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。     

腺病毒介导CD/5FC“自杀基因”疗法对人肝癌裸鼠和小鼠结肠腺癌的治疗作用研究

“自杀基因”疗法应用于肿瘤治疗时,通常是在肿瘤局部直接转染“自杀基因”,以期达到在肿瘤局部发挥抗肿瘤作用而避免全身毒性.在本实验中,我们观察了腺病毒介导的“自杀基因”疗法(CD/5FC系统)对人肝细胞癌SMMC-7721及小鼠结肠腺癌CT26的生长抑制作用,证实了腺病毒介导的CD/5FC系统在体外能杀伤人肝癌细胞SMMC-7721,并且能明显地抑制裸鼠SMMC-7721肿瘤模型的生长,对小鼠的结肠腺癌CT26也有一定的治疗作用.同时观察了以AFP启动子驱动的CD基因合并5FC的使用对AFP阳性肝癌细胞的特异性杀伤作用,证实了以肝癌特异启动子驱动的CD基因能在高表达AFP的肝癌细胞HepG2中特异表达,合并5FC的使用能在体外特异地杀伤HepG2细胞.这一组织特异性的“自杀基因”系统能特异地抑制高水平分泌AFP的人肝细胞癌裸鼠模型7721AFP( )的生长,上述研究结果表明,腺病毒介导的CD/5FC系统是一个有效的治疗方案,组织特异性的表达调控更能体现该疗法的实用价值.     

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.     

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     

5-FC/CD 自杀基因疗法结合热休克蛋白-多肽复合物瘤苗治疗小鼠黑色素瘤的研究

 目的　研究 5 -氟尿嘧啶 /胞嘧啶脱氨酶 (5 FC/ CD)基因疗法与热休克蛋白 -多肽复合物 (HSP- PC)瘤苗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黑色素瘤体内 ,腹腔注射 5 - FC,同时皮下接种 HSP70 - PC。结果　经联合治疗后 ,70 %荷瘤小鼠肿瘤体积缩小、消退 ,小鼠存活期延长 ,肿瘤组织明显坏死 ,炎症细胞、CD+4 及 CD+8T细胞浸润明显。结论5 - FC/ CD基因疗法结合 HSP- PC瘤苗免疫疗法抗小鼠黑色素瘤作用显著 ,具有临床应用前景。     

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基因疗法中的作用

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(Itn)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/Ltn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Ltn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,小鼠脾细胞分泌IL-2和IFN-γ明显增加.体内用抗CD4、CD8抗体阻断实验研究结果的表明,联合应用自杀基因和Ltn基因治疗主要通过诱导CD8~ T细胞发挥抗肿瘤作用.     

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.     

糖化重组生存素腺病毒疫苗抗肿瘤作用的实验研究

背景与目的：生存素在调控细胞凋亡和有丝分裂过程中起着重要作用,在正常分化的组织中不表达或表达极低,而在胚胎组织和大部分肿瘤组织中广泛表达,而这一特点为恶性肿瘤的基因治疗提供了很好的靶标.本研究制备糖化重组生存素腺病毒疫苗,观察其抗肿瘤作用并探讨其作用机制.方法：将重组生存素腺病毒和甘露聚糖在氧化条件下偶联,同时建立小鼠结肠癌和Lewis肺癌模型,以糖化重组生存素腺病毒疫苗治疗荷瘤小鼠,观察肿瘤体积和小鼠生存时间.对小鼠肿瘤组织作TUNEL染色观察肿瘤细胞凋亡.为了检测疫苗的保护作用,预先以糖化重组生存素腺病毒疫苗免疫接种小鼠,或合用抗CD4、CD8和NK单克隆抗体阻断相应的淋巴细胞亚群,再接种肿瘤,观察小鼠肿瘤生长情况.结果：糖化重组生存素腺病毒疫苗治疗组小鼠肿瘤生长受到明显抑制,无明显不良反应发生,小鼠的生存时间明显延长,肿瘤细胞凋亡明显增加.同时,糖化重组生存素腺病毒疫苗能诱导小鼠产生抗肿瘤免疫,这一免疫反应依赖于CD4和CD8淋巴细胞,也部分依赖于NK细胞.结论：糖化重组生存素腺病毒疫苗能诱导机体产生特异性的主动免疫反应,诱导肿瘤细胞凋亡,具有明确的抗肿瘤作用,值得进一步研究.     

腺病毒介导的肝癌自杀基因疗法的实验研究

本文观察了胞嘧啶脱氨酶(CD)基因/5-氟胞嘧啶(5FC)自杀基因疗法对肝癌模型的治疗作用。以CMV启动子调控CD基因的重组腺病毒载体AdexCMV.CD在体外能有效转染人肝癌细胞株SMMC-7721和HepG2,转染后的细胞体外生长能力无明显变化,对5FC的敏感性明显增高。当以AFP上游调控序列驱动CD基因的重组腺病毒载体AdexAFP.CD分别转染SMMC-7721和HepG2时,CD基因能在HepG2中表达,使HepG2对5FC的敏感性增高,但不能使SMMC-7721的生长受到5FC的抑制。[~3H]TdR掺入法观察体外旁观者效应时发现,当细胞总数中转染细胞数超过20％时,其生长明显被5FC抑制。将AdexCMV.CD直接注射入裸鼠接种SMMC-7721细胞形成的皮下肿瘤中,并全身应用5FC后,与对照组相比,肿瘤大小在开始治疗后第8天约缩小3倍,第18天约缩小4倍,以上结果表明,腺病毒介导的CD/5FC自杀基因系统能在体内、外有效地抑制肝癌的生长。以AFP上游调控序列驱动CD基因的腺病毒载体介导的基因转染能在AFP阳性的肝癌细胞中特异表达。     

p16基因重组质粒的构建及其对人肺癌细胞的抑制作用

表达大肠杆菌胞嘧啶脱胺酶(CD)基因的重组腺病毒AdCD体外转染小鼠黑色素瘤细胞B16F10,结果显示转染了CD基因的B16F10细胞对5-氟胞嘧啶(5FC)的敏感性显著提高.将经AdCD/5FC系统处理的B16F10细胞上清倍比稀释后.加至野生型B16F10细胞中,发现当上清仅占6.25%时即可对野生型B16F10细胞发挥明显的杀伤作用,提示AdCD/5FC介导的旁观者效应可能是通过5FC经CD酶代谢产生的毒性产物扩散而实现的.本实验还观察了CD基因体内转染后的杀伤效果,荷瘤小鼠经注射AdCD并连续10天给予5FC治疗后,与PBS、对照病毒AdLacZ/5FC治疗小鼠比较,小鼠肿瘤生长明显受到抑制,小鼠存活期明显延长.     

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。     

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？…

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     

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.     

Dendritic cells transduced with tumor-associated antigen gene elicit potent therapeutic antitumor immunity: comparison with immunodominant peptide-pulsed DCs

Several studies have shown that vaccine therapy using dendritic cells (DCs) pulsed with specific tumor antigen peptides can effectively induce antitumor immunity. Peptide-pulsed DC therapy is reported to be effective against melanoma, while it is still not sufficient to show the antitumor therapeutic effect against epithelial solid tumors such as gastrointestinal malignancies. Recently, it has been reported that vaccine therapy using DCs transduced with a surrogate tumor antigen gene can elicit a potent therapeutic antitumor immunity. In this study, we investigated the efficacy of vaccine therapy using DCs transduced with the natural tumor antigen in comparison with peptide-pulsed DCs. DCs derived from murine bone marrow were adenovirally transduced with murine endogenous tumor antigen gp70 gene, which is expressed in CT26 cells, or DCs were pulsed with the immunodominant peptide AH-1 derived from gp70. We compared these two cancer vaccines in terms of induction of antigen-specific cytotoxic T lymphocyte (CTL) responses, CD4+ T cell response against tumor cells, migratory capacity of DCs and therapeutic immunity in vivo. The cytotoxic activity of splenocytes against CT26 and Meth-A pulsed with AH-1 in mice immunized with gp70 gene-transduced DCs was higher than that with AH-1-pulsed DCs. CD4+ T cells induced from mice immunized with gp70 gene-transduced DCs produced higher levels of IFN-gamma by stimulation with CT26 than those from mice immunized with AH-1-pulsed DCs (p < 0.0001), and it was suggested that DCs transduced with tumor-associated antigen (TAA) gene induced tumor-specific CD4+ T cells, and those CD4+ T cells played a critical role in the priming phase of the CD8+ T cell response for the induction of CD8+ CTL. Furthermore, DCs adenovirally transduced with TAA gene showed an enhancement of expression of CC chemokine receptor 7 and improved the migratory capacity to draining lymph nodes. In subcutaneous models, the vaccination using gp70 gene-transduced DCs provided a remarkably higher therapeutic efficacy than that using AH-1-pulsed DCs. These results suggested that vaccine therapy using DCs adenovirally transduced with TAA gene can elicit potent antitumor immunity, and may be useful for clinical application.     

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 …

以腺病毒作为载体,将大肠杆菌胞嘧啶脱氨酶基因与小鼠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的重要腺病毒ＡｄＩＬ－２和表达的ＣＤ的重组腺病毒ＡｄＣＤ,然后连续０天给予５－氟胞嘧啶３００ｍｇ／ｋｇ进行治疗。     

Intratumoral administration of immature dendritic cells following the adenovirus vector encoding CD40 ligand elicits significant regression of established myeloma

Our previous study showed that J558 myeloma cells engineered CD40L lost their tumorigenicity in syngeneic mice, and the inoculation of J558/CD40L tumor cells further led to the protective immunity against wild tumors. In the present study, we investigated whether the vaccine can exert more efficient antitumor immunity by combination with adenovirus mediated CD40L gene therapy and immature dendritic cells (iDCs). The results demonstrated that intratumoral administration of iDCs 2 days after AdVCD40L injection, not only significantly suppressed the tumor growth, but also eradiated the established tumors in 40% of the mice. The potent antitumor effect produced by the combination therapy correlated with high expression of MHC, costimulatory and Fas molecules on J558 cells, which was derived from CD40L transgene expression. In addition, transgene CD40L expression could dramatically induce J558 cell apoptosis. Effectively capturing apoptotic bodies by iDCs in vivo could induce DC maturation, prime tumor-specific CTLs and tend to Th1-type immune response. Finally, in vivo depletion experimentation suggested both CD4+ and CD8+ T cells were involved in mediating the antitumor immune responses of combined treatment of AdVCD40L and iDCs, with CD8+ T cells being the major effector. These findings could be beneficial for designing strategies of DCs vaccine and CD40L for anticancer immunotherapy.