RESUMO
In this paper we review our experimental findings concerning the capacity of bone marrow cells (BMC) to control leukemic cell growth. It has been shown that the cells isolated from normal bone marrow can provide dose dependent suppression of the proliferative activity of leukemic cells in vitro. BMC cytostatic effect is antigen non-specific and does not associate with cell death. Cytostatic BMC differ from mature macrophages, T and B lymphocytes and have the lower floating density. These cells are detected in both aggregated and non-aggregated fraction of BMC, stimulated by wheat germ agglutinin. During long-term cultivation of bone marrow the cytostatic activity was associated with the radioresistant stromal cells. Both soluble factors and cell-to-cell interactions are involved into the cytostatic process generated by BMC. Based on the obtained results, we suggest that the cytostatic activity of BMC may be increased under the influence of lymphokines, such as IL-2 and IFNgamma.