Immunotherapeutic effects of dendiritic cells vaccine pulsed with tumor cell lysate in mice with pancreatic carcinoma

Objective To observe the immunotherapeutic effects of dendritic cells vaccine pulsed with tumor cell lystate on mice with pancreatic carcinoma. Methods Dendritic cells (MTSC4) were pulsed with tumor cells lysate. The immune preventative and immnotherapeutic effects of DC vaccines on mice with pancreatic carcinoma were assessed. Results After vaccination of the DC vaccines,mice remained tumor-free for at least 25 days in DCs vaccines group,but in other groups the subcutaneous implantation tumorigenesis were found beginning 3 to 9 days. CTL stimulated by DC vaccines effected cytolytic activity against pancreatic carcinoma cells. The survival period was obviously prolonged in DCs vaccines group (56 ±9)d than in other groups P<0.01) and tumors (1.4 ±0.8)g in DCs vaccines group were significantly smaller than that in other groups (P < 0. 05). Conclusion Tumor cell lysate-pulsed dendrtic cells vaccines can induce a specific and effective immune response against pancreatic carcinoma cell implanted in mice. 4     

Induction of protective antitumor activity of tumor lysate-pulsed dendritic cells vaccine in RM-1 prostate cancer model

Objective： To investigate the antitumor activity of tumor lysate-pulsed dendritic cells vaccine in RM-1 prostate cancer mice model with the survival time of mice calculated and the tumor size measured in DC vaccine therapy. Methods： C57BL/6 mice were immunized on the dorsal flank by s.c. inoculation of Lysate-DC, ova-DC, and non-DC on day -7. On day 0, 2× 10^6cells of RM-1 tumor cells （H-2b） were injected s.c. in C57BL/6 mice pre-treated by s.c. inoculation of modified DCs, correspondingly. DTH assay was performed with modified DCs. In partial test, for the determination of which immune cells were required for antitumor activity, mice were immunodepleted of CD4, CDS, or natural killer （NK） NK1.1 cells with the corresponding monoclonal antibodies. The survival time of nude mice loaded with tumor cells was calculated and the size of tumor measured. Results： In RM-1 mice prostate cancer model, immunized with lysate-DC, compared with ova-DC and non-DC, the pre-infection vaccine resulted in 100% clearance of primary tumors, whereas on day 0 of injection vaccine cleared 40-60% of primary tumors. On day 0, C57BL/6 mice （H-2b） were immunized with Lysate-DC, compared with ova-DC and non-DC by caudal vein injection, then on day 15, RM-1 cells were inoculated. On day 30, average diameters of tumor in different groups of modified DC were 23.7±5.4 mm, 22.1±4.9 mm, 4.3±2.6 mm, respectively. Lysate-DC, compared with ova-DC and non-DC, can greatly depressed RM-1 tumor cell growth （P〈0.01）. The mean survival time of C57BL/6 mice in Lysate-DC, ova-DC and non-DC groups were 15.8±2.6, 16.6±3.2, 39.0±5.6, respectively, and there was a significant difference in the mean survival time in lysate-DC group between ova-DC and non-DC group （P〈0.01）. DTH test showed that lysate-DC could prime T lymphocyte and elicit tumor antigen specific immune response, and over 80% mice in groups of lysate-DC showed obvious swelling in their foot pad. This response was strengthened with repeating inoculation, whereas DTH response was not seen in control group. In vivo depletion of NK cells resulted in a 40-60% reduction in growth suppression within the primary tumor, and depletion of CD4^＋ cells resulted in a 20% reduction in growth suppression. Conclusion： The minor lysate-pulsed dendritic cells vaccine could elicit antitumor activity in RM-1 loaded C57BL/6 mice, and prolong the duration of RM-1 loaded C57BL/6 mice. So DC-based immunotherapy with hormone-refractory prostate carcinoma yielded protective immunity, generated efficient cellular antitumor responses, thereby providing further preclinical support for feasible immunotherapy approaches for prostate cancer.     

In vitro inducing effect of dendritic cells cotransfected with survivin and granulocyte-macrophage colony-stimulating factor on cytotoxic T cell to kill leukemic cells

Background Survivin is a rather specific gene in tumor tissue. We transfected dendritic cells （DCs） with recombinant adenovirus （Ad） containing survivin gene and granulocyte-macrophage colony-stimulating factor （GM-CSF） gene and tested the inducing effect of the transfected DCs on cytotoxic T lymphocytes （CTL） to kill leukemic cells.
Methods After derived from the peripheral, DCs was assayed by mixed leukocyte reaction （MLR） tests. Lactate dehydrogenase （LDH） release test was used to evaluate cytotoxicity of CTL.
Results Expression of survivin in transfected DCs was confirmed by Western blotting analysis. GM-CSF expression was confirmed by enzyme-linked immunosorbent assay （ELISA）. In MLR assay, DCs coinfected with Ad-survivin and Ad-GM-CSF induced higher allogeneic lymphocyte reaction than control DCs at ratios of 1：5, 1：10, 1：50 and 1：100. DCs coinfected with Ad-survivin and Ad-GM-CSF had much higher activity of CTL to HL-60 cells than DCs infected with Ad-survivin only, Ad-GM-CSF only, or control DCs. Levels of interleukin-12 （IL-12） and interferon gamma （IFN-γ） in lymphocyte supernatants containing DCs coinfected with Ad-survivin and Ad-GM-CSF were significantly higher than those in the control group.
Conclusion DCs coinfected with Ad-survivin and Ad-GM-CSF induce much higher anti-leukemic response in vitro than those infected with either factor. Therefore, adenovirus vectors containing survivin and GM-CSF genes may be promising vaccine candidates for leukemia therapy.     

Macrophage activation of lymphoma-bearing mice by liposome-mediated intraperitoneal IL-2 and IL-6 gene therapy

Objective To investigate the antitumor mechanism of interleukin-2 (IL-2) and interleukin-6 (IL-6) gene therapy. Methods Liposome encapsulated IL-2 DNA and IL-6 DNA were intraperitoneally (i.p.) injected into mouse lymphoma cell line (EL-4) lymphoma-bearing mice. Macrophage function (MФ) from the mice was assessed. Results Cytotoxicity, major histocompatibility (MHC) Ⅱ expression and IL-1 and TNF secretion of the macrophages all augmented after i.p. injection of liposome encapsulated IL-2 DNA or IL-6 DNA. More efficient activation of macrophages was observed in mice treated with liposome encapsulated IL-2 DNA than IL-6 DNA. IL-2 gene therapy combined with IL-6 gene therapy showed the maximal activation of macrophages in the lymphoma-bearing mice.Conclusion IL-2 and IL-6 gene therapy can relieve the supression of macrophages of the lymphoma-bearing mice, and efficiently activate the antitumor immune responses.     

1-MT enhances potency of tumor cell lysate-pulsed dendritic cells against pancreatic adenocarcinoma by downregulating the percentage of tregs

This study examined whether 1-methyl-tryptophan [1-MT,an indoleamine 2,3-dioxygenase(IDO) inhibitor] could reduce CD4+CD25+ regulatory T cells(Tregs) proliferation and improve the anti-tumor efficacy of dendritic cells(DCs) pulsed with tumor cell lysate in the mice bearing pancreatic adenocarcinoma.The models of pancreatic adenocarcinoma were established in C57BL/6 mice by subcutaneous injection of Pan02 cells.Eight mice which were subcutaneously injected with PBS served as control.The expression of IDO was...     

Induction of T-cell immunity against Epstein-Barr virus-associated tumors by means of adenovirally transduced dendritic cells

Background Dendritic cells (DCs) are the most powerful antigen-presenting cells to induce specific T-cell immunity, which plays an important role in the body‘s anti-tumor responses. In this study, we assessed the feasibility and efficacy of inducing T-cell immunity against Epstein-Barr virus (EBV)- associated tumors in vivo using dendritic cells transfected with EBV latent membrane 2A (LMP2A) recombinant adenovirus.Methods Cytokine-activated bone marrow-derived DCs transfected with EBV LMP2A recombin antadenovirus were infused into BALB/c mice. Splenic cytotoxic T-cell responses were evaluated by cytotoxicity and interferon-γ production assays, in vivo immune protection was then assessed in the mice tumor models implanted with tumor cells expressing EBV LMP2A. Results DCs transfected with EBV LMP2A recombinant adenovirus could strongly induce EBV LMP2A-specific cytotoxic T-cell responses and upregulate interferon-y production in vivo. Vaccination using these DCs led to prolongation of overall survival rates in the mice tumor models and retarded tumor growth.Conclusions The results suggest that DCs transfected with EBV LMP2A recombinant adenovirus can serve as a feasible and effective tool for eliciting LMP2A-specific cytotoxic T-cell responses against EBV LMP2A in vivo in the treatment of EBV-associated tumors.     

Anti-tumor effects and cellular mechanisms of Pistacia atlantica methanolic extract against Ehrlich solid tumor in mice

Objective:To assess the anti-tumor effects of Pistacia atlantica methanolic extract(PAME)compared with cyclophosphamide against Ehrlich solid tumors in mice.Methods:Swiss albino mice(n=40)were divided into five groups:normal control mice,mice with Ehrlich solid tumors treated with normal saline,mice with Ehrlich solid tumors treated with cyclophosphamide intraperitoneally once a day for 14 d,or 50mg/kg or 100 mg/kg PAME orally once a day for 14 d.Tumor growth inhibition,body weight,tumor markers,liver and kidney enzymes,oxidative stress markers,antioxidant enzymes,tumor necrosis factor-alpha level(TNF-α),and apoptosis-regulatory gene expression were evaluated.Results:Treatment of mice bearing Ehrlich solid tumors with PAME at 50 and 100 mg/kg orally significantly decreased tumor volume,body weight,tumor markers,liver and kidney enzymes,oxidative stress markers and TNF-αlevel in comparison with mice with Ehrlich solid tumors receiving normal saline.whereas PAME at 50 and 100 mg/kg/day significantly elevated the level of antioxidant enzymes(P<0.05).Conclusions:Pistacia atlantica methanolic extract has potent antitumor activity in mice.Therefore,the extract might be considered as an alternative anticancer agent against tumors,however,additional studies especially in the clinical setting are required to confirm this finding.     

Enhancement of Immunological Activity of CpG ODN by Chitosan Gene Carrier

To investigate the enhancement of immunological activity of CpG ODN by chitosan gene carrier in mice, the effect of lymphocyte proliferation was detected in mice by using MTT, the levels of IgG and cytokines (IL-2 and IL-12) in serum were measured by ELISA and peripheral blood T lymphocyte subsets CD4 , CD8 were analyzed by flow cytometry. Our results showed that spleen lymphocytes isolated from the CS-CpG ODN group of mice showed the strongest proliferation (SI =1.551), and the levels of IgG, IL-2 and IL-12 in serum were higher than those of other groups. Com- pared with the immunization with CpG ODN, the immunization with CS-CpG ODN gene carrier was more efficient in up-regulating the percentage of CD4 T cells and the ratio of CD4 /CD8 of mice. It was concluded that CS gene carrier of CpG ODN was much more effective in improving immunity of CpG ODN in mice.     

Antitumor effects of interleukin-18 gene-modified hepatocyte cell line on implanted liver carcinoma

Objective To investigate the antitumor effects of intrasplenically transplanted interleukin-18 (IL-18) gene-modified hepatocytes on murine implanted liver carcinoma. Methods Embryonic murine hepatocyte cell line (BNL-CL2) was transfected with a recombinant adenovirus encoding IL-18 and used as delivery cells for IL-18 gene transfer. Two cell lines, BNL-LacZ and BNL-CL2, were used as controls. One week after intrasplenic injection of C26 cells (colon carcinoma line), tumor-bearing syngeneic mice underwent the intrasplenic transplantation of IL-18 gene-modified hepatocyte cell line and were divided into treatment group (BNL IL-18) and control groups (BNL-LacZ and BNL-CL2 ). Two weeks later, the serum levels of IL-18, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) in the implanted liver carcinoma-bearing mice were assayed, the cytotoxicity of murine splenic cytotoxic T-lymphocytes (CTLs) was measured, and the morphology of the hepatic tumors was studied to evaluate the antitumor effects of the approach. Results In the treatment group, the serum levels of IL-18, IFN-γ, TNF-α and NO increased significantly. The splenic CTL activity increased markedly (P&lt;0.01) , accompanied by a substantial decrease in tumor volume and the percentage of tumor area and prolonged survival of liver carcinomo-being mice. Conclusions In vivo IL-18 expression by ex vivo manipulated cells with IL-18 recombinant adenovirus is able to exert potent antitumor effects by inducing a predominantly T-cell-helper type 1 (Th1) immune response. Intrasplenic transplantation of adenovirus-mediated IL-18 gene-modified hepatocytes could be used as a targeting treatment for implanted liver carcinoma.     

Co-modification of IL-2-TNFα fusion gene and B7.1 gene to murine breast tumor cells leads to improved tumor rejection and vaccine effect

Objective To improve the vaccine potency of gene-modified tumor cells.Methods Using recombinant adenoviruses, we expressed the B7.1 gene in murine breast tumor cell line EMF(6) and a subline previously transfected with retrovirus vector XdF harboring the IL-2-TNFα fusion gene.Results Immunization/challenge experiments demonstrated that IL-2-TNFα/B7.1 co-modified tumor cells possessed a lower tumorigenicity in vivo and an improved tumor-specific vaccine potency compared with single gene transfectant (P&lt;0.05). Three weeks after immunization with a variety of tumor cells, the mixed lymphocyte and tumor cells reaction assay (MLTB) and (51) Cr-release assay were performed to test cellular immunity function. The results indicated that IL-2-TNFα and B7.1 together induced a more potent antitumor immune response than either molecule alone, 25% higher than IL-2-TNFα and 20% higher than B7.1, respectively.Conclusion The IL-2-TNFα fusion gene and B7.1 gene act in concert to improve their antitumor effectiveness.     

淋巴细胞趋化因子基因修饰增强肿瘤抗原多肽致敏的树突状细胞的 …

目的 通过选择性增强树突状细胞（ＤＣ）与Ｔ细胞的体内相互作用。优化其体内抗原提呈的微环境,为进一步增强ＤＣ介导的肿瘤免疫治疗效果。方法 体外培养的小鼠骨髓树突太细胞体外经Ｌｔｎ重组腺病毒感染后（Ｌｔｎ－ＤＣ）,用３ＬＬＬｅｉｗｓ肺癌细胞株的Ｍｕｔｌ抗原肽冲击致敏,按不同剂量免疫正常同系小鼠体内,观察其体内诱导的细胞毒性Ｔ淋巴细胞（ＣＴＬ）活性保护性免疫反应。通过体内阻断试验探讨免疫细胞亚群及免疫分     

抗原致敏树突状细胞诱导CTL对MCF-7细胞的体外杀伤效应

目的:采用MCF-7乳腺癌细胞裂解物致敏树突状细胞(DC),观察其体外诱导人T淋巴细胞产生特异性抗乳腺癌免疫的效能。方法:联合应用细胞因子从外周血单个核细胞(PBMC)中诱导出DC,体外负载MCF-7细胞冻融抗原,活化自身T淋巴细胞,采用ELISA法测定γ-干扰素(IFN-γ)、白介素-12(IL-12)水平,乳酸脱氢酶释放法检测细胞毒性T淋巴细胞(CTL)对MCF-7细胞的杀伤效应。结果:负载抗原DC与T淋巴细胞共培养产生IFN-γI、L-12的水平,显著高于未负载抗原DC组(P<0.05)、单纯抗原组(P<0.01)和对照组(P<0.01);负载抗原DC诱导CTL对MCF-7的杀伤效应,显著高于其他3组(P<0.01)。结论:MCF-7细胞裂解物致敏DC诱导的人CTL,对MCF-7细胞具有明显的特异性杀伤效应。     

肿瘤抗原致敏树突状细胞诱导机体产生抗肿瘤作用的实验研究

目的：探讨肿瘤抗原冲击致敏的树突状细胞（Dc）诱导机体产生的特异性抗肿瘤作用。方法：体外培养的小鼠骨髓树突状细胞用小鼠结肠腺癌细胞株CT26细胞抗原冲击致敏；混合淋巴细胞反应检测肿瘤抗原致敏DC刺激同基因型T淋巴细胞增殖的能力；观察小鼠经皮下免疫肿瘤抗原致敏DC后诱导产生肿瘤特异性细胞毒性T淋巴细胞（CTL）和抵抗CT26细胞再攻击的能力。结果：肿瘤抗原致敏DC能有效刺激同基因型T淋巴细胞增殖反应；小鼠经肿瘤抗原致敏DC免疫后可诱导强烈的CT[，杀瘤活性，产生免疫保护作用，能有效抵抗CT26细胞再攻击，肿瘤生长明显减缓，与未经抗原致敏DC免疫的小鼠组比较，差异有统计学意义（P〈0．01）。结论：肿瘤抗原致敏的DC能有效诱导机体产生特异性的抗肿瘤作用。     

肿瘤抗原脉冲致敏的树突状细胞疫苗抗肿瘤作用的实验研究

目的：进一步研究体外肿瘤抗原脉冲致敏的骨髓树突状细胞瘤苗主动免疫诱导小鼠体内抗肿瘤免疫应答,并观察其抵抗野生性肿瘤攻击的免疫保护作用及对荷瘤小鼠模型的免疫应答。方法：采用本室建立的骨髓树突状细胞分离与细胞因子体外扩增培养方法,并在体外经灭活ＮＳ１骨髓瘤细胞及其裂解产物脉冲刺激后直接作为疫苗,然后进行免疫预防与治疗的在体动物实验。结果：可从１只小鼠股骨中获得（３～５）×１０５个树突状细胞（ＤＣ）,其纯度为９５％以上,对混合Ｔ淋巴细胞具有强刺激活性。主动免疫同系健康ＢＡＬＢ／Ｃ小鼠的试验显示,ＤＣ疫苗能诱导抗原特异的细胞毒性Ｔ淋巴细胞（ＣＴＬ）活性,免疫１次的动物首次受到肿瘤攻击后诱发肿瘤形成率为０％,再次攻击的肿瘤形成率为２０％;而免疫３次的动物两次攻击的肿瘤形成率皆为０％。主动免疫治疗同种荷瘤动物的试验表明,ＤＣ疫苗也能抑制肿瘤生长,荷瘤动物存活率提高及生存期明显延长。结论：肿瘤抗原体外致敏的树突状细胞能诱导宿主体内的抗肿瘤免疫保护性反应,且对荷瘤模型动物具有明显的免疫治疗作用。     

肿瘤抗原多肽致敏白细胞介素18基因修饰的树突状细胞治疗小鼠转移性肺癌

目的探讨肿瘤多肽致敏的白细胞介素18(IL-18)基因修饰的树突状细胞(DC)对自发性肺转移癌的治疗作用。方法小鼠足垫注射3LLLewis肺癌细胞建立自发性肺转移癌模型,经骨髓来源的IL-18基因修饰、3LL特异抗原多肽Mut1体外致敏DC(DC-IL-18/Mut1)皮下免疫2次,观察荷瘤鼠肺脏重量、肺表面转移结节、存活期的变化及相应免疫指标等变化,实验分8组,组间差异行t检验,生存期行时序检验。结果与对照病毒组(DC-LacZ/Mut1)及未处理DC组相比,DC-IL-18/Mut1组肺脏重量最轻(215mg±20mg与398mg±23mg和987mg±45mg比较,t值分别为14.7及38.4,P均<0.01)、肺表面转移结节最少(0与7.8±2.7和49.4±4.3比较,t值分别为7.07及16.2,P均<0.01)、存活期最长(χ2分别为6.78、10.49,P均<0.01),其诱导细胞毒性T淋巴细胞(CTL)活性(53.4±3.1与41.3±2.6和9.8±2.1比较,t值分别为7.3及28.5,P均<0.01)和天然杀伤细胞(NK)活性(35.8±2.4与15.6±2.8及13.6±2.5比较,t值分别为13.4及15.7,P均<0.01)最显著,且CD4+T、CD8+T及NK细胞比例增加。结论MHCⅠ类限制性肿瘤抗原多肽致敏的IL-18基因修饰的DC能通过诱导显著的抗肿瘤免疫反应而对自发性肺转移癌有明显的治疗作用。     

肿瘤坏死因子—α预刺激对培养树突状细胞形态学的影响

目的：研究肿瘤坏死因子（TNF）－α预刺激对树突状细胞形态学的影响，方法：Ficoll密度梯度离心分离健康人外周血，获得单个核细胞，培养基用含有10％胎牛血清的RPMI 1640，分两组进行培养，一组用TNF－α预刺激4h后加入粒细胞－巨噬细胞集落刺激因子（GM－CSF）及白细胞介素－4（IL－4），每48h再次加入上述3种细胞因子；另一组则在培养初始加入GM－CSF及IL－4，每隔48h再次加入上述2种细胞因子，第5天加入TNF－α，两种中所用细胞因子浓度完全一样，且均于第8天收获细胞，前者记作T－DC，后者记作DC。光镜及扫描电镜观察DC形态学变化及差异，结果：T－DC与DC相比，具有更多，更典型的树突状突起，结论：TNF－α预刺激DC前体细胞4h与TNF－α在培养第5天加入相比，所诱导出的DC的树突状形态更为明显，典型。     

肾癌冻融抗原致敏树突状细胞介导的CTL对肾癌786-0细胞株的体外杀伤作用研究

目的：研究肾癌冻融抗原负载树突状细胞（DCs）诱导的特异性细胞毒性T淋巴细胞（CTL）对肾癌786-0细胞株的体外杀伤效应；方法：利用人外周血体外经重组人粒细胞-巨噬细胞集落刺激因子（rhGM-CSF）、人白介素-4（rhIL-4）和肿瘤坏死因子（TNF-α）诱导产生的DCs负载肾癌冻融裂解物后诱导产生特异性CTL，观察杀伤后肿瘤细胞的形态变化，MTT法测定细胞毒性试验，ELISA测定细胞因子的分泌。结果：（1）负载肾癌抗原的DCs能促进T细胞的增殖；（2）诱导产生的特异性CTL对肾癌细胞具有高杀伤率，显著高于非特异性T细胞（P〈0．05）；（3）肾癌冻融抗原能够上调DCs人白介素-12（rhIL-12）的分泌，提高抗肿瘤的作用。（4）杀伤后的肾癌细胞发生明显凋亡。结论：由肾癌冻融抗原致敏的DCs所诱导产生的抗原特异性CTL对肾癌786-0细胞株有明显的杀伤效应，提示DCs瘤苗具有为肾癌患者进行特异性过继免疫治疗的临床应用前景。     

子宫颈癌患者树突状细胞体内外诱导抗肿瘤免疫

目的探讨子宫颈癌患者的树突状细胞(dendritic cells,DCs)在体内外能否诱导出高效而特异的抗肿瘤免疫应答。方法应用粒细胞-巨噬细胞集落刺激因子(GM-CSF)和白介素-4(IL-4)从子宫颈癌患者外周血诱导DCs,Hela子宫颈癌抗原致敏,MTT法检测DCs激活的细胞毒性T淋巴细胞(CTLs)对肿瘤细胞的细胞毒作用。皮下接种Hela子宫颈癌建立荷瘤鼠,给予抗原致敏的DCs回输;或先给予DCs免疫,后用癌细胞攻击,观察其抑制肿瘤的效果。结果从子宫颈癌患者外周血诱导的DCs高表达CD86、CD12、HLA-DR、CD54和CD83,激活的CTLs在体外特异性杀伤子宫颈癌细胞。DCs回输小鼠具有免疫保护作用,减低成瘤率;又能引起免疫治疗作用,有效抑制肿瘤的生长。结论用GM-CSF及IL-4从子宫颈癌患者诱导的DCs能有效提呈Hela子宫颈癌抗原给T淋巴细胞,并且在体内外诱导出高效而特异的抗肿瘤免疫,有望成为有效的肿瘤特异性免疫治疗新途径。     

吞噬凋亡肿瘤细胞的树突细胞疫苗抗肿瘤效果观察

目的：研究吞噬凋亡肿瘤细胞的树突细胞疫苗的抗肿瘤效果,以确定一种有效的树突细胞疫苗。方法：由黑色素瘤细胞（BLb-10)生成凋亡细胞,树突细胞（DC）与凋亡肿瘤细胞培育后,收集和提纯吞噬凋亡肿瘤细胞的树突细胞,再对其表型变化及抗肿瘤效果进行检测,并与加肿瘤细胞肽（mTRP2)的树突细胞的结果比较。结果：吞噬凋亡肿瘤细胞后,DC更加成熟。表现出促炎症细胞因子（IL－1,IL－6,TNF－α,IFN--γ和GM－CSF）,趋化因子（MIP－1,MIP－1和MIP－2）,细胞表面分子（HMC-Ⅱ,CD11bCD40和CD86）以及某些趋化因子受体（CCR7）表达增加而某些趋化因子受体（CCR2和CCR5）表达减少。吞噬了凋亡黑色素瘤细胞的树突细胞疫能（i）更强地刺激体外T细胞增生,（ii）诱导体内Th1型免疫反应而导致更有效的肿瘤特异细胞毒CD8＋细胞 介导的免疫,和（iii)防止了免疫鼠肺肿瘤转移,而加肿瘤细胞肽的树突细胞疫苗只能减少免疫鼠的肺肿瘤转移。结论：吞噬凋亡黑色素瘤细胞的树突细胞疫苗为癌细胞疫苗研究提供了新的途径。     

树突状细胞体外刺激对HBV特异性细胞毒T细胞影响的研究

目的探讨通过聚肌胞体外作用树突状细胞后改善慢性乙型肝炎患者树突状细胞功能,并在体外活化自身T细胞获得高频数HBV特异性细胞毒性T细胞(CTL)的方法。方法分离慢性乙型肝炎病人外周血单个核细胞,在粒巨噬细胞集落刺激因子(GM CSF)和白细胞介素4(IL4)的诱导下培养树突状细胞。培养的第7天加入聚肌胞刺激获得成熟树突状细胞,经HBVcore1827肽负载后与自身T淋巴细胞共培养,通过酶联斑点计数法(Elispot)及MHC肽四聚体法(Tetramer)比较病人T细胞未经自身树突状细胞刺激组、经HBVcore1827肽负载的自身树突状细胞刺激组、经聚肌胞促成熟的HBVcore1827肽负载的自身树突状细胞刺激组中HBV特异性的CTL的功能和频数。结果慢性乙型肝炎病人外周血单核细胞体外经GM CSF和IL4诱导可转化为树突状细胞,树突状细胞转化过程中聚肌胞的刺激可显著上调树突状细胞表面分子CD80、CD83的表达(P<0.01),促进树突状细胞的成熟。Elispot法检测分泌IFNγ的CTL的频数病人T细胞未经自身树突状细胞刺激组分泌频数为(9～28)/1×105T细胞,均值16;经HBVcore1827肽负载的自身树突状细胞刺激组频数为(30～67)/1×105T细胞,均值为46;经聚肌胞促成熟的HBVcore1827肽负载的自身树突状细胞刺激组频数为(59～130)/1×105T细胞,均值为98。三组数据