The role of natural killer cells in transplantation.

Natural killer cells express receptors for polymorphic MHC class I molecules that inhibit cytotoxicity mediated by natural killer cells. The genes encoding the mouse and human natural killer cell receptors for MHC class I have recently been cloned, and there is rapid progress in elucidating their structure and function. These receptors may be important in bone marrow transplantation and explain the phenomenon of hybrid resistance.