凋亡肿瘤细胞抗原致敏的树突状细胞瘤苗治疗大鼠颅内胶质瘤的实验研究

An experimental study of vaccines for treatment in intracranial gliomas by dendritic cells pulsed with apoptotic tumor cells

目的观察凋亡肿瘤细胞抗原致敏的树突状细胞(dendriticcell,DC)瘤苗对颅内胶质瘤免疫治疗的效果。方法通过立体定向接种建立Wistar大鼠C6胶质瘤动物模型;从大鼠骨髓分离DC前体细胞,经重组大鼠粒细胞巨噬细胞集落刺激因子(rrGM-CSF)+白细胞介素4(rrIL-4)诱导培养、扩增获得功能性DCs;DCs经采用热诱导凋亡的C6胶质瘤细胞体外致敏后皮下回输荷瘤大鼠体内,1次/周,共5次。观察荷瘤大鼠的存活期,MRI观察颅内肿瘤生长情况,循环血中CD8+T淋巴细胞水平及体外细胞毒反应、增殖反应均以流式细胞仪检测。结果经过治疗的荷瘤大鼠生存期明显延长,MRI显示实验组大鼠肿瘤被明显抑制,外周血中CD8+T淋巴细胞比例增加,体外细胞毒试验提示经凋亡肿瘤细胞抗原致敏的DC瘤苗可以诱导针对C6胶质瘤的特异性细胞毒性T淋巴细胞,并且未观察到自身免疫反应的发生。结论经凋亡肿瘤细胞抗原致敏的DC瘤苗对于颅内胶质瘤是一种安全有效的治疗方法。

Objective To investigate the effect of dendritic cells pulsed with apoptotic tumor cells for treatment of intracranial gliomas in rats. Methods C6 glioma cells were injected into brain of Wistar rats under stereotactic monitor to establish an animal model of glioma. The precursors of dendritic cells were isolated from bone marrow of rats, stimulated in vitro with recombinent rat granulocyte-macrophage colony-stimulating factor (rrGM-CSF) and interleukin-4 (rrIL-4). Cultured cell populations were confirmed to be functional DCs. These DCs were then pulsed exvivo with apoptotic C6 tumor cells induced by heating and subsequently injected subcutaneously into rats harboring intracranial C6 tumor. Rats from different group were treated with five weekly subcutaneous injections of either control media, unpulsed DCs, or DCs pulsed with apoptotic tumor cells. The animals were followed for survival, volume of tumor by MRI. CD8+ T cells, cytotoxicity assay in vitro and proliferational function in peripheral blood were determined by FACS. Results Our results indicated that C6 glioma model rats treated with apoptotic tumor cells pulsed DC prolonged survival time, inhibited the tumor volume and increased the CD8+ T lymphocyte in peripheral blood in comparing with control group. Cytotoxicity assays suggest that vaccination with these apoptotic cells pulsed DCs can induce specific cytotoxic T lymphocytes against C6 tumor cells compared with control group, No autoimmune response were detected. Conclusions Our data demonstrated that systemic vaccination with DCs pulsed with apoptotic cells is a safe and effective therapy for intracranial glioma.