树突状细胞及其负载胃癌细胞总RNA的抗肿瘤作用

Antitumor effects of dendritic cells and those pulsed with total RNA of gastric cancer cells

目的 以小鼠胃癌细胞总RNA负载树突状细胞(DC),研究其抗肿瘤免疫作用。方法 磁性细胞分选器(MACS)自小鼠脾细胞中分选出CDllc+的DC作短期培养,以小鼠前胃癌细胞株的总RNA脉冲DC,分别以RNA脉冲的DC(RNA/DC)和未脉冲的DC(UDC)皮下注射免疫小鼠2次;免疫后7d,皮下接种小鼠前胃癌细胞MFC 5×105/鼠,以未作免疫注射的小鼠作为对照。接种肿瘤细胞后21d,处死实验动物,测量肿瘤体积,检测自然杀伤细胞(NK)、细胞毒性T淋巴细胞(CTL)活性和血清IL-12含量。结果 RNA/DC免疫组、UDC免疫组和对照组的皮下肿瘤体积分别为(0.3688±0.6571)、(0.7536±0.3659)、(2.6323±1.1435)cm3。RNA/DC免疫组外周血和脾细胞NK活性均明显升高,较对照组分别高出66.2％和65.4％;其肿瘤特异性CTL也明显升高,较对照组升高49.5％。UDC组NK和CTL活性也明显高于对照组。结论 短期培养的DC和以肿瘤细胞总RNA作为抗原脉冲的DC均可诱导较强的抗肿瘤免疫。

Objective To investigate the immunotherapeutic potential of vaccines consisting of dendritic cells (DCs) pulsed with total RNA from MFC gastric cancer cells. Methods DCs were prepared from the spleens of strain 615 mice by magnetic cell sorting (MACS) . After culture for 24h, DCs were pulsed with total RNA from MFC gastric cancer cells. One group of mice were immunized with tumor RNA pulsed DC ( RNA/DC , n=12 ) at the dosage of 1×106 on day 14 and 7 by s. c. inoculation. Another group of mice were immunized with unpulsed DC (UDC, n=10) at the same dosage and days as the RNA/DC group. The control group of mice (n=12) were left untreated. On day O,all of the mice were challenged with s. c. injections of 5×105 MFC gastric cancer cells. After inoculation, the mice were monitored closely with respect to tumor growth. Activities of natural kill cells (NK) in PBL, splenocytes and cytotoxicity T lymphocytes (CTL) were tested. Results After immunization with tumor RNA pulsed DC, the mice of the RNA/DC group acquired immunity against gastric cancer. By day 21 after tumor cell inoculation, the tumor volume of the control group attained a mean of (2. 6323±1.1435) cm3 , followed by the UDC and RNA/DC groups with mean volumes of (0.7536 ±0.3659) cm3 and (0.3688±0.6571) cm3 , respectively. The activities of NK cells in PBL and splenocytes in the RNA/DC group were 66.2% and 65.4% , respectively, higher than in the control group. The tumor specific CTL activity in the RNA/DC group was 49.5% higher than in the control group. Conclusion The tumor vaccine of DCs pulsed with total RNA from gastric cancer cells was found to possess the ability to stimulate tumor specific CTL activity and to establish anti-tumor immunity when administered in vivo.