EVIDENCE THAT ACTIVATION OF HUMAN T CELLS BY PORCINE ENDOTHELIUM INVOLVES DIRECT RECOGNITION OF PORCINE SLA AND COSTIMULATION BY PORCINE LIGANDS FOR LFA-1 AND CD2

In this study we present a comprehensive evaluation of the molecular interactions between human T cells and porcine aortic endothelial cells (PAEO that contribute to human T cell activation. Binding assays demonstrated that porcine erythrocytes (E) and PAEC express ligand(s) for the human T cell glycoprotein CD2. Prior incubation of human T cells with a blocking monoclonal antibody directed against CD2 (αCD2-BL) completely inhibited T cell/E and T cell/PAEC interaction. Xenogeneic mixed lymphocyte reactions (XMLR) revealed that human PBMC, or highly purified T cells were activated by PAEC in the absence of human antigen-presenting cells (APC)