T cell proliferation assay
The PBMCs were obtained from heparinized peripheral blood of patients. Cells were put into 96-well plates at 1×104 cells/well and cultured in X-VIVO 15 containing 2% autologous serum and allowed to adhere for 1 h. The suspended cells were then collected and induced to become CIK cells using 1,000 U/mL rhIFN-γ for the first 24 h followed by stimulation with 100 ng/mL OKT-3, 1000 U/ml rhIL-2 and 100 U/mL IL-1α. The cells were counted 1, 3, 5, 7, 9, 12 and 15 days later. All experiments were performed at least three times and the mean was calculated.