NDV联合热固化瘤苗的抗肿瘤作用

为了研究新城疫病毒（ＮＤＶ） 联合热固化瘤苗抑制肿瘤生长和免疫调节的作用，检测了荷瘤小鼠的抑瘤率和细胞免疫。结果显示，实验组Ⅰ与Ⅱ抑瘤率分别为２４．８％ 、４１．１％ ，２ 组的平均瘤重明显小于对照组，实验组Ⅱ在不同时间段的ＮＫ 细胞活性高于对照组（ Ｐ＜０ ．０１） 。提示ＮＤＶ联合热瘤苗对荷瘤小鼠的抑瘤作用和增强ＮＫ 细胞活性均比单独应用ＮＤＶ效果好。     

新城疫病毒对人胃癌细胞的抑制杀伤作用

目的：研究新城疫病毒（ＮＤＶ）对人胃癌细胞株的作用。方法：利用ＭＴＴ方法检测ＮＤＶ对人胃癌细胞株的杀伤性。结果：ＮＤＶ作用后的人胃癌细胞株的细胞活性比对照的细胞活性有显著下降（Ｐ〈０．０１），且ＮＤＶ血凝效价值显著升高，表明ＮＤＶ能杀死肿瘤细胞。结论：ＤＮＡ能够直接杀死肿瘤细胞，可作为治疗肿瘤的一种新生物制剂。     

鸡新城疫病毒抗肿瘤作用及其机制的研究进展

鸡新城疫病毒（ｎｅｗｃａｓｔｌｅ ｄｉｓｅａｓｅ ｖｉｒｕｓ,ＮＤＶ）感染机体可以诱导产生干扰素、白细胞介素、肿瘤坏死因子等细胞因子,这些细胞因子能够在患瘤机体内发挥抗肿瘤作用。ＤＮＶ的随着蛋白（ｈｅｍａｇｇｌｕｔｉｎｉｎ－ｎｅｕｒａｍｉｄａｓｅ,ＨＮ蛋白）具有增加瘤细胞对淋巴细胞的粘附力、刺激淋巴细胞的分化和改变肿瘤细胞的免疫原性等作用,同时ＮＤＶ可以激活患瘤机体的免疫细胞,使免疫细胞发挥细胞毒     

新城疫病毒瘤苗对荷瘤小鼠的主动免疫治疗作用

将小鼠原发性肝癌细胞（Ｈ２２）经γ射线照射灭活后，与新城疫病毒（ＮＤＶ）共同孵育，制备病毒瘤苗，透射电镜下见ＮＤＶ吸附于Ｈ２２细胞表面。以病毒瘤苗皮内注射治疗不同负荷的Ｈ２２肿瘤荷瘤小鼠，连续２次，间隔１周，每次每只小鼠免疫剂量为１．５×１０７个肿瘤细胞。结果表明病毒瘤苗能抑制肿瘤生长，对荷瘤小鼠有主动特异性免疫治疗作用。各免疫组小鼠存活时间较对照组明显延长，肿瘤重量较对照组轻，肿瘤的平均直径也较对照组小，免疫组荷瘤存活小鼠肿瘤病理切片显示肿瘤细胞呈中、重度坏死，坏死的肿瘤细胞之间及其周围可见大量淋巴细胞及单核样细胞浸润，并有纤维组织增生。     

热瘤苗和新城疫病毒的联合抗瘤作用

高温处理肿瘤细胞能增强肿瘤细胞的免疫原性,这已被许多研究者所证实［１,２］。我们利用普通水浴方法制备的热瘤苗免疫小鼠,使荷瘤小鼠的生存期得于延长［２］;而新城疫病毒（ｎｅｗ　ｃａｓｔｌｅ　ｄｉｓｅａｓｅ　ｖｉｒｕｓ,ＮＤＶ）也被证实能直接杀伤肿瘤细胞,而对人无毒性,并在肿瘤患者治疗中取得可靠疗效［３］。而用两者联合抵抗肿瘤的作用未见国内报道。在此,我们研究了两者抵抗肿瘤的协同作用,现报告如下。１材料与方法１．１　动物 昆明系小鼠,雌性,体重２０ｇ左右,购自华西医科大学实验动物中心。小鼠肝癌细胞（…     

复合瘤苗TVPBH治疗肿瘤的临床应用研究

目的重点评价人用复合瘤苗的安全性及有效性。方法应用３０例恶性实体瘤手术切除的自身肿瘤组织制成多因素处理的病毒异种化瘤苗ＴＶＰＢＨ,对术后患者进行主动免疫治疗,以１５例患者作为对照。结果发现治疗组患者外周血ＣＤ＋４／ＣＤ＋８细胞比值及ＮＫ细胞活性在治疗后显著高于术前水平（Ｐ＜０．０１）,对照组变化不显著（Ｐ＞０．０５）;两组ＴＮＦ－α和ＩＬ－２含量在治疗前后均有显著变化（Ｐ＜０．０１）,治疗组变化辐度高于对照组（Ｐ＜０．０５）;治疗过程中未观察到明显的毒副作用;通过透射电镜还观察到瘤苗中的新城疫病毒（ＮＤＶ）对来源于消化道的肿瘤细胞易感而对乳腺来源的瘤细胞不易感。结论ＴＶＰＢＨ是一种高特异性的安全有效的免疫制剂。远期疗效在进一步观察中。     

树突状细胞局部免疫抗瘤作用的初步研究

目的：探讨树突状细胞（ＤＣ）瘤内注射的局部免疫方式对小鼠Ｈ２２肿瘤的治疗效果。方法：体外诱导生成树突状细胞,经Ｈ２２肿瘤裂解抗原致敏,实验分为对照组、ＤＣ组和ＤＣ＋ＣｐＧ-ＯＤＮ组,分别与Ｔ细胞共培养,收获的Ｔ细胞与肿瘤细胞共培养,观察其对肿瘤细胞的杀伤。体内试验：ＢＡＬＢ／ｃ小鼠皮下接种Ｈ２２肿瘤细胞制作成荷瘤鼠,第４天时进行局部瘤内免疫治疗,分为３组：生理盐水组、ＤＣ组和ＤＣ＋ＣｐＧ-ＯＤＮ组,免疫治疗１０天后处死小鼠,观察其治疗小鼠Ｈ２２肿瘤的效果。结果：体外实验中,对照组、ＤＣ组和ＤＣ＋ＣｐＧ-ＯＤＮ组的肿瘤杀伤率分别为（１０.８０±３.２７）％、（３８.２６±５.６０）％和（４２.６６±９.００）％,后两组杀伤率均高于对照组（Ｐ＜０.０１）;体内实验中,生理盐水组、ＤＣ组和ＤＣ＋ＣｐＧ-ＯＤＮ组的平均瘤重（ｇ）分别为１.８０４±０.４２２、１.２１６±０.３３５和０.７３３±０.１９１（Ｐ＜０.０１）。结论：ＤＣ瘤苗局部瘤内注射可抑制小鼠Ｈ２２肿瘤的生长,联合应用非甲基化ＣｐＧ-ＯＤＮ可以明显提高抑瘤效果。     

新城鸡瘟病毒诱导小鼠腹腔巨噬细胞产生肿瘤坏死因子的细胞毒…

目的 观察新城鸡瘟病毒Ｌ系（ＮＤＶ－Ｌ）诱导小鼠腹腔巨噬细胞（ＰＥＭΦ）产生的肿瘤坏死因子－α（ＴＮＦ－α）对肿瘤细胞的细胞毒性作用。方法 采用噻唑蓝（ＭＴＴ）和＾３Ｈ－脱氧胸苷（＾３Ｈ－ＴｄＲ）标记肿瘤细胞的方法。结果 ＮＤＶ－Ｌ可诱导小鼠ＰＥＭΦ产生ＴＮＦ－α其产生的量随ＮＤＶ－Ｌ感染量的增加而活性增强，当ＮＤＶ－Ｌ感染剂量一定时，ＴＮＦ－α释放量在ＮＤＶ－Ｌ作用ＰＥＭΦ２４ｈ时为最强（１００     

新城鸡瘟病毒诱导小鼠腹腔巨噬细胞产生肿瘤坏死因子的细胞毒活性研究

目的观察新城鸡瘟病毒Ｌ系（ＮＤＶ－Ｌ）诱导小鼠腹腔巨噬细胞（ＰＥＭΦ）产生的肿瘤坏死因子－α（ＴＮＦ－α）对肿瘤细胞的细胞毒性作用。方法采用噻唑蓝（ＭＴＴ）和３Ｈ－脱氧胸苷（３Ｈ－ＴｄＲ）标记肿瘤细胞的方法。结果ＮＤＶ－Ｌ可诱导小鼠ＰＥＭΦ产生ＴＮＦ－α，其产生的量随ＮＤＶ－Ｌ感染量的增加而活性增强。当ＮＤＶ－Ｌ感染剂量一定时，ＴＮＦ－α释放量在ＮＤＶ－Ｌ作用ＰＥＭΦ２４ｈ时为最强（１００Ｕ／ｍｌ）。用３Ｈ－ＴｄＲ标记肿瘤细胞（小鼠乳腺癌细胞系Ｃａ７６１－８６和小鼠肥大细胞瘤Ｐ８１５）做ＴＮＦ－α的细胞毒试验，表明其具有明显的杀伤活性。结论ＮＤＶ－Ｌ诱导小鼠腹腔巨噬细胞产生的ＴＮＦ－α具有明显的细胞毒活性。     

新城疫病毒修饰的自体肿瘤疫苗研究进展

新城疫病毒 (ＮＤＶ )是一种禽类的副粘液病毒 ,具有多组织亲和性的免疫刺激性特点 ,它能在肿瘤细胞质中选择性的复制而不依赖于细胞的增殖 ,属于非致癌性的病毒。能有效而安全的转染肿瘤细胞[1] 。ＡＴＶ ＮＤＶ是用ＮＤＶ感染已经灭能但存活的患者自体肿瘤细胞制成瘤苗 ,对肿瘤患者进行术后主动特异性免疫治疗 (ＡＳＩ)。ＮＤＶ感染种瘤细胞后 ,在细胞表面引入了病毒自身的神经氨酸酶分子 (ＨＮ)和融和蛋白 (Ｆ) ,诱导Ｔ细胞共刺激活性、诱导细胞因子和局部趋化因子 ,增强肿瘤特异性抗原的表达 ,产生特异性抗肿瘤作用。ＡＴＶ ＮＤＶ因具…     

新城疫病毒Lasota 弱毒株对人肿瘤细胞的体外修饰作用

 目的 研究新城疫病毒（NDV）弱毒株Lasota对体外培养的人肿瘤细胞株免疫功能的影响。方法 以不同病毒滴度作用于肿瘤细胞，采用MTT染色法检测NDV对肿瘤细胞的杀伤作用，同时用NDV处理过的小鼠黑色素B16细胞免疫小鼠，检测其对小鼠NK细胞活性影响。结果 NDV Lasota株对4种癌细胞株均具有较强的杀伤作用，用其处理小鼠黑色素瘤细胞株后，再次接种可提高小鼠体内的NK细胞活性。结论 NDV能够抑制肿瘤细胞生长，诱导其凋亡，免疫接种小鼠后，可提高小鼠的细胞免疫功能。     

莪术醇生物修饰构建的瘤苗治疗胃癌的实验研究

目的探讨中药莪术的提取物——莪术醇修饰构建的肿瘤细胞疫苗对SGC-7901胃癌的抗瘤效应及联合新城鸡疫病毒(NDV)疫苗的综合效应。方法对SGC-7901胃肿瘤细胞进行系列处理,用莪术醇及NDV对其进行系列生物构建,修饰构建的瘤苗经免疫小鼠(1次/周×3)21天后,接种SGC-7901胃肿瘤细胞,根据设计观察各组抑制肿瘤肺转移、皮下结节形成、生存时间状况及LAK细胞的杀伤效应。结果经莪术醇修饰构建的SGC-7901肿瘤疫苗与对照组相比能明显阻止胃癌细胞的肺转移,显著抑制皮下肿瘤结节形成,明显延长荷瘤鼠的生存时间(P<0.05);用各组免疫接种后长期存活的脾细胞制备的LAK细胞,较同龄未免疫小鼠的脾细胞制备的LAK细胞具有更强的抗瘤效应(P<0.05);由NDV构建的疫苗的抗瘤作用低于莪术醇瘤苗组,莪术醇与NDV联合构建的瘤苗其抗瘤作用未呈现生物放大及相加效应。结论莪术醇修饰构建的SGC-7901新型肿瘤疫苗可以增强胃肿瘤细胞的免疫原性,对胃癌有较好的实验治疗作用。     

SC及NDV修饰的瘤苗治疗胃癌的实验疗效研究

目的 :研究中药三棱、莪术的提取物SC修饰构建的肿瘤细胞疫苗对SGC 790 1胃癌细胞株的抗瘤效应及联合新城鸡疫病毒疫苗的实验杀瘤疗效。方法 :对SGC 790 1胃肿瘤细胞进行系列处理 ,用SC(sparganiumstoloniferumBuehhum、Curcumazedoariarosc SC ,Chinesetraditionalmedicine )及NDV (新城鸡瘟病毒 )对其进行生物构建 ,修饰构建的瘤苗经免疫小鼠 (1次 /周× 4 ) 2 8d后 ,接种SGC 790 1胃肿瘤细胞 ,观察抑制肿瘤肺转移、皮下结节形成及生存时间状况。结果 :经SC修饰构建的SC SGC 790 1瘤苗能明显阻止胃癌细胞的肺转移 ,显著抑制皮下肿瘤结节形成 ,能明显延长荷瘤鼠的生存时间 ,与对照组相比差异有显著性 (P <0 0 5 )。由NDV构建的疫苗的抗瘤作用低于SC瘤苗组 ,在延长荷瘤鼠生存期方面和单瘤苗组相近 ,SC与NDV联合构建的瘤苗其抗瘤未呈生物放大及相加效应。结论 :SC修饰构建的SGC 790 1新型疫苗可以增强胃肿瘤细胞的免疫原性 ,对胃癌有较好的实验治疗效果     

Ubiquitinated proteins enriched from tumor cells by a ubiquitin binding protein Vx3(A7) as a potent cancer vaccine

Background

Our previous studies have demonstrated that autophagosome-enriched vaccine (named DRibbles: DRiPs-containing blebs) induce a potent anti-tumor efficacy in different murine tumor models, in which DRibble-containing ubiquitinated proteins are efficient tumor-specific antigen source for the cross-presentation after being loaded onto dendritic cells. In this study, we sought to detect whether ubiquitinated proteins enriched from tumor cells could be used directly as a novel cancer vaccine.

Methods

The ubiquitin binding protein Vx3(A7) was used to isolate ubiquitinated proteins from EL4 and B16-F10 tumor cells after blocking their proteasomal degradation pathway. C57BL/6 mice were vaccinated with different doses of Ub-enriched proteins via inguinal lymph nodes or subcutaneous injection and with DRibbles, Ub-depleted proteins and whole cell lysate as comparison groups, respectively. The lymphocytes from the vaccinated mice were re-stimulated with inactivated tumor cells and the levels of IFN-γ in the supernatant were detected by ELISA. Anti-tumor efficacy of Ub-enriched proteins vaccine was evaluated by monitoring tumor growth in established tumor mice models. Graphpad Prism 5.0 was used for all statistical analysis.

Results

We found that after stimulation with inactivated tumor cells, the lymphocytes from the Ub-enriched proteins-vaccinated mice secreted high level of IFN-γ in dose dependent manner, in which the priming vaccination via inguinal lymph nodes injection induced higher IFN-γ level than that via subcutaneous injection. Moreover, the level of secreted IFN-γ in the Ub-enriched proteins group was markedly higher than that in the whole cell lysate and Ub-depleted proteins. Interestingly, the lymphocytes from mice vaccinated with Ub-enriched proteins, but not Ub-depleted proteins and whole cell lysates, isolated from EL4 or B16-F10 tumor cells also produced an obvious level of IFN-γ when stimulated alternately with inactivated B16-F10 or EL4 tumor cells. Furthermore, Ub-enriched proteins vaccine showed a significant inhibitory effect on in vivo growth of homologous tumor, as well as allogeneic tumor, compared with Ub-depleted proteins and tumor cell lysate. Tumor growth was regressed after three times of vaccination with Ub-enriched proteins in contrast to other groups.

Conclusion

These results indicated that Ub-enriched proteins isolated from tumor cells may have a potential as a potent vaccine for immunotherapy against cancer.     

三棱、莪术提取物修饰的肿瘤细胞疫苗的非特异性抗瘤实验研究

目的:研究SE(三棱、莪术)提取物修饰的肿瘤细胞疫苗对B16小鼠恶性黑色素瘤的抗瘤效应。方法:用丝裂霉素等对K562肿瘤细胞进行灭活处理,用SE提取物进行修饰异构,经SE提取物修饰的肿瘤细胞(K562)作为瘤苗免疫小鼠,14天后再接种B16细胞,观察其抗瘤效应。取小鼠脾细胞制备LAK细胞,将LAK细胞注入小鼠腹腔,观察小鼠的存活时间。结果:SE修饰的瘤苗组存活时间为(52.71±8.26)天,与单纯瘤苗组、单纯SE中药组相比,瘤苗免疫后的小鼠存活期明显延长,有显著性差异(P<0.05);SE中药对照组治疗后其LAK细胞及NKC对B16、S180的杀伤效应明显低于SE修饰的瘤苗组(P<0.05),而正常对照组的LAK细胞对B16、S180的杀伤效应低于SE中药对照组(P<0.05);利用SE中药修饰的瘤苗免疫长期存活的小鼠脾细胞制备LAK细胞,较同龄未免疫小鼠的脾细胞制备的LAK细胞具有更强的抗瘤性。生存时间实验组(SE中药+K562+LAK)为57.26天,均长于其它对照组(P<0.05)。结论:SE中药修饰肿瘤细胞疫苗可以明显增强对B16的抗瘤效应。     

Effectiveness of a Simply Designed Tumor Vaccine in Prevention of Malignant Melanoma Development

We investigated the efficacy of a simple syngeneic tumor vaccine to induce specific antitumor immunity in female C57B1/6 mice. Tumor vaccine was prepared by mixing irradiated B-16 melanoma tumor cells with the pleiotropic biological response modifier—maleic anhydride divinyl ether (MVE-2). Experimental animals were pretreated with the vaccine in order to prevent the development of intraperitoneal (i.p.) B-16 melanoma tumors after inoculation of viable tumor cells. More than 40% of prevaccinated animals challenged i.p. with 5×10⁵ viable tumor cells were completely protected from tumor development and remained tumor-free 100 days after tumor cell inoculation. The percentage of tumor-free animals (survivors) rose to as much as 90% when the application of tumor vaccine was repeated two weeks after the first vaccination (i.e. one week after the inoculation of viable tumor cells). The induced antitumor response depended predominantly upon macro-phage function, since vaccinated animals which were depleted of peritoneal macrophages died within the same time range as animals in the control group. Also, tumor-type specificity of the vaccine was confirmed by the fact that the animals vaccinated with B-16 melanoma vaccine were not protected from the development of another type of tumor. In conclusion, comparison of the experimental data with the data from the literature suggests that our simple tumor vaccine may be as effective as genetically engineered tumor vaccines. At the same time, this kind of vaccine is easier to control and thus safer to apply in humans when compared to genetically engineered vaccines.     

Effectiveness of a simply designed tumor vaccine in prevention of malignant melanoma development.

We investigated the efficacy of a simple syngeneic tumor vaccine to induce specific antitumor immunity in female C57Bl/6 mice. Tumor vaccine was prepared by mixing irradiated B-16 melanoma tumor cells with the pleiotropic biological response modifier-maleic anhydride divinyl ether (MVE-2). Experimental animals were pretreated with the vaccine in order to prevent the development of intraperitoneal (i.p.) B-16 melanoma tumors after inoculation of viable tumor cells. More than 40% of prevaccinated animals challenged i.p. with 5 x 10(5) viable tumor cells were completely protected from tumor development and remained tumor-free 100 days after tumor cell inoculation. The percentage of tumor-free animals (survivors) rose to as much as 90% when the application of tumor vaccine was repeated two weeks after the first vaccination (i.e. one week after the inoculation of viable tumor cells). The induced antitumor response depended predominantly upon macrophage function, since vaccinated animals which were depleted of peritoneal macrophages died within the same time range as animals in the control group. Also, tumor-type specificity of the vaccine was confirmed by the fact that the animals vaccinated with B-16 melanoma vaccine were not protected from the development of another type of tumor. In conclusion, comparison of the experimental data with the data from the literature suggests that our simple tumor vaccine may be as effective as genetically engineered tumor vaccines. At the same time, this kind of vaccine is easier to control and thus safer to apply in humans when compared to genetically engineered vaccines.     

Antigen-specific immunotherapy for murine lung metastatic tumors expressing human papillomavirus type 16 E7 oncoprotein

An important goal of cancer immunotherapy is to prevent and treat tumor metastasis. We have previously reported a recombinant vaccinia-based vaccine (Sig/E7/LAMP-1) that demonstrated significant anti-tumor effect in a subcutaneous tumor challenge model. In this study, we investigated the potency of the Sig/E7/LAMP-1 vaccine in preventing and treating metastatic tumors. A tumor metastasis model was generated by injecting human papillomavirus type 16 (HPV-16) E6/E7 expressing tumor cells, designated TC-1, into the tail vein of syngeneic C57BL/6 mice. All the naive mice injected with 1 × 10⁶ TC-1 cells developed tumors confined exclusively to the lungs within 1 month. For in vivo tumor prevention experiments, mice were vaccinated with Sig/E7/LAMP-1 followed by tumor challenge. While tumor growth was observed in all of the mice (10/10) in the control groups, 8 of 10 vaccinated mice (80%) remained tumor-free 2 months post-tumor challenge. For in vivo treatment experiments, mice were first inoculated with TC-1 cells and then vaccinated with Sig/E7/LAMP-1. Treatment with Sig/E7/LAMP-1 was effective in eliminating preexisting tumor cells in 4 of 5 vaccinated mice. Most importantly, treatment with Sig/E7/LAMP-1 resulted in regression of fully established lung tumors in 50% (5/10) of vaccinated mice. Our data suggest that the Sig/E7/LAMP-1 vaccine is effective in controlling the hematogenous spread of TC-1 tumor cells. In addition, the TC-1 lung metastasis model can be used to test the efficacy of various E6/E7-specific vaccines and immunotherapeutic strategies. Int. J. Cancer 78:41–45, 1998.© 1998 Wiley-Liss, Inc.     

应用细胞因子缓释微球的肿瘤疫苗治疗肝癌的研究

目的 探讨采用细胞因子缓释微球的肿瘤疫苗预防和治疗肝癌的疗效及抗癌机制。方法 我们研制开发了一种肿瘤疫苗,其组成是固定的肿瘤细胞或组织碎片、细胞因子缓释微球和免疫辅助药。采用多聚甲醛固定的小鼠Hepal-6细胞或肿瘤碎片、微球包装的GM—CSF和／IL—2和合成TiterMax Gold等不同成份的瘤苗皮内接种C57BL／6J小鼠,随后肝内接种活体Hepal-6细胞。结果 对照组15只小鼠全部发展成肝肿瘤;含有固定Hepal-6细胞和IL-2及GM—CSF微球的肿瘤疫苗,80％小鼠获得保护。再加入免疫辅助剂TiterMax Gold的肿瘤疫苗,则87％小鼠获得保护。将Hepal-6细胞接种于左躯干皮下。肿瘤长至直径5mm时,皮内接种肿瘤疫苗2次。结果显示,对照组肿瘤继续生长。疫苗组在第2次接种后7—10天,10只小鼠中9只肿瘤生长受到抑制,随后明显缩小。60％小鼠的肿瘤完全消散。细胞毒性实验结果显示,未接种疫苗的小鼠脾细胞不能杀灭Hepal-6细胞和其他肿瘤细胞;而接种疫苗的小鼠脾细胞对Hepal-6细胞杀瘤活性达41％,但对B16—Fl,Lewis肺癌细胞(LLC),肾癌细胞(Renca),膀胱癌细胞(MBT-2)则无效。疫苗的Ⅰ期临床实验结果显示肝癌疫苗能有效地预防肝癌术后复发,诱导DTH反应。结论 肝癌疫苗能有效预防和治疗原发性肝癌,其抗瘤机制是诱导内源性抗原特异性CTL反应,其杀瘤特性是由典型的：MHC—Ⅰ限制的CD8^ T细胞所介导的。     

Novel vaccination protocol consisting of injecting MUC1 DNA and nonprimed dendritic cells at the same region greatly enhanced MUC1-specific antitumor immunity in a murine model

In order to induce specific antitumor immunity in mice, we attempted to immunize C57BL/6 mice with DNA vaccine encoding MUC1 polypeptide. When the mice immunized with MUC1 DNA were challenged with EL4-muc, MUC1-transfected syngeneic lymphoma cells, they completely rejected tumors. When DNA vaccine was given to the EL4-muc tumor-bearing mice, this vaccination was insufficient to suppress tumor growth in the mice. However, activated, but nonprimed dendritic cells (DCs) obtained from syngeneic mice and MUC1 DNA vaccine were given simultaneously to the same site of EL4-muc tumor-bearing mice, tumor growth was markedly suppressed accompanying prolongation of survival time. MUC1 antigen was detected on the DCs at the vaccination site and in regional nodes in the mice which received MUC1 DNA vaccine and DCs. These mice showed markedly enhanced cellular immune responses specific for MUC1 compared to those in mice vaccinated with MUC1 DNA alone. No significant difference in titers of antibodies to MUC1 between the two groups was observed. These results suggest that nonprimed DCs inoculated at the DNA vaccine site are essential for eliciting strong antitumor cellular immunity to suppress tumor growth efficiently in DNA-vaccinated mice. This animal model is useful for developing DNA vaccine for anti-cancer immunotherapy.