ABSTRACT
The mechanism of bone marrow inhibition is not clear; it may result in part from a direct lysis of progenitors by interleukin (IL) -2-activated killer cells or could be mediated by various cytokines produced by IL-2-activated lymphocytes. Since treatment of cancer patients with IL-2 and IL-2-activated lymphocytes was reported to result in hematological disturbances such as anemia, thrombocytopenia, lymphopenia, and eosinophilia, the authors investigates the effect of IL-2-activated natural killer and T cells on the growth of human bone marrow (BM) cells and their progenitors. Although there has been general consensus that IL-2-activated killer cells did not affect normal tissues, some investigators have shown that the effectors were cytotoxic for normal peripheral blood (PB) lymphocytes and monocytes. The authors examine the phenotype of PB effector cells mediating inhibition of BM proliferation and GM-CFC clonogenic activity by using monoclonal antibodies and a complement-dependent lysis technique.
