SCF或(和)GM-CSF体内基因转染对"自杀基因"疗法抗肿瘤作用的增强效应及其相关机理的研究

目的通过增强体内抗原提呈功能提高“自杀基因”疗法疗效，探讨其相关免疫学机理。方法采用腺病毒介导的ＳＣＦ、ＧＭＣＳＦ基因体内转染联合ＣＤ／５ＦＣ“自杀基因”疗法治疗小鼠的ＣＴ２６结肠腺癌，观察肿瘤的生长和荷瘤小鼠的存活期、不同方法所诱导的ＣＴＬ杀伤活性及肿瘤局部的细胞因子表达。结果一次性低剂量腺病毒介导的ｍＧＭＣＳＦ或（和）ｍＳＣＦ基因的体内转染，能增强“自杀基因”疗法的疗效。在肿瘤局部出现新的细胞因子表达，包括ｍＩＬ４、ｍＩＬ２、ｍＩＦＮγ和ｍＴＮＦα。脾细胞对ＣＴ２６细胞的杀伤作用增强。结论ｍＧＭＣＳＦ或（和）ｍＳＣＦ基因的联合转染对“自杀基因”系统的疗效具有明显的增强作用，其与机体特异抗肿瘤免疫功能以及肿瘤局部分泌的细胞因子有关。     

腺病毒介导的人GM-CSF基因转染瘤苗增强机体免疫功能的实验研究

目的 研究腺病毒介导的人ＧＭ－ＣＳＦ基因转染瘤苗体内抗肿瘤免疫作用极其机理。方法 应用ＧＭ－ＣＳＦ基因转染、的瘤苗对小鼠肝癌模型进行免疫基因治疗,观察该疗法对荷瘤小鼠脾细胞ＮＫ、ＬＡＫ、ＣＴＬ活性的影响、脾淋巴细胞围化反应的影响以及荷瘤习的生存期。结果 经ＧＭ－ＣＳＦ基因转染瘤苗治疗后,插细胞ＣＴＬ活性显著升高,而ＮＫ、ＬＡＫ细胞活性未见明显增强、脾淋巴细胞转化反应显著增强、生存期显著延长。结论     

腺病毒介导的CD／5FC自杀基因疗法对小鼠结肠腺癌的治疗？…

大肠杆菌胞嘧啶脱氨酶ＣＤ可以将前体药物５ＦＣ代谢为毒性产物５ＦＵ，具有抗肿瘤作用。本课题我们观察了腺病毒介导的ＣＤ／５ＦＣ自杀基因治疗对小鼠结肠癌生长的治疗作用并探讨其作用机理。结果表明，首次，ＣＤ／５ＦＣ自杀基因疗法小鼠结肠癌ＣＴ２６体内外生长均具有显著的抑制作用，４０％的荷瘤小鼠经过治疗后长期存活；其次，我们还研究了自杀基因疗法治疗肿瘤时可能涉及的免疫机理。结果发现在以ＣＤ／５ＦＣ系统治疗结肠     

CD自杀基因联合淋巴细胞趋化因子基因疗法的肿瘤治疗？…

本研究以腺病毒作为载体，将大肠杆菌胸嘧啶脱氨酶（ＣＤ）基因与小鼠淋巴细胞趋化因子（Ｌｔｎ）基因体内联合转染，观察了其抗肿瘤效应并分析了免疫机理。小鼠皮下接种结肠腺癌ＣＴ２６细胞后３天，肿瘤局部注射表达Ｌｔｎ的重组腺病毒ＡｄＬｔｎ和表达ＣＤ的重组腺病毒ＡｄＣＤ，然后连续１０天给予５－氟胸嘧啶（５－ＦＣ）３００ｍｇ／ｋｇ进行治疗，结果表明，联合治疗组荷瘤小鼠皮下肿瘤结节的生长受到明显抑制，小鼠存活期明     

腺病毒介导的胞嘧啶脱氨酶自杀基因联合IL-2基因疗法的肿瘤治疗作用及免疫机理分析

目的以腺病毒作为载体，将大肠杆菌胞嘧啶脱氨酶（ＣＤ）基因与小鼠ＩＬ－２基因联合转移，研究其体内抗肿瘤作用及免疫机理。方法小鼠皮下接种黑色素瘤Ｂ１６Ｆ１０细胞后３天，肿瘤局部注射表达ＩＬ－２的重组腺病毒ＡｄＩＬ－２和表达ＣＤ的重组腺病毒ＡｄＣＤ，然后连续１０天给予５－氟胞嘧啶（５－Ｆｃ）３００ｍｇ／ｋｇ进行治疗。结果联合治疗组荷瘤小鼠皮下肿瘤结节的生长明显受到抑制，小鼠存活期明显长于ＡｄＩＬ－２、ＡｄＣＤ／５－Ｆｃ、ＡｄｌａｃＺ／５－Ｆｃ或ＰＢＳ组。经联合治疗后，小鼠脾细胞的ＮＫ活性和ＣＴＬ杀伤活性明显增强；肿瘤瘤体内ＣＤ４、ＣＤ８细胞浸润增加；肿瘤细胞表达Ｈ－２Ｋｂ和Ｂ７－１分子明显增加。结论联合应用自杀基因和ＩＬ－２基因治疗，一方面可以明显抑制荷瘤小鼠肿瘤生长，另一方面可以提高机体对肿瘤细胞免疫应答，增加机体的抗肿瘤作用，是肿瘤基因治疗中一条行之有效的途径。     

CD基因联合mIL-2/mGM-CSF基因治疗胃癌的研究

目的：观察ＣＤ基因联合ｍＩＬ－２／ｍＧＭ－ＣＳＦ基因对小鼠胃癌的治疗作用。方法：ＣＤ基因构建于逆转录病毒载体ｐＬｘＳＮ,ｍＩＬ－２和ｍＧＭ－ＣＳＦ基因构建于ｐＩＲＥＳ。先用ＣＤ／５－ＦＣ治疗胃癌细胞株,然后联合ｍＩＬ－２／ｍＧＭ－ＣＳＦ两种细胞因子基因治疗小鼠模型胃癌,以期产生显革的抗肿瘤作用。ＲＴ－ＰＣＲ检测基因表达。结果：体外结果显示２０％的转基因细胞即可杀灭７０％￣８０％的肿瘤细胞。动物实验     

SCF或/和GM-CSF体内基因转染对“自杀基因”疗法抗肿瘤作用的增强效应

“自杀基因”疗法一般在治疗之初都疗效显著,随着治疗进程的推移,治疗效果就明显减弱.联合一个辅助性的治疗方法以增强“自杀基因”疗法所介入的某些环节的作用或许会提高“自杀基因”疗法的疗效.本实验着重探讨了从提高机体的免疫功能入手,为提高“自杀基因”疗法疗效而进行联合基因治疗的可行性和合理性.结果发现在以“自杀基因”疗法治疗肿瘤的同时转染mGM-CSF或/和mSCF基因后,并未明显提高其疗效.为了探讨是否可以通过提高抗原提呈功能来增强“自杀基因”疗法的疗效,小鼠在荷瘤前1周,先低剂量地转染mGM-CSF或/和mSCF基因重组腺病毒,而后再进行“自杀基因”的疗法的治疗,结果是预力转染mGM-CSF和mSCF基因能提高“自杀基因”疗法的疗效,mM-CSF的作用要强于mSCF,两者还有一定的协同作用.以同样的方法转染mGM-CSF和mSCF基因并给小鼠荷瘤,而不给予“自杀基因”疗法的治疗,各组小鼠的肿瘤均呈进行性生长,组间无差别.可见实验中所用的低剂量mGM-CSF和mSCF重组腺病毒的预转染并不能产生直接的抗肿瘤作用.     

GM—CSF基因转染瘤苗预防性免疫保护作用的实验研究

为了观察低肿瘤负载时ＧＭＣＳＦ 基因转染瘤苗抗肿瘤作用及其效果。应用粒细胞巨噬细胞集落刺激因子（ＧＭＣＳＦ）基因转染的、６０Ｃｏγ射线照射后制成的瘤苗,进行预防性免疫保护作用的研究;对荷瘤小鼠,手术切除肿瘤结节,研究该基因疗法对预防术后肿瘤复发的影响。结果表明, ＧＭＣＳＦ 基因转染瘤苗预防性免疫治疗后,能诱导小鼠产生特异性免疫反应,抵抗随后野生型亲本肿瘤细胞的攻击,并能有效地预防手术后肿瘤复发。以上结果揭示了应用该疗法进行肿瘤基因治疗的可行性。     

T细胞及相关免疫分子在淋巴细胞趋化因子增强肿瘤自杀 …

本室以往的研究表明，用腺病毒作为载体将大肠杆菌胞嘧啶脱氨酶（ＣＤ）基因与小鼠淋巴细胞趋化因子（Ｌｉｎ）基因联合体内转染，具有显著的抗肿瘤效应。本文对其免疫机理进行了进一步研究，发现ＣＴ２６结肠腺癌细胞体外经过ＣＤ／Ｌｉｎ基因转染并给予前体药物５－ＦＣ后，ＣＴ２６结肠腺癌细胞表达ＣＤ８０和ＣＤ５４分子明显增加，提示经ＣＤ自杀基因和Ｌｉｎ基因联转移后，肿瘤细胞免疫原性增加。荷瘤小鼠体内经联合治疗后，小     

重组人GM—CSF逆转录病毒基因转移系统的建立及其在人肿瘤细胞中的稳定…

建立逆转录病毒介导的ＧＭ－ＣＳＦ基因转移系统,为ＧＭ－ＣＳＦ基因悠我肿瘤细胞疫苗研究奠定实验基础。应用基因重组技术将ＧＭ－ＣＳＦｃＤＮＡ克隆于逆转录病毒载体ｐＤＯＲｎｅｏ,获得重组载体ｐＤＯＲＧＭ。经脂质体介针其转染于病毒包装细胞系ＰＡ３１７细胞,经ＮＩＨ３Ｔ３细胞检测病毒滴度,ＮＩＨ３Ｔ３放大实验检测辅助病毒,并用同熵度病毒感染人乳腺癌细胞系ＭＣＦ－７。     

腺病毒介导的CD/5FC自杀基因疗法对小鼠结肠腺癌的治疗作用及相关免疫机理的研究

大肠杆菌胞嘧啶脱氨酶CD可以将前体药物5FC代谢为毒性产物5FU,具有抗肿瘤作用.本课题我们观察了腺病毒介导的CD/5FC自杀基因疗法对小鼠结肠癌生长的治疗作用并探讨其作用机理.结果表明,首先,CD/5FC自杀基因疗法小鼠结肠癌CT26体内外生长均具有显著的抑制作用,4O%的荷瘤小鼠经过治疗后长期存活;其次,我们还研究了自杀基因疗法治疗肿瘤时可能涉及的免疫机理.结果发现在以CD/5FC系统治疗结肠腺癌小鼠过程中能在一定程度上诱导出机体的抗肿瘤免疫反应,包括脾脏CT6L活性的增高、肿瘤局部浸润免疫细胞表达,DEC-205、B7-2、I-A~(b,d)分子增加等.本实验结果提示虽然CD/5FC系统可以诱导机体产生一定的抗肿瘤免疫反应,但其程度不够显著.     

脂质体介导mIL-12基因与MHCⅠ基因联合对小鼠实验性肝癌的治疗作用

背景与目的：白细胞介素-12及MHCⅠ基因均已单独用于肿瘤基因治疗,为探索两者的抗肿瘤协同效应,本研究探讨小鼠白细胞介素-12（mIL-12)基因与同种异型的MHCⅠ（小鼠为H-2K）基因联合治疗Balb/C小鼠实验性肝癌。方法：分别应用含mIL-12基因,C57BL/6小鼠H-2K^bcDNA及绿色荧光蛋白（GFP）报告基因的真核表达质粒载体pcDNA3。体外经新型脂质体LipofectAMINE2000(LF2000)介导转染小鼠肝癌细胞株MM45T.Li,检测转染细胞外源基因的表达,将经LF2000介导pcDNA3/mIL-12与pcDNA3/H-2K^b转染的MM45T.Li细胞,注射于小鼠皮下,观察致瘤性的变化,在荷瘤Balb/C小鼠瘤内注射上述脂质体-DNA复合物,观察瘤体生长情况及小鼠生存期的改变。结果：LF2000介导pcDNA3/GFP转染MM45T.Li细胞的最佳条件为脂质体与DNA为3：1（μg：μg）,转染效率达30%,经LF2000介导pcDNA3/mIL-12与pcDNA3/H-2K^b转染的MM45T.Li细胞,RT-PCR检测有mIL-12和H-2K^bcDNA的特异扩增片段,WesternBlot检测显著有57kDaH-2K^b蛋白表达,ELISA检测mIL-12分泌量达48ng/ml/10^6细胞,经LF2000介导pcDNA3/mIL-12与pcDNA3/H-2K^b转染的MM45T.Li细胞,其致瘤性下降;荷瘤Balb/C小鼠瘤内注射该脂质体-DNA复合物,FACS检测显示小鼠脾脏淋巴细胞中CD3^ ,CD4^ 和CD8^ 的数量治疗组较对照组高,肿瘤生长相对缓慢,且pcDNA3/mILp-12与pcDNA3/H-2K^b联合治疗具有一定的正协同效应。结论：mIL-12基因与MHCⅠ基因联合治疗小鼠肝癌具有正协同效应,增强了抗肿瘤效果。     

联合自杀基因与IL-2基因转移疗法的抗肿瘤效果及其抗肿瘤免疫应答的诱导作用

单用自杀基因疗法或单用细胞因子基因疗法抗肿瘤效果不理想,本研究中我们观察了大肠杆菌胞嘧啶脱胺酶(CD)基因与白细胞介素2(IL-2)基因联合转移对荷瘤小鼠的治疗效果及其对抗肿瘤免疫的诱导作用。复制荷瘤小鼠模型后在荷瘤部位注射表达CD基因的重组腺病毒(AdCD)及表达小鼠IL-2基因的重组腺病毒(AdIL2),并连续10天、每天1次腹腔注射5氟胞嘧啶(5FC)对荷瘤小鼠进行治疗。结果表明,AdCD/5FC/AdIL2联合基因治疗能显著抑制荷瘤小鼠皮下肿瘤的生长,并明显延长其生存期(P<0.01)。联合基因治疗组小鼠肿瘤细胞发生明显的坏死,瘤内及瘤周有大量的炎性细胞浸润,瘤内CD4~ 和CD8~ T细胞明显增加,脾细胞NK和CIL杀伤活性明显高于单用AdCD/5FC、对照病毒AdLacZ/5FC或PBS组。实验结果表明,联合应用自杀基因与细胞因子基因治疗可更有效诱导机体的抗肿瘤免疫反应,从而更显著地抑制荷瘤小鼠肿瘤的生长。     

Enhanced antitumoral effect of adenovirus-mediated cytosine deaminase gene therapy by induction of antigen-presenting cells through stem cell factor/granulocyte-macrophage colony-stimulating factor gene transfer

Suicide gene therapy has been studied intensively for the treatment of cancer. A limited antitumoral effect was obtained by intratumoral injection of adenovirus harboring Escherichia coli cytosine deaminase gene (AdCD) in tumor-bearing mice followed by continuous administration of 5-fluorocytosine (5FC). To address the drawbacks of the limited potential for the induction of antitumoral immunity by CD suicide gene therapy, we hypothesized that antigen-presenting cells (APCs) might contribute to the efficient induction of an antitumoral immune response in tumor-bearing mice undergoing suicide gene therapy. We preinjected the mice with murine stem cell factor (SCF)-encoding adenovirus (AdSCF) and murine granulocyte-macrophage colony-stimulating factor (GM-CSF)-encoding adenovirus (AdGM-CSF); after 7 days, the mice were inoculated with CT26 colon adenocarcinoma. AdCD was injected intratumorally into tumor-bearing mice followed by 5FC administration. The results showed that AdSCF/AdGM-CSF treatment could increase the number, surface molecule expression, and function of APCs efficiently. A more significant growth inhibition of established tumors and a prolongation of the survival period were observed in tumor-bearing mice after AdSCF/AdGM-CSF pretreatment in combination with AdCD/5FC therapy when compared with mice treated with AdSCF or AdGM-CSF in combination with AdCD/5FC, or AdCD/5FC alone (P < .01). Cytotoxic T-lymphocyte activity was induced efficiently after the combined therapy, and mRNA of tumor necrosis factor-alpha, interleukin-4, interferon-gamma, and interleukin-2 was present in the tumor mass after combined therapy, suggesting that a more potent antitumoral response was induced by enhanced APCs. Our results demonstrated that AdSCF/AdGM-CSF pretreatment could activate APCs, and that these APCs could present the tumor antigens released from AdCD/5FC-killed tumor cells and activate the antitumoral response of the host, thus increasing the therapeutic efficiency of suicide gene therapy.     

Oncolytic virotherapy with an HSV amplicon vector expressing granulocyte-macrophage colony-stimulating factor using the replication-competent HSV type 1 mutant HF10 as a helper virus

Direct viral infection of solid tumors can cause tumor cell death, but these techniques offer the opportunity to express exogenous factors to enhance the antitumor response. We investigated the antitumor effects of a herpes simplex virus (HSV) amplicon expressing mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) using the replication-competent HSV type 1 mutant HF10 as a helper virus. HF10-packaged mGM-CSF-expressing amplicon (mGM-CSF amplicon) was used to infect subcutaneously inoculated murine colorectal tumor cells (CT26 cells) and the antitumor effects were compared to tumors treated with only HF10. The mGM-CSF amplicon efficiently replicated in CT26 cells with similar oncolytic activity to HF10 in vitro. However, when mice subcutaneously inoculated with CT26 cells were intratumorally injected with HF10 or mGM-CSF amplicon, greater tumor regression was seen in mGM-CSF amplicon-treated animals. Furthermore, mGM-CSF amplicon treatment prolonged mouse survival. Immunohistochemical analysis revealed increased inflammatory cell infiltration in the solid tumor in the mGM-CSF amplicon-treated animals. These results suggest that expression of GM-CSF enhances the antitumor effects of HF10, and HF10-packaged GM-CSF-expressing amplicon is a promising agent for the treatment of subcutaneous tumors.     

氟胞嘧啶/胞嘧啶脱氨酶自杀基因疗法结合热休克蛋白-多肽复合物治疗小鼠胃癌

目的；研究氟胞嘧啶／胞嘧啶脱氨酶（5－FC／CD）基因疗法与热休克蛋白－多肽复合物（FSP70－PC）免疫疗法联合抗肿瘤效果。方法；将携带CD基因的重组腺病毒注射到小鼠MFC瘤体内，腹腔注射5－FC，同时皮下接种HSP70－PC。结果；经联合治疗后，70％荷瘤小鼠肿瘤体答缩小，消退，小鼠存活期延长，细胞毒T淋巴细胞（CTL）杀伤活性增高，CD4^ 及CD^8 T细胞浸润明显。结论：5－FC／CD基因疗法结合HSP－PC免疫疗法抗小鼠MFC瘤作用显著，具有临床应用前景。     

Combined liposome-mediated cytosine deaminase gene therapy with radiation in killing rectal cancer cells and xenografts in athymic mice.

PURPOSE: The aim of this study was to assess the antitumor efficacy of combination of cytosine deaminase (CD) suicide gene therapy with radiation and to grope for new therapeutic strategy for local recurrent rectal cancer. EXPERIMENTAL DESIGN: HR-8348 cell line of human rectal cancer was used to assess efficiency of transfection with plasmid pEGFP-N1 and PXJ41-CD. The cells were exposed to radiation followed by liposome-mediated transfection. Cell inhibition assay was done with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Antitumor efficacy of combined liposome-mediated CD suicide gene therapy with radiation was determined by treatment of nude mice bearing HR-8348 cancer cell xenograft. RESULTS: The efficiency of liposome-mediated CD gene transfection can be improved by radiation. With radiation at 2, 4, 6, and 8 Gy, the efficiency of liposome-mediated transfection increased from 21.3% to 62.2%, 78.0%, 83.2%, and 87.8%, respectively. CD expression was enhanced as well. Cancer cell inhibition experiment showed that combined liposome-mediated CD gene therapy with radiation had much stronger antitumor effect. With HR-8348 tumor xenograft model, suppression of tumor xenograft was observed. Compared with control group, tumor volume was inhibited by 81.5%, 48.5%, and 37.4%, respectively, in the combined CD/5-fluorocytosine with radiation group, CD/5-fluorocytosine group, and radiation group and the wet weight of tumor was decreased by 80%, 41.7%, and 37.7%, respectively. CONCLUSION: These findings suggested that combination of liposome-mediated CD gene therapy with radiation is a safer and efficient anticancer method. Its therapeutic efficacy may meet clinical treatment on local recurrent rectal cancer.     

CD自杀基因联合淋巴细胞趋化因子基因疗法的肿瘤治疗作用及免疫机理研究

本研究以腺病毒作为载体,将大肠杆菌胞嘧啶脱氨酶(CD)基因与小鼠淋巴细胞趋化因子(Ltn)基因体内联合转染,观察了其抗肿瘤效应并分析了免疫机理.小鼠皮下接种结肠腺癌CT26细胞后3天,肿瘤局部注射表达Ltn的重组腺病毒AdLtn和表达CD的重组腺病毒AdCD,然后连续10天给予5一氟胞嘧啶(5-FC)300mg/kg进行治疗,结果表明,联合治疗组荷瘤小鼠皮下肿瘤结节的生长受到明显抑制,小鼠存活期明显长于单用AdLtn治疗组或单用AdCD/5-FC治疗组.经联合治疗后小鼠脾细胞的NK活性和对(37结肠腺癌细胞的CTL杀伤活性明显增强.瘤体细胞FACS分析结果表明,经联合基因治疗后,肿瘤组织CD4~ 、CD8~ 细胞浸润增加,结肠腺癌细胞表达H-2Kd和B7-1分子明显增加.提示经CD自杀基因和Ltn基因联合治疗后,肿瘤细胞免疫原性增加.本研究结果表明联合应用自杀基因和Ltn基因治疗可以提高机体对肿瘤细胞免疫的应答,增加机体的抗肿瘤作用,是肿瘤基因治疗中一条新的途径.     

Effects of hMIP-1beta gene modification on in vivo tumorigenicity and vaccine efficacy of tumor cells

OBJECTIVE To explore the effects of human macrophage inflammatory protein-1 beta (hMIP-1beta) modification on the in vivo tumorigenicity and vaccine efficacy of tumor cells. METHODS: Murine colorectal adenocarcinoma CT26 cells were transfected with a recombinant adenovirus carring the hMIP-1beta gene (AdhMIP-1beta). The efficacy of gene transfection was tested by X-gal staining. The hMIP-1beta level in the supernatant of hMIP-1beta gene-modified CT26 cells was assayed by ELISA, and the chemotactic activity for CD4+ T cells, CD8+ T cells, NK cells and immature dendritic cells (imDCs) were assayed by a transwell chamber. The changes of growth characteristics and in vivo tumorigenicity of hMIP-1beta gene-modified CT26 cells were also assessed. BALB/c mice were immunized with hMIP-1beta gene-modified CT26 tumor vaccine and the antitumor effect was evaluated. RESULTS: hMIP-1beta gene could be transfected into CT26 cells by AdhMIP-1beta with an efficiency over 95%. The level of hMIP-1beta in the culture supernatant of hMIP-1beta gene-modified CT26 cells was 980 pg/ml and the supernatant displayed ramarkable chemotactic activity to CD4+ T cells, CD8+ T cells, NK cells and imDCs compared with LacZ gene-modified CT26 cells and control. When the hMIP-1beta gene-modifited CT26 cells were subcutaneously inoculated in BALB/c mice, the tumorigencity was delayed and suppressed, and overt necrosis and lymphocyte infiltration were observed in the tumor tissue, but not in those inoculated with LacZ gene-modified CT26 cells or parental CT26 cells. The mice immunized with hMIP-1beta gene-modified CT26 tumor vaccine could induce tumor specific CTL activity and nonspecific NK activity, and exhibited resistance to later challenge with wild-type CT26 cells. CONCLUSION: hMIP-1beta gene-modified CT26 cells exhibit decreased tumorigenicity, and hMIP-1beta gene-modified tumor vaccine may induce a powerful specific and nonspecific antitumor response. The data suggested that hMIP-1beta gene-modified tumor vaccine may play a potent role in prevention of metastasis and recurrence of malignant tumors.