粒细胞-巨噬细胞集落刺激因子基因修饰的树突状细胞疫苗增强体外抗肿瘤免疫效应

目的 研究粒细胞-巨噬细胞集落刺激因子(GM-CSF)基因修饰树突状细胞(DC)后形态、表型及功能的变化,以及增强DC疫苗对肿瘤细胞的体外杀伤作用.方法 小鼠尾静脉注射趋化因子配体3(CCL3),分选得到B220- CDllc+细胞,经细胞因子培养诱导分化DC.在体外用含GM-CSF基因的重组腺病毒(AdGM-CSF)转染DC,酶联免疫吸附试验(ELJSA)检测转染后GM-CSF的水平.通过细胞形态学观察、表型分析及混合淋巴细胞反应(MLR),检测GM-CSF基因修饰前后DC的变化.反复冻融法制备胃癌可溶性抗原,将其与GM-CSF基因修饰的DC共同培养,制备DC疫苗,四甲基偶氮唑蓝(MTT)法检测活化的T淋巴细胞在体外对小鼠前胃癌细胞(MFC)的杀伤作用,ELISA法检测干扰素γ(INF-γ)的分泌情况.结果 CCL3注射后,外周血中B220- CD11c+细胞明显增加,48 h达到高峰[占外周血单个核细胞的(13.88±1.10)%].AdGM-CSF转染后,培养液上清中GM-CSF浓度升高,当感染复数(MOI)为1:100时达到高峰[(130.00±12.61)pg/m1].经GM-CSF.基因修饰的DC在形态上更趋成熟,MHCⅡ类分子、CD80、CD86等细胞表型明显上调,具有更强的刺激T细胞增殖的能力.荷载胃癌抗原的DC激活的T淋巴细胞对MFC细胞具有特异性杀伤作用,并产生高水平的INF-γ[(1245.00±13.75)pg/ml].结论 GM-CSF转染DC后,能大量表达GM-CSF,DC形态及细胞表型更趋成熟,刺激T细胞增殖能力明显增强.GM-CSF基因修饰的DC在体外可诱导出针对靶肿瘤细胞的特异性杀伤作用.     

粒细胞-巨噬细胞集落刺激因子基因修饰的树突状细胞疫苗增强体外抗肿瘤免疫效应

Objective To investigate if granulocyte-macrophage colony stimulating factor (GM-CSF) gene-modified dendritic cells ( DC) enhance antitumor immunity in vitro. Methods Mice were injected with chemokine ligand 3 (CCL3) via the tail vein. Fresh B220-CD11c+ cells were sorted from the peripheral blood mononuclear cells (PBMCs) and cultured into DCs by cytokines. DCs were transfected with AdGM-CSF gene at different ratios of multiplicity of infection ( MOI) to determine the optimal gene transfection conditions, and the expression of GM-CSF was detected after transfection. The variation of GM-CSF gene-modifiedDCs were analyzed by morphological examination, phenotype analysis, and mixed lymphocyte reaction (MLR). DCs were loaded with gastric cancer antigen obtained by freezing and thawing method. The killing effect of DCs vaccine-stimulated T lymphocytes on gastric cancer cells was assessed by MTT assay. INF-γ production was determined with the INF-γ ELISA kit. Results B220- CD11c+ cells increased obviously after CCL3 injection. The ELISA results showed that after GM-CSF gene modification, DCs could produce high level of GM-CSF. When DCs were transfected with AdGM-CSF gene at MOI equal to 100, the GM-CSF level in culture supematants reached saturation [(130.00±12.61) pg/ml]. After GM-CSF gene-modification, DCs tend to be more maturated as detected by morphological observation and phenotype analysis. At the same time, the capacity of activating the proliferation of allogeneic T lymphocytes was enhanced greatly. T lymphocytes stimulated by DCs transfected with GM-CSF gene showed a specific killing effect on gastric carcinoma cells and produced high level of INF-γ[ ( 1245. 00±13. 75) pg/ml].Conclusion After GM-CSF gene modification, DCs can produce high level of GM-CSF, which tend to be more maturated, and the capacity of activating the proliferation of allogeneic T lymphocytes is enhanced greatly. GM-CSF gene modified DCs can induce specific CTL to target tumor cells in vitro.     

粒细胞-巨噬细胞集落刺激因子基因修饰的树突状细胞疫苗增强体外抗肿瘤免疫效应

Objective To investigate if granulocyte-macrophage colony stimulating factor (GM-CSF) gene-modified dendritic cells ( DC) enhance antitumor immunity in vitro. Methods Mice were injected with chemokine ligand 3 (CCL3) via the tail vein. Fresh B220-CD11c+ cells were sorted from the peripheral blood mononuclear cells (PBMCs) and cultured into DCs by cytokines. DCs were transfected with AdGM-CSF gene at different ratios of multiplicity of infection ( MOI) to determine the optimal gene transfection conditions, and the expression of GM-CSF was detected after transfection. The variation of GM-CSF gene-modifiedDCs were analyzed by morphological examination, phenotype analysis, and mixed lymphocyte reaction (MLR). DCs were loaded with gastric cancer antigen obtained by freezing and thawing method. The killing effect of DCs vaccine-stimulated T lymphocytes on gastric cancer cells was assessed by MTT assay. INF-γ production was determined with the INF-γ ELISA kit. Results B220- CD11c+ cells increased obviously after CCL3 injection. The ELISA results showed that after GM-CSF gene modification, DCs could produce high level of GM-CSF. When DCs were transfected with AdGM-CSF gene at MOI equal to 100, the GM-CSF level in culture supematants reached saturation [(130.00±12.61) pg/ml]. After GM-CSF gene-modification, DCs tend to be more maturated as detected by morphological observation and phenotype analysis. At the same time, the capacity of activating the proliferation of allogeneic T lymphocytes was enhanced greatly. T lymphocytes stimulated by DCs transfected with GM-CSF gene showed a specific killing effect on gastric carcinoma cells and produced high level of INF-γ[ ( 1245. 00±13. 75) pg/ml].Conclusion After GM-CSF gene modification, DCs can produce high level of GM-CSF, which tend to be more maturated, and the capacity of activating the proliferation of allogeneic T lymphocytes is enhanced greatly. GM-CSF gene modified DCs can induce specific CTL to target tumor cells in vitro.     

IL-18基因增强肿瘤抗原致敏DC诱导的CTL特异性杀伤肝癌细胞

目的: 探讨腺病毒介导的白细胞介素-18(IL-18)基因转染能否使肿瘤抗原冲击的树突状细胞(dentritic cell,DC) 在体外诱导出更强的抗肝癌免疫反应.方法:携IL-18 的重组腺病毒载体感染经肝癌细胞株HepG2冻融抗原致敏的DC(AdIL-18-HepG2/DC), FACS分析AdIL-18-HepG2/DC表面分子的表达, ELISA法检测IL-18的分泌水平, 3H-TdR掺入法检测T淋巴细胞增殖能力, MTT法检测细胞毒性T 淋巴细胞杀伤效应.结果:AdIL-18-HepG2/DC较未转染DC能高水平地表达CD1a、CD11c、CD80、CD86以及HLA-DR;较未经IL-18转染的DC分泌较高水平的IL-18.AdIL-18-HepG2/DC 能非常有效地刺激自体T 细胞增殖(CPM 值为228 018±1 079),其刺激强度显著强于AdIL-18DC、HepG2/DC、AdlzcZ/DC及DC(均P＜0.05).当靶细胞为HepG2时,AdIL-18-HepG2/DC诱导的CTL杀伤活性显著高于其他各组(均P＜0.05),并且其杀伤能力与效应细胞数量成正比.结论:IL-18 基因转染且肝癌抗原致敏的DC可以显著增强DC的特异性抗肝癌效应.     

IL-18基因增强肿瘤抗原致敏DC诱导的CTL特异性杀伤肝癌细胞

目的:探讨腺病毒介导的白细胞介素18(IL18）基因转染能否使肿瘤抗原冲击的树突状细胞(dentritic cell,DC) 在体外诱导出更强的抗肝癌免疫反应。方法：携IL18 的重组腺病毒载体感染经肝癌细胞株HepG2冻融抗原致敏的DC(AdIL18HepG2/DC), FACS分析AdIL18HepG2/DC表面分子的表达, ELISA法检测IL18的分泌水平, 3HTdR掺入法检测T淋巴细胞增殖能力, MTT法检测细胞毒性T 淋巴细胞杀伤效应。结果： AdIL18HepG2/DC较未转染DC能高水平地表达CD1a、CD11c、CD80、CD86以及HLADR;较未经IL18转染的DC分泌较高水平的IL18。AdIL18HepG2/DC 能非常有效地刺激自体T 细胞增殖(CPM 值为228 018±1 079),其刺激强度显著强于AdIL18DC、HepG2/DC、AdlzcZ/DC及DC（均P＜0.05）。当靶细胞为HepG2时,AdIL18HepG2/DC诱导的CTL杀伤活性显著高于其他各组（均P＜0.05）,并且其杀伤能力与效应细胞数量成正比。结论： IL18 基因转染且肝癌抗原致敏的DC可以显著增强DC的特异性抗肝癌效应。     

Intranodal immunization with tumor lysate-pulsed dendritic cells enhances protective antitumor immunity

We developed a technique for direct inguinal lymph node injection in mice to compare various routes of immunization with tumor lysate-pulsed dendritic cell (DC) vaccines. Syngeneic, bone marrow-derived, tumor lysate-pulsed DCs administered intranodally generated more potent protective antitumor immunity than s.c. or i.v. DC immunizations. Intranodal immunization with ovalbumin peptide-pulsed DCs induced significantly greater antigen-specific T-lymphocyte expansion in the spleen than either s.c. or i.v. immunization. Furthermore, a significantly more potent, antigen-specific TH1-type response to the ovalbumin peptide was induced by intranodal, compared with s.c. or i.v., immunization. Intranodal immunization, designed to enhance DC-T cell interaction in a lymphoid environment, optimizes induction of T lymphocyte-mediated protective antitumor immunity. These results support the use of intranodal immunization as a feasible and effective route of DC vaccine administration.     

人肺腺癌细胞系SPC-A1 mRNA修饰的树突状细胞体外抗肿癌免疫反应

目的探讨人肺腺癌细胞系SPC-A1mRNA转染的人外周血树突细胞(dendriticcell,DC)疫苗在体外诱导特异性抗肿瘤免疫反应的能力。方法从健康人外周血分离外周血单个核细胞(peripheralbloodmononuclearcells,PBMC),在白细胞介素-4(interleu-kin-4,IL-4)和人粒细胞集落刺激因子(granulocyte-macrophagecolony-stimulatingfactor,GM-CSF)作用下诱导培养成DC。体外扩增、转录的方法获得人肺腺癌细胞系SPC-A1mRNA,并利用脂质体转染的方法导入DC,流式检测转染后DC表面标记,并与淋巴细胞共孵育,激活T淋巴细胞,MTT法检测其对人肺腺癌细胞的特异性杀伤活性。结果转染后的DC特异性表面标志及功能相关分子表达显著升高(CD8680·32±1·60;HLA-DR86·03±2·58;CD8326·97±1·62),诱导的特异性杀伤反应能力与经肿瘤细胞裂解物负载的DC、未经转染的DC及空白淋巴细胞组相比显著提高(80·34±2·71,P<0·01)。结论人肺腺癌细胞系SPC-A1mRNA转染的DC疫苗体外诱导的特异性抗肿瘤免疫能力显著增强。     

Interleukin 18 gene transfer expands the repertoire of antitumor Th1-type immunity elicited by dendritic cell-based vaccines in association with enhanced therapeutic efficacy

Dendritic cells (DCs) are potent antigen-presenting cells that can prime and boost systemic antitumor immunity. Here, we have evaluated the ability of DCs transfected to secrete the potent Th1-biasing cytokine interleukin (IL)-18 to promote enhanced antitumor immunity in a mouse sarcoma model. DCs infected with a recombinant adenovirus encoding IL-18 (AdIL18DC) expressed higher levels of MHC and costimulatory molecules and were better stimulators than control DCs in mixed leukocyte reactions in vitro. Immunization of BALB/c mice bearing established day 7 CMS4 tumors with tumor peptide-pulsed control Adpsi5-transfected DCs or nontransduced DCs significantly inhibited the growth of established tumors but did not lead to complete regression of established tumors. Importantly, immunization with antigen-loaded AdIL18DC resulted in tumor rejection or further suppression of tumor growth when compared with controls. The repertoire of naturally presented tumor peptides recognized by splenocytes (as deduced in IFN-gamma ELISA assays) from AdIL18DC-treated animals was far more diverse and of greater magnitude than that of all other groups, in association with improved therapeutic outcome. These results support the ability of IL-18 gene transfer to enhance the capacity of DCs to drive broadly reactive Th1-type therapeutic immunity prompted by single peptide epitope-based vaccines (i.e., epitope spreading).     

Experiments evaluating antitumor immunity induced by cholesterol hemisuccinate-treated syngeneic cell vaccines

Evaluation of the efficiency of immunizations with syngeneic tumor vaccines prepared from cells treated with cholesterol hemisuccinate (CHS) was performed in five animal models: P815 mastocytoma in DBA/2 mice, MCA-103 fibrosarcoma in C57BL/6N mice, L1210 leukemia in DBA/2 mice, Ehrlich ascites carcinoma in C57BL/6N mice, and CBP pancreatic cancer in CB/SsLak hamsters. Animals received two to four weekly intraperitoneal immunizations with 10(6) or 10(7) tumor cells, followed by challenges with syngeneic viable tumor cells. Survival and tumor growth rates were observed. No significant differences were observed among animals immunized with CHS-treated irradiated tumor vaccines, nontreated irradiated tumor vaccines, and nonimmunized controls in the P815, MCA-103, L1210, and CBP models. Mice immunized with nontreated irradiated Ehrlich ascites cell vaccines showed longer survival than those immunized with CHS-treated irradiated cell vaccines and nonimmunized controls. Results indicated that CHS-treated tumor cell vaccines were not effective in protecting against tumor challenges in five different syngeneic tumor models.     

树突状细胞诱导的抗肿瘤免疫预防肝癌转移

目的 探讨树突状细胞（ＤＣ）体外诱导的抗肿瘤免疫在肝癌患者体内的抗转移作用。方法 直癌患者外周血ＤＣ及Ｔ淋巴细胞,ＨｅｐＧ２细胞抗原激活ＤＣ,粒／巨噬细胞集落刺激因子和白细胞介素－４联合刺激ＤＣ,ＤＣ诱导自体Ｔ淋巴细胞增殖分化为细胞毒性Ｔ细胞（ＣＴＬ）,ＤＣ及其诱导的ＣＴＬ回输肝癌患者,检测肝癌患者外周血ＡＦＰ为ｍＲＮＡ。结果 ＡＦＰ ｍＲＮＡ阳性组经ＤＣ及其诱导的ＣＴＫ,治疗２月后,治疗组９例Ａ     

Impaired dendritic cell function in aging leads to defective antitumor immunity

We recently reported that bone marrow-derived dendritic cells (DC) from aged miced are less effective than their young counterparts in inducing the regression of B16-ovalbumin (OVA) melanomas. To examine the underlying mechanisms, we investigated the effect of aging on DC tumor antigen presentation and migration. Although aging does not affect the ability of DCs to present OVA peptide((257-264)), DCs from aged mice are less efficient than those from young mice in stimulating OVA-specific T cells in vitro. Phenotypic analysis revealed a selective decrease in DC-specific/intracellular adhesion molecule type-3-grabbing nonintegrin (DC-SIGN) level in aged DCs. Adoptive transfer experiments showed defective in vivo DC trafficking in aging. This correlates with impaired in vitro migration and defective CCR7 signaling in response to CCL21 in aged DCs. Interestingly, vaccination of young mice using old OVA peptide((257-264))-pulsed DCs (OVA PP-DC) resulted in impaired activation of OVA-specific CD8(+) T cells in vivo. Effector functions of these T cells, as determined by IFN-gamma production and cytotoxic activity, were similar to those obtained from mice vaccinated with young OVA PP-DCs. A decreased influx of intratumor CD8(+) T cells was also observed. Importantly, although defective in vivo migration could be restored by increasing the number of old DCs injected, the aging defect in DC tumor surveillance and OVA-specific CD8(+) T-cell induction remained. Taken together, our findings suggest that defective T-cell stimulation contributes to the observed impaired DC tumor immunotherapeutic response in aging.     

Epigallocatechin-3-gallate enhances CD8+ T cell-mediated antitumor immunity induced by DNA vaccination

Immunotherapy and chemotherapy are generally effective against small tumors in animal models of cancer. However, these treatment regimens are generally ineffective against large, bulky tumors. We have found that a multimodality treatment regimen using DNA vaccination in combination with chemotherapeutic agent epigallocatechin-3-gallate (EGCG), a compound found in green tea, is effective in inhibiting large tumor growth. EGCG was found to induce tumor cellular apoptosis in a dose-dependent manner. The combination of EGCG and DNA vaccination led to an enhanced tumor-specific T-cell immune response and enhanced antitumor effects, resulting in a higher cure rate than either immunotherapy or EGCG alone. In addition, combined DNA vaccination and oral EGCG treatment provided long-term antitumor protection in cured mice. Cured animals rejected a challenge of E7-expressing tumors, such as TC-1 and B16E7, but not a challenge of B16 7 weeks after the combined treatment, showing antigen-specific immune responses. These results suggest that multimodality treatment strategies, such as combining immunotherapy with a tumor-killing cancer drug, may be a more effective anticancer strategy than single-modality treatments.     

A dendritic cell-derived receptor counteracts antitumor immunity

The TIM-3 receptor on dendritic cells inhibits nucleic acid-stimulated antitumor immunity.     

Signaling through OX40 enhances antitumor immunity

The existence of tumor-specific T cells, as well as their ability to be primed in cancer patients, confirms that the immune response can be deployed to combat cancer. However, there are obstacles that must be overcome to convert the ineffective immune response commonly found in the tumor environment to one that leads to sustained destruction of tumor. Members of the tumor necrosis factor (TNF) superfamily direct diverse immune functions. OX40 and its ligand, OX40L, are key TNF members that augment T-cell expansion, cytokine production, and survival. OX40 signaling also controls regulatory T-cell differentiation and suppressive function. Studies over the past decade have demonstrated that OX40 agonists enhance antitumor immunity in preclinical models using immunogenic tumors; however, treatment of poorly immunogenic tumors has been less successful. Combining strategies that prime tumor-specific T cells together with OX40 signaling could generate and maintain a therapeutic antitumor immune response.     

粒细胞-巨噬细胞集落刺激因子基因修饰的树突状细胞疫苗增强体外抗肿瘤免疫效应

Objective: The aim of the study was to investigate whether dendritic cell (DC) precursors, recruited by injection of chemokine ligand 3 (CCL3), induce enhanced anti-tumor immunity after granulocyte-macrophage colony stimulating factor (GM-CSF) transfection in mice ex vivo. Methods: The 615 mice were injected with CCL3 via the tail vein. Freshly isolated B220–CD11c+ cells were cultured with cytokines. For adenoviral (Ad)-mediated gene transduction, DCs were transferred AdGM-CSF gene at different ratios of mu...     

Engineered fusion hybrid vaccine of IL-4 gene-modified myeloma and relative mature dendritic cells enhances antitumor immunity

Dendritic cell (DC)-tumor fusion hybrid vaccine which facilitates antigen presentation represents a new powerful strategy in cancer therapy. In the present study, we investigated the antitumor immunity derived from vaccination of fusion hybrids between wild-type J558 or engineered J558-IL-4 myeloma cells secreting cytokine interleukin-4 (IL-4) and immature DCs (DC(IMAT)) or relative mature DCs (DC(RMAT)). DC(RMAT) displayed an up-regulated expression of immune molecules (Ia(d), CD40, CD54, CD80 and CD86) and certain cytokines/chemokines, and enhanced ability of allogeneic T cell stimulation when compared to DC(IMAT). These DCs were fused with myeloma cells by polyethylene glycol (PEG). The fusion efficiency was approximately 20%. Our data showed that immunization of C57BL/6 mice with DC(RMAT)/J558 hybrids induced protective immunity against a high dose of J558 tumor challenge (1x10(6) cells) in 3 out of 10 immunized mice, compared with no protection seen in mice immunized with DC(IMAT)/J558 hybrids. Furthermore, immunization of mice with engineered DC(RMAT)/J558-IL-4 hybrids elicited stronger J558 tumor-specific cytotoxic T lymphocyte (CTL) responses in vitro and induced more efficient protective immunity (10/10 mice; tumor free) against J558 tumor challenge in vivo than DC(RMAT)/J558 hybrid vaccines. The results demonstrate the importance of DC maturation in DC-tumor hybrid vaccines and indicate that the engineered fusion hybrid vaccines which combine gene-modified tumor and DC vaccines may be an attractive strategy for cancer immunotherapy.     

Pretreatment with cisplatin enhances E7-specific CD8+ T-Cell-mediated antitumor immunity induced by DNA vaccination.

PURPOSE: Because the combination of multiple modalities for cancer treatment is more likely to generate more potent therapeutic effects for the control of cancer, we have explored the combination of chemotherapy using cisplatin, which is routinely used in chemotherapy for advanced cervical cancer, with immunotherapy using DNA vaccines encoding calreticulin (CRT) linked to human papillomavirus type 16 E7 antigen (CRT/E7) in a preclinical model. EXPERIMENTAL DESIGN: We characterized the combination of cisplatin with CRT/E7 DNA vaccine using different regimen for its potential ability to generate E7-specific CD8+ T-cell immune responses as well as antitumor effects against E7-expressing tumors. RESULTS: Our results indicate that treatment of tumor-bearing mice with chemoimmunotherapy combining cisplatin followed by CRT/E7 DNA generated the highest E7-specific CD8+ T-cell immune response and produced the greatest antitumor effects and long-term survival as well as significant levels of E7-specific tumor-infiltrating lymphocytes compared with all the other treatment regimens. Furthermore, we found that treatment with cisplatin leads to the cell-mediated lysis of E7-expressing tumor cells in vitro and increased number of E7-specific CD8+ T-cell precursors in tumor-bearing mice. In addition, we observed that E7-specific CD8+ T cells migrate to and proliferate in the location of TC-1 tumors in mice treated with cisplatin. CONCLUSIONS: Thus, our data suggest that chemoimmunotherapy using cisplatin followed by CRT/E7 DNA vaccine is an effective treatment against E7-expressing tumors and may potentially be translated into the clinical arena.     

Depletion of dendritic cells delays ovarian cancer progression by boosting antitumor immunity

Dendritic cells (DC) and cytokines that expand myeloid progenitors are widely used to treat cancer. Here, we show that CD11c(+)DEC205(+) DCs coexpressing alpha-smooth muscle actin and VE-cadherin home to perivascular areas in the ovarian cancer microenvironment and are required for the maintenance of tumor vasculature. Consequently, depletion of DCs in mice bearing established ovarian cancer by targeting different specific markers significantly delays tumor growth and enhances the effect of standard chemotherapies. Tumor growth restriction was associated with vascular apoptosis after DC ablation followed by necrosis, which triggered an antitumor immunogenic boost. Our findings provide a mechanistic rationale for selectively eliminating tumor-associated leukocytes to promote antitumor immunity while impeding tumor vascularization and to develop more effective DC vaccines based on a better understanding of the tumor microenvironment.