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。     

莪术醇瘤苗治疗胃癌的实验研究

目的：研究中药单体莪术醇生物修饰构建的肿瘤细胞瘤苗对荷瘤小鼠（SGC-7901胃癌）的免疫功能影响及治疗效率。方法：观察莪术醇-SGC-7901细胞瘤苗体外激活脾淋巴细胞的能力，体内成瘤性变化及作为瘤苗对荷瘤胃癌的小鼠治疗作用。结果：莪术醇-SGC-7901细胞瘤苗在体外能有效诱导免疫细胞活化增殖和特异性CTL活性的产生，体内的成瘤能力明显下降，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）；经莪术醇修饰构建的SGC-7901瘤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）；接种瘤苗后对荷瘤胃癌小鼠有较好的治疗效果。结论：莪术醇修饰构建的SGC-7901新型疫苗可以增强胃肿瘤细胞的免疫原性，对荷瘤胃癌小鼠（SGC-7901）有较好的治疗效果。     

CD_3单克隆抗体激活细胞的体外抗肿瘤作用

目的:观察CD3单克隆抗体激活的杀伤细胞(CD3AK)的体外杀伤肿瘤作用。方法:采用MTT法测定不同时期CD3AK细胞的杀伤活性。结果:培养到第4天的CD3AK细胞已有明显的杀伤活性,第10天达高峰;CD3AK对K562、H7402和MNK45肿瘤细胞的杀伤活性显著高于LAK和NK细胞(P<0.05),对Hela-3肿瘤细胞的杀伤活性略低于LAK细胞。结论:CD3AK是一种广谱、高效的肿瘤杀伤细胞,但它对不同种类的肿瘤细胞的杀伤效应又存在着较大的差异。     

携带TIP30与人IFN-γ 基因的重组减毒鼠伤寒沙门氏菌的构建及抗腺样囊性癌的初步研究

目的:研究锚定表达GM-CSF的小鼠黑色素瘤作为肿瘤疫苗的有效性.方法:GM-CSF基因嵌合GPI信号肽修饰序列实现在B16小鼠黑色素瘤细胞表面的锚定表达,研究锚定修饰的B16细胞于同源C57BL/6小鼠的成瘤性及诱导抗肿瘤免疫的效果.结果:抑瘤实验结果表明,锚定修饰GM-CSF的肿瘤细胞免疫原性增强,成瘤性明显下降;成瘤率为58.8%,而肿瘤对照组为100%.活瘤苗接种实验结果显示锚定修饰的肿瘤细胞可以预防肿瘤的发生,肿瘤发生率仅为20%,说明抗肿瘤的免疫应答有记忆性,能够有效地防止野生型肿瘤细胞的攻击.结论:锚定修饰GM-CSF的肿瘤细胞可以诱导抗特异性的抗肿瘤反应,这种设计可以应用于肿瘤疫苗的研究中.     

树突状细胞对肿瘤浸润淋巴细胞抗小鼠肝癌活性影响的研究

目的探讨H22细胞全细胞性抗原致敏的DC激活的TIL体外抗小鼠肝癌活性,并将H22-DC-TIL过继免疫荷瘤小鼠,研究其对荷瘤小鼠免疫功能的影响及抑瘤作用。方法从小鼠四肢长骨骨髓中获取DC,应用粒/巨噬细胞集落刺激因子(GM-CSF)、白介素-4(IL-4)和肿瘤全细胞性抗原致敏DC,然后用DC激活TIL,观察TIL在体外对H22细胞、Hepal-6细胞和B16细胞的杀伤活性;检测应用H22-DC-TIL后荷瘤小鼠的脾淋巴细胞的NK、LAK、CTL活性、血清TNF活性、抑瘤作用以及瘤体病理改变,并与对照组相比较。结果①H22-DC-TIL具有很强的对H22细胞杀伤活性[杀伤率为(71.31±3.11)%],明显高于其对Hepal-6和B16细胞的杀伤活性[杀伤率分别为(50.11±3.03)%,(30.31±2.89)%],也明显高于未经DC激活的TIL、H22-DC-脾淋巴细胞和未经DC激活的脾淋巴细胞对H22细胞杀伤活性[杀伤率分别为(49.80±3.21)%,(48.76±3.60)%和(19.23±2.71)%]和对Hepal-6细胞杀伤活性[杀伤率分别为(39.40±3.21)%,(38.62±2.87)%和(18.73±2.40)%]以及对B16细胞杀伤活性[杀伤率分别为(26.38±2.51)%,(25.82±2.70)%和(18.34±3.01)%],同时B16-DC-TIL(TIL来源于H22瘤体)也可诱导相对较低的对B16细胞的特异性细胞杀伤活性。②H22-DC-TIL可明显诱导提高荷瘤脾淋巴细胞NK、LAK和CTL活性[活性为(30.43±1.35)%、(31.40±1.80)%、(35.30±1.20)%],并可检测到血清TNF水平明显上升[血清TNF为(40.41±1.85)U/ml],它们均达正常对照组水平,与未经DC激活的TIL组、H22-DC-脾淋巴细胞组、未经DC激活的脾淋巴细胞组、生理盐水组分别对应比较,差异均有显著性(P<0.01)。该组瘤体内淋巴细胞浸润程度也高于对照组,其瘤体生长明显受到抑制。结论①H22-DC-TIL可产生很强的体外针对H22细胞的特异性杀伤活性。②H22-DC-TIL具有很强的特异性抗小鼠肝癌作用。     

半抗原修饰的黑素瘤细胞激活树突状细胞诱导特异性T细胞反应

目的：探索半抗原[二硝基氟苯（DNP）]修饰的恶性黑素瘤细胞（恶黑）激活树突状细胞（DC）体外诱导特异性T细胞反应的抗肿瘤效应。方法：采用DNP修饰恶黑细胞B16（H-2^b），然后在体外激活C57BL／6小鼠（H-2^b）外周血来源的DC，观察其诱导T细胞的增殖和特异性T细胞杀伤功能；在小鼠皮肤迟发性超敏反应实验和荷瘤实验中观察DNP修饰瘤苗＋DC的特异性。结果：经DNP修饰的B16细胞激活的DC，诱发T细胞增殖能力和对B16细胞的特异性杀伤效应均明显高于未修饰的B16细胞和DC。动物实验显示DNP修饰瘤苗联合DC具有明显的诱发皮肤迟发性超敏反应作用和抑瘤作用。结论：DNP修饰B16所激活的Dc可以诱导更强的恶黑特异性T细胞效应。     

利用gp96-肽复合物免疫小鼠脾淋巴细胞治疗H22肝癌的实验研究

目的探讨肿瘤细胞中提纯的热休克蛋白gp96-肽复合物的特异性肿瘤免疫作用对小鼠脾淋巴细胞的影响及其抗瘤作用和机制。方法将经gp96-肽复合物免疫过的小鼠的脾淋巴细胞作为效应细胞,用M TT法测定其体外细胞毒性;用gp96-肽复合物免疫小鼠的脾淋巴细胞进行特异性免疫腹腔回输,观察荷瘤鼠的生存时间;将上述效应细胞注射入直径约1 cm的小鼠皮下移植肝癌内,观察其抗瘤效果;用透射电镜观察瘤细胞的变化。结果gp96-肽复合物免疫小鼠的脾淋巴细胞较未经免疫小鼠脾淋巴细胞对靶细胞的杀伤率显著提高;gp96-肽复合物免疫小鼠脾淋巴细胞治疗组的小鼠瘤重最小,与各对照组相比差异有显著性;体内回输特异性免疫脾淋巴细胞显著提高了H 22荷瘤小鼠的生存时间。结论经gp96-肽复合物免疫激活的淋巴细胞,其毒性杀伤作用可能是引起肿瘤细胞凋亡的重要原因。     

融合基因mGM-CSF/hIL-2在肝癌细胞瘤苗特异性免疫治疗中的作用

背景与目的:手术切除是治疗肝癌的主要方法,但对其术后的复发转移却无更好的办法。近年来,免疫学的发展使肝癌的治疗有了更好的治疗方法。本研究旨在通过制备人白细胞介素2(hIL-2)与鼠粒-单核细胞集落刺激因子(mGM-CSF)融合基因修饰的H22肝癌瘤苗,观察其特异性抗肿瘤免疫作用。方法:用含hIL-2与mGM-CSF融合基因的真核表达载体,在体外转染H22细胞,制成疫苗,皮下接种小鼠,同时建立荷瘤小鼠模型。用51Cr释放法测定瘤苗免疫组、空载组、未转染组小鼠脾细胞对亲本H22细胞的杀伤活性。取血检测血清中IL-10、IFN-γ水平,观察小鼠存活期。结果:成功制备了含有hIL-2与mGM-CSF融合基因的H22肝癌瘤苗。免疫小鼠脾细胞体外对H22细胞的杀伤率为38.3%,显著高于对S180细胞的9.1%,以及空载组和未转染组的13.6%和7.5%(P<0.05)。转基因瘤苗免疫组血清IFN-γ为(12.83±0.75)pg/mL,较空载瘤苗组的(7.83±0.65)pg/mL明显升高(P<0.01),血清IL-10[(4.58±0.34)pg/mL]较空载瘤苗组的(8.15±0.28)pg/mL明显降低(P<0.01)。同时,转基因瘤苗免疫组小鼠存活期为(40±6)d,较对照组[空载瘤苗组(30±3)d,未转染组(19±4)d]明显延长。结论:转染hIL-2与mGM-CSF融合基因的同系肿瘤细胞瘤苗可激发特异性细胞介导的免疫反应,改善抗肿瘤免疫反应,延长荷瘤小鼠存活期。     

AFP基因转染的树突状细胞的生物学特性及靶向性CTL细胞毒作用

目的:观察基因转染的树突状细胞生物学特性及靶向性CTL对肿瘤细胞的杀伤作用。方法:用重组IL-4和GM-CSF诱导扩增小鼠骨髓来源的单个核细胞,将表达AFP基因的重组腺病毒转染DC(dendriticcells,DC),构建基因转染的DC瘤苗,并免疫C57BL/6小鼠。用流式细胞术(FCS)检测转染前后DC细胞表面分子MHCI、MHCII、LFA、ICAM、B7.1、和B7.2等的变化。取免疫小鼠脾细胞诱导细胞毒性CTL,LDH非放射性细胞毒性试验检测其对不同肿瘤细胞的杀伤作用。用ELISA法检测CTL诱导过程中TNF-α和IFN-γ分泌变化规律。结果:AFP基因转染后的DC分子表面高表达MHCI、MHCII、LFA、ICAM、B7.1、和B7.2等分子,尤其是MHCII、ICAM和LFA分子,与转染前比较具有显著性差异(P<0.05)。与对照组比较,AFP抗原诱导的靶向性CTL对AFP分泌性肿瘤细胞具有更强的杀瘤活性,且在CTL诱导过程中TNF-α和IFN-γ分泌水平较对照组也有显著性差异。结论:AFP基因重组腺病毒修饰的DC能表达高水平的MHCI、MHCII、LFA、ICAM、B7.1、和B7.2等分子,为CTL进一步活化提供了共刺激信号;用该瘤苗免疫C57BL/6J小鼠,能诱导出针对AFP抗原的靶向性CTL,从而实现对AFP分泌性肿瘤细胞的特异性杀伤作用。     

双自杀基因CD和TK对K562细胞体内外杀伤作用的实验研究

目的:探讨双自杀基因CD和TK对K562细胞的体内外抑制作用及前体药物对肿瘤的杀伤作用。方法:将目的基因转染入K562细胞,MTT法观察细胞在体内外的增殖状况及5-FC/GCV对转染细胞的杀伤作用,电子显微镜观察其超微结构变化。将K562/CDgly TK和K562细胞接种于裸鼠皮下,观察各种肿瘤细胞在体内的成瘤情况及对前体药物治疗的敏感性。结果:单独使用GCV或5-FC对K562及K562/CDgly TK细胞产生明显的杀伤作用,联合应用该2种药物对肿瘤细胞的杀伤作用更强。将K562细胞和K562/CDgly TK细胞接种于小鼠皮下后小鼠成瘤率为100%,GCV或5-FC可明显抑制裸鼠体内的肿瘤形成,联合应用GCV和5-FC治疗K562/CDglyTK细胞在小鼠体内形成的肿瘤,较单独应用GCV和5-FC及对照组小鼠形成的肿瘤体积明显缩小,生存期也明显延长。结论:双自杀基因在体内外对K562细胞均有明显的抑制作用,可增加前体药物GCV和5-FC对瘤细胞的杀伤率。     

THE HUMORAL ANTITUMOR RESPONSES INDUCED BY IL-4 GENE-MODIFIED TUMOR VACCINE

ＴＨＥＨＵＭＯＲＡＬＡＮＴＩＴＵＭＯＲＲＥＳＰＯＮＳＥＳＩＮＤＵＣＥＤＢＹＩＬ４ＧＥＮＥＭＯＤＩＦＩＥＤＴＵＭＯＲＶＡＣＣＩＮＥ１ＹｕＹｉｚｈｉ于益芝ＣａｏＸｕｅｔａｏ２曹雪涛ＺｈａｎｇＭｉｎｇｈｕｉ张明徽ＬｅｉＨｏｎｇ雷虹ＴａｏＱｕｎ陶群Ｄｅｐ...     

树突状细胞诱导的LAK细胞对肺癌的生长抑制作用

目的　研究肺癌细胞裂解物负载的树突状细胞 (DC)诱导的淋巴因子激活杀伤细胞 (LAK )对肺腺癌裸鼠移植瘤的生长抑制作用。方法　肺腺癌患者手术切除标本接种裸鼠皮下建立肺腺癌移植瘤模型 ,同时将手术切除标本用反复冻融的方法制备肿瘤细胞裂解物 ;同一患者外周血分离得到的单个核细胞中 ,贴壁的细胞加入DC生长因子 (DCGF)培养得DC ,未贴壁的细胞加入rhIL 2培养得LAK细胞。用肿瘤细胞裂解物负载自体DC ,诱导LAK细胞生成DC LAK细胞 ,注射荷瘤裸鼠腋下以观察DC LAK细胞对肺癌移植瘤的生长抑制作用。结果　用肺癌手术标本能成功建立裸鼠移植瘤模型。DC LAK组、LAK组、DC组和生理盐水对照组肿瘤瘤重平均值分别为 0 .47、1.0 5、1.3 0和 1.5 8g ,DC LAK组、LAK组和DC组肿瘤生长抑制率分别为 70 .3 %、3 3 .5 %和 17.9% ,DC LAK细胞具有抑制裸鼠肺癌移植瘤生长的作用而且强于LAK细胞 (P <0 .0 5 )。结论　通过荷瘤裸鼠体内抗瘤实验证实了DC LAK细胞的抗肺癌作用明显高于LAK细胞 ,提示DC LAK细胞治疗是更为有效的抗肺癌生物治疗方法 ,为DC疫苗用于肺癌的临床治疗提供依据     

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.     

腺病毒介导IL-2基因转染的瘤苗体内抗肿瘤作用

目的 :探讨重组腺病毒介导的 IL- 2基因转染的瘤苗的体内抗肿瘤作用及其免疫学机制。方法 :应用腺病毒介导的鼠 IL- 2基因转染 CT2 6小鼠结肠癌细胞 ,灭活后用作瘤苗治疗荷瘤小鼠 ,观察皮下肿瘤生长及其存活期。采用乳酸脱氢酶释放法检测荷瘤小鼠脾细胞 CTL、L AK、NK细胞的杀伤活性。结果 :鼠 IL- 2基因转染瘤苗治疗能显著抑制荷瘤小鼠皮下肿瘤生长并明显延长其存活期 (P<0 .0 1)。体内免疫功能检测表明 ,鼠 IL- 2基因转染疫苗治疗组小鼠脾细胞 CTL 活性、L AK活性和 NK活性显著高于对照组 (P<0 .0 1)。结论 :腺病毒介导鼠 IL- 2基因转染的瘤苗体内具有较强的抗肿瘤效应 ,其机制可能是提高了荷瘤小鼠特异性和非特异性抗肿瘤免疫反应     

Antigen-specific cancer immunotherapy using a GM-CSF secreting allogeneic tumor cell-based vaccine

Granulocyte-macrophage colony-stimulating factor (GM-CSF)-transduced autologous tumor cell-based vaccines are currently one of the major forms of cancer vaccines. However, the preparation of GM-CSF-transduced autologous tumor vaccines is time-consuming and technically challenging. In addition, the host antigen presenting cells, rather than the tumor vaccine cells themselves, present tumor-specific antigens and prime the host T cells. Therefore, we tested the efficacy of antigen-specific allogeneic tumor vaccines. We used human papillomavirus 16 (HPV-16) E7 protein as a model tumor antigen, which is associated with the development of most cervical carcinoma. B16, a C57BL/6 (H-2(b)) derived melanoma cell line, was genetically engineered to produce GM-CSF alone (B16GM), HPV-16 E7 alone (B16E7), or both (B16GME7). These vaccine cells were injected into BALB/c (H-2(d)) mice (10(6) cells/mouse). Two weeks later, mice were challenged with 10(5) live HPV-16 E7(+) BL-1 (H-2(d)) tumor cells and monitored for tumor progression twice weekly. To determine the effective cell population in the antitumor immunity elicited by B16GME7, we carried out in vivo antibody depletion experiments using CD4 and CD8 specific antibodies. In addition, as a measure of the immune responses produced by B16GME7, we performed an in vitro cytotoxic T lymphocyte assay using a standard chromium release method. We found that all of the mice vaccinated with B16GME7 remained tumor free 49 days post-BL-1 challenge. In contrast, mice vaccinated with B16GM and B16E7 did not show any tumor protection against a similar dose of BL-1 cells. Furthermore, the antitumor immunity produced by B16GME7 was dependent on both CD4 and CD8 T cells. In addition, E7-specific cytotoxic T lymphocyte activity could be readily demonstrated in mice immunized with B16GME7. These results suggest that allogeneic tumor cells transduced with GM-CSF and the tumor antigen, HPV-16 E7, cannot only generate an E7-specific cytotoxic T lymphocytes response in vitro, but can also elicit a potent antitumor immune response against an E7 expressing tumor in vivo.     

猪endoglin胞外段DNA疫苗诱导抗小鼠结肠癌免疫反应

背景与目的:研究表明,endoglin是肿瘤血管生成的标志性分子,用抗endoglin单克隆抗体被动免疫治疗可以有效抑制肿瘤生长,而异种DNA疫苗可以打破自身同源分子的免疫耐受。因此,本研究用猪endoglin胞外段真核表达质粒(ppEDG)作为异种DNA疫苗,了解该DNA疫苗是否具有抑制小鼠结肠癌生长的作用,并探讨其作用的免疫学机理。方法:观察免疫治疗后的荷瘤小鼠肿瘤体积和生存情况,用免疫组化方法(抗CD31)观察肿瘤组织血管生长并计算肿瘤微血管密度,用Westernblot和ELISA方法检测荷瘤小鼠免疫治疗后的血清是否含有抗自身endoglin的抗体以及抗体亚型,用ELISPOT方法检测荷瘤小鼠脾脏中分泌抗自身endoglin抗体的B淋巴细胞。结果:肿瘤接种18天后,ppEDGDNA疫苗主动免疫治疗组肿瘤体积明显小于空质粒(e-p)对照组及生理盐水对照组(P<0.05),存活时间明显延长(P<0.001)。ppEDG组、e-p组和生理盐水组肿瘤组织微血管密度计数分别为19.2±4.5、76.9±14.4和81.4±16.9(P<0.001)。治疗组小鼠血清中含有抗自身endoglin的抗体,抗体亚型主要为IgG1和IgG2b。三组小鼠分泌抗自身endoglin抗体的B淋巴细胞数分别为82.5±14.1、3.6±1.3和4.7±2.0(P<0.001)。结论:ppEDGDNA疫苗诱导抗自身endoglin抗体产生,从而抑制肿瘤血管生成和肿瘤生长。     

IL-23基因修饰的树突细胞疫苗联合β-榄香烯对小鼠胰腺癌生长的影响

背景与目的:树突细胞(dendriticcells,DC)疫苗是目前最具应用潜能的治疗性疫苗,功能性细胞因子能显著增强DC的活性及其诱导的宿主抗肿瘤作用,利用细胞因子基因修饰DC是当今肿瘤免疫治疗中最活跃的领域。本研究探讨β-榄香烯联合白细胞介素-23(interleukin-23,IL-23)修饰的DC疫苗对胰腺癌小鼠的协同抗肿瘤作用。方法:克隆并构建IL-23基因真核双表达载体,转染DC并负载肿瘤抗原后制备成疫苗。将IL-23基因转染的DC疫苗、空质粒转染的DC疫苗、未转染的DC疫苗及对照生理盐水分别注射小鼠,体外观察各组小鼠脾脏T淋巴细胞IFN-γ及IL-4的分泌。体内观察β-榄香烯联合DC疫苗对荷胰腺癌小鼠肿瘤生长的抑制作用及对小鼠存活期的影响。结果:基因测序证实IL-23基因克隆及双表达载体构建成功,转染后DC共刺激分子MHC-Ⅰ和MHC-Ⅱ的表达增强。接种IL-23转染DC疫苗后小鼠的免疫防御能力显著增强,有效地延缓并防御接种肿瘤的发生。DC介导的免疫应答促进了IFN-γ生成型Th1细胞的产生,未转染DC疫苗组和空质粒转染DC疫苗组IL-4分泌量与IL-23转染的DC疫苗组比较差异有显著性(P<0.05);IL-23转染DC疫苗组IFN-γ的分泌与其他各组比较差异有显著性(P<0.01)。β-榄香烯联合IL-23转染DC疫苗组肿瘤生长受到显著抑制,该组小鼠存活期与DC组、NS对照组及β-榄香烯组比较差异有极显著性(P<0.01)。结论:IL-23修饰DC疫苗可强化宿主针对特异肿瘤的Th1及CTL的免疫应答,使宿主不仅产生防御性免疫反应而且增强自动免疫能力。β-榄香烯有一定的协同抗癌作用。     

Immunotherapy of tumors with protein vaccine based on chicken homologous Tie-2.

PURPOSE: Tie-2 is an endothelium-specific receptor tyrosine kinase known to play a key role in tumor angiogenesis. The present study explores the feasibility of immunotherapy of tumors by using a protein vaccine based on chicken Tie-2 as a model antigen to break the immune tolerance against Tie-2 in a cross-reaction between the xenogeneic homologous and self-Tie-2. EXPERIMENTAL DESIGN AND RESULTS: In this study, a chicken homologous Tie-2 protein vaccine (chTie-2) and a corresponding mouse Tie-2 vaccine as a control were prepared and the antitumor effect of these vaccines was tested in two tumor models (murine B16F10 melanoma and murine H22 hepatoma). Immunotherapy with chTie-2 was found effective in two tumor models. Autoantibodies against mouse Tie-2 were detected in sera of mice immunized with chTie-2 through Western blot analysis and ELISA assay. Anti-Tie-2 antibody-producing B cells were detectable by ELISPOT. Histologic examination revealed that autoantibodies were deposited on the endothelial cells of tumor tissues. Purified immunoglobulins from chTie-2-immunized mice could induce the apoptosis of human umbilical vein endothelial cells in vitro. Importantly, adoptive transfer of purified immunoglobulins led to antitumor effect in vivo; apparently, angiogenesis was significantly inhibited in these tumors. Furthermore, the antitumor activity and production of autoantibodies could be abrogated by depletion of CD4+ T lymphocytes. CONCLUSIONS: Our findings may provide a vaccine strategy for cancer therapy and show the potential utilization of interference with Tie-2 pathway.     

Antitumor immunity after vaccination with B lymphoma cells overexpressing a triad of costimulatory molecules

BACKGROUND: The costimulatory molecules B7-1, intercellular adhesion molecule-1 (ICAM-1), and leukocyte function-associated antigen-3 (LFA-3) play pivotal roles in the activation of T cells. We investigated whether in vivo vaccination with lymphoma cells infected with a recombinant, nonreplicating fowlpox (FP) virus encoding this triad of costimulatory molecules (TRICOM) could stimulate lymphoma-specific immunity. METHODS: TRICOM-infected A20 B lymphoma cells were analyzed for expression of B7-1, ICAM-1, and LFA-3. Mice (10 per group) were vaccinated with irradiated A20 cells infected with either the TRICOM vector or the wild-type FP virus (WT-FP), challenged with live A20 tumor cells, and followed for survival. Mice with established A20 tumors were also treated with irradiated TRICOM-infected A20 cells. Survival curves were compared with the log-rank statistic. The mechanism of the antitumor effect was studied by in vivo depletion of CD4(+) and CD8(+) T cells and in vitro cytotoxicity assays. All statistical tests were two-sided. RESULTS: A20 tumor cells infected with TRICOM expressed high levels of B7-1, ICAM-1, and LFA-3. Mice vaccinated with irradiated TRICOM-infected A20 cells had prolonged survival relative to mice vaccinated with WT-FP-infected cells (80% versus 20% survival at 110 days; P<.001). In mice with established tumors, tumor growth was slower in those treated with TRICOM-infected tumor cells than in those treated with WT-FP-infected cells, and this treatment provided a survival advantage (P<.001). Depletion of CD4(+) or CD8(+) T cells reduced the antitumor immunity provided by the tumor cell-TRICOM vaccine, and lymphocytes from vaccinated mice displayed in vitro cytotoxic activity toward A20 cells. CONCLUSIONS: Increasing expression of costimulatory molecules on B lymphoma cells by infection with a recombinant FP virus encoding B7-1, ICAM-1, and LFA-3 stimulates antitumor immune responses in vivo and may provide a novel strategy for treating patients with B-cell malignancies.