树突状细胞治疗前列腺癌的实验研究

THE EXPERIMENTAL STUDY IN THE TREATMENT WITH DCs AGAINST PROSTATE CANCER

目的 用转输人脐带血单个核细胞 (CBMNC)于严重联合免疫缺陷鼠 (SCID)的方法 ,建立有效的具有人体免疫环境的实验动物模型 ,并以此种模型评估用树突状细胞 (DCs)治疗前列腺癌 (PCa)的可行性。方法 从脐带血中采集CBMNC ,注入 6～ 8周龄雄性SCID鼠体内 ,2周后检测血清中人免疫球蛋白 (Ig) ;将由CBMNC中分离得来的DC在rhGM CSF、rhIL 4条件下培养 3～ 4周。以反复冻融的PCa细胞株 (PC 3 )为抗原刺激由人脐带血单个核细胞诱导衍化而来的树突状细胞 ,并用其治疗荷前列腺癌的hu CBMNC SCID鼠动物模型 (经尾静脉、瘤内 ) ,观测肿瘤体积、PSA值及生存期的变化 ,与分别给予生理盐水及雌激素的对照组相比较。结果 中、小剂量 ( 10 6 、10 7)DCs静脉治疗组及瘤内注射组其瘤体积、生存期与对照组相比有显著性差异 (P <0 0 5 ,P <0 0 0 1,P <0 0 1) ,PSA与对照组相比亦显著下降。结论 本实验通过在SCID鼠体内模拟人的免疫内环境 ,提示肿瘤抗原刺激的DC经静脉和瘤内注射后对PCa有一定的疗效 ,对预防PCa的复发有一定的作用 ,为DC治疗PCa的临床应用提供理论依据。

Objective: Injection of human cord blood mononuclear cells (hu-CBMNC) can result in a stable long-term reconstitution of a functional human immune system in mice with severe combined immunodeficiency (SCID). This experimental model was used to assess the ability of dendritic cells (DCs) pulsed with antigen of PC-3 cells against prostate cancer (PCa). Methods: CBMNC were collected from heparinized cord blood and injected into male SCID mice. 2 weeks later, only mice that tested positive for human Ig in serum were studied. The incubation condition of DCs from CBMNC was rhGM-CSF and rhIL-4. The culture time of DCs was 3～4 weeks. Hu-CBMNC-SCID mice beared prostate cancer were given DCs pulsed with PC-3 cells frozen repeatedly generated from human cord blood with different cell quantity and different way (administrated via tail vein, intratumoral). The SCID mice in control group were given NS/esreogen. The tumor volume and survival time and PSA of serum were recorded and compared with the control groups by χ 2 test. Results: The mice in intravenous groups (10 6, 10 7) and in intratumoral group lead to significant regression of established tumors and significant prolonged survival. (P<0.05, P<0.001, P<0.01 respectively). The PSA of mice in therapeutic groups descended significantly that compared with the control group. Conclusions: The results indicate that DCs pulsed with tumor cells mixture as a source of tumor antigen can induce an effective antitumor immune response. These findings provide a rational and protocol for the use of cultured DCs in immunotherapy of prostate cancer