Phage display is a new technology developed in recent years. Random peptides displayed on the filamentous phage surface offer a rich source of molecular diversity in searching for ligands that bind an antibody, receptor and other proteins. The phage display system has been effective in the discovery of various ligands. Potential applications of the peptide library include investigation of the protein protein interactions and discovery of mimetic drug candidates.

AIM: To investigate the differentiative and apoptotic effect of CpG-oligodeoxynucleotides on HL60 cells and its mechanism. METHODS: After HL60 cells were exposed to synthetic CpG-oligodeoxynucleotides, non-CpG-oligodeoxynucleotides or ZpG-oligodeoxynucleotides for 72 hours, respectively, the inhibition of HL60 cells were detected using MTT method, NBT test was used and CD14 expression were determined. Apoptosis of HL60 cells were mensurated with flow cytometry and transmission electron microscope, and caspase 3, Bcl-2 and Bax expression of HL60 cells treated with oligodeoxynucletides were detected using immunohistochemistry. RESULTS: Treatment with CpG-oligodeoxynucleotides induced the differentiation and apoptosis in HL60 cells, but non-CpG-oligodeoxynu- cleotide and ZpG-oligodeoxynucleotide had no effect on HL60 cells. CONCLUSION: CpG-oligodeoxynucleotides can induce the differentiation and apoptosis in HL60 cells. It may provide a new approach for the immunological treatment of leukemia.