低剂量环磷酰胺增强MHCⅠ类限制性肿瘤抗原多肽冲击致敏的树突状细胞的抗肿瘤转移效果

目的:研究低剂量环磷酸胺(Cy)联合MHC Ⅰ类限制性肿瘤抗原多肽Mutl致敏、白细胞介素2(IL-2)基因修饰的树突状细胞(DCs)对转移性肺癌小鼠的治疗作用及其免疫学机理.方法:制备小鼠骨髓来源的DCs,用转移性Lewis肺癌特异性多肽Mutl预激经IL-2基因修饰的DCs联合低剂量Cy治疗转移性肺癌小鼠.通过FACS分析其脾细胞内T淋巴细胞比例的变化,~51Cr释放法检测CTL和NK细胞杀伤活性.结果:肿瘤抗原多肽致敏、IL-2基因修饰的DCs与小剂量Cy联合后,能比单用DCs更有效地治疗转移性肺癌,小鼠脾细胞中CD8~+T细胞和NK1.1~+细胞明显比例升高,联合治疗组诱导出的CTL杀伤活性最高.结论:以肿瘤抗原多肽冲击致敏的IL-2基因修饰的DCs联合小剂量Cy能更有效地促进荷瘤宿主免疫应答,具有显著地体内抑制肺癌转移的效果.     

低剂量环磷酰胺增强MHC I类限制性肿瘤抗原多肽冲击致敏 …

目的：研究低剂量环磷酰胺（Ｃｙ）联合ＭＨＣ Ｉ类限制性肿瘤抗原多肽Ｍｕｔｌ致敏、白细胞介素２（ＩＬ－２）基因修饰的树突状细胞（ＤＣｓ）对转移性肺癌小鼠的治疗作用及其免疫学机理。方法：制备小鼠骨髓来源的ＤＣｓ,用转移性Ｌｅｗｉｓ肺癌特异性多肽Ｍｕｔｌ预激经ＩＬ－２基因修饰的ＤＣｓ联合低剂量Ｃｙ治疗转移性肺癌小鼠。通过ＦＡＣＳ分析其脾细胞内Ｔ淋巴细胞比例的变化,＾５１Ｃｒ释放法检测ＣＴＬ和ＮＫ细胞杀伤     

白介素12基因修饰的树突细胞疫苗治疗自发性转移性肺癌

背景与目的:对转移性肺癌的治疗已进行了大量研究,但仍缺乏有效的治疗方法。本研究目的是探讨白介素12(IL-12)基因修饰的树突细胞(DC)疫苗对自发性转移性肺癌的治疗作用。方法:小鼠足垫注射3LLLewis肺癌细胞,建立自发性转移性肺癌模型,经IL-12基因修饰、3LL特异抗原多肽Mut1体外致敏DC疫苗(DC-IL-12/Mut1)皮下免疫2次,观察荷瘤鼠肺重量、肺表面转移结节数量、存活期及相应免疫指标的变化,组间差异行t检验,生存期行时序检验。结果:与对照组(DC-LacZ/Mut1)相比,DC-IL-12/Mut1组肺重量轻、肺表面转移结节数量少、存活期长(P<0.01),细胞毒性T淋巴细胞(CTL)活性和NK活性增强(P<0.01)。结论:IL-12基因修饰的DC疫苗对自发性转移性肺癌有明显的治疗作用,其可能机理是诱导特异性CTL和增强NK活性。     

肿瘤抗原多肽诱导的CD8~+CTL的体内外抗瘤效应

利用海绵移植模型,将Friend小鼠白血病病毒gag编码的二个多肽CCLCLTVFL(gPr80 gag 85-93)和RSPTNLAKV(Pr65 gag P30 131-139)分别注入正常或经FBL-3肿瘤细胞免疫过的C57BL/6小鼠皮下的植入海绵中,10天后,收集海绵中浸润淋巴细胞,在体外用免疫肽周期性刺激培养扩增。实验结果表明:用多肽体内免疫正常或经FBL-3免疫的B6小鼠均能诱导出对免疫多肽特异的CD8~ CTL。其中,P85-93多肽诱导的CD8~ CTL除能杀伤该多肽致敏的同系靶细胞外,还能特异性杀伤FBL-3瘤细胞.抗原多肽诱导的CD8~ CTL在体外经用免疫多肽致敏的同系小鼠脾细胞作周期性刺激并在低浓度IL-2的条件下培养,可长期生长并大量扩增。用体外培养扩增的P85-93多肽特异性CD8~ CTL过继转输治疗FBL-3荷瘤小鼠,能有效治愈FBL-3白血病荷瘤小鼠。上述结果表明,用肿瘤抗原多肽替代肿瘤细胞体内免疫动物可诱导特异性抗瘤效应的CD8~ CTL,并可在体外扩增用于肿瘤过继性免疫治疗。     

CB6F1小鼠树突状细胞诱导细胞毒性T淋巴细胞的杀伤作用

[目的]探讨CB6F1小鼠脾树突状细胞(DC)的培养及其诱导针对小鼠路易斯肺癌(LLC)的细胞毒性T淋巴细胞(CTL)对肿瘤的杀伤效应.[方法]应用CB6F1小鼠脾细胞在GM-CSF、IL-4等细胞因子作用下培养出DC,反复冻融法制备LLC抗原致敏DC,与淋巴细胞及IL-2混合培养诱导出肿瘤特异性CTL,利用乳酸脱氢酶法检测CTL的杀伤活性.[结果]用GM-CSF、IL4联合培养小鼠脾细胞第4d,可见细胞形态发生改变,培养第8d,可见典型的刺突样DC,通过流式细胞术检测了DC表型高表达CD80占76.5％,CD86占60.0％,MHCⅡ占67.4％,CD11C占80.6％.[结论]应用GM-CSF、IL-4、LPS等细胞因子培养CB6F1小鼠脾细胞经过肿瘤抗原冲击,可以培养出成熟DC,并且DC可以诱导出具有杀伤活性的肿瘤特异性CTL.     

IL-18基因修饰增强肿瘤细胞裂解物致敏的树突状细胞的抗肿瘤效应

目的:观察经肿瘤细胞裂解物致敏的白细胞介素18(IL-18)基因修饰的树突状细胞(DC)体内诱导的抗肿瘤免疫应答反应.方法:体外培养的小鼠骨髓树突状细胞经IL-18重组腺病毒感染后(IL18-DC),再经Hepal-6肝癌细胞裂解物冲击致敏后通过皮下注射用于荷瘤小鼠的治疗.用ELISA检测细胞因子,4 h51Cr释放法检测NK细胞活性及CTL杀伤活性.结果:致敏IL18-DC组体内诱导NK细胞活性与未致敏IL18-DC组无明显差别(P＞0.05),但明显高于致敏DC组和DC组(均P＜0.01);致敏IL18-DC组体内诱导特异性CTL杀伤活性明显高于IL18-DC组、致敏DC组和DC组(均P＜0.01);致敏IL18-DC组免疫治疗作用明显优于未致敏IL18-DC组、致敏DC组和DC组(均P＜0.01).结论:肿瘤细胞裂解物致敏的IL-18基因修饰的DC疫苗进行体内免疫治疗,能诱导出显著的抗肿瘤免疫反应,为DC介导的肿瘤基因治疗开辟了新的途径.     

抗原冲击致敏的脐血有核细胞体外诱导特异性CTL的实验研究

目的研究抗原(Ag)冲击致敏的脐血有核细胞的抗肿瘤作用.方法用密度梯度离心法提取人肺癌组织抗原,并与IL-2协同刺激脐血有核细胞,测定不同时间CTL和NK活性.结果脐血中NK活性变化不明显,但CTL于第7天增强至最高值.结论抗原与IL-2联合应用可明显提高脐血CTL活性.     

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     

IL-2和IL-12基因联合治疗小鼠头颈鳞癌的实验研究

目的观察白细胞介素-2(IL-2)基因与白细胞介素-12(IL-12)基因联合治疗小鼠头颈鳞癌的疗效. 方法建立小鼠头颈鳞癌动物模型,在荷瘤部位将脂质体包裹的IL-2基因和IL-12基因直接注入肿瘤中,观察肿瘤大小变化,并检测此两种基因在肿瘤细胞中的蛋白表达情况、小鼠脾脏自然杀伤细胞(NK)和细胞毒T淋巴细胞(CTL)活性. 结果 IL-2基因和IL-12基因联合治疗组,肿瘤生长明显受抑制,疗效显著优于单独治疗组和对照组(P<0.01).在注射有IL-2、IL-12基因的肿瘤组织中,其相对应的IL-2、IL- 12蛋白水平明显升高,小鼠脾细胞NK活性和CTL杀伤活性增强. 结论 IL-2、IL-12基因治疗可抑制小鼠头颈鳞癌生长,提高机体的抗肿瘤免疫应答.二者联合应用,可产生协同效应并加强其抗肿瘤效果.     

冻融抗原冲击致敏的树突状细胞对结肠癌小鼠的治疗作用

目的 :研究冻融的肿瘤抗原冲击致敏的骨髓来源的树突状细胞 (DC)对结肠癌小鼠是否具有治疗作用。方法 :用小鼠结肠癌细胞株C2 6冻融抗原体外冲击致敏BALB/c小鼠骨髓来源的DC ,观察其体外刺激荷瘤小鼠脾细胞增殖的能力及其诱导的CTL对C2 6肿瘤细胞的杀伤活性 ;体内以 3× 10 5DC /只一次或多次接种于已荷瘤 10d结肠癌的小鼠同侧腹股沟皮下 ,观察抗原冲击的DC对肿瘤生长的抑制作用以及对荷瘤小鼠生存期的影响。结果 :体外抗原冲击致敏的DC能显著刺激荷瘤小鼠脾脏T细胞增殖 ,其诱导的CTL对C2 6肿瘤细胞具有显著的杀伤作用 ,在效靶比为 10∶1,5∶1,2 .5∶1时其杀伤率分别 88 1% ,71.4%和 5 0 .0 % ;抗原冲击致敏的DC体内多次皮下免疫后对肿瘤的生长具有显著的抑制作用 ,能显著延长荷瘤小鼠的生存期。一次性DC体内免疫接种对荷瘤小鼠的治疗作用不明显。结论 :肿瘤细胞冻融抗原体外冲击致敏的DC多次皮下免疫对结肠癌小鼠具有显著的治疗效果     

Enhanced antitumor immune responses of IL-2 gene-modified tumor vaccine by combination with IL-1 and low dose cyclophosphamide.

To enhance the antitumor immunity induced by IL-2 gene-modified tumor vaccine, we proposed a combined protocol to treat tumor-bearing mice using IL-2 gene-modified tumor vaccine in combination with IL-1 and low-dose Cyclophosphamide(Cy). After treatment with IL-2 gene-modified B16 melanoma cell vaccine alone, the pulmonary metastases of tumor-bearing mice were reduced and their survival time was prolonged. The anti-metastases effect was improved when the vaccine was used in combination with IL-1 or low-dose Cy. The best therapeutic effect was achieved when the IL-2 gene-modified vaccine was combined with IL-1 and low-dose Cy. The cytotoxicity of the splenic CTL, NK, and the levels of IL-2, TNF secreted by splenocytes increased after tumor-bearing mice were treated with the IL-2 gene-modified tumor vaccine. The above antitumor immune functions were augmented more significantly when IL-1, low-dose Cy were used in combination with IL-2 genemodified tumor vaccine. These results demonstrated that the IL-2 gene modified vaccine could exert more potent anti-metastases effects when it is combined with IL-1 or/and low-dose Cy by activating the specific and non-specific antitumor immune responses more effectively.     

Engineered fusion hybrid vaccine of IL-18 gene-modified tumor cells and dendritic cells induces enhanced antitumor immunity

Dendritic cell (DC)-tumor fusion hybrid vaccines that facilitate antigen presentation represent a novel powerful strategy in cancer immunotherapy. In our study, we investigated the antitumor immunity derived from the vaccination of fusion hybrids between engineered J558/IL-18 myeloma cells secreting Th1 cytokine IL-18 and DCs. DC/J558/IL-18 could secret a higher level of IL-18 than DCs, efficiently expressed J558 tumor antigen P1A, and enhanced ability of allogeneic T cell stimulation when compared to J558/IL-18. Our data showed that the immunization of BALB/c mice with DC/J558/IL-18 hybrids induced the most potent protective immunity against 1 x 10(6) cells with a J558 tumor challenge, compared to those immunized with the mixture of DCs and J558/IL-18, J558/IL-18, or J558. Furthermore, the immunization of mice with engineered DC/J558/IL-18 hybrids elicited stronger NK activity and J558 tumor-specific cytotoxic T lymphocyte (CTL) responses in vitro. In addition, DC/J558/IL-18 tumor cells into syngeneic mice induced a Th1 dominant immune response to J558 and resulted in tumor regression, which indicated that the antitumor effect mediated by DC/J558/IL-18 appeared to be dependent on TH1 cytokine production. These results demonstrate that the engineered fusion hybrid vaccines that combine Th1 gene-modified tumor with DCs may be an attractive strategy for cancer immunotherapy.     

Apoptotic pancreatic tumor cells are superior to cell lysates in promoting cross-priming of cytotoxic T cells and activate NK and gammadelta T cells

Tumor vaccines using dendritic cells (DCs) have been shown to induce antitumor CTL responses. The choice of the tumor antigen preparation used for DC loading is still an unresolved issue. We compared DCs pulsed with cell lysates, whole apoptotic tumor cells or their supernatants of the HLA-A2(+) human pancreatic carcinoma cell line Panc-1 for their capacity to activate T cells. Monocyte-derived DCs from HLA-A2(+) donors were pulsed with tumor antigen, matured subsequently, and cocultured with autologeous peripheral blood mononuclear cells. After three weekly restimulations with DCs, T-cell activation was assessed by intracellular IFN-gamma staining and cytotoxicity assays. Compared with lysate, pulsing DCs with the supernatant of apoptotic tumor cells induced a higher frequency of activated CTLs and T-helper cells, as well as an enhanced MHC class I-restricted tumor cell lysis. No activation of natural killer (NK) or gammadelta T cells was detected. Pulsing DCs with whole apoptotic tumor cells induced an even more pronounced lytic effect. However, in this case, MHC class-I blocking was only partially effective, and unrelated cell lines were also killed. IFN-gamma staining revealed activation of CTLs and T-helper cells, as well as NK and gammadelta T cells. Trans-well cultures of NK cells, apoptotic tumor cells, and DCs showed that NK cell activation was dependent on direct cell-to-cell contact with tumor cells and the presence of interleukin-12 produced by DCs. These results indicate that the choice of antigen preparation is a critical determinant in the induction of antitumor immunity. Tumor vaccines consisting of DCs and apoptotic tumor cells may be able to activate CTLs, as well as effector cells of the innate immune system.     

负载肝癌抗原的树突状细胞瘤苗诱导的抗肿瘤作用

目的 探讨原发性肝癌患者外周血树突状细胞（DC）体外经自体肝癌细胞抗原致敏后诱导的抗肿瘤作用。方法肝癌患者外周血经梯度密度离心法分离，获得DC前体细胞，用重组人粒细胞-巨噬细胞集落刺激因子（rhGM—CSP）和重组人白细胞介素-4（rhIL-4）联合培养，诱导扩增DC。制备自体肝癌细胞抗原，体外脉冲DC，检测DC诱导自体T细胞增殖能力及细胞毒性T细胞（CTL）在体外对自体肝癌细胞的杀伤活性，并检测肿瘤抗原致敏DC分泌的IL-12水平。结果经自体肝癌细胞抗原致敏的DC能分泌IL-12和诱导较强的自体T细胞增殖，且能诱导特异性CTL，该CTL对自体肝癌细胞具有很强的杀伤活性，杀伤率明显高于DC、未经肝癌细胞抗原致敏的DC激活的CTL及T淋巴细胞的杀伤率，而对3LLLEWIS肺癌细胞、H22肝癌细胞则无明显的．杀伤作用。结论肝癌患者外周血DC经自体肝癌细胞抗原致敏后能诱导高效而特异的抗肝癌免疫，其机制可能与增强T细胞应答和诱导机体产生肿瘤特异CTL而发挥特异性的抗肿瘤作用有关。     

Immunotherapy of spontaneous metastatic lung cancer with tumor antigen-pulsed,interleukin-12 gene-modified dendritic cells

Interleukin-12 (IL-12), with the ability of inducing production of interferon-gamma and enhancing of NK activity and Th1 response, has potent antitumor role and has been used in treatment of tumors[1-7]. Dendritic cells (DC) are the uniquely potent APCs involved in the initiation of immune responses. As adjuvants for Ag delivery, DC pick up Ags in the periphery and carry them to T cells area in lymphoid organs to prime the immune responses. With the development of the methods for propaga…     

Fusion hybrid of dendritic cells and engineered tumor cells expressing interleukin-12 induces type 1 immune responses against tumor

AIMS AND BACKGROUND: Dendritic cell (DC)-tumor fusion hybrid vaccinees that facilitate antigen presentation represent a novel powerful strategy in cancer immunotherapy. Preclinical studies have demonstrated that IL-12 promotes specific antitumor immunity mediated by T cells in several types of tumors. In the present study, we investigated the antitumor immunity derived from vaccination of fusion hybrids between DCs and engineered J558/IL-12 myeloma cells secreting Th1 cytokine IL-12. METHODS: The expression vector pcDNA-IL-12 was generated and transfected into J558 myeloma cells and then bone marrow-derived DCs were fused with engineered J558/IL-12 cells. The antitumor immunity derived from vaccination of the fusion hybrid DC/J558/IL-12 was evaluated in vitro and in vivo. RESULTS: DC/J558/IL-12 cells secreted recombinant IL-12 (1.6 ng/mL), and inoculation of BALB/c mice with DC/J558/IL-12 hybrid induced a Th1 dominant immune response and resulted in tumor regression. Immunization of mice with engineered DC/J558/IL-12 hybrid elicited stronger J558 tumor-specific cytotoxic T lymphocyte (CTL) responses in vitro as well as more potent protective immunity against J558 tumor challenge in vivo than immunization with the mixture of DCs and J558/IL-12, J558/IL-12 and J558, respectively. Furthermore, the anti-tumor immunity mediated by DC/J558/IL-12 tumor cell vaccination in vivo appeared to be dependent on CD8+ CTL. CONCLUSIONS: These results demonstrate that the engineered fusion hybrid vaccines that combine Th1 cytokine gene-modified tumor cells with DCs may be an attractive strategy for cancer immunotherapy.     

树突状细胞负载MAGE-n表位肽的体外免疫学效应研究

目的：研究树突状细胞（dendritic cell,DC）负载MAGE-n表位肽QLVFGIEVV体外诱导特异性CTL的能力及其抗肿瘤效应。方法：MAGE-n表位肽以固相多肽合成技术合成,并用HPLC进行纯化,质谱法（MS）鉴定,以流式细胞仪筛选HLA-A2＋人外周血PBMC,连续贴壁法分离培养人外周血来源树突状细胞,用成熟的DC负载MAGE-n表位肽QLVFGIEVV反复刺激活化诱导抗原特异性CTL,用51Cr释放法检测CTL的杀伤活性,并用抗HLA-A2分子单抗进行杀伤抑制实验。结果：用DC负载MAGE-n表位肽QLVF-GIEVV可诱导特异性CTL反应,对MAGE-n阳性表达细胞有较强的杀伤作用。结论：DC负载抗原肽QLVF-GIEVV在体外可诱发较强的特异性免疫反应。     

TRAIL基因原核表达载体的构建、表达与抗体制备

目的:观察罗勒多糖对肿瘤细胞不同途径转移行为的影响,并从细胞间通讯功能的恢复以及体内NK细胞活性的变化两方面探讨其抗肿瘤转移的可能作用机制.方法:Metfigel穿膜法体外观察罗勒多糖对肿瘤细胞移动活性的影响;建立不同途径的肿瘤转移模型,体内观察罗勒多糖对肿瘤转移行为的影响.SLDT技术检测罗勒多糖对细胞通讯功能的影响;51Cr释放法检测罗勒多糖对NK细胞活性的影响.结果:罗勒多糖在体内外均具有显著的抗肿瘤转移作用;与对照组相比细胞间通讯功能有一定程度的恢复;NK细胞的活性明显提高.结论:罗勒多糖具有明显的抗肿瘤转移作用,可能是一种具有潜在开发价值的新的抗肿瘤转移药物,其抗肿瘤转移作用是通过多个药效靶点综合作用的结果.     

Antitumor Activity of Lentivirus-mediated Interleukin -12 Gene Modified Dendritic Cells in Human Lung Cancer in Vitro

Objectives: Dendritic cell (DC)-based tumor immunotherapy needs an immunogenic tumor associatedantigen (TAA) and an effective approach for its presentation to lymphocytes. In this study we explored whethertransduction of DCs with lentiviruses (LVs) expressing the human interleukin-12 gene could stimulate antigenspecificcytotoxic T cells (CTLs) against human lung cancer cells in vitro. Methods: Peripheral blood monocytederivedDCs were transduced with a lentiviral vector encoding human IL-12 gene (LV-12). The anticipated targetof the human IL-12 gene was detected by RT-PCR. The concentration of IL-12 in the culture supernatant of DCswas measured by ELISA.Transduction efficiencies and CD83 phenotypes of DCs were assessed by flow cytometry.DCs were pulsed with tumor antigen of lung cancer cells (DC+Ag) and transduced with LV-12 (DC-LV-12+Ag).Stimulation of T lymphocyte proliferation by DCs and activation of cytotoxic T-lymphocytes (CTL) stimulatedby LV-12 transduced DCs pulsed with tumor antigen against A549 lung cancer cells were assessed with methylthiazolyltetrazolium (MTT). Results: A recombinant lentivirus expressing the IL-12 gene was successfullyconstructed. DC transduced with LV-12 produced higher levels of IL-12 and expressed higher levels of CD83than non-transduced. The DC modified by interleukin -12 gene and pulsed with tumor antigen demonstratedgood stimulation of lymphocyte proliferation, induction of antigen-specific cytotoxic T lymphocytes and antitumoreffects. Conclusions: Dendritic cells transduced with a lentivirus-mediated interleukin-12 gene have anenhanced ability to kill lung cancer cells through promoting T lymphocyte proliferation and cytotoxicity.