Objective      To determine the effect of K562 cells on mitochondrial function and energy metabolism of co-cultured dendritic cells (DCs).       Methods      The monocytes were purified from fresh peripheral blood of healthy voluenteers with immune magnetic beads

and then were cultured in the media containing 100 ng/mL rhGM-CSF and 100 ng/mL IL-4 in RPMI1640/10% FBS to

induce the cells into immature DCs (imDCs). And then mature DCs (mDCs) were developed by adding 20 ng/mL rhTNF-α into the culture medium of imDCs. Then the obtained imDCs and mDCs were respectively co-cultured with K562 cells in Transwell chamber for 48 h

and the cells cultured in normal medium for 48 h and those cultured in the medium without cytokines for 48 h served as controls. Mitochondrial membrane potential and intracellular Ca

2+

concentration in the cytoplasm of DCs were respectively measured by flow cytometry

mitochondrial enzyme activity were studied by MTT assay

cell energy metabolism were investigated by Fourier transformed infrared spectrum scanning.       Results      Compared with the control cells

co-cultured with K562 resulted in decreased mitochondrial membrane potentials (P0.05)

increased intracellular Ca

2+

concentrations (P0.01)

and decreased mitochondrial enzyme activities in the imDCs and mDCs (P0.05

P0.01)

moreover

the cell energy metabolism were also suppressed. Wherever there were no obvious differences between the 2 groups of control cells.       Conclusion      Mitochondrial functions and energy metabolism status of DCs were impaired by K562 cells

so migration and immune function of DCs were impaired

this could be one of aspects of tumor immune escape

so as to realize the proliferation

spread and metastasis of leukemia cells.