体内致敏的树突状细胞诱导特异性抗肿瘤免疫的基础研究

A fundamental research of specific anti-tumor immunal effects of DC sensitized in vivo

目的证实树突状细胞(dendritic cells,DC)可在体内通过吞噬凋亡肿瘤细胞获取抗原物质,探讨其在肿瘤免疫治疗中的意义。方法以615小鼠的前胃癌细胞株造模,在体外用rmGM-CSF和rm IL-4从荷瘤小鼠骨髓细胞分化、诱导未成熟树突状细胞。分为4组:小剂量化疗组、树突状细胞组、小剂量化疗+树突状细胞组和对照组,以BAX试剂盒检测肿瘤细胞凋亡。在瘤体内注射树突状细胞,观察给药侧瘤体及对侧瘤体体积,生存期,和特异性细胞毒性T淋巴细胞(CTLs)对肿瘤细胞的特异性杀伤作用。结果小剂量化疗能诱导肿瘤细胞凋亡。小剂量化疗后瘤内应用树突状细胞,给药侧瘤体及对侧瘤体体积明显缩小(P<0.05),小鼠的生存率提高,体内凋亡肿瘤细胞致敏的DC诱导的CTL对MFC有显著的杀伤作用,在效靶比为40∶1、20∶1、10∶1和5∶1时72 h的杀伤率分别为87.64%、70.32%、34.63%和13.87%。并能特异性杀伤小鼠前胃癌细胞MFC(P<0.01)。结论体外诱导分化的未成熟DC,能于体内捕获小剂量化疗诱导的凋亡肿瘤细胞所携带的肿瘤抗原,诱导机体特异性抗肿瘤免疫反应。

Objectives Dendritic cells could take up antigen by phagocytizing apoptosie tumor cell in vivo and to investigate its value in immunotherapy. Methods Injected MFC into 615 mice to get tumor model, and induced immature DC from bone marrow in vitro by rmGM-CSF and rmIL-4. All animals were divided into 4 groups as ：low dose chemotherapy alone （ 5-Fu, DDP）, DC alone, both low dose chemotherapy （ 5-Fu, DDP） and DC, control. Apoptosis of tumor cells was detected by using LASB. We analysed gross tumor volume ,survival of mice ,and the proliferation of CTLs ,as well as its specific lethal effect on tumor cells. Results Low dose chemotherapy （5-Fu, DDP） could induce apoptosis of tumor cells. Intratumoral administration of DC enhanced the effect of low dose chemotherapy （ 5-Fu, DDP）, gross tumor volumes of both sides reduced obviously （P 〈 0. 05 ）. It also increased the survival rate, proliferation and activation of CTLs, which reinforced the lethal effect on MFC （P〈0, 01）. When the effector-to-target ratio were 40：1,20：1,10：1 and 5：1 ,the killing and wounding rate after 72 h averaged 87. 64% ,70. 32% ,34. 63% and 13.87% respectively. Conclusions Immature DC administrated intratumorally which were induced in vitro,eould capture antigen of apoptosie tumor cells by low dose chemotherapy, enhance specific anti-tumor immunity.