热休克肿瘤细胞抗原负载的树突状细胞对结肠癌小鼠的治疗作用

Treatment of established colon carcinoma-bearing mice by dendritic cells plused with lysates of heat-shocked tumor cell antigen

背景与目的:目前通过树突状细胞诱导机体抗肿瘤免疫已经成为肿瘤免疫治疗的一种重要途径,热休克处理肿瘤细胞可提高肿瘤细胞抗原负载的树突状细胞分化成熟,增强其体内抗肿瘤作用。本实验研究热休克肿瘤细胞抗原负载的骨髓来源的树突状细胞(dendritic cell,DC)对结肠癌小鼠的治疗作用。方法:20只小鼠随分为4组,将小鼠结肠癌细胞CT26热休克处理后超声破膜,以其细胞裂解液负载BALB/c小鼠骨髓来源的DC,观察DC诱导肿瘤特异性细胞毒性T淋巴细胞(cytotoxic Tlymphocyte,CTL)杀伤活性;并将DC接种于荷瘤小鼠皮下,观察其对肿瘤生长的抑制作用及对荷瘤小鼠生存期的影响。结果:与冻融抗原-DC组、DC组、PBS组相比,热休克抗原-DC诱导的CTL对CT26肿瘤细胞具有显著的杀伤作用,相同效靶比(P=0.00)下其肿瘤特异性细胞毒活性强于前者{(0.99±0.19)g vs.[(1.27±0.28)g、(2.19±0.35)g、(2.14±0.27)g],P均=0.00};用其进行免疫后对小鼠肿瘤的生长具有显著的抑制作用[(128±18)mm3vs.(313±52)mm3,P=0.04],并能显著延长荷瘤小鼠的生存时间{(57±7)d vs.[(40±3)d、(25±3)d、(24±3)d],P均=0.00}。结论:热休克肿瘤细胞抗原负载的树突状细胞对结肠癌小鼠具有显著的治疗效果。

Background and purpose： It is an important pathway of tumor immunotherapy that dendritic cell induce anti-tumor immunity at present, pre-heated tumor cells could induce maturation of dendritic cell, and enhance the antitumor effects. The aim of the study was to investigate the therapeutic effect of dendritic cells plused with lysates of heat-shocked CT26 colon carcinoma cells. Methods： Bone marrow-derived DCs plused with lysates of heat-shocked tumor cells were used to immunize BALB/c mice. The response of cytotoxic T lymphocyte （CTL） was detected, DCs were injected （5 × 10^5/ mouse） on the day 7, 10, 13 repeatedly after the CT26 tumor cells were inoculated. The therapeutic effect induced by DCs was observed by tumor weight and survival time. Results： We divided 20 mice into 4 groups. Compared with freeze-thaw antigen-DC, DCs plused with lysates of heat-shocked tumor cells could induce the specific cytotoxic activity of CTLs promi- nently, the specific cytotoxic activity of CTLs induced by heat-shocked antigen-DC was more markable than that of CTLs induced by freeze-thaw antigen-DC at the same E： T ratio（P = 0.00）. After the heat-shocked antigen-DCs were injected, the tumor growth were significantly inhibited and the survival time of tumor-bearing mice were prolonged conspicuously comparing with freeze-thaw antigen DC group. The tumor weight （0.99 ± 0.19） g in heat-shock antigen-DC group were significantly lower than that of freeze-thaw antigen-DC group （ 1.27 ± 0.28） g, DC group（2. 19 ± 0.35） g and PBS group（2. 14 ± 0.27） g. The survival time of tumor-bearing mice （57 ± 7） d were notably prolonged in heat-shock antigen-DC group compared to the other groups [ （40 ± 3） d, （25 ± 3） d, （24 ± 3） d, P = 0. 00]. Conclusions： DCs plused with lysates of heat- shocked tumor cells have an obvious therapeutic effect on the established colon carcinoma-bearing mice.