Genetic resistance to bone marrow transplantation as a leukemia-lymphoma defense mechanism: correlation of "in vivo" lymphoma resistance and "in vitro" NK activity.

(C57 X AKR) F1 hybrid mice, which show genetic resistance to C57 parental bone marrow cells and to AKR lymphoma but not to AKR bone marrow cells in vivo, also show high natural killer cell lysis versus lymphoma cells in vitro. (C3H X AKR) F1 hybrids which show no genetic resistance to parental bone marrow cells or to lymphoma cells in vivo have low levels of NK activity like those of the low responding AKR strain. Thus genetic resistance to bone marrow transplantation and to lymphoma in vivo, correlates with NK lytic activity versus lymphoma cells in vitro, adding to the evidence linking these phenomena.