Mature dendritic cells pulsed with exosomes stimulate efficient cytotoxic T-lymphocyte responses and antitumour immunity

Exosomes (EXO) derived from dendritic cells (DC), which express major histocompatibility complex (MHC) and costimulatory molecules, have been used for antitumour vaccines. However, they are still less effective by showing only prophylatic immunity in animal models or very limited immune responses in clinical trials. In this study, we showed that ovalbumin (OVA) protein-pulsed DC (DC(OVA))-derived EXO (EXO(OVA)) displayed MHC class I-OVA I peptide (pMHC I) complexes, CD11c, CD40, CD80, CCR7, DEC205, Toll-like receptor 4 (TLR4), TLR9, MyD88 and DC-SIGN molecules, but at a lower level than DC(OVA). EXO(OVA) can be taken up by DC through LFA-1/CD54 and C-type lectin/mannose (glucosamine)-rich C-type lectin receptor (CLR) interactions. Mature DC pulsed with EXO(OVA), which were referred to as mDC(EXO), expressed a higher level of pMHC I, MHC II, and costimulatory CD40, CD54 and CD80 than DC(OVA). The mDC(EXO) could more strongly stimulate OVA-specific CD8(+) T-cell proliferation in vitro and in vivo, and more efficiently induce OVA-specific cytotoxic T-lymphocyte responses, antitumour immunity and CD8(+) T-cell memory in vivo than EXO(OVA) and DC(OVA). In addition, mDC(EXO) could also more efficiently eradicate established tumours. Therefore, mature DC pulsed with EXO may represent a new, highly effective DC-based vaccine for the induction of antitumour immunity.     

肝癌高表达抗原MAGEC2 CTL表位肽的鉴定

目的:观察肝癌高表达抗原MAGEC2的改造表位是否有HLA-A2限制性抗肿瘤能力。方法:通过Net CTL 1.2、SYFPEITHI和IEDB软件预测打分选取MAGEC2的HLA-A2限制性表位;替换MAGEC2抗原锚定位点氨基酸获得改造肽;结合力实验检测候选表位与T2细胞表面HLA-A2分子的结合能力,ELISPOT实验和胞内因子染色检测候选表位肽诱导细胞毒性T淋巴细胞(CTL)分泌干扰素γ(IFN-γ)的能力,体外细胞毒实验检测诱导CTL的能力。结果:P248、P248-1Y、P356、P356-1Y、P356-2L和P356-1Y2L具有较好的结合力,且P248-1Y和P356-1Y2L等改造肽与HLA-A2的结合力高于原肽。胞内因子染色和ELISPOT实验结果显示,表位肽P248、P248-1Y、P356和P356-1Y2L诱导的CTL具有分泌IFN-γ的能力,且P248-1Y和P356-1Y2L诱导特异性T细胞免疫分泌的IFN-γ略高于原肽(P0.05)。细胞毒实验结果显示表位肽P248、P248-1Y、P356和P356-1Y2L对Hep G2细胞均有一定的杀伤作用,且P248-1Y和P356-1Y2L特异性CTLs对Hep G2细胞杀伤率高于原肽特异性CTLs(P0.05)。结论:MAGEC2抗原改造表位P248-1Y和P356-1Y2L分别与天然表位P248和P356相比有更高的HLA-A2分子亲和力,保留了原有的免疫原性,并且改造肽抗肿瘤免疫效应强于天然表位。P248-1Y和P356-1Y2L是优秀的MAGEC2抗原的HLA-A2限制性CTL候选表位,可以成为新的抗肿瘤多肽免疫治疗疫苗的候选表位。     

转染肿瘤总RNA的DC疫苗诱导抗肝癌特异性免疫

目的：探讨转染人肝癌总RNA的树突状细胞(DC) 疫苗体外诱导特异性细胞毒性T淋巴细胞(CTL)的作用。 方法： 采用原发性肝癌（HCC）病人外周血单核细胞（PBMC），在粒/巨细胞集落刺激因子(GM-CSF)和白细胞介素-4(IL-4) 刺激下增殖分化为DC细胞；从人肝癌细胞中体外扩增肝癌RNA。以HCCRNA转染DC细胞，并与PBMC混合培养诱导扩增CTL。MTT法测定CTL的杀瘤活性。 结果： 转染HCCRNA 48 h后， DC表面分子CD83、CD86和HLA-DR表达明显增高。转染HepG-2细胞HCCRNA的DC和病人HCCRNA诱导的CTL对HepG-2细胞和病人HCC细胞的杀瘤活性均明显高于正常肝细胞RNA+DC、脂质体+DC、Opti-MEM+DC以及空白对照组；而对胃癌SGC-7901细胞无杀伤活性。 结论： 以肝癌RNA为肿瘤抗原，DC作为疫苗的抗原提呈细胞，体外冲击致敏DCs，能诱导肝癌特异性CTL。本研究为HCC术后复发和转移的防治提供一种可能有效的疫苗治疗方法。     

CD34-derived dendritic cells transfected ex vivo with HIV-Gag mRNA induce polyfunctional T-cell responses in nonhuman primates

The pivotal role of DCs in initiating immune responses led to their use as vaccine vectors. However, the relationship between DC subsets involved in antigen presentation and the type of elicited immune responses underlined the need for the characterization of the DCs generated in vitro. The phenotypes of tissue-derived APCs from a cynomolgus macaque model for human vaccine development were compared with ex vivo-derived DCs. Monocyte/macrophages predominated in bone marrow (BM) and blood. Myeloid DCs (mDCs) were present in all tested tissues and were more highly represented than plasmacytoid DCs (pDCs). As in human skin, Langerhans cells (LCs) resided exclusively in the macaque epidermis, expressing CD11c, high levels of CD1a and langerin (CD207). Most DC subsets were endowed with tissue-specific combinations of PRRs. DCs generated from CD34(+) BM cells (CD34-DCs) were heterogeneous in phenotype. CD34-DCs shared properties (differentiation and PRR) of dermal and epidermal DCs. After injection into macaques, CD34-DCs expressing HIV-Gag induced Gag-specific CD4(+) and CD8(+) T cells producing IFN-γ, TNF-α, MIP-1β, or IL-2. In high responding animals, the numbers of polyfunctional CD8(+) T cells increased with the number of booster injections. This DC-based vaccine strategy elicited immune responses relevant to the DC subsets generated in vitro.     

Dendritomas formed by fusion of mature dendritic cells with allogenic human hepatocellular carcinoma cells activate autologous cytotoxic T lymphocytes

Mature dendritic cells (DCs) have highly expressed CD1a, MHC class I, MHC class II, B7-1, B7-2 and ICAM-I molecules, all of which are essential for activation of na?ve T cells. In this study, dendritomas were formed by fusion of hepatocellular carcinoma (HCC) SMMC-7721 cells with autologous DCs in vitro. DCs were obtained from adherent monocytes cultured in the presence of GM-CSF and IL-4 and were matured in monocyte-conditioned media. Expression of MHC class II and HCC-specific antigen by these dendritomas were determined using a specific murine anti-HCC monoclonal antibody (mAb) specific for HCC cell line SMMC-7721, and a murine anti-human HLA-DR mAb, and was also confirmed using bi-dimensional flow cytometry and immuno-histostaining. Dendritomas were co-cultured with autologous T cells, resulting in activation of T cell proliferation and priming of na?ve T cells to induce MHC class I restricted lysis of HCC SMMC-7721 cells. The results imply that these dendritomas may have potential for use in HCC immunotherapy.     

MUC1 mRNA体外负载树突状细胞诱导细胞毒性T细胞对非小细胞肺癌的杀伤作用

 目的：将体外扩增的黏蛋白1 （MUC1） mRNA转染入成熟的树突状细胞（DCs）,观察其体外诱导的特异性抗肿瘤效应。方法：将分离提纯的单核细胞培养诱导为DC并用流式细胞术鉴定。构建pcDNA3.1（+）-MUC1质粒,体外转录为mRNA,电穿孔法转染DCs。定量 PCR检测转染的DCs中MUC1的表达;MTT法检测T细胞增殖情况;流式细胞术检测CD8+ 在T细胞的表达;LDH释放法测定细胞毒性,ELISA检测IFN-γ分泌水平。结果：流式细胞术结果表明成熟DCs标志表型的表达明显高于对照组。定量PCR结果说明转染后的DCs MUC1 mRNA相对表达量增高。转染组DCs与T细胞按1∶10共培养时,刺激增殖能力明显高于未转染组,且CD8+  T细胞表达率高于未转染组,诱导产生特异性的细胞毒性T细胞杀伤表达MUC1蛋白的靶细胞,而未转染组的杀伤作用较弱。转染组DCs与T细胞共培养的上清中IFN-γ的分泌水平高于未转染组。结论：电穿孔法可以将MUC1 mRNA成功转染至DCs,产生特异性杀伤效应,为以MUC1为靶点的非小细胞肺癌的免疫治疗提供实验和理论依据。     

Induction of cytotoxic T lymphocyte respones in vivo after immunotherapy with dendritic cells in patients with nasopharyngeal carcinoma

The aim of the present study was to determine the efficacy of immunotherapy with dendritic cells to elicit EBV-specific CTL-immunity in advanced cases of EBV-positive patients with nasopharyngeal carcinoma (NPC) and to determine the safety and toxicity of this preparation. Nine cases of histologically confirmed patients with NPC undergoing treatment with radiological therapy were enrolled in this study. Dendritic cells, generated in vitro from blood monocytes of patients were cultured and matured with cytokines and then infected with recombinant adenovirus vaccine containing EBV-latent membrane protein-2 (Ad-LMP2). On 9 days' cultivation of cells, the matured DCs were harvested, irradiated with Co and then injected intradermally to patients with NPC. The injections were performed 3 times totally. After immunization, the CTL responses were assayed by means of cytotoxicity and epitope-specific IFN-γproduction. The results of this trial showed that all patients could tolerate this kind of treatment without any side effect, during which marked increase of LMP2-specific CTL-responses could be demonstrated in 5 patients of this group. And the level of IgA/VCA antibody decreased in 8 of 9 patients, thus accounting for a better prognosis for these patients. All patients will be followed up for another one year. At least, the present work shows that intradermal vaccination with autologous DCs infected with recombinant Ad-LMP2 adenovirus is a safe procedure in NPC patients, in which this procedure can enhance the LMP2-specific CTL responses in patients. These data are encouraging to develop more effective vaccine strategies for the treatment of nasopharyngeal carcinoma.     

树突状细胞负载肝癌可溶性抗原后的免疫应答

目的 用负载肝癌可溶性抗原的DC诱导肝癌特异性T细胞。方法 在体外用GM－CSF和IL－4诱导健康人外周血单核细胞，使其分化为高纯度树突状细胞（DC）。用负载人肝癌细胞株SMMC－7721可溶性抗原的DC诱导自身淋巴细胞。结果 诱导后淋巴细胞增殖指数大于1．5，表面CD56分子表达下降，CD3^ T/CD4^ T和CD3^ T/CD8^ T细胞比例增加，以CD3^ T/CD4^ T细胞比例增加最为明显。CD4／CD8比例由诱导前的0．84增加为1．04，活化前后γδ比例没有改变。活化后的淋巴细胞不但可杀伤SMMC－7721细胞，同时还可不同程度的杀伤其它3株肝癌细胞。另外，诱导7d的DC可不同程度的抑制4株肝癌细胞和胃癌细胞。结论 实验结果为肝癌DC疫苗的研究提供了理论基础。     

In vitro generation of cytotoxic and regulatory T cells by fusions of human dendritic cells and hepatocellular carcinoma cells

Background

Human hepatocellular carcinoma (HCC) cells express WT1 and/or carcinoembryonic antigen (CEA) as potential targets for the induction of antitumor immunity. In this study, generation of cytotoxic T lymphocytes (CTL) and regulatory T cells (Treg) by fusions of dendritic cells (DCs) and HCC cells was examined.

Methods

HCC cells were fused to DCs either from healthy donors or the HCC patient and investigated whether supernatants derived from the HCC cell culture (HCCsp) influenced on the function of DCs/HCC fusion cells (FCs) and generation of CTL and Treg.

Results

FCs coexpressed the HCC cells-derived WT1 and CEA antigens and DCs-derived MHC class II and costimulatory molecules. In addition, FCs were effective in activating CD4⁺ and CD8⁺ T cells able to produce IFN-γ and inducing cytolysis of autologous tumor or semiallogeneic targets by a MHC class I-restricted mechanism. However, HCCsp induced functional impairment of DCs as demonstrated by the down-regulation of MHC class I and II, CD80, CD86, and CD83 molecules. Moreover, the HCCsp-exposed DCs failed to undergo full maturation upon stimulation with the Toll-like receptor 4 agonist penicillin-inactivated Streptococcus pyogenes. Interestingly, fusions of immature DCs generated in the presence of HCCsp and allogeneic HCC cells promoted the generation of CD4⁺ CD25^high Foxp3⁺ Treg and inhibited CTL induction in the presence of HCCsp. Importantly, up-regulation of MHC class II, CD80, and CD83 on DCs was observed in the patient with advanced HCC after vaccination with autologous FCs. In addition, the FCs induced WT1- and CEA-specific CTL that were able to produce high levels of IFN-γ.

Conclusion

The current study is one of the first demonstrating the induction of antigen-specific CTL and the generation of Treg by fusions of DCs and HCC cells. The local tumor-related factors may favor the generation of Treg through the inhibition of DCs maturation; however, fusion cell vaccination results in recovery of the DCs function and induction of antigen-specific CTL responses in vitro. The present study may shed new light about the mechanisms responsible for the generation of CTL and Treg by FCs.     

鼻咽癌患者树突状细胞对EBV特异性细胞毒T细胞的免疫反应

目的：用负载EB病毒抗原LMP-2表位肽段的鼻咽癌患者树突状细胞（DC）诱导自身CD8^＋T细胞，观察其细胞毒性T细胞的免疫应答能力。方法：在体外分离并诱导成熟HLA—A2基因型鼻咽癌患者自身的DC，分别负载EB病毒抗原LMP-2的HIA—A2限制型两个表位肽段CLGGLLTMV（CLG）和LTAGFIFL（LTA）后，诱导自身CD8^＋T细胞，培养2周后，运用酶联免疫斑点法（Elispot）和HLA-肽四聚体法（Tetramer）检测诱导后T细胞的免疫应答情况。结果：经DC抗原呈递后分泌IFN-γ的CLG和LTA特异性CD8^＋T细胞数，分别为（42．67±33．79）个／孔和（25．67±18．25）个／孔，而呈递前分别为（2．67±1．97）个／孔和（5．33±1．86）个／孔。两者IFN-γ^＋CD8^＋T细胞数均有明显增加（P〈0．05）。CLG和LTA肽段特异性细胞毒性T细胞（CTL）的中位数在呈递前分别为0．135％和1．14％；呈递后则为1．045％和1．945％。两者较呈递前均明显增加（P〈0．05）。结论：负载EB病毒抗原LMP-2表位肽段的DC诱导鼻咽癌患者自身CD8^＋T细胞，可产生特异性CTL，对鼻咽癌患者的免疫治疗具有潜在的应用价值。     

肝细胞癌患者树突状细胞免疫功能的研究

 目的：研究肝细胞癌患者树突状细胞(DCs)的免疫功能变化。方法：从人外周血中分离单个核细胞（PBMC），用GM-CSF和IL-4体外诱导、培养和扩增DCs，流式细胞仪测定DCs表面分子的表达，分别用ELISA、ELISPOT、MTT法测定HCC患者和健康人的DCs分泌IL-12；T淋巴细胞分泌IFN-γ和T淋巴细胞的增殖反应。结果：GM-CSF和IL-4能成功地体外诱导、培养和扩增DCs。HCC患者DCs的CD86表达明显低于健康对照者（91.7％ vs83.5%, P<0.05）。HCC患者DCs分泌IL-12与健康者差异不显著［（324.6±171.0）ng/L vs（436.5±142.7）ng/L, P>0.05］，接受内毒素LPS刺激后，差异更明显［（478.6±142.7）ng/L vs（630.0±151.9）ng/L, P<0.05］。DCs刺激T淋巴细胞分泌IFN-γ 的量在HCC患者明显低于健康者［（133.4±51.2）103U/L vs (183.0± 60.2)103U/L, P<0.05］，DCs刺激T淋巴细胞的增殖能力在HCC患者明显低于健康者（2.3±0.7 vs3.5±0.8, P<0.01）。CTL杀伤实验表明，当效靶比为 10∶〖KG-*2〗1 和 20∶〖KG-*2〗1 时，HCC组的CTL对肝癌细胞Hep G2的杀伤活性明显低于健康组。结论： HCC患者DCs功能和T淋巴细胞功能低于健康者，HCC患者DCs诱导的CTL杀伤活性亦明显低于健康者。     

Induction of single and dual cytotoxic T-lymphocyte responses to viral proteins in mice using recombinant hybrid Ty-virus-like particles.

The induction of cytotoxic T-lymphocyte (CTL) responses to viral proteins is thought to be an essential component of protective immunity against viral infections. Methods for generating such responses in a reproducible manner would be of great value in vaccine development. We demonstrate here that the recombinant antigen-presentation system based on the yeast transposon (Ty) particle-forming p1 protein is a potent means of inducing CTL responses to a variety of viral CTL epitopes, including influenza virus nucleoprotein (two epitopes), Sendai virus and vesicular stomatitis virus nucleoproteins, and the V3 loop of human immunodeficiency virus type-1 (HIV-1) gp120. CTL were primed by hybrid Ty-virus-like particles (VLP) carrying the minimal epitope or as much as 19,000 MW of protein. Ty-VLP carrying two different epitopes (dual-epitope Ty-VLP) were capable of priming CTL responses in two different strains of mice or against two epitopes in the same individual. Furthermore, co-administration of a mixture of two different Ty-VLP carrying single epitopes could induce responses to both epitopes in the same individual. Ty-VLP appear to represent a reproducible and flexible system for inducing CTL responses in mice, and warrant further evaluation in primates.     

Presentation of SIVgag to monkey T cells using dendritic cells transfected with a recombinant adenovirus

To pursue the capacity of monkey dendritic cells (DC) to be modified by adenoviral vectors and present the encoded antigens, we generated DC from blood monocytes and infected them with recombinant adenoviruses encoding GFP reporter and SIVgag or nef genes. Recombinant, E1- and E3-deleted, adenoviruses could transfect immature DC to >90% efficiency. When differentiated in the presence of a maturation stimulus, the infected cells were identical to control uninfected DC in surface markers and potent stimulatory activity for the mixed leukocyte reaction. Recombinant adeno-SIVgag was comparable to vaccinia-gag in stimulating IFN-gamma-secreting CD8(+) T cells from PBMC of macaques vaccinated with SIV(mac239) Deltanef and challenged with pathogenic SIV or chimeric SIV/HIV. Small numbers of adeno-SIVgag-infected DC were sufficient to trigger specific ELISPOT responses by CD8(+) T cells from these animals. Some CD4(+) IFN-gamma-secreting cells were also found in the three of eight vaccinated animals with the highest CD8(+) responses. T cells from control animals did not respond to DC transfected with adeno-gag. Therefore recombinant adenoviruses efficiently transfect monkey DC in a nonperturbing fashion, and these DC efficiently present antigens to SIVgag immune CD8(+) T cells. These findings will allow autologous DC, expressing SIV genes with high efficiency, to be tested in vivo to achieve strong specific T cell immunity.     

Co-evolution of human immunodeficiency virus and cytotoxic T-lymphocyte responses

After more than a decade of intensive research, the precise of human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL) in determining the course of the infection remains open to argument. It is established that HIV-specific CTL appear early in the infection and are temporally associated with the clearance of culturable virus from the blood; that CTL are generally detectable at very high levels throughout the asymptomatic phase and decline at the time of progression to AIDS; and that CTL-mediated killing is sufficiently fast to prevent production of new virus by HIV-infected cells. However, viral turnover is throughout the course of the infection, and –infected individuals progress inexorably to disease in spite of the CTL response. In order Co address the question of whether CTL play an active part in influencing the course of HIV infection, one approach has been to seek evidence for CTL-mediated selection pressure on the virus. Several clear examples of CTL epitope-specific mutations selected to fixation are described. We argue that CTL escape is a common event which occurs at all stages of the Infection. Detailed longitudinal studies are required to detect CTL escape and to nd the complexities contributed by factors SUC h as a polyvalent CTL response and the presence of epitope variants which antagonise the CTL response. In conclusion, there is strong evidence of a dynamic process in which CTL impose important selection constraints upon HIV fro m which the virus attempts to escape; ultimately, at the time of disease progression, the tenuous control of CTL over the virus is lost.     

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。     

抗原基因修饰的树突状细胞诱导机体产生特异性免疫应答的实验研究

目的：探讨腺病毒介导的肿瘤抗原基因修饰的树突状细胞（ＤＣ） 体内免疫后对抗原特异性抗肿瘤免疫反应的诱导作用。方法：以βｇａｌ 为模拟抗原,以转染有ＬａｃＺ基因并稳定表达βｇａｌ 的淋巴瘤细胞Ｅ２２ 为肿瘤细胞模型,用携带编码βｇａｌ的ＬａｃＺ基因的重组腺病毒载体（ＡｄＬａｃＺ） 转染小鼠骨髓ＤＣ,检测转染的效率及ＬａｃＺ基因修饰ＤＣ刺激Ｔ细胞增殖的能力,观察皮下免疫ＬａｃＺ基因修饰ＤＣ后小鼠引流区淋巴结细胞数量和组分的变化以及诱导产生ＣＴＬ和抵抗Ｅ２２ 细胞再攻击的能力。结果：ＬａｃＺ基因修饰后２４ 、４８ 、７２ ｈ,均能检测到８０％ 以上的ＤＣ表达βｇａｌ,此基因修饰的ＤＣ可有效刺激同基因型小鼠脾脏Ｔ淋巴细胞增殖反应;将其皮下免疫小鼠１ ｗ 后再接种Ｅ２２ 细胞,小鼠的存活期较其他ＤＣ免疫小鼠显著延长,但对Ｂ１６ 黑色素瘤细胞的攻击无免疫保护作用。此外,ＬａｃＺ基因修饰的ＤＣ免疫小鼠的引流淋巴结细胞数量显著增加,且产生了针对Ｅ２２ 的而非ＥＬ４ 或Ｂ１６ 的特异性ＣＴＬ。结论：腺病毒介导的肿瘤抗原基因修饰的ＤＣ能有效诱导机体产生特异的抗肿瘤免疫反应。     

Immunization with dendritic cells transfected in vivo with HIV-1 plasmid DNA induces HIV-1-specific immune responses

We evaluated the importance of dendritic cells (DCs) in the induction of the immune response after immunization of mice with DNA plasmid Auxo-GTU^?-MultiHIV. First, GTU^?-encoded protein was shown to be expressed by DCs of the draining lymph nodes (LNs) following intradermal (i.d.) immunization. Next, donor mice were immunized with the MultiHIV DNA plasmid, and DCs were enriched and further used to immunize na?ve recipient mice. For the first time, the results show that i.d. immunization with Auxo-GTU^?-MultiHIV transfects DCs in vivo, enabling them to present antigens and induce HIV-specific immune responses in recipient mice.     

小鼠肝癌总RNA转染的树突状细胞体外诱导特异性细胞毒T淋巴细胞的研究

目的 :探讨小鼠骨髓树突状细胞 (dendriticcell,DC)体外经Hepa 1 6肝癌细胞株总RNA转染后 ,对特异性细胞毒T淋巴细胞 (CTL)的诱导作用。方法 :自小鼠骨髓分离DC前体细胞 ,经GM CSF IL 4培养、扩增 ;制备Hepa 1 6小鼠肝癌细胞株总RNA ,体外转染DC ,检测DC诱导同基因型小鼠T细胞增殖及其特异性CTL的反应能力。结果 :经Hepa 1 6肝癌细胞总RNA转染的DC ,其组织相容性分子 (MHC I、II)及共刺激分子 (B7 1 、B7 2 )表达明显增高 ,刺激同基因型小鼠T细胞增殖能力增强 ,且能诱导Hepa 1 6特异性CTL。结论 :以肝癌总RNA转染DC ,构造肝癌疫苗为肝癌的临床治疗提供了新的策略。