Possible involvement of natural killer cells in bone marrow graft rejection.

In the present study comparison between Natural killer (NK) cells and cells responsible for rejection of bone marrow grafts was made. Both cell populations were found to be inhibited by cyclophosphamide, silica, carrageenan, and C. parvum. The reactivity of both cell populations occurred late in life and was not expressed in infant mice. Mice tolerant to bone marrow grafts and, therefore, accepting parental marrow transplants showed also decreased NK cell reactivities. These common features between NK cells and bone marrow effector cells suggest but not prove that these cells could represent the same cell population.