脂质体RNA负载慢性粒细胞白血病来源树突状细胞的性能比较

目的研究人慢性粒细胞白血病(CML)总RNA经过脂质体负载后体外转染自体慢性粒细胞白血病 树突状细胞（CML-DC）,并诱导特异性细胞毒T淋巴细胞（CTL）免疫反应。方法CML患者骨髓单个核细胞（CML-BMMNC）在rhIL-4、rhGM-CSF、rhTNF-α细胞因子联合培养诱导出CML-DC。采用Trizol法提取CML-BMMNC的总RNA;反复冻融法制备CML BMMNC抗原。于CML-DC培养第5天,加入脂质体转染的CML总RNA、CML总RNA、CML肿瘤冻融抗原及不加抗原。倒置显微镜观察DC形态学变化;流式细胞仪器检测免疫表型变化;染色体G显带技术检测其染色体核型及逆转录聚合酶链反应（RT-PCR）检测Bcr-abl融合基因的表达;用MTT法检测CTL作用。结果CML BMMNC诱导成CML-DC, CD_1α、CD₈₃表型表达较诱导前明显上调,形态学有典型的DC形态,且均存在Bcr-abl基因带和Ph₁染色体,提示CML-DC为白血病源性。总RNA经脂质体转染CML-DC、CML肿瘤冻融抗原负载CML-DC、总RNA不经脂质体转染CML-DC、未负载抗原CML-DC分别致敏的CTL及IL-2培养的T淋巴细胞在效：靶比为20∶1时的杀伤效率依次降低。结论CML BMMNC来源的 DC既具有CML白血病源性,又具有DC细胞的特性,能诱导特异性CTL杀伤作用;总RNA经脂质体转染的CML-DC诱导的CTL杀伤性对CML细胞的杀伤作用最强。     

负载肝癌抗原的树突状细胞瘤苗诱导的抗肿瘤作用

目的 探讨原发性肝癌患者外周血树突状细胞（DC）体外经自体肝癌细胞抗原致敏后诱导的抗肿瘤作用。方法肝癌患者外周血经梯度密度离心法分离，获得DC前体细胞，用重组人粒细胞-巨噬细胞集落刺激因子（rhGM—CSP）和重组人白细胞介素-4（rhIL-4）联合培养，诱导扩增DC。制备自体肝癌细胞抗原，体外脉冲DC，检测DC诱导自体T细胞增殖能力及细胞毒性T细胞（CTL）在体外对自体肝癌细胞的杀伤活性，并检测肿瘤抗原致敏DC分泌的IL-12水平。结果经自体肝癌细胞抗原致敏的DC能分泌IL-12和诱导较强的自体T细胞增殖，且能诱导特异性CTL，该CTL对自体肝癌细胞具有很强的杀伤活性，杀伤率明显高于DC、未经肝癌细胞抗原致敏的DC激活的CTL及T淋巴细胞的杀伤率，而对3LLLEWIS肺癌细胞、H22肝癌细胞则无明显的．杀伤作用。结论肝癌患者外周血DC经自体肝癌细胞抗原致敏后能诱导高效而特异的抗肝癌免疫，其机制可能与增强T细胞应答和诱导机体产生肿瘤特异CTL而发挥特异性的抗肿瘤作用有关。     

人肺癌组织总RNA转染树突状细胞诱导特异性抗肿瘤免疫的研究

目的:探讨以人肺癌组织总RNA体外转染树突状细胞(dendritic cells,DCs)诱导细胞毒T淋巴细胞(cytotoxic T lymptocyte,CTL)发挥特异性抗肿瘤免疫的作用.方法:10例肿瘤组织经免疫组化测定为CEA、MUC1双阳性.一步法提取肿瘤组织总RNA和10例正常肺组织RNA.采集患者外周血单个核细胞体外诱导未成熟DCs,电穿孔法转染肿瘤和肺组织RNA,刺激DCs成熟后,部分行流式细胞仪检测,部分用于体外诱导CTL.以原代培养的肿瘤细胞和肺上皮细胞作为靶细胞,定量乳酸脱氢酶法测定杀伤率.结果:体外培养的DCs形态典型,高表达CD86、CD80、CD40、HLA-DR和CD83.转染肿瘤组织RNA DCs的CEA和MUC1表达量为(20.53±3.64)%和(65.39±9.33)%,明显高于转染肺组织RNA的DCs[(0.78±0.39)%和(18.32±4.24)%],P＜0.01.肿瘤组织RNA转染DCs诱导的CTL可产生针对肿瘤细胞的特异性杀伤;且用自身肿瘤组织RNA转染DCs诱导的CTL对自身肿瘤细胞杀伤活性最大.结论: 以人肺癌总RNA体外转染DCs诱导CTL可以产生特异性抗肿瘤免疫,此方法构建肺癌疫苗是可行的.     

Caveolin1对KDR信号通路的作用

目的:研究以小鼠结肠癌细胞CT-26RNA作为抗原体外转染经mIL-12基因修饰的树突状细胞(dendriticcells,DC),观察其诱导特异性抗肿瘤的效应。方法:小鼠骨髓细胞体外以rmGM-CSF、rmIL-4诱导培养获取树突状细胞,流式细胞术检测纯度;293细胞扩增携带mIL-12基因的重组腺病毒,体外转染树突状细胞;Trizol法提取CT-26细胞总RNA,应用Trans-Messenger体外转染mIL-12基因修饰的树突状细胞,免疫接种小鼠。ELISA法检测细胞上清及小鼠血液中mIL-12水平,LDH释放法检测小鼠体内细胞毒性T淋巴细胞(CTL)杀伤活性。结果:小鼠骨髓细胞经诱导培养后,获得大量高纯度的树突状细胞,流式细胞术检测CD11c 的树突状细胞>90%;提取的CT-26细胞总RNA体外经TransMessenger介导,转染mIL-12基因修饰的树突状细胞后,回输小鼠,可以诱导体内生成较高水平的特异性CTL活性,亲本肿瘤接种后小鼠100%长期存活,而以该RNA转染Ad-LacZ修饰DC后的对照组及RNA转染DC的对照组,诱导机体生成的特异性CTL活性显著低于实验组(P<0.01),亲本肿瘤接种后小鼠60%长期存活,DC、PBS对照组则均未诱导机体生成特异性CTL活性,小鼠无长期存活。结论:树突状细胞经小鼠结肠癌CT26细胞RNA转染和mIL-12基因修饰后免疫接种小鼠,可在体内有效提呈肿瘤抗原,诱导机体产生高水平的CTL,更有效地诱发特异性抗肿瘤效应。     

Hep-2细胞总RNA转染树突状细胞诱发抗喉癌特异性免疫效应的研究

目的:研究转染喉鳞状细胞癌总RNA对树突状细胞(DC)免疫功能的影响,观察肿瘤总RNA修饰后的DC在体外诱导高效而特异的抗喉癌免疫效应.方法:采用分离脐血单核细胞体外诱导DC,Trizol法提取喉鳞状细胞癌细胞株Hep-2总RNA后转染入DC,流式细胞仪分析DC表面分子CD40、CD80、CD83、CD86的表达,LDH法评估转染肿瘤总RNA的DC瘤苗的细胞毒性T淋巴细胞反应.结果:转染后的DC表面分子表达CD40(60.6±0.15)%,CD80(60.2±0.21)%,CD83(85.1±0.06)%,和CD86(91.9%±0.09)%,而在未转染的未成熟DC中低表达;转染RNA的DC瘤苗对于Hep-2细胞株有特异性杀伤效应,在E/T为40:1时,杀伤效率达45.6%,而对对照组靶细胞杀伤效率较低.结论: 喉鳞状细胞癌总RNA转染修饰的DC能特异性诱导细胞毒性T淋巴细胞,显著提高DC的抗原提呈功能,在体外能诱导高效而特异的抗喉癌免疫效应.     

DC和NK细胞诱导的抗肿瘤CTL反应

细胞毒性T淋巴细胞（CTL）介导的细胞毒效应能够高效、特异性杀伤肿瘤细胞而不损伤周围组织。树突细胞（DC）是已知体内抗原提呈功能最强的抗原提呈细胞，能摄取各种抗原，体内外能激发T细胞增殖，诱导特异性CTL生成。自然杀伤（NK）细胞在由DC引起的抗肿瘤免疫中发挥重要作用。近年来NK-DC细胞的相互作用在CTL反应中的作用引起关注。现综述DC、NK细胞在诱导抗肿瘤CTL反应中作用的研究进展。     

肝癌细胞抗原致敏树突状细胞诱导的体外抗肿瘤作用

目的　探讨原发性肝癌患者外周血树突状细胞 (DC)经自体肝癌细胞抗原致敏后诱导的体外抗肿瘤作用。方法　对肝癌患者外周血采用密度梯度离心法分离 ,获得DC前体细胞 ,用重组人粒细胞 巨噬细胞集落刺激因子 (rhGM CSF)和重组人白细胞介素 4(rhIL 4)联合培养 ,诱导扩增DC。制备自体肝癌细胞抗原 ,体外脉冲DC ,检测DC诱导自体T细胞增殖能力及细胞毒性T细胞 (CTL )在体外对自体肝癌细胞的杀伤活性 ,并检测肿瘤抗原致敏DC分泌的IL 12水平。结果　经自体肝癌细胞抗原致敏的DC能分泌IL 12和诱导较强的自体T细胞增殖 ,且能诱导特异性CTL ,该CTL对自体肝癌细胞具有很强的杀伤活性 ,杀伤率显著高于DC、未经肝癌细胞抗原致敏的DC激活的CTL及T淋巴细胞的杀伤率 ,而对CT 2 6细胞、BEL 740 2细胞无明显的杀伤作用。结论　肝癌患者外周血DC经自体肝癌细胞抗原致敏后能诱导高效而特异的抗肝癌免疫 ,其机制可能与增强T细胞应答和诱导机体产生肿瘤特异CTL从而发挥特异性的抗肿瘤作用有关。     

负载肺癌抗原DC疫苗抗肿瘤免疫实验

 目的探讨负载人肺癌细胞株A549冻融抗原DC疫苗体外抗肿瘤免疫效应。方法自脐血分离单核细胞，经rhGM-CSF、rhIL-4和rhTNF-α诱导树突状细胞（DC），负载人肺癌细胞株A549冻融抗原、LPS诱导成熟，利用免疫磁珠分选获得功能性肺癌DC疫苗（UbDC／AgL），ELISA测定UbDC／AgL培养上清中细胞因子浓度、LDH法测定特异性细胞杀伤（CTL）活性及MTT法检测自身混合淋巴细胞反应（AMLR）。结果UbDC／AgL细胞组IL-1、IL-12、IL-6和IFN-β含量明显高于UbDC／Ag和UbDC组（P〈0．01）；UbDC／AgL疫苗细胞能有效诱导肿瘤特异性CTL活性，对A549细胞有特异性杀伤作用（P〈0．01），并能有效促进淋巴细胞增殖。结论负载肿瘤冻融抗原DC疫苗，能有效激活T淋巴细胞进而诱导肿瘤特异性杀伤效应。     

树突状细胞的肿瘤抗原负载

树突状细胞（DC）是体内功能最强的专职抗原提呈细胞，在诱导特异性抗肿瘤免疫反应中起着至关重要的作用。通过体外负载肿瘤抗原致敏DC可以有效地增强其抗原提呈能力，所制备的肿瘤抗原DC疫苗回输体内后可促进机体产生特异性细胞毒T淋巴细胞（CTL）和其他抗肿瘤免疫应答机制，有效地杀伤肿瘤细胞。目前已发展了多种针对DC负载肿瘤抗原的方法，有些方法已被应用到了人体肿瘤治疗。     

白介素-12基因转染致敏树突状细胞体外诱导特异抗前列腺癌效应的实验研究

背景与目的前列腺癌是泌尿系统疾病中发病率和死亡率较高的恶性肿瘤,临床积极寻求最佳治疗方案。白细胞介素-12(IL-12)具有促T细胞增殖分化和抗肿瘤免疫作用,负载肿瘤抗原的树突状细胞(DC)疫苗可诱导机体产生特异性的抗肿瘤免疫效应,联合两者抗肿瘤效应,探讨逆转录病毒介导白细胞介素-12(IL-12)基因转染DC体外诱导特异免疫杀伤前列腺癌细胞的效能及其机制。方法构建IL-12基因逆转录病毒重组质粒,转染PA317细胞后获得相应病毒,转染前列腺癌(PCa)患者外周血DC成DC-IL-12细胞。以HSP70-PC-3m肿瘤混合肽负载DC-IL-12细胞得致敏的DC。MTT法检测T淋巴细胞(1×105个/ml)增殖分化能力,细胞毒实验检测DC-IL-12诱导的细胞毒T淋巴细胞(CTL)及其上清液对PC-3m细胞株杀伤作用。结果DC经IL-12修饰后48h分泌高水平IL-12(26.35±3.12)ng/L及IFN-r(778±28)ng/L,均显著高于未转染组(P<0.05)。DC-IL-12细胞诱导的CTL及其上清液对前列腺癌PC-3m细胞均有显著杀伤作用,杀伤率显著高于未转染组,分别为(76.43±6.20)%vs(42.12±2.80)%和(66.38±7.56)%vs(14.23±5.42)%(P<0.05),对膀胱癌细胞EJ无明显杀伤作用。结论IL-12基因修饰增强PC-3m细胞抗原致敏DC体外诱导同源T淋巴细胞产生特异性的抗前列腺癌免疫效能,其机制与IL-12基因转染DC后促进分泌IL-12、IFN-r及增强T淋巴细胞活化状态密切相关。     

CpG ODN加强树突状细胞疫苗抗Lewis肺癌的研究

目的　探讨CpGODN对树突状细胞 (DC)疫苗抗肿瘤作用的影响。方法　应用ODN182 6作为DC的成熟刺激信号 ,体外控制DC充分成熟 ,以混合或融合的方式将肿瘤抗原负载于DC制备DC疫苗。以特异性杀伤细胞活性和淋巴细胞增殖反应测定疫苗的体外免疫活性 ,并将疫苗经小鼠腹腔注射 ,观察治疗和预防实验肿瘤的生长情况。结果　经ODN 182 6刺激后的DC细胞形态呈成熟状态 ,流式细胞仪分析检测刺激前后DC细胞表面分子CD4 0的表达分别为 11和 2 4 (MFI) ,CD86的表达分别为 33和 75 (MFI) ,刺激后的DC培养上清中IL 12的分泌水平为刺激前的 10倍。刺激后DC融合疫苗组CTL活性、T淋巴细胞增殖活性及体内Lewis肺癌移植瘤的抑瘤率均明显高于未刺激的DC融合组 (P <0 .0 5 )。结论　CpGODN能通过诱导DC成熟 ,增强DC疫苗的抗肿瘤作用 ,有效诱导机体产生特异的抗肿瘤反应。未成熟的DC可通过与肿瘤细胞混合的方式 ,获得较好的抗原捕获效果 ,产生一定的抗肿瘤效应 ,而对于刺激成熟的DC则需通过融合手段负载抗原 ,达到有效的抗肿瘤活性。     

Targeting the immunoregulator SRA/CD204 potentiates specific dendritic cell vaccine-induced T-cell response and antitumor immunity

Although dendritic cell (DC) vaccines offer promise as cancer immunotherapy, further improvements are needed to amplify their clinical therapeutic efficacy. The pattern recognition scavenger receptor SRA/CD204 attenuates the ability of DCs to activate CD8(+) T-cell responses. Therefore, we examined the impact of SRA/CD204 on antitumor responses generated by DC vaccines and we also evaluated the feasibility of enhancing DC vaccine potency by SRA/CD204 blockade. DCs from SRA/CD204-deficient mice were more immunogenic in generating antitumor responses to B16 melanoma, compared with DCs from wild-type mice. Similarly, siRNA-mediated knockdown of SRA/CD204 by lentiviral vectors improved the ability of wild-type DCs to stimulate the expansion and activation of CD8(+) T cells specific for idealized or established melanoma antigens in mice. Using SRA/CD204-silenced DCs to generate antigen-targeted vaccines, we documented a marked increase in the level of antitumor immunity achieved against established B16 tumors and metastases. This increase was associated with enhanced activation of antigen specific CTLs, greater tumor infiltration by CD8(+) T cells and NK cells, and increased intratumoral ratios of both CD4(+) and CD8(+) T-effector cells to CD4(+)CD25(+) T-regulatory cells. Our studies establish that downregulating SRA/CD204 strongly enhances DC-mediated antitumor immunity. In addition, they provide a rationale to enhance DC vaccine potency through SRA/CD204-targeting approaches that can improve clinical outcomes in cancer treatment.     

抑制SOCS1联合OK-432刺激的DC疫苗抗肿瘤效应的初步研究

BACKGROUND & OBJECTIVE: Suppressor of cytokine signaling 1 (SOCS1) plays a critical role in antitumor immunity. Down-regulating SOCS1 in antigen-presenting dendritic cells (DCs) could enhance antigen-specific antitumor immunity. This study was to investigate the antigen-specific antitumor effect and mechanism of DCs with siRNA-mediated inhibition of SOCS1, stimulated by OK-432 and pulsed with hepatocellular carcinoma cell line HepG2 antigens. METHODS: The expression of SOCS1 in immature DCs was down-regulated by RNA interference (RNAi). DCs were pulsed with lysate of HepG2 cells and stimulated with OK-432. The morphology of DCs was observed under converted phase microscopy. Phenotypic changes in cells after stimulation were characterized by flow cytometry (FCM). The Alamar Blue assay was adopted to evaluate the activation and proliferation of autologous lymphocytes induced by mature DCs. The cytotoxicity of cytotoxic T lymphocytes (CTLs) elicited by modified DCs to HepG2, EC109 and K562 cells was tested by the lactate dehydrogenase (LDH) assay. RESULTS: Cells displaying a typical morphology and phenotypic properties of mature DCs were obtained successfully. The expression of SOCS1 in DCs was down-regulated by SOCS1 RNAi. Mature DCs showed high expressions of CD80, CD83, CD86, and HLA-DR. Pulsing of DCs with lysate of HepG2 had no influence on the phenotypic properties of DCs. Down-regulating SOCS1 expression enhanced the maturation of DCs. The modified DC tumor vaccine stimulated the proliferation of autologous lymphocytes effectively, and the proliferation rate of T cells was (110.7+/-22.2)%. After being activated by modified DCs, TCLs exerted a specific and effective killing effect on HepG2 cells, but not on EC109 and K562 cells. CONCLUSION: Mature DCs could induce antigen-specific antitumor immunity against hepatocellular carcinoma after silencing of SOCS1 by siRNA, stimulation by OK-432 and pulsing of DCs with HepG2 cell antigens.     

树突状细胞与肾癌融合细胞疫苗诱导抗肿瘤免疫

目的探讨自体树突状细胞(DC)与肾癌融合细胞疫苗诱导特异性抗肿瘤免疫应答。方法利用肿瘤细胞纯化技术,从手术切除的肾癌组织中分离出高纯度的肾癌细胞,用10%胎牛血清(FCS)的RPMI-1640进行原代培养。分离外周血单核细胞(PBMCs),在含重组人粒细胞-巨噬细胞集落刺激因子(rhGM-CSF)和白细胞介素4(rhIL-4)的培养条件下,诱导分化为DC。用细胞融合技术将DC与肾癌细胞融合制备DC与肾癌融合细胞疫苗。用流式细胞仪检测肾癌细胞、DC和融合细胞的表型;用噻唑盐(MTT)比色法检测融合细胞刺激自体T细胞的增殖能力,乳酸脱氢酶(LDH)释放的细胞毒实验检测融合细胞刺激的细胞毒性T淋巴细胞(CTLs)的杀瘤活性。结果DC高表达主要组织相融性复合体(MHC)Ⅰ类分子、MHCⅡ类分子和共刺激分子(CD86,CD80);原代肾癌细胞高表达一种高分子量的糖蛋白(MUC-1);自体DC与肾癌融合细胞疫苗同时表达肾癌细胞和DC细胞的表面抗原,并能有效刺激自体T细胞增殖,诱导产生的CTLs对自体肾癌细胞具有显著的杀伤活性。结论自体DC与肾癌融合细胞疫苗能诱导特异性抗自体肾癌细胞的免疫应答,为自体DC与肾癌融合细胞疫苗在治疗肾癌的临床应用中提供了实验依据。     

Improvement of DC vaccine with ALA-PDT induced immunogenic apoptotic cells for skin squamous cell carcinoma

Dendritic cell (DC) based vaccines have emerged as a promising immunotherapy for cancers. However, most DC vaccines so far have achieved only limited success in cancer treatment. Photodynamic therapy (PDT), an established cancer treatment strategy, can cause immunogenic apoptosis to induce an effective antitumor immune response. In this study, we developed a DC-based cancer vaccine using immunogenic apoptotic tumor cells induced by 5-aminolevulinic acid (ALA) mediated PDT. The maturation of DCs induced by PDT-treated apoptotic cells was evaluated using electron microscopy, FACS, and ELISA. The anti-tumor immunity of ALA-PDT-DC vaccine was tested with a mouse model. We observed the maturations of DCs potentiated by ALA-PDT treated tumor cells, including morphology maturation (enlargement of dendrites and increase of lysosomes), phenotypic maturation (upregulation of surface expression of MHC-II, DC80, and CD86), and functional maturation (enhanced capability to secrete IFN-γ and IL-12, and to induce T cell proliferation). Most interestingly, PDT-induced apoptotic tumor cells are more capable of potentiating maturation of DCs than PDT-treated or freeze/thaw treated necrotic tumor cells. ALA-PDT-DC vaccine mediated by apoptotic cells provided protection against tumors in mice, far stronger than that of DC vaccine obtained from freeze/thaw treated tumor cells. Our results indicate that immunogenic apoptotic tumor cells can be more effective in enhancing a DC-based cancer vaccine, which could improve the clinical application of PDT-DC vaccines.     

树突细胞-食管癌融合细胞体外诱导特异性抗食管癌免疫反应

背景与目的:树突细胞(dendritic cells,DC)是人体专职的抗原呈递细胞,以DC为基础的DC/肿瘤细胞融合疫苗可以有效地诱导特异性抗肿瘤免疫应答.本研究旨在探讨成熟的DC与人食管癌细胞株ECl09细胞融合疫苗体外诱导特异性抗食管癌细胞的免疫反应.方法:从健康志愿者外周血中分离出单个核细胞(peripheral blood mononuclear cells,PBMC),在重组人粒/巨噬细胞集落刺激因子(recombinant human granulocyte-macrophage-colony-stimulating factor,rhGM-CSF)和白介素(interleukin-4,IL-4)作用下体外诱导DC,采用聚乙二醇(polyethylene glyco1,PEG)融合法使DC与EC109细胞融合制备DC/EC109细胞融合疫苗,四甲基偶氮唑盐(MTT)实验检测融合疫苗刺激T淋巴细胞增殖的活性,乳酸脱氢酶(LDH)实验检测融合疫苗活化的细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)在体外特异性杀伤EC109细胞的活性,并与对人胃癌细胞株SGC7901及人乳腺癌细胞株MCF7的杀伤作用进行比较.结果:DC与EC109细胞的融合效率最高达到22.25%.DC/EC109细胞融合疫苗能有效地刺激T淋巴细胞的增殖反应,其刺激T淋巴细胞增殖的能力显著高于DC或EC109细胞(P＜0.05).DC/EC109细胞融合疫苗活化的CTL对EC109细胞具有特异性的杀伤作用,对EC109细胞的杀伤作用显著强于对SGC7901细胞及MCF7细胞的杀伤作用(P＜0.05).结论:DC/EC109细胞融合疫苗能有效诱导抗EC109细胞的特异性免疫应答.     

The first 1000 dendritic cell vaccinees

Dendritic cells (DCs) are potent antigen-presenting cells that have the ability to stimulate primary T cell antitumor immune responses in animals and humans. Since the first published clinical trial of dendritic cell vaccination in 1995, 98 studies describing more than 1000 vaccinees have been published in peer-reviewed medical journals or presented at the annual meetings of the American Society for Clinical Oncology, the American Association of Cancer Research, or the American Society of Hematology. Trials have been performed in 15 countries. Trials included patients with more than two dozen tumor types; most trials studied patients with malignant melanoma, prostate cancer, colorectal carcinoma, or multiple myeloma, using autologous DCs pulsed with synthetic antigens or idiotype antibodies. The DC vaccines were also prepared by pulsing DCs with tumor lysates or RNA, by transfection with tumor DNA, or by creating tumor cell/DC fusions. Various approaches to vaccine cell numbers, length of vaccine program, site of vaccination, frozen preservation of vaccine, and use of a maturation step for DCs were used. Adverse effects associated with DC vaccination were uncommon; most were mild and self-limited and none were serious. Clinical responses were observed in approximately half the trials. The DC vaccination may provide a safe approach to cancer immunotherapy that can overcome the limited reach and immunogenicity of peptide vaccines.     

冻融人树突状细胞基因疫苗体外抗肿瘤免疫效应

目的：观察人外周血和人脐血来源的冻融树突状细胞（dendritic cell,DC）基因疫苗的形态、表型及体外诱导的CTL抗肿瘤活性。方法：细胞因子扩增人外周血和脐血DC,分别将EBV-LMP2、HPV16E6基因转染2种来源的冻融DC制备疫苗。动态形态学观察和流式细胞术检测疫苗表面分子表达,体外诱导并测定CTL活性。结果：人外周血和脐血冻融DC疫苗均高表达CD80、CD86和CD83,低表达CD14,高表达CD1a,体外均能诱导高效的CTL活性（P=0.001）,并与新鲜DC疫苗差异无统计学意义,P=0.138。结论：负载肿瘤相关病毒抗原基因的冻融DC疫苗保持了功能成熟DC的形态特征,且能诱导高效的特异性抗肿瘤免疫应答。     

Allogeneic mRNA-based electrotransfection of autologous dendritic cells and specific antitumor effects against osteosarcoma in rats

Vaccination with dendritic cells (DCs) transfected with tumor-derived mRNA antigen has emerged as a promising strategy for generating protective immunity in mammals. However, the integration of allogeneic osteosarcoma mRNA and autologous DCs has not been fully examined. This study was designed to investigate the antitumor effects of tumor vaccine produced by autologous DCs transfected of allogeneic osteosarcoma mRNA through electroporation in tumor-bearing rats model. In the present study, extraction of Wistar rat tumor mRNA was performed as a two-step procedure. First, total RNA was extracted by use of Trizol; then, mRNA purification was performed by use of polyT-coated magnetic beads. Then, we transfected the allogeneic-derived tumor mRNA to Sprague?CDawley (SD) rat bone marrow-derived DCs through electroporation. The tumor vaccine was applied to tumor-bearing rats model, and the specific antitumor effects of the tumor vaccine were observed. The immunization using autologous DCs electrotransfected with allogeneic osteosarcoma total RNA induced specific CTL responses, which were statistically significant (P?<?0.05), and the cytotoxic activity was confirmed in cold target inhibition assays and using mAbs blocking MHC class I molecules. In in vivo experiments, 70?% of the rats immunized with allogeneic osteosarcoma RNA transfected to DCs were typically able to reject tumor challenge and remained tumor-free. Vaccinated survivors developed long immunological memory and were able to reject a subsequent rechallenge with the same tumor cells but not a syngeneic unrelated tumor line. In the present study, we demonstrated that allogeneic tumor mRNA isolated from rat osteosarcoma cell line could be applied to produce tumor vaccine inducing specific antitumor effects, especially in DC-based immunotherapy strategy. This study also provides the foundations for an effective and broadly applicable treatment to a wide range of cancer indications for which tumor-associated antigens have not been identified.