Effect of monocyte/macrophages activated by CpG-oligodeoxynucleotides of bacteria on K562 cells

AIM: To study the effect of monocyte/macrophages treated with CpG-oligodeoxynucleotides on leukemic K562 cells. METHODS: The monocytes/macrophages from peripheral blood cells were isolated and induced. The expressions of CD14 and CD16 on monocytes/macrophages were detected by means of flow cytometry. After treated with synthetic CpG-oligodeoxynucleotides, and nonCpG-oligodeoxynucleotides for 24 hours respectively, the inhibiting effect of monocyte/macrophages on K562 cells were detected using MTT method. The secretions of TNF-α and IL-12 from monocytes/macrophages were determined using ELISA method. RESULTS: The monocytes/macrophages treated with CpG-oligodeoxynucleotides enhanced their antitumor effect on K562 cells and increased the secretion levels of TNF-α and IL-12. Whereas, there was no significant difference between antitumor effect and cytokine secretion of the monocytes/macrophages treated with nonCpG-oligodeoxynucleotide. CONCLUSION: CpG-oligodeoxynucleotides increases the cytotoxicity of macrophages on K562 cells in vitro, as well as facilitates the IL-12 and TNF-α secretion. It provides a new approach for immunologic treatment of leukemia.