INDUCTION OF SWINE MAJOR HISTOCOMPATIBILITY COMPLEX CLASS I MOLECULES ON PORCINE ENDOTHELIUM BY TUMOR NECROSIS FACTOR-?? REDUCES LYSIS BY HUMAN NATURAL KILLER CELLS1

These results imply that SLA class I molecules can bind to inhibitory receptors on human NK cells, and that these interactions can be augmented by increasing the level of SLA class I molecule expression on porcine endothelium. Strategies that can increase porcine endothelial cell expression of either swine or human major histocompatibility complex class I molecules may reduce human NK activity against porcine xenografts.