MIP-1β基因修饰增强肿瘤相关抗原致敏树突状细胞的抗肿瘤免疫效果

目的：探讨通过增强树突状细胞(dendritic cells, DC)与T细胞的相互作用来进一步增强DC介导的抗肿瘤免疫效果。方法：体外培养的小鼠骨髓DC体外经携带人MIP1β基因的重组腺病毒(adenovirus expressing human macrophoge inflammatory protein1 beta, AdhMIP1β)转染后(MIP1βDC)，用小鼠CT26结肠腺癌细胞相关抗原冲击致敏，然后免疫正常同系小鼠，观察其体内诱导的细胞毒性T淋巴细胞(cytotoxic T lymphocyte, CTL)的保护性免疫反应；通过体内阻断试验探讨免疫细胞亚群及免疫分子在DC诱导抗肿瘤免疫应答中的作用。结果：经抗原致敏的MIP1βDC能更有效地诱导特异CTL活性，能使免疫动物产生更有效的免疫保护作用，抵抗肿瘤细胞的攻击。通过对其抗肿瘤免疫机理的分析发现，CD4+、CD8+ T 细胞共同参与了经抗原致敏的MIP1βDC介导的抗肿瘤免疫反应，是主要的抗瘤效应细胞，NK细胞作用不明显。结论：通过基因修饰增强树突状细胞对T细胞的体内趋化活性，能更有效地诱导抗肿瘤免疫反应，为树突状细胞介导的肿瘤免疫基因治疗开辟了新的途径。     

MIP-1β基因修饰增强肿瘤相关抗原致敏树突状细胞的抗肿瘤免疫效果

目的:探讨通过增强树突状细胞(dendritic cells,DC)与T细胞的相互作用来进一步增强DC介导的抗肿瘤免疫效果.方法:体外培养的小鼠骨髓DC体外经携带人MIP-1β基因的重组腺病毒(adenovirus expressing human macrophoge inflammatory protein-1 beta,AdhMIP-1β)转染后(MIP-1β-DC),用小鼠CT26结肠腺癌细胞相关抗原冲击致敏,然后免疫正常同系小鼠,观察其体内诱导的细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)的保护性免疫反应;通过体内阻断试验探讨免疫细胞亚群及免疫分子在DC诱导抗肿瘤免疫应答中的作用.结果:经抗原致敏的MIP-1β-DC能更有效地诱导特异CTL活性,能使免疫动物产生更有效的免疫保护作用,抵抗肿瘤细胞的攻击.通过对其抗肿瘤免疫机理的分析发现,CD4 、CD8 T细胞共同参与了经抗原致敏的MIP-1β-DC介导的抗肿瘤免疫反应,是主要的抗瘤效应细胞,NK细胞作用不明显.结论:通过基因修饰增强树突状细胞对T细胞的体内趋化活性,能更有效地诱导抗肿瘤免疫反应,为树突状细胞介导的肿瘤免疫基因治疗开辟了新的途径.     

表达VEGFR-2的减毒鼠伤寒沙门氏菌疫苗诱导特异性抗胶质瘤血管免疫应答

背景与目的:血管内皮生长因子(vascular endothelialgrowth factor,VEGF)及其主要受体血管内皮生长因子受体-2(vascular endothelialgrowth factorreceptor-2,VEGFR-2)在肿瘤新生血管和肿瘤基质形成过程中起着重要作用。本研究的目的是观察表达鼠VEGFR-2的重组减毒沙门氏疫苗菌诱导的抗血管特异性免疫应答及抗胶质瘤作用。方法:构建真核表达载体pcDNA3.1-VEGFR2,通过电转化法将pcDNA3.1-VEGFR2导入减毒鼠伤寒沙门氏菌SL7207中,经由胃管饲予C57BL/6J小鼠,对小鼠进行基因免疫。采用ELISA法检测免疫小鼠血清中特异性抗VEGFR2-IgG抗体,分离免疫小鼠的脾细胞,分析重组疫苗菌免疫后小鼠体内的特异性细胞毒性T细胞(cytotoxic T lym phocyte,CTL)应答。用携带pcDNA3.1-VEGFR2的重组沙门氏菌免疫治疗胶质瘤荷瘤小鼠,通过测量荷瘤小鼠肿瘤大小,检测肿瘤微血管密度及肿瘤细胞凋亡,评价重组疫苗菌的抗血管及肿瘤生长抑制作用。结果:重组疫苗菌免疫后小鼠产生了高水平的抗VEGFR2-IgG抗体,诱导小鼠脾淋巴细胞产生针对VEGFR2的特异性CTL活性。重组疫苗菌的免疫能够明显抑制胶质瘤的生长。NaH CO3对照组、载体对照组、重组疫苗菌组的平均微血管密度分别为26.5±5.8、27.2±4.5、8.8±1.9,平均凋亡细胞数分别为4.41.2、3.     

CD4+T细胞与肿瘤免疫

在肿瘤免疫中细胞免疫发挥着重要作用,其中T细胞介导的特异性免疫应答反应更为重要.近年来CD4+T细胞在抗肿瘤免疫中的作用越来越受到重视.在肿瘤免疫中CD4+T细胞启动后可以通过多种机制启动细胞毒性T淋巴细胞(CTL),维持和加强CTL的抗肿瘤反应,并且可以作为效应细胞发挥抗肿瘤作用,CD4+T细胞中的一个亚群细胞CD4+ CD25+T调节细胞对肿瘤免疫有抑制作用.     

CD4+T细胞与肿瘤免疫

在肿瘤免疫中细胞免疫发挥着重要作用,其中T细胞介导的特异性免疫应答反应更为重要.近年来CD4+T细胞在抗肿瘤免疫中的作用越来越受到重视.在肿瘤免疫中CD4+T细胞启动后可以通过多种机制启动细胞毒性T淋巴细胞(CTL),维持和加强CTL的抗肿瘤反应,并且可以作为效应细胞发挥抗肿瘤作用,CD4+T细胞中的一个亚群细胞CD4+ CD25+T调节细胞对肿瘤免疫有抑制作用.     

DC肿瘤融合瘤苗抗肿瘤效应的实验研究

目的:观察DC与肿瘤细胞融合后的瘤苗体内诱导的抗肿瘤免疫应答以及对荷瘤小鼠的治疗作用.方法:应用免疫磁珠分选和贴壁培养方法收集融合细胞,应用3H-TdR掺入法、4h51Cr释放法观察T细胞增殖反应的能力和CTL活性,并观察瘤苗对荷瘤小鼠保护性免疫反应和免疫治疗作用.结果:DC肿瘤融合瘤苗具有强烈的激活T细胞增殖和抗原提呈的能力,在体外、体内诱导出更强的特异CTL细胞毒活性,使免疫小鼠产生一定的免疫保护作用,抵抗Hepa1-6肝癌细胞的再次攻击,使治疗的小鼠肿瘤的生长明显缓慢,具有更明显的治疗作用.结论:DC与肿瘤细胞融合后进行体内免疫和治疗,能诱导出显著的抗肿瘤免疫反应,为DC介导的肿瘤免疫治疗开辟了新的途径.     

雷公藤内酯醇对人宫颈癌细胞的凋亡诱导效应

目的:探讨腺病毒介导AFP基因修饰的DC(AFP-DC)瘤苗经不同途径免疫后机体抗肿瘤免疫应答反应.方法:采用皮下注射、静脉注射和瘤体注射三种途径回输AFP-DC瘤苗,比较观察AFP-DC瘤苗对荷瘤小鼠免疫治疗作用,应用4h51cr释放杀伤实验、T细胞与NK体内剔除实验等方法,观察AFP-DC瘤苗对荷瘤小鼠免疫治疗作用及保护性免疫反应.结果:皮下注射AFP-DC瘤苗治疗效果在抑制肿瘤生长、延长小鼠存活期方面都明显优于瘤体内注射或尾静脉注射(P＜0.05),AFP-DC瘤苗体内能更有效地诱导特异CTL细胞毒活性,能使免疫动物产生一定的免疫保护作用,抵抗肿瘤细胞的再攻击.在AFP-DC瘤苗诱导抗肿瘤免疫排斥反应过程中,必需有CD4 T和CD8 T细胞的参与;而在其效应阶段,则依赖于CD8 T细胞的参与,CD4 T细胞为非必需;在免疫诱导及效应阶段剔除NK细胞对抗肿瘤免疫应答无明显影响.结论:皮下注射AFP-DC瘤苗能有效诱导机体产生抗肿瘤免疫反应,为DC介导的肝癌免疫治疗开辟了新的途径.     

携带flk1的重组减毒沙门氏菌的构建及其抗肿瘤血管生成的研究

目的:观察携带鼠血管内皮生长因子受体-2(vascular endothelial growth factor receptor-2,flk1)的重组减毒鼠伤寒沙门氏菌诱导的flk1特异性免疫应答及抗肿瘤血管生成作用.方法:构建真核表达载体pcDNA3.1-flk1,并将其转化到减毒鼠伤寒沙门氏菌SL7207中,体外感染小鼠巨噬细胞,用Western印迹对表达产物进行鉴定,将重组菌口服免疫小鼠,分析免疫后小鼠体内的特异性CTL应答.采用藻酸盐微囊实验观察其对体内肿瘤血管生成的影响.结果:免疫印迹试验表明携带pcD-NA3.1-flk1表达载体的重组菌感染的小鼠巨噬细胞能表达flk1蛋白,免疫小鼠脾淋巴细胞产生针对flk1的特异性CTL活性.重组疫苗菌的免疫能够明显抑制小鼠体内肿瘤血管的形成.结论:携带flk1的重组减毒沙门氏菌经口服免疫,诱导小鼠产生抗flk1的特异性免疫反应,且能明显产生抗肿瘤血管生成作用.     

共表达基因疫苗MAGE-1/IL-18的抗肿瘤免疫治疗作用

目的观察已构建的共表达基因疫苗pcIL-18-MAGE诱导特异性免疫应答的能力和抗肿瘤免疫治疗作用。方法共表达疫苗肌注小鼠,间隔十天加强免疫一次,共免疫三次,以pcMAGE-1、 pcIL-18、pcDNA3和PBS为对照,检测小鼠脾细胞上清液IL-12和IFN-γ的浓度、脾细胞CTL杀伤活性及小鼠T细胞亚群情况;观察基因疫苗免疫MAGE (+)小鼠的成瘤时间和生存时间。结果pcIL-18-MAGE质粒免疫的小鼠,其脾细胞对SMMC-7721的杀伤率最高,与各对照组相比,差异有统计学意义;脾细胞CD3⁺、CD4⁺、CD8⁺ T细胞和上清液中细胞因子IL-12和IFN-γ均明显升高。共表达疫苗免疫MAGE (+)小鼠后,小鼠成瘤时间明显延迟,生存时间明显延长。结论共表达基因疫苗pcIL-18-MAGE在实验动物体内有显著的诱导特异性抗肿瘤免疫作用,且对肿瘤的生成有一定的抑制作用。     

DC 荷载α－GalCer 联合肿瘤特异性 CTL 对小鼠 Heps 肝癌移植瘤生长的影响

目的：探讨树突状细胞（DC）荷载α－半乳糖神经酰胺（α－GalCer）联合肿瘤特异性细胞毒 T 淋巴细胞（CTL）对小鼠 Heps 肝癌移植瘤生长的抑制作用。方法：诱导扩增小鼠骨髓来源的 DC 细胞和 T 淋巴细胞,培养成为具有肿瘤特异性的 CTL,DC 细胞体外荷载α－GalCer。建立 Heps 肝癌移植瘤模型,将36只模型鼠随机分为4组（n ＝9）,分别尾静脉给予生理盐水（对照组）、CTL（CTL 组）、DC 荷载α－GalCer（DC 荷载α－GalCer 组）、DC 细胞荷载α－GalCer ＋CTL（联合治疗组）输注。每隔两天测量移植瘤体积,观察体积变化。于治疗后第14d,处死小鼠,取眼球血及瘤体组织。流式细胞术（FCM）检测外周血 CD4＋、CD8＋ T 细胞比例。免疫组织化学染色观察肿瘤组织中 Bcl －2／Bax 凋亡蛋白的表达。结果：与对照组相比,各治疗组均可抑制肿瘤的生长,差异具有统计学意义（P ＜0．01）;联合治疗组较 DC 荷载α－GalCer 组及 CTL 组肿瘤体积明显减小（P ＜0．05）。联合治疗组小鼠外周血 CD4＋、CD8＋ T 细胞数量较另外三组显著升高（P ＜0．05）;对照组、CTL组、DC 荷载α－GalCer 组小鼠外周血中 CD4＋、CD8＋ T 细胞含量无明显差异（P ＞0．05）。与对照组相比,各治疗组移植瘤内 Bax 阳性细胞数量明显增加（P ＜0．05）,Bcl －2阳性细胞数量明显减少（P ＜0．05）;与 CTL组和α－GalCer 组相比,联合治疗组移植瘤内 Bax 阳性细胞明显增加（P ＜0．05）,Bcl －2阳性细胞明显下降（P ＜0．05）。结论：DC 荷载α－GalCer 与肿瘤特异性 CTL 联合应用能够对小鼠 Heps 肝癌移植瘤具有协同杀伤作用。     

Therapeutic effect of dendritic cells loaded with a fusion mRNA encoding tyrosinase-related protein 2 and enhanced green fluorescence protein on B16 melanoma.

Dendritic cells (DCs) loaded with messenger RNA (mRNA) have been proposed to be useful for inducing specific cytotoxic T lymphocytes against tumor antigens. It is now also apparent that tumor antigen-specific T cell tolerance limits the efficacy of active immunotherapy. To improve the efficacy of mRNA-loaded DCs, we constructed a fusion mRNA encoding tyrosinase-related protein 2 (TRP2), which has a late endosomal/lysosomal sorting signal and enhanced green fluorescence protein (EGFP), and evaluated its effect in a murine melanoma model. C57BL/6 mice were challenged subcutaneously (s.c.) with 3 x 10(5) B16 tumor cells, and 3 and 10 days later, 3 x 10(5) DCs loaded with mRNA (DC/mRNA) were injected s.c. in the vicinity of the tumor site. Treatment with DC/TRP2 mRNA or DC/TRP2-EGFP mRNA significantly inhibited tumor growth compared to DC/PBS on day 17 after B16 challenge (DC/PBS vs. DC/TRP2 mRNA, p = 0.0411; DC/PBS vs.DC/TRP2-EGFP mRNA, p = 0.0253), whereas no antitumor effect was observed in mice treated with DC/EGFP mRNA or DC/TRP2 peptide. Moreover, the survival rate in mice immunized with DC/TRP2 mRNA or DC/TRP2-EGFP mRNA was significantly improved as compared with that in mice receiving DC/PBS (DC/PBS vs. DC/TRP2 mRNA, p = 0.0228; DC/PBS vs. DC/TRP2-EGFP mRNA, p = 0.0049). Depletion of CD4+ T cells or CD8+ T cells with antibody administration completely abrogated the therapeutic effectiveness of DC/TRP2-EGFP mRNA, suggesting the induction of a T cell immune response against the B16 tumor.     

人AFP腺病毒载体感染的树突状细胞诱导小鼠抗肝癌免疫

目的探讨复制缺损型腺病毒载体(Ad)介导异种AFP修饰的树突状细胞(DCs)诱发抗肝癌免疫、打破肿瘤免疫耐受的效果。方法从HepG2和Hepa16细胞中克隆人和小鼠AFP,插入Ad中构建AdhAFP和AdmAFP。用AdhAFP或AdmAFP感染小鼠骨髓来源的DC后,在无或有删除CD4或CD8情况下免疫C57BL/6小鼠,7d后取脾细胞行51Cr释放实验,检测特异性CTL杀伤活性;或给免疫小鼠接种Hepa16肝癌细胞,观察荷瘤小鼠成活情况。结果AdhAFP/DCs免疫小鼠1周后其细胞毒性T淋巴细胞杀伤活性明显强于AdmAFP/DCs。AdhAFP/DCs免疫小鼠后1周接种5×106Hepa16肝瘤细胞,2个月后仍然有80%的小鼠无瘤生长;而接种1×106Hepa16细胞至AdmAFP/DCs免疫小鼠,2个月后小鼠成活率为20%。删除小鼠CD4或CD8T细胞均使AdhAFP/DCs诱发的抗肿瘤免疫反应消失。结论Ad介导异种AFP修饰的DCs能有效地打破肿瘤的免疫耐受,诱发强烈的抗原特异性细胞免疫反应,这种特异性细胞免疫反应是CD4和CD8依赖性的。     

Induction and clonal expansion of tumor-specific cytotoxic T lymphocytes from renal cell carcinoma patients after stimulation with autologous dendritic cells loaded with tumor cells

Melanoma and renal cell carcinoma (RCC) are considered to be the most immunogenic tumors in humans. To generate conditions to induce primary T-cell responses against RCC and to allow further expansion of tumor-specific cytotoxic T lymphocytes (CTL) for adoptive transfer, peripheral blood mononuclear cells from RCC patients were stimulated with primary autologous tumor cells or monocyte-derived dendritic cells (DC) loaded with either tumor lysate (TU-LY) or apoptotic tumor cells (TU-AP). Whereas repetitive stimulation (4x) with tumor cells alone induced a predominant population of CD3(-) natural killer cells, 4 weeks of stimulation with tumor-loaded DC favored induction and expansion of CD4+ T cells (>80%). However, 2 weekly stimulation cycles with tumor-loaded DC followed by restimulation with autologous irradiated tumor cells alone were optimal for induction of tumor-specific CTL responses in vitro. Using these culture conditions a marked increase of CD4+ T cells was observed during the first 2 weeks of stimulation with tumor-loaded DC. Subsequent restimulation with autologous tumor cells alone gave rise to 500-fold expansion of CD8+ T cells. These CD8+ T cells were shown to exhibit strong major histocompatibility complex class I-restricted cytotoxic activity against the autologous tumor. Comparison of TU-LY and TU-AP as a source of tumor antigen for loading DC did not show any difference in stimulating tumor-specific CTL. Length pattern analysis of the complementary determining region 3 (CDR3) of the T-cell receptor Vbeta chain revealed expansion of oligoclonal CTL populations with outgrowth of 1 or 2 clones after prolonged stimulation with autologous tumor cells. Our study demonstrated an efficient method for generating tumor-specific CTL in vitro that may be used to identify tumor cell antigens or that can be expanded for adoptive T-cell transfer in tumor immunotherapy.     

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.     

Engineered fusion hybrid vaccine of IL-4 gene-modified myeloma and relative mature dendritic cells enhances antitumor immunity

Dendritic cell (DC)-tumor fusion hybrid vaccine which facilitates antigen presentation represents a new powerful strategy in cancer therapy. In the present study, we investigated the antitumor immunity derived from vaccination of fusion hybrids between wild-type J558 or engineered J558-IL-4 myeloma cells secreting cytokine interleukin-4 (IL-4) and immature DCs (DC(IMAT)) or relative mature DCs (DC(RMAT)). DC(RMAT) displayed an up-regulated expression of immune molecules (Ia(d), CD40, CD54, CD80 and CD86) and certain cytokines/chemokines, and enhanced ability of allogeneic T cell stimulation when compared to DC(IMAT). These DCs were fused with myeloma cells by polyethylene glycol (PEG). The fusion efficiency was approximately 20%. Our data showed that immunization of C57BL/6 mice with DC(RMAT)/J558 hybrids induced protective immunity against a high dose of J558 tumor challenge (1x10(6) cells) in 3 out of 10 immunized mice, compared with no protection seen in mice immunized with DC(IMAT)/J558 hybrids. Furthermore, immunization of mice with engineered DC(RMAT)/J558-IL-4 hybrids elicited stronger J558 tumor-specific cytotoxic T lymphocyte (CTL) responses in vitro and induced more efficient protective immunity (10/10 mice; tumor free) against J558 tumor challenge in vivo than DC(RMAT)/J558 hybrid vaccines. The results demonstrate the importance of DC maturation in DC-tumor hybrid vaccines and indicate that the engineered fusion hybrid vaccines which combine gene-modified tumor and DC vaccines may be an attractive strategy for cancer immunotherapy.     

致敏树突细胞治疗膀胱肿瘤血液细胞毒性T淋巴细胞的变化

目的观察致敏的树突细胞（DC）治疗膀胱肿瘤（BT）后血液细胞毒性T淋巴细胞（CTL）的变化并探讨其机制。方法选取F344大鼠44只，称重后随机分为4组；均采用膀胱灌注N-甲基亚硝基脲（MNU）制成BT；第11周4组分别经皮下注射磷酸缓冲液（PBS）、未致敏DC、肿瘤抗原及致敏DC，每周1次，共4次；实验第15周，经显微镜和流式细胞仪（FCM）检测。结果致敏DC组膀胱重量比其他三组轻（P〈0．05）。致敏DC组BT病理分期低于PBS组和未致敏DC组（P〈0．05）；CD3^＋ T细胞在致敏DC组低于其余三组（P〈0．05）；CTL在致敏DC组高于其余三组（P〈0．001）。结论应用致敏DC经皮下注射治疗大鼠BT可降低肿瘤的病理分期，未致敏DC皮下注射对膀胱肿瘤治疗无效，肿瘤抗原皮下注射对膀胱肿瘤治疗效果欠佳。致敏DC可通过呈递抗原来激活CTL增生而发挥其免疫杀伤作用。     

负载抗原肽的树突状细胞增强腺病毒载体介导hTRP2诱发抗小鼠黑色素瘤免疫

目的探讨人黑色素瘤相关抗原TRP2(hTRP2)MHCⅠ多肽TRP2p180-188 (SVYDFFVWL)修饰小鼠骨髓来源的树突状细胞(DC),增强腺病毒载体介导hTRP2(Ad hTRP2)诱发的抗小鼠黑色素瘤免疫效果。方法Ad hTRP2免疫C57BL／6小鼠,3周后分别用Ad hTRP2或DC／SVYDFFVWL再免疫一次。用体内细胞毒性T淋巴细胞(CTL)杀伤实验和细胞内IFNγ染色(ICS)分析CTL杀伤活性和IFNγ的产生;或给免疫小鼠皮下接种B16．F10细胞,观察荷瘤小鼠的成活情况。结果测定脾脏中6 h CTL杀伤率和产生IFNγ的CD8+T细胞比例,结果分别是:Ad hTRP2(初免)- Ad hTRP2(加强)组为68．40％±5．50％和0．67％±0．16％,DC／SVYDFFVWL(初免)-DC／SVYDFFVWL(加强)组为28．50％±6．40％和0．22％±0．07％,而Ad hTRP2(初免)-DC／SVYDFFVWL(加强)组为98．90％±0．90％和1．05％±0．21％。荷瘤实验显示,小鼠接种1×106 B16．F10细胞后3个月,DC／SVYDFFVWL(初免)-DC／SVYDFFVWL(加强)组小鼠无一成活,Ad hTRP2(初免)-Ad hTRP2(加强)组只有40％的小鼠存活,而Ad hTRP2(初免)-DC／SVYDFFVWL(加强)组小鼠100％存活。结论用DC／SVYDFFVWL加强免疫能显著地增强Ad hTRP2初次免疫的效果,表明Ad hTRP2(初免)-DC／SVYDFFVWL(加强)免疫是一种克服重复应用腺病毒并不能提高抗肿瘤免疫效应的有效方式。     

重组白介素-12治疗小鼠Lewis肺癌的实验研究

背景与目的:白介素-12(interleukin-12,IL-12)是具有抗瘤活性的细胞因子,本研究建立稳定表达小鼠IL-12(murineinterleukin-12,mIL-12)的小鼠Lewis肺癌(Lewislungcarcinoma,LLC)细胞系LLC/mIL-12,评估mIL-12重组质粒及LLC/mIL-12瘤苗治疗小鼠Lewis肺癌移植瘤的疗效。方法:脂质体转染LLC获得LLC/mIL-12瘤苗。于C57BL/6小鼠皮下接种LLC细胞2×106个,成瘤后将小鼠随机分成4组(n=10),第1、4、7天瘤内注射质粒或瘤苗,第14天处死小鼠,观察肿瘤生长曲线、脾细胞中CTL细胞和NK细胞活性以及肿瘤浸润淋巴细胞。结果:LLC/mIL-12瘤苗组和pcDNA3.1( )-mIL-12质粒组肿瘤体积显著缩小,mIL-12能增强NK细胞和CTL细胞活性,两者均以LLC/mIL-12治疗组更显著,LLC/mIL-12和pcDNA3.1( )-mIL-12治疗组有大量CD4 、CD8 淋巴细胞浸润。结论:mIL-12基因能增强NK细胞和CTL活性,LLC/mIL-12及pcDNA3.1( )-mIL-12均能产生抗瘤免疫反应,且前者作用更强。