双胰腺癌相关抗原RNA转染树突细胞诱导特异性抗癌免疫反应的实验研究

目的研究人胰腺癌MUC4与Survivin mRNA联合转染树突细胞(DC)诱导的特异性抗肿瘤免疫反应,为构建负载多抗原表位DC疫苗治疗胰腺癌提供实验依据。方法自胰腺癌患者外周血单核细胞中分离、培养DCs。使用体外转录和胰腺癌PCR技术扩增MUC4和Survivin mRNA后用电穿孔法将其联合转染DC。采用Western blot技术检测DCs中MUC4和Survivin的表达。用四甲基偶氮唑盐(MTT)法检测转染前后DCs存活率变化;使用IFN-γ酶联免疫法检测MUC4 mRNA与Survivin mRNA联合转染后DC诱导的细胞毒性T淋巴细胞(CTL)的活化反应。采用51Cr标准细胞毒实验检测转染MUC4和Survivin mRNA后DCs诱导的特异性CTL对体外胰腺癌细胞的杀伤作用。结果 MUC4与Survivin mRNA联合转染后72 h DCs中两者的相对表达量低于其分别转染。顺序转染后96 h DCs存活率降至50.2%,低于MUC4 mRNA与Survivin mRNA分别转染时DC 80%的存活率(P0.05)。MUC4和Survivin mRNA联合转染DC诱导的特异性CTL 24 h IFN-γ释放量达(33.84±3.51)U/mL,高于MUC4与Survivin mRNA分别转染DC诱导的CTL IFN-γ释放水平[(21.87±4.12)U/mL和(16.61±2.09)U/mL,P0.05]。DCs经MUC4 mRNA与Survivin mRNA联合转染后,可有效诱导HLA-A2+/MUC4+/Survivin+特异性CTL免疫反应,对体外培养的胰腺癌细胞具有显著的杀伤作用。结论 MUC4与Survivin mRNA联合转染的DCs可较单胰腺癌相关抗原负载DCs诱导出更加显著的特异性CTL抗肿瘤免疫。     

两种不同抗原致敏方式负载DC疫苗对Lovo细胞的体外杀伤作用

目的比较重组痘苗病毒负载人癌胚抗原（CEA）基因转染方式与Lovo细胞裂解物诱导方式对产生DC疫苗的影响。方法分别采用重组痘苗病毒负载CEA基因转染方式及Lovo肿瘤细胞裂解物转染方式转染未成熟DC,诱导特异性细胞毒性T淋巴细胞（CTL）。体外培养CTL并检测其活性;MTT法检测两组CTL对kovo细胞的杀伤作用。结果两种方式致敏DC均可诱导激活CTL并分泌INF-γ,而重组痘苗病毒转染Dc组CTL诱导率高于细胞裂解物组;重组痘苗病毒转染组诱导的CTL对Lovo细胞的特异性杀伤活性显著高于细胞裂解物组。结论两种不同抗原致敏方式负载DC疫苗均能够诱导高效而特异的CTL杀瘤活性,而使用重组痘苗病毒转染CEA至DCs的方式明显优于肿瘤细胞裂解物的抗原负载方式,为DC疫苗用于结肠癌的免疫治疗奠定基础。     

DC与CIK或LAK联合对结肠癌细胞株SW480杀伤作用的研究

[目的]研究树突状细胞(DC)联合细胞因子诱导或未诱导的杀伤细胞(CIK)或淋巴因子激活的杀伤细胞(LAK)对结肠癌细胞株SW480的杀伤活性.提供DC联合CIK或LAK治疗结肠癌的实验依据.[方法]取人外周血分离出单个核细胞(PBMNC),诱导生成DC、CIK、LAK细胞;流式细胞仪检测DC经SW480肿瘤抗原冲击后的表型变化;以CIK+DC细胞、CIK细胞、LAK+DC细胞及LAK细胞作为效应细胞,SW480为靶细胞,以15∶1、30∶1、45∶1为效靶比,LDH释放法测定细胞杀伤试验活性;ELISA检测杀伤试验中干扰素γ(IFN-γ)、白细胞介素2(IL-2)、IL-12、IL-17的分泌水平.[结果]流式细胞仪检测DC经SW480肿瘤抗原冲击后,其表面分子HLA-DR、CD40、CD80和CD86表达分别平均为90.23％、73.68％、85.96％、57.55％,与未经肿瘤抗原冲击DC比较,DC成熟的表面标志分子表达明显增加(P＜0.01).相同效靶比下,CIK+DC细胞组对SW480的杀伤作用最强,明显高于其他细胞组(P＜0.01);CIK+ DC细胞组在效靶比为45∶1时,杀伤活性最强(P＜0.01);单独CIK细胞组的杀伤活性明显高于LAK+DC细胞组(P＜0.01);LAK+ DC细胞组的杀伤活性明显高于单独LAK细胞组(P＜0.01).效靶比为45∶1时,各杀伤试验细胞组上清液中IFN-γ、IL-2、IL-12、IL-17的分泌量,CIK+DC细胞组的IFN-γ、IL-12的分泌量显著高于其他细胞组(P＜0.05);LAK+DC、单独LAK细胞组IL-2的分泌量明显高于CIK+DC、单独CIK细胞组(P＜0.05);单独CIK细胞组IFN-γ的分泌量明显高于LAK+DC、单独LAK细胞组(P＜0.05).[结论]CIK+DC细胞组对SW480的杀伤活性明显强于单独CIK、LAK+ DC组、单独LAK细胞组.其机制可能是,SW480抗原致敏的DC分泌IFN-γ、IL-12等刺激、诱导CIK细胞的活化和增殖,明显增强CIK细胞杀伤SW480的活性.     

胰腺癌细胞总RNA转染树突细胞与胰腺癌-树突融合细胞激发特异性细胞毒T淋巴细胞能力的比较研究

目的比较人胰腺癌MiaPaCa-2细胞总RNA电转染树突细胞(Dendritic Cell,DC)与DCMiaPaCa-2融合细胞体外激发抗原特异性细胞毒T淋巴细胞(Cytotoxic T Lymphocyte,CTL)能力的差异。方法自6例胰腺癌患者外周血单核细胞中分离、培养DC。使用电穿孔法将MiaPaCa-2细胞总RNA转染DC,使用细胞融合方法将胰腺癌MiaPaCa-2细胞抗原负载DC,以未负载抗原的DC为对照。使用流式细胞术(FCM)检测PE-MUC/FITC-CD86抗体双标细胞评估融合效率;四甲基偶氮唑盐(MTT)检测转染各组DC存活率;混合细胞培养法评价各组DC体外刺激自体T淋巴细胞增殖能力;ELISA法检测各组DC体外激发抗原特异性CTL因子释放量。结果采用PEG-DMSO诱导的DC与MiaPaCa-2的融合细胞同时表达DC表型和MUC1分子,CD86与MUC1双阳性表达率为(42.3±7.30)%;融合细胞组DC存活率呈时间依赖性下降,转染后96h的存活率降低至62.81%,而MiaPaCa-2总RNA转染组DC细胞存活率稳定在85%左右,两组间差异有统计学意义(P0.05);转染MiaPaCa-2总RNA DC刺激自体T细胞增殖指数(DC:T=1:10)为8432±611.25,显著高于DC-MiaPaCa-2融合细胞(DC:T=1:10)5672±107.51(P0.05);且MiaPaCa-2总RNA转染DC激发特异性CTL分泌IL-12p70、IL-10和IFN-γ细胞水平亦显著异于DC-MiaPaCa-2融合细胞(P0.05)。结论胰腺癌细胞总RNA转染DC较胰腺癌-树突融合细胞有更强的体外抗原特异性CTL激发能力。     

胃腺癌BGC-823细胞总RNA转染人树突状细胞分泌exosomes的抗肿瘤效应研究

目的研究人外周血树突状细胞（DC）体外经人胃腺癌BGC-823细胞系总RNA转染后,提取培养上清液中DC分泌的外泌体（exosomes）,诱导出特异性抗胃癌效应。方法分离外周血单核细胞,经GM-CSF、IL-4培养5d后,获得未成熟DC（imDC）;体外以脂质体转染BGC-823细胞总RNA。第7天收集上清,利用超速离心法提取exosomes。分别将DC以及exosomes与T淋巴细胞共培养3d,获得细胞毒T淋巴细胞（CTL）,检测CTL对BGC-823细胞的杀伤作用。结果与未转染组相比,转染BGC-823总RNADC来源的exosomes明显促进T细胞对BGC-823的杀伤活性（P〈0．05）。结论应用BGC-823总RNA转染DC分泌exosomes能够诱导出强烈的抗肿瘤免疫反应。     

胰腺癌细胞总RNA转染树突细胞诱导特异性CTL能力的体外研究

目的观察人胰腺癌Mia Pa Ca-2细胞总RNA电转染树突细胞(Dendritic Cell,DC)体外激发抗原特异性细胞毒T淋巴细胞(Cytotoxic T Lymphocyte,CTL)的能力。方法自6例胰腺癌患者外周血单核细胞中分离、培养DC。使用电穿孔法将Mia Pa Ca-2细胞总RNA体外转录和PCR扩增的MUC1m RNA转染DC,以未负载抗原的DC为对照。采用实时定量PCR技术检测各组DC中MUC1表达。四甲基偶氮唑盐(MTT)检测转染各组DC存活率变化;混合细胞培养法评价各组DC体外刺激自体T淋巴细胞增殖能力;ELISA法检测各组DC体外激发抗原特异性CTL细胞因子释放量。结果 Mia Pa Ca-2总RNA与MUC1 m RNA分别转染后48 h DC中目标抗原的相对表达量分别为37.24±3.17和34.53±2.02,两者比较无显著差异(P0.05)。电转染后96 h Mia Pa Ca-2总RNA转染组DC存活率降至60.81%,低于MUC1 m RNA单转染时DC的存活率(80%左右)(P0.05)。转染Mia Pa Ca-2总RNA DC刺激自体T细胞增殖指数为8 432±611.25,显著高于MUC1单独转染组3 664±305.17(P0.05);且转染Mia Pa Ca-2总RNA DC激发特异性CTL分泌IL-2、IL-10、Granzyme B、IFN-γ水平亦显著高于MUC1 m RNA单独转染组(P0.05)。结论胰腺癌肿瘤细胞总RNA转染的DC较单一胰腺癌相关抗原负载DC有更强的体外抗原特异性CTL激发能力。     

白介素-21对细胞毒T淋巴细胞杀伤非霍奇金淋巴瘤的影响

目的 研究白介素-21( IL-21)增强细胞毒T淋巴细胞(CTL)杀伤非霍奇金淋巴瘤(NHL)的作用机制.方法 以NHL细胞株(Raji)冲击树突细胞(DCs),诱导产生CTL;将培养原液随机分为两组,实验组加入100 ng/ml的IL-21,同时设空白对照组.以ELISA、RT-PCR检测干扰素(IFN)-γ和肿瘤坏死因子( TNF)-α水平.结果 实验组IFN-γ与TNF-α水平分别为(469.32±2.83) pg/ml、( 82.52±4.72) pg/ml;对照组IFN-γ与TNF-α水平分别为(27.63±2.76)pg/ml、(11.63±1.54) pg/ml,两组对比有显著差异(P＜0.05).结论 IL-21可以促进IFN-γ与TNF-α的分泌,从而增强CTL杀伤NHL的作用.     

胰腺癌MUC1 mRNA转染树突细胞疫苗诱导特异性抗肿瘤的免疫反应

目的 研究人胰腺癌MUC1 mRNA转染树突细胞(DC)诱导的特异性抗肿瘤免疫反应,为DC疫苗治疗胰腺癌提供实验依据.方法 从外周血中分离单核细胞(PBMC)并培养成DC,从细胞形态和表面标志进行鉴定.通过RT-PCR扩增胰腺癌MiaPaCa-2细胞的MUC1 mRNA后用电穿孔法将其转染DC.采用实时定量PCR和蛋白质印迹法检测培养不同时间点DC的MUC1的表达.用四甲基偶氮唑蓝法检测DC存活率.采用51Cr标准细胞毒实验观察转染MUC1 mRNA的DC诱导的特异性细胞毒性T淋巴细胞(CTL)反应;应用ELASA法检测CTL的IFN-γ释放量.结果 培养获得的细胞呈现典型的DC形态特征和表面标志(CD40+、HLA-DR+、CD83+、CD86+).MUC1 mRNA转染DC48 h后,细胞MUC1 mRNA表达水平最高,为38.43(36.89 ～48.06),蛋白表达亦最强.转染后DC的存活率稳定在80％左右.转染MUC1 mRNA的DC可有效诱导HLA-A2 +/MUC+特异性CTL免疫反应;胰腺癌Capan-2细胞与转染MUC1的DC刺激MUC1特异性CTL的24 h IFN-γ释放量分别为(28.44±4.96)和(16.31 ±2.54) U/ml,差异具有统计学意义(P＜0.05).结论 人胰腺癌MUC1 mRNA体外转染DC后可诱导CTL产生特异性抗肿瘤免疫反应.     

转染T-bet鼻咽癌细胞肿瘤疫苗的体外抗肿瘤效应中干扰素-γ的表达

目的研究转染T-bet鼻咽癌细胞肿瘤疫苗的体外抗肿瘤效果。方法构建转染T-bet鼻咽癌细胞肿瘤疫苗,体外培养鼻咽癌患者的外周血淋巴细胞,用肿瘤疫苗刺激后ELISA检测上清中细胞因子干扰素(IFN)-γ的分泌量。结果淋巴细胞+TCV-T-bet组细胞因IFN-γ的含量24 h、48 h、72 h与淋巴细胞+培养液组及淋巴细胞+TCV-CNE-2组相比差异显著(P0.01)。结论表达T-bet基因的人鼻咽癌细胞CNE-2肿瘤疫苗在体外能够诱导有效的抗肿瘤免疫反应。     

凋亡U937细胞负载的树突细胞介导的免疫应答

目的:探讨凋亡U937细胞负载的树突细胞(DC)能否介导抗白血病免疫应答。方法:用紫外线辐照诱导U937细胞凋亡。从正常人外周血单个核细胞诱生DC,用凋亡的U937细胞负载DC并添加肿瘤坏死因子-α(TNF-α)诱导DC成熟,然后与自体T淋巴细胞共育,并联合白细胞介素(IL)-2以诱生肿瘤特异性细胞毒T淋巴细胞(CTL)。采用免疫荧光标记和流式细胞术测定DC膜分子的表达;Dextran-FITC内吞试验检测DC的抗原摄取能力;用ELISA法检测IL-12p70的产生;采用MTT法分别检测CTL的增殖和细胞毒效应。结果:U937细胞经紫外线辐照后培养2h,凋亡指数明显增高,并于照射后4～8h时达高峰(56.61%～66.96%)。DC在未成熟阶段时吞噬Dextran-FITC的能力最强,负载凋亡U937细胞之后并不能促使未成熟DC(i DC)分化为成熟DC(mDC)。凋亡U937细胞负载后的i DC在TNF-α的作用下成为mDC后其分泌IL-12p70显著增加的同时可显著诱导T细胞增殖生成对U937细胞具有特异杀伤作用的CTL。结论:凋亡细胞负载的DC能有效地诱导抗白血病效应。     

Glucose-responsive insulin-producing cells from stem cells

Recent success with immunosuppression following islet cell transplantation offers hope that a cell transplantation treatment for type 1 (juvenile) diabetes may be possible if sufficient quantities of safe and effective cells can be produced. For the treatment of type 1 diabetes, the two therapeutically essential functions are the ability to monitor blood glucose levels and the production of corresponding and sufficient levels of mature insulin to maintain glycemic control. Stem cells can replicate themselves and produce cells that take on more specialized functions. If a source of stem cells capable of yielding glucose-responsive insulin-producing (GRIP) cells can be identified, then transplantation-based treatment for type 1 diabetes may become widely available. Currently, stem cells from embryonic and adult sources are being investigated for their ability to proliferate and differentiate into cells with GRIP function. Human embryonic pluripotent stem cells, commonly referred to as embryonic stem (ES) cells and embryonic germ (EG) cells, have received significant attention owing to their broad capacity to differentiate and ability to proliferate well in culture. Their application to diabetes research is of particular promise, as it has been demonstrated that mouse ES cells are capable of producing cells able to normalize glucose levels of diabetic mice, and human ES cells can differentiate into cells capable of insulin production. Cells with GRIP function have also been derived from stem cells residing in adult organisms, here referred to as endogenous stem cell sources. Independent of source, stem cells capable of producing cells with GRIP function may provide a widely available cell transplantation treatment for type 1 diabetes.     

Insulin expressing cells from differentiated embryonic stem cells are not beta cells

Aim/hypothesis Embryonic stem (ES) cells have been proposed as a potential source of tissue for transplantation for the treatment of Type 1 diabetes. However, studies showing differentiation of beta cells from ES cells are controversial. The aim of this study was to characterise the insulin-expressing cells differentiated in vitro from ES cells and to assess their suitability for the treatment of diabetes.Methods ES cell-derived insulin-expressing cells were characterised by means of immunocytochemistry, RT-PCR and functional analyses. Activation of the Insulin I promoter during ES-cell differentiation was assessed in ES-cell lines transfected with a reporter gene. ES cell-derived cultures were transplanted into STZ-treated SCID-beige mice and blood glucose concentrations of diabetic mice were monitored for 3 weeks.Results Insulin-stained cells differentiated from ES cells were devoid of typical beta-cell granules, rarely showed immunoreactivity for C-peptide and were mostly apoptotic. The main producers of proinsulin/insulin in these cultures were neurons and neuronal precursors and a reporter gene under the control of the insulin I promoter was activated in cells with a neuronal phenotype. Insulin was released into the incubation medium but the secretion was not glucose-dependent. When the cultures were transplanted in diabetic mice they formed teratomas and did not reverse the hyperglycaemic state.Conclusions/Interpretation Our studies show that insulin-positive cells in vitro-differentiated from ES cells are not beta cells and suggest that alternative protocols, based on enrichment of ES cell-derived cultures with cells of the endodermal lineage, should be developed to generate true beta cells for the treatment of diabetes.Abbreviations ES Embryonic stem - LIF leukemia inhibitory factor - ITSF insulin-transferrin-selenite-fibronectin.Bleackley and Korbutt laboratories contributed equally to this paper     

Dendritic cells: specialized antigen presenting cells

Renewing interest in cancer immunotherapy reflects the excellent results that have been obtained in animal models and the promising results in early clinical trails with dendritic cell (DC) based approaches. The central role that DCs play in the initiation of an immune response raises the possibility of using them to trigger specific anti-tumor immunity. In addition, deeper knowledge of DC biology will allow better understanding of the mechanism(s) underlying allergic and autoimmune diseases as well as tolerance phenomena. These crucial issues were critically reviewed during a workshop organized by the Italian Society for Experimental Hematology in Florence, Italy, on March 18th, 1999. The chairmen have prepared this report for the readers of Haematologica.     

树突状细胞联合细胞因子诱导的杀伤细胞对胃癌细胞杀伤作用

目的探讨树突状细胞联合细胞因子诱导的杀伤细胞对胃癌细胞的杀伤作用。方法采用胃癌患者自身血液中单个核细胞(peripheral blood mononuclear cells,PBMC),经体外诱导分别扩增出DC和CIK细胞,二者共同培养后,利用MTT法检测DC细胞联合CIK细胞体外杀伤人胃癌细胞株(MNK-45、MNK-28、SG-7901)的活性。结果DC与CIK细胞共培养后得到的细胞群高表达CD3 CD56 ,平均值达到(56.74±7.63)%。通过彼此相互作用诱导出的细胞群体对胃癌细胞株MNK-45、MNK-28、SG-7901有杀伤作用,且杀伤活性随着效靶比的增加而增强。结论DC与CIK细胞共培养后有很强的增殖能力,对胃癌细胞具有杀伤活性,且其杀伤作用与胃癌细胞类型无相关性。