腺病毒介导G250基因转染树突状细胞激活免疫效应细胞治疗肾癌的实验研究

目的 探讨以腺病毒(Ad)载体介导肾癌相关抗原G250基因转染制备树突状细胞(DC)瘤苗.体外诱导自体T淋巴细胞特异性抗肾癌免疫效应. 方法 自健康人外周血中提取单核细胞,将贴壁细胞分为3组(Ad-G250基因转染组、G250蛋白致敏组、未致敏组),用粒细胞-巨噬细胞集落刺激因子和诱导活化;3组DC细胞中分别加入自体T淋巴细胞,获得细胞毒性T淋巴细胞(CTL).RT-PCR检测G250在DC细胞内的转录情况;流式细胞仪检测DC表面标志分子和G250抗原蛋白的表达情况;四甲基偶氮唑盐法检测3组CTL对肾癌细胞株786-0和肺癌细胞株A549的杀伤活性. 结果 Ad-G250高效转染DC,G250阳性细胞率为(52.2±1.5)%,G250蛋白在DC:内成功表达:基因转染组DC中成功扩增出G250产物;Ad-G250转染的DC表面标志CD_(80)、CD_(83)、CD_(86)、CD_(1a)、HLA-DR表达高于其他2组.差异均有统计学意义(P<0.05).Ad-G250基因转染组、G250蛋白致敏组、未致敏组诱导的3组CTL对786-0靶细胞杀伤活性分别为(83.4±2.8)%、(79.6±2.4)%、(77.3±2.1)%,组间比较差异有统计学意义(F=69.172,P=0.000);3组CTL对A549靶细胞杀伤活性差异无统计学意义(F=0.373,P=0.693). 结论 以Ad为载体介导抗原基因转染DC,并诱导特异的CTL,技术上可行,所诱导的CTL杀伤活性强,有望成为一种肿瘤免疫治疗方法.

Experimental study of transfecting adenovirus carrying G250 antigen gene to dendritic cells and to activate immune effector cells in kidney cancer treatment

Objective To investigate T cell-mediated effects of dendritic cells(DC)transfected with kidney associated antigen G250 gene using adenovirus(Ad)as vector in the treatment of kidney cancer. Methods Peripheral blood mononuclear cells(PBMC)were isolated by standard FicollPaque density gradient centrifugation of heparinized blood obtained from healthy donors.After removal of the nonadherent ceils,the adherent cells were divided into gene transfer group,protein pulsed group and control group.The gene transfer group was infected with Ad/G250 virus;the protein pulsed group was added with G250 protein; the control group was added with PBS.The DCs were cultured and proliferated in vitro using recombinant human granulocyte macrophage colony stimulating factor and inlerleukin-4.The autologous T cells were added into the 3 DC groups(responders:dendritics,20:1).After 5 d co-culture,3 eytotoxic T lymphocyte(CTL)groups were collected.TheG250 mRNA expression was detected in transduced DCs using RT-PCR.The G250 protein translation products and cell surface marker of DCs were analyzed by flow cytometry.The specific cytolytic activities of CTL to different target cells(renal carcinoma 786-0 cell line and lung cancer A549 cell line)were assessed by MTT method. Results Ad/G250 transfected DC successfully and the G250 expression was confirmed by RT-PCR. The expression levels of CD_(80), CD_(83). HLA-DR and CD_(86) in the Ad/G250 group were higher than those in the other 2 groups. The cytotoxicity to 786-0 of T lymphocytes activated by Ad/G250 transfecting DCs(83. 4±2. 8)% was greater than those of T lymphocytes in the protein pulsed group(79. 6±2. 4)% and control group(77. 3±2. 1)%. There were no significant differences of the cytotyxicities to A549 among the 3 cytotoxic T lymphocyte groups(F=0. 373.P=0.693). Conclusions Ad-loading DCs may be useful for immunotherapeutic protocols against self-antigens for the kidney cancer.