAEC. PBL adhesion to PAEC would be a first step in a cellular mediated rejection in xenotransplantation.