ABSTRACT
This chapter discusses experiments that show that Natural killer (NK) cells likely are responsible for marrow graft rejection and explains why this rejection shows Hh specificity. The observation that NK clones cause specific marrow graft rejection in vivo is unexpected because NK cells do not express H-2 specificity in in vitro cytolytic assays. Since antibody in responder mice appears to induce NK cells for specific bone marrow graft rejection it was interesting to find out whether nonresponder marrow graft recipients could be converted into responder recipients by injection of antibody. Antibody-dependent marrow allograft rejection by NK cells is the first demonstration of its kind in vivo. In a communication we reported that human melanoma tumors that grow progressively in immunodeficient mice can be rejected with the help of NK cells and target-specific monoclonal antibody. NK cells are very likely identical to К cell, i.e., to those cells that mediate in vitro cytolysis of nucleated targets.
