低剂量X射线诱导NK细胞增殖治疗白血病裸鼠的实验研究

Study on therapy of leukemia through proliferated NK cell induced by low-dose radiation in nude mice

目的通过NK细胞分离液直接分离得到小鼠NK细胞，探讨低剂量辐射诱导的NK细胞增殖对K562细胞白血病模型是否有杀伤作用。方法采用流式细胞术和。H-TdR掺入法分别检测低剂量（照射剂量在20cGy以内的低LET或5cGy以内的高LET射线）对NK细胞增殖及活性的影响；流式细胞术检测外周血CD13＋细胞表达，ELISA法检测外周血TNF-α含量；体内实验观测实验组和对照组NK细胞输入后裸鼠外周血白细胞计数、肝脏、脾脏及肾脏指数等改变。结果分离得到的NK细胞纯度达（82．54±0．18）％。80mGy照射后24h，NK细胞增殖指数达到最高，为（36．31±1．32）％（t=24．69，P〈0．05）；低剂量照射后NK细胞杀伤K562活性为（12．59±0．63）％（t=6．63，P〈0．05），其抑制率为29．52％。结论低剂量辐射诱导的NK细胞增殖输入对裸鼠白血病的发生发展具有明显的抑制作用。

Objective To separate NK cells of mice from NK cell separation medium and study inhibitory effect of proliferated NK cell induced by low dose radiation on the leukemia model of K562 cells. Methods Flow cytometry and 3 H-TdR methods were respectively used to measure proliferation index and activity of NK cells treated with low-dose radiation（which means exposure dose in 20 cGy low LET beam or 5 cGy high LET beam）. CD13 ＋ cells were measured by flow cytometry and TNF-α content in blood-serum was detected by ELISA. In vivo, peripheral blood leucocyte count, index of liver, indexes of spleen and kidney were observed in control group and experimental group. Results The purity of NK cell separation was （82.54 ± 0. 18） %. The proliferation index of NK cells at 24 hours after 80 mGy irradiated was 36.31 ±1.32% , （t =24.69,P 〈0.05）. Killing activity of NK cell induced by low dose radiation to K562 cell was （ 12.59± 0.63 ） % （t = 6.63, P 〈 0. 05） and the inhibition ratio was 29.52%. Conclusion The injection of proliferated NK cell induced by low dose radiation demonstrated significant inhibitory effect on the growth of leukemia nude mouse.