Objective: To evaluate the killing effect of IL-2 and IFN-alpha activated bone marrow cells on K562 cells.
Methods: Semi-solid colony assay was used.
Results: Bone marrow from leukemia patients in remission was activated in vitro with IL-2 for 3 days. The activated bone marrow (ABM) displayed killing effects of 0.31 approximately 2.30 logs on K562 cells, this killing effects was further increased to 0. 30 approximately > 3.15 logs when IFN-alpha added with IL-2 to the marrow for activation. IL-2 alone or in combination with IFN-alpha showed no inhibition of CFU-GM and K562 cells. Compared with IL-2 or IFN-alpha alone, the combination of the two cytokines could more effectively maintain the killing effect of ABM on leukemic cells.
Conclusion: IFN-alpha can augment the purging effect of IL-2 ABM and combination of the two cytokines can effectively maintain the cytotoxicity of ABM.