Experimental study on effect of low dose radiation on autologous CIK cell immunity functions of tumor patients / 中华放射医学与防护杂志

ABSTRACT

Objective To observe the effects of low dose irradiation (LDI) on autoiogous CIK cell proliferation, phenotype and killing activity in tumor patients, and to provide the evidence for clinical application of adoptive immunotherapy with CIK cells. Methods Peripheral blood mononuclear cells (PBMC) were separated from 10 patients with malignant tumor, and CIK cells were cultured with different cytokines. (1) After 10 d culture, C1K cells were irradiated with different doses as 30, 50, 80, 100 and 200 Gy of X-rays was also detected. The CIK cell proliferation and killing activity were measured with 3H-TdR incorporation assay and 3H-TdR release assay, respectively and the percentage variation of CD3 +CD56 + were measured with flow cytometry after 24 h. ( 1 ) Autologous CIK cells were irradiated with 80 mGy X-rays. At different culture time ( 12, 24, 48, 72 h) after irradiation, the killing activity was measured with 3H-TdR release assay. (3) The effect of 3d low dose irradiation of 80 mGy X-rays on thekilling activity of CIK cells was also detected. Results After the CIK cells were irradiated with different doses as 50, 80, 100, 200 mGy of X-rays, the CPM values were 20 048.6 ± 2332. 2 ( t = 2.2, P ＜0.05), 21 832.2 ±2975.9 (t=3.5, P＜0.01), 21 000.3 ±2451.1 (t=3.3, P＜0.01), 19908.1 ±2051.0 ( t = 2.2, P ＜ 0.05 ), respectively and the proliferation of CIK cells were significantly higher than that of control group. The CD3 + CD56 + cell percentage of 50, 80, 100 mGy groups were ( 30.3 ±3.8)% (t=2.3, P＜0.05), (32.3±3.4)% (t=4.2, P＜0.01), (29.742.9)% (t = 2.4, P＜0.05 ), respectively. The killing activity of CIK cells of 80, 100 mGy groups were 55.2 ± 5.0 ( t = 3.3, P ＜ 0.01 ), 52.8 ± 4.1 ( t = 2.3, P ＜ 0.05 ), respectively. The killing activity of CIK cells up-regulated significantly at 24 h, dropped to normal levels at 48 h and 72 h. After 80 mGy X-ray irradiation for 3 consecutive days, the killing activity of CIK cells at different time points were 55.2 ± 5.3 (t = 2.6, P ＜0.05),61.9 ± 4.4 (t = 4.7, P ＜0.01), 67.2 ±5.7 (t = 5.7, P ＜0.01) for 24, 48, 72 h,respectively. Conclusions LDI might have the hormesis effect on CIK cells.