冻融抗原负载树突状细胞诱导细胞毒性T淋巴细胞特异性杀伤急性白血病细胞的实验研究

我们应用基因重组人白介素 4 (rhIL 4 ) ,基因重组人粒 /单细胞集落刺激因子 (rhGM CSF)联合培养体系自健康志愿者骨髓单个核细胞诱导产生DC ,使其负载急性髓系白血病 (AML)细胞冻融抗原 ,体外诱导细胞毒性T细胞 (CTL) ,观察负载AML细胞冻融抗原后DC的状态对所激发的T淋巴细胞表型及功能的影响及CTL对AML细胞特异性杀伤活性。我们发现负载AML冻融抗原后DC的CD1a、CD83、CD86、CD11C、HLA DR表达率为较培养前明显增高 (P <0 .0 1) ,且负载AML冻融抗原的DC诱导的CTL中CD3 CD8 T细胞比例 ,较诱导前明显增高 (P <0 .0 1) ,而负载AML细胞冻融抗原的DC诱导CTL对AML细胞有较强的杀伤作用 ,明显强于加或不加IL 2培养的T细胞对照组 (P <0 .0 1) ,而对K5 6 2细胞无明显的杀伤活性。通过以上实验我们认为经rhGM CSF ,rhIL 4培养产生的DC为CD14CD1a DC ,能诱导CTL对AML细胞产生明显的特异性杀伤作用 ,另外 ,负载AML细胞冻融抗原DC诱导的CTL中CD3 CD8 T细胞比例明显增高 ,提示CD8 T细胞在抗肿瘤免疫中具有极其重要的作用。     

肿瘤细胞冻融裂解物上清对凋亡细胞负载的树突状细胞生物学特性的作用研究

目的:探讨Balb/c小鼠骨髓瘤SP2/0细胞冻融裂解物上清对SP2/0凋亡细胞负载的骨髓来源的树突状细胞(DC)的成熟、生物学特性及功能的影响。方法: 采用小鼠重组粒细胞-巨噬细胞集落刺激因子(GM-CSF)和白介素4(IL-4)诱导骨髓来源的DC, 100Gyγ射线辐照诱导SP2/0细胞凋亡, 与未成熟DC共育16-20h;SP2/0细胞冻融裂解物上清和脂多糖(LPS)分别作用于DC48h。采用免疫荧光标记和流式细胞术分析DC表型;[³H]-TdR掺入试验和[⁵¹Cr]释放试验测定DC刺激T细胞增殖和细胞杀伤效应。采用腹股沟皮下DC主动免疫治疗SP2/0荷瘤小鼠, 每间隔14d治疗1次, 共3个疗程, 观察肿瘤生长情况及小鼠生存期。结果:(1)经SP2/0冻融裂解物上清和脂多糖(LPS)诱导凋亡肿瘤细胞负载的DC高表达共刺激分子CD40、CD80、CD86和MHC-Ⅱ分子, 但抗原摄取能力均下降;(2)SP2/0冻融裂解物上清组和LPS组DC体外刺激T细胞增殖和激活CTL能力均高于对照组(P＜0.05);(3)经SP2/0冻融裂解物上清组主动免疫治疗小鼠存活期长于其它各组(P＜0.05)。结论:小鼠SP2/0细胞冻融裂解物上清可诱导凋亡细胞负载的树突状细胞成熟, 能够刺激T细胞增殖和激发肿瘤特异性细胞毒性T淋巴细胞(CTL), 主动免疫治疗可激发荷瘤小鼠体内有效的肿瘤特异性免疫力, 延长荷瘤小鼠生存期。     

树突状细胞体外诱导抗肿瘤血管内皮细胞特异性免疫的研究

目的:探讨肿瘤内皮细胞抗原负载的树突状细胞(DC)诱导的细胞毒性T淋巴细胞(CTL)的特异性杀伤效应。方法:采用肿瘤细胞的培养上清诱导人脐静脉血管内皮细胞(HUVEC)增殖,制备肿瘤血管衍生的内皮细胞(TdEC)。用RTPCR检测肿瘤内皮标志物(TEM)的表达。制备TdEC的冻融抗原,负载从外周血中扩增的DC,用MTS比色法检测DC刺激自体淋巴细胞增殖的效应;用LDH法检测DC诱导的CTL的特异性杀伤效应。结果:TdEC可表达TEM1和TEM8。负载TdEC抗原的DC,可显著刺激自体淋巴细胞增殖。由其诱导的CTL对TdEC具有特异性的杀伤作用。在效靶比为20∶1和10∶1时,杀伤率分别为33%和27%,高于对照组的14%和10%。结论:TdEC抗原负载的DC,在体外可有效地诱导CTL产生,并特异性地杀伤TdEC。     

卵巢癌细胞株冻融抗原负载的树突状细胞诱导CTL抗卵巢癌免疫应答的体外研究

目的研究卵巢癌冻融抗原负载的树突状细胞(dendriticcells,DC)诱导细胞毒性T淋巴细胞(CTL)体外杀伤卵巢癌细胞的细胞毒性效应。方法利用免疫磁珠分离法(MACS)分离纯化脐血CD34 细胞并在体外诱导分化为DC,用反复冻融法从卵巢癌细胞系SKOV3中提取的可溶性相关抗原负载DC。流式细胞学检测负载抗原后DC表面各种分化相关抗原的表达,ELISA法检测DC上清中IL12的表达,混合淋巴细胞反应(MLR)测定DC体外刺激T细胞增殖的能力,MTT法检测抗原负载DC激活的抗原特异性CTL对卵巢癌细胞的杀伤作用。结果与未经抗原负载的DC相比,经卵巢癌抗原负载的DC不仅能更高地表达各种DC分化相关抗原CD1α(73.35%±2.94%vs34.1%±2.35%)、CD83(73.9%±8.46%vs54.68%±3.26%)、CD80(91.95%±2.48%vs52.53%±3.18%)、HLADR(70.05%±2.35%vs48.7%±2.07%)以及CD54(88.9%±5.52%vs71.45%±2.29%),同时具有更强的刺激同种异体T淋巴细胞增殖和IL12分泌的能力(P均<0.05)。此外,卵巢癌细胞SKOV3冻融抗原负载DC激活的CTL在体外对SKOV3的杀伤率为77.35%,显著高于未经抗原负载的DC(P=0.0001)。结论经卵巢癌细胞冻融抗原负载DC激活的CTL在体外具有更强的增殖能力和杀伤卵巢癌细胞的作用。     

乳腺癌患者腋下淋巴结来源的DC诱导自体特异性CTL的实验研究

目的:研究乳腺癌患者腋下淋巴结单个核细胞来源的树突状细胞(DC)诱导抗原特异性细胞毒T淋巴细胞(CTL)的能力。方法:以多种细胞因子联合诱导腋下淋巴结单个核细胞中的贴壁细胞为DC,非贴壁细胞与IL-2共培养后诱导成为肿瘤区域引流淋巴结细胞(TDLNC),用自体乳腺癌细胞冻融抗原刺激DC,并和TDLNC共培养,以诱导肿瘤抗原特异性CTL。结果:淋巴结细胞经体外培养后,贴壁细胞在DC诱导前,其特异性表面标志物CD1a、CD83、CD86的百分比(%)分别为11.0±2.4、26.6±5.2和33.0±6.1,经与rhGM-CSF、rhIL-4共同培养,并经自体肿瘤冻融抗原加TNF-α诱导后3种标志物的水平升高,其百分比(%)分别为50.2±5.7、60.5±16.5和56.2±16.4(P<0.01)。TDLNC中CD3 和CD8 细胞含量(%)分别为73.9±2.2和32.8±3.2;经DC和肿瘤抗原诱导后,DC-Ag-TDLNC中的CD3 和CD8 细胞含量升高,其百分比(%)分别为82.7±2.8和62.5±2.5(P<0.01)。结论:乳腺癌患者腋下引流淋巴结中的单个核细胞在rhGM-CSF和rhIL-4刺激活化和自体肿瘤抗原及TNF-α的诱导下,可以分化为典型的DC。成熟的DC具有较强的抗原提呈功能,可以促进TDLNC增殖、分化为抗原特异性CTL。     

CTL识别的HLA-A2限制性人卵巢癌相关抗原OVA66表位的鉴定

目的：鉴定CTL识别的HLA—A2限制性人卵巢癌相关抗原OVA66表位。方法：以细胞因子从外周血单个核细胞(PBMC)中诱导树突状细胞(DC)，通过形态学观察和流式细胞术进行鉴定。用表位预测法选取并合成两种肽分子，分别脉冲成熟的DC，并刺激HLA—A2^ 健康人自体CD8^ T细胞，1wk后，用脉冲肽的自体PBMC以每7d的间隔刺激该CD8^ T细胞3次。以共接受4次抗原肽刺激的T细胞作为CTL，用乳酸脱氢酶(LDH)释放试验，检测CTL对靶细胞的杀伤效应。用酶联免疫斑点法(ELISPOT)．检测CTL中抗原特异性分泌IFN-γ的T细胞数。结果：形态学和流式细胞术的结果显示．PBMC可诱生成熟的DC。肽1235(FLPDHINIV)诱导的CTL．可特异性杀伤1235脉冲的T2细胞和OVA66^ 、HLA—A2^ 的SW480细胞，且L235诱导的特异性分泌IFN-γ的T细胞数增加。结论：卵巢癌相关抗原OVA66的HLA—A2限制性CTL表位1235．能激发对肿瘤抗原的特异性免疫应答，为制备肿瘤特异性肽疫苗奠定了实验基础。     

SP2/0细胞膜抗原负载DC诱导体外特异性CTL效应

目的 研究SP2／0细胞膜抗原负载树突状细胞（DC）诱导的特异性细胞毒性T淋巴细胞（CTL）对肿瘤细胞的杀伤活性。方法 密度梯度离心法分离SP2／0细胞膜，负载经rmGM-CSF和rmIL-4诱导扩增的小鼠骨髓来源的DC，活化T淋巴细胞获得肿瘤特异性CTL，MTT法检测对SP2／0细胞的杀伤效果。结果 骨髓单个核细胞在rmGM-CSF和rmIL-4作用下获得了高表达CDS0、CD86和MHC-Ⅱ分子的DC，致敏的CTL对SP2／0骨髓瘤细胞具有高杀伤率，显著高于对I5178Y淋巴瘤细胞的杀伤活性（P〈0．01）。结论 SP2／0细胞膜抗原负载DC能诱导明显的特异性抗肿瘤免疫应答。     

WT1多肽致敏树突状细胞诱导杀伤K562细胞实验研究

目的：研究来自健康人外周血单个核细胞的树突状细胞（DC）负载WT1多肽抗原，体外诱导产生特异性细胞毒性T淋巴细胞（CTL）对K562细胞的杀伤作用。 方法： 应用重组人粒-巨噬细胞集落刺激因子(rhGM-CSF)、重组人白细胞介素4（rhIL-4）、重组人肿瘤坏死因子α（TNF-α）等细胞因子，自外周血单个核细胞诱导扩增，培养出DC，使DC负载WT1多肽抗原。实验分3组，WT1多肽致敏DC为实验组A，未致敏DC为实验组B，单纯自体淋巴细胞未加DC激活为对照组C，观察CTL对K562细胞的杀伤作用。 结果： 培养出具有典型特征的DC，体外能诱导强烈的同种异体混合淋巴细胞增殖反应。在效靶比为20∶1时，实验组A诱导的CTL对K562细胞的杀伤率为86.1%±26.8%；实验组B为47.1%±20.8%；对照组C为27.7%±15.3% (P＜0.05)。 结论： WT1多肽抗原致敏DC能促使CD8阳性淋巴细胞扩增，并诱导激活特异性CTL，对K562靶细胞具有明显的杀伤作用。     

人脐血树突状细胞分泌外来体的特性及其增强CTL杀伤活性的研究

目的探讨脐血树突状细胞(UBDC)及其分泌的亚细胞结构外来体(exosomes)的特性,以及他们对细胞毒性T细胞(CTL)杀伤活性的增强作用。方法分离脐血单个核细胞(UBMC),用rhSCF、rhGM-CSF及rhIL-4诱导12d,加入经反复冻融提取的肿瘤细胞膜抗原,继续培养2d。收集DC并从其培养上清中通过离心(1×105g)分离外来体。用流式细胞术、SDS-PAGE、透射电子显微镜(TEM)和MTT比色法,对DC和外来体的特性及其对CTL杀伤活性的增强作用进行分析。结果用3种细胞因子体外诱导UBMC12d,可使其扩增10倍,并出现DC典型的形态特征。负载肿瘤抗原后,细胞表面可高表达MHC-I、MHC-II、CD40、CD80、CD86、CD11c和CD54。利用超速离心法能从DC培养上清中分离出外来体。混合淋巴细胞反应(MLR)和CTL杀伤活性的分析表明,脐血DC分泌的外来体能有效地刺激T细胞增殖并增强CTL的杀伤活性。结论由UBMC可诱导出大量的DC并分泌外来体。后者可有效地向CTL细胞递呈肿瘤抗原使之活化并增强其杀伤活性。     

不同大鼠胶质瘤抗原致敏的DC体外诱导CTL活性的研究

目的: 比较大鼠骨髓来源的树突状细胞(dendritic cells, DC)体外经由大鼠C6胶质瘤细胞由不同方式制备的不同抗原致敏后,对特异性细胞毒性T淋巴细胞(cytotoxic T lymphocyte, CTL)的诱导作用。方法: 自大鼠骨髓分离DC前体细胞,经重组大鼠粒细胞巨噬细胞集落刺激因子(rrGM-CSF)+白细胞介素4(rrIL-4)诱导培养、扩增;由C6胶质瘤细胞经由反复冻融、煮沸灭活及超声破碎细胞抽提其总蛋白的方法制备各种不同抗原致敏DC,致敏的DC与T淋巴细胞进行共培养诱导CTL;以ELISA法检测CTL诱导过程中淋巴细胞趋化因子(lymphocyte chemoattractant factor)及细胞因子IFN-γ分泌水平:以 -TdR掺入法检测DC诱导T细胞增殖及其特异性CTL杀伤活性。 结果: 体外应用煮沸灭活瘤细胞制备的肿瘤抗原致敏DC,能诱导更强的刺激T细胞增殖的能力、并且可以诱导杀伤活性更强的CTL。结论: 应用煮沸灭活的瘤细胞制备瘤抗原负载DC获得瘤苗可获得更强的抗肿瘤保护作用。     

Generation of Potent Cytotoxic T Lymphocytes Against Castration‐Resistant Prostate Cancer Cells by Dendritic Cells Loaded With Dying Allogeneic Prostate Cancer Cells

To induce a potent cytotoxic T lymphocyte (CTL) response in dendritic cell (DC)‐based immunotherapy against prostate cancer, various tumour antigens should be loaded onto DCs. The aim of this study was to establish a method of immunotherapy for castration‐resistant prostate cancer (CRPC) using prostate cancer–specific CTLs generated in vitro by DCs. Monocyte‐derived DCs from patients with CRPC were induced to mature using a standard cytokine cocktail (in IL‐1β, TNF‐α, IL‐6 and PGE₂: standard DCs, sDCs) or using an α‐type 1‐polarized DC (αDC1) cocktail (in IL‐1β, TNF‐α, IFN‐α, IFN‐γ and polyinosinic:polycytidylic acid) and loaded with the UVB‐irradiated CRPC cell line PC‐3. Antigen‐loaded DCs were evaluated by morphological and functional assays. The αDC1s significantly increased the expression of several molecules related to DC maturation, regardless of whether the αDC1s were loaded with tumour antigens or not, compared to sDCs. The αDC1s showed a higher production of interleukin‐12 both during maturation and after subsequent stimulation with CD40L, which was not significantly affected by loading with tumour antigens, as compared to standard DCs (sDCs). Prostate cancer–specific CTLs against autologous CRPC cells were successfully induced by αDC1s loaded with dying PC‐3 cells. Autologous αDC1s loaded with an allogeneic CRPC cell line can generate greater CRPC‐specific CTL responses as compared to sDCs and may provide a novel source of DC‐based vaccines that can be used for the development of immunotherapy in patients with CRPC.     

Development of Immunogenic Tumor-Loaded Dendritic Cells Through Physical Perturbation and Apoptotic Cell Loading

To improve understanding of the forces that drive monocytes to transition into dendritic cells (), we developed an experimental system that converts monocytes to DC by passage of leukocytes through a 400 μm silica bead column. The results demonstrate that overnight culture of column-treated monocytes causes a phenotypic conversion that is characteristically displayed by immature DC. These phenotypic changes were enhanced when the DC were loaded with apoptotic cells, leading to increased expression of the DC maturation-associated markers CD83, CD80 and the chemokine receptor CCR7. The DC demonstrated potent induction of allogeneic T cell proliferation and the capacity to activate autologous CD8⁺ T cells. The CD8 T cells expressed augmented levels of perforin, IFN-γ and TNF-α and mediated CTCL cell apoptosis. These studies demonstrate that physical contact with silica beads combined with loading of apoptotic tumor cells induces synchronized, rapid conversion of human monocytes to DC, which can efficiently stimulate CD8⁺ T cells. These results may aid in the development of more efficient DC vaccines that can be loaded with the universe of antigens available in apoptotic tumor cells in a rapid, clinically practical fashion.     

In vivo depletion of DC impairs the anti‐tumor effect of agonistic anti‐CD137 mAb

Anti‐CD137 mAb are capable of inducing tumor rejection in several syngeneic murine tumor models and are undergoing clinical trials for cancer. The anti‐tumor effect involves co‐stimulation of tumor‐specific CD8⁺ T cells. Whether antigen cross‐presenting DC are required for the efficacy of anti‐CD137 mAb treatment has never been examined. Here we show that the administration of anti‐CD137 mAb eradicates EG7‐OVA tumors by a strictly CD8β⁺ T‐cell‐dependent mechanism that correlates with increased CTL activity. Ex vivo analyses to determine the identity of the draining lymph node cell type responsible for tumor antigen cross‐presentation revealed that CD11c⁺ cells, most likely DC, are the main players in this tumor model. A minute number of tumor cells, revealed by the presence of OVA cDNA, reach tumor‐draining lymph nodes. Direct antigen presentation by tumor cells themselves also participates in anti‐OVA CTL induction. Using CD11c diphtheria toxin receptor‐green fluorescent protein→C57BL/6 BM chimeric mice, which allow for sustained ablation of DC with diphtheria toxin, we confirmed the involvement of DC in tumor antigen cross‐presentation in CTL induction against OVA_257–264 epitope and in the antitumor efficacy induced by anti‐CD137 mAb.     

Effective priming of cytotoxic T lymphocyte precursors by subcutaneous administration of peptide antigens in liposomes accompanied by anti-CD40 and anti-CTLA-4 antibodies

Recently it has been shown that modulation of CD40 molecules on antigen (Ag) carrying dendritic cells (DC) can bypass T cell help, resulting in priming cytotoxic T lymphocytes (CTL) specific for the Ag. In the present study we attempted to prime peptide Ag-specific CTL by a new method in which a peptide Ag in liposome (liposomal peptide), consisting of phosphatidylserine and phosphatidylcholine (3:7), was administrated subcutaneously with anti-CD40 and/or CTLA-4 monoclonal antibodies (mAb) to mice. We found that the subcutaneous administration of the liposomal peptide with both anti-CD40 and anti-CTLA-4 mAb enhanced CTL responses comparing with those induced by the liposomal peptide alone or the liposomal peptide plus each mAb. It was shown that liposomes were critical for induction of the CTL activity. Flow cytometry analysis of a peptide-bearing DC in lymph nodes (LN) and measurement of serum IL-12 indicated that anti-CD40 mAb promoted migration of DC to the LN, where DC might differentiate and acquire ability of priming CTL. These findings provide a possibility that our procedure is applicable to cancer patients.     

Both Langerhans cells and interstitial DC cross-present melanoma antigens and efficiently activate antigen-specific CTL

Dendritic cells (DC) have a unique capacity to present external antigens to CD8(+) T cells, i.e. cross-presentation. However, it is not fully established whether the ability to cross-presentation is restricted to a unique subset of DC in humans. Here, we show that two major myeloid DC subsets, i.e. Langerhans cells (LC) and interstitial DC (Int-DC), have the ability to cross-present antigens to CD8(+) T cells in vitro. LC and Int-DC were obtained from DC generated by culturing human CD34(+)-hematopoietic progenitor cells with GM-CSF, FLT3-L, and TNF-alpha (CD34-DC). Both DC subsets were able to capture necrotic/apoptotic allogeneic melanoma cells and present antigens to CD8(+) T cells, resulting in efficient priming of naive CD8(+) T cells into CTL capable of killing melanoma cells. Strikingly, a single stimulation with either subset (LC or Int-DC) or total CD34-DC loaded with necrotic/apoptotic melanoma cells was sufficient to activate melanoma-specific memory CD8(+) T cells obtained from patients with metastatic melanoma to become effective CTL. Thus, this study provides the rationale to use CD34-DC loaded with necrotic/apoptotic allogeneic melanoma cells in a clinical trial.     

重组人CD40配体对卵巢癌SKOV3细胞生长特性的影响

目的： 观察重组人CD40配体（rhCD40L）对卵巢癌细胞株SKOV3增殖、表面抗原变化、细胞周期、凋亡相关基因及肿瘤坏死因子受体相关因子( TRAFs)的影响。 方法： 在体外将SKOV3细胞与不同浓度的rhCD40L作用72 h后MTT法测定细胞增殖；直接免疫荧光标记流式细胞术测定细胞表面抗原及TRAFs变化，RT-PCR法测定凋亡相关基因c-myc、bcl-2、bcl-xl的表达程度，并用Annexin V和PI双标记测定细胞凋亡水平。 结果： rhCD40L在100 μg/L的低剂量时即可抑制SKOV3细胞增殖（0.65±0.10 vs 0.81±0.05），其作用随着rhCD40L浓度的增加而加强，10 mg/L时抑制率达（0.13±0.12 vs 0.83±0.15，P＜0.01），呈明显的浓度相关性，并使细胞分裂阻滞于G1期；rhCD40L可上调SKOV3细胞CD95的表达（42.4% vs 59.2%, P＜0.05），下调抗凋亡基因bcl-2和bcl-xl的表达，促进其凋亡；SKOV3细胞高表达TRAF2（81.3%±9.2%）、TRAF5（47.2%±7.2%）和TRAF6（44.5%±6.3%），rhCD40L可显着下调TRAF2（50.4%±5.3%，P＜0.05）、TRAF5（7.2%±2.1%，P＜0.01）和TRAF6（5.1%±1.1%，P＜0.01）表达，而上调TRAF3（25.2%±6.2% vs 68.8%±5.3%，P＜0.01）表达，对TRAF1（4.3%±1.2% vs 5.1%±1.4%）和4（7.4%±1.2% vs 8.1%±1.4%）的表达则无作用。 结论： rhCD40L通过下调bcl-2和bcl-xl基因表达，并改变细胞内TRAFs表达，使SKOV3细胞的增殖受阻滞于G1期，并促进其凋亡。     

PD-L1和PD-L2在树突状细胞上的表达及其生物学意义

探讨小鼠髓系DC (CD8α )中PD L1和PD L2的表达及其在T淋巴细胞活化中的作用。采用mCD4 0L CHO和TNF α分别刺激凋亡肿瘤细胞负载DC 4 8h ;免疫荧光标记检测DC表型 ;RT PCR和realtime PCR检测PD L1和PD L2mRNA转录水平 ;ELISA测定IL 2的分泌水平 ;3 H TdR掺入试验和51Cr释放试验测定DC体外激发T细胞的增殖和细胞毒杀伤率。结果显示 :PD L1和PD L2随着DC的成熟呈上调表达 ,CD4 0配基化DC的PD L1和PD L2均为中度表达 ,TNF α激发的DC为高度表达 ,二者呈现差异性表达 (P <0 0 5 ) ;CD4 0配基化髓系DC分泌IL 2的量明显高于TNF α组 (P <0 0 5 ) ,体外刺激T增殖和激活CTL能力在CD4 0配基化DC组最高 (P <0 0 5 )。提示CD4 0配基化的小鼠髓系DC呈现PD L1和PD L2的中度表达 ,IL 2大量分泌 ,这些均有助于激发有效的特异性免疫应答     

RNA干扰survivin基因提高淋巴瘤细胞对阿霉素的敏感性

目的：探讨RNA 干扰下调Burkitt淋巴瘤Daudi细胞系凋亡抑制基因survivin的表达对阿霉素敏感性的影响。方法：构建survivin发夹RNA（shRNA）真核表达载体, 脂质体介导转染Daudi细胞。多重RT-PCR 检测 survivin mRNA 表达；Western blotting 检测Survivin蛋白表达；流式细胞仪（FCM）检测干扰前后细胞凋亡率；MTT 法检测干扰前后细胞对化疗药物阿霉素（adriamycin,ADR）敏感性变化。结果：与无功能control-shRNA处理组和PBS处理组比较，转染survivin-shRNA 细胞的survivin mRNA和蛋白表达率显著降低，抑制率分别为62.32% 和61.88% (P<0.05)；FCM结果示转染组细胞凋亡指数（apoptosis index, AI) 显著高于两对照组(P<0.05)； MTT结果显示，转染组细胞的阿霉素半数抑制浓度(IC50)为（0.25±0.43） μmol/L，显著低于无功能control-shRNA处理组（0.87±0.21） μmol/L和PBS处理组(0.91±0.36) μmol/L,P<0.05；相同剂量ADR对转染细胞的生长抑制率明显高于PBS组和control组。结论： 发夹RNA干扰survivin基因可显著提高Daudi细胞凋亡率和对化疗药物阿霉素的敏感性。     

激动型CD40单克隆抗体体外抑制结肠癌细胞增殖的实验研究

目的 探讨激动型CD40单克隆抗体在体外对结肠癌细胞增殖的抑制作用.方法 树突状细胞(DCs)经结肠癌冻融抗原致敏后予以不同条件激活,分为激动型CD40单克隆抗体组、阴性对照组及肿瘤坏死因子-α(TNF-α)阳性对照组,诱导培养至第7天,用流式细胞仪检测各组DCs表面分化相关抗原CD80、CD83、CD86和HLA-DR的表达,酶联免疫吸附测定法检测DCs培养液上清中白细胞介素-12(IL-12)的质量浓度,噻唑蓝比色法检测DCs体外刺激T淋巴细胞增殖的能力,进而检测DCs所诱导的肿瘤特异性细胞毒性T淋巴细胞(CTL)对人结肠癌细胞HCT116的杀伤作用.结果 与阴性对照组相比,激动型CD40单克隆抗体组活化的DCs表面抗原CD80、CD83、CD86和HLA-DR的表达率均显著升高(均P＜0.05),DCs上清中IL-12的质量浓度亦显著升高((716.80±53.43) pg/ml比(405.51±12.17) pg/ml,P＜0.05),活化的DCs具有更强的刺激T淋巴细胞增殖的能力(刺激指数2.006 2±0.438 3比1.365 0±0.209 8,P＜0.05),活化的DCs所诱导的CTL对HCT116细胞具有更强的杀伤作用(抑制率(66.08±0.41)％比(46.60±1.10)％,P＜0.05);而与TNF-α阳性对照组相比,其差异均无统计学意义(均P＞0.05).结论 激动型CD40单克隆抗体在体外可促进DCs的活化与成熟,进而诱导肿瘤特异性CTL的产生,从而抑制人结肠癌细胞HCT116的增殖.